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By William J. Campbell

The purpose of this investigation by the Federal Bureau of Mines was to design and construct a fluorescent X-ray spectrograph for dynamic rate studies of selective oxidation in molten metals and to establish basic principles for interpretation of data obtained by this method. An X-ray spectrograph was constructed in which the sample holder is a resistance wound furnace; it was operated up to 800° C. in oxidizing atmospheres. No difficulties were experienced with the cooling or heating systems nor with the protective layer of mica around the X-ray tube window, even though the oxidizing surface of the metal is only 0.5 inch from the X-ray tube window, Means are provided for heating under controlled atmospheres for selected time? temperature cycles.

Jan 1, 1961

By Michael G. Pojar

This Bureau of Mines report estimates the population of the principal types of machinery in use by the coal mining industry during 1982 in surface and underground mines. Estimates were arrived at using 1976 coal equipment population estimates as baseline data with modifications made for new mine development, expansion, and closure occurring during 1976-82. Estimates were broken down into 3 regions which included all 26 coal-producing States. Modifications made to the baseline data were computed using (1) actual equipment information when available, plus (2) equipment information hypothesized from representative generic mine models, which were predicated on mine size and mine method. Roughly half of the equipment fleet at new or expanding coal operations was known; the remainder was hypothesized. The mine models used to generate equipment information are included in this report, along with the hypothesized equipment use data. The equations and various factors used to determine the equipment adjustments for mine closings, new mine openings, and small coal mine operations are also identified.

Jan 1, 1986

By Steven D. Scott

Several polymetallic sulfide deposits (copper, zinc, f lead, silver, f gold) presently exposed at the surface of the ocean floor are of sufficient size and apparent grade that they will someday be seriously considered as mineable resources. Responsible ocean mining may have some real environmental advantages over land mining, although they both share the same downstream problems caused by smelting and refining. The area of disturbance for an ocean mine would be much less than for an equivalent sized deposit on land around which considerable rock has to be excavated in order to get at the ore. Acid mine drainage, a very serious problem in land ming, would not be a concern in the alkaline and oxygen deficient environment of the deep ocean. There would undoubtedly be loss of habitat for some marine organisms but this could be minimized by mining deposits that are no longer hydrothermally active and therefore support little life. The risk of severe corrosion and thermal damage to the mining equipment at hydrothermally active sites would probably preclude their recovery in any event. The scientific community and environmental advocates should take advantage of the long lead time before ocean mining commences to insure that the environmental mistakes of the past, as encountered in some land mining, are not repeated. In order to fully understand and thereby mitigate the consequences of recovering seafloor sulfides, test mining of a small deposit using the German-designed high capacity television grab, preceded and followed by detailed observations of the mining site from a submersible, is proposed.

Jan 1, 1992

The Longwall Strata Control and Maintenance System (LoSCoMS) is designed to monitor shield pressures in real-time from longwall faces and to provide on-line information related to underground strata behavior and longwall mining operation. The information includes shield pressure data with statistical analysis of setting, developing and final pressures, prediction of shield pressures for the following shift or day, etc. and maintenance data on the shields. The LoSCoMS has been installed and tested at Shoal Creek Mine operated by Drummond Company, Inc. The system is providing valuable information to mine operators for better understanding of underground behaviors. As a result, it has become an effective tool for minimizing ground control hazards and reducing out of seam material.

Jan 1, 1997

By R. B. Haagensen, E. Martinez, V. Kudryk

The sample under investigation contained approximately 16% BaSO, and was 80% -325 mesh. Established methods for floating barite did not produce concentrates of satisfactory grade or barite recovery because of low barite content and the presence of 6% calcite in the feed. By using a new long-chain sulfosuccinamate collector in combination with relatively high concentrations of sodium silicate, a barite concentrate was produced that would be acceptable as an oil-drilling mud using a simple rougher-cleaner circuit. No desliming of the fine-ground feed was necessary. Barite recovery was over 80% and the concentrate produced had a specific gravity higher than 4.3. During the course of the investigation, a procedure was developed to obtain semiquantitative determinations of barite, calcite, quartz, and feldspar in test samples using an infrared spectrophotometer. Samples were also analyzed in a thermobalance for determination of the calcite content. The use of these instruments made it possible to obtain quick mineralogical assays and proved to be of invaluable assistance in guiding the flotation testing.

