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By Brian Putland

Single stage semi-autogenous / autogenous (S/AG) milling has become a common design for a variety of ore types with the advantages of being comparatively low capital cost and flexible for future expansion. The single stage SAG/AG milling option is ideal for starter projects with significant exploration and expansion potential. Currently a number of the largest SAG mills designed are installed in single stage configuration. This paper discusses the challenges associated with the process design of single stage SAG/AG milling circuits, the design flexibility required to ensure a robust circuit and the operating techniques adopted at successful installations.

Jan 1, 2012

By J. D. Galloways

The northern part of the P. G. E. railway traverses and opens up that part of the province known as the Cariboo district, comprising the Cariboo and Quesnel Mining Divisions, which are a part of the Northeastern Mineral Survey District. Williams lake, a divisional point on the P. G. E. is near the southern boundary of the Quesnel Division and from this point the railway runs northerly to Quesnel, its present terminus. From Quesnel the railway is projected and partially constructed to Prince George on the Canadian National railway; therefore its general trend is northerly through the heart of the Cariboo district. Early History There is no need to outline at any length the early history of mining in the Cariboo. It is sufficient to say that the great gold rush to the Cariboo, in the early sixties, was practically the commencement of mining in British Columbia. These early placer mining operations centred around the old towns of Quesnel Forks, Keithley Creek, Barkerville and Van Winkle, the latter now called Stanley. Many millions of dollars of placer gold have been taken out and the end of production is not in sight yet. The maximum yearly production was reached about 1863, after which there was a gradual decline in output. During the war years production was at a very low figure but a steady, even if small, increase has occurred in the last three years and prospects are encouraging for a much greater output.

Jan 1, 1925

By J. Shanks

In 1920 the writer presented some notes, embodying his experience with storage-battery locomotives as main under-ground haulage-motors at Brazeau collieries. (1) Since that date these motors have stood up well to the test of maximum output and heavy overloads, having accomplished all that was expected of them. The notes presented in 1920 gave a brief description of the conditions under which these motors were working at Brazeau collieries, also the cost, per ton mile, of operating them. The cost per ton mile has since then been appreciably reduced, by working the locomotives nearly to capacity and under more ideal haulage conditions, on both shifts. It is not the intention of the writer to repeat what was written in 1920, but rather to give members the benefit of his experience in operating different types or designs of locomotives; to draw their attention to the drawbacks of some designs, and to the improvements made in some of the more recent storage-battery locomotives put on the market, as regards efficiency, upkeep, and safety. Because of their flexibility storage-battery locomotives have advantages over any other type of haulage, where grades are suitable to their use. The number in use in the mines in the United States has increased enormously during the past few years, and this method of haulage is, at the present time, attracting the attention of British and Continental mining engineers.

Jan 1, 1924

By A. Tohn, L. May, Adham. K.

The path from process conception to commercial implementation poses significant technical, economic, and sometimes political challenges for every project team. Solving the technical challenges typically distinguishes successful projects from those that fail. Here, the authors provide an outline for technical success based on lessons learned from years of experience in process design and R&D. Challenges faced by new technology developers, with regard to design and definition, are described. Experience-based methods to avoid missteps are shared. Special emphasis is placed on the selection of viable unit operations, definition of known and unknown parameters, experimental screening of options, and piloting for scalable design information. Use of computational models to define, assist, and interpret the pilot operations and results are described. Furthermore, the value of active collaboration amongst the design, research, and owner team is demonstrated.

Jan 1, 2011

By LUKE O. LINDOE

A major clay products industry in the Medicine Hat area since before 1910 has maintained a continued interest in the clays of the Cypress Hills. For the first forty years the materials used were local red-burning Cretaceous and Pleistocene clays and sands and high-quality stoneware clays of the Whitemud Formation at Eastend, Saskatchewan. Recently a much broader spectrum of raw materials has been brought into use. Including the exposures of the Eagle Butte structure, the Cypress Hills present a 1200 m section of clay-like sediments. Of this 1200 m about 94 per cent, the high montmorillonite shales of the Upper Cretaceous, can be considered useless, or nearly so; the remaining six per cent, all fresh-water beds, presents a wide variety of potentially useful materials. The development of these clay resources is complicated by deep surface creep on the south flank of the Cypress Hills, by largescale slumping on the north flank and by a structural complex in the Eagle Butte area.

