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By J. F. Papp

The microstructures of a CF2Br2-inhibited methane flame and its uninhibited analog have been determined using molecular beam-mass spectrometry. The slightly lean flames were stabilized on a cooled porous plug burner at reduced pressure. Composition profiles of stable, intermediate, and radical species and temperature profiles were obtained. Comparisons of the uninhibited and inhibited flame profiles revealed the following inhibition effects; a shift of the primary reaction zone to higher temperatures, a higher maximum flame temperature, an increase in the CH3 concentration, and a reduction in the H2CO, H, 0, and OH concentrations. Kinetic analyses of the data yielded rate coefficients at flame temperatures for the reactions H + CH4 ? CH3 + H2, H + O2 ? OH + O, CO + OH ? CO2 + H, and CH3 + O ? H2CO + H. CF2Br2 is judged to decay by thermal decomposition and abstraction reactions.

Jan 1, 1981

By W. W. Odell

Engineers interested in the manufactured-gas industry have witnessed p pronounced improvements in gas-generating equipment and marked changes in operating procedure during the past decade. In spite of these changes, however, the trend of development in the near future seems to be doubtful. Uncertainty exists mainly because no one can yet accurately calculate the number of years which will elapse before petroleum products become too expensive for, general use in making gas. Research in this field has been active, and the ultimate results are awaited with interest. Some engineers predict that in the future coking coal will be carbonized on such a large scale that coal gas will be used (straight or modified) for city distribution; others maintain that gas oil will be used in large quantities in the production of base gas; they believe that it will be economical to use oil even at appreciably higher prices. The question involves, among other; factors, consideration of initial and relative costs of equipment, flexibility of operation, salability of coke, cost of distributing different gases, and the relative value of by-products, It is common belief that for many years large quantities of oil will be used in gas-making, particularly in the generation of peak gas or that water gas will be used for the synthetic production of hydrocarbons to enrich additional water gas. In this paper interest centers in a discussion of the practicability of employing synthetic processes in view of reported investigations of the chemistry of the synthetic reactions. For many years it has been known that the chief components of water gas would react chemically under proper conditions to form methane. As long ago as 1903 a patent3 was issued in this country for a gas-making process which included the synthetic production of methane. More recently the studies of numerous investigators here and abroad have shown that besides methane it is possible to produce other paraffins, olefins, and additional, materials adaptable for enriching water gas or for other uses. The question arises: In what manner, if at all, can such processes be incorporated, as a part of the gas-making scheme in a city-gas plant?

Jan 1, 1928

By R. W. Schultz

Mineral exploration carried out in Ireland since the mid-1950s has resulted in the discovery of ore deposits that are now in production atTynagh (Pb-Zn-Cu-Ag), Silvermines (Zn-Pb) and nearby Ballynoe (barite), and Gortdrum (Cu-Ag-Hg); a major Zn-Pb deposit at Navan that is now being drilled prior to development; potentially productive deposits at Keel (Zn-Cd-Pb), Ballinalack (Zn-Pb) and Aherlow (Cu-Ag); and a number of interesting prospects, including one of spodumene. Underground exploration of a formerly extensively mined copper deposit at Allihies has outlined new, albeit currently uneconomic, reserves at depth. The copper and pyrite deposits at Avoca have in recent years been re-explored and are now again being worked. Most Irish ore deposits are in the lower half of the Lower Carboniferous succession of limestones and subordinate shales and sandstones, and this stratigraphic zone is being most intensively explored at present. Other geological units under active exploration are Ordovician sediments-volcanics belts, Caledonian granites, and parts of the Old Red Sandstone and Dalradian series. Surface prospecting is made difficult in many places by glacial and other superficial deposits, including peat and alluvium. Geochemical prospecting methods have been outstandingly successful and primarily responsible for most new discoveries. Boulder hunting and outcrop prospecting have proved effective in detailed investigations of geochemically anomalous areas. Some parts of the country have been covered by three separate airborne geophysical surveys, albeit without success so far. The induced polarisation technique, the most widely used ground geophysical method, has contributed to several discoveries. The scope of application of electromagnetic surveys is more restricted than that of induced polarisation, but the method has been effective in a few cases and has contributed to the Tynagh discovery. To date, the resistivity and self-potential methods have found little application. Magnetic surveys are not applicable directly in the search for ore deposits of the various known types, but can be helpful in outlining geological structures in some areas. The gravity method has been used successfully in a survey over the Zn—Pb deposit at Navan ; it has also proved effective in trials over a blind sulphide deposit at Tynagh that cannot be detected with geoelectrical methods. An appendix lists summary descriptions of 15 Irish deposits and occurrences

