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By A. G. Loomis

Although secondary-recovery methods have not been applied widely in California, it is apparent that increasing attention and effort must be given to this phase of recovery if the State is to maintain its high rank as a petroleum producer. Steadily increasing demands for petroleum products and decreasing rates of discovery of new oil fields, with rapid depletion of existing reserves, emphasize the prospect of an adverse situation of supply and demand in the not-far-distant future. If the trend of discoveries becomes more favorable or if more complete economic recovery of the oil in place can be obtained by secondary recovery, this situation can be averted. Not only are these reserves of economic importance to the petroleum industry for meeting increasing market demands; but economic reclamation of such reserves is an important conservation measure, which will prolong the productive life of many fields. Accordingly, progressive operators in California are alert to the possibilities of secondary recovery and have done much to implement such operations wherever feasible. Most current operations are of the pressure-maintenance type, in which the reservoir pressure is maintained or partly maintained by injecting natural gas to in-crease oil recovery. The possibilities of recovering additional oil from stripper fields by gas drive and water flooding (including water disposal) also are being tested in experimental field projects. Table 1 summarizes current gas-and water-injection projects in California.

Jan 1, 1952

The Johnny Mercer lyrics 'You've got to accentuate the positive, Eliminate the negative, Latch on to the affirmative à' would best sum up the traditional approach to community relations in the mining industry. This '90s 'Public Relations spin' approach, usually backed up by scientific data, technical reports and graphs outlining risk probability and the impact potential on people and communities, is being challenged. Challenged by communities who have greater access to information, demand greater levels of transparency and corporate responsibility of large corporate operations and possess greater awareness of the communities they live in.   The growth of the environmental movement, of anti-globalisation, anti corporatism, apprehension of a large corporate's ability to deal with community issues, and a lack of faith in the abilities of regulators to regulate corporate activities, means our industry faces challenges on multiple fronts. It must now be able to address these from a personal/community perspective if it is to remain relevant within communities.   One of the keys to this is linking the internal activities and responsibilities to the externals concerns and demands for higher levels of operation and care.   This presentation draws on Corporate Public Affairs trends, functions and approaches and the application to External Affairs activities within Newmont Waihi Gold's operations in Waihi and regional exploration activities throughout the Hauraki Goldfields.   The approach presented works on the philosophy that communities don't necessarily have to like what we do, but should be able to identify and recognise the way in which we involve them in decision making, communicate our intentions and respond to issues.

Jun 1, 2010

By L. C. Lang

Effective and profitable mining begins with good blasting results. While the importance of sufficient energy to break the rock is recognized, more attention should be paid to the time factor in blasting. Fragmentation, looseness and the shape of the muckpile can be improved and energy levels lowered through the use of proper delays. The long delay is also the most important parameter in establishing stable walls along the final limits of the pit. The time factor in blasting is explained through the rock acceleration process and its practical application is demonstrated by case histories.

Jan 1, 1981

By E. García-Ramos, P. Flores-Sánchez, E. G. Palacios, B. Zeifert, A. Romero-Serrano, M. Hallen-López

Chromium containing slags from stainless steelmaking may eventually be leached by acidic environments, therefore they should be treated before being stockpiled or land filled. In this work, synthetic slags were prepared and the effect of CaO/SiO2, Cr2O3, MgO and Al2O3 contents on the stability of the mineralogical species formed was analyzed. The morphology and composition of the slags were analyzed by XRD and SEM-EDS, whilst their chemical stability was evaluated by leaching with an aqueous acetic acid solution. It was found that CaCr2O4 and CaCrO4 are present in slags prepared with neither MgO nor Al2O3. The Al2O3-based slags mainly produced Ca2Al2SiO7 and the Cr(VI)-containing oxide complex Ca4Al6CrO16, whilst MgO-based slags produced MgCr2O4 as main mineralogical species. Additionally, Eh-pH diagrams for the Ca-Cr-H2O and Mg-Cr-H2O systems at 25 °C were constructed. The lowest Cr concentration levels in the leaching liquors corresponded to MgO-based slags owing to the stable binding of Cr in spinel with MgO. It was also observed in the Al2O3-based slags that increasing the slag basicity from 1 to 2 the leachability of the slags are notably increased.

