Process technology for producing mineral wool from blast furnace slag

Process technology for producing mineral wool from blast furnace slag

Blast furnace slag is a by-product produced during the blast furnace ironmaking production process. Its output is large. The technology of using blast furnace slag to produce mineral wool products is of full benefit to it. It also reduces the environmental pollution caused by blast furnace slag and provides excellent transformation. Waste becomes treasure. The process of producing mineral wool products is mainly divided into four links: melting, making cotton, collecting cotton, and forming. According to the different melting processes, it can be divided into cupola method and blast furnace melt direct production of mineral wool method. The difference between the two lies in the raw materials and smelting equipment.

The cupola method uses cold blast furnace slag as the main raw material and coke as the fuel. At the same time, an appropriate amount of modifier (limestone, fly ash, etc.) is added to smelt and temper in the cupola. However, this method has definite shortcomings: a large amount of smoke and dust are generated during the production process, which pollutes the environment; cold blast furnace slag is used as feed material, which requires fuel to be remelted. The production of 1 ton of mineral wool consumes approximately 400kg of coke, thus increasing energy consumption and Production cost; the mineral wool products produced contain liquid balls, thick fibers and poor hand feel.

The direct production method of mineral wool from blast furnace slag uses blast furnace slag as the main raw material. The liquid blast furnace slag is introduced into a heat-replenishing quenching and tempering furnace, and a conditioning agent is added at the same time. Electrodes or gas heating are used for temperature regulation and quenching and tempering. , mineral wool fibers are made into fiber-forming systems. Then mineral wool products with different properties and uses are obtained through cotton collection and post-processing procedures.

Compared with the cupola method, using blast furnace slag to directly produce mineral wool can recover more than 80% of the sensible heat of the slag. Its energy consumption is less than 30% of the cupola method, and the production cost is only 60% to 80% of the cupola method. It has a relatively high Strong market competitiveness. At present, the methods for directly producing mineral wool from blast furnace slag in many regions mainly include JFE's blast furnace slag preparation mineral wool technology, Dalian Environmental Protection Design Institute's new one-step mineral wool production technology and the direct fiber forming technology proposed by Hebei United University.

For steel companies, the blast furnace slag produced from ironmaking is mostly used to produce cement, with low added value. If blast furnace slag, especially blast furnace molten slag, is used to produce mineral wool, it will provide a new way to create profits for the development of non-steel industries for steel companies. At present, the selling price of mineral wool products ranges from 2,500 yuan to tens of thousands of yuan per ton. At the same time, the sensible heat resources of blast furnace slag can be fully recovered, which has huge environmental benefits. Therefore, no matter in terms of economic, environmental or social benefits, the use of blast furnace slag to prepare mineral wool products is a cutting-edge value-added utilization model.