COAL MINING INDUSTRY INFORMATION

The largest coal producing countries are not confined to one region – the top five hard coal producers are China, the USA, India, Australia and Indonesia. Much of global coal production is used in the country in which it was produced; only around 15% of hard coal production is destined for the international coal market.

The quality of a coal deposit is determined by: Types of vegetation from which the coal originated; Depths of burial; Temperatures and pressures at those depths; Length of time the coal has been forming in the deposit


Two types of coal mining

Coal is mined by two methods: surface or ‘opencast’ mining or underground or ‘deep’ mining.

The choice of mining method largely depends on the geology of the coal deposit. Underground mining currently accounts for a bigger share of world coal production than opencast; although in several important coal producing countries surface mining is more common.


Surface mining

Surface mining is only economic when the coal seam is near the surface. This method recovers a higher proportion of the coal deposit than underground mining as all coal seams are exploited – 90% or more of the coal can be recovered. Large opencast mines can cover an area of many square kilometres and use very large pieces of equipment, such as draglines, power shovels, large trucks, bucket wheel excavators and conveyors.

The overburden of soil and rock is first broken up by explosives; it is then removed by draglines or by shovel and truck. Once the coal seam is exposed, it is drilled, fractured and systematically mined in strips. The coal is then loaded on to large trucks or conveyors for transport to either the coal preparation plant or direct to where it will be used.

Surface & Underground mining


Underground mining

There are two main methods of underground mining: room-and-pillar and longwall mining.

Room-and-pillar mining

In room-and-pillar mining, coal deposits are mined by cutting a network of ‘rooms’ into the coal seam and leaving behind ‘pillars’ of coal to support the roof of the mine. These pillars can be up to 40% of the total coal in the seam – although this coal can sometimes be recovered at a later stage.

Longwall mining

Longwall mining involves the full extraction of coal from a section of the seam, or ‘face’ using mechanical shearers. The coal ‘face’ can vary in length from 100-350m. Self-advancing, hydraulically-powered supports temporarily hold up the roof while coal is extracted. When coal has been extracted from the area, the roof is allowed to collapse. Over 75% of the coal in the deposit can be extracted from panels of coal that can extend 3km through the coal seam.

Technological advancements have made coal mining today more productive than it has ever been. To keep up with technology and to extract coal as efficiently as possible, modern mining personnel must be highly skilled and well-trained in the use of complex, state-of-the-art equipment.


Types of coal

Coal is a burnable carbonaceous rock, classified as sedimentary. Coal is divided into four major types, based generally on the amount of transformation undergone from the earlier plant and peat stages, heating value and other characteristics:

Lignite

A brownish-black coal with generally high moisture and ash content and the lowest carbon content. Significant resources and mining operations are in Texas, North Dakota and Montana.

Subituminous

Coal with higher heating value than lignite. Wyoming produces the bulk of sub-bituminous coal in the Powder River Basin (PRB) area.

Bituminous

Soft, intermediate grade of coal that is most common and widely used in the United States. It is mined mainly in Appalachia and the Midwest regions of the US.

Anthracite

The hardest type of coal, consisting of nearly all carbon. Mined in the Appalachian area of Pennsylvania, it has the highest heating value and lowest moisture and ash content.

Coking Coal

Coking coal is a bituminous coal with special characteristics that allows it to be converted into coke and used in the steel manufacturing process.


Factoids
  • Coal provides America’s railroads with more traffic and revenue than any other commodity.
  • A typical train car holds between 115 and 117 tons of coal.
  • Wyoming is the largest coal-producing state.
  • Coal accounts for half of the electricity use in the U.S.
  • Coal costs less than any other major fossil fuel source.
  • The world’s largest producers and consumers of coal are China, Poland, Russia, India and the United States.
  • Total world consumption of marketed energy is projected to increase by 57 percent from 2004 to 2030.
  • Coal’s share of total world energy use climbed from 25 percent in 2003 to 26 percent in 2004 and is expected to increase to 28 percent by 2030.

