利用拜尔法赤泥制备烧结砖

Preparation of burned brick by red mud of Bayer process

以拜尔法赤泥为大宗原料制备烧结砖。采用正交试验法探讨烧结砖制备中的影响因素:m(赤泥)∶m(煤矸石)值、煤矸石细度、成型压力、烧结温度和烧结时间,结合实验结果及成本分析,最佳工艺参数为:m(赤泥)∶m(煤矸石)=75∶25,煤矸石细度为100目,烧结温度1000℃,保温时间120min,成型压力10～15MPa。在此工艺条件下制备的烧结砖各项性能指标符合GB5101—2003的要求,抗压强度达到MU20级。检测表明无明显碱溶出,XRD分析表明赤泥中的碱转化为稳定的钠铝黄长石。

Burned brick was prepared using red mud of Bayer process as raw material. The influential factors on preparation of burned brick were discussed by using orthogonal test such as value of RM/gangue, fineness of gangue, molding pressure, sintering temperature and holding time. In combination with experiment result and cost analysis, the optimum process parameters are as follows：m（RM）：m（gangue0）=75：25, fineness of gangue 100 mesh, sintering temperature 1000 ℃ and holding time 120 min and molding pressure 10-15 MPa.The performance index of burned bricks prepared under above conditions can meet the requirements of standard GB 5101--2003 and the compression strength is up to MU20. Alkali dissolve test shows that the value of pH doesn＇t alter obviously. The XRD result also shows that the alkali in the red mud has transformed into stabilized NaCaAlSi2O7.