SUBDRILL AN IMPORTANT PARAMETER IN BLASTING

 

SUBDRILL: AN IMPORTANT PARAMETER IN BLASTING

BACKGROUND OF THE ARTICLE

To a non mining Engineer or Blasting Engineer, the question must have come to you most time that, 

1. why subdrill in Blasting, what is the important?

2. Why most subdrill be included in of rock blast and which formation will subdrill not required?

This article provides brief answers to the above knowledge gap.

1. INTRODUCTION

Subdrill by definition is the additional hole length included to the Bench height to improve Blasting result and Bench safety. Most drillhole blasted in the mine especially in small scale miners and artisanal blasting Operation don't include subdrill because they tend not to know it important.

As I have define earlier, there is a specified bench height design to mine an orebody, but the extended hole length beyond the bench height is known as subdrill length. Subdrill is one of the most important Blasting parameters that is use to improve not just the fragmentation rate at the bench toe but also to enhance safety by producing a stable and smooth bench floor and toe.

What are the important of subdrill in Blasting?

The following are the major important of subdrill in blast design:

1. subdrill improve fragmentation at the bench floor

2.subdrill assist the blaster in planing for next blast operation.

3. It aid the mine slope from failing.

4. Subdrill produce a smooth and reliable new bench floor during blasting.

As I have explained in my previous video on Explosive and Rock Interaction part 1&2 and in my journal publication on effect of charge distribution on fragmentation (Taiwo, 2022), I explained that the efficiency of rock fragmentation depends on; powder weight, Burden distance which are few but the major factor that determines the rate of micro-fracturing in rock before explosion. Explosive release shock Energy for fracturing and gas Energy.

The efficiency and performance of the gas Energy depends on the fracturing rate during shock energy distribution according to Sushil Bhandari (1997). The fracturing rate is maximum at tensile slabbing because rock is weak in tensile than in compression (check Ash&Konya,1978 work)

At the toe of a mine bench, the tensile strength of the rock or ore deposit is high due to small or no free face available. This reduce the efficiency of Explosive shock an gas Energy at the toe resulting into poor fragmentation and rough floor. Most time the oversize and boulders are formed from the bench toe, in other cases like underground mine you have put out with sockets in Boulders. 

You have boulder and sockets (hollow cavity) in rocks due to pull out of Explosive charge because the Explosive released shock wave Energy is lower than the rock intact Strength at the toe level. What about this! at the point of Detonation, the shock wave fracture by compression at the crushing zone round the hole collar because the Explosive compressive strength is high at initiation point, the wave further fracture by shearing due to rock Anisotropic and heterogenous nature then fracture by tensioning through tensile slabbing using change in medium impledence and Sonic Velocity. At the bench toe, the rock is intact at all dimension, there's less weak zone.

The Explosive energy is also weak and exhausted, because the primer charge or bottom charge make use of it release energy to initiate the column charge and also perform fracturing, this makes the toe fragmentation becomes difficult and in efficient. Also, note that, the base charge is initiate first and the energy only split without complete tensile slabbing because of unavailability of free face for shock wave reflection, this makes the bench toe yield poor fragmentation.

With this, subdrill provide additional charge length, Explosive charge weight at the bench toe to overcome the high tensile strength. It confirmed that the longer the drill hole the higher the powder factor, the higher the blast powder factor, the higher the Explosive energy (shock and gas) release at Detonation. Having subdrill help to provide sufficient energy which is ultilize to intoxicate initiation and also gear up tensioning time at the CJ plane to ensure completion of wave reflection within hole cracks before explosion and casting time of the insitu rock. Other important of subdrill in Blasting is that, subdrill help to ensure smooth and stable bench floor.

subdrill also ensure the production plan and schedule per blast is achieved.As a Mining Engineer we have plan and Target per blast, our mill and beneficiary plant must operate Continuous non stop, therefore all fleet operation had been planned with several target production per day. If for example 50holes are blasted and we expect 100Tonnes of material, and According to our plan, three haul trucks is needed with one loader to ensure 20 trips per day. Which is expected to keep the mill working for days. Assuming the blast failed at the toe, Producing oversize material, and only 60Tonnes are loadable. This will not only affect operation plan it will also affect operation cost. More diesel will be waste on selective loading, haul truck will be underused, plant will also operate in efficiently.

Subdrill is important, it makes the bench floor smooth and good for Tyre mounted trucks ploughing, in most case after Blasting a need for leveling and surveying to ensure pit is accessible for haul trucks, this becomes additional cost and stress. Subdrill will not just solve this challenge it will improve Blasting fragmentation.

 Is subdrill needed for all type of rock formations?

No, not all formation requires subdrill.

Bedded sedimentary formation Like limestone among others don't require subdrill because of there stratigraphy.strata or layered formation response positively to bottom charge energy because if the weakeness status of the beds. The bed tend to shift under low Explosive Energy because the shock wave will propagate along the cleavage plane (weak plane) of the formation and improve fracturing at the bench toe. Also, the bedding nature of the rock will support creation of smooth bench floor after Blasting.

 In conclusion, bedded formation will support high tensile slabbing with low Explosive Energy. This makes subdrill unimportant.

"How to design subdrill length for a typical Blasting operation" Subdrill is calculate according to rule of thumb as 0.3*Burden distance.

For Langford research work he proposed 0.3*Maximum Burden distance. Subdrill can also be calculated using drill bit diameter using 7.5*D. Subdrill increase charge length by 15.8%. subdrill is important and most be use to optimize Blasting result.

Blast it safely and profitably, all workers and blasters working on the mine site must return home safely to have a happy dinner with their families.. say no to all unsafe Blasting act and conditions...

® Giant Miner

CHECK, VERIFY AND ENSURE IS SAFE: MINING OPERATION PROFIT METER IS NOT MONEY IS SAFETY

IF SAFE AND PRODUCTIVE IS MINABLE

Explosive charge can vary from rock to rock due to the different in discontinuity property, rock Strength, rock impedance, rock type, rock grains packing and other non controllable factors.

Make a good pre-planning before Blasting and also use test Blasting to build a standard blast design for your mine. SAFTEY and Profit must be balance.

Our miners must return home to their children and wife safely. We mine the ore and keep the earth healthy for the next generation.

