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By C. A. Young

"The stabilization of tailings has been a matter of concern to the Mining Industry for many years. In earlier times, when mines were small and only high grade ore deposits were mined, the problem was not a great one. But, more recently - during the last 30 to 40 years - the increased world demand for various metals, combined with the vast strides that have been made in the improvement of metallurgical extraction processes, have resulted in the development of lower grade ore bodies.About 30 years ago The International Nickel Company started experiments to stabilize the surface of the tailings and prevent them from becoming a dust source under certain weather conditions. The use of chemicals to form seals, covering with crushed stone, mulching with straw and some early seedings were some of the stabilizing methods tried. Results were either unsuccessful or impractical economically.In 1954 a series of experiments to establish vegetation on the tailings began. Varying degrees of success were achieved but however unsuccessful a particular scheme turned out, the attempt to find a solution was never written off. As we look back, we realize that the first significant break-through came as the result of three test plots planted in the spring of 1957. Each plot covered an area of approximately one-third of an acre. One plot was successful and persisted until it was covered up by the expansion of the tailings area in 1961.In 1960 a review of all our test plots to that date was carried out to assess the factors which effect the chance of grass being established."

Jan 1, 1969

By Peter Godbehere, Christian Desroches, Viken Baboudjian

"Noranda Copper Smelting and Refining is a unit of Noranda Metallurgy Inc., comprising the Home smelter in Rouyn-Noranda, Quebec and the C.C.R. Refinery in Montreal East. The Home smelter provides custom smelting services for a wide variety of copper and precious metal bearing concentrates and recyclable materials, producing over 200 000 tonnes of anodes and 450 000 tonnes of sulphuric acid annually. The C.C.R. Refinery has an annual production of 360 000 tonnes of copper cathode, and is a major refiner of precious metals.Over the past twenty years, Noranda Copper has developed innovative processes and operating techniques to treat the ever increasing complexity of primary feed materials, while improving the quality of its final products, working conditions and reducing environmental emissions.This paper presents an overview of the operating practices of Noranda Copper with particular emphasis on the impact of impurities in the smelting and refining processes.IntroductionThe treatment of custom materials has been practiced by Noranda Copper since commencement of operations at the Home smelter in 1927 and the CCR refinery in 1931. Copper concentrates from a wide variety of regional, North American and overseas producers account for the bulk of the 800 000 tonnes treated annually, although recyclable and secondaries have increased in importance as feed sources in the past two decades. The geographical disadvantage of the Horne smelter compared with most custom smelters located on tidewater has provided an important incentive for Noranda Copper to develop the necessary technology and operating practices at its smelter and refinery to treat high value complex concentrates and other feeds containing significant concentrations of bismuth, antimony, arsenic, lead, tellurium, mercury, etc."

Jan 1, 1995

By John Eggert, Paul Benford

"Since 1982, Placer Dome Inc. -Dome Mine has steadily increased mill throughput. Tonnage has increased from a nominal design capacity of 3000 short tons per day, attained in 1985, to 4130 stpd by the end of 1992. Many minor and major circuit adjustments were tried to maximize tonnage.Having utilized most conventional means of increasing tonnage, further increases required a newer approach. This paper discusses the Dome experience in the development and implementation of an expert system.The Comdale/C system was chosen for a controlled trial. The criteria for acceptance were: increased tonnage had to be sufficient to pay for the system; the increase had to be visibly sustainable and the mill operators had to be willing to accept the system.The criteria for purchase were met during the trial and the system was purchased. The system continues to perform well. The tonnage throughput increase has been sustained while operator acceptance remains high.IntroductionPlacer Dome Inc. -Dome Mine is Canada's oldest operating gold mine. The mine was among the first established in the Porcupine camp in what is now Timmins, Ontario. The City of Timmins is located approximately 500 miles or 800 kilometres north of Toronto. Figure 1 shows a map of the province of Ontario and the mine location.In 1912, milling began at a rate of 350 short tons per day. With two minor exceptions, milling has been continuous since this time. The first of these shut downs was in 1918 during the first world war. The war created labour shortages which forced the mine to stop production for more than a year. The second was in 1930 when fire destroyed the mill."