Solutions Case Studies

ASGCO® Solves Southwest Coal Fired Power Plant Rail Car Dump Transfer Point Problems

Objective: To replace the existing corroded, mild steel chutes with stainless steel, redesign the To replace the existing corroded, mild steel chutes with stainless steel, redesign the  transfers to center the material on the receiving belt, and be able to complete…

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Objective: To replace the existing corroded, mild steel chutes with stainless steel, redesign the To replace the existing corroded, mild steel chutes with stainless steel, redesign the  transfers to center the material on the receiving belt, and be able to complete the job  within a very short time-line during their shut down.

Challenge: After the material was dumped it went through a series of grizzly bars, then through all of the chute work below on 4 different levels. With the existing design the material was off-center loading which was pushing the belt to one side and causing the material to spill and wear the belt unevenly. They also had internal deflector plates installed at the bottom of the chutes to try to guide the material, but it wasn’t working and they were wearing out. The chute needed to be re-designed to center the material flow onto the belt.

Solution: Part of the project was to replace the grizzly bars, along with four of the chutes, exactly as they were originally designed. The lower portions had to be re-designed to solve the off-center loading issue. ASGCO® engineers performed an on-site Point Cloud Laser Scanning survey to provide accurate measurements of the existing transfers. Then a 3-DEM® simulation was developed to validate that the flow would fall onto the center of the belt through the new chutes.

Results: Since it was coal and various sized material, the simulation process took several weeks to complete. We scanned it, designed it, detailed it, fabricated the chutes and delivered it all before the shutdown deadline. The project was installed with no issues and the material flow is center loading onto the belt. The customer is extremely happy. No spillage and everything is center loading.

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ASGCO® Conveyor Products Reduce Airborne Dust and Eliminate Spillage at This Mid-West Coal Fired Power Plant.

Objective: To reduce airborne dust and to eliminate spillage at the conveyor load zone. Challenge: The maintenance personnel at the plant complained that the existing wide open loading chute was causing spillage of product, tremendous airborne dust and belt mis-tracking…

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Objective: To reduce airborne dust and to eliminate spillage at the conveyor load zone.

Challenge: The maintenance personnel at the plant complained that the existing wide open loading chute was causing spillage of product, tremendous airborne dust and belt mis-tracking due to off center loading.  These issues were creating downtime due to clean up issues and hazardous working conditions caused by the airborne dust.

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Recommendations: After a complete survey of the conveyor systems, the recommendation was made to install an ASGCO® Dual
Return Tru-Trainer® on the return side of the conveyor to keep the belt centered around the tail pulley. ASGCO® Impact Cradle Bed
and Slide-N-Roll Beds were also recommended to help seal the skirting. The Conveyor Hoods and Dust Curtains™ were needed
to control the large amounts of dust being dispersed from the open chute application.

Results: After the installation of the ASGCO® products, the Maintenance personnel claim that there is reduced maintenance downtime
and improved housekeeping.   The reduced dust in the area, allows the employees to work safely around the area. The ease of access
to maintain the ASGCO® equipment allows for less maintenance hours in the area and safer working conditions while performing
maintenance.

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ASGCO® Engineering Design, Point Cloud Scanning Technology, Chute Fabrication, Syntron Feeders and Product Installation Provide Complete Turnkey Service at This Eastern Coal Fired Power Plant.

Objective: The older existing feeder was clogging and not producing enough product flow to supply the operation. The objective was to restore and control the material flow from an above ground surge to the underground conveyor belt that feeds the…

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Objective: The older existing feeder was clogging and not producing enough product flow
to supply the operation. The objective was to restore and control the material flow from
an above ground surge to the underground conveyor belt that feeds the power plant.

Challenge: The conveyor descended down an incline into a narrow underground tunnel making movement difficult. The existing heavy feeders and knife gate needed to be removed but getting over the obstructions (such as existing equipment, detouring around piping and railings) was extremely challenging. In addition, five to six layers of stainless steel liners in the surge pile that feeds into the hopper had to be trimmed and cut in order to fit the new hopper against the ceiling. The need for accuracy in the design and prefabrication of the feeder system and chutes to fit the existing structures was extremely important to meet the plant’s capacity flow of 300 TPH of 2” minus coal.

