| The majority of metal mines discharge a large amount of metal ore tailings during the period of extracting and choosing ore. The tailings are usually stacked in ore tailings bank or natural lands, which not only occupy much land, but also damage the surrounding environment. At the same time, much money should be invested for constructing and maintaining the tailings bank. Therefore, the utilization of ore tailings has become an important topic in the comprehensive utilization of mineral resources and protection of ecological environment.Gold mine tailings is a kind of waste emission discharged from gold mines after gold is extracted from gold ore. It mainly contains SiO2, CaO, and quantitative Fe2O3, Al2O3, MgO as well as few noble metals. According to the characteristics of gold mine tailings, combining with the feature of cement industry, two research works have conducted in this paper to broaden the range of the comprehensive utilization of gold mine tailings in cement industry and reduce the cost of cement production. Firstly, gold mine tailings was used to produce high-belite cement clinker. Then the high-belite cement clinker partly replaced the silicate cement to prepare C80 high performance concrete. Secondly, gold mine tailings was directly used as admixture of cement with high content. A series of experiments were carried out and investigated by modern equipment analysis, the main conclusions were as follows:The high-belite cement clinker could be prepared by milling and burning gold mine tailings with limestone at 1350℃. This high-belite cement clinker is rich in C2S, and its mainly minerals areβ-C2S, C3S, and few C3A, C4AF. In the above clinker,β-C2S has fine crystallization with the size of 10μm～40μm, high mineral content and regular shape, plate-like or long prismatic C3S can also be found with the size of 20μm～50μm. The hydration products of high-belite cement clinker have lots of AFt crystal phases which plays a positive role in compensating shrinkage and improving the structure of the hardening cement. The high-belite cement has good cementitious properties with high compressive strength of early stage, rapid strength development of the middle and late stage.When from 30% to 55% silica cement was replaced with high-belite cement clinker powder, in combination with high efficient water reducing agent, high performance concrete can be prepared with good working performance and excellent durability. Compared with traditional C80 concrete, the C80 concrete with high-belite admixture has good adaptation, low slump loss, good water retention, high compressive strength and better durability, such as impermeability, frost resistance, anti-carbonation, corrosion resistance and so on.In addition, when gold mine tailings was dried and milled, it can be directly used as cement admixture to produce cement. The ordinary Portland cement of 32.5R grade with a content of 15% gold mine tailings powder can be made. When gold mine tailings was burned at temperatures from 1000℃to 1200℃, its activity increased and the content of gold mine tailings in the 32.5R Flash cement can be increased to 30%. The complex cement admixture can be made by mixing gold mine tailings powder with slag powder, which satisfied the needs to produce Composite cement of 32.5R grade with an addition of 40% complex cement mixture.In general, gold mine tailings can be very feasible to be used as primary raw materials or cement admixture, which would play an important role in the resource utilization of gold mine tailings and the sustainable development of cement industry.
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