Search Documents

By D. S. Hines

The purchase of mechanical equipment for mines is not unlike the purchase of other materials or supplies in general principle, but on account of the major part such equipment plays in the operations, and of the fact that life and valuable property are at stake, the matter demands the most careful attention on the part of the purchaser. The problems and difficulties encountered are dealt with below in their sequence in the purchasing procedure. Requisiting Although it is quite a common practice to submit a tentative specification of requirements to recognized manufacturers of equipment- soliciting alternative propositions or recommendations for study in the selection of certain equipment-as a rule the first step in purchasing procedure is the requisition. Primarily, it is the form that carries to the purchasing department the record of equipment wanted. A full and complete description or specification, and accuracy of record, are the important points to be insisted on in a requisition. Too much attention cannot be given to this detail, as this is one of 'the most important phases of purchasing work. Incomplete information, either in specification or detail, leads to delay in handling the requisition, and, if not detected in the purchasing department, may mean receipt of material which cannot be used for the purpose intended. In addition to description of material or equipment to be ordered, the requisition should also show where or what the equipment is for, whether for operating or new work. If for capital account, the number of the authority for expenditure should be given for record and distribution purposes.

Jan 1, 1930

By E. Godin, M. Rigaud, S. C. Panigrahy, I. Malinsky

"RésuméDes boulettes de concentres d'hématite spéculaire à basse silice ont été produites en substituant la bentonite par de la tourbe, adéquatement traitée, additionnée d'une faible quantile de soude caustique durant le boulettage. La réductibilité de telles boulettes et leur gonflement pendant la réduction ont été évacues, en utilisant quatre mélanges gazeux différents, formes de H2 - CO - N2.L'influence du pouvoir réducteur du gaz utilise, sur le gonflement des boulettes, à été mis en évidence. Quelles que soient ces conditions réductrices, les propriétés mesurées sur les boulettes liées a la tourbe sont comparables aux propriétés obtenues avec des boulettes traditionnelles liées à la bentonite.ABSTRACTAdditions of peat moss and small quantities of NaOH during balling of low silica specular hematite concentrates have eliminated the need to use bentonite as a binder. The reducibility and swelling of such pellets have been evaluated using four different gas mixtures, consisting of H2 - CO -N2. The influence of the reducing power of the gases, on the swelling behaviour of pellets has been documented. Under the different reducing conditions, this new type of pellets exhibit properties similar to the ones obtained using bentonite."

Jan 1, 1987

By M. Desjardins

The Hoyle Pond underground mine, located in the Porcupine Gold Camp, east of the city of Timmins, Ontario, Canada, is the cornerstone of Goldcorp Canada Ltd?s Porcupine Gold Mines. Cut and fill, shrinkage, longhole and panel mining methods are employed to excavate the narrow gold bearing structures. In order to meet increased flow requirements of 256 m3/s at the mine, a new Fresh Air Raise (FAR) and new surface fans were commissioned in early 2005. The newly acquired fans were capable of supplying the desired volume of air within a range of 1.5 and 2.0 kPa. Upon commissioning of the surface fans the total pressure was found to be exceedingly high; far beyond the design capabilities of the new installation. Consequently only one surface fan could be operated at any given time providing about half the required volume of air. Extensive work was immediately started aimed at reducing the system resistance in order to permit operation of the two fans in parallel and achieve the required mine flows. Larger booster fans were installed in parallel at the 900 m level, a 3 m raise bore linking the 450 and 900 m levels was developed to twin the existing fresh air circuit, and the FAR from surface to the 450 m level was twinned with the original FAR. This strategy, completed in 2012, resulted in a drastic reduction in system resistance and pressures, allowing the two surface fresh air fans to be safely operated in parallel and meeting the flow requirements. This paper describes details of the engineering design work and commissioning of the modified ventilation system, successfully ensuring the long term viability of the project.

