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By L. Tong

"The oxidation of Quebracho was evaluated by acid-butanol assay, which indicates depolymerization of Quebracho. Anthocyanidin, an oxidation product of Quebracho, is stable at 95?C for up to 2 h. The ionization, complexation, and oxidation properties of Quebracho were discussed. Complexation of metal-Quebracho occurs at ambient temperature. The formation of complex precipitates is influenced by the acidity of the solution. Temperature is another important parameter that influences the oxidation and the complexation of Quebracho. Quebracho-ferric complex precipitate forms at 90?C, 0.1 mol/L H2SO4. The formation of Quebracho-metal complex in the leach solution is a possible reason for the consumption of Quebracho. Quebracho molecules adsorption on the mineral surface is reduced by consumption of Quebracho, resulting in poor sulfur dispersing effect in the leaching process. INTRODUCTIONQuebracho is used as a sulfur dispersing agent (SDA) in the pressure leaching of zinc concentrate as stated in U.S. Patent No. 3,867,268 (1975). It prevents the zinc sulfide particles from being coated with molten sulfur, thus preventing the inhibition of the zinc leaching reaction. Recently, the sulfur dispersing effect of Quebracho was investigated in the oxygen pressure leaching of nickel concentrate. The oxygen pressure leaching of pentlandite can be represented by reactions 1-3."

Jan 1, 2012

By Andre L. Du Preez

Global mine hoisting regulations require safety fall arrest systems to be installed on vertical conveyance systems capable of safely decelerating and supporting a fully loaded conveyance in the event of a rope severance. Most current arresting systems are incapable of producing controlled safe deceleration rates. Although safety ?dogs? achieve marginally acceptable results on wooden guides, difficulties arise in achieving safe deceleration performance requirement where safety arrest systems operate on steel shaft guides. Previously, arresting systems capable of operating with steel guides have been incapable of producing controlled deceleration rates during the arresting of free-falling conveyances. Most are ?instanton? systems, whereby an occupant inside a conveyance being arrested would be subjected to unacceptably high deceleration forces. This paper briefly highlights the background to the selection process of Rio Tinto?s Technical Staff of a suitable Mine Conveyance Safety Fall Arrest System for #1 Shaft at Rio Tinto Oyu Tolgoi Mine, Mongolia. It also describes the Drop Test and Free Fall Test procedure and the results leading to the acceptance of the Horne Group Levelok® Emergency Braking Technology for the Oyu Tolgoi #1 Shaft in Mongolia. The paper highlights Rio Tinto?s primary objective for the selection of this advanced technology on their primary production shaft cage system as an emergency safety catch braking system combined as an advance hydraulic chairing system. It describes the design and operational parameters and the 'Fail to Safe' interfacing with current automated mine hoist systems.

Aug 1, 2013

By J. -C. Parisien-La Salle, D. Blais, G. P. Demopoulos

"In this work the dissolution, precipitation and adsorption behaviour of gold in acidic iron sulphate media containing small amounts of chloride ions is investigated via batch laboratory tests and OLI thermodynamic calculations over the temperature range 25-250°C. Chloride ions may be present in industrial pressure oxidation/pressure leaching (POX/PL) operations due to elevated water salinity levels or due to intentional addition as is the case of the CESL Copper Pressure Leaching Process. Thermodynamic calculations show that AuCl4 - may form depending on the free Cl-/Au ratio and temperature, its stability increasing with increasing Cl- concentration and decreasing with increasing temperature. On the other hand during POX/PL, we know that massive precipitation of iron in various hydrolysis products and compounds occurs. Hence of interest is the question how AuCl4 - that may form during leaching interacts with the iron precipitation products. Gold(III) chloride was found to co-precipitate with iron(III) (oxy) hydroxides and arsenates forming in the autoclave but not with natrojarosite. Upon further investigation it was discovered that activated carbon added in the autoclave (as done in CIL) acts as preferential sink for the mobilized gold, hence opening the potential for the development of a direct cyanide-free gold recovery process in acidic sulphate leach reactors.INTRODUCTIONThe recovery of gold from ores and concentrates has evolved over the years with processing routes becoming increasingly complex. Given the high value of gold, any reduction in losses during recovery operations constitutes an important economic benefit. One such loss that needs to be addressed is the potential solubilisation of gold during pressure oxidation (POX) of refractory sulphidic gold feedstocks. For example, Agnico Eagle Mines reported a loss in gold recovery due to the formation of a gold chloride complex (Garofalo, 2009). Gold is known to form complexes in solution, such as gold(III) chloride, if an excess of chloride ions are present. The fate of such soluble gold chloride during pressure oxidation and the subsequent neutralization of the acidic discharge slurry will determine if gold is lost or recovered in the downstream cyanidation operation. Thus it is of interest to know under what conditions gold chloride may stay soluble or co-precipitate along primary (formed in the autoclave) or secondary (formed during neutralization) precipitates. Furthermore, the mode of co-precipitated gold, such as adsorption on iron compounds, like goethite and hematite (Machesky et al., 1990; Nachayev, 1984); substitution in one of the precipitated phases; or finally chemical reduction to metallic state would have consequences in terms of gold recovery."

