Nickel-iron wet treatment method and application thereof

Abstract

Disclosed are a nickel-iron wet treatment method and an application thereof. The treatment method comprises: in a high-pressure oxygen environment, mixing a crushed nickel-iron material, sulphuric acid and a corrosion aid, performing an acid leaching reaction, then performing solid-liquid separation on slurry subjected to acid leaching, adding an oxidant into the obtained filtrate, performing heating, removing the corrosion aid, adding a precipitating agent into the filtrate, controlling the pH value of the filtrate, and performing solid-liquid separation to obtain a ferric hydroxide precipitate and a nickel-containing filtrate; and performing extraction and back extraction on the nickel-containing filtrate to prepare battery-grade nickel sulphate. According to the present invention, the nickel-iron is subjected to oxidation acid dissolution in cooperation with the corrosion aid under the high-pressure oxygen and acidic conditions; the nickel-iron is extremely prone to oxidation in the high-pressure oxygen environment; and a strong oxidant is added into the filtrate subsequently, so that ferrous ions in the filtrate are completely converted into ferric ions, and the corrosion aid can be oxidized to generate pollution-free carbon dioxide and water, thereby avoiding the impact of the corrosion aid on the subsequent extraction process.