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By E. H. Henderson

Introduction Stamp-Milling and amalgamation is, perhaps, one of the oldest processes of recovering gold from its ores. Many papers, theses, and textbooks have been written on the subject of stamp-milling practice in general, but, to my knowledge, there have been no publications describing the modern stamp-mill as designed, developed, and operated in Nova Scotia. Although it may be said that the gravity stamp-mill is the most primitive, and perhaps the crudest, crushing machine in existence, it is at the same time the most satisfactory all-round milling and amalgamating device yet contrived. Originating in Saxony, and used in North America first in Virginia and Georgia, the stamp-mill, in a primitive form, later found its way to California and Colorado. Here, it speedily developed from an affair of wood shod with iron, and operated with the crudest gearing, to substantially its present form. Briefly, it consists (see Figure 1) essentially of a series of hammers (the stamps), which fall upon a mixture of ore and water contained in a cast-iron box (the mortar). The resulting crushed ore (the pulp) is splashed out through a screen on the front of the box. For some years after the discovery of gold in Nova Scotia, in 1861, the ? arrastra and Chilean mill were used to recover the gold from the rich ores. The stamp-mill followed, and various types were used, principally the California and Gilpin County types. Then, in 1895, Mr. M. R. O'Shaughnessy, one of our foremost amalgamators, conceived the idea of a new type of stampmill, which has since become standard in Nova Scotia gold mines. This mill, unique in its design and operation, is specially adapted for the most efficient extraction and recovery of gold as it occurs in our Nova Scotian ores. It is commonly known as the Underwater Feed type, as opposed to the usual Overwater or Top Feed type, and it may be rightly termed The Nova Scotia Self-Classifying Stamp Amalgamation Mill. It is conceded by experienced mill-men that it is superior to any other type of mill for recovering the very coarse and granular gold typical of the ores of this Province. The particular installation and practice to be described in this paper is that of the Guysborough Mines, Limited, at Goldenville, Guysborough county. Emphasis will be laid on certain operating innovations of extreme simplicity and high efficiency.

Jan 1, 1935

By G. J. Birnie

Introduction The preparation of the following paper has been undertaken in the belief that a description of the development methods and equipment used at Lake Shore, at the present time, will prove of general ? interest. Working depths of nearly a mile and a half in shaft sinking and of more than one mile for stoping operations have imposed problems not encountered at shallower horizons. Among the problems contributing to the difficulty of mining at extreme depths might be mentioned: Rock pressures Ventilation Hoisting Shorter work period at the face Geological considerations In the main, the effects of these factors add to the difficulty of mining at depth, but it is not entirely true to say that each must necessarily become more pronounced as mining operations proceed to greater depths. Corrective measures may, in some cases, retard the effect and in others may even relieve some of the difficulty. It is proposed here to discuss these features in the light of the experience at Lake Shore, and to present, in some detail, the current practice in shaft sinking and in driving ore and waste passes, raises, drifts and cross-cuts.

Jan 1, 1950

By Carl Lausen

Within recent years several mining companies have sent expeditions co the east end of Great Slave lake co determine the mineral possibilities of that area. Little was known of the geography of the region, and even less of the geology; and, not until Blancher's survey was made and the results published, was an accurate map of the lake available. Early explorers followed the Inconnu channel and the north shore of McLeod bay to Port Reliance, and, just prior to Blancher's survey, Hornby showed that the southern passage was feasible. Apparently, but few geologists have ? travelled through the country, for geological information is meager. In 1900, Robert Bell, of the Geological Survey, made a trip to Fort Reliance by way of the north shore of McLeod bay, and he gives a brief description of the geology. The present paper is the result of an expedition into this little-known region by Mr. Geo. M. Douglas and the writer in the summer of 1928. The south shore of Great Slave lake was followed to the east end of Tochatwi bay, and an extensive exploration was made of Kahochella and Pethei peninsulas. The prime object of the expedition was co determine the presence or absence of the copper-bearing Keweenawan basalts.

Jan 1, 1929

By Paul M. Clifford, David M. Baird

The Great Northern Peninsula of Newfoundland consists of a Precambrian core of gneisses and granitic rocks, cut by numerous diabase dykes. This complex is surrounded by an envelope of sedimentary rocks of Cambrian to Carboniferous age. Radiometric dates from two granite masses in the core give a mini-mum age of -945 m.y. (Grenville) for the last major tectonic activity. This Grenville deformation conferred upon the core substantially its present structure which has controlled later events to a marked degree. Block movements of the core, dominantly in a vertical sense, have ex-posed it to erosion at intervals. The nature and distribution of the flanking sedimentary rocks and the present relief of the peninsula suggest four such movements. THE Great Northern Peninsula extends some 150 miles north-northeast from the northwest corner of the main body of the island of Newfoundland. It separates the Gulf of St. Lawrence from the Atlantic Ocean, except for the 12 mile wide

