Preparation method of coal active carbon with low heavy metal content

Abstract

The invention provides a preparation method of coal active carbon with low heavy metal content. The preparation method comprises the following steps: respectively carrying out stone removal and flotation on a first coal type and a second coal type, thereby obtaining a first type of float coal and a second type of float coal, wherein for the first coal type, the ash content is 4 to 6 weight percent, the volatile component content is 31 to 36 weight percent, and the caking index is 0.8 to 2.6, and for the second coal type, the ash content is 2.5 to 5 weight percent, the volatile component content is 27 to 30 weight percent, and the caking index is less than or equal to 1; the densities of heavy liquid for floatation of the first coal type and the second coal type are independently 1.35 to 1.45 g.cm<-3>; mixing the first type of float coal and the second type of float coal, and carrying out grinding, briquettingm carbonization and activation on the mixture, thereby obtaining an activatedmaterial; crushing and washing the activated mixture in sequence, thereby obtaining the coal active carbon with the low heavy metal content, wherein washing comprises alkaline washing, water washing,acidic washing and water vapor heating washing. The preparation method can obviously reduce the heavy metal content of the coal active carbon.

Description

technical field [0001] The invention relates to the technical field of solid adsorption materials, in particular to a method for preparing coal-based activated carbon with low heavy metal content. Background technique [0002] In recent years, with the improvement of people's awareness and understanding of environmental protection, activated carbon has been widely used in the fields of gas phase adsorption, liquid phase adsorption, solvent recovery, refined decolorization, food and pharmaceuticals, etc., and the requirements for the content of heavy metal elements in activated carbon are also increasing. Getting stricter. Taking activated carbon for water purification as an example, the CJ343-2010 water quality standard for sewage discharged into urban sewers stipulates that the heavy metal content is less than 1ppm for Pb, less than 1.5ppm for Cr, less than 0.02ppm for Hg, and less than 0.1ppm for cadmium and Cd. content needs to be lowered. [0003] Coal-based activated ...

AI Technical Summary

Problems solved by technology

In the production process of coal-based activated carbon, in the process of coal conversion and utilization, except for a small part of heavy metal elements and their compounds volatilized, most of them will be enriched in the activated carbon, so that the content of heavy metals in coal-based activated carbon is relatively high, and the lead content is 88. ~113ppm, chromium content is 21.2~29.8ppm, mercury content is 1.08~2.01ppm, cadmium content is 1.01~2.18ppm, which limits its application