Activated alumina regeneration

Activated alumina (molecular formula Al2O3-x(OH)2x, 0<x<0.8) is one of the most widely used inorganic chemical products in the world. Because activated alumina has a porous structure, a high specific surface area and an unstable transition state, it has greater activity. In the petrochemical industry and fertilizer industry, it is widely used as a catalyst and catalyst carrier. Activated alumina also has adsorption properties, so it is used as a desiccant for gases and liquids, an adsorbent for gas purification, a defluorinating agent for drinking water, and a color and odor elimination agent for industrial sewage. The main industrial activated alumina products obtained today are all produced by rapid dehydration. Activated alumina refers to the calcined alumina that has been sufficiently finely ground and has a primary crystal size of 1μm α-Al2O3 as the basic composition (20% to 90%).

Sodium hydroxide solution is used as the regenerant, and aluminum sulfate solution can also be used. The solution concentration of sodium hydroxide regenerant is 0.75% to 1%. The consumption of sodium hydroxide can be calculated based on 8-10g of solid sodium hydroxide needed to remove 1g of fluoride. The amount of regenerating solution is 3-6 times the volume of the filter material. . The solution concentration of the aluminum sulfate regenerant is 2 to 3%, and the consumption of aluminum sulfate can be calculated based on the 60-80 g solid aluminum sulfate required to remove 1 g of fluoride.