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By F. J. Hrach, K. P. Flynn, P. J. Miranda

"ST Equipment & Technology, LLC (STET) has developed a processing system based on tribo-electrostatic belt separation that provides the mineral processing industry a means to beneficiate fine materials with an entirely dry technology. In contrast to other electrostatic separation processes that are typically limited to particles greater than 75 µm in size, the triboelectric belt separator is ideally suited for separation of very fine (<1 µm) to moderately coarse (300 µm) particles with very high throughput. The high efficiency multi-stage separation through internal charging/recharging and recycle results in far superior separations that can be achieved with a conventional single-stage free-fall tribo-electrostatic separator. The triboelectric belt separator technology has been used to separate a wide range of materials including mixtures of glassy aluminosilicates/carbon, calcite/quartz, talc/magnesite, and barite/quartz. Separation results are presented for selected industrial mineral sources. An economic comparison of using the tribo-electrostatic belt separation versus conventional flotation for barite / quartz separation illustrates the advantages of dry processing for minerals.INTRODUCTIONThe lack of access to fresh water is becoming a major factor affecting the feasibility of mining projects around the world. According to Hubert Fleming, former global director for Hatch Water, “Of all the mining projects in the world that have either been stopped or slowed down over the past year, it has been, in almost 100% of the cases, a result of water, either directly or indirectly” (Blin et al., 2013). Dry mineral processing methods offer a solution to this looming problem."

Jan 1, 2016

By C. Paulo, W. N. Wheeler, M. Kalin, M. P. Sudbury

Many researchers have tested the addition of various phosphatic materials, including Natural Phosphate Rock (NPR), to mining wastes. It was assumed that iron in the waste would form FePO4 precipitates, restricting oxygen access to pyrite surfaces and reducing oxidation. Phosphate additions were based on stoichiometry (phosphate mass to sulphide content of waste). Although some interesting, positive results were obtained with low dosages, these were considered accidental, not having followed the expected stoichiometry. In 1991, we began experimenting on tailings and waste rock with NPR, postulating that if chemo-lithotrophic microbes on the mineral surface accelerate oxidation, then heterotrophic (oxygen-consuming) microbes would reduce oxidation. All wastes with NPR produced effluents with elevated pH and low metal acidity. Later, microscopic investigations of the rocks found an organic layer on the mineral surface, which was confirmed by independent research organizations repeating experiments with very low NPR mass additions to sulphidic wastes. In 2013, heterotrophs were identified and quantified as they grew on German lignite with NPR. These data conclusively showed that the development of heterotrophic biofilms is a consequence of adding waste NPR leading to a reduction of sulphide oxidation and improved effluent from sulphidic mining wastes. We document our gradual understanding of the effects of NPR on the reduction of sulphide oxidation, covering 23 years of research.

Jan 1, 2014

By Bryon Bisiaux, Walter Valery, Sonny Mwansa, George Amonoo, Adrian Dance

"Newmont Ghana Gold Limited’s Ahafo operation have been working with Metso Process Technology & Innovation (PTI) since early 2009 to increase mill throughput from a combination of controlled blasting practices and optimised primary crusher and grinding circuit conditions. For such Mineto-Mill projects, PTI’s methodology is termed Process Integration & Optimisation (PIO).Ahafo operate a SAG mill, ball mill and pebble crusher (SABC) circuit that processes a range of primary ore of varying hardness from different pits which is blended with soft oxide material. The PTI study focussed on ball mill limited material from the Apensu open pit.Following a benchmarking study of all blasting, crushing and grinding practices in January 2009, PTI recommended changes in both blasting and crushing conditions in order to generate a finer feed size to the SAG mill. Additional operating changes in the grinding circuit were recommended.A series of trials were conducted in November 2009 where three blasts were fired using a different blast design (hole diameter and explosive type) in the same area of the Apensu pit as the benchmarked material in January 2009. Top and bottom benches (or flitches) from each blast were sent exclusively to the grinding circuit and the material was tracked using PTI’s SmartTag™ system.The results from the six trials showed a significant increase in primary ore throughput at a reduced blend of oxide material. Ahafo have since standardised on these modified blasting conditions for all Apensu ore zones and have been able to sustain higher throughput compared to historical performance on similar material.This paper summarises the phases of the PIO project, the changes made in operating practices and the outcomes of the blasting trials that validated the predicted increase in mill throughput."

