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By Andrew Dobson

The assessment and control of environmental noise from mines has become increasingly important in recent years, due to urbanization and population growth, increased regulation of environmental factors, and overall awareness and sensitivities to noise exposure. Minimizing adverse effects on communities and achieving compliance with local ordinances is now commonplace, and consideration of noise during the design and/or operation of a mine cannot be ignored. Ventilation equipment can represent the loudest and most bothersome equpiment at mines, however there are complexities when attempting to control the assocaited noise, due to the acoustical nature of mine vent fans. In fact, the utilization of traditional and/or industry standard methods can intensify the noise impact, or simply not work as intended. This paper provides recommendations on specific noise control methods that are suitable for mine ventilation equipment, based on recent assessment work and field experience.

Oct 1, 2024

By H. Salamanca

Recently, the mining industry has become one of the leading target markets for the technology industry as they need to innovate in their productive processes in order to boost productivity, reduce operation costs, increase operation safety, and improve the quality of life of their workers. This work presents the technological developments that HighService has done in different stages of the mining productive processes to include robotic manipulators in their automation solutions as well as the development of new equipment and sensors. The robotic technology integration is presented in different applications such as handling and selection of cathodes in E-W machines, automation of base plate maintenance, automation of cathode stripping machine, and multi-tools handler for liner bolt replacement in SAG mill liner maintenance activities. The proposed solutions show technical and economical viability with low initial investment and short implementation period of six (6) to ten (10) months. The results have been validated in plant, obtaining higher production rates and availability.

Jan 1, 2007

By W. G. Hatch

Introduction In November, 1927, a paper was presented at the Annual Meeting of the British Columbia Division by H. A. Pearse(l), in which he described the milling practice at Britannia and set forth the metallurgical results which were being obtained at that time. In the intervening four years, various changes and additions have been made in equipment and practice, which have resulted in marked improvements in efficiency and costs. These changes and their effects are discussed in the present paper. During the past few years two major changes have been made in plant equipment. The first of these was the. elimination of an intermediate crushing stage by discarding two gyratory crushers in favour of two Symons cone crushers. The latter installation-now effects in one stage a greater reduction than was formerly accomplished in two, that is, by the gyratories together with a set of rolls. The second important change in equipment took place when the original M.S. flotation machines were replaced by six Forrester pneumatic machines, so that now the flotation department consists entirely of machines of this type. A number of minor changes and some further additions to equipment have also been effective in raising plant capacity and concentrate grade, while making noticeable reductions in tailing losses and costs of ore treatment.

Jan 1, 1932

By M. R. KEYS

"The property is about 120 miles north of Red Lake in the Favourable Lake area, district of Kenora ( Patricia part) , Ontario. The original discovery was staked by K. Murray in December, 1927. The first development work was done by the Favourable Lake Mining and Exploration Company. In 1936 Newmont Mining Corporation acquired control of the property and developed it to production by September, 1939. Production to the end of 1945 had a value of $7,534,656 from 441,457 tons of ore, an average value of $17.04 a ton . This production was mainly from gold and silver, with lead and zinc of subordinate importance.The rocks in the vicinity of the mine trend in a north-south direction. From east to west the sequence is: (1) A dark-coloured, massive rock, presumably a flow, composed mainly of quartz and biotite. ( 2) A buff- coloured, scricitized rock locally containing quartz phenocrysts and black hornblende. This is an alteration product of the dark variety and is later than the folding. It occurs mainly within the dark rock. (3) A series of sediments comprising thin beds of greywacke, grit, quartzite, conglomerate, and iron formation. ( 4) A gabbro sill, now largely altered to amphibolite.With the exception of the buff type, these rocks dip 80°E. The buff rock has a very irregular outline in comparison with the other rocks and appears to dip somewhat more flatly east. Felsite and diorite dykes are also present. These have a general strike of S.60°E. and dip 65°S .W. A post-ore diorite dyke trending N.15°E. occurs about 2,000 feet east of the mine area."

Jan 1, 1954

By R. ZapataN.

"In the following report, Altonorte Smelter owned by Xstrata will explain its experience with its denominated furnace called ""Continuous Altonorte Reactor"" since started up in March 2002. The Reactor is the main and only smelting furnace since the operation of Reverb Furnace was stopped (15 days after the start up of the Reactor) and it can be operate with dry concentrate for injection by tuyere and wet concentrated via Garr Gun when the injection system fails. From the started up of the Reactor, three operational campaigns have been carried out where in each one they have been increased their smelting throughput and availability. The flexibility reached by the technology bath smelting has allowed a high level of smelting of concentrate and revert materials. The high availability of the Reactor and overcoming problems that were considered of high complexity like the extraction of white metal and slag, refractory campaign, etc. has allowed the Altonorte smelter to project to smelting 1,200,000 tonnes per year with its only Reactor in next year."

