WC/97/020 Local Development of Affordable Lime in Southern Africa
Total Page：16
File Type：pdf, Size：1020Kb
0 0 0 0 DFID Department For 0 lnternat ional Development 0 0 British Geological Survey 0 TECHNICAL REPORT WC/97/20 0 Overseas Geology Series 0 0 LOCAL DEVELOPMENT OF AFFORDABLE 0 LIME IN SOUTHERN AFRICA 0 0 CJ Mitchelll, SDJ Inglethorpe', P TawodZera2,S Bradwel13& EJ Evans' 0 with contributions from DJ Harrison', A Kufa2, EJ Evansl, S Mabuku4,B Muibeya', E Chikambwe4and D Kapindulaq 0 'BGS Mineralogy and Petrology Group, * Intermediate Technology Zimbabwe, 0 Technology Development and Advisory Unit, University of Zambia, Lusaka, 'Zambian Geological Survey Department, Lusaka a This report is an output from a project funded by the UK Department for 0 International Development (DFID) under the UK provision of technical assistance 0 to developing countries. The views expressed are not necessarily those of the Department 0 0 DFID cIassifwation : Subsector : Geoscience 0 Theme :G1, Promote environmentally sensitive development of non-renewable natural resources Project title :Local development of affordable lime in Southern Africa 0 Project reference :R6492 Bibliographic ri$erence : 0 Mitchell, CJ, Inglethorpe, SDJ,Tawodzera, P, Bradwell, S & Evans, EJ 1998. L.oca1 development of affordable lime in Southern Nrica 0 BGS Technical Report WC/97/20 0 Keywords :Limestolle, agricultural lime, Southern Africa, Zambia 0 Frmt mer illustration :Outcrop of dolomite (Mujimbeji Marble), Solwezi, North-westem Province, Zambia 0 0 NERC 1998 0 0 Keyworth, Nottingham, British Geological Survey, 1998 0 0 0 a e 0 CONTENTS Page No. a CONTENTS 1 0 EXECUTIVE SUMMARY v1 ... 0 INTRODUCTION Vlll 0 SECTION A: MARKET SURVEY OF AGRICULTURAL LIME USE IN ZAMBIA 0 1. INTRODUCTION A1 2. METHODS A1 0 3. RESULTS A2 0 3.1. Demand for lime A2 a 3.2. Quality of lime A3 3.3. Quantity of lime A4 0 3.4. Where lime is most needed A4 0 3.5. Questionnaire survey of aglime users A5 A6 0 4. DISCUSSION 4.1. Factors affecting demand for agricultural lime A6 a 4.2. Local production of agricultural lime A7 0 5. CONCLUSIONS A9 APPENDIX Al: Questionnaire on the use of lime in Zambian farming A1 1 e APPENDIX A2: Selected comments arising from aglime questionnaire survey A12 0 SECTION B: REVIEW OF THE CARBONATE RESOURCES OF ZAMBIA 0 1. CARBONATE GEOLOGY OF ZAMBIA B1 0 1.1. Basement complex B1 1.2. Katanga Supergroup B2 1.2.1. Geology B2 0 1.2.2. Monze Group B2 B3 0 1.2.3. Broken Hill Group 1.2.4. Mine Series Group B4 0 1.2.5. Mwashia Formation, Middle Katanga B4 1.2.6. Kundelungu Group B4 1.2.7. Undifferentiated Katanga B6 0 1.2.8. Commercial extraction from the Katanga B8 e 1.3. Post Katanga B8 0 1.4. Miscellaneous B9 1.5. Occurrences of limestone with potential for use as agricultural lime B10 0 2. CONCLUSIONS B10 0 0 1 0 0 0 0 0 0 CONTENTS Page No. 0 B11 0 APPENDIX B1: Simplified geological succession of Zambia APPENDIX B2: Carbonate Occurrences in Zambia B12 0 APPENDIX B3: Sources of information B18 0 APPENDIX B4: Potential agricultural lime sites B20 0 SECTION C: LABORATORY ANALYSIS OF LIMESTONE AND DOLOMITE e FOR USE AS AGRICULTURAL LIME 0 1. INTRODUCTION - c1 2. AGRICULTURAL LIME TEST METHODS AND LABORATORY