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By D. G. Dixon

A novel technology for leaching copper from primary copper concentrates has been developed at UBC. This patented technology takes advantage of the galvanic couple between pyrite and chalcopyrite to ensure rapid and complete oxidation of chalcopyrite under mild conditions in acidic iron sulfate solution, without the need for microbes, ultrafine grinding, or chemical additives such as chloride, nitrate, or surfactants. Copper recoveries of 98% or greater can be achieved at 80°C under atmospheric conditions in as little as 4 hours of residence time. The process is selective for chalcopyrite over pyrite, generates near-quantitative levels of elemental sulfur, and is fully compatible with conventional solvent extraction and electrowinning of LME Grade A copper cathodes. In this paper, the fundamentals of the Galvanox ? process are reviewed, and selected results of batch leaching tests on various concentrate samples are presented and discussed.

Jan 1, 2007

Accountability for profit realized or lost, and responsibility for continued safe operation are the main impetus behind operator training. Efficiency in operation enables production at lower unit costs. An inefficient operation eats profitability of the operation, creating short term losses, and also affecting longer term viability particularly when commodity prices fluctuate and competition erodes market share. Safe operation and efficient operation are ultimately conjoined entities which may not be able to be sustained without dual effort. Training is a very valuable tool to engage operations in adopting more efficient and safe practices. Training requires time, facilities and trainers. One novel way of minimizing both the trainers and the facilities is through the use of Computer Based systems. Included amongst this are Computer based equipment simulators, following an identical philosophy as flight simulators used for pilot orientation and training for different aircraft types.

Feb 1, 2008

By M. A. N. Rosa, L. C. R. Machado, R. A. Fonseca, A. M. Mendonça

"Sossego Mine was the first Vale SAG mill operation to process copper-gold ore. It is located in the state of Para, in the south-eastern Amazon region of Brazil. In the first six years of continuous operation, Vale investigated different alternatives for improving circuit performance by investigating operating conditions, mainly focusing on the SAG mill.Today, after a steady increase over five years the annual production rate seems to have stabilized. It is hoped this work will show how the SAG operating practice have been perfected with time and as new data are collected. Historical data of mill grind-outs and crash stops helped create operation curves depending on the ball charge volume and total charge volume. Also noted were impacts on throughput due to the effect of reducing liner weight and the ore type characteristics."

Jan 1, 2012

By J. H. Hodgson

"Those of us who have been concerned with the problem of geophysical exploration in southwestern Ontario have followed the development of the Poulter method with much interest. I have much appreciated the opportunity of reading an advance copy of Dr. Poulter's clear exposition and of preparing the following brief remarks on the probable applicability of the method to the Palaeozoic area of southwestern Ontario.During the years 1944 to 1946, the Ontario Department of Mines, in co-operation with the Union Gas Company and the Dominion Natural Gas Company, operated an experimental party in the hope of establishing a seismic technique appropriate to the •area. The results were completely negative. During two summers' field work, no reflections whatever were obtained except in one area near Windsor. It is the •purpose of these remarks to inquire whether Dr. Poulter's techniques might yield favourable results.It was the conclusion of the report on our work that two principal causes contributed to the failure of the method. In the first place, the geological column possesses few elastic discontinuities and those that exist appear to have low reflection coefficients. In the second place, the area is drift-covered in general. This drift complicates the situation by absorbing seismic energy and by giving rise to groups of complicating refracted phases which obscure the entire interesting section of the record. The situation is further complicated by the high reflection velocities and the relative shortness of the Palaeozoic section, these factors combining to bring in a reflection from the basement in about half a second."

