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By G. Issid, J. McGinty, C. Lee, Y. Pepin

For more than a decade, Hatch has used process and logistics models to assist Rio Tinto Fer et Titane (RTFT) with capacity planning, debottlenecking, and optimization to help ensure design capability, capital effectiveness, and operational efficiency of the integrated production chain. Process models are used to optimize the physics-based aspects of the system, such as mass and energy balances, flow rates, yields, and equipment specifications. Dynamic logistics models are used to optimize how the various plant areas work together to achieve the desired ends and deal with such things as plant scheduling and synchronization strategies, sizing of buffers between processes, defining the required number of process and material handling units, and designing a plant layout that minimizes plant interferences and inefficiencies. The combined use of process models and logistics models enables the overall plant to be optimized from both a productivity and quality point of view, with each plant area working in harmony with one another to achieve targeted capacities and efficiencies. This paper describes the many benefits derived from such modeling efforts over the past 15 years for each of the major plant areas at RTFT: Beneficiation Plant, Smelter Plant, Steel Plant, UGS Plant, and Powder Plant (RTMP).

Jan 1, 2011

By M. Rafati

In this investigation, the effects of T4 and T6 heat treatments of AZ91 magnesium cast alloy have been studied. The effects of different microstructural details such as morphology, size and distribution of precipitates and their influence on fracture mechanisms were investigated by optical and scanning electron microscopy. The mechanical strength of the alloy after T6 treatment was found to increase in comparison to the T4 treatment, due to the formation of discontinuous precipitates in the grain boundaries. Precipitation in this alloy occurs in two ways: continuous precipitation, which nucleates and grows inside the grains, and discontinuous precipitation, which forms at the grain boundaries. During ageing, the length of the continuous precipitates increases, and, hence, interprecipitate distance decreases. The formation of discontinuous precipitates causes initiation and propagation of cracks at and the weakening of the grain boundaries. This is the principal reason for the reduction of the ultimate tensile strength in T6 heat treatment in comparison to the T4 condition.

Jan 1, 2006

By M. Bigdeli Karimi

In this study, the effect of strain level and holding time in semisolid temperature range via SIMA process on AS21 Mg alloy was investigated. Some cylindrical samples of this alloy with 1cm in height and 2.5cm in diameter (H/D=0.4) were compressed to 10%, 20%, 30% and 40% at 300-C. Then, the samples were reheated in semisolid temperature range at 614°C for various times. The results of optical microscopy and image analysis showed that with increasing of strain and holding time, dendritic structure changed to equi-axed structure, gradually. Also, the best conditions to obtain good globular structure were achieved. Furthermore, it was seen that after compression and reheating, Mg2Si intermetallics with Chinese script morphology converted to dispersed-fine particles which were distributed into the ci-Mg grains.

Jan 1, 2007

By W. B. Boggs

Part 1 Originally, the copper produced at the Noranda ?smelter was shipped in the form of blister bars to the Laurel Hill refinery of the Nichols Copper Co., New York. In 1930 a refinery was built at Montreal East for the purpose of refining Noranda copper and copper from the Hudson Bay Mining and Smelting Co., at Flin Flon. After investigation of the probable costs of making anodes at Noranda and at Montreal, it was decided to make them at Noranda rather than to continue to make blister bars there. Fuel is a major item of expense in making anodes: and since less fuel would be required in making anodes from molten copper than in making them from blister bars, a lower anode furnace cost could be expected at Noranda than at Montreal. Further, the expense connected with making blister bars at Noranda would be eliminated. The cost of treating anode and wire bar furnace slags is a serious item in a refinery, and it was found that the cheapest method would be to ship such slags back to Noranda. With the anode furnace at Noranda, much less anode furnace slag would be made at the refinery. Against these savings which would be effected by making anodes at Noranda must be set the high operating cost of an anode furnace at Montreal, using only tank-room scrap and the Flin Flon copper. This furnace would be handling a comparatively small tonnage and would have a high cost per ton. The usual equipment for making anodes from. liquid copper consists of either a stationary reverberatory furnace or a tilting Tacoma-type furnace together with an anode wheel of the Clark or Walker type. The reverberatory type of furnace has been developed from the furnace used in the old Welsh process of smelting and refining copper, while the tilting furnace is a development of the holding furnace, which is essentially a Peirce Smith converter without tuyeres and provided with burners.

