Microbial Extraction of Uranium from Ores

Abstract

CONTENTS 3.1 Introduction 3.2 Uranium Leaching Methodologies 3.2.1 Chemical Leaching 3.2.2 Bioleaching 3.3 Modes and Mechanism of Uranium Bioleaching 3.3.1 Direct Mechanism 3.3.2 Indirect Mechanism 3.3.3 Bioleaching by Heterotrophs 3.4 Factors Influencing Bioleaching 3.4.1 Mineralogy of the Ore 3.4.2 Microorganisms 3.4.3 Temperature 3.4.4 pH 3.4.5 Nutrients and Energy Source 3.4.6 Importance of Iron Oxidation 3.4.7 Sulphur Reduction 3.5 Bioleaching Techniques 3.5.1 Laboratory Investigations 3.5.1.1 Submerged Leaching 3.5.1.2 Column/Percolation Bioleaching 3.5.2 Large Scale/Industrial Operations 3.5.2.1 Dump Leaching 3.5.2.2 Heap Leaching 3.5.2.3 In Situ Leaching 3.5.2.4 Tank Leaching 3.6 Bioleaching of Uranium in the Indian Scenario. 3.7 Conclusions References