Search Documents

By E. M. Timoshenko, A. V. Tarasov

The results of laboratory, bench-scale and semi-commercial investigations of a method for adding surfactant (technical-grade lignosulphonate) to the process of pressure leaching of nickel-containing pyrrhotite concentrates have been discussed. Lt has been demonstrated that feeding of technical-grade lignosulphonate distributed along the length of an autoclave ensures a reduction in its requirement by a factor of 1.5 to 2 as compared with single-point feeding; it also results in a decrease by 5% in the unit requirement of metallized iron-bearing precipitator in the process of non-ferrous metals precipitation and reduces by 0.05 to 0.1% (abs.) the nickel and copper contents in the tailings of the given process. Technical solutions have been proposed for commercial introduction of the process.

Jan 1, 2004

By Edward R. Lauer

Energy conservation is an integral part of Canada's energy strategy. We must pursue conservation and energy management vigorously if we are to remain competitive in domestic and world markets, and minimize our reliance on external energy sources. Energy management in industry is discussed from three viewpoints: (l) as a means of directly improving profitability; (2) as a major factor in the supply picture; and (3) as a significant influence on Canada's balance of payments and over-all economic well-being. The Federal role in promoting a voluntary industrial energy conservation program is described.

Jan 1, 1977

By Jing Chai

The Cenozoic unconsolidated strata with the thickness of 100 to 240m in the east area of China are composed of clay, sandy clay and hardpan, etc. Numerous shafts of the coal mines in these areas have been damaged to various degrees since 1987, with the main reason for this being the subsidence of the super-thick unconsolidated strata. To prevent the continuing settlement deformation of unconsolidated strata caused by groundwater removal, long-term water injection through multiple boreholes controlled the settlement deformation of unconsolidated strata. A new type of fiber Bragg grating (FBG) sensing system was successfully used for real-time strain monitoring of the unconsolidated strata during water injection at a coal mine in China. A mathematical model for the compression settlement induced strain calculation is proposed which can assist understanding of the effect of water injection on the ground. With the increase in water injection, the unconsolidated strata compressed state was improved by the transition of the stress state from compressive to tensile stress. The wavelength change of fiber Bragg grating sensors corresponded with the trend of the water level in the same strata. Engineering practice indicates that these sensors can normally, safely and reliably survive conditions associated with hydrous unconsolidated strata. The FBG sensing can be used for continuous lifetime monitoring of the system, starting with real-time monitoring during low-pressure water injection process of multi-borehole. The results will give important guidance for water injection and mastering stratum subsidence.

Aug 1, 2013

By L. R. Plitt

A series of experiments were carried out in an effort to develop a universally applicable mathematical model of the hydrocyclone classifier. The design and operating variables studied were: cyclone diameter and height, the inlet, vortex finder and apex diameters, the feed pressure and the solids content of the feed slurry. The model consists of four basic equations which express the cut size ( dso), volumetric split between overflow and underflow, volumetric throughput, and sharpness of separation in terms of the operating and design variables. Although empirical, the model is nevertheless in general agreement with fundamentally derived models. The model clearly 1•eveals the effect of the major variables on the operation of a hydrocyclone. Because of its broad data base and the inclusion of all the major variables, the model may be used without experimental data to predict the operation of cyclones over a wide range of different operating conditions. With operating data, the equations may be modified to serve as an operational model.

