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By S. Fox, Y. Fujita

Increasing demand for rare earth elements (REE) is expected to lead to new development and expansion in industries processing and or recycling REE. For some industrial operators, sending aqueous waste streams to a municipal wastewater treatment plant, or publicly owned treatment works (POTW), may be a cost effective disposal option. However, wastewaters that adversely affect the performance of biological wastewater treatment at the POTW will not be accepted. The objective of our research is to assess the effects of wastewaters that might be generated by new rare earth element (REE) beneficiation or recycling processes on biological wastewater treatment systems. We have been investigating the impact of yttrium and europium on the biological activity of activated sludge collected from an operating municipal wastewater treatment plant. We have also examined the effect of an organic complexant that is commonly used in REE extraction and separations; similar compounds may be a component of newly developed REE recycling processes. Our preliminary results indicate that in the presence of Eu, respiration rates for the activated sludge decrease relative to the no-Eu controls, at Eu concentrations ranging from <10 to 660 µM. Yttrium appears to inhibit respiration as well, although negative impacts have been observed only at the highest Y amendment level tested (660 µM). The organic complexant appears to have a negative impact on activated sludge activity as well, although results are variable. Ultimately the intent of this research is to help REE industries to develop environmentally friendly and economically sustainable beneficiation and recycling processes.

Jan 1, 2016

By Z. F. Lodhi, J. H. W. De Wit, H. A. Terry

Zinc and its alloys have been extensively used as replacements for Cadmium coatings in aeronautical and automobile industries. Zn alloys with low Co or Fe have been highly investigated but coatings with higher amount of Co are very difficult to achieve due to anomalism associated with these coatings. Anomalous Zn-Co-Fe alloy is a relatively recent addition to the family of Zn alloys. It is found that the addition of Fe in the electrolyte assist in overcoming the anomalism. In this research Zn-Co-Fe alloys especially with higher amount of Co (>15%) and Fe (~1%) are investigated, after overcoming the anomalism associated with its deposition, and the corrosion resistance is compared with pure Zn and Cd. It is found that an increase in Co to higher than 25 % accounts for a shift in the OCP to a level near Cd yet keeps it electronegative to steel. The coating shows superior corrosion resistance, in terms of its sacrificial and barrier properties in 3.5% NaC1 as compared to Zn and Cd.

Jan 1, 2006

By Michael S. Moats, Shijie Wang, Timothy Robinson

In 1987, John Schloen published a survey and analysis of copper electrorefining tank room data. Following this paper, a series of copper electrorefining surveys have been conducted and presented at each of the Copper-Cobre meetings over the past 20+ years (1991, 1995, 1999, 2003, 2007, 2010 and 2013). For each of these surveys, William Davenport has been key driving force in the collection and analysis of data. To honour Professor Davenport’s contribution to copper processing, a review of the data was conducted. Historic trends and possible future technologies are discussed.

Jan 1, 2014

By M. Labrie, H. L. Gibson, G. Doiron, J. J. Watkins, D. H. Watkinson

The Corbet deposit is one of 17 proximal Cu-Zn massive sulfide deposits located. within the Noranda Cauldron which occurs within the core of the Noranda Volcanic Complex. The deposit is located at the top of the Havrian Formation, the lowermost formation of the 3000 m thick Mine Sequence; the deposit has Yielded 2.75 M tonnes of ore grading 3% Cu, 0.96% Zn, 2.06 g/t Ag and 1.0 g/t Au. The multi-lens Corbet deposit formed within a 250 m wide crater that occurs within a localized breccia pile. The Corbet breccia pile was constructed by explosive magmatic and hydrovolcanic eruptions localized along the south flank of a larger andesitic shield volcano that formed during the waning stages of Havrian volcanism. The breccia footwall of the deposit allowed unfocused and widespread hydrothermal discharge that resulted in the development of a large area of chlorite and fringing sericite alteration that exceeds, by six times, the size of the sulfide lenses and represents a significant exploration target.

