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By D B, M A. Sares, D W. Coulter, D C. Peters

This presentation discusses NASA-funded research on the ability of hyperspectral remote sensing to map diagnostic acid rock drainage (ARD) mineralogy that adversely affects water quality within watershed and to determine the relative contributions of natural ARD sources of metals and acidity to that drainage. Ground-based reflectance spectroscopy, combined with water chemistry, is used to identify mineralogical and chemical variations throughout a watershed. Integrated with hyperspectral data acquired from airborne remote sensing platforms, such as the NASA Airborne Visible Infrared Imaging Spectrometer (AVIRIS) sensor, a methodology has been developed that should improve environmental assessments and tracking of impacts on and from drainages. Phase I of this project focuses on a drainage basin (Lake Creek), tributary to the upper Arkansas River in central Colorado, which is impacted by natural acid rock drainage from areas of high-sulfide hydrothermal alteration. This project builds upon research and inventory efforts by the Colorado Geological Survey (CGS) to identify hydrothermal alteration that is the primary source or is contributing to acidic and toxic drainage in Colorado. This presentation will cover ground and airborne hyperspectral remote sensing techniques and results and water analyses for seasonal high-flow and low-flow conditions in Lake Creek. Identifying correlations between mineralogy, especially mineralogy that can be identified through airborne remote sensing, and water chemistry is a key focus of this project. Of particular interest are low-pH iron phases such as jarosite, ferrihydrite, schwertmannite, copiapite, and transitional amorphous phases as well as AlOH phases from higher, although still acidic, pH environments which are observed to mix with the iron precipitates within the streams draining from the hydrothermal systems. Drainage in the Lake Creek watershed derives from the Grizzly Peak caldera (Oligocene), which exhibits extensive hydrothermal alteration. Alteration types include silicic, quartz-sericite, quartz-sericite-pyrite, advanced argillic, and argillic. By understanding the chemistry of a naturally impacted drainage and its relationship to the surrounding geology, the project goal is to allow more efficient and complete identification of such sources in mineralised terranes through remote sensing technology.

Jan 1, 2003

By N. Hanief

This research involves the investigation of phase transformations in the platinum-chromium coated system. Single-layer 0.1 µm platinum coatings were deposited via electron beam deposition on 99.98 percent pure chromium substrates. Specimens were subjected to systematic heat treatment in a vacuum furnace at 900°C for up to 20 hours. Phase formation and the changes in surface morphology were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM).Both CrPt and Cr3Pt phases are formed during heat treatment for different times at 900°C. Significant changes in the morphology of this coated system were detected after heat treatment at 900°C for 20 hours.

Jan 1, 2012

By Jafar Safarian, Leiv Kolbeinsen, Stian Seim, Hossein Salehi

The present work aims to investigate the link between the oxidation and reduction of a weathered ilmenite concentrate in terms of phase transitions, microstructural changes, and element distribution. An ilmenite concentrate sample was pelletized and fired at 1000 °C in air, and as a result, the pellets were oxidized. The oxidized pellets were reduced by hydrogen gas at 1000 °C, which yielded almost complete metallization of the iron content of the pellets. The ore and the pellets were characterized in each step by XRD and SEM techniques, and distribution of elements and phases were investigated. Ilmenite, pseudorutile, and rutile were the main phases detected in the ilmenite concentrate sample, and depending on the weathering degree of the particles, different fractions of the phases were identified in their microstructure. It was found that irregular rutile grains dispersed in a pseudobrookite matrix is the morphology of the oxidized ilmenite phase. However, increasing microcracks and porosities were the only microstructural changes in the pseudorutile phase after oxidation in air. Studying the specific types of the ore particles and their oxidized and reduced forms indicated that the phase distribution in the ilmenite ore particles dictates the phase distribution in the oxidized and reduced ones. Results show that the morphology of the reduced particles includes a titanium (III) oxide matrix in which reduced iron globules are dispersed.

