The Studies On The Preparation Of Activated Carbon

Activated carbon is an important adsorbent, and is extensively used in industry such as environmental protection, chemical industry, food processing, pharmaceutical processing, and military chemistry etc.The properties especially on the adsorption study is depended on the pore structure, the studies of the new methods to prepare activated carbon of special pore distribution is worth paying more attention in recent years.Different active carbons are prepared from starch through adding a ratio of addictive and a ratio of calcium carbonate by CO2 activating. Adding calcium carbonate can improve the rapidity of physical activating and suitably control the distribution of pores. Improving the content of calcium and reaction time to a certain degree is in favor of transitional pores' development.It was found that potassium hydroxide was efficient activation agent. The activated carbon with excellent adsorption capacity could be got from the char of coconut, starch graft-polymered acrylonitrile and the mixture of starch and additive. The optimal temperatures for potassium hydroxide were 8000C,850癈,900癈 respectively. The coconut carbon with high degree of carbon is suited for the potassium hydrogen to activate. Compared with starch graft-polymered acrylonitrile, to adopt the mixture of starch and additive for raw material is helpful to improve the micropores' volume of activated carbon.Under the experimental conditions investigated, the impregnation ration of 100?50%, activation temperature of 500癈 and the activation time of 2 hours were found to be the optimal condition for preparing activated carbon with good adsorption capability, by zinc chloride activation. Compared with starch graft-polymered acrylonitrile, the products made from the mixture of starch and additive have larger volume of transitional pores on the same conditions.The activated carbon with potassium carbonate activation would have excellent adsorption capacity when the activation temperature was 900 癈,and ration of potassium carbonated / carbon was 2:1.