摘要:
以硫酸与氟化钠混合溶液为浸出剂,采用常压浸出工艺处理普通磁铁精矿制备超纯铁精矿.考察了浸出温度,浸出时间,硫酸浓度,氟化钠浓度,浸出液固比对铁精矿品位、回收率以及二氧化硅脱除率的影响.通过浸出前后主要化学成分对比表明:以硫酸与氟化钠混合液为浸出剂,可以有效除去杂质,提高铁精矿品位,在未加入氟化钠时,主要发生的是碱性氧化物的简单酸溶反应,二氧化硅脱除率较低,铁精矿品位提高不高.加入氟化钠有效可以除去SiO2,随着氟化钠添加量的增加,铁精矿品位不断提高,同时二氧化硅脱除率明显提高,但氟化钠添加量不宜过多.此外,铁精矿品位浸出时间和浸出液固比的增大而提高,浸出温度不宜过高.浸出过程最佳的条件为温度60℃,浸出时间60 min,硫酸浓度60 g/L,氟化钠浓度12g/L,液固比3∶1.在此条件下SiO2脱除率为70.53%,可以得到品位71.82%,回收率92.78%的超纯铁精矿.
Abstract:
Using mixed solution composed by sulfuric acid and sodium fluoride as leaching agent,ordinary magnetite concentrate was treated by leaching process to to prepare super pure iron concentrate.The effects of leaching factors including leaching temperature and time,dosage of sulfuric acid and sodium fluoride,liquid to solid ratio on tenor of iron ore and recovery rate and removal rate of silica were systematically investigated.By comparing the main chemical composition before leaching and after leaching,show that using mixed solution as leaching agent can remove impurities effectively,and improve the grade of iron concentrate.When no added sodium fluoride,mainly of the reaction is alkali oxides,simple acid-soluble,and removal rate of silica is low,improve the grade of iron concentrate not high;While sodium fluoride may be removed SiO2,with the increase of sodium fluoride content,the grade of iron concentrate and removal rate of silica increased obviously,but the sodium fluoride can't excessive.In addition,the leaching rate of copper increases with the increase of leaching time and liquid to solid ratio,and leaching temperature can't be too high.The best conditions for leaching process is leaching temperature of 60℃,leaching time of 60min,sulfuric acid concentration of 60g/L,sodium fluoride dosage of 12g/L,liquid to solid ratio of 3∶1.On this condition,a 70.53% removal rate of SiO2,super pure iron concentrate with the iron grade up to 71.82%,and the recovery of 92.78% can be obtained.
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