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By C. Mills, A. O. Burt

"The paper examines the role of gravity concentration in both an historical context and within the modern mineral processing industry. It discusses the principles of the process on both a theoretical and practical level. The importance of more mineralogy and its effect on the choice of the wide range of equipment available is discussed. The paper concludes with a discussion on the relative merits of gravity concentration with other forms of processing.IntroductionIt is an unfortunate, albeit popular, misconception among otherwise enlightened engineers in the mineral processing industry that gravity concentration was a process developed in the dark ages, perfected in the middle ages, and abandoned in the modern ages.Gravity concentration was developed in the dark ages - long indeed before that. Agricolau: cited examples of gravity concentration, crude examples admittedly, being practiced over 3000 years ago. However, gravity concentration is not dead. Far from it. As recently as 1978 it was reported that the total mineral tonnage treated by this process in the United States was greater than that processed by flotation. Coal represents the bulk of the or e treated by gravity separation in the U.S.A., with iron ore representing a major portion of the balance."

Jan 1, 1985

Purpose of TSUG Continuous Improvement in Mining Share Best Practises Exchange Ideas Network for Frontline Supervisors and Middle Management Meetings ? Two per Year -Spring and Fall ? Thirty Five to Forty Attendees ? Rotate Between Host Properties ? Host Mine Provides ? Meeting Room for One Day Tour of Mine and Maintenance facilities on Second Day

May 1, 2010

By Chin J. Chang

Powder metallurgy (P/M) technique is known for its capability of producing near-net-shape parts. Its specific characteristics have resulted in low cost and eliminated of many secondary machining. However, more and more P/M parts do require additional operations to fulfil their complex geometric features and surface roughness. Many of the machining factors that influence the machinability of cast and wrought steel parts, such as cutting speed, feedrate, coolant, tool geometry and shape, are also considered in the machining of P/M components. The special feature in P/M structure is the porosity that can decrease the machinability and shorten the tool life. Different variables have been considered in the machinability of P/M materials. Densities and the free machining additive manganese sulphide (MnS), are the two main factors of material composition, which dominate the P/M machining performance. Machining process is the main method that generates the desired working surface of machining components. This paper will discuss the metallurgical structure of the powder metallurgy components, their physical properties and possible issues when encountering machining operation. Turning operation has been tested in this investigation to show the relationship between the cutting speed, federate, cutting forces and chip formation. This investigation also discusses how the free machining additive, manganese sulphide, affects the P/M structure and machinability in order to understand how the metallurgical structure can affect the machining operation and, how to obtain the optimised surface results.

May 1, 2001

By J. Boldy

This paper is an attempt to place Canadian Precambrian volcanogenic deposits in perspective, by examining and compiling data regarding certain neglected fundamentals of size, grade, value, frequency distribution and spatial density. The discovery roles played by various exploration methods are compared and contrasted, and. using empirical methods, the probabilities of discovery are discussed, combined with the use of an effective 'cost-per-target' program. From these basic observations, realistic exploration judgments may be made. Using similar methodology, this format may be applied to other types of deposits. Precambrian volcanogenic deposits occur in a natural geometric progression in size. They number 110, of which 70% are pre-producers, producers or past-producers. These deposits are bonanzas and generally have a 'net pre-smelter' value of between $43 and $62 per ton. The statistically typical deposit is that which occupies the modal position, has 400,000 tons of ore, a value of $20 million and occurs with a frequency of 40%. A median deposit has 1.4 million tons of ore, a value of $70 million and occurs with a frequency of 15%. An upper-decile deposit ha s 13.3 million tons of ore. a value of $750 million and occurs with a frequency of 6.5%. The major, mid-upper-decile deposits have a minimum of 50 million tons of ore, a value of $3 billion and occur with a frequency of 4%. Five major volcanogenic deposits occur in the Precambrian and account for 54% of production. This contrasts with 55 deposits (all below the median) which account for 3.9% of production.

