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By Vicken Aprahamian

"The Royal Canadian Mint (RCM) operates a gold and silver refining toll operation in Ottawa, Ontario, Canada. The silver refining line is a recent addition and was commissioned in 2005. One source of silver in the refinery is from gold doré which undergoes Miller chlorination before electrorefining to 99.99% cathode gold. Treatment of the Miller salt or silver-copper chloride produced consisted of a 2-stage high temperature reduction process step using soda ash prior to 2005. Copper-rich silver bars were produced and shipped offsite for further refining.The copper-rich bars could not be blended into sufficient high grade silver doré to dilute the copper and allow electrorefining in a silver nitrate medium. A new wet process was developed and commissioned to replace the high temperature reduction and allow removal of bulk copper. Thus upgraded impure silver produced was cast into anode for electrorefining to 99.9% purity silver flake. The 2005 RCM Hydromet Slag process is presented as well as its more current version. In addition, mention is made of a novel processing scenario for the introduction of Miller chlorination silver into the electrorefining circuit."

Jan 1, 2015

By Pingyang Zhang, Caichu Xia, Shuwei Zhou, Yu Zhou, Yongsheng Hu

A lined rock cavern (LRC) is an alternative container for compressed air energy storage (CAES) to store high-pressure air that is later used to produce electricity. A critical requirement of CAES in LRCs is that the inner seal should provide adequate sealing capacity to prevent air leakage from LRCs. In many studies, rubber sheets are applied to build the inner seal. However, air leakage through rubber seals has not been given much attention and rubber seals are usually assumed to be absolutely airtight. Given that rubber is permeable especially under high air pressure, such as in CAES, air therefore leaks through rubber seals during CAES operations. In this study, a numerical analysis was conducted based on the permeation equation of polymers and the governing equations of thermodynamics of CAES caverns to analyze the characteristics of air leakage from CAES caverns through rubber seals. A planned CAES plant in China was considered as a case study. Results show that air leakage rate increases with increasing cavern temperature and pressure during air injection and decreases as cavern temperature and pressure decline during air withdrawal. However, in total, the daily air leakage percentage is in the order of magnitude of 10-3% in a typical operation cycle, which is much smaller than the critical value of 1%. Under a common range of realistic operations conditions, the daily air leakage percentage is still of the order of 10-3%. Therefore, rubber seals can be used to prevent air leakage in LRCs for CAES. However, the experience of Japanese pilot cavern indicates that the specifications for the on-site vulcanization jointing and installation methods of rubber seals still need improvement.

Jan 1, 2015

By Wignall. T. K., J. De Geoffroy

Statistical models are fitted to the observed distributions of eighteen characteristics of the population of commercial porphyry deposits of North and South America. The statistical base required for the formulation of the statistical models includes 58 commercial porphyry-copper-molybdenum deposits of the Cordilleran Belt from which geological, geometric and economic data were collected. Predictive and composite models are derived from the statistical study to assist explorat10n. planning, engineering studies and fmanc1al analyses as required for the development of new porphyry deposits in the Cordilleran Belt.

Jan 1, 1973

By Georgy A. Cherkashov, Andrey V. Efimov, Yury S. Borodaev, Nadezhda N. Mozgova, Sergey G. Krasnov, Tamara V. Stepanova, Alexander M. Ashadze

