一种红土镍矿直接还原-磁选回收镍铁工艺研究

Study on the nickel and iron extraction by direct reduction magnetic separation

以红土镍矿为主要原料,通过改变不同还原温度、还原时间、配碳量及生石灰配加比例进行还原焙烧-磁选来提取红土镍矿中的镍和铁。结果表明:还原温度是影响镍、铁回收率的最主要因素。在焙烧过程中,镍和铁的氧化物均得到还原,反应产物结构更加致密,且有少量细小珠铁粒的产生。在本实验条件下,当温度为1 230℃、配碳的碳氧比为1.4、生石灰配加量10%时、恒温35min时的铁和镍回收率均达到最高,此时铁的收得率为91.35%,镍的收得率为86.54%。

Nickel and iron in nickel laterite were extracted by reduction roasting and magnetic separation. The effects of different reduction temperature, reduction time, carbon content and the addition proportion of limestone in the process of reduction were studied. The results show that the reduction temperature is the most important factor that affects nickel and iron＇s recovery. In the roasting process, the oxides of nickel and iron were reduced; The structure of the reaction product was more compact, along with little production of small bead iron particles. When the reaction temperature was 1 230 ℃, C/O molar ratio was 1.4, the addition of limestone was 10% and the temperature stays constant for 35 min, the recovery of iron and nickel are 91.35% and 86.54%.