Preventing Silicosis

in the Mining Environment

1. Prevention of Silicosis to Improve Mine Workers Health and Quality of Life.

2. Compliance with MSHA respirable dust regulations.

Importance of Respirable Dust Control

Silicosis• One of the worlds oldest occupational diseases

dating back to ancient Greece

• Common names: grinders asthma, grinder’s dust consumption, mason’s disease, miner’s asthma, potter’s rot, stonemason’s disease.

• Considered serious health threat in 1930’s – major focus of federal, state, and professional attention

Effects of Silica (Quartz)

• Lung tissue becomes scarred due to silica being trapped and fibrous tissue developing over it

Typical Quartz Content in Rock

Type Percent Quartz

Granite 10% to 40%

Shales 22% average

Sandstone 70% average

PREVENTION MEASURES

Prevention Measures

Ventilation

•Assure that plan requirements are being followed. Do they appear to be adequate?

•Is the air carrying the dust away from miners. Example - was the section just rock dusted with men going to work in it?

•Limit exposure in work areas downwind of cutting, mining, loading, and bolting operations

Prevention Measures

• Scrubber – check air quantity at the end of curtain with CM in place with scrubber off and scrubber on to assure the air quantity is within the scrubber’s range.

• Longwall – ensure air flow prevents dust exposure to the shearer operators and shield setters

Prevention Measures

Water Sprays

• Is the material damp as it is being loaded?

• Are water spray types and patterns providing good water coverage where material is being cut or transferred?

• Are sprays provided to prevent rollback? If so, are they effective?

Prevention Measures

• Section Mobile Equipment–Continuous Miner

• Sprays on• Scrubber• Air• Bits• Cleanliness• Cut sequence – undercut rock

Prevention Measures

• Scrubbers

– Assure the duct work and inlets are clean and in good condition

– Screen not damaged (no holes in it)

– Screen fits duct ( proper size)

– Screen spray operating and covering entire screen

– Screen cleaned at proper intervals

Prevention Measures

• Scrubbers – Screen replaced at start of shift clean / dry

screen

– Full traverse reading on record and in

compliance with plans– Center line reading above minimum

Prevention Measures

• Section loading points

–Feeder Crushers

»Sprays»Belt air

direction

Prevention Measures

• Belt Transfer Points

–Spray bars

»Belt damp

Prevention Measures

Curtain / Tubing

• Maintain set back per plan

• Properly installed – Tubing joints in good condition /

connections tight– Curtain properly hung and in good

condition

Prevention Measures

• Section Mobile Equipment

–Roof Bolter• Air

• Dust Boxes - Cleaning

• Drill Steels – plugging at start of drilling

• Cleanliness

Prevention Measures

Roof Bolter Dust Collection System Maintenance

• Filters – cleaning & seal• Hoses• Dust box• Water box• Plugged drill steels• Dust residue in muffler

outlets (contamination)• Dust from bolter

suspended in the air

Prevention Measures

The vacuum setting used for testing is based on blower performance (check your parts manual for your specific blower). This vacuum setting is stamped on the dust approval tag that is usually located in the tram deck. This is the minimum vacuum that can be used with the dust approval.

Prevention Measures

Roof Bolter operator

• Cleaning dust boxes– In low velocity areas– Dumping - Handling– Bagging – Handling

Prevention Measures

• Section Mobile Equipment

–Shuttle Car• Roadways

• Ventilation devices

• Cleanliness-

Prevention Measures

• Outby Mobile Equipment

–Scoop / Rubber Tired Mantrips• Roadways

• Ventilation devices

• Cleanliness

Prevention Measures

• Body Positioning

–CM Operators

–Roof Bolters

Prevention Measures

• Hanging Curtains–Cleanliness – hang from intake

side –Properly hung

• Tight to roof• Proper area for air flow• Proper overlap

Prevention Measures

• Proper wearing of pump

–Are clothes clean?

–Location• Do not cover, turn over or tamper with the sample head.

–Time of operation

–Operated portal to portal

Prevention Measures

Environmental Equipment Cabs

• Gaskets / Latches in good condition

• Cab Clean

• Windows sealed

• Pressurized

• Heating / Air conditioned to

keep doors closed