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By R. Stach, S. Gola, P. Zgrzebski, K. Soroko

"At the moment climatic conditions are a primary problem of the exploitation of copper ore. The efficiency of preventive actions in order to improve climatic conditions is connected with the knowledge of changing air in underground excavations. This article demonstrates the analysis of types of ventilation dams which are used in sealing abandoned areas on the maintenance of climatic working conditions in excavations has been conducted at the exploitation in Polish copper ore mines. INTRODUCTION The basis for mining activity performed by KGHM Polska Miedz S.A. is mining copper ores from the deposit lying at depths between 600 and 1,200 m below ground level. Activity has continued since 1963. The copper ore deposit is mined in ‘Lubin’, ‘Rudna’ and ‘Polkowice-Sieroszowice’ mines, where difficult climatic conditions occur. The major factor moulding the climatic conditions in headings is the original temperature of rocks, being the result of geological conditions of the lying of the deposit and the existing geothermal degree. In the faces of present opening-out and preparatory headings, driven from mining areas of ‘Rudna’ and ‘Polkowice-Sieroszowice’ mines in order to open out deeper parts of the deposit, the original temperature of rocks reaches 45°C. Excluding the original temperature of rocks, the following are additional factors affecting the deterioration in the climatic conditions: • thermal properties of deposit rocks, • employed room-and-pillar mining systems, which are characterised by a large surface of exposure of rocks, • using self-propelled mining machines with diesel drive, • a high concentration of mining works, • setting up high-power electrical equipment in headings, • complex structures of mine ventilation networks, • a limited number of ventilating shafts, • constantly longer air-transport routes, • a significant accumulation of water increasing the humidity of supplied air. According to the valid Polish provisions (§21, 2013), the primary criterion of assessment of a climatic hazard is the occurrence at a workstation in an underground mining heading of an equivalent climate temperature of more than 26°C, which temperature is determined according to the following dependence:"

Jan 1, 2019

By J. Zhang, T. Oleniuk

It is well-known that Saskatchewan has the world’s richest uranium deposits and advanced processing technologies. Unlike the Saskatchewan deposits, complicated mineralogy is common for other places in the world. Mineralogy dictates the process. Mineral Processing at the Saskatchewan Research Council has been working with the uranium industry worldwide since its inception to develop effective processing technologies to suit the unique mineralogy of each deposit. This paper reviews the research and development of uranium processing technologies in the current major uranium production areas such as Canada, as well as the potential development regions like Argentina and Sweden. Acidic and alkaline leaching processes, as well as by-product recovery technologies are discussed based on mineralogy.

Jan 1, 2020

By R. E. Ray

"As real estate for new development in urban settings becomes scarce, commercial high rises are being constructed above open passenger rail tracks and vehicular roadways. Rail and roadway overbuilds are treated as tunnels requiring emergency ventilation systems for train or automobile and truck fires. The value of floor space in residential and office towers poses challenges to engineers responsible for designing fan rooms and shafts for tunnel ventilation systems within the towers. This paper describes a case study of the unique incorporation of tunnel ventilation fan plants in the overbuild structure of a passenger railyard and an adjacent roadway.INTRODUCTIONTunnel ventilation systems are required for passenger rail and transit (subway) tunnels by the NFPA 130 Standard for Fixed Guideway Transit and Passenger Rail Systems, and the NFPA 502 Standard for Road Tunnels, Bridges, and Other Limited Access Highways requires tunnel ventilation systems for vehicular (road) tunnels. Passenger rail and transit (subway) tunnels are typically ventilated with a series of shafts placed longitudinally along the tunnels to provide piston relief for normal train operations and emergency ventilation of train fires utilizing reversible axial flow fans. The shafts are incorporated in dedicated ventilation buildings that house the tunnel ventilation fans and starters, switchgear to power the fans and other equipment and systems in the building, Programmable Logic Controllers (PLCs) to control fan operation with Supervisory Control and Data Acquisition (SCADA) software, and HVAC fans and ductwork to ventilate the spaces in the building. These ventilation buildings may also provide access to the tunnels below with ingress/egress stairs for use by first responders and firefighters entering the tunnels and train or transit system passengers exiting the tunnels in an emergency. A photograph of a passenger rail ventilation building that encompasses four tunnels is shown in Figure 1."

