Search Documents

By C. P. Patel

"The Sturgeon Lake Joint Venture volcanic massive sulpide deposit was discovered in 1970. Milling was started by Falconbridge Copper Ltd. at Sturgeon Lake in September 1974. The Sturgeon Lake pit and mill are located 88 kilometers by road northeast of Ignace, Ontario. IgnE1ce is a town of some 2800 people located on the Trans-Canada Highway, 241 kilometers west-northwest of Thunder Bay. The mill is treating an average of 1100 TPD producing separate concentrates of copper, lead and zinc. Initially, difficulties were experienced in achieving accept-able concentrate grades and recoveries but these were eventually overcome. This presentation describes current metallurgical strategy as practiced at the Sturgeon Lake mill.But first, a few words about the type of ore being treated. In geological terms the ore is classified into two main categories. They are the massive sulphides with underlying zones of stringer sulphides as illustrated in Fig. 1. The plan view is shown in Fig. 2. The areas of East-limb and North-limb are as shown. These last two ores have suffered enough alteration to cause problems during treatment. The massive sulphides consist of chalcopyrite, sphalerite, galena, tetrahedrite and small amounts of pyrrhotite among other gangue materials. The stringer ore is comprised of predominantly chalcopyrite intrusions into rhyolite and has lesser amounts of sphalerite and tetrahedrite. At present we are treating a predetermined blend of massive and stringer ores from zones that have been metallurgically tested to ensure compatibility with current treatment procedure in the plant. Ore responding to this treatment is classified as normal ore while the ore proving incompatible is classified as north-limb ore or east-limb ore."

Jan 1, 1980

By J. A. Singmaster

IT will perhaps be wise to define my terms in begin-ning to talk about my subject, especially so where the popular and commercial terminology are as con-fused as they are in the case of zinc. While our French friends know zinc by its true name, and we find Balzac, Daudet, and other literary celebrities using it correctly in their novels, it is quite the contrary in English, particularly here in America. The quotation of a definition for zinc recently appearing in one of our leading technical magazines, "zinc is the place where they wash the dishes," will emphasize the difference. Zinc suffered in the first place by becoming an article of commerce long after its alloys with copper were in common use under the name of brass. Then again, when the art of zinc coating iron and steel objects was commercialized, we called it galvanizing, which is really a meaningless term. The French and Germans use the obvious terms-zinguerie and verzinken-for the opera-tion. Since these two uses of zinc, brass making and galvanizing, have been by far the largest consumers of zinc, is it any wonder that the popular knowledge of zinc is as vague as it is? In fact, since the disappear-ance of the sheet of zinc along with the parlor stove, the zinc-lined bath tub and refrigerator, there has been little popular contact in this country with the undis-guised metal zinc. On the Continent, where zinc has been used for over a hundred years under its real name, particularly for roofing and building purposes, the situ-ation is quite different. It is quite refreshing to turn for a moment to the contrast offered by my friend, Dr. Merica's specialty, nickel. They put 2 or 3 per cent of it into steel, and we have nickel-steel, or a larger amount into an alloy, and we have nickel-silver. To be sure there is no silver there, but what need that matter, nickel is used in the alloy and is first in the name. They plate with nickel and call it nickel-plating, no galvanizing about that. And, finally, they take that noble coin which admits us daily to underground New York, composed of three parts of copper and one part nickel, and get away with nickel as its popular name.

Jan 6, 1927

By D. C. Peck, H. D. M. Cameron, N. M. Halden, L. S. Jobin-Bevans

Abstract-The late Archean Pipestone Lake anorthosite complex (PLAC) is a 0.9 x 17 km sill-like layered intrusion that is part of a suite of coeval megacrystic anorthosite bodies in the Cross Lake region, northwestern Superior Province. Exploration for Ti-V-Fe oxide mineralization and concurrent geological investigations have contributed to a greater understanding of the lithostratigraphy of the PLAC and its oxide mineralization. Mapping and drill core studies have established a laterally continuous igneous stratigraphy comprising six leucogabbro/anorthosite zones and three melagabbro/gabbro zones. Field evidence, including disrupted blocks of layered units, scour contacts, and size-graded and modally-graded layering, suggests younging towards both the northern and the central parts of the complex. A decrease in the anorthite content of the feldspars from An75 in the south to An30 in the north suggests that the magmas become more evolved to the north. Macrorhythmic layering and gross morphological features suggest that the PLAC crystallized from four major influxes of geochemically similar basaltic magmas. The paucity of magmatic erosional features in the PLAC indicates that layering developed in a relatively static magma chamber, so that in-situ crystallization processes are required to account for the observed petrologic diversity. Drilling has confirmed that a significant Ti- V-Fe resource is contained in two of the four discrete mineralized subzones in the PLAC. Textural evidence and the stratiform nature of the oxide-enriched subzones are consistent with a magmatic origin for the oxide mineralization.

