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"Cambior now holds a 49% interest in the Valdez Creek Placer, having acquired American Barrick's 23.125% interest in May 1990. At the same time, the company assumed the management of the operation and received environmental permits to divert the river. Plans are underway to divert the Valdez River in order to continue mining the deposit upstream, and to construct a new, higher capacity wash plant (by 60%) closer to the operations. Mining operations, which were suspended in October 1989 pending higher gold prices, resumed in August 1990. The mine is expected to produce 10000 ounces of gold in 1990and more than 80 000 ounces in 1991.IntroductionThe Valdez Creek Placer is located in the Valdez Creek mining district of Alaska on the western flank of the Clearwater mountain range, about 150 miles northeast of Anchorage by air (Fig. I) . The mine is accessible by air or by road.The mine is situated at an elevation of about 3000 ft and is isolated from towns and villages. Consequently, the mine site contains the facilities necessary to house and feed 135 people at any given time. The Valdez Creek Placer has 159 employees, including 130hourly and 29 salaried employees. The hourly employees are divided into three rotating teams. The daily schedule consists of two shifts of 12 hours, and each team works 14 days followed by seven days off, resulting in a weekly rotation of teams.The salaried employees work normal hours for ten consecutive days followed by four days off. A weekly rotation ensures continuity of services and management.Gold was first discovered at Valdez Creek in 1903, when a team of four men led by Peter Monahan left the village of Valdez to explore the area up the Susitna River, to the east of Mount McKinley. They discovered gold at the mouth of a creek that they immediately named Valdez Creek, in honour of their native town. In 1904, they discovered the Tammany Channel to the right of Valdez Creek. This was the beginning of a long period of mining in the area which continued until the beginning of World War II .In 1980, the Denali Mining Co. was formed. Geophysical work and drilling carried out through 1980 and 1981 led to the discovery of Channel A, a second channel which is older than the Tammany Channel. In 1983, Denali Mining optioned its claims to Camindex to explore, develop and mine the Valdez Creek property. A joint venture agreement was signed among Camindex, Talcorp, BCP Alaska (Barrick), Sum Resources (Cambior), Norfran and WGM to form Valdez Creek Mining Co., Inc., and production began in 1984. Valdez Creek Mining Co., Inc. (VCMC) was subsequently restructured and in 1989 was held by the following three companies: Camindex Mines Ltd. - 51070; Cambior Inc. - 25.875%; and American Barrick - 23.125%.VCMC is managed by a committee of the partners. Decisions made by the committee are subject to a 70% majority vote. Cambior receives its share of production in kind, and contributes in the same proportion to the expenses of the joint venture (VCMC)."

Jan 1, 1990

By J. R. Bradfield

THOSE familiar with the development of the Horne mine can readily appreciate that more and more accommodation bas been required for underground labour as the mine has grown. A permanent fire-proof change house, 30ft. by 75 ft., was built in 1927 to accommodate 194 men. This was extended ro 30 ft. by 92 ft. in 1928 to accommodate 296 men, and to 30ft. by 110 ft. in 1930 to accommodate 398 men. By 1933 this building was again overcrowded and tentative plans for a new change house were drawn up. However, it was realized that future operations would be centred around No. 4 shaft and a proposed new shaft, and the decision as to the location of the new change house had to be deferred until the area which seemed most suitable for the new shaft had been thoroughly explored underground. In the spring of 1934, the basic idea was accepted of drying the wet clothes in open mesh compartments or baskets located between rows of standard steel street-clothes lockers and built so that the covers or lids would serve as seats or benches.

