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By S. S. Chabot, S. E. James

A recent survey of major steel companies worldwide revealed the importance of recycling zinc units from electric arc furnace (EAF) dust, mill scale, blast furnace dust and other zinc containing streams within the steel industry. Many processes have been developed and installed in response to this challenge. The most successful approach involves the production of a crude zinc oxide and its sale to primary zinc producers to recover the metal values. The problem with this process is the high concentration of halides in the crude oxide. This type of material cannot be processed directly in an electrolytic zinc plant because of the corrosion problems it will cause in electrolysis. In 1999, Big River Zinc installed a zinc oxide receiving and washing plant to minimize the impact of halides in its electrolysis circuit. A description of the washing plant and the initial operating results are presented in this paper.

Jan 1, 2000

The figures given here were received through the courtesy of the Bataafsche Petroleum Maatschappij and the Standard-Vacuum. There is an increase in production for the year of approximately 4½ million barrels. In November the average production indicated that during the year 1935 the total production would probably exceed 50 rnillion barrels. To maintain this production, only 106 wells were drilled during the year, mainly in South Sumatra.

Jan 1, 1935

By David A. Paul

Over the past several years a great deal of information on blasting vibrations and their effects on structures has been generated. Much of this knowledge has been gained through the use of ground vibration measuring equipment. While this type of information is valuable and gives us great insight into damage that can be incurred by structures from this source, very little, if any, information of this quality is available for the vast majority of cases in which an engineer is called upon to investigate alleged damage from ground vibrations. For the investigative engineer, then, the problem becomes one of accumulating whatever data is available and drawing a conclusion as to whether or not the subject structure was in fact damaged by the blasting vibrations. Such an analysis certainly requires a working knowledge of the literature on the subject and as much experience as he can bring to bear. Even thus armed, however, the data is often ambiguous, confusing, and/or contradictory. A practical approach is presented herein to aid the engineering investigator in arriving at the best possible conclusion available with the information at hand.

Jan 1, 1983

The classical view of island arc geology is that of a plutonic intrusive/volcanic extrusive complex, derived from the products of oceanic lithosphere subdu.ction and constructed on an over-riding plate of oceanic origin. Such an arc is typically backed by a marginal basin, formed by seafloor spreading of a more or less conventional kind. Various studies undertaken over the last decade have modified this picture and provided a new tectonic framework within which to explore for resources. Formation of Marginal Basins During the 1970s, seafloor spreading magnetic anomalies were identified in various marginal basins in the SW Pacific. In one of these, the South Fiji Basin, there was clear evidence of a ridge-ridge-ridge triple junction, although no kinematic relationship to the major plate boundaries was determined. Palaeomagnetic studies conducted in Vanuatu and Fiji, and in the Bismarck Archipelago of PNG provided evidence of large scale arc rotations relative to major plates. This indicated a general pattern of marginal basin formation by ridge-ridge-ridge triple junction growth together with island arc growth by trench-ridge-trench triple junction evolution. Formation of Primitive Island Arcs The triple junction growth model strongly suggests that at least a significant amount of arc evolution occurs by the initiation of subduction at a spreading ridge. This has predictive implications for the nature of island arc basement.

Jan 1, 1987

By A. Mikula, S. Karlhuber

"Unique physical and mechanical properties made the Pb-Sn solders attractive for low temperature joining of electronic parts. But since lead in solder materials has become a great enviromental problem and health concern, lead will be slowly replaced by other materials in soft solders. Some of these materials which are currently under investigation are ternary tin alloys. Many different physical properties like wetting behavior, electrical and thermal conductivity and surface tension are measured on these alloys, but on the thennodynamic properties and the phase diagram of the alloys under discussion there is only little information available. We investigated the (Ag, Au, Cu)-Sn-Zn systems and determined the thermodynamic properties over the whole composition range by emf-measurements. From these measurements we also got some information on the liquidus. In the Sn-rich corner the phase diagrams are still under investigation.IntroductionSoldering is technically defined as the joining of two base materials, mostly metals or metal coated nonmetallic substrates, with a third metal. The melting temperature of the third metal or metal alloy should be well below those of the substrates. Solder alloys can be categorized in soft and hard solders. Soft solder alloys usually contain lead, tin, bismuth, indium or cadmium and hard solders gold, zinc, aluminium or silicon. The difference between soft and hard solders is the melting temperature of the soldering material. This temperature is around 350°C.An interesting brief history of solders is given by Vianco and Frear [1]. They report, that in 4000 B.C. solders were already used in Mesopotamia. From archaeoligical evidence those solders were gold-based hard solders.Tin-lead soft solders and their use are not easily found, because in course of time tin has been reduced to stannic acid, making the identification quite difficult. Well preserved soft solder artifacts were discovered in King Tut's tomb dating from 1350 B.C. In ancient time Pb-Sn solders were used primarily for the manufacture and repair of cooking utensils and metal tools. The Romans used lead-tin solders extensively in the construction of the aqueducts."