Feb 8, 2021

By A. Blake Caldwell

Tyrone-a complete mining and concentrating facility built by Phelps Dodge Corp.-straddles the Continental Divide where surface water on either side flows in opposite directions although all water is taken from and returned on the northwest side of the Divide. At the outset, Tyrone was saddled with a problem of an adequate water supply, and the Gila River some 23 miles distant appeared to be the logical source. This in itself presented a major obstacle to Phelps Dodge because of the distance water had to be pumped and because of an adverse head which had to be overcome between the Gila River and the two 4-million-gal-capacity terminal water supply tanks at the mill. Having acquired water rights on the Gila River and in order to control the seasonal fluctuations in water volume, the company built the Bill Evans, off stream, earth-filled dam. This reservoir will contain 2100 acre-ft of water when full and it was constructed by the Hamilton Construction Co. for Phelps Dodge. The dam impounds fresh water for the Tyrone plant's use and four vertical turbine pumps (4500 gpm each) lift the water 275 ft from the Gila River into the reservoir. Since construction, Phelps Dodge has optioned the lake to the New Mexico State Game Commission for recreational purposes. In addition to the lake, land around the reservoir has been optioned to the State Game Commission for public use. The lake has already been stocked with trout and by next summer some keepers should be available for the taking.

Jan 12, 1969

By Craig H. Olson

"A new ship dock at a Philadelphia area refinery will be capable of docking the largest tanker to travel the Delaware River, the Stena V-MAX, which will induce significant lateral loads. The loads at the dock, a system of mooring dolphins and platforms, will be resisted by over 150 pipe piles, including some 20- and 30-in diameter, reinforced, concrete-filled pipe piles and H-piles. Construction included driving the pipe piles to the required ultimate capacity, flushing the pipe pile casing clean of overburden materials, followed by drilling rock sockets into the underlying Wissahickon Formation. The Wissahickon Formation is a complex subsurface that includes variations in depth to bedrock, rock quality, degree of weathering and the presence of very hard quartzite lenses or inclusions. Because of the problematic subsurface, the designers and client requested extensive pile dynamic analysis (PDA) testing by TRC Engineers (TRC).Before beginning, the contractor requested that TRC perform the WEAP (wave equation analysis program) to evaluate the proposed hammer (APE D30-32 open-end diesel) to drive the piles into the proposed bearing strata while maintaining allowable compression stress levels. The WEAP provided a prediction of blow counts and stresses for various ultimate capacities, and showed that for the HP14x89 piles with a required ultimate capacity of 480 kips, a blow count of at least four blows per in at a stroke of 8.0 ft was necessary.New Approachway RampThe PDA testing began at the new dock approachway ramp, parallel to the existing one. The new structure is a 300-ft-long by 21- ft-wide concrete deck supported on seven bents; each has two 24- ft-diameter steel open-ended pipe piles. Every pipe received an HP 14 x 89 x 80-ft pile that was later driven beyond the pipe pile tip to create a composite pile. The pipe piles were later cleaned of overburden materials and finally filled with concrete and rebar. At each bent, a cap was installed on top of each pair of pipe piles, and then a prefabricated concrete deck was added."

