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By H. Deveci, E. Y. Yazici, A. D. Bas

The leach solutions of waste of printed circuit boards (WPCB) may contain a wide range of base and precious metals with different concentrations due to heterogeneity of these wastes in composition. Therefore, selection of a suitable metal recovery method is of practical importance for downstream processing of pregnant leach solutions of WPCB. Sulphuric acid leaching of WPCB in the presence of a suitable oxidant is capable of dissolving base metals as well as precious metals such as silver. In this study, cementation of silver from sulphuric acid leach solutions of WPCB using metallic copper, aluminum and zinc was studied. The WPCB sample was assayed to have a silver content of 694 g/t. A synthetic leach solution containing 20 mg/L Ag in sulphuric acid solution (0.51 M H2SO4) was prepared based on the silver concentration in pregnant leach solutions of oxidative sulphuric acid leaching tests. Total sulphate concentration ([SO4 2-]T) was kept constant using sodium sulphate at 1 M. Metallic powders of copper (-850 +600 µm), aluminum (-425 +45 µm) and zinc (-45 µm) were used in the cementation tests. The effects of metal type (Cu, Al or Zn), dosage of metal powders (above the stoichiometric ratio by up to 2000-fold) and temperature (20-80°C) on the rate and extent of silver extraction from the solution was investigated. The effect of presence of copper on the cementation performance was also tested. Under suitable conditions high silver recoveries (>90%) was achieved using metallic copper and zinc while aluminum yielded the lowest silver recovery (i.e. 40% Ag). The kinetics of cementation by zinc was comparatively higher than that of other metals. Increasing the temperature was observed to significantly enhance both the rate and extent of silver cementation. SEM-EDS studies were performed to characterise the metallic powders after cementation.

Jan 1, 2016

By N. Maleki

Magnesium matrix composites are widely used in automotive and aerospace industries for achieving higher performance due to their light weight. The Mg2Si intermetallics compound in Mg/Mg2Si composite exhibits many excellent properties such as high melting temperature, high hardness, and low thermal expansion coefficient. However, under normal cast conditions, the primary Mg2Si phase exhibits coarse Chinese script or dendritic morphologies and the eutectic structures is very brittle resulting in the low ductility and strength of the alloys. Modification treatment is a very effective method to obtain fine microstructure and improve the mechanical properties of the alloys due to low production cost. In this investigation various amount of bismuth addition have been carried out on Mg?5wt %Si alloy to refine and modify the morphology of coarse Mg2Si in order to improve the corrosion resistance of the composite product. The effect of Bi content on microstructure of Mg2Si/Mg composite was investigated by optical and scanning electron microscopy followed by EDX analysis and X-Ray diffraction. In order to compare corrosion resistance of unmodified and modified specimens, Immersion test and potentiodynamic polarization (PD) were used. The results showed that by Bi addition, the size of primary phase Mg2Si was considerably reduced and the morphology was modified from a coarse dendritic shape to a polyhedral shape. The results also indicated that the corrosion resistance of Mg?Si alloys was improved by the addition of 1%wt of Bi due to the reduction, refinement and evenly distribution of Mg2Si phase. Indeed, both the morphology and distribution of Mg2Si intermetallic had a great influence on the corrosion behavior of Mg/Mg2Si composite.

