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By David A. Milligan

This paper outlines the research and development of a process to treat flotation tailings from the Darwin mill in lnyo County, California. A flowsheet was developed incorporating an agglomerated heap leach process using sodium cyanide to extract the silver values. Agglomeration was the key to developing this resource as the mill tailings averaged only 13% plus 100 mesh. Percolation through the heap would have been impossible without agglomeration to improve the permeability. The various tests that went into this research program are described with particular emphasis on the agglomeration techniques developed at the Anaconda Minerals Research Center. Start up and operation are discussed.

Jan 1, 1984

By John Birkinbine

FOR two years past the Warwick Furnace, at Pottstown, Pa., has attracted attention by the remarkable work done in it, and a statement giving details of its operation and the unexpectedly short blast of 1880 will be acceptable to every member who studies blast-furnace practice. There are so many interesting features in con¬nection with this blast, and so much to be learned from investigating it, that the results of a thorough examination are offered to the Institute sans theories. In collecting the information, the courtesy of the various officers of the Warwick Iron Company was of material advantage, every facility for investigation being extended and an inspection of records being kindly permitted. In the following description these authoritative data are given in full where practicable, without making the paper too prolix, and the

Jan 1, 1881

By B. Mueller

Altered concepts regarding the raw material used in conventional blast furnace plants as well as new technologies for the reduction of iron ores make it necessary to reconsider the design of pelletizing plants. The incorporation of a pelletizing plant within a conventional integrated steel mill involves considerations of the problems of using in-plant fines. A modern pelletizing plant in Mexico serves as an example of the technical solution. In recent times, pelletizing plants are also being integrated within steel mills based upon direct reduction processes. The design of such pelletizing plants must take into account special product quality requirements.

Jan 1, 1977

By Uros Bajzelj

To mine very weak carboniferous schists subjected to high ground pressures the underhand cut-and-fill stoping method was proposed using an artificial plate roof. An experimental stope was mined using three consecutive levels. Rock pressures, deformation of the reinforced concrete plate, and the quality of stowing were evaluated. It was found that roof deformations were minimized if the reinforced concrete plate and uncemented backfill were replaced with cemented backfill containing reinforcement near the bottom. The mining method prevented the occurrence of high rock pressures at the face. The method is suitable for mining subvertical ore bodies with large horizontal areas.

Jan 1, 1984

By Ian Campbell

THE year 1952 was marked by several new alltime highs in industrial mineral production; by an easing of the critical situation with respect such minerals as fluorspar and sulphur; by important production of asbestos, lithium, and rare earths; by the perfecting of new products which will place new demands upon industrial mineral supplies, such as "Fiberfrax", and the finding of new uses for old minerals, such as wollastonite; by continuation of basic and applied research; and publication of a notable study of the national mineral economy, viz., the "Paley Report".

Jan 2, 1953

By H. S. Hanna, C. Rampacek

The problems and limitations encountered in the Physical beneficiation of the Appalachian Red Iron Ores are discussed. Two major problems are identified - the high phosphorus content and the fine dissemination or encapsulation of mineral impurities in the iron-bearing minerals. A process that combined extreme fine grinding techniques with magnetizing roasting or flotation-separation methods is suggested. By these methods, concentrates assaying 60-61 % Fe, exceeding the widely accepted upper limit of 56% Fe set for these ores, were produced with 75-90% iron recovery. Moreover, it was shown that the phosphorus content of these concentrates could be reduced from 0.25% to 0.03% phosphorus by acid leaching. A brief discussion on production costs based on current and future developments in iron ore processing is given.

Jan 1, 1983

By H. E. Sadler, B. Silliman

INTRODUCTORY NOTE. THE research here recorded was undertaken early in the present year, and has been prosecuted steadily for about eight months. While the work has been under my constant supervision and advice, the labor has all been performed by Mr. Sadler, to whom is chiefly due the development of the successive steps which have led to the final result. The process is better than I dared to hope, and we are able to place at the command of chemists and engineers interested in the matter an apparatus of continuous and uninterrupted action, and methods of analysis by which the daily averages of the two variable and inconstant factors of illuminating gas, ammonia and sulphur, may be determined with all needful accuracy, even by those little skilled in chemical manipulation, and with very little loss of time. This research has been carried out in the laboratory of the New Haven Gaslight Company. B. SILLIMAN. October 17th, 1876.

