Study On The Preparation Of Activated Carbon From Brow Coal By Chemical Activation With H₃PO₄

It is a state-of-the-art commercial and little pollute technology that activated carbon is prepared from lignite by chemical activation with HaPO4 In this paper, the procedure of activated carbon production from lignite with HaPO4 as an activator is studied in detail, the dynamics of the carbonization and activation of lignite activated by H3PO4 is reviewed and the optimum process conditions have been worked out.The effect of carbonization-activation reaction temperature and time, the content of additive and the concentration of activator has been investigated. The experiment results show that the concentration of activator H3PO4 and the content of additive HaSO are prevailing factors for the iodine value of product, and that temperature and time of carbonization and activation are prevailing factors for yield of activated carbon. The experiment results of single factor studied show that at temperature of 430 C, H3PO4 concentration of 60%,the additive content of 0.9g/10(lignite), carbonization-activation time of 30 min, the iodine value and yield of activated carbon is up to 783.01mg/g and 42% respectively. The results also show the reaction rate of burn-off B is first-order reaction. According to Arrhenius equation, it is calculated that the apparent activation energy of carbonization-activation reaction is 46.96kJ/mol, and the pre-exponential factor is 6.101xl03. In the last of the paper, the mechanism of carbonization-activation reaction of lignite activated by HjPO is discussed preliminarily.