Baogang Group, China's major steel producer in Baotou, Inner Mongolia, started the construction of the second stage of its first phase carbonation-based iron and steel slag treatment utilization project on July 31, which has a demonstration production line that can produce 100,000 metric tons of slag.

This is the world's first solid waste, carbon dioxide mineralization and utilization project to be put into use, and is considered highly significant for recycling solid waste and reducing carbon dioxide emissions during the process of making iron and steel.

The project uses the latest iron and steel slag treatment technology developed by Columbia University to turn solid waste into products such as high-purity calcium carbonate and ferrous materials. The ferrous materials can be recycled as raw materials for making iron. And the high-purity calcium carbonate can be used in a range of industries including paper, plastic, paint and rubber. Through this process, both limestone mining and the deforestation will be decreased, carbon emission will be reduced, and it will promote the development of a sustainable low-carbon economy.

Yu Wenjian, vice general manager at the Baotou Steel Energy Saving and Environmental Protection Technology Co, introduced that the project presented a revolutionary innovative way method of iron and steel slag treatment. It turns wastes into reusable materials through a chemical process of mineral carbonation, and at the same time, reduces overall carbon emissions by using industrially emitted carbon dioxide as one of the reactants.

With a total investment of 600 million yuan ($92.75 million dollars), the first phase of the project was planned to be carried out in two stages. The first stage focused on industrial production based Columbia University's pilot scale. According to the measurement of current production, the consumption of a ton of steel slag is able to sequester about 0.21 to 0.4 tons of carbon dioxide, and the purity of calcium carbonate produced can reach more than 99 percent. The PVC pipes that produce this high-purity calcium carbonate feature low intensity and are very durable.

The second phase focuses on a production line project with a yearly consumption of 100,000 tons of steel slag, and produces over 10,000 tons of carbon dioxide, 40,000 tons of high-purity calcium carbonate and 70,000 tons of ferrous materials. The project is expected to be put into production early next year.

The cutting-edge project will lay a foundation for commercializing cleaner production and carbon emission reduction technologies in the iron and steel industries, and promote the sustainable development of the industries.

Wang Xin, a local ecological environment authority official, stated that its long-term goal for production capacity is 3 million tons, consuming all the slag produced by Baogang Group, and reducing 1.2 million tons of carbon dioxide emissions.

Wang also said that the project can be replicated by other industries such as the power sector as well as help cities reach a carbon dioxide emissions peak, and achieve carbon neutrality as soon as possible.