Jan 1, 1962

By The Staff

BEFORE going into detail on the subject to be presented, a brief outline of the Company's earl y history would not be out of place. Prospecting and mining on a small scale was started in 1876 on the site of the present open pit at Thetford Mines. The property was purchased from the Crown in 1878 and Johnson's Company was incorporated in 1885. It is owned and operated today by descendants of the original shareholders. Many employees, through their fathers and grandfathers, have service records dating back three generations. The principal asbestos deposit at Thetford Mines is pear-shaped, with surface dimensions of about 2,200 feet in length by 1,300 feet in maximum . width. Its long axis strikes northeast and the dip is nearly vertical, but irregular in detail. It is known to extend to a depth 1,200 feet below the original surface, but its area at that depth has not been determined. Ownership of this deposit is divided among three active Companies: the Asbestos Corporation, Limited; Bell Asbestos Mines, Limited; and John-son's Company. Johnson's Company owns a section about 1,000 feet in length and 500 feet in width, bounded on the northeast by the King mine of the Asbestos Corporation and on the northwest by the Bell pit. On Johnson ground, there was originally a large outcrop o~ asbestos rock which dipped toward the south below overburden. This was mined until recently by open pit, the overburden being stripped off as far southward from the original outcrop as was economically possible. As the. pit was deepened, within side walls maintained at a maximum safe slope, its floor area, of course, became progressively smaller, and eventually the pit would have wedged out against the Bell property line. It became necessary, there-fore, to introduce some other method of mining before production became seriously curtailed by a shrinkage of the pit area.

Jan 1, 1941

"Many advances in glass technology and processing are being made and the possibilities for glass as a material in the future appear unlimited. Float glass, glass-ceramics, high-strength sheet and container glass, glass-reinforced plastics, glass for electronic equipment, aerospace glass, glass fibres, glass vehicles, glasses with selective-reflective coatings and glare-reducing glasses, to name a few, provide areas of significance at present and for the future. There appear to be great opportunities, in certain localities of Canada, to develop new sources of raw materials for an expanding Canadian glass industry.New developments in the structural clay products industry have centered around facing brick as a structural load-bearing material, prefabricated brick panels, large-sized units, isostatic pressing of sewer pipe and auto-matic settmg of brick. Fast-firing techniques, using prefired or calcined raw materials, and the development of high-strength products will result in the use of a wider range of raw materials in the whiteware and structural clay products industries.Porcelain enamel, a material used for many years in domestic appliances and for sanitary ware, now is used extensively in architecture, agriculture, water tanks, highway signs and reflectors, and in products where resistance to corrosion-plus-temperature is important. Exotic composites of ceramics and metals, and specialized ceramic coatings applied on metals by various techniques such as flame spray, plasma jet, or vapour and chemical deposition have proved useful in materials for aircraft power plants, rockets, missiles and nuclear applications."

Jan 1, 1967

By A. A. Ruitenberg, L. R. Fyffe

"This paper compares several distinct types of mineral deposits associated with different families of granitoid rocks in the New Brunswick Appalachians. Porphyry copper deposit s are associated with late-stage differentiates of Lower to Middle Devonian I-type igneous complexes. Contact metasomatic deposits were formed where these plutons intrude carbonate rocks and they gave rise to vein deposits in fracture zones near wrench faults. The I-type granitoids were emplaced mainly in areas of thin continental crust and locally along prominent faults in areas of thick continental crust.In contrast, tin-tungsten-molybdenum-bearing greisen deposits and skarns, and antimony-bearing quartz veins are associated with predominantly S-stype granitoid complexes ranging in age from Middle Devonian to early Carboniferous. The mineral deposits occur within or along the contacts of very fractionated (specialized) late phases of these intrusive complexes, which are characterized by high K2O/Na2O, Rb/Sr and Rb/Ba, and low Fe, Mg, Zr and Ti contents. These specialized granitoids are in a large wrench fault zone that cuts across thick continental crust in southwestern and central New Brunswick.IntroductionA great variety of igneous intrusions and subvolcanic stocks were emplaced in the New Brunswick Appalachians during the latter stages of and immediately after the Acadian Orogeny (late Lower to Middle Devonian) and during the subsequent Hercynian Orogeny (Carboniferous). The presence or absence and characteristics of mineral deposits associated with these intrusions reflect the level of intrusion, the composition of the associated igneous rocks and the composition of the invaded sequences.Nickel-copper sulphide deposits occur in mafic intrusions in the St. Stephen area of the southwestern Magaguadavic - St. Croix Zone and in the Goodwin Lake area of the northeastern Mirarnichi Zone. Contact metasomatic and vein-type copper-rich base metal sulphide deposits and porphyry copper deposits with or without molybdenum are related mainly to high-level granitoid stocks of intermediate composition in the Matapedia-Tobique and northwest Miramichi zones. Tintungsten - molybdenum deposits with or without base metal sulphide minerals and antimony-uranium deposits are mainly associated with Upper Devonian and Lower Carboniferous biotite-muscovite granites and related 'subvolcanic intrusions that occur in an arc-shaped belt extending from the southwestern Magagaudavic - St. Croix Zone into the central Mirarnichi Zone."