Jan 1, 1984

By S. D. A. Hannot, H. Knapp

"High pressure grinding rolls (HPGR’s) are an energy efficient solution for comminution of industrial minerals and metal ores. The technology is successfully applied in an expanding field of applications throughout the minerals industry. HPGR’s compress and grind the particle bed in the operating gap between two counter-rotating rolls. The equipment provides a high capacity, low energy alternative for applications with conventional tertiary and quaternary crushing and grinding, with size reduction reaching from 100mm down to 25 microns product. In this process, maintaining a controlled and evenly distributed operating pressure between the rolls is very important. Due to feed segregation, the pressure distribution along the roll’s length can become uneven, resulting in a coarser product. This paper will show that the best approach to compensate and adapt for the uneven pressure is to allow the rolls to skew relative to each other. Coarser products are also caused by an inadequate pressure distribution: the much-discussed edge effect. To minimise the consequence of the edge effect, an optimised ratio for the roll length to diameter will be calculated. Furthermore, the design philosophy behind a cheek plate will be detailed. This cheek plate is used to retain the material between the rolls, reducing the edge effect while still allowing roll skew. Together these design considerations help optimise HPGR’s performance.INTRODUCTION Initially developed for the cement industry during the energy crisis in the 1980’s , high pressure grinding has been an accepted technology for many years. It has been successfully implemented throughout the minerals industry, with applications in base and precious metals, as well as industrial minerals processing. The comminution process relies mainly on size reduction through to compression and inter-particle crushing in a particle bed in the operating gap between two counter-rotating rolls. The equipment typically has a high unit capacity and low energy consumption, and is increasingly used as an alternative to conventional tertiary and quaternary crushing and grinding, in particle size ranges reaching from 100mm down to 25 microns. It can be applied to moist ores and dry material, in open circuit arrangement or in a closed circuit with dry or wet classification (screening, air classification)."

Jan 1, 2019

By Inga Tuzovskaya1i

Three types of gold species were observed for gold-zeolites, prepared by reduction of ionexchanged Au species in a series of zeolites: (i) Au3+cations, (ii) neutral Au0 n or charged Aus+ n clusters suggested to be inside the zeolite channels, (iii) Au nanoparticles with diameter varied from 2 through 20 nm located on the external surface of zeolite microcrystals. Contribution of the gold species formed in zeolite after the ion exchange was found to depend on zeolite type, acidity of zeolite, temperature of reduction and time of storage of the exchanged and reduced Au-containing zeolites. Au3+ ionic species and clusters Aun were formed after the ion-exchange procedure (in contrast with the familiar production of Agn in same zeolites). Gold nanoparticles were observed only as the result of reduction of the Au-exchanged forms at elevated temperatures due to reduction of Au3+ species and aggregation of clusters.

Oct 1, 2003

Diverse and considerable energies are associated with mobile equipment operated and maintained on mine sites. Loss of control of these energies is a common cause of injury on mine sites and this is well recognised by the mining industry. In 2006, 4 multi-national mining companies formed the Earth Moving Equipment Safety Round Table (EMERST), with the aim of engaging collectively with the manufacturers of equipment to accelerate improvements in mining equipment design. Originally focused on surface mining equipment, and particularly haul trucks, the focus of EMESRT widened to include underground and exploration equipment. Since 2006, EMESRT has maintained a program of regular visits and other engagements with a steadily increasing number of manufacturers. The membership of EMESRT has also increased, with 15 companies being members in 2012. An initial step undertaken by the EMESRT members was the development of ?Design Philosophies? which drew of the collective experience of mining companies to identify potential unwanted events which cause equipment related injuries and illness. A technique for analysing risks associated with operation and maintenance tasks, the Operability and Maintainability Analysis Technique (OMAT), was subsequently developed and trialled. In 2011, the EMERST members resolved to propose a common form of safe design information to be requested by all members companies during procurement, and the resulting EMERST Design Evaluation for Equipment Procurement (EDEEP) process was launched at MINExpo in Las Vegas in September 2012. The outcomes of OMAT risk assessment and control activities are integrated during this process into a common ?Safe Design Information? template for communication to prospective purchasers. The aims of requesting manufacturers to follow this process are to provide equipment purchasers with a common way of assessing how well the issues in the EMESRT Design Philosophies are addressed in the equipment design; and to provide manufacturers with additional information for use during equipment design. The process involves identifying priority tasks based on frequency and the severity of the consequences of potential unwanted events identified in the EMESRT Design Philosophies; undertaking a task-based risk assessment of priority tasks in conjunction with site-based personnel; evaluating the effectiveness of control measures; and providing information about safe design features in a standardised format.

