MANUAL ON LABORATORY TESTING FOR URANIUM ORE PROCESSING The following States are Members of the International Atomic Energy Agency: AFGHANISTAN HAITI PARAGUAY ALBANIA HOLY SEE PERU ALGERIA HUNGARY PHILIPPINES ARGENTINA ICELAND POLAND AUSTRALIA INDIA PORTUGAL AUSTRIA INDONESIA QATAR BANGLADESH IRAN, ISLAMIC REPUBLIC OF ROMANIA BELGIUM IRAQ SAUDI ARABIA BOLIVIA IRELAND SENEGAL BRAZIL ISRAEL SIERRA LEONE BULGARIA ITALY SINGAPORE BYELORUSSIAN SOVIET JAMAICA SOUTH AFRICA SOCIALIST REPUBLIC JAPAN SPAIN CAMEROON JORDAN SRI LANKA CANADA KENYA SUDAN CHILE KOREA, REPUBLIC OF SWEDEN CHINA KUWAIT SWITZERLAND COLOMBIA LEBANON SYRIAN ARAB REPUBLIC COSTA RICA LIBERIA THAILAND COTE DTVOIRE LIBYAN ARAB JAMAHIRIYA TUNISIA CUBA LIECHTENSTEIN TURKEY CYPRUS LUXEMBOURG UGANDA CZECHOSLOVAKIA MADAGASCAR UKRAINIAN SOVIET SOCIALIST DEMOCRATIC KAMPUCHEA MALAYSIA REPUBLIC DEMOCRATIC PEOPLE'S MALI UNION OF SOVIET SOCIALIST REPUBLIC OF KOREA MAURITIUS REPUBLICS DENMARK MEXICO UNITED ARAB EMIRATES DOMINICAN REPUBLIC MONACO UNITED KINGDOM OF GREAT ECUADOR MONGOLIA BRITAIN AND NORTHERN EGYPT MOROCCO IRELAND EL SALVADOR MYANMAR UNITED REPUBLIC OF ETHIOPIA NAMIBIA TANZANIA FINLAND NETHERLANDS UNITED STATES OF AMERICA FRANCE NEW ZEALAND URUGUAY GABON NICARAGUA VENEZUELA GERMAN DEMOCRATIC REPUBLIC NIGER VIET NAM GERMANY, FEDERAL REPUBLIC OF NIGERIA YUGOSLAVIA GHANA NORWAY ZAIRE GREECE PAKISTAN ZAMBIA GUATEMALA PANAMA ZIMBABWE The Agency's Statute was approved on 23 October 1956 by the Conference on the Statute of the IAEA held at United Nations Headquarters, New York; it entered into force on 29 July 1957. The Head- quarters of the Agency are situated in Vienna. Its principal objective is "to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world". © IAEA, 1990 Permission to reproduce or translate the information contained in this publication may be obtained by writing to the International Atomic Energy Agency, Wagramerstrasse 5, P.O. Box 100, A-1400 Vienna, Austria. Printed by the IAEA in Austria June 1990 TECHNICAL REPORTS SERIES No.313 MANUAL ON LABORATORY TESTING FOR URANIUM ORE PROCESSING INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 1990 MANUAL ON LABORATORY TESTING FOR URANIUM ORE PROCESSING IAEA, VIENNA, 1990 STI/DOC/10/313 ISBN 92-0-145190-3 ISSN 0074-1914 FOREWORD Laboratory testing of uranium ores is an essential step in the economic evalua- tion of uranium occurrences and in the development of a project for the production of uranium concentrates. Although these tests represent only a small proportion of the total cost of a project, their proper planning, execution and interpretation are of crucial importance. The main purposes of this manual are to discuss the objectives of metallurgical laboratory ore testing, to show the specific role of these tests in the development of a project, and to provide practical instructions for performing the tests and for inter- preting their results. Guidelines on the design of a metallurgical laboratory, on the equipment required to perform the tests and on laboratory safety are also given. This manual is part of a series of Technical Reports on uranium ore processing being prepared by the IAEA's Division of Nuclear Fuel Cycle and Waste Manage- ment. A report on the Significance of Mineralogy in the Development of Flowsheets for Processing Uranium Ores (Technical Reports Series No. 196, 1980) and an instruction manual on Methods for the Estimation of Uranium Ore Reserves (No. 255, 1985) have already been published. The IAEA wishes to thank the consultants who took part in the preparation of this report for their valuable contributions: E.G. Joe (Canada Centre for Mineral and Energy Technology), T.K.S. Murthy (Bhabha Atomic Research Centre, India), D.C. Seidel (Bureau of Mines, United States of America) and A. Stergarsek (Jozef Stefan Institute, Yugoslavia). A significant portion of the section on acid leaching was adapted from a paper by R. Ring and D.M'. Levins (Australia). Thanks are also due to the consultants' Member States and organizations for their generous support in providing experts to assist in this work. The IAEA officer responsible for this work was S. Ajuria of the Division of Nuclear Fuel Cycle and Waste Management, who contributed much original material to the manual. EDITORIAL NOTE The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation on the part of the IAEA. CONTENTS 1. INTRODUCTION 1 1.1. Summary review of uranium ore processing technology 1 1.2. Development of a metallurgical project 3 1.3. Objectives of laboratory testing of uranium ores 8 1.4. Objectives of pilot plant testing 9 2. SAMPLING AND CHARACTERIZATION 10 2.1. Sample selection and compositing 10 2.2. Sample identification 11 2.3. Sample preparation 