Search Documents

By Albert J. Kritscher

The Similkameen Copper Project located near Princeton, British Columbia, is operated by the Similkameen Mining Company Limited, a wholly-owned subsidiary of Newmont Mining Company. The orebodies for this project are located on both sides of the Similkameen River for which the project is named. The project involves the processing of an average of 15,000 STPD of andesitic ore, mineralized largely with Chalcopyrite, at an overall plant availability rating of 90 percent. Project life is nominally 15 years. Design for the plant and its ancillary facilities was undertaken by Bechtel Corporation with procurement and construction management by Canadian Bechtel Limited. Construction began in June 1970 and first ore was introduced into process in March 1972. This paper concerns itself only with the project tailing system. The processing plant is located on a bench of glacial stream gravels which overlooks the river canyon. This site represented the only relatively flat area of sufficient size to accomodate processing facilities near to the ore- bodies. Reference is made to Figs. 1 and 2 showing the relationship of project features in plan and profile.

Jan 1, 1973

By Malte J. M. Gurgel, Axel Preusse

Recent three-dimensional surveying techniques have opened up new opportunities for the registration and monitoring of underground cavities. There are essentially two main methods available: Laser scanning, which is used both above surface and increasingly underground, and photogrammetry, which is also experiencing a renaissance with techniques like structure from motion through the algorithm-based orientation of high-resolution images. Both methods provide the capability to reconstruct reality by various 3-D products like points clouds and meshed models. However, they differ significantly in the steps of registration and calculation as well as in the resulting evaluation options.

By P. Petropoulakis

Computer technology in the mining activities of our company has been applied in the last decade. In this presentation the experience gained by applying this computer technology in mining spescific applications are reported. Attention is given to the problems phased out and to the methodology used for software selection, centralized and decentralized development, data processing personnel and end users training and support. The paper concludes with a report of the first results obtained and a look at the future developments of the system.

Jan 1, 1989

By Bijan Taheri, Behrouz Maghsodi, Monireh Heshami, Reza Kohan

A common problem recently encountered with the increase in the rate of input feed at Enrichment Plant 2 of the Sarcheshmeh Copper Complex is the loss of value to the tails, translating to lower recoveries. The feasibility of the direct transfer of part of the high-grade concentrate from rougher stages to an appropriate position along the circuit was studied, and two positions were proposed for direct transfer of the concentrate. One position was the feed flow into cleaner cells, and the other was the feed flow into the recleaner cell. The results indicated that transferring the concentrate from the first unit of the rougher stage to the feed flow into the cleaner cells was feasible, with no limitations, while the second position required the installation of a set of hydrocyclones. It was found that the transfer of concentrate to the proposed positions not only addressed the problem of limited cell capacity, resulting in debottlenecking of the circuit, but also improved metallurgical separation efficiency up to 1.4%.

By Cliff G. Paton, Sheldon B. Bland, Roger E. Melley

This paper looks at four critical lubricants used in the conveyor systems of the northern Albertan oil sand facility. The requirements for the lubricants used in the electric motors and gear boxes of the drive systems, the pulley bearing and the idler bearings are discussed in terms of the applications and the environment. A number of developments that have occurred in recent years are presented. Data from the field and from custom designed testing in the laboratory are used to support the role of simulation testing in problem solving in this area of technology.

Jan 1, 1996

By L. F. Delgado

Environmental and cost pressures sparked renewed interest in gravity separation. Industrial sands in Mexico are generally processed by screening, desliming, and flotation. Gravity separation with spirals was evaluated as an alternative to flotation in order to lower operating costs and decrease water pollution. Outstanding operating results are obtained in glass and foundry sand operations, plus a more competitive position for Mexican producers due to lower operating costs. Coal fines, generally recovered by flotation, have the same cost and environmental advantages when processed with spirals.

Jan 1, 1994

By Amy McBrayer, Andrea Brickey

Limited research has been conducted related to the development of mathematical optimization models for production scheduling at large surface coal mines using the area, i.e., strip, mining method. Increased economic and technical challenges have led to a new interest in production schedule optimization models for these type of mining operations like those currently applied to model underground and open pit mines. While area mines share similar characteristics to both open pit and underground metal operations, neither an open pit nor underground production scheduling model adequately depicts an area mine mathematically. We present an integer programming model with blending constraints and discuss the challenges and opportunities related to the implementation for area mines as well as future research in area mine production scheduling.

