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By H. J. Meyer

"A hydrostatic elevation difference meter has been developed for use in measuring elevations along gravity traverses. Elevations of stations 100 feet apart can be obtained at a rate of 1/2 mile per hour and to an accuracy better than 1/3 foot. This can be done along traverses which have not been cut and chained. The instrument is durable, lightweight and constructed of materials which will withstand any temperature encountered in field work.It is believed that this device will more than double the rate at which gravity surveys over mining prospects can be carried out."

Jan 1, 1972

By A. Zangooi, J. A. Finch

Flotation is a separation process based on the collection of particles on the surface of bubbles. Flotation machines disperse air into bubbles using a variety of techniques. The characteristics of the bubble population are strongly affected by the selection of frother type and concentration. As metallurgical results depend on the bubble distribution, the measurement of frother concentration is vital to understand and control performance. A previously developed colorimetric technique was refined to work with low solubility frothers and to increase daily analysis rate. Field-testing demonstrated that the method is robust, reliable and accurate. As well as relating frother concentration to gas dispersion measurements, the results can be used to answer operational questions including: how well a frother dissolves, how reliable and stable frother delivery is, how evenly frother is distributed down a bank, and whether frother distributes between the pulp and froth zones. Some of these points are illustrated from plant experiences. Advances in Mineral Processing Science and Technology Proceedings of the 48th Annual Conference of Metallurgists ofCIM Sudbury, Ontario, Canada Edited by

Jan 1, 2009

By M. K. Senicie

IN July, 1937, Asbestos Corporation, Limited, installed an automatic conveyor-belt scale at their King mine, Thetford Mines. The equipment was purchased 'on trial' and its performance has proved entirely satisfactory to the staff. The scale was manufactured by the Toledo Scale Company, of Toledo (Ohio) and Windsor (Ont.) and was installed by one of the Scale Company's engineers. The electrical recording equipment was installed by Keith Mercer, Reg'd, of Montreal, Canadian agents for the manufacturers, the Builders Iron Foundry, of Providence, Rhode Island. The recording equipment consists of a duplex weight-transmitter attached to the scale-head, a duplex totalizer with differential relays, a belt-speed compensator, a rate-of-delivery recorder, and a rate-of-delivery indicator. As it was desired to run the mill at maximum capacity, it was necessary to know the rate of feed at all times, so that any lessening of rate of feed or delays would be recorded and could be corrected. After having determined the rate of feed to the mill (100 per cent capacity), it was required to have weighing and recording instruments which would show: (1) The rate of feed per hour. (2) Any variations .in the load. (3) Any delays and the duration and time of the delays. Rate of tonnage recorders in the mill superintendent's office and at the point of feedi.ng were necessary, as was automatic control between the mill superintendent and the feed man. It was desired to have a permanent record of total tonnage fed per shift or day; weighing and recording mechanism had to have sensitivity to record all previously mentioned conditions. Mechanism had to be of rugged construction, and be so built that it would stay in good operating condition, with the minimum amount of adjustment and supervision.

Jan 1, 1938

By A. Uribe-Salas, J. A. Finch, B. J. Huls

Froth depth or interface level is an important control variable in column flotation which can influence both grade and recovery. A common method of locating the level is based on sensing the hydrostatic pressure at one or more points along the column. The level indicated can be in considerable error, largely because of variations in froth and collection zone bulk densities. A portable conductivity probe has been developed to detect the position of the interface from conductance measurements across the interface. The location of the interface corresponds to the position where a large change in conductance is observed, which is primarily a consequence of the difference in gas holdup between the collection and froth zone. This probe detects the position of the interface to an accuracy of ± 5 cm. The probe can be used while the column is in operation, which allows for on-line recalibration of the level detection system. Results obtained in its application in a pilot-scale column (0.91 m in diameter) are described.

Jan 1, 1990

By Edgar L. Horner

"The objectives of the Wabush Mines tailings stabilization program are to control dust Ii/t-off and to rehabilitate the disposal area. The evolution of the program started with test plots in 1970, these being continued and expanded upon through 1974. In 1976, a 35-acre vegetation field trial was attempted and failed, part of the failure being attributed to lack of adequate equipment. Subsequently, equipment was purchased and during the summer of 1979-80 extensive areas were treated. The program was also expanded to include the evaluation of chemical and water spray stabilization versus vegetation in areas where shorter-term control is required. In addition, during the summers of 1979-80, spruce bog material was spread over about 100 acres and seeded.The approach to reclamation by vegetation at Wabush is one of soil building. Work to this point indicates that iron ore tailings can be converted to a soil capable of supporting plants. Plans for the Wabush tailings disposal area should make dust lift-off from inactive tailings areas negligible within the next few years."