Aug 1, 2013

By A. P. Williams

"This paper presents an overview of plant electrical systems in general, a discussion of the problems that may occur due to plant growth, the maintenance required to maintain the reliability and safety of the electrical system, and the selectivity of the relay protection system. It is divided into two main areas: short circuit levels within the plant electrical system; and relay protection systems.This information is directed at maintenance supervisors, mine managers and electrical superintendents who have been away from detailed short circuit and relay coordination calculations for some time. It points out the potential problem areas within an operating plant electrical system. Short Circuit LevelsTheoryThe electrical equipment in a plant such as breakers, switches and starters has two short circuit ratings, the momentary rating and the interrupting rating. These ratings may be given in MVA or current (amperes) depending on the equipment and manufacturer's preference. Since for a three-phase system MVA and amperes are related by the formula"

Jan 1, 1987

By Henrik Saxén, Mikko Helle

The operation of hot stoves used for preheating the blast in the ironmaking blast furnace has a strong effect on the consumption of reductants, economic performance of and CO2 emissions from the steelmaking site. Generally, it is recommended to maintain as high blast temperature as possible, because this minimizes the rate of reductants in the blast furnace. The blast temperature is affected in a complex way by the time periods of heating and cooling of the stoves, and by the amount of gas combusted in the stoves. Furthermore, as the hot stoves show degraded performance with age, it is a non-trivial task to select optimal operation parameters for the stoves. The paper addresses this computationally by applying a one-dimensional heat-transfer model of the hot stoves for optimization of the performance of the system. The complexity and strong coupling of the decision variables is demonstrated by numerical examples, where the blast temperature is maximized under different constraints.

Jan 1, 2015

By D. W. R. George, J. L. Stewart

Developments in the last decade, which have contributed to increased productivity and decreased coke rates in the iron blast furnace, are reviewed. Future progress in blast-furnace practice is also considered.

Jan 1, 1966

By M. S. Fotheringham

Recognition of the Growing Importance of Iron and Steel Few Canadians have yet become aware that Canada's vast iron ore resources, the greater part of which is only now beginning to be developed, will inevitably have a profound effect on the entire Canadian economy, benefitting in some measure the lives of all Canadians. The great iron mining developments of Ontario, Newfoundland, Quebec, and Labrador are destined to make Canada one of the world's major producers and exporters of this material, on which our industrial civilization is?based. These developments will create new employment, new communities, new transportation facilities, and new investment opportunities. Iron ore is the foundation and the keystone of modern mechanized civilization. The most prosperous nations of the world are the highest per capita consumers of iron and steel, and in these countries the per capita consumption is increasing steadily despite the advent of light metals, plastics, and other competitive materials. Three-quarters of the human race have too little steel -and consequently too little mechanization -to provide for themselves the necessities and comforts of civilized living. Progressively they will demand, and acquire, the machines, the transportation and communication facilities now lacking, and they will win them by making greater use of the world's iron resources. It is the good fortune of this generation that Canada's 'iron age' is just getting well under way.

Jan 1, 1951

By Rick Coleman, Chelvan (Chevy) Veloo

"P.T. Freeport Indonesia's lrian Jaya Operation has been producing copper concentrate continuously since 1972. Numerous ore discoveries and five mill expansion programs have seen the initial milling rate of 7,200 MTPD escalate to the present rate of 125,000 MTPD, producing 2.5 million pounds of copper and 3,500 troy ounces of gold per day. The latest expansion, commissioned in February 1995, incorporates a 34 foot Semi- Autogenous Grinding (SAG) Mill, two 20'x30' Ball Mills, conventional roughing, cleaner column flotation, and attendant upgrades to the existing concentrate pumping and dewatering facilities. This paper will describe the SAG Plant flowsheet, and focus on the key training issues which contributed to a successful plant start-up.IntroductionP.T. Freeport Indonesia's operations in the Ertsberg mining district are located in the Jayawijaya Mountains of Irian Jaya, the easternmost province of the Republic of Indonesia. P.T. Freeport Indonesia (PTFI), the operator, is owned by Freeport MacMoRan Copper and Gold (81.3%), the Government of Indonesia (9.4%), and private Indonesian investors (9.4%). Geographical location, and sailing distances are provided on the attached location map.The operation stretches over 7 4 miles ( 114 km) from the dewatering and concentrate shipping facility at the Port of Amamapare on the Arafura Sea to the Grasberg open pit located at 3400m. The regional geology is covered in detail by Van Nort et al (1991 ), with current proven and probable reserves estimated at 1.13 billion metric tonnes grading 1.30% Copper, 1.42 ppm Gold, and 4.06 ppm Silver. The Grasberg open pit mining operation provides 92% of the mill feed, and is described in detail by Hickson (1991). The remainder of the mill feed is derived from several underground block caving operations. Current production rates provide a mine life in excess of 25 years. However, very favorable geology in the area leads to expectations that additional reserves will extend the life of the operation considerably."

