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By A. H. Lindley, Fraizer M. Stewart

For many years large mining companies were able to finance nearly all of their capital requirements from internally generated funds. However, during the last decade, funds needed for capital expenditures, dividends, and scheduled debt retirement have grown faster than cash flow. As a result the minerals industry has had to rely increasingly on other sources of funds. Getting the capital for new mining projects is a challenge, particularly for smaller companies. New methods of financing and new variations to old methods have been developed and more are needed. Commercial banks are short-term lenders. By policy their loans are limited to low risk loans-those made solely on the borrower's general credit, and secured loans where cash flow is sufficient to provide repayment within a comparatively short term. To maintain liquidity, banks prefer to make loans of less than seven years' term. If a longer loan is needed an insurance company or pension trust may take the long-term part.

Jan 1, 1971

By N. A. Ziegler

A certain amount of interest has been indicated recently in the resistance to oxidation at high temperatures of iron-aluminum alloys (rich in iron). Hautmanl published a paper in which some interesting results are given. According to his paper, only alloys containing at least 8 per cent aluminum indicate a marked improvement in their resistance to oxidation. At about this aluminum content, however, alloys become brittle, which considerably reduces their commercial value. About two years ago the author performed a series of experiments, the results of which are presented here. A series of iron-aluminum-carbon alloys was prepared by melting electrolytic iron, aluminum and high-carbon iron alloy in an induction vacuum furnace.2 The list of these alloys is given in Table I. Each alloy was forged in the ordinary way to All carbon determinations were performed by " Yensen " method. [N. A. Ziegler: Recent Developments in Analysis of Carbon in Iron and Iron Alloys. Trans. Amer. Electrochem. Soc. (1929) 56, 231.1

Jan 1, 1932

By M. Beus, R. Iverson, A. Dreschler, V. Scott

This paper describes research to improve safety during transport of ore and waste in underground mines. Field tests are underway in mines in Idaho and Montana. Strains measured on structural support members in an ore pass provided information about total forces acting on the structure as material was dumped into it. Results show that measured static loads were considerably less than actual total weight of the material dumped and that dynamic loads were subject to many factors, such as effects of blasting to remove hang-ups. Comparisons of measurements and computer results using a particle flow code indicated that several difficulties remain before achieving realistic determinations and models of the dynamic effects of particle flow in ort: passes and impact loads on the gates. Impact loads were overestimated in computer analyses as compared to loads measured in field tests. An alternative design approach based on softening the chute and control gate assembly is being proposed.

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who registered at Institute headquarters during .the period Jan. 10 to Feb. 10, 1915: N. H. Emmons, 2d, Dover, Mass. R. 0. Hocking, Redruth, England. Paul W. Gaebelein, Cornucopia, Ore. G. H. Carnahan, New York, N. Y. H. D. Kinney, Easton, Pa. W. A. Wilson, Salt Lake City, Utah. W. D. McDougall, New York, N. Y. H. V. Winchell, Minneapolis, Minn. Kirby Thomas, New York, N. Y. Mrs. H. V. Winchell, Minneapolis, Minn. V. T. Lawshe, Newark, N. J. Keijiro Nishio, Tokyo, Japan. Henry S. Stebbins, who has been connected with the firm of Oglebay, Norton & Co., Cleveland, since 1892, has resigned to accept a position with M. A. Hanna & Co. of the same city. E. L. Newhouse has been chosen First Vice-President of the American Smelting & Refining Co. in place of the late Barton Sewell.

Jan 3, 1915

By D. Harney

Accurate measurement, tracking, and planning are vital for efficient utilization of energy in any mining operation, the major focus of this paper. This can be done with a number of assessments: 1) accurately measure KWH usage and track peak demand periods first; 2) identify the electrical equipment that affects your usage and the conditions that require it to be running; 3) remotely monitor and control as much equipment as possible, especially larger pieces of equipment; 4) with your utility determine that you are on the most suitable rate for your usage profile, then understand how your utility company calculates your electrical bill; 5) recognize how production affects energy usage and utility costs; 6) keep historical records of everything you monitor; 7) make information, live and historical, available to everyone; and finally, with the knowledge of your equipment and energy needs, automate controls that you have identified to optimize your energy usage and time of usage.

