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By N. Dixon

This report summarizes all work performed under U.S. Bureau of Mines Contract J0377014, "Development and Evaluation of Noise Control Techniques for Taconite Processing Equipment." Three areas of taconite processing equipment, grinding mills, fine screens, and crusher screens have been investigated. Extensive noise and vibration measurements have been made on grinding mills in which the process parameters that affect mill noise have been identified, and the level of shell impact noise around the mill defined. A multiplexing telemetry system was used to obtain shell vibration measurements from a rotating mill. Mill noise control methods were investigated and a partial mill barrier was built and tested on a semi-autogeneous mill. A noise reduction of approximately 3 to 6 dBA was achieved on the falling side of the mill. The use of rubber mill liners on autogenous mills has been evaluated. The noise sources on fine screens have been quantified, and noise control treatments developed. Noise reductions of 11 to 13 dBA were achieved at positions around the fine screen and some in-service testing has been done. Noise measurents of crusher screens were obtained and noise control through resilient screen decks appears to hold the most promise. Additional benefits might be lower life-cycle cost, since the service life of resilient decks is claimed to be longer than steel.

Jan 1, 1983

By A. Taylor, E. Thorn Corthay, R. Storey

In response to requests from its stakeholders, the International Standards Organisation is engaged in development of an international standard for Energy Management Systems (EnMS) which will become "ISO 50001". This new standard will build on the successes of both the EN16001 EnMS standard that has been used by dozens of European companies, as well as the ANSI/MSE 2000:2008 EnMS standard that is currently being used in several pilot projects in the USA and Ontario. This paper provides an overview of the key points of the EnMS standards, and describes how they can be used to drive sustainable energy reductions in the metallurgy industry.

Jan 1, 2010

By R. H. King

Underground coal mining machinery utilizes portable electric sables, "trailing cables." to obtain power from load centers or distribution boxes. Cables are frequently damaged since mobile equipment, poor lighting, and restricted space are inherent to coal mining operations. Normally, the damage is repaired by splicing--the joining of one or more severed conductors and replacing insulation and jacket. Figure 1 illustrates a typical single conductor splice. Although the repair seems simple, difficulty of the splicing process is exemplified by the many safety hazards and frequent production delays that result from defective splices. Forty-two cable splice related injuries were reported to the U.S. Bureau of Mines in 1972 and 1973. Additionally, 17 splices related fires were reported in the three year period prior to December 1972. Assuming the damaged area is quickly located, an average splice time for a two conductor cable is twenty minutes. Some operators estimate this delay is incurred once per day per operating section. If one ton per minute is averaged throughout the shift, each unit could loose 4800 tons per year from splice delays. An estimated cost for materials and labor to make a splice is $20. The expenditure could result in a $4800 annual cost per section. The estimated expense does not include wages of other personnel waiting for the repair to be completed. Nevertheless, labor and materials cost is minor compared to the income lost from decreased production.

Jan 1, 1975

By Alfred Bellows

The objective was to develop and design a remotely operated temporary roof support system that provides a safe working environment between a freshly cut coal face and the last line of permanently supported roof in which to perform roof bolting activities. This system was to take the form of a retrofit package which could be adapted to a majority of the bolters currently in service. The result is an integrated piece of hardware which will retrofit onto virtually all single boom bolters by removing the drill boom and relocating and modifying the hydraulic controls. The system is composed of three basic components: a pair of cantilevered roof supports which reach forward to the desired line of support, a mast type drill unit for drilling holes and torquing bolts, and a transverse slide assembly to carry the drill from hole to hole across the entry without relocating either the bolter or the roof support. A converted bolter not only provides a much safer operation but is projected to increase the production speed as well as reduce the manpower required to operate a section.. This improvement in productivity is shown to make the job of retrofitting a bolter cost effective in less than two months and provide a potential profit thereafter. Based on the findings presented in this report it is recommended that a proto-type be built and tested in an underground coal mine to demonstrate its effectiveness.

