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By Jean-Paul Drolet

"This paper charts, briefly, the :salient facts of international trade in minerals and their products and Canada's place in it. It also reviews inter-national agreements, economic groupings and national measures to channel and regulate production and trade in minerals. Canada's mineral industry now produces raw materials worth $3.7 billion per year, making this country a giant among mineral producers. Two-thirds of this production is exported, chiefly to the United States, accounting for about 30 per cent of Canada's merchandise exports and topping all other classes.However, several other nations are also pressing the development of their mineral resources and markets. The Soviet Bloc, China and principally Australia and Africa are becoming important suppliers of basic raw materials to some traditional markets of Canada in Europe and Japan.The outlook for Canadian mineral exports to the countries of the Common Market, Great Britain and Japan is good, although some tariff barriers remain troublesome.Concerning the United States, our most important market, Canada is seeking to have that country lift import quotas on lead and zinc, and re-cent statements by U.S. authorities give hope that this may be achieved soon. Moreover, Canada wishes to obtain easier access to the American market for several of its metals and minerals.Canada is now participating in the Kennedy Round of tariff talks under the auspices of the General Agreement on Tariffs and Trade (GATT), and is seeking to open wider doors for its exports of products.In summary, Canada has done reasonably well in some mineral commodities on world markets, but has lost ground in others. Any slackening of Canada's efforts in the development and marketing of mineral resources would soon lead to the decline of its role in the world miueral economy."

Jan 1, 1966

By S. Nafisi

Permanent mould casting may be regarded as a near net shape manufacturing process where simple to very complex shaped engineering components are fabricated with high degree of precision in a metallic mould, In this group, High Pressure Die Casting (HPDC), have attracted more attention because of its production rate, where both liquid and semisolid metals (SSM) can be cast with high degree of precision and versatility. The SEED process, Swirled Enthalpy Equilibration Device, the new process for semi solid metals slurry production route, consists of two steps: The initial step involves extracting specified amount of heat from the molten metal to generate liquid-solid slurry, i.e, mushy structure, followed by drainage of remaining liquid to produce a compact free standing feedstock for rheocasting operation. In this paper, microstructural evolution during the process and some initial casting results of automotive components an also reported.

Jan 1, 2005

By M. Abdollahi, M. R. Khalesi, Y. Kianinia, A. Khodadadi Darban

High cyanide consumption during the processing of gold ores with high sulphide minerals can make the typical cyanidation uneconomic. Also cyanide is a toxic material and environmental concerns of cyanide compounds are serious. Optimization of cyanide consumption requires a methodology to estimate the amount of exposed cyanicides, the kinetic of their dissolution and estimation of formation of cyanide complexes which consume the free cyanide. In this paper, a methodology to estimate cyanide consumption by modeling the minerals and gold leaching kinetic based on a liberation model and speciation of all possible cyanide related species in the solution is presented. The results showed that this methodology could successfully estimate the cyanide consumption based on mineralogical data with very lower number of parameters compared to empirical models present in the literature, while it offers the prediction of formation of all cyanide complexes which could be used for optimization purposes.

Jan 1, 2017

By S. Shairp

The first commercial application of the Dynatec two-stage zinc pressure leach process commenced operation at the metallurgical complex of Hudson Bay Mining and Smelting Co., Limited in Flin Flon, Manitoba in 1993. A key feature of the successful leaching operation is the presence of iron in solution, which facilitates oxygen transfer in the autoclaves and enables rapid oxidation of zinc sulphide minerals. At the same time, the solution from which zinc is recovered must be essentially iron free. Precipitation of iron from the solution starts in the autoclaves and is completed in subsequent atmospheric purification steps. Conveniently, these iron precipitation steps also remove nuisance elements such as arsenic and fluoride from the solution, while producing solids with good liquid-solid separation characteristics. This paper provides an overview of the current operations in Flin Flon, with particular reference to the behaviour and deportment of iron throughout the zinc plant.

