Myths and Realities in Artisanal Gold Mining Mercury Contamination
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Significance of Mineralogy in the Development of Flowsheets for Processing Uranium Ores
JfipwK LEACHING TIME REAGENTS TEMPERATURE FLOCCULANT CLARITY AREA COUNTER CURRENT DECANTATION It 21 21 J^^LJt TECHNICAL REPORTS SERIES No.19 6 Significance of Mineralogy in the Development of Flowsheets for Processing Uranium Ores \W# INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 1980 SIGNIFICANCE OF MINERALOGY IN THE DEVELOPMENT OF FLOWSHEETS FOR PROCESSING URANIUM ORES The following States are Members of the International Atomic Energy Agency: AFGHANISTAN HOLY SEE PHILIPPINES ALBANIA HUNGARY POLAND ALGERIA ICELAND PORTUGAL ARGENTINA INDIA QATAR AUSTRALIA INDONESIA ROMANIA AUSTRIA IRAN SAUDI ARABIA BANGLADESH IRAQ SENEGAL BELGIUM IRELAND SIERRA LEONE BOLIVIA ISRAEL SINGAPORE BRAZIL ITALY SOUTH AFRICA BULGARIA IVORY COAST SPAIN BURMA JAMAICA SRI LANKA BYELORUSSIAN SOVIET JAPAN SUDAN SOCIALIST REPUBLIC JORDAN SWEDEN CANADA KENYA SWITZERLAND CHILE KOREA, REPUBLIC OF SYRIAN ARAB REPUBLIC COLOMBIA KUWAIT THAILAND COSTA RICA LEBANON TUNISIA CUBA LIBERIA TURKEY CYPRUS LIBYAN ARAB JAMAHIRIYA UGANDA CZECHOSLOVAKIA LIECHTENSTEIN UKRAINIAN SOVIET SOCIALIST DEMOCRATIC KAMPUCHEA LUXEMBOURG REPUBLIC DEMOCRATIC PEOPLE'S MADAGASCAR UNION OF SOVIET SOCIALIST REPUBLIC OF KOREA MALAYSIA REPUBLICS DENMARK MALI UNITED ARAB EMIRATES DOMINICAN REPUBLIC MAURITIUS UNITED KINGDOM OF GREAT ECUADOR MEXICO BRITAIN AND NORTHERN EGYPT MONACO IRELAND EL SALVADOR MONGOLIA UNITED REPUBLIC OF ETHIOPIA MOROCCO CAMEROON FINLAND NETHERLANDS UNITED REPUBLIC OF FRANCE NEW ZEALAND TANZANIA GABON NICARAGUA UNITED STATES OF AMERICA GERMAN DEMOCRATIC REPUBLIC NIGER URUGUAY GERMANY, FEDERAL REPUBLIC OF NIGERIA VENEZUELA GHANA NORWAY VIET NAM GREECE PAKISTAN YUGOSLAVIA GUATEMALA PANAMA ZAIRE HAITI PARAGUAY ZAMBIA PERU 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. -
Curbing Illicit Mercury and Gold Flows in West Africa: Options for a Regional Approach
Curbing Illicit Mercury and Gold Flows in West Africa: Options for a Regional Approach i INCLUSIVE AND SUSTAINABLE INDUSTRIAL DEVELOPMENT ii Curbing Illicit Mercury and Gold Flows in West Africa: Options for a Regional Approach iii November 2018 iv © UNIDO 2018. All rights reserved. This document has been produced without formal United Nations editing. The designations employed and the presentation of the material in this document do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations Industrial Development Organization (UNIDO) concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries, or its economic system or degree of development. Designations such as ‘developed’, ‘industrialized’ or ‘developing’ are intended for statistical convenience and do not necessarily express a judgement about the stage reached by a particular country or area in the development process. Mention of firm names or commercial products does not constitute an endorsement by UNIDO. Unless otherwise men- tioned, all references to sums of money are given in United States dollars. References to ‘tons’ are to metric tons, unless otherwise stated. All photos © UNIDO unless otherwise stated. Cover photo by Sadibou Sylla Acknowledgements This report was authored by Marcena Hunter of the Global Initiative Against Transnational Organized Crime. The report is part of the United Nations Industrial Development Organization (UNIDO) project, funded by the Government of Switzerland, to assist the Economic Community of West African States (ECOWAS) in its early implementation of the Minamata Convention. More information about the Minamata Convention and UNIDO’s work can be found on UNIDO’s website <https://www.unido.org/mercury> or by emailing Gabriela Eigenmann at [email protected]. -
S Ndlovu (PDF)
