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By J. S. Fox

It is generally recognized that the interpretation of bedrock geochemical data in volcanic terrains can be improved by adjusting for rock-type. Various chemical attributes of volcanic rocks have been put forward in the literature as rapid indicators of rock-type, but there is some question as to which of these is the most reliable . Only one such attribute, total iron, seems to have seen systematic use in geochemical mapping in the Flin Flon region. Discriminant analysis of 500 basalts, andesites, dacites and rhyolites suggests that SiO2 is the most important rock-discriminating variable and that MgO, CaO, TiD2, AI2O3 and FeOtot, are successively poorer discriminators. Lithological normalization in the subalkaline volcanic environment should therefore be made over ranges of this variable. Trace-metal data from drill core through the sulphide orebody at Hanson Lake, Saskatchewan are used to demonstrate various approaches to lithological correction, including silica normalization, factor analysis and trend analysis. All of these extract economically important information from the core that is not apparent in the raw data logs. However, silica normalization does not seem to be subject to as many serious limitations as factor and trend analysis in this case, and therefore seems to provide the most reliable basis for the interpretation of subsurface exploration geochemical data.

Jan 1, 1978

By R. Cottam

The deformation and recrystallisation of magnesium yttrium alloys containing 0.23, 0.84 and 2.71wt% yttrium and commercially pure magnesium extrusion has been investigated at temperatures between 200 and 350°C. The alloys were produced as billets 7.5 cm diameter, solution treated at 525 °C for 8 h and extruded into 3 cm diameter bar at 390°C. Channel die compression was employed to deform the samples at a strain rate of 1x10-3s-1. For the 0.23 wt% yttrium alloy and the pure magnesium, dynamic recrystallization (DRX) occurred at all temperatures and the amount of DRX increased as the temperature was raised. In the alloys containing 0.84 and 2.71 wt% yttrium DRX was almost completely suppressed at all temperatures. The absence of DRX in the 0.84 and 2.71 wt% yttrium alloys was accompanied by a decrease in the ductility, except at 350°C the highest deformation temperature. It was observed that this increase in ductility was accompanied by a reduction in deformation twinning and the initiation of pyramidal slip. This work highlights the important role that DRX plays in enhancing the ductility of magnesium alloys.

Jan 1, 2006

By M. Tadie, J. Wiese, K. Corin

The use of potential control in the flotation of ores has been applied in a variety of operations and presents an opportunity for improvement of selectivity and recovery of valuable minerals. Although it is possible to vary the redox potential (Eh) using chemical additives such as sodium hypochlorite or hydrogen peroxide this is more commonly done by varying the pH and dissolved oxygen (DO) concentration. The present study involves an investigation into the effect of varying dissolved oxygen concentration, ionic strength (IS) and pH on the flotation response with the aim of application to a South African lead-zinc ore. In all cases the Eh is measured as a function of the different DO, IS and pH values. The main objective was to achieve selective flotation of galena from sphalerite. The first part of the work was micro-flotation tests conducted on single minerals with galena used as the basis for effect of the factors studied on redox potential and ultimately recovery. The DO was varied by alternating between the use of air and nitrogen as the gas source to the micro-flotation cell. PH was varied between pH 9.2 and pH 11.8 using sodium hydroxide. In the first part of this study a factorial design approach was used to determine the interactive effects of the variables tested, viz. DO, ionic strength and pH, on the Eh and on the recovery. Redox potential was measured using a combination electrode made up of platinum wire and Ag/AgCl reference combination. Recoveries indicated that pH had the most significant effect on recovery and Eh. The influence of redox potential on recovery was found to be of relevance to the condition of high dissolved oxygen concentration and less so at low dissolved oxygen concentrations. It was also noted that that the combined interaction between ionic strength and dissolved oxygen concentration had a positive effect on recoveries, however this was not so with Eh. The chemistry of the ions in solution was observed to play a dominant role on the recovery due to changes in solubility arising to pH modification. The longer term objective of this work is to determine the optimal Eh conditions for the separation of galena from sphalerite.

