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By G. E. Joe

"This is a panel discussion on the milling experience with large volume flotation machines in Canada. Over the past ten years, the Canadian milling industry has been characterized by treatment of ever increasing tonnages of lower grade ores. In order to treat these ores efficiently, mineral processors have been employing increasingly larger volume flotation machines. In older established mills, standard flotation cells have been replaced by the larger volume models with very apparent savings in mill floor space as noted in the Opemiska copper mill.We are pleased to hear from four mill operators with extensive experience on large volume flotation machines. They are:1. I. E. Wahn, metallurgist with Falconbridge-Manibridge, who will describe their mill experiences with the Tank cell and the Maxwell cell.2. G. M. Hughes, mill superintendent of Sherritt Gordon-Ruttan, will detail recent experience with the Agitair cell.3. J. R. Maxwell, mill superintendent of Opemiska Copper, will report on their Maxwell cell installation and operation.4. A. H. Winckers, superintendent of Development and Technical Control, Sullivan Mill, will present a paper written by H. J. Chalmers describing Cominco's past experiences with large volume flotation machine installations including Denvers, Wemcos and Maxwells."

Jan 1, 1974

By S. H. Lucas

"This paper describes the development and application of single-stage fluidized bed continuous ion exchange to the following processes: removal of base metals from mine water; cyanide removal from gold mill waste; uranium removal from sulphuric acid leach liquor; and uranium removal from mine water. IntroductionThe recovery of metals by fixed bed ion exchange has been practiced for many years. However, the operation has been semi-continuous and can only treat clarified liquors. Substantial savings could be made if the operation were continuous, thus reducing the resin inventory, and if the costly filtration and clarification steps could be eliminated. Work has been in progress over the past twenty-five years on the recovery of metals from unfiltered ore leach slurries, heap leach liquors and mine drainage waters containing a small amount of suspended solids. In the case of dilute waste solutions, with suspended matter and high flow rates, filtration is usually prohibitively expensive.Continuous ion exchange operation using fluidized beds has made it possible to reduce considerably the resin inventory and to allow the treatment of unclarified liquors and slurries. The subject has been reviewed on several occasions (1. 2. 3, 4). Although fluidized beds in multi-stage columns are an improvement over previous resin-in-pulp treatment, they have complicated internal structure and I or involved automatic control systems to move the resin stages.Slater and Prud'homme performed studies on multi-stage fluid beds, and concluded that the performance of single, deep fluidized beds of resin with continuous or semi-continuous flow of both phases would be worth investigating, particularly in the case of very dilute metal solutionsoi, A pilot plant was designed and built at CANMET in a cooperative project with Dr. Slateroi. The use of deep fluidized beds of resin (with a large height/diameter ratio) for treating dilute solutions has the attraction of engineering simplicity. Extreme simplicity of equipment design is considered of paramount importance when treating, for example, mine waters at high flow rates, possibly of the order of several million gallons per day. This paper describes the development of the concept of single-stage fluidized bed continuous ion exchange arid reviews the pilotplant development of processes for the treatment of base metal mine water, cyanide waste water, uranium leach liquor and uranium mine water."

