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At VNOR, we are more than just a project builder but a pioneer of technological innovation in MVR evaporation and crystallization. The MVR evaporation and crystallization technology distinguishes itself through its energy efficiency and minimal environmental impact. By recompressing and reusing vapor, our systems significantly reduce energy consumption compared to traditional methods, making them both cost-effective and eco-friendly.
At VNOR, we specialize in MVR (Mechanical Vapor Recompression) evaporation and crystallization technology, offering advanced solutions tailored to the unique needs of our clients. Our long term collaboration with BYD, a global leader in electric vehicles, highlights our expertise across five projects.
Each device we crafted for BYD was tailored to meet specific production needs, showcasing our ability to deliver custom solutions. Our team worked closely with BYD to understand their unique requirements, ensuring that each device was optimized for maximum efficiency and output quality.
In our first project, we developed a highly efficient lithium sulfate cooling and crystallization system. This solution was designed to meet BYD's specific requirements for purity and efficiency, ensuring a high-quality end product essential for their battery manufacturing process.
Commissioning date: March 2014
Designed capacity: processing capacity 1000kg
Feedstock: Sodium Sulfate Wastewater
Evaporator type: Double Effect Evaporator
The sodium precipitation requirement of the saturated lithium sulfate & sodium hydroxide mixed solution is to obtain a crude lithium hydroxide solution with a sodium ion content of less than 2% after two stages of cooling and sodium precipitation, and the obtained sodium sulfate decahydrate crystal contains lithium ions less than 1000ppm.
*Using double-stage freezing crystallization equipment to obtain sodium sulfate decahydrate.
Key Equipment:
1. Crystallizer
The primary vessel where the solution undergoes crystallization. It's insulated to maintain stable temperatures and lined with glass flakes to prevent crystals from adhering to the walls.
2. External Cooler (External Cooler)
It helps in controlling the temperature of the solution. Allows for valve-free operation which facilitates maintenance.
3. Axial Flow Circulation Pump
Keeps the solution moving consistently through the system. Ensures even distribution and temperature consistency.
4. Material Turnover Pumps and Tanks:
These are used for moving materials in and out of the system smoothly.
5. Krystal Crystallizer (or OSLO Crystallizer)
This specialized type of crystallizer is designed to minimize the formation of crystal buildup on the walls. Facilitates the separation of crystallization stages within the vessel.
Key Stages of the Process:
1. Feeding the Solution
The process starts with continuously feeding the solution into the crystallizer.
2. Rapid Cooling
The solution is quickly cooled to 0°C, initiating the crystallization process.
3. Maintaining Metastable Zone
The concentration of the solution is controlled to stay within a metastable zone. This is crucial for uniform crystal growth and avoiding rapid, uncontrolled nucleation (formation of new crystals).
4. Continuous Operation
The system operates continuously, with materials consistently fed in and out.
5. Filtering and Recovery
The resulting crystal slurry is filtered to extract sodium sulfate decahydrate. The system includes a mechanism to recover some of the cold energy, improving efficiency.
6. Separation and Final Processing
The mother liquor (the liquid remaining after crystal removal) is still supersaturated and needs further processing.
It is sent to a thickener to reduce supersaturation, followed by a centrifuge for solid-liquid separation.
Based on the success of the first project, our second venture involved a continuous evaporation and crystallization system for lithium sulfate. This project showcased our capability to handle large-scale production needs, significantly boosting BYD's production capacity.
Commissioning date: March 2014
Designed capacity: processing capacity 2000kg/h
Feedstock: Lithium Sulfate Product
Evaporator type: Double Effect Evaporator
The sodium precipitation requirement of the saturated lithium sulfate & sodium hydroxide mixed solution is to obtain a crude lithium hydroxide solution with a sodium ion content of less than 2% after two stages of cooling and sodium precipitation, and the obtained sodium sulfate decahydrate crystal contains lithium ions less than 1000ppm.
*Using double-effect evaporation crystallization process.
Double-effect evaporation concentration and crystallization equipment are used, which mainly uses steam heating to evaporate water from the solution to achieve the purpose of concentration or crystallization. It is mainly composed of a heating chamber and an evaporation chamber.
The heating chamber provides the heat required for the evaporation of the liquid, causing the liquid to boil and vaporize; the evaporation chamber completely separates the gas and liquid phases. The steam generated in the heating chamber carries a large amount of liquid foam. After reaching the evaporation chamber with a larger space, these liquids can be separated from the steam through their condensation. A demister is usually installed on the top of the evaporation chamber to eliminate mist entrainment.
Our third project focused on lithium hydroxide, a critical component in battery manufacturing. We delivered a high-capacity evaporation and crystallization system, ensuring consistent quality and scalability to meet growing market demands.
Commissioning date: September 2014
Designed capacity: processing capacity 10000kg/h
Feedstock: Lithium Carbonate Product
Evaporator type: Triple Effect Evaporator
In the process of extracting lithium from ores using the sulfate method, a multi-stage process such as grinding, conversion roasting, acidification, leaching, purification, and filtration is required to obtain a relatively clean dilute lithium sulfate solution. Lithium sulfate crystals can be obtained through evaporation and crystallization of the solution.
*Although the technical key is the same as Project 2, this time the three-effect evaporation and crystallization process is used, and the production capacity is greatly increased.
