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By Soumitry J. Ray

Poor visibility of powered industrial vehicles, such as forklifts, used in industry is often the cause of accidents that include pedestrians. Current standards allow up to 20 % non-visible regions for forklifts where measurement of these regions is performed by using lamps. A collaboration of research organizations, including National Institute of Standards and Technology, Georgia Institute of Technology (NIST), and Direct Dimensions, has been evaluating advanced methods for measuring a forklift operator?s visibility. These methods can potentially improve visibility standards. They can also help forklift and sensor manufacturers to determine (1) how visibility-assist sensors and algorithms can be designed and (2) where sensors can be mounted on forklifts. This paper includes explanation of visibility measurement experiments performed and results, associated language suggested to standards organizations, and a prototype design for measuring the visibility of forklifts automatically.

Aug 1, 2013

By Xing-Liang Sun, Xian-Min Han, Zheng-Guo Zhu

The study on the material properties of frozen soils in China was being developed quickly in the past decades of years, because of the increase of the engineering constructed in frozen soil regions on the Qinghai–Tibet Plateau, and numerous research results were achieved mainly about strength and deformation behaviour and constitutive models of frozen soils. Studies have shown that the deformation procedure of frozen soils is irreversible; therefore, it is more appropriate to research mechanical properties of frozen soils by means of damage mechanics theory. In this paper, an elasto-viscoplastic anisotropic damage model is presented by introduction of Perzyna viscoplastic equation into analyzing the deformation of frozen soil. In addition, an anisotropic damage evolution equation is obtained by means of extending non-viscous damage to viscous damage. Triaxial tests at different strain rates are chosen to illustrate the application of this model, and good agreement between experimental data and numerically simulated results is obtained. The calculated results indicate that, under the same conditions, the damage at higher strain rate is less than that at low one. So the phenomena are explained from damage mechanics that the frozen soil has larger elastic modulus and shear strength at higher strain rates, and explained from mechanism that the emergence and development of micro-cracks in the body of frozen soil can be to some extent retarded at higher strain rates.

Jan 1, 2015

By Jiuhua Xu, Yuling Xie, Fenglei Bie, Neng Jiang

"Abstract - The Xiaoqingling Mt. area is one of the most productive gold districts in China. The gold-bearing quartz veins are controlled by a series of east-west shear zones within the Archean Taihua Group, and related to the late Yanshanian (Cretaceous) granite. The major metallic minerals are native gold, electrum, pyrite, galena, chalcopyrite and sphalerite, with gangue minerals dominated by quartz, sericite, ankerite, and calcite. The host rocks are mainly amphibolite, plagioclase gneiss, and migmatites. Principal alteration is sericitization, silicification, pyritization, and carbonization.There are four generations of hydrothermal quartz in altered rocks of gold deposits. The earliest generation of quartz, (Q1), occurs in altered amphibolite gneiss and migmatite, and typically contains fluid inclusions with halite crystals (type A) and two phases, (L+V), of fluid inclusions (type B). The salinities of type A inclusions are 32 wt% to 52 wt%, with dissolution temperatures of halite crystals being from 155°C to 465°C. The second generation of quartz, (Q2), occurs as a fine-grained aggregate associated with sericite, and has small (less than 3 µm) type B inclusions. The third generation of quartz, (Q3), occurs in mylonitic, intensively altered rocks and specially beresite (a type of rock composed of quartz, sericite, and pyrite) near the veins, and contains large amounts of CO2-rich fluid inclusions (type C-fluid inclusions with liquid CO2 and type D-fluid inclusion with high density CO2). The CO2 contents of type C range from 72.6 to 87.4 mol% in gas phases, and 35.7 to 68.3 mol% in liquid phases, based on Laser Raman analysis. The homogenization temperatures of fluid inclusion type A and C are from 215°C to 380°C, and from 210°C to 325°C, respectively. The minimum trapping pressure of fluid inclusions is estimated as 80 MPa to 170 MPa for type A, and from 57 MPa to 190 MPa for type C, which approximate to those of fluid inclusions in vein quartz.The ?18O of quartz are from 10.4‰ to 11.0‰ for Q3 of altered rocks, and from 10.7‰ to 12.8‰ for stage I quartz. The calculated ?18O of fluid inclusions varies from -1.3‰ to 6.0‰. The ?D of fluid inclusions ranges from -67‰ to -59‰ and from -81‰ to -48 ‰, respectively. It is concluded that the water in the hydrothermal fluids both reacting with wallrocks and precipitating orebodies could have been mainly of magmatic and/or metamorphic nature. However, local meteoric water might have been important in late mineralization, because of a distinct oxygen-shift toward the meteoric water. The ?34S values for pyrite of the ores range from -7.1‰ to +7.1‰, with an average of +2.9‰. Those of other sulfides (chalcopyrite, galena, and sphalerite, range from -12.5‰ to 8.3‰. The ratios of lead isotopes for galena of the ores are: 17.06 to 17.31 (206Pb/204Pb), 15.43 to 15.74 (207Pb/204Pb) and 37.58 to 38.45 (208Pb/204Pb). In summary, ore-forming fluids in the Wenyu-Dongchuang gold deposits may have originated from a mantle and/or lower crust source, and ore materials were derived from the Precambrian basement, the Taihua Group."