Jan 1, 2006

By A. V. Corlett

THE use of the diamond-drill hole as a means of breaking clown ore and waste is not new. Years ago, the method was adopted in mines in northern Ontario and in the western United States to reach out to bad pillars, or to remnants of ore left on walls, the winning of which by any other method might be dangerous or too expensive. The practice is still in vogue and has generally proved a success. Of the known mineral deposits in Canada and elsewhere, many are of very low grade. Some are marginal and not even worthy of being classed as 'ore' until some means is found and proved of exploiting them economically. Other conditions being favourable, if a mining method could be found that would give a large 'bulk break' with a sufficiently low cost of development and a low cast of mining per ton, mineral deposits of this latter type might be brought into the classification of ore. We know that any block-craving system whereby the ore may be undercut and allowed to crush and cave will give a very high breakage and low costs. In some cases, however, the physical characteristics of the ore do not lend themselves to this method. In such ore-bodies, the alternative system of 'bulk-breaking' might be aided by long diamond-drill blast holes. We could obtain this 'bulk breaking' by the use of long diamond-drill holes in conjunction with a sub-level system using extremely thick benches, or possibly by the adaption of modified open-pit methods to underground mining. ln fact, if conditions are favourable, the idea would be simply ta open up a slot or free face and break into it on a larger scale with longer holes. The use of deeper benches-that is, using each level as a sub-level and thereby eliminating much development footage, slashing, setting up, and mucking time-would naturally be expected to lead to cheaper mining.

Jan 1, 1940

By A. Blackmore, D. Baker, L. Human

"Mechanical mixing equipment is common in a wide variety of mining, metals and process applications, such as hydrometallurgical reactors, solvent extraction, digestors, and tanks for storage of slurry or hydrocarbons. Computational Fluid Dynamics (CFD) has been applied successfully to single-phase mechanical mixing problems for several decades and is established as a reliable design tool. As computational power and CFD codes have improved over the years, there have been significant advances in modelling capabilities including improved models of turbulence, interaction of rotating and stationary components, multiphase flows, and modelling of free surface interfaces, for example. This paper will provide an overview of the application of CFD to mechanical mixing problems. First, it will review the traditional single phase Multiple Reference Frame (MRF) approach and introduce a range of advanced modelling techniques. Three examples of the application of CFD to industrial mixing problems will be given. It will be demonstrated that CFD is an effective tool for reducing technical risk in design, for identifying the root-cause of mixing problems, and testing modifications to existing operations."

Jan 1, 2015

By J. A. Abols, P. M. Grady

Recovery via gravity is one of the oldest mineral processing methods available. Unfortunately, the use of gravity techniques for gold recovery has been in decline for the past century as more effective chemical processes such as flotation and leach/CIP have been developed. Recently, with the push towards more sustainable environmental outcomes, the benefits of gravity separation have become more apparent. While gravity as a unit process is not usually capable of achieving as high a recovery as flotation or whole ore cyanidation, a combination of gravity devices alone or in conjunction with these processes can offer significant advantages to the operator. This paper reviews the range of gravity devices available, their application and the results that can be achieved by maximizing gravity through the use of a combination of gravity recovery devices. Three case studies are provided.

Jan 1, 2005

By Norman A. M Macleod

FOR the past seven years, all flotation at the Britannia mill has been done in Forrester Air-Lift cells. Prior to 1931, the roughing and part of the cleaning operation had been performed in four 21-cell and two 14-cell M.S. machines. The resulting economies in reagent, power, maintenance, and general operating costs, and the increased recovery, more than justified the exclusive use of the Forrester machine. About three years ago, the possibility of still further improving the efficiency of the flotation section was the subject of considerable discussion and experiment. Arising from these experiments, tests were made of the practicability of using a cell of greater depth than that of any pneumatic or mechanically-agitated machine in common use. Cells were constructed with depths of 7 .5 feet, 10 feet, and 15 feet, and, in all cases, a very definite improvement in operation was indicated. The cell now being used in the mill treats from 5,500 to 6,200 tons of dry feed per day. It is 100 ft. long by 5 ft. wide by 8 ft. deep, and has replaced a total length of over 500 feet of standard Forrester machine. The choice of a depth of 8 feet was governed by the type of blower which was available-in this case, a Roots-Connersville blower, driven by a synchronous motor and delivering 6,000 c.f.m. of free air at 4.0 pounds per square inch. At the Chelan Division of the Howe Sound Company, where a new mill was recently built, all flotation is carried on in cells 10 feet deep, with good results.

Jan 1, 1938

By George Rice

Foreword Following the explosion in the Hillcrest mine, which occurred in the evening of Sunday, September 19th, 1926, and in which two men lost their lives, the writer was invited by the Hon. J.E. Brownlee, Premier of Alberta, to conduct an investigation into the causes of the disaster, and to make such recommendations as seemed advisable with a view to minimizing as far as possible the chance of future explosions in this and similar Alberta coal mines. Accordingly, the mine was visited, and extensive investigations were made underground on October 21st, 2.2.nd, and 25th, in company with Mr. John T. Stirling, Chief Inspector of Mines for Alberta, Mr. Moses Johnson, District Inspector for the Crowsnest Pass District, Mr. J as. A. Richards, Inspector of Mines, Edmonton, and also Mr. Thomas Davies, manager, and other officials of the Hillcrest mine. Hearings of the coroner's inquest were also attended on October 20th and 23rd, when testimony regarding the explosion was given by various witnesses. The following paper summarizes my general observations in tracing the place of origin of the explosion, and my efforts to determine the cause of ignition. Certain recommendations arc also made, and the writer invites discussion on these and the other matters dealt with in the paper.