Jan 1, 1932

By John D. Carriere, Jean Leung, Daniel. Laguitton, Michael .. J. Burrows

"The objective of this expert system application in a copper-zinc concentrator, is to increase the availability of assay data through substitution for erroneous data. The assay data is used by the Operations personnel and automatic process control strategies to control flotation circuit performance. Two online X-ray fluorescence analysis systems analyze 24 streams across four divisions to provide the required data. Data availability of individual streams average 90% while the resulting circuit availabilities are 70%. The unavailability of correct data results from mechanical, X-ray or process problems. The erroneous data can be identified by process experts using knowledge relating stream interdependencies and historical process behaviour. An expert system was devised to provide real time identification of erroneous data and substitute for that data with the ultimate aim of improving metallurgical response by both the operator and automatic control systems.The paper discusses the early development work and architecture of the knowledge base designed using Neuron Data's expert shell NEXPERT.INTRODUCTIONThis paper describes the early development of an expert system (ES) prototype at the Kidd Creek concentrator. The project is a joint undertaking of the Kidd Creek Division of Falconbridge Limited and CANMET. Kidd Creek entered into the project to apply heuristic rules to the XRF assay data to improve the metallurgical control of the flotation process by increasing availability of analysis data. This project provided a problem of suitable size and future expandability while making use of a wide base of in-house expertise and experience. Another important benefit is the introduction of expert system technology to the site providing tools and experience for future system selection and technology application. CANMET has an on-going interest in assessing various aspects of ES technology (hardware, software, knowledge engineering, integration) while addressing problems in process operations that could most readily benefit from the technique. CANMET's role in the project was to provide project assistance, financial support, substitution algorithm assistance and software for data substitution. The knowledge bases (rules) have now been completed and are to be tested in the online environment."

Jan 1, 1989

By David Dreisinger

Arsenic occurs in nature in association with many valuable metals including copper, nickel, cobalt, gold and platinum group metals. The recovery of these valuable metals is of course complicated by the need to extract and stabilize arsenic in a form suitable for disposal. In this paper, a review of some recent developments related to hydrometallurgical treatment of arsenic bearing materials is provided. The key aspects of metal dissolution, arsenic stabilization and disposal are discussed.

Jan 1, 2014

By H. M. Roscoe

Fifty per cent. increased lump coal production and at the same time a reduction of from 20 to 40 per cent. in explosive consumption. These results were achieved by the use of the rock-dust cartridge method of stemming shots in the Ruhr coal mines, as announced by Dr. Alfred Stettbacher in the September 1923 number of the Explosive Engineer. Immediately, the explosive and the coal-mining industries on this continent became intensely interested. Considerable experimental work has been carried on in a number of American and Canadian mines during the past year, by which our engineers have become assured that the use of rock-dust cart-ridges for stemming shots increases the efficiency of explosives and promotes safety in coal mines.

Jan 1, 1924

By R. M. Graves, C. B. McKenzie, D. Barbour, D. W. Desnoyers

"The prospective Tulks volcanic belt hosts five significant massive sulfide deposits, Tulks Prospect, Tulks East, Jack's Pond, Daniel's Pond and Victoria Mine, as well as numerous showings and indications throughout its 70 km outcrop length. Regionally, the 498 Ma sequence consists dominantly of felsic pyroclastic rocks and flows with interbedded mafic volcanic units and finegrained sediments, commonly graphitic. Contemporaneous granitoid rocks occur in the south half of the belt. Rocks usually display a strong NE-SW, steeply dipping, penetrative foliation and other shear-related high-strain fabrics. Facing directions are normally northwest, although there is local evidence of folding. Sulfide bodies and their alteration systems are deformed and shape-modified in the style of ambient strain.The Tulks, Tulks East and Jack's Pond prospects appear to occupy a similar stratigraphic level, on or near the contact between a thick felsic pile and an overlying broad, conductive package of graphitic sedimentary rocks. All are pyritic deposits with well-developed footwall alteration systems. The Tulks prospect comprises four polymetallic lenses totalling 750 000 t. Three lenses constituting more than 6 000 000 t of sulfide mineralization are indicated at Tulks East but only the 210 000 t ""B"" lens contains significant base metals. Jack's Pond consists of a very extensive, zoned alteration complex in which four lenses of massive to semi-massive pyrite + chalcopyrite are known. The central part of the system, characterized by Mg chlorite and carbonate, is enveloped by pervasive sericitization and capped by intensely silicified and pyritized volcanics. The sulfide lenses are interpreted as part of the footwall zone and are beneath that part of the system most likely to hostpolymetallic massive sulfides.Daniel's Pond differs from the other prospects in such fundamental ways as metal content, associated alteration and structural setting. The deposit comprises strongly tectonized, Ag-rich, Zn-Pb mineralization distinguished by a pronounced Ba-As-Sb signature. Mineralization is confined to a narrow, north-south high-strain zone which separates unstrained mafic volcanic rocks to the east from well-foliated felsic rocks. The deposit lacks an extensive alteration halo and at its north end is associated with a lens of barren, undeformed massive pyrite.The Victoria Mine deposit, the most cupriferous of the five, is related to a moderately dipping structure that separates well-foliated Tulks volcanic rocks from an overlying, less deformed volcanic sedimentary sequence that may be as young as 462 Ma. The structure is also the locus of black chlorite, dolomite and quartz alteration. Structurally remobilized precursor sulfide mineralization is one possible source for the deposit."

