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By B. M. O Harra, George M. Fowler, R.E. Illidge

The Tri-State district comprises an area of about 2000 square miles in southwestern Missouri, southeastern Kansas, and north- eastern Oklahoma. The part that is in and contiguous to Missouri is still sometimes designated as the Joplin district (Fig. I). Early Operations Mining operations in what is now the Tri-State district date from about 1848 and have been continuous to the present. Apparently the first discoveries of ore were made about the same time near the present sites of Joplin, Oronogo, and Granby. Lead minerals were found at grass roots, probably in shattered rock in shallow excavations, then these minerals were followed in shear zones to deeper horizons. The mining of zinc followed. Before 1874, zinc ore was worthless and discarded as waste. According to published records, the total production of lead to that date was 49,000 tons of metal from 70,000 tons of concentrates. Production The a.ggregate ore production from the Tri-State district was recorded at intervals

Jan 1, 1943

By I. E. Rosenzweig

The problem considered in this paper is as follows: An arbitrary horizontally stratified area is given. The electrical properties of this area are characterized by a function p(z) (Fig. I), which shows the relationship between resistivity p of the soil and the depth z. For such general case the apparent resistivity p* will be computed, by earth-resistivity measurements carried out by any given configuration of electrodes. General solutions of this problem appear to be very important for interpretation of field results of resistivity measurements, concerning structural investigations. Such solutions have been given by many authors for the special case of a finite number of homogeneous layers (Fig. 2)lV4 as well as for the more general case of continuously ranging resistivities.5-8

Jan 1, 1940

By Thomas R. Couzens

This chapter covers certain aspects of open pit production planning based on experience, pointing out approaches to planning that may help produce a realistic picture for evaluation and operation The subjects discussed are roads, preproduction stripping, dump planning, dewatering, the relationship of production planning to equipment selection, and computer methods for the short-range or operational pit planning process Actual determination of ore limits, pit design, and production schedules are covered in other chapters This discussion is somewhat general. Specific problems that occur in mine planning are extremely varied, and it is not possible to cover many of them in a chapter, therefore, only some of the principles that are important in the approach to open pit production planning problems will be discussed.

Jan 1, 1979

By Bruce R. Lipin

Chromite, the only ore of chromium, occurs almost exclusively in mafic-ultramafic rocks and their weathering products. However, not all kinds of mafic-ultramafic rocks are favorable hosts for possible low-grade chromite deposits. For instance, chromium-bearing basalts are not favorable because they commonly contain <0.3% Cr203, and chromite is almost always less than 50 mp in diameter, if it is present at all. Chromite-bearing ultramafic rocks in stratiform and alpine complexes tend to be either ore grade (>25% chromite) or very low grade (<2% chromite); intermediate rocks are scarce. In most complexes, large tonnages exist only in the <2% chromite rocks and the composition of the chromite in those rocks may be unsuitable for metallurgical use. Some nickel laterite districts contain more than lo8 tons of material with 2.0 to 5.5% Cr203, and hence, chromium could be a byproduct of nickel in some laterite districts. In addition, some chromiferous sand placers may contain tens to hundreds of millions of tons of material between 2 and 5% Cr203

Jan 1, 1983

ALTHOUGH everybody is familiar with coal, few persons have an exact idea of, the great impor-tance of this precious fuel. Coal is the black bread of industry. Without it, industrial activity is much restrained; and so the great industrial countries of Europe and the United States of America are the great producers of coal. The 1913 production of coal in Belgium was 22,842,-000 tons, valued at 418,700,000 fr., nearly a half billion. In 1919, it was 18,483,000 tons, about 81 per cent. of the production before the war; in 1920, it had reached 22,414,000 tons, approximately the production before the war. To show the importance of coal production of Belgium, let us say that the coal industry employed 168,000 workers in the year of 1920, the metallurgical industry only 129,000 and the textile industry 103,000. The coal industry, then, employs the greatest number of workers. The value of the coal production in 1919 is estimated at 1,121,000,000 fr. On the basis of the production before the war, the value of the production of iron in 1919 would have been 701,000,000, of finished steel 1,086,000,000, and of zinc 415,000,000; therefore, in 1919 the value of the coal industry was greater than that of the metallurgical production.

Jan 8, 1922

By George M. Fowler, B. M. O Harra, R. E. Illidge

The Tri-State district comprises an area of about 2000 square miles in southwestern Missouri, southeastern Kansas, and north- eastern Oklahoma. The part that is in and contiguous to Missouri is still sometimes designated as the Joplin district (Fig. I). Early Operations Mining operations in what is now the Tri-State district date from about 1848 and have been continuous to the present. Apparently the first discoveries of ore were made about the same time near the present sites of Joplin, Oronogo, and Granby. Lead minerals were found at grass roots, probably in shattered rock in shallow excavations, then these minerals were followed in shear zones to deeper horizons. The mining of zinc followed. Before 1874, zinc ore was worthless and discarded as waste. According to published records, the total production of lead to that date was 49,000 tons of metal from 70,000 tons of concentrates. Production The a.ggregate ore production from the Tri-State district was recorded at intervals