Oct 1, 2011

By G. S. Cole

By 2025, the U.S. automotive industry will have to average 54.5 mpg (4.3l/100km) Corporate Average Fuel Economy (CAFÉ). While new/improved powertrain technology (turbocharging, electrification, diesels, transmissions and stop/start) will be critical, it is estimated that 25-40% of the new CAFÉ standards will require significant mass reduction, and lightweight structural materials will be required. This presentation examines vehicle mass reduction based on new developments in manufacturing automotive structures and components using light metals (aluminum and magnesium), conventional heavy metals (iron and steel), polymers, and carbon-fiber reinforced polymer composites. Components that used to be sand cast or pressure die cast provided minimal fatigue strength and ductility. But greater mass reduction uses more light metals in structural applications. They require eliminating porosity and inclusions to improve ductility and fatigue strength. Improved casting processing, with vacuum die casting, counter pressure and squeeze casting, and new forging and extrusion applications are being developed for this purpose. New grades of ultra-high strength steels can be made thinner, and save over 1/3 the mass vs conventional mild steels. But more complex and expensive processing, such as hot stamping and in-mold quenching, is required. Most engine block structures have migrated from grey cast iron to aluminum over the past 40 years. But compacted graphite cast iron has higher strength at high combustion temperatures and pressures so that high powered engines can be smaller and even lighter than aluminum. Assembling a range of lightweight materials into vehicle structures requires specialized assembly techniques, including sophisticated structural adhesives that can mitigate vehicles’ unique corrosion environment. The presentation will conclude with discussing lightweighting strategies of Asian, American and, European marques and the materials, component designs and assembly techniques used to achieve 2025 CAFÉ.

Jan 1, 2016

By J. Wild, M. Ounpuu, G. Chevalier

"The requirements for a finer grind at Heath Steele have resulted in the investigation of agitated milling as a cost effective alternative to conventional tumbling ball mills.The grinding unit is a vertically agitated, or stirred ball mill. Grinding occurs as the result of the motion of a single vertical rotor equipped with protruding pins which impart a stirring action to the ball charge. A comparative evaluation of a 30 kW SALA Agitated Mill (SAM), and a 1.5 m x 2.5 m copper-lead regrind ball mill has been conducted at Heath Steele.An overview of agitated milling as it applies to the reduction of sulphide ore will be the primary topic for discussion. Specific parameters including energy efficiency, media consumption, operating costs, and the mechanical aspects of the SAM operation will be presented.Evaluation of the agitated mill has shown that improved grinding performance at much lower work indices than those of the conventional ball mill is possible. Media consumption has proven to be comparable on an average g/kWh basis, but the mechanical availability of the mill has been low.INTRODUCTIONConventional tumbling ball mill grinding has proven to be an energy inefficient process. Energy losses occurring within the ball mill itself can be attributed to particle friction without breakage, kinetic and potential energy losses, plastic and elastic deformation and the production of heat and sound (Lynch, 1977). It can be generally stated that a certain amount of the input energy will be converted to another form as a necessary by-product of particle breakage. Theoretical interpretation of experimental results indicate that the energy required for breaking the ore particles in a ball mill varies between I% and 25% of the total energy input (SME, 1985)."

Jan 1, 1993

By A. J. Sinclair

Abstract-Exploratory data evaluation is an essential part of every high quality, mineral inventory estimate. Efficient analysis involves a thorough organization of available quantitative data that are the basis of the estimate and perhaps the formation of composite grades. Data organization and evaluation can involve more than 50% of the time necessary to conduct a mineral inventory estimation. The principal purpose of exploratory data evaluation in mineral inventory work is to improve the quality of estimation by providing insight into characteristics of the variables under investigation. Specific aims include: (1) to recognize and eliminate errors; (2) to provide a comprehensive knowledge of the statistical characteristics of all variables of interest for resource/reserve estimation; (3) to document and understand the interrelationships among the variables of interest; (4) to recognize systematic spatial variation of variables such as grade and thickness of mineralized zones; (5) to recognize and define distinctive geological domains that require independent estimation of mineral inventory; (6) to identify and characterize outliers; and (7) to evaluate similarity/dissimilarity of various types of raw data, especially samples of different supports. These aims are not mutually exclusive but they can all have their own impact on resource/reserve estimation. Error must be minimized. Individual variables can have characteristics that lead to different decisions in the course of estimation. Similarly, interrelations of variables might contribute to the ease (or difficulty) with which estimates of several variables can be obtained. Trends can impose the need for two or more domains, each of which might be estimated independent of the others. Outliers, a perennial problem, require detailed evaluations because they impact on reserves much out of proportion to their abundance. Data, of widely different supports, generally must be standardized if all are to be used for purposes of estimation.