Jan 1, 2008

By J. Muller

Keywords: Pyrometallurgy, blast furnace, slag viscosity, slag liquidus temperature, phase equilibria The viscosity of molten slag in blast furnace operations is an important process variable, influencing the rate and location of reactions inside the furnace, as well as the ease with which the final slag could be removed from the furnace. To optimize these processes, it is necessary to estimate the slag viscosity and liquidus temperatures as accurately as possible, and know the target values. Models to predict viscosities and liquidus temperatures, incorporating phase equilibrium calculations, have been developed and validated with measured data. Various diagrams have been developed to illustrate how the properties vary with composition and temperature, including pseudo-ternary diagrams of SiO2-MgO-CaO-Al2O3 for viscosity and liquidus temperature. Models were also applied and methodologies developed to analyse historical blast furnace operations and determine target values.

Jan 1, 2011

By Mark Tsirlin

Kinetics of the initial oxidation stages of diffusive silicide coatings on 8 molybdenum and niobium at 1100 - 1700 and under the pressure of 400 and 1330 Pa has been studied using methods of gravimetry and gas phase analysis of oxygen, as well as by SEK, XRD and EDMA methods. The first oxidation stage described by asymptotic equation in case of NbSi coating changed over to the stage described by parabolic equation. The asymptotic law was shown to depend on non - stationary conditions on the oxide layer boundaries. Interconnection between silicides and quartz structures, on the one hand, and peculiarities of oxidation kinetics, on the other, is [discussed. The possibility of estimation oxygen atom jump frequency in quartz and fractions of oxygen reacting with metal and with silicon proceeding from the analysis of the kinetic data was ascertained. Conditions of oxidation kine- tics transfer from asymptotic (or parabolic) stage to a non - protective "linear" stage, associated with volatile ~roduct formation, are also discussed.

Jan 1, 1995

By R. W. Raymond

THIS meeting was held in the new home of the Institute, the United Engineering Society Building, 29 West 39th Street, New York City, directly following the Dedication ceremonies. The first session was held in the large Auditorium, Thursday, April 18. The meeting was called to order by Mr. John Hays Hammond, President of the Council, who said Before taking up the reading and discussion of papers, I will call upon Dr. Rossiter W. Raymond, the oldest living past-President of the Institute, who has been in harness almost continuously for thirty-six years, and who has contributed more than any one else to bring this society to its present great success and to establish the reputation of the American mining engineer the world over, for a few words supplementary to those which were uttered to engineers generally, during the sessions of yesterday and the day before. ADDRESS BY R. W. RAYMOND. The generally accepted Darwinian doctrine of the survival of the fittest is sometimes illustrated by persons who are supposed to be the fittest because they have simply survived. I fear that I come under that category. Almost all of my contemporaries in the early history of this Institute have passed away. Only one or two of the original founders remain, and I may fairly say that scarcely any remain who were active at that : time in shaping the organization and the future career of the Institute. In May, 1871, I was thirty-one years old. Next week I shall be sixty-seven years old. All the intervening years have been devoted to the service of this Institute almost continuously, either as President or Vice-President or Secretary. You may easily imagine, therefore, with what pleasure I greet you on this occasion. I am not here to extend to you the welcome of the City - of

May 1, 1907

By Renato G. Bautista

"The development of processing methods for the preparation .of three electronic materials with rare-earth components is discussed. The resulting processing innovations are the results of a search for an economically competitive pilot scale or industrial production flowsheet without compromising the required properties of the final products. The three cases highlighted in this presentation are: 1) The preparation of high energy (Pr-Nd-Ce)FeB magnets for MRI application from a mixed-rare-earth oxide with a narrow range of composition directly prepared from the solvent extraction circuit of bastnaesite ore. 2) The kg production of the giant magnetocaloric effect Gds(SixGe1-x)4 magnetic refrigerant materials from commercial grade gadolinium metal (95 to 98 at. % pure) instead of high purity gadolinium metal (99.8 at. %); and 3). An industrial chemical synthesis flowsheet for the production of the superconductor precursor of YBa2Cu3O7.INTRODUCTIONIn the laboratory discovery stage, the synthesis of a new material is carried out using very high purity components, usually the highest purity available. As the new material is studied and characterized, the effectiveness of its desirable properties becomes better defined and understood. The evaluation of the effectiveness of the .property over the range of a given parameter and other interactions are further studied. Once it's potential application becomes clear, a practical and economical processing method need to be developed. The successful material processing flow sheet does not necessarily have to be a scale up of the laboratory procedure. At this stage, substitution of starting components and with lower purity materials is considered as the economics of the processing becomes a major issue. In addition, other approach to it's synthesis"

