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By T. Yeomans

NVI Mining’s Myra Falls operation is a forty-year-old underground mining operation feeding a 4,000 metric tonnes per day concentrator. The current mill, built in 1985, was designed to process a massive sulphide ore-body. This orebody, known as the HW, contains about 50% pyrite. Minerals of value are chalcopyrite and sphalerite, with precious metals occurring in all mineral types. By 1997, mining of a new ore-body, known as Battle-Gap, commenced. Mineralogically complex, the new orebody contains about 15% pyrite copper minerals, including primary chalcopyrite and secondary bornite, chalcocite and tennantite, combined with increased galena and sphalerite. Flotation performance generally decreased with increasing amounts of Battle-Gap ore types, with both copper concentrate quality (increased lead and zinc content) and copper recoveries being affected. Following significant metallurgical test-work, a new, fully sequential copper-lead-zinc flotation flow sheet and reagent scheme was developed. This sequential flow sheet was progressively installed and commissioned during 2006. Copper concentrate lead and zinc smelter penalty contents have been reduced by some 40%, while increasing copper recovery by 10%.

Jan 1, 2009

These proceedings consist of papers presented at three Bureau of Mines Technology Transfer Seminars on ergonomics in the mining industry. These seminars were held in December 1981, and covered topics relating to ergonomics and mining in the areas of the man-machine interface, and design of the work environment. This area of research is directed toward reducing accidents traditionally associated with human error.

Jan 1, 1981

By P N. Holtham

Magnetic separation is routinely used in the processing of titaniumminerals, and the efficiency of these operations can be determined bymeasuring the magnetic properties of the process streams. The valuable components in the feed to a titanium minerals plant have specific magnetic susceptibilities ranging from -10-9 m3 kg-1 (zircon) to 10-6 m3 kg-1 (ilmenite). However, in an industrial environment, in which the mineral temperature may range from 20 to 120¦C, it is difficult to measure susceptibilities lower than about 10-7 m3 kg-1. Hence laboratory testing of spot samples from magnetic separators is currently required to obtain accurate performance data. This is an inherently slow process and where feed grades are variable, optimum performance of magnetic separators is generally not achieved.This paper describes the development of an inductance-basedinstrument for measuring very low levels of magnetic susceptibilityon-line. The signal from the instrument can be used for process control purposes to maintain optimum magnetic separator performance.A prototype instrument has been installed in the zircon scavengercircuit in an Australian titanium minerals plant. The circuit consists of a roll magnetic separator treating a feed consisting mainly of monazite and stained zircon. The monazite-rich magnetic fraction is returned to the mine site for disposal, while the non-magnetic fraction is recycled to the zircon wet circuit. Splitter positions in the separator are adjusted when the final zircon product fails to meet specification, or the magnetic fraction contains more than 30 per cent zircon. Weekly composite grain counts show that sub-optimal operation of the magnetic separator results in significant zircon losses into the magnetics fraction.Using the instrument, the zircon content of this stream can now beaccurately determined from the measured magnetic susceptibility,provided a correction for the effect of mineral temperature is applied using the Curie - Weiss relationship.

Jan 1, 2001

Jan 1, 1995

By Dominique Vié

Standards methods covers the procedures for testing deep foundation to determine the force and velocity response to an impact of a pile driving hammer or similar device. The results of analysis generally include an assessment of pile integrity and the value of maximum dynamic stresses. But evaluation of static bearing capacity remains a matter of individual engineering judgment. A new 1D finite elements model has been developed for dynamic stresses and velocity analysis. Following an international benchmark of bearing capacity prediction organised by the Belgium Building Research Institute (BBRI), 12 piles in a site of fissured stiff tertiary clay tested in 1999, and 12 piles in a site of dense sand tested in 2001, comparison are proposed between analysis of dynamic tests and static tests results. A procedure is proposed to take in account the results of dynamic test for evaluation of bearing capacity.

