(Summary description)The vast majority of China's furnace slag is water quenched slag, which has good potential hydraulics and can be used as high-quality cement raw materials or directly replace part of cement for concrete production. At present
In 2018, on the supply side reform continues to advance, to capacity and prevent "DeTiaoGang" resurgence, fight already resolve the excess capacity and production limit production, heating season no "one size fits all" and a series of factors influence, concussion running patterns in the domestic steel market, overall, in 2018 the national pig iron, crude steel production are presented positive growth. The annual output of pig iron was 77.1054 million tons, up by 3.0%. Crude steel output reached 928.26 million tons, up 6.6% year on year; The output of ferroalloy was 31.234 million tons, down 5.03 percent year on year. It is estimated that 269.8689 million tons of furnace slag, 139.239,000 tons of steel slag, 62.468 million tons of ferroalloy slag, and 84.966 million tons of iron-containing dust and mud were produced nationwide in 2018.
During the 13th Five-Year Plan period, China's iron and steel industry will no longer focus on simple layout adjustment, but take industrial upgrading as the main theme. According to statistics, In 2018, Hebei, Jiangsu, Shandong, Liaoning and Shanxi are the top five provinces in China in terms of the output of iron and steel slag, accounting for about 60 percent of the country's total output. Among them, hebei alone accounts for more than a quarter of the country's total output.
Blast furnace slag, steel slag, iron-containing dust and ferroalloy slag produced in the process of iron and steel production are collectively referred to as iron and steel metallurgical slag. Blast furnace slag is molten silicate and aluminate discharged from blast furnace during smelting pig iron. Steel slag is the molten material discharged in the process of steelmaking. According to the different steelmaking process, the steel slag produced includes converter steel slag, electric furnace steel slag, refining slag, pretreatment slag, casting residual slag, etc. Ferroalloy slag is the waste residue produced in the smelting process of ferroalloy. The mineral composition is mainly calcium silicate. According to the different varieties of ferroalloy, it can be divided into nickel-iron slag, ferro manganese slag, silico iron slag, ferrochrome slag, high-carbon ferrochrome slag, etc.
The vast majority of China's furnace slag is water quenched slag, which has good potential hydraulics and can be used as high-quality cement raw materials or directly replace part of cement for concrete production. At present, China's furnace slag has not been fully utilized in gansu, Inner Mongolia and other remote areas, while other areas are basically fully utilized. The iron-bearing dust has been basically used through impurity removal and production reuse. Steel slag is one of the most difficult solid wastes for resource utilization due to its poor stability, poor abrasion resistance, low activity, heavy metal content and unstable composition, etc. At present, the comprehensive utilization rate of steel slag is less than 40%
The comprehensive utilization rate of blast furnace slag and iron-bearing dust and mud is estimated at 90%. The comprehensive utilization rate of ferroalloy slag is mainly used for extraction of valuable elements, reaching 80%. The comprehensive utilization rate of steel slag is estimated at 35%.
In terms of different regions, the better development and utilization are mainly concentrated in the large iron and steel enterprises in the eastern and central regions of China. The surrounding regions have developed economy, large amount of infrastructure construction, tight market demand for industrial solid waste, and high comprehensive utilization rate of iron and steel residue. In other regions, due to technology, scale effect, utilization of steel residue products market and other factors, the western region and small and medium-sized enterprises of steel residue high value-added utilization is difficult to promote.