Study On The Preparation And Adsorption Properties Of Coal Gangue Composite Materials

Coal gangue is the solid waste produced in coal washing and coal mining process. It isthe largest cumulants of industrial waste in our country. The main components are SiO2and Al2O3, contained varying amounts of CaO, Fe2O3, MgO, K2O, Na2O, P2O5and rareelements. Because it has mineral and chemical properties, taken the appropriate method toadsorb wastewater.In this paper, the raw materials are coal gangue, limestone and aluminium chloride. Toexplore the optimum process conditions of preparation of adsorbent. It explored thestructure performance characterization of adsorbent. Determined optimum condition of Cr,Pb,Zn. And the adsorption mechanism are discussed.The optimum conditions were obtained as follows: when the adsorbent preparationgangue particle size of200mesh, with the ratio of2:3mixed with limestone, joined thealuminum chloride of10%, mixed in a muffle from room temperature slowly heated to800oC, holded90min, and colled to room temperature, the composite type of alkalinesorbent.SEM spectrum showed that: the surface of composite adsorbent was uneven, and hasmany apertures, which is favorable for the adsorption process. XRD spectrum showed that:the reaction emerged the unstable substances: Mg2Al4Si5O18, Al2Si2O5(OH)4, C2CaO4,CaSiO3. Boehm showed that the content of Al-O group and Ca were increased. ThePZC was high. It was beneficial to remove heavy metal ions.Composite adsorbent was used to adsorb chromium, the removal rate was94.79%.Low concentration was fitted with Langmuir, Freundlich fitting with high concentration.Physical adsorption of monolayer was the main process. The adsorption of lead removalrate was96.68%. Low and high concentration were fitted with Freundlich. Physicaladsorption of monolayer was the main process. The adsorption of zinc removal rate was96.28%. Low concentration was fitted with Freundlich, Langmuir wasfitting with high concentration. Chemical adsorption was the main process. At the same time, single molecular layer adsorption was included. Two order kinetic equation canbetter describe the adsorption process of three kinds of heavy metal ions.Preparation of adsorbent by using coal gangue can save resources, reduce the cost butalso to ease polluted environment from the solid waste. It achieved waste treat waste.