Jan 1, 1981

By P. R. A. Andrews

"Areas of bubble contact were delineated for cassiterite in the presence of chloride, fluoride, sulphate, phosphate, oxalate and citrate ions using dodecylamine hydrochloride collector. The limits of pH, and the minimum collector concentration were established using the bubble pick-up technique.Bubble contact did not occur below the p.z.c. (point of zero charge), estimated to be 4.7, in the presence of chloride ion, and fluoride ion showed only a weak response in the same pH range. These anions are considered to act as indifferent electrolytes. Activation at pH values below the p.z.c. was obtained with sulphate, phosphate, oxalate and citrate ions; the greatest response was by oxalate and phosphate ions extending pick-up to between pH 2.0 and 2.5.Activation appeared to be strongest when anionic protonated species were in maximum concentration. Strong activation also corresponded to the formation of very stable metal ion species, thought to be formed on the surface of cassiterite, between exposed stannic ions and modifying anions; dodecylammonium ions being absorbed on the surface so modified."

Jan 1, 1991

By R. Heikkilä

As a part of a large research and development program in Finland, a system calibration for an UAV measurement method having practical experiments in a Jorvas Railway Yard design and construction project. The Railway yard construction are was measured using an UAV measurement device by Smartplanes (Smartone) and using some reference points measured by a GNSS device. The measured data was cleaned, combined and adjusted through Least Squares Optimization using the software developed by a Finnish company Pieneering Oy. As references, two different laser scans as well as total station surveys were used. For applicability evaluation, the accuracy of measurement, the reliability of measurement, and the economy of measurement were used. Based on the comparisons, the achieved precision of the UAV measurement was high, instead the accuracy of measurement was not sufficient in this case. The principle of this photogrammetric measurement includes a lot of redundant observations making it possible to achieve a high level of reliability. The economy in this Railway Yard Design project was not able to achieve.

Aug 1, 2013

By G. N. Carlson, C. H. Hazelroth, D. R. Dorrance

"Located on the north shore of the St. Lawrence River at Pointe Noire, Quebec are the agglomeration and ship-ping facilities of the Wabush Mines complex. Here, the specular hematite concentrate from the Scully Mine is received for further processing. Modern facilities for handling the ore, either to the 1plant or to stockpile, provide quick and efficient operation of the ore receiving station. Physical preparation of the ore for balling is accomplished with regrind ball mills, filters, bentonite crushing and drying facilities, pumps and related conveying circuits. Rotating table feeders deliver the reground and de-watered ore from storage bins to balling drums, where green ball or green pellet formation is achieved. The green balls are then conveyed to the indurating section. Three Dravo-Lurgi travelling grates, producing a total of 6,000,000 long dry tons of pellets per year, are used in the indurating phase of the operation. These grates, having 38 windboxes and firing at a temperature of 2,500°F, harden the pellets for shipment to various blast furnaces throughout the world."

Jan 1, 1969

By Benoît Valley

Optimization of the mining sequence in terms of economics (maximizing net present value) often leads to multi-front mining methods generating pillars. Significant resources are tied up in these pillars, but mining them is often challenging. In order to improve our understanding of rock mass behaviour while extracting these pillars, an extensive monitoring program has been designed and implemented at Vale?s Coleman mine (Sudbury, Canada). The program focuses on existing and new technologies that have potential for monitoring deformation and rock mass property changes. It includes both active and passive methods: gravimeters, multi-point borehole extensometers, fiber optic strain meters, fixed and portable three-component seismic arrays, borehole imaging and sonic logging, and, repeated LiDAR surveys. This paper reports results from an initial project phase, when only a small amount of mining has taken place. The goal was to test and compare technologies in order to assess their sensitivity, accuracy, repeatability and suitability for underground mining conditions. Value is gained by having a broad range of monitoring devices running side by side, enabling comparisons and benchmarking.

Jun 1, 2012

By M. Wu, G. Plascencia, A. E. M. Warner, A. Vahed, T. A. Utigard

Nickel oxide granules formed by pyrohydrolysis of a chloride solution, were reduced in hydrogen. Below 400 °C, an incubation period was observed, followed by very slow reduction. In the temperature range from 400 to 600 °C, the rate of reduction increased with increasing temperature and increasing hydrogen pressure. Microscopic analysis showed that in this temperature range the reaction followed the shrinking core model. Above 600 °C, the reduction rate decreased noticeably before suddenly becoming very fast at and above 950 °C. Microscopy showed inner bands of metallization inside the outer metallic rim, indicating partial blockage of the interface between the reacted and un-reacted NiO core. At these temperatures, particle agglomeration and sintering were also found to take place. Surface segregation of sulphur may account for the slow down in reduction rate above 600 °C. From an industrial point of view, reduction should be carried out from 550 to 600 °C with as high a concentration of hydrogen as possible. If sintering and agglomeration are not of any concerns, reduction can be carried extremely fast at about 1000 °C.

