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By B. K. Gorain

"The Air-Metabisulfite (AMBS) process has been developed to treat complex copper, molybdenum and precious metals (gold, silver) bearing ores using brackish and sea water. This process was able to produce significantly better copper concentrate grades and higher recovery than possible using conventional lime and/or cyanide based processes for certain complex ores with high sulphide gangue minerals. The AMBS technology in now used commercially following a rigorous evaluation process emanating from laboratory curiosity to plant applications. In addition, many projects have embraced this technology at a feasibility level involving various complex ore bodies.This paper presents a summary of the findings from testing the AMBS technology on various ores types. Experiences gained from this successful development from bench to piloting and then to plant applications are also presented in this paper.INTRODUCTIONProcessing of sulphide copper, molybdenum and precious metal ores typically involves flotation of copper bearing minerals while depressing non-sulphide and other non-copper sulphide minerals such as pyrite, pyrrhotite and sometimes arsenopyrite. Though in many precious metal ores, the values are in these sulphide minerals as well. The conventional method employed in the industry to produce a saleable copper concentrate requires depression of these non-copper sulphide minerals using an alkaline pH above 9.5, though 10.5 to 11.5 is more common. Alkalinity is controlled by the addition of a pH modifier. Lime is normally employed as a pH modifier due to its relatively low cost; however, the costs associated with adding lime can be significant and the effectiveness of lime as a depressant could be drastically reduced when the process water supplied to the flotation circuit contains high level of dissolved salts. In some cases, a small amount of cyanide is used along with lime to depress non-copper sulphide minerals especially when its proportion to copper sulphide minerals in the ore is higher than three."

Jan 1, 2016

In the leaching and recovery of gold from copper containing gold ores using cyanidation, some copper minerals also dissolve which can have a detrimental effect on the process efficiency and economics. There are also environmental concerns with current operations discharging cyanide and copper cyanide species into tailings dams, and strict regulations prohibit this for greenfield plants. Cyanide destruction however is not an economic option for new plants treating copper-gold ores. This paper evaluates a potential recovery process to overcome the copper cyanide problem. Despite gold dissolution occurring in copper cyanide solutions having no free cyanide, gold recovery from ores is lower compared to free cyanide. Thus, cyanide addition has to be optimised to maximise the gold recovery whilst endeavouring to eliminate free cyanide at the completion of leaching (CN:Cu less than 3:1). Subsequently, copper cyanide can be recovered using activated carbon. The loaded copper cyanide is easily recovered from the carbon with a cyanide soak and distilled water wash such that the eluted CN :Cu ratio is less than 4:1. The copper could be recovered efficiently by electrowinning, by decreasing the pH of the eluant to 5. The remaining cyanide solution, after electrowinning, is then neutralised to form NaCN and recycled.

Jan 1, 2005

"Decreasing gold-in-ore grades is one of the main drivers of poorer productivity and rapidly escalating unit costs. Grinding costs, water use and reagent consumption are all intimately related to the ore grade processed. Various pre-concentration technologies have been developed that can be applied at various stages of crushing prior to ore grinding. This paper will review the amenability of ores to coarse particle barren gangue rejection for fine crush sizes in the pumpable particle size range (i.e., particles between 5 mm and 0.3 mm in size). The liberation of oxide gangue achieved during crushing is evaluated by proxy using sink-float analysis and the deportments of gold, sulfur, and arsenic into sinks and floats are monitored. Amenability of gangue rejection by continuous gravity separation is evaluated after various crushing modes (vertical shaft impact crushing, cone crushing, and HPGR crushing). The potential to identify coarse particle mineral association and liberation using three-dimensional x-ray computed tomography will be discussed.INTRODUCTIONThe aim of research in this area is to explore some of the attributes which make some ores amenable to preconcentration, or rejection of a significant component of the feed mass to tailings at a coarse liberation size. Characteristics such as ore type, mineralogy, breakage pattern, particle shape, and liberation characteristics may need to be examined to identify amenability to pre-concentration amenability.It is intended to focus on continuous gangue rejection in the pumpable size range (0.3–5.0 mm) as this remains one of the key opportunities to reduce processing costs through a combination of techniques including screening (for mineral differentiation rather than size classification only) and gravity separation (using jigs). This is to be contrasted to conventional preconcentration as performed with automatic ore sorters."