Extraction of Gold Then, Now and the Future Prof Sehliselo Ndlovu DST/NRF SARChI: Hydrometallurgy and Sustainable Development University of the Witwatersrand, Johannesburg Building a Robust Minerals Industry 3 – 4 July 2017, Cresta Lodge, Harare University of the Witwatersrand Johannesburg Founded Oct. 1896: School of Mines Approx. 37 000 Students 5 Faculties, 33 Schools, 3610 Courses >160 000 Degrees Conferred since 1922 55% Female Students 10 National Centres of Excellence Home to the Bidvest Football Club( Current PSL league Champions) Evolution in Gold Processing Past Technologies • Amalgamation • Panning Current Technologies • Cyanide leaching • Processing of Emerging and Future refractory ores Technologies • Bio-oxidation • Ionic liquids • Alternative leaching • Ultrasonic leaching reagents • Corn starch?? Past Technologies Used in Ancient Times History of gold extends back at least 6,000 years. Egypt and Mesopotamia around 4000 BC. Gravity Separation: Gold Panning Gold concentrated by washing lighter river sands with water Leaves dense gold particles Alternative- wash gold-bearing sand and gravel over a woollen fleece Traps heavier gold dust that would sink into the wool fibres. Advantages • Simplicity Disadvantages • Labour intensive Gravity Separation: Sluicing • Water is channelled to flow through a sluice-box. • Sluice-box is essentially a man-made channel with riffles (barriers) at the bottom. • Riffles create dead-zones in the water current which allows gold to drop out of suspension. Sluicing and panning results in the direct recovery of small gold nuggets and flakes. Gold Parting: Salt Cementation Process • Invented to remove Ag from Au-Ag mixtures around 6th century BC. Mix: argentiferous gold foil, common salt, brick dust or burnt clay and urine in a sealed container. -
Metal Extraction Processes for Electronic Waste and Existing Industrial Routes: a Review and Australian Perspective
Resources 2014, 3, 152-179; doi:10.3390/resources3010152 OPEN ACCESS resources ISSN 2079-9276 www.mdpi.com/journal/resources Review Metal Extraction Processes for Electronic Waste and Existing Industrial Routes: A Review and Australian Perspective Abdul Khaliq, Muhammad Akbar Rhamdhani *, Geoffrey Brooks and Syed Masood Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia; E-Mails: [email protected] (A.K.); [email protected] (G.B.); [email protected] (S.M.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +61-3-9214-8528; Fax: +61-3-9214-8264. Received: 11 December 2013; in revised form: 24 January 2014 / Accepted: 5 February 2014 / Published: 19 February 2014 Abstract: The useful life of electrical and electronic equipment (EEE) has been shortened as a consequence of the advancement in technology and change in consumer patterns. This has resulted in the generation of large quantities of electronic waste (e-waste) that needs to be managed. The handling of e-waste including combustion in incinerators, disposing in landfill or exporting overseas is no longer permitted due to environmental pollution and global legislations. Additionally, the presence of precious metals (PMs) makes e-waste recycling attractive economically. In this paper, current metallurgical processes for the extraction of metals from e-waste, including existing industrial routes, are reviewed. In the first part of this paper, the definition, composition and classifications of e-wastes are described. In the second part, separation of metals from e-waste using mechanical processing, hydrometallurgical and pyrometallurgical routes are critically analyzed. -
Cip and Cil Circuit Modelling
SGS MINERALS SERVICES – T3 SGS 1338 02-2014 CIP AND CIL CIRCUIT MODELLING The SGS carbon-in-pulp (CIP) / carbon- in-leach (CIL) modelling package is used to estimate the performance of a full-scale CIP or CIL plant and to derive the optimum design criteria based on the results of small scale experiments. It is a powerful design tool that uses the results from standard leach and adsorption tests (bottle roll tests) to generate kinetic data that are fitted to leaching and carbon adsorbtion rate equations (Figure 2). The rate data and mass balance equations are then applied to the SGS model to calculate the concentrations of gold in solution, on the carbon and in the ore for each stage of a multi-stage leach- adsorbtion circuit. The model allows for the generation of multiple operating scenarios, where • the number of leach and adsorption stages can be varied, • the carbon concentration per tank can be adjusted, • the carbon loading and final barren