As you resume to morning, evening and afternoon shift take note of the possible hazards in the mine due to previous operation. Check the mine face in case of overbreak, check the ramp in case of slabbing effect, check blast pile for undetonated Explosive charge, cord, check drilled hole dimension and accuracy, check the operation Condition of your equipment. Check records from last shift person, try and look into any recommendations and complain in the Reports to put them in order. Understand the production target for the day, Design the blast that will produce the target in a good fragment, plan on need items to make the blast and mine run safely and efficiently. 

Reach out to your team, be concerned about their welfarism, get your team into action as a team player, start mining with prayer and end with thanks giving. What we do is simple, liberate the ore from the host rock, load the material into a haul truck, stock pile the run off mine at the processing plant.but more than this, we check for consequences of every operation, carryout job safety analysis JSA, adjust blast controllable factors to sweet and blend the uncontrollable factors. Work with the design slope angle to avoid increase in stripping ratio,and to ensure safety in place of slope face stability. Mining is just a profession you will like to involve in, let the firing Begins 

 As you extract and exploit the earth, check the health of the lithosphere also, treat any form of weaken rock stability Malaria, every possible slope discontinuity daylight fever in the rock face, every typhoid in the continuity of intact rocks must be treated with perfect design. Some need to be eliminated, suspended, isolated, control with Engineering design, administration policy of avoid high risk level on workers through the use of safety PPE. Let understanding be available for all your workers, let all Engineering design be with optimum factor of safety and let all policy, rules and regulations be fully enforced by concern supervisor and Mine managers.  In most mine oversight is the disease consuming their profitability, managers should be involved and carry along in all operation. Blasting most not be done without the *ALL CLEAR* order from the blast coordinator or Blasting Engineer. Let all blasting time be consistent and made known to all workers, let all alarm be sound at least three times before the blast and then after the blast. Working equipments should be trekked away from blast zone do not use them as shield to hold flyrock. Get the machine to a safe place, let all Explosive be use without additional combustive material. Don't do this to increase Explosive Energy it affect the Explosive design OXYGEN BALANCE. 

 Have an emergency response team, and incident Management plan to handle any form of mine emergency, let all policy be in place and visible to all workers. Where Blasting is carried out in unstable temperature or pressure condition proper Explosive and Blasting accessories selection must be done and adjustment must be done to blast design to suit the Working condition. Let all holes be checked properly for in filterated edge water before charging, using ANFO swelled or dissolved in water result in the release of Carbon monoxide fume or other notorious gases with brownish or pale brown color which is toxic and irritants great source of harm to human lungs and health generally. Let mining be a safe Mining and blast be a safe and productive mining. Blast fragment should contain less than 5%undersize and oversize material to ensure smooth run-in of processing plant as planned. Plan ahead of raining season also, design your dewatering system and make it clear to bear your producing capacity. Disappointing buyer is a sign of demolition in market and a sign of reduction in mine revenue. Raining season is know to be a time of low production due to limited access to the mine and low efficiency in productivity, poor pit accessibility, small working space, low haulage operation, unstable mine face due to increase in material bulk density, high rate of misfire. Plan ahead, work ahead and work safely.

Let you mine be safe and let you workers be secured, make environmental health and safety garantee for community, release of dust, ground vibration and high decibel noise during your Blasting and other operations will add to the people's problem, likewise projection of rock debris can break human skull and tear brain appart, it can also break door, crash cars and even amputate body part avoid over charging of hole and control your fly rock. We must make peace with nature to make peace with men, control the rate of ozone layer depletion, reduce rate of green house gases release into the atmosphere. Let make mining work out, if the material is not mine, then it is grown. Industry feed on us let production rate increase to reduce poverty rate through production of materials, employment, source of income to people, infrastructural development, social economy growth among others. Mining Engineer is a profession and not a hand skill, let all company be managed by competent person, supported by as many as needed assistance to make things work.

Be safe and make the mine safe.. Follow my page, read my blog articles @ giantminer.blogspot.com

 ® Giant Miner

HOW TO MINIMIZE MINE OPERATION COST WITH DRILLING AND BLASTING OPTIMIZATION

HOW CAN OPERATING COSTS IN SURFACE MINING BR REDUCE THROUGH DRILLING AND BLASTING OPERATION

 This article is divided into the following subtopics:

1. What is mine operation cost?

2. Key factors that affect operation cost

3. Drilling and Blasting operation influence on operation cost.

4. How to optimize drilling and Blasting to minimize operation cost.

BRIEF ON MINE OPERATION COST

 As a Mining Engineer working in a mine, we are all concerned about safety first then profit and constant cash inflow.

It obvious that, if their is no profit then there is crisis as this will be a tunnel to salary payment delay and even lost of our company customers.

"As continuity is the code of Continuous demanding"

MINE OPERATION COST: This is define as the total cost incur to produce a unit ton of an ore from the earth crust.

OPERATION COST IS DIVIDED INTO THREE

1. LABOUR COST

2. RAW MATERIAL COST

3. MISCELLANEOUS COST

1.Labour cost is the cost incur to compensate human effort as contribution to material production in the mine.

2. Raw material cost is the operation cost that includes all expenses incur to ensure all operation unit in the mine is operating efficiently. This includes diesel bought for loader, trucks, ANFO mixing, Tyre and equipments maintenance costs among others

3. miscellaneous cost are other cost put in place to ensure operation in the mine run smoothly and at high efficient rate. Thou may not be constant but are usually use to optimize productivity such as transport expenses from mine to city, food bought for labourer as compensation and to energies them. Having define and explain what mine Operation cost mean, I will like to submit to my readers that, this operation cost can be affected by various factors, various operating conditions.Miscellaneous cost is also known as overhead cost in economists term.

This is the money use

For other activities during production to enhance operation efficiency.

This can include the  bonus given to worker due to extraordinary job done, money for recharge card to mobilize workers to the site among others)

It not usually constant per day or per ton of Run-off-mine produce per day.

Even though during the short run of any mine it understood that operation cost per ton of ore production is usually high why at long-run it usually low.

>>Then why do operation cost increase at the shortrun (start up stage) of a mine and reduce at the long-run (future stable stage) of a mine?

Let me quickly differentiate between operation cost and operating cost..

Operation cost is the total money budgeted to carryout an operation in the mine.

Why

Operating cost is the actual cost or money incur to ensure that an operation is successfully executed or carryout.

As a Mining Engineer planing to produce say 50Tons per day at a projected operation cost of $1 per Ton there is possiblity of poor Blasting reducing the production rate for days or possibility of water infiltration into the pit from aquifer or surface water inflow which may require dewatering operation, then increasing operation cost per ton to say $1.5 per ton.

