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Recently, renewed interest in the recovery of uranium from leach solutions has necessitated a re-examination of the hydrometallurgy methods used for uranium in the 1960?s to 1970?s. A synthesizing overview of the lessons learned in those decades together with examination of recent developments in this area is warranted. This paper considers uranium recovery chemistry from acid and alkali leach solutions using solvent extraction and resin ion exchange, and provides information on circuit selection and configuration, equipment selection and design, as well as operational considerations. The unique thermodynamics of uranium solvent extraction are also presented and discussed.

Aug 1, 2010

By Shamil Shaikhutdinov

CO adsorption on gold particles deposited on well-ordered alumina and various iron oxide films has been studied with temperature programmed desorption (TPD) and infrared reflection adsorption spectroscopy (IRAS). Structural characterization has been performed with scanning tunneling microscopy. Data show that the CO adsorption exhibits a size effect in that small particles adsorb CO more strongly. The effect generally vanishes after annealing to 500 K. For annealed samples, CO TPD and IRAS spectra are nearly independent of the particle size and supports studied. The results indicate that the CO interaction with gold surfaces is essentially similar and involves low coordinated atoms.

Oct 1, 2003

By T. Hidayat, D. Shishin, V. Prostakova, M. Shevchenko

The chemical compositions of copper feed streams are becoming increasingly complex following the growing demand for metals and corresponding shortages of primary sources. The optimisation of process conditions requires an accurate description of phase equilibria and thermodynamics. Integrated experimental and thermodynamic modelling research program on the characterisation of the complex, multi-component, multi-phase gas-slag-matte-speiss-metal-solids Cu2O-PbO-ZnO-Al2O3- CaO-MgO-FeO-Fe2O3-SiO2-S-(As-Bi-Ni-Sb-Sn-Ag-Au) system is being carried out to support companies undertaking the pyrometallurgical primary production and recycling of copper. The experiments involve high temperature equilibration in controlled gas atmospheres, rapid quenching and direct measurement of equilibrium phase compositions with quantitative microanalytical techniques, including electron probe X- ray microanalysis and Laser Ablation ICP-MS. The thermodynamic modelling is undertaken using FactSage computer package with advanced thermodynamic solution models. The continuing development of research methodologies has resulted in significant advances in research outcomes. Implementation of the results of these fundamental studies involves an ongoing collaboration of researchers and industry technologists. An overview of recent progress in research, implementation and applications in industrial practice are given in the paper. INTRODUCTION Rapidly developing technologies increase the demand for various metals in number and volumes. Modern technological devices such as mobile phones, computers, other electronic devices, have dozens of metals—all those metals have to be a) produced and b) recycled. The fast transition in mobility from fossil energy delivered through combustion to renewable energy first stored in bakeries and delivered through electric engines introduce a significant change in the metal demand in terms of both type and volume of metals. Pyrometallurgy is playing a key role in supporting these changes in our industrialised society.

Jan 1, 2019

By J. E. Udd, L. B. Geller

"Mine-shaft wire-rope discard regulations include, among other criteria, a limited amount of permissible loss-of-breaking-strength (LBS). Currently, this parameter is estimated on the basis of non-destrutive-testing (NDT) with electro-magnetic (EM) type instruments. This paper analyses the accuracy with which these estimates have, so far, been obtained in practice.It concludes that while certain types of testers have produced better results than others, the desired accuracy level has not been attained. Also discussed are the putative reasons for this situation, and appropriate actions that the mining industry might wish to take."