Jan 1, 1997

THERE are three objectives in translation of works of this character : to give a faithful, literal translation of the author's statements ; to give these in a manner which will interest the reader ; and to preserve, so far as is possible, the style of the original text. The task has been doubly difficult in this work because, in using Latin, the author availed himself of a medium which had ceased to expand a thousand years before his subject had in many particulars come into being ; in consequence he was in difficulties with a large number of ideas for which there were no corresponding words in the vocabulary at his command, and instead of adopting into the text his native German terms, he coined several hundred Latin expressions to answer his needs. It is upon this rock that most former attempts at translation have been wrecked. Except for a very small number, we believe we have been able to discover the intended meaning of such expressions from a study of the context, assisted by a very incomplete glossary prepared by the author himself, and by an exhaustive investigation into the literature of these subjects during the sixteenth and seventeenth centuries. That discovery in this particular has been only gradual and obtained after much labour, may be indicated by the fact that the entire text has been re-typewritten three times since the original, and some parts more often ; and further, that the printer's proof has been thrice revised. We have found some English equivalent, more or less satisfactory, for practically all such terms, except those of weights, the varieties of veins, and a few minerals. In the matter of weights we have introduced the original Latin, because it is impossible to give true equivalents and avoid the fractions of reduction ; and further, as explained in the Appendix on Weights it is impossible to say in many cases what scale the Author had in mind. The English nomenclature to be adopted has given great difficulty, for various reasons ; among them, that many methods and processes described have never been practised in English-speaking mining communities, and so had no representatives in our vocabulary, and we considered the introduction of German terms undesirable ; other methods and processes have become obsolete and their descriptive terms with them, yet we wished to avoid the introduction of obsolete or unusual English ; but of the greatest importance of all has been the necessity to avoid rigorously such modern technical terms as would imply a greater scientific understanding than the period possessed. Agricola's Latin, while mostly free from mediaeval corruption, is somewhat tainted with German construction. Moreover some portions have not

Jan 1, 1950

This report presents the results of a study for the Bureau of Mines to compare loan terms for non-fuel mineral projects in developing countries, from various International Financial Institutions (IFIs), and from private sector commercial sources. The study compares IFI and commercial loan terms for seven mineral projects in developing countries. The International Financial Institutions represented are: ? International Bank for Reconstruction and Development (World Bank) ? International Finance Corporation (IFC) ? Inter-American Development Bank (IDB) ? Asian Development Bank (ADB) ? International Monetary Fund (IMF) In addition, the costs of financing for these mineral projects were compared with the costs of long-term debt to the five largest U.S. mineral producers.

Jan 1, 1986

By Edward A. Metz, R. Larry Grayson, Douglas F. Scott

We describe inconsistencies in disease and illness reporting in U.S. mining, identify under-reporting of disease and illness in U.S. mining, and summarize selected disease and illness in U.S. mining from 1983 through 2001. Methods: We summarized information on mining-related disease and illness data for the years 1983-2001 from the Mining Safety and Health Administration database (MSHA). Results: Discrepancies exist in types of information collected by the Centers for Disease and Control, the National Institute for Occupational Safety and Health, and the Mining Safety and Health Admin¬istration database. Several factors, including a worker's fear of losing his or her job, health insurance, or other job-related benefits contribute to under-reporting of disease and illness information in the US mining industry. Conclusions: Since 1997, both number of workers employed in mining and disease and illness rates have decreased; however, the highest disease and illness rates in mining continue to be coal worker's pneumoconiosis and hearing loss.

