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"In a continuing investigation into the development of uranium alloys for armament applications, some complex base alloy corn positions were modified by varying the amount of alloying elements and by removing one or two of the alloying elements in turn from the base alloys. These uranium-base alloys were specially formulated in a search for heat-treatable, high-strength, ductile, high-density alloys. All alloys studied were ternary, quaternary or more complex alloys of uranium with molybdenum, zirconium, niobium and vanadium. Each cast alloy was studied under three different heat-treatments, and its mechanical and corrosion properties were determined. It was found that although most of the alloys studied had the hardness and strength required, they were extremely brittle and notch-sensitive under tensile stresses."

Jan 1, 1968

By Richard J. Haslinger, C. Mark Rebagliati, James L. Oliver

Abstract - Exploration at the Specogna gold deposit has identified a geological resource of 65.0 Mt grading 1.63 g/t Au, which equates to 3 million ounces of contained gold. This resource is hosted in a low-sulfidation epithermal deposit of Miocene age that is localized along the northwesterlytrending Sandspit fault. The fault has juxtaposed Late Cretaceous mudstone of the Haida Formation to the west, with Late Tertiary coarse clastic sediments and lesser andesitic volcanic rocks of the Skonun Formation to the east. A plagioclase porphyritic dacite dike intrudes the Haida mudstone and Skonun sediments along the fault. Gold mineralization, in hydrothermal breccias, veins and stockworks developed mainly in Skonun sediments and dacite. These are formed in an 800 m long zone that roughly parallels the Sandspit fault. The gold zone is funnel-shaped in cross-section, approximately 300 m wide at surface, 220 m above sea level, and narrows to approximately 50 m, at sea level. The deposit lies within an elongate zone of moderate to intense hydrothermal alteration that, at surface, extends over a known area of approximately 2 km2. Its western extent is bounded by the Sandspit fault. There is an asymmetric alteration zonation, with a core of silicic-potassic (adularia) and smectite-illite clay alteration that is bounded to the east by argillic alteration. Similar zoning defined by the distribution of metals reflects the position of the main feeder conduit. Mineralization of altered wallrock is dominated by 1% to 4% auriferous pyrite and marcasite. Gold and silver occur as electrum; individual silver minerals have not been identified. Other sulfides are rare, and are identified only microscopically. The mineral suite is typical of low-sulfidation epithermal systems. Gold occurs in early, multi-phase, variably bladed and banded quartz veins and breccias, which are cut by barren, single phase, drusy quartz veins.

Jan 1, 1998

By D. A. Beck

The load-deformation response of discontinuous rock under static and dynamic loading conditions has been simulated using Explicit Finite Element models. The intent of the analysis was to investigate the effects of specimen size and confining stress on strength, dilation and comminution. The simulations allow the development of homogenised constitutive material properties for discontinuous rock masses using laboratory scale measurements and representative Discrete Fracture Networks (DFNs). A procedure for this is presented which includes a comparison of measured seismic response in a mine to the Dissipated Plastic Energy (DPE) that is released in the simulated rock masses. The models also show how confinement and scale affect the stress-strain and DPE response of the simulated rock specimens, reproducing a number of known rock phenomena that are often poorly captured in geotechnical modelling. A case study is presented showing a satisfactory match between the model-derived, homogenised material properties and values achieved by calibration of a mine-scale model where many thousands of seismic, displacement and damage measurements were available.

May 1, 2009

By Craig Haase

A. Introduction

Jan 1, 2003

By K. Raht

LEAD poisoning is perhaps the oldest and, until recent years, the most misunderstood of all industrial diseases. Hippocrates appears to have recognized a relationship in the colic experienced by a patient who worked with metals, and the ancient literature is filled with references to the colics and 'dry bellyaches'. The colic and other sequalæ following drinking of lead-bearing waters and, particularly, wines has excited possibly more comment in the older medical literature than any other ætological factor. It was not until1656, when Stockhusen definitely connected the colic of the workmen with the fumes given off in the process, that the true danger to those working with lead was recognized. Unfortunately, something over 200 years elapsed before industry took any note of Stockhusen's discovery; it remained for Legge and Goodly and investigators of the early 1900's to forcibly educate their profession and industry to the manner in which lead gained entrance to the body. The work of Legge and Goodly was published in 1912 and the clearness with which these investigators presented the scientific data which they had accumulated will mark this volume as perhaps the first and most important contribution to our modern knowledge of the subject. It also ushered in a period when, in the short space of thirty years, lead poisoning has been reduced from one of the most baffiing and widespread o industrial diseases to one which can be anticipated and controlled. The next great contribution came in 1926 with the publication of the work of the Harvard group. Here, for the first time, was the physiological behaviour of lead laid bare, and it is to the discoveries of these authors that we owe our modern treatment of lead poisoning.