Jan 1, 1935

By D. M. Rippley

THE St. Lawrence Seaway Project ranks with the greatest engineering undertakings of all time. A summary of major materials going into the construction of this project, shown in Table I, will assist in an appreciation -of this fact. These data relate to Seaway construction only, and it should be remembered that two large-scale power projects are in the construction stage on the St. Lawrence river concurrently with construction of the Seaway. A project of such magnitude as the Seaway would attract widespread interest even if it were being constructed in a remote area. The fact that it is located in a heavily populated and developed section of both Canada and the United States has done much to enhance this interest, and in many ways complicates the problems confronting the engineer in the design and construction phases. Many consider the St. Lawrence Seaway to be a new idea that has developed within the past decade - such is far from the fact, because the St. Lawrence River canal systems have existed for more than a century, and the Seaway Project is but a new, larger, and more efficient version of a continually expanding facility.

Jan 1, 1957

By F. R. Archibald

MR. A. F. B. Norwood: Having been associated in the past few years with nine different plants roasting aurif erous concentrates in Australia, two of which were new installations for which design and construction were undertaken by the writer, I read Mr. Archibald's paper with very great interest, and I deem it a great privilege, as a member of a sister Institution, to be invited to contribute to the discussion on the paper. I wish to congratulate the author on a very informative and interesting paper, and, although situated many thousands of miles away, I feel I have gathered from it a very close idea of the operating conditions and of the work that has been carried on at the Beattie gold mine. Working along somewhat different lines, it is interesting to note that the conclusions drawn by the author run closely parallel to those accepted in Western Australia, viz., that the object of roasting is to obtain a porous calcine, and that this can best be achieved by roasting first at a temperature below 900 deg. F. to 1,000 deg. F., and then raising the temperature at the finish of the roast. Turning first to the laboratory work, the materials I have studied in Western Australia cover a range from those with little or no arsenic to concentrates carrying as high ?as 20 per cent, i.e., even higher than in the analysis quoted for the eoncentrates from Nepheline Products, Limited. In the ease of arsenic-free pyrite concentrates, the roast is ideally carried out at a temperature ranging from 900 deg. F. to 1,000 ferric oxide is one cause of the refractory gold remaining In deg. F. No improvement in extraction is obtained when the calcines are cyanided by raising the final temperature above this point; nevertheless, in technical practice it is desirable to finish the roast at 1,200 deg. F. in order to decompose basic ferric sulphate and thereby reduce the consumption of chemicals in the subsequent cyanidation step. However, if at any stage of the roast the temperature is raised above 1,200 deg. F., the extraction by cyanidation falls, and continues to do so the higher the maximum temperature that is reached. Line A in the accompanying graph typifies this effect.

Jan 1, 1949

By G. Cailletaud, I. Guillot, D. Larouche, R. Martinez, D. Massinon

The precipitation of Al2Cu particles in a 319 T7 aluminum alloy has been modeled. A theoretical approach enables the concomitant computation of nucleation, growth and coarsening, based on an implicit scheme using the finite differences. The equation of continuity is discretized in time and space in order to obtain a matricial form. The inversion of a tridiagonal matrix allows us to determine the evolution of the size distribution of Al2Cu particles at t + dt. The fluxes of solute in-between the boundaries, as well as the ones at the boundaries, are computed in order to respect the conservation of the mass of the system. The main results of the model are compared to TEM measurements. Simulations provide quantitative features on the impact of the cooling rate on the size distribution of Al2Cu particles in good agreement with the TEM measurements. This metallurgical model is integrated into FEA software in order to perform mechanical computations. This kind of multiscale approach allows new perspectives to be investigated in the process of designing cylinder heads. It enables a more precise prediction of the microstructure, its evolution as a function of continuous cooling rates and its impact on the integrity of the structure.

