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By H. M. Callaway

There are key words common to Government and the minerals industry, the use of which immediately spark interest, argument and confusion. Among these is productivity, a term ranking for widespread misunderstanding with mineral self-sufficiency and mineral conservation. Each interpretation of these words tends to emphasize a single aspect and either minimize or ignore the complex dynamic system of things that influence the Nations mineral productiveness. This paper1, abstracted from a monograph on lead now being prepared for publication by the Bureau of Mines, not only sheds light on the trend of productivity in the lead-zinc mining industry but it presents the basis for forming a common general notion of what the term productivity implies.

Jan 11, 1961

By Lawrence F. Schubert

Instrumentation is not a stranger to the minerals processing industry. In fact, very few plants now exist that haven't to one extent or another adapted operations to instrumentation. But with the rapid growth of such controls has come the need for effective departments composed of men trained to maintain and repair the instruments; here is where many firms fall short. The importance of the role an instrument department should play is underscored by the omnipotent effects which instruments often exert over an operation. Reserve Mining Co. is an example: while instrumentation at this taconite plant represents approximately 2% of the process equipment cost, a breakdown of instruments may result in the ineffective use (or complete shut-down) of the other 98% of plant investment.

Jan 7, 1966

By John F. Abel

"The most conservative persons I ever met are college undergraduates." Woodrow Wilson said that in 1905. No one is saying anything like it today. Chaos on the campus was a cliche of the sixties. Since 1905, education has expanded in every direction. Many more people are being educated for much longer periods of time. The school-leaving age has risen from 14 years to 20 years, on an average. Many are in school until after their 25th birthday. On the surface this situation appears all to the good. Our technical society needs a massive yearly infusion of semitrained (or educated, if you prefer) new blood. The efficiency of our economy and our standard of living are tied to high individual productivity which can be achieved only with an educated work force. Our democratic institutions are said to be founded on an educated electorate.

Jan 1, 1970

By F. W. von Batchelder

The principles of microradiography and their application practically coincided with the discovery of X-rays. These principles were first used in the metallurgy field by Heycock and Neville1 in a study of the dendrite structure of alloys of Au-Na, Au-A1, Cu-A1, and Ag-A1. The method was introduced in the USA by clark2 after a visit to France. Scores of papers have been written, and a very complete bibliography on this subject was compiled by the Eastman Kodak company. Although a number of papers have discussed X-ray

Jan 1, 1959

By T. F. Petty

During 1935 there were drilled in North Central Texas 1071 wells, of which 565 were dry holes, 469 were oil wells with an initial production of 43,766 bbl. and 37 were gas wells with an initial production of 129,332,000 cu. ft. Production has been 14,180,042 bbl., or a daily average of 38,849 bbl. In Table 1 are listed the various pools of the district. Most of the smaller pools are of minor importance and are merely productive spots. Numerous other similar spots might have been listed as pools but their production is included in other fields. There are a few flowing wells but practically all of the wells are being pumped. The estimated potential is about 50,000 bbl. and the allowable production is based on the Texas Marginal Well Law. In Table 2, wildcat wells that have resulted in the discovery of pools or important extensions to old pools or that have contributed to the geological information of the area are listed.

Jan 1, 1936

By F. Hulsmeir

The increase in drilling activities in Venezuela noted during the latter half of 1932 continued, and 132 wells were completed in 1933 as compared to only 60 completed during 1932. Notwithstanding these new wells, 114 of which were producers, and also the appreciable increase in artificial lifting installations during the year, Venezuelan production was maintained at only a slightly higher level than in 1932, amounting to 120,356,000 bbl. in 1933 as compared to 118,167,000 bbl. in 1932. However, at the end of the year the daily average production of 358,-860 bbl. was 16 per cent higher than that at the end of 1932. Exports from Venezuela recorded an increase of approximately 4 per cent, totaling

Jan 1, 1934

By Thomas E. Howard

Scientific research in mining has a comparatively short history. So long as it was possible to maintain adequate mineral supplies by long-established methods, there was little need for the scientific approach. That the end of this comfortable situation is at hand is evinced by the variety and rapidly growing amount of mining research in progress all over the world. The pattern of development of mining research in other countries shows that it started only after a problem became critical. Therefore, the work generally has been short range and usually concentrated on a specific problem. An example is the preoccupation in western Europe with the problem of strata control.