Jan 1, 1994

By Ali Roshanfekr

Linear mine-waste dumps at open-pit mine sites essentially represent expedient places to deposit large quantities of waste rock. Being in valleys in most cases, the effect of the water flowing through and out of the deposit often raises questions about their hydraulic behaviour and geotechnical stability, especially the zone of the downstream toe. In order to provide better tools to assess the behaviour of these dumps a laboratory and analytical study was conducted. Firstly, physical models were built to assess the flow capacity and hydraulics associated with the linear growth of such dumps. It was found that the elevation of the point of first-emergence on the downstream side becomes constant after the dump grows to a certain length, but that the upstream depth concurrently increases. The limits of applicability of the theories of Hansen et al. (1995, 2005) are discussed in this regard. Secondly, in analysing the seepageface downstream, two approaches for solving this spatially varied flow (SVF) problem were undertaken. Under one of the approaches links to SVF depths were merely made to the hydraulic heads of the body (interior) and flux was calculated using conventional surficial nodes after the fact, Under the other approach flux nodes were used to link the SVF algorithm to the hydraulic heads further ?inside? the body of the rockfill. Although there are inherent uncertainties, it was found that these two methods can be made to perform equally well. Research continues but it appears that a linear variation in depth can be assumed without inducing any unrealistic exit gradients in the zone of primary concern with respect to unravelling.

May 1, 2011

By John Drobe, Robert M. Cann

"Abstract - The Minas de Oro Cu-Au skarn and replacement deposits are located in the highlands of central Honduras, 90 km north-northwest of the capital of Tegucigalpa.The deposits formed in Cretaceous volcano-sedimentary rocks following the emplacement of an early Paleocene granodiorite to dacite intrusive complex. Three types of skarn (Type IA, IB, and IC) and a low-temperature replacement mineralization (Type II) are recognized. Type IA skarn consists of massive brown-green andradite and lesser magnetite and pyroxene. Type IB skarn has magnetite + hematite as the main constituent and garnet <50%. Type IC skarn comprises >50% pyrrhotite + chalcopyrite with interstitial garnet or pyroxene. Au and Cu occur in potentially economic concentrations in all skarn types while other metals such as Ag, Pb, Zn, and Mo are locally present in significant quantities. The highly variable distribution and nature of the skarn deposits is controlled by: (1) intrusive activity, (2) composition of host rocks, (3) faulting and fracturing, and (4) attitude of host carbonates.Type II Au-Cu-As mineralization occurs in calcareous sandstone and conglomerate 2 km distal from skarns and comprises clots of Cu sulfides hosted within a zone of brecciation and quartz flooding. Garnet and/or magnetite skarn is not present and the mineralizing event appears to have been a low-temperature replacement type.The similarity of coeval Au-Cu-Fe skarns in central Guerrero, southern Mexico to Minas de Oro skarns, and the similar local stratigraphy is consistent with the generally accepted theory that the Chortis block originated from southern Mexico and during the Tertiary moved southeast to its present position."

Jan 1, 2000

By Robert B. Parsons

"Recent amendments to the so-called ""flow-through share"" rules in our income tax legislation have given a new lease on life to this once popular investment vehicle.The original ""Dome funds"" for exploration in the Beaufort sea recognized the usefulness of flow-through share arrangements, but, by and large, flow-through shares have until recently not been able to compete effectively with other tax shelter instruments-mainly , limited partnership interests.This month, Tax Notes examines the new tax rules for investing in flow-through shares.IntroductionRecent income tax amendments have helped to rekindle investor and industry interest in so-called ""flow-through shares"" as a mechanism for mobilizing funds toward mineral exploration and development activities. In competing for investment funds, flow-through shares have historically placed a distant second in terms of investor popularity, being unable to compete with the more attractive features of limited partnership arrangements. However, primarily as a result of favourable changes to the income tax law, flow-through shares may be well poised for a comeback.This article examines the income tax considerations pertaining to issuing and investing in flow-through shares, and compares the former and the new income tax rules relating thereto. Of course, inasmuch as a flow-through share issue can involve various contractual arrangements between the investor and the issuer, there is a wide range of legal and business factors that generally have to be taken into account. A discussion of these matter s is beyond the scope of this paper, which is restricted to a summary of the special income tax factors attributable to flow-through shares."