Jan 1, 1996

By Brett Pielstick, E Emery Gray

"Construction of the new Acosta Bridge in downtown Jacksonville, FL required the removalof an historical center lift span bridge once one_half of the new bridge had been opened totraffic. This paper discusses the potential problems faced with the demolition phase of the projectas observed by the CEI (Construction Engineering Inspection) and the blasting consultants"

Jan 1, 1993

By A. E. Beasley, Ike McKinney

Scale is a broad term which includes many types of mineral deposits which have limited solubility in water. These mineral components precipitate when combinations of scale-forming cations and anions exceed their solubility. Scale deposits are tightly bound to each other and to the metal surfaces of a water system. Precipitates that do not readily adhere to each other or to metal surfaces are known as sludges. Sludges are easily removed from a system by flushing. For example, a sludge is formed in the internal treatment of boiler waters with orthophosphates where the calcium is purposely precipitated as hydroxyapatite. Calcium phosphate would have a tendency to adhere to the boiler tubes except for the addition of tannins or lignins. These sludge conditioners maintain the precipitated calcium phosphate as a sludge which can be readily removed by boiler blowdown.

Jan 3, 1973

By Hanry A. Guillén Vilca

La estabilidad de una excavación subterránea y el trabajo estructural del sostenimiento depende de tres factores principalmente: la calidad del macizo rocoso, tipo de sostenimiento y procedimiento constructivo. En ese sentido, el presente texto tiene como objetivo optimizar las operaciones de minado en CMHSA, bajo los términos de seguridad, productividad y economía a través del análisis de respuesta determinística de las variables de decisión tiempo de autosoporte (relación Esfuerzo – Deformación)y la interacción de la Curva Característica del Terreno vs Curva Característica del Sostenimiento planteada por Lombardi.

Jan 1, 2017

By H. J. Schwellenbach, J. J. Strohl

This paper relates the results obtained by decreasing the size of feed to a rod mill screen circuit. As would be expected, added production was gained and a finer grind with no tonnage loss was made possible. THE MacIntyre mill of the National Lead Co. has four parallel sections in which magnetic and gravity separations are made. Ore from a 5000-ton bin is fed by Hardinge constant weight feeders to a 6x12-ft open-end Marcy rod mill in each section. Rod mill discharge is bucket elevated to two 4x10-ft Tyrock screens whose oversize is returned to the rod mill. Screen undersize is pumped to Crockett separators for magnetite removal, and the Crockett tailings are sized and tabled to make an ilmenite concentrate. Minus 200-mesh material, overflowed by the Crockett and Dorrco sizers is thickened, de-slimed, and concentrated by flotation.' By 1948, the development of a successful slime flotation process and numerous improvements in the gravity circuit of the mill had increased the capacity of the available concentrating equipment. At the same time, improvements in the operating techniques of the dry crushing plant and improved feeding of the crusher by the mining department had appreciably increased the production rate per operating hour in that plant. Therefore, it was decided to take advantage of the added crusher capacity to produce a finer rod mill feed and in that way increase grinding capacity. At approximately the same time, finer screens were installed in the rod mill circuits to give finer grind and thus improve liberation of the magnetite and ilmenite from the gangue and from one another. Prior to the first part of 1948, a 3/4-in. limiting screen was used for sizing rod mill feed. The first reduction in crushing plant screen size was to 1/2 in. With this screen, the circulating load in the tertiary crushing circuit was too high and plant capacity dropped below a practical hourly rate. A 9/16-in.-sq opening screen, installed next, proved satisfac-

Jan 1, 1951

By Michael F. Jeglic

Dust control methods are practiced throughout the mining industry in order to protect the health and safety of its workers, the integrity of the environment, and to guard against the loss of valuable product. The use of water is often the best and most economical method of controlling dust. Increasingly, chemical agents are being chosen over more traditional mechanical means of controlling dust. Some chemicals are used alone, and many are used to enhance the dust controlling properties of water. This paper describes the various types of chemicals available and their applicability to specific problems encountered by industry.

