Hydraulic separation in spiral classifiers. Part 1. Theoretical justification for a mathematical model compiling

Abstract

Purpose. Improving the accuracy of evaluating the separation mode of the spiral classifier. The methodology of research consists on establishment of the indicative size of the separation in accordance with the theoretical constructions and quantitative ratios of the classification parameters. Findings. The analysis of physical processes occurring in the pulp stream located just before the overflow weir was performed. A mathematical model of the solid phase stratification in this part of the flow was obtained. Originality. According to the theoretical constructions and quantitative relations, the dependence of the value of the maximum particle size in the pulp flow located above the crest of the overflow weir was obtained. That is, the indicative size, which determines the boundary of the division of the particle size distribution function into two parts: larger particles settle and are carried to the sands, and thinner ones – go into the overflow. The value of this size depends on the regime parameters of the classification, and the distribution function depends on the physical properties of the processed ore. It is sufficientto simulate the process of solidparticlesseparation in spiral classifier in the near-wall area of its overflow, since the scale of turbulence can be compared with the size of the classifier. In addition, the calculations should take into account the change in pulp temperature to calculate the viscosity of the medium. Practical implication. Indicative particle size, which was obtained on the basis of this mathematical model,determines all further qualitative indicators of the enrichment process, and can be established on the basis of indicators that can be directly measured or calculated automatically in real-time mode. Thus, it becomes possible to manage the preparatory process to achieve stable quality indicators of the concentrate.