The application of Steel Slag Powder in Cement Concrete Production Process
A variety of abandoned industrial solid residue, it is a great threat to our living environment, steel slag is a typical representative. Due to the variety of chemical composition and mineral composition, small amount of unfavorable ingredients, poor wear resistance and difficult pretreatment of raw materials, steel slag still lacks the basic theory of steel slag utilization and thus seriously hinders its application in modern concrete widely used.
The basic characteristics of steel slag:
Composition and activity fluctuations: Because of the steel varieties, sources of raw materials and slag production process, slag composition and activity fluctuations.
High iron content: steel slag containing 5-15% metal paste and 14-30% of the magnetic material containing iron, broken and grinding parts wear more serious.
Easy to wear poor: the average wear-resistant 25kWh / t or so.
The composition and microstructure characteristics of hydration products containing slag powder, slag powder and fly ash cement paste were deeply studied. The experimental results showed that the order of activity of the early hydration admixture was steel slag powder> slag powder> pulverized coal Ash, and the latter is the order of activity: slag powder> steel slag powder> fly ash. For the filling effect, slag powder has the strongest filling effect, followed by steel slag powder and fly ash. In the same hydration age , The filling effect of the steel slag powder and the slag powder composite is higher than that of the single mixed slag powder, that is, both of them have good super-superposition effect. The steel slag powder, slag powder and fly ash mixed with single or mixed Can reduce hydration heat of cement to different extents; if considering the early activity of three kinds of admixtures, it can be considered that it is more advantageous to prepare large volume concrete with relatively high early strength by using steel slag powder.
Steel slag can be used as a composite powder in the production of cement concrete to improve the strength and activity of concrete. Great Wall Machinery can produce more than 200,000 tons of steel slag grinding production lines, to provide one-stop service.
In 2010, Xuzhou Steel cooperated with chaeng build a slag powder production line project with a designed capacity of 300,000 tons / year. Using the most advanced vertical mill machine equipment, the steel slag was finely ground and mixed as cement with concrete or concrete In the significantly increased its strength, impermeability, frost resistance.
After the project is completed, the major cement plants and mixing plants around Xuzhou will be sold well and will be widely used in key projects in the province