Jan 1, 2016

By C P. Gravenor

In 1953, a deposit of sedimentary oolitic iron ore was discovered in the Clear Hills area of northwestern Alberta. Since that time, detailed drilling has outlined reserves in excess of 200 million tons of ore grading 30 to 35 per cent iron. Attempts to physically beneficiate the ore to meet blast furnace or direct reduction feed specifications have been, in general, unsuccessful. In 1960, Premier Steel Mills Limited and the Research Council of Alberta jointly sponsored a pilot-plant test at the R-N Corporation at Birmingham, Alabama. About 5,000 tons of ore were treated, and briquettes containing 90 per cent Fe were produced, with 83 per cent recovery. At the same time that the R-N tests were being made, the Research Council initiated a program to produce high-purity powders by chemical methods. Several purification techniques were investigated; hydrochloric acid dissolution of reduced ore was finally adopted. Briefly, the steps involved in this acid process are as follow

Jan 1, 1964

By Erol Yilmaz

This poster presents results obtained from an experimental test set-up called CUAPS (curing under applied pressure system) allowing to assess the performance and quality of cemented paste backfill (CPB) materials. CUAPS can be used for carrying out a series of tests: one-dimensional consolidation, saturated hydraulic conductivity, pore-water pressure dissipation, and curing under uniaxial stress. The poster presents CUAPS testing preliminary results including uniaxial compression tests (UCS) and mercury intrusion porosimetry (MIP). It was demonstrated that CUAPS-consolidated CPB materials cured under time-dependent stresses provide higher UCS values than standard mould (undrained and unconsolidated) CPB samples. This may be explained by the release of excess pore water within backfill that gives rise to a significant reduction in the total porosity of fresh CPB materials prior to hardening and thus, to higher mechanical strength (UCS) gain. The results obtained from MIP highlighted a good correlation between CUAPSconsolidated and mould-unconsolidated CPB samples. MIP results were also related to UCS values in order to predict the final CPB mechanical strength.

Nov 1, 2008

By Arthur Notman

Since addressing the Institute a year ago on The Future of the Copper Industry (l), many things have happened, most of them bad. It has been a hard year for profits and prophets. It was, therefore, with consider-able perturbation that I accepted the gracious invitation of your Committee to reappear. On reviewing my remarks of a year ago, I. have wondered whether, under pressure of more important matters, the Committee had neglected to make a note of them, or whether they felt that further explanations from me were in order. In either event, I am glad that I am here and welcome the opportunity to make any contribution I can to a clearer understanding of the problems of copper to those concerned. The English-speaking nations own 80 per cent of the present world-production of the metal. Col. P. E. Barbour, Secretary of the Mining and Metallurgical Society of America, and I recently completed an estimate of the known world resources of copper. We placed the figure, in round numbers, at 100,000,000 tons of metal. Of this amount, about one-third lies in the United States, one-third in the British Empire, and one-third in South America; and all but 4 per cent of this is owned by British Empire and United States capital. Our figures do not include any estimates for Russia, Japan, or Europe, on which there are no available data. It is true, consequently, that the British Empire and the United States are the ones concerned. It seems to me to be a matter of great importance to the world at large, and of even greater importance to those nations themselves, that the known sources of supply of this metal, so essential both in peace and war, rest so strongly in their hands. I cannot believe that in the long run they will neglect their responsibilities in the wise administration of these resources.

Jan 1, 1932

By P .. H. Grimley, N. Champigny

"Fourteen companies (Appendix) representing senior mining organizations in Canada were canvassed in order to assess: (1) the current usage and trends, and (2) the usefulness of computer applications in ore reserve estimation and grade control. The results of the questionnaire suggest that:• computers are unsurprisingly, predominant in the mining industry for calculating reserves and performing grade control;• time and cost savings are realized;• computer-based approaches are applicable to underground situations;• geological information is incorporated to the computerization process; and• computer usage does not hinder the collaboration of geologist and mining engineer.A clear need is identified for case histories comparing computer-calculated ore reserves and actual production data.IntroductionAmong the management and technical staff of some mining companies there is a perception that the application of computer based technology for the estimation of ore reserves and grade control, has as many drawbacks as benefits. Some of the objections raised against the utilization of computers for ore reserve estimation are that:• computer-based reserve models work for large open pit mines but not for underground situations;• computer-generated reserves ignore the geologist's knowledge base; they are strictly a number crunching exercise; and• the use of computers for ore reserves hinders collaboration between the geologist and mining engineer.In order to determine (I) the extent of current computer usage and future trends and (2) whether the objections noted above are borne out by experience, a number of senior Canadian mining companies were canvassed.The respondents were asked to provide:• an assessment of the importance of the computer in the ore reserve estimation and grade control process;• the level of involvement of individuals and staff groups with computer-based ore reserve estimation;• the advantages perceived and realized from the utilization of computer-based ore reserve approaches;• the current and future human resources requirements for the evaluation, implementation, maintenance and development of computer-based ore reserve systems;• the hardware and software resources presently used and planned; and• the developments needed to increase the use and acceptance of computer-based ore reserves."