Jan 1, 2012

By Alan Bauer

New developments in drilling, blasting and explosives in both open-pit and underground mining operations are discussed, as well as novel surface blasting techniques such as are used in tar sand mining.

Jan 1, 1978

By V. J. Southey

HOLLINGER mining operations have required development by 24 vertical shafts having a total length of 28,160 feet. Seventeen of these are sunk from surface and seven are interior shafts. Four surface shafts and three interior shafts are now active and, excepting the recently completed new main ore-hoisting shaft, the remainder are either abandoned, or are used for passes or for ventilation. The new shaft bottoms 60 feet below the 3,050 level, but there is much work to be done before it is placed in service. The term 'shaft practice' is intended to include shaft construction and a general treatment o typical equipment. It is a large subject for an organization the size of Hollinger and this paper is intended only to present the salient features. The writer wishes to thank the management for permission to publish this information and to acknowledge the advice and criticism o A. G. Irving, chief engineer, and the willing co-operation of other members of the Hollinger staff.

Jan 1, 1939

By D. N. Thurston

Luscar Stereo commenced construction of the mine at Coal Valley, Alberta, in August, 1976. It is designed to produce approximately 2.5 million clean short tons of steam coal annually - 2.0 million tons per year being committed to Ontario Hydro and 0.5 million tons per year being committed to Neptune Terminals for sale on the export market. The project involves constructing a heavy-media coal preparation plant, erecting a 42-cubic-yard dragline, constructing a shop/office complex, and developing three surface mining zones and associated facilities. As there were no existing facilities in the Coal Valley area, it was necessary to establish access roads, an airstrip, temporary utilities, fuel supplies, a construction camp, rail upgrading and communication services.

Jan 1, 1978

By M. Greyling, C. Panaou, M. Bellino

Commonly the most frequent method of calculating the overall mass balance of a multi mineral platinum-group metal (PGM) concentrator circuit in Southern Africa has been through the use of spreadsheets, typically Microsoft EXCEL®. While there are some advantages in using spreadsheet based mass balances during the conceptual design phase of the project, their use becomes limited in the detailed design phase of the project. This paper discusses the successful application of METSIM® for mass balancing of a PGM concentrator and highlights the benefits gained during the conceptual and design phase of the project.

Jan 1, 2005

By M. A. Cawley, J. W. Jordan

"IntroductionTHE ORE PILLARS in the lower ""A"" ore body of Waite Amulet Mines, Limited, can be divided into two groups, those mined in the open by sub-level blast-hole methods, and those to be mined .against coarse rock fill. Of the three pillars in the last group one has been mined and is dealt with in this paper. The method of mining pillars against coarse rock fill was suggested by the late Dr. Oliver Hall, who was Consulting Engineer for the Company when recovery of No. 2 East pillar was being planned.HistoryThe Waite Amulet mine is in northwestern Quebec, nine miles north of the town of Noranda. The property is approximately three miles long by one mile wide. The present Company, which was formed by the amalgamation of Amulet Mines, Limited, and Waite Ackerman-Montgomery Mines, Limited, commenced operations in the summer of 1937. In the fall of 1939 a new .flotation mill was erected with a capacity of 1,200 tons per day, which was increased to 1,800 tons per day in 1943. The mill is presently operated at 1,400 tons per day.To date, seven orebodies have been found, the major ones being Lower A, East Waite, and Waite. Three separate concentrates are produced, copper, zinc, and pyrite. Total tonnage mined to the end of 1954 from all orebodies has been 7,340,000 tons, which averaged 4.6 per cent copper, 5.3 per cent zinc, and 0.037 oz. gold and 1.27 oz. silver per ton."