Jan 1, 1998

By R. W. Pugh, S. L. Ma

"High carbon rods are typically used as the grinding media in rod mills. Usually an AISI I 090 grade of steel is used which provides the high hardness needed for abrasion resistance and sufficient toughness to prevent rod breakage.Work to improve performance in the past has mainly concentrated on increasing the hardness for improved abrasion resistance. This has been accomplished by adding alloys to the steel which uniformly increase the hardness across the rod section.However uniformly increasing the hardness of the rod produces a more brittle product and at high hardness l1evels can lead to rod breakage problems. Heat treatment processes can be used to selectively increase the surface hardness to high levels while maintaining the core at lower hardness levels to give a product that wears slower without breakage. AltaSteel has developed and mill tested a higher hardness heat treated grinding rodThis paper describes the development of a simple model to predict performance improvement with different hardness profiles and the AltaSteel heat-treated grinding rod process. Mill characteristics of the Endako operation are summarized and predicted performance improvements based on hardmess are compared to the approximate 25% achieved in trials running since July, 1991 at this mill. Early results of other mill trials are also presented.INTRODUCTIONAltaSteel, in Edmonton is a major supplier of grinding media. We have a strong desire to continually increase the quality and performance of our products and thereby improve the efficiency of our customers' processes. In the area of grinding rods, we wanted to produce a product with a significant improvement in wear rate. Second to energy, rod consumption usually represents the next highest cost in processing. This paper presents our development of a heattreated grinding rod that has reduced consumption by about 25% in trials to date."

Jan 1, 1993

By C. R. Kerr

"This paper describes the revisions to the heating and ventilating system at the Frood-Stobie mill, which resulted in substantial savings in energy costs.IntroductionInco Metals Company, a unit of Inco Limited, is involved in the mining and processing of nickel-copper ores. The Ontario Division of Inco Metals consists of 10 operating mines, with 5 mines and open pits on a standby basis, and 10 pro- cessing facilities, located in Sudbury, Port Colborne and Shebandowan. In 1980, the Ontario Division's energy expenditures amounted to $87,000,000.Due to the accelerating cost of energy, the Division established an Energy Management Program in 1975 to define, evaluate and implement measures to reduce energy cost and consumption per unit of output by 10% by 1980. This falls in line with the goals set by the mining and metallurgical task force on voluntary energy conservation.To effectively implement the program, Plant Committees were established at each plant and mine area, with an energy management coordinator appointed to coordinate the activities. The Plant Committee's responsibilities include identifying the major areas of energy consumption, isolating areas with large potential losses and determining what action should be taken to improve energy efficiency.Within a five-year period from 1975 to 1980, the Ontario Division has been able to cut its energy consumption by 8.9 trillion BTUs, the equivalent of 1.5 million barrels of oil."

Jan 1, 1981

By S. Esmaeili

The yield strength model developed by Esmaeili, Lloyd and Poole [1] has been adapted to model isothermal aging in Cu-containing AA6xxx alloys, with (a) a moderate and (b) a very low Cu content in the solution-treated, as-quenched, condition, Isothermal calorimetry has been used to analyze the kinetics of precipitation in these alloys, While the kinetic parameters for the low Cu alloy has been derived from the present experiments, the previously determined kinetic parameters for the high Cu alloy AA6111 has been used to model the precipitation kinetics in the moderate Cu alloy. The age hardening responses of both alloys have been well predicted by the model.