Jan 1, 2002

By Russell R. McLellan

Under the Heavy Metals Program, investigations were conducted at the old Badger dill placer mini in Nevada County California to collect data and information regarding drilling and sampling methods and deposit characteristics. The studies contributed to a team effort by five Bureau of Mines research groups to develop new or improved placer mining technology in the Tertiary gold-bearing channel gravel of northern California. This report describes the techniques used and the results obtained in the sampling and drilling stage of deposit delineation studies that were conducted by the Denver Mine Systems Engineering Group. Sampling included the collection and processing of 400 tons of largo and small volume samples from drill holes, underground workings, surface pits, and blast hole rounds. A total of 355 samples averaging 2,296 pounds per sample provided reasonably accurate data for analysis of the gold distribution. These studies indicate that the bulk of the gold is within 40 foot of bedrock in stacked, lenticular zones of cemented gravel that are largely confined to the relatively narrow, meandering course of the deepest portion of the bedrock channel. Drilling studies involved the testing of three types of truck-mounted drills including rotary, bucket and vibratory, none of which proved to be a completely versatile tool for sampling quickly and reliably both consolidated and unconsolidated gravel.

Jan 1, 2012

By Marco D. Boscardin, Benjamin H. MacKinney, Kenneth R. Allard, Kenneth A. Pidgeon, Adriane G. Boscardin

This paper presents a case history for a unique application of a system of vertical micropiles with horizontal soil nail bracing and shotcrete facing for underpinning. The system was used to support and protect an existing 2-story hospital building during demolition and renovation. The goal was to limit building movements and have the building remain in use during construction of an abutting addition. Soils at the site consisted of clean, loose to dense, sand and gravel. The original underpinning design was revised after the initial excavation revealed unsuitable soil conditions for traditional underpinning pits. An alternative system consisting of vertical micropiles (hollow bars) through the footing, combined with shotcrete and soil nails was proposed, accepted by the owner, and successfully constructed. Excavation depths were up to 15 feet (4.6 m) below the existing footings. Wall movements were monitored at regular, horizontal and vertical intervals along the hospital wall, and less than 0.6 inches (15 mm) of settlement and 0.1 inches (3 mm) of horizontal displacement throughout underpinning and construction were reported. The challenges with the original proposed support of excavation design and other alternative approaches considered will also be discussed.

Oct 1, 2022

By Ronald Althouse

During the past five years under contract with the U. S. Bureau of Mines (BOM Contract J0308002). West Virginia University's Mining Extension Service (WVU-MES) has designed, developed) and delivered to the mining industry a comprehensive training program for Mine Rescue (MR) teams and a management planning tool for Mine Emergency Preparedness. The Mine Rescue team program is systematically built on a set of training objectives, backed up by content, allowing mine operators to conduct team training activities. These materials are user-ready, provide the MR principles and practices for both initial and advanced training, and supply teams with exercises geared to problem-solving activities. In addition to an instructor's program guide, the eight (8) modules that comprise the initial (20 hour) MR training are: an Introduction to Mine Rescue, an Introduction to Self-Contained Breathing Apparatus (SCBA), a set of modules covering each approved minimum 2-hour SCBA (i.e.) the Draeger BO 174-A. the McCaa) the Aerolox. & the Scott Rescue-Pak), and a manual on Auxiliary Apparatus as well as the Chemox Auxiliary SCBA. Advanced, annual refresher training (40 hour) is covered by seven (7) modules that spell-out the principles and practices needed to establish surface organization, to handle mine gases as well as mine ventilation, to conduct exploration, for fires, firefighting, and explosions, to rescue survivors and recover bodies, and to accomplish a mine recovery. Approved by MSHA in 1984 to meet requirements for 30 CFO. Part 49, these materials provide a basis for trainers' instruction, for comparison of team capabilities, for modifying programs resources, and services, and for program planning. The Mine Emergency Preparedness Program (MEPP) is used by management as a tool in the preparation of company personnel for handling a mine emergency operation. As a wholly new program. MEPP depends upon development of a Mine Emergency Organization and Emergency Operations Procedures. It also requires regular scheduling of drills) periodic mock emergencies, and evaluation of organizational responses and program performance beyond required training of mine rescue teams. MEPP materials are arranged into three sets of guides: 1) the Preparedness Program System Guides include an Executive Summary, a Program Director's Guide Mine Emergency Organization, and Emergency Operations Procedures; 2) the Emergency Organization (MEO) User's Guides cover the Rescue and Advisory Division, the Technical/Safeguarding Division, and the Surface Support Division; and 3) the Emergency Procedures (EOPS) User's Guides detail Containment Level Procedures, Notification Level Procedures. Mobilization Level Procedures, and Deployment Level Procedures.