Jan 1, 1976

By R. M. Santmyers

Caesium, rubidium, and lithium are sometimes described as the minor or rarer alkali metals. They generally occur together in nature, although, lithium is distributed more widely and is far more abundant than either of the other two. The chemical, and even the physical, properties of these three elements can best be considered In conjunction with the more familiar members of the alkali group, sodium and potassium. The five elements lithium, sodium, potassium, rubidium, and caesium show an interesting gradation properties from member to member with the increase in atomic weights. All are silvery white and soft enough to be cut with a knife. They tarnish rapidly in air and decompose water at ordinary temperatures. The lowest temperature at which the action of the several metals on water can be de¬tected is -98°C. for sodium, -105°C, for potassium, 108°C. for rubidium, and -116°C. for caesium. The chemical activity appears to increase steadily from

Jan 1, 1930

By S. Epstein

THE new low-alloy high-strength steels are obviously here to stay. With 75 per cent higher yield strength and 50 per cent higher tensile strength than plain carbon structural steel, they permit 20 to 40 per cent weight savings and 10 per cent or more increase in pay load in the con-struction of railroad cars, buses, trucks, and a great variety of material-handling equipment. Their cost is low enough so that the extra cost of the new lighter construction over that with carbon steel offers an attrac-tive self-liquidating investment; in some instances new construction with these low-alloy steels may even be as cheap as with plain carbon steel. A considerable and rapidly growing demand for the low-alloy steels has already sprung up. The many steel compositions that have appeared on the market lately 18,27,28,29,30 to meet this demand would seem to indicate that no single composition is uniquely fitted for the purpose. However, no doubt some compositions are more suitable than others. The purpose of this study was, therefore, to compare the effects of the various alloying elements that might be used in the low-alloy steels in order to choose the metallurgically most logical composition, paying due regard, of course, to the economic aspects involved.

Jan 1, 1936

By Barry Silverman

As a significant mineral supplier, consumer of primary fuels, and producer of wastes and emissions to air, water, and land, the domestic copper industry through its investment and operating decisions influences the nation's economy and the environment. In turn, the copper industries' decisions are influenced by various factors: government energy and environmental policies, economic conditions, and technological considerations. The authors have developed a framework for assessing in an integrated manner the impact of these factors on the future investment and operating decisions made by copper firms. Specifically, this model is designed to capture the technology forcing nature of regulatory constraints, the differential situation of individual copper deposits and plant locations, and the price of factor inputs and conditions in the nation's economy. The capability to do this has only become real because of the decision of the U.S. Bureau of Mines to create Mineral Availability system1 or MAS. This system contains detailed but confidential information about each mine and mill in each of 35 mineral industries." Without MAS or a similar information system, the utilization of the methodology we offer would be impractical, but with. MAS it offers a unique technique of dealing with environmental-resources policy questions.

Jan 1, 1979

By R. Karl Zipf

Highwall mining is an important surface coal mining method, and it may account for approximately 4% of total U.S. coal production. Highwall stability is the major ground control related safety concern. Ground control plans for highwall mining should specify hole width, web pillar width, barrier pillar width and number of holes between barriers. This paper offers simple design charts for these parameters aimed at providing “ball park” checks. Web pillars containing pre-existing auger holes are analyzed and a design chart for estimating their minimum width is also presented. Finally, close proximity multiple seam highwall mining, which may have caused several serious highwall failures, is analyzed. Web and barrier pillar recommendations for this special situation are presented.