Jan 1, 1990

By Lionel C. Kilburn

"This geological engineering method is based on jour main characteristics of mineral properties, viz; location: inclusion of valuable mineralization; inclusion of geophysical and/or geochemical targets; and inclusion of geological targets. These are subdivided into a total of 19 subcategories, which are used to determine the value of the property.The nineteen subcategories are prioritized and assigned relative value factors from 1.3 to 10. Value of each mineral claim unit is determined by applying the appropriate subcategory factors to a base value of $400per 16.2 hectare unit. Property value is calculated by totalling the values of such individual claim-units.The boundary between ore grade and sub-ore grade must be estimated for each property under valuation, thereby making the method sensitive to mineral commodity prices.A clear and disciplined sequence of decisions based on personal experience forms the basis of this method. The method utilizes all factors normally used to value a mineral property.IntroductionIt is generally accepted in the exploration industry that valuation of exploration properties is a subjective rather than objective process (Roscoe, 1986; Lawrence, 1988; Lawrence, 1989; Woodcock, 1985), and that it is greatly influenced by the experience and qualifications of the person who is doing the valuation. However, the significantly low degree of objectivity in mineral property valuation at this point in time invites effort to achieve a more quantitative engineering basis.Value of a mineral property depends basically upon metal prices, recoverable grades, mining and metallurgical practices, commodity supply and demand , and political-economic conditions, all of which vary with time. Therefore, any valuation is valid for only that point in time when it is made. Mineral deposits can decrease as well as increase in technical value with time."

Jan 1, 1990

By Roger Lafrance

"This paper discusses various aspects affected by the use of large-diameter boreholes in underground mines. Topics covered consist of noxious fumes, vibrations, post-blast effects, various types of explosives, the cordine system in production blasts, the slider primer system and wall-control methods. In general, the paper is an overview of this important fact of underground mining.IntroductionWith economical factors leading the way, many reasons motivated drilling equipment companies to develop equipment that can drill holes up to eight inches in diameter and even larger for underground applications. One of these other reasons is the fact that many orebodies were considered marginal, given the high costs of conventional mining methods utilizing small diameter boreholes. With these criteria in mind, accelerated programs were put in motion to develop equipment that would reduce both-development and production costs in underground mines. Change s in any basic program often affect other areas down the line. This is particularly true with the ad vent of large-diameter boreholes underground.C-I-L Inc. is certainly no stranger to this phenomena. Whether production headings increase in size and tonnage or whether production increases due to lower costs, one fact remains unchanged and that is the fact that all development and production holes are loaded and blasted whether they be of small or large diameter. Due to this fact, C-I-L Inc., as a leading explosives manufacturer, initiated a program to examine blasting methods in use in surface work with the intent of revising these method s for underground applications. Research facilities were also oriented toward developing appropriate products. This was a task that was accepted with anticipation, with the result that many new blasting systems and methods were brought forward, thanks to the collective efforts of both the consumers and manufacturers."

Jan 1, 1984

Cameco Corporation is in the process of revitalizing the Key Lake mill. As part of this process, the company is considering installing the Rabbit Lake style strong acid stripping in solvent extraction. This would lead to using hydrogen peroxide for uranium precipitation. The process currently employs ammonia stripping and ammonia precipitation. As part of the process evaluation, an indirect fired drier pilot plant test was conducted. This paper will discuss the results of that test work, including the relationships between the following: ? Drying temperature and product grade ? Drying temperature and product colour ? Drying temperature and product reactivity with water ? Drying temperature and energy input requirements ? Drying temperature and shipping costs

Aug 1, 2010

By Juan Pablo Vielma

In this work we study how to incorporate risk control to the generation of ultimate pits when orebodies are modeled through a finite number of conditional simulations. To control risk we consider a chance constraint on the value of the ultimate pit. We incorporate this measure into the generation of ultimate pits by solving a stochastic programming version of the ultimate pit problem. We compare this stochastic programming problem to previous approaches such as generating the ultimate pit for each simulation and the hybrid pit approach introduced by Whittle and Bozorgebrahimi. We also study the effect of using different number of simulations in the generation and evaluation of ultimate pits.

Oct 1, 2009

By K. D. Mills, R. G. Robins, C. G. Anderson, L. G. Twidwell

Arsenic is a metalloid which has attracted great environmental scrutiny in recent decades. Moreover, its control and deportment is becoming increasingly important in the metallurgical processing of modern complex ores and concentrates. As such the authors of this publication have a combined professional experience of well over 100 years in the study and hydrometallurgical treatment of arsenic. Hence, this paper will cover arsenic fundamentals along with a review of technology for removal, fixation and stabilization. Finally, an application of industrial Alkaline Sulfide Leaching (ASL) of a copper enargite concentrate will be elucidated.