Jan 1, 2007

(Under this heading will be published notes sent to the Secretary of the Institute of members or other persons introduced by members) Young mining engineer, and geologist, member, technical, graduate with four years' varied mining experience in the West and Southwest as miner, surveyor and engineer. Past 18 months, work in mine geology, mapping and examinations. Would prefer assisting consulting engineer or work with exploration company in foreign service. Unmarried. Age, 28. No. 331. Member; aged 35, married, with 10 years' experience in the Southwest, thoroughly competent to take full charge of mining and milling operations. Particularly fitted to handle either gold or tungsten producers. At liberty February 1. Will go anywhere. No. 340. A member wants a roving commission to examine old mines of the Mother Lode in. California, especially those which can be bought for their taxes. Some of these mines are reported to contain large quantities of low-grade ores which can now be treated at a profit. No. 341.

Jan 2, 1917

By C D. Ogg, P B. Pope, K M. Lynch, B K. C

Iron-reducing bacteria are able to couple the oxidation of an electron donor to the reduction of Fe(III) to Fe(II) under anaerobic conditions in the generation of cellular energy. Recent evidence suggests that these bacteria are phylogenetically diverse and widely distributed in nature. Our laboratory has isolated thermophilic, thermotolerant and mesophilic iron-reducing bacteria from numerous petroleum reservoirs with varying conditions, groundwaters of the Great Artesian Basin (GAB), and petroleum-contaminated soils. Some of these isolates have been identified as novel species and from genera such as Deferribacter, Bacillus, Alkaliphilus, Clostridium and Thermoanaerobacter. Further investigations have shown that these bacteria are metabolically diverse, not only capable of reducing different metal species but also able to use a range of organic compounds, including polycyclic aromatic hydrocarbons, for growth. Due to their abundance and metabolic capabilities, it is possible that iron-reducing bacteria may be important in microbially-enhanced oil recovery processes and in the bioremediation of contaminated soils and aquifers, particularly in anaerobic zones.

Jan 1, 2004

By Kewu W

Kaolin used as an industrial mineral, especially that in the paper-manufacturing industry, must be of fine size, with high brightness, a low impurity content, and good crystal shape. However, in most kaolin deposits there are various impurities which have a very bad effect on the quality of the kaolin. Therefore, it is necessary to remove these impurities from kaolin ore. Owing to their similar surface properties, the separation of kaolin and iron oxide minerals, especially microkaolin and iron oxide minerals, has been regarded as difficult. The iron oxide minerals often intergrow with kaolin in fine and complicated forms, such as thin films, which make separation difficult. In order to overcome this difficulty, many workers have suggested various treatment methods and obtained great success. Based on research work by Fuerstenau (1980), Huang, Li and Hu (1984), Hui and Wei (1991), Shergold (1978), and Zambrana et al (1974), we have investigated a two-liquid flotation technique for iron removal from kaolin and obtained some success.

Jan 1, 1993

By H. B. Charmbury, D. R. Mitchell

Recovery of fine coal from solids reporting to wash water has become increasingly important. These solids range from about 28 mesh to 0 and constitute 3 to 7 pct by weight of the feed tonnage to a coal preparation plant. In the past they were usually wasted to streams, but present clean stream legislation makes it necessary to remove them from the wash water and, if economically possible, recover the associated coal as a saleable product. Where these solids are not wasted to streams or to slime ponds they are recovered by thickeners and filters. Since filter cake is often high in ash or sulfur, or both, it is not readily marketed or used. Common practice is to mix it with other plant products, generally slack or cleaned run-of-mine. Uniform blending is difficult, not only because the impurity is usually high, but also because during certain operating periods it is possible to get a concentration of this filter cake in a railroad or barge.

Jan 2, 1959

By Dobias B

A new separation method based on a combination of coagulation and colum flotation was used to treat fine sphalerite in the range 90 per cent - 15 pm with a relative high superfical gas velocity and a thick froth layer. Minerals studied include sphalerite, calcite, kaolinite and baryte. A new developed sedimentometer was used for sedimentation analysis to characterise hetercoagulation of mixture and coagulation after addition of active ions or reagents. A comparison between use of selective frother and depressant (SHMP) was made to deactivate activated minerals. Selectivity of frother for sphalerite was found in flotation test. The depression function of Flotanol for activated minerals was confirmed in sedimentation alalysis. The use of small quantities of HPAM can improve the flotation of fine sized sphalerite particle and reduce recovery of activated gangue minerals in the neutral or alkaline pulp. A satisfactory separation of fine sphalerite from its gangue was achieved by using alkylpolyglycolether (Flotanol) and copolymer polyacrylamide (HPAM hydrolysed polyacrylamide) as frothing and flocculating agents Respectively.