Jan 1, 1976

By Walter K. Utt

The vibration levels of the heavy machines used in surface mining are much greater than for vehicles used on highways. In order to assure the proper functioning of electronic equipment placed on the surface mining vehicles, the U.S. Bureau of Mines has conducted a program of field measurements to define their vibration environment. The information in this report is for a class of vehicle that has a blade for scraping and wheels with rubber tires. The statistical information derived from these measurements can be used as a basis for laboratory testing to qualify equipment for a surface mining vehicle of this class. The envelope that would encompass 99 pct of the vibrations encountered in normal operations is presented for each location on the vehicle. The five locations for which data were recorded are the floor of the cab, the engine, the frame, the drive train (gear, differential, and torque converter), and the axle. Tabulated data are provided for those who wish to use a different probability level. The appropriate test profile for the laboratory testing can be determined from the information presented in this report.

Jan 1, 1993

By H. W. Gillett

MAINTENANCE of membership by the technical so¬cieties and the activity of these societies in spite of the adverse business situation have been noteworthy. This forcibly brings home the fact that industry recognizes that sound technical guidance is well worth its cost. The numerous difficulties and losses due to defects of various kinds arising from gas-metal reactions are now generally recognized and interest in these problems is widespread. The forthcoming A. I. M. E. round-table discussion of gas-metal problems will do much to clarify the situation and will permit us to assay our present knowledge and to suggest the proper direction for profitable future research. "The Age Hardening of Metal" was the title of the annual I. M. D. lecture delivered by Dr. Paul D. Merica. A critical review of the known facts relating to age-hardening phenomena was first given, followed by the presentation of a theory correlating the detailed observations which have been made regarding the mechanism of the hardening.

Jan 1, 1933

By Willem P. C. Duyvesteyn

"Scandium International Mining Corp (SCY) has been involved in the commercial development of its Nyngan Scandium Project for about ten years. Various studies at a variety of global R&D organizations have been carried out in an attempt to define the deportment of scandium in both the limonite as well as the saprolite phases of Nyngan ore to assist with process development. Technologies such as sulfuric acid baking, high pressure acid leaching, sulfuric and hydrochloric acid atmospheric leaching and heap leaching have been extensively investigated both at the bench and pilot scale level to arrive at the most economic process flow sheet that will be discussed in some detail in this paper. Solvent extraction, ion exchange and other refining technologies have been tested and an optimum configuration has been established for the Nyngan project which is expected to be the first primary scandium mine and metallurgical plant in the world.Because of a lack of product availability the current scandium market is limited to less than 20 tons per year. Technologies have been identified to produce product with different specifications for aluminum alloys and solid oxide fuel cell applications. Preliminary economics have identified that Nyngan will be a robust and low capital cost project that can readily be expanded as the size of the scandium market increases."

Jan 1, 2016

By Northcutt Ely

This volume- summarizes mining and petroleum legislation in 18 European jurisdictions. Within these jurisdictions, primary attention is given to requirements that must be met in each country for acquisition of rights to permit development of mineral resources. Coverage includes: First, identitication of the controlling laws or statutes governing minerals acquisition and reference to the administrative authority; second, analysis; of the laws governing mines and quarries and their products; third, analysis of laws applicable to natural gas, petroleum, and related materials; and fourth, mention of laws regulating offshore operations. Where pertinent, sections dealing with historical background or administration have been added in countries where minerals are subject to control of States or Provinces, those areas are considered separately from the central government.

Jan 1, 1974

By Ryan Marsters, Adam Pring, Robin Dornfest

Raw water supply in the central Rocky Mountains often relies on trans-basin conveyance. Many of these older diversions incorporate high-elevation, miles-long tunnels driven over a century ago in hard rock. Tunnels were excavated using conventional drill-and-blast mining and weak ground was supported by timber sets and other various means. Over time, timbers rot and fail, rock quality deteriorates, and the timbers are gradually replaced by more timber, steel patches and braces, formed concrete, rock bolts, split sets, shotcrete, and other means which are commonly applied over existing support, thereby reducing tunnel cross sections, obscuring previous support systems, and rarely addressing the failing rock itself, leading to further deterioration of both the rock and the existing support. Traditional investigation techniques to assess compromised areas are often unfeasible due to access, depth, rubble and voids behind weight-bearing existing supports, confined space, poor invert conditions, poor ventilation, and flowing water. This presentation will discuss design procedures for assessing obscured ground conditions, assigning support classes which accommodate for unknowns, and implementing contractual means to address inevitable surprises or quantity overruns. Case studies include raw water supply tunnels in the Rocky Mountain region constructed between early to mid-20th century.

