全尾砂膏体搅拌剪切过程的触变性

膏体触变性是一种复杂的流变现象，涉及到膏体的搅拌制备、管道输送、采场流动等多方面，但是对膏体的触变性机理目前还缺乏统一的认识，对全尾砂膏体处置技术中出现的各种与触变性相关现象还难以解释。针对全尾砂膏体搅拌剪切过程中的触变行为，对某尾矿全尾砂膏体在不同条件下进行流变测试，研究全尾砂粒级、膏体中固相质量分数、水泥添加量、静置时间等因素对膏体触变的影响规律，分析全尾砂膏体触变行为及其对全尾砂膏体稳定性能的影响。研究结果表明，全尾砂颗粒以三维网状结构弥散于浆体空间，其触变性与屈服应力及膏体料浆稳定性相关，受到料浆中超细成分、灰砂比、固相质量分数等影响，膏体触变特征可划分为剪切破坏及静置恢复两个过程，其流变特性具有随时间而变化的特点。

Thixotropy of unclassified pastes in the process of stirring and shearing

The thixotropy of pastes is a complex rheology phenomenon, which concerns paste mixing preparation, pipeline trans-portation, flowing in stopes and many other aspects. But currently it is difficult to interpret many kinds of thixotropy-related phenomena in unclassified tailing paste technology due to the lack of a common understanding of its mechanism. To explain the thixotropic behav-ior of a unclassified tailing paste in the process of stirring, the impacts of unclassified tailing particle size, slurry concentration, addi-tion of cement and standing time on the paste thixotropy were studied by conducting rheological experiments of the paste in different conditions of a certain mine, and the thixotropic behavior of the paste and its influence on the stability were analyzed. The results show that unclassified tailing particles disperse in the slurry in the form of three-dimensional network structure, and their thixotropy and yield stress are relevant to the stability of the slurry. Influenced by ultrafine composition, cement- tailing ratio and slurry concentra-tion, the thixotrophic characteristics of the paste can be divided into two process, shear failure and standing recovery. Besides, the paste’ s rheology characteristics will change over time.