Jan 1, 1986

By Scott Giltner, Allan Koski

Blasting is one of the lowest cost yet most critical parts of the mining cycle. This paper discusses the findings of an audit conducted on the blasting operation at an iron ore mine. The purpose of the audit was to review current blasting practices in order to identify opportunities for production/cost improvements. The approach taken in the audit was to observe general blasting practices, their related downstream effects and to compare current procedures to established best practices.

Jan 1, 2009

By M. J. Collins

Pressure leaching of zinc sulphide concentrates has been practiced commercially for nearly two decades. The process, which includes direct leaching of concentrate with spent electrolyte in an autoclave, has been commercialized at four separate locations to date. In pilot studies carried out in the Dynatec lab in Fort Saskatchewan, dozens of additional zinc concentrates have been shown to be amenable to pressure leaching. This paper highlights recent improvements in zinc pressure leaching that have been identified through process development studies, and how the experience gained in these studies has been utilized in the development of a new copper pressure leach process.

Jan 1, 2000

By Henry Hibbard

AT THE beginning of a Henry M. Howe lecture it seems fitting to refer to Howe's great contributions to steel metallurgy, and particularly to the literature thereof. Most of my predecessors in this role have been able, from their association with him, to give direct testimony as to his great services; but although connected with him for years in a business way, I am less familiar with what might be called his academic side, except as .it is embodied in his utterances, written and oral. Howe was adept in his genial way in extracting information in any line which, at the time, was of interest to him. In a technical lecture one expects as a rule new knowledge-something about recent advances relating to the subject. On this occasion, however, I will ask you to go back with me to the primary department of steel lore, as the title of my lecture shows, to review the more fundamental features in that field for the purpose of seeking some gaps which we can fill and so give the subject renewed interest. In thus going back one must inevitably repeat many familiar facts, but that seems to be necessary in order to reach a clear understanding of the unrecorded matters. The full interpretation of a steel analysis is at present unattainable, though much progress toward that end has been made. The ultimate analysis, giving the percentages of the five commonly determined elements, does indeed usually give a fair idea of what the steel is, and is ordinarily enough, with knowledge of its history and physical condition, to enable it to be assigned to some purpose or use for which it is reasonably suitable. But discrepancies arise. Every maker and every user of steel knows, from at least occasional examples in his own experience, that the ultimate analysis is insufficient by itself to enable one to tell positively, from its interpretation, either the mechanical properties of the steel or its adaptability to the purpose for which it was made. Further, if, while having the specified composition, it is abnormal or unsatisfactory, why it is so. Good, bad and indifferent steels may have substantially the same ultimate analysis.

Jan 1, 1928

The Century zinc deposit is located in Queensland approximately 250 kilometres north north-west of the provincial city of Mount Isa, on Lawn Hill Station and within 150 kilometres of the Gulf of Carpentaria.ThefirstMining Lease in this area was pegged in 1887. The Silver King vein is the largestvein deposit in the area and has produced lead and zinc, in addition to 74,000 ounces of silver during its history.A total of forty three veins containing silver, lead and zinc are now known, all of which were discovered by prospectors within 10 years of the first vein being recognized.