Jan 1, 1955

By H. F. Maulson

For the benefit of those who are not familiar with the history of the western Provinces-Manitoba, Saskatchewan, and Alberta-as regards our natural resources, a few words of explanation may be in order before taking up the consideration of the Mines Act of 1930. In 1867, The British North America Act was passed by the Imperial Parliament. That Act, which is our constitution, created a union between the provinces of Nova Scotia, New Brunswick, and Upper and Lower Canada (now known as Ontario and Quebec respectively) under the name of the Dominion of Canada. Provision was made therein for embracing other parts of Canada from time to time. That portion of Canada which today comprises the Provinces of Manitoba, Saskatchewan, and Alberta and the lands to the north of them, was then known as Ruperts Land and the North West Territory. In the year 1670, King Charles II had granted by Letters Patent to Prince Rupert and his associates, known as ?The Governor & Company of Gentlemen Adventurers of England, Trading into Hudson's Bay?, commonly known as the Hudson's Bay Company, the lands and territories therein described, being roughly all the lands adjacent to and west of Hudson's bay; also the gold and silver to be found or discovered therein and other rights as more fully described in said Letters Patent. The land so granted was called 'Ruperts Land'.

Jan 1, 1930

By C. Villaseca, F. Penna, R. Villarroel

Acid mist is the undesired result of copper electro-winning (EW) process, generating a contaminated and hazardous environment in the working areas, as well as promoting high corrosion conditions for structures and equipment in the EW tank-house due to the buoyancy of sulfuric acid in aerosol form. Likewise, organic entrainments that occasionally occur in this process contaminate the cathodes, as well as increasing the risk of fire. LateralVex® and LateralFlow® are technologies that effectively and efficiently solve these problems, without affecting the usual activities of the operators, thus presenting a significant distinction with respect to other technologies that seek to solve these problems. Minera Antucoya, an AMSA group company, which produces 80,000 tons of electrolytic Cu per year, decided to install both technologies for its EW tank-house, LateralVex® in commercial cells and LateralFlow® in scavenger cells to keep both the acid mist and the organic entrainments under control. This paper presents the effects of applying these technologies in Minera Antucoya’s electro-winning plant, the challenges addressed, the difficulties encountered, the problems and opportunities that their implementation involved, as well as the surprising results obtained at the time of measuring the acid mist— less than one hundred’s part of the Allowed Weighted Limit—in samples taken with the plant operating at maximum current capacity. Additionally, the paper includes some of the improvements identified during the period, more than 3 years, in which these technologies have been in operation in Minera Antucoya. INTRODUCTION Electrowinning is the most used electro-chemical process in the hydrometallurgical industry for the recovery of highly pure metallic copper as its final product, which is formed in previous stages in an aqueous medium that goes through a selective process using organic solvents to separate impurities and concentrate the metal in a sulfuric acid solution. In the last stage, this solution goes through a process in which high- density current at a low voltage is applied, so that the metal in the solution will deposit in solid state on a plate, usually a stainless-steel plate. This last process involves the generation of other sub-products due to the electro-chemical dissociation of the electrolyte’s components, or to the addition of chemical additives, or due to specific physical conditions or lack of controls during the operation.

