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By Eric Johnson

"IntroductionHistoricalCyanidation is a leaching process, in world-wide use, to extract gold (and silver) from ores and concentrates. The process has many inherent advantages on account of its adaptability:a. to any scale of operation;b. to a wide range of ore types and mineral associations;c. to a wide range of physical characteristics of the gold particle size, alloy (electrum) or mineral (telluride);d. to relatively simple plant controls and operating procedures;e. to simple marketing procedures and quick cash return.The basic idea for cyanidation was first described and patented by a German chemist, L. Elsner, in 1846. Some forty years later, J.S. McArthur, a metallurgical chemist and R.W. and W. Forrest, medical doctors, all of Glasgow, Scotland, came to realize the import of the discovery and accordingly, registered patents in Great Britain in 1887 and in the United States in 1889. The keystone of the McArthur-Forrest patent registration was the use of weak (0.05o/o) instead of strong (1.0%) solution.The years 1890-1910 saw much progress in equipment design and the advance from batch to continuous processing to increase efficiency and reduce operating costs.In later years, technological progress followed advances in materials of construction and control systems. Current innovations include large-scale equipment, high-capacity thickeners, belt type filters and Steller, candle-type filters for plants using zinc dust precipitation. As well, environmental protection is increasingly a major concern.The technology of gold adsorption from cyanide solution onto activated carbon has made rapid strides in recent years. This has followed the initial efforts of Potter, Salisbury, Zadra and their colleagues of the U.S. Bureau of Mines Research Station in Salt Lake City, Utah, and the field work of Homestake Mining Company personnel, in Lead, South Dakota."

Jan 1, 1989

By R. J. Allan

"CANADA HAS A GREATER LAKE AREA than any other country. Discountin the Great Lakes, this fresh-water area, mainly in the Canadian Shield, is listed as approximately 300,000 sq. mi. Densities of lakes range up to 7,500 in a 5,294-sq. mi. area of the Shield, southwest of Reindeer Lake, Saskatchewan. Five areas chosen randomly from the Shield (Figure 1) contained sufficient lakes to provide samples at a density of at least one per 10 sq. mi. Regional geochemical surveys in the Appalachian area (Nova Scotia, Boyle et al., 1958; New Brunswick, Boyle et al., 1966) and in the Cordilleran area (Yukon, Gleeson, 1965) of Canada and in many other areas of the world have relied heavily on analyses of stream sediments. These surveys show that sampling of material related to the drainage system reflects the over-all trace element content of the rocks and surficial deposits in the drainage basin. In the Shield, the classic types of dendritic (and other) stream systems found elsewhere in the world are very rare. However, impeded and disorganized stream systems that abound with lakes can provide the exploration geochemist with an ideal composite drainage system sample in the form of lake sediment. This paper attempts to demonstrate the feasibility of, and review the theory and problems involved in, the use of lake sediment as a regional geochemical exploration medium. Most of the references to field examples are taken from a regional survey using lake bottom sediment as the sample medium over 1,500 sq. mi of the Coppermine basalt group and adjacent rocks (Figure 2). During this regional survey, detailed sampling of several lakes was carried out and the results are referred to at appropriate places in the text."

Jan 1, 1971

By J R. M Hutcheson

Advocate Mines Limited came into initial production on June 30, 1963, with an annual capacity in excess of 60,000 tons of high-quality chrysotile asbestos fihres, thus strengthening Canada's position in world production. The history of this development is traced from discovery through initial exploration, financing, orebody delineation and evaluation, pilot-plant production and product evaluation, construction of the plant, construction of deep?-sea shipping facilities, provision for a closed shipping season, and provision for the remoteness and for the lack of services, through to realization of full production capacity. The many unique aspects of the project are given special attention, particularly in the light of the first year of full-capacity operation. The marketing of the products in a highly competitive world market is reviewed, with special emphasis on product evaluation, quality control and the shipping of high-quality products to consumers throughout the world. C ANADA'S newest asbestos producer, Advocate Mines Limited, is located at the north end of the Burlington Peninsula, White Bay District, Newfound-

