Research On Recycling Technology Of Rice Husk Ash

Rice husk is a byproduct after rice processing. Rice husk is a rich resources, according to statistics, China’s annual output of rice husk is more than40million tons. The use of rice husk has been biased as an energy source, but there will still be a large amount of rice husk ash after using. Rice husk ash which after produced generation has become secondary pollution. The most notable feature of rice husk ash is the high carbon and high silica content. We have carried out studies on the recycling technology of rice husk ash is not only to conserve resources, but also has significant environment and social benefits.Our study mainly consists of two aspects:Research on preparation of sodium silicate and activated carbon from rice husk ash;(1) The analyzation and evaluation of the two rice husk ash:Take a analyzation to different raw rice husk ash, and simulate the formation process of rice husk ash in laboratory (rice husk carbonized), we found ash is a major factor in quality of raw rice husk ash. Influence of particle size distribution on the adsorption properties of activated carbon should be ignored.(2) Preparation of sodium silicate from rice husk ash:Under atmospheric pressure, material ratio(g:g)40:6, alkali concentration1.5mol/L, reaction time2h, modulus of sodium silicate prepared was3.3. Under the high pressure, the best reaction condition is:material ratio40:6, reaction pressure0.8MPa, reaction time1h, preparation of sodium silicate modulus is3.5.(3) The preparation of sodium silicate and activated carbon by rice husk ash:The optimum process conditions is, reaction time2h,selected material ratio followed by10:1.5,10:3,10:6,10:10. After the first step (material ratio10:1.5), modulus of first sodium silicate products prepared3.3; after the second step (material ratio10:3), modulus of second sodium silicate products prepared2.3; After the third step (material ratio10:6), methylene blue adsorption of primary activated carbon product prepared is174.0mg/g; After the third step (material ratio10:10), methylene blue adsorption of primary activated carbon product prepared is199.5mg/g;Research on preparation of acidified rice husk ash and bleaching performance.The best reaction condition is:calcination temperature500℃, calcination time3h, the concentration of sulfuric acid solution20%, adsorption time5h,washed with pH control after4-5,120℃dried, acidified RHA decolorization of the frying oil is40.95%, oil absorption of2.0mL/g,apparent density of0.45g/cm3.