Dec 1, 2022

By Bruce Bryant

Silver ore was discovered at Aspen in 1879, but the district did not reach full production until 1888 after lawsuits were settled and railroads furnished less expensive transportation to the outside world. The boom years were 1888-92; production declined thereafter. From the middle 1920's until 1950, the Midnight mine in the Richmond Hill district furnished most of the output in the Aspen quadrangle. Since 1950, little mining has been done at Aspen. The metals produced were silver, lead and zinc. Native silver dissolved from the sulfide ores was redeposited by waters circulating as deep as 300 m below the land surface, resulting in great secondary enrichment of many of the deposits. Over 100 million ounces of silver were produced in the Aspen quadrangle. Low-grade lead-zinc deposits remain between the old workings locally, and data available suggest that primary ore below levels mined is also of low grade. The ore occurs in the Mississippian Leadville Limestone and the lower part of the Pennsylvanian Belden Formation in sites that were made favorable for deposition by a number of stratigraphic and structural factors.

Jan 1, 1982

By M. Hao, L. Wang, Y. Yin, B. Yang

This study established a coupled fluid-electromagnetic numerical model to systematically analyzse the effects of molten steel flow, inclusion transport, and temperature gradients on refractory erosion behaviour within an induction-heated tundish. The results demonstrate that increased induction heating power significantly exacerbates both flow-induced erosion and magneto-thermal corrosion of the refractory lining in the channel region. The erosion rate exhibits a linear increase with power, while the wear coefficient follows a power-law relationship. Concurrently, a higher power level intensifies the inclusion collision source term by a factor of ten, substantially promoting inclusion collision, growth, and removal (increasing the removal rate by 14.86%). However, this also leads to a 51.3% reduction in the outlet inclusion particle size. This research provides a quantitative basis for balancing metallurgical benefits (temperature control and improved steel cleanliness) with the longevity-oriented design of refractory linings.

May 8, 2026

By A. R. Barnes, N. Stubina

Increasingly, gold producers are forced to treat ever more refractory ores. While ores containing pyrite, arsenopyrite and carbonaceous material have been subjected to complete pressure oxidation (PDX) as the standard process for such ores, recent improvements in fluid bed roasting technologies have led to a resurgence of interest in roasting as a viable alternative. The lower capital and operating costs of roaster installations add further impetus to this trend. The Extractive Metallurgy Group at Xstrata Process Support operates four fluid bed reactors of various sizes which have been utilised on a large number of projects to treat highly refractory ores. Preliminary mineralogical modelling of both the physical and chemical aspects of the roasting process and subsequent testing under carefully controlled conditions has allowed clients to obtain gold recoveries approaching or matching those achievable by PDX. The flexibility of the units to operate in various modes- " bubbling bed", circulating bed, two stage, sub-stoichiometric and combinations of these, and the range of sample sizes accommodated, from a few kilograms to a few tons, has enabled XPS to accommodate clients with a wide variety of gold bearing refractory ores from all over the world. This paper outlines the key challenges of fluid bed roasting of refractory gold ores, describes the methodology used to design the testwork program and provides some results from select test campaigns.

Jan 1, 2011

By Francis J. Quinn

The Natural Gas Act, of 1938, which put interstate pipelines under the jurisdiction of the Federal Power Commission, did not place a protective competitive shield around such companies - nor does any provision of the act guarantee them a profit. Natural-gas pipelines are competitive with each other and also with the coal and oil industries. Gas distributing companies must compete not only with the coal and oil industries, but also with the electric industry. Natural gas has captured markets from oil, which had taken them from coal. Oil men contend that gas prices have: been, held to an artifically low level by regulation. The electric industry is moving into the space-heating market, which pleases the coal people because the coal industry's largest customer since losing the railroads to dieselization has been the electric companies. The coal industry is attempting to monopolize the industrial and electric generating market through government intervention, and this is being done under the guise of concern for the national welfare through advocation of a "National Fuels Policy purporting to, further the cause of fuel conservation. Such a policy is contrary to American principles and would result in the individual's loss of freedom of choice and ultimately, in less reserves of preferred fuels because of diminished exploration efforts.