Jan 1, 2000

By D. R. Tesarik

The factor of safety, the traditional measure of stability for earth embankments, is graphically presented in factor of safety charts in this Bureau of Mines report. Factor of safety contours are drawn for homogeneous earth embankments for two contrasting situations: (1) no phreatic surface and (2) a phreatic surface that assumes 10-pct freeboard. The factor of safety can be read directly from the charts if the physical properties of the soil and the geometry of the embankment are known. The curves provide a quick first approximation of the "most stable" and "least stable" condition of the embankment. The Simplified Bishop Method was used for the safety factor calculations, and a sequence of least squares curve fitting steps was used to present the factor of safety in final chart form.

Jan 1, 1981

By Thomas B. Faddies

The Trixie mine is located in the East Mining District. Since production began in 1970 over 450 000 tonnes of ore grading 239 grams of silver, 6.9 grams of gold, and 1.2% Cu have been mined from veins in Cambrian Tintic Quartzite. Detailed geologic mapping and extensive sampling are essential for compiling the data base required for efficiently developing and mining known reserves as well as planning exploration and development work. Although the basic techniques used by the geology group at the Trixie were developed many years ago, the reduced activity in underground precious metal mining in the U.S. have made these techniques less familiar to many presently active geologists. The increased activity in precious metals search and exploration again offer cause for the application of these techniques as a prerequisite to efficient exploration, development and production.

Jan 1, 1983

By M. Albertson

UNITED STATES petroleum pro-dU6tion during 1937 materially exceeded? that of any previous year. Firm control of the production rate was maintained under State and Federal laws and aided by the' Interstate Compact. During the first ten months," crude oil prices were stable, except for a slight increase early in the year. Toward the end of the year, uncertainty of price structure be-came evident and a sharp reduction in allowable production was under way. Exploration for new pools and development of .pools already discovered continued active throughout the year. Production control agencies in Texas, and to a less extent in New Mexico and Louisiana, appear to have had increasing difficulty in holding crude oil output to allowable limits. The situation elsewhere is less well known but probably the same condition exists in other important producing States whether control is by State commissions or by unofficial bodies.

Jan 1, 1938

By Oliver C. Ralston

The growing popularity of perlite (sometimes spelled pearlite) as a raw material for thermal expansion into pumicelike products in the Western States has prompted a preliminary investigation of the properties of such material and the problems that want solution to put a perlite industry on a firm foundation. The Bureau of Mines is undertaking the gathering of data and the solution of these problems, and the following paper records some of the available information. and the promise of the material, with some comparisons of advantages of the various competing lightweight aggregates that can be made from siliceous volcanic glasses and rocks containing entrapped or dissolved water that causes their expansion on' quick heating to their softening points. This new industrial rock has caught the fancy of the mineral industry in the western States because it has Fume advantages over natural pumice. Chemically, it is typified as rhyolitic in composition, and one may find obsidian, rhyolite, pumice, pumicite, and perlite from the same vant and contemporaneous in origin. The material need not be rhyolite but should be a siliceous or acid lava and contain 2 to 5 percent water still in "solution" in the rock. On quick heating to the softening temperature the material puffs, due to conversion of the contained eater into bubbles of steam. Slow heating causes gradual release of the imprisoned water by decrepitation and. cracking and-results in, very little puffing. Perlite is often in the form of ovoid volcanic bombs formed by explosive eruption of large masses of lava into the air, where they, quickly cool, with escape of little of the contained water, exceptt perhaps for a hollow interior. Since they cool in layers they have an onion-type structure and a pearly luster from interference of light between the. layers, which is' the origin of the name "perlite." Perlite may occur in intruded flows that have been quickly cooled and partly expanded but retained most of their magmatic water content. Obsidian may be the same lava cooled quickly under conditions that prevented crystallization of feldspars and other minerals, leaving the volcanic glass that may or may not retain all of the original contained water.

