Search Documents

By A. P. Page, G. E. Alexander, L. L. Sirois, A. A. Winer

A knowledge of the electrical surface characteristics of minerals is all-important in the choice of treatments to up-grade and beneficiate them. At their solid-liquid contacts, there are transfers of ionic species, which for insoluble oxide minerals are the H+ and OH-ions. The adsorption density of these ions can be detected by carrying out potentiometric titrations, and this paper describes the automation of such an apparatus. The details are discussed fully and the validity of the method is demonstrated by flotation tests.

Jan 1, 1969

By Tom Shumka

"All mineral processing facilities that use girth gear driven mills need to inspect the gear teeth on a routine basis, whether it be every six months to every three years. The inspection frequency depends on gear tooth condition, and the objective is to ensure the operational integrity of the gear teeth. Conventional methods such as magnetic particle testing, visual inspection or dye penetrant examinations rely heavily on operator interpretation. At best, these techniques can determine whether a defect exists, but are unable to provide information on defect severity. This paper describes the use of combining combined eddy current array (eca) and alternating current field measurement (acfm) to provide a complete survey of all surface breaking indications on the whole gear tooth depth. This method accurately determines the size, length and depth of any cracks found on the surface.INTRODUCTION In order to gain a fundamental understanding of the evolving operational and production behavior of a piece of machinery over a specified time period as part of an effective condition monitoring program, a robust data collection process must be firmly established and adhered to. To be effectively implemented within an organization, a condition monitoring program must have support of not only the maintenance, production and engineering staffs, but also executive management support to ensure successful roll out to realize the maximum productivity of the machinery and subsequent cost-savings. One of the key elements of a mineral processing facility that use gear driven SAG Mills as a primary stage for grinding solution, is the integrity of the critical gear unit that drive the mill. For the maintenance team, condition monitoring on the gear unit is crucial for preventative maintenance. A catastrophic failure in the critical gear unit would require a minimum of ten days to replace the gear set, depending on the damage occurred. This, of course, would only be applicable if the client had a spare critical gear set in inventory. If a gear set had to be ordered, it could take from four months to two years to receive a new gear set. For example, in 2007, there was a global backlog of these types of gears sets resulting in a two year delivery. The maintenance costs associated with a catastrophic failure of this type would easily cost in the millions."

Jan 1, 2012

By I. Jackman

"Gold is present in different forms and associations in different ores. Flotation is used to recover gold and minerals associated with gold, but the applicability and type of flotation vary. The purpose of flotation in a gold recovery plant is largely dependent on the mineralogical association of the gold, and environmental and economic considerations. In this paper, the role of flotation in the recovery of gold is reviewed. The paper will describe examples of gold recovery by flotation including flotation of native gold, gold associated with sulphides including specifically copper sulphides, gold associated with tellurides, gold ores containing carbonaceous material and gold contained in tailings.INTRODUCTIONFlotation is widely used in the recovery of gold. However, the objectives and the mode of application are quite variable dependent on the type of ore, the gold association(s), other metal values, marketing considerations and environmental requirements. In this paper, a range of different applications of flotation incorporated in the recovery of gold are discussed. The reasons for each particular application are outlined and metallurgical results are presented.The mineralogy of the ore and the gold associations are fundamental influences on gold recovery. The use of flotation to concentrate gold is dictated by the mineralogy of the ore and gold. The fundamental factors are mineral/gold size, liberation size, association of the gold and type of gangue minerals or other valuable minerals. Gold can exhibit a range of sizes in a host from relatively large size (+50 µ) to refractory size (1 µ and sub-micron size). Similarly, the gold can occur in a number of phases in the same host. For example, the gold was present as petzite (AgAu telluride), calaverite (AuTe2) and native gold in a gold telluride ore and each of these minerals was associated with the pyrite host.Understanding the gold mineralogy and association is important in establishing the correct process route. The gold mineralogy is established by good mineralogy, use of diagnostic tools such as diagnostic leaching and assay by size fraction analyses and basic metallurgical testwork."