Jan 1, 1993

By Jr. Wilkinson

Suncor Energy currently mines approximately nine hundred thousand tonnes of ore and waste per day at its open pit operations in the Athabasca Oilsands near Fort McMurray, Alberta. Modeling these deposits for planning purposes is particularly challenging given the characteristics associated with the deposit - stratigraphic deposition coupled with gradational grade distribution. The identification of ore and waste is a combination of bitumen cutoff grade, minimum mining thickness and separable waste thickness subject to criteria established by provincial regulatory agencies. Suncor along with Mincom Inc. have collaborated on this project to derive a methodology, automated by computer software, to streamline the ore and waste identification process. This paper explains the methodology and programs created to identify ore and waste in use at Suncor Energy and how this identification is used to categorize reserves and to generate mine design surfaces.

Apr 1, 2005

"This contribution is concerned with adaptive processing decisions, where the process parameters are optimally adapted to the varying properties of the material input stream. Our starting point is the geometallurgical paradigm that the varying properties of the input stream are considered known e.g. from a geometallurgical model of the mined ore body, and optimal processing parameters are computed from them, by finding the parameter seaming optimal in a computer simulation.This approach however has to work with a lot of uncertainties: The prediction of the geometallurgical ore parameters can only be done with some geostatistical uncertainty. The parameters themselves are only proxies for true ore properties. Model prediction can differ relevantly from actual process results, due to model simplifications. Due to these uncertainties the computed processing choices can turn out to be inferior to simple non-adaptive processing. In this contribution we focus on the uncertainty of the ore properties and analyse this effect systematically, by modelling this uncertainty effect mathematically and in computer simulations. The most important findings are:(a) Processing choices not taking into account the uncertainty sometimes even perform worse than simple non-adaptive processing, for the sole reason of ignoring the uncertainty effect.(b) Ore properties, not adequately reflected in the ore description, might require different approaches, in which the observed processing behaviour feeds back into process control.(c) Bayesian decision theory allows computing optimal processing choices combining the information from the mine (geostatistical predictions) and from the process feedback. These choices give much more robust choices and do not suffer from the drawbacks described for the simple approach we started from.These new approaches can substantially improve the performance of adaptive processing in existing plants."

Jan 1, 2016

By Patrick Andrieux

Cet article décrit une nouvelle méthodologie qui quantifie les chances de succès d’un sautage confiné à grande échelle de relaxation des contraintes dans un pilier de mine souterraine, pour un massif rocheux et un régime de contraintes donnés. La méthode est basée sur un nouveau paramètre nommé « Indice de relâchement », qui considère huit paramètres géomécaniques et de forage-sautage qui contrôlent ultimement le procédé. La rétro-analyse d’études de cas bien documentées a démontré que l’approche peut indiquer de manière fiable si une situation donnée de hautes contraintes de terrain est susceptible d’être améliorée par un tir de relâchement confiné à grande échelle et si le design proposé est adéquat pour atteindre ce but.

Jan 1, 2009

By E. G. Joe

"The continuing increase in costs for power and fuel are affecting significantly the cost for milling of Canadian ores. In order to ascertain the scope and source of energy consumption in Canadian mills for further energy conservation opportunities, CANMET, in cooperation with the Canadian Mineral Processors carried out a detailed survey on the metallic mineral processing plants. Sixty-seven mills representing almost 300 million tons of annual capacity participated in the survey. The results indicated that in general, copper and iron ore mills, representing the bulk of the tonnage, consumed relatively low levels of energy per ton. Nickel-copper, zinc-copper and lead-zinc ore mills were moderate in energy consumption, while uranium and some copper-lead-zinc mills reported much higher energy consumptions due primarily to the increased heat requirements of the ore pulp. While the plant heating costs varied somewhat with the location in Canada, it was apparent that the lowest heating costs were achieved by those built with proper insulation and energy conservation design. If the cost per million British Thermal Units is taken as $2.00, the mill energy costs generally ranged from 40¢/ton up to $1.20/ton.IntroductionEnergy consumption in milling has always been of significant interest to Canadian mineral processors who traditionally calculate their milling costs down to pennies per ton. Even the measure of an ore's grindability is expressed empirically by Bond in kilowatts hours per ton milled. Some of the mills located in isolated areas were obliged to generate their own electrical energy from fossil or petroleum-based fuel at a cost substantially higher than that obtainable from captive or public hydro-electric installations. These mills practiced energy conservation long before the advent of O.P.E.C. energy cost inflation. One example of this was the use of electric boilers to produce process and heating steam during off-peak electrical load periods."