The budgeted operation cost is $1 but the operating costs is $1.5

 Mine project has two basic stages of production, technically and generally:

Short run stage and long run stage.

The short run stage is the starting point of a newly open mine. In this short run stage, the operation cost is usually very high and the mine is known to be at loss margin, most case low or no profit because operation cost is very high.

This is because various operations that dictates the operation cost amount are usually very capital consuming and of poor result.

what are the operations that factors and affect mine operation cost??

Professionally, a typical mine have 5 operation life cycle and each of this cycle influence the operation cost of the mine per day, per shift, monthly and yearly.

These operation cycles are:

1. Development operation.

2. Drilling operation,

3. Blasting operation.

4. Loading operation and

5. haulage operation

These five operations are carryout in a cyclic sequence through out the life of a typical mine.

You develop the deposit, drill holes into the formation, load the holes with exolosive, blast the hole to produce rock fragments, load the muckpile into dump truck, Transport or haul it to the processing plant.

Then development for a new drilling and blasting starts again....

This is why it is a cyclic operation and Continuous through out the mine life until the ultimate pit life is reached.

The five operations at short-run are usually capital intensive.

To start a new surface  mine say open pit mine.

The cost of stripping the overburden at the beginning is so high and capital intensive compare to other developmental Operation including pit maintaining cost after every Blasting.

Likewise the first Blasting operation may produce high dilution rate due to intrusion or overburden caving or overbreak due to unavailability of mine face at the first Blasting.

The important of free face in Blasting control and efficiency is so important that we can't just bypass it, even if not sufficient we use box cut to create new at the rock mass center.

Likewise in case of a mine at short run, the first Blasting is called the face creation Blasting, it not usually productive, it includes more of external dilution. This and many other reasons makes a typical Quarry or mine to have low profit at short run stage.

Time won't permit I will have talk on haulage also, the ramp for the first bench is not usually of imperfect gradient, the fleet Design plan may likely not even work at the starting point of the mine it takes time to get the best design to make haulage work in a new mine.

You have more trucks queueing, sometimes the loader or excavator may need to separate the muckpile, select material base on size and even dilution control purpose by this under using the dump truck operation time.

 Now, for long-run stage all the mine face had be created, the fleet Design formula had been perfected, good ramp gradient had been ultilize to efficiently transport run-off-mine to the mill, good blast Design had been Design with rule of thumb to avoid overbreak, external and internal dilution so time waste in selective loading can be minimized.

This is why, operating cost is usually low at long-run compare to short-run stage of any mine.

Since I have mentioned the basic operation factors affecting the variation of operation cost in the mine, i will dip into:-

 How Drilling and Blasting operation affect Operation cost and how to optimize this operation to minimize operation cost.

It is not new to us as an engineer that rock is a combination of various Mineral and Mineral is a combination of various elements. This characteristic makes rock very Anisotropic (not having constant Strength all over) and heterogenous (not uniform both in composition and in physical and chemical property).

Also, we understand from scholars research that rock expecially the igneous and metamorphic are of high Uniaxial compressive strength due to their thermogenesis and metagenesis origination.

And we as a Mining Engineer, we befriend rock mass to win the ore (occurrence of Mineral accumulation with economic use).

To win this ore we need to librate the rock mass so we can convey only the concentrate (valuable) material to the Mineral processing plant for comminution (crushing and grinding operation) and Separation process.

As a Blasting Engineer we aim at using the best Explosive quantity to break down the rock mass into transportable sizes which requires less loading and milling operation.

When a Blasting Engineer failed to produce good fragmentation it automatically increase the mine operation cost.

This is very serious and imperative unlike other operations, drilling and Blasting don't just increase the mine operation cost but also increase the milling and mineral processing cost.

Starting from drilling operation and it's effect on Blasting and then on operation cost...

Selection of small drill hole diameter reduce the Burden and spacing of Drillholes, it reduces the Drilling depth and then increase the number of drill hole per Blasting.

Let me prove this shortly using Langford or rule of thumb formula to design a blast with two different hole diameters.

Considering two Blasting:

Hole 1: diameter is 0.004m (jack hammer drill machine)

Hole 2: diameter is 0.065m (say wagon drillhole)

For hole 1: 

Using rule of thumb

Burden (B)=25-45*hole diameter (using 30*d)

B=30*0.04

Burden=1.2m

Spacing=1.15*B (staggered pattern)

S=1.15*1.2

S=1.38m

For hole 2: 

Using rule of thumb

Burden (B)=25-45*hole diameter (using 30*d)

B=30*0.065

Burden=1.95m

Spacing=1.15*B (staggered pattern)

S=1.15*1.95

S=2.24m

Assuming we are to Blast a bench of 25m by 25m

The implementation of this two holes diameter is that,

For  hole 1, more hole will be drill on the bench Why for hole two, less holes will be drilled:

Let proof that also

For hole 1

Number of hole per column (Nc)= bench area÷Bench

Nc =(25m*25m)/1.2

Nc=625/1.2

Nc=521holes

Numbers of holes let row on the bench (Nr)=Bench area/spacing

Nr= 625/1.38

Nr=453holes per row

Total holes to be drill is Nr*Nc

Total hole= 236,013 holes.

 For hole 2

Number of hole per column (Nc)= bench area÷Bench

Nc =(25m*25m)/1.95

Nc=625/1.95

Nc=321holes per column

Numbers of holes let row on the bench (Nr)=Bench area/spacing

Nr= 625/2.24

Nr=279holes per row

Total holes to be drill is Nr*Nc

Total hole= 89,559 holes.

The implementation is that the diameter affect both spacing and burden, it affect the number of holes drilled.

Imagine a different of 146,454holes between the two hole diameter.

More hole means more working days to carryout Drilling operation, more working days implies more diesel consumption per day, more operator allowance per day, more equipment cost per day..

This affect operation cost directly without any measure.

Drilling accuracy of drillhole collar and column also affect the efficiency of Blasting, it create problem in the stope after Blasting.

Poor drilling accuracy affect the distribution of Explosive Energy withing the hole thereby resulting into 

1.poor fragmentation

2. Generation of flyrock

3. Overbreak

4. Ground vibration and others

1.Poor fragmentation increase operation cost by prolonging loading time. Loading time prolonged result into decrease in production per day.

