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By Shinji Shirakawa

The gold wire bonding technology is widely used for electrically connecting aluminum pads on IC devices to external terminal of semiconductor. In 1960?s, the tensile strength of gold bonding wire was about 100 MPa only. However, recently the wire with 300 MPa in strength has been developed. Since the gold bonding wire was started to use for IC package in early 1960?, the many types of gold bonding wire has been developing continuously in order to meet market?s needs, such as high density, small size and thin type of IC packages. Moreover, electronic equipments were used in automobile applications and also demanded good reliability under severe temperature environment. Thus Au-Pd alloy wire has been introduced instead of the wire with 4N(99.99wt%) purity gold to provide excellent reliability in Au-Al bond interface. The phenomena at Au-Al interface in the high temperature storage have been already explained by several studies as follows. There are five phases of inter metallic compound (IMC) between gold and aluminum. Just after bond gold ball on aluminum pad, Au5Al2 phase was formed and occupied almost all of IMC area. During high temperature storage test, Au5Al2 phase transformed to Au4Al phase, then this phase was corroded by Bromide (Br) ion that was isolated from molding resin. Thus the reliability between Au and Al degraded. In case of Au-Pd alloy wire, the concentrated palladium phase (Au-Pd-Al) was formed at the interface between Au alloy ball and Al pad. The Au-Pd-Al phase prevented from transforming between Au and Al, therefore Au5Al2 phase was hard to transform to Au4Al phase. Consequently the reliability at the interface between Au alloy ball and Al pad was less degradation. However, in recent study using several advanced analysis technique, Au4Al phase was found at the interface between Au alloy ball and Al pad same as the case of conventional gold wire (4N purity gold bonding wire). It was suggested that the formation of concentrated palladium phase (Au-Pd-Al) related the excellent reliability at ball bonding process.

Oct 1, 2003

By J. A. R. Faucher

"Autogenous grinding may be an efficient and economical solution to your ore comminution problem.An important potential economic advantage of autogenous mills results from the availability of very large capacity units.Autogenous grinding could be more economical in terms of both capital and operating costs.Satisfactory pilot plant testing and thorough economic evaluation are required for a sound decision in comminution plant selection.INTRODUCTIONMankind's first weapon was probably the wooden club, but men soon learned to shape, smooth and polish stone for tools and weapons by pounding and rubbing them with sand and water. It was only about four thousand years ago that rocks were first broken to concentrate, smelt and return the metals they contained. In spite of our recent great technological advances we still break rock in essentially the same manner that was used thousands of years ago - by pounding, rubbing and squeezing - and we still waste much energy and metal in the process"

Jan 1, 1969

By Helen Morrison, Chris Staun, James Vaughan

"Mercury is introduced into the Bayer refining process as a trace element in bauxite. During the digestion stage, a portion of the mercury is extracted which partitions between the flash tank off-gas, vapour condensate and bauxite residue streams. A technology or treatment that stabilises mercury in the solid phase during digestion would prevent environmental management issues that may arise from the presence of mercury in condensate and non-condensable gases. This study examines the effect of process additives on the deportment of mercury under Bayer digestion conditions. Bauxite digestion experiments were conducted in batch autoclaves in the presence of additives. Process liquor was analysed for mercury content using a thermal desorption technique. Pyrite and copper hydroxide were evaluated for their suitability as additives.INTRODUCTIONMercury is an ancient metal characterised by electrochemical nobility, volatility, low solubility in water and a liquid state at room temperature (Holleman and Wiberg, 2001). The biogeochemical cycle of mercury is complex. Elemental mercury may enter the atmosphere due its volatility, where it can be transported long distances. After settling and adsorption to sediments, methylation is catalysed through microbial metabolism (Qureshi et al., 2009). Methylated mercury species are potent neurotoxins, and bioaccumulation of mercury is well documented, particularly in seafood (Kozin et al., 2013, Pan et al., 2014, Pollman, 2014). Environmental regulations for mercury emissions are becoming increasingly stringent (UNEP, 2015). Considerable research has already been performed and technologies developed for the remediation of mercury in wastewater and the trapping of mercury from industrial stack emissions. Wastewater technologies usually target ionised mercury using adsorbent, ion exchange and complexation mechanisms (Krishnan and Anirudhan, 2002, Li et al., 2015a, Chiarle et al., 2000), while stack emission technology is dominated by impregnated activated carbon adsorbents (Gao et al., 2013, Zheng et al., 2012). Related developments include piezoelectric amalgamating sensors for in line detection of gaseous elemental mercury in industrial stack emissions (Kabir et al., 2015, Sabri et al., 2011). There is a paucity of research regarding removal of mercury from the Bayer process."

