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Of the world's total production of gold the largest proportion comes from the more regularly consistent ore bodies, but in the aggregate an important part comes from those which are often irregular, uncertain and small. These smaller ore bodies are often high in grade and, as the capital required to work them is not large, they appeal to people seeking a quick and profitable return for a small outlay.These small mining concerns cannot afford detailed geological and petrological investigations and mapping, so they are very often dependent on local knowledge and experience which admittedly may be of really great value.Nevertheless the absence of skilled guidance may not only cause good opportunities for intelligent exploration to be lost, but discourage the seach for other ore bodies.lVIining engineers in the course of their travels in the examination of mines often come across such cases and also others where problems of finding lost ore bodies have been solved by the man on the spot. As records of cases are valuable and useful additions to the knowledge of ore occurrences, the writer now proposes to describe one such case coming under his observation in recent years.It is that of a small mine, known as the Idaho, at the southern end of the famous "Golden Mile" at Kalgoorlie (see Fig. 1). This mine has been a small and very erratic producer ever since it was abandoned by an English company which owned it forty years ago. Except for one period of four years it has always been owned and worked by parties of co-operative miners and during its time has gone through a tortuous career. Although it has often...

Jan 1, 1938

By J. H. . MORGAN

Talc-soapstone deposits exist in Patton Township of Quebec and have been mined by Bakertalc Inc. or its predecessors since 1938. The company produces products ranging from purified and micronized talc through to soapstone lumps. The deposits are found within serpentinite dykes and are zoned. Zoning grades from a serpentine core through zones of talcmagnesite, schistose talc and talc-chlorite schist be/ ore reaching the wall rock of quartz-sericite-chlorite schist. Talcmagnesite zones generally comprise 80 to 90% of the mined rock. The serpentinite dykes containing the talc probably were originally post-Ordovician peridotite of the same series that hosts the Eastern Townships asbestos deposits. Alteration of serpentine to talc-soapstone and magnesite apparently resulted through addition of silica and carbon dioxide along shears and fractures. Talc concentrations occur also at the intrusive contact between dykes and wall rock. The present Bakertalc Inc. operation at the Van Reel Mine is being worked from an inclined shaft 200 m below surface. The talc rock undergoes a variety of milling processes, depending on its particular market, be/ ore being bagged and shipped.

Jan 1, 1984

By Stephen Utter

This report summarizes the results of preliminary investigations concerning the influence of block caving mining upon adjacent mine openings and discusses possible methods for reducing critical rock pressures and damage to these openings. These investigations are one part of a general study of the rock mechanics of block caving by the Denver Mining Research Center of the Federal Bureau of Mines. The purpose of this part of the study Is to obtain an estimate of the stress concentrations around mine openings adjacent to block caving stopes for use in developing better designed openings and improving mining methods. When mine openings such as slusher drifts, grizzly drifts, and haulage drifts are damaged by rock pressures induced by block caving mining, the mining cost increases, mine production decreases, and ore recovery may be consider- ably lessened. Methods of mining that result in lower rock pressures and methods of design that enable mine openings to withstand these pressures are desirable. The development of these methods, in turn, requires a fuller understanding of the following: The stres concentrations around the mine openings and the changes in stress induced by adjacent mining; the physical properties, such as the compressive strength and modulus of elasticity of the rock surrounding the openings; and the support supplied by the concrete lining, timber sets, or other types of supports used in the openings.

