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By Amyn S. Dahya, David J. King

"The object of the paper is to discuss the developments in Carbon-In-Pulp (C.I.P.) technology for gold recovery. The CIP process is comprised of four major operations:(a) adsorption of precious metals onto activated carbon;(b) elution (stripping) of precious metals from the loaded carbon;(c) electrowinning of the precious metals from the concentrated eluate;(d) regeneration of the eluted carbon before recycle to the adsorption process.A detailed review of the technological developments in each of the above operations is presented together with a brief theoretical background of the underlying processes. The advantages and disadvantages of the CIP process are discussed in comparison with conventional zinc precipitation. IntroductionThe carbon-in-pulp (CIP) process involves the use of activated carbon for treatment of pulps containing dissolved precious metals, and provide s an alternative to the conventional gold recover y processes using filtration or counter-current decantation in conjunction with the Merrill-Crowe zinc precipitation process. The commercial application o f the CIP process in gold processing technology is a fairly recent development and it is of growing importance around the world.The fact that activated carbon ha s the property of adsorbing precious metals from solution was first published in 1847. In the following years , a great deal of work was carried out to develop an over-all recover y process using carbon, but all attempts were uneconomical because the loaded carbon had to be smelted to recover the gold.It was not until 1950 that Zadra, at the United States Bureau of Mines Research Centre in Reno, Nevada, developed a technique for stripping the loaded carbon using sodium sulphite-sodium hydroxide mixtures and then recovering the gold from the stripping solution by electrolysis. However, this process was not effective for stripping silver and further testwork was carried out on alternative stripping techniques. In 1952, Zadra published a paper describing the use of a hot sodium hydroxide- sodium cyanide stripping technique, which was effective in stripping both gold and silver. This paper included a description and flowsheet for the CIP process which is essentially the same as we know it today. This technique was used in the first major CIP plant, constructed and commissioned in 1973 by Hornestake Gold Mining Company. Since then there have been numerous CIP plants built in the U.S A., South Africa and Australia."

Jan 1, 1983

By F. C. Nicolli, J. P. Barbosa, P. S. M. Soares, A. V. Estevez

INTRODUCTION Spent household dry cell batteries are frequently disposed of with metropolitan wastestream (MSW) in landfills where they can leak due to handling or aging. Frequent rain and sun cycles, especially in tropical environments, coupled to the action of leachate, dissolve their metal constituents which will eventually reach rivers, lakes and underground water. It is well known that some of these metals are fundamental to sustain life and that is why living organisms concentrate them through their metabolism, but it has been also recognized that beyond specific limits they can definitely be deleterious to the environment. In other words, high concentration of heavy metals are proven to cause chronic or acute diseases and toxic reactions, by acting on mammals' kidneys, liver and nervous system. In addition, some metals frequently used in household batteries, as mercury and cadmium, are said to be carcinogenic (Landis et al. 1995, Silva et al. 1988). Occasionally, plants to treat MSW are coupled to compost production. Household batteries present in MSW can be dragged into these plants, contaminating their products and eventually reaching vegetables making them not proper to consume by people and animals. Alternatively, batteries are also conveyed to incinerators and burned, throwing into the atmosphere volatile species. These can either act as contaminants as toxic vapor species or be delivered by winds and scavenged by rains contaminating soils and water far away from their source. In conclusion, despite the treatment applied to MSW, one can say that battery residues are potentially environmentally hazardous. The careful assessment of the environmental impact caused by residues of household batteries it is not an easy task and it can be referred as a multivariable problem. First, many different household batteries are produced by industry and the potential environmental hazard associated to their disposal depends primarily on the type of battery and manufacturer's technology. These characteristics will dictate how resistant the battery case is to handling and the

Jan 1, 1998

By Gregory J. Chekan

In order to reduce waste and improve resource conservation, mine planning, and development, the U.S. Bureau of Mines is investigating multiple seam interactions associated with longwall mining. Longwall gate entry and panel stability have been influenced by previous mining in coalbeds above and below a mine in Virginia that operates in the Lower Banner Coalbed. Directly superjacent, approximately 115 ft, the Upper Banner Coalbed has been partially worked by room-and-pillar mining. Directly subjacent, approximately 730 ft, the Tiller Coalbed has been worked by partial room-and-pillar retreat mining. The study mine has experienced problems during development of gate entries in areas of overmining and undermining. It is anticipated that stress fields associated with adjacent mining may further affect gate entry stability and face advancement during the extraction of the longwall panel. To assess overmining and undermining effects on ground stability, the Bureau gathered geotechnical information at the site. Headgate entries and pillars were instrumented and monitored to study loading behavior as the longwall face approached and passed potential problem areas. Measurements indicate that although increases in average pillar pressure were greater than predicted values, previous mining in adjacent coalbeds had little effect on headgate stability.