Jan 1, 1990

By R. Scheepers

"Mineral deposits and prospects of the Pan African Saldanian orogenic belt in the southwestern Cape Province South Africa, are reviewed. Despite the entire absence of operating base or precious metal mines in the area, this study has established at least four metal associations that offer enticing exploration potential.The poly-phase deformed, low-grade metamorphosed volcano-sedimentary Malmesbury Group constitutes a complex, poorly understood supracrustal sequence that has been loosely subdivided into the Tygerberg, Swartland and Boland tectono-stratigraphic terranes by northwesterly trending fault zones. Syn- and post-tectonic granitoids of the Cape Granite Suite selectively intruded these terranes. Early S-types preferred the Tygerberg terrane whereas the later I-types dominate the remaining areas. Anorogenic A-type granites, however, occur in all three domains. Known metallization is directly or indirectly related to the intrusives, yet syngenetic deposits are conspicuously absent from the supracrustals. Four metal associations have been identified.• Cassiterite-wolframite (± Au, Cu, Mo, Fe-sulfides) in quartz and quartz/aplite veins hosted by tourmalinized and locally greissenized S-type granite. Similar exo-granitic veins occur in proximal metamorphites.• Juxtaposed disseminated, stockwork, breccia and vein style Cu-Mo-Fe-(Au)-sulfide mineralization hosted by mafic to intermediate intrusives of high K calc-alkaline, I-type affinity. • Cu-Mo-Au-sulfides hosted by hydraulic breccia pipes, stocks and veins occurring in anorogenic A-type alkali feldspar granites and amphibole quartz syenites.• Scheelite with minor Cu-Mo-sulfides and Au-associated with endo- and exo-skarns spatially related to I-type monzogranite, granite and alkali feldspar granite.The first three associations occur along the Yzerfontein-Helderberg-Zone, a 180 km lineament in the Tygerberg terrane, a zone exploited by syn-, late- and post-tectonic intrusives and their related mineralization. The fourth association is typical of the Boland terrane. The spatial and temporal relationships between the various metal associations is interpreted as the result of sequential intrusion of relative early high level S-type, followed by intermediate level I-type and finally anorogenic A-type granitoids during the evolution of a contracting continental margin arc and its irmer arc. This plate tectonic setting suggests subduction in an easterly direction underneath the Kalahari craton. The spatial configuration of the various terranes at the present erosional levels is the result of rifting and significant differential vertical displacement following cessation of subduction, a terminal tectonic event possibly synchronous with intrusion of the A-type granitoids.Near surface preserved roof zones and cupolas of both S- and I-type granitoids in the Tygerberg and Boland terranes, respectively, render these areas extremely prospective for Sn, W, Mo and Au mineralization. The presence of intermediate to mafic volcanics, a diversity of calcareous lithotypes and favorable plate tectonic setting of the Malmesbury Group suggest potential for the thus far elusive VMS, MVT and Sedex base metal and minor precious metal deposits."

Jan 1, 1994

By K. W. Fritzsche

The prosperity of any nation depends, to a large extent, on its natural resources such as oil, coal, 'metal, timber, waterpower, and fertile soil. Each one of these resources forms the basis of a huge industry. The mining and smelting industry ranks among the first since it paves the way for a number of other industries. The mines and smelters provide a market for electric power, coal, timber, and agricultural products: other industries in turn provide a market for metals and non-metals. The real pioneering, however, is done by the prospector who goes into the wilderness to search for the ores from which the metals are to be extracted for the use of men. Prospecting is an interesting and fascinating occupation. There are many difficulties and hardships in the way but the lure of gold and the vision of finding an outcrop that may develop into a large bank account, within a reasonably short time, will urge the prospector forward. Thus, on the outskirts of this northern hemisphere hundreds of prospectors are searching and toiling and of whom nothing is known or heard until they reach civilization and announce a new discovery. Then a mad rush takes place and everybody who can afford to go will take a gamblers chance and plant stakes in the neighbourhood of the new discovery, or wherever an outcrop of mineralized rock can be found, with the hope of winning a fortune.

