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By Carl Faessler

Abstract Some Canadian geologists believe chat, in the Grenville sub-province of Eastern Canada, there is no granitic intrusion older than the anorthosite. The writers are among those who hold the contrary view. They suggest a new means to distinguish between rocks belonging to intrusions respectively older (Laurentian) or younger (Pine Hill) than the anorthosite. This new method is based on microscopical observations which demonstrate that the Pine Hill intrusives contain a large amount of exsolution perthite, whereas the Laurentian intrusives are completely devoid of exsolution perthite. Where perthite is present in Laurentian rocks, it is the result of lacer hydrothermal replacement. Introduction The present paper is the result of a systematic study of some acidic intrusive rocks in the Grenville sub-province. These rocks underlie large areas of the Canadian shield in the Province of Quebec, mostly along the southern border of the shield.

Jan 1, 1946

By C. Fortin

The subject of gold flotation has been reviewed extensively in a number of publications. The focus in most of these reviews has been on the theories of gold flotation as well as the physical and chemical effects that may impact the efficacy of the gold flotation process. It is evident that the current status of gold flotation chemistry as it is being applied in industry has not been addressed widely. It is the intent of this paper to review current gold flotation practice and how these applications tie in with the current understanding of the chemistry of gold flotation.

Jan 1, 2011

By M. I. Kalashnikova, Y. M. Shneerson, E. E. Zhmarin, Y. V. Degtiarev, E. M. Vigdorchik

Separation of a magnetic fraction from nickel concentrate following matte flotation, and its treatment in a separate circuit enable reduces precious metals losses. The magnetic fraction is treated in two stages of oxidative leaching: atmospheric and pressure leaching. A study of the atmospheric stage, using mathematical modelling, is described in this paper. The mathematical model and experimental data were used to carry out industrial process calculations. The model enabled extrapolation of the results of batch laboratory test to industrial-scale continuous processing and the selection of optimal process conditions and large-scale equipment. In December 2004, commercial oxidative leaching tests were performed on the magnetic fraction at the Severonickel Plant (Monchegorsk, Russia). A comparative analysis of the mathematical modelling results and the actual process parameters is presented.

Jan 1, 2005

By J. Basi, D. F. Rucker

"A review of historic operating practices of the heap leach pads at the Los Filos Mine, Mexico, revealed periods of restricted cyanide addition, reduced leach time, and insufficient irrigation flow. These issues all led to the buildup of partially leached recoverable gold inventory within the leach pads. Drawing down this inventory represented an opportunity to bring value forward. This paper outlines the strategic initiatives which were implemented as efforts to accelerate the inventory drawdown, including geophysical mapping and pressure injection.INTRODUCTION Los Filos is a heap-leach operation located in the Guerrero gold belt in southern Mexico. Operational and hydraulic challenges at the Los Filos Mine have led to a buildup of gold in inventory within the leach pads. Operationally, periods of restricted reagent addition, reduced leach time, and insufficient irrigation flow have compounded over the last eight years, and resulted in significant inventory growth. Hydraulically, the leach pad has issues with low permeability and solution channeling due to the fines and clay content of the ore. The leach pad is storing high-grade pregnant leach solution (PLS) as perched aquifers above areas that are compacted and difficult to drain. These operational and hydraulic challenges made it particularly difficult to spatially predict the precise locations of the inventory build-up. Fortunately, the challenges at Los Filos are not unique to the mine, and others have taken steps elsewhere to reduce metal inventory through a program that targets areas for inventory drawdown. For example, Ghorbani et al. (2016) noted that a method of injecting barren reagent solutions, applied directly to specific areas of a leach pad to reduce inventory, was presented by Wan and Brierley (1997) and Wan (1997). Seal (2004; 2007), Seal and Jung (2005), and Seal et al. (2012) have put the injection methodology into practice in Nevada and Colorado gold mines with a technology called Hydro-Jex®. The goal of Hydro-Jex has been to supply reagents at a high pressure over a short duration, followed by periodical low pressure rinse periods to remove leached metal and resupply fresh reagent to the ore."