By Fathi Habashi

While it is commonly known that the precious metals and to some extent copper occur in the native state, it is less known that mercury, iron, nickel, and cobalt do occur also in the native state; the last three (Fe, Ni, and Co) usually occur together in form of an alloy. The particle size varies greatly from less than 10 microns (gold and mercury) to about 400 tons boulders (copper).

Jan 1, 1993

By Zay Jeffries

From the title of this chapter the reader could expect an attempt to outline the anticipated shape of things to come, mineralwise. We have no crystal ball and if we possessed one we could claim no expertness in its use. In the first place no one can tell the future status of man. No one has any way of knowing to what extent peace will prevail, nor to what extent changes may occur in national sovereignties or forms of government or in international relationships. So future man is an uncertainty. Nor can we predict new developments that may result in significant changes in man's status or in the mineral industry or both. If, for example, this chapter had been written in the middle 1930's, nearly everything that has happened since in the field of atomic energy would have been missed. Yet what a vast change this has made in the status of man! Also the changes in the mineral industry have been important. A writer would have been bold indeed had he prophesied that uranium would play such an important role. But we need not confine our foggy vision to the atomic energy field. The steep rise in the use of aluminum, titanium, and germanium reflects the unpredictable in what may be thought of as the more normal pursuits. This should not discourage one from using the past and currently observable trends as bases for limited predictions. To do this, however, it is desirable to make certain assumptions about man's status without even a pretense that these assumptions have a high probability of fulfillment: 1. Only minor changes will occur in the geographical boundaries of the nations of the world. 2. World War III will not take place in the near future. 3. As a consequence of (2), man will not destroy himself by wanton use of atomic weapons. 4. Disarmament will take place, if at all, gradually rather than all at one time. Under the above assumptions the world will enjoy a period of relative peace even though the status may be one of an armed truce. The assump-

Jan 1, 1959

By Dirk van Zyl, S. Chander

Minerals have been critical to human society from the earliest and their use has been intertwined with the development of civilization. In the Western World, the mining, processing and extractive metallurgy associated with ores was first described in detail by Agricola in the 16th century. He considered these collective activities to be the most necessary and the most profitable of professions, and wrote, "without doubt, none of the arts is older than agriculture, but that of the metals is not less ancient; in fact they are at least equal and coeval, for no mortal man ever tilled a field without implements. In truth, in all works of agriculture, as in the other arts, implements are used which are made from metals, or which could not be made without the use of metals; for this reason the metals are of the greatest necessity to man." Ours is still a materials-dependent society that relies heavily on minerals for raw materials. Today our dependence on minerals is exceptionally great. To meet the need for fuel and non-fuel minerals in a representative year, in the United States alone, about one billion tons of coal and 2.7 billion tons of ore are mined. These mineral products are essential for fertilizers, for construction materials, metals and alloys, for manufacturing household and industrial items, for transportation, and for the generation of electric power. It is instructive to consider the diversity of uses found in our society for a single mineral product - silver, for example. Experts believe that in the past 5000 years we have mined about a million tons, or 31.9 billion troy ounces of silver. In 1988, 133 million troy ounces of silver were used in the Unites States. Most of the silver used was for techno- logical, medicinal and industrial purposes, Table 1. X-ray films, for example, carry comparatively large amounts of silver to lessen patient's radiation exposure. Silver does not prevent tooth decay, but each year about two million troy ounces of silver is used for dental work in the United States. In small quantities it is used in medicine. No metal - not even copper conducts heat and electricity so efficiently as silver. Silver wires lace solar cells, and silver oxide batteries power hearing aids, calculators, submarines and satellites. Hardened with tungsten or molybdenum, miniature discs of silver pass current from wire to wire in cars, telephones and computers. A dish- washer timer alone may have 50 such electrical contacts, which open and close without excessive heat or friction. Silver is an important component of solar reflectors, since no other material reflects light so well or uniformly. In our personal lives, silver remains in high esteem to adorn our tables, provide precious objects and jewelry. In many parts of the world, silver in the form of coins, jewelry and bullion is used for financial independence and security against the vagaries of paper currency. In India, silver is used in its purest form as thin foils to decorate sweets and other edibles. It is obvious that this mineral product, silver, is of great value and utility in our society. Minerals and Environment The benefits of minerals do not come without problems. Much of the silver, for example, lies locked up in copper, lead-zinc or precious metal ores; to extract it creates vast quantities of waste material. On the average, in order to recover one ounce of silver about a quarter ton of ore must be mined. To meet the world's annual demand for silver, approximately 100 million tons of waste is generated every Year. The problem with silver is repeated with all minerals. Conversion of mineral ores into usable materials necessitates the generation of large quantities of waste products that create tremendous disposal problems. In addition to waste material discarded during mining, wastes may be generated during processing as gases, liquids or solids that must be subsequently converted into forms more acceptable for disposal. Associated with the handling, treatment and management of waste products are a number of environmental problems. Environmental problems are not new to the minerals industry. In his Geographia, Strabo (63 B.C. - 20 A.D.), gives an account of the conditions of labor under which men