Jan 1, 2012

By J. G. Peacey, G. Csicsovszki

The target of this study was to clarify the role of lead on the dissolution of gold in the (NH4)2S2O3-Cu leaching system via chronopotentiometry, linear sweep voltammetry and chronoamperometry. It was found that the dissolution of gold was significantly increased with lead concentration up to 10 mg/1 Pb in the system of 0.1 M (NH4)2S2O3 and 50 mg/1 Cu. \/oltammograms suggested that the anodic dissolution of gold was virtually independent of lead concentration in the range of 1-10 mg/1 in 0.1 M (NH4)2S2O3 solution while in solutions containing copper as well, addition of lead increased the anodic dissolution of gold.

Jan 1, 2011

By H. Clare Horwood

"In the Red Lake area in northwestern Ontario the relationships between general structures and structures containing ore deposits are among the most unusual and most interesting of any in the Precambrian Shield. The more important orebodies, which are in the central-eastern part of the area, occur in a variety of rocks on the northeastern, eastern, or southeastern sides of a series of granite stocks. Other deposits in the western part of the camp also are structurally associated with granite masses .The relationships were determined in the course of general and detailed geological mapping by detailed analyses of the fracture patterns in the rocks adjacent to the orebodies. In every case it was found that the structures containing the ore were produced by compressive stresses from the direction of intrusion of the granite masses( 2).The Red Lake area lies in the Patricia part of the district of Kenora and is accessible by boat from Hudson or by airplane from Kenora, Sioux Lookout, or Winnipeg. A road from Vermilion lake, on highway No. 17, was opened in August, 1947.The first discoveries of mineralization in the area that proved to be of economic importance were made in 1925 by Lorne Howey and George McNeely for Haileybury interests and by Ray Howey and W. F. Morgan for Mcintyre-Porcupine Mines, Limited. Both prospecting ventures were organized because of information presented by Bruce(l) in his map and report for the Ontario Department of Mines. The discoveries, which were both along the same structure, a quartz porphyry dyke, later developed into the Howey and Hasaga gold mines. Other discoveries were made at intervals as a result of prospecting and development work on ground staked for its location."

Jan 1, 1954

By Alisa M. Caswell

Outline: 1. Syncrude: Who are We? 2. Energy Use at Syncrude 3. Historical Energy Focus at Syncrude 4. Case Studies for Process Variable Monitoring 5. Extraction Flood Water Temperature Management 6. Fired Heater Tuning 7. Critical Factors for Success Syncrude: Who are We? ?Syncrude is a Joint Venture Operating Company with one product: Synthetic Crude ?Production Capacity: 350 kbbls/day ?Primary Energy Sources: ??Fuel Gas + Natural Gas ?? Coke ?? Electricity ?? Diesel

May 1, 2008

By Garnet T. Page

"ABSTRACTThese societies •can help in such aspects of a vocation.al guidance program in secondary schools as: provide vocational and technical information, and assist with vocational exploration, such .as plant visits, films, etc. -as .an aid to the student in making a self-inventory. Evidence is increasing that employers' needs for engineers and scientists will not be adequately met in the future. Therefore, the E.I.C., C.I.M., .and C.I:C. recently revised and extended the activities of the Canadian Counselling Committee on Engineering and Science. This co-•operative .action is to be integrated with the educational system, nationally .and locally, and with provincial associations •of engineers and other groups interested in the provision of vocational information in engineering and science.DEFINITIONTHE scientific treatment of any subject requires consistent use of carefully defined terms. The National Vocational Guidance Association of the United States studied the problem of the definition of vocational guidance for .about 16 years, and in 1937 finally arrived at:""Vocational guidance is the pro-cess of assisting the individual to choose an occupation, prepare for it, enter upon and progress in it. It is concerned primarily with helping individuals make decisions and choices involved in planning a future and building a career -decisions and choices necessary in effecting satisfactory vocational adjustment.""RANGEAs a school enterprise, vocational guidance begins at that point in the individual's life when he finds it necessary to make choices that have a definite significance for his future vocation."

Jan 1, 1952

By L. E. C. Pignatari

Mine reconciliation is seen, for many, as a test of the quality of model estimates, while in fact it should be seen as a powerful tool for detecting and correcting problems in each step of mining operations, from resource estimation to metal production. Adequate reconciliation practices allow a more efficient control of the mining processes; however, its results can be illusory unless all parties involved have been in compliance with the principles of sampling correctness. This paper presents a new, segmented reconciliation matrix, which is based on the Theory of Sampling (TOS), developed to monitor gold operations and reserve estimation.

