Studies of uranium leaching from core sample in tubes using an oxidizer

Abstract

Clay content of ore, gangue and clayey cement governs in many ways the primary permeability of rocks and the consumption of chemical agents during uranium leaching. Clayey minerals neutralize sulfuric acid. Consequently, it is necessary to increase sulfuric acid consumption, power input and labor content, and the cost/performance ratio decreases therefore. The article describes application of the borehole uranium mining technology in Kazakhstan. The factors affecting permeability of productive layers are studied in detail. The processes occurring during borehole uranium mining using sulfuric acid as a solvent, as well as the conditions and causes of decrease in the borehole uranium production performance in complex mining and geological conditions in the fields of Kazakhstan are considered. The granulometric composition of core samples from the Chu-Sarysu uranium province was determined. The contents of uranium, calcium, aluminum, iron, magnesium and carbonate in the samples were found using the method of atomic emission spectrometry. The features of the mineral composition of ore-containing rocks were determined by the X-ray phase analysis. A method was developed and the experiments were carried out on a laboratory scale for leaching uranium from the core sample material in tubes, with iron (III) chloride used as an oxidizer in various modes of acidity of working solutions. The laboratory testing data are analyzed and discussed, and the change in the permeability factor Kp, uranium concentration in solution, uranium recovery and sulfuric acid consumption is plotted as function of L:S. The effectiveness of the mild acidity regime with ferric chloride added as an oxidizer is determined and shown.