Jan 1, 1980

By X. -G. Chen, J. Qin, K. Liu, D. Racine

"Understanding the thermo-mechanical fatigue (TMF) behavior of materials plays a significant role in the safety design of critical components used in aerospace and automotive industries, such as engine blocks and cylinder heads, which undergo the cyclic change of temperature and stress. However, the cyclic changes of temperature, stress and strain make it difficult using the traditional testing methods to accurately simulate the TMF process. In the present work, the Gleeble® 3800 system was successfully applied to develop a reliable procedure to measure the TMF behavior of aluminum alloys. The modified setup together with the new designed program allows the Gleeble system to precisely simulate the cyclic profiles of temperature and mechanical strain. The novel procedure includes the calibration and verification of the TMF setup to ensure the test validity with Young’s modulus measurement, multi-cycle measurement of the thermal strain and zero stress adjustment followed by online monitoring the TMF cycles. The results of the TMF testing of an AA6061 alloy under cyclic temperatures (60–300°C) and various strain amplitudes (0.2–0.6%) were demonstrated. Its TMF behavior was characterized by the typical hysteresis loops and cyclic stress-strain response.INTRODUCTION The thermo-mechanical fatigue (TMF) behaviour becomes increasing important to evaluate the elevated-temperature properties of materials used as the critical components in automotive and aerospace industries, such as the gas turbines (Hu, Shi & Yang, 2016; Moverare, 2007; Segersäll et al., 2015) and engine blocks (Grieb, Christ & Plege, 2010; Javidani & Larouche, 2014). During the cycles of start-up and shutdown of the engines, these components undergo a complex change of loading. Meanwhile, a dramatic temperature gradient exists on the components due to the cooling system. Therefore, the cyclic changes of load and temperature can give rise to the TMF and may limit the use life of such components (Hu, Shi & Yang, 2016; Javidani & Larouche, 2014; Moverare, 2007). Hence, performing the TMF tests to precisely simulate the cyclic changes of load and temperature to understand the TMF behaviours of materials is playing a significant role in the safety design of these components. For TMF tests, two principal types of cycles are generally employed, including the in-phase (IP) cycle where the load and temperature are at the same phase (i.e. maximum load at highest temperature) and out-of-phase (OP) cycle where the maximum load is applied at minimum temperature (Kliemt, 2012; Miller, 2014). The most significant damage mechanisms in engine components are reported to be OP TMF cycles (Javidani & Larouche, 2014; Kliemt, 2012)."

Jan 1, 2018

By M. DeLucia

"Over the past 15 years, technical innovations have improved the properties and performance of monolithic refractories. As these improvements have occurred, aluminum cast-house refractory selections have changed from brick to monolithic refractories supplied as either cast in place, or precast, ""Big-Block"" installations. A review of the properties of monolithic and brick refractories is presented, as well as the technical advantages of brick for highly demanding applications. Operating conditions and issues such as temperature, alloying, corundum growth and other variables are also reviewed."

Jan 1, 2004

By L Tafaghodi Khajavi, M. Barati

The distribution of phosphorus between solid silicon and iron-silicon melt was determined to investigate the degree of phosphorus removal from silicon by solvent refining with iron-silicon alloys. The distribution coefficient which is the ratio of the mole fraction of phosphorus in solid to that of liquid is as follows: 0.22±0.02 (1310°C), 0.29±0.02 (1260°C) and 0.33±0.02 (1210°C). The removal percentage of phosphorus is: 84.2% (1310°C), 72.5% (1260°C), and 63.7% (1210°C). The average phosphorus content of produced silicon in the proposed solvent refining process would be over two times less than that of the conventional directional solidification. The values of interaction coefficient of phosphorus on iron at different temperatures were obtained as -3460±155 (1310°C), -3595±159 (1260°C) and -3694±119 (1210°C). Self interaction parameter of phosphorus at different temperatures are as follows: 68±4 (1310 ?C), 78±10 (1260 ?C) and 103±19 (1210 ?C). The calculated values for distribution coefficient of phosphorus at infinite dilution are: 0.22±0.00 (1310°C), 0.30±0.00 (1260°C) and 0.34±0.00 (1210 °C).

Jan 1, 2015

By S. C. Livanou, S. P. Tampouris, E. N. Zevgolis

In ferronickel (Fe-Ni) production from oxidized nickeliferous ores, mechanical losses of ferronickel in the slag are reduced by magnetic separation. Slag from the electric furnaces (E/Fs) contains 0.16% Ni. Its magnetic separation gave a pre-concentrate with 0.76% Ni, weighing approximately 6.5% of the feed. Nickel recovery was 29.7%. This pre-concentrate was then treated in a second (concentration) plant. Concentration treatment involves screening, crushing and magnetic separation. A pre-concentrate with 0.76% Ni gave a magnetic concentrate with 2.58% Ni and a non¬magnetic part with 0.35% Ni. Smelting of the non-magnetic part without the addition of a reduction agent in a laboratory electric arc furnace, gave a ferronickel alloy with approximately 20% Ni and a slag with 0.16% Ni.

