Report

A. Schmidt, S. Hofmann

This report presents an investigation into the microwave processing of gold ores, focusing on the effectiveness of microwave energy in enhancing the elimination of total organic carbon from the ores. The objective is to evaluate how selective superheating of carbon components can improve the leachability of gold, which is vital for the mineral extraction process. Methodologically, the study employed experiments in a microwave heated fluidized bed reactor, analyzing various gold ore samples including roaster feeds and deslime tail materials. Results showed that microwave treatment significantly reduced carbon and sulfur content in ores, with notable improvements in the leachability of the gold. Furthermore, a secondary microwave heat treatment of the carbon-in-leach (CIL) tail evidenced additional reductions in carbon content. The findings indicate a positive correlation between microwave energy application and mineral processing efficiency, leading to recommendations for future process development, particularly emphasizing the need for industrial scale investigations and energy-saving strategies in processing. This research contributes to the field by identifying the potential for microwave technology in enhancing gold ore processing efficiency and suggests paths for scaling up the process in appropriate settings.

KALWANI KIBEYA Luc

Ce rapport présente les résultats d'un stage effectué au sein de la Kamoto Copper Company (KCC), une entreprise minière renommée située à Kolwezi dans la province du Lualaba. L'objectif principal de ce stage était d'appliquer les connaissances théoriques acquises au cours de la formation universitaire en électromécanique. La méthodologie adoptée comprenait une immersion dans les ateliers de Heavy Mobile Cranes et Forklifts au sein du département Engineering Central Services. Les résultats montrent que ce stage a permis de comprendre en profondeur l'importance de l'électromécanique dans la gestion d'une entreprise et d'explorer diverses facettes du métier d'ingénieur. Les tâches réalisées ont non seulement contribué à l'efficacité des opérations, mais ont également enrichi mes compétences pratiques dans un environnement industriel exigeant. Ce stage a été une expérience formatrice et enrichissante, renforçant la motivation pour une carrière future dans le domaine de l'ingénierie électromécanique.

Dr. A. Rosin, Dipl. Ing. A. Schmidt

This report provides an investigation into the microwave processing of gold ores aimed at enhancing extraction efficiency. The objective is to evaluate the effectiveness of microwave heating in a fluidized bed reactor for processing gold-bearing materials. Methodologically, varying samples were subjected to microwave irradiation at different temperatures and treatment durations, followed by comprehensive analyses including scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis, and gas adsorption techniques. Results indicate significant alterations in material properties post-treatment, with reductions in sulfur content and variations in particle size distribution observed. The findings contribute to the understanding of microwave-assisted processing in mineral beneficiation, highlighting its potential to optimize resource recovery in gold extraction processes.

Kilborn Limited

This paper presents a detailed examination of the layout and design considerations of a modern gold concentrator based on a case study of the Kiena Gold Mines Limited concentrator project. The objective is to share insights from the engineering process that will enhance understanding for future projects in similar contexts. The methodology encompasses an analysis of the existing facilities, the design of new ore storage, grinding, leaching, and refining processes, alongside a collaborative review with Falconbridge Limited on cost developments. Results indicate that an innovative and compact design was achieved, optimizing space and efficiency within the concentrator, measuring 60,000 mm in length by 27,300 mm in width. The layout incorporates essential processing features including a semi-autogenous mill, a ball mill, and multiple facilities for carbon processing and tailings management. The findings underline the importance of strategic design and layout in achieving effective operational outcomes in gold processing facilities.

M. Kalamo

Ce rapport aborde les enjeux et défis liés à l'exploitation artisanale du cuivre-cobalt dans la région du Haut-Katanga et du Lualaba en République Démocratique du Congo (RDC). L'objectif principal de cette étude est de fournir une analyse approfondie des dynamiques socio-économiques et politiques entourant ce secteur, souvent perçu comme un double tranchant pour les communautés locales. La méthodologie adoptée combine une revue de la littérature existante, des études de cas, et des entretiens avec des acteurs locaux et des experts afin de cerner les implications de cette industrie. Les résultats révèlent que, malgré la richesse en ressources, les activités artisanales sont confrontées à de nombreux obstacles, y compris un cadre légal inadapté et des conflits entre creuseurs et forces de sécurité. En conclusion, le rapport soulève des questions sur la viabilité d'un secteur réformable et propose des pistes de réflexion pour un débat éclairé sur les solutions à apporter aux problèmes identifiés.