Dec 1, 1971

By Louis A. Panek

An improved centrifugal-testing apparatus has been designed and built in the Bureau of Mines laboratory at College Park, Md., which is unique in that it incorporates the use of resistance gages to measure directly the strains in a rotating model without testing it to failure. Owing to this feature, a more rapid testing method can be used; furthermore, model materials need not be restricted to those of the prototype. The behavior of any structure in which strains of significant magnitude are produced by its own weight may be studied in a small model subjected to simulated gravity loading. The model is rotated in a centrifuge to induce in it centrifugal forces, which, like the gravitational forces in the full-size structure, act on the volume elements and are proportional to the masses thereof. Centrifugal testing is, therefore, applicable to the design of mine openings and to the study of similar ground-control problems. It constitutes an experimental method for determining the state of strain in a structure for which analytical methods are excessively laborious or even impossible. In previous applications of centrifugal testing by other investigators, the models usually were tested to failure, and the analysis was made from-the type of break produced. The models were made of the same materials as the proto-type, and the test results were applied only to the particular prototype represented by the model. Beam deflections were measured from photographs of the rotating model, but no means was employed either to determine the actual distribution of stress in the model or to determine quantitatively the degree of restraint imposed on the ends of the loaded model beam, that is, to determine whether the loaded model behaved as a beam with rigidly fixed ends or as some other type of beam. With the apparatus described, it is possible to determine the state of strain, and thus the boundary conditions, in a rotating test model weighing up to 90 lb., which can be subjected to centrifugal forces up to about 2,600 times the force of gravity. The load-strain relationship, applicable directly to the prototype, can be determined from a Single model test. The test results can be presented as quantitative relations between the loads, strains, and dimensions and mechanical proper-ties of the structural members and can be applied to any prototype, whatever its component materials, that satisfies the similarity requirements.

Jan 1, 1952

By G DeschOnes, M Fulton

The Eleonore property (James Bay district of Northern QuTbec), owned by Goldcorp, hosts gold within stockworks of quartz-tourmaline-arsenopyrite veins and veinlets contained within microcline (potassic alteration) and brown tourmaline replacement zones. The preliminary investigation to recover gold from drill core samples showed that flotation followed by ultra-fine grinding and cyanidation is the preferred option. Ultra-fine grinding is used to liberate gold finely disseminated in sulfides. The flotation concentrate used in the investigation had a P80 of 11 ¦ and contained 75.5 g/t Au, 5.0 g/t Ag, 10.3 per cent S, 0.07 per cent Cu and traces of antimony (0.03 per cent). The mineralogical characterisation showed the presence of 65 per cent gangue minerals, 23 per cent pyrrhotite (hexagonal), 9.6 per cent arsenopyrite, 2.2 per cent pyrite and 0.08 per cent chalcopyrite with trace amounts of galena (0.05 per cent) and sphalerite (0.03 per cent). Gold was in the form of native gold and electrum. A straight cyanidation conducted at pH 11.0, DO of 3 - 5 ppm, 2000 ppm NaCN, 20¦C and for 72 hours extracted 97.0 per cent Au and consumed 31.5 kg/t NaCN. The equilibrium was reached within 24 hours. Increasing the dissolved oxygen to 16 ppm reduced the consumption of cyanide to 22.0 kg/t with 96.7 per cent Au extraction. A 16-hour pretreatment with 2.0 kg/t lead nitrate, followed by a 24-hour cyanidation reduced the cyanide consumption to 6.0 kg/t with a gold extraction of 97.5 per cent. Increasing the lead nitrate addition to 6.0 kg/t reduced the cyanide consumption to 1.2 kg/t by passivating the surface of pyrrhotite. The gold extraction remained at 97.0 per cent. It was possible to decrease the concentration of cyanide to 800 ppm NaCN without compromising gold extraction. The associated cyanide consumption was 1.2 kg/t NaCN. The passivation of gold grains was an issue when the cyanide concentration was decreased to 550 ppm NaCN. The gold extraction decreased to 92.2 per cent. The average lime addition for all the tests was 7.4 kg/t and the average silver extraction was 80 per cent. Efficient cyanidation of an ultra-fine sulfide concentrate with only 800 ppm NaCN represents an advance in leaching of ultra-fine sulfide concentrates. The high addition of lead nitrate would certainly make cyanide destruction easier; consequently reducing the effluent treatment costs and making possible to meet the discharge regulations criteria.CITATION:DeschOnes, G and Fulton, M, 2013. Design of a leaching strategy to extract gold from Eleonore Mine ultra-fine sulfide concentrate, in Proceedings World Gold 2013 , pp 71-78 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By J. A. Herbst, G. E. Agar

