Search Documents

By A Misra

In pursuit of solving the development rate problem the coal industry has investigated various development systems. While all the systems may improve the development rate they may not necessarily he cost effective. This paper carries out an economic analysis by developing cost models for present and future development systems for retreating longwall faces with particular reference to Australian longwalls. A critical cost analysis of various development systems is presented by taking into consideration all the costs associated with development systems. The costs have been divided into equipment, face and panel services, belt and structure, wages, roof and rib support, ventilation, consumables, power and maintenance. The annualised cost of various equipment has been obtained on the basis of depreciation rates prescribed by the Australian Taxation Office.

Jan 11, 1996

By AIME AIME

EVEN though most of the program of the joint meeting at Easton, Pa., on Oct. 30 to Nov. 1. was devoted to the interests of combustion engineers rather than to coal-mining engineers, nevertheless the A.I.M.E. Coal Division was well represented, with 83, or close to one third of those in attendance giving this as their affiliation. The fuels division of the American Society of Mechanical Engineers had 108 representatives, and an equal number reported no society affiliation. Added to the men's total registration was that of some twenty ladies so the total attendance was in the neighborhood of 325, exceeding that of the last two joint meetings, at Birmingham and Columbus, and equaling the 1938 crowd at Chicago.

Jan 1, 1941

By Anthony William Deller

MAJOR battles in the present war have been fought in American research laboratories. Without the outstanding contributions made by our scientists, engineers, and technologists in mining and metallurgy, many of our achievements in the present war would have been impossible. All recognize the fact that modern research has found the answer to problems which seemed insuperable. For the duration, many of these inventions must be maintained as war secrets. But aside from these, the record of accomplishment in peace and war, especially in the past few decades, known to all, demonstrates what scientific and industrial research can accomplish. It may be regarded as axiomatic that the development of modern industry is based principally upon research devoted to making inventions and discoveries. We have come a long way from the sixteenth century, when Agricola published his classical "De Re Metallica:" With our vastly increased knowledge we are now commercially producing dozens of metals entirely unknown at that time. Further, with our modern methods of research and development, a large number of invaluable alloy compositions have been produced. These include numerous age-hardenable alloys, cupronickels, "Everbrite", "Everdur", "Duralumin", "Elinvar", "Hastelloy", "Inconel", "Invar", "Monel", "Ni-chrome", "Ni-Hard", "Ni-Resist", "Permaloy", "Silcrome", stainless steels and irons and other alloy steels, "Stellite", and zinc die-casting alloys.

Jan 1, 1945

By Howard N. Eavenson

DURING the past year, as in the preceding ones, prices continued to fall, production to decrease, and more mines were closed. Much attention is being given by the industry to suggested plans for betterment of its position, and if the scheme recently brought out for consolidation of sales agencies into district agencies is loyally carried out, it cannot but help to improve conditions. The progress in the anthracite industry is shown in the report of its chairman, E. H. Suender; changes in coal preparation are outlined in the report of J. B. Morrow, chairman of Committee on Coal Preparation, while increased mechanization of the western mines is described by Eugene McAuliffe, chairman of the Committee on Machine and Strip Mining. In spite of the depression, interest in the Coal Division has been increasing, its meetings have been well attended, and its committees are active and have been doing excellent work.

Jan 1, 1932

By Dozier Fircley

SOME nonmetallic minerals and their products, such as portland cement, common brick and hollow tile, sand, gravel, crushed rock, vitrified salt-glaze clay pipe, and the like, are a necessity in every community. They are mineral in nature but the establishment of plants for their production is usually a local and elementary problem. Yet it is probable that an economic study of the problem in every locality will show that such nonmetallic mineral commodities are not always obtained in the most economical way, or in the best quality. Other nonmetallic minerals are of such value that they may be shipped for long distances and sold in sufficient quantities to establish prosperous commercial ventures. Among these are phosphates, barium compounds, borates, nitrogen compounds, magnesium compounds, sulfur, asbestos, and potash. Success in marketing such products depends on quality, production cost, transportation, and similar conditions.

Jan 1, 1932

By Arnold Hoffman

A RESPONSIBLE steel executive recently declared that scrap shortages, despite fantastic prices reaching up to $50 per ton, are responsible for the loss of 140,000 tons of steel a month and that in March 1947 alone 25 more steel furnaces could have been operating were it not for scrap scarcities. His answer to this serious situation was to ask for a speedier flow of scrap and also abolition of Government control over pig iron distribution. It would be more logical, perhaps, if an answer to this growing problem of scrap deficiency were sought within the steel industry itself. As long ago as 1933, L. B. Lindemuth, a consulting steel metallurgist, warned the steel industry that a shortage of scrap was inevitable and that beyond 1938, adequate supplies for open-hearth furnaces could not be expected. The outbreak of war, with consequent phenomenal demands on the industry, accelerated production of steel and further worsened the scrap situation. Today we are suffering from a condition which could have been prevented had the industry been more far-seeing and provided for an inevitable contingency. However, better late than never, and measures can now be taken to alleviate permanently scrap shortages in the future. This can be done by greater utilization of heavy sinter which experience proved is an excellent substitute for scrao and lump ore.