Jan 1, 1995

By Nilce Alves Santos, Vânia Lúcia de Lima Andrade, Keila Lane Carvalho Gonçalves, Harold Wyslouzi1

"When confronted with the difficult decisions on advancing an exploration project to the feasibility and construction stages, it is important to know how various regions of the ore body will react in the milling and concentration processes. While bench scale test work is common and inexpensive, the results and information provided are somewhat limited due to the difficulty in accurately predicting the effects of recirculating middling streams or gradual changes in solution chemistry.Conventional Pilot Plants, processing 100 to 1,000 kg/hour of sample ore, provide the detailed engineering data required to develop a final process flowsheet and to size the equipment. They are, however, expensive to set-up and operate, and are really only viable for major projects that are well advancedIn the latter part of 1999, the Mineral Development Center at CVRD (MDC) purchased a new piece of mineral processing equipment which can run continuous flotation tests using drill core samples. To evaluate its performance, and to compare it with conventional testing methods, various types of flotation tests were carried out using two different types of copper ore. The limitations and advantages of open circuit and locked cycle bench tests, as well as the Mini Pilot Plant and the Conventional Pilot Plant were evaluated.Open circuit tests carried out at the bench scale only provide basic information. More complete and trustworthy information is obtained, in terms of the recirculation of flows and reaching a permanent and stable flotation regime, as the dynamics and complexity of the tests increases. The data obtained showed that the MPP’s metallurgical performance was equivalent to that of a conventional pilot plant."

Jan 1, 2002

By A. A. Beland, R. J. Dawson, S. Shewchuk

"Shovel buckets, scraper blades, dipper teeth, mine car wheels and hammermills are examples of equipment which require routine maintenance due to abrasion. Service life can be extended by the use 0/hard/acing and buildup materials. Mining and milling applications are described and field welding procedures discussed.A high-stress abrasion test used to select hard/acing and buildup materials/or hammers in a hammermill is described in detail. Field tests of the selected alloys confirmed their performance, and maintenance records showed a significant saving in down time and cost.The relationship between the abrasion resistance of the alloys and their hardness, work hardening, composition and microstructure is summarized. IntroductionLarge volumes of ore are handled daily by the mining industry. The abrasive nature of most ores results in extensive wear to both handling and processing equipment. If such wear is neglected it may cause lost production time and also, in extreme cases, require the complete replacement of expensive equipment. The well-planned maintenance of components subject to abrasive wear by means of buildup materials and hard facing can result in substantial economic benefits. Such benefits can , however, only be realized through the correct choice of welding process, consumables and deposition methods available to maintenance personnel. Hardfacing MethodsHardfacing is applied by a variety of methods; the three most widely used being arc welding, oxyfuel gas and thermal spraying. Table 1 summarizes the major processes used within each method. Filler metals in the form of rod, wire or powder are necessary to fulfill the individual requirements of each process. The filler rods are available in the cast form or, in the case of ductile metals or alloys, as wrought rod or tube. All types are supplied bare or flux covered. Wire is supplied in two forms, drawn flux cored and drawn solid. Powder filler metals are available in many metals or alloys; they may be simple mechanical mixtures or prefused and atomized alloys made to a specific size range and shape for optimum results for each applicable process."

Jan 1, 1980

By C. Carlson, W. Muir

"The oxygen demand of the complex lead-zinc-iron feed at the Cyuro Anvil concentrator was determined denendent on the cyanide ion con-contration of the pulp. By redistribution of the cyanide [ ] the grinding circuit in direct proportion to the amount of surface area created, a more activated flotation feed in obtained.Monitoring the oxygen demand of the flotation feed and grinding mill discharge has proved useful in diagnosing metallurgical problems day to day operation."

