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By Sidney M. Cohen

[Portland cement is a product made from a combination of limestone and argillaceous material which would supply the necessary amounts f calcium, silica, alumina and iron to form cementious compounds when fired at high temperatures. The resulting mixture, usually around 80% limestone and 20% argillaceous, is ground nine (80% -200 mesh), blended and then fired1 (2600-2700°F) to produce a cement clinker from which the final cement product is produced by grinding. The argillaceous component can be shale, clay, slate or other sources of the individual components of silica, alumina and iron. This paper deals with a case where a clay component was under consideration. The planned Plant site was to be located at a well defined limestone deposit. When it came to the argillaceous component, the nearest uniform deposit of clay was over 50 miles away and would require purchase of land or clay from the owner plus the daily delivery costs to the plant site. This situation made the plant site economically questionable. It was decided that a local clay deposit, which was available at the plant site but was orginally not considered due to lack of chemical uniformity and its high free silica content, would be reconsidered.]

Jan 1, 1983

By J. H. Kelley

In this paper, we show that the methane emission and the dust generation in under-ground mining currently and in the future pose operational, health and safety conditions which adversely Impact face productivity and worker satisfaction. One solution is the use of a dual-aircourse system of ventilation. In this concept, one aircourse captures and exhausts to the surface the dust generated and the methane emitted in coal/mineral fragmentation while a second aircourse provides workers with cleaner air for breathing and comfort. Various dual-aircourse configurations adapted to the Variable Wall Miner are analyzed and compared with conventional mining in gassy seams, indicating a marked reduction in the required air quantity and the number of aircourses.

Jan 1, 1996

By I. H. Warren

The high temperature lubricant molybdenite, MoS2, is usually produced by a complex sequence of processes involving mineral dressing of molybdenite concentrates followed by leaching with hydrofluoric acid to remove abrasive impurities such as silica (1). Many attempts have been made, mostly by techniques involving, direct fusion of molybdenum compounds with sulphur, to produce synthetic molybdenite. However, apart from some experiments of geochemical interest (2) in which aqueous solutions of sodium sulphomolybdate, Nat MoS4, were decomposed under pressure at temperatures between 300°C and 700°C, no attempts to produce the mineral by hydrometallurgical procedures have been reported. Since molybdenite is nominally a compound of tetravalent molybdenum with sulphur, and the most common state of molybdenum is +6, production of molybdenite is likely to involve reduction and sulphidization. The present study, therefore, describes the reduction, with hydrogen and carbon monoxide, of molybdenum in the hexavalent state in alkaline aqueous solutions containing sulphide ion. In these

Jan 1, 1972

By Abegail Endraca, Allan Sebastian, Andrew Raine, Allan Patdu

The project involves the construction of a new aqueduct tunnel by an Earth Pressure Balance TBM tunnel for the Novaliches-Balara Aqueduct No 4 (NBAQ4) project in Metro Manila. It comprises a 7.3 km long and 3.1 m internal diameter tunnel that can deliver up to 1,000 MLD of raw water and the tunnel passes under urban residential and urban populated areas adjacent to and along Commonwealth Avenue. A new reservoir intake structure was constructed in the La Mesa reservoir by a cofferdam and the TBM breakthrough connected the reservoir to the outlet surge shaft structure and the downstream pipe network system connecting to the Balara Water Treatment Plant. The TBM incorporated a double articulated head configuration to allow tight 80 m radius curves to navigate some of the difficult alignment considerations. The alignment passed very close to some existing foundations for MRT7 and needed to clear several tight curves to remain within government land ownership. The project excavated through the local Guadalupe weak rock formations and there was minimal ground movements observed as a result of the work.

Jun 13, 2023

By K. D. Luxbacher, E. C. Jong

Perfluoromethylcyclohexane (PMCH), a member of the perfluorocarbon tracer group of compounds, has been shown to be a viable supplement to the widely used tracer gas sulfur hexafluoride (SF6). This viability stems from the fact that PMCH can be used concurrently with SF6 while maintaining adequate chromatographic separation and comparable sensitivity during analysis. However, the release of PMCH in an underground mine ventilation system is challenging due to its physical characteristics. While SF6 exists as a gas at room temperature and pressure and can be accurately released by a variety of means, PMCH exists as a volatile liquid at room temperature and pressure, preventing it from being deployed in a similar manner. One method to release PMCH is to use a permeation plug passive release vessel (PPRV), which allows for the controlled release of the gas. This paper presents the results of a study evaluating various preparation techniques, plug thicknesses and plug materials of an aluminumvessel PMCH release source, so that a source appropriate for the mine scale may be developed.

