混合赤泥自凝干法筑坝工艺参数研究

低温拜耳法赤泥具有颗粒细、渗透性差、胶凝成分含量低等特点,难以单独筑坝;而烧结法赤泥颗粒粗、渗透性较好且胶凝成分含量高;针对低温拜耳法赤泥难以单独筑坝的难题,提出了利用烧结法赤泥与拜耳法赤泥混合自凝干法筑坝的技术方案;测试了两种赤泥的物化性质,并根据各自特点选取烧结法赤泥:拜耳法赤泥混合比例为1∶9和2∶8分别开展了最佳干密度试验,确定了各自在获得最佳干密度条件下的含水率;并通过水稳性试验及强度试验证明了拜耳法赤泥加入一定的烧结法赤泥不仅能够具有较强的抗崩解能力,同时能够稳定其强度,综合考虑推荐混合赤泥比例为2∶8;最终通过SEM微观测试分析显示混合赤泥硬化体中均形成了大量的胶凝物质,而纯拜耳法赤泥硬化体中未发现明显胶凝物质,从而揭示了混合赤泥强度以及抵抗崩解的主要原因。

Study on Technical Parameters of Mixed Red Mud Self-coagulation Method for Dam Construction

The low temperature Bayer red mud has the characteristics of fine particles,poor permeability and low content of cementitious components,so it is difficult to build dam alone.However,the red mud by sintering method has the characteristics of coarse particles,good permeability and high content of cementitious components.In order to solve the problem that low temperature Bayer red mud is difficult to build dam alone,the technical scheme of using sintering red mud and Bayer method to build dam is put forward in this paper.The physicochemical properties of the two kinds of red mud were tested,and the optimum dry density test was carried out with the mixture ratio of sintering red mud to bayer red mud at 1∶9 and 2∶8.The water content under the condition of the optimum dry density was determined respectively.Through the water stability test and strength test,it is proved that the Bayer red mud adding certain sintering red mud can not only have a strong anti-disintegration ability,but also can stabilize its strength.Considering comprehensively,the ratio of mixed red mud is recommended to be 2∶8.Finally,the SEM microscopic test analysis showed that a large number of cementifying substances were formed in the hardened body of mixed red mud,while no obvious cementifying substances were found in the hardened body of pure Bayer red mud,which revealed the main reasons for the strength of mixed red mud and its resistance to disintegration.