Green method for hydrometallurgical production of nickel-cobalt-manganese new energy raw material from laterite nickel ore

A green method for the hydrometallurgical production of a nickel-cobalt-manganese new energy raw material from laterite nickel ore, comprising the following steps:

• (1) subjecting a laterite nickel ore raw material to a pre-treatment procedure of ore blending, ore washing, beneficiation, grinding, and thickening to obtain a chromite and a laterite nickel ore pulp;
• wherein the chromite is obtained by sorting in the beneficiation treatment, and the content ratio of nickel-cobalt-manganese in the laterite nickel ore pulp is adapted to the content ratio of nickel-cobalt-manganese in a nickel-cobalt-manganese ternary precursor;
• (2) mixing the laterite nickel ore pulp with a reducing agent and a leaching promoter and then performing pressure leaching or oxygen pressure leaching to obtain a mixed pulp composed of leaching solution containing nickel, cobalt, and manganese and a leaching residue containing iron, aluminum, and silicon;
• (3) subjecting the mixed pulp composed of the leaching solution containing nickel, cobalt, and manganese and the leaching residue containing iron, aluminum, and silicon to cyclic leaching and multistage neutralization successively to obtain a neutralized pulp;
• (4) subjecting the neutralized pulp obtained by cyclic leaching and multistage neutralization treatment to dilution, multistage counter-current washing and tailing neutralization, and recovering iron metal from the obtained tailings by means of reduction roasting-magnetic separation;
• (5) subjecting an end-stage liquid phase after the multistage counter-current washing to multistage iron-aluminum-chromium removal, thickening, and separation under conditions of adding a neutralizer and a precipitation promoter;
• wherein the multistage iron-aluminum-chromium removal is composed of one-stage iron-aluminum-chromium removal, two- and more-stage iron-aluminum-chromium removal;
• a liquid phase after a former-stage iron-aluminum-chromium removal is subjected to a latter-stage iron-aluminum-chromium removal treatment, and a residue phase after the one-stage iron-aluminum-chromium removal is returned and subjected to multistage counter-current washing again, and the residue phase after the two- and more-stage iron-aluminum-chromium removal is reused and subjected to cyclic leaching and multistage neutralization treatment again;
• (6) subjecting a tail-stage liquid phase after the multistage iron-aluminum-chromium removal to multistage nickel-cobalt-manganese synthesis, and subjecting the obtained mixed nickel-cobalt-manganese hydroxide to acid dissolution and liquid phase extraction to obtain a purified liquid, or subjecting the tail-stage liquid phase after the multistage iron-aluminum-chromium removal to liquid phase extraction directly to obtain a purified liquid, wherein the purified liquid is a solution composed of any one or more of a mixed nickel-cobalt-manganese salt, a nickel salt, a cobalt salt, and a manganese salt;
• and concentrating the purified liquid by evaporation to obtain purified crystals, wherein the purified crystals are crystals composed of any one or more of a mixed nickel-cobalt-manganese salt, a nickel salt, a cobalt salt, and a manganese salt, and the liquid phase extraction comprises liquid phase co-extraction and liquid phase selective extraction;
• (7) taking the mixed nickel-cobalt-manganese salt solution as a mother liquor, or taking an aqueous solution of the mixed nickel-cobalt-manganese salt crystal as a mother liquor, according to the content ratio of nickel-cobalt-manganese in the nickel-cobalt-manganese ternary precursor, adding the solutions or crystals of the nickel salt, cobalt salt, and manganese salt into the mother liquor, formulating the content ratio of nickel-cobalt-manganese in the mother liquor, and performing a controlled precipitation reaction with a precipitant and a complexing agent under a protective atmosphere to obtain the nickel-cobalt-manganese ternary precursor;
• or according to the nickel-cobalt-manganese content ratio in the nickel-cobalt-manganese ternary precursor, mixing and formulating the solutions of the nickel salt, cobalt salt, and manganese salt or aqueous solutions of the nickel salt, cobalt salt, and manganese salt crystals, so that the nickel-cobalt-manganese content ratio in the formulated mixed solution matches the nickel-cobalt-manganese content ratio in the nickel-cobalt-manganese ternary precursor, and performing a controlled precipitation reaction with a precipitant and a complexing agent under a protective atmosphere to obtain the nickel-cobalt-manganese ternary precursor;
• wherein the multistage nickel-cobalt-manganese synthesis is composed of one-stage nickel-cobalt-manganese synthesis, and two- and more-stage nickel-cobalt-manganese synthesis and a liquid phase after a former-stage nickel-cobalt-manganese synthesis is subjected to a latter-stage nickel-cobalt-manganese synthesis;
• the tail-stage liquid phase of the multistage iron-aluminum-chromium removal is subjected to one-stage nickel-cobalt-manganese synthesis treatment;
• the mixed nickel-cobalt-manganese hydroxide is obtained after the one-stage nickel-cobalt-manganese synthesis;
• and the mixed nickel-cobalt-manganese hydroxide synthesized in the tail-stage of the multistage nickel-cobalt-manganese synthesis is returned and subjected to cyclic leaching and multistage neutralization treatment again.