Jan 1, 2008

By Craig H. Olson

"Anew ship dock at a Philadelphia area refinery will be capable of docking the largest tanker to travel the Delaware River, the Stena V-MAX, which will induce significant lateral loads. The loads at the dock, a system of mooring dolphins and platforms, will be resisted by over 150 pipe piles, including some 20- and 30-in diameter, reinforced, concrete-filled pipe piles and H-piles. Construction included driving the pipe piles to the required ultimate capacity, flushing the pipe pile casing clean of overburden materials, followed by drilling rock sockets into the underlying Wissahickon Formation. The Wissahickon Formation is a complex subsurface that includes variations in depth to bedrock, rock quality, degree of weathering and the presence of very hard quartzite lenses or inclusions. Because of the problematic subsurface, the designers and client requested extensive pile dynamic analysis (PDA) testing by TRC Engineers (TRC).Before beginning, the contractor requested that TRC perform the WEAP (wave equation analysis program) to evaluate the proposed hammer (APE D30-32 open-end diesel) to drive the piles into the proposed bearing strata while maintaining allowable compression stress levels. The WEAP provided a prediction of blow counts and stresses for various ultimate capacities, and showed that for the HP14x89 piles with a required ultimate capacity of 480 kips, a blow count of at least four blows per in at a stroke of 8.0 ft was necessary. New Approachway RampThe PDA testing began at the new dock approach way ramp, parallel to the existing one. The new structure is a 300-ft-long by 21- ft-wide concrete deck supported on seven bents; each has two 24- ft-diameter steel open-ended pipe piles. Every pipe received an HP 14 x 89 x 80-ft pile that was later driven beyond the pipe pile tip to create a composite pile. The pipe piles were later cleaned of overburden materials and finally filled with concrete and rebar. At each bent, a cap was installed on top of each pair of pipe piles, and then a prefabricated concrete deck was added."

Jan 1, 2008

By Anievas JB, Sevillano AC

This paper describes the acquisition, exploration, development, initial operation and subsequent financing of the Bulawan mine by means of a listing on the Toronto Stock Exchange of a subsidiary of the parent company, Philex Mining Corporation.Located on the island of Negros in the Philippines the property is unique on at least two counts: it is a disseminated gold deposit that occurs in a region of predominantly porphyry copper mineralisation; and it is a gold deposit that is mined by a bulk method of extraction (front and block cave) instead of the normal selective mining methods.

Jan 1, 1997

By Libby R. Ricafort, Nonato S. Retardo, Jose B. Anievas

This paper shows the metallurgical test results that led to the design of the heap leach facilities of Philex Mining Corporation. The design incorporates a water management model as process solution circulation is excessive with high rainfall intensity in the area. This poses problems in the operations requiring stringent controls than would be necessary in a less severe environment. The corporate perspective embraces on environmentally-sound mineral development. A budget is always provided to environmental management making certain that no industrial development is moved forward at the expense of the environment.

Jan 1, 1996

By John A. Haggman

Philippines is a country that is richly endowed in mineral wealth. In 1988, Climax Arimco Mining Corp. (CAMC) geologists found the Dinkidi porphyry gold-copper deposit in Nueva Vizcaya province. It is the most significant mineral discovery in that country in recent times. To date, the company has defined indicated resources of 124 Mt (136 million st) of 1-g/t (0.029-oz/st) gold and 0.4% copper. This includes a high-grade core of 7.9 Mt (8.7 million st) of 6-g/t (0.175-oz/st) gold equivalent. Total contained metal is 124.4 t (4 million oz) of gold and 499 kt (1.1 billion lb) of copper. Dinkidi's discovery resulted from initial geologic reconnaissance and recognition of the intrusive complex that is exposed at surface and anomalous in its topographic expression. This was followed by systematic exploration. This includes extensive gradient array induced polarization (IP), ground magnetics, geochemical sampling and diamond drilling. This later defined a further 16 satellite porphyry targets in the Didipio region. Climax was been granted a Financial and Technical Assistance Agreement contract with the Philippine government. It allows 100% foreign ownership of mining projects. After four years of negotiations, Climax was the first company to have such an application granted. Some 120 applications from numerous international mining companies are waiting for approval following implementation of new Philippine Mining Act of 1995. Exploration history Didipio is located 200 km (125 miles) north of Manila at an elevation of about 700 m (2,300 ft) in the remote Sierra Madre mountains. This region remains mostly unexplored. The property is accessed by 25 km (15 miles) of logging track from the town of Cabarroguis, Quirino. The area experiences an average rainfall of about 3,000 mm (118 in.) a year. Most of it falls during the July-to-November typhoon season. Didipio was first recognized as a gold province in the 1970s when native Ifugao and Ilongot hunters discovered alluvial gold in the region. The region had been prospected over the years by local companies. They were mostly prospecting for alluvial gold. However, in 1988, Climax Mining geologists identified the potential of an obscure razorback ridge protruding from the alluvial valley floor. This ridge, later named Dinkidi by Climax, was the site of several small- scale tunnels. Locals had mined narrow quartz stockwork veining and sluiced soft argillic alteration zones, using irrigation canals and sluice boxes to catch free gold.