This equipment is a complete set of three-effect evaporation, concentration, and crystallization equipment. The heat exchange heat source is steam and the material flows through it. The first effect, the second effect, and the third effect are both forced circulation, but the separator of the third effect evaporator is designed in the Oslo form for the crystallization of lithium sulfate monohydrate.
A cleaning port should be provided at the sight glass of the crystallizer to flush away the accumulated crystals on the sight glass, or the sight glass should be designed to prevent crystal accumulation. After the crystals are discharged, they enter the thickener and are then separated by a two-stage pushing centrifuge. The mother liquor is collected by the mother liquor tank and returned to the crystallizer.
In this project, we further enhanced the lithium hydroxide production process with a cutting-edge multi-effect evaporation system. This innovation allowed for even greater efficiency and sustainability in BYD's operations, setting a new standard in the industry.
Commissioning date: January 2016
Designed capacity: processing capacity 28000kg/h
Feedstock: Lithium Hydroxide Product
Evaporator type: Four-Effect Combined Evaporator
Lithium hydroxide monohydrate is one of the most important lithium compounds. It is mainly used to produce lithium-based grease and can also be used to produce other lithium compounds. It is an additive for alkaline battery electrolytes.
*Although the technical key is the same as Project 2, this time the three-effect evaporation and crystallization process is used, and the production capacity is greatly increased.
This equipment is a complete set of three-effect evaporation, concentration, and crystallization equipment. The heat exchange heat source is steam and the material flows through it. The first effect, the second effect, and the third effect are both forced circulation, but the separator of the third effect evaporator is designed in the Oslo form for the crystallization of lithium sulfate monohydrate.
A cleaning port should be provided at the sight glass of the crystallizer to flush away the accumulated crystals on the sight glass, or the sight glass should be designed to prevent crystal accumulation. After the crystals are discharged, they enter the thickener and are then separated by a two-stage pushing centrifuge. The mother liquor is collected by the mother liquor tank and returned to the crystallizer.
Our fifth collaboration marked a significant milestone, introducing MVR evaporator technology to their lithium hydroxide production line. This project not only enhanced production efficiency but also committed to sustainable and environmentally friendly manufacturing practices.
Commissioning date: June 2017
Designed capacity: processing capacity 21000kg/h
Feedstock: Lithium-bearing Mother Liquor
Evaporator type: Forced MVR Evaporator
Lithium hydroxide monohydrate is one of the most important lithium compounds. It is mainly used to produce lithium-based grease and can also be used to produce other lithium compounds. It is an additive for alkaline battery electrolytes.
*This project is the first time to use MVR evaporator technology since Zhejiang Huannuo and BYD have cooperated several times.
Key Components of the DTB Crystallizer:
1. DTB Crystallizer
The main vessel where the crystallization process occurs.
2. Propeller and Circulation Pump
Drive the solution upwards and maintain circulation within the crystallizer.
3. Annular Channel
A pathway along which the solution flows inside the crystallizer.
4. Guide Tube
Directs the solution and facilitates internal circulation.
5. External Tube Heat Exchanger
Cools the solution by removing heat.
6. Sight Glass with Cleaning Port
Allows observation of the process and can be cleaned to prevent crystal accumulation.
7. Discharge Pump
Used for removing the crystal slurry from the crystallizer.
8. Two-Stage Pushing Centrifuge:
Separates the crystals from the mother liquor.
9. Mother Liquor Tank
Collects and stores the mother liquor for reuse or disposal.
Key Stages of the Crystallization Process:
1. Initial Solution Addition
The solution to be treated is added to the DTB crystallizer.
2. Circulation and Mixing
Driven by the propeller and circulation pump, the solution rises to the liquid surface, then flows down along the annular channel and is sucked back up, creating a high-speed, repeated internal circulation.
3. Enhanced Production Capacity
The fully mixed feed liquid within this circulation system enhances the crystallizer's production capacity.
4. Heat Removal and External Circulation
The external tube heat exchanger cools the solution. The cooling liquid removes heat from the clarified mother liquor and sends it back to the bottom of the crystallizer, forming an external circulation channel.
5. Crystallization and Separation
The crystal slurry is discharged from the bottom of the crystallizer, then separated in a two-stage pushing centrifuge and dried.
6. Handling of Mother Liquor
The clarified mother liquor is either recycled back into the crystallizer after impurity removal and thickening or directed to the next process step.
7. Maintenance and Observation
The sight glass, equipped with a cleaning port, allows for monitoring of the process and easy maintenance.
Expertise in MVR Technology: Our team consists of seasoned experts in MVR evaporation and crystallization, equipped with deep knowledge and hands-on experience.
Customized Solutions: We believe in a bespoke approach, understanding that each client has unique needs and challenges.
Sustainability Focus: Our technology is designed to minimize environmental impact, aligning with global sustainability goals.
Proven Track Record: The successful BYD project is a clear example of our capability to handle large-scale, complex projects with precision and excellence.
We are proud of our collaboration with BYD and are excited about the potential of our technology in further advancing the electric vehicle industry and beyond.
If you are looking for a partner who can provide advanced, customized, and sustainable MVR evaporation and crystallization for lithium extraction or other solutions, contact us, VNOR will never let you down.
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