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By Cheryl L. Allen

The increasing energy costs associated with mining has become an issue that needs to be addressed for future sustainable production. Vale Inco is undertaking a Ventilation on Demand (VOD) Project in an effort to minimize costs, continue to mine at depth and reduce green house gas emissions. A dynamic VOD system is very complex with potential high risk. Therefore, a systematic approach is being taken for successful development and implementation of the concept. The physical components of the system are currently being tested at various Vale Inco mine sites. While the operability of the physical components are being tested, the strategy for optimizing the architectures of the system is being defined. This presentation discusses the method of developing a VOD system at Vale Inco.

Feb 1, 2008

By A. Iizuka

This study was aimed at separating and recovering arsenic, antimony, and tin from refining byproducts generated in a nonferrous smelter. The target byproduct was a silicate slag containing the above elements. The silicate structure of the slag was destroyed by alkali roasting, which then enabled leaching of arsenic, antimony and tin in solution effectively. Arsenic was selectively leached out by hot water after alkali roasting of the slag, while remained antimony and tin in the residue were leached out by a hot hydrochloric acid solution. However, when the solid-liquid ratio in the leaching solution was increased, hydrous gelatinous silica (gel-like silica) was formed during the hydrochloric acid treatment and filtration became difficult. Therefore, high temperature and high pressure leaching was attempted to improve the filterability of the silica leaching residue. In the high temperature and high pressure treatment, the hydrous gel-like silica was transformed into easily filterable aggregated silica, and thus, filtration became easy. By investigating the neutralization and sulfurization treatment for the obtained hydrochloric acid leachate (second leachate), it was possible to separate antimony and tin. INTRODUCTION This study aims to separate arsenic and recover valuable metals such as antimony and tin from refining byproducts generated in a nonferrous smelter. The target smelting byproduct is antimony-containing slag in this study. In many cases, alkali roasting was adopted as pretreatment for extraction and recovering valuable metals from smelting residues and wastes (Rao, 2006). For antimony-containing slag in this study, one effective method for separating arsenic is to convert arsenic to sodium arsenate (Na3AsO4) by roasting with a sodium compound and then to remove arsenic by hot water leaching. In addition, by alkali roasting, the silicate structure of the slag is destroyed, and effectively alkalizing tin and antimony is accomplished. Then, precipitating and recovering tin and antimony leached into the acid solution are considered possible by sulfurization and neutralization treatments. In this research, we conducted basic studies on the following. 1) Destruction of silicate structure in slag by alkali roasting and leachability of arsenic. 2) Conversion of hydrous gelatinous silica to aggregated silica by hydrochloric acid treatment of residues after arsenic leaching under high temperature and high pressure, as well as leachability of antimony and tin. 3) Separation and recovery of antimony and tin by sulfurization and neutralization treatments of hydrochloric acid leachate. These topics of investigation can support to consider the separation and recovery process of arsenic, antimony, and tin from antimony containing slag.

Jan 1, 2019

"The Code was developed in 2004 through the Collaboration Agreement between Institution of Mining Engineers of Chile (IIMCh) and the Ministry of Mining (Chile) in Dec 2002. It is an amalgamation of current practices with respect to standards and procedures for exploration prospects, mineral resources, and reserves for the purpose of public reporting. Certification is required to prepare and issue information on mineral assets according to the guidelines that regulate the technical, economic, and environmental aspects that satisfy the conditions set by the Chilean capital and financial markets.The Mineral Resources Committee of the Instititution of Mining Engineers of Chile (IIMCh) is pleased to introduce theCode for the Certification of Exploration Prospects, Mineral Resources and Reserves which is the result of a Collaboration Agreement between the IIMCh and the Ministry of Mining established in December, 2002.This code synthetizes the present practice of the mining industry in regard to standards and procedures applied to exploration prospects, mineral resources, and reserves with the purpose of reporting publicly on financial instruments based on these mine assets in the capital markets. These standards follow general criteria already adopted and applied by capital markets in those countries characterized by a very dynamic and well developed mining sector such as Australia, Canada, Southafrica, United Kingdom, and others. The work done by the Mineral Resources Committee of the IIMCh has had the recognition of the Combined Reserves International Reporting Standards Committee (CRIRSCO) that leads the establishement of an international code in these matters. CRIRISCO is an entity formed by representatives of the countries previously mentioned, a representative of the Society of Mining Engineers of the UStates and a representative of the IIMCh. The Institution thanks the Ministry of Mining, the representatives of these Ministry in the Mineral Resources Committee, and specially the Minister of Mining, Sr. Alfonso Dulanto Rencoret due to the genuine support given to the IIMCh in the preparation of this Code.The Institution also thanks the Superintendencia de Valores y Seguros (SVS) because of the help given continuously to the Committee as well as by the interchange of opinions and suggestions received during the preparation of this document."