Jan 1, 1982

By J. B. Heslop, D. S. Bubar

"The Gondor Zn-Ag-Pb-Cu deposit is a stratabound massive sulphide lens occurring within Archean volcaniclastic rocks of the Yellowknife Supergroup. The deposit is located in the west-central portion of the Slave Structural Province, approximately 350 km north of Yellowknife.Initial diamond drilling at Gondor has outlined a steeply dipping, L-shaped, folded, massive sulphide body, which may be traced over a strike length of approximately 800 m, and to a depth of 350 m. True widths of up to 40 m have been intersected in the thickest part of the deposit. Preliminary estimates suggest that the deposit contains a minimum of 7.5 million tonnes grading 6% Zn, 50 g/tonne Ag and less than I% combined Cu and Pb. In addition, significant gold, grading up to 2.8 g/tonne, occurs in some parts of the deposit. The mineralization is open both down-dip and along strike.The Gondor deposit lies conformably within a predominantly east-west striking, north-facing sequence of felsic to intermediate volcaniclastic rocks. Coarse fragmental rocks are abundant in the hanging wall, whereas ash and lapilli-tuffs predominate in the footwall. The main structural feature in the area is a large-scale, steeply northeast-plunging, Z-shaped fold. The sulphide mineralization lies within the synformal portion of this fold, with the thickest part of the deposit coinciding with its hinge zone. Several episodes of faulting have also affected the local stratigraphy.The wallrocks of the Gondor deposit were hydrothermally altered prior to the onset of medium-grade regional metamorphism. A halo of altered rocks surrounds the massive sulphide lens, with no apparent difference in the degree of alteration between the hanging wall and footwall strata. The alteration zone is characterized by the addition of MgO and K20 and by the depletion of Na20 and CaO. These changes are reflected in the mineralogy of the altered wallrocks by local enrichment in chlorite, biotite, muscovite and cordierite.The mineralized zone is medium- to coarse-grained, well-banded and is composed largely of pyrite, quartz, and sphalerite with subordinate galena and chalcopyrite. Preliminary studies of metal distribution indicate that a lateral zonation is present, with lead enrichment in the central part of the deposit, and copper enrichment toward both ends. Stringer-type copper mineralization has not yet been discovered in the footwall of the Gondor deposit."

Jan 1, 1985

By J. Esson, R. A. D. Pattrick, M. K. Nimfopoulos, D. A. Polya, K. M. Michailidis

"Economic Mn-oxide ore deposits of commercial grade occur in the Rhodope massif near Kato Nevrokopi in the Drama region, Northern Greece. The Mn-oxide mineralization has developed by weathering of continental hypogene rhodochrosite-sulphide veins. The vein mineralization is con-?ned by tectonic shear zones between marble and metapelites, extending laterally into the marble astabular, pod or lenticular oreshoots (up to 50 m x 20 m x 5-10 m). Supergene oxidation of the hypogene mineralization led to the formation of in-situ residual Mn-oxide ore deposits, and secondary infills of Mn-oxide ore in embryonic and well developed karst cavities.Whole rock geochemical pro?les across mineralized zones con?rm the role of thrusts and faults as solution passageways and stress the importance of these structures in the development of hydrothermal and supergene mineralization at Kato Nevrokopi. Three zones are recognized in the in-situ supergene veins: (A) a stable zone of oxidation, where immobile elements form (or substitute in) stable oxide mineral phases, and mobile elements are leached; (B) a transitional (active) zone in which element behavior is strongly in?uenced by seasonal ?uctuations of the groundwater table and variations in pH-Eh conditions; and (C) a zone of permanent ?ooding, where variations in pH-Eh conditions are minimal. Zone (B) is considered as the source zone for the karst cavity mineralization. During weathering, meteoric waters, which were CO2-rich (PCO2~10-3.8 to 10-1.4) and oxygenated (fO2~10-17 for malachite), percolated downward within the veins, causing breakdown and dissolution of sul?des and marble, and oxidation of rhodochrosite to Mn-oxides. Karst cavity formation was favored by the high permeability along thrust zones. Dissolved Mn2+was transportedinto karst cavities in reduced meteoric waters at the beginning of weathering (pH~4-5), and as Mn(HCO3)2in slightly alkaline groundwaters during advanced weathering (pH~6-8). Mn4+-oxide precipitation took place by fO2increase in ground waters, or pH increase by continuous hydrolysis and carbonate dissolution. In the well developed karst setting, some mobility of elements occurred during and after karst ore formation in the order Na>K>Mg>Sr>Mn>As>Zn>Ba>Al>Fe>Cu>Cd>Pb."

