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By D. G. Cerigo

"INTRODUCTIONAn interim report covering an uncompleted project on revenue mill optimization was presented at the invitation of Mr. C.S. Stevens, the Secretary of the Canadian Gold Metallurgists. The work described summarizes the preliminary work carried out at the Noranda Research Centre on computer mill optimization and is an attempt to arrive at a model of a circuit using the ""black box"" approach and hence by using economic factors related to concentrate dollar value to maximize revenue. The help and cooperation of Mr. J.D. Wild, Mr. M.J.S. Bennett of Noranda and Dr. A. Bobkowicz of McGill University is gratefully acknowledged.DERIVATION OF MODELHistorical data from the Normetal mill were used for the study. Normetal ore contains chalcopyrite, sphalerite, gold, silver, pyrite and pyrrhotite. For simplicity, data were chosen for days when only two concentrates had been derived, a copper concentrate which also contains the gold and silver, and a zinc concentrate. In these periods when pyrite concentrate was not produced, its circuit was used as an extra zinc scavenger unit. Figure I is a schematic drawing of the circuit and Table I explains the nomenclature.The mill had been operated to obtain a fixed grade of copper and zinc in the copper and zinc concentrates respectively, at the same time insuring acceptable recovery levels. The target grade for the copper and zinc concentrates had been derived by manual calculations based on past experience. The data used were 170 sets of daily mill reports, a sample of which is shown in Table II. The data consist of daily tonnages of feed, concentrates and tailings and their average compositions obtained by taking samples every twenty minutes from each stream and analyzing the daily composite samples."

Jan 1, 1967

By M. M. Helm

Samples sourced from the Goldstrike property in Nevada USA, have been evaluated in terms of their preg-robbing capacity and the physical structure of the graphitic carbon component in the carbonaceous gold ore. The study highlights a wide range in preg-robbing capacity between samples collected from the Betze-Post open pit and Rodeo underground mine. The physical structure of the graphitic carbon was assessed using Raman spectroscopy, and is found to play an important role in influencing preg-robbing behaviour. Differences observed in the physical structure of graphitic carbon are thought to be the result of hydrothermal events that occurred at Goldstrike.

Jan 1, 2011

By M. L. Smith

"In the Phosporia formation of SE Idaho, ore quality varies by depth, seam and distance along strike; phosphorus recovery is sensitive to these variations. Plant ore feed can be blended over time to minimize this fluctuation by using a combination of mine production and inventory stockpile scheduling. Mixed-integer and goal programming has been used to optimize short-term mine production, but the seasonal nature of mine haulage requires the use of stockpiles both at the mill and the mine. The contents of the stockpiles can also be optimized as part of the production scheduling problem, but introducing inventory control introduces a nonlinear term into the formulation. A solution using a piecewise linear formulation is modelled and solved using AMPL/Cplex, and solution strategies are discussed for similar large-scale problems. IntroductionIdaho’s minable deposits of phosphate rock are found in the Meade Peak member of the Phosphoria Formation; two separate zones of this formation are mined with a combined thickness of 30 ft to 60 ft. A generalized stratigraphic section of the Phosphoria section is shown in Figure 1, illustrating the degree of complexity encountered when scheduling mine production. Alteration of the formation results in higher grade ore zones near the surface and variable in P2O5 levels between seams and along strike. This variability is seen as well in other quality characteristics critical to the production of acid and elemental phosphorus. Further, plant recovery and nodule quality are sensitive to variations in ore feed; variability in SiO2, carbonates, moisture, organics (carbon), P2O5 and other constituents of the ore can strongly affect plant recovery. Because ore quality characteristics can vary as a function of the alteration zone (or seam) being mined as well as the depth and distance along the strike of the formation, scheduling of mine production can have a highly significant effect on recovery in the plant. As illustrated in Figure 1, there are nine seams containing 20% to 35% P2O5. Phosphoric acid and elemental phosphorus production requires an ore content of 30% and 25% P2O5, respectively. Variability between numerous beds that are mined and quality variation within a seam due to alteration greatly complicates production scheduling with the result that erratic mill feed characteristics greatly decrease recovery."