Aug 1, 2013

By T. Macpherson

ABSTRACT: Drawing on past research experience with sprayable polymer mine support agents (TSLs), Spray On Plastics Ltd. has developed a TSL ground support system called RockWeb. Using a relatively new polyurea polymer technology, RockWeb has been engineered to solve problems encountered underground with polyurethane liners by incorporating rapid curing, moisture insensitivity and superior physical performance. RockWeb possesses a unique, patented ability to be sprayed in a ?cobweb? like consistency allowing the applicator to span fissures in the rock, ensuring no initial defects in the liner, and maintaining design thickness over highly irregular surfaces. This ability, coupled with the high strength and elasticity of polyurea, allows RockWeb to mitigate rock movement through yielding, while maintaining intimate surface confinement. RockWeb provides reduction in logistics through the transport of 1/25 of the material quantities required for shotcrete, rapid deployment rates of as little as 30 minutes per round, and immediate return to the work area. This paper will discuss the technology and advantages of RockWeb as well as opportunities for overall mining cycle cost reduction. The safety benefits, as well as health and environmental considerations regarding application of isocyanate-based liners will also be discussed.

May 1, 2009

By D. R. Winchester

"I wish to thank you and your organizers for inviting me to address you at this point in time when we are all concerned for the future of the mineral industry in Canada.My topic ""Some Initiatives of Government Assistance to Industry Applicable to Mineral Processing"" is purposely limited in scope. To cover the entire range of initiatives in detail would take me all day, and at best, would be a mere recital of program titles, and a one sentence summary of the contents of the program. As you know, OREE or Regional Economic Expansion, is in the process of being amalgamated with elements of the Department of Industry, Trade and Commerce. We will become Regional Industrial Expansion or ORIE. If the name Canada Dry becomes popular, I don't think we will object as we hope to become a good mixer. The entire departmental thrust has been re-evaluated, and is in the process of being re-constituted to better serve the nation, and industry as a whole. Amalgamation of the industrial, trade promotion and marketing support skills of IT&C, with the regional development orientation and decentralization program delivery mechanisms of DREE, will, it is believed, provide better support to industry on a national and regional basis."

Jan 1, 1983

By R. Tipman

"In 25 years, processing of tar sand progressed from two small pilot plants to two major commercial operations owned by Syncrude and Suncor. These plants mine tar sand and extract the bitumen which is then converted into a synthetic crude oil. Considerable research on extraction of bitumen from tar sand has been undertaken by these two companies as well as other major oil producing companies, private individuals, universities and the federal and provincial governments. These studies have produced a number of alternate processing schemes which have yet to be commercialized. The producing companies are focusing their efforts on achieving increased processing efficiency, which includes improved bitumen recovery, reduced unit cost, energy conservation, and equipment reliability. In this review, the Syncrude process and examples of new process developments will be briefly described. IntroductionTwenty-five years ago, tar sand processing was limited to two pilot plants owned by Cities Service Athabasca Ltd., and Great Canadian Oil Sands. Earnest Manning was Premier of Alberta and was inviting proposals for the construction of a commercial tar sands plant. The invitations called for a much larger operation than those which had been undertaken in the past. All of the previous attempts at commercial operations up to 1960's had failed, largely because of a poor technical understanding of the process requirements, lack of suitable equipment, and lack of adequate capital. The previous record was not good. The pending new large scale plant was based on improved but not proven technology and equipment, which were developed from the pilot plant studies. In addition, the surplus of conventional oil in Alberta and low world oil prices were factors reducing the need for such a plant."

Jan 1, 1987

The Cadia mine is shifting from the open pit operation to the Cadia East underground block cave. The resulting increase in milled tonnes and the decrease in fines production through shifting to block caving require an increase of over 25% in installed power. This expansion is being accomplished via the installation of up-front crushing and HPGR milling of the ore, with the SAG mill receiving a secondary crushed feed. This design, criteria and rationale for selection is presented. Over the coming years, the mine will further expand capacity. The target is to accomplish this with minimal addition of installed power or use of fresh water. This presents a challenge that epitomizes the future constraints on our resource dependent and intensive industry. The approach and proposed options to this longer-term expansion are also presented.