KASONGO MWEMA Salem, ROGER RUMBU

Ce document présente un travail pratique sur la technologie des batteries lithium-ion, en examinant leur fonctionnement, les risques associés, et les méthodes de recyclage. L'objectif est de fournir une compréhension approfondie des mécanismes d'intercalation des ions lithium, ainsi que des composants critiques tels que l'anode, la cathode, et l'électrolyte, tout en détaillant leurs risques respectifs de dégradation, d'instabilité thermique et d'incendie. La méthodologie inclut une analyse comparative de différentes chimies de batteries, mettant en lumière leur densité énergétique, leur sécurité, et leurs coûts de fabrication, ainsi que les applications privilégiées dans lesquelles elles sont utilisées. Les résultats révèlent les avantages et inconvénients des méthodes de recyclage, comme la pyrométallurgie et l'hydrométallurgie, en soulignant les compromis entre efficacité énergétique et récupération des matériaux. Enfin, le rôle des systèmes de gestion de batterie (BMS) est discuté pour prévenir des événements d'emballement thermique. Ce travail forme une base pour des études futures et une utilisation prudente des batteries lithium-ion dans diverses applications.

François Kerr-Gillespie, Eric Kinnan

Ce document est un rapport technique conforme à la norme canadienne NI 43‑101 portant sur les permis aurifères de Nampala et Mininko au Mali, incluant une nouvelle estimation des ressources minérales de la mine d’or de Nampala. Il est préparé pour la société Robex Resources Inc. par la firme de consultants InnovExplo Inc., dont trois géologues qualifiés (François Kerr‑Gillespie, Eric Kinnan et Alain Carrier) signent et certifient le rapport. Les auteurs détaillent leur formation, leur expérience professionnelle, leur statut de personnes qualifiées indépendantes au sens de la NI 43‑101, ainsi que leurs visites de terrain et les sections du rapport dont ils assument la responsabilité. Le projet est localisé dans la région de Sikasso au Mali (11º09'14" N, 06º12'58" O), et le rapport couvre notamment la description de la propriété, le cadre géologique et la minéralisation, les travaux de forage et d’échantillonnage, la vérification des données et la méthodologie d’estimation des ressources. L’objectif global est de fournir une information scientifique et technique complète, conforme à la réglementation, permettant d’évaluer la quantité et la qualité des ressources aurifères présentes sur les permis de Nampala et Mininko.

R E Lueders, T C Frankiewicz

This document is a compiled listing of patents related to acid leaching processes for mineral extraction and metallurgical refining, primarily from 1974–1981 across several jurisdictions (US, Canadian, British, and French priority filings). It summarizes hydrometallurgical methods for selectively leaching and recovering metals such as copper, nickel, cobalt, zinc, lead, silver, gold, antimony, and especially alumina from various sulfide and oxide ores, kaolin, anorthosite, and other low‑grade aluminosilicates. The entries briefly describe reagents and process conditions including nitric, hydrochloric, sulfuric, and hydrofluoric acids; complexing agents such as acetonitrile; and regeneration or recycling of gases (NOx, SO₂, HCl, HF). Many of the processes emphasize selectivity (e.g., dissolving copper while leaving iron largely insoluble, or extracting nickel and cobalt from limonitic laterites) and closed-loop reagent recovery to improve efficiency and reduce waste. The document functions as a technical survey of contemporary patent developments in acid leaching for mineral exploration, mining, and processing.