solutions can be manipulated, • and carbon advance and elution rates adjusted. PHILOSOPHY The SGS CIP/CIL model is based on a model developed by Fleming and Nicol • Robust predictions of steady state as (1984). The philosophy then was to strive APPLICATIONS well as transient carbon adsorption for simplicity and user-friendliness, rather behaviour from simple laboratory The SGS CIP/CIL model can be used for than precision through complexity. This batch tests, feasibility or production stage projects. is still true today in SGS‘ CIP and CIL • Economic sensitivity analyses of It is a cost effective way to determine modelling package. -
Recovery of Gold and Iron from Cyanide Tailings with a Combined Direct Reduction Roasting and Leaching Process
metals Article Recovery of Gold and Iron from Cyanide Tailings with a Combined Direct Reduction Roasting and Leaching Process Pingfeng Fu 1,2,* ID , Zhenyu Li 1, Jie Feng 1 and Zhenzhong Bian 1 1 School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China; [email protected] (Z.L.); [email protected] (J.F.); [email protected] (Z.B.) 2 Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, Beijing 100083, China * Correspondence: [email protected]; Tel.: +86-10-6233-2902 Received: 25 June 2018; Accepted: 19 July 2018; Published: 21 July 2018 Abstract: Cyanide tailings are the hazardous waste discharged after gold cyanidation leaching. The recovery of gold and iron from cyanide tailings was investigated with a combined direct reduction roasting and leaching process. The effects of reduction temperature, coal dosage and CaO dosage on gold enrichment into Au-Fe alloy (FexAu1−x) were studied in direct reduction roasting. Gold containing iron powders, i.e., Au-Fe alloy, had the gold grade of 8.23 g/t with a recovery of 97.46%. After separating gold and iron in iron powders with sulfuric acid leaching, ferrous sulfate in the leachate was crystallized to prepare FeSO4·7H2O with a yield of 222.42% to cyanide tailings. Gold enriched in acid-leaching residue with gold grade of 216.58 g/t was extracted into pregnant solution. The total gold recovery of the whole process reached as high as 94.23%. The tailings generated in the magnetic separation of roasted products, with a yield of 51.33% to cyanide tailings, had no toxic cyanide any more. -
Simulation Study of the Optimal Distribution of Cyanide in a Gold Leaching Circuit
Minerals Engineering 19 (2006) 1319–1327 This article is also available online at: www.elsevier.com/locate/mineng Simulation study of the optimal distribution of cyanide in a gold leaching circuit L.R.P. de Andrade Lima a,b,*, D. Hodouin a a Department of Mining, Metallurgical, and Materials Engineering, Laval University, Quebec City, Canada G1K 7P4 b Department of Materials Science and Technology, Federal University of Bahia, C.P. 6974, Salvador, BA 40810-971, Brazil Received 25 September 2005; accepted 1 December 2005 Available online 19 January 2006 Abstract The mineral industry has been using cyanidation to recover gold from ores for more than a century; however, a systematic study of the best reactant addition strategy in a cascade of agitated leaching tanks is not available in the open literature. A phenomenological math- ematical model of the gold cyanidation process, calibrated with a set of industrial data from an Australian plant, together with an eco- nomic performance index is used to analyze this problem. The simulated results show that the best compromise between the two antagonistic effects, cyanide consumption and gold recovery, which are both function of cyanide concentrations, leads to a reagent dis- tribution that depends on the leaching and cyanide consumption kinetics, pulp feed characteristics, and economic factors such as the gold market value. For the specific studied plant, in the operating range of low cyanide consumption and fast gold dissolution, all the cyanide must be added in the first tank; however, in the operating conditions of high cyanide consumption, cyanide has to be distributed in the first, second and third tanks. -
Tungsten and Gold Recovery from Alaskan Scheelite-Bearing Ores