Jan 1, 1983

By D. C. Reid

This paper describes the latest results in research and development currently being undertaken by the CSIRO Mining Technology Group to advance the automation capability of continuous mining equipment in underground coal mining operations. This research delivers enabling technologies that are essential in achieving increased roadway development rates as well as providing a safer working environment for underground mine personnel. Details are presented on technical developments and results of large-scale above-ground experiments conducted under field-realistic conditions. These experiments demonstrate the performance of the ?self-steering? capability which will enable a continuous miner (CM) to automatically maintain a given mining heading and mining horizon under production conditions. A primary technical requirement of this automated functionality is the means to accurately determine both the location and orientation of the CM in real-time. Test results of a high performance navigation system utilising vehicle motion aiding technologies are presented. This system combines high performance inertial sensors, and custom-developed radar to achieve a navigation-grade guidance system. Comprehensive performance evaluation has been conducted using a scale skid-steer mobility platform operating autonomously through a typical roadway development mining pattern with a total path length of 2700 m and mission duration of 112 min. Results from this evaluation demonstrate that the sustained accuracy of the navigation system exceeds the original project expectations and is well suited to the requirements for this underground mining application. There are presently no known alternative methods for providing a practical and accurate three-dimensional guidance solution in this application. This achievement represents a significant milestone in delivering a step change improvement in underground coal mining roadway development.

Aug 1, 2013

By N. Plint, D. Philips, J. Sweet, B. Durant

A pilot scale AG milling campaign was conducted at the AngloAmerican Platinum pilot plant in South Africa. Different blends of hard: soft (silicate: chromite) and coarse: fine particles in the AG mill fresh feed were tested. The effects of multi-component feed on the pilot scale autogenous grinding are presented in this paper, and can be used as a guideline for multi-component feed blends for AG mil

Jan 1, 2012

By K. Johanson, M. Hubert, C. Eckert, D. Ghose

The mining industry routinely processes material with different particle sizes. Coal, nickel ore, copper ore, lignite, shale, and phosphate ore are all examples of materials with wide particle size distributions. It is often assumed that these materials are homogenous and that any particle size distribution has the same chemical activity and composition. It is entirely possible, and quite likely, that chemical composition is a function of particle size distribution. In addition, particle size distributions in ore materials are often responsible for the difference in flow behavior in process equipment. This is evident in coal electrical production facilities. Fine coal may have the same ash content, sulfur content, and BTU value as coarse coal. However, all electrical production facilities know the extreme flow problems that result when attempting to handle wet fine coal. Segregation of these bulk materials is an important issue that must be understood to prevent these cohesive flow problems. Additionally, fertilizers are mixtures of particles with different shape and sizes. These mixtures must remain homogenous to optimize fertilizer performance. Segregation leads to poor product quality. This paper presents a method of measuring the magnitude of sifting segregation occurring in bulk material and the relationship between the strength of the bulk material and the separation tendency. It shows an inverse relationship between the yield strength of the material and the bulk segregation.

Jan 1, 2004

By M. B. M. Monte, M. L. Torem, E. R. Pecanha, A. G. Merma

The recent literature has unveiled the potential use of microbial strains in mineral bioprocessing. This study presents the use of a Gram-positive bacterium (Bacillus subtilis) as bioreagent for hematite flotation. The bacterium presents the ability to modify the properties of mineral surface (electrophoretic mobility and hydrophobicity). It was studied the electrokinetic behavior of hematite particles, before and after the interaction with the bacterial cells. The results revealed a shift of the isoelectric point (IEP) of the hematite after interaction with bacterial cells, suggesting a chemical adsorption mechanism. Moreover, after bacterial conditioning, the zeta potential curve of hematite presented high values in the alkaline pH range. The hematite and the bacterial surfaces presented contact angle values around 27.4° and 41.0°, respectively. According to the results, the B. subtilis strain was capable of modifying the hematite surface, and after interaction the hematite surface presented a contact angle value around 46.0°. The flotation tests were carried out in a modified Hallimond tube. The experiments revealed a significant increase in hematite flotability using the Gram-positive strain as bioreagent. The tests pointed out a maximum recovery of hematite in the presence of 600 mg/L and pH 5. Therefore, the results from this study showed the potential use of the B. subtilis strain as a biocollector for hematite flotation, and its possible application in the mineral flotation industry.

