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By K. D. Genn, A. Mucha

This paper deals with Hilton Mines' approach to the maintenance of wear items such as truck boxes, shovel buckets, tractor pads, crawler sprocket idlers and the drop-ball. Each will be given a brief. description as to application, design, kind of materials involved and type of wear. The maintenance procedure is then outlined in terms of materials used, preliminary preparation, and welding and machining practices. The service history of new and re-paired items and the relative economics of repair vs replacement will then be presented.

Jan 1, 1969

By Kenneth Blower

This paper gives a detailed coverage of the ore flow through the primary crusher, cobbing plant and concentrator, including equipment sizes, recoveries, reagent consumptions and product descriptions. Special features, such as rubber chutes, rubber-lined mills, pebble-mill grinding, steam-hooded filters and process control instrumentation, are also discussed.

Jan 1, 1968

By L. M. Scovell

The Internet and its related technologies will radically change the way that mines manage and control their maintenance, repair, and operating supply chains. The Internet is creating new distribution channels and offers new technology platforms with significant advantages over more traditional methods. Mines will have to re-evaluate both the strategies and the tactics employed in these areas. Mines will use e-commerce to integrate their maintenance, repair, and operating supply chains. The integration will extend beyond traditional trading partners to a worldwide network of communities with similar interests and goals. The changes will transform the way mines operate, lower mining costs, and thereby increase their chances of success in an increasingly competitive environment.

Jan 1, 2000

By X. Cao, J. J. Jonas, Wanjara. P., J. Gholipour, E. Dalgaard

The linear friction welding (LFW) behaviour of near-ß titanium alloy Ti-5Al-5V-5Mo-3Cr (Ti- 5553) was investigated. Microhardness measurements were performed in order to evaluate the mechanical properties of the welded material. The linear friction welded (LFWed) Ti-5553 was examined with optical microscopy and scanning electron microscopy (SEM) to evaluate the microstructure’s response to the thermomechanical conditions. Characterization of the welds included analysis of the microstructural features of the weld region and thermomechanically affected zone (TMAZ) in relation to the parent material.

Jan 1, 2010

By L. Gutierrez, M. Pawlik

The rheology artificial mixtures of bitumen with fine quartz of varying bitumen content, as well as actual oil sand ores, was investigated under different physicochemical conditions (pH, temperature). All rheological measurements were conducted using a Haake Rotovisco VT550 rotational viscometer, connected to a fixture specifically designed to measure properties of settling suspensions. It was found that at low bitumen contents (1 %, wt.) the pH of the slurries was the most important parameter that controlled the rheology of quartz-bitumen slurries. At higher bitumen contents (10%, wt.), it was a combination of high temperature and high pH that gave the lowest apparent viscosities and yield stresses of the model mixtures. These model observations correlated well with the rheology data obtained for slurries of actual oil sand ores. The overall results were discussed in terms of aggregation-dispersion phenomena between bitumen and mineral particles.