Jan 1, 1977

By E. Best

In 2003, Phelps Dodge Mining Company decided to pursue the design and construction of a Central Analytical Laboratory to provide chemical analyses for their Arizona and New Mexico operations. This centralized approach was selected in place of refurbishing six (6) older laboratories that operated at the various Phelps Dodge sites, and which would not have permitted full automation and use of robotics. The new lab was designed by the Process Technology Center (PTC) Material Characterization Group in cooperation with IMP Group. The Central Analytical Service Center (CASC) encompasses fully automated sample preparation of blast holes and geological samples weighing up to 15 kg/sample. The CASC also includes the first "wet chemistry module" worldwide to be operated by robotics systems to perform Total Cu, Acid Soluble Cu, and Quick Leach Tests (QLT), and a fully automated lab for electrowon copper cathode. The new lab also offers flexibility for handling specialty samples and analyses by either semi-automated or manual mode. Data handling and transfer is accomplished using the commercially available StarLIMS system. Commissioning was accomplished within five (5) months of startup during which the CASC also handled 86% of a full production load. The 24/7 lab operation has already exceeded its design capacity, has achieved considerable savings in operating cost, reduced sample preparation errors, and significantly increased analytical quality.

Jan 1, 2007

By A. Golabchi

Building Information Modeling (BIM) is an increasingly popular method for generating and managing facility information during the life cycle of a building, ranging from facility conceptualization, through design, construction and its operational life. Organizations involved in Facility Management (FM) have the opportunity to use BIM as a knowledge repository to document evolving facility information and to support decisions made by the facility managers during the operational life of a facility. This paper demonstrates the potential of using BIM to develop algorithms that automate decision making for FM applications. The potential of utilizing BIM as an analysis tool is demonstrated through the scenario of HVAC (Heating, Ventilation, and Air Conditioning) system failure in an operating facility. In case of a typical HVAC malfunction today, facility occupants record complaints in a ticketing database maintained by the FM organization. Upon receiving notification of HVAC system failure, facility inspectors visit the location to confirm the reported failure. Upon confirmation, facility managers review building plans and specifications to develop a detailed plan of action to repair any HVAC components suspected of damage. Based on the plan of action, inspectors visit the facility to inspect and, in case of damage, repair the appropriate HVAC system components. These FM practices ? as currently implemented across the industry ? are labor intensive, time consuming, and often rely on unreliable and outdated information. To address these shortcomings, the authors propose an alternative methodology of HVAC fault detection in operational buildings. The authors implement an algorithm that leverages complaint ticket data and automates BIM to determine potentially damaged HVAC system components. Based on the list of HVAC components suspected of damage, the algorithm develops a plan of action for the facility inspectors. Finally, the authors discuss the advantages of the proposed method as well as the challenges of implementing automated BIM-enabled decision making processes in the FM industry.

Aug 1, 2013

By Denghong Wang

Abstract- The Ashele Cu-Zn deposit is a recently discovered volcanogenic massive sulfide deposit in Xinjiang, China, hosted by Lower to Middle Devonian submarine bimodal volcanic rocks. The primary ores of this polygenetic deposit are represented by massive syn-depositional pyrite, chalcopyrite, and sphalerite, and were formed by submarine exhalation. Hydrothermal alteration consists of strong sericitization, chloritization, silicification, and carbonatization of the metavolcanic rocks beneath the massive orebodies. Depletion of Na2O is an obvious chemical change in the hydrothermal halo. Geological and geochemical evidence suggest that the Ashele Cu-Zn massive sulfide deposit was formed by submarine exhalation related to bimodal volcanic rocks, trapped in a rifting basin, then deformed by shearing, and thermally metamorphosed by the intrusion of dacitic porphyry. Sulfur and lead isotopic studies indicate that metals such as copper and zinc may have originated from spilites, but that volatile components, especially sulfur, were derived directly from submarine volcanic magmas.

Jan 1, 1999

By J. Kochhar, Robert G. Cooper

"The Cape Breton Development Corporation is a federal Crown corporation which was formed in 1968. Initially, the Corporation had two divisions - the Industrial Development Division, whose purpose was to stimulate Cape Breton Island's economy, and the Coal Division with a mandate to phase out the operating coal mines. However, that strategy changed in the early 1970s with the Middle East oil crisis. As a result of that crisis, Nova Scotia Power Corporation adopted an ""off oil"" policy. Today, approximately 700/0 of Nova Scotia power needs are met by generation of electricity from coal. Therefore, since the early 1970s, emphasis has been on the rehabilitation of the Cape Breton coal mining business with the opening of three new mines.Today, Devco is solely a coal mining company which employs 3300 people.Physical DescriptionThe mines operate in the Sydney coal field which is located on the eastern tip of Cape Breton. The Corporation leases the deposit from the province of Nova Scotia and its leases cover all coal from the outcrop to the 4000 ft depth. The seams outcrop along the shoreline and dip beneath the ocean floor at dips varying between 5% and 100%.There are eleven seams, of which three - the Harbour, Phalen, and Hub - have been extensively mined."