Jan 1, 2015

By Lawrence L. Davis

This paper describes current research by the Bureau of Mines to develop technology for improving efficiency and productivity in metal/ nonmetal mines. The research program addresses a wide variety of problems associated with each of the major categories of mining: underground mining, surface mining, in situ mining, and premining investigations. An overview of the Bureau's research activities is given with emphasis on underground mining. In particular, two innovative and promising concepts currently under development are described: a unique shaft sinking system that uses an impact hammer for rock fragmentation, and a low-profile, portable crusher for underground hard-rock applications.

Jan 1, 1979

By S. Natansohn

A prevalent technique for the recovery of silver from wastes generated in silver-tungsten electrical contact fabrication is electrowinning. Such scrap is placed in a permeable plastic basket which constitutes the anode compartment and this basket is suspended in a larger cell in which the cathode is mounted. A silver nitrate solution is used as the electrolyte and, upon application of an electric field, the silver migrates to the cathode where it deposits out. At times, there is tungsten migration to the cathode compartment and consequent co-deposition with the silver. This W contamination, which may amount to several thousand ppm, necessitates additional purification of the deposited Ag and its removal would therefore be advantageous. The elimination of the W impurity would also extend the operating period of the cell with corresponding increase in the Ag output and savings in labor costs.

Jan 1, 1982

By D. Seneviratne

Iron transfer from the pregnant leach solution (PLS) to the electrolyte can have a major economic impact on solvent extraction (SX) operations. High iron transfer will lead to greater operational costs, due to increased reagent consumption through electrolyte bleed and make up, or increased power costs due to decreased electrowinning current efficiency. Bioleaching of low-grade copper sulfide ore from the Kennecott Utah Copper Mine was investigated in a large scale piloting program including SX and electrowinning. Plant data and lab test work conducted throughout the course of operation, show that the unique containing PLS high ferric iron with high pH can lead to lower Cu: Fe selectivity than is typically seen in traditional copper SX operations. The impact of high ferric iron on the plant operation, and methods to reduce iron transfer will be discussed. Special considerations need to be taken for plant operating conditions and selection of SX reagents (including both extractant and aromatic content of diluent) based on the feed PLS characteristics.

Feb 23, 2014

By P. A. Mingione

AEROPHINE® 3418A is a unique sulfide mineral promoter produced by Cyanamid, based on phosphine (PH3) chemistry. It has proven effective as a collector for the sulfide minerals of copper and particularly lead (galena), as well as for secondary gold and silver values. AEROPHINE 3418A has widest application as a Cu and/or Pb collector for complex ores of Cu-Zn and Pb-Zn, which frequently have significant quantities of associated precious metal values. Advantages shown in the use of AEROPHINE 3418A are improved selectivities against Zn-and Fe-sulfides, increased precious metals recoveries, reduced total collector consumptions for Cu and/or Pb flotation, and increased flotation kinetics leading to higher recoveries of these values. Operating plant, pilot plant and laboratory test data from treat-ing different ores are presented, demonstrating the advantages in use and preferred application of AEROPHINE 3418A.

Jan 1, 1991

By B. Barry, M. S. Klima

"Testing was conducted to evaluate the effects of hydroacoustic cavitation (HAC) treatment on two bituminous coal slurries and the subsequent separation of each slurry in a classifying hydrocyclone. HAC treatment was performed using a pilot-scale circuit fabricated by Furness-Newburge Inc. The circuit was designed to induce cavitation by means of flow through an ultrasonic resonator chamber or enhanced cavitation by initial flow through a cavitation chamber followed by flow through the ultrasonic chamber. The test materials were nominal -1,500-micron and -150-micron Illinois-basin bituminous coal slurries, which were obtained from an operating coal preparation facility. After 5 sec of HAC treatment, the median size of the -1,500-micron material was reduced, with ash values for certain size fractions decreasing more than 5 percent compared with untreated samples. Extending treatment time led to greater degradation of the +1,180-micron material and an increase in the -25-micron material, with ash reductions occurring for material in the -850+150-micron size range. Size degradation was less for the -150-micron material. Subsequent separation of the treated slurries was carried out in a hydrocyclone with diameter of 102 mm. HAC treatment led to a decrease in the ash value and an increase in the heating value of the underflow stream compared with the feed material. For example, the ash value was reduced by about 16 percent for the -1,500-micron material and 25 percent for the -150-micron material with heating value increases of 7 and 33 percent, respectively, after HAC treatment. Overall, HAC treatment appeared to have a slight effect on the size selectivity curves.IntroductionUltrasound in the range of 20 to 1,000 kHz, referred to as power ultrasound, consists of high energy waves that can create zones of compression and expansion when used to irradiate liquids (Frederick, 1965; Leighton, 1994; Mason and Lorimer, 1988). This action generates varying pressure regions leading to cavitation or the formation, growth and near-immediate collapse of microscopic voids or bubbles (Frederick 1965; Leighton 1994; Mason and Lorimer 1988). Collapse occurs when the bubble reaches critical size and cannot absorb additional sound field energy, and the critical size is governed by the ultrasound frequency (Shchukin et al., 2011)."

