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By P. C. Good

To meet a growing need for thorium metal of high purity and amenability to fabrication, the Bureau of Mines devised a method for preparing thorium metal by the reduction of thorium tetrachloride. Thorium tetrachloride was prepared by chlorinating calcined thorium oxalate with carbon tetrachloride. The crude thorium tetrachloride, containing oxygen-bearing compounds, was purified by a double vacuum distillation at 800 to 900° C., and thorium metal was made in the form of a dense sponge by the reaction of metallic sodium or magnesium with thorium tetrachloride at 800° C. Vacuum arc melting was used to consolidate the sponge metal to ingot form for evaluation of its physical and chemical properties.

Jan 1, 1960

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

By N. Djilali

Many of the transport phenomena encountered in proton exchange membrane fuel cells occur intrinsically at the microscale level. Physically representative models that fully account for the salient physico-chemical and transport processes in PEM fuel cells are necessary to achieve truly predictive models that can be used with confidence to: (i) gain a better understanding of in-situ processes and couplings, (ii) explore new concepts, and (iii) support design and optimization. The development of more general, rationally based macroscale models requires use of knowledge on the microscale level to provide guidance, and to determine the required parameters and coefficients (model "constants"). In this paper we present a new membrane transport model, the binary friction membrane model (BFM2), recently developed to account for coupled protonic and water transport in polymer membranes. This general model is based on rational and physical consideration, removes several of the limitations of the empirical models used to date, and is formulated for all purfluoro-sulfonic acid membranes. The use of the BFM2 in a fuel cell model is illustrated highlighting significant performance predictions compared to existing empirical model. The second part of the paper addresses the fundamentals of two-phase transport in hydrophobic gad diffusion media. Computational and experimental visualizations resolving the microscale dynamics of water transport between the fibres of a GDL are presented, revealing transport mechanisms that are, contrary to assumptions used to date, dominated by fingering and channeling.

Jan 1, 2005

By A-A. Bogno, M. Rappaz, J. Valloton, H. Henein

"Rapid solidification of Al-Cu droplets of eutectic composition was carried out using Impulse Atomization in an argon atmosphere, to study the microstructures forming at different cooling rates and undercoolings. Two distinct morphologies were observed within the investigated Al-33wt%Cu droplets microstructures: (i) A regular lamellar morphology and (ii) an undulated morphology. The volume fraction of each type of morphology was measured as a function of the droplet size and the nucleation undercooling was deduced using the hypercooling limit equation. The scale of the microstructures was determined through measurements of inter-lamellar spacing across and along the growth direction. Growth velocity and undercooling were deduced using Jackson and Hunt (1966) eutectic growth theory. Finally, mechanical properties were estimated through micro-hardness analysis using a Vickers hardness tester, revealing exceptional properties for an aluminum-copper alloy. Indeed, the hardness values, increasing with growth rate and undercooling, were 3 times higher than the values obtained in hypo-eutectic Al-Cu alloys.INTRODUCTION Eutectic alloys are very attractive due to their good fluidity allowing ready shaping of parts in casting processes as well as in thermal spray deposition. In addition, they yield microstructures with high mechanical properties, by the virtue of their scale/size which is defined by the solidification parameters and the thermodynamic and thermophysical properties of the given alloy. Therefore, it is important to understand the relationship between the microstructures and the solidification parameters of eutectic alloys in order to control their solidification path and mechanical properties. The latter could be improved by either adding an appropriate strengthening component to a base eutectic material (Böyük, MaraslI, Kaya, ÇadIrlI, & Keslioglu, 2009) or by refining the microstructures for more effective dislocation pinning (Campbell & Campbell, 2003). Tailoring the microstructure can also be beneficial to chemical (Freitas, Osório, Spinelli, & Garcia, 2014; Osório, Freire, Caram, & Garcia, 2012) or electrical (Kaya, 2012) properties of the material. Eutectic-type microstructures, usually formed from liquid (eutectic transformation) or solid (eutectoid transformation), are made up of two or more different phases, generally of lamellar or fibrous (rod like) morphologies (Kurz & Fisher, 1998). In general, a binary eutectic structure can be regular (when both phases are non-faceted) or irregular (one of the two phases is faceted), the two solid phases having roughly the composition of the liquid from which they are formed."