Jan 1, 1965

By N. Pajunen, R. Mäkikoskela

"The current state of environment has been achieved by acting linearly. At the same time, we know that transition towards circular economy cannot be made the same way that we have used to, trusting only a market economy and economic growth. Environmental improvements have been promoted, some progress has been made, but major steps towards sustainability have not been taken. Industry is now facing significant change, from process related environmental thinking to product-based environmental thinking.Engineers make decisions which have lifelong influence and even longer on environment and society. Material engineers in case of saving natural resources and increasing material cycle, have an important role to play in the transition towards sustainability. Best knowledge of minerals and materials is in the material development phase. If we want to increase the cycle of different materials, it is vital to make decisions towards circular economy in early phase of product´s life cycle.The target of this study is to promote circular economy; to increase material efficiency; to save natural resources; and to extend product lifecycles in process industry via product design and material development. In this study we have a new kind of cooperation. We combine two disciplines, engineering science and fine arts. We promote sustainability via breaking out the silos. We bring the cyclic artistic thinking into engineering science and environmental research. The new research combination makes the existing information visible in a new way, and it will change attitudes and ways to act by means other than traditional linear rationality.We have tested the new working method via the industrial case study with the chosen product: the sandwich panel of construction industry. The target of the study was to create something new from the chosen product with artistic thinking. The working method will be presented in this paper."

Jan 1, 2016

By Karl J. C. Harries

"2.1. INTRODUCTIONNo agreement can be perfect in the sense that it contemplates and provides for all eventualities. Mineral acquisition agreements are usually negotiated and drafted at a time when an orebody is no more than a gleam in a geologist’s eye, so it is hardly possible to provide for development and operation in other than the most general terms. However, an agreement that stops short of contemplating the possibility of an orebody and production is ill-advised. Accordingly, it is important to provide procedures to make decisions that will let the project proceed, even in the face of a fallingout between parties. Whether the parties are shareholders in a corporation or venturers in a contractual common undertaking like a joint venture, differences of opinion and disputes will occur. Unfortunately, more and more are ending up before the courts. Besides greed and the growing tendency in society to fight rather than talk, there are other factors that contribute to the increase of litigation. In some jurisdictions, agreements have tended to become complicated, often defying interpretation, even by a lawyer, and explorationists want their budgets to go into the ground as constructive work rather than into a lawyer’s pocket. All this has led to a growing tendency for corporations to take the attitude that the chances of finding a mine are, at best, marginal and there are lots of earlier agreements in the files to draw from, so why not prepare their own agreements? As discussed in the preceding chapter, this can be folly. All these factors can quickly have parties facing each other in court while a project sits idle. Added to this is the problem that, in some jurisdictions, lawyers may take cases on a contingency-fee basis, sometimes promoting the pursuit of a nebulous claim.When an orebody is discovered, someone will always want some, or more, for himself. There is a breed of “prospectors” who prospect for legal actions, on the somewhat sound grounds that a major corporation will buy off nuisance litigation, rather than incurring the cost and effort of attacking even a poorly founded claim in the courts. They may even find a winner. Besides, it is far more comfortable and relaxing to prospect for problems and legal niceties than to prospect for an orebody.1 In short, it is appropriate to consider briefly some of the factors relating to lawsuits and judgments. Although many of the comments are made in the context of the common law and the Canadian legal system, most of the concepts and suggestions are applicable to any legal system."

Jan 1, 2003

By Michael T. McCaffrey

The wide range of potential feed materials, process steps, and products in metallurgical facilities means that standard equipment might not be available to adequately meet the project technical and economic needs. Custom designed equipment should be considered only after rigorous research precludes purchasing standard equipment. However, the decision to use custom equipment introduces a new element of risk into the project. To manage the risk, custom equipment design should be developed through the same front end loading (FEL) phases as project development. If more than incremental development of custom equipment is required, appropriate test work or pilot trials are required to test key uncertainties. Important activities during custom equipment design include maintaining clearly defined performance objectives, conducting appropriate reviews, carefully crafting commercial and intellectual property agreements with design and fabrication partners, and assembling a multidisciplinary team with sufficient development expertise.