Jan 1, 2019

By H. G. Stephenson, C. W. Gregory

"This article describes the methods used for pillar extraction in the Wilson Seam at Canmore Mines, Alberta. The Wilson Seam is extremely gassy and varies in thickness between 7 and 30 ft, with an average of 12 ft. The gradient varies from 5 to 30 degrees, with an average of 15 degrees. The seam was developed using Lee Norse miners to form pillars which the company intended to extract using the same machines. Before pillar extraction commenced, an abandoned and inaccessible mine 160 ft above the Wilson had to be drained of 360 million gallons of water. When this was done pillar extraction commenced. Conditions in the mine slowly deteriorated and after 6 months the decision to withdraw the continuous miners was taken. Slusher hoists were installed to replace the continuous miners, with the result that roof conditions and safety steadily improved."

Jan 1, 1972

By Alim Ullah

Danieli entered into the Direct Reduction (DR) field in order to offer its clients complete turnkey facilities for steelmaking?from processing of raw materials through finished products. The Danarex® Process produces a passivated product, called the Supermetallic (SPM), without hot-briquetting. One of the main features of the Danarex® Process is its ability to produce approximately 50% of the Direct Reduced Iron (DRI) through reduction gas generated in a reformer and another 50% through recycling preheated furnace exit gas. Some other distinguishing features are: separation of carburising and cooling zones and the use of double bustle for better distribution of gas inside the shaft furnace. A pilot plant was set up at Hazen Research, Inc., Golden, CO in order to show that the integrated process works as expected and to obtain process data. The SPM obtained was of a very high quality, evidenced by metallization levels of 92% to 98%. The carbon content could be controlled between 1.5% to 4.0% by varying the operating conditions and approximately 75% of this carbon was present as Fe3C. The product was tested for inertness by Chilworth Technology, England, using UN standard tests and was found to be safe for outdoor storage and transportation.

May 1, 2003

By K. Iturralde

The article discusses the possibility of automation in refurbishment processes of social dwelling built from 1950 to 1970. These massively produced buildings were mostly designed prior to the law enforcement regarding thermal insulation or accessibility. Nowadays, many of these buildings are being retrofitted. The article focuses on the works in the external envelope. The task of renewing the whole social building stock is big and it requires a systematic process that facilitates a rapid upgrading, without neglecting the specific situation of each case. How could an automatic refurbishment process of these buildings be defined? The process should start with the data collection of the building and the creation of a 3D model using software such as BIM. The project, drafted in 3D, should facilitate the manufacture of building elements by robotics. In turn, it should be noted that during the assembly at the site, the pieces must be fixed quickly and efficiently. Is it possible to implement an automated process for the refurbishment of apartments built in the second half of the twentieth century? To approach the answer, a virtual refurbishment project is performed. The article focuses on the rehabilitation of the building envelope. Furthermore, it gives special attention to the double skin facade. It is well known that a second skin in this type of building can be an element that integrates several functions. Finally, needless to say that refurbishment of residential buildings is a need in our society. By extending its life cycle, robotic refurbishment provides more favorable socioeconomic and environmental capabilities than the sole construction of new buildings.