Jan 1, 1998

By W. E. Coates

The social ecology of surface mining in urban areas is illustrated by a case study of a recent application for the opening of a new gravel pit in the city of Guelph, including the design of a progressive extraction-rehabilitation sequence for the property, investigation of the ecological impact of the proposed operation, history of the application procedure for a zoning change and the relationship of the operating plan to provincial legislation controlling surface mining.

Jan 1, 1972

By S. Flewelling, M. Scobie, G. R. Baiden

"SynopsisA feasibility study to develop a research program, the Mine Automation Plan (MAP), was recently completed. This was undertaken by a team comprised of Inco Ltd., Falconbridge Limited, the Canadian Centre for Automation and Robotics in Mining (CCARM) and the Centre for Resource Studies (CRS). The study was sponsored by PRECARN Associates, which is a consortium of thirty-six Canadian companies focussed on research and development in artificial intelligence and robotics. PRECARN Associates was formed in 1987 when a number of research proposals were funded in the fields of process control systems, robotics systems and intelligent engineering systems. In July 1991, PRECARN accepted the next round of proposals for research. The MAP project was one of the successful proposals, being awarded $100,000 for the development of a feasibility study defining a long-term R&D plan for underground hardrock mining automation.The development of the feasibility study started by addressing the fundamental structure of the mining process, and its relationship to the metallurgical process, over-all infrastructure support and management systems (Fig. I).Mining may be considered as comprising five subprocesses: (I) delineation; (2) development; (3) production; (4) backfilling; and (5) infrastructure support services. Within these subprocesses many applications for artificial intelligence and robotics exist. The mining process is dependent upon the interaction between the physical mining process and information. For example, the delineation process is dependent on geomechanical, geochemical and geophysical techniques to develop a model of the orebody based upon access to such data. This same relationship between the physical and information models holds true through the development, production, backfill and infrastructure support systems.The foundation for the MAP study has been the recent development by Inco Ltd. of an underground communications system (Fig. 2). The system has the ability to supply high bandwidth communications, over voice, data and video to mobile and stationary locations within the mining operation. It is seen to be the future backbone of a comprehensive, automated information system which should permit the application of the concept of Computer Integrated Manufacturing (CIM) to underground mining. CIM, through the automated flow of information, has been successful in integrating the engineering, production and various support groups in manufacturing."