Jan 1, 2016

By R. Carter, C. S. Samis

"SummaryThe results of this investigation indicate that the gold in the cyanide tailing of refractory gold cyanides is occluded in fused •particles formed during roasting. This conclusion was reached following microscopic examination of calcines produced at various furnace temperatures with different atmospheres, and a •comparison with calcines produced by decomposing samples of completely sulphated concentrate under conditions such that the maximum particle temperature varied between 6•50°C. and 1,100°C. This comparison showed that the particle temperature during a normal roast may be several hundred degrees higher than the furnace atmosphere, or that the fusion is associated with a low melting (950°C.) eutectic mixture of FeO and FeS.Because of the unavoidable particle fusion during a furnace roast, and because low particle temperatures are essential for gold extraction by cyanidation, aqueous medium oxidation under high oxygen pressures was studied. Gold recovery from calcines produced by this means was over 98 •per cent •compared with a maximum of 80 per cent from furnace calcines.IntroductionMANY arsenical gold ores are called 'refractory' because much ' of the gold cannot be satisfactorily extracted by cyaniding the raw ore or concentrate. Even when such ores are roasted to oxidize .the iron and arsenic and 'release' the gold, often 10 to 25 per cent of the gold present is lost in the cyanide residues."

Jan 1, 1952

By H. Sahay

"DISCLAIMER NOTICEThe views and conclusions contained in this presentation are those of the author and should not be interpreted as necessarily representing the official policies or recommendations of the Department of Mines and Energy, Government of Newfoundland and Labrador. ABSTRACTThis paper describes the main testing procedures that should be carried out to evaluate the capacity and capability of the service brakes on the large-size diesel-electric trucks now in common use at open-pit mining operations. Brake testing programs in general are described, and then consideration is given to different techniques of service brake testing, brake performance evaluation, braking energy and typical performance characteristics.IntroductionThe first diesel-electric truck with a capacity of about 85 tons was introduced in 1963 by Unit Rig and Equipment Company of Tulsa in cooperation with General Electric Company, who successfully developed and supplied the most important component- motorized wheels. Since then, its popularity and numbers have continued to grow, and now more than 3700 such units are in operation in mines around the world. In Canada alone, their number is more than 700, including about 150 in the Province of Newfoundland and Labrador. Similarly, their size has also grown from that initial capacity of 85 tons to 350 tons.Although the introduction of the electric trucks proved to be invariably economical, their indiscriminate use was not without severe consequences. Many runaways and even fatalities occurred when the dynamic retarder failed while the truck was travelling loaded down severe grades. The service brakes in such cases proved incapable of stopping runaway trucks, mainly due to their limited capability and the fading caused by excessive heat produced during the act of braking itself. This eventually led the various governments, the open-pit operators and the manufacturers to seriously question the braking capability as well as function of both service brakes and dynamic retarders. Extensive testing"

Jan 1, 1980

By H. Kuno, H. Kobayakawa

A borehole inclinometer with FBG optical fiber sensors has been developed to clarify very slow slope movements, and the results of its application to a real slope have been shown. The main characteristics kept in mind while developing this inclinometer are as follows. Firstly, the workability must be good so that only one cable is required for taking the measurements, because the inclinometer is composed of several FBG sensor elements constructed on an optical fiber. Secondly, the minimum interval of the distorted measurements must be close, namely, within 100 mm. Thirdly, the inclinometer must excel in thunder resistance. The measurements were executed by setting up the developed borehole inclinometer on a slope where the rate of displacement is several millimeters per year. The movement of the device was developed by comparing it with that of the results of an existing borehole inclinometer. The area of the displacement concentration, 1 m in width for 4-m sections, was confirmed by the existing borehole inclinometer. The boring core, recovered using a high-quality drilling technique, was examined. Landslide clay was not permitted at the location where the displacement had concentrated as a result of comparing the measurement results with the boring core, and the rotation of gravel by the movement of the slope’s land block was allowed. These results show the slope being caught in the stage just before a primary landslide. In addition, the feature whereby the slope behavior depends on the depth was analyzed by comparing the information on the underground displacement with precipitation and earthquake records.