Jan 1, 1997

By J. Esson, R. A. D. Pattrick, M. K. Nimfopoulos, D. A. Polya, K. M. Michailidis

"Abstract-Economic Mn-oxide ore deposits of commercial grade occur in the Rhodope massif near Kato Nevrokopi in the Drama region, Northern Greece. The Mn-oxide mineralization has developed by weathering of continental hypogene rhodochrosite-sulphide veins. The vein mineralization is confined by tectonic shear zones between marble and metapelites, extending laterally into the marble as tabular, pod or lenticular oreshoots (up to 50 m ?? 20 m ?? 5-10 m). Supergene oxidation of the hypogene mineralization led to the formation of in-situ residual Mn-oxide ore deposits, and secondary infills of Mn-oxide ore in embryonic and well developed karst cavities.Whole rock geochemical profiles across mineralized zones confirm the role of thrusts and faults as solution passageways and stress the importance of these structures in the development of hydrothermal and supergene mineralization at Kato Nevrokopi. Three zones are recognized in the insitu supergene veins: (A) a stable zone of oxidation, where immobile elements form (or substitute in) stable oxide mineral phases, and mobile elements are leached; (B) a transitional (active) zone in which element behavior is strongly influenced by seasonal fluctuations of the groundwater table and variations in pH-Eh conditions; and (C) a zone of permanent flooding, where variations in pH-Eh conditions are minimal. Zone (B) is considered as the source zone for the karst cavity mineralization. During weathering, meteoric waters, which were CO2-rich (PCO2 ~10-3.8 to 10-1.4) and oxygenated (fO2 ~10-17 for malachite), percolated downward within the veins, causing breakdown and dissolution of sulfides and marble, and oxidation of rhodochrosite to Mn-oxides. Karst cavity formation was favored by the high permeability along thrust zones. Dissolved Mn2+ was transported into karst cavities in reduced meteoric waters at the beginning of weathering (pH~4-5), and as Mn(HCO3)2 in slightly alkaline groundwaters during advanced weathering (pH~6-8). Mn4+-oxide precipitation took place by fO2 increase in ground waters, or pH increase by continuous hydrolysis and carbonate dissolution. In the well developed karst setting, some mobility of elements occurred during and after karst ore formation in the order Na>K>Mg>Sr>Mn>As>Zn>Ba>Al>Fe>Cu>Cd>Pb."

Jan 1, 1997

By A. Christoffersson, T. Nillson-Wullf, H. R. Manouchehri

"Mining industry has been the building blocks for human development through millennia and will continue to play its role in sustainability and meeting society’s needs for raw material. In the way towards sustainability, the next generation of efficient and heavy duty of Sandvik’s crushers, CH860 and CH865, are introduced for efficient crushing. As the secondary, tertiary and/or pebble crusher, these new crushers are designed to over perform in tough mining environment. Featuring higher crushing forces relative to the mantel diameter and 500 kW motor, combined with advanced automation system, i.e., sophisticated HydrosetTM and Automated Setting Regulation (ASRTM), combined with overpressure system with dedicated air supply in dust collar, etc., the new crushers provide higher safety, productivity, and reliability with the same foot-print of conventional cone crushers.Since crushers are more energy efficient than mills it makes sense to effort in fine crushing to save energy and protect environment. That has been the logic behind development and introducing stronger and more efficient crushers by Sandvik. The results on crushing hard iron and gold ores by CH865 have proven its efficiency in fine crushing at a higher productivity, availability and reliability rates through increasing throughput for defined size fraction and extended crushing chamber liner life.Within this paper the performance of the CH865 to deal with two different ores are presented discussed with a glance at how the downstream milling process can be benefited by saving energy and reducing the operation cost. In plant practice, the implementation of the new CH865 provides between 25 and 30% of the crushed ore in the size range of first step milling, i.e., < 2 mm, that offers opportunity for reduction in energy consumption in milling and even changing the process plant configuration by directly forwarded that part to gravity separation. Furthermore, potential of converting the rod mill to ball mill to improve productivity has been considered by plant engineers. Furthermore, some potential applications for such efficient crushers are brought into considerations and discussed. The new developments provide about 30% higher crushing force to efficiently deal with competent ores and pebbles. The CH860 and CH865 crushers are well suited to replace conventional secondary and tertiary crushers respectively; nevertheless, CH865 is virtual option for pebble crushing in SAG and AG milling circuits."

