煤矸石-赤泥基全固废陶瓷材料制备机理

Preparation mechanism of ceramic material with solid waste of coal gangue and red mud

在我国中西部部分地区同时存在煤矸石和赤泥两类大宗难利用固废,利用这些区域内的煤矸石和赤泥协同制备陶瓷材料是实现其大规模资源化利用的有效途径。以山西河津地区煤矸石和赤泥为原料,制备了煤矸石-赤泥基全固废陶瓷样品,并采用XRD、SEM和碱金属浸出实验等手段,研究了原料配比、烧结温度和烧结时间对样品物理性能和微观结构的影响。研究表明,原料配比影响样品的矿相和孔洞结构,最佳质量配比为煤矸石∶赤泥=1∶1,较好烧结温度为1200℃,较好烧结时间为15 min,此时样品的吸水率为0.15%,抗折强度为90.40 MPa,结构致密,主要矿相为钙长石、蓝方石。赤泥中的碱金属得到了有效固化,相对于烧结前,钠、钾离子固结率分别达到了97.17%和96.76%,钙长石和蓝方石是碱金属离子的主要赋存矿相。

Coal gangue and red mud,are solid waste found in the central and western parts of China,and are very difficult to be recovered.It is an effective way to realize high-value utilization of solid waste by using them to prepare ceramics.In this paper,the coal gangue and red mud from the Hejin area of Shanxi province were used as raw materials to prepare the whole-solid waste ceramic samples.The effects of raw material ratio,sintering temperature and sintering time on the physical properties and microstructure of the samples were studied by XRD,SEM and alkali metal leaching tests.The results showed that the raw material ratio could affect the crystal phase and pore structure of the samples.The optimum conditions were the raw material ratio between coal gangue and red mud of 1∶1,the sintering temperature of 1200℃and the sintering time of 15 min.Under these conditions,the water absorption rate of the samples was 0.15%,and their flexural strength was 90.40 MPa.The structure was dense and the main mineral phases were anorthite and hauyne.The alkali metals in the red mud were effectively solidified.Compared with the samples before sintering,the consolidation rates of sodium and potassium ions reached 97.17%and 96.76%,respectively.The main occurrence mineral phases of alkali metal ions were anorthite and hauyne.