红土镍矿加压浸出工艺残积型红土镍矿中和试验研究

残积型红土镍矿是一种重要的红土镍矿,镁元素含量较高(10%~27%),在红土镍矿加压浸出项目中,通常用来中和加压浸出的矿浆,矿浆中硫酸浓度通常为30~50 g/L。但残积矿用量对镍、钴浸出率有较大影响,为了更好地利用残积型红土镍矿,本文进行了常规浸出试验和还原浸出试验。试验结果表明:随着残积矿用量的增加(液固比降低),终点酸度逐渐降低,镍、钴浸出率逐渐降低;当磨矿细度增加时,钴浸出率明显升高;该反应进行迅速,工业上可以考虑缩短浸出时间;当常规浸出和还原浸出残积矿用量相同时,还原浸出镍浸出率比常规浸出高5%~25%;当残积矿用量较低时,还原浸出镍浸出率提升明显;当残积矿用量不超过90 g/L时,还原浸出钴浸出率比常规浸出高,当用量继续增加时,还原浸出钴浸出率则会低于常规浸出。

Neutralization test of residual laterite nickel ore in pressure leaching process of laterite nickel ore

Residual laterite nickel ore is an important kind of laterite nickel ore,with a high content of Mg(10%~27%).In the laterite nickel ore high-pressure leaching project,it is usually used to neutralize the pressure leaching pulp,and the concentration of sulfuric acid in the pulp is usually 30~50 g/L.However,the dosage of residual ore has a great impact on the leaching rate of nickel and cobalt.In order to make better use of residual laterite nickel ore,this paper carried out conventional leaching tests and reduction leaching tests.The test results show that as the dosage of residual ore increases(liquid-solid ratio decrease),the end-point acidity gradually decreases,and the leaching rate of nickel and cobalt gradually decreases;when the grinding fineness increases,the cobalt leaching rate increases significantly;the reaction proceeds rapidly,and the leaching time could be shortened in industry;when the dosage of leaching residual ore is the same in the conventional leaching and reduction leaching tests,the leaching rate of reduction leaching nickel is 5%to 25%higher than that of conventional leaching;when the dosage of residual ore is lower,the leaching rate of reduction leaching nickel is significantly improved;when the dosage of residual ore is less than 90 g/L,the reduction leaching cobalt leaching rate is higher than that of the conventional leaching;when the dosage continues to increase,the reduction leaching cobalt leaching rate will be lower than that of the conventional leaching.