Jan 1, 1999

By M. Hames, K. Larmour-Ship, B. Grinbaum, E. Buchalter, R. Hackl, B. Wassink

Sodium cyanide continues to be the lixiviant of choice for gold dissolution. Many gold ore-bodies contain a significant amount of cyanide-soluble copper which increases the cost of processing due to high cyanide consumption and high cyanide destruction and disposal costs. Several cyanide destruction processes are in use today, however, there are just a few cyanide recovery plants operating. A solvent extraction process to recover cyanide has been developed which utilizes the organophosphorous extractants Cyanex 923, di-butyl-butyl-phosphonate (DBBP) or tri-n-butyl phosphate (TBP) in Bateman Pulsed Columns. Copper cyanide species are first converted to hydrogen cyanide (HCN) by acidification, with or without sulfide addition. HCN is extracted by the organic and stripped using a suitable base (eg. NaOH) resulting in a high strength cyanide solution (eg. NaCN) for recycle to the gold recovery process. Continuous pilot plant testwork on HCN extraction using a 40 mm diameter Bateman Pulsed Column demonstrated a cyanide recovery of greater than 99% with final levels of cyanide in solution of less than 10 ppm. These results illustrate the potential of this technology to recycle cyanide and to detoxify final effluent streams.

Jan 1, 2005

By J. Pepin

When using alternating current submerged arc welding (SAW) to produce pipes from microalloyed linepipe steels, it is critical to balance penetration depth and deposition rates, in order to minimize the number of weld passes while still maintaining good heat affected zone (HAZ) microstructures and properties. A series of bead-on-plate (BOP) submerged arc welds were performed on X70 steel, using different waveform variable settings (i.e., balance, offset and frequency). Weld bead cross-section profile deposition and penetration areas were measured, and both Vickers hardness and Charpy V-notch impact testing were performed. Both single electrode and tandem electrode welds were evaluated.

Jan 1, 2011

By N. Tassé

Les substrats organiques sont à la base des biofiltres utilisant la réduction des sulfates pour générer de l&apos;alcalinité et diminuer la concentration des métaux dans des effluents contaminés. Afin de tester l&apos;efficacité de résidus forestiers utilisés dans de tels contextes, cinq types d&apos;écorce de nature et d&apos;âge variables ont été placés dans des contenants hermétiques et mis en présence d&apos;une solution synthétique de drainage minier acide. Le pH, l&apos;alcalinité et les concentrations de Fe2+ et SO4 2- ont été mesurés à intervalles réguliers pendant 70 jours. L&apos;importance d&apos;un éventuel neutralisant minéral et du type de souches de bactéries sulfato-réductrices pour l&apos;initiation et l&apos;évolution des réactions d&apos;oxydo-réduction ont été évalués en utilisant de la dolomite ainsi que des inocula de sédiments portuaires réducteurs et de boues d&apos;usine d&apos;épuration. Une augmentation de pH et des diminutions de Fe2+ et SO4 2- ont été notées dans tous les réacteurs. En l&apos;absence de dolomite, le pH augmentait de 1.6 à 5-6, Fe2+ diminuait de 400 à moins de 5-100 mg/L, et SO4 2- diminuait de 2500 à 750-1250 mg/L. Les échantillons inoculés avec des sédiments s&apos;avéraient légèrement plus performants que ceux avec boues. En présence de dolomite, le pH atteignait 6.5-7.0, et Fe2+ et SO4 2- tombaient à <5 et 20-40 mg/L, respectivement. Le degré de réactivité des résidus forestiers n&apos;était pas une simple fonction inverse de leur âge. Les échantillons ayant le mieux réagi, bien que parmi les plus vieux testés (années 1980), étaient ceux contenant une proportion significative d&apos;écorces de feuillus et peu de bran de scie. Les échantillons avec des proportions élevées d&apos;écorce de conifères ou de bran de scie étaient associés à des taux de réduction moindre. Nonobstant l&apos;amélioration rapide des conditions obtenue avec la dolomite, grâce à une neutralisation initiale plus prompte, il s&apos;avère que le type de résidus forestiers éventuellement utilisé dans une barrière réactive est de première importance pour l&apos;efficacité des mécanismes de réduction. Un système basé sur l&apos;utilisation de résidus forestiers devrait utiliser des écorces (plutôt que du bois) provenant de feuillus (plutôt que de conifères).