Jan 1, 2005

By S. M. Bulatovic, D. M. Wyslouzil

"This paper presents the results of a study of the effect of flowsheet configurations on metallurgical results and describes a general method for developing and optimizing flowsheets used in the treatment of massive sulphide ores. The flowsheet configuration can have a significant effect on recovery and selectivity between valuable minerals and gangue minerals. Placing of intermediate products within the flowsheet, positioning of various pretreatment units, such as conditioners or regrinding mills, and the ability of the flowsheet to cope with wide swings in the feed grade and composition are the major parameters that determine the optimum flowsheet configuration. The complexity of the flowsheet is largely a function of the ore itself and of the number of final, marketable products that have to be recovered from the ore. INTRODUCTIONTechnological ExpansionThe trend of past decades has been towards larger equipment and a better understanding of the chemistry of the flotation process. Despite appreciable progress in these areas little attention was given to the study of the actual configuration of the flowsheet, although the arrangement of the flotation equipment significantly affects the overall performance of the circuit."

Jan 1, 1989

The Shortage of Mining and Metallurgical Engineers I N many parts of the Western World attention has recently been drawn to the acute shortage of mining and metallurgical engineers produced by the universities. Naturally, the reasons for this shortage have been discussed, and various remedies for it have been proposed. In this paper, I want to examine some of them. It is now fairly generally ac-cepted among mining men that the easy attractions of modern urban life have left the career of mining in the metaphorical as well as in the literal backwoods. The industry finds it increasingly difficult to recruit adventurous and intelligent young men; for such men now seek their intellectual, if not physical, adventure in more glamorous occupations from a safe social base in suburbia. The salaries, opportunities and security offered by the mining industry do not complete effectively with the rewards offered by other industries and by commerce, taking into account the social disadvantages of a mining life. The excitement and other non-material attractions of mining

Jan 1, 1965

By S. Kelebek, E. Yalcin

"Diethylenetriamine (DETA) and/or triethylenetetramine (TETA) are reagents that can generally be categorized under ""flotation modifiers"". These polyamines are known to be effective for the deactivation/depression of pyrrhotite that is present in Canadian nickel-copper sulphide ores in large quantities. Recent bench scale testing on some of these complex ores indicated that chalcopyrite flotation can also be adversely affected under certain conditions involving polyamines, which may be taken to be an evidence of their specific affinity towards chalcopyrite. In general, DETA shows no significant depressant action on chalcopyrite while TETA's promotion of hydrophilicity for this mineral has been observed even in the presence of xanthate. This prompted an investigation on thermodynamic equilibria involving these polyamines and copper ions. Results serve a useful purpose to identify conditions for deactivation phenomena. CuDETA2+ and CuTETA2+ chelates as products of sequestration have large predominance areas covering a wide range of redox and pH conditions, where copper xanthate species are not stable, especially in the presence of TETA."

Jan 1, 2009

By B. Dyck, L. Verhelst

"Colloidal silica in Key Lake’s Solvent Extraction (SX) feed solutions has presented an operational problem for the mill throughout its history. The colloidal silica stabilizes aqueous continuous emulsions, resulting in elevated solvent losses and operational downtime. Through the years, many attempts have been made to solve this problem, but no viable solutions were found. By revisiting an idea dating back to the 1979 feasibility study and re-evaluating it under current operating conditions, a practical solution was achieved. This paper discusses Key Lake’s history around colloidal silica removal, starting with coagulation using a polyethylene oxide polymer (PEO), and ending with coagulation using a polyethylene glycol (PEG) polymer. The results of a mill trial using POLYSIL® RM1250 introduced at doses up to 300 ppm into the counter current decantation (CCD) circuit to clarify SX feed solutions are discussed with a focus on the benefits to SX.INTRODUCTION Colloidal silica has historically been a significant operational problem in the Key Lake mill. Silica originates from clays in the ore as well as concrete backfill intermixed with the ore resulting from the mining method used at Key Lake’s ore source, the McArthur River mine. The silica is dissolved as silicic acid into solution in the mill’s sulphuric acid leaching circuit. Once in solution, silicic acid polymerizes (Hearn, Smethurst, & Boskovic, 2016) forming a fine suspension of stable colloidal particles. These silica colloids are unaffected by flocculants and sand filtration reporting to the pregnant leach solution (PLS) as a fine turbidity in solution. Silica concentrations typically ranged from 700 to 1200 mg/L Si in the PLS fed to SX. Throughout Key Lake’s history, silica interactions in the Solvent Extraction (SX) process have made SX a mill bottleneck and a source of significant reagent costs."

