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By J. H. Zimmerman

JET-PIERCING experiments were first conducted over ten years ago underground at the Soudan mine of the Oliver Iron Mining Co. Results were successful enough to encourage further research. The next field tests were made on the Reserve Mining Co. property at Babbitt in 1941. These tests showed that blastholes could be produced in taconite ore by the use of a flame and proper fluxing agents. The war put a stop to the experimental program shortly after these tests. Extensive field tests were resumed at Babbitt in 1946. In these tests nominal 6-in. blastholes were produced at an average rate of 10 ft per hour. Rates as high as 17 ft per hour were obtained for short periods. The experimental equipment used resembles a portable rotary-drill rig mounted on a truck. The standard steel mast has been extended to 46 ft to accommodate a blowpipe capable of producing holes over 30 ft deep. All auxiliary equipment including winch for raising and lowering the blowpipe, drive motor for the rotary table, pumps and tanks for process fluids, electric power plant, and control instruments are mounted on the truck. The jet-piercing process consists of

Jan 1, 1948

By Tedd B. Bodimer

Why complicate an already complex machine such as a continuous miner by adding roof drills? Immediate permanent roof support is an immediate thought of the mining engineer just as elimination of frequent time-consuming places changes is a thought of the methods engineer. The realization of those two objectives has the potential for improved safety with increased production is the thought of the general manager. Miner-Bolters Used a Generation Ago These are not new thoughts as the 1CM continous miner equipped with two integral roof drills was introduced twenty-five years ago. Approximately two hundred of these machines were sold in the next five years for use in medium and high seam operations. The 1CM miner chassis that remained stationary in the center of an entry or room while the ripper bar was swung and sumped hydraulically provided an ideal platform for mounting two roof drills that could be operated during the continuous miner's production cycle. Two roof bolts could normally be installed in less time than required for the mining cycle. A typical roof drill unit is shown in Figure I.

Jan 1, 1981

By C. Woofter

Quarry operators must continue to change and adapt environmental compliance methods to meet the increasingly demanding regulations. To fulfill industry needs, a computer-based decision support system is being developed to facilitate decision making that mine operators are required to make regarding environmental responsibilities. This system can help to determine permitting and compliance measures needed for air, surface water, groundwater, noise, aesthetics, vegetation, wetlands, hazardous wastes, storage tanks and wildlife habitats during the development, operation, and closure phases of mining. Operators will utilize the system's user-friendly interface consisting of mouse driven responses and limited keyboard entries on a desktop computer. The system is easy to upgrade according to the user's needs and changes in current laws and regulations. Data input models, user interfaces, and support of decision making are explained. The program permits inclusion of the decision maker's own insights through "what-if' analysis, in which the user can change ad hoc entries and check the related consequences. Using this approach, the user has complete control over all steps of the decision making process. A storm water example is selected to demonstrate the potential benefits of the support system to environmental decision makers.

Jan 1, 1995

By Gökhan Hardal, Berat Yüksel Price

Nickel manganite based negative temperature coefficient (NTC) thermistors have good temperature sensor characteristics and electrical stability for temperature measurement applications. In this study, the electrical and microstructural properties of Ni0.5Co0.5Cu0.3Zn0.3Mn1.4O4 NTC thermistor were investigated. The samples were fabricated by the conventional solid-state reaction method. The powders were calcinated at 900 °C for 2 h and the samples were sintered at 1200 and 1300 °C for 5 h in air. The bulk density of samples was 5.07 and 4.96 g/cm3, respectively. The microstructure of samples was observed using a scanning electron microscope. The electrical resistance was measured in a temperature programmable furnace between 25 and 85 °C. The electrical resistivity of the Ni0.5Co0.5Cu0.3Zn0.3Mn1.4O4 sample increased from 52 Ω cm to 95 Ω cm when the sintering temperature increased from 1200 to 1300 °C. The material constant “B”, sensitivity coefficient “α” and activation energy “Ea” values were also calculated for the NTC thermistors.

