Search Documents

By W. Petruk

A study was undertaken to determine whether interrelations between mineral grains affect ore breakage during grinding, and to establish a correlation between ore breakage and mineral liberation. A base metal ore from the Brunswick No. 12 deposit in New Brunswick was ground for different periods of time in a laboratory ball mill, and both the unbroken ore and the ground products were analysed by image analysis. The results show that the mode of breakage is strongly influenced by the behaviour of pyrite. Similar size distributions were obtained for material from the 15 minute grind in a laboratory ball mill, for the grinding circuit discharge from a commercial mill, and for pyrite grains in the unbroken ore. This similarity indicates that a 15 minute grind breaks poorly bonded pyrite grains along grain boundaries, and represents the limit of easy breakage for the ore. Such a grind liberates both large separate grains of ore minerals and poorly bonded mineral grains that occur in interstices among pyrite. On the other hand the 15 minute grind does not separate moderately bonded mineral grains nor release moderately bonded interstitial minerals from pyrite; a 45 minute grind in a laboratory ball mill is required. It is assumed that, for Brunswick No. 12 ore, a 45 minute grind in a laboratory ball mill is equivalent to regrinding in a commercial mill. Grinding beyond 45 minutes in a laboratory ball mill breaks the ore by fracturing pyrite across grain boundaries and by chipping grain edges. Such intense grinding does not markedly increase sphalerite liberation from Brunswick No. 12 ore, because most of the sphalerite that can be released was liberated at the 45 minute grind. In contrast the intense grinding increases galena liberation because a significant proportion of the galena occurs as minute inclusions in pyrite. These findings show that ore breakage and coincident liberation depend upon size distributions, intergrowths, and mode of occurrence of the minerals in an ore.

Jan 1, 1988

By A. H. Winckers

"The Sullivan Mine and Concentrator are owned and operated by Cominco Ltd. and are located in the Rocky Mountain Trench, in Kimberley, British Columbia.The Sullivan Concentrator commenced operation in 1923 at approximately 2,500 tons per day. The concentrator was enlarged in several stages and by 1945 was treating 8,500 tons of ore per day. In 1949, the capacity of the concentrator was expanded to 10,000 tons per day with the completion of the sink and float plant, the installation of the rod mill, an underground crushing plant and a 4-mile underground and surface electric railway from the underground crushing plant to the concentrator. Throughput now averages 7,000 tons per operating day, or 2,400,000 tons per year.The concentrator operates 7 days per week, 24 hours per day while the underground crushing station operates 5 days per week, 24 hours per day. The ore is essentially a replacement deposit in argillaceous quartzite of Precambrian age. The ore bodies are massive deposits consisting of fine grained mixtures of sulphides, sometimes interbanded with the country rock and varying widely in their content of lead, zinc, iron and silicates. The principal economic minerals are galena and marmatite (7 ZnS:FeS). Iron is mainly present as pyrrhotite, and to a much lesser extent as pyrite. The intimate association of these sulphides necessitated the development of a successful differential flotation process before the ore could be beneficiated profitably."