Less material will be move from the mine to the mill.

More diesel will be waste as the loader tries to separate oversize boulders to load optimum size.

2.Generation of flyrock can cause damage to equipment, house and even break someone's head leading to total close down of the mine. Damage to equipment will cost more money, why breaking of someone's head or causing injury can cost the company weeks of no work or total closure of the mine which can be open after payment of compensation and diver fine if license is not withdraw from mine operator.

3.Overbreak directly weakens the bench wall and may lead to plane or wedge failure. Sliding down of rock mass on workers will be a disastrous senario, also closure of pit will cost high development cost, you know high cost of equipment for loading sand and debris, high cost of moving waste out of the mine...

4. Likewise ground vibration distabilies structure, cause disturbance to nearby fellows which can lead to submission of petition against your company...

Also, if the mine site location is closed to the earth tectonic plate edge region possibility is that earthquake may surface or land subsidence...

Drilling and Blasting operation really affect operation cost a lot.

Beyond that it affect milling and process cost for both metallic and non metallic Minerals.

 Poor Blasting is define by me as that which generate environmental illness like airblast, ground vibration, flyrock among others and that Blasting which produce  poor fragmentation with poor loading processing efficiency.

When a Blasting is confirmed to be a poor Blasting, it increases overbreak, increase dilution rate and also subject other downstream operations into chaos.

In case of metallic ore, production of external dilution due to overbreak and internal dilution due to backbreak not only cause a delay in loading and increase in mine operation cost, it also increase the cost of milling, increase the cost of separating the gangue (waste materials, barren rocks, host rocks) from the run-off-mine.

This not only affect the operation cost it gradually increase the mine life, it affect the mine capital payback period, reduce the company productivity Net present value.

Payback period is the schedule time for a mine or any business to return the initial investments back and begin to make profit.

 Net present value NPV is a project Profit analysis tool use to compare the present value of the initial capital cost of a project to the present value of the cash inflow.

Having more diluted run-off-mine affect the profit margin of a mine beyond just affecting operation cost 

So as a mining and Blasting Engineer we need to hold our position well and plan well to ensure we deliver a good blast that will not just be safe but also profitable to load, transport and Mill to process.

It confirmed that initiation pattern with poor timing will also create problem to blast result,

Likewise poor burden distance, poor stemming length, poor Explosive selection among others.

Having  misfire is also another problem that will affect operation cost of a mine.

How can drilling and Blasting be optimize  to minimize operation cost?

I have answered this question in my words above indirectly.

But I will stretch my time to give clear rib support and crown pillar support to the answer  (Don't mind I just go underground to borrow terminology)

To Carry out a good Blasting, there are three things you need to know and implement:

1.Proper Blast Pre-planning 

2. In charge planing

3. Post Blasting planing

1.Pre-planning include:

 a.understanding the Rock material

b. Mapping of rock formations to understand the discontinuity condition

c.selection of best blast Design and blast parameters (hole diameter, burden, spacing, Stemming length, bottom charge length and weight, column charge length and charge weight, powder factor e.t.c) all this are very important.

d. Selection of best Explosive with the sufficient property to function at the blast location

e.selection of best drilling machine Among others

Taking a sharp look at powder factor:

 it is the economic control loop for Blasting operation, it determine the quantity of explosive you will use and the cost to fragment a ton of the ore.

If powder factor is high that implies that more Explosive will be purchase, operation cost will increase.

If powder factor is low, poor fragmentation is certain, increase in loading cost and haulage cost.

All this parameters must be optimzed and balance.

If burden distance is large, poor fragmentation is certain, as this dictates the rate of tensile slabbing at the Explosion CJ plane. If burden distance is to much the shock wave will not complete micro-fracturing before the gas Energy is release meaning more of oversize material will be produced..

 All the parameters are important, as blast Engineer we should consider balancing them with the uncontrollable factor of the rock (Uniaxial compressive strength, rock elasticity, discontinuity nature, and rock geotechnical properties)

2.In charge planing:

This is an action control measure.

There are basically three key elements of production optimization and safety garantee in a mine.

1. Engineering level: This involves blast design and preparation.

2. Education: this includes educating and training personnel on how to implement the blast Design on site to provide the expected result.

3. Enforcement: human will always be human as we are not machine, you need to supervise workers to ensure complete and correct implication of Design.

No oversight supervision, no unsafe act supervision.

All Blasting operation stages are well monitored and supervise by competent Engineer..

If poor Stemming length or material is used, you have pull out and other poor result from Blasting operation.

If workers decided to steal Explosive and Blasting accessories then use low quantity material due to your absence on site, this is directly going to affect Blasting output an increase production cost

 Finally, the post Blasting plan include checking out the blast result and making proper plan and recommendation for next Blast operation.

In conclusion:

As a Mining Engineer or mine  company CEO reading this article, the best way to minimize operation cost is to plan, implement and supervise the implementation on site.

Blasting is for safety and not for damage.

Thanks for reading

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® GIANT MINER 

Committed to advancing mining knowledge..... 

ROCK BLASTING CREATE SHOCK IN ABUJA COMMUNITY

By GIANT MINER Saturday ,26th of March 2021

Mining as an operation that involves the Exploitation of valuable ore or rock from the earth crust must be carryout at safety to health and to the environment (including general public).

Mining operations both surface and underground should be  such that is environmental safe and not causing hazard to workers and general public health and safety. Taking a transparent look at the  Nigeria Minerals and mining Act 2007 and the Nigeria Minerals and  Mining Regulation 2011, the chapter 1, part iv Section 4(j), and its Regulation 2011 section 3(b) empowered and state the obligation of the Nation Minister for Mines and steel development to ensure that a measure is put in place to ensure that the welfarism and safety of all workers and general public relating with mineral operation is garantee. The section 17(b) of the ACT and the

Section 5(2)(h) of it regulation make it as an obligation to the mine inspectorate Department MID to supervise the enforcement of this Act and other health and safety laws in force on the mine operators and Mineral title holders. The regulation give room for the obligation of MID, mines environmental compliance Department MECD and other offices of MMSD to ensure mine operation are carry out with no environmental impact and good health and safety condition.

The ACT part v section 70(I) and the 2011 regulation also order the compliance of all mine operator in Nigeria to the act and all mining legislation and require that all mine operation be carry out in a safe condition.

Starting a Quarry close to community and Dam station is not a safe acts?

