Ternary Precursor Liquor at pH 2 to 3: Oil Below 2 ppm Without Activated Carbon
New-energy battery chemistry has quietly imported a wastewater problem into the chemical plant. Ternary precursor liquor - the saturated sulfate solution from which nickel-cobalt-manganese cathode materials are grown - must be scrupulously clean, yet the organic solutions introduced during production leave it carrying oil and total organic carbon (TOC) that directly degrade the properties of the finished material. The liquor itself is aggressive: various saturated sulfates dominate the composition and pH sits between 2 and 3. Reducing oil and TOC without disturbing the ionic balance is therefore not a generic water treatment job but a product-quality operation.
What the activated carbon route really costs
Most existing processes answer the problem with conventional adsorption: activated carbon plus resin. The approach works chemically, and that is about the only kind thing that can be said for it at production scale.
Product requirements force the use of coconut-shell activated carbon and special resins, both expensive consumables rather than ordinary plant media. Once saturated, spent carbon is classified as hazardous waste and must be handed to an external contractor for disposal, a recurring liability that grows with every campaign. Operation is relentless - the carbon saturates and must be replaced every two days, which effectively demands staff on permanent duty around the replacement schedule. Resin regeneration then adds its own hazard: the process requires ethanol, so the site carries flammable-solvent handling requirements, safety reviews and a degree of risk that has little to do with the wastewater itself.
There is a quieter technical flaw as well. Activated carbon and resin barely remove TOC from this liquor, so the parameter that matters most for material properties stays largely unaddressed.
The CDOF route for precursor liquor
The answer from SINOKLE is CDOF, an integrated ozone flotation unit, running with an independently developed modified heterogeneous ozone catalyst. The process removes oil and TOC thoroughly without disturbing the liquor's ionic composition or impairing its purity - the constraint every alternative fails - and drives oil content, dissolved oil included, below 2 ppm, with TOC removal above 60%.
The mechanism layers two actions. Catalytic ozonation, hydraulic cyclonic separation and flotation-based oil removal operate together, while the specially modified heterogeneous catalyst adsorbs and catalytically oxidises oil and TOC simultaneously. Adsorption concentrates the organics onto the catalyst surface; ozone oxidation then decomposes them, dissolved oil is released and separated through demulsification, and both oil removal and TOC degradation proceed rapidly without reagents dissolving into the product liquor.
The advantages, point by point
- Multiple technologies working together - a combination that is a domestic first and internationally leading in this application.
- High ozone utilisation with low energy consumption, holding operating cost to 1/3-1/2 of activated carbon or resin adsorption, with no hazardous waste generated.
- No chemical agents added and no secondary pollution produced, so downstream crystallization and material formation are unaffected.
- Fast treatment with short residence time and a small equipment footprint.
- Enclosed, pressurised operation with no ozone leakage - safe for the site and without impact on neighbouring operations.
- Fully automatic intelligent control with remote guidance, removing the need for a dedicated operator.
- A new acid-resistant catalyst that works under the liquor's acidic conditions without introducing metal contamination.
- Verified end results: oil below 2 ppm including dissolved fractions, and TOC removal above 60%.
Why purity tolerates no shortcuts here
It is worth spelling out why the ionic composition constraint dominates the whole design space. Precursor liquor is not a waste stream being cleaned for discharge; it is an intermediate product on its way to becoming cathode material. Any reagent dissolved into the liquor, any metal leached from a catalyst surface, any change in the sulfate matrix shows up downstream as impurity incorporation or crystal defects in the finished powder. That is why processes that would be perfectly acceptable for ordinary industrial effluent - chemical oxidation with metal salts, solvent extraction, aggressive pH adjustment - are disqualified before their performance is even discussed. The treatment step must subtract oil and TOC and add nothing. This requirement, more than any flow consideration, is what pushes the industry toward adsorption today and toward processes like the one described here tomorrow.
Comparing the two ledgers
Set side by side with activated carbon plus resin adsorption, the differences compound quickly. Water treatment effectiveness is higher, especially on TOC, where the adsorption route barely performs. There is no frequent media replacement, so the two-day carbon cycle disappears along with the staffing it demands. Hazardous waste falls dramatically, since saturated activated carbon and non-regenerable resin are precisely the waste streams the conventional route manufactures. And cost lands at 1/3-1/2 of adsorption, before counting the safety value of eliminating ethanol handling.
Why this matters for the new-energy sector
Precursor quality decides cathode quality, and cathode quality decides battery economics. A treatment process that lowers oil and TOC while leaving the sulfate matrix untouched is therefore a process control improvement as much as an environmental one - it removes an uncontrolled variable from the crystallization step. Running fully automatically and enclosed, easy to operate and stable in performance, the CDOF route has broad application potential across new-energy material plants, wherever precursor liquor needs cleaning without compromise.