As is well known, the process of direct reduction and magnetic separation is effective route to deal with low-grade saprolite laterite, but generally limited by the reduction of nickel (iron)-bearing minerals and growth of Fe-Ni alloy particles in the reduction process, causing the low recovery of nickel and iron. To improve beneficiation of nickel and iron from low-grade saprolite laterite with 1.29 wt.%Ni and 16.31 wt.%Fe, co-reduction with limonitic laterite ore and basicity optimization were adopted as strengthening measures in this paper with better economic efficiency than before. The enhancing mechanism was investigated via the thermodynamics analysis and mineralogical study. The phase transformation and growth behaviors of metallic alloy particles during reduction process were revealed as well. The results indicated that co-reduction with limonitic laterite ore is capable of promoting phase transformation from Ni₂SiO₄ in saprolite laterite to NiFe₂O₄. CaCO₃ can not only destroy the structure of magnesium silicate to release nickel(iron)-bearing phase, but also enhance the reduction of Fe₂SiO₄ to form efficiently iron-based eutectoid with nickel and liquid phases to accelerate the growth of Fe-Ni fine particles larger than 40 μm. A superior crude alloy was obtained with 5.11 wt.%Ni and 82.15 wt.%Fe with corresponding recovery rates of 91.89% and 85.15% respectively.

众所周知，直接还原和磁选工艺是处理低品位腐泥土红土的有效途径，但通常受到还原含镍（铁）矿物和还原过程中Fe-Ni合金颗粒生长的限制。过程中，导致镍和铁的回收率低。为了改善镍和铁从1.29 wt。％Ni和16.31 wt.Fe的低品位腐泥土红土的选矿效果，本文采用与褐铁矿红土矿石共还原和碱度优化作为强化措施，具有比以前更好的经济效益。 。通过热力学分析和矿物学研究了强化机理。揭示了还原过程中金属合金颗粒的相变和生长行为。腐泥土中的₂ SiO ₄为NiFe ₂ O ₄。CaCO ₃不仅可以破坏硅酸镁的结构以释放出含镍（铁）的相，而且可以增强Fe ₂ SiO ₄的还原，从而与镍和液相有效地形成铁基共析物，从而加速Fe- SiO ₂的生长。 Ni细颗粒大于40μm。获得了具有5.11重量％的Ni和82.15重量％的Fe的优质粗合金，相应的回收率分别为91.89％和85.15％。