金属矿尾砂浆压缩与剪切屈服应力的关系

膏体流变学的研究是矿业浆体流变学的热点和难点。膏体技术包括脱水、搅拌、输送、堆存(充填)4个阶段，均涉及到非牛顿流体流变特性。在脱水阶段，全尾砂的压缩屈服应力影响了尾砂浆的脱水浓度，浓度是剪切屈服应力的宏观表现，继而影响了混合搅拌和管道输送过程中浆体的剪切屈服应力。所以，压缩屈服应力和剪切屈服应力之间的关系成为了膏体充填技术领域中的关键问题。在压滤理论指导下，开展相关实验，提出了全浓度范围内床层脱水阻力和浆体输送性能表征方法，以表征全尾砂浆的可浓密性能。对全尾砂高压力作用下的可浓密性能进行测试，得到高压力下全尾砂浆体的压缩屈服应力；使用控制剪切速率法(CSR)操作桨式流变仪检测剪切屈服应力；继而得到两者之间的关系为：浆体屈服应力为剪切应力，压缩屈服应力为压缩应力；浆体的压缩屈服应力、剪切屈服应力与浓度指数均呈指数关系。并且压缩屈服应力远大于剪切屈服应力，因此剪切作用更易破坏絮团，是脱水的主要外部动力，从而解释了搅拌脱水的力学机理。

Relationship between compression and shear yield stress of metal mine tailing mortar

The study of paste rheology is a hot and difficult point in the rheology of mining slurry. Paste technology includes four stages: dehydration, stirring, transportation and storage (filling), and all the stages involve rheological properties of non-Newtonian fluids. In the dewatering stage, the compressive yield stress of the whole tailings affects the dewatering concentration of the tailings mortar, and the concentration is the macroscopic expression of the shear yield stress, which in turn affects the shear yield stress of the slurry during mixing and pipeline transportation. Therefore, the relationship between compressive yield stress and shear yield stress has become a key issue in the field of paste filling technology. Under the guidance of pressure filtration theory, relevant experiments were carried out, and the characterization methods of bed dehydration resistance and slurry transportation performance in the full concentration range were put forward to characterize the thickening performance of full-tail mortar. The thickening performance of the whole tailings under high pressure is tested, and the compression yield stress of the whole tailings mortar under high pressure is obtained. Using controlled shear rate method (CSR) to operate paddle rheometer to detect shear yield stress; Then the relationship between them is obtained as follows: the yield stress of slurry is shear stress, and the compression yield stress is compression stress; Compressive yield stress and shear yield stress of slurry are exponentially related to concentration index. And the compression yield stress is far greater than the shear yield stress, so the shear action is more likely to destroy flocs, which is the main external force of dehydration, thus explaining the mechanical mechanism of stirring dehydration.