Jan 1, 1941

By G. M. Mason

History Due to its strong affinity for oxygen, aluminium as an element was isolated only after many other rarer metals had been prepared and studied. It was just over one hundred years ago that two scientists, Hans Christian Oersted and Friedrich Wohler, produced the first few pellets of aluminium and determined its physical properties. These early investigators used metallic potassium as a reducing agent. Later, St. Claire Deville, by using sodium instead of potassium, improved the yield in the reduction and produced some pounds of aluminium. From a figure of about $110 per pound in 1855, the price had fallen to about $4 per pound by 1886. In that year, a very important discovery was made independently by Charles Martin Hall in Oberlin , Ohio, and Paul . Heroult in France. Stated in its simplest terms, the discovery of Hall and Heroult was that aluminium could be produced by electrolyzing a solution of the oxide in molten cryolite. The application of the Hall-Heroult process made the metal immediately available in commercial quantities and, by 1900, the price had fallen to 23 cents per pound. The growth of the industry in the past fifty years is well known, and is outside the scope of this paper. It is, perhaps, not generally known that aluminium was first produced in Canada at Shawinigan Falls in 1901. Since that time, production has been continuous at one or more smelters in the Province of Quebec. The largest of these smelters, which is also the largest aluminium smelter in the world, is at Arvida, Quebec, on the Saguenay river. A large power potential and access to ocean shipping were the two principal reasons for the establishment of aluminium production facilities in the Saguenay district. It is interesting to note that the aluminium industry, as a large user of power, took an active part in the early industrial development at Niagara Falls and Shawinigan Falls, and is now repeating the process in the Saguenay valley.

Jan 1, 1949

By H. R. Stoger

"In 1994 world trade grew by 9%, the fastest annual increase since 1976. Dry cargo shipping rates are at an all time high.Panamax size bulk carriers are receiving19 000 US dollars per day for trans Atlantic round trip voyages. This is good news for the ship owners but not such good news for the industrial users of ocean shipping.The main emphasis of this paper will be on bulk carriers, the charter market and what industrial companies can do to reduce their costs of ocean transportation which is critical to Canadian exporters. Let us look at the charter market in general.Bulk carriers come in four main sizes:1.The Capesize bulk carriers of 110 000 to160 000 tons that are primarily used to transport iron ore and coal;2.the Panamax bulk carriers of about 70 000tons dwt. This is the largest size (with a beam of 105 ft) that can transit the Panama Canal.3.the Handymax bulk carriers of 40/45 000tons dwt; and4.the Handysize bulk carriers of 20/35 000tons dwt.The handysize vessels are usually craned or geared and carry a variety of bulk cargoes including steel. Ship sizes have increased over the years and the mining industry now uses primarily capesize or Panamax bulk carriers.International chartering is conducted through an international network of shipbrokers. There is usually one broker representing the ship owner and another broker who represents the charterer. The major chartering centers are London and New York but a great deal of chartering activity is conducted in regional markets such as Hongkong, Oslo, Montreal and Hamburg.The Biffex Index or Baltic Freight Index is a good measure of dry bulk freight rates. The Biffex is composed of ten major routes. In May1995, the Biffex was at 2310 points. A year earlier it was at 1354, an increase of about 56%."

Jan 1, 1996

By Philippe Monier, Frank C. Basham

"This paper outlines the scope and applications of 'COALMOD', the British Columbia Ministry of Energy, Mines and Petroleum Resources' computerized financial simulation model for coal mining developments. After a description of the computer system and language of implementation, the logic and scope of current model sub-routines are presented. This is followed by a presentation of examples on the current applications of the model to public policy evaluation, including benefit-cost analysis, fiscal analysis and evaluation of the effects of public infrastructure investments made in support of mining projects.IntroductionThis presentation has been developed in response to a number of requests from coal mining companies and various public agencies who have indicated interest in understanding our application of contemporary analytical techniques to public policy in the coal sector. In particular, the subject of this paper is an explanation of COALMOD. a mnemonic given to a computerized, mine-specific, financial simulation model which is assisting the Government of British Columbia in evaluations of new coal projects, assessment of public sector investments made in support of these projects and. more generally, measurement of the financial effects of current or proposed government policies, and factors outside immediate government control such as coal prices and transportation costs."

