FYF Reaction kettle (6)

The simplified process for producing ternary precursor materials mainly includes salt, alkali, ammonia configuration, crystallization reaction, isothermal aging, washing, and drying.

 

The liquid nickel sulfate, cobalt sulfate prepared in the previous process, and newly purchased crystalline manganese sulfate are accurately weighed using an automatic weighing instrument. These materials are then added to a salt-making kettle with purified water to produce a sulfate solution of a certain proportion (the salt-making kettle needs to be heated with heating wires to 60°C). Meanwhile, soda ash tablets and purified water are added to an alkali kettle to produce an alkali solution of a certain concentration (32%). Both the sulfate solution and the alkali solution are pumped into corresponding tanks and treated by a precision filter before use. The sulfate solution, the alkaline aqueous solution, and ammonia (purchased or recycled from water treatment) are stored in two tanks for use. These three materials are pumped into corresponding balancing tanks using pipeline iron removers. Among them, the salt balancing tank and the alkali balancing tank are heated and insulated with heating wires (40°C). The above three materials are pumped into a titanium reactor through metering pumps. Through the reactor's flow, stirring speed, automatic pH control, and PLC temperature control, as well as the introduction of nitrogen, the nickel, cobalt, manganese, and hydrogen bases are uniformly complexed and precipitated. Subsequently, the mixture enters an aging kettle for isothermal aging (heated with heating wires to 60°C for 4-8 hours). After aging, it is pumped into a washing machine, where hot water is used to wash away sodium ions, alkaline water is used to remove sulfates, and compressed air is used for pressurized drying to achieve solid-liquid separation. The mixture is then transferred to a pulping kettle, where hot purified water is used for pulping. After pulping, it is pumped into a centrifuge to control the water content of the nickel, cobalt, manganese, and hydrogen base to about 10%, and then it enters a disk dryer. After drying, it is fed into a mixer through a vacuum loader. After screening and iron removal, unqualified materials and magnetic impurities on the screen are removed to improve dispersion, obtaining qualified ternary cathode material (nickel-cobalt-manganese hydroxide) precursors. Mother liquor and washing liquor are collected in storage tanks and pumped into an ammonia evaporation and stripping tower for treatment. The ammonia recovered during the ammonia evaporation and stripping process in the tower is returned to the ammonia storage tank for reuse, while the ammonia-stripped wastewater enters the wastewater treatment station for treatment, and some distilled water can be returned to the purified water storage tank for reuse.