Jan 1, 2016

By Jean-Pierre Birat, François Hanrot, Gérard Danloy

Global warming presents an enormous challenge to the steel industry, which is both carbon-intensive and energy efficient. Lean production can provide some short-term emission mitigation, at the level of the Kyoto requirements. In the middle term, more use of scrap will also help alleviate emissions. But to reach much larger reductions in GHG emissions, on a par with the likely targets that will be set after the Kyoto period, the steel industry will have to imagine new production paradigms, which constitutes its most formidable challenge for the years to come. Carbon capture and sequestration, processes leaner in carbon use, electricity and hydrogen from green sources will have to be added together in a patchwork of process routes, which will have to be developed at great risk in the next decade, hopefully through broad international cooperation.

Jan 1, 2004

By R. A. Ford

The paper outlines: methods used for the determination of wear metals in motor and transmission oils; contaminents in motor, transmission and crusher lubricating oils; and viscosity determinations. Case histories and costs are presented to illustrate the value of an oil analysis program. Introduction NORANDA MINES LIMITED (BELL COPPER DIVISION) is located on the shores of Babine Lake, approximately 450 miles north of Vancouver, British Columbia. Access to the mine is by road from Topley, B.C., about 40 miles away. When a preventive maintenance analysis program was first considered, it was obvious that if samples were to be sent out for analysis, results would not be available for at least a week, due to the distance from any commercial laboratory. The assay laboratory was asked to investigate the possibility of determining wear metals on site. A limited program was started soon after production commenced, and this has now grown to include all large mobile equipment as well as crushers and grinding mills. The laboratory also now determines viscosity, fuel dilution, dirt and abrasives, glycol and water. All these results are ready within two days. This paper will outline the methods used, data interpretation, several case histories and the benefits from such a program.

Jan 1, 1977

By Dong-min Lee

As the construction industry is becoming more large-scaled and complex, the BIM technology has been utilized throughout the industry. Since 2008, the construction industry in South Korea (Korea) has required carrying on BIM-based project continually. According to this trend, BIM S/W market, as well as BIM library market is also gradually activated. Many countries have already been establishing Web-based BIM library market, also Korea has been trying to establishing this Web-based BIM library market. In this study, through market research of Web-based BIM library market of advanced countries including the U.S.A. and U.K., establishment strategy of BIM library market to be derived by late starters that introduce BIM such as Korea, Japan and China was deduced based on current establishment status of BIM library market in Korea. In addition, deal with an issue that a clear revenue-sharing system between business principals of Web-based BIM library market is not available at the current stage was presented as a factor of inhibiting activation of BIM library market. So in order to offer a reasonable revenue-sharing strategy in BIM library market as conceptual level, a methodology and process of applying Game theory being used for deriving. It is expected that a reasonable revenue-sharing model between business principals would be presented as its standard of BIM library market to be more activated in the future.

Aug 1, 2013

By J. E. Hawley

This paper constitutes a report from the Committee on Geological Research to the Geology Division of the Institute. Two years have elapsed since a formal report was made containing several resolutions aimed at assisting geological research, a review of research equipment available, a summary of research projects suggested for consideration, and a list of research then in progress (see July, 1947, Bulletin, pp. 351-370). At this time we may note what action has been taken on the various resotions and suggestions of the Committee, indicate the more important accomplishments of independent investigators, and present a summary of the rather imposing volume and variety of research currently being carried on throughout the country. I.-Committee Resolutions and Suggestions 1.-A National Advisory Committee on Research in the Geological Sciences The original resolution adopted on the setting up of this Committee was approved with despatch by Council and was forwarded to the Minister of Mines and Resources. Due to a reorganization in the Department and possibly other reasons, no action on this important matter has yet been taken, but we are assured that some time this year such a Committee will be established by the Department of Mines and Resources. Unquestionably, it will give a fresh impetus to research in the geological sciences. When the noteworthy progress made by the research committees on Geophysics and on Soil and Snow Mechanics, established by the National Research Council, is considered, it is indeed regrettable that the Department of Mines and Resources has not acted more decisively in this matter.