Nov 1, 2002

By Eric Barnard, Andreas Nashitati, John Tero, Guy Deschênes, Setta Mbalamba, John Rajala

The Otjikoto Mine, owned at 90% by B2Gold Corporation, is located 300 km north of Namibia’s capital city of Windhoek. The reserves from the open pit mine, estimated at 25.9 million tons with an average grade of 1.28 g/t Au, contain gangue minerals, pyrite and pyrrhotite, and have an estimated 10 year mine life. The feasibility study included an optimisation of gold leaching using CSTR for the original design. The results of the test work were used to establish the design criteria. Gravity tails from three composites (drill cores), representing the major ore types, were used. The XR3 sample (gravity tails) contained 0.32 g/t Au, while the XR2 and XR1 gravity tails samples (used for variability) contained, respectively, 0.30 g/t Au, and 0.47 g/t Au. The optimum leaching conditions were: a pre-treatment of 7 h at pH 10.5 with 100 g/t lead nitrate, DO > 5 ppm followed by cyanidation at 300 ppm NaCN, pH 10.0, DO > 5 ppm for 48 h. The gold extraction was 91.5% (97.2% overall extraction gravity/leach) and the cyanide addition was 0.57 kg/t NaCN. Increasing the DO to 16 ppm did not show any economic benefits. No pre-treatment or a 4-h pre-treatment reduced the gold leaching kinetics. The XR2 and XR1 gravity tails samples had gold extractions of 92.9% and 92.3%, respectively. At the plant scale, an 11 h pre-treatment is used followed by 42 h cyanidation with 250 ppm NaCN and an average DO of 8 ppm and 230 g/t lead nitrate in 2016. The cyanide addition was 0.49 kg/t NaCN. The commercial operation started on February 28th, 2015. The overall gold recovery and production were 98.4% and 145,696 ounces for 2015 and 98.1% and 166,286 ounces for 2016. It was found that retention times, gold content of leach residues and cyanide addition are comparable for the lab and the plant. Details of the Otjikoto process flowsheet are discussed in this paper along with the results of the lab leach optimisation test program and the plant leach circuit performance and improvements.

Jan 1, 2017

By A. W. White

Introduction To discuss all the technical details of incorporation laws, security laws, underwriting procedures, codes, and ethics-as laid down by varous associations -would be impossible in the time which has been allotted to me. My remarks, therefore, will be made in a very general way and will naturally be coloured with experiences which my firm and I have had. There is a common expression that "money makes the mare go". I hardly have to mention here that the best prospect in the country is of very little value unless its prospects can be developed-and this requires large capital expenditures. The art and problems surrounding the raising of this money is a long and interesting story. Since by its very nature mining is risky, the appraising of its risks in the many phases of its development programme is continuous. Very few men-if any-and very few corporations -if any -can afford to take all the risk of mining. Because of taxation policies-and the very scheme of present-day living -the truth of this statement can be seen throughout the whole industry by a close examination of the records. Since this is so, it is essential that the mechanics of distributing risk on a sound, and equitable basis be known to those engaged in the business and to the investor or spectator who proposes to risk his funds in the industry. Perhaps the greatest stimulant to modern business activities has been the creation of corporate bodies. It is evident, from the number of charters being granted by various jurisdictions, that this method of doing business is becoming more and more important. A limited company -or corporation-can be defined as a fictitious person existing solely in contemplation of the law.

Jan 1, 1951

By Lucas G. Thompson

My topic, "The Administration of Mineral Rights&apos;.&apos; is possibly an unusual one, as it deals with a subject upon which many of us have a more than passing interest, I thought ?it might prove consistent with the objects of this meeting, more especially as I propose to deal, not with those broad subjects of nation-wide importance which are often the subject&apos;? of learned (and sometimes futile) academic discussion, but rather with problems in their practical light. To the scientist, the important question is What is it? to the technician, Can it be utilized? to the business-man, Will it pay? All three questions are important, and so quick has been the march of business on the heels of science? that the one question follows the other with astonishing rapidity and all three must be considered in the modern management of a mineral estate. A .good illustration of the force of this can be found in the recent advance of our knowledge of the element helium in which we have advanced from a solution of the first question to the last question in the short period of 55 years. It is to be borne in mind, however, that in the administration of mineral rights, the question "Will it pay?:&apos; is of primary importance. What forms a mineral estate ? A former practice in western Canada in selling lands was to sell the hair with the hide. All transactions sold the lands in fee simple, which included all mines, minerals and rights and privileges whatsoever, excluding only the royal metals, gold and silver, which by imputation, though not by specific reference, in deeds. of title are reserved to the Crown. At that time the country was in the first ?stages of settlement and the value of our mineral resources was hardly appreciated and little understood.

