Steel slag can be used as blast furnace and converter raw materials in steel plants, and can also be used for road engineering, building materials, agricultural fertilizer and pit filling.
In sintering ore with steel slag instead of flux, it can not only recycle the residual steel, FeO, CaO, MgO, MnO and other valuable components, but also significantly improve the quality of sinteter, improve the drum index and agglomeration rate, reduce the weathering rate, and increase the yield.In addition, due to the oxidation and exothermic heat of Fe and FeO in steel slag, the heat needed for the decomposition of calcium and magnesium carbonate in sintering ore is saved, and the fuel consumption of sintering ore is reduced.The blast furnace uses the sintering ore mixed with steel slag. Due to the high sintering ore strength, although the iron grade is slightly reduced and the slag quantity is slightly increased, the blast furnace operation is beneficial to the increased output and reduced coke ratio. The enrichment of phosphorus should be paid attention to steel slag in sintering, and the proportion of steel slag in sintering ore should be controlled.
The main advantage of steel slag directly returning to the blast furnace as flux is that CaO in slag instead of limestone, which saves flux consumption. However, most blast furnace uses high alkalinity sintering ore, basically without limestone, so the amount of steel slag back to the blast furnace is limited.In addition, the higher iron content in steel slag can replace part of iron ore; MgO in steel slag can replace part of dolomite, increase the fluidity and stability of slag.The MnO in the steel slag can be recycled into the molten iron.
The return of steel slag to the converter for smelting can improve the furnace age, promoteslagging, shorten the smelting time, reduce the consumption of auxiliary raw materials, and reduce the total amount of slag in the converter.
The mixtures of Steel slag, flyash, blast furnace water slag, cement and lime can be used as the base layer, cushion layer and surface layer of the road.In addition, steel slag can also be used in asphalt concrete pavement.Steel slag has high wear resistance and stability in asphalt concrete, is a valuable material in highway construction. The steel slag is also suitable for winter repair hot asphalt mix, because it does not freeze in winter, low heat consumption, significant capacity, good fixability, for road repair can be well fixed in place.
Because the steel slag contains active minerals such as three calcium silicate, two calcium silicate and calcium fericate similar to cement, which has hydrohard coagulation, so it can be the raw material for the production of no clinker cement or less clinker cement, and can also be used as cement admixture. The steel slag cement not only has the same physical and mechanical properties as slag cement, but also has the excellent characteristics of low hydration heat, wear resistance, frost resistance, corrosion resistance and high folding strength.
The concrete prepared with steel slag powder has high wear resistance, carbonization resistance, low hydration heat, high folding strength, good toughness, but low early strength.
The active steel slag and fly ash in a certain proportion with, grinding, forming and curing, can produce different specifications of bricks, tiles, blocks and slabs and other building materials products.
The steel slag is used for foundation backfilling and soft land foundation reinforcement.
The steel slag contains the elements needed for plant production, which can be used as fertilizer. In addition, because the steel slag is weak alkaline, it can also be used as acidic soil amendments after grinding. Due to the different raw materials of various steel enterprises, some steel slag contains other trace elements. Before it was used in the production of fertilizer or soil amendments, strict leaching test and biology must be carried out.