Jan 1, 1993

By A. S. H. Kabir, I-H. Jung, J. Su, S. Yue, M. Sanjari

The final mechanical properties of wrought magnesium alloys are mostly controlled by microstructure and crystallographic orientation or texture. In common magnesium alloys, grain coarsening occurs during annealing process and formation of undesirable basal texture cannot be changed markedly. The aim of this work is to investigate the effect of static precipitation on microstructure and texture evolution during annealing at 250 °C after warm rolling of Mg-Al-Sn alloy. Mg-3Al-3Sn (wt. %) alloy has been designed using thermodynamic modeling software, FactSageTM, based on forming target stable and incoherent Mg2Sn precipitate within the industrial deformation temperature range. Microstructures and precipitation were investigated by optical and scanning electron microscopes and macro-texture was measured by X-ray diffraction (XRD) techniques. It was found that static precipitates form in a large scale at the recrystallized grain boundaries and retards the grain growth during annealing. Slight weakening in basal texture was also observed during annealing.

Jan 1, 2014

By M. G. Lipsett

General Challenges for Mining & Mineral Processing Operations ? Capital-intensive industry ? Ongoing cost pressures ? Remote locations ? Workforce demographics ? Dynamic, unstructured, rugged environment

May 1, 2008

By Jan Rosenkranz, Anders Sand, Lisa Malm, Nils-Johan Bolin

Within flotation technology the general trend is towards very large cells. Scale-up is usually done by postulating geometrical similarity, which implies keeping the aspect ratio constant when increasing cell volume. Consequently, the design of flotation circuits typically involves several cells of identical geometry within a bank. Using a few standard sizes in a flotation plant simplifies design, manufacturing and maintenance of the cells, but does not necessarily guarantee optimal performance and selectivity of the flotation process. Geometry parameters for a given cell volume that influence flotation cell performance include cell height, which causes changes in the hydrostatic pressure and suspension hydrodynamics, and also influences the travel distance of particle-bubble agglomerates as well as the homogeneity of the mixing. Also the thickness of the froth layer depends on the aspect ratio of the cell. The objective of this work is to gain a better understanding of material distribution and properties within a flotation cell and, based on this information, elucidate how alterations of the cell geometry can influence separation efficiency. For this purpose systematic measurements and analyses of the spatial distribution of the different phases within a 160 m3 flotation cell have been carried out with a particular focus on an industrial, low-grade copper ore beneficiation process. The concepts for sampling at different vertical and lateral positions of the flotation cell are introduced. The results from the experimental work give an understanding of internal material distribution within flotation cells. Based on the measured phase distribution and concentrations as well as particle properties at various positions within the cell, the implications for an optimized scaling and design of individual flotation cells within a flotation circuit are discussed.

Jan 1, 2016

By Fulchand Shende

Around the world many potash mines experience brine inflow problems. The presence of brine in underground excavations may induce structural and stability problems. A study has been carried out to simulate the effect of brine on the performance of pillar support. The testing program consisted of loading potash specimens in a creep frame, and simulating inflows by continuously pumping brine into an experimental cell. Brine temperatures and load conditions were varied to simulate several mining and inflow conditions. Specimens were fitted with acoustic emission transducers to monitor energy emissions during an eight-hour test duration. Samples of brine were also collected to provide K+ and Na+ concentration data necessary for an accurate assessment of the dissolution process. Test results indicated that dissolution rates are highly dependent on brine temperature and load conditions. Loads approaching 50% UCS tend to generate very high rates of energy emissions, often leading to the failure of the simulated pillars. This study demonstrated that acoustic emission could be effectively used for predicting the performance of pillars when exposed to inflow brine.

