改性赤泥免烧砖的制备与放射性屏蔽机理分析

针对赤泥免烧砖广泛存在的高放射性问题进行了制备工艺优化，并对所制改性赤泥免烧砖进行了性能测试，分析了其强度形成机理与放射性屏蔽机制。研究发现:通过常压石灰水洗法改性处理赤泥、添加复合外加剂、提高早期养护温度等优化措施可以改善并解决这些问题，经优化后的制备工艺可以制成满足相关标准规定MU15级的改性赤泥免烧砖；赤泥免烧砖的强度是由机械挤压作用、赤泥的水化反应、石灰水玻璃的水解和原料的水化反应等共同作用的结果；硫酸钡、硼砂及水化硅酸钙的固结等因素共同作用致使赤泥免烧砖的放射性得到有效控制。 

Preparation and Radioactive Shielding Mechanism Analysis of Modified Red Mud Baking-free Brick

The optimization of the preparation process for the high-radioactivity of red mud baking-free bricks was performed. The properties of the modified red mud baking-free bricks were tested. Their strength formation mechanisms and radioactive shielding mechanism were analyzed. It was found that these problems could be improved and solved by optimizing measures such as treating red mud with lime washing at normal pressure, adding compound admixtures and improving early curing temperature. The optimized preparation process which met the requirements of relevant standards could be used to produce the MU15 modified red mud baking-free bricks. The strength of red mud baking-free bricks was the result of the combined effect of mechanical extrusion, hydration reaction of red mud, hydrolysis of lime-water glass and hydration of raw materials, etc. The combined effect of barium sulfate, borax and the consolidation of calcium silicate effectively controlled the radioactivity of red mud unburned bricks.