Jan 1, 1986

By W. K. Collins, C. L. Dahlin, D. C. Dahlin, W. K. O’Connor, G. E. Rush

Direct mineral carbonation has been investigated as a process to convert gaseous CO2 into a geologically stable final form. The process utilizes a slurry of water, with bicarbonate and salt additions, mixed with a mineral reactant, such as olivine (Mg2SiO4) or serpentine [Mg3Si2O5(OH)4]. Carbon dioxide is dissolved into this slurry, resulting in dissolution of the mineral and precipitation of magnesium carbonate (MgCO3). Optimum results have been achieved using heat pretreated serpentine feed material and high partial pressure of CO2 (PCO2). Specific conditions include: 155°C; P002=185 atm; 15% solids. Under these conditions, 78% conversion of the silicate to the carbonate was achieved in 30 minutes. Process mineralogy has been utilized to investigate the appropriate feed characteristics, identify the process products, and interpret the mineral dissolution and carbonate precipitation reaction paths.

Jan 1, 2001

By Leonardo de Oliveira Turani

A energia eólica, fonte de energia renovável e de baixo impacto ambiental, vem crescendo rapidamente na última década, em especial no Brasil. A conversão da energia cinética dos ventos em energia elétrica é realizada por aerogeradores, que são acopladas em torres, que na sua maioria são constituídas de anéis sobrepostos de aço, os quais são fabricados e montados com o emprego de várias etapas de soldagem. Em função disso, o conhecimento da soldabilidade dos aços estruturais é um fator importante para indústria eólica, dando subsídios para a elaboração de procedimentos que permitam a redução dos custos de soldagem e a seleção adequada dos aços empregados. Este trabalho objetivou a avaliação da soldabilidade do aço estrutural EN 10025-4 S355M através de ensaios mecânicos e metalográficos de juntas soldadas pelo processo de arco submerso (SAW) em duas diferentes técnicas: Single Arc e Tandem Arc. Os resultados mostraram que o aço S355M apresentou excelente soldabilidade, com destaque para o processo SAW Tandem Arc, o que possibilita a maior exploração desta técnica como uma excelente alternativa para a redução do tempo de soldagem durante a fabricação de torres eólicas.

Aug 8, 2018

By A. Tylczak, C. Norman, C. Shook, S. Loif

"There are a lot of good reasons to manage energy use at mining operations. Optimizing process energy use reduces operating costs. Tracking energy use can help identify unplanned process changes or malfunctioning equipment early, which allows problems to be corrected promptly.Sacré-Davey Engineering in Vancouver has performed over 50 Energy Management studies for various industries including: mining, pulp and paper, oil and gas, etc. Energy Management programs can be used to identify energy reduction opportunities, assess project feasibility, complete equipment selection trade-offs, as well as to monitor and manage energy costs. Benefits of energy management programs are reduced energy costs, reduced maintenance, and increased plant automation. Additionally, energy management can provide access to utility incentive funding and quantify savings which can greatly improve the return on investment of potential projects.Energy management studies are funded by many Utility programs across Canada. There are various programs available for existing plants energy audits, project feasibility studies, new plant design reviews and energy monitoring and targeting, etc. There are capital incentives available which can significantly reduce payback period.This paper discusses how energy management can be used to support mill/mine operations groups, maintenance programs, as well as expansion or green field projects. This paper will also provide an overview of Canadian Utility companies programs and how they can assist mining companies.IntroductionThere are a lot of good reasons to manage energy use at mining operations. Optimizing process energy use reduces operating costs. Tracking energy use can help identify unplanned process changes and identify malfunctioning equipment early, which allows problems to be corrected promptly."

Jan 1, 2015

Using Positron Emission Particle Tracking (PEPT) to Investigate Industrial Systems

Sep 13, 2010

By W. A. Wright

The use and abuse of social media restate common employee relations issues. Business solutions to these issues require advanced preparation. Employers should establish and enforce social media policies to guide their reactions to employees? social media posts that reflect on the employer and its business.

