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By C. Juers

Laboratory chromate coating was applied on AM50 and AZ91D alloys and compared to phosphate-permanganate one. Evaluation of the corrosion behaviour was performed using electrochemical DC and AC methods in ASTM water D1384-87. This electrolyte was chosen because it was moderately aggressive and found to give generally good correlations with long period exposure results in atmospheric conditions. Electrochemical impedance spectroscopy was used to determine more accurately the corrosion rates from the analyses of the high frequency capacitive loop. Anodic polarization was applied in order to evaluate the pitting resistance of the different coatings. These results were correlated with weight loss data evaluated from experiments performed by immersion tests in ASTM water D1384-87 and climatic cyclic chamber tests.

Jan 1, 2006

The Anglo Platinum Mogalakwena North concentrator was one of the first three hard rock mineral processing applications to utilise a HPGR circuit in preference to a SAG milling circuit. This was driven by the extreme competence of the ore that had given rise to throughput issues on the original South Plant. Despite more than adequate capacity and performance of the individual comminution units, the circuit has struggled to obtain full design capacity. A thorough review of the integrated performance of the circuit revealed a wide range of bottlenecks and underutilised parts of the circuit arising from design issues. Interestingly, the major opportunities lie in materials handling issues and mismatch of loads about the circuit. This paper presents the high-level outcomes and the associated opportunities, and is pertinent to all HPGR circuit designs.

Jan 1, 2012

By S. B. Mishra

Ni-20Cr metallic coating was deposited on a Ni-based Superalloy (3Fe-19.5Cr¬0.3Ti-Balance Ni) by a shrouded plasma spray process; NiCrA1Y was used as a bond coat. Erosion studies were conducted on uncoated and plasma-spray coated superalloy specimens using an air-jet erosion test rig at a velocity of 40 m/s and impingement angles of 30° and 90°. The coating has been characterized for porosity, microhardness and microstructure and X-Ray Diffraction (XRD). An electron probe micro analyzer (EPMA) was used to obtain X-ray elemental mappings of the coating along the cross-section. Scanning electron microscope (SEM) with EDAX attachment was used to analyze the eroded surfaces.

Jan 1, 2005

By D. S. Speakman

The copper-zinc orebody at Sherritt Gordon's Ruttan Mine occurs in a structurally complex area of the Rusty Lake greenstone belt in northern Manitoba. Problems in interpreting drill results indicated a large deviation, and the structural complexity an erratic deviation, of drill holes. This was confirmed when a surface hole was intersected 420 feet to the left of line on the 800 level. This problem acted as a catalyst in promoting a search for a suitable down-hole survey method. The instruments investigated included magnetic multishot and gyroscopic units as well as the ABEM Reflex-Fotobor. Only the Fotobor came close to meeting the company's needs of simplicity, reliability, accuracy and ownership. In this paper, the methods of operating this instrument, as well as the data extraction and reduction techniques, are described. Data on the accuracy and repeatability of the instrument are presented, and a tabular presentation of the results of surveying on 86 holes totalling 64,000 feet of drilling is made. Preliminary statements of the results of ongoing research on causes of hole deviation are presented and recommendations for minimizing deviation are given. The use of the survey device is recommended in areas of structural complexity, for very steep or backsight holes and where expected ore intersections are missing.

