| With serious resource depletion caused by over-use of fossil fuel, it is urgent to seek the substitute energy. Among many substitute energies, oil shale resource has caused widespread attention due to huge reserves. Oil shale is a low-heating-value solid fuel with ash content in the range from 70wt% to 90wt%. According to the calculation of ash content, the ash yield will be in the range from 170.28 to 218.92 billion ton when the exploited oil shale is completely utilized and will be in the range between 287.87 and 647.95 billion ton when oil shale resource is completely utilized. With the exploitation and utilization of oil shale, the environmental pollution caused by waste slag with huge annual yield become more and more serious. There are some acid and alkali materials in oil shale waste slag, especially heavy metals. The potential hazard of pollutants can not be ignored due to contaminating surrounding soil, water area and atmosphere through surface runoff and floating dust. Therefore, it is necessary to realize the safe treatment of oil shale waste slag in order to maintain vigorous development of oil shale industry.In this paper, oil shale and oil shale fly ash (OSFA) were selected to discover the translocation regularity of heavy metals during circulating fluidized bed combustion through their fraction and content. Considering the enrichment of heavy metals in OSFA, some matters need attention will be put forward in the treatment of OSFA. By melting and sintering methods, nucleated glass-ceramics were produced from OSFA. The specific works are as follows:(1) The research on heavy metals with different fractions and content was carried out by Tessier sequential extraction in order to investigate the enrichment level of heavy metals in OSFA. The translocation regularity of heavy metals with different fractions during circulating fluidized bed combustion was studied through principal component analysis. Moreover, the toxicity assessment of heavy metals in OSFA was carried out by STI model.The resluts indicated that there were accumulations of heavy metals such as Cu, Cd, Pb, Zn in fly ash, and the enrichment mass of Pb and Zn added up to 117.02μg g-1 and 71.06μg g-1, respectively. The ecological risk of OSFA was notably intensified due to the high content of heavy metals with iron-manganese and exchangeable fractions.(2) The granularity distribution analysis of OSFA was carried out by mechanical grading. The feasibility and advantage of OSFA treatment by melting were expounded on the basis of the chemical compositons analysis of fly ash and the assessment of traditional ash treatment technique. Five glass materials prepared with CaO additive converted to molten-slag like glassiness by melting treatment. Then, the glass ceramics was produced by nucleation and crystallization treatment. The effect of alkalinity and heat treatment time on the performance index of glass ceramics was investigated in order to provide scientific information for commercial run.(3) Physicochemical characteristics analysis indicated that OSFA with thin granularity mainly consisted of multi-basic oxides such as SiO2, Al2O3, CaO, which were good raw materials for CaO-Al2O3-SiO2 system glass ceramics. The co-melting phenomenon occurred during the melting process of raw materials because a lot of metal oxides destroyed the interphase balance of CaO-Al2O3-SiO2 system and reduced the co-melting temperature which maintained the system balance.(4) The effect of alkalinity on the crystallization behavior of molten-slag like glassiness was investigated by differential scanning calorimeter named DSC404 F3 produced by German NETZSCH Company in order to determine the nucleation temperture and crystallization temperature. The results indicated that the increase of alkalinity conduced to bring down the nucleation temperture and crystallization temperature. Metal oxides such as Fe2O3, K2O, Na2O, Ti2O, MgO can accelerate the crystallization of molten-slag. CaO was considered as network modifier to be effective at reduction of energy input in crystallization transition.(5) The effects of alkalinity (AK) and heat treatment time on the physicochemical characterics and microstructure of glass ceramics were investigated by virtue of compressive strength, corrosion resistance, immersion cleaning of heavy metals, XRD and SEM analysis. The results indicated that the increase of alkalinity led to the transition of main crystallization phase in nucleated glass-ceramics from wollastonite to anorthite. Additionally, there were also calcite, mullite, diopside and gehlenite in glass ceramics. When AK3=0.33, the content of anorthite was high in glass ceramics, in which there were a lot of close sphere-shaped crystals with satiation and same size.(6) By first principles calculation on the basis of density functional theory, the CASTEP module of Materials Studio molecule simulation software was used to optimize the structure of silicate crystals and calculate the binding energy of crystal system adulterating heavy metal atoms in order to analyse the solidification mechanism of heavy metals in silicate crystals. The results indicated that energy barrier should be destroyed in order to make heavy metals escape from body system by virtue of external force. The body system had better effect on solidification of heavy metals entering into inner space of crystals when the energy barrier was stronger due to higher binding energy.
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