Jan 1, 1925

By M. Sakata, H. Hata, K. Haiki

"Most of the secondary ZnO contains fluorine (F) in large quantities. Serious troubles at the zinc electrowinning are occurred by the cathode corrosion caused by F, therefore we developed iron compounds as F-adsorbents used in zinc sulfate solution. The iron compounds can be reused repeatedly as F-adsorbents because they can adsorb/desorb F alternatively depending on the pH. Moreover, if the adsorptive capacity decreases, we can dissolve and re-synthesize them easily. In this paper, results of the experimental process which consists of five steps (leaching, F removal, Cl removal, purification and electrowinning) to produce high purity electrolytic zinc from the secondary ZnO are reported. INTRODUCTIONThe recycle material for zinc, secondary ZnO, contains large amounts of fluorine (F) and chlorine (Cl) which are halogen elements, compared with calcine obtained by roasting of zinc sulfide concentrate. The halogen elements cause adverse effects in the zinc electrowinning process and particularly F causes corrosion of aluminum cathode plates and eventually sticking of electrodeposited zinc and therefore, F concentration in the electrolyte is controlled to less than approximately 20 mg/L. There are several methods to remove F from secondary ZnO, such as leaching with Na2CO3 or NaOH solution [1-2], vaporizing in a rotary kiln by roasting at 1000 to 1200 degrees C [3-4]. However, up to the moment, there has been no effective method for the removal of F from zinc electrolyte and it has been a big obstacle in treatment of secondary ZnO in electrowining of zinc.The authors, therefore, developed an iron compound used as an adsorbent of F in the zinc sulfate solution [5-8]. This iron compound is Akaganeite that has a crystalline structure of ß-FeOOH. Akaganeite is synthesized by neutralization of FeCl3 solution containing a small amount of SO4 2- with Na2CO3. When this iron compound is immersed into weak acidified zinc sulfate solution, F in the solution is adsorbed. F adsorbed in the iron compound is removed by immersing in weak alkaline solution and the iron compound can be reused as F adsorbent."

Jan 1, 2012

By H. R. Bullis

"A 2003 paper discussed the idea that as gold mining companies grow larger it becomes more difficult for them to discover or acquire new gold deposits large enough to replace extracted reserves on an annual basis. Deposits of the size required to replace annual production of very large gold producers (VLGPs) are statistically few. An update in 2005 reviewed VLGPs with respect to production, reserves, and reserve life and observed recent changes in the gold mining industry. Now, more than 12 years later, this paper explores how those VLGPs have fared and how the gold mining industry has changed. KEYWORDS Gold, Gold price, Production, Reserves, Very large gold producer (VLGP) RÉSUMÉ Un article de 2003 examinait le concept selon lequel, à mesure que les sociétés d’exploitation aurifère se développent, il leur devient de plus en plus difficile de découvrir ou d’acquérir de nouveaux gisements aurifères suffisamment grands pour remplacer les réserves qu’elles extraient annuellement. Statistiquement, il existe très peu de gisements de la taille requise pour remplacer la production annuelle des très gros producteurs d’or. Une mise à jour de l’article en 2005 se penchait sur la production, les réserves et la durée de vie des réserves des très gros producteurs d’or ; elle portait sur les récents chan¬gements au sein de l’industrie de l’exploitation aurifère. Aujourd’hui, plus de 12 années plus tard, cet article explore l’évolution et les résultats de ces très gros producteurs d’or, ainsi que les changements qu’a connu l’industrie de l’exploitation aurifère. MOTS CLÉS or, prix de l’or, production, réserves, très gros producteurs d’orINTRODUCTION In 2005, the world’s top five gold producing companies were Barrick (after purchasing Placer Dome; 9.1 million ounces; Barrick Gold Corporation, 2005; Placer Dome, 2005), Newmont (8.2 million ounces; Newmont Mining Corporation, 2005), AngloGold Ashanti (6.2 million ounces; AngloGold Ashanti Limited, 2005), Gold Fields (4.2 million ounces; Gold Fields Limited, 2005), and Harmony Gold (3.0 million ounces; Harmony Gold Mining Company Limited, 2005). During the years leading up to that point, there had been a flurry of activity in the gold sector directed at consolidating production and reserves to create very large gold producers (VLGPs). As defined in Bullis (2005), a VLGP is a mining company whose primary busi¬ness is gold production and that has annual gold production more than 5 million ounces. A stated corporate goal of several of the VLGPs at the time was to become the largest gold producing company in the world."