"Abstract - A horizontal mineralogical-geochemical ore zonation with a southeast to northwest trending succession of Cu and Fe (Zn) main zones has been discovered in the Logatchev hydrothermal field (14°45??N Mid-Atlantic Ridge). The major minerals are pyrite, chalcopyrite, bornite, isocubanite, digenite and chalcocite. Zn-sulfide, marcasite and covellite are less abundant. Rare minerals are native copper, zincian copper and cobalt pentlandite (first found in oceanic massive sulfides), Cu and Cu-Co-bearing Fe-disulfides. Two groups of the main sulfide assemblages with different copper contents are recognized: Group I comprises assemblages with primary sulfides (isocubanite, chalcopyrite, pyrite and Zn-sulfide; Cu up to 35 wt% in Cu-bearing minerals); Group II contains assemblages with secondary Cu-rich sulfides (bornite, digenite, chalcocite; Cu ~60 wt%) as well as rare minerals (cobalt pentlandite, native copper and zincian copper). The assemblages of Group I formed at a temperature of about 300°C; the sulfur fugacity (log fs2 atm) at 300°C is probably 9.9. Relations between minerals of this group are contradictory, attributed to non-equilibrium environments, and no unified sequence of crystallization of minerals has been determined. Minerals of Group II replace, rim or cross the assemblages of Group I. Group II minerals crystallized in a distinct sequence (cobalt pentlandite-bornite-digenite- chalcocite-native copper), with increasing copper content from the start to the end of the depositional sequence. This may correspond to pH from 7 to 8 near Eh = -0.2 at 250°C. Minerals of this group were generally formed under hypergene alteration processes. Compositions of ore minerals were studied by means of electron microprobe analysis (EMPA) (150 analyses). Narrow composition fields were revealed in all main sulfides, which comprised known experimental data. ZnS contains 6.0 to 28.0 mol.% FeS, which is close to data known for other hydrothermal massive sulfides from the Mid-Atlantic Ridge (MAR). A common admixture in ZnS is Cu (0.16 to 1.32 wt%). Rare grains of unusual anisotropic Fe-disulfides, (Fe0.95Cu0.05)S2 and Cu(Fe,Co)9S20, were found among the ore minerals."

Jan 1, 1999

By A. Ignatieff

"Excavation, the principal mining process, 'which hitherto has been based largely on the intuition and logic of mining men, is increasingly receiving the attention of engineers and scientists versed in rock mechanics. The paper intro-duce the principles of this science in simplified form, directed both to underground and open-pit mining. Reference is made to the large annual tonnage from ore and rock excavations, which in 1967 were responsible for 250 million tons of mineral production in Canada.The urge to transform excavation into a continuous instead of an interrupted process is discussed with references to the various types of energies employed or proposed in rock breakage or excavation. Due to the rapid decay of applied energy in the discontinuous and heterogeneous rock environment, large confined blasts proposed for in-situ mining do not give much expectation of success as yet. Raises and ventilating shafts are already bored in reasonably hard rock. Tunnelling machines will be used for drifting and cross-cutting in the future, but continuous mining machines of the cuttmg and shearing type are not 'around the corner' for stoping typical orebodies. On the other hand, bed mining, particularly of coal, has led the way in continuous mining, and Remotely Operated Long-wall Face (ROLF) experiments are progressing in an encouraging way. Some reflections on the mining environment in relation to the human element are made."

Jan 1, 1970

By Robert B. Parsons

"A t last the legal red tape which has tied up flow-through share financing has been cut. New rules effective for deals signed after 1986 simplify flow-through financing by removing the necessity f or cumbersome agency relationships. But there is no free lunch-the new rules require increased government reporting. And beware federal tax reform promises to have a good look at the new flow-through share rules. IntroductionFlow-through shares have always worked better in theory then reality as an effective financing tool. The concept is straightforward: a transfer of risks, tax deductions, and potential returns. But the mechanics of the old flow-through rules made the transfer of risk impractical to impossible by placing the responsibility for incurring Canadian exploration expense (CEE) on investors. The new rules are significantly more realistic, shifting that responsibility to the issuing corporation. However, every silver lining must have a few clouds around it. In the case of the new flow-through rules, the more obvious negatives are increased reporting requirements and reductions in CEE eligible for flow-through by amounts of assistance received. The new rules are effective for deals signed after 1986, however, so a few old-style deals are still around. Practical Difficulties with Old RulesThe old rules which applied to investments in flow-through shares were structured so as to make it the responsibility of the investor, rather than the issuing corporation, to perform the Canadian exploration expense for flow-through. Since most investors had neither the expertise nor the inclination to incur the CEE, this requirement necessitated the use of cumbersome arrangements whereby the investors would appoint an agent (usually the issuing corporation) to incur CEE on their behalf. Although the issuing corporation might consequently be the party which actually spends the flow-through share funds on CEE, the awkward legal structure of such an arrangement made the investor the ""principal"" incurring the CEE. As such, the requirements of the old rules were met and the investors could receive their flow-through share s."