Jan 1, 1990

By Å. Partapuoli, M. Henriksson, P. Wikström, J. Worth, G. Adolfsson

The control of AG mills fed by ores with harder and softer components can be challenging due to the sensitivity of the mill to the ratio of hard to soft components. The mills at LKAB’s iron ore operations are generally well controlled, but there are periods when the throughput falls off dramatically, due to a loss of mill filling. As the ore is upgraded in the sorting plant through magnetic separation prior to milling, this presents an opportunity to manipulate the feed blend in advance. In order to assess this opportunity, a fullscale mill charge was dumped and assayed by size to quantify the build-up of competent waste in the mills. This was supplemented by pilot and locked-cycle laboratory tests at a wide range of feed blends in order to facilitate the development of an appropriate multi-component AG mill model. This paper reports the experimental campaign requirements and methodologies, as well as the major outcomes from analysis and modelling exercises using the industrial, pilot and laboratory multi-component data.

Jan 1, 2012

By J. S. Godard

The mining developments in western Quebec have shown the ores of this district to be more complex in character than was at first expected. When the initial discoveries were made it was thought that the ores would be similar in character to those of Kirkland Lake and Porcupine areas. Developments have since shown that although the ores along the southern margin of the belt are somewhat similar, those within the belt, constituting by far the greater proportion, are vastly different, being complex mixtures of base-metal sulphides carrying values in the precious metals. These mixtures of base-metal sulphides of copper, zinc, and iron, present several problems to the metallurgist, especially in their concentration into marketable products. For the purpose .of this paper the following classification may be made of the ores of the district. Group I. - Milling Ores: (a) Ores in which~ arsenopyrite is the predominating sulphide. In this class of ore the gold occurs in fractures in the quartz and is associated to a lesser extent with the arsenopyrite and pyrite. Examples of this class of ore are the Granada, south of Pelletier lake, and the O'Brien and the Thompson in Cadillac township. (b) Ores in which iron pyrite is the predominating sulphide and gold is the valuable constituent. This may also be classed as a concentrating ore-Group III.

Jan 1, 1928

By J. Robison, H. Pieterse, C. C. Smith, M. Luque, S. Chipman

Phase change during pressure let down releases significant amounts of energy that must be controlled to avoid undo wear and tear on equipment. Hydrometallurgical slurries require flow control equipment (valves and tanks) made of expensive materials to withstand the abrasive, and often corrosive nature of the slurry. Presented is a model of the nozzle of a let-down choke which is designed to control the flow pattern that exits the choke (valve) as it enters the receiving tank. This model can be used to design chokes which allow for the dissipation of the energy released during pressure let down by spreading the stream over a significant portion of the slurry pool in the receiving tank to minimize wear on equipment near the nozzle exit and the bottom of the slurry tank. An example uses the model to choose the nozzle expansion (area) ratio to select the outlet slurry velocity and slurry expansion angle.

Jan 1, 2004

By Mark Richards

Highland Valley Copper is a large, open-pit copper mine in the southern interior of British Columbia. Reclamation has been in progress on the site since 1987. Some 6,300 hectares will have been disturbed at the end of the mine?s life, the majority of which will eventually be reclaimed. The establishment of vegetation and the development of a self-sustaining vegetative cover are the central components of the mine?s reclamation plan. The present vegetation-monitoring program for the reclaimed area represents a significant commitment of resources and only addresses a small portion of the site each year. In an effort to expand the area surveyed while improving the efficiency of the monitoring, the use of remote sensing is being investigated. Airborne multispectral imagery was acquired in the summer of 2001, and the results of the multispectral classification were compared to ground observations made during the routine 2000 and 2001 monitoring program. A thematic map with 17 vegetation classes was produced. Within the vegetation classes, there was a strong spectral separation between ? dry grasses? and ?legumes? with further separation according to their density. Green biomass could also be quantified remotely across a wide variety of vegetation types. During summer 2002, further aerial imagery was acquired in combination with a targeted ground-truthing program to determine characteristic vegetation types associated with recognized spectral signatures, which can be used in a supervised classification. It is anticipated that after some fine-tuning, it will be possible to shift the ground-sampling effort from areas where the aerial classification confidence is high to more complex areas.