Jan 1, 1947

By ROBERT R. RICHARDS

My. first paper, read at the Cobalt Meeting of the Institute,1 July, 1907, dealt with the behavior of a small Wilfley table when concentrating galena from quartz, the table being fed with natural products, with sized products; and with classified products. Since galena, having a specific gravity of 7.5, is among the heaviest minerals ordinarily concentrated by Wilfley table, it was desirable that a similar set of tests upon a mineral of, lighter weight should be made. Chalcopyrite, of a specific gravity of 4, would have been the best mineral for this purpose, on account of its great importance as an economic mineral, but in carrying out the test, however, I was obliged to content myself with a cupriferous pyrite, the specific gravity of which was 4.68 and the contents in copper 8.80 per cent. Through the kindness of Mr. H. 0. Cummins, this material was obtained from Shasta, Cal.,in very pure, clean, homogeneous condition. It was broken by rolls to 2 mm. in size, taking care to make a minimum of slimes. The quartz used to mix with it was pure, white, New England quartz, broken in the same way to the same size. In studying the accompanying tables, it should be borne in mind that the material concentrated was of low copper-content, and in many cases the quantity fed to the machine was 1 kg: or less.. As a consequence of the smallness of the 'quantity treated it was very difficult to adjust the table and get it in condition to do its best work before the feed became exhausted, and for this reason many results were obtained which appear irregular.

Sep 1, 1908

By H. S. Baloyi, J. J. Rust

Spiral concentrators are widely applied to beneficiate commodities such as Cr2O3, mineral sands, and ferrochrome. The application of spirals for heavy minerals has been limited to a feed top size of 1 mm. At particle sizes larger than this, friction retards heavy particles and the particles' primary velocity approaches zero, resulting in a solids build-up, therefore inhibiting further separation. Recently, a new Multotec SC25 spiral model was introduced to the industry, which aids in beneficiating particles of up to 3 mm, with successes having been demonstrated in ferrochrome slag and titanium-bearing minerals. This spiral also has potential in electronic waste applications. This paper examines the applicability of the SC25 spiral in coarse Cr2O3 recovery. This stems from the fact that junior chrome miners tend to discard particles larger than 1 mm as they neither have milling nor dense media circuits. Also, alluvial chrome miners discard +1 mm even though this size fraction contains recoverable and liberated Cr2O3. The SC25 spiral has shown better Cr2O3 separation efficiencies than the SC21 model and with higher SiO2 rejection at saleable grades, thus providing an additional revenue stream specifically for the coarser (+820 μm) size fractions. Keywords: Spiral concentrators, chromite recovery, specific gravity, SC25 spiral, coarse spiral

Jan 1, 2020

By J Canterford

Although we have access to a wide range of sophisticated process design and improvement tools in combination with a significant range of case studies, the mineral resource industry still manages to be plagued by the negative publicity surrounding operating plant failures because they were neither smart nor safe, together with proposed projects that fail at the first or second hurdle. The general public and the finance industry are generally totally uniformed about projects that ramp-up to name plate capacity on time and on budget and even more so when ahead of schedule and under budget. As the saying goes, good news does not cut the mustard.The following is a summary of the author’s sometimes jaundiced view about why metallurgical plants do not live up to their technical and commercial expectations. In no way should the summary be construed as a negative reflection on the skills of the metallurgical profession. Rather, it is to be taken as a positive acknowledgement of those skills and is intended to highlight some of the major considerations that need to be assessed as a potential project transforms into a sustainable technical and commercial reality.While a considerable portion of the summary is directed at developing hydrometallurgical flowsheets, the general principles are equally important to all aspects of extractive metallurgy.For convenience, the summary covers the following five basic discussion points – project, people, process, patents and politicians.

Aug 8, 2011

By A. D. Garman

This digest of Brazilian mining law is based upon Decree 4265 of January 15 , 1921 , and its regulation , Decree 15,211 of December 28 , 1921. Unless otherwise stated , the references are to the latter exclusively , since it includes practically everything contained in the law itself . It should be borne in mind that these regulations do not necessarily apply to mines other than those on private and national land . Each State of the Union is free , in respect to State land , to regulate or interpret the national mining law , which is very general in its terms , as it sees fit . Whether such local regulations are anywhere in force with respect to the law of 1921 the bureau has not been informed . Article 64 of the Constitution indicates that only such portions of territory as are required for the defense of the frontiers , for fortifications , military constructions , and federal railways belong to the Union . Lessees of such lands , unless in debt to the Treasury , have preferential prospecting rights for one year ( art . 28 ) . This carries with it the right to work any mines discovered (Law , art . 12 ) .

