Occupational harmfulness of powder dust and control technology in coal preparation plant

  Objective   To find out the key control points and to put forward suitable control techology by investigating occupational harmfulness of powder dust in coal preparation plant.

  Methods   The Rule of hazard analysis and critical control point(HACCP)was used in the research program. Field researches of technological process and working environment in coal-cleaning plants were surveyed. And the factors of occupational harmfulness of all working posts were identified. Based on the serious degree of occupational harmfulness from the concentration & dispersal degree of powder dust and the health damage of workers, key control points were found out and prevention methods were advanced.

  Results   More harmfulness happened on the positons of crashing, filtering, loading and unloading workshop. Powder dust harmfulness in coal preparation plant mainly came from coal dust. The mean concentration of free SiO₂ coal dust was 4.9%. The concentrations of coal powder dust were various in different coal plants. It was 250.8 mg/m³ averagely in Jiangxi patients of dust lung in coal separation plants of Jiangxi had not been found out, which suggested that the harmfulness in coal- cleaning plant was less than that in other positions of coal.

  Conclusion   The powder dust concentration of some working positions in coal preparation plants were beyond the relative national standard, which would by potentially harmful to workers. Besides the management of coal preparation plants should be reinforced, powder dust-removing methods should be improved form eight aspects.