May 1, 2001

By Tsuyoshi Adachi

Photovoltaic (PV) system is especially taken notice as one of important renewable energy resources, because PV has potential to provide a certain amount of energy supply as well as without greenhouse gases emission. Considering recent rapid increasing demand for PV system, more expansion of PV system is expected in the future. However, some precious metals and minor metals such as silver, indium and others are used as component materials of solar cell in PV system. Even if energy supply would become renewable, strict limitation of these metals still remain because amount of natural resources and recycling of metals has restrictions intrinsically. The aim of this study is to reveal the possibility of materials supply restrictions for Photovoltaic system quantitatively and to propose several measurements to assess supply risks for materials. Especially, silver supply potential which is used as wire line in PV system as well as PV demand forecast to estimate material use in the future are focused on. We divide underlying supply risk into 5 measurements and analyze them by time series, i.e. price volatility, resource potential, recycling ratio, production type and supply concentration are investigated. Comparing these factors of silver with other metals, the potential of silver supply for PV is presented. In addition to it, we propose another method to quantify country risk applied an insurance pricing model in finance pricing theory and combine it with the supply concentration measurement. As a result, supply risk of silver will increase gradually in the near future because of its resource constraints and supply-demand balances although silver market is sufficiency competitive one. From the country risk analysis, Peru is not only a significant supply country but also has the highest country risk. Some higher risk countries will increase the level of supply risk even if the concentration ratio of supply indicates moderate level.

Aug 1, 2013

By R. D. Brown

Higher metal prices have resulted not only in increased exploration and production, but also increased activity in the purchase of mining properties and mines. This article discusses some of the basic income tax considerations to be taken into account on the disposal of an interest in a mining claim or an active mining operation. It notes the importance ofan appropriate allocation of the purchase price amongst the various categories of assets, and discusses the tax implications to both vendor and purchaser of the transfer of the comm on types ofassets involved in mining operations. In the space available, the article can only outline the basic tax considerations, and point to areas where both vendor and purchaser need to be o

Jan 1, 1980

By James Tuer, John R. Goode, Jim Cambon

"Hudson Resources Inc. (Hudson) has defined a major resource of high purity anorthosite (calcium feldspar) assaying about 30% Al2O3 at the White Mountain (Naajat) deposit in Western Greenland. Extensive beneficiation and evaluation testwork has shown that the material can be simply beneficiated to produce a feed material ideal for the production of low-alkali E-glass used for making glass fibre. An offtake agreement is in place with a major US fibreglass manufacturer and, subject to the mine construction schedule, shipments are scheduled for late 2016 or early 2017. In parallel with the E-glass program, Hudson has completed an initial program of metallurgical testwork which shows that the White Mountain anorthosite can be processed by hydro- and pyro-metallurgical processes to yield either smelter-grade alumina (SGA), suitable for conversion to aluminium metal, or a high purity, chemical/specialty-grade alpha-alumina (CGA) commanding a premium price. The process includes dissolution of the anorthosite in hydrochloric acid, HCl sparging to precipitate aluminium chloride hexahydrate (ACH), recycle of the ACH filtrate to leaching with a bleed stream processed for HCl regeneration from CaCl2, and two-stage calcination of the ACH to regenerate HCl and produce SGA and/or CGA. Calcium silicate and amorphous silica are marketable by-products. This paper discusses the White Mountain anorthosite deposit; the process testwork completed to develop production processes for SGA and CGA; production plans, and indicative economics.INTRODUCTIONHudson Resources Inc. (Hudson) holds a 100% interest in the Naajat Exploitation Licence in Western Greenland that cover the White Mountain high-calcic anorthosite deposit. Anorthosite is a calcium aluminosilicate of slightly variable composition but generally containing about 30% Al2O3. The alumina content is similar to that in bauxite and anorthosite has long been studied as a feedstock for the production of alumina. Other potential uses include feedstock for the high-end fiberglass (E-glass) industry and as a filler for use in paint and plastics."