TRIALS c1 0 2.1. Methods and samples c1 0 2.2. Results c3 3. CONCLUSIONS c4 0 3.1. Literature review c4 0 3.2. BGS laboratory trial c4 0 3.3. Rationale for laboratory testing c5 APPENDIX C1: Key properties of agricultural lime C6 0 APPENDIX C2: Recommended methods for testing limestone and dolomite for 0 agricultural lime use. Method 1. Calcium Carbonate Equivalent test method C13 0 APPENDIX C3: Recommended methods for testing limestone and dolomite for 0 agricultural iime use. a Method 2. CaO and MgO by EDTA titration method C15 APPENDIX C4: Recommended methods for testing limestone and dolomite for agricultural lime use. m Method 3. Grindability index test method c20 APPENDIX C5: Recommended methods for testing limestone and dolomite for 0 agricultural lime use. 0 Method 4. Sieve analysis of agricultural liming materials method c22 0 APPENDIX C6: Recommended methods for testing limestone and dolomite for agricultural lime use 0 Method 5. Reactivity by the resin suspension method C23 0 e a 0 .. 0 11 0 0 0 0 0 a CONTENTS Page No. 0 0 SECTION D: LIME EVALUATION PROGRAMME: FINDINGS & RESULTS 1. INTRODUCTION D1 0 2. METHODS D1 0 2.1. Field sampling & preparation D1 2.2. Test methods D2 a 3. RESULTS & DISCUSSION D2 0 4. CONCLUSIONS D4 APPENDIX D1: Lime evaluation sampling programme - Sample list D5 0 APPENDIX D2: Petrography of limestone and dolomite from Zambia D8 a APPENDIX D3: Test results D11 a SECTION E: REVIEW OF SMALL-SCALE LIME PRODUCTION IN 0 ZIMBABWE El 0 0 SECTION F: THE MILLING OF AGRICULTURAL LIME 1. INTRODUCTION F1 a 2. AIMS F2 0 3. METHODOLOGY F2 4. RESULTS F4 a 4.1. Milling performance F4 0 4.2. Particle-size analysis F4 0 5. DISCUSSION AND CONCLUSIONS F6 APPENDIX F1: Some cash flow analysis for service milling of limestone F8 0 0 SECTION G: LOCAL DEVELOPMENT OF AFFORDABLE LIME IN SOUTHERN AFRICA WORKSHOP G1 a APPENDIX G1 Workshop delegate listing G9 0 0 SECTION H: RECOMMENDATIONS FOR THE EVALUATION AND SMALL-SCALE PRODUCTION OF LIME H1 e 0 SECTION I: REFERENCES 11 0 0 e ... 0 111 0 a 0 a 0 0 CONTENTS Page No. 0 TABLES 0 0 A1 Actual, projected & potential demand for agricultural Lime in Zambia A2 A2 Summary of lime questionnaire survey responses A6 0 B1 Chemistry of Basement complex, Zambia B1 a B2 Chemistry of Monze Group carbonates, Zambia B2 0 B3 Chemistry of Mujimbeji Marble, NW Province, Zambia B3 B4 Chemistry of Broken Hill Group carbonates, Zambia B3 e B5 Chemistry of marble, Upper Roan Formation, Mpongwe area, e Copperbelt Province B4 e B6 Chemistry of Mwashia Formation carbonates, Zambia B4 B7 Chemistry of Kundelungu Group carbonates, Zambia B5 0 B8 Chemistry of dolomitic marble (Luapula Beds), Luapula Province B5 0 B9 Chemistry of dolomitic carbonate, Mkushi B6 B 10 Chemistry of the undifferentiated Katanga carbonates, Zambia B6 0 B11 Chemistry of calcitic marble, Mapanza Carbonate Formation, a Macha Mapanza Mission, Southern Province B7 B7 0 B12 Typical chemistry of Mvuvye Marble, Nyimba area, Eastern province B13 Chemistry of limestone, Masangu Farm B8 0 B 14 Chemistry of commercial limestone products, Zambia B8 0 B 15 Chemistry of carbonatites, Zambia B9 B16 Typical chemistry of dolomitic carbonatite, Nkombwa Hill, Isoka, 0 Northern