Jan 1, 1978

By Osvaldo A. Bascur

Industrial complexes rely on measurements of flow rates, qualities, and concentrations for monitoring and optimizing their operation. Corporations use the data from the various sensors and measurements to make business decisions, which affect the profitability of the operation. However, gross errors, due to a variety of reasons like faulty sensors, bad instrument calibration, or incorrect process models may corrupt the actionable information supplied to operations, quality managers, and maintenance personnel. The solution is to use the sophisticated new tools to model the process, sift through the available data to locate the gross errors, and use statistical data reconciliation to validate the sensors and instruments. In this way the data are unified to give the most accurate plant information for use by the monitoring and decision making processes. Most mining and metallurgical plants use predictive maintenance policies based on statistical analysis and special techniques, like vibration analysis, and oil and lube analysis for critical equipment. Process control strategies are installed in several metallurgical sites. All of these depend on reliable and accurate data. The data unification methods validate the individual measurements by using the concept of balances and statistical techniques where each instrument is no longer independent of the other measurements in the facility. This paper refers to the data unification and analysis methods required for profitable plant operations. Continuous improvement and monitoring of the measurement system at the plant and analysis of the reconciled data provide the best information for the decision-making process. On-line gross error detection and elimination methods are required to ensure efficient evaluation of process performance and process optimization. An open discussion of the new methods for gross error detection and data unification will be presented.

May 1, 2001

By Dirk Claessens

The term ?cost? is too small when describing the destructive power of safety incidents for mining companies. Breaches in employee or environmental safety are felt way beyond the bottom-line: human life can be taken; ecosystems tarnished; the ire of peoples, media and government inflamed; significant halting of production; and high levels of legal and financial challenges. According to a recent survey of Mining executivesi, ?ensuring workforce safety? was the most important issues identified above any other, with a plurality of 31 percent, reigning above capital projects, product efficiency, and equipment reliability. We accept that safety is a most paramount issue, yet for many reasons we keep approaching the problem the same way we have in the past. We need to stop doing the same things decade over decade and try something new. New innovations are significantly changing the fundamentals of how mining companies explore, excavate, produce, refine and distribute their valuable commodities. Technologies such as visualization, analytics, location awareness, and gaming simulation are making these enterprises smarter. Now, attention turns to an area we?ve long held as integral to our business: safety. By using the same breakthrough technologies that are changing our business, we can now boldly imagine ? and credibly strive for ? a world of zero incidents.

Aug 1, 2013

By Ron Doucet

Industry today is now more than ever dependent on its assets and on the standard of maintenance. Changes in technology, environmental regulations, a continually improving focus on safety and global competitiveness has made maintenance a key activity in sustaining safe, financially viable and environmentally integral operations. Maintenance used to be looked upon as a cost centre with a sole focus of fixing equipment to attain high availability. Maintenance today affects all aspects of the business: safety, environmental integrity, energy efficiency, productivity, costs, and product quality. These new demands on the function of maintenance requires us to think vastly differently about what maintenance is all about, even to the point of contradicting old beliefs. In the following paragraphs we will examine some of the changed thinking that has evolved over the last 50 years. These new concepts will lay the foundation for the implementation of 21st century best practice maintenance.

May 1, 2003

By G. R. Guillet

Important resources of kaolin, refractory clay and lignite, not found elsewhere in Ontario, occur with quartz sand of glassgrade quality in unconsolidated Mesozoic sediments of the Moose River Basin in northeastern Ontario. These materials comprise the Mattagami Formation of Lower Cretaceous age, which overlie in some places a thin Jurassic unit and a thick Paleozoic section, and underlie as much as JOO m or more of glacial and marine sediments and a uniform capping of muskeg. The Mallagami Formation is known from deep boreholes to exceed 100 m in thickness and to consist of two phases: an earlier Type A unit of dark-coloured carbonaceous clays and lignite, and a later light-coloured (Type B) unit of kaolin-bearing quartz sands and bright-coloured refractory clays. Remoteness, poor access, and difficult physical environment have inhibited the exploration and development of these resources.