Jun 25, 2023

By Chee Theng

The Mineral & Metallurgical Processing Division (MPD) of the Society for Mining, Metallurgy & Exploration held the 13th MPD Student Poster Contest on March 1, 2023, during the MINEXCHANGE 2023 SME Annual Conference & Expo. The event showcased the work of 24 graduate and undergraduate students from U.S. and international institutions. The contest began in January when the students submitted one‐page abstracts for judging. In February, they prepared and presented posters that explained their research, and each student had five minutes to showcase their research to a panel of judges during the conference. In recognition of their efforts, the MPD provides monetary rewards to all participants. For graduate students, first place receives $1,000, second place $500, and third through seventh places $200 each, and for undergraduate students, first place receives $1,000 and second place $500. The main authors of nonplacing entries receive $125 each. Participation in the contest also includes a free ticket to the MPD Luncheon, where the winners are announced.

Nov 28, 2023

By L. Laage, R. Greur, W. Pomroy

MFIRE is a mine ventilation and fire interaction computer simulation program. It allows transient state ventilation simulation and features mass based flow rates, natural ventilation, air recirculation, fan curve fitting, airflow reversal and product of combustion tracking. MFIRE was designed to accommodate the needs of the mining industry, for routine ventilation calculations and mine emergency planning. This paper describes recent work by the US Bureau of Mines and Michigan Technological University to improve MFIRE by incorporating humidity in the mass flow and heat exchange calculations, a data file preparation program, and variable reference density in the network calculations. Recent bug fixes are also discussed.

Jan 1, 1995

By J. A. Folinsbee

Placer Dome Canada owns and operates the Campbell Mine at Balmertown, in the Northwestern corner of the Province of Ontario, Canada. The mine operates at 1500 stpd and produces in excess of 300,000 oz of gold annually. Recent changes to the gravity concentration circuit have resulted in a 10-15 % increase in gravity recovery. The circuit changes responsible for these improvements will be the focus of this paper.

Jan 1, 1997

By Nikhil Dhawan, Shrey Agrawal, Veeranjaneyulu Rayapudi

India’s steel vision of 2030 requires a huge amount of quality iron ore. The utilization of low-grade iron ores such as banded iron ores will play an important role to achieve the same production. The absence of alumina impurities in the banded hematite jasper (BHJ) ore provides it an edge over other low-grade iron ores. The conventional beneficiation techniques such as magnetic separation and washing were found to be ineffective to produce suitable feed (Fe ~ 60%) for the blast furnace. It was found that microwave exposure provides significant enrichment to the low-grade iron ore and can be used as a pretreatment step in the beneficiation of similar low-grade iron ores. The above study reveals that hematite phase is susceptible to microwave exposure which enhances the separation of iron values from impurities. Under optimum conditions, an iron-enriched concentrate with 61% Fe, 85% Fe recovery at 50% yield can be achieved from BHJ feed ~ 38% Fe. The pretreatment process for BHJ beneficiation includes only microwave exposure without any chemical additive and may prove economical and industrially feasible.

By Thomas E. Shufflebarger

Definition of glass sand prospects may be modified by constraints which range from demography to critically important product-control. Characteristics of usable raw materials, physical and chemical, are discussed; an ideal raw material is defined. Following field investigations and preliminary sampling, evaluation of selected prospects includes use of modern drilling techniques, viz.: core, percussion (air-hammer), auger, jet, rotary jet, split-spoon and other. Nearly complete core (sample) return is mandatory. Land-use regulations, availability of water and transportation continue to direct exploration in a major sense. But fitting a prospect to burdensome politics nay be considered a decidedly negative factor.