Jan 1, 1961

By Yutaka Shiraishi

Two methods were developed to measure the viscosity of the slag from the glassy to the liquid states in an ascending temperature process. The first method employs rotating parallel plates within which is placed a solid cylindrical sample in line with a sphere. The second method uses a tube which is pushed into a sample held in a rotating crucible. Both methods were tested using standard glasses, including boron trioxide and NBS standard glass #711. The main difference between these two methods is in sample preparation. Comparative measurements between two methods were performed using a sodium boro-disilicate glass containing 5%mol of alumina. The results showed good agreement in the mid-range of glassy viscosities, 105 to 107 Pa.s. In the liquid state, there were no significant differences between the two methods.

Jan 1, 2003

By Peter Bates

"HIsmelt has faced and overcome many challenges in the understanding and development of injection technologies that satisfy process and engineering requirements for further scale up to a commercial plant.An overview of the design basis of bottom and top injection systems with plant results are described in this paper.IntroductionAn appropriate way to introduce this paper is to initially reflect on the genesis of the HIsmelt Process.It is appropriate that Professor Womer is the one we are honouring as it can be claimed that by the involvement of CRA in the WORCRA process that the concepts for irijection systems in iron and steel pyrometallurgical processes achieved significant attention by the company. The development of water cooled injection lances and their application injecting solids and gases with success was certainly a pre-cursor to the development of other injection systems commonly used today in arc furnaces and for top injection at HIsmelt.HistOrically it was the work of Savard and Lee in Canada with shrouded tuyeres and the subsequent commercialisation of this technology at the Maxhiitte Steelworks spawning the suite of bottom oxygen blown process as known as QBOP; OBM and the subsequent combined blowing process such as KOBM that first commercially succeeded in injecting solids under a molten metal bath. The next progressive step from the injection of calcined lime in the technology development was the injection of coal for coal gasification as developed by Klöckner technologies being called KG, KSG and KMS and also the injection of coal for increased scrap melting.A paradigm shift in thought process to leap from steelmaking and coal gasification to direct smelting by injecting coal and iron ore into a molten metal bath in the correct stoichiometric ratio to maintain the bath at a constant temperature and carbon level was the true genesis .of HIsmelt.A good overview of the state of the art of tuyere type injection technology is given in Ref. 1."

Jan 1, 1996

By R. HOLROYD

The Ludwigshafen and Oppau plants are largely independent I. G. factories situated some 23 miles apart on the west bank of the Rhine facing lannheim. The former factory is a general organic chemical works specializing in dyes, dye intermediates, plastics and synthetic rubber,. while the latter is a heavy organic chemical factory producing ammonia, methanol, higher alcohols and their derivatives. Before the war much of the I. G. research and development work was carried out at Ludwigs- hafen; in particular the high pressure research section directed by Dr. Mathias Pier played a very active part in all hydrogenation developments. Apart from the possibility that a full scale hydrogenation or Fischer Tropsch plant had been erected at Ludwigshafen/Oppau during the war, the main objectives of an oil team investigation were: - (a) To obtain from Dr. Pier and his staff an advance general picture of German fuel production processes. (b) To study the fuel developments still in the research and pilot plant stage. (c) To examine any new developments in hydrogen or synthesis gas manufacture. (d) To look for new processes for production of high anti-knock fuel constituents and for new fuel additives. (e) To investigate new chemical syntheses based on raw materials obtainable from oil. The Ludwigshafen and Oppau factories were first visited by the large team listed in Appendix A during the period 25-31st March. The investigation revealed that no large plant for synthetic fuels or lubricants had been operated at this target. All the important members of the Fuel Research Section staff had been evacuated to Heidelberg and information on the work of this department was therefore limited to that contained in seized documents, the greater part of which have still to be examined in detail. Valuable information on synthesis gas production from hydrocarbon gases was obtained as well as interesting data on a num- ber of chemical syntheses. Two members of the above team Holroyd and Faragher accompan- ied by Major Tilley (interrogator) went on to Heidelberg, contacted Dr. Pier and the chief members of his staff on April 1st and obtained from them the hydrogenation information given later in the body of the report. Later, after visiting Leuna, Holroyd, Faragher and Ellis paid a second visit to Heidelberg and to Ludwigshafen/Oppau on 27th-30th May to check a number of details, particularly with respect to hydrogenation costs, and to obtain information on the pressure.conversion of water gas to hydrogen and on the manufacture of Wickel pressure vessels.

