Solid waste pelletizing process and efficient sintering method thereof

Abstract

The invention discloses a solid waste pelletizing process and an efficient sintering method thereof, waste magnesium oxide powder, iron-containing solid waste and a binder are adopted as raw materials, and solid waste pellets are prepared after burdening, surface modification and pelletizing; and mixing the solid waste pellets and a mineral mixture prepared by adopting a mixing granulation process as sintering raw materials, and sequentially carrying out material distribution, ignition, sintering, cooling and whole grain screening to obtain a finished product of sintered ore, the binder is prepared from waste magnesium oxide sludge, municipal sludge, first quick lime and corn starch; the waste magnesium oxide powder and the waste magnesium oxide sludge are magnesium oxide wastes. According to the method, the magnesium oxide waste, the municipal sludge, the rotary hearth furnace fine powder and other solid wastes inside and outside the steel plant are fully recycled, local concentrated heterogeneous sintering of magnesium oxide is realized, the adverse effect of uniform distribution of MgO on the sintering productivity is avoided, the quality of solid waste pellets is improved, and the production cost is reduced. Therefore, the quality index and the heat energy utilization efficiency of the finished sinter are remarkably improved, and fuel consumption and CO2 emission are reduced.

Description

technical field [0001] The invention belongs to a sintering process in the metallurgical industry, relates to a solid waste recycling technology, and more particularly relates to a solid waste pelletizing process and a high-efficiency sintering method thereof. Background technique [0002] According to data released by the National Bureau of Statistics, China's crude steel output in 2019 was 996 million tons. Calculated by the amount of various solid wastes generated per ton of steel, the amount of solid waste generated by China's iron and steel industry reached about 99.6 million tons in 2019. If recycling is not carried out well, it will cause more serious ecological problems such as waste of resources and environmental pollution. [0003] At present, domestic and foreign iron and steel enterprises mainly recycle the solid waste with low zinc content by directly distributing it into sintering; for the solid waste with high zinc content, after dezincification treatment, the...

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Problems solved by technology

Although the above scheme can realize the recycling of solid waste in the iron and steel plant by the sintering process, there are still the following problems: 1) When the solid waste is separately briquetted or pelletized, the magnesium oxide solvent is not involved in the solid waste pellets Due to the problem of the addition of magnesia, it is impossible to achieve heterogeneous sintering with local concentration of magnesia, so it is also impossible to avoid the adverse effect of uniform distribution of MgO on sintering productivity; 2) Dolomite lamps containing calcium carbonate are used as magnesia flux, which will lead to Calcium carbonate decomposition consumes heat and CO 2 3) Only the solid waste in the iron and steel plant can be recycled, and the types used are relatively single; 4) There is no clear index requirement for the drop strength of solid waste pellets or briquettes, and it is impossible to avoid solid waste in the actual production process. Waste pellets or briquettes are repeatedly transported and broken due to cloth distribution. Therefore, the effect of improving the air permeability of the sintered material layer in the cold state and hot state and the height of the material layer is poor, and it cannot significantly improve the sintering productivity and reduce the cost of solid waste fuel. Consumption; 5) The bonding effect of the binder used is not ideal, and will bring SiO 2 and Al 2 o 3 and other invaluable components, which is not conducive to improving the iron grade of finished sinter ore

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