Jan 1, 1983

By James Watson Baxter

Fluxes are used to promote pyrometallurgical processes that rely on adhesion (soldering or brazing) or fusion (gas and arc welding) to join metallic surfaces. In the adhesive processes, the metal surfaces to be joined are not melted; the join is formed using a filler metal with lower melting point than the base metal. Fusion welding involves use of heat in excess of the melting point of the base metal. The fused joint may be achieved either by simply fusing together metal surfaces brought in contact with each other or by introducing additional molten metal of similar composition to form a fused joint. ADHESIVE PROCESSES--SOLDERING AND BRAZING In order for molten filler metal, solder or braze, to spread in a manner that creates a successful join; the work surfaces on the base metal must be thoroughly cleansed. Fluxes remove stubborn oxide films and other surface contaminants, promote wetting of the work surfaces, add fluidity to the solder or braze, and enhance workability and ease of spreading. Brazing processes involve higher temperatures than those reached in soldering. Brazing fluxes, which must remain active and effective at the higher temperatures, differ from those employed in soldering. Some common fluxes used in adhesive processes are rosin for soldering tin and electrical connections, hydrochloric acid for use in soldering galvanized iron and other zinc surfaces, and borax for brazing. Soldering and brazing are similar processes, the primary difference being the temperature at which the joining operation is carried out. Soldered joints, produced with low-melting-point fillers (solders) that melt and flow at temperature less that 450°C (Althouse et al., 1988) can sustain loads of 1 to 1.7 MPa for extended periods of time (Anon., 1966). Brazing involves the use of filler materials with melting points commonly above 500°C and generally provides stronger joints than those obtained with solder. Both processes require local application of heat to melt and spread the filler so that the molten filler can wet (adhere to) the base metals by alloying and diffusion. Soldering Soldering is a means of joining metals by adhesion using a metallic bonding alloy as the filler, commonly a mixture of lead and tin. However, the adhesion of solder depends more on its ability to be keyed into minute surface irregularities than on alloying. The most familiar application is to provide and secure electrical connections. Soft solders can range from 1 to 70% tin with the remainder mostly lead. However, for general-purpose, soft-solder work, the alloy is commonly 50% lead-50% tin. Higher lead contents provide a wider range in the melting temperature and, for this reason, a 60% lead-40% tin alloy, which yields a mushy mixture, is used for wiped joints in lead sheet and pipe work. Conversely, 40% lead-60% tin alloys are used in soldering tin and other low- melting-point materials for which a narrower range of melting temperature is required. There are numerous other solder compositions such as tin-silver, 95% tin-5% silver and antimony-tin, 95% tin and 5% antimony (Carlin, Jr., 1992). Heat needed to melt and spread the solders is commonly provided by electrically heated, copper-tipped soldering irons or by means of torches; the solder is applied by hand, usually face-fed by means of wire. For wiped joints in plumbing and lead-cable splicing, the solder is manipulated with cloth pads. The molten solder wets the joint surfaces and is drawn, by surface tension, into minute fissures and capillary openings. Other applications involve use of induction heaters and furnaces with pre-shaped solder appropriately placed prior to fluxing and heating. In some processes, the joints are immersed in molten solder. Constituents and Role of Soldering Fluxes: Soldering fluxes generally fall into one of three categories: highly corrosive fluxes, intermediate fluxes, and noncorrosive fluxes. These same categories are sometimes designated inorganic, organic and rosin-based respectively (Althouse et al., 1988). Common constituents of each group are discussed briefly below. Corrosive Fluxes (Inorganic). Work with aluminum, magnesium, stainless steel, high alloy steel, aluminum bronzes, and silicon bronzes is carried out at temperatures in the upper portion of the range for solder operations. Soldering these materials requires use of highly active, corrosive fluxes to remove and prevent the formation of the especially stubborn, hard, oxide films that form on these materials upon exposure to the atmosphere. The corrosive fluxes consist of inorganic acids and salts that are applied either as pastes or dry. They are active at elevated temperatures and, since they remain active after the soldering is completed, must be completely removed. The main constituent of most corrosive fluxes is zinc chloride with a melting temperature well above the solidus temperature of most commercial tin-lead solders. It is made by the action of hydrochloric acid on zinc. When zinc chloride is used alone, un- melted particles of this corrosive salt get caught up in the joint and weaken it. For this reason, other inorganic salts such as ammonium chloride (NH4Cl) or sodium chloride (NaCl) may be added to lower the melting temperature. A mixture of zinc chloride and ammonium chloride is very effective because the excellent oxide reducing properties of ammonium chloride and the protective action of the molten zinc chloride combine to produce a fluxing action superior to that achieved when either is used alone. In addition to zinc chloride, ammonium chloride, and sodium chloride; common con-