Jan 1, 1987

By Jean-Christophe Ehrström, Fanny Mas

"A specific test set-up has been developed to study at the lab-scale the high-temperature behavior of aluminium alloys in conditions close to those experienced by thick plates during hot-rolling. A particular attention is paid to reproducing both the stress triaxiality and strain fields that exist in plate during rolling. In addition to standard ductility measurements by means of secondary tensile tests (STT), multi-step plane strain compression (PSC) tests have been performed to mimic hot-rolling pass schedules. Tool and sample geometries were adapted to allow low h/a ratios (h= average specimen thickness, a= tool width) and thus guarantee depressive stress conditions at the center of the specimen during most of the test. Such conditions resulting in porosity opening can then be used to investigate the impact of rolling conditions on damage evolution. The mechanical testing was combined with post-mortem high-resolution ultrasonic scans allowing to detect small amounts of damage and quantify its evolution as a function of processing parameters such as strain and temperature. The test set-up was validated on two 2050-type AlCuLi alloys with different susceptibilities to high temperature embrittlement.INTRODUCTION Aluminium thick plates are widely used in the aerospace industry, mainly as semi-products to be machined for internal structure parts of wings (spars, ribs) and fuselage (frame). The conversion route of such products always involves a hot-rolling step, the conditions of which (temperature, speed, pass schedule) have to be optimized to maximize both mechanical properties and final plate quality. This goal cannot always be efficiently achieved by full-scale industrial trials as (a) cost limits the number of possible test conditions and (b) it is often difficult to change one parameter alone. That is why there is a need for laboratory-scale tests able to mimic the rolling process in terms of temperature, strain rate, stress triaxiality and deformation. Most laboratory hot-rolling mills do not adequately simulate industrial processing routes, especially in terms of heat loss, deformation speed and rolling geometry (maximum roll gap vs. work roll diameter). Concerning thick plate, it is of interest to achieve both similar deformation and L/h ratio (L=arc of contact, h=mean gauge) per pass as the industrial schedule because they are simultaneously involved in damage evolution and void closure during hot forming processes (Saby, 2014)."

Jan 1, 2018

By Floyd Smith

Based on underground observations made in .the coal mines of the Dominion Coal Company Ltd., this paper deals with the stress phenomena in the approach roads and headways and in the gob areas associated with the longwall method of total extraction. The deformation of roadways during development and the deformation of roadways during the total extraction period is delineated and presented in graphical form .. Conclusions are made as to the feasibility of the introduction of the retreat method of longwall extraction in one of the colhenes. The importance of future studies are enumerated, especially. those pertaining to the determination .of the opti.m.um sizes of protective pillars and to increasing the efficiency of the current methods of artificial roadway support.

Jan 1, 1967

By S. A. Willis

For the past several months 1 have been considering the functions of this Society and its reasons for continuance. The fact that it is now sixty years old indicates that it must have been of value and we all know that it has contributed much that was worthwhile to Nova Scotia and the Maritime Provinces. The question arises: "What is the future of the Society, and how might its activities be altered to suit present-day activities and to be of even greater value?" Let us analyse the various activities in which we are interested and determine which, if any, are of more value than others. First of all, at least once a year we have a two-day convention which constitutes a holiday for the members and their wives. This has always been well planned and has been much enjoyed. Second, there are many social and business contacts made during the meetings and interim meetings. These certainly tend toward better relations and co-operation between the various people concerned. Mine operators meet other mine operators, engineers, people from the education fields, Department of Mines, and so forth. Various sales contacts are made at these meetings which can be of value and use to both the Company selling and the customer. Third, and of greatest importance in any conference, is the exchange of ideas by the members and by authorities from outside, and the presentation of slides and drawings, or actual visits to operations. It is upon this phase that 1 wish to elaborate. These papers are not only presented to our meetings but are generally published in the C.I.M. Bulletin so that members throughout the Dominion have access to them. Many important papers describing new phases of operations have originated through our Society.

