开展了硫酸体系中砷铁水热共沉淀为大颗粒晶型臭葱石的研究，考察了初始Fe/As摩尔比、初始pH、反应温度、搅拌速度和氧分压等因素对砷铁沉淀率、臭葱石晶型形成及臭葱石粒度的影响. 结果表明，Fe/As摩尔比、初始pH及反应温度降低有利于形成纯净大颗粒臭葱石，臭葱石颗粒粒度与氧分压关系不大. 高搅拌速度有利于形成纯净臭葱石，但不利于大颗粒臭葱石晶体的形成. 在Fe/As摩尔比1.5、初始pH 1.0、反应温度160℃、搅拌速度500 r/min和氧分压0.4 MPa的优化条件下，除砷率高于97%，沉砷渣中砷含量大于30%，平均粒度大于20 ?m.
Coprecipitation of arsenic and iron in sulphuric acid system to produce large particle sized scorodite was carried out. The effects of initial Fe/As molar ratio, initial pH, temperature, agitation speed and oxygen partial pressure on scorodite crystalline formation, particle size distribution and the precipitation rates of As and Fe were investigated. The results showed that the decrease of Fe/As molar ratio, initial pH and temperature was beneficial to large and purified scorodite formation which was independent of oxygen partial pressure. Higher agitation speed was available for the formation of more purified scorodite but small-sized scorodite. The precipitation of As was higher than 97%, the content of arsenic in residue was larger than 30% and the average size of scorodite was larger than 20 ?m under the optimum conditions of Fe/As molar ratio 1.5, initial pH 1.0, temperature 160℃, agitation speed 500 r/min, oxygen partial pressure 0.4 MPa.
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