Jan 1, 1976

By Graham Davey

"Ultrafine grinding of minerals has been in wide spread use in the industrial mineral field for over 30 years. Within the last 10 years the metalliferous industry has shown interest in the ability to produce ultrafine particles, as chemical, physio-chemical and physical separation processes have advanced to be able to treat ultrafine metalliferous particles. Also as the primary mineral deposits are depleted, new more difficult deposits must be mined. Existing operations are also looking to maximize economic return from existing deposits, requiring new thinking and technologies.The recent development of industrially proven and cost efficient technologies for ultrafine grinding has opened up another processing option for the treatment of finegrained metalliferous and refractory gold ores. The current commercial designs are variations of stirred mills used in the industrial minerals sector for the past 30 years. For the purposes of this paper ultrafine grinding is considered to be P80 of less than 15 microns.Attrition milling to fine grind sizes presents some challenging issues relating to scale-up including the dearth of information on the quantitative impact of feed and operating conditions, as well as the precise and accurate measurement of particle size distributions. Two examples from recent installations will be analyzed including Thalanga Copper and Century Zinc Mines. Both have diverse grind size targets for the SMD, yet both have realized significant metallurgical gains."

Jan 1, 2002

By A. P. E. Dirige

Extensive field study has been performed to assess the capabilities of thin sprayon liners (TSLs) and conventional spray-on support systems for preventing rock and support material damage that often results due to mining-induced rockbursts. Support performance was studied using field scale explosive detonation trials to simulate dynamic failure effects that are known to develop during typical rockburst events. Multiple seismic and high speed photographic monitoring techniques were used to provide detailed information concerning rock motion, surface fracturing, ejected fragment motion, and support liner survivability characteristics. Results of this study have demonstrated that TSL?s and variant layer combinations may be as effective as or better than conventional support materials for mitigating rockburst or like damage in highly stressed mine environments. In this study, field results have been verified using numerical modeling procedures to better understand the support behaviour of TSLs when subjected to highly stressed mine environments and mining-induced rockbursts, a factor that is essential when designing any rock support system. A series of numerical modeling assessments were conducted using FLAC3D modeling of a half circular TSL-lined tunnel, influenced by anisotropic stresses and simulated mining-induced rockbursts, to investigate the support potential of TSLs under prototype conditions. The effect of a mine rockburst was simulated using the three-dimensional dynamic analysis option of FLAC3D. Results of TSL-lined tunnels in highly stressed and mine rockburst conditions indicated exceptional effectiveness of TSLs for suppressing rock deterioration resulting from stresses and rockbursts. The rock support potential of TSLs on tunnel surfaces was compared with that of thin shotcrete linings, and results indicated that thin spray-on lining products currently available may be equally as effective in support as shotcrete materials.

May 1, 2009

By R. H. Colquhoun, A. W. Bolland, H. J. H. Pieterse

"American Barrick Resources Corporation acquired the goldstrike property in north eastern Nevada in early 1987. Since that time, the company has undertaken an extensive development program. This paper will overview the milling, autoclaving, and heap leaching facilities which are part of the $400-million Betze development plan. Gold production at the Mine has increased from 40,000 ounces per annum in 1987 to more than 500,000 ounces in 1991. And in 1992 Goldstrike will be the single largest North American gold mine when it produces 1,000,000 ounces.1. SUMMARYAmerican Barrick Resources Corporation acquired the Goldstrike property in northeastern Nevada in early 1987. Since that time, the company has undertaken an extensive development program. This paper will overview the milling, autoclaving, and heap leaching facilities which are part of the four year, $440- million Betze Development Plan. Gold production at the Goldstrike Mine has increased from 40,000 ounces per annum in 1987 to more than 500,000 ounces in 1991. In 1992, Goldstrike will be one of the largest North American gold mines, when it produces appro approximately 1,000,000 ounces.2. INTRODUCTIONAmerican Barrick Resources Corporation is in the process of developing the Betze gold deposit, located on Barrick's Goldstrike property in the Carlin area of Nevada, U.S.A.The Goldstrike Mine has 17.9 million ounces of proven and probable reserves and an additional 460,000 ounces of possible reserves. Additionally, the Purple Vein deposit, one mile north of the Mine, is expected to add at least 4 million ounces of reserves by year end 1991.The Goldstrike ore body contains both oxide and sulphide ore. The largest part of the reserves are contained in the high grade, deep sulphide ore. Mining of the sulphide ore contained in the Betze deposit involves the removal of large quantities of overlying oxide ore. Oxide ore is treated through one of the following processes:-"