Jan 1, 1947

By J. Beddoes

Many high strength aerospace alloys undergo solution heat treatment (SHT) and aging to develop precipitate strengthening. Most simply, SHT involves an isothermal hold in a single phase region followed by relatively rapid cooling to develop a super-saturated solid solution from which precipitates form during aging. However, subsequent properties are sensitively dependent on the details of the SHT, which frequently also serves a homogenization function. Altering the details of the thermal cycle during SHT significantly improves the properties attained during aging, as presented by examples of SHT design for titanium aluminide intermetallics, polycrystalline and single crystal superalloys, and 7075 aluminum.

Jan 1, 2010

By K. Shen, A. J. Sinclair, N. Champigny

"Fluid inclusion studies from the Cinola deposit indicate low salinities and low C01 contents of the ore fluid. This supports a suggestion that the mineralizing fluids originated from pore water in the fluviatile host rock (mid-Miocene Skonun Formation). Bimodal distribution of filling temperatures suggests the existence of at least two temperature regimes centred on 160°C and 270°C during mineral deposition. Independent age and stratigraphic evidence indicates that depth of mineralization is between 1.1 and 1. 8 km, corresponding to a hydrostatic load of between 110 and 170 bars.RESUMELes donnees sur les inclusions fluides du gisement Cinola indiquent de basses salinites et basses teneurs en C01 . Ceci confirme que les fluides mineralisants ont ete derives de l'eau interstitielle prise dans les sedimentsfluviatiles hates. La distribution bimodale des temperatures d'homogenisation implique !'existence de deux regimes de temperature concentrees vers 160°C et 270°C pendant Ia mineralisation. La profondeur alaquelle le gisement s'est forme est evaluee d'etre entre 1.1 et 1.8 km a partir d'informations stratigraphiques independantes: ceci correspond a des pressions hydrostatiques de 110 a 170 bars."

Jan 1, 1982

By J. M. Ortiz, J. P. Bertini

"In mineral resource and ore reserve estimation, several sources of information are generally available, such as diamond drillholes, reversed-circulation drillholes, and blastholes, and originate from one or more sampling campaigns and are analyzed by one or more laboratories. In such a situation, the grade measurements may not have the same precision and one should distinguish between hard and imprecise data.This work aims at studying the impact of data imprecision in resource/reserve evaluation through two case studies on simulated deposits: a porphyry copper deposit conditioned to real exploration and production data, and a gold deposit simulated without any conditioning data. Several geostatistical techniques are used to estimate the grades of selective mining units from exploration samples, including kriging, cokriging, lognormal and indicator kriging. Two types of imprecision are examined— measurements with multiplicative errors and measurements defined as intervals. The results are compared to the simulated grades of the selective mining units from a statistical and economic viewpoint.The study concludes that imprecise measurements should never be discarded because they help to improve the estimates, and that simple methods such as kriging are as efficient as more sophisticated ones for resource/reserve assessment. Finally, a few indications on how to diagnose and model the data imprecision are given."

Jan 1, 2005

?Four-wheel, skid-steer, rover developed for CSA ?U-chassis for payload accommodation ?Passive geometric suspension ?Max speed 13km/hr ?Remote workstation ?275kg payload capacity ?On-board processor, IMU, motor encoders ?5.2kW-h battery capacity

May 1, 2013

By G. R. McMeekin

"THE TOPIC suggested for my contribution to this Symposium was ""Lead-Zinc Smelting - 40 Years of Pollution Control"". The history of the development of smelting industry at Trail and the control of sulphur dioxide could make quite an interesting historical study. However, in the field of environmental control, the public is not particularly interested in what you did yesterday, but rather what you are doing today and what you are planning to do tomorrow. I can't fault this approach, but because there are some subject lessons that history can demonstrate, I would like to tell enough of the story (under three headings) to bring a focus on matters of contemporary concern in regard to public relations and ecology. The three general headings suggested are: (1) time before the capture of by-product sulphur; (2) the capture of sulphur; and (3) the ecological and public relations conclusions from these."