Jan 1, 1962

By S. C. Lee

An uncoupled thermoviscoelastic finite element formulation with an application to Underground Coal Conversion (UCC) is presented. An incremental solution procedure with an implicit time stepping scheme is used under the thermorheologically simple material (TSM) postulate. The presented formulation, for a homogeneous and isotropic medium, is employed in the simulation of the UCC post-burn phase. Temperature, displacement, stress, and failure responses under thermomechanical loading are predicted. The solutions for the selected field problem indicate potential roof collapse, stress relaxation, and modest surface subsidence with a progressive thermal and failure front. The corresponding thermoelastic responses with temperature- dependent elastic properties are also presented and compared with the thermoviscoelastic results.

Jan 1, 1984

Some specific observations might be appropriate concerning the reporting of Research and Development results. Each report is usually directed towards a particular group, such as technical, operational financial, or marketing. The requirements and background of the group receiving the report must be considered, and the emphasis and coverage geared to the training of people concerned. For reports that might have large and varied distribution, it is often feasible to group, either as sections or appendixes, the special details and information of interest only to certain functions within the organization. (A check list prepared in conjunction with the various users of the report is sometimes useful to prevent omissions.) Typical points listed might be: Financial- (1) capital requirements, (2) timing of capital expenditures, (3) tax implications, including depreciation, depletion and investment credits, (4) changes in working capital.

Jan 10, 1967

By I. E. Rosenzweig

GEOPHYSICAL prospecting by earth-resistivity methods is frequently applied to investigation of structural problems in geology. Fig. 1 indicates a scheme of the general arrangement used in these methods of measurements. The battery (or generator) E is connected with two "current electrodes" II and 12. The current of intensity J, supplied by this battery, passes through the earth between these elec- FIG. 1.-GENERAL ARRANGEMENT OF APPARATUS. trodes. A potential difference U will be measured between two other electrodes V1 and V2, called "potential electrodes." According to the configuration of electrodes (Fig. 1), the resistivity of a homogeneous soil results from the formula p = 2pcaU/J [1] where c=1/a/b11 - a/b12 ? (a/b21-a/b22) [2]

Jan 1, 1938

By Frank Foote

IN recent years the constitution of the high-silver aluminum-silver alloys has been extensively investigated. Hansen1 has re-viewed the literature to 1935. More re-ently, Obinata and Hagiya,2 Hofmann and Volk,3 Taziri4 and Tishchenko5 have con-firmed the general features of the phase diagram in the region around 25 atomic per cent aluminum. In this paper we present the results of high-precision measurements of lattice con-stants of the silver-rich alpha solid solution in the homogeneous range and the neigh-boring two-phase regions. These results are used to establish the nature of the solid solution, the identity of directly measured densities with those calculated from lattice constants and the homogeneity limits of the alpha solid solution with respect to three different neighboring phases. A study of the earlier investigations indicated that the last two subjects in particular required new and accurate data.