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Recommendations/Solution: ASGCO® engineers would provide an onsite Point Cloud Scanning survey to provide
accurate measurements of the facade and structures. A 3D model would then be developed of the hopper, chute and
vibratory feeder system and then overlaid into the Cloud Point Scan to check for interferences. On this project an
XPMF-200 Syntron Direct Drive Electromechanical Feeder with VFD Controller in a Nema 4/12 enclosure, would be
designed and installed to replace an older existing feeder and meet the capacity needed. Also a Remote Control Box with
manual potentiometer and start/stop buttons in a Nema 7/9 enclosure would be provided for remote mounting.
ASGCO®’s Fabrication shop would then fabricate the new hopper and chute and line it with Nitronic SX™ wear liners
to create a surface that would work harden and have a low coefficient of friction. A Safe-Guard® Conveyor Chute
Inspection Door installed on the chute would offer safe inspection and clean out.

Results: ASGCO®’s installation crew of four (4) people, was able to remove the old feeder and knife gate and install
the new Syntron Vibratory Feeder and fabricated chute and hopper. The customer is now experiencing the desired
rate of material flow to supply their operation and they no longer have to stop operations due to blockages.

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ASGCO® Integrates Point Cloud Scanning Technology Into ASGCO® Conveyor Safety Product Installation at A Mid-West Coal Fired Power Plant.

Objective: Provide plant workers safety in the work place by the means of installing conveyor safe guard equipment. Although the plant does not fall under either MSHA or OSHA requirements, it strives for “best practice” that meets both regulations and…

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Objective: Provide plant workers safety in the work place by the means of installing conveyor
safe guard equipment. Although the plant does not fall under either MSHA or OSHA
requirements, it strives for “best practice” that meets both regulations and ensures plant safety.

Challenge: Due to fire prevention in coal handling facilities, the plant required a turn-key installation that did not require a “burn permit”, thus all safe guarding panel railing and hardware had to be bolted onto existing conveyor structures and bolt hole patterns. The project required a very strict pre-installation measurement tolerance, that provided precise, accurate coordinates. This need for accuracy was extremely important in the prefabricating of the safe guarding fastening system onto the existing conveyor structures (such as existing holes, detouring around piping conduit and emergency stops). The plant had very limited down time and called for quick and efficient installation turnaround time.

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Solution: ASGCO®’s services provided an onsite Point Cloud Scanning survey (two people @ 8 hours)
for all (3) conveyors that required safe-guarding equipment. The ASGCO® Point Cloud scanning survey provided
“as built” 3D imagery that enabled ASGCO® engineering to design and fabricate “bolt-up” safe-guard railings
with precise accuracy, so that no onsite welding or cutting would be required. ASGCO®’s Safe-Guard® Modular
Conveyor Flat Guard panels with “drop pin and wedge” design, would benefit in quick conveyor component access
for plant personnel in preventive maintenance (PM) and future conveyor component installation works,
while preventing workers from unauthorized access and away from moving parts and equipment.

Results: ASGCO®’s installation crew of four (4) people, was able to install 690′ of guarding in three (3) days
(12 hour shifts each day). No welding, cutting or grinding was required, due to the accuracy attained from the
infield ASGCO® Point Cloud scanning 3D imagery. All components bolted-up without a hitch. The plant is now
eager to proceed on four (4) more conveyors that need safe-guarding.

 

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ASGCO®’s Safe-Guard® Return Roll Changer Allows Idler Change Out in a Fraction of the Time and Under the Most Difficult Environments!

Objective: To Reduce Down Time When Changing Out the Return Rollers While Also Creating a Safer Working Environment Challenge: The only way to change the return idlers on this 72” incline conveyor enclosed in a tube, was to crawl under the conveyor…

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Objective: To Reduce Down Time When Changing Out the Return Rollers While Also Creating
a Safer Working Environment

Challenge: The only way to change the return idlers on this 72” incline conveyor enclosed
in a tube, was to crawl under the conveyor in a curved/sloped application while packing
a 130 pound roller. This was also a very difficult and unsafe environment to work in making
the procedure very timely and energy consuming. This resulted in both lost production
time and maintenance resources.