Jan 1, 2005

By R. D. Studer

"The Snow Lake massive sulphide deposits are hosted by Aphebian volcanic rocks of the Flin Flon - Snow Lake greenstone belt, which in this area were deformed and metamorphosed to the amphibolite facies during the Hudsonian orogeny. All the known deposits occur in felsic rocks a short distance below the contact with an overlying mafic rock unit.The Stall Lake copper deposit occurs close to the top of an explosive felsic volcanic sequence. Rocks stratigraphically underlying the deposit have been hydrothermally altered by the mineralizing fluids. The sulphides were probably deposited from submarine volcanic vent(s) on the flanks of a felsic dome. The ore has been tightly folded, flattened and elongated parallel to the northerly trending lineation of the surrounding rocks during the several periods of deformation. Strike lengths of the lenses range from 60 to 300 feet and plunge-to-strike ratios are as much as 15:1.Ore lenses I to 4 typically consist of massive coarse-grained pyrrhotite, chalcopyrite and pyrite. A stratigraphically higher lens differs in that it contains fine-grained pyrite and chalcopyrite, with an increase in sphalerite toward its hanging wall. The No.4 orebody has a distinct footwall alteration zone characterized by brecciation and abundant chlorite-staurolite- garnet schist, with minor kyanite, anthophyllite, cordierite and anhydrite, as well as sulphide minerals. Chemically, the alteration zone is distinguished from the unaltered felsic rocks by Na20 depletion and Mg-Fe enrichment"

Jan 1, 1982

By W. L. Strand, D. N. Madge

"Experimental and pilot operations in bituminous sand processing require due care and attention in the design and analysis of measurement programs. This paper deals with a case study in experimental design and data analysis for a series of experimental campaigns that have been conducted over the past five years by Kilborn Western Inc., acting on behalf of Bitmin Resources. Beginning with the design of the experiment and following into the use of linear and nonlinear regression models, the phenomenology of bitumen extraction is illustrated. The final testing program tested 13 oil sand types as well as a wide range of process variables for all the unit operations of the complete process.The program was successful in developing process fundamentals and scale-up criteria. Several phenomenological models were proposed and tested. Their range of applicability was explored. This paper illustrates the range of applicability of these models and discusses the development of alternative models.IntroductionOver the past five years Kilborn has conducted a series of bench scale and pilot scale experiments designed to explore the phenomenolgy of a new concept in medium temperature processing of bituminous ores. These experiments at feed rates ranging from .1 to 24 t/h were conducted on water wet sands from the .Athabasca region near Fort McMurray. They were based on experimental designs chosen to provide a systematic means of identifying the response surfaces of the process over a range of conceptual designs. The following diagram shows the experimental arrangement:"

Jan 1, 1998

By C. O. Aksoy

Operating the underground marble quarries effectively, it is important to evaluate the deposit blocks economically which are affected by the suitability of the topography and configuration of bedding. The joint sets within the deposit and the spacing between these discontinuties are also of great importance. In this study, the marble deposits that could be geomechanically eligible for underground excavation have been selected throughout Turkey and these selected reserves have been classified accordingly by Q-Rating System. These classified marble deposits that forms groups of 1,2, and 3 (groups were determined by evaluating the O-rating, topography, quarry situation, cracks, joints etc.) are convenient for this type of production. Nevertheless, when the auxiliary factors (topography, location, production method etc.) regarding the deposit have also been investigated, the most convenient sub-group of deposits (Afyon Tiger Skin, Burdur Beige, Diyarbakir Pink and Mugla White) have emerged. The sizing of the pillars have been performed utilising Bieniawski?s stress profile. The LAMODEL software, developed by National Institute for Occupational Safety and Health (NIOSH), USA and run under the laminated displacement discontinuity method, has been used to size the pillars. This work brings in a novel opportunity to Turkey, in which no underground marble quarry has been attempted up-to-date similar to its several examples in Italy, USA, etc. This study serves as a reference for the marble operators and for the pioneering application of laminated displacement discontinuity method in hard rocks.