Jan 1, 1994

By T. Krumins, F. C. Ruff, M. Eichhorn, L. Zunti

Hatch Ltd. has recently completed a project to increase refractory gold ore processing capacity at Newmont Mining Corporation’s Twin Creeks facility. The objective of the project was to increase throughput by approximately 10% by adding a third autoclave feed pump to each of the two autoclave circuits. To minimize project capital cost, autoclave feed pumps from Newmont’s decommissioned Lone Tree facility were evaluated and found to be suitable for this new service. The existing pressure oxidation circuit was reviewed in a debottlenecking study to determine other upgrades required to facilitate the increased throughput. Interruption to operations was minimized with a detailed construction plan, supplemented with detailed 3D layout model sequencing studies. The focus of this paper is project development, multi-discipline design considerations, and implementation results.

Jan 1, 2014

By J. W. McCammon

WHEN times are booming and metal prices are high, most mining men pay little attention to the industrial mineral industry. However, when metal prices drop and mines close down, many mining eyes begin to scan the less glamorous non-metallic field. For some this proves a temporary diversion, but others find this branch of mining, with its generally more stable conditions, to their liking and enter it permanently. The resulting gradual influx of trained mining men into the industrial mineral industry ?has been one of several factors responsible for the rise in production of non-metallic materials in our Province. Another and ?perhaps the most important factor influencing the production of industrial minerals has been the growth in the population of British Columbia. Because most industrial minerals .are low priced and either heavy or bulky commodities they are normally sold on relatively local markets. Thus the extent of the development of the industrial mineral industry of a region is largely governed by the size of the population and the level of industrialization of that region. This point is well shown by com-paring population and industrial mineral production statistics for 1936, 1946, and 1956 (see Figure 1)9. Note that not only has the overall production rate grown with the population increase, but that the per capita production has risen greatly.

Jan 1, 1958

"This paper deals with the reconciliation of open stope performance at Olympic Dam, South Australia, with a focus on stope stability, recovery, and operational aspects of stope reconciliation in relation to the expected or planned stope design. The observed stope performance is inconsistent with the equivalent linear overbreak sloughing criteria for assessing the performance of large open stopes. The aim is to investigate new stope performance criteria using quantitative (overbreak, underbreak, maximum depth of wall failure) and qualitative (stope productivity, observed fragmentation) information that correlates with the observed stope behaviour, providing a process for improving future stope designs.RÉSUMÉ Le présent article traite de la réconciliation de la performance des chambres ouvertes à Olympic Dam, Australie du Sud, en ciblant la stabilité des chambres, la récupération et les aspects opérationnels de la réconciliation des chambres par rapport à la conception attendue ou planifiée des chambres. La performance observée des chambres ne concorde pas avec les critères d’épaisseur équivalente du bris hors profil pour évaluer la performance de grandes chambres ouvertes. L’objectif est d’étudier de nouveaux critères de performance des chambres au moyen de données quantitatives (rupture hors profil, rupture à l’intérieur du profil planifié, profondeur maximale d’effondrement du mur) et qualitatives (productivité de la chambre, fragmentation observée) qui concordent avec le comportement observé des chambres, fournissant ainsi un processus pour améliorer les futures conceptions des chambres."

Jan 1, 2015

By G. V. Lewis

"INTRODUCTORY REMARKS""I believe we need to communicate as much as possible with the industry. I don't think that we should be a body that just goes around doing dust surveys and writing nasty letters. We should get together on these problems and try and solve them as a group. I've only been with the Department a little over 12 months. I haven't visited all of your plants. I've visited most of the major open pits and I have had a chance to observe a lot of problems that you have encountered and a lot of the problems that you have brought up this morning. I thought the best thing I could do is perhaps mention a few of the approaches to the problems that my superior has suggested to me and we have discussed in the Department, and then perhaps go over a few of the evaluating problems and what we are trying to do with our dust surveys and perhaps ways and means of improving the present setup."""