Jan 1, 2016

By L. S. Brooks

TIMBER HANDLING presents a problem for any mine where appreciable amounts are used. This problem is accentuated where the shaft compartments are too small to allow a loaded timber truck to be lowered in the mine cage. When Normetal Mining Corporation, Limited, found it necessary to resort to square-set mining it faced this problem of getting large quantities of timber down a shaft that was also required for hoisting ore. A &apos;timber car&apos; that could be suspended under the cage was developed to overcome this difficulty. Production started at the Normetal mine in 1937, at the rate of 250 tons per day. In 1938 a winze, known as No. 3 shaft, was sunk from the 800-foot level ?to the 1,385-foot level. This was later raised to surface and then deepened to 3,275 feet in three stages and became the main production shaft. The portion of the mine below the 3,070-foot level is serviced by a winze, locally referred to as No. 4 shaft, which has been developed for stoping down to the 3,990-foot level and which has been deepened to the 5,365-foot level. No. 3 shaft has two hoisting compartments, each 4 ft. 6 in. by 5 ft. 0 in. inside the timbers, through which the ?ore must be hoisted and timber and supplies lowered.

Jan 1, 1956

By Angus W. Davis

The case of the P. G. E. railway is a peculiar one. Traversing, as it does, to a large extent, a mineralized country there are as yet no producing mines along its route although I am convinced that mines will be developed in the region tributary to the railway. The Fitzimmons group of claims, a copper property near Mons station, 37 miles from Squamish is now (unless recently relinquished) under bond to the Granby Company. On Cadwallader creek, in the upper Bridge river country, certain gold properties, referred to later, are being developed. Prospectors are fairly active in the Pemberton meadows area. There are also a large number in the Bridge river, Gun creek, and Whitewater districts. East of Marguerite station some development work is being prosecuted on some copper claims located there. In addition here and there throughout the entire route of the railway prospecting is being undertaken. At Hat creek, 15 miles from Pavilion station there is an enormous deposit of lignite. It is by no means certain that this coal can be profitably mined and hauled to the railway, but as a cheap fuel it offers possibilities in the recovery of by-products by destructive distillation. Logical procedure would ? indicate the expenditure of considerable money on development and, if results justify, the construction of a spur from the main line to the deposit.

Jan 1, 1925

By J. Day, Matthew X. Yao, Lijue Xue

Hardfacing overlays are commonly applied on the shroud Z-section of turbine blades for enhanced wear resistance. Among various processes that are used to apply the hardfacing overlays, the plasma transferred arc (PTA) welding process offers several advantages including lower heat input, less base material dilution, rapid process time, and reduced operating cost associated with the capability to apply materials in the powder form. The development of a robust PTA process is crucial for overlay performance and repeatability, particularly in the aerospace industry where a quality intensive manufacturing environment prevails. For this reason, the Taguchi method of experimental design was selected to develop a test plan. A 4-factor 3-level (L9) orthogonal array (OA) was used in the experiment. The L9 OA allows for a more detailed (3 level) investigation of critical process parameters, namely plasma gas flow rate, traverse speed, powder feed rate, and arc current. Two hardfacing materials, Stellite 694 and Tribaloy T-800, both Co-based wear resistant alloys, were investigated by deposition onto a cast IN738 Ni-based superalloy substrate. Performance measurements of the hardfacing deposits included deposit hardness, substrate hardness, deposit density (porosity), degree of cracking/inclusions, and a quantified visual inspection. The procedure resulted in optimized PTA hardfacing parameters for both Stellite 694 and Tribaloy T-800 on IN738 turbine blade material.