Jan 1, 1989

By K. Adam

Uncontrolled disposal of pyrite wastes and concentrates comprise a major source of acid drainage in active and abandoned sulphide mines. In this paper, the state?of-the-art mitigation measures implemented for the final reclamation and closure of a pyrite concentrate stockpile at Platia Karra, Stratoni mines, Greece, are presented.

Jan 1, 2002

By Luis Villegas

El presente texto señala el método del relleno en pasta como elemento clave en la explotación en la mina Iscaycruz. El relleno en pasta se basa en el empleo de relaves, cemento, agua y un químico floculante, donde son dosificados y mezclados en una planta y son transportados por una línea de tuberías hacia los niveles de mina. Entre las ventajas que se presenta está la eficiencia en los trabajos de relleno, así como da una mayor vida a los depósitos de relave, minimiza el uso de equipos en la operación y reduce costos operativos. Asimismo permite obtener en los tajos rellenados características homogéneas y otorga mayor dinamismo al sistema de relleno.

Sep 12, 2005

By R. P. King

Flotation plant simulation, a relatively recent methodology in mineral processing, is defined and corresponding uses are discussed. Typical simulation structures are compared. Current problem areas exist although these are not insurmountable. Following a brief state of the art discussion, the N. I. M. simulation program is reviewed. In general, digital plant simulation is expected to be of substantial benefit in the near future.

Jan 1, 1976

By S Love, M Anderson, M Boland

"The high rate of failure of new mine developments to meet feasibility study expectations has been the subject of many fine technical papers. Yet failure rates remain stubbornly high.Similarly, the common occurrence of disastrous acquisitions resulting from failed due diligence on projects is well known. Yet such mistakes continue to be made.The authors argue that project and due diligence failure are caused at least partly by cognitive biases. These biases pervade decision-making throughout project evaluations.A wider understanding of these biases (and their effects) is necessary. Only then can mitigating actions be taken.The opportunity for this wider understanding exists. A number of best-selling books have been published on the topic in recent years. With wider understanding of key concepts and terms, cognitive biases can be recognised and discussed. They can also be challenged and mitigated.The authors believe that these concepts should be entry-level, required knowledge for anyone evaluating, developing, reviewing or financing mining projects.Perhaps the most prevalent biases in project evaluation failure are the ‘over-optimism’ biases. In particular, the planning fallacy and confirmation bias.The anchoring effect is also pervasive. This bias propagates unrealistic assumptions from scoping and prefeasibility studies through to so-called definitive feasibility studies. Unrecognised anchoring biases also undermine the validity of many ‘independent’ due diligence reviews. They are also prevalent in corporate acquisitions.The availability heuristic refers to a mental shortcut that can lead to a number of biases. One of these is the narrative fallacy. The mind constructs coherent narratives and opinions, regardless of the amount and quality of the information that support them. Narrative fallacy commonly occurs in the evaluation of social and political risk. Another is disaster neglect, which is especially common in the failure to assess risks associated with tailings management.This paper outlines the relevance of these biases to mine project evaluations. It also provides examples where the authors have observed their effects.CITATION:Love, S, Boland, M and Anderson, M, 2016. Influence of cognitive biases on project evaluation, in Proceedings Project Evaluation 2016, pp 226–235 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By I. B. Browning, N. Shiarella, Coleman D. Hunter

