Taiyuan Iron & Steel (Group) Co., Ltd. (TISCO), one of the world’s largest steel producers, has been working on environmental sustainability for many years. The company has pulled off the feat of developing and retaining its stainless steel manufacturing site in the middle of a city. It has zero emissions of industrial waste water, and has improved performance across all environmental standards, while increasing production efficiency.
Under a Joint Venture with Harsco, TISCO has entered into a 25-year environmental services contract. Harsco will apply its proprietary separation technologies to extract high-value metallic content from TISCO’s slag for production re-use. Patterned after similar Harsco facilities in other parts of the world, Harsco’s separation processes recover more than 99.8% of all metallics from stainless steel slag and also yield a calcium silicate-rich co-product that has shown significant benefits to agricultural productivity in major turf and crop-producing regions of the world.
This latter point is of particular importance in China, where approximately 300 million acres are currently in agricultural production for a wide range of food and fiber crops. Researchers estimate that some 50 million acres, however, are deficient in silicon and/or contain acidic soil conditions, reflecting years of over-use and the effects of acid rain in China’s coal mining regions. Other anticipated markets for the slag include use as an ingredient in cement and for road base construction.
TISCO has signed up to a RMB 380 million yuan ($60m) project to project to treat 80,000 tonnes of BF melt slag a year to make mineral wool for building insulation. This is a project carried out in partnership with Harsco.