Jan 1, 1950

By R. Pelletier, Herny. E., C. Allaire

Corrosion of refractory linings by molten metals is controlled by interactions between penetration and chemical reaction. Corrosion of aluminosilicates by molten aluminium is no exception. The early stage of corrosion can be described as a particular case of reactive wetting over a porous medium. Although the reactivity between aluminium and silica is great, which should improve wetting and penetration, the presence of air and the formation of a protective oxide layer disfavours initial penetration. This paper presents the results of an exploratory study on the effect of some parameters on the initial stage of aluminium penetration. Penetration kinetics and metal intrusion tests have been performed on alumina and silica powders with pure aluminium and Al¬5%Mg. Capillary models are used as tools of interpretation. Penetration kinetics tests had a poor reproducibility and the kinetics itself can not be explained very well by the capillary-tube-bundle model. On the other hand, a capillary model initially developed for ice intrusion into freezing soils produced predictions in reasonably good agreement with intrusion pressure measurements. The effect of particle size and alloy composition can be predicted using this model. However, the effects of temperature and powder chemistry need additional interpretations to be rationalised. An unusual resistance to penetration of silica powder by molten aluminium have been observed in a series of experiments. This led the authors to the strange conclusion that oxygen should be seen as an excellent non-wetting agent and that there might be ways to use it in industrial applications.

Jan 1, 2004

By E. G. C Charlesworth, M. J. Robertson

"Gold mineralization in the Main Reef Complex at Sheba Gold Mine is hosted within shear zones in a sequence of shales and greywackes of the Fig Tree Group. Competency contrasts between these rocks and a steeply dipping chert unit provided a locus for the development of right lateral steeply dipping shear zones. A set of flatter dipping shear fractures crosscut these zones with their intersections defining a system of en échelon ore shoots. Mineralization is both of vein type and disseminated strata-controlled replacement type. The latter occurs mainly within the wall rocks to the shear zones. Arsenopyrite and pyrite are the major sulfides, with arsenopyrite being confirmed largely to greywacke beds and pyrite to the more iron-rich shale units. Gold was introduced, together with minor sphalerite, pyrrhotite, chalcopyrite and early arsenopyrite, toward the end stages of a first pyrite phase. The mineralizing fluids were introduced along dilated cleavage planes and, emanating from these, produced a series of replacement fronts. Mineralization was syntectonic to late tectonic and occurred under conditions of progressive deformation, resulting in sulfides which are concentrated in the hinges of shear-related folds and semimassive sulfides within tension fractures which are folded, attenuated and fractured. An analysis of the structures shows a sequence of events in which an initial ductile simple-shear event with a steep sense of movement was succeeded by a more brittle strike-slip event. Mineralization is temporally related to the latter. This evolution in structural style was probably related to reactivation of the Sheba Fault as a transcurrent fault during emplacement of large granitoid bodies."

Jan 1, 1994

By Lastram Rolando, Larry J. Hulbert, Louis J. Cabri, J. H. Gille Laflamme, John L. Campbell, Soey H. Sib, Chris G. Ryan

"The mineralogy of samples from the Wellgreen Cu-Ni-Pt-Pd deposit, Yukon Territory, is complex and the metals of interest are contained within fine-grained minerals which vary in size and mineral associations from sample to sample.The major Ni carriers are pentlandite and violarite; the major Cu carrier is chalcopyrite. About 700/0 of the major Ni carriers and 78% of the major Cu qurier will be liberated at a grind of 80% -U,.7 ,an (-500 mesh) for typical low-grade gabbro (West zone, sample No.1). For typical ""clinopyroxenite"" (West zone, sample No.2) and typical ""clinopyroxene-rich peridotite"" (East zone, sample No.3) the liberation would be 71% and 65% for Ni, 74% and 60% for Cu, respectively. Fine grinding, however, cannot liberate the Ni contained in silicates and pyrrhotite, estimated to total 24.5% for typical low-grade gabbro (West zone, sample No. I), 15% for typical ""clinopyroxenite"" (West zone, sample No.2), and 12% for typical ""clinopyroxene-rich peridotite"" (East zone, sample No.3).The principal Pt carrier (sperrylite) varies considerably in grain-size between samples and fine grinding, required to liberate the major Ni and Cu carriers, may be counterproductive in samples where sperrylite is relatively coarse-grained, as some would then be unrecovered (e.g. sample No. 1). In addition, sperrylite in samples No.2 and No.3 is closely associated with magnetite. Palladium occurs in diverse ways. It occurs in the form of several Pd minerals (e.g. sudburyite, testibiopalladite, merenskyite), as a replacement for Ni in several tellurides, antimonides and tellurantimonides (e.g. melonite), or as very low concentrations in pentlandite (up to 34 ppm), chalcopyrite (up to 9 ppm), and pyrrhotite (up to 5.6 ppm). Palladium minerals and Pd-bearing minerals are strongly associated with chalcopyrite in sample No. 1 and will thus report to a Cu concentrate.However, 22% of the total Pd is in solid solution in pentlandite in this sample and will thus report to the Ni concentrate. In samples No.2 and No.3, less Pd occurs in solid solution in pentlandite, and the PGM are distributed mainly among pentlandite, chalcopyrite, and magnetite in sample No. 2, and among pentlandite, pyrrhotite, chalcopyrite, and magnetite in sample No.3. Therefore, the feasibility of magnetic concentration should be investigated for samples like No. 2 and No.3, in order to improve Pt and Pd recoveries. Rhodium was found to occur as rare hollingworthite, in sparse cobaltite (up to 2.7%) and, as low concentrations in chalcopyrite (to 10 ppm) and pentlandite (to 12 ppm) by proton microprobe. Iridium occurs in hollingworthite (up to 7.8%) and very rarely as the native metal or in an undefined Re-Ir-Qs..Ru alloy. Ruthenium was determined by proton microprobe analyses to occur in pentlandite (up to 13 ppm) and chalcopyrite (up to 10 ppm), in addition to rare laurite and Re alloy."

