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By R. C. Urquhart, D. D. Howat, R. I. L. Guthrie

Heat losses from ladles during teeming by R. C. URQUHART, M.Eng. (McGiII), Ph.D. (Visitor). R. I. L. GUTHRIE, B.Sc. (Eng.) (London), A.R.S.M., Ph.D., D.I.C. (Visitor), and D. D. HOWAT, B.Sc. (Glas.), Ph.D. (Fellow) In an investigation of the loss of temperature by liquid steel during a teeming operation, a numerical technique was used to calculate the heat flows and the rate of temperature drop over the entire teeming operation. The calculations show that, before teeming, approximately 50 per cent of the heat loss is into the ladle wall at the level of the metal. As teeming progresses, the amount of heat lost by radiation to the wall above the metalline increases. The effect of variables, such as initial metal temperature, the preheat of the ladle and ladle cover, and delays, on the rate of temperature loss by the metal were determined.

Jan 11, 1973

By H. C. Gunning

DURING the past year the Cadillac-Malanie area in northwestern Quebec has been catapulted to the front as one of Canada's most active gold mining districts. Late in 1934 the area was lolling along in the doldrums, with one producing mine and a handful of active prospects. 1935 passed with only slightly increased activity, but saw the start of production at Canadian Malartic mine. Lightning struck in April, 1936, when a new and phenomenally rich ore-body was found in O'Brien Gold mine, and by midsummer the camp was ablaze with activity. An important new discovery on the Pan-Canadian property, and pleasing underground developments at Sladen Malarric, East Malartic, and Lapa Cadillac, in addition to other new developments, lent fodder to the flame, and at present several dozen properties are being actively developed. For the past three seasons, the Geological Survey of Canada has been engaged in a fairly detailed study of the geology and mineral deposits across Cadillac, Malarric, and Fourniere townships. Ir is the purpose of this paper to present a brief preliminary statement of the structural and economic geology and to discuss some of the more important problems that have been found to exist. The reader is requested to remember that the paper is a preliminary one and that therefore the conclusions presented are open to revision. It is impossible to make full acknowledgment for help received, for the writers are indebted to practically every operator and prospector in the area for generous co-operation in the work, and to several private, provincial, and federal geologists for data and frank discussion of problems encountered. Over a score of student assistants from McGill, Queen's, and Toronto have given excellent service. Published reports by Wilson, Cooke, James, Mawdsley, L. V. Bell, and J. J. O'Neill greatly facilitated the work. For adequate control surveys and a topographic base-map, the writers are greatly indebted to H. N. Spence.

Jan 1, 1937

By I R. F MacCulloch, K Jones

Pintail Systems, Inc, a Colorado USA based company has developed and commercially applied bioremediation processes for biological detoxification of cyanide compounds in mine waste. Site-specific microorganisms are isolated from spent ore, tailings or process solutions and augmented in the laboratory for cyanide oxidation, denitrification and metal biomineralisation. Biological processes typically treat complex contaminants (cyanide compounds, soluble metals and nitrates) in a fraction of the time of conventional remediation processes. Cyanide is used in microbial metabolic processes as a carbon or a nitrogen source. Biological detoxification processes applied at the end of mine life can end long-term liability and perpetual monitoring and containment. Case studies from commercial application and demonstration programs for the US Environmental Protection Agency will be presented in this paper.

Jan 1, 2004

By J. Handin, S. J. Bauer, M. Friedman

Deformation mechanisms in room-dry and water-saturated specimens of Charcoal Granodiorite, shortened at 10-4s-1, at effective pressures (Pe) to 100 MPa and temperatures to partial melting (?1050°C) are documented with a view toward providing criteria to recognize and characterize the deformation for geological and engineering applications. Above 800°C strength decreases dramatically at effective pressures ? 50 MPa and water-weakening reduces strength an additional 30 to 40% at Pe = 100 MPa. Strains at failure are only 0.1 to 2.2 percent with macroscopic ductility (within this range) increasing as the effective pressures are increased and in wet versus dry tests. Shattering (multiple faulting) gives way to faulting along a single zone to failure without macroscopic faulting as ductility increases. Microscopically, cataclasis (extension microfracturing and thermal cracking with rigid-body motions) predominates at all conditions. Dislocation gliding contributes little to the strain. Precursive extension microfractures coalesce to produce the throughgoing faults with gouge zones exhibiting possible Riedel shears. Incipient melting, particularly in wet tests, produces a distinctive texture along feldspar grain boundaries that suggests a grain-boundary-softening effect contributes to the weakening. In addition, it is demonstrated that the presence of water does not lead to more microfractures, but to a reduction in the stresses required to initiate and propagate them.

