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By L. K. Sinclair

In situ leaching of copper has the potential to deliver low-cost recovery for soluble copper deposits of sufficient permeability. In order to provide key inputs for modeling of the in situ leaching process, bench scale test work can be used in conjunction with geochemical software to identify key leaching and precipitation reactions. A case study is presented in which a series of flow-through acid leaching tests were conducted on drill core sections from a porphyry copper deposit without crushing or grinding. Concentrations of copper and other key elements were monitored in the recirculating leach solution over several months. A geochemical model of each leaching test was prepared using Geochemist's Workbench using a combination of diffusion-controlled and reaction-controlled rate mechanisms. Key reactions included leaching of chrysocolla, iron oxides, and plagioclase. The model was able to simultaneously satisfy the evolving chemistry of the recirculating leach solution, mineralogy of the head and leach residue, measured acid consumption, and leaching rates for key minerals reported from previous laboratory studies. Opportunities and limitations for scaling up the model to simulate the commercial wellfield are discussed.

Jan 1, 2015

By J. F. Wright

INTRODUCTION Eighteen years ago about half a dozen experienced prospectors moved from northern Ontario to northwest Manitoba to prospect 'greenstone' areas shown on geological maps of .parts of northern Manitoba prepared by J. B. Tyrrell, D. B. Dowling, and Wm. Mclnnes. Gold-bearing quartz was soon discovered by these men in this new field, and in succeeding years many more prospectors entered the district. A number of the pioneers are still prospecting, and since 1913 mineral deposits have been discovered each year in widely separated areas of the large district extending 150 miles eastward from the 102nd meridian and 60 miles north of latitude 54°30'. The majority of the discoveries, however, have been made near Schist, Elbow, Wekusko, and Kississing lakes. One hundred or more mineral occurrences of some merit are known, the main types being sulphide replacement bodies containing nickel-copper or copper-zinc and gold-bearing quartz veins. Some underground exploration or diamond drilling has been completed on 25 or more of the prospects. Up to the present, three ore-bodies, namely, Flin Flon, Sherritt-Gordon, and Mandy, have been proved. Of these, Flin Flon, the largest, is estimated to contain from 16,000,000 o 19,000,000 tons of copper-zinc ore carrying some gold, silver, and lead. Next in importance in regard to tonnage is Sherritt-Gordon, with a calculated reserve of nearly 5,250,000 tons of copper-zinc ore carrying less than $1.00 combined gold and silver.

Jan 1, 1931

By M. Massinaei

Recently constructed circuits have included multiple stages of columns in a variety of applications, from roughing to cleaning. The Miduk copper concentrator (in south-eastern Iran) is one of the unique mineral processing plants which use column flotation cells as rougher. As the bulk of final concentrate is produced by rougher columns, optimized metallurgical performance of these cells is crucial. This paper will present the study and optimization of, a froth washing system of columns. For this purpose, the cross-sectional area of orifices was increased and their orientation altered. Concentrate assay for copper and silica, in addition to bias rate were found to be the assessment criteria. Modification of the wash water system resulted in increasing the purity of rougher and final concentrate. Negative bias and short-circuiting of wash water into the concentrate launder were the main causes of improper froth zone washing in the former system.

Jan 1, 2007

By A. Shaak

The town of Hedley is some 200 miles due east of Vancouver and lies in the bottom of the Similkameen River valley, at the junction of Twenty Mile creek, at about the 1,700-foot elevation above sea level. The Nickel Plate mine camp is on Nickel Plate mountain at an elevation of about 5,600 feet, four miles slightly east of north from Hedley, to which it is connected by 9 miles of road, and by 10,000 feet of tramway and electric railway. The latter is used both to transport the ore to the 275-ton mill at Hedley and to furnish the mine with supplies. History The Nickel Plate claim was staked in 1898 to cover the sole outcrop of the Nickel Plate system of orebodies. Soon afterwards it was optioned by the Marcus Daly interests of Butte and underground exploration commenced. Early exploration was successful, and a power plant, tramway, and mill were constructed. The mill began operations in 1904. Production under Daly control ensued from June, 1904, to August, 1909, and amounted to 167,000 tons. The Hedley Gold Mining Company was organized and commenced operations in 1909. The capacity of the mill was increased by stages to 200 tons and a steady production, except for short periods in winter, was maintained until 1930. By 1930, gold to the value of nearly $10,000,000 had been produced since the discovery in 1898. The South American Development Company optioned the property in 1932. Active exploration was conducted during 1933 and 1934 by the Kelowna Exploration Company, a subsidiary of the South American Development Company. This work was sufficiently successful that, coupled with the increase in the price of gold from $20.67 to $35.00 per ounce, production re-commenced in December, 1934, and continued uninterrupted until July, i946, when, along with all B.C. gold mines, a strike closed operations. Under the present ownership, the mill capacity was increased to 275 tons.