Jan 1, 1877

By J. L. Jernegan

In the summer and fall of 1875, the author was present during a short smelting campaign at the Hall Valley works, and having had occasion to make a number of chemical analyses of the ores, fuel, and fluxes, deems that the results of the same, and also an account of the smelting operations, may be found of interest to members of the Institute. The mines and reduction works of the Hall Valley Silver—Lead Mining and Smelting Company (limited) are situated at Hall Valley, Park County, Colorado. The smelting works are located about half way from the mouth to the head of the above-named valley, and the mines high up on the mountains, near its head. The three principal mines of the company are the Whale, Leftwick, and Coldspring. They are all on different veins, running parallel to one another, with a general trend from southwest and northeast. The

By Mark Malamphy

DURING colonial times, Brazil was famous for the richness of her alluvial gold deposits. Paul Ferrand has estimated that the gold produced during the period from 1700 to 1820 was the equivalent of some 64 million pounds sterling. Since that time, most of the more prolific alluvial deposits have been exhausted. A few gold mines are still func-tioning, notably the Morro Velho mine, which is one of the deepest mines in the world. Today, the gold production of Brazil is insignificant when compared with world figures, but there are still many gold-bearing regions and it is probable that in at least some of them profitable returns would result from an exploitation program taking advantage of all the most modern innovations in gold mining and ore treatment on a large scale. In order to demonstrate the value of some of these abandoned pros-pects and stir up interest in increasing the national gold production, the government has stimulated research. Experimental plants have been and are being established in various places, and tests on large quantities of ores are being carried out on a semicommercial basis. The Geological Survey of the State of Minas Geraes is very active in this line and the Federal Institution is also showing an increased interest in the matter.

Jan 1, 1934

By C. B. Murray

Our experience from time immemorial has been that the furnace sampler and analyst usually find one or two, and sometimes more, points less iron than the Lake Superior shippers, but, fortunately, their contracts are iron bound…

Jan 1, 1915

By H. B. C. Nitze

In view of the extensive use of vanning-machines in this country, a brief comparison of the results obtained by the plain belt generally employed, and the corrugated belt which was introduced a few years ago, may be of interest. The data given below have been abstracted from a working-journal, and hence lack the precision, and also, in several desirable particulars, the detail, which would naturally have been secured in special experiments ; but they have the advantage of being working-figures, and are sufficient as the basis of a fair comparison between the two kinds of belt working on similar ores. The conditions under which the work was done were the following :

Jan 1, 1893

By F. S. Crawford

IRON and copper are mined in the Lake Superior district. The iron mines of the district have the best safety record for that industry in the country as a whole, while the copper mines of the district rank second in two of the four years recorded (Table 1). In Utah copper comes mainly from open-pit mines, which enables that state to lead easily in safety. All of the Michigan production comes from deep underground workings. About 60 per cent of the iron miners in St. Louis County, Minnesota, are employed at open-pit mines; this favorably affects the combined open-pit and underground accident-frequency rate, as this county provides most of the Minnesota-mined iron ore. In Michigan, however, there are few open-pit mines, the bulk of the production coming from underground mines, while all of the Wisconsin production, just across the state line from Michigan, is from underground mines. In spite of the fact that fewer mines in Michigan use the safer open-pit method, the iron-mining industry of that state maintained a consistently low record from 1931 to 1934; however, it was many points behind its nearest competitor, Minnesota, with its much greater production from open-pit mines.

Jan 1, 1939

By J. L. Wilson, D. L. Emmons

The Tucker Hill perlite deposit is located in the northwestern portion of the Devils Garden lava field in Lake County, south-central Oregon. The perlite occurs in the chill margin of a late Miocene composite rhyolite lava dome that exhibits distinct cooling zonation. The chill margin is composed of an outer glass envelope, which contains commercial-grade granular and vesicular perlite, and an inner glass envelope, which contains onionskin perlite of local commercial quality. Glassy rhyolite and rhyolite compose the lava dome core. The entire dome complex encompasses at least 5 km2 (2 sq miles). Expansion tests in commercial-scale furnaces indicate that the perlites are suitable for a wide range of applications and compare favorably with commercial perlite ores. The large tonnage deposit appears competitive for markets in the midwestern and upper northeastern states, and the Pacific Northwest of the US.

Jan 1, 1986

By Howard L. Hartman

The past 15 years have seen rapid advances in the metallurgy of materials for drill machinery and bits, but rock drilling itself continues to be largely an art. Jet piercing, roller bit rotary drilling, and rotary percussion are all promising new techniques, but the percussion rock drill, still used for 90 pct of the blastholes in U. S. hard-rock mining, has under- gone no major modification since pneumatic machines were first used successfully in the 1860's. This singular lack of progress stems directly from ignorance of the nature of impact failure of rock and the fundamentals of rock penetration in general. For nearly three-quarters of a century, mining engineers did not know what went on at the bottom of a drillhole.

Jan 1, 1959

By Paul E. Dorr, Kenneth P. Pavlich

This paper covers the practical aspects of economic analysis of mineral ventures and the application of a publicly available computer program. The paper touches briefly on the time value of money concepts and the phases of project evaluation. The most comprehensive port ion of the paper deal s with the requirements for economic evaluation, including capital expenditure categories, operating expenses, required geological and engineering data, and tax considerations. Highlights of the 1981 and 1982 tax laws are covered. A case study using the MINECO computer program will be used to illustrate the economic evaluation concepts developed. Guidelines and goals of sensitivity analysis and Monte Carlo simulation will be discussed and demonstrated on the MINECO example. The MINECO software system will be displayed as an example of a "user-friendly", interactive, and flexible computer tool available to the mining professional today.