Jan 1, 1972

By A. L. Mular

"On behalf of Bob Bruce and myself I would like to begin by stressing some key points.First, most of us know that the Canadian Mineral Processors was formed in 1969 and is an offshoot of the Canadian Gold Metallurgists. I attended that first meeting in 1969, and I haven't missed a meeting since! Pretty obvious that CMP serves the best booze! At any rate, we know that our meetings are supported by CANMET. Camsell Hall is always at our disposal; Bob Bruce acts as permanent secretary pretty much free of charge; we receive a financial grant from CANMET. This brings me to a second point.Second the Canadian Mineral Processors do not enjoy a free ride in this relationship. CMP provides a genuine service to the mining industry, to government, and to universities. For the industry, CMP serves as a forum for the rapid dissemination of new ideas and new technology developed at remote locations throughout Canada. New developments outside Canada are introduced by invited speakers at our meetings. The effect is to help reduce operating costs and increase efficiency.For government, problem areas and research priorities can be isolated through mutual discussions. Direct communication at our meetings can help CANMET to temper its goals and modify its national priorities.For universities, CMP provides a wealth of operating experience and practical know how. The yearly proceedings are a major current reference source fo1· those of us who teach mineral processing. Admittedly, the proceedings are publ-shed from CMP coffers. However, I note that our fees are up this year, which brings me to a third point.Third, we face some potential problems of a financial and political nature. From a financial view, we may lose our CANMET grant and other financial good will simply because of spending constraints. Our fees are expected to climb each year thereafter.From a political view, we know that the metallurgical society of CIM is anxious to incorporate CMP as a section. The pros and cons of such a merger have been described in a recent mailing. In th2 final analysis, the political and financial problems are interrelated. There are several alternative solutions to both problems, which brings me to a fourth point"

Jan 1, 1979

By Desmond M. Levins

"Australia has almost twenty per cent of the Western World's low-cost uranium reserves, located mostly in the Alligator Rivers region of the Northern Territory. At present, only one uranium mill is operating in Australia, but a number of new mills are planned for the early 1980s.Details are given of Australian uranium mining and milling proposals and the measures taken to minimize their environmental impact. Major factors affecting environmental impact are discussed, including treatment of liquid wastes, water management, control of radon and other airborne releases, and disposal of tailings. IntroductionAustralia is entering a new phase in uranium mining and milling activity . In the first phase of operations, between 1954 and 1971, about 10,000 tonnes of yellowcake was produced at five locations. Most of the production came from the mines at Rum Jungle in the Northern Territory and Mary Kathleen in Queensland. In the 1960s, the demand for uranium slumped, and much of the yellowcake produced at Rum Jungle was stockpiled by the Australian Atomic Energy Commission. The early uranium processing operations in Australia were typical of overseas practice at that time. Environmental problems were generally given low priority and pollution control measures were unacceptable by today's standards. There was little or no recycling of process water, acid waste streams were not neutralized and tailings dams were poorly designed. At Rum Jungle, oxidation of sulphides in waste heaps, tailings dumps and ore stockpiles subsequently led to destruction of vegetation and heavy metal pollution in a nearby river.In the early 1970s, major uranium deposits were discovered in the Alligator Rivers region of the Northern Territory. Significant orebodies were also located in the Great Artesian Basin in South Australia, in calcrete formations in Western Australia and at several locations in Northern Queensland. According to latest available estimates. Australia has about 160/0 of the Western World's uranium recoverable below $US 80 per kg U. Mining these orebodies will require pollution control measures more stringent than practised previously in Australia."

Jan 1, 1980

By J. S. Edwards

The ISASMELT? process is recognized worldwide as a modem, flexible, environmentally-friendly and low capital cost smelting technology. Due to the inherent simplicity, and the advanced process control that has been developed, personnel become competent within weeks of being introduced to the ISASMELT? technology. This compares with the years required to become proficient with alternative technologies. Copper smelters in Australia, USA, India, China, Peru and Zambia have installed ISASMELT? technology under licence from Xstrata Technology. In the secondary copper business, plants in Belgium and Germany are processing copper and/or lead materials in ISASMELT? furnaces in a two stage process. In a single furnace smelting is followed by converting. Both plants have exceeded design capacities and are continuously improving their performance. The next evolutionary step for the technology is the implementation of the continuous copper converting process on a commercial scale. The present work describes the design status of the continuous converting process - ISACONVERT?.