Jan 1, 2011

By George W. Bain

Mr. Geo. W. Bain: Dr. H. C. Cooke&apos;s discussion of &apos;The Geology and Mineral Deposits of the Harricanaw and Bell River Basins&apos; possesses many of the elements of a good political address; perhaps his long residence in Ottawa has some bearing upon his method of discussing geological work. The three essential parts of the address are all included. First, the plank - "Contributed discussion on the Geology and Mineral Deposits of the Harricanaw and Bell River Basins"; second, the personal attack upon the opponent, to show antipathy to the opponent as well as to his ideas; and third, controversion of a number of statements, which have been made to appear as planks of the opponents platform, even statements and work which are in no way connected with one under discussion. In the following pages, I will confine my attention to a defense of my work in the Harricanaw and Bell River basins, leaving discussion of the other areas mentioned by Dr. Cooke until results of the re-surveys are published. It is intimated that it was impossible to make a geological examination of an area of 1,600 sq. miles on a scale of four miles to the inch (base map supplied) in three and a half months, because "the area is accessible only from the railway along the northern edge together with a few roads close to it, and from rather wide separated streams?. There is one way, known to most geologists, whereby a place can be reached other than by railway coach or motor boat, and that the oldest of all -- walking. Most of the region was reached in this fashion. The boundaries of all the 18 townships included in the map are surveyed, nine are divided into lots, and the north-south and east-west centre lines of most of the others are surveyed and have mile-posts placed.

Jan 1, 1927

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 Greg Collins

BUCKO EXPLORATION HISTORY ??1964-Discovery ??1970?s -114 holes totaling 34,000 metres drilled -vertical shaft excavated to a depth of 300 metres (1000 Level) plus 800 metres of underground development -Exploration program cancelled due to Falconbridge economic issues ??1990?S-19 holes drilled totaling 9,600 metres ??2000 -13 hole 4,600 metre exploration program by Nuinsco Res.

May 1, 2006

By C. Harold Riches

This article is directed co a commentary on the patent system in its relation to the public interest. As man gained supremacy over his environment, he could devote progressively increasing portions o his time to improving his standards of living. In the history of the human race, we have advanced from the hollowed floating log to the modern steamship of the present age; from the sickle and flail to the reaper and combine; from the trumpet and drum as a means of communication co the telegraph, telephone, and radio; from the horse and ox cart to the automobile, truck, aeroplane, and train; and so on ad infinitum through the list of inventions on which are based the industrial and political economies and standards of living we enjoy today. It has also been a long road from the day of the alchemist and his closely guarded secrets to the era of the patent system and its storehouses of knowledge open to the world. The alchemist and the craft and merchant guilds closely guarded their secrets. In fact, they largely opposed innovations on the grounds that they might injure profits and restrict employment. In these days of unrest, with great clamour out of doors for radical changes in our political and industrial economies, it may not be untimely to examine one of the keystones which support the economic structure we know as the free enterprise system, the system which is predicated upon the right of the individual to own property. Many, through impractical idealism, ignorance, confused thinking, or blind political prejudice, advocate the substitution of ownership by the State ? for the right of ownership by the individual. As civilization has advanced to the high standards of living we enjoy today through the efforts of a comparatively few inventors, the patent system which has provided the incentive that created the inventions on which our industries and our employment are based is fully understood and appreciated by a comparatively small percentage of our people. As a result, the patent system, as a keystone in our free enterprise economy, is an apt target for destructive criticism, with the thought, possibly, that by eliminating or drastically restricting the several rights to individual ownership one by one, ownership by the State will progressively replace ownership by the individual.