Jan 1, 2007

By E. J. Marcotte

"INCO LIMITED'S Shebandowan Mine and Mill is located in a scenic tourist and cottage area near the western tip of Lower Shebandowan Lake, approximately 90 Km west of Thunder Bay, Ontario. This nicely designed complex is a positive indication that mining operations can co-exist in harmony within the natural environment.The Shebandowan complex processed nickel-copper ore from 1973 to 1985, inclusive, after which operations were shut down.In late 1988, INCO LIMITED decided to place the Shebandowan complex back into operation, under contract, to mine and mill the remainder of the ore body, according to their specifications. MaclSAAC'S EXPLORATIONS was the successful bidder for the project. Following preliminary rehabilitation, operations were re-activated in late March, 1989. The ore mined to date is of a moderately lower nickel grade than the majority of previous years. However, a higher tonnage rate, combined with improved nickel recoveries, has contributed to a viable operation.A series of mill operating and equipment modifications has enabled MaclSAAC EXPLORATIONS to achieve the quality and grade of nickel-copper concentrates specified, and at the same time, expand mill tonnage throughput while attaining increased nickel recovenes."

Jan 1, 1992

By Mohan R. Srivastava

- OUTLINE - apologies and explanations - a quick bit of history - the wisdom of Wikipedia - ?Matheronian geostatistics continued to convert Bre-X?s bogus grades and Busang?s barren rock into a massive phantom gold resource?? - variogram analysis for Busang - would variogram analysis (or variance analysis) have revealed the fraud? - what went right, what went wrong

May 1, 2007

By P. Leo

Al-Mg-Si alloys are widely used as medium-strength structural materials; extrusion is the most common processing route. In the present hot deformation investigation of a 6060 alloy, the microstructure of the alloy has been analyzed in the as-cast state, after homogenization heat treatment and after hot deformation by tensile tests in the range 400-490°C and 10-4 to 10-2s-1 on both as cast and homogenized alloys. After deformation the microstructure of the as-cast alloy exhibited cavitation. The flow curves at the lowest test temperature T show a gradual softening after a stress peak, being more evident for the alloy deformed in the homogenized state in association with a high yield stress; at higher T a plateau is attained which is lower as T rises and strain rates decrease. For each fixed T, the ductility decreases as strain rate increases for the homogenized alloy whereas, for the as cast alloy, it rises with strain rate. Constitutive analysis gives Q = 240kJ1mol for the homogenized alloy in agreement with published values; this indicates a more rapid strength decline with rising T than Al, suitable for good hot workability along with the lack of cavitation.

Jan 1, 2011

By Yann Sivry, S. Subramanian, Divyasree C. Prabhakaran, Jean Riotte

The potential of a bacterial strain isolated from water samples collected from a chromite mine in Odisha, India has been assessed for the bioremediation of hexavalent chromium, a toxic environmental pollutant. The isolate was identified as Sphingopyxis sp., a Gram negative bacterium, adopting molecular biological protocols and biochemical characterization techniques. Detailed investigations on the bioremoval of Cr(VI) were carried out using Sphingopyxis sp. cells and the various parameters affecting the biosorption process were evaluated. About 55 % biosorption of Cr(VI) was obtained using Sphingopyxis sp. bacterial cells and the residual chromium in solution was found to be bio-reduced to the trivalent form, namely Cr(III). Thus, complete bioremediation of Cr(VI) could be achieved using the mine isolate, with contributions from both biosorption and bioreduction mechanisms. The Cr(VI) biosorption isotherm obtained for the isolate was found to follow a typical Langmuirian behavior and the free energy value of biosorption was determined to be ~-25 kJ/mol, indicative of involvement of chemical binding forces in the bioremediation process. The chromium biosorption kinetics by the isolate followed a pseudo second order reaction. The FTIR spectral studies revealed that carboxyl, hydroxyl, amino and phosphate groups were involved in the biosorption process. X-ray photoelectron spectroscopic studies on the bacterial cells interacted with Cr(VI) confirmed the presence of both Cr(VI) and Cr(III) on the cell surface. The electrokinetic studies revealed that the surface potential of the bacterial cells were less electronegative subsequent to interaction with Cr(VI), compared to the cells alone, which further testified to the binding of positively charged Cr(III) ions, formed by bioreduction of Cr(VI), to the bacterial cell surface. A marginal shift in the iso-electric point obtained for the bacterial cells interacted with Cr(VI), corroborated the involvement of chemical binding forces in the bioremediation process.