Jan 1, 1981

By R A. Stevenson

The purpose of this paper is to outline a recent development in ground fault protection. The paper deals with the A problems of both grounded and ungrounded systems, with regard to hazards to personnel and equipment, and shows that the increased sensitivity and speed of operation of this new detector results in increased safety to personnel and reduced stresses on equipment, and permits the detection of leakage currents before they become serious faults. The detector can be applied to all distribution systems, either A.C. or D.C., up to 15 kv., and the detector itself can be tested at regular intervals without interrupting line circuits. T HERE is always controversy among engineers as to whether distribution systems should be grounded or ungrounded. There are many experi-enced engineers on both sides of this controversy, and each have valid reasons for their choice

Jan 1, 1964

By L. W. Hamel

"Two 35 foot diameter enviro clear thickeners were tested in series as CCD units from June until October, 1978. Up to shutdown in July, we ran with automatic bed level control via the level probes and underflow pinch valves. Despite extensive efforts, we were unable to eliminate the surges created between the units by the opening and closing of the pinch valves. Early in July, the best rake speed and gap setting were determined. After shutdown, the enviro clears were run by manually controlling the pinch valves. These efforts were successful.A few mechanical problems were encountered while operating the thickeners. New units should incorporate more support for the drive coupling and a rubber feed seal. A few modifications of the instrumentation control scheme will be required before the units can be fully automated. A less sophisticated automatic flocculant addition system will accomplish the desired results. Control of the underflow withdrawal via the pinch valve should be investigated further. Our best results were obtained by keeping the feed volume to the No. 1 enviro clear constant. Surges were controlled by opening or closing both underflow valves proportionately.Capacity of the enviro clears is dependent of many variables. The ore treated during the test program was much finer than that reported on in R & D Project Report 76-02. Conditions were never steady enough to determine best flocculant dosage or addition point(s). The lowest soluble losses were obtained at very high wash rates. The underflow densities drop but the soluble losses also drop. Regression equations were developed in order to assess the effect of the various parameters. Within the range studied, these equations will predict the performance of enviro clear thickeners as CCD units on Elliot Lake ores. Our results show that the enviro clear thickeners are a viable alternative to the conventional CCD thickener."

Jan 1, 1979

By I. Filzwieser, S. Konetschnik, A. Filzwieser, A. Anzinger

Production in copper electrorefining tankhouses mainly depend on two factors: The deposition area, which is a result of the amount of installed cells and cathodes, as well as the current density - the amperage per square meter of deposition area. The present paper shows, that the most economical way of achieving a certain production is to maximize current density by using the METTOP-BRX-Technology - as building and infrastructure can be kept more compact. This industrial proven technology applies a parallel electrolyte flow in each electrolysis cell. In 2011, the first fully industrial applications started up: At the secondary smelter Montanwerke Brixlegg AG, 156 cells are equipped with the METTOP-BRX-Technology; this allows a current density of 390 A/m². Xiangguang Copper Co., Ltd. - a primary smelter and refinery - operates its new tankhouse (720 cells) at 420 A/m²; this stands for an production increase of 50% compared to the same sized ISA tankhouse which is limited to 280 A/m². The first part of the present paper gives a cost comparison between a conventional copper electrorefining tankhouse and a high current density tankhouse when assuming a Greenfield project. The second part describes the cost savings when installing the METTOP-BRXTechnology in an already operating tankhouse.

