【摘要】 采用硫酸浸出硼铁矿,通过乙醇结晶的方法从酸浸液中提取硫酸镁和硫酸亚铁,再利用低温结晶法提取硼酸,实现了低品位硼铁矿中硼镁铁的共提取。从理论上验证了采用乙醇结晶方法提取硼铁矿酸浸液中硫酸镁和硫酸亚铁的可行性,考察了溶液pH值、乙醇加入量和结晶温度对硫酸镁和硫酸亚铁在水-乙醇相中结晶析出的影响。结果表明,当溶液的pH值为2.0左右,乙醇加入体积为溶液体积的1.5倍,结晶温度为室温时,硫酸镁和硫酸亚铁有较高的结晶析出率,分别达到97.73%和97.86%,其纯度分别为99.10%和98.48%。采用低温结晶法提取硼酸的一次收率为74.66%,硼酸纯度达到99.70%,主要杂质镁和铁的含量分别为1.34×10-3%和8.54×10-3%。这种共提取方法操作条件相对温和,能耗较低,提取率高,并且所用的乙醇还可以蒸馏回收。更多还原

【Abstract】 Magnesium sulfate and ferrous sulfate were extracted by ethanol crystallization from sulfuric acid-leached solutions of a low-grade ludwigite, and then boric acid was extracted by low temperature crystallization, therefore the co-extraction of boron, magnesium and iron in low-grade ludwigite was realized. The feasibility of the extraction of magnesium sulfate and ferrous sulfate crystals from the solution using ethanol was discussed theoretically. The effects of pH, ethanol used percentage, and crystallization temperature on the crystallization ratio of magnesium sulfate and ferrous sulfate in ethanol-water were investigated. The results show that when the solution pH is around 2, the volume ratio of solution to ethanol is 1:1.5, and the crystallization temperature is room temperature, the highest crystallization yields of 97.73% and 97.86% for magnesium sulfate and ferrous sulfate were observed and the purities are 99.10% and 98.48%, respectively. The recovery ratio of boric acid is 74.66%, and the purity is 99.70%. The content of the impurities, magnesium and iron, in the recycled boric acid are 1.34×10-3 % and 8.54×10-3 %, respectively. The merits of this technology include relatively mild operating condition, lower energy consumption, higher extraction ratio and the recoverability of ethanol by distillation.更多还原