Jan 1, 2017

By D. G. E. Kerfoot

In September 1945, when the Lynn Lake nickel orebody was discovered Sherritt Gordon Mines was a small copper mining company with rapidly depleting ore reserves at its single producing mine at Sherridon in the Cold Lake area of Manitoba, 100 miles north of The Pas. The company has been formed in 1927, largely through the efforts of Eldon L. Brown, a 27-year old mining engineer, with the financial backing of Thayer and Halstead Lindsley and the Gordon family. The Lindsleys were American mine promoters who had been successful in the Sudbury area, and the Gordons had extensive interests in the lumber industry in northern Ontario. Carl Sherritt, who gave his name to the company, was an American trapper and prospector who had staked the copper property and sold his interest to the new company. Carl Sherritt died in a flying accident at The Pas in 1928. The Sherritt Gordon Mine started production in 1931, shipping copper concentrate to the new Hudson Bay copper smelter at Flin Flon, Manitoba. In 1931 the price of copper was 18¢/lb. Within a year the price had fallen to 5¢ /lb and the mine was forced to close. It remained closed through the Depression years.

Jan 1, 1999

By Andrew J. Troop

"VAUGHAN THOMPSON designed the Thompson retrievable diamond drill wedge and reaming assembly in 1948. Since 1950, the Hudson Bay Exploration and Development Company, Limited has used the method extensively. The wedge, setting tool, and reamer have been modified slightly since they were first introduced. In 1951, Mr. Thompson designed the Thompson arc cutter. The purpose of this tool is to decrease effectively the diameter of the arc cut, using standard drilling tools. This directional drilling device is usually employed when a branch hole is desired. The Thompson arc cutter has been used with success at Birch Lake, Saskatchewan, at the property of Cuprus Mines, Limited, Manitoba, and at Thompson Lake, Manitoba.UsesThe Thompson retrievable wedge provides a simple method for:(1) Re-drilling lost core sections(2) Re-sampling sections of old holes(3) By-passing lost tools Correcting the direction of a hole(4) Drilling a branch hole to obtain intersections at a higher elevation than the original holePrevious to the spring of 1951, the wedge was used only for the first four of these purposes. Recently it has been employed extensively for drilling branch holes."

Jan 1, 1953

By Lawrence G. Houk

Lithium is the lightest of all metals, but as it deteriorates rapidly in air it has no structural applications. Alloys of lithium that will float upon water can be made with other light metals, but these ultralight alloys are not useful in aircraft production or elsewhere at present. Alone or alloyed with alkaline earth meals, lithium acts as reining agent on molten metals, and as a minor constituent with other metals it imparts characteristic properties to the allay. Lithium compounds have somewhat wider application in commerce than either the metal or the alloys. They are used in the glass, ceramic, chemical, and air-conditioning industries and less extensively in the optical, pharmaceutical, electrical, and textile industries. The United States is the leading producer anti consumer of lithium ores and compounds and apparently has the largest known ore reserves. The value of lithium ores and primary chemical byproducts produced is relatively small, yet the lithium chemical industry yields products worth hundreds of thousands of dollars each year, owing partly to the high degree of purity demanded by the trade for most finished products and to the low combining weight of lithium. Fortunately, the low-grade ores can now be concentrated economically, and this fact, together with our extensive reserves, assures adequate supplies to meet any reasonable increase in demand. Lithium is listed as essential by both the American and British war agencies, and its military importance may be greatly enhanced.

