毕业论文___钙硅渣硫酸钙浸出技术的研究.doc

钙硅渣硫酸钙浸出技术研究 Research on Leaching technology of calcium sulfate in calcium-silicon slag 钙硅渣硫酸钙浸出技术的研究 摘 要 铁铝共生矿经碳热直接还原或高炉冶炼后，得到主要成分为Al2O3、CaO、SiO2的铝硅钙渣，经硫酸浸出处理后，Al2O3浸出进入到溶液，残渣为主要含有CaSO4和SiO2的钙硅渣。传统工艺对此渣一般弃之不作处理，但其中含有的CaSO4和SiO2是工业中大量使用的原料，若能将其分离，将产生很好的经济效益。 本实验利用实验室现有条件合成了工业生产中产生的钙硅渣，并用硫酸对其做了浸出研究，利用XRD对其成分及浸出产物进行了分析，并验证了(NH4)2Ca(SO4)2的存在。 在不同温度、不同浓度的硫酸铵溶液中分别进行渣中硫酸钙的浸出试验。硫酸铵溶液温度分别设定为30℃、60℃、90℃20-40℃时在硫酸铵溶液中的溶解度，分别在10min、30min和60min时取样测定，结果表明： 渣中硫酸钙溶解度与溶液温度仍呈负相关，即温度越低，溶解度越高；在1h内，渣中硫酸钙在硫酸铵溶液中的溶解度基本不变。 本课题对渣中硫酸钙在硫酸铵溶液中的溶解过程进行了热力学计算，并初步建立了溶解度模型。 关键词：钙硅渣，硫酸钙，硫酸铵，浸出，溶解度 Research on Leaching technology of calcium sulfate in calcium-silicon slag Abstract After the high-iron bauxite reducted by carbothermic or blast furnace smelting, slag with mainly composed of Al2O3, CaO, SiO2 is obtained.whats more, after leaching by sulfuric acid, the Al2O3 is dissolved, and calcium-silicate slag mainly containing CaSO4 and SiO2 is obtained. this slag is generally discarded without treatment in traditional process, but CaSO4 and SiO2 which contains are a large number of industrial raw materials, if separated, it will produce good economic benefits. In this study, calcium-silicate slag is produced and then leached by sulfuric acid, its composition were analyzed by XRD and verified (NH4)2Ca(SO4)2 is present. At different temperatures, different concentrations of ammonium sulfate solution, leaching tests of calcium sulfate in slag are made. Ammonium sulfate solution temperature was set at 30℃, 60℃, 90℃, concentrations were set to 25%, 35%, 45%. The results showed that: Calcium silicate solubility of calcium sulfate in 35% ammonium sulfate solution at the highest; solution temperature is higher, the lower the solubility, 30 ℃ Solubility best; with stirring time, but lower solubility. The effects of solubility of 35% ammonium sulfate, calcium sulfate slag when the solubility at 20-40 ℃, respectively, at 10min, 30min and 60min, samples measured, the results show