One brine in. Five salts out, each one on spec.
Fractional crystallization stands between a plant that produces landfill waste and one that produces a product. The difference is not the evaporator. It is everything decided before it.
What is fractional crystallization for ZLD?
Fractional crystallization is the process that turns a mixed industrial brine into separate, single-species salts rather than one mixed solid.
Evaporation and crystallization are applied selectively, so each salt comes out on its own and to a specification a buyer will accept.
Z-CRYST is the process that surrounds that stage: source segregation, water reuse, brine concentration, organic purification, and only then crystallization.
Mixing is the expensive decision
Blend a clean stream with a dirty one and you have just doubled the water that needs the costly treatment.
A plant does not produce one wastewater. It produces several, and they are not equally difficult. Cooling blowdown and demineralization regenerant are relatively clean. Process effluent is not. Combining them in one header is convenient, and it is the most expensive convenience in the plant.
So Z-CRYST starts before the brine system. Production wastewater and clean wastewater are treated and reused on their own routes. Only what genuinely cannot be reused becomes brine. The brine system is the costly part of a ZLD plant, and the cheapest way to cut that cost is to send less to it.
Two water routes, one brine system
Production wastewater goes through biological pretreatment, advanced treatment and its own reuse system. Clean wastewater goes through physicochemical pretreatment and its own reuse loop. Both return reuse water to the plant.
What is left of each becomes the feed to the brine system, and there the three core packages run in series: concentration, purification, then selective crystallization.
Why the order cannot change
01 HiBARS™ — concentrate before you evaporate
Membranes concentrate the brine well past conventional limits. Every cubic meter removed here never reaches the evaporator. Evaporation is the largest energy cost in the plant.
02 OROX™ — purify before you crystallize
Refractory organics are separated out and only then oxidized. Organics left in the brine stain whatever crystallizes. That is exactly how a plant ends up with salt nobody will buy.
03 SERECS™ — separate before you dry
Nanofiltration, thermal or freeze separation splits the ions according to the feed chemistry. Each salt then crystallizes on its own. This is the step that produces a product instead of a mixture.
Reverse that order and the process fails quietly. Crystallize before purifying and the salt is stained. Evaporate before concentrating and the energy bill triples. The sequence is the technology. That is why we describe these as one process rather than three products, and the same logic runs through our zero liquid discharge work.
Sodium chloride, sodium sulfate, potassium chloride, potassium sulfate and ammonium sulfate. Each is crystallized on its own, and each meets a national product standard.
Which of them appear on a given project comes out of your ion balance, not out of a catalog.
Where it is applied
Coal and fine chemicals
Coal-to-gas, coal-to-liquids and coal-to-olefins plants. High-salinity brine and strict reuse requirements arrive together.
Mining and metallurgy
Mine water and smelting effluent, where sulfate dominates and the sodium sulfate route pays for itself.
Industrial parks
Sites managing several tenants' water under one system. Source segregation is the difference between a viable brine plant and an unaffordable one.
Frequently asked questions
What is fractional crystallization?
Fractional crystallization turns a mixed industrial brine into separate, single-species salts. Evaporation and crystallization are applied selectively, so sodium chloride, sodium sulfate and the potassium salts come out individually rather than as a blend.
Why not just evaporate the brine to dryness?
Because a mixed salt has no market. Everything dissolved crystallizes together, including the organics, and the result is a hazardous waste. Separating the ions before crystallization is what makes the solid a product.
Why treat production and clean wastewater separately?
Because mixing them multiplies the volume that needs expensive treatment. A clean stream blended with a dirty one inherits its problems. Segregating at source keeps the brine system small, and the brine system is the costly part.
Which salts can be produced?
Sodium chloride, sodium sulfate, potassium chloride, potassium sulfate and ammonium sulfate. Which appear on a given project depends on the ion balance of the feed, not on the equipment we prefer to sell.
What purity is achieved?
Sodium chloride at 97.5% or better and sodium sulfate at 99.0% or better, both against Chinese national standards. The potassium salts and ammonium sulfate are produced to their own standards. These are product specifications, not laboratory results.
How is the separation route chosen?
From the feed chemistry. Nanofiltration, thermal and freeze separation each suit different ion balances, energy prices and product specifications. The route is selected per project, so there is no single answer that fits every water.
Send us your ion balance
Start here
The salts your brine can produce are already fixed by its chemistry. Send the analysis. We will tell you which ones, at what purity, and what the route costs to run.
Useful to include
- Brine flow and TDS
- Full ion balance, especially chloride and sulfate
- COD, and whether the organics are refractory
- Which streams are currently combined
- Any off-take market for salt near the site
Contact us directly
- info@jing-yu.com
- Phone
- +86 21 6593 0816
- Office hours
- Monday to Friday, 9:00 to 18:00 Shanghai time (GMT+8)