【摘要】 化学沉淀法利用（亚）砷酸根（AsO₃-3/AsO₃-4）与多种金属阳离子形成难溶化合物,进而实现砷的固化/稳定化,在含砷废水除砷及含砷废弃物固化方面被广泛应用。本文简要介绍了国内外在化学沉淀法固化/稳定化除砷技术方面的研究现状,对不同低溶解度砷酸盐,包括砷酸钙（Ca-As盐）、臭葱石（FeAsO₄·2H₂O）、砷铝石（AlAsO₄·2H₂O）,及含砷明矾石族矿物(砷黄钾铁矾(KFe₃（SO₄）_2-x（AsO₄）_x（OH）₆)、砷钠明矾石（NaAl3（SO4）2-x（AsO₄）_x（OH）₆）的砷毒性浸出特性进行了对比分析。研究表明:低溶解度的砷酸盐（砷酸钙、臭葱石、砷铝石）的砷浸出浓度均较高,超过5mg/L,不利于长期堆存。而砷黄钾铁矾和砷钠明矾石固溶体具有溶解度低,固砷效率高等优点,其中砷钠明矾石固溶体具有更好的中长期稳定性,在pH为5⁸时,其砷浸出浓度为0.01⁰.1mg/L。由此可见,利用砷钠明矾石固溶体固砷有望成为处理含砷废水和含砷废渣的一种潜在手段。更多还原

【Abstract】 Chemical precipitation process can be used to immobilize / stabilize the arsenic by forming the low-solubility compounds through the reaction between the arsenate or arsenite ions and metal cations.The progress on arsenic immobilization / stabilization with chemical precipitation method was introduced in this paper. The arsenic leaching characteristics of a kinds of arsenates with low solubility such as calcium arsenate（ Ca-As）,scorodite（ FeAsO₄·2H₂O） and mansfieldite（ AlAsO₄·2H₂O）,and arseniccontaining alunites including arsenical jarosite( KFe₃（ SO₄）_2-x（ AsO₄）_x（ OH）₆) and arsenical natroalunite( NaAl₃（ SO₄）_2-x（ AsO₄）_x（ OH）₆) were comparatively analyzed. The result showed that the arsenic leaching concentrations of the low-solubility arsenates were higher than 5 mg / L. Tthe arsenical jarosite and arsenical natroalunite had some advantages including low arsenic leaching and high arsenic capacity. Arsenical natroalunite are more stable compared with arsenical jarosite,of which arsenic leaching concentration reached 0. 01-0. 1 mg / L for p H = 5-8. So arsenic immobilization / stabilization by precipitation of arsenical natroalunite has become a perspective technology to deal with water and wastes containing arsenic.更多还原