某不锈钢炼钢连铸工作场所粉尘危害分析

Analysis of Dust Hazards in a Stainless Steel Making and Continuous Casting Workplace

[目的]识别某不锈钢炼钢连铸项目的粉尘危害,分析其危害程度并寻找关键控制措施。[方法]选取华南地区某不锈钢企业的炼钢连铸车间,经定点采样和个体采样后依据《工作场所空气中粉尘测定》（GBZ/T 192—2007）检测空气中粉尘浓度,同时采集呼吸带高度的降尘测定游离二氧化硅（SiO2）含量。[结果]在联合车间内炼钢炉及连铸机布置在中部,耐火材料拆砌炉区布置在车间东西两侧。该工作场所中产生粉尘的环节较多,现场粉尘中游离SiO2含量由车间两侧向车间中部逐渐降低,其中耐火材料拆砌炉区和相邻区域的游离SiO2含量达14.3%~60.4%,属于矽尘。现场粉尘浓度亦由车间两侧向车间中部逐渐降低。个体检测粉尘浓度范围为1.7~25.8mg/m（3TWA,总尘）,定点检测短时间浓度范围为2.47~72.7mg/m（3总尘）,超标率为57.1%。[结论]手工拆砌炉区与卧式拆炉烘烤区的耐火材料破碎、切割过程中产生的粉尘能够明显影响车间内其他区域,有效控制拆砌炉过程中的粉尘是改善车间职业卫生状况的关键。

[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 from 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 25.8mg/m3 and 2.47 to 72.7mg/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.