Jan 1, 2015

By Quin Dennis

Process Optimization ?What is it really? It is NOT ?a larger fan to increase draft through a process ?a larger pump on a wet circuit ?a wider conveyor belt for solid materials ?a larger feed elevator into or out of a process These relieve individual constraints ??bottlenecks??and allow operation to the next constraint in the process ?It is also NOT about automating the operator ?which captures consistency but is not continuous optimization

Nov 1, 2011

By S. P. Narayan

The hot deformation behavior of Pure Mg and Mg-0.29Ce alloy were studied by isothermal hot compression tests in the temperature range of 250 - 500°C and strain rate range of 10-3 - 102 s-1 in a computer-controlled 50kN servo hydraulic universal testing machine (UTM). The results show that the flow stress of Mg pure and Mg-0.29Ce alloy increases with strain rate and decreases after a peak value, indicating dynamic recovery and recrystallization. Process efficiency was increased by nearly 10 to 12% by addition of Ce in Mg. Mg pure exhibits instability zones between 250-275°C at 10 ? 102 s-1 and 400¬500°C at 101 ? 102 s-1 temperatures and strain rates respectively, rest is the safe deformation zone. Wherein, Mg-0.29 Ce exhibits two low efficiency zones from 250 ? 300°C at 10-2? 10° s-1, 400 ? 500°C at 101 ? 102s-1 and high efficiency zone at 450 ? 500°C at 10-3? 10-1s-1. 4D process maps were generated for the above said alloys which illustrate contours of power dissipation and instability in the 3D space of strain rate, temperature and strain.

Jan 1, 2011

By E. M. Timoshenko, A. V. Tarasov

The results of laboratory, bench-scale and semi-commercial investigations of a method for adding surfactant (technical-grade lignosulphonate) to the process of pressure leaching of nickel-containing pyrrhotite concentrates have been discussed. Lt has been demonstrated that feeding of technical-grade lignosulphonate distributed along the length of an autoclave ensures a reduction in its requirement by a factor of 1.5 to 2 as compared with single-point feeding; it also results in a decrease by 5% in the unit requirement of metallized iron-bearing precipitator in the process of non-ferrous metals precipitation and reduces by 0.05 to 0.1% (abs.) the nickel and copper contents in the tailings of the given process. Technical solutions have been proposed for commercial introduction of the process.

Jan 1, 2004

By G. E. Agar, W. B. Kipkie, V. K. Drylie

"This paper describes mineral processing test work on drill core samples from an ilmenite deposit in Terrebonne County just north of Montreal.Mineralogical examination showed that the intimate associa¬tion between ilmenite and hematite precluded their separation. The maximum concentrate grade was therefore limited to 22.9% Ti. Liberation of gangue from the hemo-ilmenite grains occurred around 400 µm, a size which proved to be too coarse for recovery by flotation.Other physical separation techniques, such as elec¬trodynamic, magnetic and jigging, were tried in order to take advantage of the relatively coarse liberation size. An all-flotation procedure and a combination of jigging and flotation yielded similar separations.IntroductionInco Metals Company, through its subsidiary Canico, optioned an ilmenite deposit in Terrebonne County, just north of Montreal, and conducted a drilling campaign to confirm previous geological assessments of the deposit and to provide core samples for mineralogical study. Parts of these core samples were used for mineral processing studies, which will be described in this report. The objective was to identify suitable upgrading procedures, to determine the optimum combination of concentrate grade and recovery, and to provide suitable batches of concentrate for further treatment."

Jan 1, 1980

By G. R. McMeekin

"THE TOPIC suggested for my contribution to this Symposium was ""Lead-Zinc Smelting - 40 Years of Pollution Control"". The history of the development of smelting industry at Trail and the control of sulphur dioxide could make quite an interesting historical study. However, in the field of environmental control, the public is not particularly interested in what you did yesterday, but rather what you are doing today and what you are planning to do tomorrow. I can't fault this approach, but because there are some subject lessons that history can demonstrate, I would like to tell enough of the story (under three headings) to bring a focus on matters of contemporary concern in regard to public relations and ecology. The three general headings suggested are: (1) time before the capture of by-product sulphur; (2) the capture of sulphur; and (3) the ecological and public relations conclusions from these."