Jan 1, 2005

By Azin Zangooi, Cesar Gomez, James Finch

Frother concentration is a variable which significantly affects the flotation performance by decreasing bubble size and helping froth stabilization. Variations in frother concentration, which mostly go unnoticed in industrial operations, may affect these functions. Some factors that can cause variations include the fact that frothers are normally dosed based on feed tonnage and not solution concentration, unstable frother delivery, incomplete dissolution for low solubility frothers, addition of frother-free wash water, remnant frother in recycle waters and frother partitioning to the froth. A colorimetric technique developed for determining frother concentration on site makes it possible to detect the occurrence of these problems and to establish their magnitude, allowing conditions to be adjusted to reduce frother concentration variations. By sampling and analysis, frother distribution throughout a circuit can be established, referred to as ‘frother distribution mapping’. Experiences at several concentrators processing sulphide ores are used to illustrate time restrictions for sample analysis, and to demonstrate temporal and spatial frother concentration changes as a consequence of variations in the grinding stage, recycled waters containing frother, and frother partitioning.

Jan 1, 2014

By P. B. Leavenworth, Jack F. Harang

Development during the year 1941 on the Texas Gulf Coast resulted in the dis covery of 27 new fields as compared to 26 fields for the year 1940. Drilling.—During the year, 1405 wells were drilled. Of this number, 1031 were completed as oil wells with 375,000 bbl. daily of new production; 50 were com pleted as gas wells and 324 were failures. The most active area was Jackson County, where 375 wells were drilled and 336 of them accounting for 190,000 bbl. daily of new production. Types of Fields.—Of the 2 7 new fields, 14 are considered to be oil fields, 8 are listed as gas-distillate fields and 5 as gas fields. This may be compared to 26 fields found in 1940, of which 14 were oil fields and 12 gas-distillate fields. Producing Sections.—Frio discoveries retained their predominant position by having 10 Frio fields discovered in comparison to 6 fields in the Wilcox, 4 in the Yegua, 5 in the Miocene and 2 in the Jackson. In the previous year 15 Frio fields were found, 4 in the Wilcox, 2 each in the Yegua, Cook Mountain and Miocene, and I in the Jackson. Production.—Production increased over 1940 approximately 10 per cent, being 113,726,893 bbl. for the year 1941 and 104,127,247 bbl. for 1940. The statistics in Tables I and 2 include distillate and condensate as oil production because no separate reports have been compiled. It is hoped that this separation may be possible some day, but as a great many fields produce both oil and distillate and these arc commingled in pipe lines, separation of statistics will be more difficult than for other areas. New Fields Big Hill, Jefferson County.—Stanolind Oil and Gas Company's No. I George D. Anderson was completed as a gas well from a Frio sand at 8705 to 8720 ft., on Dec. 24, 1941, after having been drilled to a depth of 9500 ft. Additional development is being carried on but it is not possible to evaluate this discovery at this time. Brushy Creek Field, Lavaca County.— Shell Oil Corporation's No. I D. G. McManus was completed as the discovery well in the Brushy Creek field on Oct. 29, 1941, from a Wilcox sand through perforations at 7225 to 7230 ft., making gas and 180 bbl. of 59° gravity distillate. This well was bottomed at 10,998 ft. in the Wilcox. No statement can be made at this time as to the importance of this discovery. Chenango Field, Brazoria County.—J. N. Rayzor et al. completed their No. I Sarah J. Christian through perforations at 8564 to 8572 ft. in a Frio sand, for 453 bbl. of 37.7° gravity oil, on Feb. 6, 1941, after having drilled to 9564 ft. Several wells were drilled in this area during the year but failed to establish important production. This is considered a minor discovery. Clodine Field, Fort Bend County.—Providence Oil Company's No. I Hatfield was the discovery well of the Clodine field, being completed through perforations at 7499 to 7502 ft. for 108 bbl. of 51.2° gravity distillate, on June 19, 1941. The well was bottomed at 8090 ft. Several wells

