2017 Technical Program
Session 1: Health & Safety
How can the CPDM Affect Miners’ Knowledge and Control of Respirable Dust Exposure?
by Emily J. Haas, PhD, National Institute for Occupational Safety and Health (NIOSH), Pittsburgh, PA, USA
NIOSH designed an intervention to increase coal miners’ knowledge and use of the dust data cards that are produced via their Continuous Personal Dust Monitors (CPDM). NIOSH is implementing these interventions to evaluate changes in knowledge, attitudes, and behaviors among miners both individually and within work crews. The intervention involves having small groups of coal miners participate in discussions about their use of the CPDM and their interpretation of the dust data. Specifically, after NIOSH researchers debrief CPDM dust data cards with coal miners, they are able to reflect about tasks and scenarios that may have caused short, elevated exposures. Initial results reveal that, when doing something out of the norm, exposure increases. Subsequently, miners discuss corrective actions they employ to reduce future exposure. Mineworkers also complete pre- and post-climate surveys and interviews about susceptibility to respirable dust exposure and perceived barriers to using their CPDMs. This presentation discusses tasks that miners have identified, to date, of which they were unaware that increased their exposure to respirable dust and common mitigation strategies they have learned since wearing the CPDM. The purpose of this presentation is to help mine operators understand ways to identify and encourage work practices that reduce respirable dust exposure both to their individual mineworkers and to their workgroup shifts.
Longwall Automation: Making Mining Safer Through Technology
by Adam Zamora , Westmoreland Coal, Waterflow, NM and Jack D. Trackemas, NIOSH, Pittsburgh, PA
The need to provide enhanced safety and working environments for miners, as well as improved efficiency during mining has provided a compelling opportunity for mines to consider automation. In 2015, forty longwall mines provided nearly sixty percent of the U.S. coal production from underground mining methods. The operation of most longwall faces are repetitive and cyclic providing an ideal situation for the use of partial or even full automation. Over the past several decades, several attempts have occurred to introduce various degrees of automation to longwall faces with limited success. Currently, most aspects of a longwall mining can now be monitored with reasonable reliability. The Westmoreland Coal Company, San Juan Mine, has had success with operating an automated longwall face utilizing this new technology.
Evaluation of Noise Controls for Longwall Cutting Drums
by Hugo E. Camargo and Lynn A. Alcorn
NIOSH conducted research to develop noise controls for longwall mining systems. Previous research determined that the dominant sound-radiating components on a longwall shearer are the two cutting drums. Therefore, NIOSH developed numerical models of these drums to predict their dynamic and acoustic responses. Upon validation, the models were used to explore various noise control options including force isolation, increasing structural damping, and increasing the stiffness of the vanes. The most practical solution was to increase the stiffness by adding gussets, and to increase the thickness on the outermost helical vane plates. A set of modified drums were built and tested at a mine in New Mexico. Results test showed noise reduction across the entire frequency spectrum with overall noise reductions of around 3 dB.
Applications of a Scaled Aerodynamic Model for Simulations of Airflows in a Longwall Mine
by Gangrade, V., Harteis, S.P. and Addis, J.D., The National Institute for Occupational Safety and Health (NIOSH)
Researchers with the National Institute for Occupational Safety and Health, Pittsburgh Mining Research Division, constructed a 1:30 scale physical model of a portion of a longwall operation to simulate the airflow characteristics along the face and along or through the gob. The Longwall Instrumented Aerodynamic Model (LIAM) is built with critical details of the face and face machinery, such as shearer, shields, conveyor belt etc., as well as a portion of the gob and the barrier pillars. LIAM is instrumented with pressure gauges, flow anemometers, temperature probes, a variable speed fan, and a data acquisition system to enable investigation of face, entry and gob flows for variable mining configurations. LIAM offers the flexibility of carrying out tests for variable mining configurations such as bleeder/bleederless and exhausting/blowing ventilation systems to supplement numerical modeling studies and mine site studies where field measurements may be limited. The LIAM design is described in detail and results are presented from a study of gob-face exchanges, distribution of air at the critical face-tailgate air split, and airflow patterns in the gob for different caving characteristics. Scaling relationships were derived on the basis of Reynolds and Richardson’s number to preserve the physical and dynamic similitude by optimally scaling turbulent dispersion, pressure gradients, flow velocity, permeability, face dimensions, transit times, and ventilation airflow. These results are compared to field data and previous numerical modeling studies.
