Behavior,distribution and environmental influence of arsenic in a typical lead smelter

A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arsenic in selected samples were evaluated. Arsenic contents in all input and output samples vary from 0.11% in raw lead to 6.66% in collected dust-2. More arsenic is volatilized in blast furnace and fuming furnace(73.02% of arsenic input) than bottom blowing furnace(10.29% of arsenic input).There are 78.97%, 13.69%, 7.31% of total arsenic distributed in intermediate materials, stockpiled materials and unorganized emissions, respectively. Matte slag-2, collected dust-1 and secondary zinc oxide are hazardous based on the arsenic concentrations of toxicity characteristic leaching procedure. According to risk assessment code(RAC) guideline, arsenic in collected dust-1 poses a very serious risk to the surrounding environment, arsenic in speiss, matte slag-2, water-quenched slag and secondary zinc oxide show low risk, while arsenic in matte slag-1, collected dust-2 and post dust has no risk to the environment.     

多点切换热电偶测温系统线路的改进

多点切换热电偶测温系统线路的改进辽宁发电厂汤景文在工业温度测量中，常常采用一个显示仪表通过多点切换开关对相同测量范围的多个温度测点进行监测（以下称多点切换热电偶测温系统），这种多点切换热电偶测温系统既便于集中监视，又节省了资金，因而在发电厂的中小型机...