Jan 1, 2019

By M. Razavi

This investigation is part an overall investigation on the effect of sodium silicate on the properties of the mine backfill. The results presented will highlight the effects of binder dosage, sodium silicate concentration, and pulp density on the performance of stabilized sodium silicate-fortified sand pastefill samples. Binders implemented for these experiments consisted of cement, slag, and sodium silicate in various proportions. The binder content varied from 3 to 9 wt% (total dry weight) and sodium silicate concentrations was adjusted at 2 and 4% (total binder weight). Moreover, pulp density was adjusted to values between 80 and 83 wt%. For completion of the aforementioned phase of the study, series of sand pastefill test samples were prepared and cured for 28, 56, or 120 days, in a humidity and temperature controlled room. The specimens were tested for uniaxial compressive strength (UCS). In order to study the effect of sodium silicate on microstructures of stabilized sand pastefill, some MIP tests were conducted on selected samples. The results of this investigation evaluate the use of sodium silicate as a partial replacement of cement in stabilized backfill. The analyses of the results demonstrates that, with an increase in binder content and a decrease in pulp density, the UCS values of sand pastefill samples increase. Further more, the results indicate that increase in addition of sodium silicate does not necessarily result in higher strength minefill.

May 1, 2007

By Guangdong Institute of Resources Comprehensive Utilization, Y. H. Tang, H. X. Hu, T. S. Dong, Z. H. Zhang

"A world class rare metals ore deposit in Africa belongs to a massive granite type poly-metallic pyrochlore-niobium resource. Successful project development in realizing the resource is vital to Africa’s economy and pyrochlore processing technology.The ore properties are quite complex due to the presence of varieties of valuable minerals, fine dissemination and intimate association of minerals and the relative abundance of easy-floatable minerals. The separation of pyrochlore from zircon, calcite and mica is generally considered difficult. Whilst studies have previously been conducted by several independent institutions overseas, no satisfactory process has yet been developed to date for the ore deposit—possibly due to the process designed being too complex; high cost of regents; lower performance.Based on process mineralogy study and extensive testwork, the authors have in recent years developed a new technology—“De-slime—Iron-rejection—Zircon (with calcite) and Calcite reverse flotation—Pyrochlore flotation”. The flow-sheet is characterized by ?1prior removal of slimes and iron minerals; ?2 Zircon (with calcite) and Calcite reverse flotation; and ?3Pyrochlore flotation applying new type of chelating collector GYX3 developed by GZRINM in conjunction with selected regulators and depressants.The process involved in the new technology is simple to implement and facilitates stable operation; the flotation reagent regime is easily adaptable; the cost of main reagent is lower largely because it is easy to manufacture and is environmental friendly. Laboratory test results demonstrated that, for raw ore assaying 0.35% Nb2O5, 0.03% Ta2O5 and 0.45% ZrO2, pyrochlore concentrate grade of >35% Nb2O5 could be obtained with >74% recovery. Meanwhile, the Ta2O5 content in pyrochlore concentrate could be recycled, and ZrO2 recovery >50% could be achieved in zircon concentrate assaying ZrO2>63%—significantly improving the technical-economic indicator. These results were verified in pilot trials of 1.44t/d throughput. The paper presents the new technology in whole, summarizes the key factors affecting its performance and discusses in simple terms the mechanism of separation."