Jan 1, 1992

By Zara Hosseini

?Microseismicity ?Seismic Systems ?Intrinsically Safe and Explosion Proof Seismic System ?Case studies: ?Gas Drainage Optimization ?Fault Identification ?Conclusion Seismic Event ?Occurrences in which energy is released in the rockmass creating a series of seismic waves propagating throughout the rockmass ?Can cause a Fall of Ground or CoalBurst Factors creating Seismicity: ?Mining at Depth ?High stress zones ?Major geological structures ?Mining practices and strategies ?Mining activities i.e. drilling and blasting

Aug 1, 2013

By S. Tuttle, R. Sisson

"Suncor Energy Inc. has proposed a 2.2 billion dollar expansion to the current oil sands operation, which will more than double the productive capability of the facility. As part of the application for this expansion, a comprehensive closure plan had to be developed and filed.Closure planning includes a systematic evaluation of the area to be developed, the development activities planned, the goals and objectives of the corporation in re-establishing landforms and ecosystems at the same time as running an effective operation. As early as is practical during the mine development, surface contouring is completed, soil is reconstructed, and vegetation, surface drainage and wetlands are re-established. Once active reclamation is complete and vegetation has been re-established, Suncor monitors maturation of landscapes and ecosystems to provide the submission basis for reclamation certification"

Jan 1, 1999

By Ross Nairn

"Tulawaka Mine is a joint venture between Pangea Minerals Limited 70% (a wholly-owned subsidiary of Barrick Gold Corporation) and Northern Mining 30%. Tulawaka Mine is located in North West of Tanzania in the Lake Victoria Goldfields. Tulawaka Mine is scheduled to process 360,000 tonnes per year at an average 11.5 g/t head grade over a 4 year mine life.The Tulawaka Process Plant uses single stage crushing, single stage SAG milling, gravity, intensive leach of gravity concentrates, CIL, Zadra desorption and cyanide detoxification to process the ore. Gold recovery exceeds (or is expected to) 95%.The Process Plant was designed and constructed under the supervision of Ausenco Engineering of Australia. Site works commenced in January 2004, Process Plant construction commenced in July 2004 and the first ore was presented to the Process Plant 26th February 2005. The first gold was poured on 15th March 2005. All construction contractors were demobilized from site 7th April 2005. Major achievements have been 3.4 million hrs LTI free during construction and operation to date, training of the Tanzanian workforce at Bulyanhulu Mine prior to commissioning, a succession plan to replace expatriate personnel with Tanzanian staff and significant over performance of the Process Plant against design.INTRODUCTIONTulawaka Mine is situated approximately 160 km south west of Mwanza in the western Lake Victoria Goldfields District of north western Tanzania. The property is held under a joint venture between Pangea Goldfields Inc (70%), a wholly owned subsidiary of Barrick Gold Corporation, and Explorations Minieres Du Nord Ltée (30%). A location map showing the position of the operation in Tanzania is shown in Figure 1.Mine site staff at Tulawaka comprises a combination of Tanzanian and Expatriate personnel. All Pangea personnel live on site and commute to their place of residence for their R&R on a 9 weeks on 4 weeks off roster."

Jan 1, 2006

By Oy Leuangthong

Red Dog mine is the world's largest Zn producer. The deposit consists of sulphide ore zones in sedimentary exhalative (sedex) deposits, and is characterized by the presence of multiple metals and multiple ore types. The objective of the case study is to characterize seven different minerals, Zn, Pb, Fe, Ba, sPb, Ag and TOC, within eight different rock types. Geostatistical models were constructed for each variable within the eight rock types, and subsequently assembled to give 40 realizations for six 25ft benches. The stepwise conditional transformation was used to account for the complex multivariate relations. In addition to reproducing the input data, histogram and variogram, the resulting models also respect multivariate relations locally and globally. This paper documents the methodology to construct these models. A thorough validation procedure was implemented. Comparisons with blasthole data show that the conditional simulations and the long-term models agree in expected value. The main advantages of the conditional simulations are (1) the explicit accounting of multivariate relations between the data in model construction, and (2) the ability to quantify variability and uncertainty at any scale. A small exercise comparing the profit from a kriged and a simulated model is also examined. Results show that the simulation approach showed a 3% increase in profit, relative to the conventional estimation approach.