Jan 1, 1949

By Alvis L. Lisenbee, Colin J. Paterson, Mustafa M. Hariri

"Abstract-The schist-, sediment-, and intrusion-hosted Tertiary Au-Ag hydrothermal deposits of the northern Black Hills, South Dakota are localized and controlled by various types of fractures. This study is an attempt to distinguish between and discuss the possible causes of these fractures in three mines: Richmond Hill, Annie Creek - Foley Ridge (ACFR), and Gilt Edge.Five models based on the structural and tectonic settings of the northern Black Hills are proposed for the fracture origin. In Richmond Hill mine, mineralized fractures within the schist-hosted deposits are in the form of veinlets and stockworks. Larger veins filling open spaces along schistosity planes are also present. Fractures in Richmond Hill mine are related to breccia pipe emplacement and influenced by the Precambrian foliation.Fractures in sediment-hosted (ACFR) and intrusion-hosted (Gilt Edge) deposits are mode I systematic joints. These fractures, and similar ones examined in seven locations outside the mines, are related mostly to the formation of the Lead-Deadwood dome. Fracture trends vary from one area to another depending on their location with respect to the dome. Other factors, such as the Black Hills uplift, pluton emplacement, and Precambrian foliation, may also affect the fracture trends. The proximity of the mines to domes formed by multiple intrusions, the associated fracture patterns and density, and existence of breccias, may be used in exploration for similar deposits in the northern Black Hills or other areas of similar geologic settings."

Jan 1, 1995

By Alvis L. Lisenbee, Colin J. Paterson, Mustafa M. Hariri

"The schist-, sediment-, and intrusion-hosted Tertiary Au-Ag hydrothermal deposits of the northern Black Hills, South Dakota are localized and controlled by various types of fractures. This study is an attempt to distinguish between and discuss the possible causes of these fractures in three mines: Richmond Hill, Annie Creek – Foley Ridge (ACFR), and Gilt Edge.Five models based on the structural and tectonic settings of the northern Black Hills are proposed for the fracture origin. In Richmond Hill mine, mineralized fractures within the schist-hosted deposits are in the form of veinlets and stockworks. Larger veins filling open spaces along schistosity planes are also present. Fractures in Richmond Hill mine are related to breccia pipe emplacement and influenced by the Precambrian foliation.Fractures in sediment-hosted (ACFR) and intrusion-hosted (Gilt Edge) deposits are mode I systematic joints. These fractures, and similar ones examined in seven locations outside the mines, are related mostly to the formation of the Lead-Deadwood dome. Fracture trends vary from one area to another depending on their location with respect to the dome. Other factors, such as the Black Hills uplift, pluton emplacement, and Precambrian foliation, may also affect the fracture trends. The proximity of the mines to domes formed by multiple intrusions, the associated fracture patterns and density, and existence of breccias, may be used in exploration for similar deposits in the northern BlackHills or other areas of similar geologic settings."

Jan 1, 1995

By G. Riveros

A new, continuous fire refining process for copper has been developed and tested at the 5 tph pilot scale. During oxidation, the blister copper flows through a packed bed of crushed refractory bricks counter-current to a hot oxygen containing gas. The resulting desulphurized copper flows then directly into a packed bed of charcoal for deoxidation. By controlling the air to natural gas ratio, both temperature and reducing conditions can be controlled. Based on extensive laboratory scale measurements of the rate of copper oxidation and reduction, the process concept was developed aided by process modeling and simulation. The industrial-pilot scale installation built at the ENAMI Paipote smelter in Chile, consists of two cylindrical, compact reactors, operating in line, with a designed capacity of 5 t/h of blister copper. The results of the industrial-pilot tests confirmed the feasibility of the new process. The blister copper processing capacity was increased to 10 t/h with satisfactory sulphur removal. The degree of oxidation as well the copper temperature was controlled with relative ease. The specially designed siphon block allowed for smooth tapping of the oxidized copper and separation of refining slag. The reduction of oxidized copper in the packed bed of charcoal appeared to be very effective while control of the degree of reduction according to the height of the bed ensured control of the oxygen content in the refined copper at the required level.