Jan 1, 1981

By J. H. Archibald

"In mines employing cut-and-fill stoping (sand fill), ore passes are built as mining progresses upward. These ore pass raises are generally made from timber and form a vertical ""chimney"", like a very tall log cabin. Traditionally the chimney, or raise, is square in shape and is constructed from square timbers with stepped ends as shown in Figure I. The timbered raise is thus surrounded by sandfill on its outside, leaving the centre open for passing ore down through it. Each layer consists of four timbers and rests flush on the layer below. The corners are frequently pinned or spiked.Under certain conditions in sandfilled stopes large horizontal loads may be transmined to the raise cribbing timbers, or the ""chimney's"" walls. In deep mines, where rock bursts are a problem, it can be shown that one of the conditions for rockbursts to occur is that the burst zone be stiffer and weaker than the surrounding rock(l). This allows a strain energy build-Up in the rock surrounding the burst zone, and the rate of release of this strain energy is known to be related directly to the over-all strength and stiffness of the rock in the burst zone. In stopes that are sandfilled, attempts are, therefore, usually made to increase the strength of the sandfill by the addition of large-sized waste rock and Portland cement. These measures usually achieve the desired strength of the sandfill and, consequently, the severity and frequency of rockbursts can be reduced.Problems may arise when the now chunky sandfill transmits high loads to the raise cribbing along with relatively large move- merits. This leads to heavily stressed and strained cribbing timbers the Coeur d'Alene district in Idaho, raise cribbing failures are common. A typical mode of cribbing failure is shown in Figure 2. One learns in statics that a structure shaped like the crib in Figure I is inherently unstable , at least from a structural standpoint. The crib has pivoted, in Figure 2, into a rhombi c shape and supports very little load. Soon the four-foot square raise cribbing made from 5 in. by 5 in. timbers will no longer pass ore."

Jan 1, 1991

By J. E. Nesset, E. R. Bobicki, K. L. Bilaniuk

The introduction of froth flotation technology in Canada, and in particular, in British Columbia, began not long after it was successfully applied in the Broken Hill mining area of Australia which began around 1905. It proved to be a revolutionary and transformative technology that resulted in marginal operations in copper, lead and zinc becoming profitable in spectacular fashion. The paper presents the technology of both oil flotation and froth flotation in the context of the challenges of the time and its early application in British Columbia at the Le Roi No.2 mine (1903), the Britannia Copper mine (1912), and at the Allenby concentrator of the Copper Mountain mine (1918-19). New-found archival documents indicate the Britannia application to be the first production application of froth flotation for copper ore outside Australia, a claim that is currently made by the Braden mine (now El Teniente) in Chile. Flotation was initially an add-on process following gravity methods but was rapidly shown to be far superior method for the bulk and selective recovery of metal sulphides. Flotation proved particularly successful for the recovery of zinc sulphide (the so-called ‘zinc problem’) which was considered a contaminant at the time. The ‘copper problem’ related to the poor recovery of fine copper sulphide particles that were not amenable to gravity methods. The success of flotation led to changes in both the scale and methods of mining, concentration and smelting in a manner that allowed integrated mining companies to flourish. Many are still with us today. INTRODUCTION The advent of froth flotation in the early 20th century was truly a revolutionary technological development, not only for the mining and metallurgical industries, but arguably more so for business and society overall. The Canadian technology historian Jeremy Mouat stated (1996) “The development of flotation was the greatest single metallurgical improvement of the modern era...it is not overstating the case to claim that flotation was of central importance to the smooth functioning of the global economy”. It should, therefore, be a story of interest to us all. The aim of this paper is not to retell the full story, that has been well covered by others (Hoover, 1912; Rickard, 1916a; Hines & Vincent, 1961; Lynch et al., 2010) but rather to add some Canadian perspective and the key role played by companies and individuals in those early days, focusing on events in British Columbia’s copper industry. EARLY DEVELOPMENTS During the later half of the 19th century, a number of flotation-related patents were issued. These include the 1860 patent (Britain) granted to William Haynes for a process to separate sulphides from ground ore by mixing it with oil (1-10% wt) followed by a separation process in a water-filled vessel; the 1877 patent granted to Georg and Adolph Bessel (Germany) for a process involving the mixing of oil and graphite ore followed by boiling in water to produce a high grade graphite froth (>90% carbon); and the 1885 patent granted to Rebecca ‘Carrie’ Everson for the separation of sulphides by mixing sulphide ore with small quantities of oil, and adding water followed by sulphuric acid. These processes are more properly referred to as bulk oil flotation due to the relatively large quantity of hydrocarbon used.

