Method for reduction leaching of cobaltic materials by sulfur dioxide

Abstract

A method for reduction leaching of cobaltic materials by sulfur dioxide includes the steps: adding the materials subjected to ball milling into an acid-resistant, alkali-resistant and temperature-resistant reaction vessel with a stirring function, adjusting liquid-solid ratio (mass percent of liquid / solid) of the materials in the vessel, adding concentrated sulfuric acid, feeding steam to increase material temperature so as to accelerate reaction, feeding sulfur dioxide gas into the cobaltic materials, and transferring valued metals (cobalt and copper) and metal impurities into a solution mixing system after the reaction in the vessel is carried out for sufficient time.

Description

technical field [0001] The invention belongs to the technical field of hydrometallurgy, and specifically relates to a method for reducing and leaching cobalt-containing materials by using sulfur dioxide. Background technique [0002] As an important strategic metal, cobalt is widely used in industrial and military fields. Since the 1990s, the rapid growth of cobalt consumption in the rechargeable battery industry, especially in the lithium-ion battery and nickel-metal hydride battery industry, has become the largest consumer of cobalt. With the continuous and stable growth of the world economy, the demand for cobalt will inevitably increase. will increase further. [0003] The current technological route of cobalt-containing material hydrometallurgy: cobalt-containing material→wet ball mill→acid reduction leaching→liquid-solid separation→solution purification and impurity removal→pure cobalt solution→cobalt salt (cobalt oxide)→solid slag (waste) ; Existing acid reduction l...

AI Technical Summary

Problems solved by technology

[0003]The current technological route of cobalt-containing material hydrometallurgy: cobalt-containing material→wet ball mill→acid reduction leaching→liquid-solid separation→solution purification and impurity removal→purified cobalt Solution → cobalt salt (cobalt oxide) → solid slag (discarded); the existing acid reduction leaching technology uses sodium sulfite or sodium metabisulfite as the reducing agent, and its chemical reaction equation is as follows: Co2O 3 + 2H2SO4 + Na2SO3 = 2CoSO4 + Na2SO4 + 2H2O; 2Co2O3 + 3H2SO4 + Na2S2O5 = 4CoSO4 + Na2SO4 + 3H2O, using sodium sulfite or sodium pyrosulfite as reducing agent, its The disadvantages are: 1. Sodium sulfite or sodium pyrosulfite brings a large amount of sodium ions into the system. After the reaction, sodium sulfate is formed in the solution, and it is easy to form co-crystallization with calcium sulfate and magnesium sulfate to block the pipeline, affecting the normal production of subsequent processes; 2. Sodium sulfite or sodium pyrosulfite brings in a large amount of sodium ions to form sodium sulfate, which brings a great burden to the subsequent sewage treatment; 3. Sodium sulfite or sodium pyrosulfite is a powder solid, and the feeding process is prone to powder flying, which is easy to cause environmental pollution; 4. When sodium sulfite or sodium pyrosulfite powder is dissolved in the solution, the reaction and operation time is prolonged; 5. Sodium sulfite or sodium pyrosulfite is used as a reducing agent, the price of unit sulfur is higher, and the corresponding production cost is higher

[0026] During the reaction process, 1 ton of metallic cobalt (calculated based on 90% trivalent cobalt) needs to add reducing agent sodium sulfite (96% Na2 SO3)=1.25 tons, the price of sodium sulfite is 2150 yuan / ton, the cost of cobalt reducing agent per ton is 2687 yuan; the reaction consumes 1.66 tons of sulfuric acid, the price of sulfuric acid is 500 yuan / ton, and the cost of sulfuric acid is 830 yuan / ton; Generated 1.53 tons of sodium sulfate. The generated sodium sulfate and the calcium sulfate and magnesium sulfate in the solution are very easy to form co-crystal precipitation in the subsequent pipelines and equipment, which affects the normal operation of subsequent production.