Controlling Dust Concentration at a Longwall Face Through Application Of A Flooded-Bed Scrubber to a Longwall Shearer
by Sampurna Arya, University of Kentucky, Lexington, KY, William Chad Wedding, University of Kentucky, Lexington, KY, Thomas Novak, University of Kentucky, Lexington, KY, and James P. Rider, National Institute for Occupational Safety and Health, Pittsburgh, PA
A full-scale physical model of a Joy 7LS longwall shearer, modified with an integrated flooded-bed scrubber, was designed and fabricated at the University of Kentucky. The mockup was assembled and tested in the longwall dust gallery at the Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH).
Test results indicate an average 68% dust reduction at the longwall face. The experimental results of the tests conducted at the PRL, as well as the validation of CFD simulations, are presented.
Session 2: Equipment and Life-Cycle Improvements
First Chinese Shields in the U.S. at the Oak Grove Mine
Transformation/Repurposing of Face Equipment
Jacob Smith, Engineering Manager- Sufco Mine, Bowie Resources
Due to recent environmental concerns and political pressure, coal producers today face unprecedented challenges to maintain profitability as market demands have decreased. Capital reduction, through the transformation and repurposing of equipment, can provide operators with a competitive advantage while maintaining productivity and occupational safety.
Sufco Mine (Sufco) is owned by Canyon Fuel Company, a subsidiary of Bowie Resource Partners, and has been continuously operated since 1941. Recently, Sufco has used this financial strategy as a solution to the unique geological constraints the mine will face in the next 5 years.
In 2016, Sufco teamed with Joy Global (JOY)) to refurbish 168 JOY powered roof supports that were previously operated at the Dugout Canyon Mine from 2002 through 2012. During the repair process, several design modifications were made; including a complete rear-bridge replacement and canopy tip-extension. Sufco also teamed with JOY to manufacture two new sets of armored face conveyor (AFC) panline. However, Sufco elected to continue using the Caterpillar (CAT) stage loader and AFC drives that are currently in operation.
This project is a great example of how detailed planning and collaboration with vendors can provide operators today with the ability to reduce capital by transforming and repurposing existing equipment.
Using a Dealer Network to Support Longwall Mining
by Bill Powell, General Manager CB Mining Inc.
In 2011, Caterpillar purchased Bucyrus International and its mining facilities and operations. Starting in 2012 and continuing through 2014, Caterpillar divested its former Bucyrus / DBT aftermarket facilities and personnel to the various Caterpillar Dealers all over the world. This became a unique challenge for the longwall mining product line, with a so many unique applications and technologies, and the fact that no two longwalls are the same with many unique challenges and conditions. In the USA, 9 Caterpillar dealers have Caterpillar longwall equipment operating in their territories, some with only one or 2 longwalls systems.
Of the 45 longwall faces currently operating in the USA, 17 or about 30%, are located in western Pennsylvania, eastern Ohio, and northern West Virginia, and separate company, CB Mining, a separate legal entity, was created by the traditional CAT dealership, Cleveland Brothers, and with their 85 people and 2 facilities, CB Mining is dedicated primarily to the longwall sales, service, and support business. This presentation will review how they created and adapted Cat Dealership principles into a dedicated longwall mining service center to support a large longwall region in the USA.
Case Study: Extending the life of Longwall Roof Supports through the use of Life Cycle Testing Management Plan
by Allan Black, Joy Global and Janse Van Rensburg, Anglo American-South Africa
Coal operating companies are faced with reduced capital expenditure whilst still needing to improve productivity and extend the life of core assets. Working directly with end user mine specialists an Extended Life Testing Program has been introduced to greatly increase the operable life of existing powered roof support installations. The introduction of this predictive tool that can determine when individual components will reach the end of their serviceable life.
This Extended Life Testing can realise an additional 15,000 to 30,000 cycles out of a roof support that was originally specified for only 30,000 cycles depending on the operational loading and duty cycle. This can sometimes push capital expenditure 5-7 years into the future. In order to gain a detailed knowledge of the duty current structural competence a representative roof support is taken out of service, striped and fully evaluated and a test schedule, using bespoke load cases, is used to replicate the actual service seen to date.
The support is then tested up to target number of life cycles and a test protocol is developed using load cases that are tailored to replicate the typical, actual service experienced by the roof support to date.
