Preparation of low ash active carbon prepared from cotton straw

Abstract

The invention relates to a preparation method of low ash active carbon prepared from cotton straw. The preparation method includes: taking cotton straw sawdust, adding a certain concentration of diluted hydrochloric acid to perform a de-ashing pretreatment; adding phosphoric acid according to a certain impregnation ratio after the pretreatment of raw materials, stirring the mixture uniformly, soaking the mixture for 12 hours, drying the mixture, putting the dried and soaked mixture into a tube furnace to perform carbonization, activation and preparation of the active carbon; and finally heating and washing the mixture with deionized water repeatedly until the mixture is neutral, and drying the mixture to obtain the active carbon product. The multistage washing current can dissolve residual activator in the active carbon into the washing solution step by step, and can make the concentration of phosphoric acid in the recovered solution reach a high equilibrium concentration.

Description

technical field [0001] The invention belongs to a method for preparing low-ash activated carbon by using cotton stalks as raw materials. Background technique [0002] At present, for the preparation of low-ash activated carbon in industrial production, there are mainly raw material deep deashing method and activated carbon sample acid elution deashing method. In the traditional method, activated carbon and hydrochloric acid with a mass fraction of 30% are mixed and boiled at a solid-liquid ratio of 1:0.15, and the ash content of activated carbon is reduced from 9% to 6%. However, the main defect of this method is that the metal impurities in the raw materials in the carbonization and activation stages will contaminate the activator, thereby affecting the recycling effect of the activator. [0003] In addition, the traditional single-tank activated carbon recovery process for phosphoric acid has problems such as high energy consumption and low recovery rate of phosphoric aci...

AI Technical Summary

Problems solved by technology

However, the main defect of this method is that the metal impurities in the raw materials in the carbonization and activation stages will contaminate the activator, thereby affecting the recycling effect of the activator.

[0003] In addition, the traditional single-tank activated carbon recovery process for phosphoric acid has problems such as high energy consumption and low recovery rate of phosphoric acid.