Beginning with the second paragraph in the second column of page 148, this paper should read: The Reynolds number in Fig. 6 was calculated from the inlet diam and it is evident from the graph that above NR = 5000 the value of K2 is as it should be, a constant. The data10 shown in Fig. 7 was obtained for fluids flowing in pipes of diam D with sharp edged orifices of diam d. To be consistent with the representation in Fig. 6 the Reynolds number was calculated with the orifice diam d. These two sets of data show similar patterns and the variation in the orifice coefficient C is believed to account for the variability of the cyclone coefficient K2. The values of C given in Table IV are derived from K2 by conversion of units. C more nearly represents an equivalent orifice coefficient for a cyclone. Armstrong1' showed that data reported by Chaston 12 and Elcox13 yielded values for C of 0.24 and 0.27, re- spectively, Dahlstrom's4 data gives a value of 0.22. As a consequence of the variability of the cyclone coefficient some caution must be exercised in substituting for Q in the split size equation.

Jan 1, 1967

By William B. Schmidt

In July of 1974 a study team comprised of the authors was formed by the Department of the Interior. It was supported in part by funding from the National Science Foundation. The purpose of this study group was to visit coal mines and research and manufacturing facilities in England and Germany, to review the status of mining in these countries, and to identify mining technology which might have application to U. S. mining conditions. The duration of the visit was 18 days. The first week of the trip was spent in England. Time does not permit a complete recitation of the team's impressions but a few of the more interesting technologic developments will be discussed. These fall into the following categories- High Speed Development Ground Support Chainless Haulage and Face Conveyors Nucleonic Steering of Shearers Miscellaneous

Jan 1, 1975

By R. A. Brown

RIGHT NOW the Canadian oil business is suffering from growing pains brought on by developments outside our borders. I would like, therefore, to place our industry in perspective for you in two ways. I would like first to describe it briefly and let you see it in relation to the world oil industry. Then I would like to bring it back and place it into perspective against a strictly Canadian background. Naturally, in such a discussion, it is necessary to use a certain amount of statistical material. I'll endeavour, however, to keep it to a minimum. Eleven years ago, before the discovery of Leduc, Alberta could boast of having 21,000,000 barrels of crude oil reserves. Five years ago we had 1,810,000,000 barrels. At year end, 1957, our remaining recoverable reserves totalled more than 3,000,000,000 barrels. In 1957, our potential production in Alberta reached an all-time high of 756,000 barrels a day. Unfortunately, our actual average daily production dropped from 393,000 barrels per day in 1956 to 376,000 barrels per day in 1957. And in 1958, to date, it has dropped sharply to around 300,000 barrels per day.