J. Boros, H. Mercier

The document is a compiled bibliography of patents related to alkaline leaching processes in hydrometallurgy, with no explicit abstract or summary section. It summarizes U.S., British, Canadian, and German patents dealing primarily with alkaline leaching of bauxite for alumina production (including Bayer process improvements, pretreatment of goethitic bauxites, desilication, impurity removal, and red mud treatment), as well as extraction of alumina from alunite. Additional entries describe alkaline processes for other ores and products, such as chromite to chromate, copper and gold recovery from sulfide ores using ammoniacal systems, tungsten extraction from scheelite/wolframite with ammonium carbonate, and selective impurity removal from molybdenite concentrates. For each patent, the document lists the core process steps, operational conditions in brief, claimed advantages (e.g., higher yield, reduced scale, minimized reagent loss, improved impurity removal), inventors, assignees, dates, and priority data. Collectively, it serves as a reference source on technological developments in alkaline leaching and related solution purification methods around the mid‑1970s.

E.J. Dugan

This document describes the development, operation, and advantages of the ammonia leaching process at the Kennecott Copper Corporation plant in Alaska. Built after successful laboratory and pilot-plant tests beginning in 1913–14, the commercial plant started in 1916 and ultimately reached a capacity of 800 tons per day, operating continuously until 1931. The ore treated is a high‑grade limestone replacement deposit with both sulfide and carbonate copper minerals; gravity concentration first recovers sulfides, while the carbonate-rich tailings are treated by percolation leaching with aqueous ammonium carbonate solutions. The process flow includes initial drainage, a “first leach” and “second leach” with circulating ammoniacal solutions, followed by an innovative hot steam wash that strips residual ammonia economically and without significant copper precipitation. Copper is finally recovered by boiling the pregnant solution with steam to drive off NH₃ and CO₂, precipitating copper oxide, while the regenerated ammonia is condensed and recycled. The paper emphasizes the process’s advantages—limited fine grinding, low water consumption, high-grade copper product, and minimal solution fouling—and outlines operating conditions, tank design, and a typical cycle for one leach charge.

DUMOULIN, Edouard

The document already contains an explicit abstract section. Cleaned up in English, it reads: The invention concerns a method for preparing hydraulic binders comprising a mixture of sulphoaluminate clinker or cement and calcium sulphate, the rehydration of which predominantly produces primary ettringite. The method comprises a step of injecting the mixture of sulphoaluminate clinker or cement and calcium sulphate in powder form into an aeraulic calcination conduit. This conduit is traversed by a turbulent hot air flow saturated with water vapour, having a temperature between 250°C and 700°C and a speed between 8 m/s and 40 m/s.

A. E. Petersen, M. B. Shirts, J. P. Allen

To reduce U.S. dependence on imports of titanium, the U.S. Bureau of Mines has investigated the recovery of titanium from perovskite (CaTiO3). Domestic perovskite deposits represent a significant, but untapped, titanium resource. An acid sulfation method was developed that will extract about 97 pet of the titanium and the columbium and 70 to 90 pet of the rare-earth byproducts from perovskite concentrates. A flow-sheet for recovering titanium as pigment-grade titanium dioxide (TiO2) is discussed. Test work performed in developing each unit operation is described. The first three unit operations have been demonstrated using laboratory-scale continuous methods of operation: acid sul­fation of perovskite concentrates, leaching sulfation residue to dissolve metal values, and precipitation of titanium oxysulfate monohydrate (TiOSO4·HP) from the resulting leach filtrate. Batch testing of other unit operations was performed: TiOSO4"H2O redissolution and iron reduction, precipitation of TiO2 by hydrolysis, and regenerating recoverable acid with rare-earth byproduct recovery. Cost evaluation results are provided, indicating that processing perovskite concentrates by acid sulfation may be an economically viable means of producing TiO2.

This report presents the results of the Fraser Institute’s 2025 Annual Survey of Mining and Exploration Companies, designed to assess how mineral endowments and public policy factors influence exploration investment decisions. The survey, conducted electronically between August 5 and November 26, 2025, was sent to 2,304 senior mining-related executives worldwide and generated 256 usable responses, allowing evaluation of 68 jurisdictions. Using the Investment Attractiveness Index—combining a Best Practices Mineral Potential index with a Policy Perception Index (PPI)—the study ranks provinces, states, and countries according to how well their geology and policy environments encourage mining investment. Nevada ranks as the top jurisdiction globally, followed by Ontario and Saskatchewan, while China, Burkina Faso, and Egypt are among the least attractive. The report also provides detailed PPI “report card” results on policy dimensions such as regulatory uncertainty, taxation, infrastructure, environmental regulation, land claims, political stability, security, and labor availability. In addition, the 2025 edition incorporates an updated analysis of permit times for mining exploration and explains the survey’s methodology, coverage, and criteria for including or excluding jurisdictions.

