Activated alumina regeneration

Activated alumina (molecular formula Al2O3-x(OH)2x, 0<x<0.8) is one of the inorganic chemical products widely used in the world. Because activated alumina has a porous structure, a high specific surface area and is in an unstable transition state, it has greater activity. In petrochemical and chemical fertilizer industries, it is widely used as 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 defluoridation agent for drinking water, and a color and odor eliminator for industrial sewage. The main industrial activated alumina products obtained today are produced by rapid dehydration. Activated alumina refers to calcined alumina whose basic composition (20%-90%) is α-Al2O3 with a primary crystal size of 1 μm after sufficient fine grinding.
The regeneration agent is sodium hydroxide solution or aluminum sulfate solution. The solution concentration of sodium hydroxide regenerant is 0.75% to 1%. The consumption of sodium hydroxide can be calculated based on 8 to 10 g of solid sodium hydroxide required to remove 1 g of fluoride. The amount of regeneration solution is 3 to 6 times the volume of the filter material. . The solution concentration of the aluminum sulfate regenerant is 2-3%, and the consumption of aluminum sulfate can be calculated as 60-80g of solid aluminum sulfate for every 1g of fluoride removal.