Jan 1, 1992

For its Hellyer project, Aberfoyle sought to establish a high degree of confidence in all aspects of the feasibility study. Accurate capital and operating cost estimates were an integral and essential part of the study. They were crucial to the evaluation of investment returns and competitive cost position. Both the capital and operating cost estimates were based on the comprehensive data available from exploratory mine development, pilot plant operation, detailed engineering design, and Aberfoyle's experience in the area. One of the principal project objectives was to maximise operating productivity and efficiencies and this created capital cost alternatives which needed thorough cost-benefit assessment. The estimated capital cost for construction and development was $90 million, and the project was completed virtually on time for $80 million. The first year's experience indicated that operating costs would settle to well within 10% of the estimates.

Jan 1, 1990

By A. F. Roberts

The subject of mine fires is a very wide one. To give reasonable coherency, the paper concentrates on the behaviour of fires in the ventilated airways of mines; spontaneous combustions are not considered. The following topics are considered in some detail: 1) Material selection: Performance requirements for mining materials in terms of flammability and smoke/fume production; methods of test and need for relevance to mining conditions. 2) Fire growth: The influence of material properties and method of use on the rate of growth of fire in a mine roadway; the influence of ventilation, slope, material orientation, proximity of walls and roof on fire behaviour. 3) The fire in the ventilation network: The influence of fire on the ventilation distribution; the circulation of fire products in the network. The influences of these topics in determining fire control strategy are then considered but topics such as fire detection and fire extinction methods are not reviewed in detail. An extensive Bibliography on papers relating to mine fires is included.

Jan 1, 1989

By James F. Reynolds

Introduction There are 1.4 Gt (1.5 billion st) of recoverable coal under less than 914 m (3,000 ft) of cover in Colorado in pitching seams. Snowmass Coal Co., in cooperation with the US Department of Energy, introduced the longwall mining method in pitching seams to North America. This venture is a coal mining research program directed toward the profitable production of coal under difficult mining conditions as found in pitching seams of the western US. Snowmass Coal classifies pitching seams into the following categories for longwall on the strike in seams 3 m (10 ft) or less thick: • Flat = 0 to 10°: Normal continuous mines and shuttle cars work efficiently. • Slight = 10° to 22°: The maximum pitch that rubber tired equipment will function. • Moderate = 22° to 40°: The angle of repose of mined coal. • Steep = 40° to 60°: The limit of safe use of this roof support. • Vertical = over 60°. The longwall roof support covered here will work in all pitches except vertical. The shearer and conveyor will work in flat through moderate conditions. Longwalling across strike with this equipment in seam pitch over 60° could be accomplished with an inclined face. Development of the first longwall panel began in 1979 and was completed in 1981. The longwall equipment was installed and mining began on Aug. 11, 1981. Mine Planning and Development The original mine plan took advantage of old works abandoned in the 1960s. The gates were developed on a two-entry system with the entries rising 2° to the strike, allowing water to drain from the face. The mining method was by Alpine F6A road header continuous miners with bridge conveyor type coal transport into 5.4-t (6-st) bottom dump coal cars hauled on 1.1-m (42-in.) gauge track by 7.2-t (8-st) battery locomotives. The initial concept was to haul coal from the longwall by battery locomotive. Lack of discipline, however, was shown in the irregular direction of the gate entries, and local rolls in the coal seams severely limited the capacity of battery locomotives. Current mining law prohibits using an intake escapeway for belts or trolley locomotives. A two-entry system is the simplest method of panel development in a pitching seam. A continuous miner cannot be trammed from one entry to another because of steep "X" cuts. Thus, the development requires a continuous miner in each entry. The configuration of the old mine works resulted in a first panel longwall block of three 108 m x 1.6 km (355 ft x 5,400 ft). In panel development, the use of battery locomotives for coal hauling became evermore costly. When the panels were completed and the setup room finished, the lower gate entry was changed to a belt entry and battery locomotives were abandoned. A new slope was driven and the mine supply system was converted to rubber tire diesel supply. The latest generation of roadheader and standard high powered shuttle car-to-belt system is now used for development. Selection of Longwall Equipment Longwall mining across the strike on pitching seams is currently practiced in many nations. Equipment similar to that used by flat seam longwalls is available for pitching seam use in Great Britian and Germany. Face equipment includes a twin outboard armored face conveyor. It was selected to give maximum retention of coal on the conveyor due to flight rigidity and to prevent coal from sliding down the face and jamming the lower belt gate. Also selected was a 22-mm (0.9-in.) Dowty twin-outboard face conveyor for a 106-m (350-ft) face with a single 112-kw (150-hp) drive