Mar 1, 2017

By H. E. Peterson, W. L. Anderson

"INTRODUCTION The great demand for tungsten incident to the war has led to the exploration of a large number of low-grade tungsten deposits. To properly evaluate the low-grade deposits it is essential to have available a dependable method of analysis applicable to all types of low-grade tungsten ores. Results reported on the tungsten content of the ores have often varied quite widely and have led to confusion. The Bureau of Mines has been requested by Government lending agencies and by companies interested in the production of tungsten to publish a general method for the determination of tungsten in low-grade ores. To meet this need, the Bureau of Mines is herein submitting two methods for analysis that have been proved on a large number of tungsten-bearing ores various types in the Bureau of Mines laboratory in Salt Lake City. Also, a third method was developed that requires no cinchonine and has proved to be applicable on most tungsten ores. The cinchonine method is the generally accepted for analysis of tungsten ores. Very reliable results can be obtained by this method if certain precautions are taken, as outlined in this report."

May 1, 1943

By Chunlin He, Xinsheng Li, Feng Yang, Lu Han, Yuezhou Wei, Feng Gao

The solvent extraction of vanadium (V) from Na2CO3–NaHCO3 solution was attempted using Aliquat-336 (methyltrioctylammonium chloride) extractant dissolved in sulfonated kerosene as diluent with 2-octanol as phase modifier. The influence factors, such as Na2CO3 concentration, NaHCO3 concentration, temperature, extractant concentration and impurity P, on vanadiumextraction were investigated. The results revealed that the single stage extraction efficiency of vanadium reached above 89%from 20 g/L Na2CO3 – 20 g/L NaHCO3 solution under the following conditions: extractant concentration of 15%, room temperature of 20–30 °C, 2-octanol of 6%, phase ratio (O/A) of 1:1, and oscillation time of 1 min. The addition of NaHCO3 into Na2CO3 solution could lower the pH value of the Na2CO3 solution, improve extraction efficiency of vanadium, and not introduce other impurities. The phosphate anion did not interact with the vanadate anion in the Na2CO3–NaHCO3 solution. The P in the Na2CO3–NaHCO3 solution had little influence on vanadium extraction.

Jul 30, 2020

By N LaBranche

The resurgence of Silicosis and Coal Worker’s Pneumoconiosis (CWP) in coalmines has placed the spotlight back on the management of worker exposure to particulate matter across all mining sectors (Coal Workers Pneumoconiosis Select Committee, 2017). There already exists a substantial body of knowledge on particulate matter and its impacts upon human health (National Academies of Sciences, Engineering, and Medicine, 2018). The contribution of silica to respiratory disease is well known and there is a growing concern for exposure to diesel particulate matter. However, it is also clear that there are major gaps in our understanding. In part, those gaps relate to the contribution to adverse health effects of mineralogical constituents in the dust (LaBranche et al, 2021a). It is also becoming evident that the size and shape of the particulate matter can affect its potential impact on human health.The University of Queensland has developed a methodology for characterising respirable and inhalable dust samples using scanning electron microscopy. Multiple samples from numerous mining operations have already been analysed using the UQ methodology. The process has been successful in showing the variety of mineralogica lcomponents and particle size distributions presentin various areas of the mines.

Oct 12, 2022

By John (Jack) D. Young, Frank M. Wheeler

Metallurgical plants are typically large, complex facilities. Their design is a multidisciplinary activity with a wide range of inputs, based on: the business case; metallurgical and process requirements; and the main processing equipment selection. Many constraints limit what can be achieved. Appropriate phasing of the design and development, and clear go/no-go decision criteria, are critical to successful implementation of a plant design project. Risk management concepts are used as a framework for successful project development, working from the business case, through project development, to implementation and startup, paying constant attention to technology, safe design, and sustainability. 1.1 INTRODUCTION The subject of “Metallurgical Plant Design” is the design of metallurgical plant facilities in the broadest sense. Plant design represents the culmination of many multidisciplinary activities: knowledge of process metallurgy is applied to design facilities to manufacture useful, economical, metal-based products. In the field of metallurgy, plant design is often overlooked, and its unique requirements are commonly not well understood, let alone appreciated. This book is a contribution to remedying this situation. The focus is the specifics of the metals industries, because an extensive literature already exists on the general topic of plant design.

