Recently, the "demonstration project of pretreatment of wastewater with high manganese salt, high ammonia nitrogen and high hardness" of Daxin Manganese Mine Branch of Guangxi Dameng Company undertaken by Tianjin Seawater Desalination and Comprehensive Utilization Research Institute of the Ministry of Natural Resources (hereinafter referred to as "the Desalination Institute" for short) successfully passed the acceptance with the precipitation recovery rate of manganese ion in wastewater exceeding 99% and the average processing cost 25% lower than the agreed cost.

　　As the first electrolytic manganese tailing percolate resource recycling project in China, the  "demonstration project of pretreatment of wastewater with high manganese salt, high ammonia nitrogen and high hardness" aims to realize tailing percolate resource recycling and environment-friendly discharge. Based on the patent technologies developed in the field of comprehensive utilization of high salinity wastewater for many years, and aiming at the characteristics of the electrolytic manganese tailing percolate, that is "high manganese, high hardness, high ammonia nitrogen, and large fluctuation of water quantity and composition", the Desalination Institute has formed the overall process route of "regulating crystallization - fractional extraction - water purification", so as to realize finally the fractional extraction and recycling of manganese, calcium and magnesium resources, reduce the quantity of by-product residue, improve the reaction efficiency, reduce the material input and energy consumption, and thus reduce the treatment cost.