Jan 1, 2014

By Daniel Hodouin, Claude Bazin

"This paper examines the economic advantages of adapting the production grade and recovery targets of a flotation circuit as a function of metal prices. The study is periormed using a steady state simulator for a Cu-Zn differential flotation circuit operating under the following strategies of 1) Maintaining constant operating targets, 2) Maximizing individual circuit Net Smelter Return and 3) Maximizing the global Cu-Zn circuit efficiency. Results are compared to assess whether or not one of the strategies produces benefits significantly higher than the others. A discussion of the tools required to achieve such a kind of control completes the paper.Paper not Available at Time of Publication"

Jan 1, 1997

By M. S. Moats, C. M. Campbell

Samples of a high impurity (90.05 wt. % Cu, 4076 ppm Pb, 1939 ppm As and 635 ppm Bi) commercial copper anode were characterized and then electrorefined in a laboratory scale cell. Anode inclusions were examined using backscatter mode scanning electron microscopy and energy dispersive spectroscopy. Hundreds of inclusions were measured for size, morphology and composition. Commonly found inclusions were copper oxide (Cu2O), complex oxides (Cu-Pb-Bi-As-O) and copper selenides/tellurides. The weight percent of lead and arsenic increased with increasing inclusion size up to 4- 5 microns. During electrorefining, starter sheet ductility was negatively impacted by thiourea addition. The importance of arsenic (V) concentration on the electrolyte concentration of bismuth was observed. INTRODUCTION Copper electrorefining is a commercial process used to produce the majority of the world’s refined copper. During this process, impure copper anodes are dissolved electrolytically, and high purity copper is deposited on cathodes. As the anodes dissolve, the impurities either accumulate in the electrolyte or report to solids that form on anodes surfaces or at the bottom of the refining cell. These solids are called slimes. Slimes contain precious metals and are collected for further processing. Slimes are also an important outlet for problem impurities such as lead, antimony and bismuth. The electrorefining process is operated in such a way to encourage the deportment of these elements to the slimes. Impurities in copper anodes have been studied extensively by Chen and Dutrizac (1990, 1993 and 2005). The most common impurities found in modern copper anodes include: Ag, As, Au, Bi, Fe, Ni, O, Pb, Sb, Se, Sn and Te. Impure copper anodes are produced by pyrometallurgical methods and have purities ranging from 97.7–99.7% Cu (Moats et al., 2019). The composition ranges of commercial copper anodes from the 2019 worldwide tankhouse survey are given in Table 1. The concentrations of anode impurities vary widely dependent on the source material and prior processing steps. Based on the work of Chen and Dutrizac, both gold and silver are predominantly found in solid solution within the copper grains while a minor amount of Ag can be found in Cu2(Se/Te) inclusions. Nickel is entirely soluble within the copper grains up to anode compositions of 2500–3000 ppm Ni; above which NiO and kupferglimmer phases are formed (Chen & Dutrizac, 1990). As, Bi, Pb and Sb are found in solid solution within copper and within oxide inclusions typically found along grain boundaries. Oxides are formed due to the presence of 0.13-0.18 wt. % O (Chen & Dutrizac, 1990). This is because during solidification of the cast anodes, impurities are enriched in the liquid phase as the copper grains nucleate and grow. The inclusions form from the last liquid to freeze, which is typically along grain boundaries (Wenzl & Filzwieser, 2007; Wenzl, Filzwieser, Mori & Pesl, 2008).