Jan 1, 1940

By H. Conrad, K. Janowski, G. Stone

The available data on the dynamics of plastic flow of sapphire indicate that the deformation rate in the temperature range .from 900° to 1700°C can be expressed either as A number of investigators1-10 have established that sapphire deforms plastically above 900°C, the most common mode of deformation being slip on the basal plane in the [1120] direction. Under certain conditions and at temperatures above 1500°C, slip

Jan 1, 1965

By Roger K. Clifford, Gary W. Hudiburgh

The amine flotation of feldspar from a magnetite concentrate produced at a domestic concentrator was investigated using zeta potential measurements, Hallimond tube flotation tests, and laboratory-scale flotation tests. The point of zero charge of six feldspars (microcline, orthoclase, albite, anorthite, anorthoclase, and oligoclase) range from pH 1.4 to 2.5. Hallimond tube flotation tests using amine flotation reagents were performed on these feldspars and on gangue material (quartz, albite, and microcline) from the magnetite concentrating plant. Laboratory-scale (623 g and 2500 g) flotation tests were performed on the magnetite concentrate to float the feldspar. The effects of three different collectors, two levels of collector concentration, three pH levels, starch, HF acid and regrind were investigated.

Jan 1, 1977

By G. S. Rice

Undoubtedly there is a serious problem through the juxtapostion of gas and oil wells and coal mines, not only at the present time, but possibly of far more serious import for the future.

Jan 1, 1915

By Kevin Clermont, William N. Kelley, William E. Bonini, John H. Vreeland

Gravitational field anomalies have been observed over many igneous intrusives of medium (4000 sq km) to small (100 sq km) size in outcrop area. These studies give good results because the residual anomalies can be separated from larger-scale crustal anomalies and density contrasts usually are present. Although unique solutions are not possible, the analysis of the gravity anomalies place important limits on both the areal and depth extent of the intrusive bodies. Of all possible geophysical techniques, gravity studies offer the most promise in the determination of the shape in depth of intrusive bodies.

Jan 1, 1972

By J. C. Wynn

This paper outlines research conducted by the US Geological Survey on the geophysical signatures of chromite. Results of the chromite study highlight the importance of a laboratory research Phase (petrophysical and petrographic studies) at the beginning of work on a new commodity; a realistic ore deposition model to serve as a conceptual framework, and the necessity to continually test, refine, and modify it during the study; and indirect geologic/geochemical indicators, secondary associations, and the use of multiple physical properties. The keystone to the success of the study is frequent and substantive dialogue among geologists, geophysicists, and geochemists.

Jan 1, 1984

By Barry H. G. Brady

A state of stable equilibrium is required in a mine structure to ensure that small increases in the mined void are accompanied by only small displacements of the rock mass. Methods of determining the stability of equilibrium in a rock mass currently require a geometrically regular stoping layout, and introduce a number of simplifying assumptions. The method reported in this paper models the mine near-field using Finite Elements, and the far-field using Boundary Elements. The stability of equilibrium in the modelled structure can be assessed directly from the value of selected principal minors of the global stiffness matrix.

Jan 1, 1981

By M. Allingham

This paper examines the contribution which econometric methods may be expected to make to the specification of commodity agreements, and how in turn computer methods may help in this. Starting from the specification of a model, the paper examines four activities: estimation of the unknown parameters; analysis of the properties of the model; simulation experiments with the model; and control of the model. In each of these activities the basic methodology is outlined, and the contribution of computer methods assessed.

Jan 1, 1977

By F. H. McDowell

About a year ago Dr. Raymond, as engineer of Messrs. Cooper, Hewitt & Co., together with Mr. Rothwell, was considering the removal of the ore-floors and pillars from the Peters Mine at Ringwood, N. J., where the limit of profitable working by the old method of mining had been very nearly reached. Mr. Ferdinand Ruttmann was engaged to make the survey which forms the basis of the accompanying diagrams. At first it was thought that some method of mining and filling might be introduced with advantage; but after a careful study of the operations at the Tilly Foster it was decided to adopt the system of stripping.

Jan 1, 1890

Ask any mineral industry executive what he considers one of the most expensive aspects of getting a product to the ultimate consumer and invariably the answer will be transportation. Some company officials say that transportation charges alone account for over half of the total cost of most products. If these judgments are correct and a recent invention turns out to be the long-awaited breakthrough that shippers have been looking for, then many producers can look forward to slashing their delivery costs by 90%.

Jan 9, 1969