Jan 12, 1983

By Mark E. Emerson

1967 will be remembered as the year the world realized it was running out of silver. In May of this year a new era in tin the history of the white metal was begun as the power of the U.S. Treasury to regulate world .silver markets was staggered by one of the most intense speculative flurries in recent times. In the past few months the price of silver has risen from $1, 29 to over $1.80 per troy ounce and with it have spiraled the prices of a host of silver-bearing consumer items. Legislation has, been enacted to conserve our coinage and meager silver stocks and today large quantities of non-existent silver are trading hands at a fast pace on the commodity exchanges throughout the world. Now that the price of silver has been set loose, forces are in motion to dull the world's appetite for silver. At the same time there is strong incentive to provide greater quantities of silver to satisfy the world's hunger' for the metal.

Jan 1, 1967

By C. E. T. White

Although trace amounts of Indium are found in many ores, commercial production of the metal has come almost exclusively from residues, flue dusts and slags generated by Zinc recovery operations. Our paper attempts to summarize the various approaches used to recover Indium from these by-products. Some comments on production and price trends are included as well as our views on future availability.

Jan 1, 1982

By H. David Swain

On Bougainville Island in Papua New Guinea, Bougainville Copper Ltd. (BCL) has successfully applied electronic data processing (EDP) techniques to pit operations and mine planning. Though the EDP program is not complete, BCL has realized significant improvements in short and long range mine planning, and equipment and manpower utilization. About 80% of BCL's 4000 employees are Papua New Guinea nationals, and most have little education or training. The operational characteristics of the computer equipment, however, have been quickly adapted by users with low educational standards.

Jan 3, 1979

De acuerdo a los últimos trabajos realizados sobre la exploración en la mina Cercapuquio, se realizó un muestreo de la veta 53 donde se observó que en la caliza, más allá del ala norte, como en el lugar llamado Chaupirange, existe grandes depósitos de carbonado estático con siderita y limonita, en bolsa de erosión de la caliza normal. Asimismo, se describe otros métodos utilizados para la exploración geofísicadel subsuelo como los electromagnéticos e inducción. En ese sentido, se trata de crear un campo (primario) a través de una corriente eléctrica alterna (primaría) en un circuito. A este campo, es concadenada una corriente (secundaria) que circula en el cuerpo conductor mismo ( en general desfasada respecto de la primaria), que genera a su vez, un campo secundario. Este último se compone con el campo primario para formar un campo total, que está relacionado con la posición y naturaleza del cuerpo conductor que funciona de circuito secundario.

