1. 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

2. 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.

3. 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 mg/m3
For Part 90 Miners and Intake Air mg/m3

4. 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

5. 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.

6. 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.

7. Wettability Increases with Contact Time and Water Temperature

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

9. 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.

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

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

12. 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 psi

13. 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.

14. 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.

15. 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.

16. 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.

17. 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

18. 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.

19. 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.

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

21. 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

22. Effect of Box and Slab Cut on HUO

23. 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

24. QUESTIONS?