Jan 1, 2015

By Mary A. Wells, Amir Hadadzadeh, Mark A. Whitney, Stephen F. Corbin

In an effort to produce less expensive titanium sheet via roll compaction, the room temperature compaction behavior of titanium sponge granules (99.9% pure, Alfa Aesar) was studied under uniaxial die compaction. The titanium sponge granules were irregularly shaped, with a high degree of porosity, having a maximum particle size of 3mm. Manual die compaction was conducted using a Carver hand press, in a hardened tool steel die with 12.61 mm inner diameter. Uniaxial die compaction in a hardened tool steel die with 9.50 mm inner diameter was also performed using a Gleeble® 3500 thermal-mechanical simulation testing system which allowed for controlled deformation rates. Compaction behavior of the titanium sponge was studied using well-established compaction equations (Heckel, Panelli-Filho and Ge), and it was observed that compaction rate influences the room temperature compaction behavior of this material. The Heckel analysis of the titanium sponge showed that the behavior of the material could be analyzed in two compaction pressure regimes. In the low pressure regime (<100 MPa) the granules exhibited high compressibility, while; in the high pressure regime (>100 MPa) lower compressibility of the titanium sponge was observed.

Jan 1, 2015

By R. E. Martin

"The Westerose Leduc (D-3) pool, a Devonian reef reservoir situated in Central Alberta, Canada, has now been producing for over seven years. As a unit operation, the pool pro-vides an interesting example of the full exploitation of gravity segregation tendencies. The reef has a 238-foot oil column, underlain •by bottom water and over-lain by a substantial gas cap. The original hydrocarbons in place were 147.96 million STB oil and 94.4 MMMCF of Taw gas cap gas. Nine-teen producing wells on 80-acre spacing have been completed, most of which are highly productive. Gas injection operations return solution gas to the gas cap. A study of the rock and fluid properties of the pool show it to be conducive to production by gravity segregation at high rates. Monthly average producing rates have varied between 800 B/D and 8,000 B/D and have recently totalled 3,000 BID to 5,000 B /D. Recovery and performance predictions under partial pres-sure maintenance at 10,000 BID indicate an ultimate recovery of 66 per cent of the original oil in place. In the absence of pressure maintenance, recovery would be only slightly less."

Jan 1, 1960

By C S. Stevens

This paper describes the problems encountered and the steps taken to solve them in milling an ore containing relatively large amounts of pyrrhotite. A complex and greatly lengthened flotation circuit was required to recover the pyrrhotite. A very low pH had to be maintained in the cyanide circuit in order to get good recovery of the gold and maintain reasonable cyanide recovery. Introduction D ELNITE Mines Ltd., a gold mine situated about 5 miles by road south and east of the town of Timmins, Ontario, is serviced by two shafts. No. 2 shaft extends from surface to the 2875-ft. level, and No. 3 shaft, an internal winze, extends from the 2875-to the 5275-ft. level. No. 2 shaft was stopped at the 2875-ft. level because of a heavy band of chloritic schist which necessitated a drive to the north for 1000 feet, where No. 3 shaft was sunk. The latter bottomed in the schist at the 5275-ft. level. From the 2500 to the 2875-ft. level in No. 2 shaft, the ore was

Jan 1, 1965

By F. Bourgeois, J. -S. Kroll-Rabotin

ABSTRACT: Falcon concentrators are enhanced gravity separators designed for concentrating fine particles. The Falcon UF model is unique in that it is dedicated to beneficiation of ultrafines, one key feature being that it does not make use of any fluidization water. We investigated the physics of particle transport inside Falcon concentrators, and concluded that separation efficiency is governed by differential settling velocity. We derived and published a predictive model of the partition function under dilute conditions. We intend to extend the initial model to concentrated ultrafine suspensions for application to industrial scenarios by adding hindered settling to account for solid concentration effects.