Jan 1, 2017

By Chas. L. Emery

"The laws of rock mechanics apply equally well to all rock structures, and open pits are not exceptions. The concepts and some arguments about the emphasis to be placed on various aspects of open-pit design are discussed in this article.RocksROCK can be described as a granular material consisting of grains and glue. The grains may be fragments of other rocks or polycrystalline aggregates. The glue may be ferruginous, calcareous, argillaceous, siliceous or other material connecting the grains. In a crystal intergrowth, the outer layers of the crystals in contact with each other may be considered to act as a glue. Water may be a glue in clay or a grain in a crystal structure. Air and other fluids or gases are grains if they occupy spaces in a granular mass. Such grains are functional either chemically or mechanically or both."

Jan 1, 1966

By Fazel G. Jahromi, Ahmad Ghahreman

"Atmospheric leaching of arsenical sulfide concentrates, and especially enargite leaching, is one of the major challenges within the current hydrometallurgy research area. One of the recent processes developed for sulfide ore treatment is atmospheric leaching in the presence of AF 5, a novel carbon based catalyst, in chloride media. The quantification of different ion concentrations during enargite and chalcopyrite leaching in the presence of AF 5 were measured and the copper recovery rates of 97% and 96% were achieved. The objective of this study is to shed light on the leaching mechanism of the sulfide minerals. Based on the speciation of iron and copper by different titration methods, the AF 5 catalyst first reduced ferric and cupric ions and then oxidized ferrous, cuprous and arsenite ions. The oxidation behavior of the catalyst enhanced the leaching results. The AF 5 catalyst also caused in situ precipitation of scorodite in leaching experiment. The speciation of ions in the chloride media were simulated by Phreeqc software and the dominant species in the leaching solution were determined.INTRODUCTION The hydrometallurgy of copper has been used for several decades and is still under development for more complex copper sulfide minerals due to their refractory nature. Most of the world copper reserves are in the form of chalcopyrite; and enargite is known as a major contaminant. Pyrometallurgical processing of enargite is problematic due to arsenic release and tight environmental regulations (Peacey, Gupta, and Ford n.d.). On the other hand, lower recoveries in the hydrometallurgical processes make most of these processes impractical. Several leaching processes have been developed for the leaching of copper sulfide minerals. Some of the common treatment methods for copper sulfide minerals are pressure oxidation leaching (POX), CESL, Activox, Albion process, atmospheric ferric sulfate leaching, Dynatec, Galvanox, and Hydro copper process (Barr, Defreyne, and Mayhew 2005; Conner and Anderson 2013; D.G. Dixon, Mayne, and Baxter 2008; Hyvärinen and Hämäläinen 2005; Palmer and Johnson 2005; Rohner, Bartsch, and Ngoviky 2012). Generally it is not viable to dissolve copper sulfide minerals at ambient pressure in mild acidic media and dissolution of these refractory minerals requires harsh conditions in the presence of oxidant materials (Biswas and Davenport 2002). Ferric ions have been used as an oxidant in different media in copper sulfide leaching processes. U. S. Bureau of Mines’ Reno Metallurgy Research Center in 1969 (Haver and Wong 1971) investigated ferric chloride leaching of chalcopyrite. Dutrizac and Macdonald (1972) studied ferric sulfate leaching of enargite. Based on this study, 50% of the copper was recovered at 80-85 ºC after 7 days of leaching. Cupric ions can also be used as an oxidant. Parker, Paul, and Power (1981) stated that cupric/cuprous couples are more effective than ferric/ferrous couples in chloride media because they are rapid and reversible. The Hydro Copper process leaches copper sulfide minerals in chloride solution catalyzed by cupric ions. In this process, copper dissolves as cuprous ions in presence of cupric ions (about 10 g/L) (Hyvärinen and Hämäläinen 2005)."

