Comprehensive Utilization Of Laterite Nickel Ore

High-grade nickel sulphide ore are drying up with the ever increasing nickel consumption to meet industrial demands.Thus,more and more countries have paid attention to the effective development and application of laterite nickel ore.High energy consumption and large slag amount exist in treating laterite nickel by thermal metallurgy.The pressure leaching process of sulfuric acid has severe operating conditions.In present,the processes of laterite nickel ore exist the disadvantage of lower comprehensive utilization of metals.Ammonium sulfate roasting-water leaching has shown great advantages in treating such laterite nickel ore.Researches on the efficient separation and utilization of metals in laterite nickel ore is of great significance to alleviate the dependence of China's laterite nickel ore on imports.In this paper,the clean and comprehensive utilization of laterite nickel ore using the process of ammonium sulfate roasting-water leaching.The technical process route of ammonium sulfate roasting-water leaching was designed;Single factor experiment and orthogonal experiment method were used to investigate the transformation of valuable mtals in roasting process,and the effect of each factor on the extractions of metals,and the parameters were optimized;The structutre and properties of sodium silicate solution were investigated;The separation of iron,aluminum,nickel,magnesium and silicon was designed,and the high value-added corresponding product were prepared;The technical prototype and theoretical basis of the extractions of valuable metals were obtained,which could provide the theoretical basis and technical support to industrial manufacture.1?Single-factor experiments were used to study on the effect of roasting temperature,roasting time,the amount of ammonium sulfate and particle size on the extraction of iron,nickel,aluminium and magnesium in the process of ammonium sulfate roasting process to laterite nickel ore.The optimum condition obtained by orthogonal experiment was that roasting temperature was 450?,roasting time was 120 min,ratio of ammonium sulfate to ore was 2:1,particle size was less than 80?m,the extraction of iron,nickel,aluminium and magnesium was 95%?98%?97%and 99%,respectively.2?Single-factor experiments were used to study on the effect of temperature,time,stirring intensity and liquid-solid ratio on the extraction of iron,nickel,aluminium and magnesium in the process of water leaching process to clinker.The optimum condition obtained by orthogonal experiment was that leaching temperature was 60?,time was 60 min,stirring intensity was 400 r·min-1,liquid-solid ratio was 2.5:1,the extraction of iron,nickel,aluminium and magnesium was more than 99%.3?The sulfating reactions of iron,nickel,aluminium and magnesium in the roasting process are controlled by internal diffusion,the apparent activation energies of there are 20.83 kJ·mol-1,19.93kJ·mol-1,17.86kJ·mol-1 and 18.96kJ·mol-1,the kinetics equations of them are as follows:Fe:(1-2/3x)-(1-x)2/3=0.05955 exp(-20829/R7)tNi:(1-2/3x)-(1-x)2/3=0.05673exp(-19925/RT)tAl:(1-2/3x)-(1-x)2/3=0.03916exp(-17856/RT)tMg:(1-2/3x)-(1-x)2/3=0.0506 1 exp(-18963/RT)t4?The leaching of iron,nickel,aluminium and magnesium are controlled by external diffusion,the apparent activation energies are 7.23kJ·mol-1,8.08kJ·mol-1,6.36 kJ·mol-1 and 8.63kJ·mol-1,,the kinetics equations of them are as follows:Fe:1-(1-x)2/3=0.2085exp(-7234/RT)tNi:1-(1-x)2/3=0.2749exp(-8075/RT)tAl:1-(1-x)2/3=0.1368exp(-6358/RT)tMg:1-(1-x)2/3=0.3991exp(-8632/RT)t5?Ammonioiarosite method was used to extract iron.The obtained optimum condition by orthogonal experiment was that temperature was 95?,pH was 2.5,time was 2.5 hours,stirring intensity was 400 r·min-1,the extraction of iron exceeded 99%.The obtained optimum condition by orthogonal experiment extracting nickel was that temperature was 50?,pH was 7.0,time was 50 minutes,stirring intensity was 400 r·min-1,the extraction of nickel exceeded 99%.The obtained optimum condition by orthogonal experiment extracting magnesium was that temperature was 30?,pH was 11,time was 70 minutes,stirring intensity was 400 r·min-1,the extraction of magnesium exceeded 99%.6?The properties of sodium silicate solution were studied.The viscosity of sodium silicate solution decreased with the increase of temperature when the concentration of silica in sodium silicate solution was within 110-150 g·L-1.The density of sodium silicate solution increased with the increase of concentration and decreased with the increase of temperature.The relationship between the surface tension of sodium silicate solution and the temperature and the concentration of sodium silicate was measured.As the temperature increases,the surface tension decreases.7?This process is proved to be feasible in production by the amplification experiment,and it has the following advantages:The novel process of green and high value-added comprehensive utilization of laterite nickel is used to separate and extract all valuable component nickel,iron,aluminum,magnesium and silicon in laterite nickel ores,realizing high value-added utilization of resources.The raw materials in the process can be recycled,and the whole process is free of waste gas,waste water and waste residue.The whole process is green.