Jan 1, 2005

By K. M. Ed

MR. J. C. NICHOLSON: The author has discussed his subject in a very thorough manner. One difficulty is the tendency to regard a 'permitted' explosive as a 'safe' explosive. There is no such article as a safe explosive; any explosive is only as safe as the man who handles it. In making up the primer, the method illustrated in the paper is alright for the ordinary explosive but not so for the sheathed explosive, for the sheathing would be punctured. MR. T. L. McCALL: I fee! quite certain that there would be little, if any, trouble from flame shots or misfires if the author's suggestions were carried out. There is a tendency on the part of the shot-firer to over-shoot, so as to bring clown more coal for the miner, and frequently a shot has not sufficient burden imposed upon it. Shooting one hole may not only lessen the burden on an adjacent hole, but may practically release it altogether, in which case the second hole should be fired with a very small charge, or perhaps it might not be necessary to shoot it at all. While the paper refers to shooting in the coal only, it should be under-stood that the instructions given are equally applicable to brushing shots. I do not wish to bring up any contentious point, but would the author say a word on cushioning with air gaps and on multiple shooting? Single shooting in rock might open up a feeder of gas which could be ignited by the ?second shot.

Jan 1, 1940

By L. Becze, B. Pierre, S. Di Carlo, G. P. Demopoulos

From January to June 2007, the autoclave production at the Kidd Metallurgical Site was severely affected as a result of plugged discharge lines and extensive precipitation/crystallization of sulphates that caused massive scaling in different autoclave compartments. Work was performed at McGill University to understand the root causes. The crystallization of zinc and ferrous sulphate salts was investigated in terms of solubility measurements. Scale samples were characterized using chemical and mineralogical-spectroscopic analysis. In this paper, following a description of the Kidd zinc pressure leach operation, highlights from this investigation are presented and solutions used to overcome the problem are outlined.

Jan 1, 2008

By Mark Sherman

One of the main functions of a process technology and engineering services provider is to select grinding equipment that will meet the client?s throughput rate target. Prudent risk mitigation strategies would suggest that throughput rate estimates be cross-checked using a variety of techniques. Whilst some comminution circuit designers have estimated specific energy requirements via the manipulation of the Bond specific power equation e.g. Barratt?s Grindpower and OMC?s FSAG approach, other designers have opined that the Bond Indices have no role to play in the calculation of SAG mill specific power. As a result, they have developed their own specific energy estimating methodologies, e.g. SMCC?s Drop Weight based power methodology, SPI, SAGDesign, etc. Each method has its supporters and its critics. The challenge facing the engineering provider is how to nominate an SAG mill based circuit throughput rate estimate when faced with significantly disparate specific energies calculated by the different methodologies. This challenge is exacerbated via the continuing evolution of contemporary circuit configurations such as two stage pebble crushing some of which incorporate HPGR technology as the second stage of pebble crushing. The methodology presented in this paper shows that the Bond Indices are an excellent tool for estimating the specific energy requirements for SAG mills in SAB, SABC and SSS circuits. The method accommodates primary crushed feeds, partial and or fully secondary crushed SAG mill feeds, and emulates the impact of pebble crushing on SAG specific energy. As a result, the new Bond Index based method has provided an additional tool for increasing Fluor?s confidence when predicting SAG mill based circuit throughput rates. Based on this outcome, the author proposes that the decades old conundrum of using Bond Indices to calculate SAG specific energies for SAG mill based circuits has been solved.

Jan 1, 2012

By D. Pawelus, J. Butra, R. Debkowski, M. Szpak

Impact of horizontal stresses on stability of underground workings in mines is a very important issue in underground mining. Identification of the initial state of stress in the rock-mass should be one of the main actions taken into account while designing and carrying out the mining activity in underground mines. The paper presents the tests on three dimensional stress pattern in Polish copper mines, owned by KGHM Polska Miedz S.A. Group, carried out in 2012. The research program covered 7 measuring stands in two mines; their average depth was about 1000 m. The main aim was to identify the values and directions of horizontal stresses in order to optimize the extraction and to improve the safety. The overcoring method with the use of CSIRO HI type probe was applied. The paper also describes the measuring technique which was developed for the purpose of specific mining and geological conditions of KGHM mines, taking into consideration the natural hazards encountered there as well as technical and operational capabilities with regard to drilling equipment. The experience gained during the underground measurements and the issue of making such measurements in underground copper mines in Poland are presented in the paper. The stress patterns obtained during the underground measurements are of application importance for the process of designing the spacing of mine workings and improving their stability and mine support selection.