Jan 1, 2018

By J. O. Marsden

Over the past eight years, Phelps Dodge (a division of Freeport-McMoRan Copper and Gold, Inc.) has developed a suite of proprietary hydrometallurgical processes for the treatment of copper concentrates as an alternative to conventional smelting and refining technology. The technical viability of two processes has been commercially demonstrated in a large scale plant at Bagdad, Arizona, designed to process approximately 52,500 metric tons per year of concentrate containing 30.5% copper. The first process utilizes high temperature (225°C) pressure leaching, followed by countercurrent solid-liquid separation, and then blending of the copper-bearing solution with low grade stockpile leach solution for subsequent treatment by SXlEW for copper recovery. The second process uses super-fine grinding, medium temperature (l60°C) pressure leaching, followed by solid-liquid separation, and treatment of high grade copper-bearing solution by direct electrowinning to recover the bulk of the copper values. The latter process will be utilized at Morenci in a commercial facility designed to treat mixed chalcopyrite-chalcocite-covellite concentrates. This facility is scheduled to start up in 2007. Other flowsheet options have been developed by Phelps Dodge for application to a variety of concentrate materials in specific situations. Examples of various flow sheet options are presented in this paper, and the advantages and disadvantages associated with each are discussed in detail.

Jan 1, 2007

By Larry M. Southwick

Processing of ores to recover metals usually generates large amounts of waste materials, such as rejects from concentrating operations, tailings from leaching and slags from smelting. These wastes often contain substantial amounts of iron and other metals, recovery of which are often considered to be of commercial value. Earlier versions of this paper investigated a number of processes built to recover iron from a variety of copper processing residues. This paper will extend that coverage to residues from nickel/cobalt, aluminum, asbestos and oil shale processing and coal plant fly ash. Products of interest are iron, ferroalloys, magnesium and aluminum. While none of these processes achieved long-term commercial success, their efforts cover the gamut of problems that must be addressed in treating dirty and difficult materials to recover generally low-value products. An Adept is an alchemist who can create a Philosopher's Stone, which could transmute base metals into gold. In 1701 in Berlin one Johann-Freidrich Böttger, a nineteen year old apothecary's apprentice, told King Frederick I that he could discover how to make the Stone. He failed and fled Frederick's wrath to Poland. He failed again, and King Augustus II threw him in jail. Then, in 1709, he discovered instead the secret of making Dresden china, certainly a more practical search. His failures in alchemy led to the nickname Adeptus Ineptus.

Jan 1, 2004

By K. Morikawa, K. Asano, J. Yoshitomi

The quality requirements for ladle shrouds have become stricter year by year to the pursuit of higher productivity and improved quality in the continuous casting of steel. The ladle shrouds must be sufficiently durable under severe conditions, such as operation without preheating and during several sequential castings. The consideration is that ceramic fibres, which have been applied in shrouds for thermal insulation during casting, could pose a risk to the worker's health. We realized materials for the ladle shrouds which show high strength and low elasticity. At the same time pursuing effective insulation, a coating which contains no fibres (Foaming Coat) has been developed, replacing the conventional one containing fibres. These materials are durable under conditions of repetitive use and consequently satisfy the customer's demands. The ladle shrouds which were improved in this way have achieved an excellent durable life in hot service of three times that of conventional ones. This paper reports the recent technological developments in ladle shrouds as well as their performance under hot operating conditions.