Jan 1, 1962

By A. Kamali Moaveni, A. Boehm

"The current research study addresses a physical separation process of basic oxygen furnace slag “BOF-Slag” (also called Linz-Donawitz “LD” slag) for the removal of phosphorous. In order to recycle the LD-Slag into the steelmaking process, the physical dephosphorization methods are considered. The systematic geometallurgical investigation carried out on particle classes of decreasing size, which were further subdivided into susceptibility classes, shows intimate intergrowth beyond 40 µm due to slag´s fast cooling rate. Generally, LD-slag is constituted of oxide and silicate phases, among which di-calcium silicate “C2S” dominates. About 0.5 mass% of phosphorous was detected in the LD- slag, which is exclusively situated in the lattice of the C2S. The comparatively high grinding resistance (Rittinger index 12.9 cm²/J) of the LD-slag reflects the energy demand to liberate the phosphorous carrying phase from the iron containing minerals, while separation efficiency decreases in the very fine particle size range. Hence, the conversion of the phase intergrowth pattern was considered alternatively to re-build the mineral phase structure of the material to a separable interlock pattern. Carbon dioxide, as the most convenient substance in the steelmaking plants, was applied to digest the C2S in the presence of water and to reduce the basicity of the slag slurry. As a result of C2S-CO2 chemical reaction, calcite and calcium silicate are precipitated at the surface of the oxide particles and carried between 25% and 75% of the total phosphorous, respectively. Accordingly, the mobility of the phosphorous content phase to the top of the grains serves the possibility to separate the precipitated layer by mechanical attrition process. This paper is focused on the impact of the intergrowth pattern alteration on the slag´s separability characteristics. Moreover, the operating conditions of the carbonization process, such as temperature and pressure, on the deconstruction kinetics of the C2S and the generated products will be considered. INTRODUCTION The steelmaking BOF-Slag is a stony aggregate waste from the steel manufacturing process. The investigated slag by the current research work was provided by voestalpine steelmaking plant in Linz, Austria. The current legislative situation in Austria restricts the historical application of slag as construction material, due to the high level of heavy metals content and corresponded land-filling and transportation costs of slag, therefore the demand for recycling of BOF-Slag to the steelmaking process has raised, as an alternative application. Statistically, voestalpine steelmaking plant produces about 130 kg BOF-Slag per ton of final steel product, which serves annual BOF-Slag production of 700,000 ton, approximately."

Jan 1, 2018

By Esko O. Nermes

Outokumpu flash smelting of copper concentrates was introduced in 1949 and flash smelting of nickel concentrates in 1959, both at Harjavalta in southwest Finland. The first flash smelter outside Finland was started up in 1956 in Ashio, Japan. Between 1956 and the present about 25 flash smelters for copper, and nickel concentrates have been put into operation in different parts of the world. Outokumpu"s research organization has been highly involved in the development of flash smelting. For example, a direct blister flash smelting process was developed in 1975 and introduced in Glogów, Poland, in 1978, and another has been designed for Zaire. This straight metal process is based on low iron content of the concentrate, which reduces the amount of recycling slag copper. Additionally, the concentrates are rather low in impurities.

Jan 1, 1982

By Leonello Sciacca

Deepening of harbours has become a priority, necessary to the ongoing operation of the wharves in the face of deeper draft merchant vessels and cruise ships. It is now standard practice in many areas to provide for harbours to be dredged to significant depths below mean sea level, in the order of 12.00 m (39 ft) for existing berths and 15.00 m (49 ft) for new wharf construction. The Ravenna Port Authority initiated a project to deepen the harbour bottom at selected wharves to a depth of 12.00 m (39 ft). In preference to reconstruction of the wharves with longer and heavier sheet piling or other equally disruptive reconstruction, they identified the structural reinforcement of the existing wharves by means of deep underwater tie rods as a possible alternative cost-effective solution. Having defined the design concept, effort was concentrated on developing the required technology. A technique, already in use for the installation of tie rods by means of robotics, was identified as potentially suitable for underwater use. It was decided to carry out the fine tuning and the evolution of the technology for a marine environment of the robot unit and of the related remote control software that controls the installation of the tie rods. An experimental test site was set up to refine the drilling, installation, grouting, monitoring and testing of underwater tie rods. The purpose was to confirm the feasibility of the proposed solution and the reliability of these tie rods for use in the reinforcement and construction of wharves. The paper also discusses the theoretical and experimental study of underwater tie rods dealing with the theoretical analysis of the interaction between tie rod and soil, aimed at identifying the correlation between the forces of applied traction and the corresponding measured elongations. A series of tests were carried out with positive results, both at the operating load of 300 kN (67 kips) and at the nominal maximum load of 630 kN (142 kips). The tests were carried out on seven tie rods, of which three were installed at a depth of 5.00 m (16 ft), principally to test the reliability of the operating and remote control systems in the presence of a significant hydrostatic pressure, and four were placed at a depth of 8.00 m (26 ft) to check the load bearing capability of the tie rods positioned at the depth called for by the current project.