Jan 1, 2015

By T. Cutard, E. Yeugo Fogaing, C. Gault, H. Marzagui, N. Prompt, M. Huger, C. Deteuf

This paper deals with studies made in the field of the French research network PROMETHEREF. Several refractory castables are considered in this program. In the present paper, one of these materials is considered, it is a low cement castable based on andalusite aggregates. A particular attention is paid to microstructural changes during the first heating and on their effects on the high temperature mechanical behavior. Microstructural evolutions have been characterized by the way of dilatometry, scanning electron microcopy and X-ray diffraction. In-situ observations by environmental scanning electron microscopy gave complementary results on these high temperature microstructural changes. They deal with microcrack formation, phase changes, crystallization, liquid phase formation and sintering. By propagation of ultrasonic waves, high temperature continuous measurements of the Young's modulus have been made. Results confirm the existence of microstructural changes and allow to quantify the Young's modulus variations all along specific thermal cycles. High temperature four point bending tests and room temperature tensile tests were made in the same temperature range. Behavior evolutions could be found and interpreted with the help of previously mentioned results.

Jan 1, 2004

A series of small scale tests have been conducted to evaluate the effect of micro-fracture development, imposed by blasting, on the material properties of the rock as well as its resistance to crushing and grinding. The uniaxial compressive strength, tensile strength, Poisson?s ratio, P-wave, Swave velocity, point load test index, crushing and grinding work indices were evaluated for samples without any blasting load and for samples which had received a variety of blast loads ranging from a single impact with low strength detonating cord, to combination of impacts at different times and significant impacts with powder factors close to those used in practical blasts. It was shown that the rock mechanics parameters change even at low impacts, suggesting easier crushing of the rock. Damage values appear to be affected by timing as stress wave superposition affects the damage process. Fragmentation is achieved at higher impact levels while work index modification of the fragments is also observed when high powder factors are used, suggesting improvements in grinding.

May 1, 2003

By J. Seidel

In 2009 Newmont Mining Corporation’s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Jan 1, 2012

By R. Therrien, L. Gosselin, J. Raymond

ABSTRACT: The ground-source heat pump is a low-carbon technology that uses the earth’s renewable geothermal energy to heat and cool buildings, with an ef?ciency 3 to 4.5 times that of conventional systems. These high performances are achieved by exchanging heat with the earth using a ?uid that is groundwater, surface water or closed loop water. Expensive installations, such as water wells or buriedcoils, are however necessary to transport the ?uid in and out of the earth, making ground-source heat pumps more costly than conventional systems. Installation costs can be reduced in mining environments due to the abundance and the accessibility of resources to be used with heat pumps. Examples of system design calculations using data from the Mouska and Doyon mines in Abitibi show signi?cant installation cost savings using dewatering mine water or ground heat exchangers installed below oxidizing waste rocks. Ground-source heat pump technology is reviewed and scoping calculations are presented to illustrate how such systems can be installed in mining environments.

Jan 1, 2010

By E. W. Johnson

"The current increase in gold price may presage a resurgence of gold milling plants in Canada similar to that of the thirties. Because the industry has been at a low ebb for almost two decades, future operating responsibilities will likely devolve upon personnel with limited cyanidation experience. My comments, which may seem elementary to experienced operators, are directed towards these industry newcomers to highlight operational features in cyanidation which forty years' experience has shown me to 0e of importance. A brief review of what actually takes place in a cyanide circuit may help give a better understanding of the topics to be discussed.These will include: (1) expose the gold (2) dissolve the gold(3) make solid/liquid separation(4) recover the gold from solution.1. Expose the GoldThe chemical key to gold recovery by cyanidation lies in the ready solubility of the metal in a relatively weak solution (0.04%-0.075% NaCN equivalent by weight) of calcium or sodium cyanide. Obviously, dissolution cannot start unless the cya1ide is in contact with the gold. As an analogy, the yolk of a hard-boiled egg can oe taken to represent the gold particle and the egg white and shell, the surrounding gangue or sulphide host. As the sl1ell and white must be fractured to expose the yolk, similarly the surrounding gorngue or sulphide host must be broken or fractured to enable the cyanide solution to contact the gold."

Jan 1, 1979

By J. Dubinski

This paper describes the key circumstances of the underground coal gasification (UCG) process, which is planned to be carried out in the Polish hard coal mine ?Wieczorek?. The construction and field tests of a UCG pilot plant have key issues that need to be addressed to realize the research project goal: the elaboration of a highly effective technology of fuel and electricity production. The project will conduct several monthly tests of gasification in the pilot geo-reactor, which will be constructed based on the results of laboratory tests. The realization of the process requires numerous appropriately prepared actions adjusted to natural conditions in the hard coal deposit. Based on scientific principles, it is necessary to elaborate the procedures related to the location of the UCG installation (including its legal and safety aspects), and to perform a technical risk analysis. In addition, it is necessary to determine the required mining, geological, technical, economic and organizational circumstances, while at the same time considering the real but constantly changing process conditions.

Aug 1, 2013