Jan 1, 1943

Man: A purely detached consideration of nature and the place of man in it may easily result in somewhat pessimistic conclusions as to man and his destiny. However, when we come to the evaluation of man&apos;s role in the development of natural resources and his achievements in this field, a more optimistic tone may be justified. Hence the possible contradictions between Man and Nature, Perfection, and the present chapter are more apparent than real. After all, progress must have a foundation of optimism, and we cannot challenge either the faculty or the students to better work and to a progressive and constructive outlook without an underlying tone of optimism and basic faith in the future. Geology is the basic science of Mother Earth; the science of the natural forces that have produced and modified the structure of our globe; the science of minerals and rocks; of landscapes and soils; of water supply and mineral resources, including mineral fuels; and of the history of life, both plant and animal, as revealed by fossils in rocks. It is difficult to reduce man and his historical significance to their proper relationship with regard to the earth and its history. Processes of rock formation have continued for at least two billion years; man&apos;s activities have been in evidence only a few thousand years. As a means of comparison, if the height of the Empire State building were to represent geologic time, the thickness of a nickel placed on the tower would just about repre-

Jan 1, 1950

US 4,181,588 - Direct extraction of lead from lead sulflde ore. Ore is leached with a solution of ferric chloride and sodium chloride. The leach liquor is filtered to remove sulfur and gangue, then cooled in a crystallizer to precipitate lead chloride The slurry from the crystallizer is subjected to electrolysis to deposit lead chloride on the cathode plate. Solution from the electrolysis cell is used in the leaching step. M.M. Wong and F.P. Haver, assigned to US Secretary of the Interior Jan 1, 1980. 6 pp. (204-115). Filed: 1-4-79 (1,026).

Jan 1, 1982

By Arthur Flagg

(New York Meeting, February, 1913.) THE Elk City mining district of Idaho occupies a position near the geographical center of Idaho county, a region of mod¬erate elevation in the western foot-hills of the Bitter Root mountains. The district comprises an area of approximately 350 sq. miles, bounded oil the west by the Newsome district and on the south by the Dixie and Oro Grande districts. There are no mining districts to the north or east. Elk City, the principal town and the seat of the mining office for the district, is situated in a hydrographical basin surrounded by low hills. The elevation is 4,200 ft. above sear level. Through this basin flow Elk Creek, Red river, and American river, which unite west of town to form the south fork of the Clearwater. The one township is set out from the Bitter Root Forest Reserve. Though a railroad starting from the Stites terminus of the Clearwater Short Line of the Northern Pacific railroad has been under consideration for some years, the camp is yet with¬out railroad facilities. The projected road would follow the south fork of the Clearwater on easy grades, but would be very expensive to build and maintain. While such a road would greatly benefit those who are now operating in the camp, and in a slight degree stimulate interest in its possibilities, there is hardly business enough to warrant its construction.

Jan 4, 1913

By Thos Egleston

The sands of Snake River, Idaho, have long been known to contain gold. They were worked by some of the first prospectors who came to Idaho, and on the banks still stand the ruins of camps abandoned for years. There are almost always prospectors searching for gold during the season of low water, and it is not an infrequent thing to find a miner of the old type actually panning the sand, or the prospect-hole which he has just left. There is more or less mystery about these miners and their methods of finding the spots where they work. They are always subjects of much speculation to the ordinary traveller. The rich discoveries are, for the best of reasons, concealed until the claims can be taken up. It is difficult to find a place where there are no prospects, but the " colors " are so very fine that they do not offer much inducement to enterprise. The California miner usually values a color at from 5 to 10 cents, often the latter; while on Snake River it would take 100 colors, or even more, to make that amount.

Jan 1, 1890

By O. A. E. Jackson

Pebble milling has been practiced in the reduction works of South Africa gold mines for well over 50 years. Originally flint pebbles were imported from Denmark to grind stamp-mill amalgamation- process tailing, which contained a good deal of extractable gold, but local operators soon found that large pieces of ore could be used for the same purpose. The ore is a hard, tough conglomerate in which quartz pebbles are cemented together by a matrix of redeposited silica interspersed with pyrite crystals. The gold, rarely visible, occurs as fine particles mostly segregated at the interface of the pebble and matrix, although a small fraction occurs within the pyrite crystals. There is seldom any gold in the pebbles themselves.

Jan 11, 1959

By Earl H. Miller, Henry H. Bruhn

COMMERCIAL beds of sylvite ore were discovered by the Snowden & McSweeney Co. while drilling a wildcat oil well some 25 miles northeast of Carlsbad, N. NI., in 1925. After a preliminary core drilling program the U. S. Potash Co. sank a 1060-ft shaft within 4 miles of the original discovery. This shaft was in an isolated location in a sand desert area with only the roughest of dirt roads connecting it with the neigh- boring town of Carlsbad some 21 ½ miles west.