A detailed report is issued indicating when components either have or will likely reach the end of their serviceable life. A detailed Life Cycle Management plan is proposed allowing the planning of future maintenance budgets with a high level of accuracy and confidence in the life of the supports or support components going forward.
A powered roof support supplied in 2009 and initially tested up to 30,000 cycles was examined with a requirement to extend the support’s life to 45,000 cycles. The support had seen 13,000 underground cycles in some pretty tough conditions. It was dismantled and visually inspected, with all cracks and damage identified and assigned unique crack identification marks. The components were then shot blasted and visually inspected with the addition of magnetic particle NDT testing to establish the location of any additional weld cracks. Hinge pins and bores were also examined, measured and recorded.
Based on the results of these inspections, a unique test program was agreed upon that best replicated the load cases the support had seen in actual service.
The test was suspended after 19,000 cycles (a total of 32,000 cycles including those seen underground) due to the catastrophic failure of the lower links. Other structures of the roof support showed signs of fatigue but still maintained their prime function. The lower links were replaced, and the test resumed. Deterioration was monitored throughout the extended testing but didn’t impact the structural performance and the support achieved the target 45,000 cycles. A comprehensive plan was devised advising on when to carry out proactive replacement of the lower links, as well as any other work required to take the supports to the required 45,000 cycles.
Extended life testing, taking a support past its original life cycles, including comprehensive plans based on test results predicting when components are likely to reach the end of their serviceable life allows maintenance budgets to be developed to a high level of accuracy giving end users and mine owners confidence going forward.
Smart Mining Technologies: Application and Outlook for the Global Longwall Mining Industry
by Dr.-Ing. Johannes Krings, Eickhoff
The general fall in prices and the strong volatility of the raw materials market are having a profound effect on the profitability and strategic alignment of the raw materials organizations and machine manufacturers. Irrespective of whether this situation prevails on a long-term basis or we are on the verge of a U-turn, it has a transformative effect on the operations and priorities of operators and suppliers. Productivity increase, efficiency, occupational safety and flexibility are at the forefront as in previous periods and they lift the subject of automation to a new level. The rapid development of digital technologies offers innovative design options in automation. Fully integrated systems with (partially) automated machines, which operated reliably in and through the environment without human intervention and take independent decisions are no longer considered Utopiain mining today. The sector has already started successfully with the implementation of mining 4.0.
This contribution refers to the longwall automation and remote control and illustrates the impulses which pave the way of digital mining towards the manless face. For more than 150 years, the Eickhoff mining technology has been playing a leading role in the technological progress of mechanized mining. And today, automation of the machine beyond system limits as well as integration of digital technologies and data management, form the salient features of current research and development activities.
Session 3: Operating Efficiencies
Improved safety and increases in performance and productivity through the implementation of a Longwall Proximity System and the use of Smart, connected LW products
by Rudie Boshoff, JoyGlobal
We have approached Hamilton County Coal (Alliance) to co-present this paper with Rudie Boshoff of Joy Global. We are awaiting a formal response from Hamilton County Coal.
Synopsis: Improved and reliable Longwall connectivity including manpower location monitoring is leading to increases in safety, production and productivity. The use of data analytics to focus on essential operational parameters that directly determine outcomes has been shown to improve both output and operating hours and, in some cases, prevent severe and sometimes devastating stoppages in longwall performance.
The paper will review the use of predictive analytics in reducing or eliminating unplanned downtime and explain how it is now an essential tool in running a lean longwall operation capable of fully utilizing the information available from today’s sensors and operating systems.
The parallel introduction of Personal Proximity Detection (PPD) on longwall faces, certified to SIL 1 (Safety Integrity Level), enables the longwall powered roof support control system, known as Joy Faceboss, to locate and monitor the position of every operator on the longwall face to within +/- one roof support. Each individual entering the longwall wears a personal Tag on their belt which transmits radio (RFID) signals. These signals are detected by the Faceboss Mimic control system providing protection against automated advancing of longwall roof supports. Information on personnel movements can be monitored at a surface station and the system is set to allow automated operator registration.
Smart, connected products, including the shearer, roof supports, pump station, AFC and BSL deliver data directly to remote JoySmart service centers where experts, in partnership with the end users, provide analysis, filtering the multitude of data and give only essential information and direct recommendations for longwall parameters, longwall operations, anticipating service needs and optimizing of machine and powered roof support performance.