But a dangerous and hazardous attempt just like suicide mission it's beyond threatening to host community to fraustrating their peace of mind.

Accident within this week in Nigeria

Quarry Rock Blasting on Wednesday create life threatening as people around Abuja community NIGERIA underwent an explosion from nearby quarry.

Read about the accident Here

The incident is what I term illegality of legal influence in Mining Act and mining regulation.

The concern quarry is said to be located near resident and near dam which is against Mining Act and regulations. The company make use of Explosive for rock fragmentation which subject the dam to be highly hazard source with high level risk.

One of the power of Enact act and regulations is to be able to control the concern event and operation strictly without any government and NGO influence.

Thou some mining operations like dredging, hydraulicing may not generate dust like Quarry operation that involves rock excavation through Drilling and Blasting operation.

Drilling operation not just a point sources for dust generation but also generate noise due to the interaction between the rotating drill bit and the insitu rock.

Blasting operation was once define as a controlled bombing use for rock breakage. Blasting operation is not just hazardous or a principal hazard source but a dangerous operation that should be handled by experts and professional.  This operation is capable of projecting rock debris in place of flyrock, cause ground vibration, airblast and noise pollution among other blast related Accidents if not we'll design. At least in no condition should a mine site be less than 500meters from building. Thou there are isolation control, preventive and suppression control measures (e.g blast mat for fly rock prevention and presplitting, post splitting, line hole drilling, cushion blasting techniques) still blasting around community and near dam for production is a bad engineering etiquette.

The origin of explosion noise during blasting

The explosion noise (airblast) from Blasting is as a result of gas energy release immediately after the release of shock wave from detonated Explosive charge. Explosive as an energetic chemical compound undergo exothermic reaction to generate heat and high pressure has called Explosion pressure.

 The Explosive charge in each blast hole recieve instantaneous shock wave from the primer which amplified the wave from the surface Detonator. The Explosive spontaneously release shock wave why the composition disintegrate continuously. At complete disintegration, the whole Explosive charge generate huge gas Energy which is maximum at the initiation point and reduce gradually with time.

The sound from the explosion is to cast the fractured rock mass, to throw it and break it down. In a bit to fulfill this obligation, there is collision between air particles and rock particles which impact change in wave traveling direction and cause a loud noise in the earth vacuum.

The release energy can travels on the ground as P-wave, S-wave and L wave.

Shock from Explosion can generate high risk hazard of principal negative impact on human if unaware talkless of residence been close to the mine.

Some of the effect of explosion gas released by Explosive Deton are:

Noise pollution

Dust pollution

Rock debris and fragment projection 

Ground vibration. Among others.

RECOMMENDATION S

1.Mining should be well regulated and monitored right from the set up time, before issuing mining license, Blasting licence and other titles, site inspection should be done.

Effect of oversight 

Swiss cheese model of human error by REASON in 1990 explain clearly the place of unsafe act supervision as one of the deficiency of accident occurrence.  Likewise latent failure in  place of ministry mine inspectorate Department and MECD believing in just submission of environmental impact assessment  (EIA) as way of assuring saftey mine setup without site inspection and monitoring. Mining, Blasting and other operation become different on ground compare to book. Oversight is a killing virus, which is fast killing than COVID19, Government bodies loss tax, royalty and annual service fees because they are far from the site. Mining is site work not file or book work. Mining is beyond reports submitted by the mine operator, good visitation to mine site by competent person is the key to effect enforcement of ACT, REGULATIONS, LEGISLATION AND MINE HEALTH AND SAFTY LAWS.

Many mine companies will die in debt because of oversight supervision, don't supervise mining, blasting from the table and board point of view. You must be involved to revolve mining productivity and safety.

Kindly like, share and comment.

Together we make mining operation safe and profitable.

Like my page @ mining knowledge and experience on Facebook, watch my videos on YouTube at TAIWO BLESSING OLAMIDE

SOFTWARE METHOD OF BLAST RESULT ANALYSIS BY GIANT MINER

Technical article

By: Taiwo Blessing olamide

INTRODUCTION

Blasting result assessment is very important to justify the efficiency and Productivity of every blasting operation. This is also to view the need to optimize the blast design in order to add value to downstream operation and reduce the cost of transporting run-off-mine, prevent transportating waste materials www the mine to the mill, minimize the cost of crushing and separating the gangue material from the concentrate in case of metallic and gemistic mining industries. It become important that analysing the blasting result using various available software that helps the mine manager to meet up with the production rate per day at the lowest cost implication is imperative. Most mines are less concerned about the result of Blasting but still keep complaining on the low profitability of their mine and low efficiency of the working equipments. Poor loading with long loading cycle time along side with continuous separation of Boulders consume Diesel and also limit the loading equipment efficiency. 

Image analysis delineated Result from Wipfrag software

Some mine employs the use of hydraulic breaker for further breaking of boulders separated from poor blasting, while others industry engage in secondary Blasting operation. Blasting operation can be done in such as to limit secondary fragmentation cost through justification of blast output result and checking the status of each blast result to optimize the blast parameters such as to produce result that blend with the gape of the primary crusher. 

This makes blast Fragmentation analysis and other Post blast checking softwares like WipFrag software, Split desktop, Fraglist software among others Important.

Nevertheless the use of o-pit blast software, Kuz-Ram model in adjusting the blast design is also important.

Find below a simple and Introduction explanation to Blast result analysis.

BRIEF INTRODUCTION ABOUT WIPFRAG SOFTWARE

Visit WipFrag software website here

WipFrag analysis is one of the many available software use in analysing blast Fragmentation. Mostly, after Blasting, the Mining Engineers are interested in checking the Blasting aggregate uniformity and size distribution which help both in measuring the blast efficiency and the digging rate of loading equipment during loading. It is believed that, a good Blasting is that which has <5% oversize and <5%undersize.

Also, from the result of fragmentation analysis, we can determine whether their is blast misfire or improper detonation of explosive charge which can be detrimental to both mine workers and loading equipment. This makes fragmentation analysis very important.

WipFrag software make use of empirical model and other intrinsic model to justify blasting image from the view of photo analysis.

The software recieve blast picture snapped with a scaling object and provides the size distribution graph for a typical Blasting.

The software base on it design program consist of image analysis program code which  by scanning, generates an image size distribution which is justified by the scaling object provided in the picture.

 HOW DOES WIPFRAG SOFTWARE WORKS

Getting blast image from the mine site is the first thing to do.