Jan 1, 2015

By Gordon M. Miner

When I was originally invited to speak to this audience on the subject of the future supply of precious metals I was somewhat apprehensive and suggested that the Program Chairman select someone with more credentials. He declined and the results of our conversation gave me cause to reflect and recall the opportunities I have had over the years and how fortunate I have been to be associated with so many successful companies and knowledgeable people affiliated with the precious metals field. I discovered that since 1935, 1 have worked in or visited most of the gold and silver camps in the United States; have been a leaser of a gold mine in Mohave, California; have both lost and made money in the silver futures market; have worked for two of the greatest precious metals companies in the United States - Homestake Mining Company and Hecla Mining Company, have spent a considerable amount of time in precious metal related discussions with men like Don MacLaughlin, Paul Henshaw, Dick Stoehr, Abe Shoemaker, Bill Love, Phil Lindstrom, Simon Strauss, Herbert and Bunker Hunt and many others. It is those exposures and experiences that I draw onto discuss the subject at hand.

Jan 1, 1980

By John A. Folinsbee

Placer Dome Canada owns and operates the Campbell mine and mill at Balmertown, in the north western corner of Ontario. The mine operates at 1.3 kt/d (1,500 stpd). It produced more than 9.3 t/a (300,000 oz/year) of gold during the last three years. Changes to the gravity concentration circuit have resulted in a 10% to 15% increase in gravity recovery. The mill head grade at the Campbell Mill is relatively high, averaging 18.5 g/t (0.54 oz/st) over the total reserve tonnage. During the past several years, the head grade was averaging close to 20 g/t (0.6 oz/st). Before 1994, gravity concentration was achieved by using a combination of conventional mineral jigs and tables. Jig concentrates were upgraded on shaking tables to produce a concentrate, which was refined to bullion. In May 1994, management decided to buy two Knelson CD 760-mm (30-in.) concentrators. The objective was to replace the existing jigs and increase gravity gold recovery by up to 15%. Gravity recovery with jigs averaged between 30% to 35%. Gravity recovery was anticipated to increase to about 50% with the Knelsons.

Jan 1, 1997

By Frank D. Lamb, D. A. Woodard

"INTRODUCTION The iron-ore deposits near Cranberry, N. C., were worked as early as 1820, and records show that to date at least 1,500,000 tons of ore has been mined.. The early operators depended on selective mining and hand cobbing to yield a product containing 40 to 50 percent iron. Later, a magnetic concentrator was erected by the Cranberry Furnace Co. and was operated periodically until 1930. The magnetic cobbing method employed yielded satisfactory concentrates, but the plant was shut down because costs were too high. 4/Early in 1944, in connection with the sponge-iron program of the Bureau of Mines, North Carolina and Tennessee were surveyed for the purpose of finding a readily available source of high-grade iron ore for use in the experimental production of sponge iron at Salisbury, N. C., and samples from various sources were tested in the laboratory. The Cranberry ore proved to be best with respect to grade of magnetite concentrates produced, and it was decided that a pilot mill should be built on the Cranberry mine property and that the concentrate made there should be shipped to Salisbury for direct-reduction tests in a commercial brick kiln."

Dec 1, 1946

By C. Nesbit, N. Duru

During the cyanide leaching process of gold and silver, ores that come from the transition zones which typically con-tains low levels of sulfide may produce one or more of the following reduced sulfur species: sulfide (HS ), polysulfides (Sn ), thiocyanate (SCN ), thiosulfate (S2O3 ), trithionate (S3O6 ), tetrathionate (S4O6 ), pentathionate (S5O6 ) and hexathionate (S6O6 ). The actual speciation of the reduced sulfur species in the circuits will primarily depend on the re-dox potential, pH, cyanide levels and existing sulfur species in recycled process water, as well as the presence of other reac-tive metal species. Development of an accurate analytical method for sul-fur species in cyanide leaching units of gold ores where sul-fur speciation occurs has an important role in explaining the metal recovery deviations. This study presents the speciation of sulfur species and development of an ion chromatography method to analyze the reduced sulfur species thiocyanate, thio-sulfate, trithionate and tetrathionate in cyanide leaching circuits for gold ores. The method developed has resulted in the precise quantification of target sulfur species in leach solutions.