Jan 1, 1923

By Fred G. Hewett

The Cassiar orebody is located in a sill-like serpentinite body intrusive into the Devonian-Mississippian sedimentary rocks of northern British Columbia. Subsequent intrusion of the Cassiar batholith formed the McDame synclinorium and produced chrysotile asbestos. Present information indicates an orebody of approximately 16,277,000 tons amenable to open-pit mining, but continued diamond drilling will be needed to accurately define total tonnage and grade. A program has been developed at the mine to provide the required information on a daily basis, and work is continuing on more effective dollar-value prediction methods.

Jan 1, 1978

By J. Kempken, R. Hagmann, C. -P. Reip, W. Hennig

The CSP technology symbolizes a highly productive process for the cost-effective production of steel grades with a range of sophisticated properties comprising both the inner quality of hot strip, its surface formation as well as the relating technological characteristics. Thanks to extensive development work undertaken during the last 15 years, the range of steel grades that can be produced was continuously expanded and the process technology optimized. The present paper describes the ongoing development work concerning the production of higher-strength, microalloyed pipe steels. The resulting hot strip, due to the associated thickness and the potential pipe diameters, is particularly suited for being processed to HFI-welded pipes. Based both on ferrite-pearlite as well as very fine-grained, ferrite-bainite hot-strip microstructures, strength levels of up to grade API X80 can be realized. It can be demonstrated that hot strip produced in a CSP plant has very good toughness values at temperatures down to -60°C and can even make application with required sour-gas resistance possible.

Jan 1, 2005

By N. Erarslan, M. Ghamgosar

With the increased use of mechanized rock excavation, there have been developed internationally a number of methods to assess the abrasivity of rock materials. These methods range from determination of abrasive and hard mineral content using petrographic thin section analysis to weight loss or rate of wear flat development on specified test pieces. The Cerchar abrasivity index (CAI) test has been widely accepted for the assessment of rock abrasiveness and is determined as the abrasion of a steel pin after scratching over the freshly-broken or saw-cut surface of a rock. Two types of testing devices are in use today: (i) the original ‘Cerchar apparatus’, and (ii) the ‘West apparatus’, which was adopted herein. The CAI is calculated from the measured diameter of the resulting wear flat on the steel pin after 10mm scratching. This test has been considered to provide a reliable indication of rock abrasiveness for isotropic rocks. However, a great amount of rocks in natureis anisotropic. Phyllite is an anisotropic and foliated metamorphic rock and various types of phyllite specimens were tested in this research. Although phyllite is a type of rock primarily composed of quartz and the expected CAI value can be high, mechanical cutting of this rock should not be very problematic compared with igneous rocks have same CAI value. As phyllite is a foliated metamorphic rock, most of the specimens split into sheets through the quartz seam by the tip during scratching normal to the axis of quartz seams. Hence, viability assessment of Cerchar abrasivity test and F-Schimazek index values for the anisotropic rocks is investigated in this research.

Jan 1, 2015

An optimization process is described that can be systematically applied by mine planners to produce life-of-mine schedules aligned with their strategic targets, while maximizing the net present value of the mining operation. The software tool employed uses heuristics and an evolutionary algorithm to generate life-of-mine schedules of production and development activities. Generating such schedules is typically a very difficult task due to the large number of operational constraints that must be respected, and the vast number of alternative schedules; as a result the value of the mining operation can be compromised. With an expansion at Newmont?s Leeville mine in Nevada, the mine planners were given the task of producing feasible life-of-mine schedules with significantly increased production rates. Their initial efforts indicated that it would be a considerable challenge to generate such schedules in a timely manner. By systematically applying the proposed optimization process, the mine planners were able to generate optimized life-of-mine schedules with the desired production rate.