Jan 1, 2019

By G. E. Agar, W. B. Kipkie, R. A. Tenbergen

"This paper describes the successful pilot plant testing of a flowsheet, developed at Inca Ltd.&apos;s J. Roy Gordon Research Laboratory (JRGRL), for improved separation of the constituent minerals in a bulk copper-nickel concentrate.The flowsheet utilized the fact that xanthate concentration on the mineral surfaces is the most important variable affecting the high lime separation and that reduction of the xanthate concentration could be affected by an oxidative conditioning stage.When the adsorbed xanthate was reduced to a suitably low level, chalcopyrite and pyrrhotite could be floated to leave a high-grade nickel concentrate as the residue. Sodium cyanide was added to the froth product 10 depress pyrrhotite and any remaining pentlandite. The temporary depression of chalcopyrite by the sodium cyanide was overcome by introducing a conditioning step following cyanide addition . The advantages of the flowsheet; improved copper-nickel separation, operation without heating of the pulp, production of both high-grade nickel concentrate (29.5% Ni, .26% Cu) and copper concentrate (<0.5% Ni, 30% Cu) were all realized.IntroductionLaboratory test work undertaken at Inco and described previously(1) has demonstrated the importance of low xanthate concentrations on the mineral surfaces in the copper-nickel separation at the Copper Cliff mill.It was determined that oxidation of the separator feed (a cleaned bulk concentrate, grading about 11% Cu and 11% Ni) to lower the xanthate concentration on the mineral surfaces prior to separation significantly improved the quality of the separation (CI 4)*, particularly when no cyanide is used, but also when cyanide is added. As well, it was found that the oxidation permitted a pentlandite-pyrrhotite separation - the oxidation step brought about a decrease in the flotation-rate of pentlandite leaving pyrrhotite and chalcopyrite largely unaffected. Consequently, it was possible to produce a highgrade pentlandite product (30% Ni, 0.3% Cu) at ~83% Ni recovery , as well as a high-grade copper concentrate (0.5% Ni, 30% Cu at -96% Cu recovery)."

Jan 1, 1985

By Y. P. Malhotra, JE. C. Carter

"Syncrude&apos;s overburden removal requirement ranges from 20 million to 30 million bank cubic metres per year to meet tarsand demands for the production of 129,000 barrels of synthetic crude oil per day. The economic tar-sand lies beneath a variable thickness of overburden materials, composed of silts, clays, some sands of lacustrine origin, wind-deposited sand dunes, and out-wash sands and gravels.For the removal of overburden, Syncrude commissioned its own mobile equipment fleet in January 1981. This fleet consists of two Demag 241 hydraulic shovels, ten Titan 33-15B trucks and support equipment. Prior to this, all overburden removal was being carried out by contractors.This paper presents an overview of overburden removal at Syncrude, with particular reference to the performance of its own fleet.IntroductionThe Syncrude Tar Sands Plant was officially opened on September 15, 1978. After an expenditure of approximately $2.26 billion, the second and the largest commercial tarsands plant was on stream toward a permit production rate of 129,400 barrels of synthetic crude oil per day. The Syncrude Plant, a joint venture of six oil companies, the federal government and the Alberta government, is a major step forward toward the goal of Canadian energy self-sufficiency.The Mildred Lake operation of Syncrude Canada Ltd. Is located 40 km north of Fort McMurray and 480 km northeast of Edmonton in the Province o f Alberta.Synthetic crude oil leaving the plant is a blend of two-third s gas oil and one-third naphtha. The two streams combine in a pipeline and flow to Edmonton. The product takes six days to make the journey, arriving at four locations in the city Imperial&apos;s Strathcona Refinery, Gulf&apos;s Edmonton Refinery, the Interprovincial pipeline terminal and the Trans-Mountain pipeline terminal. Each Syncrude owner receives a share of oil equal; to its percentage of ownership in the project. At the present time, the oil is being utilized by Canadian refineries from Vancouver to Montreal."

