Synthesizing Cordierite Using Waste Slag Of Aluminum Factory

Using waste slag of aluminum factory to synthesize cordierite is a way for comprehensive deposal and reusing the waste. Compared with traditional synthetic method, this way has more merits, such raw material technical innovation,low cost, good economic returns and social returns.by on-line searching, no patent and report about synthesizing cordierite using waste slag of aluminum factory was found. waste slag of aluminum factory, which content mainly γ-AlOOH, is gained after processing those waste residue produced in the course of decontaminating surface, alkali washing, anodic oxidation and so on. some characteristics such as superfine particle, large superficial area, high activity, big impetus of solid state reation and sintering, help to forming cordierite. The phases composition of cordierite was tested by XRD method , the miscrostructure was tested by SEM and the cell parameter was tested by X pert plus. The results show that there are three phases at most in the fired specimens: cordierite, mullite solid solution and Mg- Al spine. In which, cordierite occurs in the same hexagonal structure as pure cordierite(space group P6/mcc), only cell parameters vary slightly. Mullite solid solution also occurs in the same orthorhombic form (space group pham) as integrated mullite, but cell parameters vary much. Mg- Al spine occurs in different structure with single crystal, both space group and cell parameters changed. By analysing the result, the 3# was determined as the optimal ingredient(waste slag 48, steatite 22%, clay 24%, addition agent 6%).The influence of sintering temperature and holding time on forming and structure of cordierite was discussed from mechanism of solid reaction and theory of forming thermal defect so that the optimal sintering temperature and the holding time were chosen. the result show that the the optimal sintering temperature was 1350℃ and the holding time was 5 hours. The mineralizer added to the ingredient can form sosoloid with primary crystal phases, that lead to increasing the consistency of crystal defect and diffusion velocity, and promote forming the cordierite. the result show that the cordierite increase with the TiO2 increasing. the optimal content of TiO2 is 3.0%.Some impurities ,such as K2O,Na2O,CaO, Fe2O3 and so on, have biggish influence on structure and performance of cordierite. the influence of fault of crystal construction, mechanics of solid state reaction and liquid phase forming on producing cordierite were discussed in this thesis so that the optimal content of inpurity was determined and credible datas was offerred for choosing other raw materials and determining optiaml ingredient. the optimal content of inpurity was show as follow: Fe2O3=0.8%,CaO=2.5%,K2O=1.1%,Na2O≤0.3%。 The cordierite used for principal raw material, with mineralizer and addition agent, was prepared into five kinds of samples according to variant proportions of raw material. by analysing the test result, the 4# was determined as the best one, which contents 90 percent of cordierite, 5 percent of addition agent and 5 percent of mineralizer.