ã€China Aluminum Network】 The coal-fired power plant in China emits more than 100 million tons of fly ash every year. The storage ash storage area has reached tens of thousands of mu, which poses a great threat to the environment. Therefore, the implementation of fly ash It is a long-term technical and economic policy for China to use, harm, and turn waste into treasure to protect the environment.
I. Necessity of project implementation Comprehensive utilization of fly ash is a promising new industry with high technological content, large market potential, broad market prospects, and environmental protection and resource recycling. At present, the comprehensive utilization of fly ash in China is mainly for the use of brick making, backfilling, paving roads, sorting and floating beads, and production of cement. Through laboratory analysis, many fly ash coals contain large amounts of AL2O3 and SiO2. If fly ash is used to extract aluminum-silicon alloys, it is undoubtedly a new way to control fly ash pollution, improve the environment, and open aluminum for the metallurgical industry. The new source of silicon alloys, for the power plant, the use of fly ash has a new way and the company's economic benefits have a new growth, for mineral resources, fly ash extraction of aluminum and silicon alloy is undoubtedly a new addition A lot of aluminum and silicon mines have eased the tense situation of aluminum-silicon raw materials, so that they can make better use of wastes to replace the original minerals. It truly embodies the phrase “no useless garbage, only misplaced resourcesâ€. The better embodiment.
At present, there are two methods for producing aluminum-silicon alloys in China: relying on the former method is using pure aluminum, pure silicon mixed after the smelting into silicon aluminum alloy, is the use of electrolytic aluminum metal and industrial silicon as raw materials, after remelting , Proportional mixing and melting. In this way, from ore to aluminum-silicon alloy finished products can be completed through many processes such as alumina plant, electrolytic aluminum plant, industrial silicon factory, aluminum alloy plant, etc., with long production process, complicated process, high energy consumption and high cost. In the entire manufacturing process, the plant construction cycle is long, and more funds are invested, which has a greater impact on the environment; the second method is to use high-grade bauxite in the submerged arc furnace to produce aluminum-silicon alloys, due to the high grade used for production. The bauxite is scarce and expensive, leading to tight raw materials and high cost; therefore, the prices of aluminum-silicon alloy produced by the above two methods remain high, forcing steel smelting companies to use only ferrosilicon instead of aluminum-silicon alloy for deoxidation during steelmaking. As a result, the quality of the steel is reduced. If aluminum-silicon alloys are used during smelting, the sensitivity of the steel to bubbles can be reduced, thereby improving the quality of the steel.
Fly ash extraction of aluminum-silicon alloy is based on fly ash contains a lot of elements such as AL2O3, SiO2, fly ash and additives, reducing agents, binders were mixed in proportion to make high-strength pellets. The submerged arc furnace is smelted and reduced to obtain a crude aluminum-silicon alloy, and then an aluminum-silicon alloy with a high aluminum content can be obtained by refining the furnace, adding refining agents, refining slag, and ingot casting. Due to the vast source of raw materials and low prices, aluminum-silicon alloys can be directly refined into smelting, which results in low production costs, good sales, and strong competitiveness in the market.
Aluminum-silicon alloy is light and tough, suitable for casting aluminum alloy castings and die-casting aluminum alloy castings with complex shape, high strength, high corrosion resistance, and high air tightness. It is generally used in automobiles, tractors, ships, aircrafts, rockets and Diesel locomotive parts and medical equipment, instrument parts, daily necessities, decorative products and other industries or fields, aluminum-silicon alloys at high temperatures when the reduction is very strong, can be used to smelt high melting point metals, such as: chromium, manganese, molybdenum, vanadium and so on.
Due to the use of fly ash to extract aluminum-silicon alloy, it not only saves energy and protects the environment, but also realizes value-added transformation; therefore, it is feasible and necessary to build a project of extracting aluminum-silicon alloy from fly ash.