¿I ri 9251 REPORT OF INVESTIGATIONS/1989 LIBRARY SPOKANE RESEARCH CENTER RECEIVED SEP5 1983 U.S. BUREAU OF MINES E 315 MONTGOMERY AVE SPOKANE, W A 99207 Tungsten and Gold Recovery From Alaskan Scheelite-Bearing Ores By J. N. Greaves, W. R. McDonald, and J. H. Maysilles M ission: As the Nation's principal conservation agency, the Department of the Interior has respon sibility for most of our nationally-owned public lands and natural and cultural resources. This includes fostering wise use of our land and water resources, protecting our fish and wildlife, pre serving the environmental and cultural values of our national parks and historical places, and pro viding for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to assure that their development is in the best interests of all our people. The Department also promotes the goals of the Take Pride in America campaign by encouraging stewardship and citizen responsibil- ityforthe public lands and promoting citizen par ticipation in their care. The Department also has a major responsibility for American Indian reser vation communities and for people who live in Island Territories under U.S. Administration. Report of Investigations 9251 Tungsten and Gold Recovery From Alaskan Scheelite-Bearing Ores By J. N. Greaves, W. R. McDonald, and J. H. Maysilles UNITED STATES DEPARTMENT OF THE INTERIOR Manuel Lujan, Jr., Secretary BUREAU OF MINES T S Ary, Director Library of Congress Cataloging in Publication Data: Greaves, J. N. Tungsten and gold recovery from Alaskan scheelite-bearing ores. (Report of investigations / United States Department of the Interior, Bureau of Mines; 9251) Bibliography: p. -
Production of Gold
Production of Gold Background A feasibility study on the production of gold at a fictitious mine (Moapa mine) in Elko County, Nevada is to be performed. The mine is capable of producing 325,800 tons of high-grade ore per year for 8 years. The deposit contains 0.12 ounces of gold per ton of high-grade ore and can be acquired at a cost of $10 per ton of ore (cost of mining ore at site). A sodium cyanide process is used to extract the gold from the ore, and various other processing techniques are used to produce 99.9% pure gold bullion from the ore. The results of the feasibility study show that the ore can be processed by agitation leaching, which is preferred over heap leaching due to the low recovery associated with the heap leaching technology. The problem is to find the break-even price of gold for this mining operation. The process is currently unprofitable with a gold price around $300 per ounce. Process Description Unit 100 – Size Reduction of Ore The BFD of the overall process is shown in Figure 1. The PFD for Unit 100, shown in Figure 2, is designed to reduce 41.5 tons/hr of gold ore from a feed range of 2- 5” to 160 microns. The mined ore is fed using a Grizzly Feeder, F-101, into a Jaw Crusher, J-101, where 80% of the ore is crushed to 1.75” or smaller. The remaining 20% are recycled back into F-101 (not shown on PFD). The ore is then sent to Screen S-101 where the ore that does not pass through the first deck is sent to the Standard Cone Crusher SC-101. -
Studying of Preliminary Roast and Smelting Gold-Containing Electronic Scrap with Copper Collector
SCIENTIFIC PROCEEDINGS IX INTERNATIONAL CONGRESS "MACHINES, TECHNOLОGIES, MATERIALS" 2012 ISSN 1310-3946 STUDYING OF PRELIMINARY ROAST AND SMELTING GOLD-CONTAINING ELECTRONIC SCRAP WITH COPPER COLLECTOR. Prof. Strizhko L.S., engineer Shigin E.S., engineer Fokin O.A. Abstract: Electronic scrap is valuable type of complex recyclable metallurgical raw. Efficient technology requires complex recovering electronic scrap with extraction ferrous, non-ferrous and precious metals. Requirement of preliminary roast to remove and recycle gases from organic combusting are shown. Optimal parameters of roast has been determined. Keywords: Gold, precious metals, copper, electronic scrap, collector smelting, recycle, roast 1. Introduction. Organic materials (polystyrene, hardened paper, One of mass valuable type of complex recyclable metallurgical polyvinylchloride etc.) make 5-27 % of electronic scrap, according raw is electronic scrap. Total value of obtained electronic scrap in to scrap’s type. Organic materials have to be