Jan 1, 2009

By F. Vagnon, A. M. Ferrero, M. Pirulli, A. Segalini

"The topic of this study is the design of flexible fences to mitigate the risk due to debris flow phenomena by means of theoretical and experimental studies analysed in framework of the Rock Engineering System (RES).The study of the interaction between debris flows and flexible barriers is a major challenge since many different aspects concerning both the slope characteristics and the structure features are involved. Debris flows are often triggered by the mobilization of debris deposits that are generated by rock fall of adjacent rock walls. The rock debris deposits are difficult to be characterized by the physical and mechanical point of view due to their large variability in volume distribution and, moreover, when dealing with high mountains environment, they are also strongly affected by the presence of water at different phases (solid or liquid) depending on the temperature. The debris deposit turns unstable in relation with the geotechnical and environmental features of the areas and the instability evolution in high mountain steep valley is often a debris flow. Debris flow destructive potential is very high and protections are often needed to reduce the debris flow risk.This complexity determines the needs of comprehensive study able to include the global basin dynamic and the environmental conditions. An a-priori analysis of the influence of the different aspects can be useful to focus on the real driving aspects of the problem. Due to the complexity of the system the application of the RES methodology is recommended in order to clearly define the different assumptions needed, their influence on the simulations and a comparison among them.RES allows investigating triggering criteria, flow and depositional processes and interaction of flows with protection fences in a rational way. For this purpose, an interaction matrix is created: it summarizes the key geotechnical parameters that influence debris flows, their interactions and debris/engineering protection opera behaviour. The goal is to quantify the diagonal-off terms to assess the residual risk after barrier construction, using back analysis from real debris flow event and data collection from literature.This methodology is applied to analyze a debris flow event in the Italian Western Alps where numerical analyses are carried on to assess flow characteristics to be used for fence design through the application of an analytical and numerical model developed by the authors (Brighenti et al, 2013). In particular, the velocity and deposition heights have been estimated using the numerical code RASH3D (Pirulli, 2010), which is a single-phase model based on depth-averaged Saint Venant equations. Pathways of different lengths are studied to assess the input data necessary to design the protection barrier and to determine the associated risk. Simulation of the barrier at different places along the valley will also allow to determine optimal barrier location in terms of minimum residual risks by comparing the velocity, the volume and the energy of the debris after the barrier impact.The work will produce a possible design scheme to be adopted in this environment."

Jan 1, 2015

By O. Lashkari

Swirled Enthalpy Equilibration Device (SEED) is a new patented Slurry-on-Demand, SoD, processing route. The semi-solid slug preparation is carried out by off-center swirling of aluminum melt in a metallic mould. As part of the current research program on the semi¬solid processing of aluminum alloys, the morphological evolution of 356 aluminum foundry alloy microstructure is reported here. Semi-solid slugs were prepared using two different pouring temperatures of 645°C and 695°C respectively. Morphological evolution of the semi-solid microstructure was characterized using image analysis through measuring of primary a-Al particle size, number density, aspect ratio and sphericity. The possible relationships between microstructural features and process parameters were also investigated. The current report covers the effect of pouring temperature on the morphology of primary a-Al dendrites and attempts are made to explain the differences between the predicted percentage primary a-Al phase and those of the actual values in the as-cast slugs.

Jan 1, 2004

By H. Clare Horwood

"Fractures and fracture zones containing veins and stringers of auriferous quartz in a quartz porphyry dyke are the principal structural features at the Howey and Hasaga gold mines. The 'break' containing the dyke was produced by a force from the northwest, the fractures in the dyke by compressive stress from the west.Both mines are in the north-central part of Heyson township, in the Red Lake area. They lie close to the southeastern side of the Dome granite stock. The Howey mine exhausted its ore reserves and ceased operations in November 1941. The Hasaga mine is producing at the present time (June, 1946).Mineralization was first discovered in the dyke in 1925 by the Howey brothers. Lorne Howey's discovery, which became the Howey mine, came into production in April, 1930; Ray Howey's find, which is now the Hasaga mine, started production in November, 1938.The total production from the Howey mine was 421,324 oz. gold and 144,253 oz. silver from 5,158,376 tons of ore hoisted ( 4,319,331 tons milled) during its 11 years of operation.The total production from the Hasaga mine from November, 1938, to December 31, 1945, was 124,434 oz. gold and 51,009 oz. silver from a total of 901,098 tons hoisted (721,361 tons milled).GENERAL GEOLOGYThe porphyry dyke containing the orebodies at the Howey and Hasaga mines lies a short distance southeast of the contact of a granite-granodiorite mass known as the Dome stock. The dyke fills a fracture trending N.65°E. in a tongue of Keewatin volcanic breccia that extends in a rather irregular manner into an elongate intrusive stock of dioritic rock known as the Howey diorite. The accompanying table presents the geological succession."