Jan 1, 1993

By Hans Lundberg

During the last few years, geophysical methods have been introduced to aid mining geologists and mining engineers in locating mineral deposits. These methods have been developed as the result of investigations of various physical characters of minerals and rocks. In prospecting for ore-bodies, electrical methods have proved most successful. These methods are based on the great differences in electrical properties, and especially in conductivity, between ore minerals and rock minerals. The electrical resistance of the common minerals, rocks, and ores in ohms per cubic céntimeter is given in the following table: [ ] The first attempts at electrical prospecting were based on observing currents of polarization around certain ore bodies, which currents it was possible to measure. This method has been developed by Prof. Schlumberger and has been utilized by him successfully. He is represented on this continent by Mr. Sherwin Kelly, who has successfully operated the method here.

Jan 1, 1926

By S. R. Izatt

The use of MRT, a highly selective separations technology, has long been demonstrated to be a cost effective, efficient, and environmentally sound process for extraction of a wide range of anions and cations that are commonly found in copper electro - refining and electro - winning circuits, as well as in environmental treatment operations. This paper provides an update of commercial MRT applications in the copper industry. Several recent installations and test programs are reviewed including recovery of bismuth from tank house electrolyte, and from chloride matrix selenium reduction solution which is generated in the anode slimes treatment process. Recovery and refining of platinum group metals originating in the anode slimes is also discussed. Various other base metal and other target separations of interest to the copper producer are also reviewed. The recovery products are high purity metal salts which can be marketed directly or readily reduced to metal.

Jan 1, 2007

By T. Hartmann

The presence of crud represents a permanent challenge for solvent extraction in the hydro-metal industry. The crud is a stable emulsion which slowly spreads along the phase boundary between the aqueous and organic phase. The crud can significantly impair the efficiency of hydro-metal extraction because the phase boundary between the aqueous and organic phases assumes substantial proportions, and the settlers cannot react flexibly. In a chain reaction, all settlers connected in series become infected with crud. The transfer of organic phase to the electrowining (EW) cell can cause 'cathode burn'. Continuous treatment of the crud is extremely effective and reliable with a 3-phase separating solid bowl centrifuge. All three phases are separated distinctly from one another. All associated process steps exhibit a steady uniform efficiency. First and foremost, they ensure a reliable, continuous extraction process and, second, they recover valuable re-usable organics from the crud.

Jan 1, 2007

By O. -J. Siljan

"Refractory materials are an integral part of aluminium production. One special feature of aluminium making is the prominent role of sodium in all parts of the production process. This presence of sodium inflicts stresses on the refractory materials through reactions and may cause severe damages to the refractory linings. The present paper address possible reactions between sodium and refractories in anode bake furnaces, electrolytic pots and casting furnaces. The discussions presented in the paper points to the importance of selecting materials with excellent alkali resistance in all parts of the aluminium making process, although alkali resistance is not the sole parameter to determine refractory life-time. ""Acid"", i.e. silica-rich alumino-silicate refractories are shown to be the best materials for aluminium electrolysis cell potlinings, whereas high- alumina refractories based on minerals like andalusite seems to be the preferred choice for anode bake furnaces as well as cast house furnaces."