Jan 1, 1942

By Corby G. Anderson, Caelen D. Anderson, Patrick R. Taylor

"The United States contains a variety of domestic rare earth element mineral sources containing such as ancylite, bastnasite, monazite, and xenotime. Research has been performed to investigate the fundamental surface chemistry involved in the froth flotation of these minerals, and apply the knowledge gained to substantiate the results through experimental testwork on a domestically sourced rare earth ore. This paper will outline the fundamentals and literature of rare earth mineral flotation, review its industrial applications and provide some recent research updates.THE RARE EARTH ELEMENTSRare earth elements (REE’s) are a unique family of elements with nearly identical physical and chemical properties. They account for approximately 1/6th of all naturally occurring elements, but the entire group occupies only one position on the periodic table. These 15 elements make up the lanthanide series (atomic numbers 57–71), and all but one (promethium) occur naturally. In addition to these 15 elements, yttrium and scandium are also considered rare earths since they tend to occur in the same deposits as the rare earths and share similar physical and chemical properties as seen in Figure 1. In particular Figure 2 denotes, a cartoon of the subtle differences in each caused by the 4f atomic sub shell (Gschneidner Jr., 1964). These subtle differences result in very difficult challenges in the selective concentration and final separation of each rare earth. (Anderson, 2015, Kronholm, Anderson, Taylor, 2013)Rare earths are separated into two different subsections; the “lights” or LREE’s (lanthanum57 through europium63) and the “heavies” or HREE’s (gadolinium64 through lutetium71). Yttrium is generally considered a heavy rare earth since its ionic radius is close to that of the HREE’s, while scandium is not considered either a light or a heavy."

Jan 1, 2016

By John L. Sundstrom

Complete systems were designed -and are in operation to recycle the effluent streams and to remove impurities from tankhouse. electrolyte, Heavy em¬phasis was placed on making usable products from as many streams as poss¬ible at minimum capital and operating costs. Almost complete recycling: and reuse of water and sulfuric acid were paramount. Techniques used in-clude solvent extraction - electrowinning, evaporation - crystallization and filtration.

Jan 1, 1992

By Ross W. Smith

In recent years there has been a considerable amount of research work done relative to the effect of pretreatment and aging in water on the surface properties of both simple metal oxides and more complex oxides such as the silicate minerals 1-6. Of particular interest is the work of Somasundaran6 who states that after preparing minerals by size reduction and washing with dilute acids "... it is essential to treat it (the mineral) with water in order to remove any effects of leaching itself." Somasundaran also states, "... it is advisable to use a solution close to the point of zero charge for conditioning purposes." Parksl notes that, "Dehydration, dehydroxylation, and increased crystallinity can be expected to decrease the PZC. The presence of anionic impurities or of pH-independent potential determining ions will decrease the PZC. Cationic species will increase the PZC." Healy and Jellett4 believe that in the Zn0-water system "the surface charge of Zn0 in water and each pH is determined by the concentration and adsorption of each hydrolyzed (charged and uncharged) Zn(II) species." Finally, according to Parks 2, "The PZC of an unaltered com¬plex oxide in a system devoid of specific electrolytes is approximately the average of the PZC's of its component oxides... Equilibration with water results in loss of mono and divalent cations by exchange with H+, thus a loss of influence on the PZC by those cations, i.e., a shift in the PZC with time in the direction of that remaining oxide. The present paper investigates the change of point of zero charge (PZC) of a number of simple oxides and several complex oxides as a function of aging time in water. In some cases acid pretreatment of minerals was performed. However, in most cases the minerals were not acid pretreated. In several systems pH change as a function of aging time in water was monitored.

Jan 1, 1972

By B. N. Nandi

This paper is a study of the application of the science of coal petrology to the use of coal in the iron and steel industry. The petrography of coal is given the most attention, with some mention of coal palynology. The history of the petrographical analysis of coal is first out-lined, with a description of the various coal entities, and then the apparatus and experimental techniques employed for coal evaluation are discussed. The coke stability factor and the relation of coke strength to petrographical data are also covered, and some space is given to the new science of coke microscopy, in particular its use in following the oxidation of coals.