Apr 1, 2005

By Jaeheon Lee

"Biooxidation of gold ores or concentrates could be a very attractive alternative to pressure oxidation (POX) or roasting to liberate the gold grains from various sulfides. Crushed heap bioleaching was successful in US and many operations using tank bioleaching of gold concentrate are currently running around the world. Many parameters need to be considered during the project of sulfidic refractory gold ore process. Capital and operation costs are among the most important ones. Run-of-mine heap biooxidation could be very inexpensive and the smaller the crush size (particle size), the more expensive the capital and operating costs for biooxidation application are expected. The capital cost of biooxidation could be a fraction of the cost for building POX plant or roaster and the operating cost could be 1/3 of POX or roasting depending on the method utilized. A new biooxidation process, Sand Farming, is introduced as an alternative to POX and tank biooxidation process. A relatively coarser particle size (P80 = 650 µm) of the process benefits the low cost of grinding against the conventional grinding size (P80 = 75 µm) for other options. The cost of Sand Farming is less than 40% of that of pressure oxidation with comparable gold recovery from the downstream process. This paper will review the laboratory scale testwork for various biooxidation process of sulfidic refractory gold ores and concentrates and provide the economic evaluation showing the biooxidation could be the most economic method without much sacrificing the overall gold recovery. INTRODUCTIONThe decreased availability and lower grade of raw materials has motivated industries to consider recovering values utilizing low cost process options. The process may treat high grade concentrates or submill grade ores that cannot be processed economically by conventional milling-flotation or leaching. Sulfidic refractory gold ores/concentrates have been economically processed by roasting, pressure oxidation, and biooxidation in stirred tank reactor. The process selection is based on a series of studies including multi-year long ore characterization and metallurgical investigations."

Jan 1, 2016

By Ming’an Wei, Qifu Duan, Chengtie Wang, Jianmin Wu, Erdenet Mining Corporation, Lusheng Zhou, Wenjian Wu

"The development and industrial applications of magnetic liners have been around for decades. A Swedish company SKEGA first introduced the rubber magnetic liner, and then followed by the Chinese metal magnetic liners. Traditionally, both liners were used in secondary and regrind ball mills, especially for ores containing magnetic materials. Mostly steel balls or equivalent forged balls, usually below 60 mm in diameter, were used as grinding media. With the development of mineral resources over the years, SAG mills and larger ball mills have become the dominating components for comminution circuit design globally. Due to the larger ball mills and thus larger grinding balls (up to 80 mm) especially in non-ferrous metal industry, the application of magnetic liners has been very limited. Based on the new development of materials, the HMR Group Limited has been exploring new designs of magnetic liners which led to the invention of the Nano Steel Magnetic Liner (NSML). Recently, NSML had a successful application in a 5.5m x 6.5m ball mill with 80 mm balls at the Erdenet Copper Mine in Mongolia. Although the first set of liner had a service life of 12 months, the design of the second set was modified and improved to accommodate the operating conditions, which is expected to reach least 24 months service life. The original manganese steel liner only had about 8 months liner life.1. IntroductionMineral processing is an essential operation for the development and utilization of mineral resources. The effective concentration of various useful minerals depends on sufficient liberation of the mineral particles in the ore. The crushing and grinding process such as ball milling are the most common way to achieve proper liberation size. Mill liner is an eternal topic for the operations, not only because it protects the equipment, but also affects the mill grinding efficiency and availability. In recent years, magnetic mill liners have been developed that can easily meet the production targets with numerous benefits, such as zero maintenance, reducing specific energy consumption and improving grinding efficiency."

