固化铬渣的解毒研究

为了处理某含有较低毒性的固化铬渣，首先通过超声破解的方法浸出固化铬渣中的六价铬，再利用水合肼对浸出液中的六价铬进行还原处理，并探讨多种因素对六价铬还原的影响。结果表明：超声处理5 h可以使大部分的六价铬从固化铬渣中浸出；在碱性范围内，投料比、反应温度、反应时间及pH对六价铬的还原影响显著。反应的最佳实验条件为：反应温度为60 ℃、浸出液的pH为8.5、n（水合肼）∶ n（六价铬）=130∶1、反应时间为30　min。在最佳实验条件下，六价铬的去除率达到了98.6%，六价铬的最终质量浓度为0.09 mg/L。

Study on the detoxification of solid chromium slag

The purpose of the experiment is to dispose the solid chromium slag with a low toxicity.Firstly，Cr（Ⅵ） from solidchromium slag  was leached by using ultrasonic treatment.Then Cr（Ⅵ） in the leaching liquid was reduced by hydrazinehydrate.Various factors affected the reduction of Cr （Ⅵ）were discussed.Results indicated that ultrasonic treatment could leachmost of the Cr（Ⅵ） from solid chromium slag in 5 h；in the alkaline range，the factors，such as amount-of-substance ratio ofreactants，reaction temperature，reaction time，and pH all had obvious affection on the reduction of Cr（Ⅵ）.The optimumexperimental conditions were as follows：reaction temperature was 60 ℃，pH=8.5，amount-of-substance ratio of hydrazine hydrate to Cr（Ⅵ） was 130 ∶1，and reaction time was 30 min.Under those conditions，the removal rate and final mass concentra-tion of Cr（Ⅵ） could reach 98.6% and  0.09 mg/L，respectively.