Jan 1, 1984

By A. Suzue, T. H. Okabe, Y. Taninouchi

Methods for the physical separation and enrichment of platinum group metals (PGMs) from autocatalyst scrap were studied in order to develop an environmentally friendly and efficient recycling process. In general, an autocatalyst has a honeycomb-structured ceramic substrate that is coated with a catalyst layer containing platinum (Pt), palladium (Pd), and rhodium (Rh). Therefore, physical separation of the PGM-containing catalyst layer directly from the ceramic substrate is favorable for upgrading the autocatalyst scrap. In this paper, the authors present a scrap-upgrade process consisting of electroless iron plating and magnetic separation techniques. Iron was plated on the surface of a catalyst sample used to represent an autocatalyst, which was then crushed and magnetically separated. The Pd in the catalyst sample was successfully extracted and concentrated in the magnetic powder. Under certain conditions, the process increased the Pd concentration by a factor of 4 and recovered 89% of the Pd in the autocatalyst sample.

Jan 1, 2014

By H. E. Johnston

There are currently a number of options in terms of plant feed comminution tests: Bond work index tests, JK drop weight and SMC tests, SPI, low impact crusher work index tests, to name a few. However, information regarding specific energy requirements for regrind mills is often requested, which can be difficult or very expensive when only a small mass of concentrate is produced from bench-scale flotation tests. This research was aimed at developing a test methodology that would produce a similar result as an IsaMill Signature Plot but require less sample mass allowing for preliminary estimates of regrinding power at a lower cost. Initially, the laboratory test methodology was completed on a single sample in comparison to the IsaMill Signature Plot for that sample. Results indicated a very good correlation between the laboratory tests and the IsaMill Signature Plot for this sample, though some parameters did impact laboratory regrind mill efficiency. The developed methodology is subsequently being applied to a range of concentrates, investigating a range of material particle sizes and material types, in comparison to a full IsaMill Signature Plot on the same sample. This new test procedure has been called ‘The Eliason Test’.

Jan 1, 2014

By Garston H. Blackwell

For ageing open pit mining operations where the economic viability of another pushback is questionable, mine life can be extended by increasing the wall slope. If the steepening is started where ore intersects the pit wall, the capital outlay for waste stripping is minimal. Such a venture must be conducted safely, and a basic requirement would include loading equipment capable of working remotely. In the application described, alternatives in the choice of loader included equipment available on site, or the purchase and assembly of used equipment. Only electric cable shovels were in use at the operation, and it was thought that these would be more capable of digging high muck piles at the productivity demanded by an increasingly efficient mill, and in a challenging environment less suited to a rubber tired loader or hydraulic front shovel. A decision was made to convert an older electric cable shovel to remote controlled operation and to include the application of semi-robotic control. The conversion was completed successfully and is described, along with methods developed for remote operation of a shovel, and the application of various sensors for semi-robotic operation. A plan of operations to mine out several completed double benches and make two quadruple benches with wide catchment berms is depicted. On completion of this task, the working benches developed would be wide enough to operate at near full production. Prior to moving the remote controlled shovel back into the pit, a large wall instability became active, eventually closing the operation. The instability could have been safely mined using the remote controlled shovel.

Aug 1, 2013

By G. E. Rodger, R. Jugoon

"SUMMARYSamples of Aunor gold precipitates which varied widely in gold content were fluxed to produce a bisilicate slag with various oxidizers and combinations of oxidizers. On the basis of some preliminary tests a flux composition was chosen which appeared to show the most promise.The different components of this flux were then incorporated into a matrix for a 23 factorial design experiment to determine what were the most important variables and what changes should be made to the flux composition to optimize the resultant total bullion fineness.The results of the 23 factorial design experiment showed that the flux composition as calculated was very close to an optimum as only very minor changes were required to give bullion in excess of 995 fine.INTRODUCTIONEarly in 1969 the results from the Aunor Gold Mines refinery showed that wide variations existed both in precipitate grade and in total bullion fineness. An analysis of this data showed that as the precipitate grade increased, the gold bullion fineness also increased (see appendix 1). Therefore, to improve the refinery results test work was initiated to: 1) improve the precipitate grade and 2) to determine, with the help of statistics, a flux composition which would be able to handle wide variations in precipitate grade and give a total bullion fineness in excess of 950 fine."

Jan 1, 1970