Jan 1, 1966

By Kurt F. Weitz

"The number of materials that can be classified as fillers covers an extremely wide range: this paper outlines those fillers of the industrial mineral type that find extensive application in the paint and plastics industriesIn the paint industry, mineral fillers are known as extender pigments. Extenders are added to paint and plastic compositions to (1) lower the cost and (2) rein-force or modify the physical properties of a composition.Commonly used extenders are classified according to chemical type and discussed in terms of the change in physical properties that they impart to a paint or plastic film. Available cost reductions and data on the consumption of extenders in the Canadian paint industry are also included."

Jan 1, 1970

Water contact angles in the air/water/francolite, fuel oil/water/francolite and fuel oil/water/quartz systems were measured to describe the wetting characteristics of these minerals. It was found that white francolite is more hydrophilic than black and tan francolite both in the absence and presence of fatty acid addition. The contact angle measurement results do not correlate very well with the flotation response and it appears that kinetic aspects of the bubble attachment process play an important role in the francolite-fatty acid flotation system.

Jan 1, 1997

By Wei Luo

Nickeliferous laterites were characterized by particle size analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX), Fourier transform infrared (FTIR) spectroscopy and thermal analysis. Results showed that the laterites consist mainly of nickel-substituted lizardite with cobble-like morphology and traces amounts of magnetite and phlogopite. As fluoride ions can react with silicon in the lizardite crystal structure and form metal-fluoride complexes, as well as increase the equilibrium constant of the lizardite dissolution in acid solution dramatically, the addition of minor fluoride salts (0.2wt.% NaF) gave a markedly enhanced metal extraction rate (Ni 81.7% and Co 52.3%) under the experi-mental conditions of particle size d50= 25 µm, 10% (v/v) H2SO4, reaction time 2 h, reaction temperature 90°C, liquid-to-solid ratio 3 mL g-1 and stirring at 500 rpm compared with H2SO4 alone (Ni 69.6% and Co 30.8%).

Jan 1, 2010

By F. L. Pirkle

The mineral zircon is mined for use as specialty foundry sands, abrasives, ores of ZrO2 and zirconium metal, refractories, and zirconium chemicals. It is produced as one of several products from heavy-mineral sand deposits associated with fossil shorelines. Because of its low coefficient of thermal expansion, its high melting point, its high refractive index, and its chemical inertness, it is an attractive refractory material. Zircon varies from deposit to deposit in terms of grain size, grain shape, and chemical impurity. Thus, there is a wide range of commercial products differing in impurity levels, particle shapes, and grain sizes.

Jan 1, 1992

By David Tisdale, Phillip Mackey, Nagendra Tripathi, Matthew Kreuh, Pascal Coursol

Xstrata Nickel’s Sudbury smelter operation is based on fluid bed roasting of Ni-Cu sulphide concentrate, followed by electric furnace reductive smelting and Peirce-Smith converting to produce a Bessemer matte for electro refining, along with sulphuric acid produced from smelter gas. While the site dates back to the 1930s, the present smelter configuration has been operational since 1978, and currently has a nominal capacity of about 67,000 tpy of contained nickel and is investigating options to expand in future up to 85,000 tpy. As part of a review of plant capacity options, a new metallurgical model of the plant was developed in order to examine a number of processing alternatives. Based on the METSIM™ platform, the present model includes the ability to examine the impact of a number of plant parameters on potential plant performance including; for example, the following: percent of sulphur elimination in roasting, matte grade, degree of matte metallization, temperature, coke requirements, sulphuric acid production, CO2 emissions and overall energy requirements. The process model also includes a number of special features adopted; for example, approaches to effectively model the complex Ni-Cu-Co-Fe-S-O matte system. This paper provides a description of the model and gives an overview of the results. As well as presenting the results of the present study, the applicability of this modeling approach to pyrometallurgical systems in general is also briefly discussed in the paper.