Jan 1, 1983

By Linda Hodgson

1. Introduction ?Northgate Minerals Corporation is a mid-tier gold and copper producer with mining operations, development projects and exploration properties in Canada and Australia. ?Kemess Mine is Northgate?s principal operation. Where in the world is Kemess? ?Kemess is located in north-central British Columbia,430 kilometres northwest of Prince George. ?The Kemess South complex consists of an open-pit mine, a 52,000 tonnes per day mill and various ancillary support facilities including maintenance shops and housing for Kemess&apos; 340 full-time employees.

May 1, 2010

By J. G. MacGregor

At this, the opening meeting of the Western Quebec Branch of the Institute, it seems fitting that the first paper presented should embrace a survey of the known mineral deposits occurring in the area, and also a review of ?the exploration methods that have brought about their discovery. And since the study of geological structures must always be the guiding principle of an intelligent exploration campaign, it also seems to be the appropriate occasion to review the geological situation from the economic angle, in an attempt to arrive at a re-statement of the known facts governing the deposition of the mineral bodies . . It is not my intention to confine my remarks entirely to the geological problems involved, but rather to pass under review the exploratory methods that have been employed in the past and that are presently being used, and to offer a forecast of the type of exploration campaign that will be largely adopted in the future search for ore.

Jan 1, 1929

By D. S. Hines

The purchase of mechanical equipment for mines is not unlike the purchase of other materials or supplies in general principle, but on account of the major part such equipment plays in the operations, and of the fact that life and valuable property are at stake, the matter demands the most careful attention on the part of the purchaser. The problems and difficulties encountered are dealt with below in their sequence in the purchasing procedure. Requisiting Although it is quite a common practice to submit a tentative specification of requirements to recognized manufacturers of equipment- soliciting alternative propositions or recommendations for study in the selection of certain equipment-as a rule the first step in purchasing procedure is the requisition. Primarily, it is the form that carries to the purchasing department the record of equipment wanted. A full and complete description or specification, and accuracy of record, are the important points to be insisted on in a requisition. Too much attention cannot be given to this detail, as this is one of &apos;the most important phases of purchasing work. Incomplete information, either in specification or detail, leads to delay in handling the requisition, and, if not detected in the purchasing department, may mean receipt of material which cannot be used for the purpose intended. In addition to description of material or equipment to be ordered, the requisition should also show where or what the equipment is for, whether for operating or new work. If for capital account, the number of the authority for expenditure should be given for record and distribution purposes.

Jan 1, 1930

By Brad Ross

? Value in number of children ? Polygamy common ? Support of extended family and friends ? HIV/AIDS ? Not a culture of savings ? Minimal mechanical experience ? Supportive ? Unintended hindrance ? Mining claims ? Export Permits Lack of funding

May 1, 2011

By M. H. Colebrook

Nickel laterites contain about 70% of all continental or terrestrial nickel resources; therefore the recovery of nickel from lateritic ores has large economic significance. The processing of lateritic ores involves the preparation and movement of concentrated aqueous suspensions. However due to complex characteristics and non-Newtonian properties, ranging from shear-thinning to shear-thickening and from thixotropic to rheopectic, a basic understanding of the flow behaviour must be developed. This understanding will assist in the development of new plants and the operation of existing plants. The work in this paper involves the characterization of three ore types from the Vermelho ore deposit to categorize them as rheologically simple to complex. Rheological testing was also conducted on pure mineral samples that represent the main minerals in these samples. The results show that the rheological properties of the ore types can be related to the surface properties and physical characteristics of the main mineral constituents.