Jan 1, 1946

By W. van der Merwe

ABSTRACT With the gold industry processing more complex ores, the online measurement and control of cyanide addition to the gold leaching circuit has become more critical. This paper compares the two commonly employed ‘free’ cyanide online analysis methods (amperometric and potentiometric endpoint silver nitrate titration) with the rhodanine endpoint silver nitrate titration and ion selective electrode methods common at site laboratories. Measurement differences between these methods are presented and discussed for cyanide solutions containing copper and zinc with varying cyanide to metal ion ratios. The resulting cyanide available to leach gold is also compared using these measurement techniques.

Jan 1, 2013

By J. Stiksma, K. Buban, J. Oftsie, R. Kalanchey, S. Sadykov, E. McConaghy

The Kazakhmys zinc refinery in Balkhash, Kazakhstan, which employs the Dynatec Zinc Pressure Leach Process, officially launched autoclave operations on December 27, 2003. The Kazakhmys plant is the world's first greenfields zinc refinery based on Dynatec's two-stage pressure leach technology. Production of zinc was realized on February 9, 2004, when the first cathode was stripped. Currently the plant start-up is ongoing, with progression to two-stage zinc pressure leach operation and ramp-up to full design capacity continuing through 2004.

Jan 1, 2004

By R. D. Parker

Location The Frood ore-body is expressed on surface as a prominent gossan ridge, with a total length of approximately two miles. The original Frood (the old No. 3 mine of the Canadian Copper Company) is at the southwest end of this gossan; adjoining it on the northeast is the Frood Extension (until 1929 the property of i:he Mond Nickel Company), while at the extreme northeast end is the Stobie mine. The first two of these divisions of the ridge form the Frood mine as it is known today.? This lies in lots 6 and 7 of the sixth concession, township of McKim, and is two and a half miles north of the city of Sudbury. The general elevation is 1,000 feet above sea level. The Ore-Body The Frood-Stobie parallel offset(l), as its name implies, has no connection in the field with the main mass of the Sudbury nickel eruptive-a norite. It lies one mile to the southeast of that body, and, in general, parallels it in strike. The ore occurs as a more or less tabular structure in what is known locally as the Sudbury series. They are the oldest rocks of the district, and have been placed by Collins(2) as earlier than the lower Huronian, of pre-Cambrian time. The series is comprised of sediments, volcanics (both acid and basic flows), tuffs, agglomerates, breccias, and basic intrusives, all highly metamorphosed, yet all forming a more or less regular picture. The controlling feature of the area has been the attitude of the sedimentary strata, from which has arisen the present sill-like character of the flow rocks, the basic intrusives, and the ore-body itself.

Jan 1, 1932

By Y. Gordon

ABSTRACT A methodology based on a two-stage approach was developed for process technology selection. The first stage includes evaluation of available technologies, followed by shortlisting the best technologies based on mass and energy balance modelling, financial analysis, and risk analysis. The second stage involves detailed analysis using refined input data, mass and energy balance modelling, and capital and operating cost estimation, as well as a more detailed financial analysis. A case study covering the selection of ironmaking technologies for a company in the Russian Federation is presented to illustrate the critical elements of the methodology and the analysis process.