Jan 6, 1954

By Warren Blauvelt

IN VIEW of the enormous wastes of natural resources, of labor and of capital, due primarily to the economic environment, established by legislation, the general neglect of this phase of the problem of the elimination of waste is difficult to understand. In such a study, the engineering method of attacking a problem should be employed. The engineer does not try to solve his problem by disregarding natural laws, but by utilizing them. The successful engineer establishes an environ-ment in which forces, acting in harmony with natural laws upon an object or objects, will produce the desired results. The engineer who notices that the water level in a vessel, into which a gallon of water per minute is flowing, is two feet higher than the level in an adjacent vessel, connected therewith by a 6-in. pipe, does not assume that the law of gravity has ceased to work, or that water no longer seeks its level; he examines the connecting pipe for obstacles which prevent the free flow of water. Some editors, many reformers and most politicians tell us that the law of supply and demand no longer works; hence governmental control of commerce is necessary. Governmental control may temporarily-that is, until trial proves its futility- "insure domestic tranquility" and "promote the general welfare;" but it cannot "secure the blessings of liberty" which it cur-tails, nor can it "establish justice" which it violates.

Jan 9, 1922

By Stewart R. Wallace

"For his achievements in unravelling the complex geology of the Climax ore body; for his leadership in the discovery of the Henderson deposit; for his continued encouragement of young geologists; and for his lecture . .."

Jan 1, 1975

By Fred C. Bond

It sometimes happens that old knowledge is forgotten, or half-forgotten, and its rediscovery is hailed as a great new advance in technology. Autogenous grinding affords such an example. The oldest-or apparently the oldest-commercial application of continuous autogenous grinding on a large scale outside of South Africa occurred at San Juancito, Honduras, where a total of more than two million tons of silver ore were ground autogenously with complete success from 1918 to the early 1940&apos;s. The history of the San Juancito silver deposits begins in 1880 when- the New York and Honduras Rosario Mining Co. started mining silver at a rate which soon reached two million ounces of silver annually. In 1912 the Company&apos;s first mill, located in the village of San Juancito, was shut down and its equipment transferred to a new cyanide plant. This plant, constructed on a mountainside near the mine, was equipped with tube pebble mills in which Normandy or Danish pebbles were used initially.

Jan 5, 1963

By P. A. Young

The historical background of on-strand cooling is given, together with a resume of recent practical developments. Laboratory test procedures are then considered in detail, for both productivity and quality parameters, with particular reference to the design of the Ravenscraig No 3 machine (Scotland). A heat transfer model is presented for a porous sinter with propagating cracks. The influence of cooling/sintering area ratio, sinter strength, granulometry, return fines, coke consumption and FeO levels are examined in relation to economics. A detailed comparison of capital and running costs for two different strands, designed for identical duties, but with off or on-strand cooling, is then given.

Jan 1, 1977

Jan 1, 1882

By V. Rajaram

The oil shales of the Green River Formation in the United States have been considered as a source of liquid hydrocarbons since 1908, with the first retort constructed in Colorado in 1917. However, it was not until 1944 that the mining characteristics of oil shale were investigated in a systematic manner. During the period 1944 through 1956, the Selective Mine and the Demonstration Mine (also referred to as the Anvil Points Mine) were operated by the U. S. Bureau of Mines (USBM) near Rifle, Colorado. Significant progress was made in developing a room and pillar mining method by which oil shale could be mined safely at a very low cost per ton. Mechanical properties of oil shale were determined, safe room spans and roof support techniques were established, and drilling and blasting methods for oil shale were developed. As a follow-on to this USBM effort, a consortium of six oil companies with Mobil Oil Company as project manager carried out a research program during the period 1964-68 at the Mobil mine, located in the vicinity of the Anvil Points mine. Rock mechanics investigations were conducted as a part of this research program, and consisted of laboratory studies, in-situ stress determinations, and roof and pillar instrumentation. This paper will discuss the findings at the Anvil Points mine and Mobil mine to illustrate the stability considerations in underground oil shale mining.

Jan 1, 1983

By W. A. Tiller, W. C. Johnston

A theoretical analysis of alloy solidification in which the effective partition coefficient, k, of the solute is allowed to vary as a function of interface position is performed. A variety of solute distm&apos;butions in the solid is predicted depending upon the functional dependence of k with interface position. Conversely, the variation of k with interface position required to produce a particular solute distributzon in the solid can be calculated. These preciictions have been tested by controlling the width of the momentum boundary layer in the liquid as a function of interface position with a rotating mugnetic field. One of the objects of controlled solidification is to utilize the freezing process for the preparation of crystals of specific materials containing a predetermined distribution of solutes. For example, a thermoelectric power generation material may exhibit a figure of merit, 2,&apos; as a function of temperature, T, and solute concentration, C, as illustrated in Fig. 1. If we wish to use this material in a device between the temperature limits T1 to T2 a significantly greater efficiency will result from the device if the thermoelectric element illustrated in Fig. 1 consists of a range of solute concentrations appropriately located with respect to the temperature distribution rather than using a sample of constant solute concentration. For this reason and many others2 we are interested in programming and controlling the solute distribution in a single crystal

Jan 1, 1962

Jan 1, 1902