Solution: ASGCO® recommended to replace the standard return roll brackets with the Safe-Guard®
Return Roll Changers allowing the maintenance personnel to safely remove the return idler from
the catwalk side of the conveyor. The Safe-Guard® Return Roll Changer also provides pinch point
protection between the idler and the belt while the conveyor is running.

Case Study_Return Roller Changer_ 3_web

Results: The Safe-Guard® Return Roll Changer became a real game changer for the customer. Not only
did it allow them to replace their return idlers in a fraction of the time it previously took (probably 75% less time),
reducing costs, but the process is now much safer. The workers no longer have to kneel under a conveyor belt
in a curved, sloped, and sometimes slippery conveyor tube while trying to physically lift a 130 lb. return idler
in place. The customer is so pleased that he has ordered several more!

Case Study_Return Roller Changer_ 2_web

  • For universal mounting, Safe-Guard® Return Roll Changer can Case Study_Return Roller Changer_ 1_web

    be mounted on either side of the conveyor system.

  • One Side Return Roller Access allows removal and replacement
    from a single side of the conveyor.
  • Provides pinch point protection to prevent injuries.
  • Reduces maintenance time for roller replacement.
  • Eliminates need for high lift equipment.
  • All steel construction coated finish with industrial grade powder.
  • Can be customized to fit any manufacturer’s roller.
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ASGCO®’s Heavy Duty Wash-Box Belt Cleaning System Reduces Airborne Dust by Over 90% at Trona Mine!

Objective: To Greatly Reduce the Airborne Irritable  Dust Levels and the Residual Material From the Belt Challenge: This Trona mine lent itself to high concentrations of extremely irritable dust. The mine was over 1500 ft deep, going through the waterline. The existing…

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Objective: To Greatly Reduce the Airborne Irritable  Dust Levels and the Residual
Material From the Belt

Challenge: This Trona mine lent itself to high concentrations of extremely irritable dust.
The mine was over 1500 ft deep, going through the waterline. The existing cleaners were
not heavy duty enough to handle the high speed belt and high pressure water.

Recommendations: ASGCO®’s engineering department listened to their concerns and
recommended designing and installing a customized stainless steel Mine Duty Wash Box™
system with a wider, deeper box that included specialized high pressure nozzles and
plumbing to withstand 750 psi, Retractable Razor-Back® secondary cleaners with Spring-Shoc
tensioners and custom designed mounting brackets to meet the customers special requirements.
The self-contained belt cleaning system also contained heavier duty pillow block bearings for
high speeds and work loads.

Wash Box_Befor and After_web

Results: The ASGCO® Wash Box™ provides the highest degree in belt cleaning technology.
Air quality tests performed, have proven that the airborne dust levels in the plant showed
a huge reduction and are almost normal fresh air quality. The Residual Materials test showed
how well the customized system worked. In addition the underground mining support and
service ASGCO® provides is second to none!Wash Box 1_web

  • Complete belt cleaning system that incorporates a series of
    spray bars, belt cleaners and pressure/deflection roll to
    maximize effectiveness and virtually eliminate all carry-back.
  • Fully enclosed system that contains the wash waste fluid and
    carry-back
  • Large removable service doors allow for easy inspection and
    service access
  • Can be customized to meet exact application needs
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ASGCO® Eliminates Belt Tracking Issues with Low Profile Tru-Trainer®

Objective: Eliminate belt tracking issues that are resulting in major belt damage and spillage from contact with steel conveyor supports. Challenge: For many years this conveyor had a hydraulic three return Idler belt training system that wouldn’t properly keep the conveyor belt…

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Objective: Eliminate belt tracking issues that are resulting in major belt damage and spillage from contact with steel conveyor supports.

