Method for preparing high grade activated carbon from rice husk ash

Abstract

The invention relates to a high quality active carbon production method using rice husk ash, belonging to active carbon manufacture technical field, which is characterized in that the water glass is made utilizing rice husk ash, and the alkali resolved filter residue is filtered and activated using potassium hydroxide as activator; the active carbon with high absorption value is made after rising and drying. The silicon dioxide in the alkali resolved filter residue is efficiently eliminated while in activation in the invention; the absorption performance of the obtained active carbon is good, and the methylene blue adsorption reaches to more than 20 mL / 0.1 g; each index meet national standard. The high quality active carbon is made utilizing the alkali resolved filter residue after the water class is made by rice husk ash; the produced active carbon has the advantages of good quality (the methylene blue adsorption reaches to more than 20 mL / 0.1 g and ash is lower than 3%) and low production cost; the pollution of rice husk ash alkali resolved filter residue to environment can be reduced.

Description

technical field [0001] The invention relates to a method for using rice husk ash to co-produce water glass and activated carbon, in particular to chemically activate the waste residue after preparing water glass from rice husk ash to produce activated carbon with high adsorption performance, which belongs to the technical field of activated carbon manufacture. Background technique [0002] Combustion heat production is currently the most common way to utilize rice husks in my country. The rice husk ash produced after combustion is mainly composed of silicon dioxide and carbon. At present, the most important way of utilization is to prepare water glass by alkali dissolution. The precipitation of silicon, the increase of erosion degree and the action of water vapor increase the pores of rice husk ash and expand the specific surface area, which can be made into activated carbon after further washing. However, because the alkali crystals blocked in the pores of the alkali-soluble...

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Problems solved by technology

[0003] In recent years, some researchers have used potassium hydroxide activation method to prepare rice husk activated carbon, and its specific surface area is as high as 2000m 2 / g (the methylene blue adsorption value is about 3 times that of the Ministry of Forestry's first-grade activated carbon standard), but they are all made of rice husk charcoal, and the cost of raw materials is relatively high, so there is no actual production application at present.

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