Jan 1, 2015

By R. Horn

The financial performance of the mining industry, measured by return on equity and capital employed, has been inadequate for many years. Consequently, mining companies are not valued highly by stock markets. Among the more important causes for the decline in the sector are the conservative working practices and reluctance to adapt to change or to develop new technology, although some relatively recent developments such as SX-EW copper and heap leach gold have made a significant impact on the cost base of these metals. The subsidiary business of metals exploration suffers from the same problems as the rest of the industry. The rate of discovery of ore deposits has been falling over many years and since the late 1990s, there has been a sharp reduction in global exploration activity that, if it continues, will further reduce the global supply of new ore reserves. New technological developments, particularly in geophysics and different operational practices may help reverse this trend. Statistical methods for evaluating the risk of ore reserve estimates will also improve the economic return on new mining ventures. The science of ore geology has potential to reduce exploration risk, but modern ore genetic theory has not contributed greatly to recent discoveries. The junior exploration market has almost ceased, but a new style of technically specialized efficient small exploration company has emerged which, in alliances with major companies, may be the vehicle for future global exploration. Exploration in virgin terrains has a higher risk discounted potential for the discovery of very large orebodies than that in known mining districts but mining companies have little financial incentive for this high risk exploration because of the very long lead time to production. Alliances of two or more companies reduce the risk in both the exploration for and development of major new mining projects. If new orebodies are not found, then metal prices will inevitably rise in the long term. Governments of industrial countries, particularly those with a significant mining industry such as Canada, should therefore provide assistance to exploration in order to maintain their existing industry and prevent a metals shortage from developing in the future with its consequent impact on the world economy and increased environmental damage as large lowgrade orebodies are developed to supply an expanding market.

Jan 1, 2002

By E. Ghali, A. D. Bas

"Treatment of oxide, e.g. roasted gold ores has received relatively less attention than sulphidic ones and recently, handling of oxide gold ores is becoming essential. In this study, the influence of roasted gold ore (RGO) slurry (at 35% solid ratio) on the electrochemical dissolution of gold has been examined using pure gold and iron oxide minerals (hematite, maghemite, and magnetite) as disc electrodes by zeroresistance ammeter mode either in one or two separate containers. The presence of slurry decreased galvanic currents, i.e. corrosion rates due to the release and increase in the amount of soluble and/or insoluble species that could retard further the anodic behaviour of gold. Higher galvanic currents were observed in two separate containers than that in one container indicating the primary importance of galvanic interactions. SEM-EDS results observed iron hydro/oxide coatings on gold surface in case of magnetite test. However, in case of RGO electrode it is not a perfect passivation, although somewhat decreasing trend was observed on gold dissolution. These findings have revealed that passivation is not only a laboratory phenomenon, but also it could be responsible for the slowdown of gold dissolution in industrial practice.INTRODUCTIONThe cyanidation of gold is an electrochemical corrosion process thus; the dissolution of gold can readily be studied by electrochemical techniques. The outcome/summary of previous electrochemical studies of gold leaching can partially be summarized as follows: Filmer (1982) and Lorenzen and van Deventer (1992) reported the negative effect of pyrite and pyrrhotite on gold leaching due to the galvanic interactions; Aghamirian and Yen (2005) studied gold galvanic corrosion in presence of sulphide mineral electrodes only in one cell using zero-resistance ammeter (ZRA) mode; Dai and Jeffrey (2006) discussed, individually, the anodic and cathodic behaviours between gold and sulphide minerals, and Azizi et al. (2010, 2011) used a bed reactor to examine the influence of sulphide minerals on gold dissolution in one and two separate cells. Accordingly, a slowdown in gold leaching has generally been attributed to the passivation phenomenon, although the indication of this phenomenon is still an undergoing debate. For instance, Mrkusic and Paynter (1970) identified the passivation as the film formation of dissolved species from calcine, Crundwell (2014) explained passivation, in the case of corrosion of metals, as the formation of a layer which is composed of a new chemical species on the mineral surface and this layer inhibits or blocks further reactions. He suggested that passivation is related to the oxidation of the metal, and the formation of a passive layer that retards the rate of dissolution by several orders of magnitude. Consequently, galvanic interactions, passivation phenomena, or combinations of them are considered significant electrochemical factors affecting gold dissolution (van Deventer, Reuter, Lorenzen, & Hoff, 1990; Azizi, Petre, & Larachi, 2012). It is important to note that generalizing the influence of a mineral/metal on gold dissolution may not be correct in all cases, since contrary behaviours/results (for pyrite) have been observed (Aghamirian & Yen, 2005). Therefore, electrochemical study of gold is still a subject of research and need to be examined further in detail."

