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By S. D. Graham

"The extractive metallurgy of gold is largely controlled by mineralogical factors such as the presence of refractory gold, particle size, gangue mineral associations, presence of preg-robbers, oxygen and cyanide consumers, and locking characteristics in base metal sulphides. Light microscopy and automated mineralogy techniques are regularly used to characterise the effect of these variables on gold recovery. However, despite their widespread application there are a range of limitations when grades are low. Typically, the analysis of low-grade samples requires the preparation and analysis of numerous polished blocks. This is often costly and time consuming, with complexities regarding analysing statistically representative particle quantities and problems overcoming stereological bias. This is compounded by the “nugget” effect and high tenor nature of gold mineralisation. X-ray Microscopy techniques have the potential to overcome many of these problems, in particular the statistical representivity of analysis, removing stereological bias and effectively locating phases that are present in ultra-trace proportions. In this paper we outline the potential benefits of employing X-ray Microscopy (XRM) in characterising gold losses from a typical Cu-Au porphyry project, which were illusive in 2D based analysis. The talk will also outline additional application areas of XRM within the extractive value chain."

Jan 1, 2017

By C. G. McLachlan

INTRODUCTION The work described in the following paper was under-taken with a view to determining, if possible, the relative importance of some of the phenomena on which flotation seems to depend, in the hope that, if this information could be obtained, it would be of value in dealing with the problem as a whole. At the outset, brief reference will be made to three papers which had a considerable bearing on the course followed in the present investigation. In 1919, Langmuir, in a paper on 'The Mechanism of the Surface Phenomena of Flotation', showed that mono-molecular films of very great stability could be produced on solid surfaces with oleic acid, but that pure paraffin oil, though spreading readily on a dean dry surface, was easily displaced by water.

Jan 1, 1926

By L. Li

Backfill is increasingly used in underground mines, as it can help reduce the environmental impact from mining operations. However, the primary objective of backfilling is to provide safe working space for miners, by improving ground stability conditions. As cement is often added to the backfill, a critical issue is the determination of the required backfill strength (cohesion) due to the binder. This value is usually obtained from a solution proposed by Mitchell and co-workers, in the early 1980?s, for stopes with an exposed backfill face. This paper presents a brief review of the Mitchell et al. solution, with some of its main limitations. Some of the recently developed solutions for backfill design are then summarized and discussed.

Aug 1, 2013

By P. -A. Bosse, J. Robitaille, P. Blatter

The LaRonde ore is a Cu-Zn-Pb ore with gold (3-4 g/t) and silver (60-100 g/t). The precious metals are recovered with copper concentrate, zinc concentrate and cyanidation of zinc tails via Merrill Crowe precipitation. Subsequent to a recent mill expansion, excessive gold was reporting to zinc concentrate with a concurrent decrease in gold to copper concentrate. Owing to the higher return obtained from the metal, the mill endeavors to recover additional gold and silver to the copper concentrate and minimize the placement of precious metals to the zinc concentrate. A gold deportment study showed that the gold occurs mainly as küstelite, with a moderate amount of electrum and a minor amount of native gold. It also showed that various sulfur-based Au-and/or Ag-bearing coatings on liberated küstelite and electrum were the major mineralogical factors that caused gold and silver to report to zinc concentrate. By frequency, such coatings were observed on 70-80% of total liberated gold particles reporting to the zinc concentrate. Based on the gold deportment and the chemistry of the coatings, the collector chemistry was reviewed and a new collector was added into the circuit which resulted in a significant increase in gold and silver recovery to the copper concentrate. The information obtained from the mineralogy confirmed and guided other process optimization. In this paper, the authors will describe the process mineralogy of the LaRonde ores, and in particular, the mineralogical evidence diagnosing the problem. Reference will also be made to the rationale behind how the problem was solved, the results achieved, and future steps in optimization.