Jan 1, 2006

By R. M. Oliver

THE Falconbridge property is almost completely covered with over-burden to a depth varying from 60 to over 200 feet. This overburden consists of grave], sand, and boulder, with bands of very fine silt, and there is usually a layer of water-bearing quicksand adjoining the r:ock surface. In previous shafts sunk at Falconbridge, this water-bearing quicksand had given considerable trouble, and further difficulties were expected in sinking No. 5 shaft, due to its greater size. The method described in this paper is the one adopted in sinking this shaft, after the matter had been carefully considered. No. 5 shaft is located 2,400 feet east of the old main No. l shaft, and is sunk in norite in the hanging-wall of the ore-body, which is, however, ? practically vertical to the deepest known intersection. The greatest depths of overburden prevail on the south side, or footwall, of the ore-body, and this, together.. with the fact that the footwall is wet and more badly fractured, swayed the final decision to sink in the hanging-wall. After the shaft site had been chosen and cleared, a diamond drill was set up a few feet away and a hole bored to a depth of 405 feet to test the over-burden and character of the norite bedrock. The depth of overbudren indicated by the hole was Ill feet, with the last 10 feet water-bearing. The norite was rusted and broken up for only a few feet below bedrock. A steel sinking shield (Figure l) was assembled at the shaft location, and consisted of 5/8-inch plate, 5 feet deep, built around a frame of 6 inch by 6 inch angle-iron, and braced at the corners with the same material. Twelve-inch I-beams held the shield as rigid as possible. In order to reduce binding against pebbles to a minimum, the shield was constructed with a 1-inch batter on all sides.

Jan 1, 1938

By A. W. Lovett

"THE last two years have been years of recession or, perhaps, years of marking time, depending upon whether the observer is a pessimist or an optimist. There has been a slackening in the industrial tempo that has been reflected in many ways in the national economy. As one of the chief barometers of economic health, the consumption and supply of energy reflect this slowing up.These same two years have also seen significant changes in the relation between the sources of energy. In periods of declining demand, it has happened in the past that coal, as the basic or residual source of energy, has shown the effects to a greater extent than the other energies. In these two years, however, in addition to this usual effect, there has been the acceleration in the Joss of market to diesels in the railway consumption category and the continuing decline in domestic consumption. The story of these years is presented in the statistical tables that form the foundation of this paper. Statistics, particularly in the form of tables, are rather dry and are sometimes difficult to follow but the overall developments are illustrated by graphs which present a more striking picture."

Jan 1, 1959

By L. Li

ABSTRACT Stope backfilling is a common operation in many underground mines, which requires a barricade at the base of the stope near the drift entrance to retain the backfill in place. In this paper, the distribution of pore-water pressure in barricades made of waste rock is analyzed. An analytical solution is introduced and applied to estimate the pore-water pressure along the base and full height of the barricade. Results show that the analytical solution generally accurately predicts the distribution of pore-water pressure obtained from the numerical calculations, especially in the upstream part of the barricade, where it is most critical.

Jan 1, 2013

By Reno Pressacco

Abstract- Agrium Inc. is a world leader in the production, distribution, and marketing of agricultural products and services in both North America and Argentina. The new phosphate mine and mill complex located southwest of Kapuskasing, Ontario, was constructed to replace an offshore supply of phosphate rock, and produces a high-grade phosphate concentrate. The Cargill Township Carbonatite Complex is one of a series of carbonatite complexes in the region that are hosted by the 1.9 Ga aged Kapuskasing Structural Zone. The carbonatites in the mine area have intruded Archean gneissic granodiorite rocks of the Wawa Subprovince, and metasedimentary rocks of the Quetico Subprovince. The Cargill Carbonatite Complex displays a typical concentric zonation pattern from an outer ring of alkalic pyroxenites, through an inner ring of sövite-carbonatite, to a central core of rauhaugite-carbonatite. The initial carbonatite intrusion and subsequent residual orebody have been modified by faulting such that the northwestern third of the complex has been displaced approximately 2.5 km northeast. The phosphate ores are composed principally of residual apatite sands that were formed by the weathering and dissolution of the soluble minerals of the carbonatite protolith. These ores are subdivided by their iron content into high grade (A ores) and lower grade (B1 and B2) ores. They are separated from the primary unweathered carbonatite by a layer of saprolite, whose thickness varies depending upon the composition of the underlying carbonatite. Cretaceous waste materials consisting of well-sorted silica/kaolinite sand and peat deposits are typically found to stratigraphically overlie the ores. A minor amount of the ore feed comes from cemented phosphate ores. All rock types are covered by Pleistocene glacial tills and clays.