Jan 1, 2004

By V. Gaudreault

Rio Tinto Alcan (RTA) has three smelters that use the Alcoa P155 technology: two in Canada (Grande-Baie and Laterrière, Saguenay, QC) and one in the United States (Sebree, Kentucky). The oldest RTA P155 smelter was built in the 1970s (Sebree) and had an initial current intensity of 155 kA. In the 1990s, RTA installed an amperage booster in Grande-Baie smelter to increase cell productivity. Since then, RTA has continuously pushed the limit of this technology and the target amperage that was 195 kA in 2005 has been increased to 210 kA in 2010.This article describes the successful plant-scale trials to increase current intensity from 195 kA to 210 kA, and the key performance indicator results. It demonstrates RTA's technology leadership to undertake such a development with its Brownfield smelters.

Jan 1, 2011

By D. Sagara, V. G. Makhado

"A model based control strategy was implemented at Loulo Gold Mine in Mali, to stabilise the thickener underflow stream density. This stream acts as the feed to the leaching circuit. pH control of the leaching circuit was integrated with the model-based controller due to slow process dynamics that are not suited to PID control. The controller performance was quantified over a period of 6 months, and was compared to the performance before implementation. The model based controller reduced process variability for both thickener underflow density and pH considerably, and resulted in a reduction in flocculant and lime consumption of 9.32 and 6.55%, respectively. INTRODUCTION Reagent consumption in gold processing plants significantly contributes to the total operational costs. In a typical Carbon-in-pulp (CIP) circuit, the reagent consumption associated with leaching, adsorption, elution and regeneration contribute to approximately 15% of the total operational costs (Stange, 1999). At Loulo Gold Mine, the reagent consumption associated with leaching, adsorption, elution and regeneration contributes to 6% of the total operational costs. As such, a reduction in reagent consumption will present a significant opportunity for savings on operating expenditure. Variability in feed ore characteristics results in continuous changes in steady state operating regions, which presents process control challenges as a result of the long residence times in some of the process units associated with gold processing plants. Overdosing often occurs in the presence of process variability to ensure safe operation and to maintain recovery targets. As a means of reducing reagent consumption and accounting for significant changes in the feed to gold plants, some of the plants have resorted to improving their process control strategies around their circuits. This paper focuses on the implementation of a model predictive based controller at Loulo Gold Mine on their thickener and Carbon-in-leach (CIL) tank to: •,stabilise the thickener underflow density, and •,the CIL tank pH."

Jan 1, 2017

By R. H. McCorkell

Radon emanation rates. J. and compositions of materials from the Canadian Certified Reference Materials Project (CCRMP) indicate that the fraction of the Rn produced that escapes, E, is usually 1% to 8% and the 238U decay chain is nearly in secular equilibrium. For some Chinese ore standards, E values are higher than f or the CCRMP materials. Standard ore tailings have 2/oPb concentrations higher than expected from their 226Ra concentrations and Rn escape rates (12 - 34%) . Biological materials have E ˜100%, their ash E ˜0%. Pelletizing ore powders at 20 000 lb/in2 reduces J by only 20 - 40% but only 2% of Rn escapes from pressed Li2B4O7 pellets and 0.01 - 0.04% from fused Na2B4O7 or Li2B4O7 discs. Large, difficult-to-explain random variations in J are observed in some situations but several highly reproducible ways of measuring emanation rates have been found.

Jan 1, 1986

By Manqiu Xu, Songtao Yang, Zongfu Dai, Robert Pelton

Five years ago, VALE Base Metals (then INCO), approached Pelton's group at McMaster and described a challenging mineral separations problem. The McMaster group has a strong track record in colloids, polymers, and chemical additives for papermaking; however, they had no experience in mineral processing. They proposed employing hydrophobic nanoparticles to replace conventional low molecular weight, water-soluble flotation collectors. Over the last five years, Vale, together with the Ontario Government (OCE) have funded two graduate students at McMaster who have worked closely with flotation experts at Vale. Experiments involving both very clean model mineral suspensions at McMaster and complex ores at Vale, have shown that hydrophobic nanoparticles do indeed function as collectors. Key nanoparticle properties and mechanisms have been identified and the technology has been protected in patent applications. Efforts to commercialize the technology are on-going. We believe that this project is a good case study demonstrating the advantages of industry-university collaboration and the use of outside experts, who may come up with novel solutions to complex problems.