Jan 1, 1996

"Real-time, on-stream analysis of the metal content of process slurries is an essential prerequisite for process monitoring and advanced control of mineral processing circuits. On-stream X-Ray Fluorescence (XRF) sensors for base metal applications are available commercially and form the basis of many plant monitoring circuits. To date, these commercial technologies have been insufficiently sensitive to measure precious metals such as gold and platinum group elements, typically present at part-per-million (ppm) and sub ppm levels. CSIRO has developed a novel X-ray based technology, called UltraGold, which enables detection of gold in slurries on a real-time basis with a precision below 100 parts-per-billion. This technology is based on the use of advanced X-ray optics, extensive Monte Carlo computer modelling for analyser design, high accuracy X-ray spectrum fitting where the X-ray intensities are matrix corrected. In this paper, we will introduce this technology and discuss the results of a proof of principle study performed in the laboratory with plant slurries (tailings and concentrate) from an Australian beneficiation plant. Finally, we will discuss further planned improvements. As projected grades in (gold) mining around the world fall and several large-scale mines approach the limits of their economic reserves, this method can enable significantly reduced operating costs by rapid analysis to improve circuit efficiency and hence improve recovery significantly.INTRODUCTION This paper describes a study undertaken to explore the feasibility of applying CSIRO?s UltraGold XRF technology to the on-stream measurement of gold in process slurries. The provision of rapid, accurate information of gold grade in feed, tailings and concentrate streams would facilitate significantly improved process control and early detection of plant upsets, resulting in substantial cost-savings. CSIRO have patented X-ray fluorescence (XRF) techniques for the analysis of key elements in slurries present at part-per-million (ppm) and sub-ppm levels. Conventional, commercially available on-stream XRF instruments generally have detection limits in the tens of ppm range, precluding their use for analysis of elements like gold that are mined and processed at much lower concentrations."

Jan 1, 2017

By A. A. Brant

Self-potential methods are based ?on measurements on the surface of voltage distributions caused by natural sub-surface oxidation phenomena. The attempt is made to. correlate voltage minima or maxima with the location of mineral materials or geological conditions which may give rise to such naturally produced spontaneous potentials. Any orebody undergoing oxidation is a source of electric current. Ground waters carrying free oxygen attack the upper surface of the body, rendering this the positive pole of a galvanic cell, with the lower portion of the body the negative pole and the surrounding weak acidic waters the electrolyte. Current flow is from positive to negative through the orebody and negative to positive through the electrolyte, i.e., through the surrounding rock. The upper end of a steeply dipping, tabular orebody is hence indicated as lying below the point on the surface where the largest negative potential is observed(l). From its basis, it is apparent that the self-potential method was developed primarily for ore exploration.

Jan 1, 1942

By T. Motegi

Semisolid casting provides grain refinement of the cast structure and prevents macro-segregation. The conventional semisolid slurry is obtained by electromagnetic or mechanical stirring. In our process, the magnesium alloy (AZ31) slurry is made using an inclined cooling plate instead of the conventional methods. The slurry obtained is cast into a twin-roll caster and makes a continuous sheet of 2 or 3 mm thick. The most important factors that influence the sheet casting are the casting temperature and twin-roll speed.

