Preparation And Compressibility Of High Purity Electrolytic Iron Powder

Since electrolytic iron powder has the advantages of high purity,small particle size and high catalytic activity.It has been widely used in food and drug additives,catalysts,ferrite preparation and high-density mechanical parts.The domestic industrial production of electrolytic iron powder has just started,the process is not yet completely stable,and the production cost is high,which greatly limits the production and application of electrolytic iron powder.In this paper,orthogonal experiment was used to study the best process for preparing electrolytic iron.The results showed that the best combination of electrolysis iron test program was when the concentration of Fe²⁺solution is 50g·L^-1,the pH value is 4,the temperature is 25?as well as the current density is 100A·m^-2.Under the optimal conditions,the electro-deposition rate was 0.565 g·h^-1,the current efficiency was 90.1%,and the total iron content of electrolytic iron reached 99.83%.Experimental electrolytic iron powder was prepared by electrolytic iron which obtained under the best process.The experiment analyzed the purity and characterization of electrolytic iron flakes and iron powder.The main results are as follows:?1?The electrolyzed iron obtained by the best process electrolysis can effectively increase its purity to 99.98%after hot water washing and ultrasonic treatment with cold water.The impurities in electrolytic iron are mainly Al,O,and S.?2?The main inclusions in the electrolytic iron flakes are compound compounds composed of Cu,Al,Ca,Si,O,etc.,iron oxides and alumina.?3?The purity of the electrolytic iron powder can reach 99.99%,and it is a high-purity?-Fe with no other impurity phases.Under the SEM observation,the shape of the iron powder is flat and rod-like,and the interior is loosely lamellar.Electrolytic iron powder produced by an electrolytic plant was used as raw material to study the compression sintering performance of electrolytic iron powder.The main results are as follows:?1?Under normal pressure and temperature pressure,the density of the green compact reached the highest when the amount of zinc stearate lubricant is 0.2%,which is 7.35 and 7.50 g·cm^-3,respectively.?2?The large-size iron powder is more favorable for the compression molding.The experimental large particle size A has a compact density of 7.515 g·cm^-3 at 600MPa.?3?Due to the large pore size of large-diameter compacts,it is difficult to completely eliminate pores during sintering.Therefore,small-diameter green compacts are more favorable for sintering,and their sintering density at 1000?reaches 7.722 g·cm^-3.Compared to the sintering temperature,the sintering holding time has little effect on the sintering density,so increasing the sintering temperature and reducing the holding time can effectively improve the sintering efficiency.