Jan 1, 2017

By J. S. Godard

The mining developments in western Quebec have shown the ores of this district to be more complex in character than was at first expected. When the initial discoveries were made it was thought that the ores would be similar in character to those of Kirkland Lake and Porcupine areas. Developments have since shown that although the ores along the southern margin of the belt are somewhat similar, those within the belt, constituting by far the greater proportion, are vastly different, being complex mixtures of base-metal sulphides carrying values in the precious metals. These mixtures of base-metal sulphides of copper, zinc, and iron, present several problems to the metallurgist, especially in their concentration into marketable products. For the purpose .of this paper the following classification may be made of the ores of the district. Group I. - Milling Ores: (a) Ores in which~ arsenopyrite is the predominating sulphide. In this class of ore the gold occurs in fractures in the quartz and is associated to a lesser extent with the arsenopyrite and pyrite. Examples of this class of ore are the Granada, south of Pelletier lake, and the O'Brien and the Thompson in Cadillac township. (b) Ores in which iron pyrite is the predominating sulphide and gold is the valuable constituent. This may also be classed as a concentrating ore-Group III.

Jan 1, 1928

By P. H. Rodriguez

The aquatic hazard classification system of the OECD and EU requires that sparingly soluble metal substances (SSMS) be tested using the OECD Dissolution/Transformation protocol in order to quantify the release of the ecotoxicological relevant species (dissolved ions). The SSMS category contains massive forms of metals, which due to their low solubility and slow transformation characteristics are a special case. The main factors that produce the release of metal into solution are exposed surface loading, pH, and stirring rate. The classification system at present prefers the use of mass loading as opposed to surface loading, in which case the amount of metal released will primarily be a function of the pH, and mass loading. Within the framework of the European Copper Voluntary Risk Assessment, coordinated by the European Copper Institute, we have proposed and developed a methodological procedure in which we demonstrate that surface area is an intrinsic property of a SSMS and we link the exposed surface loading to the toxicity reference value in order to obtain an aquatic hazard classification for massive metals. As example, the aquatic hazard classification for copper massive will be discussed. This approach is recommended for metal massives and metal powders.

Jan 1, 2007

By A. McLean, W. Q. Chen, W. Yan, M. Barati, Y. D. Yang

In order to maximally remove the harmful impurities phosphorus and reduce the loss of valuable elements from Si-based alloy for production of solar-grade silicon, thermodynamic properties of the Si-based alloy were studied. In this work a new model, the Molecular Interaction Volume Model (MIVM) derived from statistical thermodynamics, was successfully used in the Si-based and Si-Fe-based alloy. The calculation started from binary Si-Fe, Si-P and Fe-P systems, then the thermodynamic parameters of ternary systems could be derived based sub-binary systems. Using the activity coefficients of the elements in the Si-based alloys and the saturated vapor pressure of the pure substance of the components, mass fraction of P during vapor-liquid equilibrium can be calculated. The calculated thermodynamic parameters were compared with experimental data available in different publications, and it is found that the thermodynamic parameters calculated using MIVM model are in good agreement with the measured results. The calculated result shows that the mass fraction of phosphorus during vapor-liquid equilibrium of Si-Fe-P melt increases with the increasing phosphorus content and decreasing temperature. This is an important direction for experimental practice in vacuum or low-pressure EML refining of ferrosilicon for potential production of solar-grade silicon without significant vaporization loss of valuable element.

Jan 1, 2015

By H. W. Kasaini, E. Bourricaudy, T. Larochelle

Rare Element Resources Inc., a U.S. based company, has developed a three-stage process for producing a +98% mixed REO powder from hard rock feedstock (-48 mesh, 2.9-4.8% REO) consisting of bastnaesite and ancylite minerals. Firstly, the whole ore is digested in chloride media at low temperature in counter-current flow mode. Secondly, the rare earths (REEs) are selectively precipitated as oxalates directly from an impure pregnant leach solution (PLS). Finally, significant amounts of free acid and water are recovered from the REE-depleted filtrate and subsequently recycled within the process. Excess heat from the oxalate calcination process is captured and reused in the plant. Due to the low leach temperature (45 ºC) and moderate acid dosage (240-297 kg/t, HCl), rare earth oxides (REOs) are preferentially leached out of fine solids leaving most of the base metals (Ba, Fe, and Al ) in the residue. Selective recovery of REEs from the PLS is achieved by mixing dilute oxalic acid (33% H2C2O4) and PLS at elevated temperature (85-95 ºC). The REEs plus thorium are precipitated as oxalates (REE2 (C2O4).xH2O) while the base metals are left behind in the barren filtrate. Multiple batch and pilot test results have confirmed that 50-80% of the oxalic acid can be recovered from the REE-depleted PLS through low-temperature crystallization (10-15 ºC). Typical leach efficiencies of critical rare earths at 45 ºC range from 85-99% (average 93%) while oxalate precipitation at high temperature increases the crystal size of RE oxalates (>450 microns, d80) thereby improving filtration. The economic benefits of this process include elimination of flotation and magnetic separation Capex and driving hydrometallurgical Opex down to $6- 7/kg, REO produced. As part of a comprehensive risk mitigation strategy, Rare Element Resources Inc has operated multiple pilot plants at SGS in Lakefield, Ontario, Canada to optimize counter-current leaching (CCL), REE oxalate precipitation (OXP), and thorium removal circuits. This paper presents pilot testing data from CCL and REE OXP circuits.