Jan 1, 2011

By Engineering Staff

"This paper briefly describes the surface mining operations at Smoky River Coal Limited (formerly McIntyre Mines Limited, Coal Division) near Grande Cache, Alberta. Geology, mining methods, equipment, manpower and reclamation and environment topics are discussed. Introduction Smoky River Coal Limited, a wholly-owned subsidiary of McIntyre Mines Limited of Calgary, Alberta, produces a high quality, low sulphur, low volatile bituminous coking coal from its minesite located at west central Alberta, approximately 20 km from the town of Grande Cache and 360 km west of Edmonton (Fig. I). Most of the coal property is contained within a 30 km long by 20 km wide block lying in a northwest-southeast direction in mountainous terrain. Elevations vary from 920 m above sea level ·at the plant·site on the Smoky River to 1,600 mat the upper levels of current and proposed mining operations. A total of 11 coal seams have been identified. Only two seams, No. 4 Seam and No. 10 Seam are currently considered of major commercial value. These seams are recovered by both surface and underground mining. Approximately 650Jo of the plant feed coal is obtained from a conventional shovel/truck surface mine; the balance is mined underground by room-andpillar methods. Background In 1921, McIntyre Mines Limited acquired some 26,300 hectares of coal leases at Smoky River. Since then the leases were explored intermittently by different companies including McIntyre. In the mid-l 960s exploration activities increased and several feasibility studies were completed. Development of the area was undertaken by McIntyre in 1968 and, in August of the same year, a long-term contract was signed with a consortium of Japanese steel mills for delivery of 2 x 106 t of clean coking coal for 15 years commencing in 1970. Production was focussed on underground mining, using longwall methods."

Jan 1, 1985

By Alastair M. Lumsden

A study was initiated to examine the ways in which a number of foreign countries classify and regulate metal/non-metal mines which experience problems due to naturally-occurring flammable gases. Twenty countries were selected for study, and useful information was obtained from sixteen of these. Nine countries were visited (five of them twice) to hold meetings with representatives of government mine regulatory agencies and mine operators, and to visit mines encountering methane and other gases (carbon dioxide, nitrogen). In the later stages of the study seven gassy metal/non-metal mines in the United States were visited so as to provide a basis for comparison, and hence the evaluation of both the U.S. and foreign gassy mine regulations. In addition to obtaining copies of the mining laws and regulations of a number of foreign countries, nine foreign gassy mines, and the seven in the United States were documented in as much detail as possible. All this information is presented, along with appropriate conclusions and appendices. The study took two years and three months to complete.

Jan 1, 1983

By M. H. Morcali

Pistachio nut shells, an agricultural waste biomass, and Lewatit TP 214, a commercial sorbent, were investigated as adsorbents for the adsorption of platinum from dilute hexachloroplatinic acid solutions. Before the pistachio nut shells were carbonized, adsorption percentage was 65%, whereas Lewatit TP 214 ensured almost 100% adsorption. However, after the pistachio nut shell was carbonized at 1,000° C under an argon atmosphere, the platinum adsorption (%) increased two-fold. The effects of such parameters as sorbent dosage, contact time, temperature and solution pH on adsorption were studied in detail in batch mode. The adsorption equilibrium data were best fitted with the Langmuir isotherm model. The maximum adsorption capacities, Qmax, at 25° C were found to be 38.31 and 33.22 mg/g for the carbonized pistachio nut shell and Lewatit TP 214, respectively. The adsorption of platinum on both sorbents was found to be described by the pseudo-second-order kinetic model. The results indicated that the activated carbon prepared from pistachio nut shells can be effectively used for the removal of platinum from acidic solutions.

By Michael Kukay, Paul Conrad, Cosmas Opoku-Ware

This project is exploring the potential for developing trees tolerable to degraded un-reclaimed mine site soils and tailings as a solution to re-establishing long-term tree growth on those sites. The project incorporates growing tree seedlings in an underground greenhouse grown from seeds planted in the degraded mine soils in which they will eventually be planted. The outcome of the project is expected to lead to a successful solution for re-establishing tree growth in soils and tailings containing high metal concentrations with minimal post-planting human intervention. The research is being conducted in an underground greenhouse located 100 ft below the surface in the old Orphan Boy Mine Underground Mine Education Center (UMEC) located on Montana Tech’s campus in Butte, Montana.