Jan 1, 1993

By Catherine T. Aimone

A series of experiments have been performed to characterize fragmentation and microcracking in quartz monzonite copper porphyry. The flyer plate impact method was used to generate plane shock waves in rock specimens for impact pressures between 1.6 and 7.3 GPa and impact pulse durations between 1.1 and 7.0 µs. The effects of pressures up to 4.8 GPa and pulse duration on fragment size distributions and microcrack densities were studied. The results show that pressures effect particle sizes to a greater extent at higher pulse durations. However, changes in pressure and pulse duration show little influence on the density of microcracks induced during explosive loading. These results indicate that the nucleation and growth of microcracks in rock subjected to shock waves occur uniformly throughout. A substantial decrease in particle sizes for high pulse durations is attributed to more time allowed for microcracks to grow and coalesce, forming individual particles.

Jan 1, 1985

By William E. Ford, Edward Salisbury Dana

1. Simple Hydrocarbons. Chiefly members of the Paraffin Series C,H2,+2. SCHEERERITE. In whitish monoclinic crystals. Perhaps a polymer of marsh-gas (CHI). Found in brown coal at Uznach, Switzerland. HATCHEITITE. Mountain Tallow. In thin plates, or massive. Like soft wax. Color yellowish. Indices, 1.47-1.50. Ratio of C to H = nearly 1 : 1. From the Coal-measures near Merthyr-Tydvil in Glamorganshire, England; from Galicia. PARAFE-IN. A native crystallized paraffin has been described as occurring in cavities in basaltic lava near Paterno, Sicily. Indices, 1.49-1.52. OZOCERITE. Mineral wax in part. Like wax or spermaceti in appearance and consistency. Colorless to white when pure; often leelr-green, yellowish, brownish yellow, brown. Indices, 1.51-1'54. Essentially a paraffin, and consisting chiefly of one of the higher members of the series. Occurs in beds of coal, or associated bituminous deposits, as at Slanik, Moldavia; Roumania; Boryslaw in the Carpathians. Also occurs in southern Utah on a large scale.

Jan 1, 1922

By Tim O’Neil

Many mining companies try to fight their way up from small operator and exploration company to major producer. Not many companies make it. Cambior Inc., formed in 1986, is one company well on its way to making it as a major operating company. In 1993, Cambior surpassed 15.5 t (500,000 oz) of gold production and began operations at its world class Omai gold mine in Guyana. At the same time, the company has embarked on a program of geographic and minerals diversification. Cambior, a Canadian company, now has interests in eight mines, three development projects and more than 100 exploration properties in North and South America. The company’s goal is to derive 70% of its income from gold and 30% from base metals and other minerals. Cambior’s moderate diversification into base metals gives protection against negative gold price fluctuations. It also balances the typically short term gold mines and the longer term base metal mines.

Jan 1, 1994

By W. Kemp Wait

Electronic ore sorting has been in use for over 15 years at many mining operations worldwide. Photometric ore sorting, which operates on the basis of measuring light reflectance levels of a rock surface, is in use at various locations on ores such as limestone, magnesite, gold, talc, spodumene, tungsten and coal. Radiometric sorters have been employed on uranium deposits in the western U.S.A. as well as at certain South African go1 d mines where preconcentrating gold is achieved using uranium association as a detector. A new ore sorter, employing two sensing parameters has been developed. Utilizing both photometric and conductivity sensing modes, this system has application to many gold ore types of North America. The first production machine has been installed at a gold mine near Beardmore, Ontario for the purpose of preconcentrating ore both from waste dumps from past production as well as within the ongoing mining operation.

Jan 1, 1987

By Joseph Cervik

INTRODUCTION Common methods of controlling gob gas in U.S. mines are by means of ventilation of gob areas and gas drainage through surface boreholes. Costs of drilling surface gob holes increase as deeper coal- beds are mined. Where gob holes cannot be drilled because of topography, ventilation is the only means of control. Even then, sufficient air may not be available to dilute methane in the bleeder entries to acceptable levels. Thus, new methods of gob gas control need to be developed that are independent of surface topography, and of the mine ventilation system, and less costly than present systems. Except for slight variations in procedures and equipment, Great Britain, West Germany, France, Belguim, Poland, and Czechoslovakia use a common methane control method that is different from the system generally used in the United States. This Bureau of Mines paper reviews European mining methods, mining conditions, and methane control technology and discusses their applicability to U.S. mines.

