用水热法从硫铁矿烧渣制备氧化铁红

在硫铁矿烧渣与硫酸反应后的酸浸液中加入氨水，所得含Fe(OH)₃和Fe(OH)₂胶体的前驱物经水热反应可制备出氧化铁红。以广东某硫铁矿烧渣为原料，着重研究了采用该酸浸-水热法制备氧化铁红时酸浸后的适宜工艺条件，结果表明，在酸浸液总铁浓度为2.0 mol/L、水热反应温度为200 ℃、水热反应时间为0.5 h、酸浸液pH=8、酸浸液n(Fe²⁺)/n(Fe³⁺)=0.11时，可获得各项质量指标均达到国家标准一级品要求的氧化铁红产品，其主要物相为Fe₂O₃和FeO(OH)，颗粒为大小均匀的假立方形，同时还可从水热反应产物的滤液中获得工业优等品硫酸铵。

Preparation of Iron Oxide Red from Pyrite Cinders by Hydrothermal Method

Iron oxide red can be prepared by hydrothermal method from the precursor of Fe(OH)₃ and Fe(OH)₂ colloid that is obtained by adding ammonia to acidic leaching solution produced by the reaction of pyrite cinders with sulfuric acid.With a Guangdong pyrite cinder as raw material, research laid stress on the best process conditions after acid leaching for preparing iron oxide red preparation by acid leaching-hydrothermal method.The results show that at the conditions of a total iron concentration in acidic leaching solution of 2.0 mol/L, hydrothermal reaction temperature of 200 ℃ and time of 0.5 h, and acidic leaching solution's pH=8 and n(Fe²⁺)/n(Fe³⁺)=0.11, an iron oxide red that satisfies the quality indexes for state standard for Class A product can be obtained, with main phases being Fe₂O₃ and FeO(OH) and particles being uniformly pseudocubic.Meanwhile, ammonium sulfate of industrial first grade can also be gained from the filtrate of hydrothermal reaction product.