Jan 1, 1978

By E. G. Gaylord

THE material improvements which have been made in the practice of exploiting oil and gas reservoirs in the United States during recent years may be attributed largely to: (1) The necessity for drilling deeper wells at costs not much greater than was formerly expended on shallower wells. (2) The necessity for producing oil at a lower cost per barrel. (3) A growing recognition of the importance of the nature of production practice upon ultimate yield of oil and gas. The first two of these factors result, to a large extent, from the fact that a greater proportion of new development has been deeper development, and these wells have been drilled in the face of progressively lower per well allowables. In California, for instance, maximum allowables have declined from 400 barrels per day in March, 1938, to 156 barrels per day in September, 1940, and during this same period some 125 wells were drilled to the deeper 10,000-foot producing horizons discovered during this time. The third item listed above results from our increasing knowledge of the basic factors which influence the amount of recovery we may expect from reservoirs. In addition to the longer-range planning now being undertaken by the more prudent operators, State proration and conservation laws have focused attention upon the importance of methods conducive to obtaining progressively greater quantities of the hydrocarbons in place. In a paper of this length it will be possible to discuss only a few of the recent advances. An effort has been made to select the more important of these and to indicate, where possible, the factors which have made these advances possible.

Jan 1, 1941

By R. Blosser

Phelps Dodge introduced a process improvement model known as Quest for Zero in 2001. In 2004, the focus of Quest for Zero shifted from corporate-led initiatives to projects led by site personnel. The Hydrometallurgical Division at Morenci focused on two (2) significant process improvements: reducing electrolyte bleed and organic losses. In September 2004, Morenci kicked off a bleed reduction project to reduce electrolyte bleed by 45%. By the end 2005, electrolyte bleed was reduced by 55% through understanding and reduction of variance. Significant process changes made during this time period include changes in acid-addition strategy, reduction of uncontrolled bleed, and optimization of bleed placement. In April 2005, the organic reduction project began with the goal of reducing losses by 15%. Operational improvements during this project included improved organic recovery systems, mixer speed optimization, and picket fence installation. By the end 2005, this project reduced organic losses by 35% and current losses are 48% lower than at the start of the project. These projects and smaller Questfor Zero projects have resulted in sustainable annualized savings of $13 million in Morenci hydrometallurgical operations. Through the use of Six Sigma tools, process variances can be controlled and reduced.

Jan 1, 2007

By Walter Koellner

Today?s large electric mining shovels are significant users of power and represent peak loads of more than 3.5 MW to a mine?s distribution system. The power swings during normal operation can influence the line voltage at the Point of Common Coupling (PCC). The static converters for the shovel?s motions also create voltage and current harmonics which are fed back into the mine?s power grid. In addition, shovels themselves are affected by the power quality of the mine?s distribution system. This paper introduces the use of active IGBT rectifiers, also called Active Front Ends (AFE), as alternative to conventional, line commutated SCR thyristor rectifiers. The AFEs convert the AC line input into a controlled DC-link voltage. This DC voltage is then used as input to IGBT inverters, which power the AC motors of the shovel?s Hoist, Propel, Crowd, and Swing motions. The introduction of AFEs creates the following operational improvements: i) reduction of the Harmonic Current Distortion THDi from more than 40% to less than 4%; ii) full regenerative operation; iii) the potential for line voltage stabilization at the PCC; iv) high tolerance for line voltage fluctuations; v) improved dynamic performance, and, as result vi) higher availability and productivity of the shovel.

May 1, 2001

By L. Gonzalez-Sardi, W. McCombe, M. Pearson

Pressure oxidation is increasingly being used for processing refractory sulphide ores and concentrates because it offers highly effective base metal and precious metal extraction while minimizing elemental sulphur, arsenic & mercury emissions. Yet pressure oxidation processes introduce new safety concerns and process risks as demonstrated by a number of safety incidents over the last 20 years, including overfilling, oxygen-metal fires, nozzle/sparger failures, and uncontrolled pressure relief events. Chemical Process Safety regulations in the United States and Canada mandate that companies constructing or operating chemical process facilities perform a rigorous hazard and risk analysis based on either ANSI/ISA-84.00.01 or IEC 61511 safety standards to determine the level of protection required for each hazard in the plant. This paper describes the application and implementation of three (3) unique safety instrumented systems developed by Hatch for ensuring the safe operation of three different pressure oxidation processes.

