风化铬渣与新鲜铬渣中六价铬溶出特性的研究

采用直接淋浸法对风化铬渣及新鲜铬渣进行了六谷铬溶出的条件试验，60min的浸泡时间，80目以下的粒度对渣水比250g/200mL的新渣中Cr(VI)浸出率达69．4％，渣水比250g/200mL,500g/400mL,750g/600mL的风化渣中Cr(VI)的总溶出率分别为70．2％，86．3％，94．0％，其中第一次淋滤溶出率分别达48．1％，70．0％，81．6％，低PH值的淋浸水有利于Cr(VI)的浸出，在PH值为3时溶出率达高峰，Cr（VI）浸出质量比自然条件（近中性）高出14．1％－16．3％，增大管径和降低装置的滤面负荷可提高浸出效果，在直径80mm管径，500g铬渣装填料，滤面负荷9．95g/cm^2时，Cr（VI）溶出率达98．7％，真空抽滤可提高Cr（VI）浸出速率，但降低了滤液中Cr（VI）的浓度和溶出质量，上述试验结果表明了直接淋浸法回收铬渣中六价铬的可行性，并可作为工业化装置的设计参数。

Research of Solution Characters of Cr(VI) in Weathered Chromium Slag and New Slag

Experiments for solution conditions of Cr(VI) in weathered chromium slag and new chromium slag were carried out by means of direct eluviating. The solution rate of Cr(VI) in new chromium slag is 69.4%.As to the weathered slag, the solution rate of Cr(VI) is 86.3%,which is higher than that of the new slag under the same condition. The lower the water's pH, the easier the solution of Cr(VI).The solution rate is the highest when the water's pH is 3.This rate is higher than the rate when neutral water is used by 14.1% to 16.3%.The solution efficiency can be improved by enlarging the diameter of the implements. When the diameter of implement is 80mm and the mass of chromium is 500g,the solution rate of Cr(VI) is as high as 98.7%.Using air pump can help to improve the extraction of Cr(VI) solution from the soaked dregs, but it can also reduce the density and mass of Cr(VI) in the solution. The results of the experiments indicate that it is feasible to recycle the Cr(VI) from chromium dregs by means of eluviating. Besides, they supply helpful data for the design of industrial installation.