Jan 1, 1981

By C. H. Rawlins

Deep bed media filtration is used as a tertiary treatment step (after hydrocyclones and flotation cells) to remove fine oil droplets and solids from oilfield water before reinjection disposal or to remove particulate material from surface waters used for waterflood injection. Oil and solids injection requirements are typically <5 ppm concentration at <2 micron diameter. The preferred media for produced water filtration is walnut or pecan shell, however the use of this media has evolved by trial & error and the fundamental mechanisms that occur during separation and media cleaning have not been investigated. A project was initiated to fill in this knowledge gap by analyzing the physical, mechanical, chemical, and hydrodynamic properties of six types of granular filtration media (12/20 mesh size): garnet, silica, anthracite, pecan shell, English walnut shell, and black walnut shell. Comparison of bed packing, oil wetting, attrition resistance, particle strength, and fluidization has led to an understanding of the preferred filtration media for separation of fine oil droplets and solids.

Jan 1, 2010

By E House, V Lisitsin

Recent whole-rock geochemical data from nearly 900 fresh drill core and underground samples taken from seven central Victorian gold deposits confirm the presence of distinct and identifiable primary alteration haloes surrounding the deposits. Ferroan carbonate alteration extends for up to several hundred metres away from turbidite-hosted gold mineralisation outside of contact metamorphic aureoles. A less distinct phyllic alteration zone can be identified using geochemical molar ratios or short wave infrared analysis. It generally overlaps a sulfidic halo characterised by disseminated pyrite and in close proximity to mineralised structures, arsenopyrite. The extent of the sulfidic halo can be traced using low-level analysis of pathfinder elements such as S, Au, As and Sb. Recognition of these alteration features enlarges the target for exploration and provides a tool by which drilling can be directed towards mineralised structures. An&nbsp;EXTENDED ABSTRACT&nbsp;is available for download. A full-length paper was not&nbsp;prepared for this presentation.

Jan 1, 2008

By Thomas D. Henderson, Donald E. Crowell

INTRODUCTION This paper presents a "case history" of the steps taken to estimate capital and operating costs for a typical porphyry copper concentrator of ±9,070 metric tons (10,000 short tons) per day capacity. The concentrator described herein is hypothetical, but is based on experience and is, in effect, a composite of several actual projects. The numbers used are illustrative only and do not represent actual costs at any particular concentrator. These numbers are, however, representative of typical milling costs at one point in time, and. are sufficiently accurate to illustrate the cost estimating procedures described in this paper. It is not possible to publish actual, current milling costs and, in any event, actual cost figures quickly become meaningless in today&apos;s economic situation with various costs all rising at different rates. The paper is divided into three parts: (1) order-of-magnitude estimate, (2) feasibility study estimate, and (3) discussion of differences between estimated and actual costs.

Jan 1, 1978

By W. J. Travers

SEVERAL new procedures for completing oil wells have been developed in recent years. Each method when used where properly applicable promises to be a definite aid to operators in lowering development or operating costs, or in developing the full potentialities of the oil well. Multiple-zone completions are now frequently used, in contrast to the older practice of setting a solid water string over each zone to be produced. Gravel packing in unconsolidated formations often prevents sand troubles formerly experienced where a conventional perforated liner was used. Light-weight bentonitic clay muds and oil-base drilling fluids are definite steps toward eliminating mudding damage, which occurs when heavy rotary mud is used. Since in each case the new procedure developed is an alternate of older conventional methods, a problem of selection is presented. The purpose of this paper is to suggest methods of arriving at these choices and to present practical observations that may be of aid in their application.

Jan 1, 1942

By R. Hogg, E. Kaya, H. Cho

Investigations were performed on fine grinding of bituminous coal in a laboratory-scale pulverizer. The results indicated that the breakage behavior at relatively coarse sizes (i.e., greater than about 20 µm) is essentially "normal." However, at fine sizes (i.e., less than about 10 m), there is clear evidence of reagglomeration. A simplified population-balance model for simultaneous growth and breakage is formulated. Breakage rates and breakage distributions were assumed to follow the patterns typically observed in simple grinding systems. It is recognized, however, that solid particles and agglomerates may exhibit different breakage behaviors. Agglomeration rates are assumed to be determined by contact probability, i.e., by the relative numbers of interacting particles. Based on comparisons between model simulations and experimental data, it appears that agglomerate rebreakage rates and fragment size distributions are quite different from those for solid particles. The result is that product size passes through a minimum and then increases with time as agglomeration begins to dominate.

Jan 1, 1998