活性炭辅助微波活化煤矸石的“枣糕”模型

Jujube cake model of activated carbon assisted microwave activating coal gangue

采用活性炭辅助微波活化煤矸石,将煤矸石的活化时间由传统高温焙烧方法的2 h缩短到了24 min以内。将70目活性炭与200目煤矸粉以2.0∶1的质量配比充分混合后在800 W微波功率下活化24 min,铝铁浸出率可达750℃焙烧2 h的1.71倍。将微波看做实体物质,将活化过程看做是由活性炭向煤矸粉的单向微波能量传递,引入化学反应工程学方法,"枣糕"模型计算表明,在680 W功率下,活性炭的微波附着速率常数ka=0.334 min-1,微波脱附速率常数k'a=0.050 min-1,煤矸粉的微波附着速率常数kb=0.262 min-1,相关系数R=0.99997。在528、680、800 W 3个功率水平下,"枣糕"模型的计算值均与实验值拟合良好,相关系数均高于0.999,在以上3功率下,发现极限铝铁相对浸出率a与极限温升ΔTmax近似成正比。

The activated carbon was used to assist in microwave-activating coal gangue, and the gangue ac- tivation time was reduced to 24 rain from 2 h of the traditional high-temperature method. According to the mass ratio of 2.0： 1, the 70 mesh GAC and 200 mesh coal gangue powder were activated in 800 W microwave power for 24 min after mixed, and the relative A1/Fe leaching rate was up to 1.71 compared with calcinning for 2 h at 750℃. Microwave was seen as solid material, and the activation process was of the opinion that microwave ener- gy was transferred from activated carbon to coal gangue powder by one-way. The chemical reaction engineering methods was introduced, and the following conclusions can be drawn from the jujube cake model. When the mi- crowave power is 680 W, the microwave adsorption rate constant of GAC is identified as ka = 0. 334 min-l, and the microwave desorption rate constant of GAC is identified as k＇a = 0. 050 min-I Also, the microwave adsorp- tion rate constant of coal gangue powder is identified as kb = 0. 262 min-t, and the correlation coefficient is 0. 99997. Jujube cake model fits well with the experimental dates when the power is 528, 680 and 800 W,and the correlation coefficients are higher than 0. 999 . The limited A1/Fe relative leaching rates are proportional to the limited temperature nearly under the above three powers.