Jan 1, 2012

By Michael Davies

Mined Material Management Meeting or Missing the Mark? o you agree that we have the technology to consistently design robust M3 facilities? ?YES your experience do these M3 facilities perform as expected during operations? ?USUALLY hat can be done to improve performance, e.g. better communications between project and operating teams, discontinuity between design and operational input by designers, others? ?UNDERSTANDINGWHY THINGS GO WRONG an we identify the key characteristics of ?good M3 facilities?, i.e. ones that are performing well? Can we identify ?good M3 facilities?, i.e. ones that perform well and can be held up as examples? ?WITHOUT QUESTION?? your opinion, for what reason do they not perform as expected? ?NO SINGLE REASON??..

May 1, 2010

By N. Razavinia

Most mining and metallurgical industries produce relatively large quantities of low grade waste heat which they vent, for the most part, to the environment. To date, little is being done to recover some of this heat and transform it from low grade to a high grade energy form such as electricity. A few decades back this was also true of paper, plastics and metals. Recycling was not a prominent activity. Today, we all know that it is and that recycling is a must for sustainable development. To this end, we feel that we are now at that point in time when the recycling of waste heat to electricity must be given serious consideration. By recycling waste heat one can achieve at least one if not two of the following benefits: 1) reduction in the carbon footprint ? by improving the overall energy efficiency of a process, and 2) production of electricity at an economically viable cost. We have developed a process that captures, concentrates and converts (3 C?s) waste heat to electricity. The process comprises 3 distinct interacting units. The first unit captures and concentrates waste heat using heat pipe technology. The second unit converts some of the concentrated heat to mechanical work which can then be readily converted to electricity. This unit is based on the classical piston/cylinder engine arrangement that is widely used by consumers to power systems with compressed air, for example. The third unit of the process dissipates the heat that the engine cannot convert to high grade energy. It also uses heat pipe technology to achieve this. The combination of the 3 units forms a unique system for recycling waste heat. This paper describes the system and it presents some results that show how the system can be made to be economically viable.

Aug 1, 2013

By B. Schulz, T. Leißner, R. G. Merker

"Ores enriched in critical rare earth elements (CREE) keep on being of particular interest. The CREE are Nd, Eu, Tb, Dy, including Y. In conjunction with beneficiation tests on Y-mineral bearing flotation tailings of complicated mineralogy, the Mineral Liberation Analyses (MLA) was used to work out processing characteristics fraction-wise in terms of modal mineralogy, mineral recovery, locking and liberation, and particle size.Size fractions from mechanical sieving (“real fractions”) as well as fractions created virtually by using filters on the MLA-data of the unsieved head material (“virtual fractions”) were investigated comparatively thereby. The ""virtual-sizing-approach"" features a much simpler sample preparation procedure and considerably lower cost if a fraction-wise investigation of a head sample is needed. It can be conveniently applied to intimately locked ores needing a fine grinding to a particle size distribution (PSD) range below 25 microns for instance. However, its practical use is sometimes disputed in terms of the reliability of the results. Results are shown for the main Y-bearing mineral xenotime and selected main gangue minerals of a low grade REE-ore.The influence of sample representativeness, sample preparation and particle counting statistics turned out to be of crucial importance. Given that all preconditions for reliable results are met, locking characteristics, modal mineralogy, and even PSD trends can be read from virtual fractions.The authors encourage processing engineers to use the virtual approach. They propose practical measures to improve the reliability of the MLA results, identify and tackle conflicting results, and mitigate evaluation problems that may arise."

Jan 1, 2016

By Simon Weixiao Sun

Conventionally, carbon steel has been the primary material for salt mine headframe construction, protected by specialty paint layers to prevent corrosion. These layers require meticulous QA/QC during fabrication and erection, and the top UV protection layer typically loses effectiveness after an average of 10 years, necessitating ongoing maintenance. As headframes age, significant structural repairs are often required. Alternatively, stainless steel can eliminate corrosion concerns, though its high initial cost has limited its use in headframe design. However, when factoring in long-term maintenance costs, a 'maintenance-free' stainless steel headframe can be an attractive option for stakeholders. This paper compares the structural performance and economic considerations of painted carbon steel and stainless steel headframes, including initial capital and long-term maintenance costs. Additionally, it explores a hybrid approach, strategically using carbon steel in low-contamination areas to reduce initial costs and significantly minimize future maintenance efforts.