Jan 1, 2005

By Rong. G., T. Q. Lin, W. Du

Based on analysis of the evolutionary history of the valley in Baihetan, the mechanism of asymmetrical evolution, gradual migration-incision evolved from left bank to the right, is revealed in Baihetan river valleys. The process of in-situ stress evolution is carried out by using the Universal Distinct Element Code (UDEC). Consequently, the numerical results which indicate the main regulations of that stress field are as follow: (1) The phenomenon termed "high in-situ stress fold" appears in the bottom of the valley. With the maximum principal stress being 28-34 MPa, the stress increases significantly at a vertical depth of approximately 130 m. (2) The in-situ stress presents zonal distribution along the bank slope. It is apparent that the in-situ stress field consists of stress relaxation zone (SRZ), stress concentration zone (SCZ) and original stress zone (OSZ). The horizontal depth of stress relaxation zone varies from the left bank (roughly 200 m) to the right (about 120 m). Furthermore, the stress evolution of the left bank slope is studied. As a result, it is found that asymmetrical erosion contributes to the difference of the in-situ stress distribution as a critical factor, between the left bank and the right. And for an asymmetrical valley, the evolutionary process of in-situ stress field is a circular procedure, which includes the incision of valley, the accumulation of landslides and the migration of valley.

Jan 1, 2015

By X. Xu, J. K. -W. Wong, J. -Y. Delenne, K. Soga

Hydraulic fracturing (HF) is a mulit-scale and multi-physics process which makes numerical modelling challenging. Conventional numerical models focus on multi-physics nature of HF but the multiscale nature is compromised by idealization of reservoir to be continuous, homogeneous and isotropic. However, natural fractures take a significant role in the success of HF for exploration of unconventional resources like Shale gas. Advancement in microseismic monitoring provides useful data for simulation in a much greater details. There is an urgent need to develop a suitable numerical tool for multi-scale threedimensional simulation to better understand the roles of discontinuities and heterogeneity in reservoir and its interaction with HF, especially to address the environmental concerns such as induced seismicity. In this paper, a simple discontinuum numerical method – Lattice Element Method (LEM) is proposed to model HF in a large scale three-dimensional model. A reservoir is modelled as a lattice network composed of 1D Hookean’s spring. Fracturing is modelled simply by removing lattices that meet a specified threshold as determined by the critical energy release rate of the rock. By introducing disorder in the model, mesh dependency in modelling fracture growth is minimized. Fluid flow is simplified as flow in pipe network and the permeability of pipe is related to fracture aperture by cubic flow law. Therefore, fracture flow and rock deformation are fully coupled. In this paper, four simulations of the same configuration except with different degrees of reservoir heterogeneity are presented. Fractures formed are diffusive and two groups of fracture are identified – connected fractures and isolated fracture without clear spatial correlation. The former forms a ‘fracture cloud’ and contributes to fluid flow and modeled by pipe network. The flow of fluid is highly tortuous and pipe network is sparely connected. The degree of reservoir heterogeneity controls the growth of ‘fracture cloud’ and pipe network. Microseismic monitoring often shows diffusive fracturing during HF on site and hence the outcome of the proposed model can be compared to such monitoring results.

Jan 1, 2015

By R. Bainbridge

THE cinnabar deposits of the Consolidated Mining and Smelting Company's Pinchi Lake property, situated near Fort St. James, B.C., were discovered and reported on by a Dominion Government geological party in 1937. Claims were staked by a group of local prospectors and, later, the Consolidated Mining and Smelting Company of Canada, Limited, took an option on the property. By the fall of 1939, exploration work had indicated ore of commercial quantity and grade, and laboratory tests had shown that standard methods of reduction, namely, roasting of the ore, followed by condensation of the mercury vapour produced, would result in satisfactory recovery. In June, 1940, construction of a 50-ton unit arranged for wood firing was completed and operation commenced. The installation consisted of a 46 in. by 60 ft. rotary kiln (see Figure 1) followed by a 14-in. Sirocco cyclone, a cast-iron condenser unit, and a 1,700 c.f.m. fan, exhausting to a stack. Other equipment included a 9 in. by 18 in. Denver jaw crusher with the necessary bins and feeders. As the need for mercury was urgent, because of war requirements, construction of a duplicate unit was begun almost immediately. This first extension started operation in January, 1941, and the plant was then capable of treating about 150 tons of ore daily.

