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The second special war meeting of the New York Section was held on Thursday evening, Aug. 23,-preceded by is an informal dime The topic for discussion -was the supply of sulphur and pyrite, the raw materials for the manufacture of one of the most important of till war materials-sulphuric acid. The first speaker was William Young Westervelt, the Institute's representative on the War Minerals Committee. Before taking up the subject of the evening, Mr. Westervelt briefly described the organization and plan of operation of the War Minerals Committee.

Jan 10, 1917

By Whitham M

Prior to exploitation, the feasibility of mining and recovering ore can usually be determined to a satisfactory level of uncertainty by the consideration of conceptual scenarios, using a range of reasonable parameter values. Such values are selected on experience, knowledge of other mining operations, and the characteristics of the particular deposit being considered. Having established such feasibility, it is usually considerably more demanding to determine what the optimum set of parameters might be. Yet many decisions taken at the feasibility stage represent commitments extending at least into the medium term.

Jan 1, 1991

By Roger Nendick

The recent developments in refractory precious metal ore processing (Bio-oxidation, Autoclaving), and the revitalization of the more traditional roasting processes have attracted great attention in recent years and are indeed the focus of todays symposium. It must always be remembered, however, that the term refractory ore by definition means that the material 'must be capable of being treated at a profit". Given the high cost of the refractory processes, the requirement to be treated at a profit requires very close scrutiny during the evaluation phase of the property development. The M.G.M. film company has the latin motto Ars Gratia Artis meaning Art for Arts Sake. Ingeniatore Gratia Ingeniatoris (a very crude attempt at saying Engineering for Engineerings Sake) should not be the motto for mining companies intent on exploiting refractory gold deposits, but rather the wittily tilted heading for this paper "Take the money and run like a thief". The following hypothetical case studies show that the high technology solution is not always the best financial solution.

Jan 1, 1990

Geological Survey of Alabama, University, Ala. A complete list of publications will be sent upon request Requests for publications should be addressed to Walter B. Jones, State Geologist, University, Alabama Publications of the Survey, of most interest to the general public, comprise (1) Special Reports, (2) Monographs, (3) Bulletins, (4) Circulars, (5) Maps The Special Reports mostly deal with a special coal field, mountain, valley, or series of formations, while the Monographs treat of some industry, resource, or group of organisms throughout the state or as far as it extends The Bulletins deal with a variety of subjects, but are usually smaller and less technical than the Monographs and Special Reports Maps now available comprise a map of the Cahaba coal field, one of the Coosa coal field and a small geological map of the state, in addition to a large geological map, 28 by 42 inches, 8 miles to the inch (1926) (also bound with Special Report 14) Price of the large geological map of Alabama, folded in manila envelope, is $1.03 postpaid

Jan 1, 1933

By Guillermo Silva

A novel, ultra-low density explosive composition, particularly suited for wall control and other applications requiring customising of the explosive’s energy output, has been developed. Being reactive in nature, the low density explosive enables the controlled dilution of dry blasting agents from their nominal densities down to values slightly less than 0.10 g/cm3. The product has been detonated at densities of 0.07 g/cm3 in diameters as small as 50mm under confined conditions, using a 227 g (l/2 lb.) primer. Recorded velocities of detonation ranged between 1200 m/set and 2200 m/set for densities between 0.07 and 0.2 g/cm3. Theoretical velocities ranged from 1700 m/s to 2500 m/s for the same density range. The low density explosive was insensitive to initiation by a blasting cap which is a desirable feature for transportation purposes. Mixing of the product with ANFO has been accomplished with minimum segregation making it suitable for applications where reduction of pressures are necessary.

Jan 1, 2000

A great part of the research on froth flotation of gold ores deals with ores containing gold associated mainly with sulphides, resulting in a largely accepted view that what takes place with sulphides (eg pyrite) in a flotation cell also happens to gold particles. This paper is concerned with the influence of some inorganics (CuSO4, CaO and NaCN) on gold particles flotation, using ethyl or amyl xanthates as collectors. The bench-scale tests were carried out with ground quartz and gold particles mixtures. Some findings stemmed from this study: flotation of the gold particles of size 0.16 mm was efficient adding only frother; larger gold grains were better recovered by the use of stronger collector CuSO4 did not seem to be an activator for gold; the addition of NaCN up to 200 g/t or CaO up to 2000 g/t did not depress the gold grains when amyl xanthate was used as collector although with ethyl xanthate the gold depression was verified.

