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By L. G. Morrell

Introduction A Self-Dumping cage which combines the features of a small skip and a cage has been used in a vertical winze between the 2,000 and 2,500 levels at the Coniaurum mine for the past three years, during which time its success has been demonstrated by uninterrupted service and low maintenance charges. lt was designed by John Reddington, mine manager, and was built under his supervision in the Coniaurum mine shops. Being new in many of its operating features, a small-scale model was made and tried before the final construction was undertaken. The mechanical performance of the model suggested a few minor changes that were incorporated in the final drawings. During its three years of use, the automatic dumping device has saved the expense of deck-handling of the cars. This actually represents a gross economy of something over four times the cost of construction and installation, which totalled $1,325. The cage, empty, weighs 2,200 pounds, of which 500 pounds represents the weight of the dumping accessory and necessarily heavier construction. Besides a considerable financial saving, the time saved in unloading increases the daily hoisting capacity of the winze. In raising ore from the 2,500 level, five minutes are required for a complete trip. Allowing one minute for the alternative of decking, we believe that the automatic dumping has increased the capacity of the winze hoist nearly 20 percent.

Jan 1, 1933

By N. M. Steven, J. M. Moore, J. L. Kuyper

Mineral exploration and research has led to the identification of four types of tungsten mineralization in the NE-trending, Iargelyensialic, inland branch of the late Proterozoic/early Paleozoic Pan-African Damara Orogen. The mineralization (mainly scheelite) occurs in a terrane (the Central Zone) that is characterized by multiple deformation, greenschist/amphibolite-facies metamorphism and numerous peraluminous S-type granitic and pegrnatitic intrusions. The four major types of scheelite mineralization are (in ascending stratigraphic order of host rock): (1) thin (5 cm to 2 meter) quartz+plagioclase+diopside ± scapolite calc-silicate granofels with fmely disseminated scheelite (scheelite-bearing granofels; SBG) developed as discontinuous intercalations within the calc-silicate rocks of the Khan, Spes Bona, Oberwasser and Kuiseb Formations (Nosib and Swakop Groups); (2) gamet+pyroxene± vesuvianite+scheelite ± fluorite replacement skarns hosted by Okawayo, Karibib and lower Kuiseb Formation marbles in the aureoles of late tectonic, unrnineralized leucogranites; (3) metaturbidite-hosted scheelite- (and possibly wolframite-) bearing tourmalinites, both stratiform and crosscutting, in the Kuiseb Formation located in the 'cleavage fronts' of late tectonic granitoids; (4) scheelite-bearing vesuvianite+quartz+garnet skarnoid rocks (several hundred meters in length) in the calcareous metaturbidites of the upper Kuiseb Formation. These scheelite occurrences were discovered by the follow-up of a large number of tungsten anomalies located during a regional stream sediment sampling program. Detailed mapping, ultra-violet surveys and rock sampling proved to be the most effective surface exploration techniques for locating mineralization; soil sampling and geophysics were of almost no use. The largest, continuous scheelite-bearing skarn of economic interest, Otjua, has a drill-indicated reserve of 250 000 tonnes at 0.53 wt5 WO3 and 8 wt% CaF2•

Jan 1, 1994

By Ken Steele, Pam Sangster, Myra Gerow

Ontario leads Canada in production of structural materials and ranks third in production of non-metallic minerals. The total value of industrial mineral production in 1997 was $1.6 billion. The province is the leading producer of nepheline syenite, salt, talc, clay products, cement, lime, sand and gravel, stone and a major producer of gypsum and silica. Barite, sulphur in smelter gas, elemental sulphur, tremolite, serpentine, gemstones and peat are also produced. Table 1 shows recent actual industrial mineral production levels in Ontario. Other industrial minerals, including phosphate, petalite, diamonds, wollastonite, vermiculite, kyanite, garnet, graphite, silica, kaolin, dimension stone and anorthosite, have been the target of exploration and development projects. Investment opportunities exist at all levels from grass-root prospect through to production level.