Jan 1, 2016

By P. C. Thurston, T. Setterfield, D. H. Watkinson

"The Maybrun copper deposit IS In a succession of pillowed basaltic flows in the Wabigoon sub-province, northwestern Ontario. The rocks have primary flow morphologies and remarkably well-preserved crystallization textures, including quench-textured plagioclase, in spite of metamorphism to the amphibolite facies. The sulphide assemblage chalcopyrite-pyrrhotite-cubanite with minor sphalerite and pyrite is primarily in interpillow spaces and is stratabound. Basaltic rocks immediately enclosing the copper sulphide minerals have an enrichment in Fe, Mg and K and depletion in Ca and Na relative to surrounding flows. The Maybrun deposit is interpreted to have formed contemporaneously with volcanism and alteration, and was subsequently metamorphosed with the enclosing basalts.IntroductionThe association o f significant base metal accumulations with mafic submarine flows in the Archean is as yet poorly documented. Such deposits, where noted, have typically been small, and are therefore commonly over looked. The Maybrun Mine, a 2.6 x 106-tonne copper deposit in pillowed basalt, has many similarities with large, well-documented volcanogenic deposits. Given the interpretation of the Maybrun Mine to be volcanogenic in origin, there is n o reason why similar processes could not produce large deposit s. This is an important realization in an area where Archean submarine mafic rock s are very common, but frequently are examined only superficially. As gold commonly occurs in deposits such as Maybrun, even modest-sized deposits may be economic. The basalts at Maybrun are remarkable for amphibolite-facies rocks because of their extremely well-preserved delicate volcanic textures, including quench textures.The Maybrun Mine is one kilometre south of Atikwa Lake, in the Wabigoon sub-province of the Superior structural province, 75 km southeast of Kenora, northwestern Ontario, at longitude 93°35&apos;W, latitude 49°25&apos;N (Davies, 1973). Archean metavolcanic and metasedimentary rocks and intrusions underlie the area. Goodwin (1970) concluded that the mafic and minor felsic metavolcanic rocks, as well as the overlying metasedimentary rock s, were an eastward extension of the lower cycle of the Keewatin type section for the Lake of the Woods area. He estimated that the stratigraphic thickness of Keewatin rock s in this area is about 6900 m, of which 87% is basalt. The flows contain numerous interlayered sills, predominantly of basaltic composition; they have been extensively folded, faulted, metamorphosed to amphibolite facies and intruded by numerous felsic bodies, most importantly the Atikwa Batholith."

Jan 1, 1983

By J. G. Whellock, R. J. Phillips, J. W. Matousek, P. J. Marcantonio

"Stillwater Mining Company (SMC), a partnership of Chevron Resources and Manville Corporation, produces a copper-nickel, platinum-palladium flotation concentrate at its Nye, Montana mine. The concentrate is then toll processed in Europe. Recognizing the economic advantage of treating the concentrates at the mine site and of retaining this strategic resource in the United States, the Company commissioned Tolltreck International Limited and International Process Research Corporation to conduct pilot scale smelting tests with a flowsheet that would maximize metal recoveries while satisfying the environmental requirements of operations at Stillwater.Primary smelting was conducted in a single phase, 50 k W, submerged-arc, electric furnace. Refining the product mattes to copper-nickel ""white-metal""; containing approximately 2% iron, was accomplished in a Tolltreck, IV-litre, top blown rotary converter. Over-all platinum and palladium recoveries were approximately 99%; copper and nickel recoveries averaged 94%. INTRODUCTION(l-4)Stillwater Mining Company (SMC) a partnership of Chevron Resources and Manville, operates a copper-nickel, platinum palladium mine and concentrator at Nye, Montana, located in the valley of the Stillwater River, approximately, 100 km southwest of Billings. It is North America&apos;s only primary producer of these precious metals. The Stillwater area was mined for chrome ore during World War U and the Korean War, but it was not until 1961 that attention was drawn to the similarities between the Stillwater Complex and the Bushveld Complex of South Africa with its deposits of platinum group metals.A concentrated search for platinum was begun by Manville Corporation in 1967. Its presence, together with palladium, in mineable quantities was confirmed in the period 1976-1978, and the first partnership to develop the deposits was formed by Manville and Chevron in 1979. Anaconda joined the group in 1983, and in 1985 its share was purchased by Lac Minerals. In 1988 the interests of Lac Minerals were purchased by Chevron and Manville.The decision to develop the mine and build a concentrator was made in 1986. Construction began in the fall of that year, and the first concentrate was produced six months later, in March 1987. Underground mining is done in a two-shift, five day- week operation. Since startup, the concentrator has operated on a 24 hour/day, 7 day/week schedule, treating an average of 635 tonnes of ore per day and producing approximately 10 tonnes of concentrate."