Jan 1, 2011

By J. O. Lewis

The operation of gas-condensate fields is comparatively new and involves physical principles with which the industry was not prcviously familiar. It has been necessary to devise methods for testing gas-condensate wells and to correlate laboratory and field data. In this paper new methods are advanced for interpreting well G.P.M.† tests whereby dilution by dry gas can be estimated and information supplied on revaporization of condensates by dry gas. Inaccuracies in well test data are discussed. Changes in flow rates can cause changes in the G.P.M. of the effluent and it may take some time for a well to become stabilized after an important change in flow rate. Retrograde tests as usually conducted cannot be directly compared with field G.P.M. data, because the retrograde tests usually include solution gas in the condensates, which are reported On the cumulative basis whereas field data (G.P.M.) usually report pentaneS PlUS on a rate or instantaneous basis. Introduction Though long known to physicists, the phenomena Of retrograde condensation became known to the oil and gas industry Only in recent years, when deeper drilling disclosed that the behavior of vapors under changing pressures was different in high-pressure reservoirs than under the low-pressure operations with which the industry was familiar. These deep, high-pressure reservoirs in which condensation and vaporization behaved inversely to the accustomed manner became known as "gas-distillate," or preferably "gas-condensate" fields. Partly to prevent precipitation and retention of liquids in the reservoir, but still more to prevent the waste of residue gas, the operation known as "recycling," or preferably "cycling," was instituted, in which the residue gas is reinjected into the reservoir, thus maintaining pressure and driving the wet gas to the producing wells. For lack of field experience to serve as a guide, the industry had to assume that theory and laboratory experiments could accurately forecast retrograde behaviors in operating these gas-condensate fields, but it is obvious that these assumptions should be checked at the first opportunities against actual field experience. To make such checks, it is necessary to accumulate a large quantity of reliable field data, but experience has shown that it is difficult to obtain reliable field data and that the laboratory data as usually presented are not in directly comparable form. The problems of correlation involve the complex phase behavior on the one hand, and a knowledge of field data and a visualization of underground conditions on the other hand. This paper is an approach from field experience, The purposes of this article are to discuss the sources of uncertainty in the data and to present methods of analyzing, interpreting and correlating laboratory and field data. Data mostly from lower Gulf Coast fields are presented, from which some conclusions can be derived, but better data from more sources than those available to the writer will be required before satisfactory answers to many questions can be obtained. This paper is presented to stimulate the analysis and publication of data from other fields, the reexamination of field and laboratory methods, and the taking of more complete and reliable field tests. For these purposes, the writer presents some speculations that otherwise would not be appropriate.

Jan 1, 1947

By J. O. Lewis

The operation of gas-condensate fields is comparatively new and involves physical principles with which the industry was not prcviously familiar. It has been necessary to devise methods for testing gas-condensate wells and to correlate laboratory and field data. In this paper new methods are advanced for interpreting well G.P.M.† tests whereby dilution by dry gas can be estimated and information supplied on revaporization of condensates by dry gas. Inaccuracies in well test data are discussed. Changes in flow rates can cause changes in the G.P.M. of the effluent and it may take some time for a well to become stabilized after an important change in flow rate. Retrograde tests as usually conducted cannot be directly compared with field G.P.M. data, because the retrograde tests usually include solution gas in the condensates, which are reported On the cumulative basis whereas field data (G.P.M.) usually report pentaneS PlUS on a rate or instantaneous basis. Introduction Though long known to physicists, the phenomena Of retrograde condensation became known to the oil and gas industry Only in recent years, when deeper drilling disclosed that the behavior of vapors under changing pressures was different in high-pressure reservoirs than under the low-pressure operations with which the industry was familiar. These deep, high-pressure reservoirs in which condensation and vaporization behaved inversely to the accustomed manner became known as "gas-distillate," or preferably "gas-condensate" fields. Partly to prevent precipitation and retention of liquids in the reservoir, but still more to prevent the waste of residue gas, the operation known as "recycling," or preferably "cycling," was instituted, in which the residue gas is reinjected into the reservoir, thus maintaining pressure and driving the wet gas to the producing wells. For lack of field experience to serve as a guide, the industry had to assume that theory and laboratory experiments could accurately forecast retrograde behaviors in operating these gas-condensate fields, but it is obvious that these assumptions should be checked at the first opportunities against actual field experience. To make such checks, it is necessary to accumulate a large quantity of reliable field data, but experience has shown that it is difficult to obtain reliable field data and that the laboratory data as usually presented are not in directly comparable form. The problems of correlation involve the complex phase behavior on the one hand, and a knowledge of field data and a visualization of underground conditions on the other hand. This paper is an approach from field experience, The purposes of this article are to discuss the sources of uncertainty in the data and to present methods of analyzing, interpreting and correlating laboratory and field data. Data mostly from lower Gulf Coast fields are presented, from which some conclusions can be derived, but better data from more sources than those available to the writer will be required before satisfactory answers to many questions can be obtained. This paper is presented to stimulate the analysis and publication of data from other fields, the reexamination of field and laboratory methods, and the taking of more complete and reliable field tests. For these purposes, the writer presents some speculations that otherwise would not be appropriate.

