5t/h lithium battery MVR evaporator

A new energy technology company located in East China primarily engages in the resource recycling of spent power batteries. With capacity expansion, its hydrometallurgical production line generates approximately 120 tons of low-concentration lithium-containing mother liquor daily, containing lithium sulfate, sodium sulfate, and trace amounts of nickel, cobalt, and manganese ions. Direct discharge of this liquor wastes lithium resources and creates environmental pressure. To address this, the company partnered with Kang Jinghui in 2024 to construct a dedicated lithium-ion battery MVR evaporation crystallization system with a processing capacity of five tons per hour. This system is used for mother liquor concentration and lithium salt recovery, achieving a win-win situation for both economic and environmental benefits.

The core equipment of this project is a five-ton-per-hour falling film MVR evaporation crystallizer, equipped with a forced circulation crystallizer, centrifugal separator, and mother liquor reflux system. The main body of the equipment uses a composite structure of titanium and duplex stainless steel to withstand the corrosion of sulfate ions in the lithium-containing mother liquor. The evaporator heating chamber has a heat exchange area of approximately 380 square meters. Secondary steam is compressed by a centrifugal steam compressor and heated to approximately 12 degrees Celsius, then recycled as a heat source. The system feeds a low-concentration lithium-containing solution obtained from wet extraction, with a lithium-ion concentration of approximately 8 to 12 grams per liter. After preheating, the solution enters the MVR evaporator for concentration. Once the solution density reaches the set value, it is transferred to the crystallizer, where a mixed salt of lithium sulfate and sodium sulfate is precipitated through evaporation and crystallization. After centrifugation, the solid water content is less than 5%, and the mother liquor is returned to the system for continued circulation.

This lithium-ion battery MVR evaporator incorporates several optimized designs tailored to the material characteristics of the battery recycling industry. First, the top of the evaporator is equipped with a dual demisting device consisting of a high-efficiency wire mesh demister and a cyclone separator, effectively intercepting tiny droplets entrained in the secondary steam and preventing impurity ions such as nickel, cobalt, and manganese from migrating with the steam, thus ensuring the purity of the lithium salt product. Second, the system operates under full negative pressure, with the evaporation temperature controlled between 65 and 75 degrees Celsius, reducing the scaling tendency of lithium sulfate at high temperatures and decreasing the equipment corrosion rate. Third, the crystallization section features online density monitoring and automatic discharge control, achieving continuous and stable operation and significantly reducing the frequency of manual intervention compared to traditional intermittent crystallization. Furthermore, the compressor employs variable frequency speed control, automatically adjusting the steam compression rate based on fluctuations in feed concentration to maintain system thermal balance and enhance operational flexibility.

Since its commissioning, the 5-ton-per-hour lithium-ion MVR evaporator has operated stably, with all technical indicators meeting design expectations. The system consumes approximately 35-40 kWh of electricity per ton of water evaporated, equivalent to less than one-third of the standard coal consumption of traditional triple-effect evaporation processes, resulting in annual steam cost savings exceeding six million yuan. The overall lithium recovery rate has increased from approximately 82% before the upgrade to over 96%, with an annual increase in lithium salt production equivalent to approximately 300 tons of lithium carbonate. The evaporation condensate meets workshop reuse standards and is entirely returned to the upstream leaching process, achieving near-zero discharge of production water. The equipment operates for over 7,200 hours annually, with fewer than two unplanned shutdowns per year, ensuring controllable maintenance costs.

The successful implementation of this project provides a replicable wastewater resource recovery solution for small and medium-sized lithium battery recycling companies. With a processing capacity of five tons per hour, the equipment matches the mother liquor output of a medium-capacity wet process production line while avoiding excessive investment. Occupying approximately 200 square meters, it can be flexibly integrated into existing plant areas. By converting low-value lithium-containing wastewater into reusable lithium salt products and process water using MVR technology, companies not only mitigate environmental compliance risks but also build a cost advantage in a market environment of fluctuating lithium resource prices. With the arrival of the peak period for the retirement of power batteries, this type of dedicated MVR evaporation and crystallization equipment will play an increasingly important supporting role in the lithium battery circular economy industrial chain.