removed from Russia is millions tons per year now. During conversion to market electronic scrap preliminarily (before melt) due to high speed of economy thousands of unprofitable plants has been stopped and organic materials’ combusting significant amount of obtained gases liquidated in recent years, huge amounts equipment and hardware as well as problem with recovery and cleaning. has been formed, that should be recycled. On the one hand this In connection with the above electronic scrap with precious scrap is damage to environment, and on the other hand it’s very metals is preliminarily treated by roast. valuable recourse, that exceed raw mineral in precious components’ Degree of organic removal from electronic scrap in dependence content. Usage of complex-composition hard-processing electronic of temperature, duration has been studied when research was scrap in metal recycling is increased now. -
Gold Extraction by Chlorination Using a Pyrometallurgical Process
Minerals Engineering 22 (2009) 409–411 Contents lists available at ScienceDirect Minerals Engineering journal homepage: www.elsevier.com/locate/mineng Technical Note Gold extraction by chlorination using a pyrometallurgical process M.W. Ojeda a,*, E. Perino b, M. del C. Ruiz a a Instituto de Investigaciones en Tecnología Química (INTEQUI), Universidad Nacional de San Luis-CONICET, C.C. 290, 5700 San Luis, Argentina b Área de Química Analítica, Universidad Nacional de San Luis, San Luis, Argentina article info abstract Article history: The feasibility to recover the gold present in alluvial material, by means of a chlorination process, using Received 18 October 2007 chlorine as a reactive agent, has been studied. The influence of temperature and reaction time was stud- Accepted 4 September 2008 ied through changes in the reactant solid. The techniques used to characterize the mineral samples and Available online 15 October 2008 the reaction residues were stereomicroscopy, X-ray diffraction, X-ray fluorescence and scanning elec- tronic microscopy. Results indicate that gold extraction is favored by increasing, both, the temperature Keywords: and the reaction time. The best recovery values were of 98.23% at 873 K and 3600 s and of 98.73% at Gold ores 873 K and 5400 s, with very low attack of the matrix containing the metal. The powder of pure gold Pyrometallurgy was not chlorinated at this temperature level. Extractive metallurgy Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electronic microscopy (SEM) techniques. Over the last years, gold recovery has been the central issue in a wide range of studies as a consequence of its high demand and va- 2. -
Mercury and Mercury Compounds
United States Office of Air Quality EPA-454/R-97-012 Environmental Protection Planning And Standards Agency Research Triangle Park, NC 27711 December 1997 AIR EPA LOCATING AND ESTIMATING AIR EMISSIONS FROM SOURCES OF MERCURY AND MERCURY COMPOUNDS L & E EPA-454/R-97-012 Locating And Estimating Air Emissions From Sources of Mercury and Mercury Compounds Office of Air Quality Planning and Standards Office of Air and Radiation U.S. Environmental Protection Agency Research Triangle Park, NC 27711 December 1997 This report has been reviewed by the Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, and has been approved for publication. Mention of trade names and commercial products does not constitute endorsement or recommendation for use. EPA-454/R-97-012 TABLE OF CONTENTS Section Page EXECUTIVE SUMMARY ................................................ xi 1.0 PURPOSE OF DOCUMENT .............................................. 1-1 2.0 OVERVIEW OF DOCUMENT CONTENTS ................................. 2-1 3.0 BACKGROUND ........................................................ 3-1 3.1 NATURE OF THE POLLUTANT ..................................... 3-1 3.2 OVERVIEW OF PRODUCTION, USE, AND EMISSIONS ................. 3-1 3.2.1 Production .................................................. 3-1 3.2.2 End-Use .................................................... 3-3 3.2.3 Emissions ................................................... 3-6 4.0 EMISSIONS FROM MERCURY PRODUCTION ............................. 4-1 4.1 PRIMARY MERCURY