May 4, 2025

By D. W. McDonald, N. A. Duke, R. L. Hauser

"The NERCO Con Mine is situated in the amphibolite facies aureole of the Western Plutonic Complex overprinting the Yellowknife Greenstone Belt. Metamorphic grade of the upright monoclinal basaltic succession decreases from hornblende-amphibolite facies along the border of the batholith to greenschist facies. Metamorphic isograds, subparalleling the faulted margin of the batholith, transect volcanic stratigraphy and coincide with major goldbearing shears.Gold mineralization is confined to north-striking, west-dipping shear zones where hangingwall amphibolite facies mineral assemblages retrogress to chlorite-carbonate-sericite-sulfide bearing schists hosting multiple generations of quartz-ankerite veins. The gold-producing portions of the Con and Campbell Shears occur where these structures transect an east trending thermal corridor. The corridor is defined by granitic plugs and a number of related breccia bodies, that can be traced outwards from the batholith across the greenstone belt.Prograde reactions of greenstone during amphibolitization effectively liberate fluids that partition metals. With retrograde reactions at shear zones, gold is precipitated with quartz due to the destabilization of sulfide and arsenic complexes. The coupling of regional prograde metamorphic and restricted retrograde metasomatic overprints suggest mineralization is temporally related to emplacement of the Western Plutonic Complex. Economic gold concentrations within the intrusive corridor indicates enhanced metamorphic overprint of hornfelsed greenstones enveloping satellite intrusives peripheral to the main batholith."

Jan 1, 1993

By L. Xia, B. Hart, K. Douglas

In the flotation of Rare Earth Element (REE) bearing minerals, oxalic acid is reportedly acting both as a depressant and pH modifier. Testing has established the significance of oxalic acid in the flotation process however its specific role in either the recovery or selectivity of REE over their gangue minerals is not well understood. Pulp pH reduction trials with alternative acids have not shown the same effect on the REE mineral recovery or the depression of gangue phases. This work examines the effect of oxalic acid on the surface of gangue minerals (quartz and carbonates (dolomite and calcite)) in a series of conditioning tests. Gangue surface analyses by TOF-SIMS indicate that oxalic acid inhibits the transfer of secondary ions generated during the conditioning process from one mineral phase to another. In this regard, the oxalate anion acts to fix ions in solution through chelation, limiting their participation in surface adsorption.

Jan 1, 2014

By T. McCallum, B. Wellbrook, T. Ratnaweera

Leaching of copper (Cu) concentrates produces elevated concentrations of Cu and acid, which makes solvent extraction (SX) processing more challenging. Maintaining extraction targets can be more difficult with higher pregnant leach solution (PLS) grades, and variability of PLS Cu and acid can lead to increased chemical iron transfer. Diluting concentrate leach feeds with an existing heap leach inventory makes SX processing easier. However, considerations about how much to dilute and where to distribute the flow into the SX configuration must be carefully evaluated, given their impact on metallurgical performance. In this paper, characteristics of a concentrate leach feed are discussed, along with considerations for processing by SX. Also reviewed are pilot plant results of concentrate leach distribution into SX and plans for commercial testing. INTRODUCTION Hydrometallurgical processing of copper concentrates continues to gain interest from the industry. Treatment by smelting and electrorefining continues to dominate, accounting for ~80% of global copper production, but is faced with its own challenges (Li et al, 2017). The case for increased hydrometallurgical processing has been discussed as high grade ore deposits are diminishing, capital costs for smelting are high, and the environmental aspects present challenges for sustainable practice. The hydromet copper industry is also turning a corner as easily leachable copper oxide deposits are depleting, and excess SX-EW capacity exists in certain regions. The transition to hydrometallurgical processing of copper concentrates will take a bit of effort as leaching of copper sulfides is difficult and byproduct credits must be considered. Various POX leaching processes have been studied and proposed to the industry as viable practices. Of the many processes, commercial use has been practiced with the Mount Gordon Copper Process, total and partial pressure oxidation by Freeport-McMoRan at their Bagdad and Morenci, Arizona complexes, the Sepon Copper Process in Laos, and the bioleach BIOCOP™ process in Chile (Dreisinger, 2016).

Jan 1, 2019

By E. Ettles

This paper features some of the spectacular new advances in the fields of fluorescent penetrant inspection and magnetic particle concentration. Casting fractures in the various stages -before the repair, during the repair and in the completed repair -using the cold process method will be discussed. This cold method of repair eliminates problems of pre-heating and cooling and the stress factors that are involved in any heat repair.

Jan 1, 1971