煤粉发泡剂对赤泥陶粒烧胀特性的影响

分析赤泥、膨润土和煤粉的理化性质，并在此基础上烧制赤泥陶粒。考察不同发泡剂煤粉掺量下所烧制陶粒的烧胀性能。采用热性质分析、矿物分析和红外光谱等手段分析陶粒样品，研究煤粉的掺量和烧结温度对陶粒烧胀过程的影响以及赤泥陶粒的烧胀机理。结果表明：烧结温度为1 000℃时，随着煤粉掺量的增加，赤泥陶粒的显气孔率和吸水率升高，而体积密度和抗压强度降低；煤粉掺量为30%时，赤泥陶粒显气孔率45.13%，体积密度0.131 g·cm-3，吸水率39.0%，抗压强度14.7 MPa；掺入煤粉后赤泥陶粒生料有机组分烧失量增加，熔融温度降低，烧胀过程中还原性气氛增强；烧结温度升高能够促进易熔融矿物铁橄榄石的生成，提高陶粒的烧胀性能。

Effect of pulverized coal on sintering expansion behavior of red mud ceramsite

The red mud ceramsite is fired based on analysis of the physicochemical properties of red mud, bentonite and pulverized coal. Effect of amount of pulverized coal doping and sintering temperature on expansion properties of the ceramsite, along with related mechanisms were investigated based on thermal properties analysis, mineral composition and infrared spectrum. The results showed that, at 1 000℃, the increase of pulverized coal dosage can significantly enhance the apparent porosity and hygroscopic coefficient of ceramsite while reducing its density and compression strength. The apparent porosity, density, hygroscopic coefficient and compression strength were 45.13%, 0.131 g·cm-3, 39.0% and 14.7 MPa, respectively, under the addition of 30wt% pulverized coal. The increase of pulverized coal dosage led to enlarging of the loss on ignition and decrease of the fusion temperature, which even brought about a greater reducing gas environment during sintering process. What's more, appropriate increase of the sintering temperature plays a positive effect on fayalite formation and improving the sintering expansion property of ceramsite.