Jan 1, 2009

By E. C. Perkins

The purpose of the research described in this report was to develop techniques for using ilmenite from domestic deposits for the production of titanium tetrachloride. The research was done by the Federal Bureau of Mines in cooperation with the General Services Administration under contract DMP-116, Utilization of Domestic Ilmenite. Bench-scale continuous chlorination of an Idaho ilmenite containing 27.9 percent titanium and 35.6 percent iron yielded a crude titanium tetrachloride suitable for purification and for the production of titanium metal and pigment. A summary of the results of 380 hours of operation showed that 82.4 percent of the titanium was chlorinated, with 92.5 percent utilization of chlorine. The construction- of a. quartz tube chlorinator 4-inches in diameter and 24 inches long is described with the necessary details of operation.

Jan 1, 1961

By S. Neven

The smelting of copper anode slimes, a material which contains mostly lead, silver, copper and selenium, has been practiced for many years with a view to recovering the silver and associated small amounts of gold. However, a theoretical understanding of the process has been lacking and this handicaps efforts to improve and intensify smelting operations. In the past few years work has been done in this area and this work will be reviewed in the paper. The underlying thermodynamics of the oxidation of silver-copper selenide mattes has been developed and used as a basis for the construction of a computational thermodynamics model which attempts to predict the composition of all condensed phases during the course of smelting. The model will be outlined and its successes in matching experimental data, as well as its current deficiencies, will be considered. Supporting work on the thermodynamics of silver solubility in slags, on activity-composition relationships in the Ag-Se system and work in progress on the oxidation state of copper in the slags will be reviewed. These projects are designed to provide further detailed data which will improve the robustness of the thermodynamic model.

Jan 1, 1999

By M R. Davidson, M P. Schwarz

A model for column bioleaching is investigated to identify and understand aspects of bacteria in bioleaching applications, which have implications in heap bioleaching operations. The model is used to simulate scenarios that would otherwise be time consuming to perform experimentally. This study uses a model of bacterial transport and attachment/detachment to ore particles, with a bioleaching model for the depletion of a copper-sulfide, also accounting for liquid and gas flow and gas/liquid oxygen mass transfer. The model includes aspects such as oxygen and ferrous ion consumption, coupled with leaching of a copper-sulfide via the shrinking core model. The model is used to investigate how the rate of leaching is affected by the bacterial concentration in the columns, by the bacterial regeneration of the leaching oxidant ferric ions. The model is also used to assess the impact of oxygen limitation and inoculation method on the copper leaching. Some comparison of the model with experimental data will be shown.

Jan 1, 2004

By M. Savella

The Runruno Gold Project is located on the island of Luzon, approximately 200 km north of Manilla in the Philippines. The mine is a surface mine operation and use the proven BIOX® and carbon in leach processes to recover gold, and the ASTER™ process for detoxification of the CIL residue prior to discharge to the Residue Storage Impoundment (RSI). Work to date has defined a mineral resource of 1.39 million ounces of gold, and the operation will produce 96,700 ounces of gold per annum over a mine life of 10.4 years. The BIOX® circuit is designed to treat 140,000 tpa of concentrate with a design capacity of 404 tpd of concentrate at a design sulphide sulphur grade of 17% S2-. The Runruno project is the first BIOX® plant to implement the Generation III BIOX® design principles. As part of the Generation III BIOX® program Outotec supplied a turnkey, containerised metallurgical laboratory to facilitate the first four stages of the BIOX® and ASTER™ inoculum build up requirements. BIOX® inoculum build-up was started during early January 2015 with 5 litres of stock cultures shipped from South Africa. The BIOX® culture was successfully adapted to concentrate produced from the mini plant during March 2015. The ASTER™ inoculum build-up commenced during early August 2015 utilising 27 litres of ASTER™ bacterial inoculum already adapted to similar process conditions expected during commercial operation. This paper will detail the various stages of inoculum build-up through to commissioning and ramp-up of the BIOX® and ASTER™ Processes at the Runruno Gold Project. The paper will highlight some of the factors affecting the commissioning process as well as the improvements seen through the introduction of the Generation III BIOX® design principles.

Jan 1, 2017