Jan 1, 1994

By T. Emery, D. Sweet, J. Bourgeois, M. Gomez, B. Seymour, J. Feiler

For traditional underhand cut-and-fill mining operations, it can be challenging to design a suitable cemented paste backfill (CPB) mix that can meet the necessary strength requirements and yet maintain its ductility. In deep underground metal mines, the CPB must achieve a high enough strength to be competent under high stress conditions while also remaining ductile enough to withstand high strain from squeezing ground as underhand mining continues under backfilled stopes. To eliminate ground falls that result in injuries and fatalities, researchers from the Spokane Mining Research Division (SMRD) of the National Institute for Occupational Safety and Health (NIOSH) have partnered with Aerix Industries, a producer of concrete additives, to study the effects of foaming agents on the strength and ductility of CPB. This laboratory study examines the impact of various amounts of foam additive on the strength and ductility of CPB mix designs, using binder and tailings provided by Hecla Limited from the Lucky Friday Mine

Mar 2, 2022

By Y. Luo, S. S. Peng

This paper presents some results obtained from research on long-term subsidence over and near chain pillar systems - the area available to long-term subsidence in longwall operations. Although the long-term subsidence for most longwall operations is insignificant, it does exist in some cases. In the cases that showed significant long-term subsidence, it was found that the development process could be expressed by an exponential decaying function. The stability factor of the chain pillar system and the potential for long-term subsidence are the two most important factors that control the magnitude and development characteristics of the long-term subsidence process.

Jan 1, 2000

By C. Mark, D. M. Pappas

From 1999 through 2008, groundfall events resulted in 75 fatalities, 5,941 injuries and 13,774 noninjury roof falls in U.S. underground coal mines, according to the U.S. Mine Safety and Health Administration (MSHA). A comprehensive analysis of these events was conducted to better understand where and why these incidents occurred. The first segment of the study used the MSHA database to evaluate groundfall injury rate trends related to mining method, year, locality, seam thickness, mine size, coalbeds and seasonal effects. In the past decade, roof fall injury rates have dropped 50%, but rib fall injury rates have remained constant. Room-and-pillar mines had a roof fall injury rate that was nearly 2.5 times the longwall rate. High groundfall rates occurred in the Illinois Basin, a finding that correlates with other studies that have shown that roof rock in the Illinois Basin is weaker than that in the central Appalachian coalfields. Finally, noninjury roof fall rates in the eastern and central United States were found to be 50% higher from July through September, possibly because of the changes in humidity levels that may cause shale mine roofs to deteriorate. The second segment of the study evaluated the root causes of failure by reviewing all MSHA groundfall fatality reports for 1999-2008. Pillar recovery was the leading cause of groundfall fatalities (19%), followed by rib falls, roof skin falls and traveling under unsupported roof (16% each). Defining prominent ground control incident trends and hazards will identify areas where additional study is needed and where innovative solutions need to be developed to reduce these severe occupational hazards.