Jan 1, 2004

By W. Marnette

The copper demand is booming. New epicentres with strong dynamic economic growth have arisen in China and other emerging markets. Furthermore, Europe contributes to higher copper demand due to positive economic growth. China and India are therefore expanding their smelter industries, with the backing of a coordinated policy of global raw material sourcing, which includes investments in raw material deposits and state-run measures to support their international trade and competition. Likewise, Europe faces scarcity of copper raw materials. The copper industry in Europe is historically grown and shows excellence in environmental protection and technical leadership. Recycling has always been an important sector. This reiterates the recycling-know-how which exists in the European sector. However, Europe still relies on importing a considerable amount of raw materials from foreign countries. As a result, the global competition for copper and copper raw materials has increased. Tough competition as regards industrial location and costs, the emergence of corporate concentrations and the use of protectionist trading practices by countries like China and India, which distort the markets, now determine the picture. Hence, a copper smelter in Europe is forced to develop tailor-made concepts to safeguard and improve its international competitive position. It is imperative that this is also flanked by improved conditions on the local level and a European raw material policy which takes account of the changed situation on the world market.

Jan 1, 2007

By J. O. Marsden

Over the past eight years, Phelps Dodge (a division of Freeport-McMoRan Copper and Gold, Inc.) has developed a suite of proprietary hydrometallurgical processes for the treatment of copper concentrates as an alternative to conventional smelting and refining technology. The technical viability of two processes has been commercially demonstrated in a large scale plant at Bagdad, Arizona, designed to process approximately 52,500 metric tons per year of concentrate containing 30.5% copper. The first process utilizes high temperature (225°C) pressure leaching, followed by countercurrent solid-liquid separation, and then blending of the copper-bearing solution with low grade stockpile leach solution for subsequent treatment by SXlEW for copper recovery. The second process uses super-fine grinding, medium temperature (l60°C) pressure leaching, followed by solid-liquid separation, and treatment of high grade copper-bearing solution by direct electrowinning to recover the bulk of the copper values. The latter process will be utilized at Morenci in a commercial facility designed to treat mixed chalcopyrite-chalcocite-covellite concentrates. This facility is scheduled to start up in 2007. Other flowsheet options have been developed by Phelps Dodge for application to a variety of concentrate materials in specific situations. Examples of various flow sheet options are presented in this paper, and the advantages and disadvantages associated with each are discussed in detail.

Jan 1, 2007

By Larry M. Southwick

Processing of ores to recover metals usually generates large amounts of waste materials, such as rejects from concentrating operations, tailings from leaching and slags from smelting. These wastes often contain substantial amounts of iron and other metals, recovery of which are often considered to be of commercial value. Earlier versions of this paper investigated a number of processes built to recover iron from a variety of copper processing residues. This paper will extend that coverage to residues from nickel/cobalt, aluminum, asbestos and oil shale processing and coal plant fly ash. Products of interest are iron, ferroalloys, magnesium and aluminum. While none of these processes achieved long-term commercial success, their efforts cover the gamut of problems that must be addressed in treating dirty and difficult materials to recover generally low-value products. An Adept is an alchemist who can create a Philosopher&apos;s Stone, which could transmute base metals into gold. In 1701 in Berlin one Johann-Freidrich Böttger, a nineteen year old apothecary&apos;s apprentice, told King Frederick I that he could discover how to make the Stone. He failed and fled Frederick&apos;s wrath to Poland. He failed again, and King Augustus II threw him in jail. Then, in 1709, he discovered instead the secret of making Dresden china, certainly a more practical search. His failures in alchemy led to the nickname Adeptus Ineptus.

Jan 1, 2004

By S. Y. Mostowy, P. W. M. Shibley

"When Texas Gulf Sulphur Company discovered the Kidd Creek ore body in 1964, a crash program began almost immediately for the design and construction of a modern concentrator. It was necessary to mill two distinct ore types; one containing copper and zinc, the other lead, silver and zinc minerals. The final concentrator design was to handle 9,000 tons of ore daily in three circuits. One circuit was to treat copper-zinc and another lead-zinc ore exclusively on a permanent basis. A central circuit was designed with adequate flexibility to treat either of the above ore types in accordance with planned mining schedules. Ecstall Mining Limited, a wholly owned subsidiary, now operates the mine and concentrator complexes for Texas Gulf. The mine is located 15 miles north of Timmins and the concentrator 15 miles to the north-east along Highway 101. The ore is hauled from the mine to the concentrator over a 17-mile railroad. Initial milling operations began in November, 1966.1 - ABSTRACTThis paper deals with bulk reagent handling at the Kidd Creek concentrator. The reagent section at Kidd Creek has operated excellently since milling began in 1966. The bulk handling techniques are satisfactory. They have contributed substantially to good working conditions, economical practices and metallurgical efficiencies. The bulk handling features described should be considered in existing and proposed concentrators."