Jan 1, 2007

By Fred W. Snow

THE mines of the Consolidated Copper and Sulphur Company, consisting of the Eust1s, the Albert, and the Capel mines, are situated w Ascot township, Quebec, about ten miles southeast of Sherbrooke, on the main line of the Quebec Central railway. Of these mines, only the Eustis is now producing, and it has been operated almost continuously for the past seventy years. Mining methods have been improved in recent years but are still old fashioned when compared with those employed in more modern and up-to-date mines. The ore is of milling grade and is mined for its copper and sulphur con-tent. Silver is present in small quantity, together with a trace of gold. The ore is mined by the shrinkage stope method. Pillars are frequently left as supports for the hanging-wall to prevent serious dilution of the ore and are sometimes recovered after the ore is drawn from the stope. Occasionally, small blacks of ore in close proximity to the shaft are mined by a cut-and-fill method. HISTORY ALBERT AND CAPEL MINES: The Albert and the Capel mines, originally known as the Capelton mine, were discovered in 1863 by George Capel (1). By the end of 1866 the Albert shaft had been sunk to a depth of 121 feet on an incline of about 30 degrees where a vein five feet thick was encountered. In 1879, these mines passed into the hands of G. H. Nichols and Company, by whom they were operated practically continuously until 1907. When mining operations ceased in that year, the shafts had reached depths on the incline of approximately 2,300 feet and 1,000 feet, respectively. These mines have been allowed to cave and fill with water and have been inaccessible for many years.

Jan 1, 1936

By E. Peek, L. Becze, K. Reading

"Gallium oxide is an important semiconductor material used in optoelectronic devices (flat panel and solar cell) catalysts and sensors. One of the methods to produce ?-Ga2O3 is the so-called hydrothermal route. It is practiced by Neo Gallium Compounds and comprises of two steps: (1) the production of mainly gallium-oxy-hydroxide in a pressure vessel by reacting metallic gallium with water at 200-220 ºC and (2) the calcination of gallium-oxy-hydroxide at 700-750 ºC to convert it into ?-Ga2O3. This paper describes this pressure hydrometallurgy process supported with relevant thermodynamic data and presents the characteristics of the ?-Ga2O3 powder produced for commercial purposes. INTRODUCTIONGallium is a relatively new metal, having been predicted by D. Mendeleev in 1871, discovered by P.E. Lecoq de Boisbaudran in 1875, and first commercially produced in the USA in 1943. Gallium is not rare, being more abundant in the earth crust than antimony, bismuth, molybdenum, silver and tungsten. However, few gallium minerals exist in nature, and the dispersion of gallium within other minerals add to the complexity of its recovery. In practice, gallium is found in dispersed state primarily in bauxites and in some sphalerites, and, to a much smaller extent, in some coals. At present, a very large proportion of the primary gallium in the world is recovered as a by-product of aluminum plants, mostly Bayer plants, where gallium is extracted from a bleed of the Bayer liquor (Roskill, 2011). In 2011, world production of primary gallium was estimated at 200 metric tonnes. In addition, there is a significant contribution of recycling to the overall yearly availability of the metal.Gallium exhibits fairly remarkable properties: it is liquid above 29.76 ºC, can be supercooled, and with its high boiling point (2204 ºC), is the metal with the widest liquid range. Gallium is magnetic, and is an excellent conductor of both heat and electricity. Gallium also displays a marked anisotropic electrical conductivity (Roskill, 2011). All these properties render gallium almost irreplaceable in the semiconductors (GaAs, GaN, GaSb, GaP wafers) and the optoelectronics industry (flat panel, solar cell)."