Jan 1, 2016

By M. Maleki-Moghaddam

At the concentration plant of the Gol-E-Gohar Iron Ore Company (Iran) three 9 m × 2.05 m AG mills (fixed speed) are used in parallel in a dry operation. The performance of AG mills has been lower than the target value indicated by an increase in the product size (P80) from 450 µm (target) to 515 µm and low power draw (50% of nominal). By simulation it was found that increasing the liner lifter face angle from 7 to 30o while keeping the original lifter height (i.e., 22.5 cm) could provide an appropriate charge trajectory. When the proposed liners installed in one of the AG mills, the throughput increased by 27%; when 5% (v/v) balls were added the throughput increased by 40%. The product size also decreased from 515 to 501 µm.

Jan 1, 2012

By Glen Robertson, Jeff McLaughlin

"The Clarabelle Mill rock tailings have the potential to generate sulphuric acid through chemical and biological oxidation of sulphide minerals. Current rock tailings assay between 0.80 -1.40 %S, with sulphur occurring principally as coarse pyrrhotite. Acid generation within the tailings area can be substantially reduced by segregating pyrrhotite rich tailings in a submerged storage area and by depositing only low sulphur rock tailings in exposed areas. Laboratory tests confirmed that low sulphur tailings could be produced by flotation at reduced pH with a small xanthate addition. A plant test was conducted to evaluate the production of low sulphur tailings in conjunction with INCO's continuing commitment to environmental protection and progressive decommissioning of the metallurgical site.During the plant evaluation, approximately 5% of the mill rock tailings were reprocessed in a line of 100 tt3 Denver flotation cells. Tailing grades below 0.40% S were easily achieved through operation at pH 6 -7, with xanthate addition (dosages up to 0.02 lb/ton) and 10 -15 minutes of nominal retention time. Froth depths between 1 -3 inches combined with relatively liberal amounts of frother were required to pull the lightly mineralized froth into the concentrate which averaged 11% sulphur and less than 5% mass recovery. In addition, three field lysimeters were each filled with two hundred.ton bulk samples of low sulphur tails (0.35% S), standard rock tailings (0.98% S), and mill total tailings (2.30% S) for long term monitoring. The implications for full scale plant design, tailings area decommissioning, the possibility of increased nickel recovery and preliminary field lysimeter data are discussed."

Jan 1, 1994

By G. Knight

"Results of a program of dust research carried out at the Mines Branch Laboratory, Elliot Lake, indicate that dust-concentration estimates vary greatly, depending on the sampling instrument, the assessment technique and the properties of the dust cloud. The wide range of the ratio between the estimates by any pair of instruments shows that the correlation between the health hazard and dust-concentration estimates by most existing sampling instruments must be questionable. Important studies are being carried out to permit the definition of mine environments in more precise technical terms. The influence of size selection, the physical property measured, composition and sampling period on the assessment of the health hazard are discussed."

Jan 1, 1969

By J. R. Gill

Introduction The property and plant of the Falconbridge Nickel Mines, Limited, is situated about 13 miles northeast from Sudbury, in Falconbridge township, near the eastern extremity of the southern Nickel Range. As early as 1899 or 1900 some work was clone on this property by the late Thos. A. Edison, when a shaft was sunk through 80 feet of overburden to within a few feet of the ore-body. At this point quicksand was encountered, which made it impossible to continue with the equipment at hand. As a result, the activities of the Edison party ceased in this section. There was no further progress until 1915 and 1916, when an extensive diamond-drilling campaign, carried out by the E. J. Longyear Company, located the ore-body that is now being worked. The property was acquired by the present operators in 1928, and in September of that year active mining development was commenced. Features Influencing Design Of Plant Early in 1929 plans were prepared for a smelter and the necessary crushing and sorting plant. In spite of the general trend towards the reverberatory furnace as a smelting unit, it was decided to erect a blast-furnace plant. The limited tonnage to be treated, of course, influenced this decision to a great extent. However, it was known that, with the proper procedure, extremely favourable results, both economic and metallurgical, could be obtained in blast furnace smelting. The possibility of very low slag losses, the simplicity of operation by the elimination of roasting plant, fuel plant, etc., the ability to handle coarse feed, and the lower initial cost, were considered factors in favour of the blast furnace. Notwithstanding the fact that we might be called on to treat a certain amount of concentrate, it appeared that the blast furnace was the proper unit for the contemplated operation.