Aug 1, 2013

By S. M. Bradshaw, E. Charikinya

"Microwave induced cracks have the potential to enhance metal recovery from coarse sphalerite particles in heap leaching operations by creating new crack surface areas for lixiviant and enhancing value mineral exposure. The mode of fracture and the extent of mineral exposure due to microwave induced cracks have not yet been investigated. The objective of this study was to determine the extent of particle damage and mineral exposure in microwave treated particles. This was done using X-ray computed tomography (XCT) and image analysis techniques. XCT analysis was conducted on small (–5+4.75 mm), medium (–16+9.5 mm), and large (–25+19 mm) sphalerite ore particles before and after microwave treatment (MT). Geometrical properties, such as volume and surface area of each mineral phase in each particle was determined from the XCT reconstructed images using VGStudioMax image analysis software. These geometrical properties were used to calculate the interfacial areas of sulphide mineral grains in microwave treated particles before and after MT. The ratio of specific interfacial area after MT to specific interfacial area before treatment was used as an indicator of the degree of preferential grain boundary fracture. The results showed significant grain boundary fracture after MT at all sizes. For small sized particles, about 31% of the interfacial area was lost compared to 23 and 16% for medium and large particles, respectively. The results also showed an increase in the degree of mineral grain exposure of 28, 26, and 15% for small, medium, and large particles, respectively, after MT. These results provide experimental evidence supporting improved mineral exposure due to MT. INTRODUCTIONFor some years it has been suggested that microwave treatment (MT) of ores might result in preferential grain boundary fracture that would have benefits such as improved grain exposure and particle weakening. (Kingman, 2006). Most of the experimental work investigating the application of microwaves to mineral processing flow sheets has focused on assessing the benefits of applying microwave technology to flow sheets consisting of size reduction and mechanical flotation cells (Kingman et al., 2004). Experimental studies have shown that coarse crushing during tertiary grinding of microwave treated ore resulted in a better liberated coarser flotation feed (Scott, Bradshaw, & Eksteen, 2008). It has been suggested that improved liberation in milled flotation feed, was due to the presence of grain boundary fracture in microwave treated particles. However, this improvement in coarse particle liberation does not necessarily translate to a significant improvement in downstream flotation recovery (Kobusheshe, 2010). This is as a result of the size limit to the flotation of coarse material, due to detachment forces acting on particle-bubble aggregates, which increase as the particle size increases (Jameson, 2012). Current conventional, mechanically agitated flotation cells are not designed to float coarse material (Jameson, 2012). Hence it has been difficult to show the downstream processing benefits of applying microwaves to ores processed by comminution followed by flotation (Kobusheshe, 2010). It is clear from investigations carried out so far that inappropriate downstream exploitation of microwave treated ore would fail to realise a meaningful process benefit (Kobusheshe, 2010; Ali & Bradshaw, 2011)."

Jan 1, 2016

By G M. Young

IT IS most appropriate that this first Memorial Lecture should be given in the Province of Quebec, near the site of the first metallurgical industry in Canada. At La Forge, about seven miles north of Three Rivers, iron was produced in 1783. We are told that the early settlers obtained most of their iron-ware -stoves, kettles, axes and ploughshares -from this smelter, with its foundry and forge. The Canadian copper industry also had its beginnings in Quebec when, nearly 100 years later, in the 1880's, several small copper smelters were erected in the Eastern Townships. Later, in 1899, Canada's first aluminum smelter was built at Shawinigan. From these small beginnings has grown a vast metals industry, the export value of its products being only exceeded by that of our forest products -newsprint, pulp-wood and lumber. As we are not a large country in terms of population, our domestic capacity to consume is often small in relation to our developed capacity to produce.

Jan 1, 1963

By J. Ouellet

"ABSTRACTA brief background on in-situ testing of mine backfill, as well as pressuremeter testing is briefly described, and results from an in-situ testing on paste backfill are presented. A series of self-boring pressuremeter tests were done from the top of a backfilled stope in an underground mine. The tests were conducted along a 20-metre vertical line in the centre of the stope. Some 14 tests were performed along this depth. The instrument used was a Camkometer built by Cam Insitu, Cambridge. The instrument proved to be efficient and reliable for underground testing in a cemented paste backfill. The testing program was conducted within the planned schedule with a high success rate. The test done in this study permitted the measurement of paste backfill strength, stiffness and in-situ horizontal stress within the backfill. RésuméUn bref historique des essais in situ dans le remblai minier est présenté. L’essai pressiométrique est décrit succinctement et des résultats d’une campagne d’essai dans un remblai en pâte sont présentés. Un programme d’essais au pressiomètre auto-foreur a été réalisé à partir du sommet d’un chantier remblayé sous terre. Les essais ont été réalisés le long d’un ligne vertical d’environ 20 mètres pour un total de 14 mesures. Le Camkometer de la firme Cam Insitu de Cambridge a été utilisé. Cet instrument s’est avéré efficace et fiable pour tester le remblai en pâte cimenté sous terre. Le programme d’essai s’est déroulé à l’intérieur de l’échéancier prévu avec un taux de réussite élevé. Ces essais ont permis de déterminer la résistance, la rigidité de ce remblai ainsi que les pressions in-situ prévalant dans le remblai."