Jan 1, 2012

By R. A. Sullivan

I T IS one of the unwritten policies at Preston Mines that we examine closely any method or tool that will help us in our constant battle against rising costs. It is our personal conviction that most work methods can be improved. Therefore even though the job went well yesterday, it does not necessarily follow that it should be done by the same method today. With the arrival of the natural gas pipe line in the Porcupine area it was obvious that we would have to take a good look at the possibilities of using this source of fuel for plant heating. • Steam presently generated at Preston is for heating purposes only, no process steam being required. Prior to the fall of 1960, the heating plant consisted of two low pressure, coal-fired, fire-tube boilers, operating at an approximate pressure of 14 pounds per square inch. These boilers were underfed by stokers and could be operated either singly or together. ~o. 1 unit was a horizontal return tubular boiler, registered at 100 h.p. No. 2 unit was a fire-box boiler, registered at 75 h.p.

Jan 1, 1962

By Xiaowen (Wendy) Ma, Hans Liang, Xiaoying Chen, David Way

"The mineralogical characteristics of the process streams provide key indicators to the potential improvement in the metallurgical performance. Therefore, the process mineralogy and diagnostic metallurgy have been widely used as a tool to assist the metallurgists at the operating plants. The challenge of this study was then how to characterize the diagnostic flowsheet of the minerals of interest in the process streams across the flotation circuit. The investigation from this study indicates that the minerals chematic flowsheet can visibly demonstrate the sources that caused the gold losses during the mineral processing.In this paper, we present studies of the flotation process stream samples, representing the feeds, intermediate products, final concentrate and final tails, which were produced from the flotation concentrators of Mt Carlton mine in Queensland, Australia. This study was focused on characterizing the process streams and learns how the gold in the process streams was associated with other sulphide minerals and host minerals on a size by size basis. The automatic QEMSCAN/MLA Particle Mineral Analysis (PMA) and Trace Mineral Search (TMS) were applied to identify the minerals and to detect the gold in the sized fractions of process streams. The Laser Ablation ICP-MS (LA) spot analysis, QEMSCAN EDS spot analysis and electron microprobe spot analysis were employed to identify and quantify there fractory gold concentrations in the sulphide minerals, like pyrite, and the elemental concentrations of visible gold grains. The diagnostic flowsheet of gold recoveries by the process streams, by mineral association classes and by the particle sizes were generated and discussed."

Jan 1, 2017

By Chris Twigge-Molecey, John Peacey

To meet the business objectives of a metallurgical project, there is often a need for new and untried technology or equipment, whose very novelty can present serious risks to meeting those objectives. The key risk management approach is a rigorous stepwise progression from theoretical evaluations and laboratory tests to pilot plant trials. These must be followed by demonstration-scale trials before final construction of a commercial scale plant, paying particular attention to the magnitude of the scale-up between phases. Success depends on following a well-defined program, not eliminating any steps, and ensuring adequate resources are available to the development team. Chapter 6 discusses the nature of technology risks to metallurgical plant projects, and the rigorous management practices needed to identify, analyze, evaluate, and avoid or mitigate them.

Jan 1, 2015

By J. Béland

"Three stages, each characterized by a particular sedimentation, magmatism, mineralization and deformation, are recognized in the geological history of Gaspe. The first stage led to the formation of the Taconian orogen, the second to that of the Acadian orogen and the third stage to the accumulation of a post-orogenic cover. The Taconian orogen includes volcanic and detrital rocks of Late Precambrian or Cambrian and Lower to Middle Ordovician ages in which ultrabasic intrusions have been emplaced. Folding is severe. Mineralization is of the Cr-Ni-Cu type, related to the igneous facies.The rocks constituting the Acadian orogen include two distinctive sequences corresponding to two successive sub-stages. The second substage began in Early Devonian time with the first pulses of the Acadian orogeny. The rocks of the first substage grade southward from a nearly platformal sequence to an assemblage implying less stability and spotty volcanism. The second substage was one of synorogenic deposition of elastic rocks, first in a marine environment and later under terrestrial conditions. Granitic intrusions, surrounded by aureoles of skarn and hornfels in which Cu-Pb-Zn mineralization is found, accompanied the Acadian deformation. The second-stage"