Jan 1, 2001

By Y. Huang

Corrosion of GaAs in aqueous electrolytes is a major limitation in implementing GaAs-based photoelectrochemical solar energy conversion systems, In this work, the corrosion behavior was investigated by electrochemical methods and surface analysis approaches, in both H2SO4 and NH3?H2O solutions, Open-circuit measurements showed that the cleaned GaAs surface was very sensitive to water/air, Impedance measurements for n-GaAs showed that an inductive loop only appeared at a high corrosion rate because a reaction intermediate is the oxidant for a further decomposition step in combination with chemical reaction with water, The results suggest that the same corrosion/decomposition mechanism occurred on n-GaAs in the two solutions, When the surface-hole concentration was low, the hole injection or generation process was the rate-determining step, At large reverse bias on n-GaAs, with high-hole concentration, the corrosion rate was limited by a Faradaic adsorption process, involving an adsorbed intermediate, The different surface compositions after corrosion in the two solutions can be explained by the dissolution of As(0), Further oxidation of As(0) to As(III) in NH3?H2O solution is still slow, as suggested from X-ray photoelectron spectroscopy (XPS) analysis,

Jan 1, 2005

Agenda ?Trends in Wireless Technology ?Success and Opportunities ?Improving plants efficiency ?Improving plants reliability ?Improving plants safety and security ?Wireless Ecosystem ?Lessons Learnt / Recommendations Why Wireless? ?Lower cost (no wiring cost) ?Flexibility (no wire) ?Standards-compliant wireless devices major factor enabling growth:?Standard WLAN (IEEE 802.11)?Wireless field I/Os (IEEE 802.11, ISA100.11 and WirelessHART) ??Wireless adoption will become a milestone that will rival the introduction of Fieldbus and the distributed control system (DCS) in its importance.? ARC Advisory Group

May 1, 2009

By Y. Guglielmi, C. Gout, P. Henry, P. Dick

The key questions about fault reactivation in shales concern the potential enhanced fluid displacement through a previously low-permeability aseismic shale formation. Here we selected a critically-stressed fault cross-cutting the underground research facility of Tournemire (France) which is located in Toarcian shales. Several inclined boreholes were drilled across the 8.5 m thick fault zone characterized by a fractured damage zone (FDZ) and a central 2.4 m thick complex core (FC) made of multiple shear bands with gouge intercalated with highly fractured lenses. The fault was pressurized using a straddle packer system defining a 2.4m long injection chamber normal to the fault surface. Three fault zone intervals were tested, two in the fault damage zone and one in the fault core. A three-dimensional displacement sensor set in the chamber allowed continuous synchronous coupled monitoring of fault movements, injection pressure and flow rate. An anticlockwise 0.22-to-0.05 mm fault slip was captured associated with a 10-to-100 hydraulic aperture increase of the fault. Preliminary analyses of the experiments show that leakage in the fault zone is controlled by strength and stress magnitude contrasts between the fault core and the fault damage zone. Fault damage zone discontinuities display a much higher peak static friction angle than the fault core shear zones, respectively of 34 and 22° that could be related to complex interactions between healing and sealing processes. Fault core leakage is much more dependent on strain than on effective stress variations. Discontinuous, pulse-like leakage, develops following complex failure processes that may simultaneously take place in the gouge zones and along the large pre-existing discontinuities. Such results may be of importance in evaluating fault seal integrity in oil and gas exploration, production or CO2 storage or underground excavations monitoring.