Jan 1, 1976

By G. M. Brownell

THE Falcon Lake stock is a small igneous mass, 2.6 square miles in area, which has intruded a belt of older lavas and metamorphosed sediments. It is well exposed and the entire area of its outcrop is taken up with surveyed mining claims, the claim lines forming a grid which makes ideal conditions for a detailed petrographical study of the unusual variations which are found in the composition of this unit (see Figure 1). The study of this mass, which has revealed features of both scientific and economic significance, began in the summer of 1939 when trainees in a Prospectors' Training Camp, a Do-minion-Provincial youth-training project under the writer's supervision, were, detailed to map rock outcrops on various mining claims. Microscopic study of rock specimens taken on a line across this stock were made during the following winter and proved to be of such interest that a special trip was made the following summer for the purpose of gathering more data, the results of which are presented here. Location The stock is close to the southeast corner of the province of Manitoba, about three miles from the Ontario boundary. It lies between Falcon and West Hawk lakes and less than a mile south of the Trans-Canada highway. It is easily accessible by motor car, as a branch road from the highway leads to the Sunbeam Kirkland gold mine, which is within the inner core of the stock. Previous Work This area was the first in the Province to receive attention from prospectors, who entered it from the adjacent Lake of the Woods district during the days of the mining boom in the 1890's. Small occurrences of gold, copper, molybdenum, and tungsten ores were found, but to date there has been no production from the district, except for small shipments of gold ore. The regional geology has been mapped by the Manitoba Department of Mines and Natural Resources, the Falcon Lake stock being shown and recorded as of "varying composition". The more detailed work involved in preparing the accompanying map has necessitated only minor changes in the outline as previously mapped.

Jan 1, 1941

Who is CIBC? ? Canadian Imperial Bank of Commerce (?CIBC?) is a leading North American financial institution. ? Total Assets: US$315 billion ? Market Capitalization: US$29 billion ? CIBC comprises three strategic business lines: ? CIBC Retail Bank ? CIBC Wealth Management ? CIBC Wholesale Bank ? CIBC Wholesale Bank is a leading North American investment bank with niche capabilities in Asia, Australia & Europe. ? 1,000 + employees around the world ? Product range includes: Mergers & Acquisitions advisory and financing, Equity and Debt issues, Merchant Banking and Strategic Lending ? CIBC is ranked as the #1 investment bank in Canada across most of its key products and industries ? #1 Equity Underwriter in Canada ? #1 Mergers & Acquisitions Advisor in Canada

May 1, 2010

By L. R. Fyffe, D. R. Lentz, S. H. Mcclenaghan

"Abstract - The Eel River area in the southwestern Miramichi terrane of New Brunswick contains a complete calc-alkaline suite of volcanic rocks that are interlayered with intervals of sedimentary and polylithic fragmental rocks, and are overlain by a thick sedimentary sequence. This package, collectively referred to as the Meductic Group, was deposited in a submerged volcanic arc setting interpreted to be part of the Popelogan arc. Rifting of this arc led to the development of the Tetagouche-Exploits back-arc basin, and formation of volcanogenic massive sulfide deposits in bimodal volcanic rocks of the Bathurst Mining Camp in the northeastern Miramichi Terrane. Unlike the Bathurst Mining Camp, volcanic rocks in the southeastern Miramichi Highlands form a continuous calc-alkaline suite characterized by increasing Zr/TiO2 with increasing SiO2, in part resulting from progressive coupled assimilation and fractional crystallization of nested magma systems. Slumping of semi-consolidated volcanic and sedimentary rocks in topographically unstable areas resulted in numerous slumps and debris flows that are preserved throughout the Eel River area. In the early 1990s, the discovery of a large sulfide clast in a road cut along the Benton road sparked interest in the volcanogenic massive sulfide potential of the Eel River area. Subsequent drilling intersected smaller fragments, one clast of which graded 16.7% Zn, 5.6% Pb, 90 ppm Ag, and 220 ppb Au. The intersection of thin lenses of stratiform sulfides in another drillhole indicates favorable conditions for the preservation of massive sulfides. Their subsequent incorporation into synvolcanic debris flows resulted in the transport and deposition of sulfide clasts from hydrothermal vents to more distal locations. Similar to the Buchans deposits of Newfoundland, tracing these debris flows back to their source would be beneficial from an exploration perspective. Approximately 15 km to the southwest of the Eel River area, gold-bearing base metal sulfide clasts (11.1% Zn, 6.13% Pb, 0.19% Cu, 108 ppm Ag, and 1100 ppb Au) occur within intermediate-composition volcanic rocks at Monument Brook in eastern Maine. Sommaire - Le secteur d’Eel River dans le sud-ouest de la terrane de Miramichi au Nouveau Brunswick contient une séquence complète de roches volcaniques calco-alcalines interstratifiées avec des roches sédimentaires et fragmentaires polylithologiques, sous une épaisse couverture sédimentaire. Cet assemblage constitue le Groupe de Meductic, et a été déposé dans un environnement d’arc insulaire interprété comme une partie de l’arc de Popelogan. Le rifting de cet arc à mené au développement du bassin d’arrière-arc de Tetagouche-Exploits, et à la formation de gisements de sulfures massifs volcanogènes dans les roches volcaniques bimodales du Camp Minier de Bathurst dans le nord-est de la terrane de Miramichi. Contrairement au Camp Minier de Bathurst, les roches volcaniques des hautes terres du sud-est de Miramichi constituent une suite calco-alcaline continue caractérisée par un accroissement du rapport Zr/TiO2 à des valeurs croissantes de SiO2, résultant en partie de l’assimilation progressive et de la cristallisation fractionnée de systèmes magmatiques superposés. L’effondrement de roches volcaniques et sédimentaires semi-consolidées dans des secteurs topographiquement instables est à l’origine des nombreux slumps et coulées de débris qui sont préservés dans le secteur d’Eel River. Au début des années 1990, la découverte d’un large claste de sulfures le long de la route Benton provoqué un intérêt pour le potentiel en gisements de sulfures massifs volcanogènes dans les secteur d’Eel River. Des forages ont par la suite recoupé des fragments plus petits, dont un claste qui a retourné des teneurs de 16.7% Zn, 5.6% Pb, 90 ppm Ag et 220 ppb Au. Le recoupement de minces lentilles de sulfures stratiformes dans un autre forage indique des conditions propices à la préservation des sulfures massifs."

