钼精矿氧化焙烧-酸浸预处理后焙砂的氨浸工艺研究

Research on Ammonia Leaching Process of Roasted Sand after Oxidative Roasting-Acid Leaching Pretreatment of Molybdenum Concentrate

钼精矿经氧化焙烧-酸洗处理后,焙砂杂质元素减少,钼得到显著富集。针对除杂后的焙砂,采用氨水进行浸出,研究氨浸过程钼浸出的影响因素。结果表明,焙砂氨浸的最佳条件下,温度为60℃,氨浸时间为30 min,液固比为3.5~4.0,pH为8.5~9.0。焙砂氨浸浸出率可超过98.6%,氨浸渣率约为16%,氨浸渣含钼量为3.5%左右。氨浸渣中残存的钼主要为焙烧过程中未被氧化的MoS2,其他主要为脉石,氨浸渣真比重为2.85 g/cm^(3)。氨浸液含钼量为140~150 g/L,还含有少量的Fe与Cu,氨浸液比重为1.15~1.18 g/cm^(3)。

After the oxidation roasting acid washing treatment of molybdenum concentrate,the impurity elements in the roasted sand are reduced,and molybdenum is significantly enriched.For the roasted sand after impurity removal,ammonia water is used for leaching to study the influencing factors of molybdenum leaching during the ammonia leaching process.The results show that under the optimal conditions for ammonia leaching of roasted sand,the temperature is 60℃,the ammonia leaching time is 30 min,the liquid-solid ratio is 3.5~4.0,and the pH is 8.5~9.0.The ammonia leaching rate of roasted sand can exceed 98.6%,the ammonia leaching residue rate is about 16%,and the molybdenum content in the ammonia leaching residue is about 3.5%.The residual molybdenum in the ammonia leaching residue is mainly MoS2 that has not been oxidized during the roasting process,while the rest is mainly gangue,and the true specific gravity of the ammonia leaching residue is 2.85 g/cm^(3).The molybdenum content of ammonia leaching solution is 140~150 g/L,and it also contains a small amount of Fe and Cu,and the specific gravity of ammonia leaching solution is 1.15~1.18 g/cm^(3).