By G. Thom, A. Kay, J. B. Hyde

"This paper will initially outline the specific types of copper castings used in blast furnace iron production. Tuyeres, tuyere coolers and stack cooling plates will be discussed in some depth, with particular reference to their dimensional configuration and purpose.Following this, the failure of such cooling members will be discussed, with special focus on tuyeres. Tuyeres are the most common casting which often requires replacement. Reasons for failure and its effect on operations will also be included.The latter sections of the paper will deal with the strict specifications demanded by ironmakers regarding copper castings. The justification for such rigid demands will be explained through the material presented earlier in the paper.IntroductionThe modern 5000-tpd blast furnace, worth millions, is a large capital investment to be sitting idle. Consequently, ironmakers strive to minimize the loss in iron production and revenue from furnace downtime. Two major causes of downtime are furnace relines and shutdowns to replace damaged tuyeresor tuyere coolers. Copper ancillaries are important items in the production of iron. They are consumable items, therefore they contribute to the campaign life or to the downtime in blast furnace production.Several combinations of lining and cooling systems have been used with varying degrees of success. Blast furnace refractories have evolved from ceramic to carbonaceous linings. The Russians and Japanese have successfully introduced stave-cooled furnaces that may have several forms, such as evaporative cooling. Stelco has two furnaces which use the Russian-designed cast iron system. However, this paper will be confined to the use of copper cast cooling members in a conventional internally cooled furnace.Figure 1 is a schematic cross section of the E blast furnace. The three major sections of a blast furnace-the stack, bosh and hearth-are identified. Further, the locations of the various copper members are indicated. This furnace produces an average of 5300 tons of hot metal per day."

Jan 1, 1982

By J. Châteauneuf, R. Dupéré, D. Mrabet

"In gold processing plants, it is common to start gold cyanidation in the grinding circuit by simple cyanide addition or as a result of recycling residual cyanide. In such cases, advantages such as a decrease in gold lockup and reduced leach time have been noticed. The prevailing conditions in grinding circuits such as intense mixing, particle breakage and friction or high temperature are quite different from those found in tanks and so is the resulting cyanidation behaviour. To gain a better understanding of the cyanidation behaviour in mills and of the pertinence of cyanide addition in grinding circuits, lab tests were conducted using an industrial ore from Canadian Malartic mine. In this study, the effects of different parameters on cyanidation in grinding circuits were examined; parameters such as such as temperature, dissolved oxygen, cyanide concentration and pH. The results showed that the kinetic benefits of high temperature in the mill can overcome the low dissolved oxygen concentration thus leading to an overall gold dissolution kinetics improvement for temperatures up to 50°C. However, gold leach in the studied grinding circuit at lab scale caused an increase in cyanide consumption with a higher generation of iron cyanide and SCN-. These results were confirmed by tests in the Canadian Malartic plant where the cyanide addition was moved from the SAG mill to the leaching tanks resulting in a 20% savings in cyanide consumption.IntroductionCyanidation in grinding circuits can benefit gold processing by decreasing gold lockup and by reducing leach time. However, other aspects regarding gold and cyanicide dissolution come into play in the conditions prevailing in grinding circuits. Indeed, high turbulence, high temperature, recycling load, friction and particle breakage make cyanidation behaviour in grinding circuits different from in-tank cyanidation (Marsden and House, 2006). In several cases, cyanide in grinding is limited to a very low level or completely avoided such as in circuits with gravimetric separation, for ores requiring oxidative pretreatment or for preg-robbing ores. In other cases, water management imposes a certain recycling of residual cyanide. This problem is generally addressed by a case-by-case approach. However, the chemistry of cyanidation in mill circuits is worth investigating in order to assess the advantages and disadvantages."

Jan 1, 2016

By Hai Lin, Renshu Yang, Yongliang Li, Shizheng Fang

With the aim of solving the large deformation problem of surrounding rock in coal mine roadways with a thin sand-mudstone interbed roof, transportation roadway 1603 in Haoyuan Mine was considered. The failure mechanism of surrounding rock was studied through comprehensive on-site investigations, borehole image analysis, mineral composition analysis, and other means. Numerical simulations were performed to determine the influence of roof layer thickness, lateral pressure coefficient, and coal rib strength on the stability of the interbedded roof. The main reasons for support failure and deformation of the roadway are softening and swelling of the sand-mudstone interbed roof upon exposure to water, insufficient support capacity of the roof due to the soft coal rib, an unreasonable support scheme, or poor construction quality, which can reduce the bearing capacity of surrounding rock. Based on our analysis, a control strategy was devised for a thin coal-mudstone interbed roof. The support scheme combines long and short cable support, strengthening of the coal rib to consolidate the roof, and partially shotcrete grout, and was found to improve the overall mechanical strength of surrounding rock and maintain the stability of the thin sand-mudstone interbed roof. The results of the numerical simulations and monitoring data indicated that the proposed support scheme effectively controls the deformation of the surrounding rock of thin sand-mudstone interbed roof of coal mine roadways while maintaining the safety and stability of the surrounding rock and supporting structure.

Dec 12, 2022