Jan 1, 1958

The value of Australia's education services exports increased to over $15 billion dollars in 2009, placing education as the third overall export earner behind coal and iron ore; however there are concerns over the impact of emerging policies on the future of both the industry and the provision of mining education. Policies have impacts on the growing number of international rankings (or league tables) of mining jurisdictions and universities. A high position in such rankings might be used as a measure of perceived quality with benefit to those at the top and to the detriment to those lower down.    Top performing companies in the relatively new domain of sustainability have been shown to achieve better financial performance than their industry competitors, assisting them in attracting top quality committed staff, hence positioning themselves well for the future. The world's mining companies, jurisdictions and universities are now ranked with results in the public domain. It is argued as to the validity of the data or perceptions used in such rankings, but there is no doubt they are influential in determining the flow of dollars around the globe. By investing your pension fund assets in the shares of the top performing companies, by placing your exploration dollars in a country at the top of such a list of attractive jurisdictions, attending or recruiting from a University at the top of the rankings - risk must surely be reduced?   While savings and risk reduction can undoubtedly result from the introduction of new technologies developed through appropriate R&D (the other core activity of a university), the maintenance of a very high level of exploration and production performance through dedicated highly skilled staff every hour of every day quietly improves financial performance, while avoiding safety, environmental and/or community incidents (ie protects the 'triple bottom line'). As always risk reduction comes down to enabling quality people to do a quality job - through the actions of such people we can sustain the global mining industry and secure our social license to operate. However, there is global concern over where the numbers of such people, including those with the recently required skills in sustainability, are going to come from.   This presentation will discuss some of the complexity and interactions involved in the development of such rankings, the dangers inherent in their simple acceptance and use, plus indicate some of the directions mining educators might take to sustain and increase the supply of quality graduates to the global mining industry. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Jun 1, 2010

By Isadora Dias Perez, Monica M. Jimenez Correa, Jorge A. Soares Tenorio, Denise Crocce Romano Espinosa

The generation of mining waste has been the subject of environmental, economic and social concern. Alternative and sustainable methods of recycling metals technologies are desired. The present work focuses on the application of the ion exchange technique for the extraction of metals contained in a lateritic nickel mining effluent. The Purolite S950 chelating resin was used in the present work because it has the ability to adsorb transition metals present in an acidic solution. The experiments were carried out in a batch varying the pH in the range of 0.5–2.0. 1 g of resin was placed in contact with 50 mL of solution and stirred for 120 min at a speed of 200 rpm and temperature at 25 °C. The results demonstrated that the affinity of the resin varied with pH. The adsorbed metals were only copper, manganese, magnesium and zinc. The most extracted metal was copper, corresponding to 37%, when the solution was conditioned at pH 2.0.

Mar 1, 2018

"IntroductionNOTE.-All figures on the supply and consumption of coal in Canada cited in this paper were collected and reported by the Dominion Bureau of Statistics. The friendly and efficient co-operation of the officials of the Bureau. is the foundation upon which it has been my privilege to rely in the preparation of this and two earlier papers ( 1). My thanks are due also to our own staff on the Dominion Coal Board, who spared neither time nor effort in helping to prepare this paper.STATISTICS are comparatively dull and, to many people, coal statistics are duller than most. Coal is, however, the one basic mineral upon which our whole way of life depends and it may be well if attention is drawn to this fact by an occasional statistical review of the coal position in Canada. The recent furore over the oil and gas discoveries has so obscured the basic position of coal in many minds that a little basic coal information may be useful. It is for this reason that, for the third successive year, a factual survey of the coal position is being presented.In the previous papers (1) explanations have been given of the basic considerations in the preparation of these reports and some special phases of the overall picture have been examined. For these explanations, the earlier papers may be consulted."