Jan 1, 2014

By C. M. Diaz, S. W. Marcuson

In the late 19th century, the discovery of rich nickel-copper sulfide ore bodies in Sudbury and the need for tonnage quantities of the metal to be used in nickel steel armor provided the foundation for establishing the Canadian nickel industry. For almost 50 years, International Nickel was the key player. In 1930, Falconbridge Nickel entered the field. These two companies remain the key Canadian nickel producers. This paper discusses the factors that have influenced the evolution of nickel smelting processes. The initial Sudbury ore smelting and nickel copper separation technologies were imported from abroad. It was only in 1937 that International Nickel established a process research laboratory in Copper Cliff The explosive post WW II industrial development created a strong demand for a broader variety of nickel products. For both International Nickel and Falconbridge, R&D became an essential business tool to succeed in the new market scenery. In the last few decades, new technologies were developed and commercialized to respond to the raising cost of energy, society pressing environmental concerns, the advent of nickel laterites as an important source of new metal, the incorporation of new nickel producers to the market, and, therefore, the need to increase productivity. Canada thus became an important exporter of technology. In this paper, the authors review this history with the objective of highlighting the forces that have triggered the most important changes in Canadian nickel smelting.

Jan 1, 2005

By David C. Cook

The milling complex, situated just east of the Cassiar townsite, receives raw ore from the tramline and processes it into 105,000 tons per year of milled asbestos fibre. The ore is passed through a concentrator, where a barren rock fraction is removed. The concentrated ore, representing 70% of the feed, is dried, stored and then milled into nine separate fibre classifications. The finished product is packaged into 100-lb bags and loaded into trucks in one-ton units. New air-handling facilities were added in 1977to provide additional air for environmental control.

Jan 1, 1978

By E. Ghali, B. Arsenault

Aluminum alloys play an important role in the manufacturing of air and ground vehicles. However, with such alloys, corrosion damage is often found on structural components subjected to fatigue loading. The alloying provides large benefit in terms of the high specific tensile strength (ultimate strength/density ratio) to the aluminum alloy but causes the aluminum alloy to be more sensitive to localized corrosion due to complex microscopic heterogeneities such as secondary phases. This paper investigates thermal spray coating namely arc spraying to evaluate the protection against environmentally assisted cracking (EAC) and localized corrosion on Aircraft structural 7075 T651 aluminum alloys. In particular, EAC and pitting corrosion at the interface coating-substrate are a challenge for thermal spray protective coatings on aluminum alloys under cyclic load and immersion. To address these issues, different surface preparation techniques prior to arc spraying were considered such as chemical de-oxidation, laser ablation, shot peening and grit blasting. Results indicate that surface preparation and improved coating process parameters play an important role to provide a coating conferring a protection against both localized corrosion and EAC.