Jan 1, 2016

By R. L. Dunsmore

Introduction If one had been called upon to describe petroleum oil refining seventy-five years ago, he could have acceded to the request quite satisfactorily in about fifteen minutes. Fifteen years ago, an hour and a half would have been sufficient to give a general idea of oil refining, and of the equipment used for this purpose. Today, so extensive has been the research into all phases of the refining and manufacturing of petroleum products, and so rapid the strides in improvement in technique and equipment, that I doubt if a week would suffice to give an adequate outline of ail the ramifications of present-day oil refining. I propose to only 'hit the high spots', dealing particularly with the equipment and methods employed at the Imperoyal refinery, which you are to visit. Crude oil, the refiner's raw material, contains essentially only two elements, hydrogen and carbon. These are not present in the free state but are combined in various proportions as 'hydrocarbons'. A given crude oil is not made up of just one hydrocarbon, but of myriads; some solid, others liquid, and still others gaseous at atmospheric temperature and pressure, ail dissolved one in the other. Moreover, the nature and the relative amounts of the several hydrocarbons vary very considerably in crude oils from different sources. That is, a 'crude' from Oklahoma will contain hydrocarbons not present in crude from Mexico, and is different again from the Venezuela crude. Not only this but oil in a certain well in, say, Peru may be differently constituted from that in a well half a mile distant from it.

Jan 1, 1931

By Karl J. C. Harries

"8.1. INTRODUCTIONThe purpose of this chapter is not to provide precedents or examples of provisions, but rather to offer some comments that may be worth considering in the negotiation or review of an agreement. These comments are not intended to be exhaustive. It must also be noted that, although the chapter is written in the context of a common law joint venture, the concepts and concerns for the most part apply equally to a corporation that is owned by only a few shareholders for the purpose of participating in the project held by the corporation.The corporation has the advantage of having much of its organization established by local corporate law, but the particular wishes of the shareholders will appear in a shareholders’ agreement. The principal differences will be surprisingly small, save for the acquisition provisions that appear in a farm-in agreement1 and the substantial portion of the joint venture agreement devoted to creating and organizing the joint venture entity. Where the joint venture agreement refers to venturers and committees, the shareholders’ agreement will refer to shareholders and the board of directors, but both will have to deal with such basic matters as decision-making, default, dispute resolution, first refusals, funding, and carrying out work on the project. For convenience, this chapter usually refers to “venturers”, which may be taken to include shareholders.Negotiations give rise to many varying circumstances and concerns, and the main asset of the negotiator is an open and flexible mind. A desired result can often be accomplished indirectly in circumstances where the other side has adopted an inflexible position on a suggested approach. As precedents and standard forms tend to focus a negotiator’s thinking, they can be counterproductive. It is after the deal has been agreed to that a precedent can be of great assistance to the draftsman.The concepts are arranged in alphabetical order for convenience, not to suggest their sequence or position in an agreement or their relative importance. An agreement should adopt a progression of subjects in what the parties consider a logical sequence to read and work with. However, experience has indicated that it is best to set out in a single article the substance of the deal (i.e. the terms relating to the farm-in and what the acquiring party has to do to acquire his interest), preferably near the beginning of an agreement. The acquisition of the interest is, after all, the first order of business. The joint venture provisions will then follow in a reasonable sequence. It is also worthwhile to devote a single article to any special provisions that may apply during the earn-in period. For example, it may be provided that, although all work is to be done by the acquiring party as operator (with the duty of care, liability, and reporting requirements as set out in the joint venture sections of the agreement), but during the acquisition period, the acquiring party, acting as operator, may be at liberty to do such work as he wishes, without the need for any committee or other approvals, and committee meetings may be suspended.2An agreement is divided into paragraphs and articles to make it easier for the parties to read and understand, and to assist a party in finding “that provision” when the need arises. A comprehensive table of contents will also assist the parties who must work under an agreement. An added benefit of a table of contents is that in preparing it, the draftsman sees the overall structure of the agreement and will often catch and correct flaws."