Jul 1, 1930

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of El Salvador has been prepared from the best available information in Washington , but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State . Under the terms of the Code of Commerce ( arts . 12ff . ) , foreigners living in El Salvador can engage in business on the same terms as nationals . This involves ( = $434.00 ) - except for those with a working capital , of less than a thousand pesos inscription in the merchants ' register , which can be refused only in case of manifest disability of a permanent nature .

Sep 1, 1930

By E. P. Youngman

By a decree of March 14, 1929,5 the President of the Faitian Repub- lic, considering it to be necessary, until the mining legislation of the Republic shall have been revised, to put into effect the mining law of Decem- Der 4, 1860 (relative to mines, diggings, and quarries), by the authority given in article 55 of the Constitution, declared the law of February 14, 1919, to be abrogated and the provisions of the earlier mining law (December 4, 1050) again to be valid. No concessions were granted under the law of 1919. All citations in this paper, unless otherwise designated, refer to the law of 1930.

Jun 1, 1932

By I. AITKENS

The opal , long in disfavor because it was considered " unlucky, " has become much more popular in recent years . For variety and beauty of color the precious opal is without a peer . These colors do not come from any chemical constituent but are produced by structural peculiarities , which in varying degrees deflect the light rays entering the stone and give a prismatic play of hues .

Sep 1, 1931

By A. N. Clay, N. N. Moeketsi, S. Joubert

For many years, mine-impacted water has been regarded as a problem and linked to long-term environmental liabilities. However, this water can be a renewable and a sustainable resource, provided that it is managed in a responsible and sensible manner. South Africa’s National Water Resource Strategy (NWRS, 2013) considers water that can be used to contribute to economic activity to be a water resource. Although all water resources are considered as belonging to the State, government does not appear to have meaningfully explored the use of mineimpacted water to contribute to the country’s economic activity. Africa is blessed with more sunshine than anywhere else, apart from Australia, yet we see no rollout of vast quantities of solar panels to ensure every African family has access to affordable power. This suggests that governments are incapable of managing such a free resource. At the same time, apart from the equatorial areas, water is a seriously constrained resource and yet we expect the same entities to manage a commodity none of us can live without. This paper explores the conversion of mine-impacted water from waste to a resource and how the inclusion of other stakeholders (such as water users, landowners, and ordinary South Africans) could benefit the process.

Jan 2, 2022

By Robert C. Maxton

The foundry industry is a basic source of structural component for all industry. Millions of tons of castings are produced annually in both ferrous and nonferrous alloys. These castings are subjected to a wide variety of heat treatments, finishing techniques, mechanical tests and machining operations. Through all of these steps the quality of the casting is of paramount importance to the end use of the product. The Quality Assurance Program at Minneapolis Electric Steel Castings Company is designed and established to provide a superior product for both original equipment manufacturers and the mining industry.

Jan 1, 1982

By D Connelly

Magnetite ores can be used to produce very high-grade concentrates that are suitable feed for the direct reduction process route but the high sulfur content of some concentrates can cause substantial environmental issues. Processing of high sulfur magnetite ore is therefore increasingly problematic for the industry. Generally, the industry demands a concentrate with <0.05 per cent sulfur and <2 per cent silica. This paper reports the outcomes of a study to produce a concentrate with the requisite low sulfur content from a sulfur-rich magnetite ore. The main findings may be summarised as follows: if the sulfur is present in magnetite as nonmagnetic pyrrhotite or pyrite, it can be beneficiated using magnetic separation and hence, monoclinic pyrrhotite is magnetic and is magnetically recovered with magnetite leading to a concentrate that is too high in sulfur. X-ray diffraction and QEMSCAN analyses revealed that the magnetite concentrate was liberated at P80 30 microns and was associated with maghemite, pyrrhotite (magnetic), carbonates and hematite with very low amounts of chalcopyrite, sphalerite and arsenopyrite. Sulfur removal using flotation was the first stage of investigation and this required flash flotation in the grinding stage followed by column flotation of the initial concentrate to generate the final concentrate. At the same time, it was observed that oxidation of the pyrrhotite had a negative effect on its flotation requiring copper sulfate to activate it. Bioleaching and concentrate leaching were also considered and achieved over 90 per cent sulfur removal but were deemed unsuitable owing to the production of highly reactive wastes and high CAPEX. Reference is made to a number of operating magnetite producers and how they manage the sulfur in feed.