Jan 1, 2014

By Steven W. Wilson, Brigitte Lacouture, Nichola A. McKay

"The Aqqaluk deposit is a lead-zinc ore body that lies immediately north of the Main Pit at Teck Cominco’s Red Dog Mine in Alaska. It is scheduled to begin production in 2011 or 2012. A project team was formed in late 2004 to plan and implement an ore characterisation and metallurgical evaluation on the Aqqaluk ore. The main objective of this program was to facilitate the transition from Main Pit to Aqqaluk ore in the Red Dog concentrator. The program will develop a detailed, spatially-oriented characterisation of the Aqqaluk deposit attributes including lithology, ore geochemistry, bulk mineralogy, ore texture, as well as evaluating the metallurgical characteristics of ore hardness, process water geochemistry, bench-scale floatability and mineral liberation in ground feed, concentrate and tails. Developing correlations between the metallurgical response and the ore characterisation data is key to the emerging science of geometallurgy. This on-going program is a technical due diligence study that aims to reduce the risk associated with processing a new ore and to provide predictive information for mining and stockpile preparation.The test work to date has focused on characterising the five ore zones currently identified in the Aqqaluk deposit, namely: Siliceous (sub-divided to High Zn:Fe and Low Zn:Fe), Vein, Median Plate and Baritic ores. It identified a number of challenges associated with surface oxidation, or weathering, of the core samples and outlined a program for future sample collection and storage. Metallurgical testing evaluated ore hardness by a variety of methods. Preliminary floatability studies have been completed and some initial links have been established between the ore characteristics and the flotation response. Soluble mineral weathering products, the relative abundance of pyrite and marcasite and the iron content in the sphalerite grains have all shown a correlation to mineral recovery.As new core is received, both the ore characterisation and the metallurgical testing will be continued with a view to strengthen the existing correlations and develop new links."

Jan 1, 2007

By Lang Tao, Jun Wang, Wei Xiao, Wenqing Qin, Pan Cao, Guanzhou Qiu, Key Lab of Biohydrometallurgy of Ministry of Education, Central South University

"The effect of metal cations on the rutile flotation using styryl phosphoric acid (SPA) as the collector was investigated by micro-flotation test, bench scale flotation test, zeta-potential measurements and adsorption measurements. The micro-flotation results indicated that Fe (?) and Al (?) ions in low concentrations had obvious activation on the rutile flotation, and Pb (?) ions in low concentrations had smaller activation of rutile, but Fe (?), Al (?), Pb (?), Ca (?) and Mg (?) have strong inhibition of rutile flotation in high concentrations. The bench scale flotation results indicated ethylene diamine tetraacetic acid (EDTA), boracic acid, and sodium hexametaphospate can decrease the metal ions concentrations, and increase the recovery of rutile flotation. Adsorption measurements and zeta-potential measurements revealed that Fe (?), Al (?) and Pb (?) ions were adsorbed on the rutile surface, and had interaction with SPA. But when these ions concentration were over the largest adsorption capacity, residual metal ions could occur chemical reaction with SPA.INTRODUCTIONRutile is one of the favored minerals for production of titanium dioxide white pigment, primarily through the chloride manufacturing process (Stanaway 1994; Hou et al., 2013) However, the majority of rutile ores belong to refractory ores, while flotation is one of the most efficient methods to separate fine rutile from gangue (Dolbear et al., 1937). With the flotation development, many effective collectors were successfully applied in the oxide ore. Many reviews have indicated that organic phosphonic acid collectors showed good selectivity on oxide ores such as ilmenite and rutile (Bulatovic & Wyslouzil 1999; Liu & Peng 1999).It is inevitable that many types of metal cations are present in ore pulp. These metal cations significantly influence the flotation of minerals. Liu et al. (2015) showed that Ca2+ and Mg2+ could improve the floatability of spodumene at pH 12.5 and 10.0, respectively. The authors proposed that Ca2+ and Mg2+ ions readily form hydroxy complexes (CaOH(l) and MgOH(l)) and precipitates as (Ca(OH)2 and Mg(OH)2) in strongly alkaline solutions. Fan and Rowson (2000) investigated the effect of Pb(NO3)2 addition as an activator on ilmenite flotation and showed that it could improve ilmenite floatability. The addition of Pb(NO3)2 resulted in an increase of ilmenite zeta potential in both weakly alkaline and acidic aqueous solutions. Mehdilo, Irannajad, and Rezai (2015) studied three kinds of ilmenite of different origins and discovered that both Mg and V had a negative correlation with ilmenite flotation, while the Mn content seemed to correlate positively with flotation efficiency. A number of studies have also showed that Fe3+ can improve the floatability of ilmenite (Fan et al., 2009; Nuri, Mehdilo, & Irannajad, 2014)."