Jan 1, 1976

By J. P. Sairrlon, K. G. Wheeland, K. J. Mintz, B. J. Kiener

Iwenty-one ore dusts of varying mineralogy, sulphur content and reputed in-mine explosibility were selected from eight mines. After chemical and mineralogical analysis and sieving into two size fractions (+45/ -63 microns and -45 microns), these sarrples and seven pure minerals were tested for explosibility in oxygen in a Harbnann chamber. '!he maximum explosion pressures and maximum rates of pressure do not correlate with sulphur content alone; the types of minerals are also .important. Residues were analyzed to check the combustion reactions. Further comparisons between laboratory and mine results are planned to improve predictability.

May 11, 1988

By O. W. Borgeson, D. K. Honsberger, R. T. Bell

The Scully Mine, situated in the Labrador Trough near the Quebec-Labrador boundary, is one of the world's largest continuous ore deposits. This paper outlines the sequence of the mining operations from the planning stages to the delivery of the ore to the crusher at an average rate of 50,000 tons per day, 7 days per week. The principal equipment required to maintain this production rate includes four 12.\1.1-inch rotary drills, seven 8-cu.-yd electric shovels and a fleet of large haulage trucks. Particular attention is given to grade control, programmed by computer, drilling and blasting techniques and operational aspects inherent with open-pit mining in Canada's North.

Jan 1, 1969

By Xuanxue Mo, Kaihui Yang

"Abstract- The Laochang mine, located in the Sanjiang area of southwestern Yunnan Province of China, is a volcanogenic massive Pb-Zn-Cu sulfide deposit. It is hosted by a pyroclastic sequence of Barly Carboniferous age, namely the lower member of the Yiliu Group, which was intruded by syenite and rhyolite porphyry . The volcanic suite is basaltic or basaltic-andesitic in composition, has alkaline affinities, and is associated with the initial rifting along the margin of the Baoshan-Shanstate continental rnicroplate (Yang, 1989). The ores are typically Pb>Zn>Cu in composition, averaging 3.820Jo Pb, 3.51% Zn, from 0.01% to 1.85% Cu (0.107% av.), a high average content of Ag (113 g/t) and recoverable amounts of Au, Tl, Gd, Ga, Ge, In. A massive sulflde zone, in which lenticular and stratiform orebodies are localized in a sulflde-carbonate-silica shale unit or sulfldic tufflte horizon that usually overlies coarse-grained pyroclastic rocks, is underlain by a stringer sulflde zone developed in a subvolcanic intrusion or volcanic sequence. The sulfide mineral assemblages, from the top to the bottom of the deposit, are: realgar + orpiment - galena + sphalerite + pyrite- chalcopyrite + pyrite + pyrrhotite + arsenopyrite. Oxide and sulfate minerais occur rarely in the massive ores. The massive ores are generally fine-grained and banded, but coarse-grained ore, colloform and framboidal texture, and growth-zoned pyrite and sphalerite are common. Sedimentary features such as graded bedding, brecciated and deformed ore clasts, and chaotically emplaced blocks, are well preserved, indicating that the massive orebodies have undergone slumping and dis­ placement. Alteration is weak in the hanging-wall rocks, but strong in the stringer zone. Two dis­ tinctive alteration zones have been identified: the upper zone, characterized by an assemblage of quartz, carbonates, chlorite, albite, zeolite and sericite, and the lower zone containing diopside, trema­ lite, actinolite, gamet, clinozoisite, and epidote.The general features of the Laochang deposit are in accord with the descriptive mode! of VMS deposits (Lydon, 1984). However, it falls into neither the Zn-Cu group nor the Zn-Pb-Cu group chemically (Franklin et al., 1981). The depositional setting of the Laochang deposit is quite different from Cyprus or Besshi-type massive sulfide deposits. Laochang is hosted by alkaline lavas that were erupted in a submarine continental rift. Although some features of the Laochang deposit are similar to those of Kuroko-type deposits, there are remarkable differences in the alteration mineral assemblage, the proportion of ore-forming elements (lead enriched) and the amounts of oxides and sulfates. These suggest corresponding differences in ore fluid composition and the associated ore-forming environment. Thus, the authors suggest that the Laochang deposit may be a distinct type of VMS deposit."