Jan 1, 1945

By Charles Camsell

At the last annual meeting of this Institute the programme very properly was drawn up and carried out with the special object of calling attention to the Dominion's position and problems with regard to fuel supplies. That subject, always one of serious concern, was a source of considerable anxiety twelve months ago. It is still so, but in a decidedly less degree than at that time. So far as the immediate fuel situation is concerned our anxieties have been relieved. And I think we can safely say that such a consciousness of our difficulties and determination to overcome them, has been developed in the minds of our people that there will be no slackening of the offensive until a final solution is reached. In selecting a subject of major importance for the present occasion I have felt free to digress from the pressing problems of last year and to go back, for a starting point, to the presidential address of two years ago .. I do not, however, wish to enter the controversy that has developed as a result of that address, though in spite of my own failure to amass a fortune from participation in certain mining ventures, I am decidedly inclined to the optimistic view that Dr. Corless presented of the future of our mining industry. You will perhaps have observed that in its general wording the title of my paper bears a marked resemblance to that of that address. This simila1ity of titles is not accidental. It is intentional on my part.

Jan 1, 1924

By J. A. C. Ross

Introduction To enlighten those who may be wondering where anyone could find sufficient data to write a paper on underground concrete work, the author would like to explain that, at Copper Mountain, we have found it necessary to line numerous headings with a layer of concrete in order to keep them in a safe and serviceable condition. The majority of these headings are scram drifts and ore-pass raises. This paper will therefore deal, in the main, with the methods of and reasons for placing concrete in these headings. During recent years, radical changes have been made in the methods of mining ore at the Copper Mountain mine. After considerable experimenting, a mining system has been developed making use of diamond drills for primary breaking and transfering such broken ore through scram drifts with slusher hoists. With the advent of scram drifts, it soon became apparent that some substantial means of reinforcement and protection for the scram drifts themselves would be necessary. Since the orebodies in this mine are cut by numerous dykes or faults, and often both, it was anticipated that some means of support would be required where headings necessarily passed through these incompetent zones. Further, as experience was gained, scram drifts were driven into pillars and in close proximity to old workings so as to recover the maximum amount of ore. In such places, the ground is often severely fractured, either as a result of previous mining or from the effect of excessive rock pressures.

Jan 1, 1950

By Robert Macdonald, William Coombe, John F. Lewry

Gold occurrences have been known in the La Ronge Domain for many year . Mineable reserves have more recently been outlined and there is every prospect of a major gold camp being established in the domain within this decade. The La Ronge Domain lies in the Lower Proterozoic 'Trans-Hudson Orogen' and is part of a collage of Early Proterozoic crust comprising volcanoplutonic arcs, batholiths, associated volcaniclastics and volcanogenic sediments lying between the Superior Craton to the outheast and the reworked Archean basement/Aphebian cover terrain to the northwest. The domain has several lithostructural subdivisions, the most important of whjch , from a gold exploration point of view, is the Central Metavolcanic Belt. This belt is composed dominantly of a range of metavolcanic rocks and gabbroic to granitic intrusives, which geochemically resemble younger subduction-generated 'primitive' arcs developed on oceanic crust. U-Pb zircon geochronology indicates that the arc volcarusm and pre- to late-kjnematic plutonism occurred about 1890 Ma to 1850 Ma ago. The belt has an attained grade of upper greenschist to amphibolite facies and is relatively undeformed , though high strain zones occur locally. Most gold occurrences in the La Ronge Domain have been found in the Star-Waddy Lakes area of the Central Metavolcanic Belt, and in the Sulprude-MacKay Lakes area to the south which is interpreted as a tectonically dismembered part of the main belt. Both tratiformand vein-type gold occurrences are present in the domain; vein-type predominate and form nearly 90 per cent of the occurrences. The stratiform-type occurrences show a regional lithological a sociation with iron-rich sediments within proximal felsic volcanjc sequences. Some vein-type occurrences appear related to brittle fracturing associated with intrusive emplacement (the magmatic-hydrothermal "syn:' and "subvolcanic" veins) and faulting. However, most of the vein-type occurrences exhibit a spatial association with regionalscale ductile shear and other high strain zones, and were probably formed by metamorphichydrothermal processes.