Jan 1, 2016

By O. K. Mahabadi, A. Lisjak, B. S. A. Tatone, N. Vlachopoulos

"Numerical simulations are widely adopted in the design of several types of rock structures, including tunnels, caverns, rock cuts, and open pit and underground mines. In recent years, analyses based on the hybrid finite-discrete element method (FDEM) have been shown to provide a realistic representation of rock mass deformation and fracturing processes. To date, the FDEM approach has successfully yielded qualitative and quantitative results for several practical rock engineering applications, yet it has lacked the ability to consider the implementation of rock-reinforcement measures. Since rock reinforcement is often used in civil and mining applications to improve the strength and deformational behaviour of a rock mass, the ability to incorporate such features into FDEM analyses is essential to extend its applicability to a broader range of problems. The work presented in this paper represents an important first step towards developing a simulation tool that can be used for practical rock engineering applications, including the design of underground excavations and rock slopes.INTRODUCTIONRock support and reinforcement measures are often employed in civil and mining rock engineering projects in order to maintain or improve the strength and deformational behaviour of rock masses. The preferred type of reinforcement or support elements along with the preferred layout and timing of installation depend on the in-situ ground conditions, the nature of the rock mass and excavation method. Over the last two decades, numerical modelling has been increasingly used to design and attempt to optimize rock reinforcement and support systems. As such, most rock engineering-specific modelling software now offers various approaches for modelling different rock reinforcement and support elements."

Jan 1, 2015

By M. C. Bétournay

Mine site infrastructure for storage and delivery of hydrogen must be standardized and acceptable for routine and safe industrial use before fuel cell technology is adopted as a major power source. An initial study reviewed possible options for production, storage and delivery of hydrogen for underground equipment. The high level review included assessment of economic, operational, technical, and health and safety risks. Following this review, a subsequent theoretical study to select typical minesite infrastructure and for construction at an operating research mine is outlined.

May 1, 2007

By T. Prietl

Metallurgical vessel linings are multilayered, consisting of refractory bodies, insulation materials, joints, and additional space to control for thermal expansion. A unique biaxial hot testing press (BHTP) was installed at the RHI Refractories Technology Center Leoben, Austria to enable the three-dimensional behaviour of complex vessel lining segments to be investigated under simulated service conditions. Using the BHTP, the heat up and thermo-mechanical behaviour of magnesia chromite brick lining segments with and without mortar filled joints were examined. The results obtained during the initial heat up provided validation of CFD modelling of the lining system. In addition, after the heat up and under steady state conditions, the lining behaviour during deformation-controlled compression and relaxation was examined. These analyses generated important data regarding the stiffness, joint compressibility, and brick damage of the lining segments after cyclic loading and unloading as well as the benefits of using mortar joints in the lining. These investigations were performed in collaboration with the Christian Doppler Laboratory for Secondary Metallurgy of Nonferrous Metals, University of Leoben, Austria. The BHTP has been operational since November 2004 and is providing information regarding the thermo-mechanical behaviour of different lining segments.

Jan 1, 2007

By R. G. Hamm

A brief outline covering the shovels and draglines in use in the open-pit mines of Western Canada, including British Columbia, Alberta and the Yukon, is given, followed by the procedure for the selection of the correct wire rope for each application. Such fa ctors as wire rope constructions, lay directions and types of cores are mentioned. Once the correct wire rope has been selected, there are variousfactors that can affect the service fife ofthe rope and the reduction ofdown-time during rope change-overs. Factors such as hairpin winding, types of Becket loops, and shovel drum and bail adaptors are described.

Jan 1, 1979

By D. J. W. Piper, T. Hundert, G. Pe-Piper

"Abstract - Potentially commercial deposits of kaolin are found in the fluvial Lower Cretaceous Chaswood Formation, the sedimentologically proximal equivalent of deltaic sediments of the offshore Scotian basin. The geological setting of the kaolin deposits has been interpreted from high-resolution seismic-reflection profiles and boreholes, and mineralogical studies on one reference borehole. The kaolin is a product of early diagenesis involving meteoric water below the water table. The distribution of kaolin is controlled by the presence of intraformational unconformities that were sites of ground water recharge, and are marked by the development of oxisols above the water table. Such diagenesis was facilitated by interbedded, loosely consolidated, permeable sandstone. The highest-grade kaolin deposits are found in areas close to river belts, where overbank muds were not sufficiently drained to develop paleosols, but where later uplift created intraformational unconformities. In the sandstone, meteoric water flow altered feldspars to kaolin, thus yielding commercial silica sand deposits. It also altered ilmenite to rutile, which is concentrated as secondary placers in modern rivers that have eroded the Chaswood Formation and tills derived therefrom. Sommaire - Des dépôts de kaolin potentiellement économiques ont été notés dans la Formation de Chaswood d'’âge Crétacé Inférieur, laquelle constitue un équivalent latéral en milieu fluviatile aux sédiments deltaïques du bassin de Scotian. Le contexte géologique de ces dépôts de kaolin a été interprété a partir de profils de seismique-réflection à haute résolution, de sondages, et d’études minéralogiques sur un sondage de référence. Ce kaolin est un produit diagénétique précoce formé par de l’eau météorique sous le niveau de la nappe phréatique. La distribution du kaolin est contrôlée par la présence de zones de recharge associées à des discordances intraformationelles marquées par le développement d’oxisols au-dessus du niveau de la nappe phréatique. La présence d’interlits de grès perméables faiblement consolidés a contribué à l’efficacité de ce processus diagénétique. Les dépôts de kaolin les plus riches se trouvent en périphérie des rivières, là ou les boues de la plaine d’inondation n’étaient pas suffisamment bien drainées pour permettre le développement de paléosols, mais où des mouvements verticaux subséquents ont crée des discordances intraformationelles. La circulation d’eau météorique dans les grès a entraîné l’altération des feldspaths en kaolin, générant ainsi des dépôts économiques de sable de silice. Elle a aussi causé l’altération de l’ilménite en rutile, que l’on trouve dans des placers secondaires situés dans des rivières contemporaines qui ont érodé la Formation de Chaswood et les tills qui en sont dérivés."