Jan 1, 1993

By J. T. Sims, C. E. Karayannopoulos

Today's rare earth industry is undergoing significant and rapid evolutionary change toward greater reliability and diversity of supply, increased security of supply chains, and better price forecasting. Technology innovation is reducing rare earth production costs while decreasing the impact of producers on the environment. Advances in rare earth material science are reducing the need for relatively scarce heavy rare earths (HREEs) in high-performance neodymium-iron-boron (NdFeB) permanent rare earth magnets and opening the NdFeB magnetic market space for a broader range of downstream applications. Rare earth producers such as Molycorp are increasingly able to offer long-term supply agreements with forward price predictability, something that has not been the case for many years. All of these trends are helping to restore the confidence of customers and other stakeholders in the rare earth space. That increased confidence is likely to bolster global demand for rare earth materials and expand innovative utilization of these remarkable materials.

Jan 1, 2014

By R. C. Beard

"Heap leaching, currently being applied in the treatment of low-grade ores in the south western United States, is shown to have potential for use in north western Ontario. The history and operation of the process are described, and cost comparisons are given.IntroductionHeap leaching is a simple, low-cost method of recovering gold from low-grade ore. Although it is not currently being used in Canada on a production scale, it is being used extensively, and successfully, in the southwestern United States as well as elsewhere in the world. Especially suited for large deposits of very low -grade ore, it also appears to be practical for use on small, high-grade deposits because it avoids the high capital costs of mills. Eveleth (1980) and others suggest that the capital and operating costs required for heap leaching are approximately 20% and 40% respectively of conventional milling methods.Northwestern Ontario is noted for its large number of undeveloped, small, high-grade gold deposits. Although there are a number o f larger and higher-grade deposits in the area as well, it is the relatively small undeveloped deposits which would benefit most from heap leaching, if it could be demonstrated to be a viable extraction method.To assess the significance of these small deposits, the Ontario Ministry of Natural Resources recently commissioned a consultants' study of the gold reserves in certain parts of northwestern Ontario. This report, titled ""Feasibility of Small-Scale Gold Mining in Northwestern Ontario"", by J.N. Neilson and R.C.E. Bray (1981, OGS Open File Report 5332), documents 106 known gold deposits having sufficient information to calculate gold reserves. A total of over 7.8 million tons having a weighted average grade of 0.19 oz of gold per ton were compiled in the proven, probable and possible categories, with an additional 8.2 million tons in the speculative category. Many of these deposits could be mined by open-pit methods."

Jan 1, 1983

By J. A. González-Anaya, F. Nava-Alonso, O. Alonso-González, F. Alvarado-Hernandez, A. Uribe-Salas, C. Jimenez-Velasco

"One of the most common hydrometallurgical methods for precious metal extraction is cyanidation. The effluents of this process may contain relatively high concentrations of copper, zinc and iron, which react with free cyanide to form complexes, adversely affecting the efficiency and the economy of the process.This preliminary work studies the use of the solvent extraction technique to remove copper, zinc and iron cyanide complexes from a synthetic solution similar to that of gold mill effluents, in order to allow the recycling of the solution back to the process. For the extraction of these anions (Cu(CN)2 -, Cu(CN)3 2-, Cu(CN)4 3-, Zn(CN)4 2- and Fe(CN)6 3-), trioctyl methyl ammonium chloride (Aliquat 336) was studied as extractant, using nonylphenol as modifier in the organic phase (iso-octane). The experimental results showed that for a synthetic solution containing 450 mg/L total cyanide, 160 mg/L copper, 50 mg/L zinc and 51 mg/L iron, it is possible to extract the 96% of copper, 91% of zinc and 75% of iron when using 0.011 mol/L of Aliquat 336 (organic/aqueous volume ratio (O/A) =1) in the pH range of 9-10."