Jan 1, 1970

By R. H. Duval

"In May 1936, Pamour started producing gold by cyanidation of flotation concentrates, and in 1939 was milling about 1, 600 tons per day.Refining records dating from 1939 show two oil-fired furnaces in use, (Rockwell type 46 11 x 29 11 inside oval shell).Refining time averaged 7. 83 hours during the year 1939, indicating a complete refining shift of about 9. 33 hours. That year appears to be characteristic of the period with regard to time required and results obtained.For that year total fineness (gold + silver) of the bars averaged 940 (approx.), but it frequently dropped below this figure, sometimes far below.Furnace lining life varied widely from three to seven or more months. Sillimanite was the standard lining but Mullfrax 41 was frequently used.For many years refining practice remained practically unchanged, and in 1960 procedure still consisted essentially of mixing a flux(% Composition Borax 41, Silica 11, Soda-Ash 11, Nitre 15, Mn02 22) with cyanidation precipitate in the ratio of l. 2 to l and heating to a medium heat (yellowishred, 2000° F) with a low flame for a long time. Time required was about 10. 5 hours per refining. Results were still much as detailed above.At this time it was decided to revise refining procedure, in an effort to shorten refining time and obtain consistently good bullion fineness."

Jan 1, 1965

By S. Koski, J. Vanderbeek, J. Enriquez

"The Cerro Verde copper-molybdenum porphyry mine, majority owned and operated by Freeport- McMoRan Copper & Gold, is located 30 km southwest of Arequipa Peru. The concentrator, which produces copper and molybdenum concentrates, started operating in late 2006 with a 108,000 tpd design capacity, processing primary sulfide ore (mainly chalcopyrite and molybdenite). Plant capacity was recently increased to 120,000 tpd. The comminution circuit consists of one 60” x 113"" primary crusher, four MP-1000 secondary crushers in closed circuit with dry screens, four 2.4m x 1.6m High Pressure Grinding Rolls (HPGRs) in closed circuit with wet screens, and four 7.3m x 11m gearless ball mills in closed circuit with cyclones. The HPGR circuit is fed by the Secondary Crushing circuit product at a T80 of 35 millimeters, and the HPGR circuit product feeds the Ball Mill circuit at a T80 of 3000 microns.This paper describes operating experiences with HPGRs during these first four years highlighting improvements in operating practices and presentation of data regarding operational efficiencies, also discussed are the primary benefits provided by HPGRs such as production of micro fractured particles, reduced ore Bond Work Index, and reduced power consumption. Cerro Verde represents the first installation of HPGRs in both the copper industry and large scale hard rock mining."

Jan 1, 2012

By B. W. Brooks

"After an extensive period of University research and field trials, large scale reclamation of the Waite Amulet tailings discharge areas commenced in the spring of 1978. The Noranda program consists principally of sampling the complete dam to determine the vegetation potential of the various areas, addition of the required amelioration materials, and the use of good agricultural practices. This paper describes the development work that led to the establishment of the Noranda-Guelph Contract and the subsequent findings concerning the revegetation of tailings dams. Current revegetation procedures are presented. INTRODUCTIONThe Amulet Mine Ltd. was staked in 1924 and by 1930 had constructed a small 300 ton per day flotation plant. During the late twenties and early thirties, Noranda Mines Ltd. increased its equity in the company to gain a sixty percent share of this small mine. In 1933 the mine was amalgamated with another small producer, the Waite Ackerman Montgomery Mine Ltd., which was more than eighty per cent controlled by Noranda to form the Waite Amulet Mines Ltd.An interesting historical side point to the story of the Waite Ackerman Montgomery property is that a concentrator was never constructed. In fact, the first ore to go through the Horne mill of Noranda Mines Ltd., built in 1928, was not from the famous upper H and L ore bodies but custom shipments from the Waite."

Jan 1, 1981