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By L. López

Argentina reported about 40,000 tonnes of uranium (tU) as reasonably assured resources and inferred resources for the production cost category <130 US$/kgU in the OECD-NEA/IAEA classification scheme. These resources belong to the following projects: Sierra Pintada, Cerro Solo, Don Otto, Laguna Colorada, Laguna Salada, Meseta Central and Amarillo Grande. With three heavy water reactors in operation and an approximate installed capacity of 1.7 GWe, the current natural uranium requirements are about 220–250 tU per year. Based on various nuclear growth scenarios, it is estimated that by 2030 there will be a generation capacity of some 3,092 GWe for the reference case, with raw material needs of some 486 tU per year. Currently, there are no perspectives for local uranium production in the short term, and it is thought that uranium projects with identified resources must complete resource delineation and advance in technical pre-feasibility studies for the recovery of uranium. It is expected that Argentina continue meeting the uranium demand with imports in the next following years. In the Latin America region, both Brazil and Paraguay could be considered as potential uranium suppliers. In conclusion, despite the apparent growth prospects for the use of nuclear energy to generate electricity in Argentina, there are no immediate prospects for the provision of uranium oxide concentrates from domestic deposits for fuel fabrication. This has implications for supply and energy security.

Jan 1, 2020

By Zhiqing Zhang, Changyun Chen, Qing Liu, Lin Lin, Zhihong Jia, Guangjie Huang, Lipeng Ding

The effect of interrupted quenching (IQ) treatments on natural aging and bake hardening response of Al-Mg-Si alloy was investigated by hardness measurements, tensile test, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The results show that interrupted quenching at 100oC could effectively suppress natural aging and improve bake hardening response. The optimized interrupted quenching treatment is 100oC for 45min, which gives the alloy a relatively low T4 temper strength and higher bake hardening response. The formation of highly dense cluster(2) during the interrupted quenching could be the reason for suppressing the natural aging and accelerating the precipitation of ß? phase during the paint bake treatment. In addition, interrupted quenching at higher temperature (170oC) results in unfavorable properties in both T4 temper and paint bake treatment. The formation of large precipitates is responsible for these undesired effects.

Jan 1, 2015

By L. E. Djingheuzian

IN 1953, Lewis (1) published an article which brought forth a great amount of discussion by grinding engineers. In his contribution to discussion the present writer (2) suggested that, for the most efficient performance of a ball mill, there must be a .definite relationship between Cn, per cent critical speed, and V p, per cent mill volume occupied by the ball charge. Later, he ( 3) was able to publish some grinding data from Wright-Hargreaves milly which appeared to bear out this contention. It is with this view to establishing a fundamental relationship between Cn and Vp that the idea of this Forum was conceived. Accordingly, a questionnaire was prepared and copies of it were mailed to over eighty Canadian mill operators. This questionnaire did not include a question on dilution on the assumption that each mill operator was using the most efficient dilution for his operation, nor was a question on efficiency of classification included since it was thought that the inclusion of efficiency of dassification in the questionnaire at this preliminary stage might render the forum discussion,. while everybody was trying to find his bearings, too unwieldy. However, it is evident that, as discussions develop, this forum will have to define a uniform method for establishing most efficient classification in grinding circuits

Jan 1, 1957

By Sergio Cattalanl, Francis Chartrand

"The geology and origins of volcanogenic massive sulfide (VMS) deposits in the Abitibi belt of northwestern Quebec have been the subject of discussion since the discovery of the Horne orebodies in Noranda in 1923.The present Noranda version of the VMS model characterizes the ideal deposit as a stratabound, base-metal accumulation that is in close spatial relationship with hydrothermal alteration and stockwork zones, felsic lava domes, coarse phreatic-pyroclastic breccias, and subvolcanic intrusions that characterize vent- and proximal{acies submarine volcanic environments. Deposits tend to occur in a favorable stratigraphic interval within a mining camp, and this is well-documented in the Rouyn-Noranda and Matagami camps.However, in recent years many VMS deposits have been shown to deviate from the ideal Noranda-type. For example, the Ansi/ deposit is characterized by sulphide-bearing alteration zones that extend far above the massive sulfide lenses, and by abundant magnetite immediately underlying massive sulfide. The Horne deposit appears to lack the typical chloritic alteration pipe underlying the massive sulfide lenses, as well as laterally-equivalent exhalite horizons. The Horne and Quemont deposits, besides being the two giants of the camp, are particularly rich in gold, whereas others, such as WaiteAmulet and Millenbach, have low gold values. Finally, some deposits in the Noranda camp, such as the Ansil, Corbet and Mobrun mines, are outside the favorable stratigraphic interval. Therefore, it would appear that part of the key to renewing base metal reserves in northwestern Quebec is the use of evolving descriptive-genetic models that incorporate geological variations like those cited above."