Aug 1, 1943

By Robert L. Bates

In this paper I use the term "industrial minerals" in its broad general sense, and I distinguish two main groups. The first consists of the bulk materials, characterized by low unit price, nearness of deposits to markets, relatively simple methods of extraction and processing, and a tendency to be closely related to the construction industries. The second group includes those materials valued for exceptional purity, or for some special property such as hardness, immunity to acids, or dielectric strength. These materials are produced in smaller amounts, at high unit values, from deposits notably restricted in. distribution; and they require more or less sophisticated methods of production and beneficiation. The applications of this second group are not closely tied to any particular part of the economy. From the way in which the commodity committees of the Industrial Minerals Division are set up, I take it that the chief interest of most members is with the first group of materials mentioned above. Hence this paper will deal mainly, though not exclusively, with such bulk commodities as sand and gravel, clay, and stone. The first word in the title of the paper also requires brief explanation. It is here given a threefold interpretation. First is the role of the industrial minerals themselves in industry; this would probably be taken as the conventional meaning of the title* The second is the role of the industrial-mineral producers as citizens of the community. The third is what may be called the scientific role of these producers.

Jan 1, 1964

By J. C. Johnson

In situ stresses are important input data for the design of safe, stable stope layouts and extraction sequences. However, it is commonly assumed that normal and shear stress gradients in a stress field are negligible and, consequently, that stresses are uniform throughout the region of analysis. To evaluate these assumptions and to provide input data for an analysis of a shaft pillar mining plan, in situ stresses were measured at the Homestake Mine, Lead, SD, using overcoring on hollow inclusion cells and borehole deformation gauges. These measurements were used with conventional least squares, best fit data reduction schemes. The results showed that normal stresses within the shaft pillar were less than, but comparable to, those estimated from finite-element modeling. Shear stresses were an order of magnitude less than normal stresses and varied considerably from site to site. Possible causes of this variability include effects of scale, elastic moduli, anisotropy, and axial strain. Because of the variability, it is not possible to determine the magnitude of horizontal stress gradients.

Jan 1, 2010

By John A. Breslin

This report summarizes the principal activities and significant results of the Bureau of Mines respirable dust research program since passage of the Federal Coal Mine Health and Safety Act of 1969 and the Federal Mine Safety and Health Amendments Act of 1977. This program has investigated new and improved techniques and equipment to reduce or prevent the formation of dust during the cutting cycle; to dilute, suppress, or collect airborne dust generated during mining, handling, and processing; and to improve the measurement of dust levels for evaluation of engineering controls and for enforcement of Federal dust standards. The report is intended for mining industry dust control specialists and other interested parties. It includes a brief summary of the program to date, a section on future research plans and goals, and a list of publications resulting from the Bureau's respirable dust program.

Jan 1, 1982

By P. G. Thornhill

EARLY in 1951, Falconbridge undertook a research program aimed at the development of a sulphate roasting process for the recovery of the non-ferrous rnetals from the nickeliferous pyrrhotite fraction of Falconbridge ore, in order to reduce the tonnage of iron entering the srnelter. Such a method, it was hoped, would permit a high recovery of the nickel from pyrrhotite otherwise entering the smelter feed, thus not only raising the grade of the latter and reducing its iron content, but also providing an iron oxide residue useful as a source of by-product iron ore. At an early stage in the exploratory laboratory test work it was found that the degree to which the nickel could be solubilized by the sulphating roasting treatment was limited by particle size and the ex-tent to which the pyrrhotite concentrates were freed of the nickel occurring as physically separable pentlandite, a mineral relatively difficult to roast. ( 1) Thus the program

Jan 1, 1961