Jan 1, 2003

By M. B. Mansur, A. S. Guimarães, A. J. M. Santanilla, D. C. R. Espinosa, J. A. S. Tenório, R. A. Pini

The separation of Ni and Co from sulphate medium containing Mn, Mg, Cu and Ca was carried out by solvent extraction. The object of this study was to investigate the synergistic effect using phosphinic acid (Cyanex 272) and carboxylic acid (Versatic 10) and their mixtures in kerosene. The extraction percent of each metal ion was found to increase with increasing pH and extractant concentration. Co was preferentially extracted over Ni under the same extraction conditions. The separation factors of Ni/Co increased with the use of the synergistic systems investigated.

Jan 1, 2014

By J. Kolacz

"A new sensor based sorting system has been developed, providing a possibility for laboratory scale testing and further scale-up of the separation results to the industrial operation. The new system contains different sensors as: X-ray detectors, visible light cameras, NIR cameras, ultraviolet cameras and magnetic sensors, in the same sorting unit. The sorting unit allows advanced calibration options and fine-tuning of the installed sensors to achieve the best separation effect under controlled conditions. Finally, the processed material can be analysed and separated by the rejection mechanism, similarly to the industrial scale operation. At the same time, the process is carried out with limited amount of material allowing detailed statistical calculations for processed particles and all sensor types. The optimal settings and sensor types are specified for the industrial application.The paper describes the scale up of the results achieved for iron ore and coal, where the test work was first carried out using the new laboratory sorting system and where the industrial scale sorting system has been built, in the final stage. The industrial scale sorting results showed a very good correlation between the laboratory and full scale operation. Thanks to the detailed study carried out in the laboratory equipment, the settings of the sensors in the full scale operation provided much better separation efficiency. It was especially important to provide proper setting for the X-ray sensor data calculations, which can be very critical for achieving the best results. During the industrial scale sorting of coal, the input material had 40-55% rock particles as the direct source of ash in the coal stream. The optimal laboratory unit settings and transferring these settings to the industrial sorter, provided 98.8% efficiency for removing rock particles with only few % losses of coal."

Jan 1, 2016

By L. Voisin, K. Mühlenbrock

A new pyrometallurgical process is proposed for cleaning complex copper matte and for recovering copper from copper scrap containing lead. In the process, a given amount of pig iron is added to the complex material under a reducing condition to produce two or three liquid phases at the equilibrium, depending on the content of sulfur in system, of copper-rich and iron-rich alloys, and matte, respectively. The novel process is proposed based on the experimental results obtained by performing laboratory scale tests in an electrical furnace at 1473 K followed by a quenching method on the final stage. The samples obtained from the experiments were analyzed by using Atomic Absorption Spectroscopy (AAS), Inductively Couple Plasma (ICP) and Carbon Infrared Spectrometry (CIS) techniques. The results were discussed on the basis of the distribution of lead as impurity in the miscibility gap where equilibrated phases coexist. According to the mass balance calculations, the elimination of lead into the iron-rich alloy phase as a harmless and smaller deposit might be feasible and the process proposed for cleaning the complex matte would be promising.

Jan 1, 2014

By Robert Voisey, Robert J. Spencer

"LynnGold's MacLellan Mine is located about 8 km south east of Lynn Lake immediately to the east of the Keewatin River (Fig. I). The property is accessible by an all-weather road, leading north from the provincial highway 391, which links with the Town of Leaf Rapids and the City of Thompson to the south.The ore body, as outlined in the original feasibility study, is expected to produce in excess of 9.3 x IQ6 gm of gold and silver over the next 5 years. However, the deposit is open to depth and exploration is continuing on and around the main zone and the many satellite deposits.The start of construction of the MacLellan Mine and mill was scheduled to phase in with the closure of the Fox copper-zinc mine located 48 km west of Lynn Lake. The majority of the employees from the Fox Operation were either employed at the MacLellan Mine or relocated to Sherrin's Ruttan Operation.GeologyThe MacLellan gold ore deposit is located on the northern section of the Lynn Lake Greenstone Belt known as the Rainbow Trend. This Trend is a 40 km gold bearing rock sequence extending both east and west from the MacLellan Mine. The southern section of these two east-west trending structures is known as the Johnson Shear, this is also gold bearing."