Jan 1, 2011

By Funsho K. Ojebuoboh

With several “green” applications on the horizon, bismuth has become an even more important minor metal in the smelting and refining of lead. Smelters with a complex sulphide feed invariably deal with bismuth. Its behavior during the smelting of lead in conventional sinter-blast furnace operation is discussed. Because it readily deports to the lead phase during the refining of lead, its separation from refined lead remained unsatisfactory in early lead production. When commercial requirements of bismuth in lead became more stringent early this century, the procedure where by calcium and magnesium is used todebismuthise lead was developed. The present conduct of this 1936 process, the Kroll-Betterton process, is discussed with emphasis on operational improvements.

Jan 1, 1996

By E. Ghali, N. Sorour, G. Houlachi

"The binary Fe53Mo47 and ternary Fe54Mo30P16 coatings have been electrodeposited from citrate-based electrolyte on mild steel (MS) substrates. The electrodeposition has been conducted for 6 hours at 20 mA cm-2 and 30°C. The electrochemical tests were carried out in chlorate solutions containing 300 g L-1 NaCl and 4 g L-1 K2Cr2O7 at pH 6.4 and 80°C. A number of surface characterization techniques such as SEM-EDS, XRD and EMP were used to study the microstructure of the alloys. The electrocatalytic activity of these coatings was investigated using steady-state polarization and galvanostatic technique. This study revealed that the Fe-Mo-P coating could be considered as a promising cathode material for the hydrogen evolution reaction (HER). The results showed an important decrease of hydrogen overpotential for Fe-Mo-P alloy as compared to that of Fe-Mo and especially MS which is a traditional cathode in chlorate industry. The HER overpotential for Fe54Mo30P16 at current density of 250 mA cm-2 was decreased by 30% in comparison to that of MS (1029 mV), and by 16.5% to that of Fe53Mo47 coating (857 mV).INTRODUCTIONSodium chlorate is used for manufacturing of several daily consumption products. This chemical is mainly employed for the production of chlorine dioxide (ClO2) that is a bleaching agent used in the pulp and paper industry. The ClO2 is also consumed for generation of perchlorates, chlorites and other chlorates, as an herbicide and in uranium processing (Cornell, 2002). Sodium chlorate is produced industrially via following overall formula in un-divided electrochemical cell (Nylén & Cornell, 2009):"

Jan 1, 2016

By H. Harzer

Statistics Canada record s indicate that in recent years 70 to 80% of the entire Canadian coal production originated from Western Canadian mines, in which about 55 to 65% of the coals are bituminous. Until recently, less than 20% of the latter were extracted by underground methods , the remainder being surface-mined. However, it is estimated that within the foreseeable future up to 80 or 90% will have to be gained by underground techniques. Although Western Canadian coal resources are considerable, they are unfortunately locked in severely distorted, steeply pitching and faulted seams of variable thickness. Consequently, their economic extraction poses serious engineering problems. One possible solution to the problems is to apply hydromechanical methods to underground mining. This is a well-proven method shown to be economically viable under Western Canadian conditions. This paper endeavours to widen the scope of published data on hydraulic coal mining and is based on practical engineering and cost data gathered through contacts with West German designers and operators of hydraulic mines.

Jan 1, 1978

By Helmer Kraemer

One of the CIM 2003 conference themes is ?Globalization and the impact on mine operations?. In this context, the first official version of the new ?International Rock Excavation Data Exchange Standard? (IREDES) is being released. This new standard is a highly flexible data interface for exchange of information between production equipment and central computer systems. The standard was defined by global players in the mining industry and will soon be used to enhance local operations of global mining companies. Beside the standard definition now other aspects are coming into focus: The question how to design and how to implement IREDES compliant data exchange in practice. Implementation of IREDES covers the following aspects: !" Implementation on in-field production systems !" Communication and networking !" Implementation on databases and commercial IT systems In-field production systems are characterized by a big variety of different automation systems. Therefor, different IREDES implementation philosophies have to apply to those systems. One philosophy uses an integrated IREDES compliant automation system on every machine. The alternative method uses one shared IREDES compliant ?Proxy server? for a number of machines connected to this server using proprietary interfaces. Communication and networking can be integrated openly and independently from hardware infrastructures. The only precondition is that communication and networking has to be Ethernet - TCP/IP protocol compatible. IREDES Implementation on the commercial IT level means to exchange IREDES data sets with databases, simulation software, office packages and special applications. Interfacing is easy as long as the software or the database system provides an interface to the Extensible Markup Language (XML).