Jan 1, 1946

By Richard Thomas Newcomb

The trend towards proportionately rising volumes of surface mining through- out the world and especially in the United States has led some observers to predict that the future of underground mining is quite limited. Certainly, the simple extrapolation of current trends1 gives evidence of a compelling sort for the hypothesis that technological progress is proceeding at a faster pace in surface than in underground mining. This paper attempts to examine the basis for these predictions by searching the historical record on differential rates of productivity as these are observed in iron ore and coal mining. In recent years economists have discussed "technology gaps" among industries or segments of the same industry, by which they mean that mechanisms for invention and its diffusion are faulty or retarded in such a way that feasible cost-cutting innovations are not applied or developed, even though technicians regard them as practical.2

Jan 1, 1968

By J. Bruce Clemmer, M. F. Williams, B. H. Clemmons, Carl Rampacek, R. H. Stacy

"INTRODUCTION This report is the first of several dealing with the application of flotation methods for beneficiating the calcareous and siliceous red iron ores and ferruginous sandstones of the Birmingham district. The flotation study was part of a general investigation of the concentratability of various iron ores of Alabama and other Southeastern States undertaken by the Southern Experiment Station of the Bureau of Mines, United States Department of the Interior, in cooperation with the University of Alabama, Tuscaloosa, Ala.Batch testing and pilot-plant flotation testing of the calcareous red ores of the Birmingham district have been in progress for several years, and although some phases of the study are not yet completed, enough data are available to indicate that many of the ores will yield marketable-grade concentrates with good recovery.The first flotation tests on the calcareous red ores employing conventional methods either the iron oxides or the siliceous gangue materials failed to give the desired results. The inferior separations obtained or prohibitive reagent requirements made the methods unattractive. Other more effective flotation methods were sought. A laboratory study of various reagents was undertaken. It resulted in the development of two attractive methods embracing anionic flotation of the activated siliceous gangue from the retarded iron oxides. The methods were similar in that fatty acid or soap-collecting agents were employed in strongly alkaline pulps to float the naturally activated quartz from the iron-ore pulps. The methods differed, however, in the addition agent employed to retard the hematite or hematite and calcite. By proper choice and quantity of the addition agent, the calcite could be floated with the quartz or retarded with the hematite as desired. Ability to recover or reject the calcite gives added flexibility to the separation. Although the methods have their limitations and cannot be considered ""cure-alls,"" they have given encouraging results on a number of calcareous red ores that heretofore proved difficult to concentrate by conventional flotation procedures."

Mar 1, 1945

By JAMES BRADLEY

THE Spanish mine is in Nevada County, California, 21 miles northeast of Nevada City by road, and 3 miles north of the town of Washington. The mill and surface buildings are on Poorman's Creek at an ele¬vation of 3,000 ft. About 35 men are employed at the property, which is producing 50 tons of ore per day. Electric power, purchased from the Pacific Gas and Electric Co., is brought in from Alleghany, seven miles away. In the early days the mine was operated by F. W. and P. R. Bradley. Between 1883 and 1899 the production was approximately $900,0)0 in gold. The ore treated during; that time yielded an average of 60 cents per ton and was mined and milled at a profit. The surface, oxidized, ore deposit was 30 to 100 ft. wide and was mined by the glory-hole method. The milling-plant at first consisted of a Blake crusher an-1 a small Huntington mill; later three large Huntington mills were added to the plant. In 1893 a new mill was built at a lower adit- It consisted of 10 stamps and four Huntington mills. The gold was secured by amalgamation, the recovery being about 50 per rent.