Jan 1, 1949

By Q. Li, X. -L. Lei

Accompanying global energy shortage and high energy prices, shale gas has been the focus of exploration and it has attracted great attention from both academia and industry. The combination of horizontal drilling and hydraulic fracturing enables the extraction of huge quantities of shale gas from impermeable shale formations. During the process of hydraulic fracturing, great amounts of water, sand and chemicals must be injected into the shale formation at a high pressure, which may trigger seismicity. Such events could occur due to the presence of faults or the reactivation of these potential faults. Shale is the main component of source rock in the Sichuan Basin, China, and has the greatest contribution to the natural gas of the basin. In order to investigate the fracturing mechanism of shale in the Sichuan Basin, China, a series of rock fracture tests under triaxial compression were carried out in the laboratory in order to investigate the hydraulic fracturing behavior in relation to the seismicity. Based on the high multichannel waveform recording system, the detailed spatio-temporal distribution of acoustic emission due to micro-cracking was used to examine the deformation and fracture behavior of shale. In addition, the effects of confining pressure on the deformation and fracture in shale under triaxial compression by acoustic emission monitoring and X-ray computed tomography were discussed in the paper. The experimental results indicate that the shale samples demonstrate brittle fracture behavior. The confining pressure has a great effect on the complexity of the fracture planes and the spatial distribution of acoustic emissions, but few contributions to the location of the major hydraulic fracturing plane. The foliation of shale plays a dominant role in the rupture process and the geometry of the major hydraulic fracturing plane. The high confining pressure increases the strength and restrains the deformation of shale during compression process. These results shed some light on the understanding of onset of hydraulic fracture initiation not only for shale gas exploration and production, but also for CO2 geological storage and underground energy storage.

Jan 1, 2015

By Q. Li, X. -L. Lei

Accompanying global energy shortage and high energy prices, shale gas has been the focus of exploration and it has attracted great attention from both academia and industry. The combination of horizontal drilling and hydraulic fracturing enables the extraction of huge quantities of shale gas from impermeable shale formations. During the process of hydraulic fracturing, great amounts of water, sand and chemicals must be injected into the shale formation at a high pressure, which may trigger seismicity. Such events could occur due to the presence of faults or the reactivation of these potential faults. Shale is the main component of source rock in the Sichuan Basin, China, and has the greatest contribution to the natural gas of the basin. In order to investigate the fracturing mechanism of shale in the Sichuan Basin, China, a series of rock fracture tests under triaxial compression were carried out in the laboratory in order to investigate the hydraulic fracturing behavior in relation to the seismicity. Based on the high multichannel waveform recording system, the detailed spatio-temporal distribution of acoustic emission due to micro-cracking was used to examine the deformation and fracture behavior of shale. In addition, the effects of confining pressure on the deformation and fracture in shale under triaxial compression by acoustic emission monitoring and X-ray computed tomography were discussed in the paper. The experimental results indicate that the shale samples demonstrate brittle fracture behavior. The confining pressure has a great effect on the complexity of the fracture planes and the spatial distribution of acoustic emissions, but few contributions to the location of the major hydraulic fracturing plane. The foliation of shale plays a dominant role in the rupture process and the geometry of the major hydraulic fracturing plane. The high confining pressure increases the strength and restrains the deformation of shale during compression process. These results shed some light on the understanding of onset of hydraulic fracture initiation not only for shale gas exploration and production, but also for CO2 geological storage and underground energy storage.

Jan 1, 2015

By L. S. Brooks

TIMBER HANDLING presents a problem for any mine where appreciable amounts are used. This problem is accentuated where the shaft compartments are too small to allow a loaded timber truck to be lowered in the mine cage. When Normetal Mining Corporation, Limited, found it necessary to resort to square-set mining it faced this problem of getting large quantities of timber down a shaft that was also required for hoisting ore. A &apos;timber car&apos; that could be suspended under the cage was developed to overcome this difficulty. Production started at the Normetal mine in 1937, at the rate of 250 tons per day. In 1938 a winze, known as No. 3 shaft, was sunk from the 800-foot level ?to the 1,385-foot level. This was later raised to surface and then deepened to 3,275 feet in three stages and became the main production shaft. The portion of the mine below the 3,070-foot level is serviced by a winze, locally referred to as No. 4 shaft, which has been developed for stoping down to the 3,990-foot level and which has been deepened to the 5,365-foot level. No. 3 shaft has two hoisting compartments, each 4 ft. 6 in. by 5 ft. 0 in. inside the timbers, through which the ?ore must be hoisted and timber and supplies lowered.