May 1, 2003

By K. Meshinchi Asl

In this study the effects of T4 and T6 heat treatments on microstructural characteristics of AZ91 alloy containing Rare Earth elements have been investigated. Formation of intermetallic Al1 1RE3 needle shape particles which have a good thermal stability reduces both formation of ß(Mg17A112) and discontinues precipitation in AZ91 alloy which are dominated at the grain boundaries and are responsible for poor mechanical properties specially in elevated temperatures. For AZ91-RE samples both T4 and T6 heat treatments led to a continuous precipitation of ß particles at the grain boundaries after aging. However, in AZ91 samples (with no Rare Earths) precipitation was discontinuous at grain boundary areas. This type of precipitation is one of the main reasons of poor mechanical properties of this alloy at elevated temperatures.

Jan 1, 2007

By C. Droun

"Low back pains account for about 13 per cent of all compensation claims made to the Quebec Workmen's Compensation Commission and cost the employers a sum exceeding ten million dollars. The frequency and cost of these health problems in Quebec metal mines are proportional to the provincial trends. An elaborate review of the literature on the causes, nature and prevention of low back pain is made in this presentation. A prevention program for low back pain has been designed in cooperation with a team of seven medical specialists and two physiotherapists for the Quebec metal mines. The program is especially designed for persons who have had low back pain, in order to prevent a recurrence, and for persons beginning to feel chronic difficulties. It is based on existing programs at the Hawthorne Plant of Western Electric Company and at Minnesota Mining and Manufacturing, but it requires a much different approach because of the nature of medical care available at the mining sites. The program is difficult because it involves a change of attitude for every employee and every supervisor. The program, so far, is beneficial because several men are now seriously engaged in an active program of reconditioning and because the problem of low back pain ie beginning to be seen from a new angle."

Jan 1, 1973

By H. T. Kennedy, D. L. Flock

"The project described in this pa-per was undertaken to provide a more thorough understanding of the effect of contamination by drilling fluids on the electrical properties of porous systems. The basic work per-formed was filtration tests on both consolidated and unconsolidated sands and the determination of their resistivity profiles with the aid of screen-type electrodes spaced at convenient intervals along the core.Four drilling fluids were selected, ranging in resistivity from 447.0 ohm-cm. to •5.76 ohm-cm. The permeability of three unconsolidated and four consolidated cores, on which resistivity measurements were made, varied from 1,257 md. to 4,560 md. Five additional cores with permeabilities as low as 49 md. were tested to investigate the effect of permeability on the depth of invasion of drilling fluids.The effect of drilling fluid invasion on resistivity profiles was determined on cores containing brine only, and on those containing 80 to 90 per cent oil and 20 to 10 per cent brine. The study included measurements of (a) clay content of different sections of the core, (b) saturation of the invaded fluids and oil in different parts of the core, and ( c) changes in resistivity as a result of gravitational re-distribution of fluids and diffusion of electrolytes.The data showed that the resistivity of an invaded core is, as was expected, controlled by the resistivity of the filtrate, the resistivity of residual core water, the resistivity of the clay particles, and the amount and distribution of the filtrate, clays, residual oil, and brine. In most cases there was a significant increase in resistivity owing to the presence of clay solids which had invaded the core. The change in resistivity, as a result of the diffusion of salts, was substantial after a period of five hours. There is evidence in some cases that the residual oil and core water saturations of the unconsolidated cores, after substantial invasion, are very low, indicating almost complete displacement by invading fluid."

