高钙铬渣及其解毒后可溶六价铬含量分析方法研究

分析了铬渣中六价铬含量的测定方法、六价铬的浸取方法、解毒铬渣的评价方法等几个方面的问题。通过对比国内外大量的研究结果，指出了铬渣中六价铬浸取评价方法存在的问题。由于铬渣的强碱性及其强大的酸中和能力，所谓的酸液浸取大多名不符实，用硫酸、硝酸、盐酸稀溶液浸取铬渣中六价铬要比USEPA Method 3060A碱消解方法效果差很多；用HJ/T 299-2007和HJ/T 300-2007评价解毒后的铬渣存在很多问题；用GB 5085.3-2007 评价铬渣的浸出毒性也有不严密的地方。测定铬渣中六价铬最好用物理方法，例如XANES方法；浸取铬渣中的六价铬宜采用USEPA Method 3060A的碱消解方法。

Evaluation of methods for determination of hexavalent chromium contained in chromite ore processing residue

Hexavalent chromium(Cr6+) determination,and extraction protocols from chromite ore processing residue(COPR),and the evaluation of the harmlessness measures of COPR were reviewed.Problems of some Cr6+ leaching protocols of COPR were pointed out by referring to quite a lot of related publications at home and abroad.As the strong alkali and the great acid neutralization capability of COPR,many so-called Cr6+ acid solution extractions are untrue.USEPA Method 3060A leaches much more Cr6+ than the diluted aqueous solutions of sulfuric acid,nitric acid or hydrochloric acid.HJ/T 299—2007 and HJ/T 300—2007 methods can not determine genuine Cr6+ content of the treated COPR.GB 5085.3—2007 has flaws for evaluating the leaching toxicity of COPR.Best choice for determining Cr6+ content of COPR is physical analysis,such as X-ray absorption near-edge structure analysis;and it′s better to leach Cr6+ from COPR by USEPA Method 3060A.