Jan 1, 2019

By D. MacGREGOR, VERA TUREK

The St. Canul and Ste. Scholastique orthoquartzite sanrjstone deposits are located within the Potsdam Formation near Montreal. The sandstone lies on Precambrian basement and is Cam/3rian to Ordovician in age. The Potsdam Formation shows two distinct stages of development. One created a deepwater facies represented by impure, limey or shaley sandstone; the other produced a shallow facies composed of grey, highpurity sandstone. The shallow-water orthoquartzitic sandstone at St. Canul is being mined and beneficiated by lndusmin Limited. The operation manufactures a wide range of silica products and supplies industrial areas of Quebec and Ontario with material for the glass, foundry, silicon carbide and ceramic industries.

Jan 1, 1984

By E. T. C. Spooner, Ioannou S. E.

"Abstract- The Dixie Zone Au-Ag deposit is a low sulfidation (adularia-sericite) epithermal system located 1.4 km from the producing Ken Snyder mine (7.0 M oz Au equivalent reserve/resource), Midas Mining District, north-central Nevada. This WNW striking, steep south dipping, fault system is hosted by mid-Miocene (17 Ma to 14 Ma) felsic volcanic rocks that were erupted from a vent(s) to the northeast. The system was mineralized by approximately 250 ± 20°C (n = 86), near-neutral pH, ascending fluids of predominantly meteoric origin [volatile corrected salinity = 0.52 ± 0.35 eq.wt% NaCl (n = 86)]. Bulk analytical fluid inclusion gas chromatography identified a mineralizing fluid volatile composition of 99.68 ± 0.18 mole % H2O, 0.16 ± 0.09 mole % CO2, 0.11 ± 0.05 mole percent N2, 0.05 ± 0.04 mole % CH4, and 0.01 ± 0.01 mole % CnHn+i (n = 7). Sulfur species were not analyzed due to absorption within the chromatography system; however, a H2S concentration of 16 ppm to 160 ppm molar is estimated. The volatile content contributes approximately 50% of the microthermometrically measured freezing point depression. Cl- concentrations up to approximately 9000 ppm suggest an additional, probably magmatic, fluid component.Ascending fluids were channelled along approximately NW striking faults related to the same primary extension (17 Ma to 14 Ma) responsible for Nevada basin and range physiography. Boiling induced by CO2 effervescence led to precipitation of Au and Ag over a 150 m vertical interval. At the time, this interval was about 460 m below the water table (approximately 38 bars), but because of erosion, it is now within 90 m of the surface. A Ag:Au ratio of 25:1 has been calculated for the Dixie Zone."

Jan 1, 2000

By K. P. Wright

"Twenty-five years ago, there were about thirty-two gold mines operating in Canada; nine of these have been in continuous operation since then and are still operating. Three of these are part of the Dome Group. Operations of these three and of the newer mines in the Group are referred to in discussing process development over the last twenty-five years.Of the Dome Mines Group, Dome Mines Limited, Sigma Mines (Quebec) Limited, Campbell Red Lake Mines Limited, Detour Lake Mine and Kiena Gold Mines Limited, three have been in continuous operation for the last twenty-five years. Dome has operated for seventy-seven years; Sigma about to complete fifty years, and Campbell approaching forty. Overall, milling processes are virtually the same as they were twenty-five years ago. Tota1 go1d production from the three mines has hardly changed; 1960 production, 416,700 ozs. versus 411,300 in 1985. Milling costs have risen by a factor of six or seven and gold price from $35/oz. in 1960 to $322 in 1985.Basic flowsheets are relatively unchanged. Sigma is an all cyanidation mill grinding in cyanide solution; Dome operates gravity concentration and cyanidation; Campbell gravity concentration, flotation, roasting and cyanidation. All three use Merrill-Crowe zinc precipitation.Detour and Kiena are two examples of the major change in gold processing in the last twenty-five years - carbon-in-pulp. This process has brought along with it other changes, such as, carbon stripping and reactivation, electrowinning, and induction furnace melting. Modern mill design with its use of outside thickeners and agitators, bulk handling of reagents, instrumentation, etc., has made a radical change in operating conditions and appearance of the new plants."