Jan 1, 2014

By M. E. Holuszko

A research program has been carried out at the Mining Department of the University of British Columbia to study the effect of wettability of coal on its handleability and bulk density. The effect of moisture content on the bulk density of coal was found to be more pronounced for hydrophilic coals than for hydrophopbic ones. Altering wettability of coal surface leads to different effects of moisture on bulk density. The samples were studied at different fine fractions content, and it was shown that there was no effect of increased content of fines on the bulk density for hydrophobic coals, while for hydrophilic coals this effect was very significant. It was shown that the moisture content at which the lowest bulk density was reached coincides with the critical moisture content for studied samples, as determined from handleability tests using Durham Cone method. This critical moisture is the moisture content at which a sudden deterioration of coal handleability occurs. Based on the bulk density and handleability tests, the flow theory of moist coal is proposed.

Jan 1, 2006

By M. Samuels

"Block and panel cave mining methods are being increasingly proposed as they allow massive, deeply situated ore-bodies to be mined economically at a time when discovery rates of significant near surface deposits are declining. Cave-to-Mill, a mine-to-mill approach for block cave mines, defines ore block models with respect to both mine and mill performance. A cave-to-mill study for the New Afton block caving operation focused on identifying value opportunities related to fragmentation and sorting for a future lift as development progresses deeper. The lack of selectivity and potential for dilution associated with the block cave mining method results in many caving operations having to mine and either dispose of or process material that is below cut-off grade at certain stages of production. As an outcome of the study, the variation in cave fragmentation size and the sensitivity of mill throughput to feed size was examined. To evaluate the amenability of bulk and particle sorting, Prompt Gamma Neutron Activation Analysis and X-Ray Fluorescence sensors were tested. A conceptual bulk and particle sorting flowsheet is presented. Grade data from regular underground sampling was used to predict the performance of a bulk sorter. A heterogeneity analysis of material reporting to drawpoints helped to identify areas of the extraction level that experience high variations in grade and thereby stand to benefit from dedicated ore and waste material handling systems should underground bulk sorting be implemented.INTRODUCTION Block and panel caving are low-cost underground mass mining methods that are suitable for excavating weak, massive and steeply-dipping orebodies. Accordingly, cave mining methods have predominantly been used to mine copper porphyry and diamond bearing deposits. Due to the increasing depletion of near-surface orebodies, it is expected that block and panel caving methods will be increasingly used in the copper-gold industry. Their implementation holds significant potential to extend the life of existing open-pit operations by providing an economic means to access ore located at depths that are beyond the practical limits of open-pit mining. Examples of cave mines proposed for British Columbia include the Kwanika Mine, Red Chris underground, Kemess Underground project, and the Iron Cap and Mitchell cave mines of the Kerr-Sulphurets and Mitchell (KSM) project (Moose Mountain Technical Services, 2017; Imperial Metals, 2017; Golder Associates, 2017; Tetra Tech, 2016)."

Jan 1, 2018

By D. L. Koch, J. W. Tester, L. K. Sinclair

"In this study, hydraulic conductivity (K) geostatistics were used to predict residence time distribution of well-to-well flow. Flow profiles, fracture density measurements, and pumping tests were available from the highly fractured Florence Copper in situ leaching site. The flow profiles were used to establish the statistical distribution and spatial autocorrelation of K. Two tests were used for validation. The first test confirmed that fracture density and K are autocorrelated over similar length scales. In the second test, Monte Carlo flow simulations successfully recreated the results of pumping tests. Flow sim¬ulations were used to stochastically model well-to-well residence time distribution. RÉSUMÉ Dans cette étude, nous utilisons la géostatistique de la conductivité hydraulique (K) pour prévoir la distribution des temps de séjour (DTS) de l’écoulement entre les puits. Des profils de l’écoulement, des mesures de la densité des fractures et des essais de pompage existaient pour le site fortement fracturé de lixiviation in situ de Florence Copper. Les profils de l’écoulement ont permis d’établir la distribution statistique et l’autocorrélation spatiale de K. Deux essais ont servi à la validation ; le premier a confirmé que la densité des fractures et K sont autocorrélés sur des échelles de longueur similaires ; quant au second, des simulations d’écoulements de type Monte Carlo sont parvenues à reproduire les résultats des essais de pompage. Les simulations d’écoulement ont servi à établir un modèle stochastique de la DTS de l’écoulement entre les puits.INTRODUCTION In situ leaching is the circulation of a dilute acid or base solution in the subsurface, via a series of injection and recovery wells, to dissolve a target metal. In situ leach modelling requires forecasting the residence time distribution (RTD) of flow between wells. In fractured formations such as copper porphyry deposits, order-of-magnitude variations in hydraulic conductivity (K) can result in highly channeled flow, resulting in a heavy tailed RTD (Becker & Shapiro, 2003; Kang, Le Borgne, Dentz, Bour, & Juanes, 2015). Channeling through preferential pathways has impacted copper recovery at several past in situ leaching field tests (Cathles, Glenn, Lenzi, Nigrini, Deans, & Huff, 1978; Ahlness & Pojar, 1983; Schmidt, Earley, & Friedel, 1994; Sinclair & Thompson, 2015). The aim of this work is to combine multiple types of hydrogeological measurements to stochastically forecast the well-to-well RTD in fractured rock for the purposes of copper in situ leach modelling."

