Study On Regeneration Technology Of Nickel - Iron - Tin Alloy Waste

Membrane electrolysis technology can be used to separate the metals in waste alloy with the characteristics of low cost, high efficiency, environmentally friendly and high purity of separated metals. In this paper, tin-nickel-iron alloy scraps were used as raw material, and the technical process of membrane electrolysis, chemical recovery of tin and iron from anolyte, the preparation and recycling of nickel using membrane electrolysis technology have been investigated, and the products were characterized by XRD, SEM.It is shew that the nickel ion concentration in anolyte can reach to 15g/L with the average current efficiency of 96.32 % and the energy consumption of 0.9262 k W·h/kg under the technical conditions of alloy scraps used as soluble anode, electrolysis voltage is 1.5 V, the p H of anolyte and Na Cl concentration is 1.0 mol/L and 1.5 mol/L respectively, electrolysis temperature is 35℃, electrode distance is 30 mm and electrolysis time is 6 hours.The recovery of tin can reach to 99.99% using precipitation method for separating and recover Sn2+ in the anolyte under the technical conditions of p H is 3.5, the aging time is 24 h. The effects of precipitant type, calcination time and temperature on the particle size of Sn O2 were investigated. It is shew that the crystalline form of Sn O2 powders is excellent crystal and the average particle size is about 100 nm with narrow size distribution under the technical conditions of calcination time and temperature is 450℃ and 2h respectively using ammonia as precipitant.It is shew that the precipitation p H, reaction temperature and aging time seriously affect the separation rate of iron. The recovery of iron can reach to 99.75% during the optimum separation condition of the precipitation p H is 3.5, reaction temperature and aging time is 24 h and 8h respectively. Fe2+ in the anolyte in which tin have been removed in pre-process was separated using goethite precipitation method and the separated iron was calcinated for 2h at 650℃ to obtain Fe2O3 crystals which have good crystallinity.Nickel have been recovered using electrolysis technology in which anion exchange membrane reactor was used as electrolyzer, solution without iron and tin was used as cathode. It is shew that the electrolysis time, current density, p H, temperature and concentration of boric acid affect nickel recovery rate and power consumption of electrolysis process seriously. The nickel recovery can reach 95.432 % with the purity of 94.69% and the energy consumption for the electrolysis is 9.6237 k W·h·kg-1 under the optimum electrolysis condition,of the current density is 300 A/m2, p H is 4, boric acid concentration is 25 g/L, electrolysis time and temperature is 10 h and 35℃respectively.