Jan 1, 2004

"At the May 15, 2006 and the May 1, 2007 Canadian Securities Administrators (CSA) Canadian Institute of Mining, Metallurgy and Petroleum (CIM) meetings in Vancouver and Montreal, CSA requested CIM consider certain issues arising out of the CSA review of Technical Reports and public disclosure, in general, regarding the practice of estimation and reporting of Mineral Resources and Mineral Reserves. The following is a summary of the issues raised by the CSA and the responses of the CIM.Preamble: At the May 15, 2006 and the May 1, 2007 Canadian Securities Administrators (CSA)-Canadian Institute of Mining, Metallurgy and Petroleum (CIM) meetings in Vancouver and Montreal, CSA requested CIM consider certain issues arising out of the CSA review of Technical Reports and public disclosure, in general, regarding the practice of estimation and reporting of Mineral Resources and Mineral Reserves. The following is a summary of the issues raised by the CSA and the responses of the CIM Reserve Definition and the CIM Estimation Best Practices Committees (the Committees). This information is intended to provide the Qualified Person (QP) with further guidance when estimating Mineral Resources and Mineral Reserves and in preparing a technical report written under National Instrument 43-101 (NI 43-101). Several members of the CIM Reserve Definition Committee, the CIM Estimation Best Practices Committee and some members of the Committee for Mineral Resources International Reporting Standards have reviewed these issues and provide the following commentary.Issue 1. - CSA requested CIM review and comment on the selection of an appropriate commodity price to be used in Mineral Resources and Mineral Reserves estimates.Commodity prices are used in the estimation of Mineral Resources and Mineral Reserves and in the economic analysis of a property. In times of rapidly changing commodity prices, or when prices are at the extreme ends of a commodity price cycle, the QP has a difficult job in selecting an appropriate commodity price.• The selection of appropriate technical variables, including commodity price, is clearly the responsibility of the Qualified Person (QP). The QP must describe the reasons for selecting these variables, including price, in the technical report.• The definition of a ""Mineral Resource"" contains the wording ""reasonable prospects for economic extraction,"" therefore, a QP must select economic parameters, including commodity price, that will result in an estimate of Mineral Resources and Mineral Reserves that have ""reasonable prospects for economic extraction""."

Jan 1, 2003

By R. Stauber, B. Friedrich, S. Hilgendorf, G. Homm, C. Gellermann

Due to recent regulations limiting tolerated lead concentrations in copper alloys, new recycling strategies have to be considered. This study investigates the suitability of technical approaches in order to recycle leaded copper alloys exemplified by CuZn39Pb2 and produce an alloy in compliance with future lead regulations in the European Union. Three pyrometallurgical methods are considered to achieve this goal, namely vacuum distillation, intermetallic precipitation and fractional crystallisation. The impact of essential process parameters i.e. pressure, temperature, time, atmosphere and quantity of additives are identified using thermochemical and kinetic modelling. An experimental implementation reveals a general suitability of all three refining processes. However, the individual efficiency of the different methods strongly differs. Thus, a detailed assessment is carried out in order to provide an evaluation on the efficiencies of these methods from a technological, economical and environmental point of view. Taking a possible industrial realisation into account, the authors recommend the approach of vacuum distillation, although the energy demanded is comparatively high due to the enthalpy of evaporation for zinc, or rather, lead. However, required lead concentrations can be reached quickly without introducing an external element to the material. The prediction of selectivity and evaporation speed, which are immanent variables for a successful implementation, can be validated experimentally. INTRODUCTION In 2016 approximately 1 million tonnes of leaded copper alloy semi-finished goods with an average lead content of 2.1 Ma% have been produced in the European Union (EU). The global production in the same period exceeded 5.5 million tonnes, while the lead concentration has stayed constant at around 2.4 Ma% for the last 50 years. Up to 80 % of the current production volume is covered with end-of-life scraps, which are used for direct re-melting, depending on the alloy composition. Lead has been a popular alloying element in copper alloys in general, and in particular in brass due to its positive impact on various mechanical, physical and chemical properties, especially machinability. Health and environmental concerns were drivers for many governments to implement limitations on lead. In order to further utilise the resource potential of leaded copper scrap, it is inevitable to develop methods to efficiently eliminate lead from circulation as far as possible. (Glöser, Soulier, & Tercero Espinoza, 2013; Soulier, Glöser-Chahoud, Goldmann & Tercero Espinoza, 2018)

