Objective To identify and analyze the dust hazards in a stainless steel making and continuous casting workplace and search for critical control measures.
Methods A combined workshop of stainless steel making and continuous casting in south China was selected for the study. Personal monitoring and spot monitoring were applied to collect the concentrations of dust in the air according to Determination of dust in the air of workplace (GBZ/T 192-2007). Dustfall in respiratory zone was sampled for the determination of free silicon dioxide (SiO2).
Results The steel furnaces and the continuous caster were located in the center of the combined workshop with refractory process areas located at two flanks. Dust was formed in many production processes. The percentages of free SiO2 were gradually decreased from two flanks to the center. The dust in the refractory process areas and adjacent regions was identified as silicious dust with 14.3%-60.4% of free SiO2. The concentration of dust also decreased fr om two flanks to the workshop center. The monitoring results showed that the concentrations of total dust in the personal samplers and the stationary samplers ranged from 1.7 to 25.8 mg/m3 and 2.47 to 72.7 mg/m3 respectively with 57.1% of the samples exceeding the occupational exposure limits (OELs).
Conclusion Dust formed in the refractory process of crushing and cutting can significantly influence the adjacent regions in the workshop. Feasible and effective control on silicious dust are vital to worker's health.
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