Jan 1, 2016

By Guangdong Institute of Resources Comprehensive Utilization, Y. H. Tang, H. X. Hu, T. S. Dong, Z. H. Zhang

"A world class rare metals ore deposit in Africa belongs to a massive granite type poly-metallic pyrochlore-niobium resource. Successful project development in realizing the resource is vital to Africa’s economy and pyrochlore processing technology.The ore properties are quite complex due to the presence of varieties of valuable minerals, fine dissemination and intimate association of minerals and the relative abundance of easy-floatable minerals. The separation of pyrochlore from zircon, calcite and mica is generally considered difficult. Whilst studies have previously been conducted by several independent institutions overseas, no satisfactory process has yet been developed to date for the ore deposit—possibly due to the process designed being too complex; high cost of regents; lower performance.Based on process mineralogy study and extensive testwork, the authors have in recent years developed a new technology—“De-slime—Iron-rejection—Zircon (with calcite) and Calcite reverse flotation—Pyrochlore flotation”. The flow-sheet is characterized by ?1prior removal of slimes and iron minerals; ?2 Zircon (with calcite) and Calcite reverse flotation; and ?3Pyrochlore flotation applying new type of chelating collector GYX3 developed by GZRINM in conjunction with selected regulators and depressants.The process involved in the new technology is simple to implement and facilitates stable operation; the flotation reagent regime is easily adaptable; the cost of main reagent is lower largely because it is easy to manufacture and is environmental friendly. Laboratory test results demonstrated that, for raw ore assaying 0.35% Nb2O5, 0.03% Ta2O5 and 0.45% ZrO2, pyrochlore concentrate grade of >35% Nb2O5 could be obtained with >74% recovery. Meanwhile, the Ta2O5 content in pyrochlore concentrate could be recycled, and ZrO2 recovery >50% could be achieved in zircon concentrate assaying ZrO2>63%—significantly improving the technical-economic indicator. These results were verified in pilot trials of 1.44t/d throughput. The paper presents the new technology in whole, summarizes the key factors affecting its performance and discusses in simple terms the mechanism of separation."

Jan 1, 2016

By Walter I. Nelson

THE geology of the Copper Mountain mine has been ably described by Dr. Victor Dolmage in Memoir 171 of the Geological Survey. Reference is invited to that paper for a more extended description of the geology of the ore deposits than will be given here. The important orebodies of the mine occur in fragmencal volcanic rocks, parallel with and adjacent to the gabbro of the Copper Mountain stock. In the mine area, the contact strikes N.45°W. and dips either vertical or steeply co the southwest. For a distance of 500 feet or more from the contact, the fragmental rocks have been intensely metamorphosed both dynamically and hydrothermally. The dynamic effects are reflected in the foliation and fracturing parallel with the contact, which occurs throughout the mine, and the volcanic rocks within this foliated zone are, in places, highly schistose. Superimposed upon thi.s structure is a system of fine, straight, parallel frac-tures that strike nearly normal to the foliation (and contact) and dip between 65° and 75° to the north; it is with this last-described fracture system that the ore minerals are structurally associated. The fractures are mineralized with bornite and, to a considerably less extent, with chalcopyrite and some pyrite. A notable characteristic is the extreme fineness of the fractures; even in high-grade ore they are rarely larger than pencil lines. The tenor of the ore, therefore, varies directly with the fracture spacing. Replacemcnr of the host-rock between two or more fractures, varying in degree from finely disseminated sulphides to masses of nearly solid bornite up to 18 inches wide and 2 to 3 feet long, is not uncommon in the higher-grade portions of the orebodies. Two structural types of orebody are recognized in local nomenclature: the 'contact' orebodies, so-called because they occur along the contact; and 'outlying' orebodics, which are enclosed in the volcanics. The former arc tabular or lenticular bodies elongated along the strike and dip of the contact. The 'outlying' orebodies are coniform, chimney-like masses roughly elliptical in plan; with depth, their roots plunge at steep angles toward the contact. All of the orebodies are cut by a number of light-coloured granophyre and felsite porphyry dykes. These dykes-the so-called 'mine' dykes -enter the mine area from the north, curve gently southeasterly across the orebodies, and then cross the contact into the gabbro at the south end of the mine. All the dykes dip vertical to steeply east.