Jan 1, 1983

By Charles R. Keyes

In the dry regions of the globe many silver-deposits display certain remarkable features, which at the same time are so totally unlike anything met with among ore-bodies elsewhere that they hare long presented exceptional dificulties, not only to a satisfactory explanation of their origin, but to economical milling. A most striking peculiarity of these ores is the haloid character of many of their bonanzas. To this fact more than to any other may be ascribed most of the unusual uncertainties of mining-operations in desert countries—the marvelous local richness of the ores under certain conditions and the often abrupt transition to utter poverty; the inadequacy of ordinary prospecting customs and the constant devising of new exploratory methods; the unaccountable losses in smelting and the continual change in treatment-practice. For these anomalies certain climatic conditions seem to be chiefly responsible.

Jan 1, 1912

By Gordon M. Matheson, Charles V. Logie

The current state-of-the-art design of mine pillars can be grouped into empirical and numerical design techniques. Numerical design techniques are based on sophisticated computational techniques which analyze the stresses and strains through the interstices of a pillar. Empirical techniques are less exact, but have been widely used, particularly for coal mine pillar design, because of their ease of computation. Over the years numerous empirical equations have been proposed to calculate the ultimate strength of coal mine pillars. This paper presents a review of the various equations which are most frequently utilized and examines the fundamental assumptions, limitations and applicability of the design formulae. The review intends to provide the practicing mining engineer with an understanding of the assumptions and mathematical basis of each equation to aid in the selection of the criteria most applicable to his specific design problems. Recommendations are made of the empirical equations that are presently most acceptable for design.

Jan 1, 1983

By L. Messulam, A. S. Appleton

Iwo major studies of the Fe-Cr-C system are available in the literature. The earlier one of Kinzel and crafts' forms the basis for the data most commonly quoted in works of reference (e.g., Metnls HandDook) though the later work of Bungardt el a1.' is more extensive and amenable to analysis in terms of isothermal sections and so forth. However it is evident from examination of either of these studies that the delination of phase boundaries on the basis of the data obtained can only be very approximate. Indeed in several instances the data are so inconclusive that this delineation is a matter of opinion. This note is to report an analysis of experimentally determined carbon activity data in this system, which, originally intended as a means of checking the self-consistency of the data for a number of alloys, enables some conclusions to be drawn concerning the 10503C isothermal section of the iron-rich corner of the system as deducible from the data of Bungardt

Jan 1, 1967

By M. K. Barnett

Engineering research consists, broadly speaking, in the investigation of the effect of the variations in a number of factors on some property of a product or characteristic of a process. The unambiguous description of the product or process requires that the property or characteristic be expressible in quantitative terms. For the purpose of practical control, it is likewise desirable that the independently variable factors governing the product or process be quantities, although this ideal goal is not always attained. Maximum efficiency—i.e., the attain- ment of the maximum amount of reliable, useful information relating to the influence of, the factors on the property of the product or characteristic of the process, for the least expense—is an important requirement for the satisfactory operation of a research organization. Obviously, a necessary condition for the attainment of maximum efficiency is an adequate knowledge of the specialized field in which the experimental research lies. While necessary, this condition is not sufficient. Proper attention must also be given to the general principles of experimental design together with the modern methods for the analysis and evaluation of experimental data. The Present discussion is confined to a single design, the so-called "factorial" design. This design is of special interest in that it attains its goal, maximum efficiency, by directly departing from the

Jan 1, 1948

By M. K. Barnett

Engineering research consists, broadly speaking, in the investigation of the effect of the variations in a number of factors on some property of a product or characteristic of a process. The unambiguous description of the product or process requires that the property or characteristic be expressible in quantitative terms. For the purpose of practical control, it is likewise desirable that the independently variable factors governing the product or process be quantities, although this ideal goal is not always attained. Maximum efficiency—i.e., the attain- ment of the maximum amount of reliable, useful information relating to the influence of, the factors on the property of the product or characteristic of the process, for the least expense—is an important requirement for the satisfactory operation of a research organization. Obviously, a necessary condition for the attainment of maximum efficiency is an adequate knowledge of the specialized field in which the experimental research lies. While necessary, this condition is not sufficient. Proper attention must also be given to the general principles of experimental design together with the modern methods for the analysis and evaluation of experimental data. The Present discussion is confined to a single design, the so-called "factorial" design. This design is of special interest in that it attains its goal, maximum efficiency, by directly departing from the

Jan 1, 1948