Jan 1, 1956

By Yosuke Ota, Makoto Tawara, Tetsuya Kojima

"Dry-lube has been used in Europe to enhance formability of aluminum sheet for automotive applications, but it is difficult to ensure degreasing performance with lower degreasing bath temperature. However, newly developed, highly lubricating pre-coats utilizing a urethane resin, which is soluble in water, have been found to show excellent degreasing performance. Furthermore, a richer pre-coat weight coincides with a lower friction coefficient and better formability. Combined use of anti-rust liquid oil showed different friction coefficient depending on applied surface pressure.INTRODUCTION The global demand for aluminum alloy products, especially for automotive application, has been increasing because aluminum alloys can offer excellent corrosion resistance with good strength and low density compared with steel. Aluminum alloys can contribute to saving much more energy and greenhouse gas emissions over the lifetime of the product. On the other hand, the amount of aluminum alloys in vehicle architectures is still somewhat limited due to relatively low formability. As a consequence of this low formability, it is necessary to set a certain limit to the shape of an aluminum alloy panel for automotive applications. So far hot melt wax dry lubricants have been in use especially in Europe as they have been recognized to provide better lubrication than conventional rust protection oils (Meiler & Jaschke, 2005). The benefit of hot-melt wax for automotive manufacturing is associated with a more stable forming process and the possibility to avoid extra lubrication in the press shop. But because of the low poorer solubility of hot-melt wax in degreasing aqueous bath solution, a higher degreasing temperature is required so that no remnant of hot melt wax can be carried over to the next manufacturing process. This temperature control is difficult to impress upon a manufacturing degreasing bath originally designed for liquid oil, especially in Japan. The typical temperature of degreasing bath in Europe is around 60°C, while it is only around 40°C. in Japan. Various types of pre-coats other than hot-melt with high lubricity have been reported (Tawara, 1993; Ueda, Hatsuno & Totani, 2013), but a balance between sufficient degreasing performance and high lubricity has not yet been achieved for an actual production process line."

Jan 1, 2018

By Phillip J. Mackey, Susumu Okabe

Copper mining and smelting has been carried out in Japan for over 13 centuries and in fact stretching back into antiquity. In 1889, the first electrolytic copper refinery in Japan based on Elkington’s principles was started by Furukawa Mining at Honjyo in downtown Tokyo based on the multiple or parallel system. Within two decades, a number of other copper refineries had begun operation. Interestingly, but perhaps not surprising given Japan’s long history of copper production, this first refinery in Japan commenced just ten years after the first refinery in the USA (1879), and not long after the first plants in Europe. By 1935, as a result of growth in copper demand, there were six domestic copper electro-refineries in Japan with an installed capacity of 97,800 tonnes/a, while actual production was 71,200 tonnes/a. Since about 1932, the majority of these plants were based on the more common parallel or multiple system. In 1946, just after World War II, domestic production capacity had dropped considerably to 29,000 tonnes/a, however with reconstruction, capacity and production expanded rapidly, with production reaching 81,000 tonnes/a in 1955, 187,000 tonnes/a in 1960 and 307,000 tonnes/a in 1965. The introduction of the first refinery and the early ones that followed and subsequent developments are discussed in this paper. The major technical achievements during the high growth period from 1945 to 1963 included: the use of fire- refined anodes; the introduction of newly-developed rectifiers; the introduction of lead-lined or vinyl-lined concrete cells; improvements in the electrolyte heating system; application of improved anti-corrosion materials and the introduction of heat-insulating surface coverings. In 2018, Japan’s refined copper production totaled 1,595,000 tonnes of copper, with Japan ranking third in the world after China and Chile. INTRODUCTION In 2018, Japan’s refined copper production totalled 1,595,000 tonnes of copper and Japan ranked third in the world for refined copper after China and Chile (Wood Mackenzie, 2019). There are now eight copper refineries in Japan which provide Japan’s production of refined copper. These plants are listed in Table 1 (Wood Mackenzie, 2019), also showing the production trend since 2013; in general, production over this period has been relatively steady. The Toyo plant is now the 7th largest copper refinery in the world after several large plants as rated by capacity in China, Russia and India (ICSG, 2019).

Jan 1, 2019

By H. Stutchbury

Alberta is labouring, and has laboured, under serious difficulties in the marketing of ?her coals, due to a number of conditions which now obtain, but all of which appear capable of solution, and their elimination would insure a very largely increased market for the vast coal resources of that province. It is perhaps necessary to again mention the fact that 15 per cent of the world&apos;s coal resources are to be found in Alberta; 21 per cent of that of North America; 72 per cent of that of the British Empire, and 87 per cent of that of all Canada. While we talk largely of the great wealth of Canada, the immensity of her vast natural resources, it is axiomatic that the mere presence of any natural product in a country does not in itself constitute wealth for that country, unless these raw materials can find a market, either in their raw state, or by the process of manufacture. There are many factors, however, which enter into the marketing of any commodity. The chief of these, in my opinion, is price competition. High costs of production materially reduce the radius in which any product can be marketed, and this applies particularly to coal. Mining costs in the province of Alberta are necessarily high at the present time, due in a large measure to the ease with which the &apos;gopher hole&apos; mine can be opened with small capital.

