COCHILCO CHILEAN COPPER COMMISSION BEST PRACTICES AND EFFICIENT USE OF WATER IN THE MINING INDUSTRY “This document has been translated from the original version in Spanish” BEST PRACTICES AND EFFICIENT USE OF WATER IN THE MINING INDUSTRY CHILEAN COPPER COMMISSION 2 Good Practices and the Efficient Use of Water in the Mining Industry TABLE OF CONTENTS 1 INTRODUCTION ................................................................................................................................................ 11 1.1 General Background .................................................................................................................... 11 1.1.1 Overall availability of water resources ........................................................................... 11 1.1.2 Mining – a key production sector for Chile................................................................. 11 1.1.3 Mining and water resources ................................................................................................... 11 1.1.4 Public-private efforts .......................................................................................................... 12 2 WATER CONSUMPTION IN MINING .................................................................................................................. 17 2.1 Definition of water consumption ........................................................................................................ 17 2.2 Water consumption in copper mining ..................................................................................... 17 2.2.1 Water consumption at camps ............................................................................... 17 2.2.2 Consumption at the mine ............................................................................................................. 17 2.2.3 Consumption at beneficiation plants .......................................................................... 18 2.2.4 Transportation of minerals or concentrate ................................................................................ 20 2.2.5 Smelters ..............................................................................................................................20 2.2.6 Electrolytic refineries .......................................................................................................... 20 2.2.7 Hydro-metallurgical process .................................................................................................... 22 3 WATER CONSUMPTIONRATES IN THE MINING SECTOR ........................................................................................... 27 3.1 Background ....................................................................................................................................... 27 3.2 Freshwater extractions in copper mining.................................................................... 27 3.3 Comparison of water consumption numbers in copper mining...................................... 28 3 COCHILCO CHILEAN COPPER COMMISSION 4 BEST PRACTICES FOR THE EFFICIENT USE OF WATER RESOURCES IN MINING ................................................. 33 4.1 Introduction ............................................................................................................................................. 33 4.2 Water resource management in mining operations ....................................................................... 33 4.3 Case studies .......................................................................................................................................... 34 Case no. 1 Candelaria Mine – Efficient and sustainable management of water ....................... 34 Case no. 2 Los Pelambres Mine – Efficient and sustainable management of water .................. 35 Case no. 3: CODELCO Norte Division – Water resource management ........................................ 36 Case no. 4 BHP Billiton Spence Mine – Limited availability of water and supply by third parties .................................................................................................................. 39 Case no. 5 Michilla Mine – Direct use of sea water in the leaching process ................................ 39 Case no. 6: Coloso Plant, Escondida Mine (MEL) – Use of desalinized water in the production process. ................................................................................................................... 40 4.4 Efficiency indicators ............................................................................................................................. 43 4.4.1 Sustainability reports .............................................................................................................. 43 4.5 Actions for the efficient management of water resources ............................................................. 45 4.5.1 Monitoring ............................................................................................................................... 45 4.5.2 Management of sources ...................................................................................................... 45 4.5.3 Extraction, transportation, storage and distribution .......................................................... 46 4.5.4 Reduction of consumption in operations ........................................................................... 47 4.5.5 General practices ................................................................................................................. 47 4.5.6 Alternative uses and availability of surpluses ..................................................................... 49 4.5.7 Technological alternatives for water resource management ........................................ 49 4.5.7.1 Technologies for optimizing water resource consumption ....................................................... 52 4.5.7.2 Technologies for increasing available water resources ............................................................ 53 5 CONCLUSIONS .................................................................................................................................................... 59 6 REFERENCES ......................................................................................................................................................... 63 7 TECHNICAL GLOSSARY ....................................................................................................................................... 67 4 Good Practices and the Efficient Use of Water in the Mining Industry INDEX OF FIGURES Figure 2.1 Processing of sulfurated minerals by flotation and pyro-metallurgical processes ....................... 21 Figure 2.2: Hydro-metallurgical processing of copper production .................................................................23 Figure 4.1 Water balancing processes ................................................................................................................ 34 Figure 4.2 Unit consumption of freshwater ......................................................................................................... 35 Figure 4.3 Water recirculation system ................................................................................................................. 35 Figure 4.4 Uses of water resources at CODELCO Norte in 2007 ....................................................................... 37 Figure 4.5 Distribution of real water consumption in 2007 ................................................................................ 37 Figure 4.6 Evolution of the concentrator make up ........................................................................................... 38 Figure 4.7 Coloso Plant ......................................................................................................................................... 38 Figure 4.8 Diagram of the Escondida Mina Coloso Plant Aqueduct ............................................................. 42 Figure 4.9 Water balancing .................................................................................................................................. 43 INDEX OF TABLES Table 3.1 Average water consumption in national mining by treated mineral ......................................................... 28 Table 4.1 Environmental performance indicators related to water resources ........................................................... 44 Table 4.2 Technologies for optimizing water resource consumption .............................................................. 50 Table 4.3 Technologies and potential for increasing available water resources ........................................................ 51 INDEX OF GRAPHS Graph 2.1 Typical graph of water requirements in concentrator plant processes ....................................... 18 Graph 3.1 Total informed extraction by region (l/s) .......................................................................................... 28 Graph 3.2 Water efficiency in the beneficiation process ................................................................................. 29 Graph 3.3 Water efficiency in the hydro-metallurgical process ...................................................................... 29 5 COCHILCO CHILEAN COPPER COMMISSION LETTER FROM THE MINING MINISTER The limited availability of water resources in northern Chile has become one of the most important topics in the country’s agenda due to the importance of the resource for the