Jan 1, 2016

By Robert B. Parsons

"It is quite likely that more than a handful of junior exploration companies will receive some startling news from their accountants this spring when 1989s tax returns are being prepared. These companies could find that, for the first time ever, they will have to write a cheque to the federal government on account of a new federal capital tax which became effective July I, 1989IntroductionMany mining companies which have never had to pay a federal income tax are finding that they indeed have a tax liability for 1989. Non-producing companies, such as junior exploration companies, almost automatically assume that they don't have to pay any income tax. But, a new tax imposed under the Income Tax Act catches especially the company that has no income.Effective July 1, 1989, a federal capital tax (some call it a corporation minimum tax) is payable by any corporate carrying on business in Canada where the corporation has ""taxable capital"" exceeding $10 million. As a result of the popular use of flow-through shares in recent years, many junior exploration companies are finding that their balance sheets show capital stock over $10 million, and that they are consequently caught by the new tax. Further, some of these companies are finding, to their chagrin, that the tax for 1989 was due on February 28, 1990, and that non-deductible interest is ticking away on unpaid taxes."

Jan 1, 1990

By C. John Sullivan

Is there a relationship among the Sudbury nickel ores, the Cobalt deposits, and the Huronian, Athabascan and North Australian uranium provinces? All are within intracratonic basins, with ore near basal unconformities. There are similarities in the geochemical "fingerprints" pointing to basic igneous rock affiliations. Some show a time relationship to basic igneous activity and to great rift systems. Many basic dykes show radioactivity at their edges. A spatial relationship between the uranium-cobalt-nickel ore at Midwest Lake, Athabasca, and basic igneous rock is reported. These remarks are not meant to imply, necessarily, a direct genetic connection between the basic dykes, etc., and the ore. In some cases, the relationship may be similar to that noted between basic and ultrabasic intrusives and volcanic massive sulphide ore deposits. Crustal thinning in these areas, associated with graben, appears to have favoured volcanic activity, as well as basic intrusives. Probably, the potential of the Huronian should be re thought . Athabascan-type ore may be present . New data on mineralization in Turner Township, Ontario, suggest this. The mineral possibilities of other basins should be reconsidered. It is to be remembered that the Athabascan and Kombolgie basins were neglected for many years. Intracratonic sedimentary-igneous basins contain many of the greatest mineral fields of the world.

Jan 1, 1979

By S. Khallouk, J. Zollinger, J. R. Kennedy, E. Bouzy, B. Rouat, D. Daloz

Titanium aluminides recently replaced Ni-based superalloys as turbine blades in the last LP stage of aircraft engines. To extend their range of use at higher temperature their properties need to be improved, either by alloying or processing. An efficient solution is to reduce the grain size during the solidification process. In the first part of the paper, an overview is given on the possibilities for grain refinement of such alloys, based on literature data and new results. The most efficient grain refinement is obtained with boron addition which leads to boride formations that are detrimental for in-use properties of turbine blades. In this work, the use of the high grain refinement potency of inoculation with non-brittle particles has been used by developing new refractory-based inoculants. The effect of one of these inoculants on grain refinement of an as-cast structure in a Ti-46Al is presented; resulting in a reduction of the grain size by a factor of 3.While less efficient compared to the potency of boron containing alloys, the grain refinement is effective and does not introduce any embrittling particles.

