Studies On The Gold Adsorpion Of The Coal Based Activated Carbon In The Contained CN Solution

The kinectic properties of gold adsorption on activated carbon and the gold adsorption capability of activated carbon have been studied in present work. The adsorption behaviour of gold cyanide complex on activated carbon has been preliminary investigated, meantime, the difference of the kinectic properties of gold adsorption and the gold adsorption capability between coal activated carbon and wooden activated carbon was compared.The kinectic model of gold adsorption on activated carbon was established on the basis of the carbon in pulp process(CIP), and therefore the apparent kinetic consant (k) and the apparent kinetic order (n) have been applied to analyze and compare the gold adsorption performance in between coal activated carbon and wooden activated carbon respectively. On the basis of the mentiond above the kinectic model of gold adsorption and experimental data, the gold adsorption capability of coal activated carbon and wooden activated carbon were calculated. By means of N2 adsorption isthoerms (BET), XRD, FT-IR, TG, SEM and TEM analysis method, the effects of activated carbon (based coal and wood) microstructure characterstic on the gold adsorption behaviour were investigated. Below are the the main results as follows:1. According to the mentioned above CIP procedure, the kintics model has been founded as following: , in which it should be pointed out: (1) the equibilum of absorption-desorption process be established under the stable medium, (2) the activated carbon surface including the inner and outside be smooth and uniform, (3) the effect of the microstruture and pore sureface properties of the activated carbon, and the polarities of the gold adsorption solution on the gold adsorption process could be neglected. Under these circumantance, by using as abscissa and lgt as ordinate the curve of the was obtained, whereas lg k is intercept of line, and n is slope of line. When n=1, the adsoprtion procedure mentioned abov is in agreement with Langmuir model, when n=0.5, belongs to Fluridlich model. n is equal to during from 0.5 to 4.2. When the value of CCl4 adsorption was above 55%, the gold adsorption capability of coal activated carbon was more than that of wooden activated carbon. Particularly, when the adsorption value of CCl4 was around 63%, the gold adsorption capability of coal activated carbon could reache up to 64 g·kg-1, indicating that the gold adsorption capability of coal activated carbon is the same as or better than that of wooden activated carbon.3. The microporous surface properties of activated carbons were one of the major influence factors of gold adsorption performance, besides their microporous surface area, pore volume and pore structure. For both coal activated carbon and wooden activated carbon, it was shown that the gold adsorption amount was increased with the aboundent micropores and decreased with graphitization degree. Particularly, the oxygen-containing functional groups in the micropore surface were in favor of increasing the gold adsorption capacity.The above results might provide further theoretical basis for the exploration of the excellent gold adsorption performance of CIP method and the technological support for the relative application of coal activated carbon in the gold adsorption industry.