Jan 1, 2001

By Y. P. Wu

Steeply dipping seam refers to the coal seam with dipping angle in the range of 35?55°, which is well recognized to be very hard to mine by the mining industry all the world. In the last two decades, some fundamental researches were focused on the strata behavior of long-wall panel, complicated rock mass breaking process of the steeply dipping seam, overburden stress field developing and evolution, rock strata breaking and moving process, rock structure stability mechanism and control. Results show that it?s presenting macro stress arch-shell (MSAS) of the stress distribution of the overlying rock in steeply dipping seam. The MSAS is the spatial distribution of intensity envelope line under the strength criterion and has the geometry shape asymmetry as well as the stress distribution heterogeneity. The arch- shell base will forward as the working face mine forward and the shell roof will extend to higher overlying strata above the gob. In this paper, the stress arch-shell analysis model and coordinate system were established and analyzed the inclined masonry structure at different zone. Analysis results show that the rock damage at the key part of the arch-shell is the main factor which causes whole overlying rock structure failure. The rock structure instability modes have tension instability of the shell roof, compression-shear instability of the shell shoulder and composite instability of the shell base, meantime, instability coefficient is proposed to determine instability condition. The above research results enrich the complex coal seams mining theory and provide a theoretical basis for mining safely and efficiently in steeply dipping seam.

Aug 1, 2013

By G. W. Poling, J. R. Hoffert

"A common practice in preventing gravity-fed tailing pipeline from plugging due to sanding is to add lime at relatively high dosage rates. The lime affects the rheology of the slurry ""vehicle"" which transports the coarser particles in a heterogeneous flow-regime. This paper describes a study of the effect of lime on the critical deposition velocities and friction head losses of Highmont Mining Company's mill tailing. Testwork using an extrusion viscometer was related to the surface chemistry changes brought about by the high lime additions. Lime additions which typically increased the tailing pH from 8.4 to 11.5 reduced the critical deposition velocities from approximately 3.2 to 1.7 m/sec.IntroductionCommon practice, at least in base metal concentrators in British Columbia, is to use high lime additions in tailing slurries when the pipeline becomes partially plugged with sands. Some concentrators, such as the Highmont Mining Co. Ltd. plant, add lime on a continuous basis during low tonnage periods and during startup/shutdown transition s. Although such high lime additions often solve temporary plugging problems, the effect of lime on slurry rheology has not been well understood.Slurry pipelines are designed to transport solids in suspension with a minimum of wear and without particle deposition. These two objectives are in opposition because the velocities required to maintain solid suspension can sometimes cause high head losses in the pipeline, as well as wear problems. Thus, the optimum velocity for a long distance slurry pipeline is in the range that provides just enough turbulence to keep coarse particles in suspension."

Jan 1, 1985

By K. Sasaki

Ventilation measurements were carried out in a shallow underground-quarry space with relatively large internal volume of 14,600 m3 in order to evaluate its effective ventilation characteristics. Based on air velocity measurements with an ultrasonic anemometer in the exhaust airway connected to the space, it was found that the space was ventilated by natural ventilation airflow with intermittent changes in direction. It was difficult to measure the ventilation flow with typical methods of flow measurement provided from the intake portal and throughout the mine, because the cross-sectional area and volume of the openings were too large and the flow was variable. In the present study, a tracer gas method was applied to evaluate the effective ventilation airflow rate in the space. A photo-acoustic infra-red gas monitor, highly sensitive to SF6 gas used as a tracer gas, was set in the space to determine air exchange rates from gas concentration-time decay curves. The seasonal variations of airflow and thermal environment in the space were investigated through 13 sets of measurements taken over 15 months. Airborne rock dust concentrations were also measured at same time in the opening. The correlations between the effective ventilation airflow rate, thermal environment and dust concentrations in the opening space were analyzed and are discussed based on the presented measurements taken during year. It is concluded that seasonal variations in effective ventilation flow and the dust concentration are mainly due to differences in air temperature in the space, as affected by the rock?s surface temperature and atmospheric temperature. In summertime, the air temperature and associated air density difference generated lower natural ventilation flows resulting in higher dust concentrations.