Jan 1, 2015

By K. Webb

At both the international and country level, the issue of how the mining sector and indigenous populations should engage on issues of mutual interest or concern has emerged as one of central importance and controversy; involving the mining industry, Aboriginal communities, governments, the courts, and other stakeholders. At its heart, stakeholder engagement is an ethical issue, although it manifests itself in international instruments, domestic laws, industry guidance and agreements. At the international level, the concept of ?free, prior and informed consent? (FPIC), while not subject to widespread agreement on the finer details of evolving definitions, seems to be emerging as an increasingly recognized engagement norm. Within Canada, through a series of decisions, the Supreme Court of Canada (SCC) has articulated a fiduciary obligation of the Crown to consult with and accommodate impacted Aboriginal groups on resource management issues. Provincial governments have been variously attempting to adjust their resource management regimes to stay in alignment with SCC and lower court decisions. Mining sector organizations, working with First Nations partners, have developed agreements to work together for mutual benefit. At the individual mine and community level, there have been instances of constructive engagement, as well situations of physical resistance and legal challenges. The purpose of this paper is to examine the potential impact of new rules under the Ontario Mining Act introduced in 2012 and taking full effect in 2013, which amongst other procedural specifications, addresses the issue of mining industry-Aboriginal consultation in exploration and development activities. Leading up to the passage of the regulations, representatives from some junior mineral exploration companies have been highly critical of the new rules. Similarly, there have been a range of responses to the new rules from some in the First Nations community. The paper will review the regulation in terms of its apparent alignment with SCC decisions and the international norm, compare the regulations with existing mining sector organization guidance documents, and it will draw on the stated perspectives and commentaries of First Nations communities, mining firms, governments, nongovernmental organizations, and others. Building on the foregoing, the paper will provide a preliminary analysis of the perspectives and potential impacts of the new regulation on various stakeholders, and on that basis, possible avenues for further consideration will be suggested.

Aug 1, 2013

By S. W. Marcuson, P. J. Mackey

The 1973 Oil Embargo and succeeding disruptions in supply had a profound effect on energy costs and consumption patterns in the developed world. This was especially true in the USA where post World War II growth, fueled by low-cost imported oil, left the country dependent on uninterrupted oil shipments from the volatile Middle East. In this atmosphere, Professor H.H. Kellogg of Columbia University, convinced of the necessity of good environmental stewardship by the writings of the era’s leading environmentalists, developed a methodology for evaluating energy and process efficiency of metallurgical processes and wrote a series of papers describing and applying the techniques. One of these, "Energy Use in Sulfide Smelting of Copper" is recognized as a seminal work which both described the state of energy usage in copper smelting in the mid-1970’s and portended future developments. The background to these papers is examined and the current and past Cu-Ni matte smelting practices in Canada are examined in the context of the results. Data from early 20th century publications describing reverberatory and blast furnace operation is employed to show that energy consumption for much of the century was several multiples higher than that calculated for best reverberatory operation in the 1970’s.

Jan 1, 2015

By W. Evans, C. E. Ells

Nuclear power reactors using zirconium alloy pressure tubes generate electricity in several countries. Such reactors are particularly important in Ontario, where CANDUs* generate about 30% of the total electricity produced in the Province. Starting with the commitment of NPD-2 in 1956, the pressure tubes of the first five CANDU reactors were made of coldworked Zircaloy-Z, an alloy of Zr and Sn. This alloy was developed by the US Navy, but the decision to use it in a cold-worked condition was based on AECL work. In 1958, the USSR published information on a new alloy, Zr-2.5 wt% Nb. The Nb promotes stabilization of the (3-phase in the material, thus presenting opportunities of exploiting metallurgically strong pressure tubes analogous to the heat-treatable cx-{3 titanium alloys. After construction of two reactors using Zr-2.5 wt% Nb in a quenched and aged condition, an extensive development program on cold-worked Zr-2.5 wt% Nb pressure tubes resulted in them becoming the reference tubes for all CANDU reactors committed since 1966. Anticipating the future needs of the domestic and export markets, AECL have pressure tubes of Zr-3.3 wt% Sn-0.8 wt% Nb-0.8 wt% Mo (Excel) in an advanced state of development. These tubes will be used in an annealed condition; our projections show that they will have improved dimensional stability over the lifetime of the reactors. These improvements result from experimental programs leading to an understanding of the relationship between microstructures and fabrication variables and effects of the environment during service in nuclear reactors.