Jan 1, 2016

By H. S. Bostock

"The study of the geology of Mayo district began in 1900 with R. G. McConnell's exploration of Stewart river; and has been carried on intermittently for the Geological Survey of Canada by J. Keele; D. D. Cairnes; W. E. Cockfield; C. H. Stockwell; and the writer. It has revealed a thick group of schists; quartzites; and crystalline limestones; almost certainly Precambrian in age; placed in the Yukon group; and a group of younger intrusive igneous rocks varying in composition from granite to gabbro. These include bodies of many sizes and forms; from stocks 8 miles across to small dykes and sills.Prospecting in the district began about 1897 and has disclosed the presence of gold, silver, lead, tungsten, tin, zinc, antimony, copper, arsenic, manganese, and mercury, both in placer and lode deposits . Of these metals gold, silver, and tungsten have been produced from placer deposits, and silver, lead, and gold from lodes. This paper deals only with some structural relationships of the lode deposits, generally referred to as the silver-lead veins, which have yielded the greater part of the mineral production of the area. From 1938 to 1941 the geological mapping of the district for publication on a scale of 4 miles to 1 inch was carried out by the writer, and the ideas expressed here are based on this work. No comprehensive detailed study of the silver-lead veins has been made, but the mapping has brought to light several important facts. The rocks of the Yukon group, although of a striking sameness throughout their section, can be divided into a number of distinguishable members by means of which the main structures can be traced . The most important and readily distinguishable rock in the group is referred to here as the quartzite member. This is composed of quartzite and schist in about equal proportions. The quartzite is resistant to erosion and forms most of the outcrops of the'member and the peaks of the Gustavus mountains and mount Haldane (Lookout)."

Jan 1, 1954

By F. Habashi

"Extractive metallurgy was divided into the three sectors pyro-, hydro-, and electrometallurgy in 1959 when Professor Joseph Newton at the Idaho School of Mines in Moscow mentioned this in his book Extractive Metallurgy. Pioneer hydrometallurgists who built this discipline can be traced to the alchemists in the ninth century. It is now a mature subject of great importance in which pressure plays a vital role. Short biographies of some hydrometallurgists and the processes they invented are briefly outlined.INTRODUCTIONHydrometallurgy is the use of aqueous solutions to recover metals from ores. It is a relatively new discipline when compared with pyrometallurgy the use of fire to melt ores and recover metals which was practiced in ancient times. Hydrometallurgy can be traced to the time of alchemists whose concern was the transmutation of base metals into gold. Although alchemists did not succeed in their venture yet they described many reagents that are useful today. For example, they prepared sulfuric acid by distillation of iron vitriol, muriatic acid by distillation of sulfuric acid with salt, and nitric acid by reaction of sulfuric acid by reaction of sulfuric acid with salpeter. Jabir Ibn Hayyan the Muslim alchemist who lived in the ninth century (Figure 1) described aqua regia a mixture of nitric and hydrochloric acid that can dissolve gold although either acid has no action on gold. THE MIDDLE AGESIn the Middle Ages, it was reported that copper was recovered at Rio Tinto in Spain by allowing copper-containing pyrite to be exposed in piles to the action of air and rain. Copper sulfate solution obtained was treated with pieces of iron to precipitate metallic copper—a process that was called cementation. Georgius Agricola (1494–1555) (Figure 2) a medical doctor in Saxony who used to visit mines and smelters to examine miners and metal workers, described in his book De Re Metallica the parting of gold, i.e., separating of silver from gold by acids."

Jan 1, 2016

By G. W. H. Norman

Introduction During the past few years emphasis has been placed on the importance of major faults, fault zones, and associated structures in localizing ore deposition. This interest has developed partly through experience in mining camps in other parts of the world, and partly by the discovery of such structures associated with ore deposits in the Abitibi region, northwestern Quebec. The recognition of these structures has been brought about chiefly by detailed mapping that has been gradually extended along most of the southern gold belt of Quebec and across adjacent parts of Ontario. In the Chibougamau region of northern Abitibi, progress has been made in the mapping of major faults by using aeroplane photographs with a scale of about 1,000 feet to one inch for field mapping. These studies have shown that many large faults occur in the Abitibi region; also that there is a relationship, direct or indirect, between faults and mineral deposition. The faults are, however, of more than one type and age, and this should be clearly appreciated in any planned programme for prospecting this great region adequately. The information regarding faults and structure is so widely scattered that it is difficult to obtain a clear picture of the essential features, either for planned prospecting or for analysis and development of ideas for further study. This paper, as originally conceived, was intended only to discuss and compare the regional structure of southern Abitibi county-where detail mapping and diamond drilling have been carried on intensively for the past ten years-and of the less well-known Chibougamau district, in order that the experience gained in the one area could be usefully applied in the other. However, a comparison of the two districts leads naturally to a consideration of their common relationship to certain major late-Precambrian structures that form an important northeast system across the southeastern part of the Canadian Shield.