Jan 1, 1990

By D. Furrer, M. Dallaire

The arrival of Image analysis in the last 20 years has changed the world of quantitative metallography. Many standard measurement techniques which were previously manual can now be done with fully automated systems. This reduces subjectivity and operator fatigue and therefore enhances the quality of the statistical results. In many laboratories, Titanium Alloy microstructures continue to be evaluated by traditional methods, where quality of results is subject to operator fatigue and level of experience. Advances in Camera technology have tremendously improved image acquisition. One can often see clearly at 500x what can not be observed at 1000x, allowing for a larger area to be analyzed, without the inconveniences associated with very high magnification objectives. Powerful and versatile Image analysis software combined with a high precision motorized stage gives access to a multitude of applications, which were extremely challenging or impossible until now. Image Analysis tools such as Multilayer Grab, which reconstructs an uneven image into one plane of focus (ex. Observation at high magnification of texture resulting from etching) and Mosaic which builds an image from a number of fields of view (ex. Reconstruction of very large grains at low magnifications) expand even further the power and flexibility of IA systems. This presentation will describe how automated methods are applied to the point count method and grain size measurement. We will show how cameras and software work together to permit quantitative measurements of primary alpha and prior beta microstructures, as well as lamellar alpha plate thickness in titanium alloys.Automated and semi automated quantitative measurements of various Titanium microstrures have been assessed, using the Clemex Vision PE. Examples of the methods and steps used are presented.

Jan 1, 2006

By N. Thompson

The Right Hon. Viscount Long, late Secretary of State for the Colonies, in his inaugural address to the Empire Mining and Metallurgical Congress in London last June said: "I am more and more? convinced by every day experience that the development and strengthening of the Empire must depend upon individual effort and action, and that it is useless to look to Governments for assistance." I am inclined to agree with Viscount Long, to this extent, that the initiative must come from individual effort, but Government assistance is necessary to put the results of that effort and action into effect. It is perhaps fitting at a gathering of this kind to remind ourselves of the part the mining industry has played, not only in the development of the British Empire but in the world at large, in the promotion of modern civilization. We do know that all human progress has been coincident with the early discoveries in the recovery and treatment of metals and, as the centuries have passed, the human race has become more and more dependent on these sciences as factors of all progress, and no nation has ever become powerful and prosperous that has lacked adequate mineral supplies, or having these, has allowed them to be exploited by other nations.

Jan 1, 1925

By A. L. Irwin

THE problem of compensation for labour is probably the oldest and most complicated one in history. The wage that a man receives is possibly the most concrete thing he gets out of his job and, rightly or wrongly, is generally considered by him to be the most important item in connection with his daily work. How today workers in an equitable way has been the study of industrialists for many years, and a great number of ideas have been tried out in an effort to arrive at a reasonable solution of the question. The idea of establishing a measuring stick for various types of work has intrigued industrial management for a long time and, after considerable study, the principle of Job Evaluation has taken form unti1, at the present time, it is becoming increasingly useful to industry at large. Job evaluation is a plan which is used to determine the relative worth of occupations by means of arbitrary measuring scales. These scales are developed for individual industries and are generally 'tailor made' for each particular case. There are as yet no absolute methods of measuring the work done by human beings and, as a result, one has to depend on comparative values to arrive at conclusions. However, job evaluation has provided us with a basis of negotiation for wage rates which is more satisfactory than mere guess work or persona! opinion. It supplies a common ground for discussion which is understandable by all taking part and ensures that thinking with regard to wage setting is carried out along standard lines.

Jan 1, 1943

By Peter Moon, Lloyd G. Campbell

"How well supervisors supervise, and are supervised determines whether management's goals will be reached and ...how effective the work force will be... Upper management must recognize the potential returns of viable training programs for both management and mine workers… The key to performance, from the standpoint of safety and productivity, is the ability of the line supervisor to manage(1).In this article, the authors will share their experiences in supervisor selection and development. They also draw on the work of two men in particular, Douglas Bray and William Byham, both of whom have contributed significantly to the understanding of supervisory development and training.IntroductionYears ago, there was not much training for supervisors. They worked under an authoritarian style of management and modelled themselves on it. They were generally selected for their skill as miners, mill operators or mechanics. Things have changed. Today, companies have different needs. The selection of supervisors is far too important to rely on guesswork. Progressive companies want supervisors who think like managers - supervisors who know how to plan and organize, set performance standards and monitor them, analyze problems, develop solutions, show sound judgment and deal effectively with people. The evaluation of these supervisory ""dimensions"" is best accomplished through the use of an assessment centre. The Assessment Centre Method increases the accuracy of predicting the future success of candidates being considered for promotion.Mining and other resource companies use assessment centres to select the most suitable people for supervision. The Assessment Centre Method is based on extensive research. It eliminates hit-and-miss selection methods by using several different exercises that simulate the problems and activities that candidates would face if they were promoted into supervision . In other words, they get a realistic "" sample"" of the supervisor's job and are required to deal with and manage interpersonal and problematic circumstances."