Jan 1, 1972

By Tassos Grammatikopoulos, Gary Pearse, Massoud Aghamirian, Charlotte Forstner, Stephen Mackie

"SGS Minerals Services (Lakefield, Ontario site) has conducted a number of developmental and pilot programs that examined methods for the beneficiation, extraction and recovery of lithium from a variety of spodumene containing hard rock sources. An overview of the beneficiation programs is presented separately by Aghamirian, Mohns, Grammatikopoulos, Imeson & Pearse (2011). The focus of this discussion will be the hydrometallurgical steps involved in producing a high grade lithium carbonate (Li2CO3) sample from the spodumene concentrate. SGS has applied the standard Li2CO3 hydrometallurgical flow sheet to a number of spodumene concentrates and has determined that all of these samples respond in a similar manner to the process and produce a final product having a Li2CO3 grade of >99.5%. The standard process is sufficiently robust to accommodate the observed variability in the concentrates that have been tested. Advantage of one spodumene deposit over another will thus be gained through process optimization and innovation. Optimization at the beneficiation stage and at the hydrometallurgical stage must be considered. Some aspects of the process optimization of the hydrometallurgical flow sheet will be presented.INTRODUCTION The current activity in the exploration, development, and mining of lithium based minerals is due in large part to the key role that this metal plays in the rechargeable battery industry (U.S. Geological Survey, 2011). Lithium battery technologies are widely applied in a range of portable electronic consumer products. The expanding development and production of hybrid and fully electric vehicles has contributed to the increased interest in finding and developing new lithium sources in order to meet the expected demand from the lithium battery industry. Lithium may be sourced from continental brines (sub-surface salars), hard rock minerals (pegmatite, spodumene), hectorite clay deposits, geothermal brines and oilfield brines. Currently the majority of the lithium products are produced from Li brines. The four major lithium producing countries are Chile, Australia, China, and Argentina (U.S. Geological Survey, 2009; Roskill, 2009). These countries accounted for 97.6% of the total lithium produced in 2010."

Jan 1, 2012

By L. M. Pidgeon

MAGNESIUM metal, with a specific gravity of 1.73, is two-thirds the weight of aluminium and one-quarter that of steel. It is the lightest metal which is stable in the atmosphere. Before the war it had begun, though somewhat slowly, to take a place among the established metals. In 1939, magnesium production on this continent amounted to some 3,000 tons per annum and was confined to one company. At that time, Germany produced perhaps 20,000 tons. The advent of war, however, increased the demand to fantastic heights and introduced production problems of unprecedented magnitude. By the end of 1943, North American production is expected to reach 300,000 tons per annum (1), an increase of one hundredfold. Such a rate of expansion has not been witnessed previously in the history of metallurgy. It has given the metallurgist an opportunity to try new production methods and to learn in a short time what might otherwise have taken many years. The metallurgy of magnesium is still in its formative years and at this time widely different production methods are in operation side by side. This paper will discuss these methods in so far as information is available for publication at this time. A general description of the new Canadian industry will be included.

Jan 1, 1944

By W. L. Stuewe

For the purpose of this paper I shall, in order to limit myself, define the words 'Maintenance' and 'Equipment' as follows: Maintenance shall mean the 'care of or 'the sustaining of equipment in as nearly perfect condition as possible. Equipment shall mean any item of a mechanical nature entering into the production of coal; it will be seen that unless one limits the use of this word it could take in administration as well as operative equipment, and include metal mines, mills and smelters, and manufacturing plants. In any industry the first consideration is the proper operation of all units entering into the production of the article manufactured or produced. I wish to quote here what a man, well known internationally in financial circles, told his operators at the time a large expansion programme was under consideration. His exact words were: "I do not care how much it is going to cost. What I want to know is how much it is going to cost to operate and maintain. It is the continuous drain for repairs that costs us the most money." The truth of this statement has been proved time and again, and many companies have found the cost of maintenance to be the balance between profit and loss-so much so that, in two instances with which the writer is familiar, the mechanical equipment was practically replaced throughout. I bring this point out here to emphasize the value and necessity of keeping abreast of the times, and obtaining maximum efficiency with the minimum outlay. Time is indeed money where delays occur due to defective or poorly kept equipment, and it is absolutely necessary to prevent machinery from becoming defective or inefficient.