Jan 1, 2007

By Kenneth M. Haley

THE development of Reserve Mining Company's pelletizing practices began in 1949 in a pilot plant located at Ashland, Kentucky. Three years later the participating companies -Armco Steel Corporation, Cleveland Cliffs Iron Mining Company and Republic Steel Corporation concluded the work and the small plant was shut down. Oglebay Norton and Company was the operating manager and Armco Steel Corporation furnished labor and services. Arthur G. McKee and Company were the designers and constructors. The equipment flow sheet that was employed in that pilot operation is shown in Figure 1. This was Reserve's first step from the laboratory work per-formed by the Mines Experiment Station of the University of Minnesota in developing a commercial operation. The plant used New York state concentrate, purchased from Jones and Laughlin Steel Corporation's Benson Mine. This concentrate, minus 14 mesh, 64.3 per cent Fe, 5.7 per cent Si02, was processed at Ashland to 80 per cent minus 325 mesh in conventional ball mill, classifier, thickener, filtering

Jan 1, 1961

By Jorge M. C. Soares

The CO oxidation reaction has been studied on Au/TiO2 catalysts prepared by incipient wetness (IW) and deposition-precipitation (DP) methods. Additionally the assessment of activity was also conducted on simple gold compounds (Au2O3 and Au(OH)3) and their physical mixtures with TiO2. We have found that there are three types of CO2 production from fresh catalysts, which are only dried, namely: Non-catalytic Type I (low temperature CO2 production); Non-catalytic Type II (higher temperature CO2 production) and Catalytic Type III. The DP catalysts are far more active for Type III reaction, showing activity already at room temperature, whereas the IW catalysts generally do not show steady state conversion until T>673 K. This is due to both large particle size and the presence of residual chlorine for the latter. No truly catalytic activity was found for low temperature CO oxidation on gold precursors on their own, although both Au2O3 and Au(OH)3 react well with CO even at room temperature in an irreversible manner (Type I reaction). Despite that, catalytic activity was obtained by mixing Au(OH)3 or Au2O3 with TiO2 which gives further emphasis on the importance of a good contact gold/support and the absence of chlorine.

Oct 1, 2003

By David S. Robertson, Richard F. Douglas

"Uranium is a lithophile element of relatively low natural abundance. Concentrations of uranium form through processes of erosion and sedimentation, and over 90 per cent of the western world's uranium ore reserves are in sedimentary rocks.Proterozoic quartz-pebble conglomerates contain about 60 per cent of the known uranium reserves. These are all similar in appearance, in mode of distribution and in manner of origin. They carry uranium minerals and/or gold and abundant pyrite. Their unique distribution in Huronian time required a pre-existing crust well enough evolved to have plentiful quartz and abundant gold, uranium and pyrite. The materials of value were deposited as detrital heavy minerals prior to the appearance of an oxidizing atmosphere in late Proterozoic time.Epigenetic uranium deposits occur in arkosic sedimentary rocks through the entire geological column. About 30 per cent of the western world's known ore reserves are in _these rocks. This type of deposit is particularly prominent in semi-arid parts of the United States, having yielded most of the uranium ore produced and containing nearly all of the known reserves.The Western States type"" of deposits occur in lenticular, permeable stream-laid sedimentary rocks. The de-posits are believed to have been precipitated from moving ground water at locations where plant debris or other organic matter had accumulated. The uranium may be derived from volcanic sediments, which are commonly associated with the units containing the ore, or it may be leached from exposed granite surfaces or from granitic debris which forms the sediments.A significant part of the world's uranium resources are in black shales and lignitic rocks. The lignites that contain uranium are virtually valueless as potential sources of heat. Uranium concentrations at levels such as to be potential sources of by-product uranium occur in many phosphorites.Reworked sediments may provide uranium in pegmatites and vein-like deposits."

