RUBBING AND DESLIMING OF POTASH ORE

Potassium-sodium salts are a popular raw material in the chemical industry. The main method of enrichment of sylvinite ores is flotation. The conditions of sylvinite ore are mainly determined by the features of the flotation method, while the content of insoluble residue in the ore is regulated (no more than 2%). Today, sylvinite ores contain impurities that exceed threshold values, so preliminary operations are carried out to remove them - rubbing, desliming. Some of the important factors affecting desliming are the particle size, the degree of disclosure and the content of water-insoluble residue in the ore. The negative effect of water-insoluble residue is due to the occurrence of blocking of the sylvinite surface and the adsorption of flotation reagents-collectors by clay minerals. The degree of disclosure (separation of minerals from each other) is determined by mineralogical and petrographic studies, including determination of the shape of contours and nature of the intergrowth planes of ore and non-metallic mineral grains. This method is necessary to adjust the crushing and grinding processes. The efficiency of the technological stages and the quality of the resulting product directly depend on sample preparation. Therefore, the study of the main processing processes and the selection of optimal technological parameters allows us to improve the technology, reduce KCl losses and increase production capacity. Based on the study of the granulometric composition of crushed rock and mineralogical and technological analysis of crushed particles for each size class, the degree of disclosure of sylvite of the Verkhnekamskoye deposit was determined and the crushing dimension was outlined, less than 1 mm. The smallest number of intergrowths is determined in fractions of - 0.63 + 0.4 mm and - 0.4 + 0.2 mm. The process of sylvinite desliming with mother liquor using a laboratory paddle mixer at three ratios S:L=1:2, 1:1, 1:0.5 was studied on the fractions isolated in the work. With a decrease in the S:L ratio of the mother liquor during attrition, it was found that the yield of the solid phase in the pulp decreases. The most optimal ratio is determined to be the ratio S:L=1:1. The extraction of insoluble residue into slimes is more than 50% with a solid sylvinite ore content in the pulp of 50%, the corresponding losses of the useful component (KCl) in the slimes are for the fraction (-0.63+0.4 mm) - 1.18%, for the fraction (-0.4+0.2 mm) - 6.18%). The attrition process is described by diffusion, heterogeneous kinetics. Consequently, the clay component in sylvinite rocks limits the diffusion of desliming, increasing the contact time of the solid surface with the liquid phase. The following are considered to be the recommended process parameters for desliming: particle size - 0.63 + 0.4 mm or - 0.4 + 0.2 mm, solid:liquid ratio = 1:1, temperature = 18-23°C and mixing parameters (600 rpm, mixing time = 5 minutes). The sylvinite rough concentrate obtained during rubbing can be fed to flotation enrichment with a significantly reduced content of insoluble residue.