Jan 1, 1932

By RALPH R. STEA, John H. Fowler

Clay, quartz sand and lignite deposits overlie Carboniferous rocks in central mainland Nova Scotia. Recent evidence indicates that these deposits are fairly extensive. Sands consist of almost pure angular quartz grains. Clays are highly plastic and range in colour from black through grey and blue to mottled red and white. Palynologica/ information dates the sediments as Ear{y Cretaceous, and mineralogical studies show them to consist primarily of quartz, kaolinite and mica. There is not yet enough evidence for detailed stratigraphic description, but sequence and thickness of sediments are known to vary greatly over short distances. Drill logs from Musquodoboit Valley recorded Cretaceous sediments at 168 m thick. Of the three active pits in Cretaceous sediments of central Nova Scotia, two are for silica sand production and are located at Elmsvale and Brazil Lake while a third pit at Shubenacadie produces clay for manufacture of structural clay products.

Jan 1, 1984

By G. Bartolacci

In a COREM-McGill collaborative research and development project, gas dispersion parameters and froth properties were manipulated in a copper flotation plant to study interactions between the collection and the cleaning zones. In this paper, specific work on developing some relationships between operating conditions and froth stability in several different types of flotation cells is reported. Froth stability, measured by image analysis, was related to the following process conditions for specific flotation machines in an industrial case study: Gas flow rate, collector dosage, pH, frother type and dosage. Across the range examined, froth stability was improved through an increase in gas flow rate and/or frother dosage. Metallurgical results (grade and recovery) showed that both gold and copper were dependent on froth stability. Results indicated that flotation conditions could be optimized by monitoring froth stability.

Jan 1, 2007

By CIM Mineral Resource

On January 9, 2018, the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Council formed the CIM Mineral Resources and Mineral Reserves Committee (CIM MRMR Committee), which is a combination of the previous Standing Committee on Reserve Definitions and the Best Practices Committee. As part of its mandate, the CIM MRMR Committee updates guidelines for use by Industry, which include the Uranium Practice Guidelines. The 2024 CIM Uranium Leading Practice Guidelines were adopted by CIM Council on November 22, 2024, and supersedes the 2003 version. The main principles and guidelines relating to preparation of Mineral Resource and Mineral Reserve (MRMR) estimates are provided in the CIM Estimation of Mineral Resources and Mineral Reserves Best Practices Guidelines (MRMR BP Guidelines, as updated from time to time). The MRMR BP Guidelines provide information pertaining to metalliferous and other deposits and many sections are readily applicable to the preparation of MRMR estimates for uranium deposits. However, additional guidance is appropriate for uranium deposits due to the radioactive nature of uranium, and its amenability, in some cases, to in situ recovery (ISR) mining methods.

Nov 1, 2024

By S. Spigarelli

The creep response of the AE44 magnesium alloy was studied by means of constant load creep tests carried out at 125 and 150°C, obtaining that at the latter temperature the minimum creep rate observed under an applied stress of 100 MPa was two orders of magnitude lower in the investigated alloy than in AM50. The minimum creep rate dependence on applied stress was described by a conventional power-law, e = Aon , where A was a temperature dependent parameter and n was the stress exponent, resulting in a n value close to 30, i.e. by far larger than those observed in commercial alloys with similar Al content. This large difference in creep response was attributed to the precipitation of rare earths (RE) intermetallic phases distributed in the grain boundary zone in form of an almost continuous network of dispersoids that were observed by means of scanning electron microscopy.

Jan 1, 2006

By M. Abdellatif

Successful demonstration of The Mintek Thermal Magnesium Process (MTMP) was achieved in November 2004 at the pilot-scale, About 30 tons of magnesium producing recipe was smelted in the DC arc furnace over a continuous operation of 8-days, Twenty-two furnace batching-tapping operations were carried out at a feed rate of 525kg/h and a smelting temperature of 1600-1700°C, The MgO content in the produced slag was as low as 6,7%, and averaged 9,2% MgO, resulting in an overall magnesium extraction of 77%, which reached 87% during good operating periods, Magnesium vapour was extracted at a rate of 70-85kg/h and was delivered to the condenser that was operated at 680-720°C, The magnesium was captured in the condenser crucible in a liquid state, allowing its prompt tapping, More than 3500kg of crude metal were produced over 15 on-line metal tapping operations, On average, a condensation efficiency of 85% was achieved during the entire testwork, which peaked at 87% during steady operations, The quality of the crude metal was similar to, if not better than, that of the Magnetherm's crude magnesium, A pre-feasibility study has indicated that the MTMP has the potential for lower capital and operating costs as compared to the electrolytic process, and therefore Mintek and its consortium partners are exploring opportunities for a commercial production facility.