Jan 1, 1947

By Y. F. Jiang, K. Fang, Q. Q. Jiang, Q. Wu

Inter formational sliding of bedding planes between two different rock types in Badong formation is an important reason that leads to the instability and fracture of rock mass in this stratum. There are no specific research achievements on bedding planes between two different rock types in Badong formation. In order to study the shear mechanical properties of bedding planes between two different rock types. This paper using the software of particle flow code (PFC) and JRC model to establish several typical structures of different roughness coefficient of surface morphology based on the laboratory tests on silty mudstone and marlite in Badong formation. A great deal of numerical shear tests were carried out by ball production, radius expansion and servo infliction. The research results are as follows: First, shear strength of Badong formation is found to vary between that of silty mudstone and marlite isotropic planes by analyzing shear strength of the homogenous bedding planes and inhomogeneous rock types, we can find that the shearing strength in Badong formation is between silty mudstone and marlite isotropic planes and which is closer to the shearing strength of silty mudstone isotropic planes. Second, the basical friction angle of bedding planes between two different rock types in Badong formation is between silty mudstone and marlite isotropic planes and which is closer to the basical friction angle of silty mudstone between isotropic planes. Third, based on the experimental results, an expression is obtained to describe the relationship of the ratio of shearing strength between bedding planes of two different rock types and isotropic planes in soft rock, the rock combination coefficient, and the roughness coefficient. This study has important significance for further research on the shear mechanical properties of bedding planes between two different rock types.