Jan 1, 2011

By D. H. Steve Zou, Cui Lin

"This paper first discusses the basic attributes of sustainable mining and the responsibilities of various steak holders including mining companies, governments, and engineers. It is followed by a brief overview of the current practice on regulations, inspections, waste management and mine closure planning in Canadian mining industry. A case study is then presented as an example of sustainable mining where mine planning, mineral recovery, environment protection, reclamation and community development were integral parts of the overall strategy. A comparison of the mine site before and after mining is made to demonstrate the ""best practice"" in modern mining.Sustainability in Mineral Resource Development Extraction of mineral resources and other natural resources on the Earth has been and will continue to be an essential activity necessary to support human’s life. We live on the planet and depend on the available resources to survive. The extracted materials form the base to support modern life. However, we must be aware of the fact that mineral resources are limited on the Earth and may not last forever. Every time we extract one ton of materials, there is one ton less. They are not able to regenerate or regrow. One can ask a simple question: How long will they last? Or, is there anything left for our great grandchildren and many generations to come? The answer is not simple. Some minerals have become scarce or about to deplete. Some minerals may last longer. The reserve of a type of minerals depends on what we have discovered and the minable amount depends on accessibility and technology we have. Even if there are minerals in the deep ground, we may be limited by our technological capability. At the same time, we also need to understand the action of mineral extraction from the ground and the consequences of that action. Mineral extraction is a very hard work. We must break the ground to extract the ore, either through surface mining or underground mining. This action means disturbance of the land where we live. The disturbance is much more visible in surface mining than underground mining. The disturbed land, if not properly reclaimed after mining, is not going to be reusable. The very purpose of extracting minerals from the ground is to support our life but the action has a negative impact on our life. How can we reduce and limit disturbance of land from the action of minerals extraction? How can we make the disturbed land reusable? These issues must be properly addressed and a balance achieved."

Jan 1, 2017

By Gregory M. Rumbaugh, Todd Kostecki, Christopher Mark

From 2015 to 2021, five massive pillar collapses occurred at four underground stone mines in the eastern United States. These events resulted in powerful airblasts that damaged mine infrastructure and mobile equipment, seriously injured miners, and disrupted underground travelways. Each of these pillar collapses propagated through the overlying strata, causing a subsidence basin on the surface. Pillar collapses are particularly hazardous for miners because they can occur with little warning and can affect miners that are far from the pillar collapse area. The following case studies show that certain factors may increase the likelihood of a pillar collapse. For instance, each of the five events involved the collapse of at least twelve benched pillars with width-to-height ratios (w/h) of 0.8 or less. This study elaborates on

By K. Norris

The Amax Gold Guanaco mine is located in the Atacama Desert, approximately 260 km southeast of Antofagasta, Chile. The 6,000 tpd leach operation produces approximately 90,000 oz of gold, and 360,000 oz of silver per year. Production began in 1987, and the operation has been managed by Amax Gold since 1992. The mine has been plagued in the past by high operating costs and low production. Several significant changes have been made to the operations which have resulted in lower costs and higher operating efficiencies. A review of these changes is presented herein.

Jan 1, 1997

Well designed and maintained haul roads are the key to minimizing truck haulage on-road hazards and costs, as well as increasing productivity. However, practically designing and managing a haul road for optimal performance is often difficult to achieve. Poorly designed and built roads exhibit high rolling resistance - a 1% increase in road rolling resistance can typically reduce speed on ramp by as much as 10% - and on the flat by up to 26%. In the current economic climate, investment and operating decisions come under scrutiny. In the long run, this scrutiny returns improved efficiencies and leaner, healthier operations. The focus of this evolving evaluation process should and will certainly fall on haulage operations ? simply by virtue of their contribution to overall cost of operations ? often in excess of 50% of total costs for deep open-pit mines. Whilst the end result - improved efficiency and reduced cost per ton hauled ? is not in itself problematic, it is the route, or process followed to achieve these savings that needs to be carefully managed. We can be guided on this journey by our understanding of how a road design is developed, and, critically, the interplay between a good design and safe, cost efficient haulage. This paper briefly summarizes the evolution of mine haul road design, from the seminal USBM work of Kaufman and Ault in 1977, through to current geometric, structural, functional and maintenance management design components. These augmented design and management guidelines have been developed over the past decade, both in response to the requirements of mine operators for more safe and efficient haulage systems, and the truck manufacturers? requirements for a more predictable and controlled operating environment. These developments have been paralleled by the need to minimize haulage hazards, both from a health and safety perspective. Whilst improved mine haul road design does indeed reduce haulage accidents, recognition also needs to be given to human factors which are a significant contributor to haulage accidents. The human factor is the most problematic to address in a road design. It is often easier break the link between the interactive effects which may lead to accidents than trying to predict and reduce human error. These human factor interactive effects include the geometric, structural and functional design components and to prevent an accident or reduce the severity of its consequences, a road should be more accommodating to human error. The more that is known about human error, the better a road can be designed to accommodate those actions or non-standard practices that would, on a poorly designed road, invariably escalate an error into an accident.

Jan 1, 2010