Aug 1, 2013

By E. M. De Souza

"The mining industry has developed a strong need for monitoring underground openings since bulk mining, used for increased productivity, has become the dominant mining method industry wide. The large stopes associated with bulk mining methods generally have to remain open and stable for several months, and monitoring is essential to provide an indication of ground response to mining and stope stability. The instrumentation data is also important during design optimization, which is used to maximize recovery, to minimize the dilution of ore and to minimize costs. Monitoring is essential to implement safety and is also critical in stope and mining sequence designs. The safety related aspects of monitoring include the protection of underground workers and the prevention of accidents by providing early warnings of the onset of any ground instability. The design related aspects of monitoring involve the development of data bases used for stope dimensioning and mine sequencing and timing and the monitoring of ground behaviour as a result of mining to verify the validity of the design thus allowing for remedial action during operation.Manual instrumentation data collection is, in a number of cases, economically unfeasible and, in many situations, dangerous as instrumented areas become inaccessible or extremely unstable. Also, because more and more complex instrumentation is being installed in underground operations, in several cases it becomes practically impossible to collect readings manually. The design and development of low-cost acquisition systems for mine wide monitoring would thus constitute an important step toward automation in excavation instrumentation. A unique menu-driven automatic 32-channel analog data acquisition and analysis system with a built-in rock failure warning mechanism has been designed and developed. This low cost acquisition system is capable of receiving, processing, displaying and storing the transmitted instrument data remotely and automatically. Computer software has been designed to provide data reduction and analysis immediately in the field and to automatically display results in graphical form for quick interpretation. Automatic data interpretation is used to show trends in rock mass behaviour and the system can be used to provide early warning of rock failure to the mine personnel working in there so that immediate remedial action can be safely taken."

Jan 1, 1992

By S. Yannacopoulos, L. Bichler, P. Wanjara, J. Gholipour

Characterization of a virgin and in-service Inconel 718 alloy was undertaken to study the changes caused by the service conditions on the grain size, ?? phase, MN-type nitrides and MC-type carbides. The size, distribution and volume fraction of these phases and grain size were studied using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and electron backscattered diffraction (EBSD) analyses. A considerable difference in the grain size, as well as distribution and volume fraction of the precipitates was observed in the in-service material as compared to the virgin Inconel 718. As a result of these microstructural changes, a notable dissimilarity in hardness between the materials investigated was observed. The results presented in this study are important for proper development of repair parameters and heat treatment of in-service Inconel 718 material.

Jan 1, 2014

By Deni Lessard, Roger Demers, Noël R. Billette

"The Quebec Mining Association has for many years been supportive of the activities of the Centre de recherches minérales which were initiated to ensure regular production hoist and cable inspections to maintain safety and productivity standards in underground mines in Quebec. CRM and CANMET have agreed to fund a Quebec Mineral Development Agreement contract to capture this accumulated knowledge. Using VP-EXPERT to process the information and subdirectories to store regulations, the prototype access D-BASE III records on hoist information and LOTUS 123for simulating working conditions that meet local regulations and expert rules of thumb criteria. Objectives are to improve safety in emergency operating procedures, maximize hoist productivity and safety, and promote knowledge transfer to operators."

Jan 1, 1992

By T Salman

The construction and use of the B.E.T. (gas adsorption) apparatus is described. Examples are given for the determination of large and small surface areas using nitrogen and krypton. Introduction A NY study of the milling of ores from crushing to grinding, classification, and concentration and finally dewatering of the products involves solid particles which are either in contact with a gas or a liquid phase. The surface area of the solid and its characteristics constitute important parameters in all mineral dressing operations. The success of any particular operation is dependent on the interaction of the surface of the solid particles with the gas or the liquid phase. Particle size and specific surface (surface area per unit weight) continue to be important parameters in the flotation research associated with the adsorption of collector molecules or ions on mineral particles, as in the early years of mineral dressing research (1). In order to understand the mechanism of the flotation process, it is essential that the surface properties of the adsorbent be known.