Jan 1, 2018

By G. Armand, G. Arnold, A. Giraud, C. Auvray

The knowledge and understanding of the mechanical behavior of claystone is of critical importance in the aim of nuclear wastes storage. In this study, specimens of Callovo-Oxfordian claystone (COx) have been obtained from the ANDRA underground research laboratory in Meuse/Haute-Marne (France). This claystone is composed of carbonate inclusions (10-50µm) embedded in an argillaceous matrix (representing expanding clay minerals, such as smectites). The matrix itself is also multiphase and composed of clay aggregates of 1µm-size carbonate and quartz inclusions. This multiphase microstructure leads to a high heterogeneity witch was analysed through nanoindentation test grids. Moreover, the mechanical behavior of the claystone matrix is highly sensitive to humidity and temperature. The nanoindentation tests were performed in a climatic (i.e. temperature and humidity controlled) chamber at relative humidity levels from 50% to 98% and at two temperatures: 20°C and 60°C. In a first step, the curves of indentation were analysed using the commonly used Oliver and Pharr’s approach. Other wellknown parameters as the creep factor were also extracted. In a second step, Fisher-Cripps model (Fischer- Cripps, 2004) and Vandamme and Ulm model (Vandamme & Ulm, 2006) were used to identify viscoelastic properties. A statistical analysis is used in order to extract mechanical characteristics of the different phases. Hardness and elastic modulus decrease drastically with saturation (above 80% humidity) and to a lesser extend with temperature.

Jan 1, 2015

By W. G. Miller

An overall study was conducted to evaluate the properties and processes influencing the rate and magnitude of consolidation for oil sands fine tailings produced using different extraction processes. As part of this overall study, consolidation tests using slurry consolidometers were carried out for caustic and non-caustic fine tailings. The influence of a change in bitumen extraction process (caustic versus non-caustic) on consolidation properties, namely compressibility and hydraulic conductivity, was determined, as was the effect of adding a coagulant (calcium sulphate [CaSO4]) to caustic fine tailings. For fine tailings originating from two different oil sands ores (Ore A and Ore B), results were presented in terms of variation in average void ratio with time (settlement), void ratio with effective stress (compressibility), hydraulic conductivity with void ratio and coefficient of compressibility and hydraulic conductivity with sodium adsorption ratio. Findings indicated that chemical characteristics of fine tailings (water chemistry, degree of dispersion) do not have a significant impact on their compressibility behaviour and have only a small influence at high void ratio (low effective stress). The biggest advantage of non-caustic fine tailings and treating caustic fine tailings with coagulant is an increased initial settlement rate and slightly increased hydraulic conductivity at higher void ratios. Thereafter, compressibility and hydraulic conductivity is governed by effective stress.