This paper will show, through an actual case study, highlights of how end users have used analytics to improve their systems and operating processes thereby reducing downtime, simplifying processes, ensuring correct support loads into the roof and delivering improved performance and equipment life.
Case Study: Improved safety and productivity through the use of Advanced Shearer Automation - Tunnel Ridge Longwall
by Rob Colaw, Tunnel Ridge and James Sudworth, Joy Global
The paper will give a short system overview detailing the sensors that support Tunnel Ridge’s Advanced Shearer Automation. These sensors include inclination sensors on each ranging arm, a mainframe inclination sensor, rotary sensors on each cowl, rotary sensors on each haulage drivetrain, and several proportional control hydraulic valves to accurately control the ranging arms and cowls. The shearer is also equipped with several High definition flameproof video cameras, mounted at strategic locations along the body of the shearer. Video streaming images from the shearer are sent through fiber optic cables to a large monitor located within a Remote Operation Center situated several hundred feet outbye from the longwall face mounted on the “mule services train”. The Remote Operations center is also equipped with a handheld radio to directly control the shearer, and multiple displays that provide status and diagnostic information for the shearer, roof supports, and mine wide operations.
The shearer cutting sequence is configured, and automated, through the use of Advanced Shearer Automation. This automation sequence is developed using an offline software utility, called the Graphic Offline Planner (GOLP). Using this tool, the cutting sequence is defined by creating individual sequence steps which instruct the system which automation modes will be utilized for each ranging arm, the location along the face where each step will begin and end, the desired haulage speed and direction of travel for each step, and the desired extraction heights along the face. The shearer then executes this sequence in a persistent loop. The shearer operator is tasked with teaching the system the initial horizon of the roof. The trailing drum then follows this taught horizon at a predetermined vertical offset. The system will then repeat this cut on subsequent passes until the operator deems it necessary to re-teach any portion of the roof horizon. The shearer operator can be positioned at the shearer, walking alongside the machine, or at the Remote Operating Center, where vision of the cut is accomplished through the use of the shearer mounted cameras.
This system has been in operation for several months and mention will be made of the results achieved including the reduction in manpower on the face (increased safety) and the improved cutting horizon and increased production and productivity.
Financial Advantage of Utilizing Contractors to Perform Longwall Moves
by Neville McAlary, CEO, Delta SBD Ltd. and Ray Chadwick, Director, RC Mining Services
Protect Your Lift Leg Pockets, Protect Yourself & Your Pockets
by. Adam Lyman, Application Engineer, Henkel
This presentation will discuss a new method of protecting Longwall Mining Equipment and personnel while reducing cost and labor. Lift leg pockets are typically filled with a foam insert that is pre-cut to match the specific piece of equipment being used in the mine. These inserts do not completely fill the pocket and all dust and debris to work down in to the pocket, pushing out the insert over time. Cleaning and replacing these inserts takes time and if not done can result in a catastrophic failure of the equipment if the hydraulic lift leg is damaged. When these inserts are not present at all there is an even greater risk because there is a potential for tools and cutting tips to fall in the pocket causing more significant damage. The time and safety risk associated with this common maintenance problem should not be ignored.
Henkel’s LOCTITE® MR5898™ is a two-part foaming polyurethane that takes the place of foam inserts and provides better protection against coal dust and debris. This foaming polyurethane bonds to the pocket and hydraulic cylinder keeping out debris and other particulates that can damage or limit the movement of the roof support shield system. Two-part foam in place systems fill the entire cavity but are flexible enough to accommodate hydraulic leg movement. They are also safe for use underground and in confined spaces, can be mixed and applied quickly, and is tack free in minutes.
Session 4: Mine Development & Planning
by Christopher Popp. Section Foreman, Enlow Fork Mine; Jamie Wilson, Section Foreman, Enlow Fork Mine; and Andrew Yackuboskey, Section Foreman, Enlow Fork Mine)
This presentation will expand on the concepts, factors, restrictions and other considerations in expanding the longwall face from the current 1500 feet in width to 2000 feet. This will cover the following key issues:
History of Longwall
History of Equipment
Ultra length Longwall Panels: Critical Factors and Issues
Signal Peak Energy is the only underground coal mine in Montana, and started longwall mining operations in 2009 and is presently in its 6th panel. These panels are 1250 feet in width and typically vary between 18,000 and 22,000 feet in length since panel 2.