Jan 1, 1931

By D. I. Bardos, Paul A. Beck

A MARK, Boren, and westgrenl in their X-ray diffraction study of manganese alloys with 10 to 25 at. pct Si reported the occurrence of a phase with complex crystal structure in a Mn + 14.5 at. pct Si alloy after annealing at 800° or at 600°C. Recently Kuzma and Gladyshevskii2 identified Mn6Si as an R phase,3,4 the second binary R phase known. (A binary R phase was previously found in the Mn-Ti system by Waterstrat.5) A ternary R phase was reported earlier0 near the Mn-Si binary border of the Ti-Mn-Si system at 1000°C. In the light of the Russian work it now appears that this "ternary" R phase may be in fact an extension of the binary (Mn6Si)R phase. As already found by Amark, Boren, and Westgren, the corresponding binary phase is absent at 1000°C; the effect of titanium is evidently to stabilize it up to higher temperatures. In a recent paper Wieser and Forgeng7 gave the boundaries of this binary phase, which they referred to as 6. In order to re-examine the identity of this phase, an alloy of Mn + 14.5 at. pct Si was prepared by induction melting in helium atmosphere and annealed for 3 days at 800°C. The powder pattern, taken with an asymmetrical focusing camera of large dispersion and shown in Table I, was found to be that of the R phase, in agreement with the results of Kuzma and Gladyshevskii. For comparison, Table I also lists

Jan 1, 1965

By Wallace W. Roepke

Research to evaluate the lubricity effects achieved by spraying water on the cutting bit of a mining machine or spraying water on the coal during cutting has shown that neither practice affects cutting forces, as had been believed. However, when water was supplied to the cutting zone axially through the bit at 3,000 to 5,000 psi pressure, tangent'ial cutting forces were reduced an average of 30 pct at a I-in depth of cut while normal bit forces were reduced an average of 65 pct. Lower normal forces mean reduced bit wear, faster advance with greater depth of cut, and fewer coal fines.

Jan 1, 1985

By H. I. Aaronson, W. L. Winterbottom, G. M. Pound

On the basis of a statistical thermodynamic treatment of the data of smithz2 on the activity of carbon in austenite, a Darken and smith23 deduced that the interaction energy, wy, between carbon atoms occupying nearest-neighboring interstitial sites is repulsive. Aaronson, Domian, and pound 24 (ADP) have applied two different statistical thermodynamic analyses to the same data. One analysis, a composite of the treatments of Darken and Smith,23 Speiser and Spret-nak," and Kaufman, Radcliffe, and Cohen,26 primarily takes account of the positional entropic effects of wy in dilute solutions. The other, due to Lacher 27 and Fowler and Guggenheim," is also applicable to more concentrated solid solutions. The equations which both analyses produce for a,, can be rearranged so that, when In a,, is plotted against the appropriate function of the carbon content of the austenite, the plot will have a slope of unity when the correct value of wy is employed. Since no other constant need be simultaneously evaluated in order to make this determination, ascertaining the most probable value of wy from Smith's data on the bases of these analyses was an elementary problem in least-squares statistics. ADP demonstrated that the wy's obtained from both analyses vary with temperature in a statistically significant manner. McLellan, Gerrard, Horowitz, and sprague 29 (MGHS), on the other hand, have recently made a new statistical thermodynamic study of a,, and have concluded from this study that wy is independent of temperature. The equation which they derived for a,, is: where 0 = ratio of the mole fraction of carbon atoms to that of iron atoms, z = number of sites from which occupancy is excluded by the presence of a carbon atom and the repulsive character of its interaction with nearest-neighboring carbon atoms (z = zb in Ref. 24), and x = a geometric parameter taking account of overlapping of the exclusion shells of nearby carbon atoms. z is 1 when wy = 0 and 13 when wy = Q. For a given value of z there is a definite value of X . In the absence of an equation connecting z and X, MGHS computed geometrically the value of x at several integral values of z; x increases from 0.47 to 8.67 as z is increased from 2 to 5. MGHS fitted Eq. [I] to the a,, data of Ellis, Davidson, and Bodsworth30 at 925° and 1050°C and to the data of smithz2 at 1000°C. Confining z to integral values in the range 4 to 6, and also somewhat restricting AG, the values of z, X, and AG were sought which would minimize the average root mean square percent deviation, D, of the calculated a,, values from those obtained experimentally. Finding that D was almost always smallest when z = 5, they concluded that z is independent of temperature. Since:23, 26 where R = gas constant and T = absolute temperature, and w,, was considered to be similarly invariant, this statement cannot be strictly true. The temperature range employed, however, was small and the interval between the values of z tested was sufficiently large so that the results could still be consistent with a constant The statistical treatment of the a,, data applied by MGHS is clearly quite approximate. Since more than three values of a,, are available at each temperature, z, and X, and AG have actually been over deter mined, rather than underdetermined as their treatment implies. In order to make more complete and exact use of the a,, data, we shall employ the Legendre Method of Least Squares, as described by Whittaker and Robinson. This technique permits conversion of the overdetermined system of equations produced by the substitution into Eq. [I] of the available pairs of a,, and 0 data at a given temperature into an even determined system. Solution of the latter system yields the most probable value of each of the three constants. This procedure will allow a statistically rigorous test to be made of the conclusion drawn by MGHS in respect of the temperature dependence of In order to obtain linear iiequations of conditions" from Eq. [I], the exact values of the three unknown constants are replaced by G/RT = =/RT + y, where z, i, and aG are estimated values of the constants. This allows the conditional equations to be written in the form:'l where fi -f6, i, =/RT) = the right-hand side of Eq. [I] for a given pair of ayi and values. When applied to Eq. [I], these relationships become: The i equations of condition are reduced to three "normal equations" in the manner discussed by Whittaker and Robinson. The normal equations are then solved for a, ß, and y. Both of these operations are most conveniently performed by means of the computer technique of Winterbottom and Gjostein.32 This technique was used iteratively until the value of 0 (the most sensitive of the three correction factors) became 10.01. (Until they became small, a, 8, and y

