Environmentally friendly hydrometallurgical methods: Introduce a process for the high selective separation of cobalt from nickel-cobalt mixtures using an undiluted ionic liquid
Use a kind of undiluted ionic liquid extraction agent to separate cobalt and nickel in hydrochloric acid medium to achieve green solvent extraction.
Cobalt was extracted to the ionic liquid organic phase in a cobalt tetrachloride complex, while nickel, magnesium and calcium were left in the aqueous phase.
The advantage of this ionic liquid extraction process is that does not need to add any organic diluent to prepare the organic phase, can make the extraction process safe and environmentally friendly.
The cobalt/nickel separation coefficient will reach more than 50000 when the aqueous phase contains 8M chloride ions.
When cobalt is extracted into the ionic liquid phase, the cobalt can be easily extracted with water and the ionic liquid can be reused. Then the reaction process of continuous extraction can be realized.
The maximum capacity of cobalt can be up to 35 g/L-1 (In practical extraction process can’t use such high capacity).
When the distribution coefficient is more than 100, can use sodium chloride or sea water to supply the chloride ions.
Phosphorus ion liquid, such as three hexyl myristyl phosphorus chloride, tributyl myristyl phosphorus chloride, four (octyl) bromide phosphine, three hexyl alkyl brominated phosphorus 14. Now three octyl methyl ammonium chloride has been used in business experiment to extract cobalt from chloride medium, consider the commercial availability and comprehensive performance, finally choose three hexyl myristyl phosphorus chloride (Cyphos IL 101) as the best Ionic liquid extractant for cobalt and nickel.
Normally Ionic liquids is colorless, tasteless, non-flammable, stable substances, with a high viscosity at room temperature, for some metal ions has a high solubility (with a high distribution coefficient).
Only the physical properties of colorless, odorless and non-flammable, a lot of hydrometallurgical worker will be glad to use it.
We, Zhengzhou Deyuan Fine Chemicals Co., Ltd., had started small-scale production and offered to major domestic customers for pilot test.
Hope we will begin to do mass production soon, then will update the process greatly in metal extraction industry.