Shandong Ruby Building Materials Co., Ltd. (hereinafter referred to as Ruby Company) is a holding subsidiary of Laigang Group. Its main products include metallurgical accessories, slag powder, cement and so on. It is not only the supply base of metallurgical industrial parts in Laigang, but also the treatment base of solid waste produced in the metallurgical process of Laigang. At present, it has an annual production capacity of 2 million tons of cement, micropowder and 3 million tons of metallurgical accessories. Its industrial orientation determines its important position and advantages in developing circular economy industry chain in Laigang. The finished products of Ruby metallurgical limestone mine are used to calcine metallurgical lime, limestone tailings, steel slag and fly ash are used to calcine cement clinker, and cement clinker, slag and fly ash are used to grind cement and micropowder. In a word, most of the solid slag produced by iron and steel industry is digested in the process of cement production. It can be said that the cement production of Ruby Company is a process of circular economy and resource reuse in the main production of steel in Laigang.
2 advantages of developing circular economy in cement industry
Cement material is a multi-component mixture, the main chemical components are CaO, SiO2 _ 2, Al _ 2O _ 3 and Fe _ 2O _ 3, and its composition can be designed by matching various raw materials. Theoretically, all substances that can provide CaO, SiO2 _ 2, Al _ 2O _ 3 and Fe _ 2O _ 3 can be used as cement raw materials. Therefore, in addition to natural limestone and other mineral raw materials, there are many other industrial tailings and wastes, such as blast furnace slag, coal gangue, fly ash, steel slag, slag, copper slag, copper tailings, sulfuric acid slag and so on.
The formation of cement clinker requires high temperature sintering, and all substances that can provide heat can be used as fuel for cement production. Therefore, in addition to natural mineral fuels, combustible wastes such as waste tires, waste plastics, waste mineral oil and waste grease can all be used as fuels for calcining cement clinker.
In addition, the main function of cement in the construction industry is to provide strength by cementing other substances. Therefore, after proper treatment, industrial waste residues such as slag, fly ash, steel slag, calcined coal gangue and phosphogypsum can generate gelation under the excitation of cement, which can replace cement clinker in the construction industry in the same amount, reduce the demand for cement, indirectly save natural resources and energy, effectively improve the construction performance and durability of cement concrete, and prolong the service life of concrete.
Relying on Laigang Group, Lubi Company makes full use of metallurgical industry waste residue to produce cement, strengthens comprehensive utilization of resources, and is committed to developing circular economy and building energy-saving enterprises. The comprehensive utilization of Ruby's metallurgical auxiliary materials, cement, micropowder production and industrial solid slag produced by iron and steel industry can form a closed loop for Laigang to develop circular economy. The production process is shown in figure 1.