Jan 1, 1969

By K. G. Chipman

THE discussion on Dr. Chipman's paper, Mapping by the Topographical Survey, centred mainly on the urgent need for aerial photographic reconnaissance of unmapped portions of the country as an initial phase in the provision of suitable topographical maps for use as a guide in geological mapping, prospecting, exploration, and development work in the areas concerned. This, ir was pointed out, would necessitate an expansion of the topographical work of the Bureau of Topography to keep pace with the photographid work and to meet the demand for maps for use by geologists of the Bureau of Geology and others. A resolution requesting Institute Council to make representations to the proper authorities, urging that aerial photography and topographic map-ping be greatly expanded to meet the pressing needs of the situation, was moved by DR. W. F. JAMES and seconded by MR. L. G. SMITH, and carried unanimously. The full text of the resolution appeared on page 221 of the May BULLETIN. Others who spoke in support of the resolution were MESSRS. E. S. MOORE, L. B. ROCHESTER, F. D. SHEPHERD, and W. J. WRIGHT. Dr. Hansen then presented his paper, Mapping by the Geological Survey, discussion on which is summarized below. MR. FRANK EBBUTT(l) spoke of the very valuable service the Geological Survey bas rendered the mineral industry, and indeed the whole nation, in its century of existence, despite the very inadequate financial support it has received. Now, more than ever before, a strong and expanded Geological Survey is essential if the Industry is to continue to prosper. Our known ore reserves are being depleted very rapidly, and we are finding no new orebodies to take their place. As an aid in prospecting and exploration, and also in the development of orebodies when they have been found, we must have geological maps of the vast sections of the country which at present are unmapped or inadequately mapped. The Institute should make every endeavour to have the Geological Survey strengthened so that such maps may be made available as soon as possible.

Jan 1, 1944

By E. Henderson, L. K. Daneshmend

Drawpoint control is critical in determining the cutoff point for load-haul-dump mucking operations to minimize dilution. It is also necessary to ensure even mucking distribution and to prevent possible hang-up of material within a stope. A prototype production monitoring and reporting system has been developed for load-haul-dump operations in under-ground mines. The system generates accurate and timely information regarding mucked tonnages and drawpoint and ore/waste pass utilization. The monitoring system integrates a PLC-based load weighing system with a radio frequency identification (RFID) system for locating the vehicle. The system records the identification and time of entry and exit of each draw-point and ore/waste pass visited during a shift, as well as the weight of each bucket load. A trial of the system was conducted at the CAN-MET Experimental Mine near Val d’Or, Quebec. The monitoring and reporting system functioned as designed, with the exception that the maximum read range of the RFID tags under dynamic conditions was found to be a limitation. RFID systems with greater range capabilities have been identified for a second generation system. The system is the first of its type in North America to demonstrate that RFID tagscan be successfully applied to locate trackless underground equipment. Because of their ability to locate equipment and personnel within underground mines, RFID systems should be considered a key technology for future mine information and process control systems.

Jan 1, 1996

By Cris Sideco

This paper describes the concentration processes of the Sullivan. Concentrator, including crushing , transportation, sink-float, grinding , flotation and dewatering. Handling of hot muck has had a deleterious effect on most of the processes, resulting in significant operating problems and poorer metallurgy. These problems are described -in detail. THE SULLIVAN CONCENTRATOR is situated in Kimberley, high up in the Purcell Range of the Selkirk Mountains, at an elevation of 3,600 feet, approximately 4 miles from the Sullivan Mine (see Fig. 1). The original plant went on stream on August 23, 1923 at a designed capacity of 2,500 tons per day. This has been increased in stages to its present rated capacity of 11,000 tons per day. The latest stage was in 1949, when several major projects, including the underground crushing plant, the sink-float plant and the installation of a rod mill, were completed. Some 112,800,000 tons of ore have been treated in this concentrator to November 1975. The plant started on a 48-hour/ week schedule, but was reduced to 44 hours/week in October 1946 and down to 40 hours/week by the end of 1949. Except for a 6-month period in 1952 when the mill operated continuously, the 40-hour/week, Monday to Friday schedule was in effect.

Jan 1, 1977