旋窑和立窑生产轻烧MgO膨胀剂性能的比较分析

目前MgO膨胀剂已在贵州和广东等省份的水利工程坝体全断面或部分区域应用且效果显著。传统方法采用立窑生产轻烧MgO膨胀剂,容易造成菱镁矿表面死烧,内部欠烧或未烧,导致性质不稳定。该文首先对比分析了立窑和旋转窑生产轻烧MgO膨胀剂工艺,讨论了立窑和旋转窑生产轻烧MgO膨胀剂的活性和基本物理化学性能以及对水泥基本性能的影响。结果表明:旋窑采用回转式的结构转动,在物料进入旋窑前还会进行特殊的预热分解处理,使物料的受热更均匀,煅烧更充分,烧制的轻烧MgO膨胀剂的80μm方孔筛筛余量更少,MgO含量更高,MgO活性更稳定。对水泥胶砂力学性能与限制膨胀率而言,旋窑的综合效果更好。为保证工程的质量,建议使用旋转窑生产的轻烧MgO膨胀剂。

Characteristic Comparisons of Rotary and Shaft Kiln Light-burned MgO Expansive Agent

The MgO expansive agent has been used in water conservancy dam and the effect is remarkable in Guizhou and Guangdong Province. Traditional methods adopted shaft kiln light-burned MgO expansion agent, which causes the under-burning or over-burning of MgO, leading to poor uniformity. In order to improve the quality of MgO expansion agent and ensure the quality of water conservancy project construction. The shaft kiln and rotary kiln light-burned MgO expansion agent is analyzed, and the properties of light-burned MgO is discussed. Effects of light-burned MgO expansion agent on the properties of cement are characterized. Results indicate that the rotary kiln adopted the preheating and precalcining technology, and magnesite is heated more evenly. The properties of rotary kiln light-burned MgO expansion agent are more stable than shaft kiln light-burned MgO expansion agent. To guarantee the quality of the project, the rotary kiln light-burned MgO expansion agent is recommended.