Each panel typically has between 10 and 14 million raw tons, and will operate from 12 to 16 months. This presents several unique challenges, such as:
Insuring the equipment is rebuilt for a complete panel without significant downtime or major exchanges.
Predictive analysis of wear prior to failures of components such as chain, flights, gearboxes and sprockets.
Optimum shift and manpower scheduling to optimize the mining production and maintenance.
Roof Support asset management for optimizing the life of the reserve.
Use of face automation to maximize productivity.
This presentation will expand of these issues that SPE faces on a daily basis.
Longwall Top Coal Caving
by Matt Jones, LW Superintendent Broadmeadow Mine; Kev Meyer, LW Maintenance Superintendent Broadmeadow Mine; and Brett Moule, LW Applications, Caterpillar Global Mining
The Goonyella Middle Seam located in the Bowen Basin, Queensland Australia is a source of high quality metallurgical coal for global export. The seam sub-crops in a north/south direction at a depth of about 60m (200’) and dips to the east at 5 - 8°. Seam thickness varies from 5m (16’) to 12m (39’) with the average seam thickness in the current mining area being about 7.6m (25’).
The mine was started using a longwall extracting at 4.7m (15’) leaving the top section of the seam to fall into the gob. The adjacent open-cut mine has been mining the full seam section for more than 30 years, investigations and evaluations were made into the Top Coal Caving method and its suitability for the operation. LTCC was introduced in 2012.
The presentation will include the following:
Management of the LTCC face compared to a conventional longwall face
The operational learnings
The maintenance learnings
Controlling dilution on the rear conveyor
Successful use and advantages of automation
Overview of Current U.S. Longwall Gateroad Support Practices
By Morgan M. Sears, PhD, Mining Engineer; Ihsan B. Tulu, PhD, Associate Service Fellow; and Gabriel Esterhuizen, PhD, Senior Scientist, NIOSH, Pittsburgh Mining Research Division, Pittsburgh, PA
In 2015, 40 longwall mines provided nearly 60% of the US coal production from underground mining methods. This represents a substantial, yet gradual increase from just under 50% over the last 5 years. As a result of this increased production share, the percentage of ground fall related fatalities in longwall mines has also increased when compared to all US underground coal mines. Additionally, about 80% of ground fall related fatalities have occurred in areas where the roof was supported.
In an attempt to better understand the status quo of current US longwall support practices, a sample of 21 longwall mines were visited, representing about 40% of the currently active longwall mines in 4 of the 5 major US longwall producing regions. The resulting data was obtained from a wide variety of overburden depths, geologic conditions, mining heights, ground conditions, support practices, and gateroad configurations.
Two of the observed mines had options for cribless tailgates using cable bolts/trusses while the remaining mines used some form of standing support. The majority of mines using standing support employed can type supports (37%) while the remaining used pumpable cribs or traditional wood cribs/posts. Standing support densities in the tailgate ranged from 0.05 MPa to 0.18 MPa and up to as much as 0.35 MPa in the #2 entry. Both entries averaged a support density of 0.12 MPa.
The data collected is reported using both qualitative and quantitative methods. The results from the research update previous efforts in classifying mining accidents and injuries as well as current support practices. This data provides a necessary background for future research aimed at further reduction of ground fall accidents and injuries.Tailgate support was typically standing support with the exception of one observed mine which was currently using a cribless tailgate configuration when the depth of cover allowed. The remaining mines used some combination of pumpable cribs (31%), cans (or other preformed cementitious support, 38%), wood cribs in both the 4 and 9-point configurations (19%), and propsetters (or other yielding, wood props, 13%). Tailgate conditions, overall, were typically good and discussions with personnel revealed relatively low rates of unsatisfactory performance. It was fairly common, particularly in the east to see more than one type of support in a single gateroad and more than one type of support used in the recently mined panels. Additionally, the use or lack of cable bolts in the gate entry depends mostly on the orientation and magnitude of the regional and local horizontal stress field. This has a tendency to be more problematic in weak roof conditions in the headgate rather than the tailgate due to the inability to install standing support in the belt entry. However, standard design guidelines and practices are still relatively lacking with mine operators tending to rely on past experiences to guide future designs. Future research, involving numerical modeling of the support/rock interaction as well and field instrumentation, data collection, and support testing will be required to advance the science of gateroad support design for use in future mining operation.