The image is collected with either phone camera or drone as shown below

 After Blasting, excavator can be use to spread the muckpile in case of heap pile.

Then a scaling object is placed on the blast pile.

The scaling object can be helmet, frame of known dimension or any object with define dimension.

 In snapping the picture, the angle at which the picture is been snapped is very important, likewise the distance. The distance must not be to far and also the camera inclination must not be to dip in.

After collection of blast images,

The image is uploaded into the software.

The scaling object dimension is imputed.

Then, the scaling object image dimension is measure with an inbuilt dimensioning ruler provided by the software. See the image below

 After this, the mesh scan of the image particle size is adjust to fit in for both large boulder and fine particles. After particle mesh adjustment had been done, the graph for the size distribution is generated automatically.

Interpretation of the graph

As have said earlier, blasting Engineers are concerned with the improvement in productivity of the mine.. therefore analysing the size distribution to know if the undersize produce is to much or the oversize is to much is done on the  particle size distribution graph.

The provided graph is like this shown below,

The graph gives the particle size range and their percentage in the pile. The software also provide data like the 50% passing size and other information about the blast.

The X50 denotes the Fragment size that make up the 50% material passing opening in the blast result.

The X80 represent the Fragment size that make up the 80% material passing opening in the blast result.

The graph interpretation is also display at the right hand side in tabular form. 

This result provides other parameters such as uniformity index, Xmax, X10 to mention few.

CONCLUSION

Using analysis software will not only provide you with data to work with, it will also help you to make necessary adjustments to your blast design and output.

Haul Truck falling in a mine and Blasting relation with rock: Getting high Mining Profitability and Safety Record Assurance

Mining Engineering is the best field to be as we are concern with how the valuable Mineral deposit is Exploit from the earth crust for the benefit of manufacturing man's want.

Working bench and safety issue

Working ore deposit on a single bench may likely be hazardous if proper care is not taken to check Safety management. The failure of rock depend strictly on the bench slope angle and the discontinuity condition of the rock. Appearance of fracture and fault Vin rock mass can result from natural features and also artificial factors including poor Blast design, poor mine design among other issue relating to mining operations.

To avoid such accident like truck failing, Rolling down of boulders from level to level it important to ensure benches are wide enough and design with sufficient beam. A beam is a safety distance space left at both front and edge of a working bench width and haulage vroad (Ramp) to safely guide haulage trucks from failing into the pit and also guide rock boulder from rolling down the benches. Accident is an unplanned event and can cause high damage on both workers and equipments, therefore proper bridging of haulage road will help to prevent truck failing into the mine pit during turning time, revealing time or traveling time.

How to avoid Truck falling in a mine

1. Building beam: designing a beam is the easiest way to prevent truck and boulder fall. A beam according to standard rend in with between 10-15ft, and can also be 2-4.5% of the haul truck width, a beam should be about 0.45-7 of the haul truck Tyre in height.

In most working time, traveling truck in a bit to manover or turn can miss calculation and drone into the pit due to the dipping elevation Condit of the pit. Thou we can't just mine material without moving them to the processing plant, therefore we require a ramp or haulage road that will provide access for truck into the pit. In achieving this, we require the working bench width to be wide enough to accommodate the loading equipment turning radius, the haul truck width, the end beam width, and the front beam width.

For local quarries, where materials are stock pile in attender, an attender sometimes can be between to pits or at the end point of the pit which requires the haul truck to travel through various in between pit ramp, in such case haul truck are highly prompt to falling as the level of riskbis high. Such Quarry required the following safety Tips to avoid falling of trucks into the pit:

a. Increase in between pit haul road width to about 2.5 of the haul truck width such that two trucks can pass with half inter distance space free.

b. Building of beam at the end and front of the haulage road, this can be done using cement bag filled with overburden material. The beam bag should be  two width step and three step up to serve as guide for truck and stopper for boulder falling. Falling of boulder from moving truck or as a result of found stress readjustment under load can break workers head or damage body part seriously.

c. Finally, checking of road conditions for shear off edge or floor heave should be done before daily job by the mine supervisor.

2. Regulations of Fleet time such that each truck can access road at once in case of narrow width ramp.

Most cases may result in small width road due to poor initial design. Such road can be close down or increase a bit. With increment decision, the mine manager should design a proper fleet that make one truck travel per time on the road. In any way it may be, the road width must be at least 1.5 of the truck width, with beam in place at the two edges.

I conclude this with a word of advice to all mine supervisor who are in charge of all workers in every section of the quarry, supervisor are to supervise and shun unsafe act, good supervision will not just safe company from loss but will also safe them from accident. Let all supervisor assign as many as needed assistance supervisor among workers to ensure the full compliance of workers with company safety management system. Also, most company COO, CEO and management with no safety management system (SMS) should make provision to adopt one.  SMS helo to build a comprehensive approach through 10 key elements to garantee safety in the mine. This 10 elements approach are:

1. Policy: management build safety policy that is transparent to all workers and personnel working in the mine. This safety policy states clearly the company goal and objectives on safety assurance. It gives attention to opening and closing time of the mine, Blasting time among others.

2. Management structure: SMS make clear the company structure and provide job description of all officials in the mine.

3. Operation: SMS give information about how specific mining operation is carry out in the mine in accordance to National policy and regulations

4 hazard management: SMS of every company provides a comprehensive way of identifying hazard, assessment of hazard and management of hazard in a systematical way. Some company design their own WHAC (Workplace hazard assessment Condition)

5. Incident Management: How mine incident is to be managed

6. Workers participation

7. Maintenance

8. Training and competency

9. Emergency response

10. Record keeping.

All this 10 elements help a company to avoid unwanted and unplanned accident which can subject workers life into calamity or damage. Adopting a SMS in mine and local company is a strategic way of preventing hazard and lower the level of risk mine workers are exposed to in the mine.

Blasting relationship with rock strength

Thou we like to mine orebody but we do that with understanding of what the earth response can be. Earth is a spherical body with stable and equilibrium forces with all around balance stress field. As we mine will tend to alter the state of Earth rest, the balance of pit slope and the control of shift in tectonic plate.Thou orogeny and some other mountain reef shift may contribute to wall failure most time depending on region. Rock excavation affect the state of rock stress distribution as the concentration of normal and shear stress become altered as excavation is created into an intact rock. Most Blasting operation don in discontinuous rock mass tends to be highly risky due to the possibility of fracture daylight which can finally terminate the competency of a plane and makes it detrimental to mine worker safety. What discontinuity does to slope is to weakens both the internal resistant strength of the rock (cohesion) and decrease the internal angle of friction which dictates the stability of such plan at initial. 