Jan 1, 1946

By Robert E. McIvor

"Use of the Bond Work Index to size industrial grinding equipment was widely known. Bond also described its application for measuring grinding circuit efficiency. Bond Work Index efficiency also has been used extensively by industry, but until now without concise standard methods, or a formal guideline, for doing so. The Bond Efficiency Sub-Committee of the Industrial Comminution Efficiency work group of GMSG has produced such a guideline, which is appended hereto. It covers the methods and provides examples of how to calculate the Bond Work Index Efficiency of most industrial grinding circuits. Bond Work Index testing equipment and methods are also provided.Comminution is responsible for a major portion of mineral processing plant energy consumption and operating costs. Bond Work Index efficiency provides valuable means, first, for benchmarking one’s plant performance against others in the broad industry, and hence defining the extent of the opportunity for improvement. Secondly, improvements in circuit efficiency with implemented changes can be quantified and monitored as part of continuous improvement efforts. These two important business activities are thus facilitated, and, in the absence of any other accepted method, otherwise would be lacking without the existence and application of this standard for comparison. While often loosely applied in the past by plant metallurgical staffs, the increased precision offered by this guideline provides much clearer definition of both the conceptual and statistical meaning of these measurements. Even a small improvement can be enormously financially important, but only if differentiated by measurement. This guideline was thus intended to provide industry improved means to differentiate comminution circuit efficiencies. Carbon footprint reduction is coincidental, but nevertheless can be substantial.The next steps are: (1) to establish standard reference testing materials and one or more laboratories to serve as bases for reference testing; (2) to establish the accuracy of relative circuit Work Index Efficiency determinations; and (3), to develop and provide a public data base of industrial comminution circuit Bond Work Index Efficiencies."

Jan 1, 2016

By R. Carpenter, H. Muntanion, P. Kleespies, E. Flood, M. Tansey

Abstract - BHP Minerals discovered the Archean lode gold ULU deposit on the western margin of the High Lake Volcanic Belt in 1989. The greenschist to amphibolite facies mafic volcanic and sedimentary rocks on the property are folded into a 5 km-long anticline. There is a close spatial association of Au-As zones to the trace of this F2 ULU anticline. The largest of these auriferous zones, the Flood zone, is localized at the core of the fold. The southeast-trending Flood zone consists of several anastomosing lenses that have been traced for 435 m on surface. Overall, it dips steeply (70° to 80°) to the southwest and has been intersected to depths below 600 m. The hosting high-iron tholeitic basalt displays a lower amphibolite mineral assemblage of ferrohornblende + plagioclase + ilmenite with accessory quartz and epidote. Alteration minerals include biotite, chlorite, hornblende, actinolite-tremolite, and potassium feldspar (microcline) with minor calcite, epidote, tourmaline, and titanite. The highest gold values occur where brecciated basaltic wall-rock clasts are replaced by acicular arsenopyrite + quartz + K-feldspar. BHP Minerals completed 54,783 m of both exploration and resource development drilling before selling the ULU property to Echo Bay Mines in 1995. Development of ULU as a satellite deposit to Echo Bay’s Lupin mine began in 1996. A -15% ramp was extended to the 155-meter level, and 16,011 m of underground drilling were completed before the decline in gold prices forced a suspension of activities at ULU in August 1997. The current owners, Wolfden Resources Inc., drilled 18,569 m in 2004 to increase confidence in the resource blocks. Following this drill program, a revised resource calculated by an independent consultant determined that the ULU deposit contains an inferred/indicated mineral resource of 1,130,000 t grading 11.34 g/t gold (373,748 oz) to the 360-m level. The portal was re-opened in 2005 and a prefeasibility study is underway.