May 1, 2003

By J. L. Miller, R. W. Burns

This paper sets out the various phases of bringing a merchant bar mill into operation from feasibility consideration through financing, design and scheduling to completion.

Jan 1, 1967

By H. M. Lima, L. A. Gomiero, C. A. de Morais

ABSTRACT The Caetité-Brazil uranium facility produces approximately 400 tonnes U3O8 per year from an ore averaging 0.29% U3O8. The process steps are ore crushing, heap leaching with sulphuric acid, uranium separation and purification by solvent extraction (SX) with a tertiary amine, followed by stripping with a sodium chloride solution, precipitation as ammonium diuranate (ADU), and product drying. A change in the milling process is being evaluated to increase production and uranium recovery. Heap leaching will be replaced by conventional agitated tank leaching of the –590 µm ground ore slurry in a sulphuric acid medium. Replacement of the stripping reagent is also being considered.

Jan 1, 2012

Iron control and iron residue management and disposal are significant issues in all zinc production processes. This paper briefly reviews the most important primary zinc production routes and discusses the challenges posed by iron control in each of them. The technologies and strategies that have proven successful in controlling and managing iron are discussed. SNC-Lavalin's experience in designing and commissioning zinc plants provides a unique perspective from which to review this aspect of zinc production.

Jan 1, 2006

By Xiaoqiong Wang, Daobing Wang, Fanbao Meng, Jianbo Wang, Hongkui Ge

"Shale gas has become an important unconventional oil and gas resources. Its effective development relies on comprehensive and accurate understanding of shale gas reservoirs. Rock mechanical properties is one of the important components of reservoir evaluation. Two adjacent black shale samples, which are cored from the depth of 1145 meters in Chongqing, southwest China, are subjected to acoustic emission(AE) test under uniaxial stress and compared with coarse grained granite. The results of synchronous AE, stress-strain and ultrasonic velocity experiments show that shale has weak anisotropy. Compared with granite sample, two shale samples are similar, but their strength, velocity and brittleness are quite different, indicating that shale has strong microscopic heterogeneity. TOC, XRD, SEM microstructure analysis show that total organic content, mineral composition and natural fractures are the main impacting factors for mechanical heterogeneity. INTRODUCTIONShale gas is a typical low-grade marginal resource, which is characterized by ultra-low matrix permeability and small single well control volume. In order to enable commerical development, complex hydraulic-fracture networks must be created in the shale to allow gas to escape from the micro/nano-pores and natural fractures where it is trapped in the rock (C. Clark et al.,2013; Ge et al., 2013). The development of shale gas requires accurate evaluation methodologies to evaluate shale reservoir properties and predict production. (Jarvie et al., 2007). Rock mechanical properties are an important part of the reservoir evaluation. It is significant for efficient drilling, completion and hydraulic fracturing to understand mechanical behavior of shale gas play (John, 2011; Wei, 2013).Rock mechanical properties mainly include heterogeneity, anisotropy, brittleness and acoustic emission activity (Lockner et al., 1992; Jerome et al., 2009; He et al., 2010; Liang et al., 2012). Shale mechanical properties are evaluated from laboratory tests following a complex workflow that covers tasks from sampling to testing (Md. Aminul Islam et al., 2013). It is common to include various experimental methods such as stress-strain curves, ultrasonic velocity and acoustic emission when evaluating the mechanical properties (Rao et al., 2006). Because of the presence of organic-rich matter, mineral composition orientation and natural fractures, shale tends to have strong anisotropy and heterogeneity (Deng et al., 2004; Wang et al., 2013; Hathon et al., 2013)."