Jan 1, 1941

By Jehan Rondot

Des quartzites très pars ont été dêcouverts au cours de la cartographie de la region du lac des Martres, étape de l'étude géologique de la region de Charlevoix. On distingue quatre groupes métasédimentaires, tons con tenant des niveaux de quartzite dans an moins deux domaines géologiques différents, c'est à l'ouest, clans le domaine gneisso-charnockitique que se situent les quartzites du groupe des Martres. Quartzite et gneiss à grenat et sillimanite, en banes épais, constituent la formation de La Galette. A Pest, dans un environnement gneisso-granitique, les deux groupes métasédimentaires de Saint-Siméon, et de La Malbaie comprennent, par contraste, des bancs pen épais et de compositions variées. Les niveaux de quartzite dépassent rarement 50 m d'épaisseur. L'autre groupe metasédimentaire, celui de Saint-Tite des Caps, recoupé de nombreuses intrusions charnockitiques et granitiques, ne possède que de minces niveaux de quartzite. La pureté et la grande épaisseur des quartzites de La Galette suppose une histoire complexe qui se termine par des depots continentaux de climat aride, par opposition aux depots marins des autres groupes. D'autre part, la presence de ces quartzites an sein de roches Presque anhy¬dres et de haute temperature que sont les charnockites leur confère des caractéristiques de fusion sans decrepitation. Parmi la multitude de depots de quartzite qui existe clans le monde, peu sont de qualité supérieure. Or, de par sa composition chimique, le quartzite de La Galette se compare avantageusement à ceux des meilleurs gisements des Etats-Unis, de l'Europe de l'Ouest et de l'Afrique du Sud. D'accès facile pour l'exploitation, les gisements ne sont qu'à une trentaine de milles de Baie Saint-Paul ou de La Malbaie, sur le Saint-Laurent. L'utilisation en metallurgic prévue pour le quartzite de La Galette comprend la production de silicium, de ferro¬silicium et d'autres alliages de silicium. La composition du quartzite est en outre appropriée pour la production de carbure de silicium et de silicate de sodium. Les fines peu¬vent être utilisées pour la fabrication du verre et comme matière de charge.

Jan 1, 1977

By Oakley B. Gwillam

The study of leached outcrops as an aid in determining the character of mineralization beneath the surface is in its infancy. Practically all the work on this subject up to the present has been applied to the 'porphyry' copper deposits of the southwestern United States. Some work has been done also on the zinc-lead solid sulphide deposits of the western United States. The question has been asked, "Can this study be applied, and would it have any practical application, in northern Manitoba?" When one realizes the size of the unprospected territory in this Province and the consequent need for a cheap and rapid method of interpreting the countless outcrops which occur in order to discriminate between valueless iron sulphides and valuable sulphides of the base metals, it is readily seen that the study is of great value if it can be applied with a reasonable degree of surety. Augustus Locke, well known economic geologist of the southwestern United States and a pioneer in the study of leached outcrops of disseminated copper ore, has written much on the subject. Messrs. Blanchard and Boswell in a series of articles have dealt with the leached outcrops derived from lead and zinc sulphides in the western United States. Since this paper is essentially a comparison between the leached outcrops of the southwestern United States and those of northern Manitoba with the purpose of testing the adaptability of the study in this Province, an outline of the criteria used in the southwest will be of value to the reader.

Jan 1, 1930

By R. W. Brock

This subject is too broad and comprehensive to be dealt with adequately and authoritatively in this paper. It calls for the knowledge and experience of many men, but the results from such collaborative effort would be of great value, particularly if similar reports of the principal mining districts of the world were made on a standardized basis so that conditions everywhere might be directly and accurately compared. In considering conditions affecting mining in British Columbia, unfavourable as well as favourable factors must be taken into account. The unfavourable are apt to loom large and to be exaggerated rather than minimized; for it is human nature to see the blackness of the cloud rather than the silver lining; to think that one's own undertaking is beset with peculiar difficulties, and to attribute lack of greater success to out-side causes rather than to personal shortcomings. It should be recognized, however, that there is no country where the conditions for mining are ideal. The ideal mining country is the product of imagination, invested with every favourable condition found anywhere, but with none of the unfavourable conditions that are always present in reality. So if British Columbia has some handicaps to the industry, it is in good company. What is important is that the advantages compensate for the disadvantages, that the balance will compare favorably with that of competing states, for mining, like every other industry is competitive, and the cost of one's product must have a definite relationship to its price in the world's market.