Sep 18, 2023

By David Wilshaw

Continuous Surface Wave (CSW) testing has been the “next big thing” in ground characterization for the last 25 years. The technique uses surface geophones to measure the speed at which Rayleigh waves (generated by a vibratory source) travel through the ground over a range of frequencies. The velocity at which surface waves travel through the ground is directly related to ground stiffness; the velocity of shorter wavelengths is influenced by the stiffness of shallower soil layers, while the velocity of longer wavelengths is influenced by the stiffness of deeper layers. Measuring the surface wave velocity over a range of frequencies, therefore, allows a stiffness / depth profile to be produced. Using the small-strain stiffness data measured by the CSW technique greatly improves the accuracy of simple limit state analyses; the data are also of sufficient quality for use in Finite Element modelling. Nonetheless, the technique has suffered from a perception of high cost, low productivity, and poor repeatability. An improved Advanced Continuous Surface Wave (ACSW) testing system has been developed by Ground Stiffness Surveys in the United Kingdom, has been deployed there commercially for several years, and is now available in the United States. ACSW uses an automated electronic control system that generates vibrations (from a purpose designed and manufactured portable seismic “shaker”) at different frequencies, measured across a 3m (10-foot) array of geophones, linked to a robust data acquisition and analysis software package. The range of applications in geologic and geotechnical site characterization includes rapid preliminary non-intrusive site assessments (utilizing published soil correlations); stiffness profiling to detect discrete layers (such as a variation in rockhead); average stiffness profiling for earthwork or ground improvement control testing, Working Platform stability assessments, foundation settlement analysis, rock quality and rippability assessments, and void detection.

Oct 1, 2022

By W. J. Schitt

Section 15 covers a loose collection of topics that involve water in some way. The chapters in this section include Dredge and Placer Mining (Chapter 15.1), Solution Mining: Surface Techniques (Chapter 15.2), and Solution Mining: In Situ Techniques (Chapter 15.3). The dredge and placer systems involve water in several forms. The segment on hydraulicking or hydrosluicing discusses the use of monitors to direct high-pressure water jets to move material. As such, this represents an alternative to mechanical breakage, loading, and hauling. This chapter also covers placer mining (except dry placering) where the water provides the medium that promotes the separation of minerals based on their density and other settling characteristics. Thus placer mining is generally limited to concentration of gold, tin ore, diamonds, and other heavy minerals that are already liberated and are contained in a less dense matrix. The third topic, straight forward dredging, as in sand and gravel operations, involves water only in an incidental way. Here water simply covers the minerals of interest. Thus the dredging system need only lift a payload from the submerged location to the surface for further processing or handling

Jan 1, 2008

By H. B. Hill

The West Red River oil field, in Tillman County, Okla. (fig. 1), is approximately 8 miles northwest of the town of Burkburnett, Wichita County, Tex. The wells are in the river bed between the medial line and the south bank of the Red Diver. In the following discussion of the geology, development, and exploita-tion of the field, the authors have, by means of structure maps, crews sections through various parts of the reservoir and tabulated development data and production statistics, recorded salient information on a field whose development was unique and in some respects unusual for fields discovered and initially developed more than a quarter of a century ago. The total oil production from Government-operated leases; considered in the report was 6,900,440 barrels to January 1, 1947, from 3 proved acres developed by H1 oil-producing wells, 10 gas-injection wells, and 5 nonproductive wells. A calculated past recovery of 60P, barrels of oil per acre-foot and an estimated ultimate recovery of 6.S0 barrels of oil per acre-foot under present gas-injection methods begun in 1929 in shown.

Jan 1, 1949

By Yi-Shen Li

This report has been prepared by Lockheed Missiles & Space Company, Inc. (LMSC), under United States Bureau of Mines Contract No. H0220040 dated 21 June 1972 for the design, development, fabrication, and certification of the One-Hour Self-Rescue Breathing Apparatus (PBA). The PBA is a self-contained, oxygen-generating, CO2-removing closed-loop breathing apparatus that provides a minimum of 1 hour of breathable atmosphere during escape from a mine with a contaminated or oxygen-deficient atmosphere. This Cost-Plus-Fixed-Fee (CPFF) contract has been successfully completed in a three-phase program. The Phase I tasks included the design, development, and fabrication of prototype units developed at LMSC in accordance with the requirement of the Code of Federal Regulations (CFR) Title 30, Chapter 1, Subchapter B, Part 11 (Appendix A), and was submitted to the National Institute for Occupational Safety and Health (NIOSH) for joint NIOSH and Bureau of Mines certification testing.

Jan 1, 1974