ABSTRACT Based on the attribute of asbestos tailings rich in silicon and magnesium, the powder of asbestos tailings was pre-calcined followed by MgO addition in the green body and finally sintered to develop refractory ceramics containing phases of forsterite, magnesioferrite and merwinite. The effects of pre-calcining treatment, MgO content and sintering temperature on crystallization, phase transition, microstructure and physical property of refractory ceramics were investigated by means of X-ray diffraction, thermogravimetry-differential scanning calorimetry, scanning electron microscopy and physical properties tests. The results indicated that the hydroxyl water and volatile components in asbestos tailings were basically eliminated after pre-calcining. The addition of MgO in raw materials promoted the conversion of low melting phases into refractory phases through solid state reaction. Both the flexural strength and bulk density of the samples increased initially, then decreased with the increase in sintering temperature, while the MgO addition would increase the optimal temperature. The optimal temperature promoted grains of different phases to grow large and interweave to form a dense accumulation body, which improved the compactness and flexural strength of the sample. This study provided certain practical guidance for the preparation of refractory ceramics from asbestos tailings. GRAPHICAL ABSTRACT

中文翻译：

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石棉尾矿的预煅烧及其在耐火陶瓷中的回收利用

摘要 基于石棉尾矿富含硅和镁的特性，将石棉尾矿粉预煅烧，然后在坯体中添加MgO，最后烧结，开发出含有镁橄榄石、镁铁氧体和镁温石相的耐火陶瓷。采用X射线衍射、热重-差示扫描量热法、扫描电镜和物理性能测试方法研究了预煅烧处理、MgO含量和烧结温度对耐火陶瓷结晶、相变、微观结构和物理性能的影响。结果表明，石棉尾矿中的羟基水和挥发性成分经预煅烧后基本消除。原料中MgO的加入促进了低熔点相通过固相反应转化为难熔相。样品的抗弯强度和堆积密度均随烧结温度的升高而先升高后降低，而MgO的添加会提高最佳温度。最佳温度促使不同相晶粒长大并相互交织形成致密的堆积体，提高了样品的致密性和抗弯强度。该研究为石棉尾矿制备耐火陶瓷提供了一定的实践指导。图形概要 而添加 MgO 会提高最佳温度。最佳温度促使不同相晶粒长大并相互交织形成致密的堆积体，提高了样品的致密性和抗弯强度。该研究为石棉尾矿制备耐火陶瓷提供了一定的实践指导。图形概要 而添加 MgO 会提高最佳温度。最佳温度促使不同相晶粒长大并相互交织形成致密的堆积体，提高了样品的致密性和抗弯强度。该研究为石棉尾矿制备耐火陶瓷提供了一定的实践指导。图形概要