Jan 1, 1997

Site specific geotechnical data, deposit characteristics and method of mining are key factors when assessing an appropriate slope design philosophy. Mining geotechnics should be viewed as an iterative design process linked closely with mine planning, development and operational safety constraints. This case study presents geotechnical investigations for slope design at Macraes Flat Gold Mine using kinematic, probabilistic and economic analyses tempered with knowledge of site specific conditions. The recommended designs not only reduce early waste stripping tonnages but also provide data to optimise final walls.

Jan 1, 1992

By A. R. House, G. W. Shepherd

Newmont USA Limited owns and operates the Phoenix Mine near Battle Mountain, Nevada, USA. The existing milling facility has operated since 2006 (House, 2010). Following the startup of the milling operation, and coupled with the upswing in the copper market, Newmont realized that Phoenix had no process option to treat transition and oxide copper ores. This meant that potentially revenue generating ore would be mined as waste. With no system in place to treat the transition and oxide copper, work began to determine the most feasible approach. After evaluating multiple options, the flow sheet was set for a runof- mine (ROM) heap leach pad and solvent extraction/ electrowinning plant (L-SX/EW). This paper will discuss the eight years of successes and challenges with developing the copper L-SX/EW plant and achieving commercial production of copper cathode.

Jan 1, 2014

By Musa Karakus

The sedimentary iron ores of Alsace-Lorraine, France have very high phosphorous contents that average 0.7% and are as much as 2.19% P. Ores from the Tucquegnieux and Joeuf mines have been studied by cathodoluminescence microscopy, X-ray diffraction, scanning electron microscopy, and electron microprobe analysis in order to fully characterize the mineralogy, size, shape, and distribution of the deleterious phosphate grains. The phosphorous occurs as collophane, a carbonate fluorapatite, in ten morphological forms, most abundantly as microcoprolites, but also as intraclasts, concentric layers, and cortices in ooids, phosphate replaced ooids and bioclasts, phosphatiC shells, fossil infillings and internal molds, fish teeth, phosphatiC laminae, and cements between the goethite ooids. About 95% of the phosphate grains are sufficiently large that relatively fine grinding fol'lowed by reverse flotation would be expected to be effective in significantly diminishing the phosphorous content of the concentrates.

Jan 1, 1989

By H. W. Breathitt

World demand for phosphate rock has increased significantly in the past fifteen years. Prior to the early 1960's, most of the world production was obtained from Florida, North Africa, and Kola. As the 1960's arrived, new mines in North Florida and Eastern North Carolina, as well as expanded production in the Western United States, .increased domestic production. Many new mines overseas have also become significant. This includes countries such as Senegal, Togo, Israel, Spanish Sahara, and Jordan. Limited production, often as by-products, has been noted in South Africa, Brazil, and other countries. In recent years, and even recent months, we have learned of many new areas being considered as potential sources of phosphate rock. This includes Australia, Saudi Arabia, Mexico, Colombia, and Brazil. Many other developing countries have discoveries and are considering their new deposits, often with difficult beneficiation problems, as potential sources of phosphate. These factors all relate to expanded world, population and the demand for more fertilizer products to produce food. In this paper, four areas of the world with different types of phosphate deposits are briefly reviewed to contrast the ore beneficiation problems to Florida procedures--long considered the "standard" of the industry, at least for most of the United States' domestic production. Agrico has three large operating mines in Florida with total production capacity exceeding seven million tons per year. Here, pebble phosphate (+14 mesh material) is produced without the use of flotation, whereas all of the material finer than 14 mesh is subjected to flotation beneficiation to upgrade into high grade concentrates.