Jan 1, 1952

By Mingming Zhang, Ramana G. Reddy

A 3-D mathematical model was developed for the batch reactor of low temperature aluminum electrowinning using ionic liquid electrolytes. This model describes the deposition process by incorporating the mass transport of participating ionic species, homogeneous chemical reactions within the diffusion layer, and the associated electrochemical kinetics. Processing parameters, current and potential distribution, species concentration, fluid flow distribution, and electrode spacing were evaluated for the optimal reactor performance. The results indicated that the electrode spacing significantly affects the electrolyte fluid flow and current density distribution. The parallel electrode configuration (in line with electrolyte inlet) improved the convection and resulted in uniform current density distribution and electrolyte fluid flow. However, for this electrode configuration, electroactive species distribution was most favorable between the electrodes. Perpendicular configuration of electrodes resulted in a more non-uniform fluid flow within electrolyte domain, and it has a potential to cause non-uniform deposits. Aluminum electrowinning experiments were conducted using batch reactor at 80 °C, electrolyte flow rate of 5–20 ml/min, and applied cell voltage of 3–3.5 V. Good agreement was obtained between the model and the batch aluminum electrowinning experimental results.

Mar 1, 2017

By G. W. Smith

"The adsorption of dehydroabietylamine acetate on quartz, hematite, rutile and baddeleyite has been deter-mined for concentrations ranging from 0.3 to 5,600 µ. moles/I and for pH values ranging from 2.5 to 10.5.The surface tension, UV and IR spectra, equivalent conductance and ion concentrations for dehydroabiety lamine acetate solutions have been determined.Contact-angle and flotability studies have established that good collection may be obtained with this amine but that selectivity depends on the suitable use of depressants for some of the minerals."

Jan 1, 1971

By D. G. Kesterkel

Low-melting thoriurnrbase binary alloys or metal solutions were prepared by two different techniques involving the electrolysis of ThO2 dissolved in fluoride melts. Experiments were performed at 950° to 1,250° C using electrolytes containing ThF4 and various alkali and alkaline earth fluorides. In the first method, electroreduction of ThO2 and deposition of thorium on a nickel or iron cathode formed a molten alloy that dripped off and collected on the bottom of the cell, or in a tungsten cup. An electrocodeposition technique was used to prepare thorium-base alloys or solutions containing nickel, iron, chromium, or manganese. Electrolytic reduction of the component metal oxides and simultaneous deposition of the two metals on a tungsten cathode yielded a liquid alloy product. Complementary experiments were performed on the fused fluoride electrowinning of dendritic thorium from Th02 at 1,075° to 1,200° C in which thorium crystals were recovered and arc-melted into buttons. Major contaminants were aluminum, carbon, copper, iron, oxygen, and silicon, totaling 0.2 percent.

Jan 1, 1966

ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Technical graduate, aged-31, with experience as surveyor, chemist with a sulphur company, practical miner, and as chief engineer of an iron mining company, desires a position as mining engineer or superintendent. Speaks French and German. No. 165. Member, aged 31, married, graduate Yale and Massachusetts Institute of Technology, six years' experience in coal and iron mining, from engineer to general superintendent, desires position with large coal or iron company. Will go anywhere. References. . No. 167. Member, technical graduate, with experience as machinist, chemist, construction engineer, and manager-of mines in the United States and Mexico, desires position .as mine superintendent or manager. Speaks Spanish. No. 168. Member, technical graduate, aged 26, with experience as engineer, mine foreman, assistant superintendent for a pyrite mining company. Experience includes diamond drilling, shaft sinking, underground work, milling of pyrites, and mine accounting. No. 169.

Jan 12, 1914

By J. M. Goris

The U.S. Bureau of Mines, in a cooperative project with the University of Utah, Salt Lake City, UT, and Homestake Mining Co., Lead, SD, conducted in situ monitoring and numerical modeling of rock masses supported with cable bolts in two mechanized, cut-and-fill stopes and a shaft pillar at the Homestake Mine. Extensometers were used to measure rock displacement, while cable bolt strain gauges were installed to measure loads on both conventional and birdcage cable bolt supports. These instruments provided an assessment of rock mass behavior during mining as well as essential data for verifying results from computer analyses. The numerical modeling program FLAC was used to analyze cable bolt patterns and supports. Results from the evaluation study indicated that cable bolt strain gauges and extensometers were effective instruments for monitoring the behavior of rock masses supported with cable bolts. Also, numerical modeling of the 4S-48N stope using the FIAC code provided displacement values comparable with measurements from field extensometers.

