真空蒸馏砷铁渣提取元素砷

Extraction Arsenic from Arsenic-Ferrous Dross by Vacuum Distillation

我国所有炼锡厂在粗锡精炼过程中均产出砷铁渣,迄今为止,对砷铁渣的处理仍未有较合理的方法。本文研究了用真空蒸馏法从砷铁渣中回收元素砷的可能性及最佳技术条件,试验考查了蒸馏温度,时间,残压,加料量及试料粒度大小等因素对砷挥发率及砷挥发速率的影响关系。研究结果表明:在温度1140℃～1240℃,时间30～60分钟,残压13.3～66.7Pa的条件下真空蒸馏柳州冶炼厂固体砷铁渣时,砷的挥发率为87～93.6%,蒸馏后残渣含砷1.13～2%,砷挥发速率为3.4×10^(-3)～6.37×10^(-3)g/cm^2·min。冷凝物经二次真空蒸馏产出的元素砷含砷为94.68%。

The arsenic-ferrous dross was produced in the process of refining crude tin in all tin smelters in China. So far, none of options is satisfactory to treatment of arsenic-ferrous dross.The possibility and the optimization technique condition for recovering element arsenic from arsenic-ferrous dross by vacuum metallurgy are discussed. The effects of temperature,the time, the residual pressure,the amount of material and the pellet size etc. On the pct of evaporation of arsenic and the rate of evaporatiom of arsenic have been investigated. The test results show that under the following conditions that the temperature range 1140-1240℃ ,the time,30-40 min,the residual pressure 13.3-66.7 Pa,the arsenic evaporation pct is given as 87-93.6% by vacuum distillation solid arsenic-ferrous dross at Liuzhou Smelter. And the rate of evaporation of arsenic is 3.4x10^(-3)-6.37×10^(-3)g / cm^2min^1.The residue contains 1.13-2% As. The element arsenic contains 94.68% As, when condensate experienced second vacuum distillation.