Aug 1, 2013

By Davood Moradkhani, Maryam Rasouli

"The present study reports solvent extraction and separation of zinc from concentrated nickel sulfate solution. In our previous study, Zn and Cd in cold filter cake (CFC, 45-55% Zn, 11-16% Cd, and 2.5-4% Ni) were extracted by alkaline leaching followed by electrowinning processes respectively. The strip solution from electrowinning process, was a pregnant liquor solution (PLS) containing 16.8 g/l Ni and 4.2 g/l Zn. In this work, PLS is subjected to the solvent extraction process for separation of traces of Zn from high grade nickel. The zinc free raffinate containing 16.6 g/l Ni sulfate solution will flow to nickel electrowinning plant for cathode production. Di-(2-ethylhexyl) phosphoric acid (D2EHPA) is the organic phase used in this study. The effects of various parameters such as organic phase concentration (10- 40 % v/v), pH (1.5-3), and temperature (25 and 45°) are investigated. Zinc over nickel separation factor increases by increasing pH from1.5 to 3. The results show that 98.7% of Zn was loaded at25°C O/A ratio of 1, pH 3, and 10% vol. D2EHPA. A 10 M NaOH is used for pH control. However, replacement of pH controlling agent with ammonia solution (25%. v/v) results in interesting observations. Ammonia addition, reduces the solubility of Ni2+ cations in solution. Nickel starts to precipitate from raffinate in a crystalline bluish-green form. The obtained crystals are characterized by XRF and identified to be nickel-bearing analog of boussingaultite, a rare sulfate mineral of nickel with chemical formula of Ni (NH4)2(SO4)2.6H2O. The crystallization rate of crystals is studied. It is a slow precipitation process with 75% in 4 days.INTRODUCTION Annually, many hydrometallurgical processes such as electrowinning, solvent extraction and leaching are applied to waste filter cakes in Zanjan, Iran. These additional processes on filter cakes are critical from both environmental and economic points of view. CFC (cold filter cake) is a toxic but valuable filter cake (45-55% Zn, 11-16% Cd, 2.5-4% Ni, and 0.2-1.5% Cu) produced in many zinc production plants. Our research group at Research and Engineering Company for Non-ferrous Metals (ReCo.), developed a series of hydrometallurgical methods for extraction of zinc, cadmium and nickel from CFC (Moradkhani, & Rasouli 2012). The recovery of zinc and cadmium with alkaline leaching and electrowinning was successfully studied. The strip sulfate solution from cadmium electrowinning unit, contains high concentration of nickel with some traces of zinc impurity. This pregnant liquor solution (PLS) was analyzed and reported to contain 16.8 g/l Ni and 4.2 g/l Zn. In this work, PLS is subjected to the solvent extraction process to separate Zn from nickel (Fig. 1). The organic phase stripping solution containing 4.2 g/l zinc and 200 ppm nickel can be circulated and used in the acidic leaching step. This generates nickel solution with high purity suitable for nickel cathode production."

Jan 1, 2017

By P. G. Hallof

The exploration staff of Campbell-Chibougamau Mines Limited has used past experience to delineate several areas of geologic interest under Lake. Chibougamau. Du• ring the winter of 1964-65, a reconnaissance induced polarization survey was carried out on the lake. First, several lines were surveyed over the known mu1.erahza-tion at the Henderson mine; the grid was then extended into the areas of interest. Several anomalous zones were located and drilled; one, of these proved to be of economic interest.

Jan 1, 1967

By S. Kashani-Nejad

The formation of oxides during the dehydration of MgC12,6H20, Bischofite, was studied by heating the bischofite over a range of time and temperatures in ambient atmosphere. Using a methanol-leaching technique developed by authors, the oxides that formed were isolated, identified and assayed. Three distinct regions of oxide stability were identified. The oxide produced at dehydration temperatures less than 300 °C was Mg2(OH)3C1,2H2O; at 300 °C, mixtures of MgOHC1 and Mg2(OH)3C1.2H2O were formed and at 400 °C, MgOHC1 was the only oxide produced. The presence of MgO observed in the products of the dehydration of bischofite at temperatures above 400 °C was due to the thermal decomposition of the MgOHC1 that was formed while the sample was heating to over 400 °C.