Prince Muloko

Ngoie Gayusa Priscilla

Cette étude présente la conception d'une salle d'électrolyse pour la production annuelle de 200 000 tonnes de cuivre (Cu). L'objectif est d'optimiser le dimensionnement des cellules et le nombre de cathodes requis pour maximiser la productivité tout en évaluant les coûts associés. La méthodologie inclut des calculs détaillés basés sur le rendement Faraday, la densité de courant, et les dimensions spécifiques des cathodes linéaires. Les résultats indiquent qu'il est nécessaire d'installer 569 cellules avec un total de 76 cathodes chaque, générant un courant total d'environ 241 000 A. Le dimensionnement de l'emprise au sol pour l'installation est calculé à 14 874 m², incluant les allées et l'espace de circulation. Concernant les coûts, l'énergie consommée est estimée à 394,5 GWh par an, avec un coût total d'environ 31,56 millions USD pour l'électricité. De plus, le coût des ondes laminées en plomb-aluminium atteint environ 10,68 millions USD, en tenant compte de la masse nécessaire et du prix par tonne. Cette recherche contribue ainsi à une meilleure compréhension des enjeux de rentabilité et d'efficacité dans la production de cuivre par électrolyse.

Junias Kisimba

BANZA KITWA Jean luc

SEENRGY

This document presents an overview of the main lead–acid battery technologies, organized by applications and construction types. It first distinguishes three principal application domains: starting batteries, deep‑cycle batteries, and stationary batteries, explaining how required performance (high starting current, deep cycling, or long standby life) drives plate design and grid robustness. It then describes conventional low‑maintenance lead–antimony batteries, including their reduced antimony content, lower water consumption, and storage characteristics. Calcium lead–acid batteries are outlined with a focus on their very low self‑discharge, low water consumption, high charge acceptance, and sensitivity to deep discharge. Hybrid batteries combining antimony positive plates and calcium negative plates are introduced as a compromise offering better deep‑cycle performance and improved storage. The text explains gas‑recombination principles, leading to valve‑regulated lead–acid (VRLA) batteries that are sealed, maintenance‑free, and capable of operating in various positions with minimal gas emission. Finally, it distinguishes VRLA gel and AGM designs, noting that both immobilize the electrolyte but have different charge parameters and separator structures.

Isabelle Mouilleseaux

This document is an issue of the French investment newsletter “L’Edito Matières Premières & Devises,” sent by email on 27 January 2011, focusing on gold and other commodities. In the main article, Rafael Michaut presents a strongly contrarian view on gold, arguing that physical gold creates no real value, has no intrinsic yield, and functions mainly as a recycled, static stock whose price is driven by expectations, fear, and speculative behavior. He likens the speculative rise in gold prices since 2000 to a Madoff-style pyramid, where each buyer simply bets on finding a later buyer willing to pay more, ultimately leading to a bubble and painful losses for late entrants. The article describes the classic dynamics of speculative bubbles—media hype, institutional participation, delayed entry of small investors, and sudden reversals—warning individual investors not to treat gold as a sound long‑term investment but rather to sell it. A brief advertising segment promotes strategies to profit from the broader economic crisis. A second article by Alain Freymond offers an opposing view, stating that gold and silver have not yet peaked and should continue rising in 2011 due to fiscal uncertainties, inflation risks, currency tensions, and constrained mine supply, while also announcing favored base metals and soft commodities for that year.