Jan 1, 2000

By T. G. Ewart

INTRODUCTION FOR THE purpose of this paper, western bituminous coal is defined as steam coal produced in Alberta and southeastern British Columbia for sale primarily to railways and industries. Before examining present and future markets of this industry, it is proper to review briefly financial and operating conditions within the industry. The report of the Royal Commission on Coal, 1946, supplies financial data from which some conclusions may be drawn. In 1944, the industry as defined above had share capital of $24,886,696. In the fifteen years 1930 to 1944, inclusive, the industry produced: 44,364,211 tons of coal. The profit on this tonnage amounted to $4,678,382.58, which represented 10.6 cents per ton of production. Miscellaneous earnings increased the amount available for dividends to shareholders to a total of $8,487,952.41, which is equal to, 19.1 cents per ton of production. Dividends actually paid in this fifteen-year period amounted to $12,332,040.64, which represented an annual average rate of 3.40 per cent on share capital. It is worthy of note that, in 1944, the net current position of the industry, including investments, was $8,753,874.51. The writer believes that the financial position of the industry with respect to capital, current financial position, and net earnings, has not significantly changed from the fifteen-year period out-lined above. The figures quoted indicate the following situation: (1) The western bituminous coal industry is adequately financed. (2) The industry has followed a conservative dividend policy and has accrued funds for contingencies. (3) The industry has sold its production at very reasonable prices as evidenced by its moderate earnings per ton of production.

Jan 1, 1951

By A. H. A. Robinson

Until quite recently-practically up to the present time-all but an insignificant amount of the copper produced in Canada was shipped abroad in the form of ore, matte, blister, etc., there to undergo the further treatment necessary to bring it to the refined state in which it is required by fabricators of copper. Consequently, Canadian manufacturers were forced to import nearly all the copper required in their business; and a considerable portion of the ultimate value to be derived from a Canadian raw material was lost to the country of its origin. In the early days of Canadian copper mining, when both the production and consumption of copper in Canada were much smaller than now, such a condition of affairs was perhaps economically unavoidable, and, in any case, was not a matte~ of sufficient importance to attract general attention. Later on, however, when there had been large and rapid increases both in the production and consumption of copper in Canada, it formed the basis of much adverse criticism, deserved or not, of producers of Canadian copper-criticism that became intensified during the war and subsequent years. Happily, the chief grounds of complaint have now been removed, and there are today copper refineries in Canada, either operating or under construction, that are capable, in the aggregate, of turning out amounts of refined copper greatly in excess of any indicated Canadian consumption.

Jan 1, 1931

By Joseph J. Larry

In hard siliceous sandstone strata overlying coal seams, roof bolting is often the bottleneck in the coal production cycle. In the past, these strata have been drilled by pneumatically operated stopers. Although slow drilling is cumbersome and uncomfortably noisy, the stoper was the most effective drill in these harder strata. However, because of the (U.S.) Coal Mining Safety Act, which limits noise levels for operating drills, FMC Mining Equipment developed the water-through-the-drill-steel method of drilling high-compressive-strength strata. Although water-through-the-drill steel had been developed earlier, the real impact of wet drilling techniques surfaced when the dual-boom roof drilling machines were installed at the Virginia-Pocahontas Division, Keen Mountain, Virginia, in 1974. This paper covers some of the technical details of the water-through- the-drill-steel design and its application.

Jan 1, 1979

By H. J. Ni, M. Y. Huang, S. W. Chen

The effects of several fluxes on purification, microstructures and properties of A00 aluminium have been studied. The experimental results and analyses indicate that many cracks and large porosities exist in the surface film above the melt purified by C2Cl6 and that the film is floe and mostly composed of AhO3 and pure aluminum, which carries many carbon particles and AlCh not fully volatilized. And then over 50% of the all-melting residue is pure aluminum, which is one of the major reasons for high melting loss. Moreover, because of a mass of gas bubbles and a state of seethe, there exist many inclusions which size is under l0µm in the microstructure of A00 aluminum purified with C2Cl6 or fluxes containing C2Cl6- With this purifying method, the aluminum crystal grains are extended along the radius that was observed firstly and the average crystal size of A00 aluminum are about 100µm~150µm. In addition, small size inclusions have little affected on tensile strength and micro inclusions under l0µm have little affected on elongation.

Jan 1, 2006