The price of crude oil in Kentucky did not change very much during 1935 until the latter part of the year, but more stabilized conditions and an increase in consumption of natural gas made the year a more profitable one than the year 1934. The production of crude oil in 1935 amounted to 5,175,054 bbl. as compared to 4,814,904 bbl. in 1934. This increase was due to two developments: (1) the application of new recovery methods to old fields, which, although in operation in the state for several years, had never before reached a point where the production obtained, while highly satisfactory where applied, was sufficient to influence the totals in the production figures; (2) the development of the Fordsville area in Ohio County, where shallow depths enabled the operators to complete the development of a large number of wells with a good flush production probably accounted for most of the increase. A map showing the location of oil and gas pools in Kentucky was published last year.' The fields of eastern Kentucky, producing from the Weir sand of the Waverly group of the Lower Mississippian series, in Johnson, Magoffin, Lawrence and Elliott counties, produced 826,001 bbl. of oil in 1935 as compared with 902,247 bbl. in the previous year. No new wells were drilled in this area during the year, except those for use as intake wells in repressuring. What has been done in the few small areas within these fields in the way of repressuring has produced results sufficient to a great extent to offset the natural decline of all the field. It is probable the drilling of new wells and construction of new plants will be such as to cause these fields to produce more in 1936 than was produced in the past year. This is based on the fact that the sand is highly favorable for repressuring and the results obtained show from 300 to 500 per cent increase in production. From the "Corniferous" pools, where production is from the Cornifer-ous limestone of Devonian age, in Lee, Powell, Estill, Wolfe, Morgan and

Jan 1, 1936

By F. P. Miknis

Previous studies at the Bureau of Mines have shown that broad-line nuclear magnetic resonance (NMR) techniques have potential applications for rapid evaluation of oil-shale deposits. In a continuation of this study the techniques of pulsed NMR have been applied in a similar manner. The basis for the pulsed NMR oil-shale assay method lies in the assumption that the free induction decay (FID) amplitude following a 90° pulse is proportional to the potential oil yield. This assumption was tested on two groups of oil-shale samples, numbering 141 and 263 samples, from two different oil-shale cores. For both groups of samples a small number were selected as calibration samples. Free induction decay amplitude measurements were made on the 141 and 263 samples. The best least-squares regression line was obtained for the calibration samples, and the oil yields of the remaining samples were calculated using the slopes and intercepts obtained in the regression analyses. The agreement between measured and calculated oil yields was good, the indexes of determination being 0.93 and 0.89 for the groups of 141 and 263 samples, respectively.

Jan 1, 1974

By P. E. Arnold, G. S. Ansell

RELAXATION in metals has been studied in detail by many workers in recent years.1-5 These studies have shown that there is an energy-loss peak observed in a metal placed in mechanical resonance at low frequencies which may be correlated with various metallurgical processes. These experiments have been largely used to study single-phase materials. In order to study the effect of a finely dispersed second phase in a metal matrix upon this phenomenon, the relaxation behavior of an aluminum-aluminum oxide SAP-Type alloy in both the fine-grained as-extruded and coarse-grained recrystallized conditions was investigated by the use of internal-friction measurements. The alloys studied, designated MD 2100, consist of a matrix of commercial-purity aluminum containing a finely dispersed second phase of aluminum oxide. The aluminum oxide is present in this alloy in the form of fine platelets approximately 130A units thick and several microns on edge. The mean free path betwen dispersed platelets is approximately 0.5 p. The grain size of this alloy is extremely stable at temperatures as high as the melting temperature of the aluminum matrix. In the as-extruded condition the grain diameter is several microns, while in the recrystallized condition it is several millimeters in diameter. The damping characteristics of the alloy samples were determined using a torsional-pendulum device. The internal-friction constant was determined for this alloy in both the fine-grained as-extruded and coarse-grained recrystallized conditions over the temperature range from 343" to 923°K at frequencies of 0.9, 1.3, and 1.8 cycles per sec. An internal-friction peak was observed in testing the fine-grained alloys which was not observed for the coarse-grained alloys. This peak, which might be associated with a type of grain-boundary relaxation, was observed at each of the three different test frequencies for the fine-grained sample. The temperature at which the relaxation peak occurred for each of the three different frequencies is shown in Table I. From these data an activation energy of relaxation for each pair of frequencies was determined by comparing the temperature shift of the relaxation peak with frequency between each of the test frequencies, assuming that an Arrhenius-type rate equation is applicable. The activation energy of relaxation determined from these data is also shown in Table I. The mean value of the activation energy was about 6 kcal per mole. The activation energy for the relaxation process determined in this investigation indicates that the relaxation associated with the grain boundaries in this aluminum-aluminum oxide SAP-Type alloy is quite a different process than grain boundary relaxation in single-phase aluminum alloys. In these latter alloys, the activation energy for relaxation has been found to be the activation energy for self-diffusion, approximately 36 kcal per mole1,2 Where the activation energy is the same as the activation energy for self diffusion, it has been proposed that the relaxation phenomena is dependent upon vacancy formation and motion. It is apparent therefore, that, in this aluminum-aluminum oxide SAP-Type alloy, the relaxation must be due to another type of atom transport. It has been shown previously in studies of the high-temperature, low-stress, steady-state creep behavior of as-extruded aluminum SAP-Type alloys, that the activation energy for steady-state creep is one that may be characterized by the nucleation of dislocations from the grain boundaries. It is proposed that the relaxation behavior observed here is due to a similar effect. In this case, the internal-friction peak is a resonance behavior due to the time-dependent nucleation of dislocations from grain boundaries in the sample. A process of this type would have an activation energy which is undoubtedly stress-dependent and of the form Q = Q, + (dQ/du)u

