Preparation And Performance Of Active Carbon-Zeolite Composite Materials From Elutrilithe

Elutrilithe, a solid waste that comes from the coal exploitation and selection by washing of coal, is one of the uttermost solid wastes in our country. Zeolite molecular sieves and activated carbon are the most important and frequently used sorbents, they display different characteristics of adsorption due to their different composition,porous structure characteristic and surface properties. It is well known that sorbent is the process-technology core with respect to the gas-liquid separation, purification and water treatment. Nowdays, industrial sorbents (such as zeolites, activated carbon etc.) seldom meet with the practical requirements or bring a complication to the manufacturing process due to their oneness.The main mineral component of Elutrilithe is kaolinite with chemical composition of alumina,silicon dioxide and carbon.Recently,based on compositional and structural properties of Elutrilithe,it has been used in the preparation of many kinds of products in chemical industry. The previous usage of Elutrilithe is however utilized its partial composition, resulting in a low use ratio and a secondary pollution. Some researchers prepared the acticarbon-shape zeolite (or power zeolite) composite materials by suing the K₂CO₃ as activating reagent. It puts the application of the materials into a difficult position because the process of the chemical activation resulted in a severe corrosion of the equipment, and the content of activated carbon and molecular in the composite materials is under the control of the raw materials (namely the Elutrilithe). In this paper, we reported a novel preparation for the acticarbon-zeolite composite materials by employing CO₂ as activating agent, pitch partially added to the raw materials as shaped agent, so as to adjust the contents of activated carbon and molecular sieves in the composite materials and tune the porous distributions and modify the surface properties of the composite. The chief contents in the paper are as following:1 .The effect of activated conditions on the properties of the as-synthesis composite.1) it was investigated that the N₂ adsorption-desorption isotherms, BET, porous distribution in the term of DFT and the adsorptive capacity of benzene varied with the activation time under the condition of the activation at 850℃,900℃.2) It was studied that the effect of the addition quantities of the pitchy power (petroleum asphalt, cola-tar oil asphalt )on N₂ adsorption-desorption isotherms, BET, porous distribution in the term of DFT and the adsorptive capacity of benzene.3) The effects of the ratio (30%, 40%, 50%)of petroleum asphalt to raw materials on N₂ adsorption-desorption isotherms, BET, porous distribution of DFT and the adsorbance of benzene were further researched in this paper.2. The effect of crystallization condition on the performances of the composite materials.1) The different preparation conditions (aging temperature, ageing time, basicity and crystallization time) were investigated so as to reveal their influences on the structure and water absorbability of the activated carbon-4A zeolitic composite.2) It was investigated that the effects of the ratio (30%, 40%, 50%)of petroleum asphalt to raw materials on the structure and water absorbability of the activated carbon-4A zeolitic composite.3) It was investigated that the effect of the different preparation conditions (the ratio of silicon to aluminium, basicity, the ratio of solid to liquid and crystallization time) on the structure of the activated carbon-13X zeolitic molecular shaped composite.4) The effects of crystallization on the surface performances of the activated carbon were also studied in this paper.5) It was studied that the effects of crystallization on the porous structure and on absorbability of carbon dioxide.