Jan 1, 2006

By Andrew Dobson

The assessment and control of environmental noise from mines has become increasingly important in recent years, due to urbanization and population growth, increased regulation of environmental factors, and overall awareness and sensitivities to noise exposure. Minimizing adverse effects on communities and achieving compliance with local ordinances is now commonplace, and consideration of noise during the design and/or operation of a mine cannot be ignored. Ventilation equipment can represent the loudest and most bothersome equpiment at mines, however there are complexities when attempting to control the assocaited noise, due to the acoustical nature of mine vent fans. In fact, the utilization of traditional and/or industry standard methods can intensify the noise impact, or simply not work as intended. This paper provides recommendations on specific noise control methods that are suitable for mine ventilation equipment, based on recent assessment work and field experience.

Oct 1, 2024

By Michael J. Beus

The National Institute of Occupational Safety and Health-Spokane Research Laboratory (NIOSH-SRL) have developed a Shaft Conveyance Monitoring System (SCMS). Assessment of current hoisting technology has shown that monitoring wire rope tension and conveyance position and load directly from the skip or cage top offers several significant safety, production, and maintenance advantages. The SCMS consists of conveyance position and guide displacement sensors, a battery power supply and charging system, and a new sensor to measure hoist rope tension. This device provides a warning of the occurrence of ?slack rope? a particularly dangerous condition. A 2.4 GHz radio link transmits data to the hoistroom. A reduced scale hoisting test facility has been constructed to test these components prior to field trials. The advantages of monitoring wire rope tension and conveyance position and load directly from a skip or cage top will be discussed. Field tests are underway in full-size shafts to refine the concept and evaluate long-term reliability and maintenance requirements. Application of this technology may result in decreased maintenance costs as well as safer, more productive hoisting operations.