Jan 1, 1993

Territory Iron has seen fit to revive the old Frances Creek iron ore mine some 30 years after it ceased operations in AustraliaÆs Northern Territory. The key to this revival has been the changes that have happened since market forces, infrastructure limitations and a cyclone combined to force its closure. As it breathes life into this old mine, the Company is serious about its responsibilities to its shareholders, to its workers, to local and regional communities and to the environment. This paper addresses how Territory Iron has approached technical, operational and regulatory issues that apply in Australia. Some insight may be gained into the myriad of tasks that mining companies face to revitalise an old mine. These tasks vary from employing the latest exploration tools, best practice drilling, sampling and modelling of orebodies, optimisation of pit designs and schedules, maximising product value by blending, optimising infrastructure usage and minimising capital and operating costs. All of this has to take cognisance of commercial, environmental and other issues including Native Title.

Jan 1, 2007

By J. M. Lohr

A COMMERCIAL development requiring a suitable alloy or alloys for sealing into various grades of glass made it desirable to have a more exact knowledge of the expansion characteristics of the nickel-iron alloys than appeared in the published literature. The expansion of the more common. FIG. I.-EXPANSION CURVES OF SEVERAL FIG. 2.-EXPANSION CURVES OF TWO TYPES OF GLASS. (Courtesy of R. C. A.) TYPES OF GLASS. (Courtesy of R. C. A.) types of glass under consideration varies from 2.7 to 10.4 X 10-6 per degree Centigrade, over the range 20° to 400° C. For reference, the thermal expansion curves f several types of glass used for sealing by the lamp and tube industries are given (Figs. 1 and 2). This paper covers a detailed investigation of the thermal expansion of a series of nickel-iron alloys in which the nickel content varies from 30 to 70 per cent. Particular stress is laid on the alloys that contain between 40 and 55 per cent Ni.

Jan 1, 1938

The source and origins of the hydrothermal fluid of orogenic, or quartz-vein lode-gold deposits remain uncertain and disputed: Resolution would likely have a significant affect on exploration strategy. The gold-carrying fluid is interpreted to be a low-salinity mixed aqueous-carbonic fluid of near ambient pH and redox state, that may be derived either magmatically through crystallisation of granites at depth in the crust or through metamorphic reactions in a range of rock types. Classic isotope and geochemical tracers of fluid source have not differentiated these possibilities and have produced conflicting conclusions. Mass balance calculations show that fluid composition will be modified by wallrock reaction between source and deposit, and tracers should not be expected to give clear indications of fluid source. Fluid oxidation state can also be modified along flow paths. Tracers should be interpreted with care and with view to possible modification. Modelling of full flow paths and examination of the hydrothermal histories of proposed source rocks may be alternative approaches to determining fluid source.

Jan 1, 2002

By Harry R. Cedergren

Properly designed drainage systems can be of great benefit to many kinds of Civil Engineering works, including embankments, and often are the most economical way to protect such works from the damaging effects of water. To function properly, drains must be able to remove water without also removing soil or becoming clogged with soil or erodible rocks. The first criterion to be used in designing drainage systems, called the filter criterion, can prevent all such problems (erosion and clogging) when properly fulfilled in design and construction. The second requirement of drains is that they must be capable of removing all of the incoming water without the build-up of large amounts of head that can damage the protected works. To insure this kind of perfomance, the discharge capabilities of drains should always be verified by appropriate hydraulic and seepage calculations. This paper describes these two basic drain design criteria and also gives examples of application of seepage principles to the evaluation of the potential benefits of drains and to the design of drains for mine waste embankments.

Jan 1, 1985

By Guo-Sen Zhu

Research on the formation mechanism and control of corner transverse cracks was carried out. The optical microscope and SEM were applied to analyze the characteristics of cracks. It is found that the cracks occur at the relatively lower temperature due to unbending strain and have almost nothing to do with the mold cooling and powder. The keys to prevent corner transverse cracks are to optimize the corner temperature of slab and maintain the good state of casting machine. Increasing casting speed and decreasing the cooling water flux at the corner in the unbending segments, resulting in mild cooling, were applied during investigation to control corner temperature above the upper limit temperature of the No.3 brittle zone of Nb-contained steel tested by Gleeble-1500 system. As a result, corner transverse cracks were minimized, but centerline segregation got worse. And then increasing the cooling water flux at the corner (intensive cooling) was applied to make corner temperature below the lower limit temperature of the No.3 brittle zone. Great diminution of both corner transverse cracks and centerline segregation was achieved finally.