Jan 1, 2006

By J. Jerome MacDonald, Stephen B. Flewelling

"In the base metals industry of today, operations required to continuously improve productivity and reduce unit production costs. Consistent with these goals is the improvement of the muck haulage cycle from open stopes with the No. 12 Mine.Existing haulage from open stopes occurs with LHD units experience at Brunswick indicates that LHD units have a higher unit cost per tonne mucked than loader-truck combinations when the haulage exceeds approximately 150 m.The reintroduction of open stoping at Brunswick made existing loader-truck combinations unsuitable. It was recognized that application of recent continuous loading technology could potentially result in significant unit cost savings and productivity increases.A review of the technology resulted in the testing of the Voest Alpine AL60 loader in the open stopes located on the 1000m Le vel. Testing began in January 1988 and finished in late November 1988. The test will provide experience as well as quantified production and maintenenace parameters f or the purpose of quantifying production unit costs and system productivity, ultimately resulting in a decision to further utilize or not utilize the loader as a primarymucking unit at Brunswick .INTRODUCTIONBrunswick Mining and Smelting Corporation Ltd. produces approximately 10500 tonnes per day from the No. 12Mine located 35 km southwest of Bathurst, New Brunswick Mining is the largest (single mine) producer of zinc in the world having mined over 52 million tonnes since 1964. Many years of production still remain with proven and probable reserves in excess of 90 million tonnes. Reserves grade at an average of 3.65% Pb. 8.99070 Zn, 99g/mt Ag and 0.32% Cu . The operation employs 1446 people with approximately 800underground including operations and maintenance staff.In the No. 12 Mine two major mining methods are presently utilized . The primary method is Mechanized Cut and Fill (MCF) accounting for approximately 6500 tonnes per day from four major areas. The remaining 4000 tonnes per day is produced from open stopes with the majority of 2800 tonnes per day being produced by the 1000 level.The 1000Level contains 30 million tonnes segmented into open stope blocks 30 m high, 15m and 30 m on strike , with a transverse width of 10m to 50 m (Fig. I). Stopes are organized on a primary secondary stope arrangement along strike. Primary stopes are undercut and overcut full size with the back fully cablebolted. All stope and lateral development is driven 4.0 m high. All stopes to date are flat bottom (Fig. 2). Primary stopes are filled with cemented rock- fill , secondaries with conventional rockfill, Haulage from the stopes is primarily with 8-yard LHD units ; mucking is approximately 50% conventional and 50% remote. Haul distance to date has averaged approximately 150m with current stope haul distances of approximately 300m. Haulage is presently to a small jaw crusher situated on the 1000 Level. From August 1989on, haulage will be to a set of ore passes feeding to a large gyratory crusher situated on the 1200 Level. Start up of the gyratory crusher corresponds to an increase in tonnage from 1000 Level to 4100 tonnes per day."

Jan 1, 1989

By Unknown

We are indebted to the Consolidated Mining and Smelting Company of Canada Limited for the several pictures in this issue showing the progress made in new construction at Tadanac and at Bonnington Falls, B.C. Plate No. 1 shows the down-stream side of the No. 1 hydro-electric station of the West Kootenay Power and Light Co. Limited at Bonnington Falls, on the Kootenay river, at which 17,500 k.v.a. will be developed to meet the requirements of the enlarged zinc and lead refineries at Tadanac. The generators, exciters and switch apparatus were supplied by the Canadian General Electric Company and the step-up transformers by the Canadian Westinghouse Company Limited. The plant throughout was designed, manufactured and erected by Canadians. Plate No. 2 shows the casting room of the new lead-plant and plate No. 3 the new tank-room of the electrolytic lead refinery at Tadanac. These additions will increase the capacity of the lead refinery by some 150 tons daily. The extensions also include practically doubling the zinc plant, and the gold and silver refineries. With the exception of the new stack, all designing construction and installation of the various plants is being done by the Company's own employees at Tadanac. Plate No. 4 shows the progress made in the construction of the new reinforced concrete stack at Tadanac. This stack, of 21 feet inside diameter at the top, will be brick lined and when completed will rise 400 feet above its foundations: the tallest of its kind in the world. The construction is in charge of the Rust Engineering Company of Pittsburgh, Pa. Plate No. 5 is a panorama of the Tadanac smelters and refineries. The photograph was taken from the roof of the lead smelter and gives an excellent idea of the size of the plant and its surroundings. Tadanac produces electrolytic lead, zinc and copper and fine gold and silver. During 1924 the company treated 1,333,523 tons of ore and produced: 161,400,- 769 pounds of lead; 92,197,824 pounds of zinc; l,382,750pounds of copper; 4,074,044 ounces of silver, and 26,976 ounces of gold.