Jan 1, 1959

By A. Ignatieff

This is the second review of developments in coal mining engineering (see C.I.M .M. Transactions, Vol. LI, 1948, pp. 262- 264) and covers the period from October, 1948, to January, 1950. Mechanization The period under review was characterized by the intensive development of appliances providing for complete mechanization of coal-face operations. A variety of machines are being evolved or have already been placed on the market which embody the principle of &apos;continuous mining&apos;. This trend can be observed in all coal producing countries. In the United States, two continuous mining machines have been developed for entry and room application and by the end of 1 949 were being used in a number of mines. These are the Joy Continuous Miner in which the coal is ripped from the face by means of multiple cutter chains, and the Jeffrey Colmol employing cutters on rotating arms for chipping the coal from the face. The Joy machine is made in tw6l models, 34-in. and 48-in. high and designed for a range of seam thicknesses from 3-ft. -t-in. to 4-ft. 6-in. and from 4-ft. 6-in. to 8ft., respectively. Some experience has been gained with this machine and accounts of its performance are already appearing in the technical literature. The Jeffrey-Colmol has a more limited range of working height. The first model, 38-in. high, was designed for seams about 4 feet in thick11ess but more recently the 28-in. low model has been placed on the market for seams 2-ft. 6-in, to 3-ft. 4-in. in thickness. Conventional mobile loading machines of the gathering-arm type are continuing to yield high production under suitable conditions, and improvements or modifications of the basic principle are embodied in new machines as, for example, the Jeffrey mobile (conveyor) loader with extensible (gathering-arm) head developed for conveyor mining.

Jan 1, 1950

By Mi, Dong Liang, Jingyuan Bai, Victor Zhou, Xujun

Squirrel cage induction motors are the mostly used motors at present. Currently, the rotors of the squirrel cage induction motors are produced by aluminum die casting technique with the advantages of low cost of rotors. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size. Considering the huge quantity of motors, the die casting process is the best solution to produce copper rotor with economic cost. Because of the characteristics of copper, it is difficult to produce copper rotors by casting similar to that done in aluminum rotors. In order to improve the die casting quality of copper rotor, a new tooling structure was developed and the casting process of copper rotor was simulated and analyzed by Any-casting software. The filling process, solidification process, inner gas distribution and residual melt modulus were analyzed. It was found that the design of symmetrical runner and inner runner on both sides was helpful to reduce the impact of molten copper to the cavity surface during the filling process. The use of Slag traps array can reduce die casting defects inside the end rings. That will be helpful to improve the rotor quality. INTRODUCTION Squirrel-cage AC induction motors are most widely used in the world. In 2017, the total installed capacity of AC motors in China has reached more than 1.2 billion kW, and the annual power consumption accounts for about 60% of the total national electricity consumption. To improve the efficiency of squirrel-cage motor will be helpful to energy conservation and environment protection. There are several ways to improve efficiency of induction motors, using copper rotor is one of the most effective solutions. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size.

Jan 1, 2019

By C. Holmes, T. Holmes

Engineered-in material handling problems are responsible for significant unrealized value in mineral processing plants. At the root, is a lack of awareness and understanding of bulk material handling science and how important it is, especially in early design stages. Mineral processes add value to mined raw feedstock through physical and chemical transformations in unit operations, but only if the material can flow through them. Essentially, each unit operation receives a unique feedstock and produces a unique product to be collected, transported, and fed into the next unit operation. Such material-handling systems can only be expected to achieve design throughput if the system equipment is designed to the materials’ characteristics, over their full range of conditions. This requires quantification of flow properties to support the necessary customized equipment designs. Too often, assumptions or “library values” of a material’s properties are used as the basis for flow modelling and conceptual, and sometimes even detailed, design. This is especially true for hazardous materials like uranium ore, for which the additional precautions, costs, and time necessary for safe handling are often used to rationalize postponing or even bypassing testing. The surprises that often transpire in the wake of insufficient material handling consideration can have acute and costly effects. Fortunately, there is a better way.

Jan 1, 2020