Dust Control Training Program for Underground Personnel Research Team Members Dr. Y. P. Chugh, Harrold Gurley, John Pulliam Southern Illinois University Carbondale Project Manager Dr. Joseph Hirschi Illinois Clean Coal Institute Illinois Mining Institute August 26, 2015

Training – It Must Be Interesting….. Dukette and Cornish (2009): Adults can sustain attention for about 20 minutes. Short-term response to the stimulus that attracts attention is only eight seconds. Conclusion: I only have 8 seconds to get your attention, and if the information being presented takes more than 20 minutes, I’ve lost you.

New Dust Regulations Effective February 1, 2016 DOs, ODOs, and Part 90 Miners must be sampled quarterly with a Continuous Personal Dust Monitor (CPDM) 15 valid representative samples collected on consecutive normal production shifts required from each DO and ODO every calendar quarter. ODOs shall be sampled after DOs are completed and, if more than one type of ODO is present on the MMU, each is sampled during separate time periods 5 valid representative samples on consecutive work days from each Part 90 miner required each calendar quarter District Manager may require additional groups of 15 valid representative samples when information indicates the operator has not followed the approved ventilation plan for an MMU Effective August 1, 2016 Respirable coal mine dust standard for underground and surface - 1.5 mg/m3 For Part 90 Miners and Intake Air - 0.5 mg/m3

MSHA Dust Training Mandates – What miners are required to know? MSHA – “Dust Sweep” that began Dec. 7, 2009 placed emphasis on respirable dust control. From MSHA – “Respirable Dust Control for Miners and Mine Operators” (Health Hazard Information Sheet 41) Train miners, at least annually, on: Health hazards of respirable coal mine dust Purpose and importance of effective dust sampling and dust controls Mandatory health standards applicable to their particular operation Health provisions of the Federal Mine Safety and Health Act Dust control portion of the approved ventilation plan Importance of participating in the NIOSH X-ray program

Our Education and Training Approach Create curiosity by asking questions and using real-life situations. KISMIF “Keep It Simple, Make It Fun” Develop “Best Practices” based on lab studies validated by field experience. Highlight science behind best practices. Educate mine personnel on best practices and making them habits. Include ALL personnel, not just those at the face as dust in the intake air or from “out-by” sources can be significant and impact the face area. Training is the process of acquiring essential job skills. SIU’s dust control training program focuses on best practices as demonstrated in the laboratory and validated in the field. Continued training is necessary as it takes more than “21 days” to break or create a habit. Given new dust regulations, the goal of SIUC’s training program is to: Improve worker performance and consistency in complying with dust regulations Increase productivity Reduce compliance costs Reduce the need for supervision. SIU’s dust control training program incorporates experience gained by the project team over the last 10 years while performing R&D studies in numerous mines.

Dust Characterization Roof and floor are easily wetted. The wettability of coal varies depending on coal seam and location within the coal seam (i.e., top, middle, or bottom bench) Material Percent (%) wettability Sample 1 Sample 2 Sample 3 Top bench 40 91.2 70 Middle bench 65 81.5 79.6 Bottom bench 61 72 83 Roof 88   Floor 95 Training is the process of acquiring essential job skills. SIU’s dust control training program focuses on best practices as demonstrated in the laboratory and validated in the field. Continued training is necessary as it takes more than “21 days” to break or create a habit. Given new dust regulations, the goal of SIUC’s training program is to: Improve worker performance and consistency in complying with dust regulations Increase productivity Reduce compliance costs Reduce the need for supervision. SIU’s dust control training program incorporates experience gained by the project team over the last 10 years while performing R&D studies in numerous mines.

Wettability Increases with Contact Time and Water Temperature

Dust Sources Point of extraction – CM, LW shearer Roof support systems – bolter, LW shields Conveyor systems Intake air

Intake Dust – Higher that expected?! Intake dust levels can be surprisingly high. Average levels from SIUC studies range from 10% to 66% of the 1.5 mg/m3 limit. Have recorded values of over 4 mg/m3.

