With the increasing use of low-grade cobalt ores as the main raw material in the cobalt industry, many companies are processing these ores via hydrometallurgical methods to produce cobalt intermediates, aiming to reduce costs. However, these cobalt intermediates often contain high levels of cobalt, zinc, manganese, and other elements. After acid leaching, it is necessary to remove impurities to prepare battery-grade cobalt sulfate.
Battery-Grade Cobalt Sulfate Production Process: The process to produce battery-grade cobalt sulfate from coarse cobalt hydroxide involves several steps:
Dilute sulfuric acid leaching to remove impurities.
Reduction leaching followed by oxidative precipitation to remove iron, manganese, and arsenic.
Ammonium fluoride precipitation to remove calcium and magnesium.
P204 extraction for deep purification and impurity removal.
P507 extraction to remove sodium and separate cobalt from nickel.
The cobalt-loaded organic phase is then subjected to sulfuric acid stripping to obtain cobalt sulfate, which is used to produce battery-grade cobalt sulfate.
Challenges in Cobalt Battery Recycling Process: Currently, with the widespread retirement of power batteries, cobalt-containing battery waste mainly comes from used lithium cobalt oxide (LiCoO2) batteries and nickel-cobalt-manganese (NCM) lithium batteries. The recycling process for cobalt-containing battery waste to produce battery-grade cobalt sulfate involves two main stages:
Physical process: This is the pre-treatment stage for waste lithium-ion batteries, which involves mechanical treatment, thermal treatment, and mechanochemical methods to strip and separate the cathode materials from used lithium-ion batteries.
Chemical process: This stage involves the recovery of cathode materials from the waste lithium-ion batteries and includes processes like acid leaching, bio-leaching, solvent extraction, and electrochemical treatment.
After removing impurities such as iron, copper, and aluminum from the leachate, extractants are used to separate and purify various metal ions (manganese, cobalt, nickel) in different pH ranges. During the extraction of transition metals, these metals exist in the organic phase in the form of organic complexes. After stripping, the cobalt solution has a low level of impurities, meeting national standards and suitable for the preparation of battery-grade cobalt sulfate.
However, because the organic phase contains hydrophilic groups, the extract raffinate and stripped solution often carry oil phase components. If these oil phases are not removed, they can affect the purity and performance of the final cobalt product. These oil phases mainly consist of dispersed oil, dissolved oil, and emulsified oil. The difficulty in removal lies in the dissolved oil and emulsified oil.
Due to the presence of emulsified oil, dissolved oil, and dispersed oil, the oil content in the raffinate or stripped solution can exceed 200 ppm, which is far above the required limits for further use.
Southwind Technology’s Oil Removal Resin Application: Southwind Technology has developed the XDA Series Oil Removal Resin, a high molecular, porous adsorption resin. This resin uses its oil-loving, hydrophobic properties (through special high-temperature resistant resin) to separate emulsified and dissolved oil molecules from water. It is specifically designed for oil removal in aqueous environments and offers excellent mechanical and chemical stability, high adsorption capacity, rapid adsorption rate, easy regeneration, and long service life.
Applications:
Petroleum refineries and petrochemical facilities for removing oil from steam condensates.
Other units using petroleum products for oil removal.
Water contaminated by hydrocarbons.
This oil removal resin helps maintain the purity and performance of cobalt products during the extraction process, ensuring efficient and sustainable operations.
Oil Removal Process
Application of XDA Series Resin
The XDA series resin can be used in the following applications:
- Processing various oil-containing raffinate or stripped solutions.
- Removing impurities in the leachate, particularly for cobalt sulfate and nickel sulfate solutions, by eliminating TOC (Total Organic Carbon), including residues from P204, P507, and sulfonated kerosene. The TOC can be reduced to below 20 mg/L.
- It can also be applied in the resource recovery treatment of oil-containing wastewater generated from the extraction process.
- The resin is used for oil removal in various leachates, with desorption and regeneration using steam or alcohol, ensuring that no new impurities are introduced into the solution.