Aug 1, 2010

By W. G. Miller, J. D. Scott, D. C. Sego

An overall study was conducted to evaluate the properties and processes influencing the rate and magnitude of consolidation for oil sands fine tailings produced using different extraction processes. As part of this overall study, consolidation tests using slurry consolidometers were carried out for caustic and non-caustic fine tailings. The influence of a change in bitumen extraction process (caustic versus non-caustic) on consolidation properties, namely compressibility and hydraulic conductivity, was determined, as was the effect of adding a coagulant (calcium sulphate [CaSO4]) to caustic fine tailings. For fine tailings originating from two different oil sands ores (Ore A and Ore B), results were presented in terms of variation in average void ratio with time (settlement), void ratio with effective stress (compressibility), hydraulic conductivity with void ratio and coefficient of compressibility and hydraulic conductivity with sodium adsorption ratio. Findings indicated that chemical characteristics of fine tailings (water chemistry, degree of dispersion) do not have a significant impact on their compressibility behaviour and have only a small influence at high void ratio (low effective stress). The biggest advantage of non-caustic fine tailings and treating caustic fine tailings with coagulant is an increased initial settlement rate and slightly increased hydraulic conductivity at higher void ratios. Thereafter, compressibility and hydraulic conductivity is governed by effective stress.

Jan 1, 2010

By Nicholas C. Williams

This paper presents the development of a demand reduction and responsive strategy capable of reducing the electrical power demand, particularly during peak conditions. The work presented includes a case study of a UK colliery. Areas explained are the equipment installation at the mine; the development of the demand reduction strategy including the load profile database and prediction optimisation model. Some live production data from the power meter installation at the mine is also presented.

Aug 1, 2013

By Francis Gray

Mr. F. W. Gray: It is not my intention to read my paper as it is too long, so I will touch only on the high lights. The Sydney field is the most favourable example of undersea coal mining that exists, and I have not been able to find anything like it elsewhere. The nearest approach to it is a field in England where the Whitehaven collieries are operating, but it has a lot of faults. The net result of these faults so far met with in the seaward advance of the workings has been to increase, by something over 100 feet, the gain in depth of cover, in a distance of approximately three and three-quarter miles. In the Sydney field there are no faults of any consequence. On the east side, the English measures rise. In Australia the sea bottom fell and the cover became too light. On Vancouver Island the coal ran out, and in Japan the seams are steep and contorted. The Chilian fields resemble our own to some extent. An inundation of two collieries took place there some time ago, due, it is said, to the rise workings being allowed to approach the sea bottom too closely in the vicinity of a fault. The Cape Breton undersea field has been proved over a frontage of about thirty miles and has been attacked and penetrated for a considerable distance along that front. We have passed the prospecting stage and now generally use developed land areas as points of attack to win the undersea coal. Of our mining under the sea, it can be said that, with the exception of No. 1-B and Princess colliery, Sydney Mines, no real attempt has been made to win the undersea coal.

Jan 1, 1927

By J. R. Porter, C. Panaou

"A significant effort is expended on preparation of the capital estimate for feasibility studies. The development of the operating cost estimate is usually allocated a significantly smaller budget and less emphasis is placed on ensuring the accuracy of the operating cost. This paper presents a comparison of capital and operating costs of hydrometallurgy processing plants in order to demonstrate the importance that variations in operating costs have on the overall life-of-mine costs. The analysis is supported by a case study on the operating costs of a water treatment plant at an existing Australian hydrometallurgy facility at the feasibility design level. INTRODUCTIONDetermination of the economic validity of a minerals processing project is a critical outcome of a feasibility study. In many cases, the financial results of the feasibility study will determine if the project should proceed to execution. Ensuring that these results are reliable and built upon sound engineering practices allows companies to make informed decisions on resource opportunities and the selected technology.The methodology for developing a capital cost estimate at the feasibility level is well established. Specialist engineering estimators use budget quotations, first principle estimation and rules-of-thumb to develop an estimate with an accuracy of typically -10% to +15%. Cost reporting software packages are used to methodically build up the estimate from design information supplied by the engineering disciplines. Risk analysis and capital expense workshops are carried out to identify potential deficiencies in the estimate. It is widely recognized that in order to successfully produce a feasibility level capital estimate with an appropriate level of accuracy, a rigorous development process is necessary.The development of the operating cost estimate is typically less rigorous than the capital cost estimate. The operating cost is normally derived by the process engineering discipline and rarely are specialist estimators used to support the development. The allocated budget for producing an operating cost is usually smaller and less emphasis is placed on ensuring the accuracy and contingency reflect the most likely operating cost scenario."