Jan 1, 1942

By W. H. Bassett

IN the commercial annealing of cartridge brass there are four points regarding which definite data are essential. They have to do with the correct interpretation of grain count in its relation to annealing temperature and, incidentally, to Brinell hardness. These points are: 1. The comparison of the grain sizes of two cartridge-brass mixtures: 69 copper, 31 zinc, 0.376-in. (9.5-min.) gage; and 68 copper, 32 zinc, 0.130-in. (3.3-mm.) gage. 2. The comparison of the grain sizes of annealed metal that had previously been reduced by rolling varying amounts; for instance, 20.0, 36.6, 50.9, and 59.1 per cent. 3. The determination of standards for grain sizes on annealed brass of the composition 68 per cent. copper, 32 per cent. zinc and 69 copper, 31 zinc. 4. The comparison of grain size with Brinell hardness on identical samples of annealed metal. In their comprehensive and thorough investigation of the recrystallization of cold-worked alpha brass on annealing,1 Mathewson and Phillips have discussed the relations between temperature of anneal, degree of deformation, and structural alteration in alpha brass. They have also shown certain comparisons between the ordinary physical properties and the grain size of annealed brass. The purpose of the present investigation is mainly concerned with the grain size of cartridge brass, its relation to Brinell hardness, and the publication of sufficient data to enable those engaged in the inspection of such material to have a correct foundation upon which to work.

Jan 1, 1919

By Mary Jean Buchanan

The last twenty years have seen the advent of environmental concerns and sustainable development, and the industry has witnessed the rise of Environmental Management Systems and their registration through several international standardization systems such as EMAS and ISO 14001. Beyond EMS and ISO 14001, which new goal the mining industry should aim at. Life-cycle assessment (LCA), another tool from the Environmental Management System series, is also on the rise and currently the object of an international standard (ISO 14040:1997). Through LCA, it is possible to assess the environmental aspects and potential impacts associated with products and services, taking into account all the activities required for its fabrication, its use, its transportation and its disposal. How could LCA be applied to the mining industry ? Is the international market pressurizing on mining companies to supply an ?environmental ore?? What about the automobile industry and its use of LCA ? Will it influence the ferrous and non-ferrous metal industry, suppliers of raw materials ? This paper presents a review of possible applications of LCA for the mining industry as well as world trends.

May 1, 2001

AT THE beginning of May the German government offered to the French and Belgians the payment of 30 billion .gold marks as indemnity, accom-panied by rather involved terms, among which was the ability of the Germans to finance the foreign loan. This offer was promptly and summarily refused by the French and Belgians. Since then there have been more palavers between the two parties, while the occupation of the Ruhr continued without especial incident, except some socialist riots and workmen's strikes. The renewed conference between the Allies and the Turks at Lausanne continued, without apparently getting anywhere. The Turks demanded an indemnity from the Greeks, which the latter refused to pay, threatening a resumption of hostilities rather than to do so. A. Bonar Law, the British premier, resigned his office soon after the middle of May, owing to poor health. The King appointed Stanley Baldwin as his successor. This. Attainment to the premiership of Great Britain by a business man is a noteworthy event. It is, moreover, to be remarked that Mr. Baldwin is personally acquainted with America and is well known to be a friend to Americans. The Irish rebellion came to an end. Economically there was some improvement in the situation in Great Britain during May, which was reflected in diminution in the number of unemployed. Nevertheless the aggregate of the unemployed in Great Britain continues at a very high figure. In Germany there has been an increase in the number of unemployed ever since the French occupation of the Ruhr, which naturally has been choking German industry. Previous to this the percentage of unemploy-ment among German workers had been low ever since the Armistice. A noteworthy domestic event was the non-stop flight of an airplane, May 2-3, bearing two aviators from New York to San Diego, California, in about 27 hours.