Jan 1, 1981

By G. Morin, S. Amira, F. Chiesa, B. Duchesne

"The effect of heat treatment on the stress corrosion cracking (SCC) resistance of A206 aluminum alloy was studied using the breaking load test according to ASTM G139 standard. This method uses the residual strength measurement from tensile test specimens previously stressed axially while exposed to the 3.5% NaCl alternate immersion test according to ASTM G44 standard. The residual strength after exposure is used as a measure of SCC degradation. The performed heat treatments were conventional natural aging T4 and artificial over-aging T7 tempers in addition to artificial aging T6 temper added for purpose of comparison. These tests showed that A206-T4 has a good resistance to SCC at pre-loads up to 100 MPa while A206-T7 was prone to SCC for pre-loads of 0 and 50 MPa, and showed total loss of ductility for pre-load of 100 MPa. Both A206-T4 and A206-T7 pre-loaded at 150 MPa showed poor resistance to SCC. A206-T6 showed the worst susceptibility to SCC as it lost all mechanical resistance at the end of the alternate exposure to 3.5% NaCl solution, even without any applied pre-load. Metallographic analyses showed that the resistance of A206 alloy to SCC is mainly affected by the transition from pitting to intergranular corrosion attack. The initiation and the propagation of intergranular corrosion attack might be assisted by high stress concentrations in the pits, particularly for pre-loads higher than 100 MPa. The transition from pitting to intergranular corrosion can also be promoted by hydrogen evolution from growing pits, which supports crack propagation by hydrogen embrittlement.INTRODUCTIONA206 aluminum-copper casting alloy offers ones of the best mechanical properties among the aluminum foundry alloys. This alloy belongs to the 206 alloy family developed in 1970s as an alternative to the highly resistant and ductile but more expensive Ag containing 201 alloy (Tiryakioglu, 2009). A206 showed also good low cycle fatigue strength (Sigworth, 2002). These properties made A206 alloy a strong candidate for some vehicles lightweighting applications. In spite of its interesting properties cited above, A206 alloy was rarely used in critical applications due to its tendency for hot tearing and stress corrosion cracking (SCC). Studies of A206 hot tearing behavior showed that this tendency can be reduced by improving castability and by grain refinement (Sigworth, 2002). The optimisation of the casting design can also prevent the tendency toward hot tearing. The SCC of aluminum-copper alloys arises from their susceptibility to localised corrosion, especially in chloride containing media. The localised corrosion in Al-Cu alloys is caused mainly by their heterogeneous microstructure, where the presence of many phases leads to the formation of micro-galvanic coupling with the matrix. However, most of the studies aimed at investigate the SCC of Al-Cu alloys concerned the wrought ones, especially the AA2024 alloy tempered in the T3 (or derivative) condition and few studies concerned the 206 and cast alloys in general (Alexopoulos, 2009 and 2016; Campestrini, 2000; Vogt, 1998; Talamantes-Silva, 2008; Zhang, 2003). Jean et al. (Jean, 2009) studied the effect of heat treatment on SCC behavior of B206 alloy using alternate immersion technique and grain boundary attack method and did not find direct correlation between the two methods. Another study showed that aging of 206 alloy may make a casting susceptible to SCC (Sigworth, 2002). However, these studies did not provide detailed information about the mechanisms of SCC of 206 alloy, as well as the effect of the stress intensity. The present work investigates the effect heat treatments and the stress intensity on the morphology of the corrosion attack and the SCC behavior A206 aluminum alloy. This study uses the breaking load test according to ASTM G139. This test utilizes direct tensile specimens and was developed to give a more quantitative measure of the SCC performance of resistant aluminum"