Jan 1, 1970

By G. D. Mcdowell, L. B. Cochrane, B. D. Thompson

"Abstract - Exploration for deep underground copper and nickel sulfide deposits in the Sudbury mining camp is carried out with surface drilling. More detailed drilling, with an advanced underground exploration program, may be necessary to establish an accurate interpretation of the deposit geology and upgrade the resource estimate to the measured category for reserve estimation and feasibility assessment. Resource evaluation is a lengthy and costly process that could result in a decision not to proceed with the project. For projects that proceed to production, significant reductions in the operating and capital costs could be achieved with a more accurate interpretative model of the deposit geology and mineralization. Quality control procedures to ensure the integrity of the drilling data and interpretation guidelines are essential steps in the development of a deposit model. The use of block modeling techniques and the application of geostatistics for resource estimation further improve the quality of the resource model.Significant improvements to the interpretive models can also be achieved by incorporating additional information from geophysical measurements to validate and constrain the geological interpretation. The geophysical models must be consistent with known geological environments and oreforming processes, which has required the concurrent development of comparative models from exploited deposits. These geophysical techniques can also provide key geotechnical information required for the optimum design of the mining method and mining sequence. The objective of this program is to improve the accuracy of the deposit model and the quality of the resource and reserve estimates in order to optimize capital investments and reduce the development and operating costs of underground mining projects. Several of these techniques are currently being tested at INCO Limited’s Sudbury operations. The results from those tests are presented and their applications are discussed within the framework of resource/reserve classification systems and project evaluation objectives."

Jan 1, 1998

By Y. Mercadier, M. Ait-Ali, M. Dostie

"This paper presents the results of an analytical study to assist in the design of blast furnace tuyeres, including a prediction of the heat transfer process.IntroductionA blast furnace tuyere must be made of a material which must con serve its geometric and structural integrity in the environment of the fire-ball of the furnace. It must be cooled by a fluid forced through its internal cavities in such way as to keep its maximum temperature below the allowable limit. The prediction of the convective heat transfer coefficient inside the tuyere is of great importance in the design of new tuyeres with increased service life. We have developed a computer program which can predict the convective heat transfer coefficient for two-phase flow. This paper shows how the program work s and how it can be used for the numerical simulation of tuyeres.To simulate the h eat transfer conditions in water-cooled tuyeres, one has to predict:a) The heat flux (radiation and convection) generated by the combustion gases. This was evaluated using the single-zone gas-furnace model. This model yields results which are of the right order of magnitude. A more fundamental study of radiation heat transfer based on combustion and gas concentration s will be reported in a future publication.b) The local convective heat transfer coefficient at all points with in the tuyere.Prediction of the Convective Heat Transfer CoefficientTo calculate the convective heat transfer coefficient for refrigerant stream, semi-empirical correlations developed by the nuclear industry were adopted. These correlations permit us to analyze the entire range of the convective boiling range, as shown in Table 1. Our first attempt, with a single-phase flow correlation, has shown the need to take nucleate boiling into account."

Jan 1, 1982

By D. W. Hayley

The rapid expansion of exploration drilling with anticipated production facilities for oil and gas in the Mackenzie Delta region of the Northwest Territories has created a demand for granular construction materials. This paper discusses the technique adopted and experience gained by the authors from several major resource evaluation programs in this remote area. The first part of the paper describes a methodology for deposit identification, logistics of helicopter and ground-based drilling operations and the sampling difficulties which are unique to permafrost: soils. The second part describes the exploitation of a large glaciofluvial deposit at YaYa Lake on Richards Island. Granular construction material is sparse in the delta region relative to projected demand. Exploitable sources of granular materials for aggregates or construction borrow are found in glaciofluvial deposits of Pleistocene age or in outcrops of Paleozoic bedrock. Glaciofluvial landforms can be located by reference to published surficial geology maps coupled with airphoto interpretation. Preliminary assessment of these features in a large region is most economically carried out during the summer months with a drill that is transportable by helicopter. Once prospective borrow pit sites are identified, a detailed ground-based winter drilling program must be undertaken to establish aggregate quality and quantity, and to provide information on natural features which could affect development. The glaciofluvial terrain has been highly modified by the formation of massive ground ice within the gravel deposits. This presents some unique pit development problems which are not encountered in a normal bedrock quarry operation.

Jan 1, 1977

The major factors limiting the establishing of vegetation on the shale and sandstone wastes at Minto are high exchange acidity and low pH (shale pH 4-5, sandstone pH < 4). In the first revegetation program (1967-74), 3.8 million trees were planted without grading on 4,000 acres (red, jack and scots pine and black locust). White dutch and sweet clover, birds-foot trefoil and red top were established in selected areas, and ponds were stocked with brook trout. In the second phase of reclamation, beginning in 1979, a comprehensive plan will be initiated which will allow for forest production, wildlife development and recreational activities.