Jan 1, 2016

By G. Dubé, A. Leclerc, P. Quinn, G. E. Agar, J. Y. Clouthiér, J. D. McLaughlin

"Gold dissolution by cyanide requires the presence of oxygen which is usually supplied by sparging compressed air into the gold containing slurry. For those ores that contain certain obnoxious substances that consume oxygen, maintaining the required minimum level of dissolved oxygen can be troublesome. One of the most economical solutions to the problem of low dissolved oxygen, especially in plants that have air compressors installed, is to enhance the rate of oxygen mass transfer.The oxygen mass transfer rate was measured in a two phase system using two different sparger arrangements, and with addition of a frother that is known to reduce the bubble size produced by the sparger. The common sparger system was shown to be inefficient compared to a readily available but under utilized method of gas dispersion which introduces air directly below the reactor turbine. Transfer of this technology to an operating plant confirmed the beneficial effect of the improved sparger system. The addition of the frother did decrease the bubble size, but it also reduced the oxygen mass transfer rate."

Jan 1, 1993

By Philippe Ribagnac, Bruno Courtaud, Jean-Marie Lambert, Valérie Weigel

Mabounié is a polymetallic deposit in Gabon containing niobium (1.2 wt.%), tantalum (0.03 wt.%), rare earth elements (REE) (1.4 wt.%) and uranium (0.03 wt.%) that are mostly carried by pyrochlore minerals. The classical route for niobium recovery is a pyrometallurgical process that consists of pyrochlore flotation, dephosphorization of the niobium concentrate and aluminothermy to obtain ferro-niobium. Pyrochlore concentrates can also be treated by a hydrometallurgical process with a mixture of sulfuric and hydrofluoric acid leaching followed by solvent extraction to separate niobium and tantalum. However, the first process does not allow recovering REE and the second one is not environmentally friendly because of the use of HF. ERAMET is looking for new opportunities on strategic metals market and has recently developed a hydrometallurgical process for the recovery of all these metals based on a sulfuric acid treatment of the ore (Donati, Courtaud, & Weigel, 2014). As for most of the oxidized ore processes, the major impurity is iron (~30 wt.%). Thus, in this hydrometallurgical process, the question arises of the elimination and stabilization of the iron as residue. The iron in solution is ferrous; goethite precipitation seems the most adapted crystalline form. Lab and pilot tests have shown kinetics of precipitation of 6 g.L-1.h-1 at pH 4.5. To reduce the salt discharge, sodium-jarosite form is more adapted, but at pH 2, 95°C only 30% of iron is precipitated in 5 hours, compared to 100% in goethite form at the same time and pH 2, 80°C. Different ways of oxidation were tested, air, pure O2, activated carbon, without drastic effect. The more efficient was ozone use, at room temperature; the kinetics of oxidation is five time faster than the other ways with 30% of sodium removed from the solution.

Jan 1, 2016

By Robert B. Parsons

"Recent amendments to the so-called ""flow-through share"" rules in our income tax legislation have given a new lease on life to this once popular investment vehicle.The original ""Dome funds"" for exploration in the Beaufort sea recognized the usefulness of flow-through share arrangements, but, by and large, flow-through shares have until recently not been able to compete effectively with other tax shelter instruments-mainly , limited partnership interests.This month, Tax Notes examines the new tax rules for investing in flow-through shares.IntroductionRecent income tax amendments have helped to rekindle investor and industry interest in so-called ""flow-through shares"" as a mechanism for mobilizing funds toward mineral exploration and development activities. In competing for investment funds, flow-through shares have historically placed a distant second in terms of investor popularity, being unable to compete with the more attractive features of limited partnership arrangements. However, primarily as a result of favourable changes to the income tax law, flow-through shares may be well poised for a comeback.This article examines the income tax considerations pertaining to issuing and investing in flow-through shares, and compares the former and the new income tax rules relating thereto. Of course, inasmuch as a flow-through share issue can involve various contractual arrangements between the investor and the issuer, there is a wide range of legal and business factors that generally have to be taken into account. A discussion of these matter s is beyond the scope of this paper, which is restricted to a summary of the special income tax factors attributable to flow-through shares."