Jan 1, 2016

By ByongPil Lee, Changkyu Lee, Jin Gyun Park, Hyung Sub Eom, Sung-Koo Jo, Jae-Young Lee, Gilsoo Han

"A new hydrometallurgical process for nickel extraction from a low grade laterite ore such as limonite has been developed by RIST and POSCO. This POSCO Nickel Extraction Process (PosNEP) consists of five main processes: ore reduction using hydrogen as a reductant; acid leaching at atmospheric pressure and temperature; cementation by the use of reduced-ore seed; production of the main product such as ferronickel or a high purity nickel compound; and production of by-products such as cobalt and iron in the forms of cobalt sulfate and iron oxide. In addition, hydrogen produced in acid leaching and hydrochloric acid regenerated in pyrohydrolysis for iron oxide production can be reused in the process, which makes PosNEP more cost-effective. The performance of PosNEP has been proven through pilot tests, showing that this process is economically and technically viable. In this paper, basic concepts and detailed test results of PosNEP are shown.INTRODUCTIONNickel has been extracted from two types of ore, sulfide and oxide ore. Nickel and cobalt usually occur together in the ores. The principal ore mineral of the sulfide is pentlandite, (Ni,Fe)9S8, which is easily beneficiated to produce sulfide concentrates(Moats & Davenport, 2014). These concentrates are usually treated by smelting and converting to make a matte. The produced matte is then purified through either hydrometallurgical or pyrometallurgical processes to produce high-purity nickel. In general, this process for sulfide ore has been known as a more cost-effective process than that for oxide ore.The oxide ore is laterite comprised of two different ore types, saprolite and limonite. The main nickel-bearing mineral of saprolite is nickeliferrous garnierite,(Mg,Ni)6Si4O10(OH)8, and that of limonite is nickeliferrous goethite (Fe,Ni)O·OH ore (Moats & Davenport, 2014). Since the saprolite has high contents of nickel and slag formers (MgO and SiO2) and a low content of iron, it tends to be treated by a pyrometallurgical smelting process such as calcination and electric furnace techniques to produce ferronickel for use in stainless steel. In this process, the cobalt in the ferronickel does not have any economic value."

Jan 1, 2017

By L. C. Galloway, P. M. Tiley

"Some progress has already been made in defining the parameters which will determine the performance of a guidance system in a mine shaft. Very little information is available, however, to help designers or operators predict the effects of varying these parameters in new or existing installations.The experience we have gained from monitoring a variety of installations has led to the development of a model which simulates the motion of a conveyance as it moves through a mineshaft, restrained by fixed guides.This paper presents a general analysis of the performance of the guidance system used in several installations, as well as a detailed description of the problem encountered at one mine and the steps taken to solve it.IntroductionOur company has investigated in some depth the problems that arise in the guidance of mine hoist conveyances.We have a telemetering accelerometer which we obtained to test mine hoist brakes. Frequently, during brake tests, the mine owners request us to use this instrument to measure the lateral motion of the conveyance ""to check guide alignment"". We have made such tests in shafts that have guide s of different kinds, including wooden guides, steel rail s and tubular steel guides. From these tests, we have gained some valuable information about guidance systems.In a well-aligned guidance system that is designed within common and well-known practice, the conveyance will experience very little shock most of the time. However, on rare occasions, shocks up to .5 g will occur. That is, the conveyance exerts a force of up to half its loaded weight on the guide. If the guide slips or is damaged by this force, it will be misaligned for future trips and become the cause of future shocks. In time, the whole guidance system can become misaligned."