Jan 1, 1965

By Siavash Zamiran, Abdolreza Osouli

"One of the most concerns of room and pillar mining system is subsidence of the ground surface due to coal mining particularly in room and pillar mines. Subsidence of ground surface is a result of floor, pillar, or roof failure of the mine. At the same, due to many difficulties associated with surface disposal facilities of coal refuse, some mining companies are trying to use underground space as a disposal storage place. In this study, stability and subsidence analyses of an underground coal mine located in the Illinois Basin are conducted. This room and pillar mine was abandoned and later on was used as a storage place to accommodate the coal fine refuse with slurry backfilling method. The geological stratigrophy and geomechanical properties of the mine floor and roof were collected. Floor and pillar stability analyses were conducted for areas with various extraction ratios. The stability of the mine was evaluated both prior and after slurry backfilling. The floor and pillar stability analyses results of the mine due to moisture exposure after slurry backfilling are discussed. The subsidence potential due to mine failure is also evaluated.INTRODUCTIONA typical lithology of coal seams in the Illinois Basin consists of weak underclay stratum. The immediate weak underclay causes frequent floor instability problems in Illinois underground coal mines. There are two different stages in assessing floor stability of the mines where slurry backfilling is planned. The first stage is during the mining operation when weak underclay layer squeezes under pillar stress and results in punching or bearing capacity failure. The second stage is after slurry backfilling. During this stage, the slurry material soaks non-durable floor layers and causes strength reduction in floor material. Pillar stability conditions should also be taken into account during both the operational period and after the slurry backfilling."

Jan 1, 2015

By D. Moffat

Rio Algom Limited has mined uranium at Elliot Lake, Ontario for 20 years. The production of this energy-generating element results in the need to dispose of low-level radioactive solid wastes and liquid effluents. Because of the wet-temperate climate at Elliot Lake, the liquid effluents are of particular importance. Radium-226 is the isotope which requires most attention, and the current practice for its control is by addition of barium chloride and retention of the resultant precipitates in large settling ponds. Analyses of typical effluents and waste streams are discussed and typical levels of radium-226, thorium-230, thorium-232, thorium-228, lead-2iO, polonium-2iO, and uranium isotopes are presented.

Jan 1, 1979

By M. Mirnezami, J. A. Finch, M. S. Hashemi A.

This study examined the effects of pH and sulphate concentration on the surface charge and stability of alumina and pyrite dispersions. The relationship between these properties was investigated using measurements of electrophoretic mobility and settling velocity. The maximum aggregation for both minerals was observed near the iso-electric point (iep) where the force of repulsion is at a minimum. Aggregation decreased at pH values away from the iep, where an increased surface charge causes electrostatic repulsion between particles. Zeta potential data revealed that sulphate ions were adsorbed only on positively charged surfaces for both minerals. Adsorption of sulphates on the alumina surface increased aggregation by reducing the surface charge from >+25 mV to close to zero. These results indicate an electrostatic bonding of sulphate ions to alumina surface. Preliminary results on the interaction of pyrite and sulphate ions indicate a similar response.

Jan 1, 2004

By D. L. Mckay

"Texasgulf's 25-foot-diameter Kidd Creek No. 2 Shaft is situated next to the company's No .1 Shaft, so that both shafts can share common surface and underground facilities. Shaft construction, covering a span of five years from collaring to commissioning , started by freezing the 50 feet of grey varved clay covering the bedrock. After first completing the concrete headframe, sinking to the 5/00-foot horizon utilized two different shaft construction methods. The top 2800 feet was excavated by slashing a 6-foot-diameter borehole and hoisting the broken material up the 3OO0-foot-deep No.1 Shaft; the remaining 2300 feet was excavated by conventional benching methods. Prior to installing the 5100 tons of galvanized shaft steel on the completion of the sinking operation, the sinker was able to install all thirteen armoured electrical cables in one pass with his modified galloway stage. All loading and lip pockets were installed along with the steel guides and bun tons during the equipping operation.IntroductionOn November 21,1978, Texasgulf completed the No.2 Shaft at Kidd Creek Mine. This shaft is the largest shaft (volumewise) in North America and is unique in many respects . The purpose of this paper is to outline some of the unique features of this shaft as well as to record how this facility was constructed.Soon after sinking No.1 Shaft, Texasgulf started a program of exploratory diamond drilling from the 2800 level in No. 1 Mine. The drilling outlined sufficient ore below that level to justify a second mine. Feasibility studies demonstrated that production could be increased by one-third exclusively from this deep ore . The study called for a 25-foot-diameter shaft to the 5100-foot horizon to service a mine producing 5,000 tons of ore per working day.The site chosen for No.2 Shaft and head frame is 350 feet southwest of No.1 Shaft. This, along with No.1 Shaft, will be away from the influence of ground subsidence when mining at depth. The collar and head frame foundations are located on a flat rock ledge some 70 feet below surface. This flat ledge was found by test holing through the overburden by diamond drilling. It is fortunate that this location best satisfied the surface layout and logistics for both surface and underground ore and waste handling."