Jan 1, 1930

By A. R. Miller, R. A. Stanton, M. J. Male, G. R. Cluff

"The Dubawnt Group consists of continental sedimentary and volcanic rocks which fill structural depressions - Baker Lake Basin, Yathkyed Lake and Angikuni Lake subbasins- whose evolution was controlled by late Aphebian extension, between 1.9-1.8 Ga. Structurally controlled uranium mineralization having the signature U + Mo + Ag + Pb + Cu ± Zn is spatially related to (i) intersecting fault systems that record multiple movements, (ii) chemically reactive lithologies containing sulphide, chlorite or graphite/ carbonaceous matter in the Archean and Aphebian basement complex and as alkaline volcanics of the overlying Dubawnt Group and (iii) areas containing thick successions of basal Dubawnt Group red clastic sediments.The most significant uranium occurrence found to date is the Lac Cinquante deposit, which contains 14 million pounds U3O8 of drill-indicated reserves. Mineralization is hosted in Archean meta-volcanic and metasedimentary rocks of the Henik Group adjacent to the basal Dubawnt unconformity in the northeastern A ngikuni Lake subbasin and occurs as plunging pods in and peripheral to a fractured and brecciated tuffaceous meta-sediment- sulphide+ carbonaceous exhalite. This deposit exhibits many features typified by the classical vein deposit at Beaverlodge, northern Saskatchewan.Epigenetic stratabound U + Cu + Ag ± Mo mineralization, typified by the 74-1E prospect in the eastern Baker Lake Basin, is hosted in thermally altered Kazan redbeds adjacent to alkaline dykes.At the eastern end of the Baker Lake Basin, small prospects having an elemental signature U + Se + Cu + Ag +Au are interpreted as unconformity-related mineralization associated with the Helikian The/on Basin.The Dubawnt Group rocks of the Baker Lake Basin, subbasins and adjacent basement complex contain uranium mineralization of two eras- Late Aphebian and Helikian."

Jan 1, 1986

By W. Keith Buck

This paper defines the discipline of mineral economics. By example, it describes the application of the tools of economic analysis to mineral problems - to problems in the areas of: mineral resource analysis and forecasting, mineral industry activity from exploration to distribution and marketing, mineral commodity analysis, and mineral policy analysis and policy formulation - all in a regional, national or international context.

Jan 1, 1972

By James L. Oleson, Hunter R. Propsom, Kevan J. R. Ford, Robert D. Henderson, Bob Musgrove

"Kinross’ Fort Knox Gold mine, near Fairbanks, Alaska has successfully implemented two major metallurgical continuous improvement projects resulting in growth of gold production and an extension of mine life. In 2009, Fort Knox produced 263,153 oz of gold at a cash operating cost of $543/oz. In 2010, approximately 63% of the gold will be produced from the CIP circuit, 15% of the gold from the gravity circuit and 22% of the gold from the heap leach.In 2009, a 44,000 ton per day run-of-mine valley fill heap leach facility was constructed and commissioned as a cost effective treatment option for low grade ores to supplement the higher grade mill. The heap leach facility will produce approximately 100,000 ounces of gold per year under severe winter conditions. Heap leach gold recovery, based on test work shows 30% after a 55-day leach cycle, with long term ultimate gold recovery targeted at 65%. The paper presents the heap leach design concepts and production data.Additionally in 2009, installation of a Knelson gravity concentrator unit (XD70) was completed. This together with an Acacia intense leach reactor (AILR) has increased overall mill gold recovery from 79.3% to 80.7%. A manual shaking table gold recovery operation has been replaced by batch intensive cyanidation of the high grade Knelson concentrates. Increased removal of coarse gold and difficult-to-leach gold species from the grinding circuit, via the gravity circuit, has improved gold leach recovery in the conventional whole-ore tank leach CIP circuit. The paper presents plant operating data, showing the improvements over the old flowsheet.Focus on the metallurgical properties of the high grade and low grade end components of the Fort Knox ore has resulted in significant improvement to gold recovery."