Jan 1, 1990

By M. Dupuis, V. Bojarevics

It is well known that horizontal current density in the metal pad contributes greatly to the generation of MHD driven bath-metal interface wave. It is possible to compute very accurately the metal pad current density using a very detailed finite element model [1], but a MHD model must be compatible to this level of mesh refinement and to recalculate the current distribution at each time step, including the full busbar supply system. The accuracy of the instability prediction of the cell depends on the accuracy of the metal pad current density calculation. This study presents the comparison of the metal pad current density calculation of the detailed finite element model and the MHD-Valdis model for different metal pad heights and ledge thickness. It also presents the corresponding cell MHD stability predictions.

Jan 1, 2006

By Ralph W. Edie

"IntroductionTHIS PAPER presents some analyses of diabases from a number of metallogenic provinces in Canada and the United States. It is intended as a contribution to the literature on the genesis of mineral deposits associated with diabase.As it has been in the past, opinion today on the origin of the cobaltnickel- native silver and associated pitchblende type of deposit is sharply divided. Some geologists hold that this type of deposit is in some way genetically related to intrusive diabase; others are of the opinion that the deposits are related to granite. The controversy, like others of a similar nature, probably will not be settled satisfactorily for many years to come, •but in the meantime it is recognized that, with respect to most deposits of the type referred to, altogether too few facts are known for accurate conclusions on genesis to be drawn. To contribute in a small way to factual data on this whole .problem, the writer analyzed diabase from several districts in Canada in which deposits of the aforementioned type occur. For comparative purposes, the copper, cobalt, and nickel content of diabase from Cornwall, Pennsylvania, and of norite from the Sudbury basin of Ontario, was also determined.Insofar as is known, none of the analytical work undertaken had been previously carried out."

Jan 1, 1953

By Claudio Rocha Rosales

"Peñoles is a mining group with integrated operations in the smelting and refining of non-ferrous metals, and is also a chemicals producer. Peñoles is the world’s foremost producer of refined silver, metallic bismuth and sodium sulphate and is the leading Latin American producer of refined gold, lead and zinc. The Met-Mex Peñoles Zinc Plant commenced operations in 1973 with an annual production capacity of 105,000 t/y. Year after year the production has been increased, and at present, the production capacity is 240,000 t/y. In this paper, the leaching process,particularly the operation of the jarosite circuit is reviewed ,specifying process improvements to treat high iron calcines.INTRODUCTIONThe purpose of the leaching process is to recover the metals, mainly zinc,through a series of extraction stages with sulphuric acid solutions, which progressively increase the zinc recovery. After the series of acidification stages,the solution, which is rich in iron, is sent to the jarosite circuit to separate the zinc from the iron (Garcia & Valdez, 1996).The first step of the leaching process is the neutral leach circuit which produces a zinc sulphate solution that is sent to the purification section for the removal of impurities such as cadmium, cobalt and copper, after this solution is sent to the tankhouse to feed the electrolytic cells."

Jan 1, 2016

By N. Valkanov

This paper presents results of an investigation into the connection between minerals liberation management and flotation, responding to lead-zinc concentrator ?Erma reka?, in Bulgaria. Monitoring of a Zn flotation circuit was carried out. The causes for the high silica content in the final Zn concentrate were established. Quartz is present mainly as liberated particles (> 60?80 %) in the fine fractions of the products; therefore the selectivity of the flotation process is not effective. Two approaches were tested to reduce the quartz content of Zn concentrate: froth washing in Zn cleaner flotation and new gangue depressants in the Zn circuit. Experimental results from bench-scale flotation and industrial tests show that it is possibile to reduce the silica content of final Zn concentrate more than 2 times without the need for extensive regrinding. The depression of liberated quartz particles on all operations of Zn circuit using stage depressant addition is the right solution to produce high-grade Zn concentrate that meets the metallurgical requirements.

