材料期刊网

两段硫酸化焙烧过程是以硫酸作硫酸化剂处理某低品位含銅鈷士矿的一个新方案。用此方案可将矿石中90％以上的銅、鈷轉入水溶液,同时使90％以上的铁留于浸出残渣中。 差热和差重分析結果初步說明了分为两阶段的必要性。第一阶段(250—300℃)应滿足使氧化物硫酸化和阻止硫酸蒸汽蒸发逸散損失的双重要求。此时的反应是:(1) 脫水;(2) 各种氧化物被硫酸蒸汽硫酸化;(3) 硫酸高铁的部分分解。第二阶段(550—600℃)是利用鉄硫酸盐分解放出的SO_3使鈷、銅氧化物进一步硫酸化。温度控制的要求为既有利于鉄硫酸盐最大限度的分解;而又能使銅、鈷硫酸盐极少分解。 氧化铁、氧化銅添加物显著降低鈷硫酸盐的分解溫度,而对SO_3惰性的SiO_2的影响则很小。

The two-stage sulphating roasting process is a modified process in which sulphuric acid is used as the sulphatizing agent. This process has been proposed for treating certain highly siliceous, low grade cobalt and copper oxide ores. As a result of such a treatment, over 90％ of cobalt and copper can be converted into water-soluble products while over 90％ of iron will be left insoluble during subsequent leaching. Taking advantage of rate tests, differential weight analysis as well as differential thermal analysis, the authors examined the necessity of carrying out the roasting process in two stages. In the first stage (230—300℃) the sulphatization of oxides on the one hand and the prevention of acid evaporation loss on the other should be both satisfied. The main reactions are (1) dehydration, (2) sulphatization of different oxides with acid vapor, and (3) partial decomposition of ferric sulphate. In the second stage (550—600℃) reaction between cobalt and copper oxides and SO_3 dissociated from iron sulphate is initiated. The temperature is controlled so as to reduce the decomposition of cobalt and copper sulphate to a minimum. Certain oxides, such as Fe_2O_3, Cu_2O, act catalytically in the reactions and have been found to lower appreciably the starting temperature of cobalt sulphate decomposition, while SiO_2, being neutral to SO_3, shows little effect.