Jan 1, 2006

By S. Dubnewych, S. Kieffer, M. T. McRae, R. R. Redd

The seismic vulnerability of the existing outlet tower at Lake Mathews reservoir, located in Riverside County, California, necessitated the design of a new outlet facility to assure serviceability of the facility following a major earthquake. The components of the proposed facility include: a new outlet tower; a shaft; a new outlet tunnel; an approach channel that will be excavated underwater; and two short tunnels that will connect the new outlet tunnel to the existing outlet tunnel via the shaft. As the new facilities will be constructed while the reservoir is in operation, a cofferdam will be constructed around the site of the new outlet tower. The design for the underground facilities used a combination of empirical methods; limit equilibrium analyses, including displacement-based pseudo-static analyses for dynamic loading conditions; and numerical analyses. This paper outlines the design methodology used to develop an innovative design for the facilities which can be constructed within the time frame required by the operational schedule of the reservoir and existing outlet facility.

Jan 1, 1999

By E. L. Mann, Robert L. Virta

Asbestos is a generic name given to six fibrous minerals that have been used widely in commercial products. The six types of asbestos are chrysotile, crocidolite, amosite, anthophyllite asbestos, tremolite asbestos, and actinolite asbestos (Table 1). Chrysotile is the asbestiform variety of serpentine. Crocidolite, amosite, antho-phyllite asbestos, tremolite asbestos, and actinolite asbestos are the asbestiform analogues of riebeckite, cummingtonite-grunerite, anthophyllite, tremolite, and actinolite, respectively. Although amosite is an acronym for the Asbestos Mines of South Africa (AMOSITE) and does not specify a mineral type, it generally is composed of cummingtonite-grunerite asbestos so the terms are assumed to be synonymous.

Jan 1, 1994

By C. R. Hayward

THE CHAIRMAN (ALBERT SAUVEUR, Boston, Mass.).-I am sure we are indebted to Prof: Hayward for his addition to our knowledge of the influence of sulphur on steel. As he has said in this paper, sulphur has had many defenders in recent years. It seems to me, however, that, while it may be old school to believe in the detrimental action of sulphur, it is not yet old school to believe in segregation; that while it may be that 0.1 per cent. of sulphur has no very great effect on the physical properties of steel, a ladle analysis of 0.1 per cent. of sulphur may readily result in 0.2 or 0.3 per cent. sulphur being present in the segregated portion of the ingot, and that, it seems to me, might be a rather serious matter. J. S. UNGER, Pittsburgh, Pa.-Prof. Hayward has presented the results of an investigation along a line to which I have devoted considerable time and attention, and I am particularly pleased to note that his results are in accord with my own and further tend to prove the fact that the old, established prejudice against sulphur is based more on belief than actual facts. I have felt for years that tooo much stress was placed on the harmful influence of certain elements in steel such as sulphur, phosphorus, copper, etc., but it has only been within recent years that efforts have been made to, establish the truth. Practically all the investigations made to date have proven that these elements within reasonable limits are harmless and, in fact, that for certain purposes the addition of these elements is beneficial. In referring to copper, J. E. Stead, Vice-President of the British Iron and Steel Institute, said at their last meeting: "Even today one comes across steel specifications in which copper is barred, which can only be regarded as ail indication of ignorance, if not stupidity, of those who prescribe the composition of steel, for it has been long ago proved that copper in steel, instead of being an evil, is quite harmless, and is sometimes distinctly beneficial." Sulphur owes its evil name to the early days of the manufacture of steel. Chemical analyses were crude, and failure due to either poor raw materials or metallurgical treatment were many. Sulphur being a comparatively easy element to determine with reasonable accuracy, particular attention was called to the amount of sulphur, and the failure was attributed to it, without giving any consideration to other causes. A pre-

Jan 4, 1917

By Arthur Taggart

THE following conclusions on the work of the Hardinge mill are based on data furnished to the writer by the Hardinge Conical Mill Co. in the form of the mesh cards hereto appended. Energy units (E. U.) and relative mechanical efficiencies (R. M. E.) are computed by the "volume method" of Stadler.1 Screen apertures used are the average apertures of testing screens of the meshes given. Card 122. June 28, 1912. Vipond Porcupine Mines Co., Ltd., Schumacher, Ont., Canada. Ore from mill bin. Gangue, quartz and basalt. 4.5 ft. by 13 in. ball mill. Capacity, 48 tons per 24 hr. Charge, 4,000 lb. balls. Speed, 33 rev. per minute. Horsepower, 15 to 17. Water, 100 per cent. by weight. (50 per cent. ?) Product deslimed and oversize reground-in pebble mill, see Card 113. Feed to mill through 2-in. mesh.

