Preparation method for synthesizing high aluminum-silica gel

Abstract

The invention provides a preparation method for synthesizing a melamine high aluminum catalyst, and particularly relates to a preparation method of high aluminum-silica gel with the advantages of higher specific surface area, larger pore volume, higher strength and low wear rate. According to the preparation method disclosed by the invention, sodium metasilicate, sulfuric acid and pseudo boehmite are used as main production raw materials, wherein the sodium metasilicate and the sulfuric acid are gelatinized and then need to be subjected to aging and reaming, acid soaking and water washing, so that higher specific surface area, larger pore volume and larger pore diameter of the catalyst are guaranteed, and the activity of the catalyst is effectively improved; high-quality pseudo boehmite is added in beaten silica gel slurry, so that the content of activated aluminum oxide in the catalyst and the strength of the catalyst are effectively improved. By adopting the preparation method provided by the invention, the high-quality silica gel required by industry can be produced: the specific surface area is greater than or equal to 300 m<2>/g, the pore volume is 0.4 to 0.7 cm<3>/g, and the wear rate is smaller than or equal to 1.5 percent; the key problem of producing alumino silica gel with the high specific surface area, the high pore volume, the high strength and the low wear rate is solved; the preparation method has the advantages of simple steps, convenience in operation and high practicality.

Description

technical field [0001] The invention belongs to the field of silica-alumina gel preparation, in particular to a preparation method for synthesizing high-alumina silica gel. Background technique [0002] Melamine is an important organic chemical intermediate product and the main raw material for making triamine formaldehyde resin with heat resistance, aging resistance, acid and alkali resistance and flame retardancy. The industrial production of melamine generally adopts the normal and low pressure synthesis melamine production process with urea as raw material. This production process adopts a fluidized bed catalytic synthesis process, which requires the catalyst to have the advantages of high strength, high activity, and low price. Foreign BASF (BASF) mainly uses γ-Al2O3 as catalyst, but the price is expensive. Coarse-porous silica gel is mostly used as catalyst in China, which is cheap but has low catalytic activity and strength, and consumes a lot. Some melamine device...

AI Technical Summary

Problems solved by technology

Foreign BASF (BASF) mainly uses γ-Al2O3 as catalyst, but the price is expensive

Coarse-porous silica gel is mostly used as catalyst in China, which is cheap but has low catalytic activity and strength, and consumes a lot

Some melamine devices use low-alumina coarse-porous microsphere silica-alumina gel with an alumina content of about 8%, which is higher in catalytic activity and strength than silica gel, but due to the increased input of raw material aluminum sulfate, its cost is 10% higher than that of silica gel

Images