Jan 1, 1925

By Paul R. Terry

This paper presents a brief picture of the quality of coal produced in Eastern Canada for use in thermal generating stations. It describes, in particular, the characteristics of coals burned in six power plants -two in New Brunswick and four in Nova Scotia. Each station is dis-cussed in turn, and comments are made on the coals used therein with regards to origin and physical and chemical properties affecting station operation. A table of coal data shows, at a glance, the wide variation in the quality of coals received by these stations from producers in New Brunswick and Nova Scotia. "The promotion of improved coal quality for thermal generation can benefit our national economy." T HIS is the opening statement in a paper which was presented by Mr. D. A. Pirttinen at the Coal Division's Toronto meeting in April, 1960. In bringing the power engineer's viewpoint to the coal producers' attention, Mr. Pirttinen made a survey of utility steam plants operating in Canada, and the results of this survey formed the basis for his paper, which he titled: "Generating Station Coal Quality.

Jan 1, 1965

By Smortchevskyk N. J.

THIS paper describes the electrical features of the locomotive now (August, 1962) under construction for Craigmont Mines. Intended for non-specialists, it avoids details of design and calculations interesting to electricians only. The paper is divided into three sections. The first deals very briefly with the mine layout and with operating conditions -existing and expected. Reference is made to economic considerations leading to the selection of the type and size of locomotive, as well as to traction diagrams and the calculations. This material is not included in the paper because of its length and because it does not represent anything new. The second section deals with engineering and economic considerations and shows, in some detail, why the A.C. system was chosen. The third section describes the basic components of the locomotive, including the voltage regulator, the rectifiers, the control arrangement and the filter, and deals with considerations affecting the selection of their rating and design. A concluding sub-section describes, very briefly, the track and trolley details and the power distribution switchgear.

Jan 1, 1963

By G. M. Hughes, R. W. Dunn

"AbstractCurrently installed an analogue instrumentation devices at Sherritt 's Ruttan Concentrator control. and/ or measure mill tonnages, grind, pH, density , some reagent and slurry flows, and cell levels. On-stream analysis is used to assay the main process streams. The history of development of process control is reviewed from startup to the present stage of selection of a process control computer. A pragmatic approach has been taken to process control to ensure compatibility with the needs and resources of Ruttan. Emphasis is made of the need to have the mill performing well from a mechanical and instrumentation point of view and to have opera tor acceptance of the computer through training. Plans for the computer phase to achieve these objectives are outlined.IntroductionTHE COPPER-ZINC OREBODY at Ruttan Lake was discovered by Sherritt exploration personnel in 1969 and by mid-1973 a 10,000-tpd mine and concentrator were in operation. After a typical startup period , the major mechanical problems in the crusher and concentrator have been resolved. Metallurgical performance is now up to standards forecast in the feasibility study.The cost of the original instrumentation installations, including an on- stream analyzer, was about one million dollars or 4% of the cost of the milling complex. Although there was no intention of using a process control computer until the plant was operating smoothly, it was understood that all instrumentation was compatible with .a computer, but this did not prove to be correct. This paper cover s the development of the instrumentation loops to date and the control strategies that will eventually be implemented through a process control computer."

Jan 1, 1977

By J. S. Stewart

THE Mackenzie River Valley proper extends from Great Slave lake to the Arctic ocean (see map, Figure 1). From Fort Providence, near Great Slave lake, to Aklavik, near the Arctic coast, the distance by river is 1,000 miles. This will give some idea of the extent of the region. Throughout the length of the river valley, the Precambrian complex rocks are overlain by unaltered sedimentary rocks several thousand feet in thickness. These sediments are dominantly marine and Palaeozoic in age. In places, the Palaeozoic strata are overlain unconformable by Cretaceous an Tertiary sediments. The strata have been folded and, in general, the inclination of the beds to the horizontal is comparatively gentle. Here, then, we have the essentials for potential oil fields covering an area over 1,000 miles in length. This is probably the largest comparatively unexplored potential petroleum region in North America, and surface evidences of oil in the form of seepages occur in several places. Many of these seeps were known to the early explorers, and the first Geological Survey report on the Mackenzie River region, containing the results of field work carried out by R. G. McConnell in 1887-88, noted the petroliferous character of the Devonian strata and the indications of petroleum(l). This region is, however, handicapped by distance from markets and sources of supply of materials; by lack of modern transport facilities; by short season for river transport, and mountainous country separating the valley from the Pacific seaboard; and by the long winter season with weather that makes outdoor work difficult. These factors have tended to discourage the enthusiasm of would-be promoters, and so development in this region has been slow In 1920, a test well drilled about fifty miles northwest of Fort Norman discovered oil in commercial quantity, and three additional wells proved a small area to be productive.