Aug 1, 2013

By R. D. Brown

Higher employer costs and increased employee benefits will result from the current sweeping revisions of the un-employment insurance system now receiving consideration before Parliament. The new legislation, the Un-employment Insurance Act, 1971, will substantially increase the unemployment insurance costs of many employers through an increase in the level of employer contributions -generally, employer contributions will go to 1.4 times employee costs -as well as by extending coverage to many classes of employees now exempt. Under the new legislation, executives, technicians, teachers, institutional workers and others will be covered, and eligible for the higher benefits which it provides. For the first time, absence from work because of illness or accident may qualify individuals for unemployment insurance benefits.

Jan 1, 1971

By A. Bowles

The process of accumulative roll bonding (ARB) has been applied to wrought magnesium alloy AZ31. Accumulative roll bonding results in severe plastic deformation of sheet material. In AZ31, this process leads to the refinement of the microstructure by dynamic recrystallization. The refinement of the microstructure results in an improvement in mechanical properties with potential for producing materials for superplastic forming. In this work AZ31 was bonded with up to 64 layers and the potential of roll cladding with aluminium was also investigated. The development of microstructure and the mechanical properties are reported here.

Jan 1, 2006

By M. Cossette, V. H. Tran

"How can the durability of asphalt pavement be doubled without increasing highway budgets? Asphalt containing asbestos can provide the desired performance with additional costs being made up by longer life. The addition of a low percentage of asbestos to an asphalt mix permits a higher asphalt content without any consequent loss in stability. It is mainly the higher asphalt content that provides improved performance and durability, although the fibrous reinforcement plays a key role in preventing the propagation of micro-fissures. As well, several international studies show that, thanks to the latest production techniques, no environmental hazards need be incurred.RésuméComment doubler la durée des chaussées d'asphalte sans augmenter les budgets de voirie? L’asphalte contenant de l'amiante peut offrir les performances souhaitées et l'augmentation des couts initiaux peut être rapidement compensée par une durée prolongée. L’addition d'une faible teneur en amiante courte il l'enrobe de bitume permet des teneurs en bitume plus élevées sans subir une perte de stabilité en conséquence. C'est principalement la teneur accrue en bitume qui assure un améliorations propriétés physiques et une augmentation des performances mécaniques, ainsi qu'on prolongement de la durée. Cependant, le renforcement fibreux joue un rôle clef en prévenant la propagation éventuelles micro-fissures. Les nouvelles techniques évitent tous risques environnementaux"

Jan 1, 1991

By X. L. Song, G. W. Zhang, F. Y. He, X. Xiao, L. L. Huang

This paper presents the design of a model and process simulation of a vertical mill based on a population balance model. The simulator, Simulink, which is a systematic modeling tool within MATLAB, was used for the simulation. The model will simulate the real time variation trend of each size fraction in the feed material to the vertical mill, as well as, the size distribution of the batch grinding products. Breakage distribution and selection functions are calculated based on batch grinding laboratory experiments using Back-calculation method. The simulated size distributions correspond with those in the actual mill operation having a relative error of less than 0.50%. This work lays the foundation for future research on modelling and simulation of a closed circuit grinding operation consisting of a vertical mill with hydrocyclone classifier.

Jan 1, 2016

By Ludwig Strah

"The paper outlines the history of rubber mill liners beginning with the awarding of the first North American patent rights in 1923. It includes the early-day applications and installations of the 1920s and 1930s through to their present-day application. Over-all rubber mill liner design is discussed in relation to present day installations employing rubber mill liners in various grinding applications. A brief overview is given of a manufacturer's procedures to produce rubber mill liners.IntroductionIn early 1910, it became apparent that the productive life of the silver mines in Cobalt, Ontario, could be substantially prolonged by mining lower-grade ores.The mining of lower-grade ores required the establishment of treatment facilities which initially employed jaw crushers, stamp mills, jigs and concentrating tables. The recovery of silver in other than a coarse metallic form required the additional step which was introduced at that time: the cyanidation of silver concentrates from the tables. The resultant requirement for increased and improved recovery led to the introduction of grinding mills, i.e. tube mills.Shortly after the introduction of the tube mills to the Nipissing Mine's mill in 1914, the idea of using rubber as a mill liner material was spawned. However, no action was taken due to the advent of World War I. It is interesting to note that the idea of rubber mill liners emanated from having used pieces of solid rubber tire as an emergency repair on a set of liners when a liner had broken and no immediately available spare was on site.The credit for this ingenuity and subsequent application for a patent on rubber mill liners falls to James John Denny, the mill superintendent, and Rolla Barnum Watson, the general manager of Coniagas Mines Limited. The patent application was formally made on December 3, 1921. The U.S. Patent Office issued Patent No. 1,470,597 on October 16, 1923."

Jan 1, 1982