Prevention of flammable gas and coal dust explosions in collieries

Prevention of flammable gas and coal dust explosions in collieries

1. INTRODUCTION

The introduction of mechanical miners on a large scale in South African Coal Mines has highlighted the need for improved methods of environmental protection to ensure safe and healthy working conditions. When using this type of rapid advance modern coal winning equipment, a particular concern is the generation of large quantities of coal dust and flammable gas . Recent research has also highlighted the dangers of the lowering of the lower explosion limit when hybrid mixtures (coal dust and flammable gas ) exist. These guidance notes have been primarily prepared to assist the employers in complying with the requirements of the guideline for the compilation of a mandatory Code of Practice for the prevention of flammable gas and coal dust explosions in collieries. 2.1. This guidance note has been compiled to assist employers in preparing a mandatory Code of Practice for the Prevention of Flammable gas and Coal Dust Explosions in Collieries. 2.2. A guidance note sets out good practice and will be widely distributed by the Mine Health and Safety Inspectorate within the industry. As is the case with all other documents setting out accepted good practice, the application of inferior practices without justification could amount to negligence. 2. LEGAL STATUS OF THE GUIDANCE NOTE

3. DESIGN OBJECTIVES

3.1. Only criteria based on empirical and proven scientific design applications should be considered.

3.2. Dust should be effectively controlled where generated, and not be permitted to escape from the heading uncontrolled and untreated so as to exceed acceptable levels.

3.3. Flammable gas should be diluted to acceptable levels by providing sufficient fresh air.

DEFINITION:

Acceptable Levels

Dust Concentration (for less than 5% quartz content)

Personal sampling - a respirable eight-hour TWA concentration of less than 2 mg/m 3 as per airborne pollutant sampling programme

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