Jun 1, 2024

By L. C. IlsLey, H. B. Freeman

In connection with the approval of coal-cutting machines for service in gaseous mines , the engineers of the Bureau of Mines have been somewhat concerned as to the type of trailing cables that could safely be used on permissible outfits . While no final action has been taken on this question ( tentative approvals having been granted pending investigations ) , the Bureau has been endeavoring to collect data and information on this question which would permit a fair , yet safe , ruling to be made . For this purpose cooperative arrangements were made with three coal companies to visit certain of their mines , making inspections inside the mines to observe the cables and cutting machines in operation . In all , twenty mines were visited . A questionnaire covering the operations of trailing cables was filled out at each of these mines . In a few instances no personal inspection was made , the information being supplied by mine officials after conferences with the Bureau's engineer . At other mines the information given by mine officials was supplemented by personal observation inside the mines , usually at a time when the cutting machines were in operation .

Jul 1, 1923

By Vernon Helm, John S. Ball, Welton J. Wenger, William E. Haines

"INTRODUCTION Although the presence of sulfur causes many petroleum’s to be classified as ""low-grade"" because of the difficulties encountered in manufacturing products to meet rigid specifications, the petroleum industry is finding it necessary to use such crude oils to satisfy present needs. As the demand for petroleum products increases, and available reserves diminish, this utilization of high-sulfur crude oils will be accentuated. Programs designed to supplement the supplies of fuel available from petroleum by the manufacture of synthetic fuel from natural gas, shale oil, and coal are in progress. Such fuels, especially shale oil and, less so, oil from the hydrogenation of coal, also contain sulfur compounds which must be effectively removed. Thus, the need for fundamental research on the sulfur compounds that may be expected in petroleum and allied products is becoming greater as the industry is forced to call upon all available resources to meet the demand for petroleum products. In recognition of this need, the Bureau of Mines has inaugurated a long-range program assigned to furnish fundamental data concerning the presence, characteristics, and effects of sulfur compounds in petroleum and its products."

Dec 1, 1946

By Rodolfo V. de la Cruz

This paper describes the development of a new method and device for determining the in-situ mechanical properties of rock masses. The method involves a self-recording mechanical deformation gauge for sensing-recording she deformation of the borehole wall when loaded hydraulically. The self-recording feature of the gauge eliminates the difficult technical problem of transmitting signals over very long cables for measurements at great depths. Adopting a mechanical gauge instead of electronic, electrical, optical or grid techniques eliminates delicate instrumentation and installation problems. Moreover, mechanical gauges are inherently rugged and suitable for use in severe borehole conditions including very high temperatures. The technique was tested in limestone, basalt and granite specimen. The calculated mechanical property values for 1 the tests agree with those obtained by conventional testing methods. The self-recording mechanical deformation gauge has a minimum reading of 50 micro inches (1.27 x 10-3mm), comparable with electrical resistance strain gauges, capable of reading deformations over a range of 0.25 inches (6.35mm). The sensitivity, ease and accuracy of the method recommends it highly for in-situ rock modulus measurements.

Jan 1, 1980

By William F. Riggs

Inspiration Consolidated Copper Company, located in a semi-arid climate in Arizona, continually struggles with a water problem. This applies to quality as well as quantity. When the EPA considered installing a new centralized sewage plant to handle the combined waste from the municipalities of Globe and Miami, Arizona, they automatically assumed that He could use the sewage effluent for process water in flotation. The treatment plant was to be a tertiary system producing 1600 gpm of sewage effluent. Inspiration decided that this could possibly be a source of additional process water. It was decided to test sewage effluent from Miami Treatment Plant at the rate of 400 gpm since it was only a primary treatment plant. The 400 gpm was combined with the 5000 gpm of process water going to the Concentrator. After one week the results were disastrous. The recovery and final grade had each dropped approximately 5%. With the results from this brief run, it was concluded that sewage effluent from a primary treatment plant could not be used. Research was then brought into the problem to begin an evaluation of sewage effluent in flotation.