Jan 1, 2011

By F. W. Gray

A GEOLOGICAL study seeking to determine, for economic purposes, the value of the Sydney coalfield as a source of coal supply. Limitations of the coalfield come under two main heads: (a) Areal extent of the undersea coalfield. (b) The distance from shore at which coal can be mined at a cost of production permitting its profitable sale. Conclusions reached are that the areal extent of seams below the Phalen seam is of. small economic importance, and that non-persistence of these seams in full thickness and quality in the undersea extension of the coalfield will put an end to profitable mining before any limitations connected with distance from the shore-line become operative. With respect to the Phalen seam, non-persistence or deterioration of the seam will become effective in the western part of the coalfield, and less certainly in the eastern part of the coalfield, before operation of limitations by distance from shore. In the central portion of the coalfield, the seam probably persists in commercially workable thickness and quality to beyond the limit of mining set by distance from the shore-line. With respect to the seams above the Phalen seam between the Mountain fault on the extreme western boundary of the coalfield and the assumed termination of the deposition area on the eastern extremity of the field near South Head of Morien, there appear to be only such limitations as arise from engineering approach, distance from shore, sufficiency of strata cover between the sea-floor and the upper coal seams, and quality of the coal (with certain reservations as to the continuity of the upper seams under Sydney harbour and in the Sydney Mines-Little Bras d'Or district). Some of these seams have fragmentary land outcroppings from which their persistence seaward is assumed, and there may be other and still higher seams in the strata column which are entirely submarine.

Jan 1, 1941

By K. C. Sole, G. Robinson, M. S. Moats, W. G. Davenport, S. Sandoval

Global practice in hydrometallurgical production of copper cathode by electrowinning is reviewed, based on individual plant operating data for 2018. Data from 29 plants were collected, representing 38% of world cathode copper production. Similar surveys were carried out in 1997, 1999, 2003, 2007, and 2013. This survey includes analysis of historical and current data. Evolving trends in operating conditions and performance, as well as equipment design and process technology choices, are analysed and differences in operating practices with location are assessed. Examples of recent technology and operational choices to increase productivity, improve copper quality, and decrease electrical energy consumption are discussed. Significant project expansions, particularly in Africa, and the consolidation of numerous small Chinese operations are also presented. INTRODUCTION Global trends and operating practices in copper electrowinning (EW) in 2018 are reviewed and evaluated. Similar world and African surveys were carried out in 1997, 1999, 2001, 2002, 2003, 2007, and 2013 (Robinson, Davenport, & Jenkins, 1997; Jenkins, Davenport, Kennedy, & Robinson, 1999; Davenport, Jenkins, Robinson, & Karcas, 2001; Robinson, Garbutt, & Davenport, 2002; Robinson, Davenport, Jenkins, King, & Rasmussen, 2003; Robinson, Davenport, Moats, Karcas, & Demetrio, 2007; Robinson, Sole, Sandoval, Moats, Siegmund, & Davenport, 2013). Contributing operations included sites from the USA and Mexico (9), Chile and Peru (6), Laos (1), Kazakhstan (1), and Africa (9). Despite fewer contributions compared with past experience, this survey nevertheless represents 2018 copper EW cathode production of 1.76 Mt, or about 38% of world production of 4.64 Mt (International Copper Study Group, 2017). This drop in permission to contribute is attributed to the more competitive nature of the industry and unprecedented production pressures; furthermore, several operations in Australia have shut down, while large operations that are currently commissioning or ramping up to full production in Africa and Asia declined to participate. Of the Chinese operations, which represent an increasingly important proportion of global electrowon cathode copper, particularly in Africa, only Tenke Fungurume (Democratic Republic of Congo; DRC) participated in this survey.

Jan 1, 2019

By Brian G. Pewsey

Located in the northern part of the Province of British Columbia, the Cassiar Mine started development of its asbestos orebody in 1952, and is currently producing 105.000 tons of asbestos fibre annually. The townsite is nestled in a beautiful valley and supplies more than average facilities. The fibre is shipped to more than 40 countries and is used in many industrial products.

Jan 1, 1978