Jan 1, 1969

By F. Doxey

Introduction Numerous papers have been written dealing with the construction and functions of, and the environmental conditions created by, Diesel locomotives. Therefore, it is not my intention to attempt to deal with these phases of Diesel transportation other than to make reference to them in ?relation to and in connection with actual operation. The rapid expansion of industry during recent years and the necessity of products being made available at competitive prices in home and world markets has made the demand for cheaper coal a very serious factor for the coal industry. This condition has meant each coal producing country looking into ways and means whereby greater productivity and reduction in cost could he achieved. Surveys made show that, in addition to face mechanization, savings, in some cases substantial, can be made in transportation. Ventilation The most efficient mines are in-variably the well ventilated ones, for it is true that, where there is good ventilation, there are usually good roads. These combined factors are very essential where Diesel locomotives are used. Good roadways and track allow speed, and good ventilation dilutes rapidly any disagreeable exhaust gases. Locomotive Development In the older types of auxiliary rope haulage, coal hauled per haul-age hand is usually very low.

Jan 1, 1951

By Hector M. Henao

The FeOX-CaO-SiO2 base slag at intermediate oxygen partial pressures is very often used in non-ferrous smelting processes. This slag would also contain Al2O3 and MgO because these compounds are normal components in the ore and the refractory of a furnace. The objective of the present work is to determine the effect of Al2O3 or MgO addition on the liquidus temperatures of the plain FeOX-CaO-SiO2 slags in the atmosphere between intermediate pO2 of 10-6 and that of iron saturation at 1250 and 1300 °C. The experiments were carried out at given mass%CaO/(mass%CaO+mass%SiO2) ratios ranging from 0 to 1 and at spinel-tridimite double saturation. The experimental results show that the effect of Al2O3 or MgO addition on the plain FeOX-SiO2-CaO slag is not uniform and depends on the content of Al2O3 or MgO, the oxygen partial pressure and the mass% CaO/mass% SiO2 ratio. It is apparent that Al2O3 or MgO addition enlarges the spinel or wustite saturation area at almost all the oxygen partial pressures and temperatures of this research. The obtained phase diagrams will be useful in the metallurgical industry to assist in the selection of slag chemistry, operation condition and development of new processes.

Jan 1, 2006