Jan 1, 2019

By H. Thalenhorst

For an advanced mineral exploration project that has a ?nugget? issue making the assessment of the deposit grade difficult, a bulk sampling program using a sample tower can provide information that is otherwise not obtainable prior to actual production. This information includes the verification of predicted resource grades for the bulk sample tonnage (and, indirectly, of the methods and parameters used for the grade estimate), confirmation of the physical and grade continuity of the mineralization, and geotechnical data for a future mining operation. The information gathered will improve the input of a feasibility study, particularly with respect to expected mining grades, which are the key economic parameter for most mining projects. The bulk sample rejects can be used for pilotscale metallurgical testwork. Bulk sampling is also useful in cases of potentially biased drill-hole assay results and in the reliable determination of ore grade before shipment of ore from production or development operations to an external beneficiation plant. This paper presents a practical bulk sampling and sample preparation protocol, lists design features for the sample tower, examines the sampling errors that will be encountered, provides information on quality control procedures, and looks at the costs and benefits of such a program, based on the experience of undertaking bulk sampling programs during the period of 1985 to 2008.

May 1, 2010

By F. Hashiuchi

In 1996, the Saganoseki custom smelter & refinery successfully shifted to a single flash smelting furnace operation and increased the copper production capacity to 450,000mtpy in 1998. As the next step, Saganoseki planned to further increase the productivity, especially in the area of P.S. converters and acid plant. As the results of modifications and operational improvements, the gas washing & cooling sections of the Saganoseki acid plant were consolidated from 3 to 2 lines, and increased the gas treatment capacity. The S02 converters in the acid plant were also modified to increase the acid production. By increasing the matte grade from 65 to 68%, six PS converters have been successfully integrated into four, while maintaining the production capacity and reducing the environmental burden in 2005. This paper discusses recent operational conditions and the results of implementation of technological improvements.

Jan 1, 2007

By T. S. Golosinski

"This paper reviews the types of selective continuous miners (SCMs) available at present, and compares their main features. Furthermore, operating practices and mine planning aspects of the SCMs applications are reviewed and conditions for efficient application of this equipment are defined. Finally, the potential applications of the SCMs in surf ace mining of oil sands are discussed INTRODUCTIONIn the 1970s the United States Bureau of Mines (USBM) conducted a program of investigations, design and demonstration of various continuous surface mining concepts, This included continuous mining equipment which was an adaptation of several civil engineering and/or underground mining machinery concepts to surface mining. Upon termination of this program, the related development was continued by a number of equipment manufacturers, leading to development of several types of SCMs. This new type of surface mining equipment is able to mine selectively hard and thin multi-layered formations at high, sustained, and economically viable production rates.While used mostly in coal mining at present, the characteristic features of this equipment permit conclusion that it may prove to be an efficient tool for surface mining of oil sand, and/or related overburden stripping. Of particular interest here may be the ability to mine thin layers of hard material, without a need for its earlier fragmentation, and the ability of the SCMs to load a variety of haulage equipment, including belt conveyors."

Jan 1, 1989

By R. I. Iacobescu, Y. W. Chiang, A. Van Audenaerde, R. M. Santos, T. Van Gerven, P. Knops

In this work, we explore a novel mineral processing approach using carbon dioxide to promote mineral alterations that lead to improved extractability of nickel from olivine ((Mg,Fe)2SiO4). The precept is that by altering the morphology and the mineralogy of the ore via mineral carbonation, the comminution requirements and the acid consumption during hydrometallurgical processing can be reduced. Furthermore, carbonation pre-treatment can lead to mineral liberation and concentration of metals in physically separable phases. In a first processing step, olivine is fully carbonated at high CO2 partial pressures (35 bar) and optimal temperature (200 °C) with the addition of pH buffering agents. This leads to a powdery product containing high carbonate content. The main products of the carbonation reaction include amorphous colloidal silica, chromium-rich metallic particles, and iron-substituted magnesite ((Mg1- x,Fex)CO3). Carbonated olivine was subsequently leached using an array of inorganic and organic acids to test their leaching efficiency. Compared to leaching from untreated olivine, the percentage of nickel extracted from carbonated olivine by acid leaching was significantly increased. It is anticipated that the mineral carbonation pre-treatment approach may also be applicable to other ultrabasic and lateritic ores.