Jan 1, 1928

By L. R. P. de Andrade Lima, D. Hodouin

The paper presents a survey of the possibilities of the simulation techniques for improving the design and operation of gold processing plants. The procedure to construct kinetic models that are used in simulators is first reviewed, and examples are given for cyanide gold dissolution and gold adsorption on carbon. Then, an overview of the structures of the plant simulators is proposed, and the simulation equations formulated for a carbon-in-leach process. Finally, the potential of simulation methods is illustrated by four examples. The first one shows how it is possible to use a simulator to design a cascade of leaching tanks while optimizing an economic performance criterion. The second one illustrates the role of simulators for optimal tuning of the cyanide addition strategy in a leaching circuit. The third example focuses on the power of simulation to design carbon transfer strategies in a carbon-in-pulp process. Finally, the last example shows the role of on-line simulators for optimally supervising the automatic control of cyanide addition into leaching tanks.

Jan 1, 2005

By Zhitong Sui, Feng Zhang, Li Zhang, Tie Ou, Guangqiang Li

Researches on the recovery of iron, manganese and the removal of phosphorus from converter slag were reviewed. The carbon thermal reduction experiments were carried out by induction heating the mixture of converter slag and graphite powders at 1650°C and 1800°C in a graphite crucible. It was found that 62.7% of the phosphorus in converter slag was reduced into carbon saturated iron alloy, 32.8% of that was vaporized and only 4.5% of that remained in the final product. Totally 95.5% of the phosphorus in converter slag was removed. Almost all iron and manganese was reduced to form carbon saturated alloy. It was found that the free lime in converter slag can react with carbon to form calcium carbide at 1800°C. The main phases in the reduced converter slag are dicalcium silicate and tricalcium silicate with small amount of calcium carbide.

Jan 1, 2004

By T. Belem

In-stope backfill will cure under effective stress, which develops due to a combination of mechanical consolidation (free draining material) and ??chemical consolidation?? (self-desiccation mechanism). A good knowledge of all the drainage and consolidation characteristics of cemented paste backfill is crucial for a better design of underground backfilling sequencing. From many of the existing results and studies done by various authors, as well as the availability of some in-stope backfill pressure data measurements during and after filling, it is possible of developing a procedure of backfilling sequencing. Hence, the objective of this study is to provide a guide for underground backfilling sequencing in the view of preventing the development of excess pore pressure that will affect both the stability of the barricades and the strength development of the backfill. This will be possible by considering the interaction between consolidation/drainage rate, filling rate and binder hydration rate.

Aug 1, 2013

By S. M. Grillo, M. Fiori, R. Bornioli, C. Marini, S. Fadda

The Na-feldspar orebodies in Sardinia occur along structures belonging to a regional ENE-WSW system that developed during the late stages of the Hercynian orogeny, and that was reactived during the Alpine orogeny. The main petrographic facies include granitoids, albitized granitoids, albitites (more or less rich in quartz), and albitites containing Mg minerals. Field observations and petrological and geochemical data point toward a metasomatic origin for the albitite orebodies. Albitization involved depletion of K from K-feldspar and biotite, dissolution of free quartz, and a lowering of Sr/Na2O and CaO/Na2O ratios in the protolith, under conditions of a positive thermal gradient. The absence of later K-metasomatism implies that, during a subsequent decline in temperature, the composition of the albitizing fuids was modified by an influx of meteoric or other waters. Copyright © 1996 Canadian Institute of Mining, Metallurgy and Petroleum.

Jan 1, 1997

By W. Evans, T. Steis

"Sulphide ores under certain circumstances will react with explosives to generate an autocatalytic chemical reaction. This reaction is exothermic and results in the production of large volumes of poisonous gases and creates an unsafe, unstable condition with the possibility of a low energy deflagration or even a detonation of the loaded hole. This paper outlines the conditions that need to exist for such a reaction to take place and the precautions necessary to minimize or eliminate the problem in areas of reactive ore. A special case study involving a northern Ontario mine will be detailed.IntroductionOne of North America's leading underground gold producer's processes over 6500 tonnes of ore per day from an orebody containing high concentrations of sulphides. After six years of problem free operation, the mine experienced two serious reactions in two months between the sulphides and AMEX II, the ammonium nitrate and fuel oil explosive it uses."