Jan 1, 1977

Mining companies around the globe have long struggled with the need to ensure that earth moving equipment is designed to be operated and maintained under all site conditions without causing harm to people. Incident and accident data from a range of sources clearly identify mining equipment related issues as major causal factors. One Australian source, the NSW Department of Primary Industries? International Mining Fatality Database Project Report (2008) noted that ?Approximately 77% of mining accidents resulting in a fatality have? involved equipment?. The largest number of fatalities were associated with trucks; the next with LHDs. Many of the technical advances in equipment design over the past few decades have not been matched by advances in the human factors design of mining equipment, resulting in a ?design vacuum? that must be filled prior to commissioning new equipment. This ?design vacuum? is generally filled by local dealers. They retrofit equipment according to customer requirements to mitigate risks that have not been designed out by the Original Equipment Manufacturer (OEM). Mining companies have been frustrated by lost time and additional costs associated with this need to retrofit ex-factory designs. Some companies have attempted to address the problem by negotiating company or site-wide ?solutions? to equipment designs, but this has not simplified or clarified the issue from the point of view of the equipment manufacturers. A number of mining companies operating in Australia first discussed the concept of a joint customer approach to improve the Human Factors design of earth moving equipment at the factory level in 2004. They agreed that a new approach to engaging with OEMs was needed; one that would define the ?Problem?, in other words, the basis of the risks, rather than dictate the ?Solution?. The Earth Moving Equipment Safety Round Table (EMESRT) was formally established in 2006 by six global mining companies to establish a process of engagement between Original Equipment Manufacturers (OEMs) and mining customers.

May 1, 2009

By Ajit K. Sinha

"Electromagnetic surveys were conducted over the Yava sandstone-hosted lead deposit in Nova Scotia to evaluate the usefulness of such surveys for detecting and mapping sedimentaryhosted metallic ore deposits. Both transient and multifrequency systems were used for that purpose. The deposit consists of three zones of disseminated galena which also contain minor amounts of pyrite and sphalerite filling the interstices of the sandstone grains. Each zone overlies a basement depression and is separated from the adjacent zone by an intervening basement high. A conductive shale layer underlies the galena-rich sandstone formation at all three zones.Because the concentration of galena (3070 to 4% ) and other sulfides is too low to affect the resistivity of the sandstone formations for detection by ground electromagnetic (EM) methods, the strategy for our survey was to look for areas of basement depressions and the presence of conductive shale in those depressions by EM depth soundings. The presence of the galena-rich sandstone formations could be inferred because of the close association of these two features with the deposits in the Yava area. Both transient and multifrequency EM systems were successful in mapping the basement depressions and detecting conductive shale at the three known mineralized zones. The technique, therefore, seems to offer good prospects for mapping similar stratabound sedimentary-hosted sulfide deposits."

Jan 1, 1993

By B. S. Prosser, K. G. Wallace, A. Akansobe

"This paper describes a ventilation project at the Wassa gold mine in Ghana. Golden Star (Wassa) (GSWL), a subsidiary of Golden Star Resources, owns and operates the mine. Golden Star holds a 90% interest in GSWL, while the Ghanaian Government holds the remaining 10% ownership, earning a 5% royalty on the gross revenue of GSWL’s gold production. Construction of the underground mine began in mid-2015 and pre-commercial production started in June 2016. Commercial production from the underground mine was achieved in January 2017. This paper describes the ventilation studies performed to support the initial development and production at the mine. The initial ventilation design included four, parallel surface exhaust fans. Future designs will include booster fans, new primary fans, and additional connections to surface. The paper describes the long-term ventilation planning goals and expectations as the mine achieves a production of 4,000 tpd with truck haulage to surface.INTRODUCTIONThe Wassa Gold Mine is located in the southern portion of the Ashanti Greenstone Gold Belt in Ghana, northwest of Tarkwa as shown in Figure 1. The mine has been in production as an open pit since 1998, with some minor disruptions, but the surface minable reserves have become exhausted and the mine started a transition to an underground operation in 2015. The underground mine was initially developed with twin decline accesses extending from the base of the open pit to the mining areas. The mining method selected was sub-level open stoping with cemented rock backfill. The original production level for the mine was 2,500 tpd with ore and waste transported by trucks hauling in the ramps to surface. In 2017 the production goal was set to increase to approximately 4,000 tpd. This resulted in an increase in the truck haulage fleet in addition to a significant increase in ventilation requirements. This paper describes the ventilation upgrades at the mine as it transitioned from a surface to an underground operation and the adjustments the ventilation system needed to make in order to accommodate a significant increase in production"

Jan 1, 2019