Heavy metal smelting wastewater can be reused

Recently, Hunan Provincial Science and Technology Major Special Project “Key Technologies and Engineering Demonstration for Energy Saving and Emission Reduction of Heavy Metal Smelting” led by Hunan University and Hunan Nonferrous Metals Holding Group Corporation has made progress. A number of technologies developed by this project are expected to create direct economic benefits of RMB 160 million per year for the Hunan Non-Ferrous Metals Holding Group, and will be promoted throughout the country. The annual direct economic benefits generated will exceed RMB 2 billion. In the province of Hunan Province, it will save at least 600,000 tons of standard coal and reduce carbon dioxide emissions by about 1.2 million tons annually.

The “Science and Engineering Demonstration of Key Technologies and Engineering Demonstration of Heavy Metal Smelting” project research team has broken through key technologies for the direct advanced treatment and reuse of high-concentration heavy metal smelting wastewater biological agents, and developed no secondary pollution for heavy metal biological agents. High concentration of heavy metal wastewater after biological treatment, the mercury, cadmium, arsenic, copper, lead, zinc and other heavy metals in drinking water reach the drinking water source water quality standard, the reuse rate of wastewater is higher than 95%, and the metal recovery rate in wastewater is more than 99%.

At present, the results of this project have been industrialized and demonstrated in companies such as Shuikoushan Nonferrous Metals Co., Ltd. and Zhuzhou Smelter, with significant results. Among them, one of the project's achievements is that the high-temperature lead slag electric heat direct reduction new technology was applied in Shuikoushan Nonferrous Metals Co., Ltd. The high lead slag discharged slag contained less than 3.2% lead and the comprehensive energy consumption per ton of crude lead was 380 kg. The reduction of coal to 280 kilograms of standard coal is expected to save about 10,000 tons of coke per year for the Shuikoushan Group. The Zhuzhou Smelter uses the project's new technology to perform advanced treatment of smelting wastewater, which can reduce wastewater discharge by 5 million tons per year and save 6.6 million tons of water.