| A new technology which can treat the tailings in a reducing, harmless and recycling way, has been getting much attention for the purpose of building environment friendly and resource-saving society and the actual need of constructing harmonious development between human and nature in western Hubei province. Research showed that the tailings were a kind of complex mineral material which mainly contain hematite and quartz. The content of TFe, which come up to 31.5%, is high but that of SiO2, which accouts for 24.4%, is relatively low in tailings. Furthermore, the particles of tailings are very fine, where the particle size below 0.074mm is account for 80.90%, and the plasticity of tailings is medium. This paper prepared the building material by using the tailings on the basis of support from the the Eleventh Five-Year Plan of energy saving and emission reduction and our research group's preliminary work.In the paper, the formulation of the non-burned bricks was designed under the mineral composition, chemical composition, particle size and plasticity of tailings. This study investigated the effect of the dosage of iron tailings, cement, gypsum and additive, and appropriate molding pressure and moisture, on the performance of non-burned and non-autoclaved bricks. The prepared the non-burned and non-autoclaved bricks can meet national standards under the natural curing condition in this study. Morever, this study also prepared the higher intensity steam-cured bricks under the condition of suitable steam curing system in hydrothermal curing way. For further mechanism research, the non-burned products have been investigated by XRD, SEM etc detection means. At last, in order to provide guidance for indusrial application of this technolgy, the author also did large scale test and economic feasibility analysis.The research results showed that:(1) The optimum proportion of using hematite tailings in western Hubei province to prepare non-burned and non-autoclaved bricks is tailings:aggregate:cementitious material= 78:10:12, additive is triethanolamine with dosage is 0.01% in cement, molding pressure is 20MPa, molding moisture is 15%, natural curing period is 28 days.(2) The steam curing system is maintaining constant temperature 40℃for 6 h. (3) The performance of product meets the standard of JC/T422-2007. (4) This technology can consume 45 thousands ton tailings to produce 23 million energy conservation, which can bring 1.09 million profit per year, and the payback time and rate of return are 4.8 years and 20.76%, respectively.The preparation of non-burned and non-autoclaved bricks and steam cured bricks that meets the related standards made from tailings of hematite in western Hubei by the feasible technology was studied in this paper. The research can provide feasible scheme to utilize tailings largely and efficiently, and bring rich economic benefits to the enterprise. Meanwhile, it will also improve the ecological environment around mine field. Hence, this study is significant for the economy, resources, environment and social of western Hubei. |
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