Jan 1, 1962

By J. D. Patsey, G. T. Lineberry

Introduction A computer program was developed for analyzing drum-type hoists before modifying an existing system or designing a new one. Its use permits the preliminary evaluation of a system before seeking technical assistance from mine hoist designers and manufacturers. The user-friendly program accepts a variety of data and analyzes hoisting systems for any balance state. The program can be used to calculate skip capacity to yield a desired production rate, solve for drum face width, select a permissible wire rope, estimate total horsepower of the hoist plant, and estimate annual power cost. Whether required for a large mining complex or for a relatively small operation, a hoisting system must be carefully designed to ensure the efficient, reliable, and safe flow of material. Because shaft sinking and hoist installation can total between 2.5% and 3% of the cost of opening a deep mine, proper hoist selection is critical. Today's mining engineer has at his disposal the most powerful design and analytical aid ever, the micro- computer. There is, unfortunately, limited software for the study of hoisting systems, unlike that for other materials handling equipment (Manula and Albert, 1980; Prelaz et al., 1964; Bucklen, 1969; Thompson, 1985). HOIST reduces a time-consuming set of calculations to a concise package of interrelated subprograms. A literature review revealed no common-user pro- grams to analyze hoisting systems, although at least four major hoist designers/manufacturers/installers have their own in-house programs. To provide a tool with which the mining engineer could preliminarily analyze a materials hoisting system or could check the calculations of a hoist contractor, a computer program was developed. HOIST was written in BASIC for the IBM-PC for ease of program adaptation and to en- courage field use on compatible systems. Details of program development are omitted, since the basic principles of hoisting analyses are relatively straightforward, simple, and readily accepted (Har- mon, 1973; Nordberg, n.d.; Adler, 1957). Program features, intended usage, and benefits of the com- puterized solution are emphasized over theory development and mathematical rigor. Background The mine hoist system that is selected and installed at a mine is the "lifeline" of that mine, with installations lasting 20 years or more. Thorough study is warranted to ensure that productivity demands are met at a minimum cost per ton. The increased cost of a large, powerful, high-speed hoist must be offset by increased production to justify its selection. To optimize this tradeoff, an extensive hoisting analysis should be performed. The analyses to properly size the skip (or cage ) , the drum, and the hoist drive are conducive to computerization, permitting rapid evaluation of changeable operating and design parameters, such as velocity, acceleration, state of balance, and productivity demand. The program is particularly useful in conducting sensitivity trials, such as investigation into the effect of change of productivity on skip capacity and on horsepower of the hoist drive. HOIST is currently limited to the study of drum-type hoists with cylindrical drum(s). However, only minor changes to the program would permit analysis of friction hoists and conical drum configurations. Model development and testing The program is based on accepted equations and physical relationships. Examples of manual calculations formed the basis for decision points and program branching. Data is input in the order that it would be needed if the problems were solved manually. The choices are arranged likewise. HOIST was developed in sections, with manual solutions performed to check program logic. The testing became more rigorous as sections were completed. Output from one section becomes input for following sections, as appropriate. The simplified flow diagram of HOIST is given in Fig. 1.

Jan 1, 1988

By M. M. Tilman

Etchants containing hexavalent chromium and sulfuric acid are used in a variety of surface-finishing operations. When the resultant spent solutions are discarded, substantial quantities of chromium are lost and pollution prob¬lems are created. To minimize the undesirable environmental effects while improving metal and minerals recycling technology, the Bureau of Mines is con¬ducting research on a method for the economic inplant recycling of these waste etchants. Trivalent chromium, produced when the etchant reacts with a substrate, is oxidized in the anode chamber of a diaphragm cell; other metals, dissolved during the etching operation, are transferred to the catholyte. When waste brass etchants are treated in this manner, all of the trivalent chromium is oxidized and more than 40 percent of the copper and zinc is removed. Similar copper removal and chromium oxidation are achieved with waste printed circuit board etchants and rinse waters from plastic etching operations. The electrical energy needed to regenerate 1 kg sodium dichromate is less than 9 kwhr. Regenerated brass etchants evaluated by two companies equaled or exceeded the performance of fresh etchants.