Jan 1, 1989

By Ahmad Ghahreman, Lin Li

"In this study, the Fe(II)/Fe(III) redox reaction kinetics on the surface of pyrite, have been investigated in a 0.5 mol L-1 sulfuric acid solution for a temperature range of 22 to 65°C. Based on mixed potential theory, chronoamperometry is introduced to study the Fe(II)/Fe(III) kinetics by subtracting the current density of pyrite oxidation in an iron-free acidic solution from that in an iron-containing solution at the same applied polarized potential. Tafel behavior was established by this method to analyze the kinetics of the Fe(II)/Fe(III) redox reactions. The results showed that exchange current densities increased slightly with temperature, however remained on the order of 10-5 A cm-2. The activation energy for Fe(II) oxidation and Fe(III) reduction on the pyrite surfaces was calculated to be 102.0 and 32.7 kJ mol-1, respectively. Anodic transfer coefficients also increased, from 0.24 to 0.39, with increasing temperature, which indicates a weakened n-type semiconductor property at higher temperatures. Electrochemical impedance spectroscopy measurements have indicated that at lower anodic over potentials the charge transfer is the rate determining step of pyrite oxidative dissolution in sulfuric acid solution. In the presence of Fe ions, the major contribution of the total current density comes from the Fe(II)/Fe(III) redox reaction. INTRODUCTION Pyrite, an abundant sulfides mineral in the nature, is commonly considered a valueless gangue mineral frequently associated with other valuable sulfide minerals such as chalcopyrite, or metals such as gold, or coal (Lin & Say, 1999). Pyrite oxidation has been the subject of extensive research in view of gold metallurgy, as oxidation of pyrite is the initial step to break down the pyrite lattice and expose the encapsulated fine gold particles (Gasparrini, 1983). Fe(III) ion and dissolved oxygen (DO) have generally been considered as the two most important oxidants with respect to pyrite oxidation, having been studied extensively in previous research (Zheng, Allen, & Bautista, 1986; King Jr & Lewis, 1980). The process of pyrite oxidation can be viewed as a series of reactions amongst pyrite, ferrous, ferric and oxygen in which pyrite is initially oxidized by the dissolved oxygen in water forming ferrous (Eq. 1), and then the ferrous also is oxidized by he dissolved oxygen to form ferric (Eq. 2). The ferric, produced by reaction 2, then could potentially oxidize pyrite (Eq. 3) and convert to ferrous."

Jan 1, 2017

By Mary Kama, Kaul Gena

"Magnetic skarn ore (MSO) is one of the major copper bearing ore extracted by the Ok Tedi Copper Mine in Papua New Guinea. Copper minerals are recovered by flotation while the iron not associated with copper are discarded as tailings. The objective of this investigation was to determine the iron ore reduction kinetics for the Ok Tedi MSO and ascertain if it can be processed to produce sponge iron for a mini steel plant in Papua New Guinea.SEM-EDAX analyses of the Ok Tedi MSO indicated 10.1% C, 30% O, 0.6% Mg, 1.1% Si, 21.1% S, 0.8% Ca and 36.2% Fe. Most of the iron is in sulfide form. Both naturally occurring and roasted sinters of Ok Tedi MSO samples of different particle sizes were reduced by charcoal carbon at three different temperatures and seven different reduction times. Analyses of the reduced products indicated a metallic iron content of more than 65 wt.% on average.Results showed that there was no significant difference in reduction between fluxed and control materials. Only a slight increase in kinetics with reduced particle size, hence the reaction rate constant (K) did not vary much within the temperatures investigated. Reaction kinetics increases with increasing reduction time at 900°C. Therefore, more iron reduction is observed with particles of 106 µm size. In addition, the results also confirmed that the reduction energy used was higher at 800°C and lower at 1,000°C. In summary, iron reduction can be improved but close monitoring of temperature and reduction times are essential to determine the reaction kinetics of the Ok Tedi MSO. INTRODUCTIONMost mines in Papua New Guinea mine large quantities of iron in the form of sulfides, carbonates, oxides and sulfates that are eventually disposed off as tailings. The Ok Tedi magnetic skarn ore (MSO) contains a significant amount of hematite, magnetite, siderite, ilmenite and pyrite that can be a source of iron. The mineralogical compositions of Ok Tedi MSO reveals more iron minerals than copper, yet all iron containing minerals are collected in the tails from the main copper production stream. Therefore, this study is conducted to investigate the possibility of producing direct reduced iron (DRI), or sponge iron, from the MSO. Such sponge iron may serve as the feedstock for electric arc/induction furnace based mini steel plants in Papua New Guinea."

Jan 1, 2016

By R. Alarcón Sch., R. Abel F.