Jan 1, 2014

By W. M. Brewer

Introduction This paper describes some of the mineral resources that are tributary to that portion of the Pacific Great Eastern railway included in the Western Mineral Survey District, No. 6, of British Columbia. This district extends 38 miles northerly from Squamish, the ocean terminus of the railway at the head of Howe sound, to Alta lake. Beyond Alta lake the railway continues northerly through two other mineral survey districts: the Central Mineral Survey District No. 3, and the Northeastern District No. 2. District No. 6 includes that section of the Coast Range from which the waters flow southerly towards Howe sound. The division between District No. 6 and District No. 3 is represented by an imaginary line across the summit between the headwaters of the Cheakamus river, flowing south into the Squamish, and the Green river which flows north and empties into the head of Lillooet lake near Pemberton meadows, about 20 miles from Alta lake. History: - The history of the route of the P. G. E. railway dates back to the old Cariboo days when a pack-horse trail traversed the country northerly from Squamish to the Pemberton meadows, and also south-easterly from Squamish to the head of Seymour creek, thence southerly down that creek to the north arm of Burrard inlet.

Jan 1, 1925

By B. B. Meadows

"The Minto-Chipman Strip Mining Reclamation Project was initiated to re-vegetate the spoil piles remaining from strip mining operations.All available information was studied by the team responsible, and areas being reclaimed in the U. S. were visited, Methods applicable to the N. B. Project were noted for future use.We have both surface and underground mining operations in New Brunswick, Both deface the natural landscape and reclamation varies in difficulty, Surface operation disturbances are the most difficult to correct.Some of the surface mining is carried out next to two main highways and the results are definite eyesores, With this in mind, it was decided to landscape the spoil ground next to the highways and plant “as is"" the ground remote from the public view.The landscaping entailed various degrees of bulldozing from complete levelling to contouring, smoothing and topping, Bulldozing is, of course, the most expensive part of any reclamation project.There are two phases to the planting program; experimental and operational--experimental both prior and, later, in conjunction with the operational planting.Initially in the experimental project, the pH and composition of the spoil was determined using a grid sampling system. Soil samples were tested in a laboratory at the University of New Brunswick."

Jan 1, 1970

By L. A. Homeniuk, R. J. McH. Clark

"The Maurice Bay deposit, the Stewart Island showing, the Fond-du-Lac deposit, the Middle Lake showing and the Nisto deposit are located on the North Rim of the Athabasca Basin. They are probably unconformity-related. These occurrences tend to be small. The Fond-du-Lac and Maurice Bay deposits are the largest and contain 450,000 kg and 650,000 kg of U10 8 respectively.Pitchblende is the main uranium mineral of all the occurrences, except at Middle Lake where autunite predominates. A II of the deposits are overlain and partially hosted by the Manitou Falls Formation of the Athabasca Group, except the Nisto deposit which is entirely within basement rocks, and the Maurice Bay deposit which is partially within the basement and overlying the Fair Point Formation of the Athabasca Group.The North Rim deposits are considered to be genetically similar to the other unconformity-type deposits found in northern Saskatchewan. It is suggested that a mechanical concentration of uranium may have occurred in heavy mineral beach sand type placers. The stability of the uranium minerals may have been enhanced by special local conditions. The fossil placers, after hydrothermal alteration and enrichment, would form the apparently ""rootless"" occurrences of uranium found totally within the sandstones above the unconformity.IntroductionAt least five deposits and showings and one train of mineralized glacial erratics of unknown provenance have been located on the North Rim of the Athabasca Basin from Maurice Bay in the west to Black Lake in the east. Distributed over a distance of 250 km, (Fig. l), they occur near the edge of the Basin, and are probably unconformity-related. The following have been identified from west to east (Fig. 2): The Maurice Bay deposit, the Stewart Island showing, the Isle Brochet train, the Fond-du-Lac deposit, the Middle Lake showing, and the Nisto deposit."