May 1, 2001

By Stanley G. Butcher

"The methods generally applied to predict performance and financially evaluate beneficiation options are reviewed.Typical costs f or a western Canadian thermal coal operation are examined. Preparation-from truck dump to loadout-frequently amounts 10 over a quarter of total minesite costs. Failure to achieve projected yield-whether caused by mine or plant problems-s-substantially increases production costs because more coal has 10 he mined to meet a specific market demand. Problem identification by mass/ash balances is recommended.Thorough characterization of the coal and associated waste materials and more reliable prediction of beneficiation process performance are therefore essential to determine a project 's financial viability.IntroductionWestern Canadian coal prep a ration plant capacity is partway through a massive expansion program . In 198 1 potential product ion was 14 million tonnes, by 1985 it will be 26 million tonnes per year. Only two years ago the industry was concerned whether it could sustain this rate of growth to meet market demands : now with diminished market demand and lower coal prices being offered by our international competitors there are doubts whether t his potential will be fully employed , even by 1990.One direct consequence o f the occurrence of a variety of coals in a stunningly beautiful but complex geo logical setting such as the Rocky Mountains and their Foothills is that each project is unique. Coal is a low value per tonne product. To supply distant markets from geographically isolated deposit s necessitates expensive , dedicated , infrastructure . T o be profitable these operations must achieve eve ry advantage of the economy of scale.Each of the mi ne complexes commissioned in the 1970s experienced severe problems in the area o f co a l preparation . Most bought their way out , paying for major plant modifications by increasing the scale of their total operation . The current market recession may not allow new operations this route to profitability.The objective of this paper is to illustrate the economic impact of coal preparation problems on the profitability o f the total minesite operation and thus provide a sound basis for decision making process."

Jan 1, 1985

By S. A. Bradford

The twenty years before World War I was the Golden Age of copper smelting in British Columbia. In this short time, the smelters developed from small, primitive units to large, efficient operations. The first copper claims had been staked on Howe Sound and Knight Inlet in 1864, and there was extensive copper mining in the interior by the mid-1880s, but before 1895, all ore was shipped out of the country for smelting, converting and refining. The first interest in smelter construction was undoubtedly inspired by a Provincial bonus and Dominion land grants offered to smelter builders. The early smelters made use of small blast furnaces which were designed to smelt any kind of ore, but usually far too little ore was available. The first smelter seems to have been the McRae furnace on the Spillimacheen River (1883), followed by Vancouver (1889), Revelstoke (1891), and Golden (1891) (1). They each smelted a few tons of galena and then quickly closed down permanently for lack of ore. Only smelters that actually produced some copper matte are described in the following sections.

Jan 1, 1999

By Xiaoguang Zhao

The coal mining area in Northern Shaanxi, China, has been taken as the study area, and the damage mechanism of the ecological environment is discussed on the basis of analyzing the characteristics of natural eco-environment and resource development in this area. Mining subsidence is taken as an example, and by using the Gray Correlation Analysis method, the key impact factors have been selected. An assessment model with fuzzy comprehensive evaluation has been constructed, and 12 coal mines have been quantitatively assessed. This paper also constructs an ecosystem health assessment method and index system in the coal mine area on the basis of ecosystem health theory, and assesses the ecosystem health status in the Shenfu coal mining area from 2000?2006. The research results are expected to help the eco-environment protection process in the designated coal mining area.

Aug 1, 2013

By K. Sakai, M. Miyaue, T. Aoki, T. Tani, S. Tanaka, N. Kudo

In the planning stage of a tunnel, due to limited available technology in the geological survey and the financial restriction, tunnel supports are often designed from unsatisfactory information, and the tunnel construction is started. Therefore, "observational construction" is carried out in the construction stage, in which the design is rationally verified and modified by observations/measurements. Moreover, the ground conditions ahead of a tunnel face must be predicted for efficient and safe tunnel construction. The authors have examined effective prediction methods to the ground conditions ahead of a tunnel face under construction of a mountain tunnel (Aoki et al., 2010) in view of the established method (Schubert et al., 1995). Though the prediction method of Schubert et al. requires the displacement in the direction of tunnel axis, it is difficult to obtain its accurate data by the electro-optical distance meter. Then, we have proposed a method that uses tilt sensors installed at the tunnel crown near the face to obtain the slight tilting information. To measure inclination of the tunnel crown, this inclinometer was originally developed as a daily management measurement, such that the geological condition and its possible change behind the face could be detected early, and a steady advance and construction safety could be ensured. This paper describes the method of forward prediction mechanism and advantages of this proposed method. It then presents the typical results of a field demonstration test at a tunnel under construction. Lastly, the predictable range from the stratum boundary at which ground stiffness changes are discussed based on the results of three-dimensional numerical analysis.