Jan 1, 1986

By Ross Gallinger

In 1997 a group of Canadian mining companies met to review the Mine Environment Neutral Drainage (MEND) program and to consider future activities. They concluded (i) that Canadian industry and NRCan should fund a small secretariat in Ottawa to support technology transfer in Canada and (ii) that it was important for industry to continue the momentum of MEND on an international scale. The need for INAP (International Network for Acid Prevention) was strongly endorsed by company, university, consultant and government experts from Australia, Canada and the U.S. who were convened in Vancouver in February 1998. The initial focus was the development of a solid knowledge base covering the collective experience of INAP's members to promote the dissemination of successful practices, the identification of knowledge gaps and the formulation of effective research proposals. The sharing of information on past successes and failures alone was viewed as sufficient justification for the formation of INAP. INAP was officially launched in October 1998, and is now an effective, industry based initiative to globally coordinate research and development in the management of sulfide mine waste. Significant improvements in the management of sulfidic mine materials through knowledge sharing, research and development of technology by INAP will reduce liability associated with acid drainage. This paper will explore the international efforts and activities of INAP.

May 1, 2002

By D. Stüben, G. P. Glasby

"Abstract - Shallow submarine hydrothermal fluids from Paleohori Bay off the Greek Island of Milos have been investigated in detail. The extensive gas and warm (max. 93°C) water vents are enriched in major components such as C1-, Na+, Si, Ca2+, Mn, PO4 3-, NH4 +, K+, Sr2+, H2S and CH4 and depleted in Mg2+, O2 and SO4 2- relative to ambient seawater. Based on zero-Mg calculations, it is deduced that the submarine vent fluids are related to the geothermal reservoir beneath Milos which has a similar chemical composition. Fluid samples from each vent in Paleohori Bay represent a mixture of hydrothermal end-member fluids derived from the upper and deeper geothermal reservoir systems of Milos, a mantle-derived source, a high-chloride fluid resulting from phase separation of geo thermal fluids and a steam-heated CO2-rich meteoric water. Résumé - À l’île de Milos dans la mer d’Égée, des fluides sous-marins hydrothermaux en eau profonde ont été récherchés en détail près de la baie de Paleohori. Les larges émanations de gaz et d’eau chaude (temperature maximale: 93°C) sont enrichies en constituants principaux tels que de Cl-, Na+, Si, Ca2+, Mn, PO4 3-, NH4+, K+, Si, Sr2+, H2S et CH4 et appauvries en Mg2+, O2, SO4 2- comparé à l’eau de mer environnante. Selon le calcul du zéro-Mg, nous en déduisons que les fluides sous-marins hydrothermaux sont dérivés du réservoir géothermal sous l’île de Milos car leur composition chimique est la même. Les prélèvements des fluides de chaque source hydrothermale représentent un mélange de fluides hydrothermaux dérivés des réservoirs géothermaux supérieur et inférieur, d’une source dérivée du manteau, d’un fluide très enrichi en chlorure produit par la séparation des phases et de l’eau météorique enrichie en CO2 et chauffée par la vapeur."