Jan 1, 1986

By K. Adham

Both the dry and the wet fluorination systems require hydrogen fluoride (HF) for the process of uranium conversion to uranium hexafluoride (UF6). The dry methods depend on the electrolysis of HF to generate the fluorine (F2) required for the high temperature pyro-fluorination. The wet methods require aqueous HF in water solutions for the low temperature hydro-fluorination (Argonne, 2019). This paper uses the available HF safety guidelines and industry information to discuss the issues of transportation, storage and utilization. Health effects and environmental considerations are reviewed. Safe practices for handling the HF (both as anhydrous and as aqueous) are considered. Proper selection of different materials of construction are discussed, for both the anhydrous and the aqueous HF.

Jan 1, 2020

By L. R. Bower

"This paper describes a highly versatile variable speed unit with a torque multiplication feature as a direct replacement for a fluid coupling .The unit is comprised of a modulating clutch with torque converter and lock-up options.The UCD does not start or stop the motor. This is carried out in the normal manner.The UCD continually monitors and rapidly regulates the output speed to the requirement of a set point demand from input signals or a pre-set program with full manual override.The pre-set program can include start and stop ramps, top speed and minimum speed regulation and also mid-speed set point with security for man-riding, etc. Speed variation is from zero to 100% on a constant duty basis.The input signals can be from any source, e.g. belt weigher. load profile bunker probes, mine monitoring system, etc.The UCD when fitted with a torque converter has a torque multiplication feature which automatically provides a starting torque up to two and a half times greater than the full load torque without exceeding the normal motor power levels.IntroductionIt is common practice in the mining industry to drive conveyors, whether they be belt or chain, through a transmission system incorporating a fluid coupling between the driving motor and gear-box .However, there are drawbacks and in an effort to attain a better degree of drive and control, two-speed motors - inverters cycle- converters - hydrostatic drives, etc ., have been introduced."

Jan 1, 1986

By K. H. Singh, J. N. Szuck, J. A. Riddell

"Hydraulic rock drilling equipment has been in use at Falconbridge over the past two years in both production and development situations. This paper deals with the experience gained in the application of hydraulic drilling in the company's mines and discusses the benefits and problems encountered during their use. The paper primarily focuses on technical, operating, maintenance and economic aspects of the machines, and does not attempt to compare the performances of different machines from the various manufacturers.IntroductionThe Sudbury Operations of Falconbridge Nickel Mines Limited are comprised of five operating mines and two mines under development. All the production comes from underground mines, mostly at depths below 1000 metres. The company, faced with increases in operating costs and difficult mining conditions, has continued to seek solutions with the help of new mining technology.The development of electric-hydraulic drilling machines in Europe had been pursued with great interest and, in 1979, a decision was made to test these machines to prove their technical and economic viability under operating conditions. Since then, a number of electric-hydraulic machines have been evaluated in different situations and currently nine hydraulic machines are being used in the company's various mines. These machines are comprised of two-boom drilling jumbos for development, one-boom machines for longhole drilling and a large-hole-diameter drilling rig for blasthole drilling. One hydraulic jumbo has also been used in a cut-and-fill stope."