Jan 1, 1990

By H. Miki, S. Wheatley

The addition of precipitated silica greatly enhances chalcopyrite leaching in the presence of sodium chloride at moderate temperatures (65-90°C) in acid media with ferric ions as the oxidant. The beneficial effect increases with the increase in chloride concentration and temperature. The addition of sodium silicate and silica sand has no significant influence. The analysis of solubility data in acid/salt solutions indicates that the solubility of silica as Si(OH)4 as the dissolved species is controlled by the activity of water, as expected from the hydration theory. Kinetic analysis shows the trends that copper dissolution from chalcopyrite in the presence of precipitated silica with sodium chloride follows a shrinking sphere model indicating a chemically controlled surface reaction. The effect of temperature on copper dissolution in the presence of both precipitated silica and sodium chloride was also larger compared to the results in sodium chloride alone. The SEM analysis shows that chloride and silica facilitates the precipitation of sulfur on the surface of the silica particles rather than the chalcopyrite particles which avoids the blockage of the mineral surface and thus improves the leaching kinetics.

Jan 1, 2014

By Humphrey Dean

"Canadian mining companies now operate numerous Koepe-type friction hoists in a variety of different shafts, most of which have a depth in excess of 3,000 feet. Rope performance reliability is an absolutely essential ingredient of most installations and, for this to be provided, a more comprehensive understanding of rope reactions to applied stresses is required.It is the intent of this paper to illustrate for the operators the importance of the critical stresses encountered and to provide a maintenance program designed to circumvent potential difficulties."

Jan 1, 1970

By Alfred W. G. Wilson

THE state of development of its iron and steel industries serves as a 1eading index to the general condition of a nation&apos;s business affairs. In this paper, the authors present an economic study of the progress of this group of industries in Canada for the decade 1927-1936. The statistical data and most of the tables which accompany this article have been com-piled by John Casey, Statistician, Bureau of Mines; the text and some of the computations have been prepared by the seni0r author. The principal source of statistical information has been the publications of the Dominion Bureau of Statistics; where other sources have been consulted, they are noted in the text. All weights are given in short tons. Records for the years 1913 and 1918 are also presented in the group of tables dealing with iron ore and pig iron; they will serve as a basis for comparison with nearly normal years in the two decades prior to 1927-36, which included the abnorma1 years of the Great War. GENERAL REVIEW At the beginning of the decade under review, this group of industries had returned to almost normal production, as determined by pre-war conditions. Iron ore consumption showed a steady increase between 1927 and 1930; a marked decline began in 1930 and reached its culmination in 1932, when the recorded consumption of ore was 293,353 to11s, about 16 per cent of the average consumption during the first four years of the decade; the last four years of the decade show a gradual increase in consumption; the amount of ore used in 1936 was still slightly below the amount used ten years before, in 1927 (see Table 1, top).

Jan 1, 1938

By J. A. Russell

AS THE LOCAL electric generating plants increased in size and capacity and costs of producing electricity came down, it became apparent that it was no longer good economy to operate individual boiler plants at the Company&apos;s various collieries to power steam hoists and compressors. Great economies could be made by burning the Coal at central power plants and using electric power at the collieries. During the period after the end of the war, a steady and continuing programme of replacing first the smaller steam-driven units, and later the steam-driven compressors, was undertaken, and finally the larger hoists, those at No. 12 Colliery in New Waterford and No. 20 Colliery in Glace Bay, were the last units operated by steam.

Jan 1, 1958

By J. Butra

The underground research presented in this paper was carried out in the two Polish copper mines: Rudna and Polkowice-Sieroszowice. The aim of the research was to determine stress field parameters. The measurement method and measuring positions are described as well as the measuring technique adapted to the geological and mining conditions of the Rudna mine and the Polkowice-Sieroszowice mine. The identified values and directions of principal stresses and horizontal stresses and their importance for optimization of mining operation and safety improvement are discussed.

