对隔焰蒸馏炼锌炉——一种土法炼锌改进炉型的排污及环境影响分析

以贵州威宁高远锌厂为实例 ,对隔焰蒸馏炼锌炉的工艺、排污和环境影响进行了分析。该炉型将燃烧烟气与还原烟气分开治理 ,通过实测证明减少了污染物排放量 ,在现阶段可作为一种过渡炉型 ,同时还可进一步改进。

贵州省赫章县妈姑地区传统炼锌工艺考察

锌是一种较难冶炼的金属。氧化锌的热还原要求有强烈的还原气氛和高温条件。一般来说,氧化锌的还原反应要在1000℃以上才能顺利进行。锌的沸点约为907℃。因此,火法炼锌中(炉温在1000℃以上)还原得到的金属锌都是气态的。这种存在于炉气中的金属锌蒸气很容易被再氧化。要想得到锌产品,还应对含锌炉气进行有效的冷凝。也就是说,在生产实践中,火法炼锌必须采用相应的蒸馏法。这就增加了炼锌的困难。

Optimization of selective leaching of Zn from electric arc furnace steelmaking dust using response surface methodology

The aim of this work is to investigate and optimize the effects of the leaching parameters on the selective leaching of zinc from electric arc furnace steelmaking dust （EAFD）. The response surface method was applied on the basis of a three-level Box–Behnken experimental design method for optimization of selective leaching parameters of zinc from EAFD. The leaching recoveries of zinc （YZn） and iron （YFe） were taken as the response variables, where the concentration of sulphuric acid （X1, mol/L）, leaching temperature （X2, °C）, leaching time （X3, min）, and liquid/solid ratio （X4, mL/g） were considered as the independent variables （factors）. The mathematical model was proposed. Statistical ANOVA analysis and confirmation tests were applied. A maximum of 79.09% of zinc was recovered while the minimum iron recovery was 4.08% under the optimum conditions of leaching time 56.42 min, H2SO4 concentration 2.35 mol/L, leaching temperature 25 °C and liquid/solid ratios. By using ANOVA, the most influential factors on leaching of zinc and iron were determined as H2SO4 concentration and leaching temperature, respectively. The proposed model equations using response surface methodology show good agreement with the experimental data, with correlation coefficients （R2） of 0.98 for zinc recovery and 0.97 for iron recovery.

普发兴二三事

背景链接:普发兴,男,汉族,1936年4月生,1960年入党,云南省大理州祥云县下庄镇下庄村人,1987年担任下庄村党支部书记,2007年3月28日因积劳成疾,逝于任上,终年71岁。

疑案尚未完结

一起普通的经济纠纷,导致1人死亡,2人轻伤。