Jan 1, 1977

By V. S. Swaminathan

This year, Great Britain is looking back over a century to August 14, 1850, the day when the first "Act for the Inspection of Coal Mines" was passed in that country, an act which signaled the end of over two hundred years of hitherto uncontrolled and dangerous mining practices. It was back in the time of Queen Elizabeth that . thousands of pounds were invested in mining, particularly coal mining in England and Scot- land. By 1640 there were collieries producing 10,000 to 25,000 tons of coal per year. In the seventeenth century the Tyne district coal industry was organized into powerful partnerships, and coal took an even larger part in industry, as a source of power and as fuel for the iron industry. In the early 19th century a "phenomenal, almost devastating expansion" characterized Britain's coal industry, and it was sparked by a 111 pct in- crease in the population of England and Wales in the first half of the century. Coal production for those 50 years increased 470 pct and pig iron production was up 946 pct for the period 1801-51.

Jan 1, 1950

By Hal McVey

"Philosophy" addresses the definition and assigning of importance to the marketing of by-products. Two examples, one in metals and the other in industrial minerals, explore prime product to by-product relationships. Relative revenues from all products illustrate the importance of by-products to economic feasibility. "Mechanics" takes a broad view of the types of marketing organizations that are applicable to individual circumstances in the marketplace. In-house marketing as well as agents, merchants and trading companies are outlined and discussed. Philosophy Definition Of Terms Philosophy Definition Of Terms The definition of terns for a paper such as this is generally a necessary but not-very-interesting exercise. However, in simply trying to clearly define the term "by-product" some interesting relationships between products arise and the line of demarcation between "product" and "by-product" often becomes obscure. The search for that distinction represents the philosophy portion of the title. A couple of definitions of philosophy can even help to set the tone for what follows. According to Webster, philosophy is : 1 Pursuit of wisdom. 2. A search for a general understanding of values and reality.

Jan 1, 1983

By U. K. Custred

In 1973, the United States production of marketable phosphate rock set a record in excess of 42 million tons. This production rate is expected to continue to increase, due to the growing international requirement for fertilizer, at a rate exceeding 5% per year well into 1977. This trend contrasts sharply with the reduced phosphate rock production levels of the 1966 - 1971 period. The natural consequence of this growing phosphate rock market is an evaluation of the variety of means whereby plant capacity can be most effectively increased. One approach toward increased plant production capacity is through large capacity flotation cells provided they can be successfully applied to the recovery of the relatively coarse product which is characteristic of the phosphate rock feed. This paper will summarize the results of a nine month evaluation test program, conducted at the Haynesworth Mine at Bradley, Florida in which the flotation circuit "specific capacity" (tons feed/ft.2 floor space) and "specific input power" (Hp/ton feed) were determined, and the feasibility of achieving economically acceptable concentrate grade and recovery levels was demonstrated, using large, high capacity, flotation cells.

Jan 1, 1974

By W. L. Dalke

The Minntac complex is a facility for production of iron ore pellets located on the Mesabi Range at mountain iron, Minnesota. It consists basically of a mine, crushing plant, concentrator, and a pelletizer producing twelve and one-half million tons of pellets annually. This paper deals with some of the aspects of the grinding circuits; but prior to that discussion, it might be well to briefly describe the flow of material in the operation. The crude ore, containing from 20% to 25% magnetic iron, is mined by 14-yard electric shovels. .the blasted ore is loaded directly into 50-yard side dump railroad cars and hauled to the crushing plant. Crushing is done in three stages, originally, two 60" primary crushers; four 7-foot standard secondary crushers; and six 7-foot short head tertiary crushers were installed, when the plant was expanded to double its capacity, five secondary and ten tertiary crushers were added. These were duplicates of the original 7-foot standard and short head crushers used in the original construction, there was no expansion of the primary crushers but a one-half-million-ton surge pile of tertiary crusher feed was added.

Jan 1, 1976