Jan 1, 1977

By D. H. Lynch

This paper is a general description of current Central Florida phosphate mining, beneficiation and product transportation. It is directed and believed to be of interest to engineers not familiar with this industry.

Jan 1, 1978

By N. Edmonson

An examination of the statistics of the world phosphate fertilizer industry since 1980 reveals an increasing tendency for fertilizer manufacturing activity to concentrate in phosphate rock mining areas. The economic justification for this resource-oriented strategy is clear. The choice between shipping phosphate rock, a comparatively low-value product, and shipping more valuable finished fertilizers will always be resolved in favor of the latter if cost considerations control the decision. The historical existence of substantial phosphate fertilizer manufacturing capacity oriented toward fertilizer-consuming activities and dependent on imported phosphate rock shows that narrow cost considerations have not always determined the industry's location. One is entitled to ask what conditions have changed to precipitate the observed relocations, and how permanent these changes are. These questions are the subject of this investigation.

Jan 1, 1995

By M I. Pownceby, N Karimian, A Frierdich

These may be found with goethite through mechanisms including direct substitution or coprecipitation of nanocrystalline phases. Understanding P incorporation in goethite has significant implications for Australia’s iron ore industry as it lowers their commodity value. The current study tests a novel low-temperature technique to extract P impurities from synthetic goethite phases under O2-free ambient conditions by utilising Fe(II)-catalysed recrystallisation. The objective of this study was to examine the effect of the Fe(II)-catalysed recrystallisation of goethite on the geochemical behaviour (mobility and speciation) of co-associated P. To achieve this, we tracked changes in labile P (aqueous and 1M NaOH extractable) concentrations over time in goethite suspensions which were reacted with Fe(II)aq for 14 days under circumneutral pH conditions and room temperature conditions. Temporal changes in Fe mineralogy were investigated via synchrotron-based X-ray absorption spectroscopy. Iron K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy confirmed goethite as the only mineral phase in P-free treatments while goethite (~86 per cent) and feroxyhyte (~14 per cent) were the main phases in 1.0 per cent P-containing treatments after a 14- day reaction with Fe(II)aq. According to our findings, the treatment of P-goethite with Fe(II) for a duration of 7–14 days, followed by a 24-hour extraction of the reacted solids using 1M NaOH, results in the removal of approximately 79.5 per cent of the initial P content. This removal encompasses both the aqueous fraction (~4.5 per cent) and the surface adsorbed fraction (~75 per cent) from the 1 per cent P-bearing mineral phase. Notably, this approach demonstrates an improvement in P extractability, with approximately a 10 per cent increase compared to the 1 per cent P-goethite sample that was not reacted with Fe(II).

Sep 18, 2023

By E K. Chiw, S-M Jung, S M. Masuka, ika

The world reserves of high-grade iron ore have depleted necessitating the need to utilise any existing natural iron ore deposits to meet the demands of the world’s expanding economy using hydrogen in the reduction process to curb CO2 emission. These low-grade ores include iron ores with high phosphorus content. The thermodynamic conditions in the blast furnace allow for the reduction of phosphorus that readily dissolves into the molten iron. Phosphorus in the gaseous state readily dissolves into the molten iron and therefore must be removed due to its negative influence on the mechanical properties of steel. The removal of phosphorus from molten iron is difficult causing the phosphorus to concentrate in metallic iron. The aim of this study is to provide basic knowledge on the phosphorus distribution after reduction using the CO-H2 and possibly provide the optimum conditions for phosphorus partitioning into slag, increasing the probability of its removal by magnetic separation. Total porosity, pore size distribution and surface area of the pellets used were measured using a mercury pressure porosimeter. The reduction was carried out using thermogravimetric analyses (TGA). The reduction rate increased with increasing H2 and was highest when 100 per cent H2 was used. Metal elements distribution in the reduced pellet was clarified using electron probe microanalysis (EPMA) and showed that phosphorus was distributed in the same areas as Ca. More phosphorus was concentrated in slag when 50 per cent CO–50 per cent H2 was used, increasing the probability of dephosphorization using magnetic separation. The concentration of phosphorus into slag was related to the rate of reduction. Further investigations into the reduction kinetics of this ore by CO-H2 is suggested to validate these findings. Nevertheless, a comprehensive thermodynamic analysis of the reduction of phosphorus containing phases found in iron ore with carbon, CO and H2 was provided to assist in selecting the optimal reduction experimental conditions.