Intake Dust vs. Intake Air Velocity: Making it go faster does not make it go away… but it does help

One Culprit in Intake Dust – Rock Dust? About 25% of rock dust is < 10 micron (i.e, respirable range)

Water Sprays Maintain sprays - if its broke… fix it. Partially blocked sprays create a stream or distorted cone, which can be worse than no spray at all. Sprays must operate at the right pressure Too much pressure may blow dust away Too little pressure may not contain the dust. Research suggests pressure for hollow cone sprays should not exceed 90-100 psi

Ventilation – why it is important! KEY PARAMETERS Volume and velocity of air in LOXC. Volume and velocity of air entering LC (in LOXC) and exiting LC (at face) LC – should be close. LC properly installed – no gaps. Length of LC – effects volume. Scrubber air volume/capacity. Good balance between scrubber and LC volumes.

Miner Operator Location – End of Line Curtain (ELC) It is important for CMO to stay within the effective area of the line curtain. This area may not extend beyond ELC. Air flow patterns at the face and end of line curtain may develop recirculation zones (RC). Wet scrubber can create RC air flow patterns in the opening behind the CM. Avoiding (if possible) RC and low air velocity (LAV) zones can reduce exposure. Air flow in the LOXC, gap between end of line curtain and rib can effect air flow patterns at the face. 1 ft. 3 ft. 5 ft. 6 ft.

Miner Operator Location – End of Line Curtain (ELC) It is important for CMO to stay within the effective area of the line curtain. This area may not extend beyond ELC. Air flow patterns at the face and end of line curtain may develop recirculation zones (RC). Wet scrubber can create RC air flow patterns in the opening behind the CM. Avoiding (if possible) RC and low air velocity (LAV) zones can reduce exposure. Air flow in the LOXC, gap between end of line curtain and rib can effect air flow patterns at the face.

Difference Between CMO Standing versus Sitting/Kneeling Line curtain Higher mg/m3 Lower mg/m3 In field observations using a hand-held PDM, dust concentrations can be 50-60% lower at 3 feet above the floor compared to 5-6 feet above the floor at the end of the line curtain.

Effect of Scrubber w/ 7,000 cfm at ELC Fan OFF Without HU in place, air is pulled by the scrubber toward the face from the gap in the LOXC. It can pick up and recirculate dust as air exits into the return XC/entry. Fan ON

Effect of Scrubber on ELC Air Volume Length of LC greatly effects air volume reaching the end of the LC when the scrubber is running. Data from more than 200 cuts have been used to compare end of LC air volumes with scrubber off and on. Results: LC <10 ft = 7.5% increase LC >10 ft but <40 ft = 18.7% increase LC >40 ft but <75 ft = 29% increase LC > 90 ft = 80% increase These increases typically cause significant recirculation of dust since some of the additional air enters through gaps at the roof, floor, and overlaps that are inby the LOXC.

How long does it take for the scrubber to pull in all the air contained in a 40 foot cut? Scrubber intake = 7500cfm Volume of air 40 feet from the face = Entry height = 7 feet X Entry width = 19 feet X 40 feet = 5320 cubic feet of air 5320/7500 = 42.5 seconds Allowing the scrubber to run one minute after loading a car will significantly reduce dust in the face area.

For Ram Car Operator…The Side They Are Located On When Traveling May Make a Difference Lower dust concentration High dust concentrations

Mining a XC Straight Ahead – Curtain vs. No Curtain, Scrubber ON vs Mining a XC Straight Ahead – Curtain vs. No Curtain, Scrubber ON vs. OFF Scrubber can cause air to recirculate towards the HUO and LC can block air flow directly into return

Effect of Box and Slab Cut on HUO

Topics covered during typical Dust Control Training Program Dust parameters during production shift: Replace worn or broken cutting bits Scrubber – working properly, clean filter screen and screen cleaning spray/s operating Adequate air at end of line curtain and CMO positioned properly Clean filters on roof bolter and maintain seals of dust collection boxes Empty roof bolter dust boxes at face, not in LOXC Proper placement of dust pump cyclone on person being sampled Keep haulage roads damp

QUESTIONS?