Preparation Of Purity Iron By Low-carbon Steel Electrolysis

With the rapid development of intelligent ship system,while focusing on continuously improving the construction of virtual platform,the development of ship hardware can not catch up with the demand of software.The electrical equipment and power applications on Intelligent ships are complex,such as marine pump motor,air compressor,steering gear,windlass,winch and motors of various actuators.The core power source of them is motor.However,at present,high-purity electrolytic iron,an important material for preparing motor stator electromagnetic core in China,greatly depends on foreign imports.It is urgent to realize the independent research and development of high-purity iron by electrolytic method.In this thesis,ferrous sulfate is used as the main salt,low carbon steel as the anode and stainless steel as the cathode.The effects of initial p H value of electrolyte,temperature and mass concentration of ferrous sulfate heptahydrate on the current efficiency of Electrodeposited pure iron coating,the growth of electrolytic iron on the surface of cathode plate and the change of p H value in the anode and cathode region of electrolyte are studied by orthogonal experiment.The range of optimal initial p H value of electrolyte is mainly determined;The effects of the initial p H value of electrolyte,ferrous ion concentration and current density on the current efficiency of electrodeposited pure iron coating,the surface morphology of electrolytic iron deposited on cathode plate and the purity of electrolytic iron were studied at room temperature by orthogonal experiment in the range of optimal initial p H value of electrolyte,and the optimal experimental parameters were obtained.The experimental results show that:（1）When the initial p H value of electrolyte is 1,the current efficiency is still very low after long-time electrolysis,and there is almost no pure iron coating on the surface of cathode plate;When the initial p H value of the electrolyte is 3,the initial current efficiency is the highest and a better pure iron coating can be formed on the cathode plate,but its disadvantages are that the p H value of the electrolyte increases too fast,the hydrolysis is serious and the sustainable electrolysis time is short.When the initial p H value of the electrolyte is 2,the initial current efficiency is high,and a better pure iron coating can be prepared on the cathode plate.The p H value of the electrolyte increases moderately and the hydrolysis speed is relatively slow.Therefore,considering comprehensively,the optimal initial p H range of electrolyte should be between 2 and 3.（2）Under the same electrolysis temperature and initial p H value,increasing the mass concentration of ferrous sulfate heptahydrate can improve the current efficiency and prolong the sustainable electrolysis time;Under the same mass concentration of ferrous sulfate heptahydrate and initial p H value of electrolyte,increasing the temperature can improve the current efficiency to a certain extent,but it will shorten the duration of sustainable electrolysis.（3）At room temperature（25℃）,the electrolysis experiment,of which the initial p H is between 2 and 3,shows that the optimal current density parameter is 100 A/m²,the optimal mass concentration parameter of Fe²⁺is 50g/L,and the optimal initial p H value of electrolyte should be in a narrow range of about 2.5.Under the process parameters,the surface morphology of the prepared pure iron is complete,and the preparation efficiency is high.The average starting current efficiency is between 80%～90%,and the purity grade of the sample is between 3N2～3N7.