Jan 1, 2014

By W. D. Sinclair, R. J. Cathro, E. M. Jensen

"The Cash is one of the largest porphyry copper-molybdenum Deposits found in Yukon to date. It is 80 km northwest of Carmacks, within the unglaciated portion of the Dawson Range, and is associated with the Big Creek fault, an important tectonic feature. Part of the mineralized zone is blanketed by up to 70 m of alluvial drift . The remainder is covered by a relatively thin residual soil layer. The mineralized zone, however, was not detected by conventional stream-sediment sampling because pathfinder elements, such as Cu and Mo, have not been geochemically dispersed into the main drainage system. The deposit was discovered by a combination of soil analysis and inspection of rock fragments from small pits.Twenty widely spaced, shallow drill holes have outlined an areaover 2700 m long and 550 to over 1000m wide that grades more than 0.1% copper equivalent (% CuE = % Cu + (5 x % MoS2)). Two smaller zones grading over 0.4% copper equivalent occur within the larger area. The limits of the widest end of the deposit have not been delineated.The Cash deposit is fairly typical of high-level, calc-alkaline porphyry copper-molydenum occurrrences in the Canadian Cordillera {cf, CIM Special Volume 15) and is representative of most prospects in the Dawson Range. It is associated genetically with a subvolcanic complex of small, irregular stocks and dykes of feldspar porphyry and related breccias of Late Cretaceous age. Copper and molybdenum sulphides occur along fractures, in quartz veinlets and disseminated in feldspar porphyry and in older metasedimentary and intrusive rocks. Higher-grade zones of copper and molybdenum have associated potassic alteration. Phyllic alteration is, in part, superimposed on potassic alteration. Argillic alteration occurs locally.This paper describes the history of the discovery and the geochemical and geophysical characteristics, together .with the regional geology, and the nature and distribution of the host rocks, hypogene mineralization and hydrothermal alteration."

Jan 1, 1981

By M. L. Joy

The heat pipe is a self-contained, passive structure that uses a liquid-vapour fluid cycle to provide high thermal conductance . Through the proper selection of working fluids and container materials, heat pipes have been operated at temperatures ranging from less than -300°F to more than 3,000 °F. The passive nature, high efficiency and configuration flexibility of the heat pipe are presented. The application of McDonnell Douglas Astronautics Company Cryo-Anchor® heat pipes for foundation and support stabilization in permafrost regions is discussed. Using the proven Cryo-Anchor technology base. a proposed application of heat pipes in a cold -region mine ventilation system heat recovery heat exchanger is presented. Information obtained from the development of an air-cooled heat pipe steam condenser provides the technical basis for large -scale heat pipe applications.

Jan 1, 1978

By M. B. McClenaghan

"Abstract- The Ontario Geological Survey completed a regional till sampling project between 1984 and 1988 in the Black River Matheson (BRiM) area of northeastern Ontario. The project was designed to aid mineral exploration in the area by documenting the Quatemary stratigraphy and by providing a database of till geochemistry. This paper summarizes the results from the sonic overburden drilling component of the BRiM project carried out in areas of thick drift (> 5 m). Results from till sampling in areas of thinner drift (<5 m) have been presented in a separate paper. Approximately 1100 till samples were collected from 225 sonic drill holes. For each sample, the non-magnetic heavy mineral (> 3.3 S.G.) and fine (-250 mesh) till fractions were analyzed geochemically and visible gold grains were recovered by panning.Gold and other multielement geochemical data were plotted using proportional symbols to high­ light anomalous areas and to demonstrate how to evaluate and interpret a very large geochemical dataset. Thresholds for identifying anomalous concentrations of Au in till samples, defined using the 95th percentile, are 1500 ppb and 12 ppb for the heavy mineral and fine fractions, respectively. The heavy mineral fraction of older tills and to a lesser extent, Matheson Till, display a number of significant gold anomalies in the study area, which in a few cases, are associated with base metal anomalies. The vertical position of gold anomalies in Matheson and older tills varies from directly on bedrock to several meters above the bedrock surface and can provide information of relative ice transport distances."

