低品位硼镁铁共生矿中镁资源逐级提取富集新工艺

摘要

A novel and clean technological route for the comprehensive utilization of low-grade ludwigite ore was proposed, in which magnesium was extracted by metallizing reduction-magnetic separation, sulfuric acid leaching and ethanol precipitation operation. Meanwhile, iron-rich product, silicon-rich product and boron-rich product were obtained, respectively. In the process of metallizing reduction-magnetic separation, 94.6％ of magnesium was enriched in the non-magnetic substance from the ore reduced at 1250 °C for 60 min with the ore size of 0.50-2.00 mm and coal size of 0.50-1.50 mm. When the non-magnetic substance was leached at 90 °C for 15 min with the liquid-to-solid ratio of 7:1, 87.4％ of magnesium was leached into the liquor separated from silicon gathering in leaching residue. The ethanol precipitation was conducted for 30 min with the ethanol-to-original liquid volume ratio of 1.5:1 at room temperature. 97.2％ of magnesium was precipitated out with the initial concentration of 0.8 mol/L in the form of MgSO4·7H2O.%实现低品位硼镁铁共生矿的综合利用,提出新的清洁生产工艺路线,通过金属化还原-磁选分离、硫酸浸出和浸出液加入乙醇结晶,提取其中的镁资源,可分别得到富铁产品、富硅产品和富硼产品.金属化还原-磁选环节中,在还原温度1250°C、还原时间60 min、矿粒度0.50～2.00 mm和煤粒度0.50～1.50 mm条件下,原矿中94.6％的镁可富集到非磁性产物中.非磁性产物在浸出温度90°C、浸出时间15 min和液固比7:1的条件下和硫酸反应,87.4％的镁可富集到溶液中,从而与残留在浸出渣中的硅分离.镁离子浓度为0.8 mol/L的浸出液常温下加入原始溶液体积1.5倍的乙醇静置30 min后,97.2％的镁以MgSO4·7H2O的形式结晶析出.