Jan 1, 2006

By Jaime Meléndez Martínez

Recent interest in unconventional reservoirs motivates our work in laboratory measurements of seismic anisotropy. Seismic anisotropy is the variation in speed of a wave as a function of its direction of propagation. Analyzing anisotropy in unconventional reservoirs is important since anisotropy leads, for example, to differential stresses upon loading and could affect hydraulic stimulation (Reinicke et al., 2010, Zimmermann and Reinicke, 2009); in this sense, laboratory measurements are an important tool to study seismic anisotropy at small scales which can aid in the characterization of larger formations. The purpose of this work is to describe the laboratory methodology used to simultaneously measure ultrasonic P and S-waves in three different directions from a single core sample. Elastic anisotropy of a Proterozoic sedimentary rock from south-west Alberta is investigated. In metamorphic rocks seismic anisotropy is caused by preferred mineralogical alignment or foliation. Assuming a transversally isotropic medium, arrays of compressional and shear piezoelectric ceramic transducers were mounted on a sample trimmed from a core to measure travel times of ultrasonic P-waves and S-waves as a function of confining pressure at directions perpendicular, parallel, and oblique to the plane of foliation (bedding). Results show strong anisotropy agreeing with the assumption of a transversely isotropic medium. Dependence of travel times and hysteresis effects can be observed when pressurizing and depressurizing.

Jun 1, 2012

By Hajime Miki, Gde Pandhe Wisnu Suyantara, Tsuyoshi Hirajima, A. M. Elmahdy, Keiko Sasaki

"Seawater has been reported to depress molybdenite in a copper-molybdenum (Cu-Mo) flotation process at high pH due to the precipitation of Mg(OH)2. Meanwhile, to improve mineral recoveries, collectors are usually added into the flotation cells, thus adding the complexity to the mechanism of bubble-particle interactions involved in Cu-Mo flotation. Therefore, understanding the interaction mechanism in seawater flotation and in the presence of collectors is important to explain the minerals depression. The present work investigated the effect of kerosene on the bubble collision and attachment to pure chalcopyrite and molybdenite surfaces in MgCl2 solution as one of the seawater major components at pH 6 and 11. Mineral surfaces were characterized using atomic force microscopy (AFM). In addition, minerals floatability in the same system were tested in a column flotation. The study of bubble-particle interactions shows that following several collisions, bubble could displace the intervening liquid layer on the mineral surfaces, forming a three-phase contact (TPC). A TPC formed more rapidly in the presence of emulsified kerosene in a 0.01 M MgCl2 solution at pH 6 for both minerals. The reason is kerosene increased the surfaces hydrophobicity and destabilized the intervening liquid layer on the surfaces. Moreover, the average time required to form a TPC was shorter on molybdenite surface. This can be attributed to the effect of adsorbed kerosene on molybdenite surface and molybdenite surface roughness.INTRODUCTIONIn froth flotation, bubbles are used to separate hydrophobic mineral particles from hydrophilic particles. In this process, bubble-particle interactions (i.e., collisions, attachment, and detachment) are crucial with regard to mineral recoveries. The effectiveness of froth flotation depends on the formation of stable aggregates between the hydrophobic particles and the bubbles, allowing the bubble to carry the particles to the froth layer. To form such aggregates, the bubbles and particles must collide, and the intervening liquid layer must be drained below the liquid layer critical thickness, forming a stable threephase contact (TPC) (Ralston & Dukhin, 1999). Particles detachment may take place if the particles still have sufficient kinetic energy and the TPC is not formed. Previous studies of bubble-particle interaction in electrolyte solutions have been conducted using atomic force microscopy (AFM) (Assemi, Nguyen, & Miller, 2008), and by approaching the bubble using mica plate (Pushkarova & Horn, 2008), however, these studies did not focus on the bubble-particle collisions. Bubble collisions and attachment to hydrophobic (Teflon) and hydrophilic (glass) surfaces in a a-terpineol solution have been investigated by Krasowka et al. (2003)."

Jan 1, 2016