Jan 1, 1954

By W. R. Middagh, R. M. Garvey

"Phosphate rock is shipped by boat from Florida to Vancouver, B.C., where it is unloaded and stored in a 50,000-ton silo. It is shipped from Vancouver in 100-ton hopper cars in 80-car trains to Fort Saskatchewan. Both the ship and the hopper cars are on a back-haul with potash. The rock cars are unloaded at Fort Saskatchewan at a rate of approximately 4 cars per hour. The rock is stored in three concrete silos, 40 ft in diameter by 110 ft high, which hold 18,000 tons of recoverable rock with 2,000 tons dead space. The rock is reclaimed from the silos by gravity and fed to the phosphoric acid plant by remotely operated conveying equipment.Problems encountered in the operation include scheduling the rock shipments, contamination of the rock with potash, and handling the 80-car trains both in Vancouver and Fort Saskatchewan."

Jan 1, 1968

By J. B. Mitchell

Many of the pre-production and plant startup problems that we regard as inevitable are actually caused by poor organizational methods. Traditional methods of organization can be modified to provide clear definitions of responsibility, continuity and depth of involvement of key personnel in order to overcome these problems.

Jan 1, 1966

By A. Dave Mackintosh

Historical closure data has provided a description of the stress distribution patterns occurring around mine openings and enabled the development of a time ? distance plot predicting the location of the stress peak and its migration away from mine openings with time. Data collected from active mining areas during the 1970?s and 1980?s indicated the peak appeared to stabilize approximately 135m (450 ft.) from openings after four years. The region of high load and accompanying poor ground conditions in which the peak was centred was spread over approximately 45m (150 ft.) to 60m (200 ft.). Recent data from new development headings cut adjacent to 25 year old extraction areas suggests load transfer takes place over a much greater distance and time frame than predicted.

May 1, 2001

By S. Junnikkala, K. Föhr

"Experiments were performed with plant feeds with a continuous 1,8 m3 cell at Pyhasalmi mine with Cu flotation feed in order to test the applicability of the bubble surface area flux as an indicator of the flotation rate constant. It was found that bubble surface area flux could not predict the rate constants of coarse Cu containing fractions. In the middle size fraction, the correlation coefficient in the rate coefficient estimation was higher but not statistically significant. Only the fine fraction showed a linear relationship with a moderate correlation coefficient.The bubble surface area flux was shown not to be a function of the impeller velocity above a threshold value. The flux was an almost linear function of the superficial gas rate enabling to use the superficial gas rate instead of flux if the operation of an existing cell is to be estimated.INTRODUCTIONBubble area flux seems to offer a simple way of modeling flotation. It relates the flotation rate constant with the bubble surface area flux by a simple linear equation. Due to this, there has been a considerable interest in using the bubble area flux for flotation computations. It has even caused claims that a cell producing a high bubble surface area flux automatically produces a high rate constant and therefore a high recovery.This paper discusses some of the assumptions of the relationship and gives some plant results during two sampling campaigns.The bubble surface area flux s b is describing the area of bubbles available for flotation in a cell per unit area. The bubble surface area flux is related to the superficial gas rate J, by the Sauter mean diameter as follows"

Jan 1, 2001

By F. Rashchi, N. Naseri Joda

Recycling of electronic wastes is an important subject both from an environmental point of view and also the recovery of valuable materials. In this research, PC board scraps were leached to recover Cu, Ag, Au and Pd. Due to the high cost of the shredding process and to avoid secondary pollution from odors and dusts, board scraps were cut into 5X5 cm2 pieces. To determine the most effective leachant, aqua regia, nitric acid, hydrochloric acid, ammonium persulfate and potassium persulfate were tested. The effect of the leaching parameters, the leachant concentration, temperature, leaching time and liquid to solid ratio were studied and optimized using response surface methodology.

