Gas generating aluminum powder
Applications of Gas - generating Aluminum Powder
The primary application of gas - generating aluminum powder in aerated concrete is that during the production process, the aluminum powder undergoes a chemical reaction with silica and quicklime, releasing gas. This results in the formation of a porous structure within the produced concrete blocks. In the batching process of aerated concrete block production, the gas - generating aluminum powder slurry is added to a mixing tank. After thorough mixing, it is transferred to a metering scale for the aluminum powder slurry. Finally, it is put into a casting mixer together with raw materials such as quicklime, gypsum, and fly ash. The aluminum powder in the aluminum powder paste can react with alkaline substances in the aerated concrete slurry, releasing hydrogen and generating bubbles, which causes the aerated concrete slurry to expand and form a porous structure. As a result, the weight of the produced aerated concrete blocks is generally 500 - 700 kg/m³, which is only 1/4 - 1/5 of that of clay bricks and 1/5 of that of ordinary concrete. It is one of the lighter types of concrete, reducing the self - weight of buildings with ordinary brick - concrete structures by over 40%.
Requirements for Gas - generating Aluminum Powder
Gas - generating aluminum powder is a gas - generating material used in aerated concrete. In 1923, the Swede Exxon mastered the production technology using aluminum powder as a gas - generating agent and obtained a patent. Aluminum powder generates a large amount of gas, and the solubility of the generated hydrogen in water is low. It has high gas - generating efficiency, and the gas - generating process is easy to control. Moreover, it has a wide source, providing conditions for large - scale industrial production. Currently, the domestic aerated concrete industry commonly uses gas - generating aluminum powder paste. Made from pure aluminum foil as the raw material, it is ground in a ball mill with a medium and various additives. The resulting aluminum slurry is then centrifugally concentrated into a paste. For the production process of aerated concrete to form an ideal pore structure, the gas - generation of the aluminum powder must be matched with the thickening and hardening of the slurry, which imposes certain requirements on the quality of the gas - generating aluminum powder.
