Application of improved mechanical vapor recompression evaporator in treatment of coal mine ultra-high salinity concentrated water

Abstract

The reverse osmosis process is a commonly used process for treating high salinity mine water at present. After concentration and separation，this process will produce ultra-high salinity sodium chloride and sodium sulfate concentrated brine. This concentrated brine can only be discharged after evaporation and crystallization treatment. The traditional evaporation and crystallization process has limited its application due to its high energy consumption. In recent years，the MVR evaporation crystallization process with relatively low energy consumption has been widely used at home and abroad. Based on the MVR process，the evaporator was improved to further improve the heat transfer efficiency by adding a raw liquid preheater made of high-temperature superconducting materials in response to the ultra-high salinity characteristics generated by the concentration of coal mine water. The improved MVR evaporator（150 kg/h） was applied to the application test of ultra-high salinity concentrated water in Xiaojihan Coal Mine，Shaanxi Province. The heat transfer area has increased from 2.80 m2 to 4.89 m2，and the steam consumption has decreased from 179.40 kg/h to 149.85 kg/h，saving 30 kg of steam per hour，equivalent to about 2.8 kg of standard coal. The energy-saving and carbon emission reduction benefits are significant.

Keywords

• high salinity mine water
• evaporative crystallization
• mechanical vapor recompression
• energy consumption analysis