Advancing Cobalt Purity: Sunresin's Innovative Resin Technologies

Cobalt Refining and the Role of Ion Exchange Resins

With the cobalt industry increasingly turning to low-grade ores to reduce costs, the challenge of refining 

battery-grade cobalt sulfate has grown. These ores lead to intermediate products laden with impurities such as Cu, Zn, Fe, Mn, and Ni.

Process Steps in Preparing Battery-Grade Cobalt Sulfate:

1.Impurity Dissolution:Using dilute sulfuric acid.

2.Reduction Leaching: Extracting cobalt content from crude cobalt hydroxide using reduction agents.

3.Oxidation Precipitation: Removing specific impurities such as iron, manganese, and arsenic.

4.Calcium and Magnesium Removal: Employing ammonium fluoride for precipitation.

5.Deep Purification: Utilizing P204* extractant.

6.Sodium Removal and Cobalt-Nickel Separation: With P507*.

7.Reverse Extraction: Achieving cobalt sulfate with sulfuric acid solution.

*Extractants P204: di(2-ethylhexyl) phosphoric acid and P507: 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester

The impurity content in the cobalt solution after reverse extraction meets China national standards, making it suitable for battery-grade cobalt sulfate preparation.

However, a significant challenge arises from the presence of oil phase components in the raffinate and reverse extraction agent. These can compromise the purity and performance of the cobalt products.

These oil phases mainly consist of dispersed oil, dissolved oil, and emulsified oil. The challenge lies in removing dissolved oil and emulsified oil. The presence of emulsified oil, dissolved oil, and dispersed oil results in an oil content in the raffinate or reverse-extracted solution exceeding 200 ppm, which is significantly higher than the required specification.

The Role of Ion Exchange Resins in Quality Enhancement:

Removal of Oil Impurities:

• Suspended Oil: The resins are adept at adsorbing oil particles, ensuring their effective removal from the solution.

• Dissolved Oil: By addressing dissolved oil, the resins play a pivotal role in augmenting the purity and overall quality of the liquid.

Spotlight on Sunresin's Expertise: Sunresin leads the way with its specialized high-porosity polymer-based adsorption resins. Tailored for oil removal in aqueous solutions, these resins stand out due to their exceptional adsorption capacity, rapid adsorption rate, ease of regeneration, simple operation and long service life due to their excellent mechanical and chemical stability.

Broadening the Application Horizon: Sunresin's premium resins excel in eliminating impurities from the leaching solution, marking a significant reduction of TOC (residual P204, P507, sulfonated coal oil, etc.), COD (Chemical Oxygen Demand). This method is not only efficient but also environmentally conscious, ensuring no new impurities are introduced. The result? Enhanced economic value and benefits.

As the cobalt industry continues to evolve, pioneering solutions like Sunresin's are setting the gold standard for quality and sustainable practices.

The oil removal process can also be applied to the resourceful treatment of oily wastewater generated e.g. from extraction processes or oil removal in various liquids.

Elevate Your Production Quality with Sunresin!

Curious about our high-porosity polymer-based resins? Head to our homepage to learn more about our innovations and their impact.

Sunresin offers a wide range of polymeric adsorbents and chelating resins as well as solvent impregnated resins e.g. with Cyanex272 and D2EHPA.