Jan 1, 1981

By P. A. Verhey

"This paper describes a series of wear-resistant ceramic materials which have been successfully used in the mineral processing industry in Canada. Applications include use with metallic ores, coal, potash and asbestos, and in other processes where wear degradation is of major concern. The paper will also deal with considerations involving the selection of the different ceramic materials available. It will cover the installation of ceramic materials on support structures under varying process ' conditions, as well as the other physical and chemical factors which have to be taken into account.IntroductionIn the mineral processing industry, large volumes of ores tailings and other materials are handled. The abrasive nature of most of these materials results in extensive wear to both handling and processing equipment.Wear ratios versus cost, production losses due to down time and wear-resistant material suitability for a given application all demand particular attention when viewed against the need for increased efficiencies in existing processes. As a consequence, a very active continuous search for materials with improved wear resistance has been carried out for many years.In this search, starting about 20 years ago, dense ceramic materials were tested and evaluated in certain applications, notably in the iron ore and asbestos operations in Eastern Canada. As a result of substantially better performance both in continuous extended life and ultimate economics realized , wear-resistant ceramic applications developed progressively in many other processing applications, replacing traditionally used materials.In the vast majority of wear-resistant ceramic applications, considerable extended life over previously used materials was established. This invariably was not just a fractional increase but, in most cases , in factors of double, triple and often all the way up to 18 and 20 times the life of alternative materials used previously. In certain applications, extended life could not be measured and appears to be indefinite.Obviously, as a result of such experiences, the progressively wider use of wear-resistant ceramic materials is now an established trend."

Jan 1, 1981

By T. A. Apelt, B. J. Elliot

"In September 1993, the flash furnace at Kalgoorlie Nickel Smelter, KNS, was brought off line after almost 12 years of operation. This is a record campaign life for a flash furnace. The furnace was' totally rebuilt and the capacity of the plant increased from 540 000 tpo to 750 000 tpa of concentrate throughput. The throughput increase was' achieved through the construction of a 525 t/day oxygen plant and upgrading of various plant ancillaries. A number of significant design modifications were also built into the flash furnace and oxygen enrichment was implemented in the operation of the Peirce-Smith converters.This paper discusses the rebuilding of the flash furnace and design modifications made to furnace equipment and ancillary plant. Some preliminary post-startup operating data are presented.IntroductionIn September 1993, Campaign 6 of the flash furnace was concluded and the furnace brought off line for rebuilding. The campaign length was almost 12 years and set a new record for campaign length. Planning for the rebuild took place over the last five years of the campaign. A number of modifications to the design of the furnace and the ancillary plant were planned to coincide with the furnace rebuild. The furnace was rebuilt and recommissioned in 70 days. The increased plant capacity of 750000 tpa has been achieved by the construction of a 525 t/day oxygen plant and modifications made to ancillary plant which centred around increased p~ control, efficiency and hygiene. This paper examines the development and implementation of the modifications made to the furnace and ancillary plant. Preliminary post-shutdown performance data are presented."