Jan 1, 1924

By L. Vollert

"The application of pneumatically-assisted fluidized bed flotation, specifically the ERIEZ HydroFloatTM technology, has found widespread use in non-sulphide processing (particularly phosphate, potash and coal) for the recovery of coarse particles. In gold processing, centrifugal gravity circuits and flash flotation cells are typically employed for the recovery of coarse and near-size liberated gold which tends to accumulate in recycled grinding streams due to bypass to the classifying cyclone underflow streams owing to the higher specific gravity of these gold particles. Early removal of this gold from the grinding circuits contributes toward the reduction of downstream processing losses as a result of overgrinding and particle shape deformation in the case of flotation processing, longer leach residence times in the case of extractive processing, and surface occlusions in the case of both flotation and extractive processing. Furthermore, recovery to bullion attracts higher payment terms by way of comparison to concentrate sales in the case of copper-gold concentrators. This paper assesses the application of pneumatically assisted fluidized bed flotation for the recovery of coarse liberated gold through the analysis of piloting data generated from the operation of a continuously operated 16 inch ERIEZ HydroFloatTM unit treating a sized coarse grinding circuit stream. The paper presents the stage recovery by size performance of the ERIEZ HydroFloatTM unit together with quantitative gold deportment analysis to demonstrate the efficiency with which gold was recovered during this pilot campaign and then compared to more conventional processing units – centrifugal gravity and conventional flotation.INTRODUCTION Newcrest Mining Limited (NML) has identified that an opportunity exists for improving the recovery of coarse composite particles at its current operations, both as a means for improving overall recovery and as an opportunity for early gangue rejection. As such, Newcrest Mining Limited has taken an interest in the application of pneumatically-assisted, fluidized-bed flotation i.e. ERIEZ HydroFloatTM technology. This interest dates back to 2011 with sighter testwork carried out on their Australian-held ore bodies (Kohmuench et al, 2013). Newcrest continues to assess ERIEZ HydroFloatTM potential for coarse composite recovery and, in the case of the topic of this paper, coarse gold recovery based on examples in the literature which demonstrate the efficiency of this technology in this regard (Carmona Franco et al., (2015); Miller et al., (2016); and Kohmuench et al, 2013)."

Jan 1, 2017

By L. J. Han, Y. J. Zong, S. Y. Wen, J. J. Wei

"Stress strain curves characteristics, deformation and strength properties, and failure process and characteristics of sandstone samples under different stress states were analyzed through triaxial compression tests carried on using TAW-2000 microcomputer control electro-hydraulic servo rock triaxial test system. The experimental results reveal that peak strength, residual strength, elasticity modulus and deformation modulus increase linearly with confining pressure, and failure models transform from fragile failure under low confining pressure to ductility failure under high confining pressure. Macroscopic failure forms of samples under uniaxial compression was split failure paralleling to the axis of samples, while macroscopic failure forms under uniaxial compression was shear failure, the shear failure angle of which decreased linearly with confining pressure. There were significant volume dilatation properties in the loading process of sandstone under different confining pressure, and then based on acoustic emission damage and volumetric dilatation damage the damage evolution properties of samples were analyzed, and damage constitutive model were established, realizing the real-time quantitative evaluation of samples damage state in loading process. INTRODUCTIONDamage is a phenomenon that micro defects in material under monotonic loading or reloading will lead to progressive decrease of the cohesion and damage of volume units. Many scholars at home and abroad have carried out systematic researchers on damage evolution characteristics and constitutive model of rock, and have achieved a series of remarkable results in this field. Lu Y.D. (2004) studied the complete stress-strain curve’s characteristics of marble under triaxial compression, and established the bilinear elastic-linear strain softening-residual ideal plastic damage constitutive model. Ren J.X. (2001) studied the damage evolution laws of coal and rock mass by computerized tomography triaxial loading system, realizing the quantitative evaluation of damage state. Zhang Z.L. (2011) studied the deformation and failure mechanism of strong weathered sandstone by triaxial compression test, and analyzed the damage evolution processes and established the damage evolution equations based on the density method. Li X.J. (2012) studied the microscopic damage characteristics of siltstone under triaxial compression by scanning electron microscope and digital image technology, and analyzed the statistical distribution characteristics of cracks azimuth angle, length, width. Zhou J.W. (2012) studied the strength, deformation and fracture damage characteristics of sandstone by uniaxial cyclic loading and unloading tests, and defined damage variable based on linear damage mechanics theory and acoustic emission (AE). Cao W.G. (2006) established a new damage model and a statistical damage constitutive model of rock under specific confining pressure according to the force of damaged part and undamaged part in rock on the base of statistical damage theory. Li S.C. (2014) studied the damage evolution characteristics in the whole uniaxial compression process of sandstone by electrical resistivity and AE, and proposed a status qualitative criterion for rock damage."

Jan 1, 2015