Challenge: For many years this conveyor had a hydraulic three return Idler belt training system that wouldn’t properly keep the conveyor belt in line.  The plant was facing constantly downtime to repair the hydraulic system.  Even when operational, the belt would veer off of center and come into contact with the structural supports, leading to critical damage to the belt and costly material spillage.  To further complicate this application, the conveyor also has less than 13” of height to mount any type of return training roller.  Options for eliminating the tracking problem were extremely limited by these space restrictions.

Case Study_JS_Tracking Issue_Challenge pic_web

Solution: After surveying the conveyor and taking key measurements,
the ASGCO® Engineering department developed the Low Profile Dual
Return Tru-Trainer with a height of only 11.8”. This new low-profile
design was installed to replace the previous failing system to actively
and continually recenter the belt.

Results: After installing two Low Profile Dual Tru-Trainers® about 20′
from each stationary pulley, the belt is maintaining center alignment and
the problem of belt damage and material spillage has been eliminated.
The customer no longer has to shut down operations to repair the belt
and the hydraulic system, or to spend valuable hours cleaning up
spilled material. Performance has been greatly improved and productivity
is at an all time high. This particular customer is very satisfied with the
performance of the Tru-Trainers®, and recently placed an order for two
additional for a different 60” Stacker Reclaimer Conveyor.

 

Case Study_JS_Tracking Issue_Before After pic_web

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ASGCO® Safe-Guard™ Conveyor Return Idler Cages Solve Safety Issues at this Coal Mining Facility

Objective: Address safety concerns for unsuspecting employees, as well as, visitors in close proximity to the overland conveyors. The measures were also put in place to bring the conveyors in compliance with MSHA and OSHA standards in regards of proper…

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Objective: Address safety concerns for unsuspecting employees, as well as, visitors in close
proximity to the overland conveyors. The measures were also put in place to bring the
conveyors in compliance with MSHA and OSHA standards in regards of proper guarding.

Challenge: This coal mine facility faced many challenges, as all bulk handling facilities do. Overcoming obstacles
in improving the safety of their conveyor system was a top priority. These type of conveyor systems have a tendency
to mis-track causing the belt to cut into the hanging metal brackets holding the return roller in place. If and when
the bracket gives way the large return roller will be sent tumbling downward creating a dangerous safety hazard.

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Solution: After a thorough inspection of the conveyor it was pointed out that in addition to resolving
the belt mis-tracking issue there needed to be further changes made to ensure safety in the workplace
and to comply with OSHA and MSHA requirements. It was recommended that they install ASGCO®
Safe-Guard™ Return Idler Cages to protect the return rollers and objects from falling, preventing
injuries to workers and equipment.

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Results: ASGCO® Safe-Guard™ Return Idler Cages were installed in the work areas and along
the roadways to catch the return rollers if they fell. This brought the conveyors into compliance
with MSHA title 30 regulations and helped the mine to reach it’s safety compliance goal!
The customer was very pleased with the success.

 

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ASGCO® – Tru-Trainer® Belt Tracking Idler Solves Tracking Problem on FGD Scrubbing Conveyor

The customer is a larger coal burning power plant that has had FGD Scrubber Conveyors in service for many years to help control the plants emissions. The product that is being conveyed is a synthetic gypsum product that is either…

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The customer is a larger coal burning power plant that has had FGD Scrubber Conveyors in service for many years to help control the plants emissions. The product that is being conveyed is a synthetic gypsum product that is either conveyed or shipped to a nearby gypsum board plant. This product is very sticky and corrosive and builds up on the conventional return idlers and return trainers. This causes the belt to mis-tracks and rub conveyor structure.

Solving-Tracking-Problem-on-FGD-Scrubber-Conveyor

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ASGCO® Impact Bed Cradle Solves Aging Spillage Problem at Eastern Bituminous Coal Mine

The #1 refuse belt on the ground level is spilling badly and impact rollers cannot keep up with the seven load zones where the material is being dumped. A 28’ span needs to be supported and sealed in a manner…

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The #1 refuse belt on the ground level is spilling badly and impact rollers cannot keep up with the seven load zones where the material is being dumped. A 28’ span needs to be supported and sealed in a manner as to not increase amperage or draw on the existing belt drive.

Impact-Load-Zone-Support-System-Solves-Aging-Problem

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