Jan 1, 1987

By L. Chunpongtong

ABSTRACT Oil sands production occurs on a massive scale, making orebody estimation a challenge. In rainy conditions, operators can have difficulty accessing ore at the mapped location. Without enough inventory as a buffer, the high-cost stockpile is depleted quickly, necessitating the removal of significant amounts of overburden and interburden to meet plant feed requirements. The inventory curve—a plot of ore inventory on a period-by-period basis—plays an important role in selecting an appropriate scheduling scenario. This paper presents a programmable method for creating an inventory definition by using a pit optimization tool.

Jan 1, 2014

By M. Moats

World copper refining tankhouse practices have been surveyed. This survey is a supplement to previous surveys that have been carried out in the 1987, 1991, 1995, 1999, 2001 and 2003. On a world basis, process technology trends include the further installation of automated electrode handling systems including permanent cathode systems, automatic anode preparation and cathode handling machines, section switches, fully automatic cranes and polymer concrete cells. General plant process control has increased with more automation of material handling in the copper refining tankhouse. The general trend for most greenfield copper refining projects remains in eastern Asia.

Jan 1, 2007

By D. B. Dreisinger, M. R. Tavakoli

Vanadium has been produced from a variety of sources. This metal is known to make aqueous solutions of complex speciation as a function of vanadium concentration and pH. Considering the method of leaching, the impurities in the PLS and the planned vanadium product, different extractants and flowsheets can be applied for solution purification. In this paper, purification of vanadium leaching solution using organophosphorus, solvating and amine extractants will be reviewed. This review will be focused on vanadium separation from iron, molybdenum and uranium which are often present in vanadium resources including primary ores, fly ashes and spent catalysts.

Jan 1, 2014

By Navid Bahrani

Introduction ? Today?s economic market is motivating underground mining companies to increase development advance rates and enhance their NPVs. ? For example, block cave mining involves development of kilometers of drifts with multiple pillars. ? The cyclic nature of drill and blast, and its inherent tendency to damage the surrounding excavation rock mass and increase support demand often result in poor advance rates ? This has motivated mining companies to replace the conventional drill-and-blast as the main excavation method with alternative methods such as mechanized excavation. ? There is little experience with mechanized or non-explosive excavation methods in hard rock metalliferous underground mining.

Oct 1, 2010

By Stuart M. Jones

This paper is derived from a document that compiles autogenous and semi-autogenous mill installations worldwide, through the end of 2010. Updates have been solicited from all major mill manufacturers and most have responded. A review of AG/SAG mills sold to date and in the last five years indicates that the AG/SAG mill market is very healthy and the trend is larger diameter mills with high diameter-to-length ratios. Ring motors (gearless) are the preferred drives for large mills even though the power transmitted through a gear drive is expected to near 11,000 kW per pinion in the near future.

Aug 1, 2010

By K-A. Adamson

If fuel cells and hydrogen are to become a mass market reality a substantial amount of further research and development needs to be undertaken. Work in hydrogen storage, production, the economics of all aspects of fuel cells and hydrogen, materials balances, and product integration are just a few of the areas that are under focus. Setting R&D targets, and providing R&D funding are therefore areas that are central to the long term development of the market, and areas in which a number of governments worldwide are highly active. Some governments, such as Japan and Korea, have set a number of very ambitious, highly focused, long term targets and are backing this up with substantial funding, others such as the EU are working on a more integrated approach, wrapping some fairly fundamental R&D into large integrated projects which run in combination with a number of other market aspects, such as public acceptance and roadmapping. The US is slightly different, in that although is has a number of long term programmes and targets, FreedomCar and SuperGen being just two, the levels of funding are set annually with the passing of each years Fiscal Budget. This paper takes three high profile regions and analyses the R&D targets and funding levels for fuel cells and hydrogen. Criteria that will be looked at include: Time frame of target(s), level of ambition, funding issues, including: Funding windows, levels available, funding barriers, overall programme goals. The added value to this paper is that it will provide a clearer picture of where each region is heading, what are its strengths and weaknesses, in terms of R&D and where there may be areas for potential international collaboration.

Jan 1, 2005