Jan 1, 1983

Fault detection and identification are major challenges in process engineering and manufacturing and the key component of abnormal event management systems. Timely detection, diagnosis and rectification of abnormal or faulty process conditions can lead to savings of billions of dollars in equipment damage and lost productivity, not to mention the prevention of injury and loss of human life associated with industrial accidents. A major contributing factor to current losses in industry is the reliance on human operators to interpret high-frequency samples from hundreds or thousands of variables simultaneously. As a result, the automation of fault detection and diagnosis is seen as crucial to the successful implementation of abnormal event management, the need for which is becoming all the more urgent given the increased complexity associated with modem industrial plants. In this paper, a methodology for process monitoring that uses support vector methods to extract nonlinear features from data is discussed and applied in the diagnostic monitoring of an industrial liquid-liquid extraction column.

Jan 1, 2005

By Vern Evans

Saskatchewan has historically been recognized for farming, but in 1943 while drilling for oil, potash was discovered. The initial attempt to gain access to the potash beds was unsuccessful, however, subsequent attempts were successful and today there are ten operating potash mines in Saskatchewan. In this paper we will provide a brief overview of the historical and current Potash industry in Saskatchewan.

May 1, 2011

By M. M. Papic

"This paper describes the Sasol coal liquefaction process, as used in South Africa. It covers coal supply, coal gasification, gas purification, Fischer-Tropsch synthesis, the major utility systems involved and the economics of the process.IntroductionThe Sasol coal liquefaction process is based on Fischer-Tropsch synthesis of liquid fuels from carbon monoxide and hydrogen, which are in turn obtained by gasification of coal with steam and oxygen. The process is shown schematically in Figure I.The first step in the process is coal preparation, in which the coal is crushed and screened to a 3-50 mm size for gasification on one side and to -3 mm size for steam and power production on the other. Oxygen needed for coal gasificatoin is produced in the air separation plant.Coal is gasified under pressure by steam and oxygen in the Lurgi gasification plant, where raw, impure gas is produced . The raw gas is first washed in a scrubber with a circulating gas liquor, heat is then recovered from it in a waste heat recovery boiler and the gas is further cooled for purification. Water-insoluble materials (tar oils) in the gas liquor are separated from aqueous solution and sent to tar refining for the recovery of tar products. The aqueous portion of the gas liquor goes to a Phenosolvan solvent extraction process, where phenols and ammonia are recovered. Water then proceeds to the effluent treatment plant.The scrubbed and cooled raw gas goes to a Rectisol gas purification plant, where all components other than hydrogen, carbon monoxide and methane are removed as completely as possible by absorption in refrigerated methanol. The acid gases (CO2, H2S) stripped from the methanol in the Rectisol unit are processed in a Stretford plant for recovery of sulphur. Regenerated methanol is returned to the process. The purified synthesis gas is passed to the fluidized-bed Synthol reactors, where Fischer-Tropsch synthesis reactions take place.The synthesis products are recovered in a product recovery unit as separate streams of decant oil containing higher-molecular- weight hydrocarbons, light oil comprised of lower-molecular- weight species, the aqueous stream containing water solubles, a C3/C4 stream, a C2 stream , a methane stream and a hydrogen-rich stream. Most of the hydrogen is recycled to the Synthol reactors; a major portion of the methane is reformed to hydrogen and carbon monoxide for recycle; the C2 fraction goes to an ethylene plant; and liquid streams proceed to the product refinery.The product refinery is used to upgrade and purify the Synthol products to specification fuels and chemicals.Sasol l, the first coal liquefaction plant in South Africa , was built in 1955. It is still operating and has a product output of about half a million tonnes per year. The Sasol II plant is in a commissioning stage and will be in full operation in 1981. It is about five times the size of Sasoll. It uses over 12 million tonnes of coal and produces more than 2 million tonnes of saleable products annually (1,2,3). The Sasol llI plant, which is a mirror image of Sasol II, is under construction and scheduled for completion in 1983."