Jan 1, 2006

By J. R. Smith

"The Lake Dufault orebodies were discovered by deep surface diamond drilling. When a reasonable amount of outline drilling had been completed, the decision to go into production was made. The fact that shaft sinking, lateral development, the detailing of the orebodies and stope preparation were to be carried out as rapidly as possible necessitated very close scheduling.After a study of varions possible mining methods, an open-stoping system using long-hole blasting was chosen. Diesel-powered Transloaders were selected for the mucking and transportation of ore from the drawpoints to the orepass.At the time of writing, the choice of mining method appears to have been fully justified, although more time will be required to arrive at true operating costs and efficiencies."

Jan 1, 1966

By Xing Jin, Dan Graffi, Glenn MacPherson, Dan Rioux

"The complexity of a modern flotation circuit makes it susceptible to disturbances such as changes in feed, ore mineralogy, equipment degradation, poor measurements and faulty instruments. Good measurements and a robust control system are critical to create and maintain a stable and optimum flotation process.This paper focuses on the development and implementation of process control applications in the flotation circuits at Xstrata Nickel’s Strathcona Mill ( referred to as the mill hereafter ) in Sudbury, Ontario. Following the path of ‘stabilize-improve-optimize’, basic controls to stabilize process variables such as flotation cell pulp level, air and reagent addition rates, cleaning-column feed and wash-water rates have been established. Factors such as best practice in pulp level and valve position measurement, feedforward control and the application of an appropriate control philosophy, have contributed to the significant reduction in process variability. For instance, standard deviation reduction of 79% for the Ni impurity in the column Cu concentrate grade was experienced and is shown. The variability reduction of the flotation circuits’ key process-variables paves the way to further improve and optimize flotation performance. A grams-per-metal unit reagent addition control scheme has been improved upon, particularly for different operating scenarios and better robustness. In addition, following significant stabilization of the primary controls and columns feedrates, Cu/Ni separation cleaning-column bias-control (cascaded to the wash-water rate) and hold-up control (cascaded to air flowrate) have been developed and tested. This strategy – from stabilization to optimization - is expected to achieve a more consistent control of final concentrate grades and improve recoveries.INTRODUCTIONFlotation is considered the most important and value-added process in the milling metallurgical plant and is still undergoing continuous evolution to treat greater tonnage and different ores (Wills, 2006). Starting over three decades ago, with the advent of on-line slurry content analysis devices, flotation automatic control has received persistent interest and a large number of applications have been reported (Thwaites, 1983, 1986 ; Mckee, 1991). Bergh and Yianatos (2011) reviewed different aspects of process control in flotation circuits and have evaluated the applicability of model predictive control to the process. Mckee (1991) analyzed the difficulty in developing lasting/robust process control applications for flotation circuits and stated that the path of stabilization-refinement-optimization would more likely lead to successful flotation circuit process control. Best practice on column process control was discussed by Bouchard, etc. where a multi-layered approach was proposed, provided that the measurement of column process variables ( i.e. bias, froth depth, hold-up, etc. ) are measured reliably (Bouchard & Thwaites, 2008). Wills (2006) stated that the best practice for flotation automatic control starts with fulfilling basic control objectives, such as stabilized flotation cell level, air flow, pH, reagent flow etc., before considering more advanced, or even optimal, control of metallurgical targets, which are more closely linked to economic performance."

Jan 1, 2013