Jan 1, 1993

By H. Bartholomew, L. Bernstein

Experirmental bonds of Ag-In SLID to gold, copper, nickel, Kovar, Dumet, nickel-plated molybdenum, ALL-Pt vrzetallizing on ceramic, and nickel-plated Mo-Ti metallizing on Al2O3 ceramic have been made and exalnined. Metallographic taper sections were made of all bonds for Phase identification. In addition, failuve temperatltres were determined for bonds heated undev shear load. Sowe bonds were subjected to electvon-probe microanalysis. The ternary SLID system Ag-In-Sn was similarly evaluated. Plwtonticrogaphs and electron-probe data are discussed and related to over-all phase diagrams , diffusion effects, and wetting properties of the liquid. The rates of diffusion andor compound formation of gold, silver, and copper in indium and In-Sn liquids are found to descend in that order, as measured by the relatzve thickness of phase layers in the interfaces of bonds made at 200to 400°C. It is concluded that the SLID process enables one to produce bonds which are stable at high temperatures, after having been fabricated at low temperatures, and meet most requirements for application in interconnection, silicon bonding, or hermetic sealing of electronic devices. In a previous publication by one of the authors, the theory and principle of SLID bonding in simple binary systems was discussed. SLID bonding can be defined as a joining process using a preform with a laminated structure: a low-melting material clad on a high-melting core. During the bonding cycle a metallurgical transformation occurs such that the resultant structure can withstand, without reliquefying, temperatures higher than those at which the bond was made. The phases present in the joint interface region are high-melting compounds or, if equilibrium is reached, solid solution. Properties will depend on the phases present, ultimately approaching those of the solid substrate core of the SLID preform. The high-temperature strength of bonds made in these systems was correlated to phase identification in the interfacial bond regions from metallographic cross sections and electron-probe X-ray microanalysis data. When complex electronic components are assembled, multiphase systems result at the interfaces of bond regions. In these ternary and higher-order systems very little diffusion and phase-diagram data is available with which to predict the nature of the interfacia1 region that will result from conventional fabrication processes and subsequent field use of the component. Clarke and Rhines did early work in the field using the Al-Mg-Zn system as a vehicle. Guy and co-workers studied a portion of the Cu-Zn-Ni system and some mathematical4 and general5 aspects of multiphase diffusion. irkald' and coworkerse recently studied diffusion in the Cu-Zn-Sn system. No diffusion studies have been made on ternary systems directly applicable to this investigation but some phase diagrams are available: g-u-n, u-i-n, and CU-i-n. I) DESCRIPTION AND EXPERIMENTAL PROCEDURE The elements Au, Ag, Cu, Ni, In, and Sn are found in alloy systems commonly used in fabricating and assembling electronic components. Reference to the appropriate phase diagrams9 and the previous publication will indicate that the binary systems of any of the two low-melting elements, indium and tin, with any one of the other four higher-melting elements are capable of producing SLID bonds. It is not unreasonable to assume that any ternary or higher-order alloy system containing at least one of the elements gold, silver, copper, or nickel and one or both of the elements indium and tin could be used to produce bonds which are stable at high temperatures, after having been fabricated at low temperatures. Indeed, the liquidus contours and isothermal sections of those phase diagrams available7 do so indicate. The parameters affecting the bond and the equipment used in evaluating the bond were described in an earlier paper.' The current investigation used the

Jan 1, 1967

By John S. Berber

To improve the economics of low-temperature carbonization of coal, the Bureau of Mines is conducting research on the upgrading of the product tar to marketable chemicals. This report describes experiments on the catalytic hydrodealkylation, followed by catalytic vapor-phase oxidation of the dealkylate to phthalic and maleic anhydrides, of mixed residues from the urea adduction of lignite-neutral oil fraction and on the catalytic thermal dealkylation of high-boiling tar acids. The hydrodealkylation experiments were conducted at pressures from 1,000 to 1,750 psig and at temperatures from 600° to 1,000° F. The oxidation was, in all cases, at atmospheric pressure and 9500 F. Maximum yield of maleic anhydride, based on the liquid feed to the hydrodealky1ation unit, was 12.2 percent at 750° F and 1,500 psig; that of phthalic anhydirde was 6.9 percent at 650° F and 1,500 psig. Maximum yield of combined anhydrides was 18.8 percent at 650° F and 1,500 psig. The non-dealkylated feed material, upon oxidation, yielded 8.9 percent and 3.8 percent maleic anhydride and phthalic anhydride, respectively.