Jan 1, 1999

By R. Blosser

Phelps Dodge introduced a process improvement model known as Quest for Zero in 2001. In 2004, the focus of Quest for Zero shifted from corporate-led initiatives to projects led by site personnel. The Hydrometallurgical Division at Morenci focused on two (2) significant process improvements: reducing electrolyte bleed and organic losses. In September 2004, Morenci kicked off a bleed reduction project to reduce electrolyte bleed by 45%. By the end 2005, electrolyte bleed was reduced by 55% through understanding and reduction of variance. Significant process changes made during this time period include changes in acid-addition strategy, reduction of uncontrolled bleed, and optimization of bleed placement. In April 2005, the organic reduction project began with the goal of reducing losses by 15%. Operational improvements during this project included improved organic recovery systems, mixer speed optimization, and picket fence installation. By the end 2005, this project reduced organic losses by 35% and current losses are 48% lower than at the start of the project. These projects and smaller Questfor Zero projects have resulted in sustainable annualized savings of $13 million in Morenci hydrometallurgical operations. Through the use of Six Sigma tools, process variances can be controlled and reduced.

Jan 1, 2007

By B. Jin

Removal of fluoride and chloride by alkaline washing from direct lead smelting dust which originated from an Ausmelt furnace is reported. The results show that the fluoride removal efficiency increases with an increase of alkaline concentration, alkaline washing temperature and time. The L/S ratio has little effect on fluoride and chloride removal efficiency. A new flow sheet for removal of fluoride and chloride from the dust was successfully proposed according to the results. Fluoride and chloride removal efficiencies are more than 53.68% and 63.18% respectively using the flow sheet under the optimum parameters of temperature 338 K, L/S ratio 3:1 and alkaline washing time of 1.5 h. The contents of fluoride and chloride in the alkaline washing residues can meet the standard of zinc purity as hydrometallurgical materials for zinc processing.

Jan 1, 2014

By Robert Lee

"International competition is presenting the Canadian steel industry with a major challenge. While Canadian companies have invested in new technology, research and development, activity by Canadian industry, in general, lags significantly behind that of its major competitors. While OECD countries increased their research and development spending during the 1980s, Canada's R&D funding levels have changed little since the early 1970s and have actually dropped since 1986, despite greater public discussion on the issue. This fact is reflected in the relatively slower pace of innovation in the Canadian steel industry, despite the efforts of both government and industry.In addition, there are a number of factors that undermine the competitiveness of the Canadian steel industry, in particular in relation to the United States. Among these are higher interest rates, labour costs and tax rates, as well as an overvalued Canadian dollar. Canadian steel companies are thus feeling the full impact of the current economic recession. This recession, combined with recent strikes, have, for example, caused serious losses for Algoma and Stelco.In spite of these objective difficulties, the Canadian steel industry has been able to survive and continues to strive for a leadership position in the world market. Since World War II, heavy investment in new technology has allowed the industry to upgrade its facilities and increase productivity, while at the same time improving quality and reducing pollution. This last point is particularly important in view of public insistence on improvements to the quality of the environment. Over the next decade, this technological innovation must be maintained and intensified if industry is to meet the challenge of international competition and attain a leadership position."

Jan 1, 1991

By Veerendra Singh, Y. Rama Murthy, Sunil Kumar Tripathy, Nikkam Suresh

"High intensity dry magnetic separation is commonly employed to separate different para-magnetic minerals including mineral sand. Separation in these separators is majorly influenced by the combined effect of gravity, centrifugal and magnetic forces on a particle. These separators are included in the process flow-sheets either for pre-concentration purposes or for the beneficiation of paramagnetic minerals. Separation in these separators is majorly influenced by the difference in the magnetic susceptibility of the associated minerals, particle size and shape along with the process variables of the machine. Particle size is one of the major parameter that plays an important role and decides its probability of selectivity under the magnetic field. However, effect of particle size on the performance of these separators are not well understood which is evident from the literature.In the present investigation, an effort is made to bring out the effect of particle size on particle separation in an induced roll magnetic separator while treating ilmenite fines. Effects of operating parameters, such as; magnetic field intensity, roll speed, feed rate and splitter position have been studied and their influence on particle size has been analysed in terms of yield (wt.%) to magnetic product, particle size distribution characteristics in terms of D50 and D80 size, skewness, kurtosis. Also, the particle size distribution of each test was fitted in Rosin-Rammler equation. The test results were analysed statistically to understand and quantify the influence of each variable on particle separation. It is found that, rotor speed of the separator had maximum influence on yield to the magnetic product whereas splitter position had major influence on D50 and D80 (µm) size of the product."

