Paddy (unmilled rice) husk produces precipitated silica or liquid sodium silicate; ingredients necessary for making soap and detergent.
Production process:
The rice husks from various rice mills are collected and will be transported to the Rice husk processing plant. Unloading will be done pneumatically or with gravity flow and excavators to intermediate silos. Before entering the silos impurities are separated by means of a riddle screen. Afterwards the husks are ground and fed to storage silos. Combustion of these husks produces power and rice husk ash. Depending on the combustion technology and process parameter rice husk ash
with more or less carbon content (5% - 40 %) can be produced. The other components of the ash are amorphous silica and a small amount of crystalline silica as well as some Inerts. The ash is collected from the several hoppers and the flue gas filters of the combustion unit and is stored in storage silos.
with more or less carbon content (5% - 40 %) can be produced. The other components of the ash are amorphous silica and a small amount of crystalline silica as well as some Inerts. The ash is collected from the several hoppers and the flue gas filters of the combustion unit and is stored in storage silos.
Rice husk ash is first digested with caustic soda and than filtered. In the filter diluted liquid sodium silicate is separated from unwashed carbon filter cake. The diluted liquid sodium silicate is fed to storage tanks while the carbon cake in the filter is washed and chemically cleaned before dried in the drying section.
The special serial dryers allow the production of powdered activated carbon with a residual water content of about 8%. The powdered activated carbon is screened and stored in storage silos. Liquid sodium silicate is processed with acid and filtered. The filter separates a diluted sodium sulfate (Glauber’s salt solution) and the wet silica product. The salt solution can be evaporated or fed to a reverse osmosis and solid salt is produced as valuable by-product. The wet filter cake is finally washed and fed to the drying unit. Withspecial dryers a precipitated silica product with about 8% water content is produced. The precipitated amorphous silica powder is screened and stored in storage silos. For distribution of silica products packaging in bags of various sizes is executed in the packing unit.
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