Jan 1, 1982

RÉSUMÉ L’estimation la plus précise possible des coûts de minage est d’extrême importance pour les études de préfaisabilité afin de diminuer les risques financiers des projets miniers. Les méthodologies existantes d’évaluation des coûts de minage ne permettent pas de les évaluer avec des marges d’erreur acceptables tout au long de l’évolution des projets miniers. Elles visent à évaluer les coûts unitaires de minage des études préliminaires de faisabilité, pour les principales méthodes d’exploitation, en prenant pour l’hypothèse que ces coûts dépendent principalement du taux d’extraction journalière. Si cette hypothèse peut être justifiée pour l’évaluation du coût d’opération, elle est fort discutable pour l’évaluation des coûts de minage. Pour démontrer que cette hypothèse est inadéquate nous avons analysé la méthode d’exploitation la plus populaire sur le continent nord-américain c’est à dire celle par chambres vides avec retrait horizontal (Hr – Horizontal retreat), ou « Longhole » et celle avec retrait vertical (VCr - Vertical Crater retreat). Il ressort de cette analyse que les coûts unitaires de minage dépendent principalement des conditions géotechniques du massif rocheux et de la largeur du gisement et non pas du taux d’extraction journalière du minerai.

Jan 1, 2010

By Jerry M. Whiting, Neil J. Duncan

"Does Canada need a mining industry? Isn't it a chronically depressed collection of businesses that pollute the air and water and tear up the countryside? Wouldn't it be better if Canada's investors devoted their attention to high-technology endeavours, tourism, and other relatively pleasant tasks?Probably the answer to whether Canada needs a mining industry in the 21st century is to look at the real mining industry that is in operation today. The facts indicate that mining is a very important contributor to Canada. It has certainly encountered some challenging times during periods of recession, and it face s severe and continuing problems of cost and competition in world markets. However, uneconomic mines have been closed, others suspended, and productivity has risen dramatically with employment at 77 000, down from 101 000 in 1981. The country's metal and non-metal mines, metallurgical plants and semi-fabricated metals industries employed an estimated 378000 workers in 1986, and paid wages than any other sector of the Canadian economy. This effort resulted in the production of 60 different metals, non-metals and structural minerals valued at $13.5 billion.The trade aspects of the mining industry are of paramount importance. If there is a reason for this situation to change during the next century. it eludes the authors. Canada has the well-developed expertise to discover, evaluate, develop, operate and profit from existing and new businesses based in an enormous area endowed with a nearly unbelievable variety of mineral resources. Many countries throughout the world must rely on producers like Canada, if they are to maintain and/or improve their standard of living."

Jan 1, 1988

By Dale Scott

"The Aggregate Resources Inventory Program was initiated 10 produce reports which assess the aggregate resources of municipalities designated under the Pits and Quarries Control ACI, 1971.Each report consists of three copies accompanied by a text. The text describes the local mineral aggregate resources, extractive activity and characteristics of the ""Selected Deposits"". The first map shows the known sand and gravel resources and their quality. The second map indicates selected sand and gravel resources of primary, secondary and tertiary significance. The third map indicates both bedrock resources and bedrock areas suitable f or extraction. These maps and the text are prepared in a formal suited for use by planning personnel.Recently, the Aggregate Resources Inventory Program has undergone evolutionary changes. New sources of data are being utilized in the inventory reports; in particular, detailed field assessment by inspecting, sampling, drilling and backhoe pitting. Liaison and joint assessment with district and regional Mineral Resources staff of the Ministry of Natural Resources, and personnel of the Ministry of Transportation and Communications, are key components of the Program.Twenty-two reports were available to the public as of December 1980, with a further thirty-six awaiting publication. Our present production rate is 3.5 reports per month. The reports appear to be well accepted by the municipalities and have proven effective in conserving prime aggregate resource areas.IntroductionThe urbanization of Southern Ontario has resulted in a major increase in the production of industrial minerals, such as sand, gravel, clay, shale, gypsum and stone, for use as cru shed aggregate, building stone, lime and cement.Although mineral aggregate deposits are plentiful in Southern Ontario, they are fixed-location, non-renewable resources. The potential for extractive development is usually greatest in urban fringe areas where land-use competition is extreme. Comprehensive planning and resource management strategies are required to make the best use of available resources, especially in those areas experiencing rapid development. Such strategies must be based on a sound knowledge of the total mineral aggregate resource base at both local and regional levels."