Jan 1, 2011

By S. Zakaria

"Inco's Automated Haulage Truck System (AHT) is a revolutionary automatic guided vehicle that performs all load, haul and dump operations without human intervention. The high level of sophistication and the short period it has been in operation has only allowed a select few Inco personnel to become familiar with the ART operation and maintenance. As an aid to operations an expert system using the knowledge gained from the experienced specialists was implemented in the field.The AHT operating and maintenance assistance expert system will reason through the information given, arrive at conclusions and give advice to operations, technical and management personnel. It will provide comprehensive real-time troubleshooting assistance for the hydraulic, electrical and mechanical subsystems of the ART. The ART expert system has many benefits to Inco which include increased skill levels of ART operations and maintenance personnel, reduction in ART downtime, standardization of troubleshooting procedures and reduction in ART operating and maintenance costs. In the future, the expert system application will be linked to SCADA (Supervisory Control and Data Acquisition), maintenance and statistical software to display current and historical trends of variables from a centralized historical database. As well, a wide variety of features will be integrated into the system including AutoCad drawings, graphics, photographs, voice and video capabilities."

Jan 1, 1994

By T. Stergiou

An extensive research is being carried out on the shaft furnace operation in order to minimize down-times and reduce operational cost. The need to increase the scrap percentage on the charging mix, together with the need of cheaper spare parts has led to the investigation of alternative materials for the burner system on the shaft furnace. This system consists of a burner block and a flame holder. Traditionally these items are constructed either from SiC ? oxide bonded or SiC-nitride bonded. A lot of problems have been confronted over the past 8 years of operation. Usually, large cracks are formed on both flame holders and burner blocks. This resulted in leakage of combustion gases to the back of the lining and a quick erosion of it. Additionally, the burner blocks suffer from chemical erosion, due to the increased amount of scrap used in the charging mix and the presence of slag inside the furnace. Alternative materials such as stainless steel for the flame holder and alumina-chromia refractory for the burner block have been tested in terms of life-time and resistance on chemical erosion. Furthermore, additional changes have been made on the burner block design in order to alter the flame shape and improve the scrap melting operation.

Jan 1, 2007

By H. Son

The three-dimensional (3D) reconstruction of as-built industrial plant models plays an important role in revamping planning, maintenance planning, and preparation for dismantling during the lifecycle of industrial plants. Recently, the 3D reconstruction of existing industrial plants was conducted using laserscan data to make surveying processes more efficient. However, the current 3D reconstruction process from laser-scan data is still limited due to the need for significant human assistance. Although a great deal of effort has been made to efficiently reconstruct 3D as-built industrial plant models, the presence of objects?such as equipment, pipelines, and valves of different sizes and shapes?in existing industrial plants significantly increases the complexity of laser-scan data and makes automating the reconstruction process more challenging in practice. The purpose of this study is to propose a knowledge-based approach for the 3D reconstruction of as-built industrial plant models from unstructured laser-scan data. First, pipelines were extracted from laser-scan data based on surface curvature information and knowledge about pipelines' sizes from existing piping and instrumentation diagrams (P&ID). Once entire pipelines were extracted, they were modeled based on skeleton features. Then, the remaining objects were clustered and grouped separately via the region grouping process. Afterward, clustered objects were retrieved and modeled based on global feature-based matching from the 3D database. Finally, the resulting model was checked to ensure that it was well-reconstructed according to the information regarding the relationships among objects abstracted from the existing P&ID. The preliminary results on actual industrial plants show that integrating knowledge into the reconstruction steps played an important role in the proposed approach and that this approach obtained accurate as-built industrial plant models from unstructured laser-scan data. The proposed approach could be successfully utilized to assist in many applications during the lifecycle of industrial plants.

Aug 1, 2013