Aug 1, 2013

By H. Marquis

This paper is concerned with an analysis of a number of failures of large-size, hypervelocity light gas gun chambers and barrels. A brief description of the light gas gun principle and of the various types of guns is first given. The failures and the investigations carried out are then described in detail, with the failures divided into two groups. The first group comprises those failures caused by certain conditions to which the guns may be submitted, and includes, for example, severe local heating of the bore surface causing hardening and cracking of the steel. These conditions were accidental and steps were taken to prevent them. The remaining failures were due to faults in the material or in the heat-treatment, manufacturing or assembling procedures. Specific problems, such as hydrogen embrittlement, and the use of high strength gun barrels above their ductile-brittle transition temperature by preheating prior to firing, are briefly considered. Some interesting observations are also presented on the use of surface markings, and angles of fracture of large fragments, as an

Jan 1, 1962

By F. R. Archibald

Introduction It is the purpose of this paper to review the subject of roasting as preparation of refractory gold ores and concentrates for cyanidation, with particular reference to operations at the mill of Beattie Gold Mines (Que.), Ltd., Duparquet, Quebec. Two earlier papers relating to the Beattie roasting operations are cited as background to the ? present discussion, and more general reference is made to other publications relating? to geology and metallurgy at Beattie. The Beattie roasting plant was built in 1937 as an addition to the existing flotation and cyanidation plant to permit complete processing of the ore at the mine property. Previously, the flotation concentrate had been cyanided, yielding 70 per cent of the gold values, followed by re-flotation of a concentrate from the cyanide residue. This re-floated residue was shipped to a smelter for recovery of gold values unavailable from direct cyanidation. The roasting plant itself is of interest through application in its design of multiple-hearth roasters and a Cottrell plant for separate recovery of dust and arsenic. In the laboratory and plant studies that accompanied development of the plant into a dependable and efficient working unit have been found principles and ideas applicable to other roasting &apos;problems. Before enlarging on these aspects relating particularly to the Beattie problems and plant, brief consideration is given to roasting in general.

Jan 1, 1949

By G. E. Agar

"The distribution of gold in the grinding-classification circuit of an operating gold plant was determined by assaying the size fractions of samples from each of the streams. This analysis identified the streams with the maximum potential for gravity recovery of gold and revealed that there was up 110 seventy-five times as much gold in the primary cyclone underflow as in the concentrator feed.Laboratory jigging and tabling tests were done on samples from two of the streams to determine what the recovery might be with a gravity circuit and to show that a high grade concentrate could be produced. A numerical simulation procedure was used to calculate a material balance for a circuit that included gravity separation on the primary cyclone underflow. The numerical simulation optimistically indicated that as much as 84% of the gold might be recovered in a reasonable grade of concentrate even though the recovery in batch bench scale tests was only 14%.Incorporation of a gravity separation device would reduce the inventory of gold in the grinding-classification circuit.INTRODUCTIONMany gold concentrating plants include a gravity concentration operation while others do not and the reasons that some do and some do not is not clear. Some of the advantages and disadvantages of gravity circuits are discussed by Penman (Penman 1987) without clear cut resolution. Penman's comments elicited an interesting response from Lloyd (1989) who produced a simple way to determine if the addition of a gravity concentration circuit would enhance the recovery of gold. Lloyd's method does not consider the cost of running the circuit so it only partially answers the question. There are reports in the literature (Wells and Patel 1991, Matwijenko 1988) that as much as 60% of the entire production comes from a gravity circuit when it is used, and that the grade of the concentrate produced often exceeds 65% gold, an assay that far exceeds most Merrill-Crowe precipitates that are sent to refining. In at least one instance (Hood 1984) a range of recovery from 40-50% was indicated from laboratory test work and the plant subsequently realized recoveries in the range of 26-40%. Despite these favorable numbers other plants use gravity separation when as little as 20% of the gold is recovered in the gravity concentrate (Carter 1992)."

Jan 1, 1993

By J. Kalynchuk, R. Poulin, R. Pakalnis, D. Peterson

"A market survey of all underground mines in Canada (Fig. 1) was completed to determine the ex1ent to which cable bolts are being used as ground support. One hundred and nine questionnaires were distributed with 65% of them being returned completed. As a result, the quantity, types and locations of cable bolt installations have been determined. In addition, the grout pumps used, time required and cost of installations have been addressed. The popularity of other support types used in underground mines is summarized.IntroductionRock reinforcement consists of installing support within the rock mass (internal) or within the excavation (external). Within the past twenty-five years several new types of ground support have been introduced within the mining industry. Cable bolts were first introduced to the Canadian mining industry in the 19605 (Gramoli, 1975).Cable bolts have gained increased acceptance as a method of ground support during the past decade. The cable bolt is comprised of one central wire surrounded by six slightly smaller outside wires and typically having an over-all diameter of 15.2 nun to 15.9 nun (0.6 in. to 0.625 in.). The cable wires are made from high-strength steel with an ultimate strength of 26 tonnes (58 000 Ibs) (Goris, 1990). Current cable bolting practice consists of cement grouting one or more steel cables within a drill hole in order to reinforce the surrounding rock mass. Cable bolts are a form of internal support and are generally used in open stoping and cut-and-fill mining methods (Fig. 2).They can be either tensioned (active support) or untensioned (passive support) and may be of any length, though for underground mining applications, they are generally less than 20 m (65.5 ft) and are untensioned. A major advantage compared to previously used ground support is that the cables are flexible and can be coiled to approximately 1 m (3.3 ft) diameter coils allowing relatively long support to be installed in areas with limited head room (1.8 m).With the advent of bulk mining methods which require comparatively large stopes, it has necessitated the use of relatively long support tendons to stabilize the large spans being created. As a result, the use of cable bolts for ground support in mines has increased significantly within the past decade."

