subject: Chemical Treatment Method Of Bauxite [print this page] Bauxite beneficiation with the development of aluminum industry and the lack of mineral resources, and gradually cause for concern. To take full advantage of the geology of bauxite resources, the country in recent decades do a lot of research in the chemical processing and other technologies have made progress. (An overview of the chemical beneficiation process)
Chemical treatment of the bauxite as raw materials to produce alumina, bauxite alkali, acid, and heating method three, the acid and the heating method used in industrial chemical processing methods less soda is the main method of production of alumina. Characteristics of the production process, the soda can be divided into the Bayer process, the sintering method and the combined method. (The principles of chemical beneficiation process)
Alumina production methods, Al and Si in bauxite requirements. Bayer is 8-10, the combined method for 5-7 sintering law for 3.5-5. China's bauxite resources for the production of ore reserves of Bayer France only 10% of the total reserves; Al-Si ratio of 7-10 accounted for 20%; while the Al-Si more than 4-6 ore, accounting for about 60% of the total reserves; Al-Si than 2-4 depleted bauxite accounted for 10%, low Al-Si ratio of ore can only be combined method or sintering to produce alumina. Due to the high content of harmful impurities such as silicon, sulfur, iron, not only the complexity of the alumina production process, and becomes alkali consumption and power consumption and increased production costs. Bayer process production of alumina, silica content in the ore for each additional 1% per ton of ore to consume NaOH up to 6.6 kg, multi losses Al2O3 up to 8.5 kg; the production of alumina sintering ore, silica per 1% increase. Consume 35 kg of lime. The iron oxide will increase caustic less consumption and mechanical losses of the alumina; sulfur will destroy the alumina sintering and leaching process. If the sulfur content in the ore for each additional 1% per ton of ore and more away of NaOH 25 kg, per kilogram of sulfur to consume 3.4 kg of soda ash.