For many years, copper cathode quality has been a priority for end consumers, since it affects the variety of products that can be obtained from them. From the beginning, physical and chemical quality of the wire bars was controlled, as this product was used to obtain wire rod and other forms of copper by wire drawing. At that time, all the electro refined cathodes were melted and casted as wire bars. Subsequently, in the 80’s, with the introduction of continuous casting furnaces, it was possible to directly produce wire rod from cathodes. From then on, cathodes quality standards were consistently increased, by the introduction of uniform criteria, among which we can identify ASTM and British Standards as well. Also, producers began to use more demanding internal standards than the existing specifications, in order to differentiate their cathodes as high quality products among customers. Today the physical aspect of cathodes, including nodules, cracks, sulfates, or others, is the first element used by end customers to assess their quality. This paper aims to show a brief vision of the evolution of quality specifications for products used to manufacture copper wire. INTRODUCTION From the beginning of refined copper production for industrial purposes, mandatory minimum quality conditions were established. These quality conditions were used as the main element to determine prices and discounts of the respective sales contracts. Reviewing the copper development history, we can appreciate that its quality requirements had been constantly evolved, so that currently refined copper has an extremely high quality standard, that allows its direct use in the production of ultra-thin cables and other products applied in the industry. In each stage, refined copper production has fostered the development of technology used in their treatment. Similarly, cathode processing technology has been evolving to minimize treatment costs in order to generate a wire rod for several uses, ranging from power cables to super conductors. In this sense, to the already known type of fusion processes of the Southwire or Asarco type (capacities over 80 kt / year), wire rod production processes of the Upcast or Rautomead type (capacities between 20-50k t / year) have been added. They immediately deliver oxygen-free wire rods. In both cases, we can conclude that the clients' requirement had evolved from a chemical criteria focus, to considering more subjective aspects, such as visual control as the first stage of inspection.

Jan 1, 2019

By Charles B. Newmarch

Abstract In the course of coal studies undertaken by the B.C. Department of Mines in southeastern British Columbia, special attention was directed to problems of coal seam correlation. Methods that had been used successfully in other coalfields were found, in the Crowsnest area, to have a restricted use or furnished only additional evidence that might prove helpful when used in conjunction with other criteria. A correlation technique involving semi-quantitative spectrographic analyses of coal ashes was developed. Elements detected in the ash include Si, B, P, Fe, Mg, Mn, Pb, Ti, Cr, Ga, Ca, Al, Ge, Ba, Mo, V, Ag, ?y;b, Na, Zn, Zr, Ni, Sr, Cu, K. Of these, the elements found to be most useful in correlation were Na, Ba, Si, V, and Mg. The element Na was invariably detected in the ash from one of the seams but was not found in samples taken from any of the others. In all of the four seams sampled statistically, significant differences in the amount of certain trace elements were noted. When the values obtained for these trace elements were portrayed in the form of histograms, the resulting diagrams had a characteristic shape for each seam. The diagrams provided a basis for seam identification within the limited area (8,000 feet by 4,000 feet) that was investigated. Introduction During the field seasons of 1946, 1947, and 1948 the British Columbia Department of Mines undertook a geological investigation of the coal measures of southeastern B.C. As field work progressed in the Crowsnest area it was found that, within the Kootenay formation, which contains all the commercial seams of the region, the coal beds are the most persistent stratigraphic units. Because of relatively rapid changes in ?both the thickness of the seams and the interval between seams, difficulty has invariably been experienced in attempts at correlation. Even short-range correlati0ns by able geologists who have worked in the Crowsnest coal basin have been questioned by the operating companies. It was apparent, therefore, that a more dependable correlation technique was needed so that stratigraphic and structural studies could be of greatest value. This paper presents, firstly, a summary of the results obtained in attempted correlations using methods that have been found effective in other coalfields. Secondly, a method based on semi-quantitative spectrographic analysis of coal ash is described and the apparently promising results are discussed.

Jan 1, 1950

By J. M. Cormie

"The orebodies of the East Malarcic mine are interesting from a geological standpoint because of the very small amount of vein quartz, the occurrence of much of the ore in soft greenstone schist, the presence of innumerable bodies of porphyry and diorite, and their obvious relationship to structural features .The property lies in the northeast part of Fourniere township in western Quebec, and within the important fault zone that geological mapping in recent years has shown is traceable wesrward through the Noranda and Kirkland Lake camps and eastward to beyond the Val d'Or region . The claims included in the property were staked by J.P. Norrie and L. K. Coffin in 1932, but gold was not discovered until i934. Production began late in 1938. The total amount of ore milled up to the end of 1945 was 2,837,091 tons from which gold having the value of $16,631,758 was recovered.The region is underlain by an alternating series of Early Precambrian sediments and volcanics cut by innumerable intrusives. These are more fully described in the works of Gunning, Ambrose, and Norman. The East Malanie property is underlain by three formations, which, named from north· to south, are : the Cadillac sediments, the Blake River volcanics, and the Kewagama sediments. In addition, there are countless intrusions of porphyry and diorite, particularly in the greenstone, occurring in all sizes up to those measurable in hundreds and even thousands of feet . These constitute a large proportion of the greenstone in places. In many parts of the ore zone there is more porphyry and diorite than schist. The greenstone itself is not homogeneous but includes peridotite, andesitic lava, and soft talcose schist.Orebodies have been found in both the Blake River volcanics and the Kewagama sediments. They are not known to occur in the Cadillac group. The ore occurs in a zone of pyrite mineralization in which almost no other metallic minerals and very little vein quartz are present. Generally, the grade varies directly with the amount of pyrite. The mineralization is later than all the rocks of the area. Diorite was a particularly favourable rock for mineralization and contains the highest grade of ore, but any rock in the fault zone may be ore-bearing, whereas the same type away from the zone is not."