Sep 18, 2023

As reported in Drift last month demolition of old buildings on the 47th St. site has been completed, and detailed plans and studies for the new structure are well underway. As this issue was being sent to press the $5 million industry- business phase of the fund campaign had passed the half- way mark toward its goal. Target date for the building program is 1960.

Jan 5, 1958

By Michael Bowker

Au/TiO2 catalysts were prepared by incipient wetness impregnation and tested for the room temperature photocatalytic reforming of methanol in aqueous solution. These catalysts proved to be more active, on a molar basis, than Pd/TiO2. The dependence on loading of gold was different from that of palladium, showing a double maximum in yield at 0.1 and 2 wt. % with low rate below 0.01% and above 10%. A model is proposed for the reaction involving band gap excitation of titania electrons which are used to oxidise the methanol via adsorbed CO. With palladium, photoreforming of CO and water can be achieved, but this is much less effective on gold, presumably due to the much weaker bonding of CO on Au.

Oct 1, 2003

By Junhong Noh, Kug Sun Hong, Jung-Kun Lee, Bo Ding

"The photocatalytic splitting of water into H2 and O2 by oxide nanoparticles has received much attention. However, the full potential of photo-catalysts for efficient hydrogen generation out of water has not been fully realized yet due to unresolved limitations including the low electrical conductivity and ineffective carrier extraction. Here, we report composite oxide materials consisting of 1-dimensional (1-D) transparent conducting oxide (TCO) core and TiO2 shell. Highly conductive ITO nanowires were grown on a flexible SUS mesh as a core component. The photoelectrodes consisting of these 1-D nanocomposites have increased carrier mobility due to the TCO core, while the TiO2 shell provides the photocatalytic functionalities. In addition, the built-in-potential at the interface between TCO core and the TiO2 shell improves the collection of charge carriers from TiO2 to TCO. These factors altogether contribute to increasing the photocurrent of the device under light.I. IntroductionPhotocatalytic behavior of semicondcutors has been extensively explored since it was discovered in TiO2 in 197Os. When TiO2 is exposed to UV light, the light is absorbed and electron/hole pairs are generated in the conduction and valeence bands. Holes in valence band will oxide/mineralize pollutant target directly or indirectly (via mediator hydroxyl radical). If the adsorbed A is O 2, O 2 will react with electron from conduction band to generate hydroxyl radical as described in the second set ofreactions. The photocatalytic reaction is schematically explained in Figure 1.Photoelectrochemical (PEC) cells using the photocatalytic reaction have attracted emerging interest as a potential route to convert solar radiation into useful forms of energy by reaction such as water splitting to generate hydrogen1 or the reduction of carbon dioxide.2 Another application ofphotocatalysis is water splitting and CO2 reduction, both of which utilize the electrons that are optically excited to the conduction band. 3•4 For this purpose, the conduction level of the semiconductor should be higher than hydrogen production level (EHZ1HZO) while the valence band should be lower than water oxidation level (Eo21112O). Electrons and holes will be generated on the semiconductor site, and holes generate O 2 at semiconductor site, while electrons will migrate to counter electrode to execute reduction forming H2. In addition to that, materials should be chemically stable to resist photocorrosion and have long lifetime of electron/hole pairs. TiO2 is a suitable material from the viewpoint of band arrangement and chemical stability requirement"

Jan 1, 2012