Jan 1, 1925

By Esteban M. Domic

"T.L. Leaching ProcessCommercial PerformanceSociedad Minera Pudahuel Ltda. (SMP) has been innovating in the copper producing field with the commercial application of the Thin Layer (T .L.) leaching process in its two operating division s: Lo Aguirre and La Cascada. Since November 1980, SMP&apos; s Lo Aguirre Division has been producing high-purity copper cathodes at a nominal rate of about 16,500 metric tonnes / year, by mean s of the new route of T.L. leaching, followed by solvent extraction and electrowinning (TLlSX/EW). This has been the first commercial application on T .L. technology in the world, and the only commercial application in Chile for solvent extraction and electrowinning.By mid -1980, SMP acquired Sagasca Mining Co., renaming it as La Cascad a Division. The existing vat leaching facilities were modified to apply T.L. in the same old vats. The existing scrap iron cementation recovery circuit was kept running for the continuing production of copper precipitates. The modifications in the leaching circuit allowed shorter treatment cycles with a lower acid consumption and consequently, copper product ion increased from a previous historical high of 12,000-13,000 metric tonnes /year to a new level of about 22,000 metric tonnes/ year . These changes have been in operation since March 1981.T.L. Leaching commercial performance, both at Lo Aguirre (TL / SX /EW) and at La Cascada (TL/cementation), has been presented in several recent publications. Real operating parameters and process requirement s were reviewed in detail. A breakdown for TL / SX/ EW economics was also published based on Lo Aguirre&apos; s performance during 1982(41."

Jan 1, 1986

By Adrianus (Adrian) Halim, Tomas Bolsöy, Stina Klemo

"This paper describes the ventilation system used in underground hard rock mines in Sweden and Finland, which is very different than the system used in other major mining countries such as Australia, Canada, South Africa, and USA. The system utilizes auxiliary fans with Variable Speed Drive to distribute primary airflow to working levels instead of regulators that are commonly used in other countries. Descriptions about Ventilation on Demand in this system and ventilation regulations in Sweden and Finland are presented in this paper. This paper also quantifies a comparison between the Nordic and the system used in other countries. KEYWORDS Auxiliary fan, Regulation, Ventilation on demand (VOD), Variable speed drive (VSD) INTRODUCTION The primary objective of an underground mine ventilation system is to provide sufficient airflow to dilute atmospheric contaminants that are produced by mining activities. Typically, a mine ventilation system consists of one to four primary fans, regulators to control primary airflow distribution to levels or panels, and auxiliary fans that distribute airflow to dead-end workings via ducts. Depending on circuit geometry, underground booster fans are sometimes used. This system is widely employed in many countries such as Australia, Canada, USA, United Kingdom, and South Africa. However, mines in Nordic countries such as in Sweden and Finland employ a different system, in which auxiliary fans instead of regulators are used to control primary airflow distribution, as well as distributing airflow to dead-end workings. This paper describes the general layout of Nordic ventilation system, its VOD and heating system, its comparison with the system that is widely used in other countries which is referred as “Non-Nordic ventilation system” in this paper, and the current ventilation regulations in Sweden and Finland. The comparison was quantified by doing simulations using Ventsim Design 5 software. DESCRIPTION OF NORDIC VENTILATION SYSTEM General System Layout Figure 1 shows a schematic of typical ventilation system used in Swedish and Finnish mines. The schematic was drawn by Franzen, Myran, Larsson, and Rustan from Stiftelsen bergteknik forskning (Swedish Rock Engineering Research Foundation) and the English translation is written next to the Swedish terminologies. The system is generally a push-pull system. None of Swedish and Finnish mines use exhaust system. As shown in Figure 1, the primary airflow is distributed to levels by auxiliary fans that are bolted to a bulkhead located in the access to intake raise/shaft. These intake fans are attached to ventilation ducts that distribute airflow to all working faces. The exhaust auxiliary fans, which are not attached to any ducts and also are bolted to a bulkhead located in the access to exhaust raise/shaft, then flow the exhaust airflow into the exhaust shaft. A small quantity of this exhaust air is directed into the ramp, which acts as another main exhaust airway. The deepest level is also equipped with booster fan(s) that draw air from the intake shaft/raise and direct it into the ramp to provide fresh air in the ramp. There is no free split in this system. Figure 2 shows a schematic of a level ventilation layout in the Nordic system. Figure 3 shows a photo of these auxiliary fans."

Jan 1, 2019