12 2.3.1. Coning and quartering 13 2.3.2. Splitting 15 2.3.3. Sampling test products 19 2.4. Mineralogical characterization 20 2.5. Instrumental and chemical analysis 25 3. SIZE REDUCTION 26 3.1. Grinding tests 26 3.2. Power consumption 27 3.3. Screening and sizing 28 3.3.1. Preparations for screening 29 3.3.2. Dry screening 31 3.3.3. Wet screening 31 3.4. Size analysis 34 4. LEACHING 35 4.1. Introduction 35 4.2. Sample requirements 35 4.3. Leaching variables 36 4.3.1. Grind size 36 4.3.2. Slurry density 36 4.3.3. Degree of agitation 37 4.3.4. Acid concentration 37 4.3.5. Oxidation potential 38 4.3.6. Temperature 39 4.3.7. Leaching time 40 4.4. Experimental techniques for acid leach tests 42 4.5. Alkaline leaching 45 4.6. Preliminary testing 46 4.7. Alkaline test procedure 46 5. SOLID-LIQUID SEPARATION AND WASHING 48 5.1. Thickening 49 5.1.1. Conventional thickeners 49 5.1.2. High rate thickeners 50 5.2. Filtration 50 5.2.1. Introduction 50 5.2.2. Filtration parameters 51 5.2.2.1. Type and amount of flocculant 5.2.2.2. Cake formation rate 5.2.2.3. Cake moisture rate 5.2.2.4. Cake washing rate 5.2.2.5. Cake thickness 5.2.2.6. Wash solution consumption and washing efficiency 5.2.2.7. Type of filter cloth 5.2.3. Filtration test procedures 54 5.2.3.1. Slurry samples 5.2.3.2. Apparatus 5.2.3.3. Flocculation tests 5.2.3.4. Drum filtration 5.2.3.5. Belt filtration 5.2.3.6. Test data recording 6. URANIUM RECOVERY FROM LEACH SOLUTIONS 61 6.1. Solution characterization 62 6.2. Direct precipitation 62 6.3. Ion exchange 63 6.3.1. Characteristics of resins used for uranium recovery 64 6.3.2. Factors affecting uranium adsorption capacity 64 6.4. Solvent extraction 67 6.4.1. Uranium extraction by amines 67 6.4.2. Mechanism of extraction and stripping 68 7. URANIUM RECOVERY BY ION EXCHANGE 69 7.1. Aims of laboratory tests 69 7.2. Changes in effluent composition in the adsorption-elution cycle.. 71 7.3. Changes in resin composition in the adsorption-elution cycle .... 73 7.4. Ion exchange tests with a single column 74 7.4.1. Resin loading tests 74 7.4.2. Resin poisoning tests 78 7.5. Multicolumn ion exchange operation 78 7.5.1. Description of set-up 80 7.5.2. Sequence of three column operation 83 8. URANIUM RECOVERY BY SOLVENT EXTRACTION 85 8.1. Laboratory tests 85 8.1.1. Scope of tests 85 8.1.2. Preparation of solvent and determination of loading capacity 85 8.1.2.1. Determination of maximum loading capacity 8.1.2.2. Determination of effective maximum loading capacity 8.1.3. Rate of extraction 86 8.1.4. Extraction isotherm 87 8.1.5. Stage calculations (McCabe-Thiele diagram) 89 8.2. Batch counter-current extraction tests 91 8.2.1. Extraction 91 8.2.2. Stripping of uranium from loaded solvent 94 8.3. Continuous extraction tests 94 8.3.1. Determination of coalescence rate and settler area 97 8.3.1.1. Static method 8.3.1.2. Dynamic method 8.3.2. Characterization of dispersion 97 8.3.3. Solvent loss 100 9. PRECIPITATION 100 9.1. Solution characterization 100 9.2. Precipitation from acidic solutions 102 9.2.1. Polyuranates 102 9.2.2. Uranium peroxide 102 9.2.3. Other methods 104 9.3. Precipitation from carbonate solutions 104 10. ALTERNATIVE TECHNIQUES 105 10.1. Physical beneficiation 105 10.1.1. Gravity concentration 106 10.1.2. Flotation 107 10.1.3. Radiometric sorting 107 10.2. Roasting 108 10.3. Static bed leaching 110 10.4. Bacterially assisted leaching Ill 10.5. Acid pugging 112 10.6. Acidic pressure leaching 113 11. FLOW SHEETS AND MATERIAL BALANCES 114 11.1. Flow sheets 114 11.2. Material balances 117 12. REPORT WRITING 120 12.1. Initial research 121 12.2. Laboratory notebooks and other supporting documentation 121 12.3. Contents of test report 121 APPENDIX I: LABORATORY SAFETY 125 1.1. General safety precautions 125 1.2. Radiological safety 125 1.3. Safety rules 126 APPENDIX II: GUIDELINES FOR LABORATORY DESIGN 127 APPENDIX III: SUGGESTED LABORATORY EQUIPMENT AND SUPPLIES 130 III.l. Equipment for specific operations 130 HI.2. Glassware 132 111.3. Instrumentation 134 111.4. Safety equipment 134 111.5. Additional equipment 134 111.6. Reagents 134 111.7. Assorted supplies 135 REFERENCES 137 BIBLIOGRAPHY 138 CONTRIBUTORS TO DRAFTING AND REVIEW 147 IAEA PUBLICATIONS ON URANIUM ORE PROCESSING 149 1. INTRODUCTION Laboratory testing of ores is an important step in the development of a metal- lurgical project. Its main purpose is to study the behaviour of a particular ore in selected process environments and to provide information needed, first, to make a preliminary assessment of the economic feasibility of a proposed project and later, if the project is viable, as the basis for further development of a suitable metallurgical process and for the design of an industrial plant.