Jan 1, 2011

By JOHN DUNFIELD

Good quality sphagnum peat bogs occur across Canada in areas of ample rainfall and cool, temperate climates. Early peat production techniques were restricted primarily to hand digging blocks of peat and piling them up to be dried by sun and wind. Suburban de velopment in the 1950s and the concomitant spread of home gardening triggered a dramatic growth in peat demand; labour costs rose in the same period. Peat production techniques had to alter accordingly. The three mechanical inno vations attempted were hydraulic mining, mechanical block digging and vacuum harvesting. Of these, the last method pro ved the most successful in Canada and is used to harvest 80% of Canadian peat production. Escalating transportation costs are the most important feature affecting future development of the Canadian peat industry.

Jan 1, 1984

By J. Costigan, C. Corless

In 1997, damage as a result of Castrol R40 entering the INCO pressure carbonyl plant carrier gas stream was becoming increasingly severe. The oil in the gas stream was adversely affecting both equipment availability and process control resulting in rising unit costs. The main source of the Castrol R40 was determined to be the carrier gas and low pressure gas blowers. Plant personnel initiated a plan to prevent the Castrol R40 from entering the carrier gas stream by replacing the mechanical shaft seals with Ferrofluidics seals on these blowers. The following paper details a brief case history of the Castrol R40 in the carrier gas including impact on the plant. This will be followed by a technical discussion of the new sealing arrangement that was developed by plant personnel, Roots Blower and Ferrofluidics. Lastly, this paper will update the status of the blower upgrade project and document the results to date.

Jan 1, 2000

By R. L. Christie

"THE ISLANDS lying north of the Canadian mainland, and the large Boothia and Melville peninsulas, form one of the great archipelagos of the world; this sparsely vegetated and nearly unpeopled region extends about 1,500 miles east to west and 1,200 miles from the mainland to the northern tip of the northern-most island. Sea access to most of the islands is restricted by ice to the summer season, and the 'polar pack' ice of the Arctic Ocean presses the year round against the northwest margin of the archipelago. Although the region is remote, the accessibility has greatly increased through a network of weather stations, airfields and air routes connecting with southern centres.The area considered in this paper is that part of the island region underlain mainly by sedimentary rocks. In broad terms, this includes the land and sea areas of the archipelago and the adjacent continental shelf, but excludes the dominantly 'Shield' terrain of Baffin Island, and of Melville and Boothia peninsulas. An impression of the size and potential of this sedimentary region may be gained by comparing some areas: the land area of islands underlain mainly by sedimentary rocks is over 300,000 square miles or about 50,000 square miles greater than the area of Alberta. The total area of the region, including the continental shelf and the inter-island areas, may be double this figure, and may approximate one-seventh of the land area of Canada."

Jan 1, 1970

By K. T. Audt

The Yayoi period, from about 300 B.C. to A.O. 300, represents a time of important changes in Japanese history. During this period the advanced rice culture of the Asian continent was introduced to Japan, along with the techniques of animal husbandry, spinning, bronze casting and metal working(1) . As was the case in the Jomon period (11000 B.C. to 300 B.C.), the Yayoi period is traditionally defined by a particular type of pottery, characterized by the use of the potter's wheel and an extreme simplicity of decoration and form(2) . Pieces of this pottery were found in 1884 in a district of Tokyo, known as Yayoi-Cho, not far from Tokyo University. Within a decade the name Yayoi had come to be used for the period which also saw the first casting of metals in Japan121. During the Yayoi period, the foundation of the ancient Japanese state was laid as the individual small communities were unified and as labour specialization and social levels developed. In fact, the Yayoi may be the true ancestral culture of Japan(3) . However, the origin of the Yayoi is not definitely known. One theory indicates that the Yayoi people may have been driven from the Asian mainland (via Korea) by the dynastic wars that accompanied the unification of China under the Ch'in and Han and that these settlers rapidly displaced the Jomon. Bronze objects and the cultivation of rice may have arrived about the same time - in the third century B.C. Iron was in Japan within another century, but since it rusts badly and disintegrates, only a few small pieces are known from such an early date(4) . After about 50 B.C., the Yayoi cultures of western Japan were in fairly close and regular contact with the continent via Korea(5)

