Research on Utilization of Silicon-manganese Slag in Building Materials

Manganese and silicon in silicomanganese alloy have a strong affinity with oxygen. The melting points of the deoxidized products MnSiO4 and Mn2SiO4 produced in steelmaking are 1270°C and 1327°C respectively. They have low melting point, large particles, easy floating, and good deoxidation effect. Advantages, therefore, silicon-manganese alloys are widely used in steelmaking. With the growth of domestic and foreign market demand and the development of technologies such as continuous casting and out-of-furnace refining, the output growth rate of silicon-manganese alloys is higher than the average growth rate of ferroalloys and higher than the growth rate of steel. It has become an indispensable composite deoxidizer for the iron and steel industry. additives and alloy additives.

Silico-manganese slag is an industrial waste slag that ferroalloy enterprises use manganese ore, manganese-rich slag, lime, coke, silica and other raw materials to smelt silicon-manganese alloys in submerged arc furnaces.  The high-temperature molten silicomanganese alloy slag forms loose and porous granular silicomanganese slag after water quenching and rapid cooling, and the silicon-manganese alloy slag is naturally cooled in air or due to insufficient water quenching to form dense block silicomanganese slag.

According to the statistics and reports of relevant enterprises, 1.2~1.3 tons of silicomanganese slag will be produced for every 1 ton of silicomanganese alloy produced. In the past 10 years, about 3 million tons of silicomanganese slag are produced every year, and most of the silicomanganese slag discharged by ferroalloy enterprises has not been Any treatment is directly discarded, or discharged into rivers, seas, or dammed and piled up. Arbitrary discharge and stacking of silicomanganese slag not only occupies a large amount of land, but also pollutes the environment and causes waste of reusable resources. Therefore, it is urgent to comprehensively utilize the discarded silicomanganese slag and turn waste into treasure. There are few studies on the comprehensive utilization of silicomanganese slag produced in large quantities in recent years, and they mainly focus on the granular silicomanganese slag in the silicomanganese slag, while the research on the massive silicomanganese slag with relatively low activity and large emissions But rarely reported. At present, the comprehensive utilization of silicomanganese slag in the field of building materials has the following methods:

① Production of cement clinker by using silico-manganese slag

② Preparation of cement concrete admixture by using silico-manganese slag

③ Silico-manganese slag is used in other building materials

The utilization of silicomanganese slag in the fields of cement concrete, alkali-activated cementitious materials and pavement concrete and other building materials can not only reduce the environmental pollution of silicomanganese slag, but also obtain building materials with excellent performance, which can be widely popularized and applied.