Jan 1, 2019

By R. Druffel, P. Wittke-Gattermann, M. Wittke

"The two tubes of tunnel Hirschhagen along the highway A44 in Germany, underpass the federal road B7, a railway line and the valley of the river Losse close to the city of Hessisch Lichtenau. The ground in the area consists of Triassic sand- and siltstones (""Buntsandstein"") as well as tertiary clays. Prior to tunneling, the groundwater in the area is planned to be lowered by means of a gallery of deep wells. As a basis for the design of this dewatering gallery, two large pumping tests have been carried out. The results of these tests have been evaluated by means of 3D-Finite Element analyses. By means of the large-scale model, the influence of the anisotropy resulting from jointing and bedding and the influence of fault zones in the area have been taken into account, which lead to a thorough basis for the design of the dewatering gallery.INTRODUCTIONThe 4.2 km long Tunnel Hirschhagen of the highway A 44 crosses below the federal road B7, a railway line and the river Losse close to the city of Hessisch-Lichtenau in central Germany. Both tunnel tubes are located in a subrosion depression in which Triassic sandstone and tertiary clay prevail. It is planned to lower the groundwater table in the area of the meadow of the Losse prior to tunnel heading [1]. Groundwater lowering is planned to be achieved by means of a series of large pumping wells. The bottom of the river Losse will be sealed in order to avoid direct inflow of water from the river into the ground (Fig. 1 and 2)."

Jan 1, 2015

By J. A. Dubinski

One of the greatest threats of mining in hard coal mines are underground fires, which in the past often resulted in the mining disasters. Implementation of scientific principles of fire fighting into practice contributed to a significant reduction of fire hazard in coal mines. However, despite numerous achievements of science in the fight against the underground fires, they still occur creating a potential hazard for the miners and contributing to generate significant costs of fire-fighting operations, the temporary suspension of production or loss of longwalls. This concerns both spontaneous fires and exogenous ones. A significant decrease in the number of spontaneous fires was the result of cooperation between Polish scientists with experts in the field of new methods of fire hazard prediction and selection of new fire prevention and fire hazard monitoring methods. A significant part played here researchers from the Central Mining Institute. The original method of endogenous fire risk assessment based on calorimetric tests of coal and developed mathematical model of the process of coal self-heating allow to predict the risk of spontaneous fires and select proper fire prevention measures adequate to the involved risk. The frequency of exogenous fires is in the last few years is low, but their share in the total number of fires is relatively high and constitutes about 30%. This results from the prevention activities, carried out regularly in mines which are aimed at reducing the fire hazard connected with the use of fire-resistant conveyor belts and other non-metallic materials. Further directions to reduce the hazards connected with underground fires should focus on improving the methods for monitoring hazards together with automation of fire fighting operations.

Aug 1, 2013

By Simon C. Dominy, Alwyn E. Annels, Mark A. Noppé

Abstract - Mineral Resources and their subsequent conversion to Ore Reserves are of key importance to mining companies. Their reliable estimation is critical to both the confidence in a feasibility study, and also to the day-to-day operation of a mine. Together with sampling, assaying, geological and other errors introduced during interpretation and estimation, additional errors are likely to be introduced during the application of technical and economic parameters used for conversion of resources to reserves. There is thus a requirement for high-quality interpretation and estimation to be supported by high-quality data. Any company expecting to make sound investment or operational decisions must base this on both relevant and reliable information. An Ore Reserve statement generally contains a single set of grade and tonnage figures without a discussion of the potential inherent errors in these estimates. Some sensitivity studies may be run, but confidence limits are rarely quoted and, if they are, often do not take into account many of the factors that cause uncertainty in the grade and tonnage estimates. Mineral Resource and Ore Reserve estimates thus carry certain errors leading to uncertainty and risk; some of these are unquantifiable for various reasons, for which the operator should be aware. This paper presents a review of the potential sources of error that might occur during a resource estimation program, which are carried through into the reserve estimate. A number of methods are discussed that allow the estimator to be more transparent about the inherent risks in his/her estimate. Emphasis is placed on data quality, and the requirement for strong quality management to be linked to continuous improvement.