Jan 1, 2015

By W. C. Yates

Lack of visibility from large, open-pit haulage truck cabs has become a serious safety problem. Anaconda conducted a research program to develop a low cost system to alert haulage truck operators to small vehicles present in blind areas. Several systems were developed and tested. As open-pit haulage truck size has increased, so has the size of the blind areas. Mine utility vehicles, pickup trucks, and cars are concealed within these blind areas and become safety hazards. Figure 1 shows the typical blind areas of a 136 t (150-ton) haulage truck. The areas of greatest concern are at the rear center and front right corner of the truck. In these "no visibility" areas many small vehicles have been crushed by large haulage trucks at various mine sites. In most instances, the occupants escaped the vehicle before it was destroyed. But injuries and death have occurred. In most cases, the accidents were attributed to negligence or carelessness by the small vehicle driver. The limited visibility problem still exists, though, and a solution is needed. Initial Solution The usual plane mirror on the driver's side and the convex mirror on the right front of the haulage truck allow only limited rear visibility. The typical, right side convex mirror is generally small and difficult to locate at a glance. This convex mirror also presents an image that distorts distance perception. These mirrors are of¬ten broken and immediate replacement not demanded or made. The US Bureau of Mines, in a contract with M.B. Associates, San Ramon, CA, developed an improved visibility system. It consisted of a larger, left view mirror and unique, blind area viewer. The large 230 x 690 mm (9 x 27 in.) left mirror has a small convex spot mirror near the bottom. The entire unit can be quickly replaced if broken. The large size provides a full view of driver orientation features such as the rear tire and the top of the load bed. The right 300 x 410 mm (12 x 16 in.) mirror has a convex surface and is quite rugged. The 510 mm (20 in.) spherical radius presents the operator with some distance distortion, but objects in its view are easily seen. The "blind area viewer" consists of a modified fresnel lens that allows the driver to "look around the corner." Installation of three of these lenses on the front of each haulage truck is rec¬ommended for adequate blind area coverage. This system significantly increases an operator's field of view and allows viewing of objects within about 3 m (9.8 ft of the truck. Many open-pit mines are nor mounting on smaller vehicles a long whip with a flag and lamp or both. This increases vehicle visibility to haulage truck operators. The whip is permanently attached to the mine vehicle. It can also be magnetically attached to transient vehicles. The whip system. though, is inadequate for visibility in the critical rear and right front blind areas. Alternate Solutions All of these visibility aids as¬sume an attentive driver. In addi¬tion, areas such as the rear blinc, area are not covered. Based on the inadequacy of existing visibility systems, Anaconda made a com mitment to further the truck de¬tection technology. The best ap¬proach was considered to be ar active system. It would notify the haulage truck operator that an en¬croaching vehicle is present. Sev¬eral systems were considered, in¬cluding ultrasonics and elec¬tromagnetics. For the ultrasonic system, com mercial and in-house design were looked at. Designing an( building transducers with the spe cific beam shape to match the haulage truck blind spots re¬quired a major technological breakthrough. False alarms ap¬peared difficult to prevent en¬tirely. They were caused by pass¬ing, trailing, or leading vehicles a., well as nonthreatening objects. As a result of these problems, the ul¬trasonic technique was not pur sued. An alternative, an electro

Jan 7, 1982

By S. B. Bealko

In response to recent mining disasters and new mine rescue team legislation, NIOSH researchers conducted meetings across the United States with mine emergency response experts to investigate current needs and issues. Some of the issues include emergency response preparedness, mine rescue contests, real-life training capabilities, and training facilities. Many new teams are being formed that must be trained for mine rescue team competitions as well as be ready to respond to a variety of mine emergencies including a fire or explosion, a massive roof collapse, mine inundations, or vertical shaft rescue situations. Therefore, it is important that these teams are adequately prepared and trained. This paper presents a summary of domestic and international coal mine rescue training facilities and identifies those that provide unique, real-life, and/or state-of-the-art training. Research findings from this report will be used in further NIOSH investigations to improve coal mine rescue training. DISCLAIMER: The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

Jan 1, 2009

By A. House

Newmont Mining Corporation owns and operates the Phoenix Mine near Battle Mountain, Nevada, USA. The existing milling facility has operated since 2006. Following the startup of the milling operation, and coupled with the upswing in the copper market, Newmont realized that Phoenix needed a process option to treat lowgrade transition and oxide copper ores. This meant that potentially revenue generating ore was being 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 run-of-mine (ROM) heap leach pad and solvent extraction/electrowinning plant (L-SX/EW). This paper will discuss the synergies and challenges of developing a copper L-SX/EW plant at the Phoenix copper-gold mill.

Jan 1, 2010

By M. Sadegh Safarzadeh, Stanley M. Howard

The two-dimensional predominance area (Kellogg) diagram (PAD) surfaces bounding the three-dimensional Cu-As-S-O system were constructed at 900 K. The computations employed gases As4O6(g), O2(g), and SO2(g) as the independent coordinate species to generate diagrams of As4O6(g) − O2(g),O2(g) − SO2(g), and As4O6(g) − SO2(g), while the third gas (As4O6, O2, or SO2) was fixed. The results indicate that there is no shared boundary between enargite (Cu3AsS4) and copper sulfate (CuSO4); however, at PO2 < 10−6 atm, PAs4O6 < 10−10 atm, and PSO2 > 10−4 atm, CuSO4 is the stable phase at 900 K. The chemical driving force for oxidation of intermediate phases between enargite and copper sulfate is substantial except for basic sulfate (CuO · CuSO4).