Jan 1, 1981

By S. McCarthy, K. E. Waters, A. Jordens

The beneficiation of rare earth (RE) element bearing minerals has become an active area of research as applications for these elements grow while the supply to non-Chinese consumers is restricted by export quotas. One of the most interesting beneficiation techniques for RE minerals is froth flotation as their unique chemistry suggests that collectors with a specific affinity for RE cations should be able to selectively recover these minerals. Existing literature, focusing mainly on bastnäsite flotation, identifies hydroxamic acids as excellent collectors for RE minerals. The high stability of hydroxamate-RE cation complexes is the explanation most often offered for the observed selectivity of these reagents in bastnäsite flotation however some research has also suggested that mineral solubility plays a crucial role in the success of hydroxamic acid flotation of RE minerals. This work investigates the interaction of allanite, a relatively insoluble RE-silicate mineral, with benzohydroxamic acid using zeta potential measurements and microflotation. The effects of Fe(III) and Fe(II) ions as potential activating ions (cations that form stable hydroxamate complexes) on benzohydroxamic adsorption to the allanite surface are investigated as a potential solution to promote hydroxamic acid adsorption. The results indicate that the optimum conditions for separation of allanite from quartz occur at pH 4 using FeCl2 as an activator for benzohydroxamic acid adsorption.

Jan 1, 2014

By J. W. Matousek

"More copper concentrates are treated in flash smelting furnaces than by any other process, and such furnaces are located in most of the world&apos;s major copper producing areas. Except for perhaps two furnaces treating chalcocite-type materials, little difference is seen between the grades of the concentrates being smelted. Within individual smelters, even less variation in feed grades is found. This is both accidental and intended. Many furnaces treat concentrates from captive ores, and these tend to be of relatively constant composition over long periods. Toll smelting operations blend concentrates to ensure delivery of feeds of fixed compositions to their furnaces to avoid upset conditions. Matte grades vary between flash smelting furnaces, but most commonly, these are the result of differences in operating practices rather than because of differences in concentrate grades. This paper reviews an industrial flash smelting test in which the copper content of the furnace feed was intentionally altered over a wide range. IntroductionExcept in a few copper mining regions of the world, the principal copper mineral is chalcopyrite (CuFeSz). This results in the almost universal production of concentrates containing 25070 to 30% copper (and similar amounts of iron and sulphur). Many operators of copper flash furnaces spend their entire metallurgical careers smelting concentrates of essentially fixed grades. This is true both of smelters treating concentrates from captive mines and those processing concentrates on a toll basis. From the production staff&apos;s point-of-view, the less variation in grades seen by the furnace, the better. Fixed analyses of concentrates and constant feed rates produce consistent quantities of matte at a consistent grade for processing by the converters. The result is, even in smelters treating a variety of concentrates, efforts are expended in sampling and blending to ensure feeds of relatively uniform compositions being sent to the furnaces."

Jan 1, 1993

By A. R. Barnes, R. Pandher, T. Shannon, P. Gover

Following the closure of the Glencore Zinc Brunswick mine, the Glencore Brunswick Smelter has transitioned to treating external feeds, and currently treats a number of secondary Pb-Zn concentrates. Processing these concentrates has in some cases been challenging due to the diverse mineralogy of the feeds. Certain feeds are difficult to ignite or show inadequate sulphur removal during oxidation on the sinter strand, while in other cases, combinations of feeds produce a sinter with unsuitable properties for further handling. This paper discusses two methods developed in collaboration with XPS Consulting & Testwork Services to characterize these feeds prior to processing them and to identify which ones are most likely to pose challenges during processing.

Jan 1, 2014