Jan 1, 1999

By R. A. King, B. G. Hunt, C. E. T. White

"This paper reviews the history, occurrence, properties, and uses of indium, and describes the commercial production and fabrication of that metal by The Consolidated Mining and Smelting Company of Canada, Limited (Cominco), at Trail, B.C'. Indium is produced commercially at Trail from dross retreatment furnace D.R.F.) slag, a complex by-product of the lead smelting operations. Furnace feed prepared from this slag is smelted with coke and limerock in an electric furnace. The e1ectric furnace bullion is parted electrolytically, producing a market-able lead-tin alloy containing about 8 per cent tin, and leaving the indium in the anode slime. Recovery of indium from the anode slime involves roasting the slime with sulphuric acid, followed by leaching with water, purifying the leach solution, recovering the indium by sponging with zinc or aluminum, and re-fining electrolytically. This process yields standard grade (99.97+ per cent) indium which is either sold or refined •to high purity ( 99.999 per cent) indium for special uses requiring higher purity metal."

Jan 1, 1959

By J. W. Sanger

The establishment of a central steam-heating system in Winnipeg and its inauguration in October, 1924, has attracted a considerable amount of attention. Not only does it excite the curiosity of the engineer, but it has stirred financial and civic bodies throughout Canada to such a degree that there is now a much keener general interest in this particular type of public utility than has been shown heretofore. This does not mean that we may expect a mushroom growth of central-heating systems in all our larger Canadian cities in the near future, but it does mean that the pioneer work which Winnipeg is now doing will undoubtedly be used to guide others in their judgment as to the feasibility of similar projects elsewhere. The success of the municipal hydro-electric system in Winnipeg, and the low rates for electricity resulting therefrom, was without a doubt the most important factor influencing the citizens of Winnipeg to venture into this new field. The events which led up to the central steam-heating proposal in Winnipeg are interesting.

Jan 1, 1926

By Leopoldo Gutierrez, Sergio Castro, Lina M. Uribe, Janusz S. Laskowski

"The effect of sulfite and metabisulfite ions on the amyl xanthate flotation of copper-activated pyrite, in distilled water and seawater, has been studied by micro-flotation tests and redox potential measurements. The activation of pyrite was carried out varying copper ions concentration. It was found that in the presence of copper ions in solution, sulfite and metabisulfite are able to depress copper-activated pyrite at neutral or slightly acid pH. After the addition of sulfite or metabisulfite ions the resulting pH is more acidic with metabisulfite ions. A significant increase of the redox potential of the solution was observed as copper ions concentration increased. Then, the initial reducing conditions brought about by sulfite and metabisulfite ions, change abruptly to oxidizing conditions in the presence of copper ions. Under these oxidizing conditions, the metabisulfite showed to be an effective depressant for pyrite mainly in seawater. However, sulfite was a pyrite depressant in both distilled water and seawater. Based on these results, the pyrite depression by sulfoxy-depressants during the flotation of Cu/Mo ores in distilled water and seawater is discussed.INTRODUCTIONDepression of pyrite by sulfoxy-depressants (sulfite and metabisulfite) in the presence of copper ions is an important issue. This is particularly true when pyrite depression in the flotation of Cu/Mo sulfide ores is carried out in seawater. The use of lime in seawater must be avoided because the formation of magnesium hydroxy-complexes and precipitating magnesium hydroxide strongly depresses molybdenite flotation (Castro et al., 2014). In order to solve this problem, one large plant in Chile uses sodium metabisulfite (MBS) instead of lime to depress pyrite in seawater. In plant practice, this also improves molybdenite flotation since with the use of MBS the pyrite depression is carried out at pH 6-7, instead the pH 11-12 usually employed with lime.From a general point of view, pyrite exhibits some natural floatability over acidic pH ranges and may be partially floated without thiol collectors (a coating of sulfur/polysulfides has been claimed). Therefore, pyrite flotation with xanthates is usually high in the acidic pH region, but decreases greatly at alkaline pH (Leppinen, 1990; Fornasiero and Ralston, 1992; Zhang et al., 1997)."

Jan 1, 2016