Jan 1, 1995

By V. Barranco, K. Yliniemi, A. Hubin, B. P. Wilson, D. Janas, M. Lundström, P. Hannula

Typical copper electrorefining electrolyte contains tens of grams of copper, some nickel and a wide variety of impurities. Some of these impurities comprise trace amounts of dissolved precious metals like Ag, Pd and Pt that currently are not fully exploited. This study presents an electrochemical method to recover precious metals via a combined electrodeposition-redox replacement (EDRR) process, where energy is used only to deposit copper during the ED-step, while the RR-step relies on the spontaneous replacement of copper by the precious metals (i.e. cementation). In order to conduct the recovery successfully, process parameters such as deposition potential (EDE), deposition time (tDE), redox replacement time (tRR) and the number of cycles (n) was adjusted. Investigations performed in synthetic electrolyte (40 g/L Cu, Ag = 10 ppm) proved the possibility to recover a high purity silver. Short deposition times (tDE) were found to result in small Cu particles that provided a suitably high surface area for silver cementation. In addition, experiments performed in real industrial electrolytes containing 44 g/L Cu and 54 ppb Ag (Boliden Harjavalta, Pori), demonstrated that EDRR could attain Ag recoveries of between 46–67% in an energy efficient, additive-free manner. INTRODUCTION The raw materials used in the state-of-art primary and secondary copper smelters contain mainly base metals, but also notable amounts of Ag, Pt and other precious metals. These valuable metals distribute mostly into the copper matte during the pyrometallurgical treatment (Tirronen et al., 2017) and end up into the cast anodes. During the electrorefining stage, metals more noble than copper such as gold and platinum, are not dissolved but enrich into the anode slimes. In contrast, silver may dissolve slightly and thus, minor chloride addition is used to retain silver in the slime as sparingly soluble AgCl. Moreover, other metals less noble than copper may also dissolve, such as nickel. Therefore the electrolytes used in electrorefining typically contain substantial amounts of copper, nickel and even arsenic as well as minor metals such as antimony and bismuth. In the Boliden electrorefinery these were reported to be in the magnitude of 51.2– 60.4 g/L of Cu, 10.9–15.8 g/L Ni, 7.2–15.9 As, 0.2–0.4 Sb and 0.1–0.4 Bi with an associated sulfuric acid concentration of 139–155 g/L (Lehtiniemi et al., 2018). Copper is the most noble of the dominating base metals in the electrolyte and is thus deposited on the cathode as 99.99% purity LME-A grade. Anode slimes are collected and subjected to precious metals treatment e.g. via pressure leaching—selenium recovery— Doré smelting—Ag refining—Au/Pt/Pd leaching and reduction process (Ludvigsson & Larsson, 2003). The Pori refinery, operating in Finland since 1941, not only produces 133 000 t Cu cathode and 2300 t nickel sulphate annually but also 66 t silver, 4.6 t gold and palladium and platinum (in year 2017).

Jan 1, 2019

By C. Anderson, H. Huang, P. Miranda, E. Dahlgren, I. Chandra, M. Jeffrey

The latter part of the 20th century saw great advances in the treatment of refractory gold ores coupled with increased reliance on the use of cyanide for gold processing. Now, in many parts of the world, there is social pressure to limit or eliminate the use of cyanide. As well, treatment of some refractory ores or concentrates which have excessive cyanide consumption, gold cyanide pregrobbing or significant sulfide content remain difficult. This paper will outline the history of the development of alkaline sulfide leaching as an ancillary process to nitrogen species catalyzed (NSC) pressure leaching. Electrochemical fundamentals and the applicable thermodynamics of the alkaline sulfide hydrometallurgical system will be outlined. As well, examples of refractory gold recovery with alkaline sulfide hydrometallurgy such as an arsenopyrite gold concentrate application, a chalcopyrite gold concentrate application, a pregrobbing gold ore application, and a cyanide consuming gold ore application will be delineated in this paper.