Jan 1, 2015

By Y. Chengxian

Many factors about the HIC (hydrogen-induced cracking) resistance of pipelines are discussed in this paper. The main factors that influence the ability of HIC are environmental and material factors. The chemical compositions, non-metal inclusions and microstructure are discussed in detail, while a group of tests on HIC resistance are done according to varying C, S, Mn and P contents in pipeline steels, different experiment time and different strength to the coupon. It is concluded that decreasing the amount of C and S can obtain good HIC resistance; the test time has an effect on the different microstructure of X70; microstructure is the most sensitive factor for the initiation processes of HIC.

Jan 1, 2005

By Fan Delian, Ye Jie, Lui Tiebing

The lower and the upper parts of the Doushantuo Fonnation, Hubei Province, China, contain silicate-type K-rich beds (illite and feldspar), and intraclastic phosphorites, as well as Ag-V and V deposits in a "Black Shale Series". The K-rich beds fonned in an anoxic basin whereas the phosphorites fonned in a more oxic and higher energy depositional environment. The Black Shale Series occurs in the lower and upper parts of the Doushantuo Fonnation; that in the upper part consists of black illite shale and dark gray dolostone, and contains Se-rich Ag and V deposits. These deposits are of more industrial significance than the previously discovered Ni-Mo polyelement sulfide deposits which occur in the Lower Cambrian Black Shales Series of South China. Studies of lithotype, sedimentary sequence, and geochemistry of the Doushantuo Fonnation have led to more attention being focused on the uppennost Black Shale Series and its Ag-V and V deposits. There are three ore types: black, Ag-V-rich, illite shale; black, V-rich, illite shale; and dark gray, Ag-Vrich, fmely crystalline dolostone. The first two ore types contain 3070 to 5% Corg and the last, 1.25%. The Ag-bearing minerals are naumannite, argyrodite, aguilarite, acanthite, and native silver that occur as inclusions in pyrite associated with barite. Vanadium substitutes for AI in illite and is also related to organic-matter contents. Because (1) the pre-Sinian Kongling Group contains one to three times greater than the Clark Ag value; (2) black, illite shale has a negative Ce anomaly; and (3) there are large occurrences of black, K-rich, tuffaceous, fme siltstone, the sources of Ag are thought to include subaerial and submarine volcanic materials. It is proposed that Ag, V, and Se were absorbed by clay particles and organic matter during syngenetic deposition in an anoxic environment; Ag subsequently was reconcentrated into sulfides and selenides, whereas V was incorporated structurally into illite during early and late diagenesis. These types of Black Shale Series-hosted Ag-V and V deposits are, therefore, considered to be sedimentary-diagenetic in origin.

Jan 1, 1992

By M. Lahtinen

Traditionally, there have been three main methods for iron removal in the hydrometallurgical production of zinc. These methods are atmospheric precipitation of jarosite or goethite and pressurised precipitation of hematite. Jarosite precipitation is without doubt the leading and the most commonly used technology for iron removal. However, jarosite precipitation has some drawbacks, such as a low iron content (and, thus, high residue volume), high moisture content after filtration and often a high zinc content. These features make any environmentally acceptable way of using or disposing of jarosite more expensive, as compared to hematite and goethite. The importance of environmental regulations has grown in the zinc industry during the last decade, which will have an increasing effect on new investments. Hematite has several advantages over jarosite, such as a high iron content, low moisture and low zinc content. An important advantage of hematite is that it is suited for further use in the cement industry. However, until now the need for autoclave equipment has limited the spread and implementation of hematite precipitation in the zinc industry. Outokumpu Technology Oy has recently developed an alternative method for iron removal, which is the atmospheric precipitation of hematite. A patented method for precipitating hematite at atmospheric pressure is presented and compared with conventional methods for iron removal. The process conditions, the quality of the hematite precipitate and the environmental aspects are also discussed.

