Status and development trends of paste disposal technology with ultra-fine unclassified tailings in China

Abstract

Currently, China mostly deals with ultra-fine unclassified tailings using surface low-concentration discharge or underground backfilling. The former requires too much time for tailings slurry to consolidate, and creates poor stability for the tailings dam, and the latter has concentration problem, which can cause segregation. At the present time, China is trying to develop surface paste discharge and paste filling technologies. The paper describes the evolution of surface paste disposal in China, analyses the application requirements and technical characteristics of surface paste disposal, and describes the progress of paste filling technologies in terms of tailings dewatering and thickening, mixing and preparation, and pipeline transport. Both the Wushan Copper Mine and Huize lead-zinc mine are typical of the mines in China to use relevant technology to deal with ultra-fine unclassified tailings. These mines have the largest scale of production and higher automisation respectively in surface paste disposal and paste filling, and achieve great application success. The paper analyses the problems existing in the application of paste disposal technology with ultra-fine unclassified tailings in China, which mainly include the limitation of equipment manufacturing ability and high investment in the surface paste stacking and filling, and the key technology is developing. It puts forward the development trends of paste disposal technology, which will make breakthroughs in terms of basic theories and specific equipment for unclassified paste disposal, the spread of qualification to adopt paste disposal technology, and co-disposal technology of tailings and rock dumps.