Umicor

Germanium is an important material that is recovered in nature as a byproduct of zinc and coal mining. This document addresses its limited supply and specialized applications, highlighting its strategic importance in global technology markets. Furthermore, it discusses the historical significance of germanium, particularly its central role in the development of early transistors, which laid the groundwork for modern telecommunications. Additionally, germanium’s unique properties allow for its use in night-vision technology, thanks to its thermal sensing capabilities. This overview emphasizes the multifaceted applications and significance of germanium in contemporary technology.

ROPAFADZO JAMAKANGA

Printed circuit boards (PCBs) from electronic gadgets at the end of their useful life period are currently being dumped in landfills or incinerated, causing a serious environmental harm in the form of toxic gases or leached hazardous compounds. PCBs contain high amounts of precious metals; about 20 wt% copper, 0.04 wt% gold, 0.15 wt% silver, and 0.01 wt% palladium. The extraction of these metals from PCBs is both profitable and environmentally worthwhile. Hence, this study aims to design a commercial process to extract three of these metals, (copper, gold and silver) from PCBs of computers and mobile phones. The proposed extraction process has been divided into two stages: (1) physical separation, (2) metal recovery. Stage 1 involves size reduction followed by the corona electrostatic separator and the hydro-cyclone which separates metals from non-metals. Stage 2 separates individual target metals from each other by hydrometallurgical processing. This stage involves leaching and precipitation of the metals into their separate components. In a bid to develop an environmentally friendly technique for recovery of precious metals from electronic scrap, a critical comparison of main leaching methods is analyzed from both economic and environmental impact perspective. Experimental results have shown that cyanide leaching is the best leaching method for this research’s target precious metals from PCBs, on the basis of the economics, process applicability and recyclability.

TFM

KAFUMBILA KASONTA JOSEPH

During the design of Cobalt solvent extraction using Cyanex 272 as extractant, the presence of Magnesium in the solvent extraction feed solution makes the experimental procedure of Cobalt solvent design unusable. The batch counter current test is work at 100% mixing efficiency and it is impossible to take account the recycled solution from scrubbing circuit in the design of extraction circuit. Only the computer program can design this configuration. This publication gives the procedure for the design of Cobalt solvent extraction from solution containing Magnesium. This procedure uses the McCabe Thiele procedure in which the simplified thermodynamic equilibrium condition is used instead of isotherm curve.

Christian Kabange

This document describes the purification and precipitation circuit for cobalt at TFM, from LG raffinate through to cobalt hydroxide production. It explains that purification aims to remove impurities that would interfere with subsequent extraction or reduce product purity, using chemical precipitation aided by pH control, flocculants, and seeding. The process is divided into three main stages: precipitation of iron, aluminum, and manganese using limestone; precipitation of copper using milk of lime; and primary and secondary precipitation of cobalt using milk of magnesia. For each stage, the document outlines operating conditions (notably pH and temperature), tank and decanter configurations, and the principal chemical reactions involved. It also describes the handling of underflow and overflow streams, including filtration, recycling to upstream circuits, neutralization, and disposal to tailings. Finally, it covers downstream treatment of cobalt hydroxide, including filtration, drying, and bagging of the intermediate product (CHIP) for sale, as well as the integration of clarifier and CCD circuits for solution management.

Christian Kabange

Roger Roger

This document provides a concise technical guide for selecting an appropriate compressor for industrial and related applications. Its primary purpose is to outline a systematic decision-making process that ensures the chosen compressor meets operational, economic, and environmental requirements. The text emphasizes the importance of first defining the application’s flow rate and pressure requirements, as these parameters fundamentally constrain the range of viable compressor options. It further addresses the influence of the type of gas or air to be compressed, highlighting that specific gases may necessitate particular compressor technologies to mitigate contamination risks and ensure safety compliance. Energy efficiency is presented as a central criterion, with attention to long-term operating costs and the value of high-efficiency compressor designs. The document also discusses practical constraints such as available installation space, underscoring the need to match compressor dimensions and configuration to site conditions. Additionally, it evaluates maintenance demands, recommending equipment characterized by ease of servicing, reliability, and durability, and it identifies noise level as a critical factor in residential or otherwise noise-sensitive settings. Collectively, these considerations form an integrated framework that enables users to select compressors that provide reliable, cost-effective, and context-appropriate performance over the long term.