Jan 1, 2006

By Michael T. G. Brown

Syncrude Canada Ltd. has recently completed construction of its ambitious tar-sand mining and processing facilities at Mildred Lake, Alberta. The Syncrude site is approximately 48 km (30 miles) north of Fort McMurray near the west shore of the Athabasca River. The Syncrude operation involves the open-pit mining of approximately 270,000 tonnes (300,000 tons) of tar sand daily using draglines and a conveyor system. Bitumen is extracted from the tar sand, upgraded to oil-gas and transported to refineries in Edmonton and other locations for final processing . The Beaver Creek Dam forms part of the mining facilities for the Syncrude tar-sand mining operation. Water from Beaver Creek is diverted from the open-pit mine site south to the Athabasca River via Ruth Lake and the Poplar Creek Dam. General site layout is shown on Figure I . Design of the dam was completed by R. M. Hardy and Associates Ltd. of Edmonton, Alberta (now Hardy Associates (1978) Ltd) . Construction was undertaken during the summers of 1974 and 1975 under the direction of Canadian Bechtel Limited, managing contractors for Syncrude Canada Ltd. Total length of the dam is approximately 2.8 km (1.7 miles), with a maximum height in the order of 16 m (50 ft) The Beaver Creek Dam is located in a broad, flat, poorly drained valley. About 50 per cent of the site is covered with treeless peat deposits, which ranged in thickness from in excess of 5 m (15 ft) at the east end of the dam to less than 1 m (3 ft) at the central portion. The peat deposits overlie Pleistocene meltwater sediments on top of clay/clay shales of the Clearwater Formation and the tar sands of the McMurray Formation. The peat deposits and high groundwater levels at the site combine to make the excavation and construction of a conventional rolled clay cutoff impractical. For these reasons, the slurry cutoff trench technique was utilized to produce an efficient and effective seepage cutoff under various sections of the Beaver Creek Dam .

Jan 1, 1979

By B. A. Zaharov, J. M. Shneerson, L. V. Chugaev, M. T. Zhunusov, A. M. Markelov, S. V. Drozdov

The main direction of research was the application of autoclave technology for the flotation concentrates or biooxidation feedstocks. The industry modernization also expects the possibility of increasing the yield of the flotation concentrate, to allow an increase in gold extraction in flotation circuit. This paper provides brief description of results obtained for concentrates with the yield of 4 and 8%, as well as corresponding biooxidation feedstocks. Technological efficiency of autoclave oxidation is shown for both concentrates and biooxidation feedstocks. The process has been evaluated on a laboratory and a continuous pilot plant scale. Gold extractions from POX discharge are ranging from 94-97% for each product, with only 5-7 kg/t cyanide consumed.

Jan 1, 2014

By Y. Chengxian, F. Yaorong, Xinzhe. L.

Many factors about the HIC (hydrogen-induced cracking) resistance of pipelines are discussed in this paper. The main factors that influence the ability of HIC are environmental and material factors. The chemical compositions, non-metal inclusions and microstructure are discussed in detail, while a group of tests on HIC resistance are done according to varying C, S, Mn and P contents in pipeline steels, different experiment time and different strength to the coupon. It is concluded that decreasing the amount of C and S can obtain good HIC resistance; the test time has an effect on the different microstructure of X70; microstructure is the most sensitive factor for the initiation processes of HIC.

Jan 1, 2005

By H. J. H. Pieterse

Agitation requirements in oxidation autoclaves can vary widely depending on the mineralogy of the feed material and the specific process selected. Before selecting an agitation system it is important that the client specify the desired throughput, mineralogy, chemistry, kinetics, compartments, overall retention time, and the desired oxygen utilization. In selecting the agitation system, the factors mentioned above as well as oxygen solubility, oxygen mass transfer coefficients, and specific power are evaluated. Much research effort has been directed toward open tank systems for fermentation and oxidation processes. However, for high pressure autoclave oxidation processes little information is available. In this review the author's experience in the autoclave industry and some of the available literature are utilized to compare the installed power per unit volume with some of the methods proposed for open tank oxidation. Equations that appear to give results close to that experienced in the industry have been identified. Further work is required in this area to develop a higher degree of confidence in the ability to predict the power required for any given case.

Jan 1, 2004