Jan 1, 2006

By D J. Murray

This paper outlines the principles of friction hoisting and the components involved, and gives a description of a specific mine hoist. Friction hoisting is compared with conventional drum hoisting, and the depth of shaft at which friction hoists become more economical than drum hoists, with respect to power consumption, is determined. Introduction T HE purpose of this paper is to outline the principles of friction hoisting, to describe the components and to show the advantages of multi-rope friction hoisting. Some calculations are made to show that the power requirements and the initial costs of friction hoists are less than those of conventional drum hoists, once a certain depth of shaft has been reached. The use of multi-rope friction hoists is gradually superseding the employment of the conventional drum hoist in many parts of the world. It results in heavier payloads from deeper levels, an increase in shaft safe-ty and a more compact installation for protection against adverse weather conditions. It was observed that where drums and friction sheaves exceeded 30 feet in diameter, a number of mechanical disadvantages were being experienced;

Jan 1, 1965

By Jeanie Wills, Theresa Nyabeze, Samantha Espley, Donna Beneteau

This presentation reports survey findings that aim to modernize the definition and understanding of the term 'mining.' The survey, conducted via LinkedIn in Winter 2024, garnered responses from a diverse group of individuals, including current or former employees of mining or exploration companies, mining consulting firms, service providers, supplier firms, as well as students and retirees with industry experience. The data, ethically approved by the University of Saskatchewan, offers valuable insights into satisfaction levels within the mining sector and suggests an expansion of the identifying characteristics of definitions of mining. This marks the third CIM gaining insights paper by Beneteau, Espley, and Nyabeze, following previous works on 'Career Satisfaction for Women in Mining' (2010) and 'Mentorship Initiatives in the Canadian Mining Industry' (2018*)."

Oct 1, 2024

By S. Afshar, E. Dajoux, C. Allaire

For various reasons, molten salts, mainly chlorides and fluorides, are used in the aluminum industry. In the holding and melting furnaces, these salts may have different roles such as protecting the metal from oxidation, reducing the metal content of the skim or removing inclusions or impurities from the metal bath. However, the use of these salts may also have some undesirable effects such as easy attack of the furnace lining refractory materials by molten aluminum. The aim of the present investigation was to clarify and to compare the effects of chloride versus fluoride salts, on the corrosion process of the aluminosilicate based refractory materials. A laboratory test and procedure, simulating the conditions at the metal line in the aluminum treatment furnaces, was used. Different aluminum alloys (A1-5wt.%Mg, A1-5.5wt.%Zn and 7075 alloy) and chloride or fluoride salts (MgC12, KC1, CaCl2, NaC1, MgF2, CaF2, NaF and cryolite) were used as well as several aluminosilicate materials. Thermogravimetric measurements were also carried out in order to analyze the effect of the salts on the oxidation of molten aluminum alloys. The experimental results showed that fluoride salts are more aggressive than chlorides against the tested refractory products. It is postulated that the fluorides prevent the formation of a protective oxide layer on the metal surface, favoring at the same time the corrosion of refractories. Moreover, it was found that the presence of Na in fluoride salts increases significantly the aggressiveness of the aluminum alloy towards the refractory samples.

Jan 1, 2004

By Robert Strachanm

The East Kootenay coal-field, situated close to the boundary between the provinces of Alberta and British Columbia, is composed of four small areas locally called the Crow&apos;s Nest Pass, the Upper Elk, the Flathead and Crown Mountain, and comprises an area of about 3 78 square miles. From eleven to twenty-five seams have been exposed of two feet and over in thickness, with a total thickness of about 200 feet of coal, and reckoning about one hundred feet to be workable, gives an estimate of coal available of about thirty-seven billion tons. The coal is a high-grade bituminous, occasionally tending towards anthracite, and the majority of the seams furnish a. very good quality of coking coal as well as an excellent steam coal. The coal-field is found in the mountain ranges in long narrow strips. The age of the fonnation and the thickness of the covering beds have had considerable influence on the character of the coal, and lateral pressure and disturbances in the process of mountain-building have wrought great changes. With such an abundance of coal, it has been a disappointment that the East Kootenay field has not figured larger industrially. So far only one portion of the coal-field has been utilized. This is the Crow&apos;s Nest, where, in 1898, the Crow&apos;s Nest Pass Coal Company commenced development. Access to the coal seams was easily obtained, the mountain creeks having eroded away the covering, and mines were driven into the coal seams. In that year about ten thousand tons of coal were produced from the mine at Coal Creek.

Jan 1, 1924