Jan 1, 2016

By A. N. May

"This paper describes the present approach of the Mines Branch to the problem of measuring the stress condition in the interior of rocks surrounding underground openings. An instrument, which will be referred to as a stressmeter, has been developed at the Mines Branch to measure un-directional stress changes in absolute units. There are two modes of operation of this stressmeter. It can be regarded as a fixed instrument, in which case it is installed at the end of a diamond drill hole and left in position to record any subsequent stress changes taking place. Alternatively, three of the stressmeters can be used in conjunction with a trepanning opera-tion to allow the existing stress condition to be determined. The initial laboratory work and subsequent experiences in the field with the stressmeter are described. All the field development work on the stressmeter was made possible through the co-operation of Canadian Refractories Limited, Kilmar, Quebec."

Jan 1, 1960

By Marcel M. Djivre

The paper will outline the methods and test procedures including the evaluation criteria currently used at the Materials Testing Laboratory (MTL), Sudbury, Ontario, Canada, a laboratory approved by the Ontario Minister of Labour for the purpose of testing or examining mine shaft ropes or other hoisting appliances. Also for Canadian mines the paper will suggest proposed criteria to be used at MTL for the evaluation of ropes used in "ultra-deep" single-lift shafts. Most of the methods and test procedures currently used at MTL were adopted during the revision of the CSA Standard G4, Steel Wire Rope for General Purpose and for Mine Hoisting and Mine Haulage to be published most likely in year 2001. In this latest or sixth edition of CSA Standard G4, a new Clause 14 has been added outlining the requirements for in-service destructive testing of steel wire ropes for mine hoisting applications. The existing fifth edition of CSA Standard CAN/CSA -G4-92, which is intended for the manufacturing of new ropes, includes requirements for raw materials and construction features for round strand and flattened strand rope, and locked coil rope in bright and galvanized finish.

May 1, 2001

By J. B. Hadaway

The operation at Phu Kham commenced design and construction in early 2006 and was commissioned in May 2008. This paper will examine and discuss the project from the inception of flow sheet development and equipment selection, equipment design and manufacture, construction, commissioning and ramp up to full production. The paper will touch on the strategies employed to achieve a short schedule and the efficient use of capital, but with the main emphasis on the grinding circuit. Various challenges during the early years of operation will be discussed including the effect of ore characteristics, including competency, on the performance of the grinding circuit. Actions to overcome these challenges and to enhance performance will also be discussed. Finally, current and future plans to improve the performance of the grinding circuit and the overall plant will be summarised.

Jan 1, 2012

By J. F. Adams, V. G. Papangelakis

Chemical modelling is becoming increasingly useful in the development, analysis, design, and control of hydrometallurgical processes. The paper presents the development of reliable databases for chemical modelling of selected hydrometallurgical systems using state-of-the-art software, such as OLI. The modelling strategies are also demonstrated. The high pressure acid leaching (HP AL) of laterites, oxygen solubility in the oxidative leaching process of zinc sulfide, gypsum solubility and lead chemistry in mixed sulfate-chloride solutions are presented as case studies. This on-going work attempts to bridge the gap between theoretical research and industry needs. Computational Analysis in Hydrometallurgy 35th Annual Hydrometallurgy Meeting held in conjunction with the 44th Annual Conference of Metallurgists ofCIM Calgary, Alberta, Canada Edited by

Jan 1, 2005