Jan 1, 1993

By J. D. Tolman

In view of present interest in a revival of gold mining enterprises, papers dealing with the development of small gold properties are apropos. The present paper deals with the operation of a small gold property in the exploration and development stage, mining and milling 25 tons of ore daily, and indicates what may he expected in the way of mining costs under northern climatic conditions, by practicing rigid economy, at a property where disproportionate overhead costs are unavoidable bacause of the small rate of production. The output of this prospect is treated in a small amalgamation plant which has been described in a previous circular.. HISTORY Prospecting in the district was begun in 1909, and by 1911 the adjoining mines, Hollinger and McIntyre, were in operation. Actual work was begun on the Rochester claim in July, 1922, and carried on through 1924. The property was closed until 1928 when the present company took it over, together with the other holdings of the Canadel Mining Co. A small mill was started as a pilot plant on March 24, 1929, and is still in operation.

Jan 1, 1931

By H. B. Pulsifier

THE following report on the structure of copper is the result of work done in the laboratory of the Rome Wire Co. early in 1925. Previous work had indicated to the author that excellent results might be expected if a suitable technique in surfacing and etching could be developed. The resources of the Rome Wire Co. enabled this metal to be studied more intensively than previously, although none of the materials were investigated exhaustively. The material presented is hardly more than a preliminary summary of the most obvious character of the metal; a much longer research would have been necessary to solve many of the pressing problems connected with the casting and working of copper. The Rome Wire Co. has generously released the paper; to Dr. E. H. Darby, technical supervisor of the company, are due particular thanks for his appreciation of the importance of metallographic study of copper and for his effective support in the prosecution of the work and in making its publication possible.

Jan 1, 1926

By DEVY DYSON, Brian Hart, JOHN LANGHANS, Stamen Dimov, STEVE YOPPS

A recent Nevada Gold Mines research program focused on pressure oxidation pre-treatment of a Carlin-type double refractory ore from the Turquoise Ridge Mine. The research team found that both arsenian pyrite and carbonaceous matter were highly oxidized within an hour at 300 °C using a bench-top autoclave reactor and that the gold recovery from the residues after cyanide/carbon-in-leach approached the technical limit set by the amount of gold encapsulated by silicate minerals. Although the 60-min pre-treatment at 300 °C yields robust performance when treating a whole ore, copper additives can catalyze the oxidation rate of carbonaceous matter and reduce the residence time needed at elevated temperature. Certain gangue minerals are susceptible to dissolution in acidic solutions at 300 °C, and this may cause poor gold recovery. This recovery challenge is mitigated by keeping free acid in the discharge solution below a key threshold.

Jun 21, 2022

By Robert L. Zook

Coal refuse slurry impoundments are dams constructed of coarse coal refuse to impound fine refuse (slurry) and water (25-30% solids). Both products are waste from coal preparation plants. A number of these structures in West Virginia, Pennsylvania and Kentucky were investigated to determine embankment stability. During the investigation a variety of embankment designs were encountered. The investigation determined the soil and geological characteristics of the embankments and the sites. This was accomplished by a test drilling and monitor installation (observation wells and piezometers) program, geologic study, and large scale mapping which allowed sub-surface profiles of the embankments to be constructed. The laboratory testing program concentrated on textural classification of the coal refuse, permeability and determining strength parameters to be utilized in the stability analyses. For the stability analyses, the Modified Fellinius Slip Circle, Simplified Bishop Slip Circle and Analysis for Translational Failure -were utilized. In all stability analyses hydrostatic pressure and earthquake were considered. This investigation indicated that 62% of the embankments analyzed are in a stable condition. The coal seam mined, the type of roof rock, and the gradation of the refuse influence the degree of compaction obtainable and the permeability of refuse. The shear strength of coal refuse appears to be controlled by its composition, moisture content, degree of compaction, amount and grain size of fines present. This investigation demonstrated these em¬bankments should not be treated as pure state-of-the-art dams; consideration must be given to the particular properties of coal refuse and the total refuse disposal system. Refuse dim slurry impoundments generally lack the site se- lection phase that is standard practice with siting most other types of dams.

Jan 1, 1974