May 1, 2004

By C. R. Tang

The respirable dust real-time monitoring equipment export information is complex, and electromagnetic wave wireless transmission is affected largely under mine conditions. The respirable dust concentration information transmission method based on led light equipment is proposed. The respirable dust concentration data of the individual real-time monitoring equipment is encoded to fit the system transmission; the encoded signal is modulated onto the LED mine lamp; the light signal is transmitted by the spatial channel; the signal is received by the receiver to the photoelectric conversion to restore the respirable dust concentration data for subsequent processing. Simulation and verification experiments showed that the respirable dust concentration information transmission method based on led light equipment can achieve the LED miners? lamps visible light wireless data transmission.

Aug 1, 2013

By Manqiu Xu, Pete Winn, Steve Wilson

"In the flotation of ultramafic ores at Thompson mill, Inco Limited, CMC is used as both a floatable rock depressant and electrostatic serpentine slime dispersant. CMC, being a high molecular weight polymer, creates a serious handling problem in its introduction into the flotation processes. Typically, it is added as a 1-3% solution. This requires an enormous handling facility and makes its metallurgical gains uneconomical.Laboratory studies have shown that dry CMC addition as opposed to wet addition is feasible, as long as sufficient conditioning time is provided. Dry CMC addition into the grinding mill is also possible but its effectiveness is slightly reduced as compared to dry addition after grinding mills. Dry CMC addition using a vibratory feeder into the mill discharge is successfully applied in the treatment of ultramafic ores at Thompson mill.INTRODUCTIONManitoba Division MineralogyAt Inco’s Manitoba Division, two distinctly different sulphide ores are processed at the Thompson mill - primarily by froth flotation. The Thompson and Birchtree mines are both located within the Thompson Nickel belt. Sulphide mineralogy is relatively simple and includes both hexagonal and monoclinic pyrrhotite, pentlandite and minor chalcopyrite hosted in metasedimentary and metavolcanic rocks. The significant difference between the two mines is the amount of ultramafic rock associations in the host material. Increasingly, more of the ultramafic associated ores from the Birchtree mine are being processed through the mill with a characteristic poor metallurgy."

Jan 1, 2000

"INTRODUCTIONGold tailings retreatment plants have been operated for many years throughout the world. Several large tailings retreatment facilities have been operated profitably in South Africa since 1976 and there are tailings retreatment operations in Canada currently in production with more in the feasibility stages.The Timmins Gold Tailings Project of ERG Resources Inc. was designed to treat 8,000,000 tonnes per annum of gold tailings for an eight month operating season, and commissioning of the operation began in July 1988. The payback period for this project is about 3 years which corresponds to an IRR of 30%.This report summarizes the metallurgical characteristics of the reclaim tailings, describes the process flowsheet which was developed to enable ERG to economically recover gold from the Timmins area tailings, and reviews commissioning activities."

Jan 1, 1989

By Jacob Masliyah, Zhiang Zhou, Tshitende Kasongo, Jianjun Liu, Zhenghe Xu, Jeawon Choung