Jan 1, 1944

By Gwenaële Petit, Ulan Massimkhanov, Gilles Joubert

For its Zuuvch Ovoo uranium deposit in Mongolia, Badrakh Energy (partly owned by Orano Mining) is working on the prefeasibility study for exploitation by ISR (in situ recovery). As part of this project, Orano built a 2-cell (each cell is constituted of one producer well located in the center and surrounded by six injection wells in an hexagonal pattern) and a processing pilot plant that will be used to demonstrate the operability and economic viability of an ISR process. Another main objective of this pilot trial is to demonstrate the ability of Orano’s modeling tools to predict the ore behavior under given leaching conditions. To model uranium production by ISR, Orano uses HYTEC, a reactive transport computational software, which was adapted for its existing operation in Kazakhstan (Katco) to predict uranium recovery and reagent usage based on operating conditions. In order to perform similar simulations for this new deposit, Orano engaged in a comprehensive program including ore sampling, detailed characterization, and metallurgical testwork. The mineralogical conclusions were used to prepare a simplified geochemistry for the ore, in particular carbonate and reactive clay grades, uranium mineralization and penalizing elements such as pyrite. Then, bottle roll leach tests were used to characterize dissolution kinetics for smectite clays. Eventually, column leach test results such as pH, free acid, and uranium recovery were modeled on HYTEC to improve the fit of some of the dissolution kinetic parameters. Parameters fitted using metallurgical test work results will now be used as inputs for predictive model at the pilot scale, in order to anticipate operational results and help with operating decisions for production ramp up.

Jan 1, 2020

By Eldridge Haynes

IF you ask the average American to define 'total war' he is apt to fumble for an answer. But in Britain everyone knows the answer, because Britain has mobilized its total labour force, including women. If we were to match, proportionately to our population, Britain's mobilization of labour, we should have 60,000,000 people working full time in the armed services, civilian defence, and war industries. Actually we have fewer than 35,000,000 so employed. In Britain two out of every three persons between the ages of fourteen and sixty-five are so engaged. For the first time in the history of any democracy Britain conscripts women for service in the army, navy, and air force. Two hundred thousand British women have been conscripted for the army, known as ATS, meaning Auxiliary Territorial Service. There are more women in the air force than the total personnel of the RAF at the outbreak of the war and almost all of the land base jobs of the British navy are now handled by women. In addition to cooking and office work, Britain's women soldiers and sailors are driving trucks and motorcycles, repairing motor vehicles, packing and repacking parachutes, installing, inspecting, and maintaining gun equipment and ammunition of combat planes after each raid, raising and lowering barrage balloons, forecasting weather, manning harbour craft, sending and receiving radio messages. A normal ack-ack unit is composed of 229 women and 189 men. The women man the gun height finders and predictors, give bearings, and signal to fire.

Jan 1, 1942

By A. Koster, V. Maurel, S. Dezecot, Szmytka. F.

The aim of this work is to clarify the role of microstructure heterogeneity in the initiation and growth of cracks in a lost foam cast A319 for low cycle fatigue (LCF) loading condition. Because 2D analysis fail to establish the scenario of damage events, this study is based on 3D in situ analysis using synchrotron X-ray tomography during LCF test performed at 200°C. If X-ray tomography is now an established technique to study damage development in 3D, its application for relatively high temperature cyclic tests has never been done so far. Initial 3D observations of damage show that the cracks that lead to fracture initiate near large pores and propagate into the hard particles 3D network of the eutectic regions.

Jan 1, 2015