Jan 1, 1979

By A. Timur

Fluid flow properties of porous media have long been of interest in such varied disciplines as geology, geophysics, soil mechanics, and chemical, civil, and mechanical engineering. This interest has resulted in numerous models of porous media that have been proposed, tested, and found to be useful under, at best, only special circumstances. A critical review of most of these models is given by Scheidegger. 1 The application of each new tool to the study of porous media has helped to test some of the existing theories and to form new ideas based on the new parameters being measured. In the application of nuclear magnetic resonance (NMR) techniques to the study of the properties of fluids in porous media, the theoretical studies of Korringa et al.2 resulted in a model for the relaxation of spin polarization of protons in a hydrogenous fluid in a pore of a solid. Seevers3,4 verified this model, established a method for measuring the surface-to-volume-ratio distribution in a porous medium, and proposed a technique for determining specific permeability in sandstones. In the present investigation, the uses of NMR methods are extended and a simple model of porous media is developed from an analysis of pulsed NMR measurements. In this model, the pore spaces of a porous medium are divided into three groups on the basis of their surface-to-volume ratios. To evaluate predictions of the NMR model, laboratory measurements of spin-lattice relaxation time, porosity, permeability, and residual (irreducible) water saturation were conducted on more than 150 sandstone samples obtained from four oil fields in North America. Applications are discussed for estimating the volume of movable fluid, ?p, and the specific permeability, k, of sandstone samples. The former parameter, which can be considered as producible porosity, is expressed by ?p = [1 -- (Swr/100)]? , .... (1) where + is porosity in percent of bulk volume and Swr is the residual (irreducible) water saturation in percent of pore volume at a capillary pressure of 50 Psi. Fast, nondestructive laboratory methods are described for determining porosity, movable fluid, and permeability of sandstone samples from measurements with a pulsed NMR (spin-echo) apparatus. Procedures are given for adapting these methods to samples of irregular shape and small size. Theory General In the Korringa, Seevers, and Torrey2 (KST) model the observed decrease in the spin-lattice relaxation time, T1, of protons of a hydrogenous liquid contained in the pore spaces of a porous solid is attributed to an increase in the correlation time for the random motion of the water molecules and to the presence of paramagnetic centers at the liquid-solid interface. This KST model predicts the observed relaxation time of a hydrogenous liquid in a pore of a solid through

Jan 1, 1970

By J. J. Wilson

To explain in detail the manufacture of seamless pipe and tubes is something I venture to say that has never been done to a point entirely satisfactory. The manufacture of seamless tubes dates back to 1885, when Mannesmann Brothers invented the roll-piercing mill. Ten years later R. C. Stiefel invented the disc-piercer, which first came into general use in this country. At the present time the Mannesmann roll and the Stiefel disc-piercers are used, the Mannesmann rolls particularly for the larger size billets. Sizes produced at first were relatively small and the product was cold drawn to provide a smooth surface. The early uses of seamless material were chiefly for mechanical purposes, such as boiler tubes and bicycle tubing, and the latter for some years taking the heaviest tonnage. Improvements in the hot process were gradually made; the early Pilger type rolls were largely superseded by the two-high rolling mill for rolling out the tube after being pierced, the reeling machine for diagonal rolling, the sizing mill for giving exact outside diameter, and finally the sinking mill for reducing larger diameter tubes to smaller diameters.