Jan 5, 1923

By H. F. Silliman, Daniel R. Hull, John R. Freeman

IN the normal operation of a brass-rolling mill, sheet and strip has, for the most part, been finished in comparatively thin gauges, involving a substantial amount of coldwork and a considerable number of anneals. This condition has been disturbed by the prep0nderance of cartridge brass, which is not rolled to thin gauges, and particularly by brass for artillery cartridge cases, on which the mill may finish its work at a thickness between 0.400 and 0.900 in. Obviously, the amount of rolling and the number of anneals to which such a product can be subjected are small compared with strip that is carried to a thickness of a few hundredths of an inch. As a result, critical examination into the internal condition of metal has been made on an extensive scale at a stage of manufacture that would not, in normal times, have been chosen for complete inspection. Under these conditions, a type of defect has been recognized that is not seen at thinner gauges. It might be more accurate to call it the appearance of a defect, since it refers to an apparently laminated, discontinuous structure, which, in fact, does not exist as such, and disappears after suitable treatment. For this reason it has been called a phantom lamination, which the authors consider an appropriate term. It is the purpose of this paper to describe the phenomenon and the conditions of its occurrence and, at least tentatively, to discuss its nature and cause. Great numbers of phantoms may be found in 2: 1 brass, either hot-rolled or cold-rolled. They are also found in 70-30 brass, sometimes when hot-rolled and generally when cold-rolled. It is not believed that phantoms are confined to these alloys but this paper is limited to them for the purpose of description. HOT-ROLLED 2:I BRASS For illustration, therefore, a typical cake of hot-rolled 2: 1 brass has been chosen. This was rolled to a slab 7/8 in. thick, from a casting 5 in. thick by 24 in. wide by 18 in. high, which was believed to have been sound. After hot-rolling and cooling, the slab was sheared and a portion of such a shear cut is shown in Fig. 1. It would be difficult to convince anyone viewing this specimen that the metal was not unsound. The impression would be confirmed by the appearance of a tensile break, as shown in Fig. 2. This is an ordinary tensile-test piece from metal just described. Although there was nothing in its tensile strength or elongation that suggested unsoundness, it appeared run through with pipes and laminations. To question the reality of such a condition would imply questioning the obvious. But, considering the history of the metal, it w0uld be difficult to believe that it could be so bad as it appeared. It seemed reasonable, though, that if the defects were what they appeared to be, they could be traced back from the sheared or broken face.

Jan 1, 1945

By K J. McDonald

All commercially available zircon sands contain radioactivity sourcing from the decay of trace amounts of contained uranium (U) and thorium (Th). The fine particle size zircons of the Horsham area in the Murray Basin region of Victoria, Australia, contain significantly more (about twice) Th+U than those commercial zircon sands. The marketability of these fine-grained zircon sands is likely to rely on the removal of these radioactive impurities. CSIRO Minerals have been working for some time to develop processes for the removal of the radioactive impurities from zircon. It is generally agreed that it is quite impossible to leach U and Th from zircon, however, the Heat and Leach (HL) process, described in detail in Aral and McDonald (1999), reduces the radionuclide levels significantly. The identified (HL) process aims to leach uranium and thorium selectively from a decomposed zircon. The novelty of the process is that a large part of the leached product can be reconstituted to a low radiation zircon by a subsequent heat treatment. The HL process uses a flux mixture of sodium carbonate and calcium borate to decompose the zircon at relatively low temperatures (900 to 1150¦C) and a weak acid (0.5M HNO3; 80¦C/0.5 h; pulp density ten per cent) to leach the radionuclides selectively. The process leaves the major components (ZrO2 and SiO2) behind with little loss. The HL process for example lowers the U+Th content of a Murray Basin zircon from 1000 ppm to 400 ppm U+Th. Among the radionuclides more U progeny is removed than the Th series radionuclides. This is very significant as the radioactivity of U series is 2.5 times more that from the Th series. Therefore the reduction in the radioactivity level of zircon is more than the reduction in Th+U indicated by XRF analysis. A schematic flow sheet of the HL process is shown in Figure 1. Although the HL process successfully lowers the radionuclide levels in zircon sands, the final product contains significant amounts of sodium (up to 14 per cent Na2O) and small amounts of CaO. By comparison, the sodium content of the commercial zircon sands is in general 2O. Zircon is used mainly as an opacifier in tile glazing where the addition of ten to 15 per cent zircon to a translucent base glaze gives the sanitary white colour to the tile surface. Opacification is the result of the refractoriness of zircon particles at the glaze firing temperatures that is generally around 1050¦C.