Jan 1, 2002

By G. A. Barclay

"I - INTRODUCTIONSteel castings still comprise the largest volume of wear materials used in crushing and grinding in the Canadian mining industry. The range of impact and wear properties possible with steel castings enables them to be used successfully in both high impact crushing as well as milling where abrasion resistance is the main criterion. Approximately 15,000 tons per year of steel mill liners and crusher castings are used by Canadian mines.The properties of the main steel casting alloys used - manganese, pearlitic chrome-moly and martensitic medium carbon steels will be discussed with reference to their applications. Field data on a new application in primary gyratory crushers for martensitic medium carbon steels is presented. Liner wear life and mill efficiency can be improved through proper liner design.The liner wear pattern can be used as an indication for liner profile changes to improve wear life. Changes in liner configuration can improve through put and use of larger castings can reduce downtime. Casting performance can be improved and foundry production costs reduced by adopting certain design improvements.II - ALLOYS USEDTable I list the most common ferrous liner materials used in relation to their hardness and wear resistance (1). The most wear resistant materials are the irons at the top. In many applications the service impact exceeds the impact strength of the irons and tougher less wear resistant steels must be used. The impact resistance improves from top to bottom with manganese steel the toughest. The hardness of the martensitic steels approaches that of the Ni-Hards however the wear life, because of the absence of carbides, is less."

Jan 1, 1983

By Julie Q. Shang

The electrokinetic (EK) technology for dewatering of two tailings from the uranium mines in Northern Saskatchewan is studied in bench scale experiments. The study includes four phases: 1. Characterization of two uranium mine tailings; 2. Assessment of voltage loss on the coated Ti anode and water interface. 3. EK cell test series to measure electrokinetic permeability (ke) of two tailings; 4. EK dewatering test series to study electrokinetic enhanced gravity dewatering on two tailings samples. The results have demonstrated that both tailings responded positively to the EK process. For the tailings containing gypsum, the EK dewatering should be a short term process (within one hour) with anode conditioning (pH adjustment). The tailings containing clay minerals responded well to EK dewatering, in which pH adjustment is optional and will further enhance the EK flow. Both tailings as tested have low hydraulic conductivity and are particularly suitable for EK dewatering and consolidation.

Aug 1, 2010

By J. M. Shneerson

Gipronickel Institute, Saint-Petersburg will The copper concentrate was extracted from copper and nickel matte after its hydrometallurgical treatment and nickel removal. The concentrate containing 60-74% of copper was represented by two principal copper minerals, digenite and covellite. The oxidising leaching of this kind of concentrate was studied at the Gipronickel Institute. The effect of key parameters, such as temperature, oxygen partial pressure and initial solution compound, on the rate of copper dissolution and transfer of sulphur from sulphide to elemental form was investigated. It was shown that at temperatures about 90DC, the sulphur content of covellite converts to elemental form. Under autoclave conditions at 11ODC, the elemental sulphur dissolves as a sulphate-ion. At the temperature range from 50 to 90DC, the copper dissolution rate is in direct relation with temperature. By increasing the temperature to 130DC, this effect is reversed. Based on the research work, a technological flow sheet for the leaching of the copper concentrate was developed.

Jan 1, 2007

By Hani Henein

Most metals and alloys processed undergo a solidification processing step. Increasingly, there is a growing number of solidification processing routes that involve rapid solidification of the alloy. These include strip casting, high pressure die casting, 3D printing, and atomization for the production of powders or spray formed parts. By contrast, there are few experimental techniques developed to study the solidification path of alloys during rapid solidification. Amongst these laser melting and solidification, Electromagnetic Levitation (EML) and Impulse Atomization (IA) are the most prominent. Of relevance is the formulation of the solidification path of an alloy and the resultant identification and quantification of metastable phases and their relationship to processing conditions. This typically involves the understanding of the interplay between undercooling and cooling rate for the various phases that form. This presentation will outline some of the methodologies developed to quantify phase fractions and their solidification path as a function of processing conditions using EML and IA.

Jan 1, 2016