Jan 1, 2015

By Donald J. MacNeil

THE opinion, based upon geological knowledge, that certain areas within the Province of Nova Scotia might yield commercial quantities of petroleum, is not new. It dates back to at least 1864, when the Pioneer Oil and Salt Company drilled some shallow holes in search of oil near lake Ainslie, Cape Breton. As a matter of fact, several companies were engaged in oil exploratory work near lake Ainslie at about that time; included among them were the Inverness Oil and Mining Company, the Victoria Oil Company, the American Oil Company, and the Cape Breton Oil and Mining Company. Oil exploration by these and other companies was conducted sporadically on Cape Breton island until 1914. In several instances, the depth of the test holes exceeded 1,000 feet; the deepest was carried to 3,260 feet. The Lake Ainslie area was selected because oil seepages were present along certain sections of the lake shore, but the tests that were drilled to tap the oil-bearing zone failed to yield anything of commercial value. Currently, there are three areas in Nova Scotia wherein active exploratory work is being conducted, namely, at Pugsley Siding close to Amherst; at Kennetcook, Hants county; and near Mabou, Inverness county. The Pugsley Siding test is being drilled by the Sun Oil Company, of Philadelphia; the work at Kennetcook is under the direction of the Nova Scotia Oil and Gas Company; two relatively deep holes were drilled by the Lion Oil Refining Company in 1944 near Mabou, and, as a result of the additional geological information derived therefrom, another test probably will be drilled by this Company in the same area. Aside from these activities in the search for petroleum, the oil possibilities of several other sections of the Province are being studied by means of surface geological mapping.

Jan 1, 1945

By Ross G. Bertinshaw

"The Line Creek Mine of Crows Nest Resources started mining coal in the fall of 1981. There are seven mineable seams with thicknesses ranging from 1.5 to 13 metres and with dips varying from 0 degrees to 60 degrees. This, together with internal partings and the very friable nature of the coal, creates a number of mining problems.The coal is divided into zones depending on the dip of the seam. Each zone requires a different mining technique to ensure optimum recovery and low dilution while still keeping fines to a minimum.Line Creek employs a combination of hydraulic front shovels and backhoes to mine its coal without blasting or use of dozers. This has been very successful in reducing the proportion of fine coal hauled to the plant, thus improving quality control and reducing costs in coal processing.There have been a number of other benefits from the use of excavators instead of more conventional methods. These include better selectivity, good cleanup, reduction in traffic at the face and lower cost.IntroductionThe Line Creek Mine is situated approximately 25 km north of Sparwood in southeastern British Columbia (Fig. I). Preproduction stripping began in J98J with the first coal shipments made in 1982. In 1983 the mine produced 2.1 million tonnes of raw coal.Similar to other East Kootenay coals, the seams at Line Creek are characterized by their friability, producing a large proportion of fine coal during mining. In an attempt to reduce these fines Crows Nest Resources has instituted the use of hydraulic excavators to mine and load the coal.Hydraulic excavators offer other substantial advantages over front-end loaders and dozers, which has been the conventional system in other mines in the area."

Jan 1, 1985

By G. F. Trainor

The complex ore body at CNRL?s Horizon mine presents some unique challenges in managing ore and waste delivery. With 25m x 25m ore blocks shovels often take bucket loads from multiple blocks to fill one truck load. With CNRL monitoring 22 different qualities per material a precise calculation of the blended quality of ore on the back of each individual truck is essential to meet the daily blend requirements at the plant. Additionally, one of these qualities must be closely monitored and controlled at a singular level as delivery of certain grade and quantities can cause serious disruptions at the plant. The waste material also requires special handling and delivery for its use in dyke construction for tailings impoundment. Shale materials used in the construction contain high levels of saline that must be contained to prevent seepage into ground water. This paper will discuss how the use of Wenco?s survey-grade GNSS system on shovels, its dispatching algorithm, and fleet management applications give CNRL the ability and confidence to control and report on these three issues.

May 1, 2013

By J. B. Mawdsley

Introduction The writer was instructed to visit the Chibougamau region during the field season of 1927 and report on the mineral discoveries that had been made there since 1911. lt was deemed advisable to obtain detailed information regarding the rocks underlying the area in the vicinity of these recent discoveries. Accordingly an area 60 square miles in extent was mapped. The outcrops were studied along the water courses and along bush traverses spaced at half-mile intervals between these water courses. The completion of the rest of the summer's programme allowed only three weeks for this work. lt is from this small, mapped area, and this necessarily cursory survey, that the material for this paper was obtained. Location And Means Of Access The name Chibougamau district is applied loosely to an ill-defined area of about 1,000 square miles lying mostly north and west of Chibougamau lake in the Province of Quebec. The lake is approximately half way between lake St. John and James bay. It lies 150 miles north of the Canadian National railway and 40 miles south of Mistassini?lake.

Jan 1, 1928