Jan 1, 2001

Mining companies in order to compete and succeed in being viable business propositions must look to the future and select mining methods which guarantee improved efficiency and productivity as well as lower costs. A mining company in adopting a method of mining must now select the equipment most compatible. To some mines compatible equipment may mean the use of drilling jumbos to replace hand held rock drills or the use of load haul dump units to replace scrapers. To other more mechanised mines compatible equipment may mean the use of raise borers and road heading machines. The right decision will be where equipment compliments method in such a way that the working environment is improved, productivity is maximised, cost if reduced and all profit opportunities are optimised. An example of such is where the use of improved mining techniques in underground operations may see cut off grades reduced. By selectively mining these lower grade orebodies, smaller operation's ore reserves improve and the capacity for continued growth is enhanced.

Jan 1, 1990

By T. T. Read

"Employee representation in the management of large mining enterprises was first introduced in organized form, by the Colorado Fuel and Iron Co. in 1915. Within the past few years a number of the larger mining enterprises have introduced similar systems and there is growing interest in the subject. This will be stimulated by the final report of the President's Second Industrial Conference, in which the following statement occurs:""The conference finds that joint organization of management and employees where undertaken with sincerity and good will has a record of success. The general principles governing such organizations are stated at length under the title 'Employee Representation. It is not a field for legislation, because the form which employee representation should take may vary in every plant. The conference, therefore, does not direct this recommendation to legislators but to managers and employees.""If the joint organization of management and employees in the plant or industry fails to reach a collective agreement, or if without such joint organization, disputes arise which are not settled by existing agencies, then the conference proposes a system of settlement close at hand and under Government encouragement, and a minimum of regulation. The entrance of the Government into these problems should be to stimulate further cooperation."""

Mar 1, 1920

By D. D. Howat

The first joint colloquium between the South African Institute of Mining and Metallurgy and the South African Branch of the Institution of Metallurgists was held in Kelvin House on 23rd April, 1981. About eighty delegates registered, the majority being associated with the local branch of the Institution of Metallurgists. Types of Abrasion and Wear Professor A. Ball, of the University of Cape Town, gave the opening address, which he entitled 'Some Thoughts on Abrasion and Wear'. In his thoughtprovoking talk, he quoted some figures showing that, in the highly industrialized countries, loss by wear and abrasion might amount to about 4 per cent of the gross national product but, in the Republic of South Africa, it was believed to be about 6 per cent of the gross national productprobably associated with the massive influence of mining in our economy. Professor Ball described wear as being of three main types.

Jan 1, 1981

By D. S. Nilsson

Small-scale mines are today expected to provide much of the increased production of metals and coal this county demands. But in fact the category of larger mines tends to grow in number and size faster than the category of smaller mines. Larger mines show the highest productivity, the lowest injury frequency, and the lowest costs. Lower cutoff grades can be wed in larger mines. The paper describes how the production level affects the choice between different types of loading, haulage, and hoisting equipment; how the increased production level in a mine results in lower production costs per ton; and how this affects the profitability of mining deposits with various ore grades. The future trend is expected to favor larger and larger operations.

Jan 1, 1983