Study On Factors Affecting Grinding Performance Of Limonitic Laterite Nickel Ore

In recent years,the global electric vehicle（EV）industry has grown rapidly,and nickel demand has grown with it.Nickel is mainly extracted from laterite or sulfide ores,with minor amounts from copper and platinum group metals（PGM）refining by-products.Laterite nickel ore is the main raw material for global primary nickel production,and Indonesia’s laterite nickel ore reserves rank first globally.Since January2020,the Indonesian government has banned raw ore export,stipulating that laterite nickel ore can only be processed domestically.QMB New Energy Materials is one of several nickel processing facilities being built in Indonesia to meet the needs of the electric vehicle industry（experiments required for this study were done here）.Grinding and crushing are the critical steps in the nickel smelting process,and the grinding process consumes a lot of energy.At present,there is still a lack of systematic research on the grinding behavior and performance of Indonesian limonite-type laterite nickel ore.In order to meet the surging demand of the electric vehicle industry,Indonesia needs to process a large amount of limonite-type laterite nickel ore,and the grinding and crushing process will consume a lot of energy.This study intends to reduce the energy consumption of the grinding process by optimizing the grinding process parameters（ball distribution ratio,ball filling ratio,ball material ratio,and pulp density）of Indonesian limonitic laterite nickel ore.In addition,the chemical composition of the product under different grinding times and grinding targets were studied;the optimized ball milling parameters obtained were compared with those used in QMB New Energy Materials Company.The conclusions are as follows:The effect of ball distribution ratio on ball milling performance was studied by the Attainable Region（AR）method.The results show that:a large number of agglomerated particles are observed at the grinding time of 0.5,1,and 2 min;at the peak points of the M₁-M₂ and M₂-M₃ plots,about 14%of the feed particle size remains in the ground product;when the ball diameter is 100 At%15 mm,the grinding time to reach d₈₆=74μm is about 362 s.The effect of ball filling rate,ball to material ratio,and pulp density on the percentage of feed size was studied by response surface methodology.The results show that:the pulp density has the most significant effect on the feed size retained after grinding percentage;reducing the ball filling rate and increasing the ball-to-material ratio will reduce the feed size retained percentage;increasing the ball-to-material ratio will reduce the feed size retained percentage,but it is possible to use a broader range of pulp density;Higher grinding productivity can be achieved by maximizing ball filling and minimizing ball to material ratio.By comparing the chemical composition,it can be seen that the limonite-type laterite nickel ore used in the research is suitable for autoclave feeding,and no separation treatment is required before the leaching process;separation processes such as spiral chute,vibrating table,and magnetic separation can be used to extract Fe and Cr₂O₃.The experimental results show that increasing the grinding time and grinding target can improve the extraction rate of Ni and Co,and the content of other elements and oxides can be improved.The percentage of the grinding product was compared under the optimized parameters and under the factory ball mill parameters of QMB.The results show that the percentage of the ground product（-0.074 mm）obtained after grinding with the optimized parameter value is higher with less grinding time.The material throughput can be improved,comparable to the material throughput when the grinding time is 6.02 minutes.Compared to the QMB parameter’s value,the material throughput increased to 43%when using the optimized parameter’s value.