Jan 1, 1982

By H. C. Ko

As part of the Bureau of Mines effort to provide thermodynamic data for the advancement of mineral technology, the standard enthalpies of formation for ZnO?2ZnSO4 and COS04-6H20 were determined by HC1 acid solution calorimetry. The values are -550.31 ±0.28 and -641.33 ±0.15 kcal/mot, respectively.

Jan 1, 1982

By L. A. Haas

S02 reduction with CO was studied in an integral flow reactor at a nominal flow of 0.5 liter per minute. Reactant gas contained 3 percent SO2, 6 percent CO, and the balance He. SO2 conversion was determined for three different types of catalysts. The first consisted of 16 commercial catalysts used for various chemical syntheses. Only the commercial catalysts which contained transition metals in alumina removed more than 30 percent 80a at temperatures below 510° C. Two other types of catalysts were prepared in the laboratory either by pelletizing equal amounts of powdered alumina and transition metal oxides or by impregnating commercial alumina tablets with transition metal ions. Regardless of preparation techniques, Cr and Fe in alumina were the two best catalysts. The observed results suggest that an intermediate (SCO) is formed by the interaction of surface metal sulfides and carbonyls. Alumina then catalyzes the interaction of SCO with S02 to form the end products (sulfur and carbon dioxide). Over 80 percent S02 was removed at 460° C with 2 grams alumina impregnated with 2.5 percent iron.

Jan 1, 1972

By R. V. Tomkins

Introduction In the past fifteen years, bentonite production in the United States has increased very rapidly. From l50,000 tons in l934, it rose to 400,000 tons in l 942 and to a record 920,000 tons in 1948. Occurrences of bentonite ?in western Canada were described in the early part of the century by Ries and Keele (3), Ells (2), Spence (4). and other officer of the Dominion Department of Mines, and, in Saskatchewan, Professor W. G. Worcester (6), of the University of Saskatchewan has explored and carried out tests on deposits of the material at various times during the past thirty years. Nevertheless, Canadian developments have not kept pace with those in the United States. Exact figures for total Canadian production are not released, but it is probably under l0,000 tons annually. There are a great number of uses for bentonite, but in the United States three alone account for 90 per cent of the consumption. These are for drilling gel, foundry sand bond, and oil decolorizer. The tremendous oil exploration programme on the Canadian prairies has increased the possibility of an adequate domestic market for drilling gel. Therefore, in Saskatchewan, our efforts have been directed mainly to the production of a good drilling gel, with a minor part of the project devoted to activation of bentonites for oil decolorizing.

Jan 1, 1952

By Oberlin Smith

The object of this paper is not so much reformatory, as historical and prophetic. History tells us that, for several months past, aluminum has, in one of its largest American manufactories, been freely nicknamed " Al" by everybody connected therewith, simply because its Christian name is too long for frequent speaking and writing. In another prominent factory, for the same reason, it is spoken of by its chemical symbol merely, pronouncing it " aye ell." These facts will, perhaps, explain the use of the final word in my title, which might otherwise seem undignified in a paper of this kind.

Jan 1, 1890

By H. Stuart Auvil

Twelve samples of run-of-oven coke were taken at coke plants in the United States and Canada. Sampling procedure was directed toward obtaining the highest possible degree of uniformity in the gross samples, so that variations in results caused by sampling variations were at a practical minimum. Under these conditions the standard deviation of the screen analysis test on 500-pound samples is found to range from 1.2 percent for the 1-inch screen to 4.5 percent for the 5-inch screen. At present, the A.S.T.H. standard method of test requires that results be reported to the nearest 0.1 percent. This implies a higher than actual degree of precision, and revision of the report required by the method is suggested. Much larger Samples than are generally tested are required to reduce normal testing errors to a point where they are not appreciable fractions of the total variations found in a smoothly operating plant. For example, it is deduced that over 100,000 pounds of coke must be screened to determine if ordinary day-to-day variations in screen analysis have appreciable effects on the performance of a blast furnace.

Jan 1, 1950

By Jaime Guzman

Mineral exploration decision problems involve the economic evaluation of upgraded geological information and the costs of obtaining it. This paper presents a valuation theory of risky projects applicable to the analysis of exploration investments. The valuation model is predicated on the Capital Asset Pricing Model (CAPM) from financial economics; its parameters can be objectively measured from publicly available information. Geostatistics is used to derive simplified random cash flow models which incorporate the impact of improved deposit knowledge in terms of reduced estimation variance. The application of the theory is illustrated by means of hypothetical exploration optimization examples.

Jan 1, 1986

Jan 1, 1971

By Matsubara, A.

