硫酸渣制备高纯度硫酸亚铁

Preparation of high purity ferrous sulfate from sulfuric acid residue

以高铁硫酸渣为原料,采用酸浸—还原—除杂—结晶—重结晶—干燥工艺,合成高纯度硫酸亚铁。通过反应温度、反应时间对硫酸渣中铁的浸出率的影响,以及结晶温度、干燥温度、干燥时间对硫酸亚铁产品纯度的影响做分析实验,得出最佳酸浸条件:硫酸渣与硫酸的固液比为1∶3,硫酸质量分数为20%～25%,反应温度为80℃,反应时间为6h,搅拌强度为200r/min;最佳结晶精制条件:结晶溶液pH值为1～3,温度为60℃;除杂最佳条件:pH值约为4.5;冷却结晶温度控制在20℃,结晶干燥过程为30℃,干燥6h。

Taking sulfuric acid residue as raw material, using acid leaching-reduction-removing impuritycrystallization-recrystallization-drying process, synthesize high purity ferrous sulfate. Make analytical experiments through the impact of reaction temperature and time on the leaching rate of iron in sulfuric acid residue, as well as the impact of crystallization temperature, drying temperature, drying time on ferrous sulfate product purity. Obtain the optimum acid leaching conditions： the solid-liquid ratio of sulfuric acid residue and sulfuric acid is 1：3, the mass fraction of sulfuric acid is 20%-25%, the reaction temperature is 80℃, reaction time is 6 h, stirring intensity is 200 r/min. The best crystallization refining conditions： pH value of the crystallization solution is 1 -3, the temperature is 60℃. Optimal pH value of removing impurity is about 4.5. Control the temperature of cooling crystallization at 20℃, the temperature of crystallization and drying process at 30℃, and dry 6 h.