Jan 1, 1932

By R. B. Gilmore

The North Texas district, as herein defined, includes the counties of Archer, Baylor, Clay, Cooke, Foard, Hardeman, Jack, Kiiox, Montague, Wichita, Wil-barger, and Young. Jack and Young Counties are included for the first time so that this district will correspond with District No. 9 of the Texas Railroad Commission. This area covers generally the crest and south flank of a system of buried mountains known as the Red River uplift. The oil and gas accumulations along this feature are in traps, which, although localized by structures incident to the regional uplift, usually are modified by stratigraphic changes in the sediments. The structural deformation caused by the Red River uplift is modified by the Rend arch, which is a broad anticline plunging northward from the Llano uplift in central Texas through Young and into Archer Counties. The fields in southern Archer, southeastern Baylor, southwestern Clay, and western Jack Counties arc on the extreme north end and along the flanks of the Bend arch and have generally the same type of oil and gas accumulation as the other fields in this district. Recent exploration has been along the flanks of the Fort Worth syncline, which is east of the Bend arch and south of the Red River uplift and extends into southeastern Clay and southwestern Montague Counties and along the eastern part of Jack County. The larger part of past oil and gas produc- tion has come from Pennsylvanian strata, with less important amounts lrom the Permian, and minor quantities from the Mississippian and Ordovician. Developments during 1943 About 1100 wells were drilled in the district during 1943 and more than 500 oil wells were completed, an increase from 1942. of approximately 12 per cent in the number of successful drilling operations of the total wells drilled. The addition of Jack and Young Counties to this district accounts for part of this increase, almost 150 wells being completed in the two counties. Production increased slightly over the previous year as a result of an increase in the number of producing wells and a greater demand for this high-gravity, sweet crude oil. The average depth of discovery wells was about 400 ft. deeper than in 1942. Although more discoveries produced from horizons below the base of the Strawn series than from those above the Straw, the deeper horizons, including the Bend series of the Pennsylvanian, the Mississippian limestone and Ellenburger of the Ordo-vician, largely were dissappointing from the viewpoint of major additions to oil reserves. The largest single addition to the reserves was in the basal Strawn sand in the Walnut Bend field, Cooke County. During the year, 31 wells were completed, both in the field and as cxtensions. The most active arca Was Jack County, in which five fields or potential fields were discovered, although only 44 oil wells were completed.

Jan 1, 1944

By L. Narhi, K. Haavanlammi

"Approximately two thirds of annual nickel production is used as a raw material in the making of stainless steel, and about 60% of these nickel products are in the form of metallic nickel such as nickel cathode or briquettes. In the stainless-steel production process nickel is blended with iron and chrome-based raw materials, and metallic nickel is typically only required for final steel fine-tuning. Outotec offers a new FeCrNi technology to enhance the nickel value chain for stainless steel producers. This involves the use of an HPAL-based intermediate nickel product (e.g., mixed hydroxides or NiO) as raw material in the Outotec FeCrNi process, for the production of a FeCrNi Master Alloy. The new process, designated as the FeCrNi process, offers multiple benefits compared to existing technologies such as: higher tolerance for impurities in the HPAL intermediate product, avoiding the need for further nickel refining, and the improved recovery of all metals in the FeCr process. The complete new FeCrNi value chain is based on proven technologies such as HPAL and the Outotec FeCr-process. This new innovative and promising value chain offers improved efficiencies for the HPAL based nickel production process combined with excellent sustainability aspects.INTRODUCTION In today’s global economy there is a constant need to improve the efficiency and sustainability of the metals production. The requirements for modern metal refining are tightening and cost efficient, safe and sustainable operation is the precondition for all investment. Outotec is offering now a novel way to combine FeCr and Nickel production to create a completely new value chain to source nickel to stainless steel. BACKGROUND Nickel The current nickel mine production is in the level of 2,000 tons annually and it is split 44% from sulphide based deposits and 56% from laterite deposits (Figure 1). Most (40%) of the nickel is refined to pure nickel metal whereas other products are FeNi (19%) and Nickel Pig Iron NPI (20%) (Roskill). The remaining part, roughly 21%, is nickel chemicals and intermediates. Most of the new investments in nickel are in the direct shipping of laterite to produce nickel pig iron. HPAL process is considered in few projects but no major HPAL projects have been started since the Ambatovy plant in Madagascar. Ambatovy reached the commercial production in 2014. The main primary nickel used is stainless steel manufacturing. In the year 2016 about 68% (~1,360 kt) of primary nickel production was used in stainless steel."

Jan 1, 2017

By P. A. P. Fouché

Processing confidence for a bankable feasibility study on a green field heavy mineral deposit is inmost cases achieved only through bulk sample processing. Bulk sample is classified as a large enough concentrate sample that is processed into final products to satisfy market sample demand as well as further processing demands such as smelting. In this case study the demand was to produce 500 tons of heavy mineral concentrate from more than 5 000 tons run-of-mine on are mote location with limited to no infrastructure. The various challenges faced and lessons learned are documented as an outcome of the success of this mission.