Generally when it comes to rock excavation, failure can occur in three ways, Plane failure, wedge failure and toppling failure. All this failure has a specific required criteria that prompt there occurrence.

During Blasting we are concerned with ensuring that none of this condition is fulfilled after blasting so as not to call for a total of partial close down of the mine by rock fall. A fall in rock mass of weight less than 0.25kg at a projectile height is capable of disability if not prevented. Most rock fall occur after fragmentation, as rock mass tends to readjust stress with it's new environmental condition after Blasting.  So as an engineer in charge of Blasting or mine design, we check on both the rock characteristics, dilution control factor and the possibility of ease loading without fleet delay and damage to crestee bench floor during design.Avoiding all possible overbreak and backbreak is the main aim of powder control. Powder factor must be that optimum to ensure good fragmentation and stable bench wall. As good fragmentation with poor wall result into poor operation due to the possibility of total closure at wall caving or total closure by Ministry of mine after an occurrence of brutal accident.Mine safely.

SIMPLE EXPLOSIVE SAFETY TIPS

Safety tips in Explosive transportation and storage

Explosive is sincerely known to be highly dangerous due to the high energy emission at detonation.

Explosive can either undergo detonation or deflagration,

Depending on the type of Explosive, the intensity of the initiation energy and the present condition and sensitivity level of the Explosive.

Explosives had been design from manufacturer production point to be safe under some specified conditions.

For this reason, explosives are classified into high and low Explosive base on sensitive and energy Strength.

It also classified into primary, secondary and tertiary Explosive base on its working principle. Some country also further classify Explosive into class 1, 2...

All this attempt was to ensure good Safety storage and proper handling understanding.

Most Explosive may become unstable under temperature, handling status, environmental condition and storage. 

Having the knowledge and understanding of Explosive is not limited to just mining and Explosive Engineers. Having some simple understanding about Explosive and other Blasting accessories as an individual working in mine site, Explosive manufacturering companies, Agrochemical industry, and other related companies won't only add to you but also garantee safety management system.

Thou according to Explosive Acts and regulations only competent and certified professional person are allowed to relate with Explosive.

But in case if an ordinary person or someone working in other profession not related to Explosive come in contact with Explosive or Explosive unsafe act and working condition, having a little knowledge about this will go along way.

Safety tips on Explosive transportation, Safety tips on Explosive storage and 

Safety tips on Explosive handling and usage

The initial stage in carrying out a risk assessment is to identify the hazards associated with the explosives and their handling, storage and use in the workplace, and transport both internally and between sites. Information to help identify the hazards is available in the relevant regulations, from the manufacturer/supplier of the product and from a number of other sources. All relevant sources of information should be examined to help with the risk assessment process.

The following should be considered when identifying the hazards:

1.Where are the explosives transported and stored?

2. How are they used and transported?

3. What are the potential sources of ignition and detonation?

Where pyrotechnic articles such as fireworks are stored, e.g in shops, the primary hazard that needs to be considered is fire or accidental ignition. Do it yourself superstores would also need to consider the additional hazard presented by other flammable materials, such as white spirit.

Organisations storing high explosives would need to consider a wider range of issues, such as ignition by:

✓naked flames

✓electricity (including static electricity and electromagnetic energy)

✓sparks from mechanical or frictional contact between metal surfaces

✓heat and temperature

✓pressure

✓impact and friction

✓chemical incompatibility between certain substances such as contact with bare rusted metal

✓contamination by grit

✓reduction of stability over the life of the explosive.

The following should be considered when identifying the hazards.

✓Where are the explosives used and stored?

✓How are they used and stored?

✓What is the potential for hazardous or explosive atmospheres occurring?

✓What are the potential sources of ignition and detonation (including the likelihood of electrostatic charges, etc)?

Evaluating the risks from explosives

Once the hazards related to explosives have been identified, it is possible to consider and evaluate the risk of an explosion or fire incident occurring.

The person responsible for evaluating the risk factors should consider:

✓the possibility and likelihood of fire or explosion

✓the quantities of explosive materials (and other dangerous substances) stored on the premises

✓the structures and property that could be affected

✓the number of people on site

✓the potential severity of the damage to people and property

✓any existing safety or control measures

✓the competency of people in the workplace and involved with transport

✓any accident and emergency procedures in place

✓information available to employees and other people on site.

When evaluating the risks associated with explosives, the assessment must consider all possible effects including, but not limited to, the effects of blast and overpressure on persons, property and the environment, the projection of debris or fall area of a collapsing structure, and the potential for ignition of other flammable substances.

Serious risks should be dealt with immediately. All other risks should then be dealt with in priority order, depending on the seriousness of the risk and the likelihood of an event occurring.

The results of the risk assessment should determine the control measures necessary to prevent or adequately control any risk from fire or explosion.

Control Measures

The principal issue to be addressed in the safe storage and transport of explosives is that of preventing the accidental initiation of explosives. Primarily, this involves keeping sources of ignition away from the explosives. It also involves controlling the presence of explosives, especially in areas of activity, e•g places where work is carried out or where people or other traffic move around regularly.

The control measures (precautions) that need to be employed will be identified during the risk assessment process. These may include some or all of the following:

✓excluding naked flames

✓excluding sources of electrical energy which could produce sparks or otherwise initiate the explosives

✓preventing electrostatic charge build up and discharge

✓preventing accidental initiation from frictional or impact energy; packaging design should reduce static and shock when transporting or storing explosives

lightning protection

✓preventing accidental contact between exposed metal surfaces

✓preventing accidental contact between explosives and exposed hot surfaces

✓preventing contact between explosives and chemically incompatible substances

✓preventing contamination of explosives and ingredients

✓ensuring a suitable distance between explosive stores and site traffic or active areas of the site

✓minimising the time that explosives are in an unstable intermediate state before final processing

✓avoiding the uncontrolled build-up of waste explosives by regular disposal

✓preventing the build-up of explosive dusts, such as on the floors of magazines, through the provision of good housekeeping

✓restricting access to competent operators.

The extent of the management arrangements will depend on the complexity of the operation. A small firm that is simply storing explosives will not need as elaborate arrangements as a large manufacturer will.