By D. Farrish, W. A. Grell

"IntroductionMost base metal mines sell their concentrate to a custom smelter. The two parties concerned therefore draw up a contract which would detail the conditions under which concentrate sales will take place. The contract will identify treatment and marketing charges (including escalations), deductions for metal losses in the smelter, pricing formula, timing of payments, penalties for deleterious elements, etc.An understanding of the smelter contract is important to the mineral processor, for it will determine how he operates the plant to maximize economic return.Description of Contract ClausesUsing copper concentrate as an example, the smelter contract generally contains the following three basic charges:I. Metal Deductions- as the smelting process does not recover all the metal contained;2. A Smelting Charge- expressed per ton of material to cover costs on the bulk material such as receiving, unloading, thawing in winter, sampling, roasting to drive off sulphur, smelting through the matte and blister stages to recover mostof the copper and precious metals;3. A Refining Charge- expressed per pound of copper.The following is a review in some detail of a number of clauses which could be considered typical of a treatment and marketing type of copper concentrate sales contract. Most normal considerations in an agreement could be covered by the following types of clauses.Terminology- covers definitions, units of measurement to be used (e.g. short tons, troy ounces, etc.), currency (Canadian dollars). The term ""unit"" may be defined - l OJo of a ton of concentrate, e.g. one unit of copper means 20 pounds of copper per short ton of concentrate."

Jan 1, 1989

By Gus Van Weert

The cost of oxygen is a major and common factor in the hydrometallurgical processes developed or proposed tor the oxidation of refractory pyrites. This cost involves charges for the generation and the transfer of the 02 to the mineral slurry. Bio-oxidation faces considerable design demands which require large scale equipment to be resolved. Nitric acid assisted oxidation offers low cost oxygen units; this method of pyrite oxidation deserves a closer look for large scale plants treating pyritic gold ores and concentrates.

Jan 1, 1990

By F. Chiesa, Jeremy Carignan, B. Duchesne, D. Levasseur

"Aluminium A206 (AlCu4) is one of the strongest aluminium casting alloys with tensile properties approaching those of ferritic ductile iron. If the specification on the silicon content (< 0.05%) is easy to achieve during alloy ingot production, it is not the case in a foundry, where returns are used which are not perfectly cleaned from the silicate containing molding sand (Olivine). In alloy A206, the Si content is controlled in order to avoid the formation of a low melting point intermetallic phase (such as phase Q Al5Cu2Si6Mg2); these phases will melt during the solutionizing heat treatment to which alloy A206 must be subjected to develop its outstanding mechanical properties. This incipient melting may deteriorate the mechanical properties of Alloy A206 if the solutionizing treatment is applied at the standard temperature of 530°C.In the present study, a lower temperature solutionizing (520°C) was applied to a high Si content 206 alloy in order to reduce or eliminate the possible incipient melting. This was carried out on a complex shape industrial casting weighing 14 kg (31 lb) and 560x410x250 mm (22x16x10”) in size poured in aluminum 206 with a high silicon content (0.22% vs 0.05% max for alloy A206). Twenty ASTM E8 subsize tensile specimens were excised from two locations in the casting in order to compare the tensile properties for the two solutionizing temperature used (530 and 520°C). Optical and SEM microscopy allowed to investigate the causes of the differences in the properties observed between the 2 zones of the casting studied for 3 different heat treatments. INTRODUCTIONIn spite of their “textbook” outstanding mechanical properties (Up to twice the strength and elongation of the widely used A356 alloy), aluminum-copper alloys of the 2xx series are seldom used because of their propensity for hot tearing [Li, 2011], the segregation of copper [Cho, 2003], and their sensitivity to stress corrosion cracking [Jean, 2009, p. 113)]. Also, because of their wide freezing range and high thermal conductivity, a wide mushy zone makes feeding difficult, unless strong temperature gradients are created by liberal use of chills and risers in the critical zones of the part. Because they are prone to hot tearing, grain refining of Al-Cu alloys is particularly important, titanium playing a major role in the process [Sigworth, 2003]; grain refining has also been shown to be beneficial to fatigue strength [Jean, 2009, p. 103]. The practical basis of foundry practices pertaining to these alloys is outlined in an AFS webinar [Weiss, 2014]."