THE problem of the equilibrium between iron, carbon, and oxygen was first carefully investigated by E. Baur and A. Glaessner,1 who determined the equilibrium conditions of the two reactions Fe304 + CO ? 3FeO + C02 (1) FeO + CO ? Fe + C02 (2) within the range of temperature of 350 to 900° C. The next series of investigations was made by R. Schenck and his co-workers,2 who sought to check the results of Baur and Glaessner's work within the range of 550° to 700° C. and to elucidate the conditions of formation of iron carbide. The equilibrium conditions at the higher temperatures, however, are generally understood to be much more complicated, owing chiefly to the formation of solid solutions between iron, its oxides, and carbide; nevertheless their determination is of much more practical importance than those at the lower temperatures. It is well known that each of the reactions is reversible; equilibrium is established when the partial pressure of oxygen in the gaseous phase has become equal to the dissociation pressure of magnetic oxide in equation 1 and that of ferrous oxide in equation 2. These equilibria are subsequently designated by "the Fe304-FeO equilibrium" and "the FeO-Fe equilibrium," respectively. As the Fe304-FeO equilibrium has three phases with three components, it must be bivariant. But the reaction involves no pressure change in the gaseous phase, hence the final composition of the latter is practically unaffected by pressure. To know, the equilibrium conditions, the compositions of the gaseous phase at different temperatures must be determined. At the higher temperature, however, iron and its oxides dissolve one another in various proportions forming solid solutions; in many cases the content of oxygen in the solid phase becomes a new independent variable.

Jan 2, 1921

By Richard L. Bullock

Believe it or not, mine evaluation and feasibility studies are as old as the industry itself. In the first recorded writing on mining by Agricola (1556), he gave several clues as what to look for in evaluating a mine, to determine if it was economically feasible. Below is the guidance from Agricola, with my interpretation of what he would include today. Now a miner, before he begins to mine the orebodies must consider seven things, namely: ? The situation (the geography/topography). ? The conditions (the geologic/mineralogic and mining conditions). ? The water (availability, hydrology and ownership). ? The roads (plus the railroads, power lines, all other infrastructure). ? The climate (the weather-rainfall/environment). ? The right of ownership (the land and legal entitlement). ? The neighbors (the social environmental concerns of the area). It is amazing how much of his guidance has not changed in 455 years. Yet Agricola gives no guidance on determining the correct cost, or determining the correct commodity pricing. But he does give a few words of caution on the related ethics involved on buying mineral properties: ?A prudent owner, before he buys shares, ought to go to the mine and carefully examine the nature of the vein, for it is very important that he should be on his guard lest fraudulent sellers of shares should deceive him.? Three hundred years later (1866), to further amplify this point, in the most famous thing that Mark Twain never said, as an introduction to a lecturer to an audience of gold-miners at Red Dog, CA, the famed author/humorist allegedly described a mine as ?a hole in the ground owned by a liar? (Farrar & Rinehart, 1935). So, one might conclude that between these two dates, the mining industry did little to improve its reputation. Unfortunately, since Mark Twain allegedly made those remarks, we have not done near enough to gain accountability for the mineral industry.

Jan 1, 2011

By William A. Beck

The K.T. Dome Mine in Owen and Henry Counties, Ky., has been operated intermittently under several different owners since the early nineteen hundreds. No record of total production is available, but it is said that during 1943 and 1944, while being operated by the Twin Valley Mining Co., 30 cars of zinc concentrates and 10 cars of lead concentrates were shipped. The vein can be traced for about 10 miles along the strike from Lockport, Henry County, to Big Twin Creek in Owen County. It pinches and swells both vertically and horizontally and is reported to average 20 inches in width. In order to develop additional reserves on the property, the Bureau of Mines drilled four holes on the south extension of the vein. Drilling disclosed that the vein dips to the west on the south side of the Kentucky River and is continuous along the strike and in depth. However, the extent of mineralization in the vein varies widely.

Jan 1, 1949

By C. P. Mangelsdorf

The success of the Birmingham roof truss (Figure 1) in supporting some difficult roof conditions, particularly in the Illinois coal basin, has given impetus to the development of a number of alternate schemes. These schemes attempt to alleviate two major problems with the Birming-ham truss, namely, the time required for installation and the cost of material. Because of the difficulty of drilling angled holes and the number of different pieces of hardware which must be handled manually, most operators have been unable to install Birmingham trusses in the cycle and have had to schedule truss crews during the maintenance shift or whenever they would not impede production. Due to this delay the truss has traditionally been viewed as a supplemental form of roof support. In fact, the truss might qualify as primary support and replace at least two bolts if it could he installed in the cycle (and MSHA would accept it as an alternate in the roof plan.) [ ] Figure 1. The Birmingham truss. Two attempts to deal with the first difficulty have sought to streamline the truss hardware while preserving the essential character of the Birmingham truss. One of these, by Peabody Coal, is reported elsewhere in these proceedings by C. Bollier. Another is a contract issued by the Bureau of Mines to Bendix Corporation for the development of a machine, particularly suited for use in low coal, which will automate many of the operations currently executed manually. This machine is expected to be ready for field testing by fall of 1982. Once in place, a truss installed by either of these schemes will interact with the roof in the same way as a conventional Birmingham truss. An alternate approach has been proposed by several different manufacturers independently. Although the hardware details differ. the essential idea consists of two angle bolts, the heads of which are connected by a horizontal chord tightened to some pre-determined tension. Figure 2 shows the generalized concept and does not depict any one of the four systems proposed. The advantage of this scheme is that the angle bolts can be installed and tightened in the cycle, and as bolts, immediately satisfy the roof control plan. The horizontal chord can be added later to achieve almost any initial desired roof loading, the limits of which are defined below this scheme is referred to here as the angle-bolt truss. Because of a fundamental difference in the way in which load is transferred between chords, this design does not interact with the roof under subsequent loading in the same manner as a Birmingham truss. The purpose of this paper is to examine this fundamental difference and its consequences. [ ]