Province B9 0 B17 Carbonates with potential for use as agricultural lime in Zambia B10 e Cl List of samples analyzed for the BGS laboratory trial c2 c2 Results of the test work on limestone and dolomite samples from Zambia c3 0 D1 Summary of limestone & dolomite test results D2 0 D2 Samples with potential for use as agricultural lime D3 F1 Specification of sieve materials used F3 0 F2 Output results from milling trials F4 0 F3 Dry particle size analysis of raw material F5 0 F4 Dry particle size analysis of milled materials F5 F5 The milling efficiencies per hour and per litre for different sieve sizes F6 0 F6 The particle size of the milled output F6 0 F7 Cost analvsis of milling trials F6 0 0 iV 0 0 CONTENTS Page No. FIGURES A1 Rainfall map of Zambia overlain by carbonate deposits A13 c1 Plots of reactivity versus grindability index for some Zambian limestone and dolomite samples C25 c2 Plots of reactivity against fineness c25 D1 Preparation of limestone & dolomite for analysis Dl F1 The TD hammer mill, TDAU, Lusaka Fl F2 Schematic representation of gravity feed-gravity discharge TD Hammermill F3 F3 Dry particle size analysis of raw material F5 F4 Dry particle size analysis of milled materials F5 F5 The cost of milling agricultural lime per kg as a function of sieve size F7 H1 Recommended process route for small-scale production of lime (and other products) H3 PLATES A1 Ball milling of agricultural lime, Minceco Small Mines Ltd, Lusaka A14 A2 Calcitic (dark grey) and dolomitic (light grey) carbonate, Ndola Lime Ltd A14 B1 Outcrop of Mujimbeji Marble, Chombela, North-western Province B24 B2 Outcrop of Luapula Beds, Matanda, Luapula Province B24 B3 Outcrop of Lower Roan Formation, north of Mkushi, Central Province B25 B4 Tailings from Nampundwe F'yrite Mine, west of Lusaka B25 D1 Preparation of carbonate samples for testing, GSD labs, Lusaka D12 D2 Testing of carbonate sample by GSD geochemist (David Kapindula), GSD labs, Lusaka D12 F1 The TD hammer mill, TDAU, Lusaka Fll F2 Ground carbonate, product of TD hammer mill F1 I G1 Banner advertising workshop (+ key worker Simon Inglethorpe), Parnodzi Hotel, Lusaka Gll G2 Opening address at workshop given by Director of GSD (Davison Mulela, on right) and workshop co-ordinator (Clive Mitchell, centre) G11 V EXECUTIVE SUMMARY Lime is an important and versatile chemical used in a wide range of applications. The term lime, which is strictly calcium oxide (CaO), is applied to a range of products arising from the processing of limestone and dolomite. Many less developed countries do not have adequate lime production and this leads to problems associated with under- utilisation of lime. In particular, insufficient application of agricultural lime (aglime) can lead to soil acidification, with associated aluminium / manganese toxicity and poor crop yields. As part of the UK Government’s commitment to provide technical assistance to developing countries, a project was initiated to help solve this problem. The BGS / Department for International Development (DFID) project “Local development of affordable lime in Southern Africa” (R6492) aimed to encourage the development of low- cost lime for agriculture and water treatment.