Jan 1, 2012

By A. G. Matyas

Process improvements which have reduced the lead content of slag from the Brunswick lead blast furnace are described. Microscope examination and electron microprobe analyses, supported by the results of slag settling and viscosity tests, showed that typically about 70% of the lead in the lead blast-furnace slag was present in the form of entrained prills of metallic lead. The total lead content was found to increase with the magnetic susceptibility of the slag. Measurements in the furnace settler indicated the presence of a magnetite-rich layer between bullion and slag, arising from high magnetite levels in the slag. This layer was believed to inhibit the settling of entrained lead from the slag. Tracer tests showed that the average slag residence time in the settler was less than 2 minutes. Improvements in coke quality and sizing, which led to a reduction in the slag magnetite content, and the installation of a larger settler and a continuous Roy tapper, have all contributed to a significant decrease in the slag lead content.

Jan 1, 1977

By Manjeet Chowdhry, Qingxia Liu, Phillip Choi, Zhenghe Xu

Computational chemistry methods, such as density functional theory (DFT), are powerful tools to quantify reagent-mineral interactions encountered in sulphide mineral flotation. A quantitative relationship between theoretically calculated parameters based on chemical structure of collectors and their reactivity with different metals/minerals can provide valuable insights for design and development of more powerful and tailor-made reagents offering enhanced metal/mineral selectivity. DFT calculations at B3LYP/6-311++G(3df,3pd) level were employed to elucidate the reactivity of neutral sulphide collector reagents, including thionocarbamates (TC), thioureas (TU), xanthogen-formates (XF), dialkyldithiocarbamates (DTC) and dialkyltrithiocarbonates (TTC) with different heavy metal ions (Cu2+, Zn2+ and Pb2+) in solution. The extent of delocalization of lone pair electrons of heteroatoms (attached directly to C in C=S) over C=S group was found to be the dominant factor in determining the collector’s reactivity. Order of reactivity was established as: TU > TC > XF > DTC > TTC. All the collectors showed superior affinity towards copper followed by lead. Unidentate binding was observed through sulphur atom except for xanthogen-formate for which bidentate binding mode was observed. Effect of nature of substituent groups at N and/or O atom on reactivity of thionocarbamate and thiourea was also investigated. The results obtained through DFT calculations are consistent with the experimental data reported in literature.

Jan 1, 2015

By B. Dubé, R. Friedman, J. Oliver, R. Aubertin, M. Burson, G. Panneton, M. Hamilton, J. Ayer

"Abstract — The Detour Lake gold deposit is located within the northwestern limit of the Archean Abitibi Subprovince of the Superior Province. Mineralized zones are hosted by a sequence of pillowed and massive flows, hyaloclastite units, and altered ultramafic rocks, and are commonly oriented parallel to a series of high-strain zones that are co-planar to the regional-scale Sunday Lake Deformation Zone. Early in its kinematic history, the Sunday Lake Deformation Zone placed older (2.72 Ga) volcanic rocks of the Detour Lake Formation over younger (2.70 Ga) sedimentary rocks of the Caopatina assemblage. Gold mineralization is also parallel to the position of a laterally persistent siliceous rock unit, the 2.725 Ga ‘Chert Marker Horizon.’ The Chert Marker Horizon coincides with the boundary between the mafic-dominated upper Detour Lake Formation and the ultramafic-dominated lower Detour Lake Formation. Stratigraphic and geochronological data suggest that the Chert Marker Horizon is a deformed felsic volcaniclastic unit. At a cut-off of 0.6 g/t Au, the Detour Lake deposit contains 17.26 million ounces of Au within 445.9 million tonnes of rock grading 1.20 g/t Au. Gold occurs in shear-hosted and extensional vein arrays within rocks of the upper and lower Detour Lake Formation and within the Chert Marker Horizon. The Detour Lake deposit has many of the characteristics of a greenstone-hosted, quartz-carbonate vein deposit; its very large size may be attributed to large-scale rheological controls resulting in the formation of dilatant sites in permissive rock units. © 2012 Canadian Institute of Mining, Metallurgy and Petroleum. All rights reserved."

Jan 1, 2012