Jan 1, 2003

By R. O. Suzuki, S. Natsui, R. Nashimoto, T. Kumagai, T. Kikuchi, H. Takai

A newly developed computational fluid dynamics model based on a multi-phase particle simulation is presented for predicting the entrainment behavior of liquid metal into slag due to rising single bubble. By comparing results calculated using this model against experimental data, it was found that the transient behavior of bubbles and the two immiscible liquids can be accurately estimated by this method. The rupturing of the thin water film surrounding the bubble was less reliably predicted, but this 3-dimensional unsteady numerical model still nevertheless provides valuable new information for directly predicting the change in the liquid-liquid interface over time. This model predicted the Young-Laplace pressure, and the interface shape was simulated with volume conservation using this model as opposed to the conventional particle method. This simulation model can calculate both of dispersed phase and continuous phase seamlessly.

Jan 1, 2015

By P. Bakke

Following extensive R&D efforts, Hydro Magnesium has launched a new alloy series with remarkable combinations of properties. The AE alloy family is based on additions of aluminium and rare earth elements to control mechanical properties, including elevated temperature creep strength. By combining these alloying elements with manganese additions, high purity alloys with outstanding corrosion performance are defined. A basic philosophy behind the developments has been to simultaneously approach all the critical issues related to developing a commercial material. Apart from the obvious requirements for material properties, the critical issues relate to die casting performance, as well as alloy production, recycling and environmental compatibility. Some of the important elements related to alloy production and recycling are addressed in the present paper.

Jan 1, 2006

By C. Fortin

ABSTRACT The subject of gold flotation has been reviewed extensively. Most of these reviews focus on the theories of gold flotation and the physical and chemical effects that may impact the efficacy of the gold flotation process. The current status of gold flotation chemistry as it is being applied in industry has not been widely addressed. This paper reviews current gold flotation practice and research advancements and discusses how these applications tie in with the current understanding of gold flotation chemistry. Survey results from worldwide gold flotation operations are analyzed. Potential future areas of gold flotation research are highlighted.

Jan 1, 2013

By George Wilkinson

"AbstractThe consistent relationship between the availability of electrical energy and our economic wellbeing is well known. As we develop the energy we need to nurture industrial civilization in decades ahead, we will at the same time reduce our reliance on dwindling supplies of oil and gas. Coal and uranium will be developed as our major fuel sources to meet medium-term. energy needs, followed by fusion and solar energy for the long term.IntroductionTHIS PAPER treats the matter of energy in a way that is quite different from that of the crisis-type atmosphere which surrounds so much of it currently in the news media. On the one hand, we lift the whole subject of energy out from its present-day involvement with short-term issues and take an important longer-term look at the solutions which lie before us. On the other hand, we recognize that short-term issues are important and, as we are reading and hearing, many of the right short-term solutions continue to elude our politicians, our policy makers, and even some of those with knowledge and authority in the energy field.A year ago, if you asked people how they would go about conserving energy, they would probably have said turn out the lights. They would probably say the same thing today, but they might also include other things such as driving the automobile more slowly or putting more insulation in the attic. However, their first impulse is still to use less electricity."