Jan 1, 2005

By P. Hajiani

"Feasible and sustainable separation of lanthanides outside of China has been a dilemma for the past few years. The present technique uses REE electrophoretic mobility (Ui) variation in an electrical field to separate them. The present invention relates to a system and a method to separate and refine rare earth elements/compounds produced in hydrometallurgical processes while they are dissolved in an acidic medium, without any intermediate precipitation step. This process uses free-flow electrophoresis to isolate REE from the concentrate simultaneously without any pre-treatment or intermediate steps related to the nature of elements.INTRODUCTIONRare earth elements (REE) invariably occur together in nature, and any given mineral contains several or most of them. Production of high purity individual rare earth (RE) elements/compounds from their ores generally requires two stages of processing, including mineral processing and hydrometallurgy.Depending on the ore, mineral processing and hydrometallurgy treatment of the ore before REEs purification is relatively simple and quite achievable though conventional methods. However, producing individual REE from mixed REs compounds is tremendously tedious. RE processing often requires dozens of steps, each resulting in minute improvement in the complex RE streams. Separating and extracting a single REE requires a great deal of time, resources, and expertise. Today, advanced RE refinery facilities cost hundreds of millions of dollars to build. The high purity RE concentrates are separated into individual REE using solvent-based or ion exchange methods. Although there are several techniques to separate REEs, most of them suffer from different types of drawbacks. For instance, solvent extraction requires a great number of steps to achieve high purity REEs. The process which uses ion-exchanger for separation and refinery operates with low REE concentration in solution which leads to very large liquid volume quantity, bulky tanks, dehydrators, pumps, etc. The low concentration will adversely affect the water consumption as well as other chemicals. Similar chemical properties of those three valent elements do not allow them to be isolated easily one from one another using conventional separation techniques. Solvent extraction has been successfully applied for rare-earth refining (lanthanide, scandium and yttrium) for the past few decades in China. Since then, efforts have been dedicated to develop other techniques which could be applied industrially around the world."

Jan 1, 2016

By D. H. Rubisov, V. G. Papangelakis

Sulphuric acid pressure leaching is the process of choice to recover nickel and cobalt from laterites with variable iron and magnesium contents. The latter influences the acidity levels required for effective leaching of nickel and cobalt, and during leaching, iron is rejected in-situ as hematite. Classical solid/liquid separation is performed via a CCD circuit, the performance of which depends upon the size and shape of precipitated particles. In this paper, precipitates obtained by acid-leaching of various lateritic feeds at 270°C are characterized using SEM/EDX and laser particle size analysis. It is shown that as acidity increases, the shape of the precipitates gradually changes from platelets to spheres, thus improving the S/L separation properties of the residue. The use of hydrogen ion concentration “at temperature,” calculated from a speciation analysis, allows the explanation of this change of morphology independently of the type of the ore feed. The possibility of precipitating magnesium sulphate “at temperature” is also discussed. In order to take advantage of this precipitation for scale reduction (as has been proposed in the past) without compromising the residue quality, [H+] “at temperature” must be controlled within an optimum range.

Jan 1, 2000

By D. S. Hines

The purchase of mechanical equipment for mines is not unlike the purchase of other materials or supplies in general principle, but on account of the major part such equipment plays in the operations, and of the fact that life and valuable property are at stake, the matter demands the most careful attention on the part of the purchaser. The problems and difficulties encountered are dealt with below in their sequence in the purchasing procedure. Requisiting Although it is quite a common practice to submit a tentative specification of requirements to recognized manufacturers of equipment- soliciting alternative propositions or recommendations for study in the selection of certain equipment-as a rule the first step in purchasing procedure is the requisition. Primarily, it is the form that carries to the purchasing department the record of equipment wanted. A full and complete description or specification, and accuracy of record, are the important points to be insisted on in a requisition. Too much attention cannot be given to this detail, as this is one of 'the most important phases of purchasing work. Incomplete information, either in specification or detail, leads to delay in handling the requisition, and, if not detected in the purchasing department, may mean receipt of material which cannot be used for the purpose intended. In addition to description of material or equipment to be ordered, the requisition should also show where or what the equipment is for, whether for operating or new work. If for capital account, the number of the authority for expenditure should be given for record and distribution purposes.

Jan 1, 1930

By P. H. Oliver

"The current theory of how explosives fracture rock offers no explanation for the improvements in fragmentation and the reduction of fly rock and back break which occurs when an adequate inter-row delay time is used. Nor does it explain why fragmentation improves with rectangular drill patterns where the hole spacing may be as much as four times the hole burden.A new theory of rock fragmentation is proposed which builds on the existing theory. It offers rational explanations for the many blast effects which the current theory does not address and the need for adequate timing delays between rows. It improves on the design of inter-row delay timing by defining the length of free-blasted face needed in front of a hole *Retired from Inco Ltd., Sudbury, Ontario when selecting the delay element which will provide an adequate inter-row delay time."

Jan 1, 2003