"Slime coating is a recognized challenge in fine particle flotation, not only in decreasing recovery, but also in reducing the selectivity and hence froth quality. In this presentation, a novel method based on electrophoretic mobility distribution measurement to study slime coatings is described. By measuring electrophoretic mobility distribution of individual minerals and their mixtures, the interactions between these minerals can be evaluated.For illustrative purposes, a model system of fine coals, or oil sands with two different types of fine clays was studied. Flotation tests showed a significant decrease in coal (bitumen) flotation recovery with montmorillonite but not with kaolinite clay addition. When electrophoretic mobility distribution of a fine coal/montmorillonite clay mixture was measured, a single modal zeta potential distribution was obtained, in contrast to a bimodal distribution for fine coalkaolinite clay mixture. This finding suggests a stronger adhesion of montmorillonite than kaolinite clays on fine coal surfaces. In the case of bitumen, the bimodal zeta potential distribution was measured for the mixture of bitumen emulsion and kaolinite or montmorillonite, indicating a weak attraction of the clays by bitumen. In the presence of calcium, however, a single modal zeta potential distribution was obtained in the mixture of bitumen emulsion with montmorillonite but not kaolinite clays. These findings are in excellent agreement with bitumen flotation results, demonstrating that the electrophoretic distribution measurement is a powerful tool to study slime coating phenomenon in a complex fine particle flotation system."

Jan 1, 2002

By J G. Brady

This paper discusses the ceramic products used in the construction industry in Canada, as well as the main raw materials used in their manufacture. The products include the! following: (1) clay prorlucts -such as facing brick (glazed and unglazed), common brick, facing tile (glazed and un-glazed), terra cotta, load-bearing tile, non-load-bearing tile, structural clay floor tile, quarry tile, drain tile, sew-er pipe, conduits .and flue liners -which are made mainly from domes-tic common clays and shales and from domestic or imported stoneware clays and low-grade fire clays; (2) floor and wall tiles of the whiteware type, which are produced from ingredients such as kaolin, ball clay, feldspar, nepheline syenite, talc, pvro-phyllite and wollastonite; (3) glass products -the major ones being sheet glass, plate glass and mineral wool (glass wool, and rock or slag wool) -which are made from such materials as silica sand, soda ash, salt cake, feldsspar, nepheline syenite, dolomitic limestone, high-calcium limestone. borax and (for rock and slag wool) various rocks or slags;

Jan 1, 1963

By P. R. Day, W. K. Webster

"The introduction of large boreholes underground initially involved taking the techniques of open-pit bench blasting to the production stope, but with deeper boreholes and narrower stopes more controlled techniques must be developed in order to maintain good stope walls and prevent dilution of ore or structural damage to pillars due to blasting overbreak. The points discussed are drilling accuracy and drill pattern, the relationship between open-pit wall control and underground mining, the varied explosives products and initiation devices available, and some of the many ways that variations in loading, such as deck charging, etc., can produce desirable results.IntroductionThe use of large-diameter blastholes for underground mining began ten years ago and today they are widely employed in a variety of orebodies and stope configurations. These big blastholes, which range in size from 4.5 to 8 inches in diameter, were originally employed in the same manner ' as open-pit bench blasts; that is, the stope was silled out to full width and all holes were drilled vertical and parallel. This was suitable for competent, massive orebodies, however the popularity of the big drills saw their usage in more narrow stopes, often with poor ground conditions. The dipping orebodies and small drill sublevels resulted in inclined drilling.Today, there is full-ring drilling of 4.5-inch holes. Some 6.5-inch holes are drilled up to 350 feet deep. A 350-foot borehole may contain 6000 to 7000 pounds of explosive. The detonation of this size of charge weight within the confines of an underground stope can have considerable effect on the stability of stope walls and adjacent pillars. Obviously, precautions must be taken to minimize the damage which would result from the large charge weights possible with these big boreholes."

Jan 1, 1982

By Elizabeth Gardiner

Tailings and water management facilities are integral components of mine and mill operations. They must be managed for the long term to ensure that safe and environmentally responsible stewardship is achieved. The Mining Association of Canada (MAC) has developed and published two manuals to provide guidance to mining companies on sound practices for the safe and environmentally responsible management of tailings facilities: ???A Guide to the Management of Tailings Facilities; and ???Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities. The Guides were designed to help companies develop and implement tailings management systems that include environmental and safety criteria, to improve the consistency of application of sound engineering and management principles to tailings and water management facilities through their full life cycle, and to demonstrate this to regulators and the public.

May 1, 2003