Method for preparing silicon-aluminum composite aerogel from fly ash based on two-step leaching method

• Main Authors: SHI YANG, SUN HAIPENG, SUN KE, YUAN SHUSHAN, LOU ZHIJIE, YANG JIAKUAN, GUI LIANZHENG, LIANG SHA, HUANG LIANG
• Format: Patent
• Language: Chinese; English
• Published: 30.06.2023
• Subjects: CHEMISTRY; COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM,CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THERARE-EARTH METALS; COMPOUNDS THEREOF; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS

The invention relates to a method for preparing silicon-aluminum composite aerogel from fly ash based on a two-step leaching method. The method comprises the following steps: mixing and roasting fly ash and alkali to obtain alkali fusion ash; respectively leaching silicon and aluminum components in the alkali fusion ash in two steps by adopting water and acid, and mixing to obtain a solution rich in silicon and aluminum; dropwise adding alkali liquor into the solution rich in silicon and aluminum to adjust the pH value, and aging at a certain temperature to obtain wet gel; and carrying out water washing, solvent replacement and normal-pressure drying on the wet gel to obtain the fly ash-based silicon-aluminum composite aerogel, wherein a water washing solution of the wet gel is recycled for the next round of alkali fusion ash leaching. The method has the beneficial effects that the leaching rate of silicon and aluminum elements in the fly ash is increased, meanwhile, a large amount of alkaline substances in t