Jan 1, 1954

By N. E. Nelson

"The Hidden Creek mine is about l~ miles north of the north end of Granby bay; a nearly landlocked body of water on the west side of Observatory inlet; 90 miles north of Prince Rupert; British Columbia.The main haulage way of the mine at 385 feet above sea-level has been driven north into the somewhat precipitous end of a north-south ridge that rises from the tide flats between the east and west forks of Hidden creek. The outcrops of the principal orebodies, two prominent bluffs of stained rocks and sulphides, were higher on the face of the ridge and extended from about 530 to 850 feet elevation. North from the bluff tops, the ridge comb rose gradually to about 1,200 feet elevation. The name of the discoverer and the date of discovery of the Hidden Creek orebodies are probably unknown, but the discoverer is believed to have been an Indian from one of the reservations along Observatory inlet. The deposit was brought to the attention of John Flewin, Government Agent at Post Simpson, near the beginning of the present century. Mr. M. K. Rodgers, developer of the Nickel Plate mine at Hedley, did the first organized work on the deposits. Next the Hidden Creek Copper Company prospected the property. Rodgers acquired the prospect a second time, did more work, and finally in 1910 optioned the property to the Granby Consolidated Mining, Smelting and Power Company, Limited, at that time operating at Phoenix and Grand Forks in the Boundary district of British Columbia. The optionees stepped up the development work and brought the property to production in 1914. The ores were direct smelted until 1924. In that year a mill was built. From 1930 until the end of the productive life of the properties in 1935, all of the ore was milled and the concentrate smelted. From March 17, 1914, until July 31, 1935, the production from the Hidden Creek mine was, in round numbers, 18,000,000 tons of 1.70 per cent copper ore and 6,000,000 tons of low grade dilution rock. The Hidden Creek mine ""died with its boots on"". During 1934 the average monthly production was 146,377 tons of 1.06 per cent copper ore. For 7 months of 1935 the average was 161,750 tons of 1.03 per cent ore, and for the final month, July 1935, the production was 156,950 tons."

Jan 1, 1954

By Aalbert Zwijnenburg

One of problems connected with the use of gold/titania-based catalyst systems is the low yield in propene oxide (up to 2 wt %). It is shown that the low propene oxide yield is due to product inhibition. New options for propene epoxidation with hydrogen and oxygen are discussed. INTRODUCTION The direct gas-phase synthesis of propene oxide (PO), by the use of molecular oxygen, is still aimed for. Agbased catalysis is in principle possible, but selectivity at present is not promising. Highly dispersed gold on titanium containing catalysts show an extraordinary selectivity in the oxidation of propene to the corresponding epoxide (> 99 %), using a combination of H2 and O2 as oxidation mixture [1]. Additional studies of the epoxidation reaction have indicated several drawbacks of the Au/TiO2 catalyst. Firstly, the low conversion (1- 2 %) obtained under typical reaction conditions (atmospheric pressure, 323 - 423 K) cannot be increased by increasing the reaction temperature, because this leads to extensive by-product formation. Secondly, the low efficiency of hydrogen (relatively large amounts of water are formed) is hard to prevent. Finally, significant deactivation of Au/TiO2 catalysts within several hours on stream has been observed. Deactivation can be almost completely prevented by using dispersed TiO2 supports, such as TiO2/SiO2 and Titanium-Silicalite-1 (TS-1) [2]. In recent literature [2,3] a hydroperoxide-like intermediate has been proposed to be responsible for the selective epoxidation. This oxidising species is said to be formed over gold and subsequently used for epoxidation over the Ti-containing support. The support is responsible for the slow desorption of PO. One of the problems for future industrial application might be the low yield in propene oxide. Furthermore, the presence of minor amounts of by-products, not detected on lab-scale catalyst testing, might complicate the separation unit in an industrial process. The reason for the low PO yield over Au/TiO2-based catalysts will be discussed in this paper. Temperature Programmed Desorption (TPD) and micro-flow experiments have been carried out to study PO desorption and catalyst performance, respectively. A catalytic cycle is proposed together with its consequences for the maximum yield in PO. Finally, several process and catalyst options are discussed in view of potential future industrial application.

Oct 1, 2003