Jan 1, 2007

By J-P. Rossetti, A. Guerin, M. Jaboyedoff, L. Baillet, A. Mariscal, J. D'Amato, D. Hantz

"The processes leading to the fall of rock compartments from rock walls are poorly known as well as their velocity. It ensues that quantitative prediction of the failure time for a rock compartment which is presently stable, is not possible by a purely geomechanical approach. However a quantitative probabilistic prediction of rockfalls at the scale of a rock wall is possible if the spatial-temporal rockfall frequency can be determined or estimated (Hantz, 2011). For a better knowledge of failure processes and frequency, rockfalls have been detected in several rock walls, using annual terrestrial laser scanning, allowing comparison of the frequencies in different geological conditions. For one of these rock walls, the spatial detection have been completed by a precise dating of the events, using a quasi-continuous photographic survey (one photo every 10 mn), allowing the study of the influence of meteorological factors.The precise dating of rockfalls has been carried out for the Saint-Eynard cliff which towers above a residential area of the town of Grenoble (French Alps). The South-East facing cliff consists in bedded limestone gently dipping North-West and located at an elevation between 850 m and 1100 m. The surveyed zone is about 750 m large and 250 m high. Between 01/02/2013 and 26/11/2013, 65 rockfalls ranging between 0.01 m3 and 20 m3, have been detected by diachronic comparison of laser scanner data and dated by comparison of photographic images. The temperature at the elevation of the cliff has been calculated from the temperature measured (every 5 mn) at a meteorological station located at an elevation of 245 m and 2.5 km away from the cliff, using a temperature gradient of 0.003°C/m (D’Amato et al., 2014). The precipitation were measured 900 m away from the cliff at an elevation of 469 m. Different meteorological conditions have been defined: (a) “freeze” qualifies days with negative mean temperature (but with a thaw period, except for two days); (b) “thaw” qualifies days with positive mean temperature, but following a freeze day; (c) “rain” qualifies days with precipitation.Table 1 shows the rockfall temporal frequency for the different meteorological conditions. It appears that the frequency is about 6 times higher the freeze days, 2.5 higher the thaw days and 3 times higher the rain days than days without freeze, thaw or rain."

Jan 1, 2015

By G. F. Doggett

In describing accounting methods at Lake Shore Mines, it is the intention of the writer to limit the discussion to the principal features of the system used in securing cost figures and other statistics. The subject can be conveniently treated under the following divisions: (1) Time-keeping and Labour Distribution (2) Supplies: Handling and Distribution (3) Method of Assembling Data for Cost Purposes (4) Details of Operating Costs Time-Keeping and Labour Distribution After a new employee has gone through the routine of being 'hired on', he is assigned an employment number corresponding with the group applying to his occupation. This is for identification purposes in the plant and time office. He is also given an individual serial number, the use of which will be refer-red to later. On entering and leaving the plant, each employee passes through the clock room adjoining the time office, where he registers the time in and out on time recorders, on the clock card (Figure 1) bearing his name and number. It is the duty each morning of the time clerk to extend the hours worked by each employee, as indicated by the clock for the previous day, and at the end of the half-month period the total hours are multiplied by the rate and entered in the space provided for total wages at the bottom of the card.

Jan 1, 1935

By T. A. Utigard

To improve recoveries of Ni, Cu and Co in the Inco flash furnace, a new operating concept was investigated. By adding sufficient coke to form a supernatant coke layer, a reducing barrier would form allowing for improved reduction of descending oxidized sulfide mineral particles formed in the flame. The objective of this investigation was to study the kinetic mechanism and efficiency of the coke layer to produce a sulfur deficient matte. The mechanism and rate of carbon reduction of each of the phases formed in the flash flame, i.e. sulfides and oxysulfides were investigated by means of X-ray visualization tests. Graphite-slag reduction was also conducted for comparison purposes. In the case of slag, poor wettability and the formation of a gas film on the surface of the carbon reductant are often blamed for limiting the reaction surface area that ultimately results in poor reaction kinetics. The X-ray visualization tests confirmed that matte and oxysulfide wet coke better than slag and that the rates of reduction of matte and oxysulfide are faster than that of slag.

Jan 1, 2005