Jan 1, 1995

By Mark Stephenson, Paul Henharen

"The objective in the mineral processing of primary ores is to liberate and effectively recover each individual economically viable diamond with minimal reduction in its potential value.There are three distinctive phases in diamond processing:Feed PreparationWhere the diamonds are liberated and waste material finer than the economically selected cut-off size is rejected. In this section we will discuss the various techniques utilised worldwide to effect feed preparation.Primary ProcessingWhere the diamonds are recovered into a high grade concentrate suitable for the more expensive and selective final recovery process. In this section we will discuss the development of primary processing from jigs and pans to the more current techniques utilised worldwide.Final RecoveryWhere there is selective rejection of waste particles until only diamonds remain. The diamonds may then be acidised prior to packing and marketing.Within these distinct phases a variety of unit processes have been utilised and this paper will discuss their relative merits, limitations and suitability in respect to the various stages of diamond project development from prospecting through to production.Basic capital and operating costs are compared for the autogenous milling route developed in the CIS and the crushing and scrubbing route utilised in the west."

Jan 1, 1994

By Francis Dakubo, Courtney Young, Avimanyu Das

"Hydrometallurgy of copper ores typically involve acid leaching followed by solvent extraction and electrowinning (SX/EW). EW is the final purification stage in which a voltage is applied across two electrodes causing the copper ions to reduce and deposit on the cathode. Applied voltages are near 2 volts with current densities around 300 amps/m2. In this study, research was undertaken to decrease the energy consumed in the EW process. To do this, various cell designs were constructed and tested in which a membrane was used to separate the cathode and anode compartments with concentrated solution from SX serving as catholyte and raffinate from SX serving as anolyte. Therefore, copper in the concentrated solution would be deposited on the cathode while ferrous in the raffinate would be oxidized to ferric at the anode. Because it is assumed that ferric acid leaching is used, resulting ferric would be recycled to the leaching process. A positive side effect of the envisioned process would be the elimination of oxygen evolution at the anode and thus the prevention of acid-misting. After a cell design was selected, it was used to test a number of variables: flowrate, concentration, temperature, ion-exchange membrane, and applied voltage. Following experiments in which variable ranges were determined, statistical modeling was conducted using STATEASE software. Optimal results indicate the voltage can be decreased to 1.5-1.7 volts with current densities of 300-400 amps/m2. Significant reduction in the energy consumption was accomplished by reducing the applied voltage. Furthermore, current efficiencies and copper production rates was increased by application of the membrane.INTRODUCTIONLeaching of copper ores is achieved using mostly sulfuric acid. The copper pregnant solution is contacted with an organic solvent or resin adsorbent which picks up copper ions as in Equation 1:"

Jan 1, 2016

By Li Xibing

The In order to mine safely with reasonable cost, it is necessary to research the fracture characters of backfill and its matches with rock mass. Four kinds backfill with cement-tailing ratio of 0.250, 0.125, 0.100 and 0.083 respectively were tested, and basing on stress-strain curves tested, the deformation characters and fracture laws as well as the damage constitutive equations investigated with damage mechanics whose calculating results are coincided with experiment results well were proposed. The results of damage analysis show that there have different damage characters in different backfill, e. g. the lower the ratio of cement to tailings the lower the damage values when stresses reach to peak value; the lower the content of cement the more rapid in damage and the more abrupt in breakage process. In addition, using catastrophe theory, an energy model was proposed for backfill and rock mass acted each other in mechanics, and the unstable condition of the system was obtained. Research results show that the higher is the stiffness of rock mass the more stable the system, and the lower is the ratio of cement to tailings, the more unstable the system will be. Further more, according to the catastrophe model proposed, the reasonable matches between backfill and rock mass were researched, and a calculation formula that designs reasonable strength of backfill during mining was put forward. It has been proved by practice that the model and theory researched in this paper can guide filling design in mining. Keywords: Cemented tailings backfill, constitutive equation, catastrophe theory, match of backfill and rock mass

May 1, 2007

By Dirk van Zyl

The world is consuming more and more electronic products every year. This has caused a dangerous explosion in electronic scrap (e-waste) containing toxic chemicals and heavy metals that cannot be disposed of or recycled safely. But this problem can be avoided. We are pressing leading electronic companies to change; to turn back the toxic tide of e-waste. Every year, hundreds of thousands of old computers and mobile phones are dumped in landfills or burned in smelters. Thousands more are exported, often illegally, from the Europe, US, Japan and other industrialized countries, to Asia. There, workers at scrap yards, some of whom are children, are exposed to a cocktail of toxic chemicals and poisons.

May 1, 2008