Jan 7, 1915

By I. Iwasaki, R. H. Heerema

The presence of calcium and magnesium ions in iron ore pulps that are upgraded by selective desliming can result in indiscriminate flocculation of both iron oxide and siliceous gangue slimes. The removal of these alkaline earth cations in pulp solutions by chemical precipitation was ineffective as a means of deflocculation of quartz. It was shown by using various techniques (electron micrographs, abstraction, and streaming potential measurements, and cationic flotation tests) that heterocoagulation between the precipitates [Mg(OH)2, hydroxyapatite, and CaCO3] and quartz particles was the reason behind that observation. In addition, the precipitates adversely affected the recovery of quartz by cationic flotation, due to slime coating, a case of heterocoagulation. Magnesium hydroxide produced a uniform layer of coating across the quartz surface, while hydroxyapatite and calcite produced discrete, localized deposits dotting the surface.

Jan 1, 1981

ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Member, aged 25, recent graduate, with some experience in laboratory of steel plant, desires position as metallurgist or assistant in copper, aluminum, or steel works. No. 118. Member, aged 52, technical graduate, with 20 years' experience as engineer with coal-mining companies, desires position as engineer or superintendent of coal mine. No. 119. Member, aged 39, technical graduate, with extended experience in surveying, assaying, milling, and copper smelting, desires position along cyaniding, concentration, or copper-smelting lines. No. 120. Member, aged, 38, technical graduate, with several years' experience in research work, in mine operation and as professor of mining engineering, is desirous of engagement in planning concentration and metallurgy of odd and difficult ores. No. 121. Member, aged 32, graduate M. I. T. in mining and metallurgy, at present and for last five years superintendent of Western lead smeltery, will consider engagement with solid company, if opening promises advancement. Specialty, smelting of lead ores, high in lead and zinc content. Ten years' experience in the operation, design, and erection of a large lead plant. Now desirous of bettering position.. No. 122.

Jan 8, 1914

By C. F. Tolman

Discussion of the paper of C. F. TOLMAN, JR., presented at the New York meeting, February, 1916, and printed in Bulletin No. 110, February, 1916, pp. 401 to 433. Louis C. GRATON, Cambridge, Mass.-Of particular interest at this time is any paper that deals with chalcocite, the characteristic product of secondary enrichment and the copper mineral of greatest commercial importance, and that seeks to aid in the distinction between primary and secondary chalcocite-a distinction of much scientific and practical importance but one which thus far it has proved difficult to draw. The present paper on this subject by Professor Tolman, like the ,many preceding it which he and his colleagues at Stanford have published in the last couple of years, contains much of interest and suggestiveness. Without endeavoring at this time to review or comment upon Professor Tolman's conclusions in detail, I may say that many of them are in accord with the findings that my associates and I have been accumulating in the course of studying secondary enrichment in many of the copper deposits of the country. On the other hand, it goes without saying that in this comparatively new field of research or, at least, a field in which

Jan 5, 1916

By V. C. Kelessidis

Demand for multifunctional drilling fluids continuously increases. In the quest for more hydrocarbons, drilling has extended to deep water areas (now in excess of 2.000 m) and to very deep wells (now in excess of 6.000 m). In these extreme conditions, low temperatures, as low as 1-5°C on the sea bed, high temperatures, in excess of 200°C, and high pressures, more than 1.000 bars, in the bottom of the well, are frequently encountered. In these harsh environments, synthetic oil and oil based drilling fluids are used, but the former are expensive while strict environmental requirements have limited the use of the latter. Thus, drilling industry has turned back to water based drilling fluids which use bentonite as primary viscosifier and as a fluid loss control additive. However, in conditions of high temperatures, bentonite suspensions gel and loose their exceptional low temperatures properties, thus, additives are needed to overcome such problems. In this article we review these challenging drilling environments and establish the requirements for the multifunctional drilling fluids. Our research indicates that demand for continuing use of bentonite by drilling fluid industry is strong. Furthermore, we bring forward the opportunities for new additive development which can expand the operational ranges of bentonite suspensions.

Jan 1, 2007

By Azizan A

The paper presents the results of chlorination of beneficiated rutile and struverite (a tantalum-niobium bearing, rutile type mineral in alluvial tin deposits) by carbon tetrachloride in the range 623¦K to 773¦K. The chlorination of rutile could reach near completion at 773¦K in about an hour. The process was found to follow a modified pore-blocking law, with the basic reaction constant K varying inversely with the particle size, so that the basic process may be a reaction under interface control (chemical control) as modified by the pore blocking effect. The pore blocking factors for the various experimental conditions were evaluated and the predicted curves showed good agreement with the experimental data. In the case of Struverite, a similar kinetic behaviour was observed but the chlorination process was relatively slower than that in rutile. It was also observed that in struverite, niobium got chlorinated faster, followed by tantalum and titanium, indicating a good possibility of separation by chlorination using carbon tetrachloride.

Jan 1, 1996