Jan 1, 1956

Pese a tener cajas sólidas en su estructura, algunas vetas desarrollan un relleno frágil, ocasionando problemas futuros de sostenimiento para el "corte y relleno" de los mismos. Por ello, se utilizó el método de los "Square Sets", donde además de ser costoso, implicaba eliminar una proporción de la roca encajonante y diluía el contenido metálico de los filones. En ese sentido, el objetivo del texto es señalar la viabilidad del "método Cornish"como método alternativo, económico, de rendimiento óptimo y que no presenta riesgos para el personal o la labor realizada. Este método es aplicable en aquellas vetas uniformes no falladas, que tengan desde una potencia pequeña hasta aquella que sea posible apuntalar, así como en aquellas que requieran sostenimiento del techo en la veta mima o donde se realizen Shrinkages. El proceso del método se basa en la preparación de los tajeos, luego en la explotación(perforación y disparos), enmaderado, relleno del tajeo, recuperación de madera, las variantes en la preparación del tajeo y la recuperación del mineral. La única desventaja que ofrece este método es su peligrosidad, dado que si se aplica en zonas inadecuadas o sin la supervisión que garantice el cumplimiento de las normas preventivas, es preferible el uso de los "Square Sets". Sin embargo, la aplicación del método resulta mucho más productiva en rendimiento teórico puesto que alcanza de 7 a 10 toneladas por tarea de 8 horas y responde satisfactoriamente siempre y cuando las condiciones de las vetas lo permita.

Jul 20, 1957

By Schumacher, Earle E.

THE solidus line above the solid solution field in the lead-antimony system was originally determined by Dean and his associates1 from heating curves. They did not regard this line as having been accurately fixed and in their more recent publications2 the curves drawn do not follow closely the original data. The precise location of the solidus line is of importance in the extrusion of lead-antimony cable sheath, as the temperature of the metal in this process must be less than the lowest temperature at which any part of the alloy in the lead-press charge becomes liquid. It is very desirable, however, to operate at as high a temperature as possible, as the rate of extrusion for a given pressure is approximately doubled for an increase of 10" C. in temperature. The precise location of this line is also important in the investigation of ternary systems of lead, antimony and a third metal. For these reasons, and because of the differences reported in the literature, data were secured on the lead-antimony solidus line by the classical quenching-test procedure.

Jan 1, 1927

By E. S. Moore

"The Centre of the silver-producing section of the Gowganda area lies about 55 miles northwest of Cobalt, and the village of Gowganda is 71 miles by road from New Liskeard. The geological similarities of the Gowganda and Cobalt areas led prospectors westward from the rich Cobalt field, first to Elk Lake and then on to Gowganda, where mineralization was found in 1907. A year later many showings were found, and rich hand-picked ore was shipped. Most of the ore has come, however, from two mines, both of which are still operating; the Miller Lake-O'Brien, which was purchased by Siscoe Metals of Ontario Ltd. in 1945, and the Castle-Trethewey. The annual production of these two mines runs over one and one-half million ounces of silver and considerable cobalt. The total production of the camp has reached about 32,000,000 ounces of silver and a large amount of cobalt, the total not recorded.General GeologyThe general geology of Gowganda is in many respects much like that of Cobalt. There are areas of Keewatin basic and acid Javas mixed with tuffs and basic intrusions. These rocks are deformed and partly altered to schists, and have been intruded by some Haileyburian basic and ultra-basic rocks and by Algoman granite. These were followed by a large number of porphyritic Matachewan quartz diabase dykes. After a period of extensive erosion the Huronian sediments were deposited on a pene-planed surface over all the older rocks; these sediments include large quantities of conglomerate (partly tillite), quartzite, and greywacke. The Keweenawan rocks include the Nipissing quartz diabase sill, later quartz diabase dykes, and one long olivine diabase dyke, the latest Precambrian rock. The area has been extensively glaciated.Structural FeaturesThere has been little folding in the area since the Algoman batholiths were intruded, and the Huronian sediments lie nearly flat, with dips of 10, 15, or rarely 25 degrees. The Matachewan dykes show a remarkably uniform, nearly north strike, indicative of east-west tension when they were intruded. On the other hand, the dykes later than the sill strike nearly east, tangentially to the northeasterly and northwesterly strikes of the Miller Lake basin."

Jan 1, 1949

By S. K. Singh

To meet increasing demand of coal, underground mining is largely being replaced by the exploitation at deeper horizons and with greater complexities. The exploitation-proposition may be below not-to-be-disturbed surface properties or below water-bodies, posing a constant threat of inundation. Also, the mounting pressures to limit the adverse impacts on the environment bring the extraction-undertaking to face more challenges. An understanding of subsidence-mechanism and a rational quantification of subsidence parameters is a requisite herein. This paper presents such pragmatic quantification, validated at mine-sites in India. In comparison, better productivity, conservation and safety is ensured in this approach.

Jan 1, 1999