Recycling Of Iron Resources From Pressure Acid Leaching Of Laterite Nickel Or

China’s iron ore resources are insufficient to meet the current needs of rapid social development,and the proportion of rich iron ore is relatively small.Only 53%of the total reserves can be developed and utilized,and due to the complex types of ores,the quality of the iron resources developed is also poor,making them uncompetitive.The shortage of iron resources has become the primary problem facing the country,and a certain proportion of iron resources are also present in laterite nickel ore resources.Therefore,in the face of China’s iron resource scarcity,extracting iron from laterite nickel ore has become the key at present.In recent years,most large international enterprises have adopted the wet process of pressurized acid leaching for the development of laterite nickel ore,and the pressurized acid leaching technology has received great attention.For the limonite laterite nickel ore with high iron content,after pressurized sulfuric acid leaching,the leaching residue contains a large amount of iron resources.According to the analysis of the leaching residue,iron mainly exists in the form of Fe₂O₃.This part of iron resources can be enriched and recovered from the acid leaching residue through the magnetization roasting magnetic separation process.Enrichment and recovery of iron from the high-pressure sulfuric acid leaching residue of limonite laterite nickel ore can alleviate the lack of iron resources in China on the one hand,and reduce the environmental pollution caused by the massive accumulation of acid leaching residue on the other hand.This paper takes a limonite laterite nickel ore in Indonesia as raw material,obtains the leached residue by traditional pressurized sulfuric acid leaching method,and then carries out the research on the magnetic roasting magnetic separation process of the leached residue to recover iron.On the basis of discussing various constraints,it focuses on the research on the effect of adding dispersants in magnetic separation on the magnetic separation effect.And through thermodynamic theory,X-ray diffraction analysis,SEM electron microscopy scanning,multi-element chemical analysis,energy spectrum analysis and other detection techniques,the influence of various factors on the results of magnetization roasting magnetic separation was studied.Through experimental research,the following conclusions were drawn:（1）The best conditions for magnetically roasting the high-pressure sulfuric acid leaching slag of limonite laterite nickel ore are as follows:roasting temperature 775℃,holding time 45min,and the proportion of reducing agent semicarbon in the material is 4%.At this time,the magnetic property of the material after roasting is the strongest.According to detection and analysis,the iron content under this condition reaches 53.76%.（2）The optimal magnetic field strength obtained by magnetic separation of the materials roasted under the above optimal conditions is 91m T.At this time,the grade of iron in the iron concentrate is 62.68%,and the recovery rate of iron is 89.05%.（3）Dodecylamine polyoxyethylene ether is used as a dispersant,and under the condition of magnetic field strength of 91m T and p H=8 of the solution,the magnetic separation effect is the best.At this time,the grade of iron in the concentrate is 69.26%,and the recovery rate of iron is 90.83%.This article combines the magnetization roasting magnetic separation process,by adding dispersants before magnetic separation to make small particles of magnetic separation materials carry repulsive charges,thereby reducing the mutual encapsulation of materials and improving the grade of magnetic separation materials.The above research work enriches the theoretical foundation of magnetization roasting magnetic separation and provides valuable technical solutions for the magnetic separation and enrichment of iron from acid leaching slag of laterite nickel ore.