Jan 1, 2016

By Morgan NeSmith

The Port of Palm Beach is a full-service landlord port in Riviera Beach, Florida. The port and its tenants process more than $14 billion in commodities. About 80% of these are exports, which makes the Port of Palm Beach one of only 16 "Export Ports" in the U.S. More than 2.5 million tons of cargo move through the port every year. Ozinga, a fourth-generation family- owned construction materials company, has supplied ready-mix concrete for commercial, residential, public works, landscaping and excavation projects from several of its Florida locations. It planned to build a one-of-a-kind cement storage facility to receive and store international ship- ments of cement for transport to other facilities for the production of ready- mix concrete. Dome Technology, of Idaho Falls, Idaho, designed and constructed the 125 ft (38 m) diameter storage facility. The design and working volume of cement for the facility was just under 27,000 cu ft (765 m3). The design loads required to be supported by the foundation system are shown in this table:

Apr 1, 2023

By H. DeWitt Smith

THE mine operated by the United Verde Copper Co. is situated near Jerome, Ariz., on the eastern flank of the Black Hills, at an elevation of approximately 5500 ft. (1676 m.) above sea level. The mine and the town of Jerome are located on a steep hillside, which slopes rapidly to the valley of the Verde River. The smelter town of Clarkdale is situated in the Verde valley 4.1 mi. (6.5 km.) distant in an air line from Jerome, and at an elevation of 3560 ft. The two towns are connected by the standard-gage railroad of the Verde Tunnel & Smelter R. R., a subsidiary of the United Verde Copper Co. This road is 11 mi. long and has a compensated 4 per cent. grade. At Clarkdale, it connects with the Verde Valley branch of the Santa Fe R. R. The narrow-gage (36-in.) line of the United Verde & Pacific Ry. was, until 1919, Jerome&apos;s only rail connection with a main trunk line. This road connects with a branch line of the Santa Fe system at Jerome Junction, after traversing 26 mi. of mountainous country. From the time of its location, in 1876, until its purchase by Senator W. A. Clark, of Montana, in 1889, the United Verde mine was worked on a small scale and shipments of high-grade gold-silver ore were made from the surface workings. Until 1894, when the narrow-gage railroad to

Jan 8, 1920

By B. Q. By

TiO2 is an ideal material for catalytic technology due to its unique properties. In this paper, Sm3+ doped TiO2 photo-catalyst was developed to improve the efficiency of TiO2 and to use the natural light as irradiation source, which was made from Titanium Tetrabutoxide and Samarium Oxide with the Sol-Gel process. The Sm3+-TiO2 photocatalyst was used to degrade reactive orange 4 (RO4) in Azo Dyes. The effects of solution pH, Sm3+ concentration and catalytic time on the degradation rate of RO4 were studied. The characteristics of the catalyst were analyzed with XRD and TEM. The experimental results show that the catalyst has high activity in the degradation of RO4. The Azo bonds of RO4 are active and easily broken by oxidation. The catalytic activity of the Sm3+ doped catalyst greatly depends on the pH of solution. The catalyst has high photo-catalytic activity at both neutral and alkaline conditions. The degradation mechanism of the Sm3+ doped TiO2 photo-catalyst was also discussed.

Jan 1, 2014

By H. Lowers, P. Hageman, S. Diehl, D. Fey

Understanding relationships between mineralogy, texture, microstructural features, and element distribution and residence in minerals, is critical for accurate modeling of mineral weathering in waste-rock piles. The morphology of minerals and deformation structures, such as veins and faults, are important factors that control: (1) fluid access to the mineral surface to initiate dissolution, (2) the distribution of trace elements, and (3) formation of secondary minerals. We characterized the mineralogy, textures, and chemical properties of waste-rock material at three sites at scales ranging from outcrop to micrometer scale. A comprehensive hand-sample to thin-section scale methodology utilizing light microscopy, scanning electron microscopy, electron microprobe, and laser ablation ICP-MS was used to thoroughly characterize the waste-rock material.

Jan 1, 2007