Jan 1, 2004

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"This paper briefly summaries the status of a recent program aimed at identifying new chemistry for use as sulfide mineral frothers and collectors. The background motivation and planning behind this work is given along with the general families of chemical structures synthesied and studied in detail followed by typical flotation application results in various laboratory and plant scale tests. Flotation testing to date has been very encouraging with often improved recoveries of certain minerals and improved pyrite selectivity being observed over commercially available reagents. In addition, in some cases, the dosage and lime requirements of these new collectors are significantly less than that associated with standard sulfide mineral collectors. INTRODUCTIONFroth flotation is one of the most widely used and economic means of concentrating metal sulfide ores. There are numerous reference books that have been published on the chemical aspects of flotation [e.g., ref. 1-7] which are based on studying the influence on selected minerals of chemical structures that have been used commercially for many years. In fact, almost 98% of the volume of flotation collector and frother reagents used at the industrial level today were known and manufactured in some form 25 years ago [8]. There are many reasons for this lack of significant new flotation reagent development [9] including the general utility and relative cheapness of existing collectors such as xanthates and existing frothers such as the alcohols and glycol ethers. Another reason is the inherent complexity of the flotation process itself coupled with highly variable and difficult to standardize feed materials. This environment makes reliable reagent comparisons difficult and seriously limits the use of theoretically based chemical structure studies to predict new or optimal reagents. In addition, the higher cost of specialty flotation reagents demands that their performance attributes be significantly greater than that achieved with existing all-purpose commercial reagents - something often difficult to prove in practice."

Jan 1, 1988

Adaptive Processing as proposed in geometallurgy has to rely on spatially interpolated information on geometallurgical parameters like phase composition, size distributions of particles of different phases, grain shape parameters, and portions of value elements in different grains. Using the geostatistically predicted values for adaptive processing, e.g. for the selection of milling diameters, thresholds in physical separation, or choices on using an extra pre-separation step, is typically not optimal. Mathematically this effect is introduced by two forms of nonlinearities: 1) The nonlinear scales of compositions, distributions, and shapes have special properties with respect to geostatistics. Classical geostatistics creates some artefacts for these nonlinear scales. On the other hand, modern geostatistical procedures adapted to these scales do not provide unbiased results with respect to linear transformations of the data (e.g. biased block estimates). 2) Neither economic nor ecological effects (e.g. monetary gain) of processing decisions are linear in the interpolated geometallurgical parameters. These nonlinear transforms are not unbiasedly estimated by the likewise transformed unbiased geostatistical predictions of the geometallurgical parameters. Furthermore, we need to optimize the conditional expectation of the gain, rather than obtain an unbiased estimate. Standard geostatistics as such does not provide the "right sort" of estimates for adaptive processing. A nonlinear kriging procedure is needed to approximate the nonlinearities mentioned before. We propose to solve these problems simultaneously using a nonlinear geostatistical technique for predicting the target function (the monetary gain), rather than to predict the geometallurgical parameters and compute the gain from them. The optimization can then be performed directly on this estimated function. It can be shown that this optimization performed on the conditional expectations, not on unbiased predictions, would yield the best possible processing choice. We propose a procedure choosing the processing parameters on an approximation of the conditional expectation. The difficulties with the classical approach and the effectiveness of this new approach are illustrated by a simplified simulation example with a single processing parameter and a simple dependence on the microstructure.

Aug 1, 2013