Jan 1, 1967

By Robert M. Dreyer

The first time that a geologist is confronted with the necessity of evaluating a lateritic ore deposit, he may feel that nothing could be easier. Why should there be any problems in making an economic evaluation of a relatively flat-lying, surficial ore body? After several hundred thousand dollars worth of frustrating work often culminating in a series of non-reproducible data - the evaluator may be a sadder and wiser man. This paper will try to illustrate why the evaluation of lateritic bauxite and nickel deposits is among the most difficult problems confronting an economic geologist - and, more especially, how this problem can be solved. Volumes have been published on descriptive and genetic studies of lateritic ores. Obviously, there is time today only for the briefest description of such an ore body. The laterite is a soil formed under tropical conditions and resulting in the concentration, within the soil zone, of certain tri-valent metals.- especially, aluminum and nickel. The soil zone is divided into two parts: (a) the true soil or lateritic zone and (b) the zone of, partially altered bed rock or saprolite. It is important to remember that, whereas bauxite generally is confined to the laterite zone, nickel deposits occur in both the laterite and

Jan 1, 1977

By D. L. Johnston

"Function and ApplicationsWater-only cyclones, (WOC) are a dynamic mineral separator which cause minerals to separate in a water medium by virtue of difference in specific gravity. Figure 1 shows diagramatic plan and sectional views of a water-only cyclone.A slurry of mineral matter and water is fed through the inlet opening under gravitational or pump pressure. The combined effect of centrifugal action and conical shape is to concentrate the heaviest fraction of mineral on the periphery and bottom of the cyclone. This layer of higher specific gravity particles increases in thickness and density between the cyclone inlet and apex. The action in the bed of higher gravity particles formed in the flattened portion of the cone surrounding the tip of the vortex finder deter;nines the specific gravity of separation or cut-point. Mineral particles of lower specific gravity flow with the bulk of the water, out the vortex finder. Mineral particles of higher specific gravity flow with little water out the apex. A more technically e:mct description of the functioning of the water-only cyclone can be found in previous publications noted in the references.The water-only cyclone was invented and refined by J. Vis man, formerly of the Canadian Mines Branch staff, between 1958 and 1965. The first industrial application noted in the literature was when it was introduced as a cleaner for fine coal in 1962. Since 1970 the water-only cyclone has become a common separation apparatus in many Canadian and foreign coal processing plants. The only other mineral industry application known to the author is in separation of gold bearing heavy minerals from sand<'>. The potential does exist for other applications and this area deserves to be investigated more thoroughly than it has been."

Jan 1, 1989

Presentation Topics ? Low and Intermediate Level Waste ? Project Location and Site ? Geological Setting ? Key Features ? Project Overview ? Licensing and EIS ? Next Steps DGR Waste Package Inventory Approximately 50,000 packages over 35 years: ? ~40,000 packages or 80% of inventory are LLW Bins ? ~7,000 ILW Shields (concrete boxes) ? ~2,000 resin liner packages

Oct 1, 2010

By Strathmore R. B. Cooke, Iwao Iwasaki, Hyung Sup Choi

The effect of temperature as a parameter in ore flotation has not been systematically studied, although for some ores it has been known for many years that selectivity and grade of concentrates can be improved by conditioning or flotation at moderately or substantially elevated temperatures. In 1934 Coghill and Clemmer&apos; stated that "elevated temperature seems to make hard water more tolerable" in soap flotation, and a cursory examination of the literature indicates that some earlier investigators were aware of beneficial results obtained by floating above room or mill-water temperatures. Tartaron,&apos; Mitchell et al.,3 and particularly Hamilton et al." have shown that high pulp temperatures give high recovery and selectivity in soap flotation of fluorite from a variety of gangue minerals. As a result of the work of these and of other investigators, high-temperature flotation has been successfully applied to industrial flotation of fluorite. Falconer" stated: "The use of high temperature conditioning (above 35°C and preferably above 60°C) in connection with the soap flotation of nonsulphide ores, as covered in B. Kalinowski&apos;s French Patent No. 847,- 215, Dec. 7, 1938, is claimed to provide more intense activation, better separation of values from gangue, and reduction in quantity of reagents." The various investigations quoted above clearly demonstrate the improvements to be realized by increasing the temperature at which fluorite is floated, and it is surprising that little or no information has been published on systematic investigation of the same method as applied to other ores.

Jan 5, 1960