Application Cases

In the production and recycling of lithium-ion battery cathode materials, mixed wastewater rich in sodium sulfate and lithium sulfate is generated. This wastewater has a complex composition and high salt content, and traditional treatment methods often only allow it to be disposed of as hazardous waste, which is not only costly but also results in a significant waste of sodium and lithium resources. Faced with the urgent need for sustainable development in the lithium battery industry and increasingly stringent environmental regulations, a well-known lithium battery material manufacturer commissioned Conqinphi to design and build an industrial-grade solution capable of simultaneously recovering high-purity sodium sulfate and lithium sulfate from wastewater.

In the process of lithium battery recycling and cathode material production, a complex and highly corrosive lithium-containing waste electrolyte is generated. This electrolyte contains highly valuable lithium, but also contains impurities such as aluminum and iron, as well as fluorides. Traditional treatment methods result in low recovery rates, high costs, and are prone to secondary pollution. Faced with this common industry challenge, a leading battery recycling customer of Conqinphi urgently needed a dedicated system capable of efficiently and stably removing impurities from aluminum electrolyte and enriching and recovering lithium resources.

With the rapid development of the lithium battery industry, electrolyte recycling has become a crucial issue. Traditional electrolyte processing methods suffer from low lithium resource recovery rates, compromised electrolyte performance, and high energy consumption. A large lithium battery manufacturer faces a technological bottleneck in electrolyte recycling and urgently needs an innovative solution that can efficiently extract lithium while maintaining electrolyte performance.

Objectives: 1.Lithium recovery rate ≥98%, by-product Na₂CO₃·10H₂O reaching industrial grade; 2.Comprehensive energy consumption per ton of water ≤28 kWh, zero live steam replenishment; 3.System continuous operation ≥8,000 h/a, shutdown for cleaning ≤4 times/year; 4.Delivery cycle ≤4 months, 3-year warranty, full life-cycle service.

Facing this challenge, our company successfully designed, built, and put into operation this lithium carbonate MVR evaporation crystallization system with a processing capacity of 120 tons/day. This system, based on mechanical vapor recompression (MVR) technology, deeply integrates the physicochemical properties of lithium carbonate, achieving a high degree of efficiency, cost-effectiveness, and product quality in large-scale production, providing strong technical support for the client's sustainable development.

This bromine-phosphorus flame retardant manufacturer produces 23,000 tons of tetrabromobisphenol A and decabromodiphenyl ethane annually. The production process generates 5 m³/h of highly concentrated saline mother liquor with a complex composition: NaCl 12%, Na₂SO₄ 8%, sodium bromide 3%, zinc borate 1%, organophosphorus 0.5%, COD 20,000 mg/L, pH 1–2. The raw water is classified as HW18 hazardous waste, with an outsourced disposal cost of 2,800 RMB/ton and an annual cost of nearly 120 million RMB. The company urgently needs a comprehensive solution for "reduction of mixed salts + resource utilization".

Adhering to the circular economy concept of "turning waste into treasure," Kangqinfei designed and delivered a sodium chloride MVR evaporation crystallization system with a processing capacity of 3 tons/hour. This system employs mature mechanical vapor recompression (MVR) technology and precisely controls the crystallization characteristics of sodium chloride, successfully achieving the recovery of high-purity sodium chloride and near-zero wastewater discharge.

Based on a deep understanding of the characteristics of calcium chloride, Conqinphi designed and built a 2-ton/hour MVR forced circulation evaporation and concentration system for the client. This solution utilizes mechanical vapor recompression (MVR) technology as its core, combined with special anti-scaling and anti-corrosion designs, successfully concentrating the low-concentration calcium chloride solution to a high concentration, laying a solid foundation for subsequent resource utilization.

Addressing the client's pain points, Conqinphi customized a 2-ton/hour ammonium sulfate MVR evaporation crystallization system. The core of this solution is the use of MVR (Mechanical Vapor Recompression) technology, an advanced process, to achieve efficient, energy-saving, and environmentally friendly wastewater treatment and resource recovery.

The 15t/h CBS wastewater triple-effect evaporation and crystallization system is specifically designed for the production wastewater of CBS (N-cyclohexyl-2-benzothiazole sulfenamide), a rubber accelerator. A single unit has an evaporation capacity of 15t/h (360t/d), employing a "triple-effect cross-flow forced circulation + DTB staged crystallization" process. Steam consumption is ≤0.24t/t water, and the byproduct anhydrous Na₂SO₄ has a purity ≥99% and a whiteness ≥88, which can be directly supplied to ion-exchange membrane caustic soda enterprises, achieving zero discharge of CBS wastewater and high-value utilization of salt resources.

Conqinphi designed a 300t/d triple-effect evaporator for this client, suitable for wastewater from mixed processes involving accelerators M, DM, CZ, and NS. The designed evaporation capacity is 12.5t/h, employing a "triple-effect cross-flow forced circulation + low-temperature DTB crystallization" process. Steam consumption is ≤0.26t/t water, and the purity of byproduct Na₂SO₄ or NaCl is ≥98.5%, helping the client achieve the dual goals of "zero discharge" and resource recovery.

This system is supporting equipment for a newly built 30,000-ton/year RD (2,2,4-trimethyl-1,2-dihydroquinoline) production line of a rubber additives group. The designed processing capacity is 3500 t/d (145 t/h). It adopts an integrated process of "triple-effect forced circulation + DTB fractional crystallization + mother liquor enrichment and incineration," with steam consumption ≤0.25 t/t water, Na₂SO₄ purity ≥99%, RD residue calorific value recovery, and zero wastewater discharge, making it the world's largest zero-discharge RD wastewater treatment plant.

The 10t/h triple-effect sodium chloride evaporator is a continuous evaporation system specifically developed by Conqinphi for the rubber additives industry. It is suitable for high-NaCl mother liquor generated during the production of accelerators M, DM, and NS. The system has an evaporation capacity of 10t/h (240t/d) and employs a "triple-effect cross-flow + forced circulation + DTB crystallization" process. Steam consumption is ≤0.25t/t water, NaCl crystal purity is ≥99%, and whiteness is ≥85, making it directly usable as a feedstock for ion-exchange membrane caustic soda.

Project Background This agrochemical company is constructing a new 30,000-ton/year pyraclostrobin project, producing 8 tons/hour of saline wastewater as a byproduct. The wastewater composition is: Na₂SO₄ 15%, NaCl 12%, CODcr 800 mg/L.

In the pigment chemical industry, the treatment of saline wastewater has always been a crucial aspect of environmental protection and resource recycling for enterprises. A well-known pigment chemical company, specializing in the production of high-end organic pigments such as azo and phthalocyanine pigments, has an annual production capacity of 30,000 tons. During its production process, it generates a large amount of sodium chloride wastewater daily, with concentrations fluctuating between 8% and 15%.

Based on steam price of 180 yuan/t and electricity price of 0.65 yuan/kWh, the four-effect compressor saves approximately 11 million yuan annually in steam costs; resource utilization of miscellaneous salts generates an additional 9 million yuan annually. Carbon reduction per ton of water is 0.32tCO₂, resulting in a total annual emission reduction of 48,000 tons.

The 10t/h sodium sulfate and lithium sulfate MVR evaporation crystallization system is another milestone for our company in the field of "zero discharge" of high-salt waste liquid in rare earth functional materials.