Settling Performance Of Nickel Laterite From Different Ore Strata

Laterite reserves account for more than 60% of the global nickel supply,and its clean and efficient utilization is the primary way to solve the shortage of nickel supply.High-pressure acid leaching(HPAL)is one of the most potential laterite nickel ore treatment processes,and solid-liquid separation is a problem that should be paid attention to in the wet smelting process.In this paper,the laterite nickel deposits in different layers of Morowali,Indonesia,are systematically indicated.Then,the settlement process of laterite nickel ore slurry in different layers was studied by static settlement experiment,and the optimized process parameters of the slurry settlement were obtained.It is found that limonite-type and saprolite-type laterite nickel ore slurries have different sedimentation characteristics,and the types and addition of flocculants,slurry concentration,and mixing degree is the main factors affecting the sedimentation process.The main conclusions of this paper are as follows:(1)From static,the optimal settling parameters of limonite laterite nickel ore slurry are as follows: Mineral particle size > 44 μm,slurry concentration 2.5%,adding 0.1% of 60 g/t flocculant and mixing for six times.The slurry can settle within 0.25 minutes.The settled liquid contains suspended solids of 16 mg/L,the solid sediment content is17.87%,and the optimal settling parameters of the saprolite laterite nickel ore slurry are as follows: The mineral particle size is > 44 μm,the slurry concentration is 5%,adding 0.1% of 160 g/t flocculant and mixing for 6times.The slurry can settle within 0.20 minutes.The settled liquid contains suspended solids of 31.33 mg/L and the solid sediment content is 27.17%.(2)From dynamic,the result of limonite bottom mud concentrations from three locations are 33.14%,35.17%,and 36.03%,respectively,with the average bottom mud concentration being 34.78%,and for saprolite ore,the result is that bottom mud concentrations from three locations are38.27%,38.06%,and 42.11%,respectively,with the average bottom mud concentration being 39.48%.(3)Response surface methods result from the overall desirability calculations,it could be concluded that the optimal factors for limonite ore were 5 % of solids concentration,180 g/t flocculant dosage,and six times mixed degree,which is estimated to result in 6 minutes sedimentation time,16.78 % underflow concentration and 6.86 mg/L suspended solid of supernatant.For saprolite ore from the overall desirability calculations,it could be concluded that the optimal factors were 5 % of solids concentration,180 g/t flocculant dosage and 5 times mixed degree which is estimated to result in 0.12 minutes sedimentation time,33.07 % underflow concentration and 5.04 mg/L suspended solid.According to the verification experiment,the relative errors between predicted and measured results do not exceed 5%,implying that the proposed models are reliable.The above research results can effectively support the optimization of the liquid-solid separation process of laterite nickel ore wet treatment.Figure 93;Table 32;Reference 78...