Jan 1, 1982

By Dale Scott

"The Aggregate Resources Inventory Program was initiated 10 produce reports which assess the aggregate resources of municipalities designated under the Pits and Quarries Control ACI, 1971.Each report consists of three copies accompanied by a text. The text describes the local mineral aggregate resources, extractive activity and characteristics of the ""Selected Deposits"". The first map shows the known sand and gravel resources and their quality. The second map indicates selected sand and gravel resources of primary, secondary and tertiary significance. The third map indicates both bedrock resources and bedrock areas suitable f or extraction. These maps and the text are prepared in a formal suited for use by planning personnel.Recently, the Aggregate Resources Inventory Program has undergone evolutionary changes. New sources of data are being utilized in the inventory reports; in particular, detailed field assessment by inspecting, sampling, drilling and backhoe pitting. Liaison and joint assessment with district and regional Mineral Resources staff of the Ministry of Natural Resources, and personnel of the Ministry of Transportation and Communications, are key components of the Program.Twenty-two reports were available to the public as of December 1980, with a further thirty-six awaiting publication. Our present production rate is 3.5 reports per month. The reports appear to be well accepted by the municipalities and have proven effective in conserving prime aggregate resource areas.IntroductionThe urbanization of Southern Ontario has resulted in a major increase in the production of industrial minerals, such as sand, gravel, clay, shale, gypsum and stone, for use as cru shed aggregate, building stone, lime and cement.Although mineral aggregate deposits are plentiful in Southern Ontario, they are fixed-location, non-renewable resources. The potential for extractive development is usually greatest in urban fringe areas where land-use competition is extreme. Comprehensive planning and resource management strategies are required to make the best use of available resources, especially in those areas experiencing rapid development. Such strategies must be based on a sound knowledge of the total mineral aggregate resource base at both local and regional levels."

Jan 1, 1982

By C. A. Pickles

Microwaves are being applied industrially in a number of fields and possess a number of potential advantages that could be applied in extractive metallurgy. Microwave heating has a number of unique characteristics, which distinguish it from the conventional heating methods. In microwave heating, the absorption of energy occurs at the molecular or atomic level and therefore the heat is generated within the material itself. In conventional heating, the exterior temperature is usually higher than the interior, but with microwave heating, the temperature gradient is inverted and thus the interior temperature can be much higher than that of the surface. The energy densities in microwave systems can be relatively high and this in combination with the low thermal conductivities of oxide ores, can lead to very high internal heating rates. In this research, the application of microwave energy for the reduction of a nickeliferous silicate laterite ore has been investigated. The real and imaginary permittivities are the two fundamental properties which determine the microwave absorption characteristics of a material and these were measured for the ore, both with and without carbon additions using the cavity perturbation technique. The microwave heating and reduction experiments were performed in a 0 to 2 kW CTC microwave system. The effects of power input, processing time, sample mass and charcoal additions on the microwave absorption were investigated. Then reduction experiments were performed and the nickel grade of the magnetic concentrate and the nickel recovery in the concentrate were determined.

Jan 1, 2005

The Red Lake greenstone belt is an irregular mass of lavas sedimentary rocks and intrusives which is approxiately 35 miles long 18 miles wide and 7 miles deep. Basaltic volcamcs are the oldest rocks w1thm the belt. They are believed to have been laid down on an ancient crust which is at least 3 billion (3 x 109) years old and was composed partly of sediments. The basaltic rocks are overlain by acid volcanics and sedimentary rocks which have been complexly folded and are preserved as a down-folded remnant of younger rocks within the older crust. The volcanics and sedimentary rocks of the greenstone belt have been cut by intrusives with a wide range of composition. The emplacement of the intrusives and the accompanying regional metamorph-ism which terminated the orogenic activity in this area are believed to have occurred approximately 2.4 billion years ago. The basalts and many of the basic and ultrabasic intrusives undoubtedly had their source in the sub-crust or mantle. At least some of the granitic intrusives are believed to have had

Jan 1, 1965