Employers must also take appropriate measures to limit the extent of a fire or explosion. This involves:

✓managing stocks of explosives to limit the amount of explosives in areas in which people are likely to be present

✓limiting the number of people in areas where explosives are present

✓keeping explosives away from flammable or combustible materials which could fuel a fire, and away from toxic substances which could be released in the event of a fire.

It may also be necessary to take other steps to contain and safely release the blast effects. At its simplest, this means taking steps to ensure that in the event of a fire, anyone in the immediate area of the explosives can quickly and safely escape. This may include:

✓the establishment of emergency procedures

✓fire precautions

✓fire detection and warning systems

✓means of escape and evacuation

✓fire-fighting equipment

✓measures to protect against explosion

Protecting people

There are several techniques that may be used to protect people in the event of a fire or explosion. The measures to be used should be determined by the risk assessment process and may include some, or all, of the following:

✓the appropriate use of safety screens and barriers

✓remote working

✓personal protective equipment (PPE).

✓Remote working will be the preferred choice in cases where the potential for serious injury or death is significant, including:the manufacture of primary explosives, incorporation of pyrotechnic compositions, mixing and handling of propellants and blasting explosives, medium and large-calibre ammunition shell filling, making detonators.

Safe Disposal of Explosives and Decontaminating damage or deteriorated Explosive.

There are diver approach in selecting the most suitable method of disposal. This should be determined through the risk assessment process. The assessment needs to consider the nature of the explosive and its hazards, the disposal method and hazards created during the disposal process, and the type and position of the disposal site. Anyone disposing of explosives must, so far as is reasonably practicable, ensure that they are disposed of safely. Similarly, those who decontaminate explosive-contaminated items must also ensure, so far as is reasonably practicable, that they are decontaminated safely. The four ways to dispose of, or to destroy, explosives are:

✓burning

✓detonation

✓dissolution or dilution

✓chemical destruction.

Due to environmental concerns, dumping at sea or landfill are no longer considered to be suitable methods of disposal.

Restrictions on the Employment of Young Persons

No one under the age of 18 years should be permitted to work in the manufacture or storage of explosives, except under appropriate supervision. This extends the duties of the Management of Health and Safety at Work Regulations 1999.

Control of Unauthorised Access

ER 2014 places prohibitions on entering an explosives building or area without permission from the licensee or the licensee's representative. The legislation also requires anyone who has entered without permission to leave when requested to do so and permits the occupier to remove the person. It is recommended that the police are called if the person refuses to leave. The occupier should remove unauthorised people themselves only in situations where they consider that there is an imminent threat to the safety of the explosives.

Only reasonable means may be used and these will depend on the severity and imminence of the threat to the explosives. The operator should, normally, make suitable arrangements to mark the boundaries of the site. The decision on whether to erect boundary markers and warning signs will take into account the circumstances of the explosives stored, especially their location. Where further guidance is required, this may be sought from the Police Explosives Liaison Officer.

 IN CONCLUSION,

Storage, usage and Transportation of Explosive from the manufacturer to the magazine or from magazine to the mine site should be done with this safety Tips in place:

1. Never transport high Explosive and other Blasting accessories together

2. Ensure Explosive transportating van is in good condition

3. Ensure the driver is enlighten on what Explosive is capable of doing

4. Check van driver to ensure he is not carrying matches or any flammable material

5. Van wiring parts must be highly insulated

6. Smoking during Explosive transportation is highly prohibited, it can led to the death of thousand

7. Explosive squared and anti bomb security show excort the transportation van

8. Speed limit must be considered for the van as started in Explosive regulation 2014 and others

9. During transportation, Explosive must be store in proper conducive and stable condition

10. Earth electrostatic neutralizer chain must be attached to the van during transportation

11.Ensure all Explosives are properly and formally check in when delivery is made to the magazine.

12. Follow the FIFO (First in, First out) structure when checking out the Explosive in the magazine

13. Proper arrangements should be made for security protection in the magazine

14. Sign indicating danger should be boldly place at the magazine entrance and in strategic positions within the magazine.

15. Precaution tips and symbols should be position in strategic point within the magazine

16. Damage or expired Explosive should be properly dispose by certified Engineers.

17. Misfire Explosive recovered should in no way be placed with other Explosive.

18. Magazine should be barricade by a fence with one entrance.

19. High Explosive must not be store in the same place with other Blasting accessories like cap, booster, safety fuse, detonators.

20. During charging of blast hole, leftover Explosives should be move away from the blast site

21. Exploder should be check properly before use for charge initiation to avoid insufficient release of energy to the charge loop.

22. Explosive charge must not be tamp with iron rods, also during stemming of already connected charge holes is total disastrous.

23. Opening of Explosive cartridge is unsafe

24. Transportation of Explosive with bike or animals I'm an unconducive condition is unsafe.

25.storing Explosive in room, containers or in the mine as the case of many ASM is unsafe

26. All retrieved Explosive from misfire blast should be returned to the magazine for necessary action

27. Boulder sockets from misfire blast should be check properly for undetonated Explosive.

28. Blasting cap and detonators must not be kept in the blastman pocket or take home.

29. If you locate Explosive in any place, report to the nearest police station or Explosive inspectorate in your area

30. Smoking During blast charge or chaining is a death sentence automatically.

31. All unused Explosive must be returned back to the magazine

32. Blast Misfire site must be barricade and abandoned for some time as specified in Explosive regulation and safety Act.

33. During blast hole charging, pulling the Detonation cord or the lead wire in case of electric Blasting is a bad etiquette that can result into misfire

34. Pulling Explosive charge by force or with knife or other metal from misfire holes or boulder socket is a direct call for accident, avoid that

35. Drilling deviated retrieve hole into MISFIRE rock mass is a deadly act and unsafe

36. Standing closer  (<30m) to Blasting site to watch how detonation occur is a direct decision to experience accident.

37. Using a very short safety fuse in a bit to minimize cost is a bad and unsafe act, never try such

38. Improper placement of primer or primer cord into the Explosive before lowering the bottom charge is an easy way to cause blast misfire.

39. High powder factor in secondary blasting is a call for high rate of flyrock, avoid such

40. Positioning Explosive industry near power station, train station and other unsafe location is unsafe

Let all who work with Explosive and other dangerous materials be careful not to subject others into trouble.

Avoid any form of unsafe act and unsafe condition.

Thanks

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Most prefer reference for this article is ER2014