Jan 1, 1995

By J. Farrell

The Canadian government ratified the Kyoto Protocol in December 2002 and, prior to ratification, committed to equitable distribution of the burden of implementation. The Federal government&apos;s Large Final Emitters group is working with industry to develop covenants that will consider the unique nature of the company&apos;s operations and not unreasonably burden any one sector or company. Ensuring equitable distribution must consider local, national and international issues. From a Canadian iron ore producers perspective, the fact that most of the iron ore production in the world is in countries that have no Kyoto commitment is a critical issue. Another issue unique to this sector is the increased addition of fluxing agents in iron ore pellet production which has shifted some process related greenhouse gas emissions from steel producers to iron ore producers. While the objectives of the Kyoto Protocol are primarily environmental, the economic implications for Canadian industry are not trivial. For decades Canadian companies have been actively improving energy efficiency and reducing greenhouse gas emissions to maintain a global competitive position. Production of iron ore pellets is an energy intensive process and the Iron Ore Company of Canada (IOCC) is the largest Canadian producer. In 2002 IOCC identified energy and Kyoto Protocol implementation as critical risk factors for their organization and appointed a full time Energy Manager. In January 2003, IOCC initiated a comprehensive process for identifying energy cost reduction opportunities and established an Energy Master plan. This process included:

Jan 1, 2004

By Louis Frost

"A FIRE which forced the sealing -of the east side of Dominion No. 16 Colliery in the Town of New Waterford, Nova Scotia, occurred on October 6th, 1952 (Figure 1).So far as can be ascertained, the fire was first noticed in the roof of No. 7 East Lateral, after a brushing shot had been fired in the pavement. There appears to .be no doubt that this shot •blew out, igniting a small feeder in the roof.Regular air measurements and air samples, taken over a long period prior to the fire, indicated that the ventilation was adequate, for at no time had the percentage of CH4 in the general air current exceeded one per cent in this location. The last regular monthly samples and air measurements, taken at the end of September, showed the condition of the ventilation to be:Return at the Top of No. 8 East WallQuantity .... 27,700 cu. ft. per min.CH4 .......................... 0.32 per centC02 ................................ 0.10 per centHowever, in the week preceding the fire the mine examiner on four occasions had reported small feeders of gas at the face of the brushing in No. 7 East Lateral.Figure 2 is a diagram of the working place where the shots were fired. The face brushing had been shot down at 3 :45 p.m. and cleaned up. Two 'hurdle screens' had also been erected, one close to the face brushing and the other fifteen feet from the face."

Jan 1, 1953

By Zhibao Li, Lanmu Zeng

The behavior of dicalcium silicate in NaOH-NaAl(OH)4-Na2CO3 solution is of significance for controlling the silica level in the production of alumina via the sintering process. Dicalcium silicate samples were obtained through a twostep approach: coprecipitation of calcium and silicate from CaCl2-Na2SiO3-NaOH solutions; and calcination of the hydrated precursor at 1200°C for 4 hours. The optimization of the synthesis parameters including temperature, solution concentrations and aging time was also investigated. Xray diffraction (XRD) and chemical analysis show that the calcined solids include dicalcium silicate with trace amounts of wollastonite. The solubility of the synthesized dicalcium silicate in HCl, NaOH, mixed NaOH-NaAl(OH)4 and NaOH-NaAl(OH)4-Na2CO3 solutions was determined. It was found that the solubility increases with increasing HCl and NaOH concentration. The effect of temperature on the solubility in HCl solutions is limited, but the solubility decreases with increasing temperature in NaOH solutions. The solubility of dicalcium silicate in NaOH-NaAl(OH)4 and NaOH-NaAl(OH)4-Na2CO3 solutions was shown to increase with increased temperature, Al(OH)3 and Na2CO3 concentration. The BromleyZemaitis model for the aqueous electrolyte system was selected to predict the solubility of dicalcium silicate. The model’s predictions yielded certain success compared with experimental solubility data.