Jan 1, 2007

By W. J. Witte, M. K. Witte

"INTRODUCTION A pilot heap leach project was conducted on the B. P. Selco Hope Brook ore located in southwestern Newfoundland. The pilot heap leach was undertaken to assess and confirm the following:1) To confirm that heap leach technology now currently used in the United States could be applicable to Canadian sites.2) To confirm gold recovery by the Heap Leach technology3) To assess and study potential heap leach environmental concerns in cold and wet climate.PROJECT LOCATIONThe Hope Brook Project is located near the southern coast of the island of Newfoundland, approximately 100 kilometers southeast from Stephenville, approximately 25 kilometers west of Burgeo, Newfoundland. Access to the property is limited to helicopter, float plane or by sea through Couteau Bay. The property was covered with muskeg and very few trees. Surface relief was moderate with many poorly drained boggy sections confined to small areas. Many small unnamed lakes were located on the property which provided water to small brooks and streams flowing to Couteau Bay.Several locations were reviewed for the installation of the pilot heap leach facility. Important parameters used to select a suitable location included sufficient land area, close proximity to but not on the ore body, reasonable protection from wind, sufficient supply of fresh water, close to a suitable location for a portable crushing plant, reasonable access to aggregate material for preparation of the test pad and ponds and suitable contours to minimize site preparation."

Jan 1, 1987

By William Glenn

The taking of proper samples of crude ores seems to he less thoroughly understood, or less carefully practiced, than its impor tance requires. We all know how often we encounter the reports of very accurate assays and analyses, the weight of which as evidence wholly depends on the method of obtaining the sample, and is very probably nil, because there has been no proper sampling. Pissages might be cited from technical books, and from current technical literature (all the work of writers whom we delight to honor) to show that even among high scientific authorities there is too little acquaintance with the practical art of the sampler. There is no metallurgical or chemical establishment which does not frequently receive samples truly representing nothing. They consist usually of bits of ore, or what not, selected because they are worse or better than the average of what they are meant to represent. And they are worthless, no matter who made the selection. Where conscious choice is permitted to enter into the operation, a fair sample will not result, unless by a miracle. The work of sampling is often looked upon as within the realm of boys and of pensioners only. At least, though the manual labor be left to subordinates, the principles on which it is conducted and the safeguards with which it is surrounded are not unworthy of the study of experts; and experts should he ready to teach these principles and enforce them in practice. For exact sampling is the indispensable first step towards learning the value of any boxful, carload or shipload of ore. I propose to give a simple account of the method of sampling by hand, such as I have always pursued. There is nothing new about it. So far as I know, it is the immemorial old method, as old at least as Cornish copper-mining. Perhaps my fellow-members in the Institute may suggest improvements in it. If not, it will constitute a record in our Transactions to which laymen and beginners may be referred.

Jan 1, 1892

By H. M. Chance

(Butte Meeting, August, 1913.) ADEQUATE treatment of the difficulties surrounding the valuation of mineral lands requires that agreement be first reached defining value as understood for the purpose of appraisal. To define value as the price of a product is not sufficient, and does not assist us in using the factors that cause variations in values and in relative values. The real value of any product depends primarily upon its relation to the necessities, comforts and pleasures of mankind. As the necessities, comforts and pleasures of the civilized races differ from those of more primitive man, the value of products varies with the degree of civilization and the environment of the consumer. Coal has no value to the savages of warm climates, and arrow-head flint none to the residents of New York. It has long been recognized that what has been termed ? intrinsic value " must be limited to materials that are essential to existence-air, water, food. But "intrinsic value" cannot be measured in monetary terms. The intrinsic value of a bushel of wheat is due to the fact that it will support the life of an individual for a certain definite time, but this fact does not enable us to measure or to express that value in monetary terms. It has often been proposed to adopt as a measure of the value of any product the quantity of labor necessary to produce it, but this method is of limited application, and will not apply to what may be termed "intrinsic values." For many reasons it might be well, while assenting to the fact that any material may he intrinsically valuable, to abandon the use of the term " intrinsic value." One of these reasons is the tendency to confuse the idea of intrinsic value with a value that is conferred by economic conditions, that is purely artificial and that may be permanent or evanescent; Intrinsic value must from its nature be permanent and unchangeable.

Jan 7, 1913