Jan 1, 1994

By K. Forsberg, A. Rasmuson, R. Rodriguez Varela, J. Martinez De La Cruz

"This study analyzes the separation of rare earth elements by means of a supported liquid membrane (SLM) with the final objective of recovering REE from an apatite concentrate (Alemrajabi, Forsberg, & Rasmuson, 2015; Mohammadi, Forsberg, Martinez de la Cruz, & Rasmuson, 2015). In this study, the feed phase consists of an aqueous phase containing REE, the membrane phase contains the organic solvent and carrier (D2EHPA and EHEHPA), and the stripping phase is a hydrochloric acid solution. An evaluation of mass fluxes, separation efficiency, and membrane performance is conducted. In order to analyze the suitability of liquid membranes in the extraction of REE, a deeper insight into the mechanisms causing instability is needed. In this study, surface tension is considered as the key factor of Marangoni instabilities and spontaneous emulsification.INTRODUCTIONThe demand of REE and their compounds has increased considerably due to their special physicochemical features that make them crucial elements for numerous high-tech applications, including wind turbines, hybrid cars, mobile phones, and defense technologies. They are also extensively utilized in traditional industries such as nuclear energy, petroleum, metallurgy, agriculture, and textiles (Xie, Zhang, Dreisinger, & Dyole, 2014; Zhang, Wu, Bian, & Zeng, 2014).Solvent extraction is widely used for the separation of REE (Xie et al., 2014; Zhao, Huo, Pan, Li, & Liu, 2014). Di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHEHPA) are two of the most effective extractants for the separation of rare earth elements among organophosphorus extractants (Gupta & Krishnamurthy, 2005). However, the difficulty in stripping loaded D2EHPA extractant, especially for heavy REE, has limited its utilization. Yttrium can be stripped at lower acidities in EHEHPA systems compared to D2EHPA systems (Gupta et al., 2005), but the extraction efficiency is lower. Conventional solvent extraction by mixer-settlers is restricted by its large solvent inventory and loading limits, and suffers from phase disengagement, emulsification, loss of solvent, and flooding problems (Swain, Jeong, Lee, & Lee, 2007). In this context, supported liquid membranes (SLMs) present a potential alternative due to their advantages, being low solvent inventory, process simplicity, low energy and operational costs, great enrichment ratio, and combination of extraction and stripping into one single step. A SLM is a system in which two aqueous phases are separated by an organic liquid membrane suspended in the pores of a porous support by capillary forces. One of the aqueous phases is the feed solution with the solute and the other is the stripping or receiving solution. The solute diffuses through the liquid membrane and then is extracted into the stripping solution (Kislik, 2010)."

Jan 1, 2016

By Trevor R. Ellis

"The valuation of mineral properties in the U.S. is only partially regulated. The regulations which have jurisdiction or impact appear to have such mainly as a consequence of unintended fallout, since the regulations were designed for other purposes. Court case history can also be important. The combined results are a mixture of bad and good, with important lessons to be learned.Since 1981, the Securities and Exchange Commission has prohibited U.S. listed companies from reporting quantitative estimates of mineralization and the value of mineralization, other than proven and probable reserves. This results in the minerals appraiser (valuator) working with a shortage of data in his everyday work, both on the subject property and in sales analysis.Between 1989 and 1995, all 50 states and essentially all Federal agencies adopted the Uniform Standards of Professional Appraisal Practice (USPAP) for real property appraisals (valuations). The major national appraisal societies also require their members to abide by USPAP. A significant portion of minerals appraisals must now follow these standards. This paper will discuss the content of USPAP. It provides a very good framework for the valuation of a minerals property or a mine, both as real property and as a business. However, the credentialing standards for real property appraisers are now prohibitive for minerals appraisers."

Jan 1, 2003