Jan 1, 2014

By G. Chahal, L. C. So, S. Faucher, S. Mostaghel, S. -Y. Oh, S. K. Lee

Slag dumping and water granulation are the most commonly used slag treatment methods in the metallurgical industries. In both processes, water is present (by desire for cooling and dispersion or as a result of rain accumulation) and thus equipment and operations are designed to minimize and mitigate the risk of steam explosions resulting from the inappropriate contact of slag with water. Slag handling practices have, therefore, never been inherently safe; even good design, operation, and maintenance are not sufficient to prevent explosions or other related injuries from occurring. For slag handling to become inherently safe, our industry must eliminate the potential contact of water with molten slag. This is today feasible with the advent of dry granulation technologies, a review of which is presented, and it thus falls to us, in the metallurgical sector, to lead the way in their final stages of development and adoption. Furthermore, while slag dumping and water granulation offer some metallurgists the means of valorizing their slag as a by-product, for most, this is not the case. The energy in slag is lost through dumping and water granulation processes, and where slag is sold as a by-product, it is for its chemical content only. Here, dry granulation processes also offer advantages including the production of by-products which hold value in both their chemical content and physical properties and heat recovery. Dry granulation, therefore, augments the methods by which slag may be valorized over traditional processing methods.

Jan 1, 2015

By W. Leblanc, J. C. Marsh, D. Kettle, J. Tompkins, G. Hartley

"The Lingan Mine is the newest of the four operating collieries of the Cape Breton Development Corporation and is located on the east coast of Cape Breton Island. Development of slopes began in 1969 using four Dosco Roadheaders. Production commenced in October 1972, when a partial extraction section utilizing a continuous miner, loader and shuttle car was installed. A second Joy unit is scheduled to begin production early in 1973. This paper describes the production and development operations, the ventilation system and the equipment in use at the mine."

Jan 1, 1973

By D. B. Dreisinger, M. Rasouli

"Developing technology to address the environmental hazards associated with selenium in mine-impacted waters has been a serious challenge. Ion exchange (IX) has been identified as a potential treatment technology. This paper begins with a review on selenium adsorption with commercially-available basic anionic exchangers (BAS). It then looks at the use of resins for selenium removal via modification with the addition of -O, -N, or -S-containing chelating ligands and chelating polymeric ion exchangers pre-loaded with immobilized metal cations. The synthesis of chelating exchangers requires a final product with a highly stable metal in the ligand-metal complex. The nature, oxidation state, size, and affinity of the metal for the target oxyanions and the size, degree of protonation and space configuration of the oxyanion are among critical factors affecting the oxyanion uptake. There is a limited number of studies on the critical parameters affecting the selenium affinity for chelating exchangers. Such a study could fill in the gaps of our understanding of selenium-metal-chelating ligand interactions and assist in developing a new ion exchanger. In addition to commercial IX resins, layered double hydroxide materials (LDH) have received attention for oxyanion removal from waste water. The adsorption capacity of the LDHs are affected by the crystallinity of LDH, the nature of metal components, the ratio of metals, charge and type of anion, and the space between the layers. In particular, the Friedel phase (FP), a member of the LDH family, showed high adsorption capacity for selenate removal from synthetic solution. A study is currently underway at the University of British Columbia to investigate the effect of different synthesis methods and aging on the suitability of FP for selenium removal from mine waste water."

Jan 1, 2017

By T. W. Wlodek

"AbstractThe results of research into the fatigue properties of SAE 1080 carbon steel and nickel-chromium-molylbdenum steel for mining drill rods are analysed and described in detail.The effect of water corrosion on the fatigue strength of drill rods of these two steels in the as-rolled condition has ,been investigated and the beneficial influence of shot-peening on their dry and water-corrosion fatigue strengths determined by employing the method developed previously (1).Eight S-N curves for as-rolled and shot-peened mining drill rods under both dry and water corrosion conditions have been derived and their shape and relative position are discussed. The main features relating to field performance of the drill rods are analysed.Purpose of Research and Outline of ProgrammeDRILLING holes in rock and ore by means of drill rods attached to a pneumatic drill is a basic procedure required in mining operations. Detonation of explosives placed in these holes is at present the only practical method of breaking down the rock and ore.A drilling rod is supported by its bit end in the drilled rock. Its shank end, fixed in the drilling machine, transmits impact energy to the cutting edges of the bit. On the field performance of the drill rod depend a number of basic mining operations such as sinking, drifting, and stoping. The drill rod is there-fore regarded as one of the most important tools used in the mining industry."

Jan 1, 1952