MVR Evaporator for Lithium Sulfate Concentration

Project Background

In the production of lithium carbonate from spodumene, the purified leach solution after acid roasting and leaching contains lithium primarily in the form of lithium sulfate (Li?SO?), typically at a concentration of around 100?g/L. This concentration is too low for efficient lithium precipitation. Therefore, it is necessary to concentrate the solution to around 200?g/L before lithium carbonate precipitation can occur efficiently.

Among evaporation and crystallization technologies, MVR (Mechanical Vapor Recompression) technology stands out for its low energy consumption and significant advantages in handling various salts. With proper design and application, it can efficiently perform the evaporation and crystallization of salt-containing solutions derived from different battery raw materials. 

Working Principle of MVR Evaporator

MVR (Mechanical Vapor Recompression) evaporators recycle and compress the secondary vapor generated during evaporation using a mechanical compressor. This compressed vapor is then reused as the heating medium in the evaporation process, significantly reducing the need for fresh steam. MVR systems are highly energy-efficient, environmentally friendly, and ideal for continuous large-scale operations.

Application in Lithium Sulfate Concentration

a. Process Objectives

– Concentrate lithium sulfate from approx. 100?g/L to over 200?g/L;

– Achieve Li?O concentrations above 60?g/L;

– Minimize lithium loss during concentration;

– Minimize energy consumption.

b. System Configuration

The MVR evaporator system for lithium sulfate concentration consists of the following components:   

? Condensate preheater

? Exhaust vapor preheater

? Exhaust condenser

? Forced circulation heater

? Liquid-vapor separator

? Vapor scrubber

? Steam compressor(MVR)

? Pump group

? Piping system

? Electrical control system

These components work together to concentrate the lithium sulfate feed solution to the desired concentration, providing a stable and continuous stream for the subsequent process.

Conclusion

MVR (Mechanical Vapor Recompression) technology plays a vital role in the battery material production chain, particularly in the evaporation and crystallization stages. Its low energy consumption, high operational efficiency, and environmental benefits make it a preferred solution for concentrating and purifying lithium sulfate, cobalt sulfate, nickel sulfate, and other battery-related compounds. With proper system design and stable operation, MVR technology not only ensures consistent product quality but also contributes to reducing overall production costs and carbon footprint—supporting the sustainable growth of the battery industry.