Jan 1, 1982

By L. C. Galloway, P. M. Tiley

"Some progress has already been made in defining the parameters which will determine the performance of a guidance system in a mine shaft. Very little information is available, however, to help designers or operators predict the effects of varying these parameters in new or existing installations.The experience we have gained from monitoring a variety of installations has led to the development of a model which simulates the motion of a conveyance as it moves through a mineshaft, restrained by fixed guides.This paper presents a general analysis of the performance of the guidance system used in several installations, as well as a detailed description of the problem encountered at one mine and the steps taken to solve it.IntroductionOur company has investigated in some depth the problems that arise in the guidance of mine hoist conveyances.We have a telemetering accelerometer which we obtained to test mine hoist brakes. Frequently, during brake tests, the mine owners request us to use this instrument to measure the lateral motion of the conveyance ""to check guide alignment"". We have made such tests in shafts that have guide s of different kinds, including wooden guides, steel rail s and tubular steel guides. From these tests, we have gained some valuable information about guidance systems.In a well-aligned guidance system that is designed within common and well-known practice, the conveyance will experience very little shock most of the time. However, on rare occasions, shocks up to .5 g will occur. That is, the conveyance exerts a force of up to half its loaded weight on the guide. If the guide slips or is damaged by this force, it will be misaligned for future trips and become the cause of future shocks. In time, the whole guidance system can become misaligned."

Jan 1, 1982

By A. Makinen

There is an increasing trend between increasing consumption of water and the production of metal concentrate. Along with this trend we see that ore grades are declining and getting more complex to concentrate around the world. This will not only complicate processing but also generate new requirements for the management of water and waste streams on mining sites. The mining industry is a large user of water and its water consumption is growing rapidly. The processing of lower quality ores requires greater volumes of water. For these reasons, the need for efficient use of water and water management at mine sites is becoming more urgent. The perception of water in the mining industry has changed from thinking about it only in terms of "water treatment" to actually seeing it as a valuable resource, a resource that needs proper management. This resource management needs to involve various aspects, such as optimizing water usage of the entire mine or concentrator site, minimizing fresh water usage, minimizing or eliminating waste generated in water treatment and implementing practices for water reuse and water recycling. This paper presents trends and new developments relating to waste and water management in the mining industry.

Jan 1, 2015

By J. Scrimgeour

"The word ""instrumentation"" has expanded from its original meaning, which in engineering perhaps referred to measuring apparatus alone. In its broadest form, it now includes sensors, display instrumentation, standard pack-aged controllers and, most recently, the use of stored program computers for on-line process control. The paper traces the evolution, in tutorial form, of the successive application of mechanization, measurement instrumentation, automatic control, central operating systems, programmed control, process computer control, direct digital control and, finally, hierarchies of computers used for process control and corporate management as a fully integrated business system. In the field of industrial minerals, the cement industry has seen the most widespread acceptance of these techniques. Computer control has been accepted as the way of life for the blending of chemical materials and for on-line control of the cement kiln. Accordingly, the cement application is selected for further presentation in the paper. This illustrates the trend progressing from control of single loops on process variables toward the objective of total control of the product quality. The economic justification for instrumentation, centralized control, automatic control and computer control is .discussed with reference to savings in fuel, maintenance, operating labour, depreciation, power and product quality improvements."

Jan 1, 1967

By G. J. Hutchins

Precision surface mining is gaining traction in the iron ore, copper, iodine, limestone, bauxite, coal and gypsum markets. In this paper, we first address the possible improvements of a surface miner control using GPS techniques. An application in an iron ore mine in Western Australia is presented. The second item addressed is improvements of a new drum driving technique for a 100 ton surface miner. This technique involves installing a slow speed hydrostatic motor directly on the cutting drum rather than driving the drum through chain and sprockets. Details of the performance of this direct-drive versus the chain-drive are detailed. In addition to the 100 ton machine, we also present a 200 ton surface miner. This larger machine has 1600 hp (894.8 kg), and has been successfully introduced into a large iron ore mine in Western Australia. Performance of the 200 ton surface mining machine in various rock hardnesses is detailed. Some comments on the cost effectiveness of using a built-in loader versus loading with wheel loaders are included.

Aug 1, 2013