Jan 1, 2015

By K. J. G Hedges

"Once a health based guidance limits for exposure to diesel exhaust have been established, and as part of a multi-disciplinary team, the program for exposure reduction should incorporate the plan-do-check-adjust cycle. Setting a suitably protective (health based) occupational exposure limit (OEL) for diesel particulate matter (DPM) and nitrogen dioxide is a key driver to reduce exposure. It is important to go beyond regulations and reduce exposure to diesel exhaust, DPM, as low as reasonably achievable (ALARA) such as that prescribed under the Australia, Queensland Mining and Quarrying Safety and Health Regulation 2017 where under section 135 Limiting workers exposure, the workers exposure must not exceed the exposure limit applying to the worker for the hazard; and is ALARA. It appears that previously acceptable OELs are no longer safe. Therefore it is important that the internal responsibility system be implemented and the precautionary principle approach be followed, especially as it may be some time before a suitably protective OEL specifically for DPM is in place. One leading multi-national mining company BHP Billiton has acknowledged a significant lag that exists between regulatory action and the level of science that informs health risk. This company is managing exposure to diesel exhaust to as low as technically feasible. This same company that has set an interim target for managing diesel exhaust to 0.03 mg/m3 is achieving these levels which paves the way for other mining companies and general industry including construction. The Occupational Cancer Research Centre 2017 recommends reducing personal exposure to within 0.02 mg/m3 (EC) for underground mining and 0.005 mg/m3 for other workplaces. Controlling DPM is important to prevent cancer however it is also important that that nitrogen dioxide (NO2) be reduced (ALARA) and that careful selection of control technology be considered such as the proper selection of a diesel oxidation catalyst so that the level of NO2 does not in fact increase. The example from BHP Billiton provides a leading practice including using a multi-disciplinary approach and the importance of controlling emission at source and having an auditable diesel emissions based monitoring program in place."

Jan 1, 2019

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 Charles G. Kemsley

IN January, 1939, Dome Mines, Limited, purchased a few bars of an alloy drill-steel for the purpose of testing its fatigue resisting qualities as compared with those of a straight carbon-steel then in general use at the mine. A steel of the following analysis was selected: Carbon 1.00% Sulphur 0.022 Chromium 1.26 Silicon 0.17% Phosphorus 0.028 Vanadium 0.1 Manganese 0.32% Molybdenum 0.30 This steel has a tensile strength of 180,000 lb. per square inch and a Brinell hardness of 380, as compared with a tensile strength of 114,000 lb. per square inch and a Brinell hardness of 230 for the standard carbon drill steels, in the as rolled&apos; condition. The result of this test showed that about five times as many runs could be obtained from the alloy steel before failure from fatigue. It was therefore decided to replace gradually the one-inch quarter-octagon carbon steel, then in use, with seven-eighths quarter-octagon alloy steel. In January, 1940, six machines was placed on the seven-eighths steel and this was gradually increased until now (March 15th, 1941) fifty per cent of the steel being used is alloy steel. An O&apos;Donovan furnace is used at the Dome for heat-treating their carbon drill-steel. In this furnace, a magnet withdraws the steel when the critical temperature has been reached, and the operator then places the steel in the quenching tank. Not being able to use this furnace for the alloy steel, the management felt that some means should be developed to determine the quenching temperature without depending upon the operator&apos;s judgment of the correct &apos;colour&apos;. With the assistance of the Canadian General Electric Company, a radiation-type vacuum thermocouple pyrometer was adapted to this purpose, with excellent results; in fact, with this instrument no previous experience in hardening is necessary and results are remarkably uniform.

Jan 1, 1941