Jan 1, 1977

Gold recovery from refractory ores can be very difficult and complicated depending on the causes of the refractoriness. Typically, a fine wind and/or the oxidation of the gold-bearing sulfide minerals are required to liberate gold from the host rock matrix. Mineral separation techniques, particularly surface¬wettability based separation (i.e., flotation) and magnetic separation, can be used to pre-concentrate the gold and sulfide minerals, or to remove mineral species that are harmful either to the oxidation of the gold-bearing sulfides or to the cyanidation following the oxidation. In this paper, several processes are described, including oil-agglomeration flotation recovery of fine-grained gold and sulfide, reverse flotation of carbonate minerals prior to pressure or bio oxidation, reverse flotation of elemental sulfur after pressure or bio oxidation but prior to cyanide leaching, and magnetic concentration of gold-bearing iron oxides. The integration of these techniques with gold hydrometallurgical processes may make the economic recovery of gold from an otherwise uneconomic refractory ore possible.

Jan 1, 2011

By T. T. Ni

FOR MORE THAN 200 years, the Kochiu district of Yunnan province has been, and it still is, the hub of China's tin industry. The district produces annually from 80 to 90 per cent of that country's out-put of tin, which averages about 9,300 tons a year and places China fifth among the tin producing nations of the world. The tin ore reserves of the country are estimated (1) at 1,873,370 metric tons, of which 1,500,000 tons are in the Kochiu district. The mill of the Yunnan Consolidated Tin Corporation, described in this paper, is the only one of its kind in China. MINING AND SMELTING There are only two tin mines in the Kochiu district operating with modern equipment -the Hsin-Chang and the Lao-Chang, both owned by the Yunnan Consolidated Tin Corporation, a government company. The Hsin-Chang mine has four working levels with cross-cuts 6 ft. by 6 ft. and is equipped with steel mine cars and trucks to haul the ore. The ore is hoisted to surface in a three-compartment shaft and transferred to the mill by a 4-kilometer aerial tram. The Lao-Chang mine has two circular shafts 656 feet apart, each equipped with two cages. Haulage-ways 1,600 meters and 1,000 meters long, respectively, have been driven to the southwest from these shafts and are connected by three cross-cuts.

Jan 1, 1951

By The Staff

"IntroductionThe published information concerning treatment of uranium ores has been very limited as far as Canadian ores are concerned. Such information has dealt mainly with refining processes for concentrates or rich ores, designed to recover radium rather than uranium; these methods could not be economically applied to low-grade ores.The purpose of this paper is to describe treatment possibilities for some of the .ores that have been treated at the Mines Branch, and .to show how the character of these ores influences methods and results.What is a Uranium Ore?Prospecting for uranium has been extremely active during the past two years and a great many occurrences of radioactive minerals have been recorded. Such prospecting has been based to a large extent on the use of the Geiger counter in the fie1d. This equipment is an invaluable aid when the results are properly interpreted.Most definitely, indications of high radioactivity do not always prove the presence of a valuable orebody. First we have to determine:(1) Is the radioactivity due to uranium or to thorium. There is no immediate market for thorium.(2) Can the uranium in the ore be economically recovered.Chemical analysis is the most exact method of determining uranium content, but a fair estimate of the uranium, and also of the thorium, content can be made from the difference in gamma and beta activity. The Mines Branch guards against misinterpretation by determining both beta and gamma activities and, if more than a minor amount of thorium is indicated, then a Chemical analysis is made."

Jan 1, 1950

By I. Kirman, B. Waters

World wide applications for nickel use will be summarized and examples of those uses given. Nickel products are critical to many important aspects of modern society. These products are just as important for modern China as they are in other parts of the world. It is argued that future pattern of nickel use in China should be expected to be very similar to that in the rest of the developed world. Total use of nickel in products in China is already very large. In 2004, it was the largest market for stainless steel (nickel containing) in the world. A survey of Chinese stainless steel applications will be presented. Current high nickel prices have revived speculation about substitution, particularly for nickel containing stainless steels. The presentation will discuss some of the complicating factors that need to be taken into account when considering substitution. These factors are as valid in modern China as they are in other developed economies. Recent substitution efforts and the reaction to them will be examined. The Nickel Institute position regarding appropriate application of the various grades of stainless steel will be discussed. Price-motivated substitution in China, and elsewhere, will occur but it is argued that the extent will probably be limited.

Jan 1, 2005