Roger Rumbu

DJUBA DJA DJESE Moise, ct roger rumbe

This practical report provides an introductory overview of metallurgical science with a focus on the transformation of iron ore into steel sheets. It first defines metallurgy as the science and technology of extracting, refining, transforming, and utilizing metals, distinguishing between extractive metallurgy and physical metallurgy. The document then identifies the principal factors governing the choice of metallurgical processes, including ore type and grade, energy costs, required properties of the final metal, environmental considerations, and economies of scale. A central section systematically describes the industrial route from iron ore (e.g., hematite) to steel sheets, covering ore extraction, crushing and grinding, beneficiation by magnetic separation, reduction in the blast furnace to produce hot metal, conversion to steel in an oxygen converter with alloying additions, continuous casting into slabs or brames, and subsequent hot rolling into steel sheets of controlled thickness. A tabulated overview of minimum useful metal contents required for economic exploitation is presented across different domains (metallurgy, industrial chemistry, electromechanics, and mining) for selected elements such as Au, Ni, Li, Cu, Zn, Fe, Pb, U, Ge, Mn, and Ti. Finally, the report briefly highlights key applications of several metals, notably copper, iron, platinum, and uranium in electronics, structural engineering, advanced steels, energy systems, and aerospace. Together, these elements offer a concise didactic synthesis of fundamental metallurgical concepts and industrial practices.

Christiane Ilunga

This document addresses fundamental concepts and applications of surface treatment processes in materials engineering, with particular emphasis on steels. It first establishes a comparative framework between surface treatments and heat treatments, highlighting that surface treatments modify only the external layer to improve wear resistance, corrosion resistance, and aesthetics, whereas heat treatments alter the internal structure of the material to adjust mechanical properties such as hardness, toughness, and tensile strength. The document then examines the brunishing (brunissage) of steel, described as a chemical process forming a black magnetite (Fe₃O₄) layer either at hot or cold conditions, more commonly cold in industrial practice. The advantages and limitations of brunishing are detailed, including its aesthetic finish, dimensional stability, temporary corrosion protection, and good electrical conductivity, contrasted with its restricted corrosion resistance, maintenance requirements, and limited applicability to carbon steels. The text further discusses the choice between electrolytic zinc plating and hot-dip galvanization, recommending electrolytic zinc plating for small, precision parts where thin, uniform, and aesthetically superior coatings are required. Finally, a quantitative electrochemical calculation is presented to determine the current necessary to deposit a 5 µm chromium layer on a steel sphere of 50 mm radius in 20 minutes from a CrO₃–H₂SO₄ bath, using Faraday’s laws, leading to an applied current of approximately 70 A.

Ilunga Fumbo Marceline

This practical report, prepared within the Department of Metallurgy at the Université de Kolwezi, examines fundamental concepts and applications of surface treatment processes in contrast to thermal treatments for metallic materials. The first section establishes a systematic comparison between surface treatments and thermal treatments based on objectives, depth of action, modified properties, and typical applications. Surface treatments are shown to primarily alter superficial properties such as corrosion resistance, wear resistance, and aesthetics, while thermal treatments modify the internal microstructure to enhance hardness, toughness, and global mechanical performance. The report then focuses on specific surface treatment techniques. Brunishing of steel is described as a chemical process forming a thin black oxide (Fe₃O₄) layer, with analysis of its advantages, notably improved appearance and moderate corrosion resistance, as well as limitations in durability compared with galvanization and chroming. The document further contrasts electrolytic zinc coating and hot-dip galvanization, clarifying selection criteria based on thickness, surface finish, corrosion protection, and component size. Finally, a quantitative electrochemical calculation is presented for chromium electroplating of a steel sphere, determining the required current intensity using Faraday’s law, material properties, and process efficiency. Overall, the work provides a concise introduction to the theoretical principles and practical considerations guiding the choice and implementation of surface treatments in metallurgical engineering.

Kapalaba Ilunga Victor