Jan 1, 1982

By Theo B. Comstock

Since 1892 the writer has published several articles in the Engineering and Mining Journal concerning the relations of the

Jan 1, 1901

By Armando Diaz

Vedanta Resources plc is a London listed diversified metals and mining group. The group produces aluminium, copper, zinc, lead and iron; also commercial energy. In this sense, the paper show all the steps on how this expansion is going on, because is the beginning of the plan.

Sep 12, 2011

By D. Vanni

Constructing new infrastructure in urban areas increasingly entails the use of sophisticated techniques for soil improvement in order to minimize surface disturbances in adjacent areas and damage to existing structures. In Naples, at the new Piazza Garibaldi subway station, TREVI built a 45 m deep shaft using a hydromill, and utilized soil freezing for the excavation of the four station's tunnels, fifty meter long, located approximately 30 meters below the water table. An innovative use of directional drilling was specially developed by TREVI to successfully complete this challenging job.

Jan 1, 2006

By Denis Huber

The technical assessment of the final works on the "Stéphany Palace" project at Menton in France's Alpes-Maritimes region shows the importance of daily project monitoring based on the observation method recommended by the European standard Eurocode 7 which applies to Foundations and Geotechnical Engineering. Excavation operations to a depth of 10 m near the France-Italy railway track and adjacent buildings required precise observation of land deformations, regular piezometric monitoring as well as special design arrangements. Temporary active tie-rods were thus placed in phases in order to control deformations in the retaining structures resulting from excavation operations. The Menton region, terminating the Alpine arc of mountains, naturally required the consideration of seismic forces in phase in the lower floors of the building, directly linked to the buried walls. These calculations were carried out in accordance with the PS69/92 rules, calling for an increase in dynamic thrust under the effect of gravity field rotation.

Jan 1, 2002

By B. S. Blakeney, E. P. Abrahamson II

The effect of the transition elements in binary solid-solution additions upon the recrystallization temperature of iron has been investigated. All these elements immediately raised the temperature, the majority having their greatest effect in less than 0.10 at. pct. A correlation is noted between the rate of change of recrystallization temperature with atomic percent solute and the electron configuration of the solute element. THE work of Abrahamson and rant' on binary chromium-base alloys indicated that a correspondence existed between the effect of each solute element on the brittle-to-ductile transition temperature of chromium and the ground-state electron configuration of the element added. This was felt to be a bonding phenomenon and would be expected to be observed in measurements of other properties involving the breaking or exchange of atomic bonds. From this work it was postulated that a like correspondence should be found for other properties of binary alloys, such as recrystallization. This study is an effort to check this postulation using binary solid-solution iron-base alloys. Previously, the majority of recrystallization studies were carried out on steels. However, Tammann2 investigated the recrystallization of iron as effected by Co, Ni, Si, Mn, Mo, and Cr and stated that elements with the same crystal structure at room temperature as iron appeared to be more effective in raising the recrystallization temperature. Austin, Luini, and Lindsay3 studied the effects of Ni, Cr, Mn, Co, Si, and Mo on cold rolling and annealing, but noted no trend. Abrahamson and rant,' in their work on the effect of both substitutional and interstitial elements upon the brittle-to-ductile transition of chromium, have shown that the outer electron configuration in the ground state of the solute element appears to be the prime determinant of the transition temperature. PROCEDURE All alloys were made using 99.95 + pct Fe with 0.02 wt pct 0, 0.004 pct C, and 0.001 pct N. All alloying elements were 99.9 + percent pure. Metal-lographically the alloys, out to at least 0.1 at. pct, appeared to be in solid solution. Though several published phase diagrams tend to dispute this.4 All alloys were arc melted six times and cast into square 400-g ingots under an argon atmosphere.

Jan 1, 1961