The conference on environmental protection technological achievements appraisal took place in Beijing, hosted by the Chinese Association of Environmental Protection Industry. Our proprietary technology of recycling steel dust and nonferrous metal smelting slag was appraised in the conference. The appraisal committee includes research fellow Wang Qi, from the Chinese Research Academy of Environmental Sciences, research fellow Hu Hualong, from the Solid Wastes and Chemicals Management Technology Center of Ministry of Ecology and Environment, professor Li Jinhui from the Tsinghua University, research fellow Zhang Hui from the Institute of Processing Engineering of Chinese academy of sciences, professor Cang Daqiang from the University of Science and Technology Beijing, professor Chen Dexi from the China ENFI Engineering Corporation, and research fellow Zhou Lianbi from the BGRIMM Technology Group. The experts reached a consensus that GreenNovo’s new technology provided an effective treatment technique to reclaim the heavy metal solid waste, meeting the international high standard goal.
The steel, non-ferrous, and chemical engineering industry, produces large amounts of residues, such as slimes, dust, and other solid wastes containing heavy metals like lead, zinc and cadmium, rare and precious metals like indium, bismuth, tin, impurities like chlorine, fluorine, sulfur every year, and most of them are just stockpiled. Complicated components make it hard to process. It has always been a challenge to address in environmental protection.
Our independently developed core technology of “Pyrometallurgical Enrichment and Hydrometallurgical Separation Integrated with Multi-segment Coupling” reclaims zinc, lead, cadmium, bismuth, tin, indium, iron, iodine and other valuable elements from zinc bearing steel dust and non-ferrous smelting slag innovated based on traditional technology utilizing. Steel dust and non-ferrous smelting slag as raw materials, GreenNovo adopts an oxygen enrichment technology to improve the Waelz kiln operation, optimize efficiency and lower air pollutant emissions. Zinc sulfate purification technology, such as dechlorinating via monovalent copper ion, removing iron via oxygen, removing cobalt and nickel at mid and low temperature can improve the recovery of valuable metals. Blowing out and oxidant methods of recovering iodine from the steel dust for the first time, begins filling the gap in the iron recovery technology in China. Joint iron separation technology can separate iron from impurities in the slag efficiently.
Our technological achievements are consistent with environmental protection and the circular economy policy, and can be applied to recycle solid and hazardous waste like steel dust and non-ferrous smelting slag and effectively reclaim zinc, lead, cadmium, bismuth, tin, indium, iron, iodine and other valuable elements. The valuable elements are separated, extracted, and turned into resources from metallurgical solid waste. The steel dust and heavy metal metallurgical waste is thus recycled without causing more pollution to the environment.
This technology was put into production in Gejiu factory in Yunnan Province, and has gone smoothly for years. After ten years of development, GreenNovo is capable of processing 2 million tons of heavy metal solid waste like steel dust every year and has grown to be the largest, and leading enterprise with the biggest industry chain operation in the area.