Jan 1, 2015

By Adil Jamali, Taufiq Hidayat, Imam Santoso, Zulfiadi Zulhan, Indah Suryani

The study investigates the segregation of iron and titanium in iron sand concentrate pellets reduced using coal under an isothermal-temperature gradient profile. The results show that metallic iron migrates to the surface while titanium and other oxides move to the center of the pellet. The study provides insights into the reduction process and the behavior of iron and titanium during heat treatment.

Mar 2, 2022

By Xuchen Fan, Chenyang Zhou, Yuemin Zhao, Liang Dong, Chenlong Duan

A gas–solid fluidized bed using magnetite particles is an effective methodology for coal beneficiation in the field of dry coal cleaning. Broadening the size range of magnetite used in the bed decreases medium preparation cost. In this study, a tapered fluidized bed was used to investigate a magnetite particle size range of −0.5 + 0.074 mm. The results showed that a tapered fluidized bed effectively strengthens mixing of magnetite with a wide size range (−0.5 + 0.074 mm). The results of beneficiation experiments indicated that with increasing tapered angle, separation efficiency increased and then decreased. The highest separation efficiency was obtained at a tapered angle of 10°. The optimal results showed that the ash content of the concentrate decreased from 31.82% to 12.33% with a probable error of 0.11, which indicated that a tapered fluidized bed was efficient to improve fine coal beneficiation performance.

By Shilpa S. Haramkar, Bhaskar N. Thorat, Sachin V. Jadhav

The filtration of phosphogypsum is a ubiquitous step in the manufacturing of phosphoric acid. It is highly desired to achieve the minimum concentration of P2O5 in the phosphogypsum cake. This work is aimed at addressing P2O5 losses in phosphogypsum (PG) along with the recovery of P2O5 from slurry by using constant pressure filtration at 1 bar pressure. Laboratory tests were carried out in the phosphoric acid production plant situated in Paradeep, India. Recycled water source near acid plant (i.e., pond water) was used for cake washing to reduce the burden on fresh water stock. The findings indicated that pressure filtration offered the most effective P2O5 recovery (nearly 93.48%). The moisture was reduced to 14–16%, and watersoluble P2O5 in the gypsum cake was found to be negligible. A narrow particle size distribution was observed, which offered effective filterability with average cake resistance of 2.38 × 1010 m/kg, indicating a moderately separable cake.

Aug 23, 2023

By A. Bruynesteyn

The results of a 2 phase evaluation program designed to determine the amenability of an oxide ore from the Butte, Montana mine of the Anaconda Company to a sulfuric acid leach is presented. In the phase 1 preliminary evaluation, using roll tests and percolation leaching in small columns, it is shown that the ore is highly extractable at low acid consumption ratios. In the phase 2 confirmatory tests in large columns on l-l.5 tons of material, the amenability of the ore to the leaching process is proven and pregnant solution grade profiles from planned commercial heaps established.

Jan 1, 1978

By Ewald H. Kurt

The story of America's progressing standard of living is the story of machines. The automobile, the airplane and the telephone for example have made our transportation and communication systems what they are today. Even they depend in turn on another machine -- the rock drill. By making it possible to economically mine and quarry minerals in large quantities, this versatile machine supports virtually every American industry relying on the earth for its buried raw materials. And, like all machines, the rock drill's mechanical evolution was stimulated by production demands placed upon it. All percussion drills are mechanized versions of the original drilling unit -- man, Figure - illustrates a double jack team at work before the turn of the century. The man with the sledge hammer is the impact device while the man sitting is the rotation mechanism and feed motor. The first drifter drills (Figure 2) performed the same function but with increased mechanical efficiency. A piston controlled by a valve produced impact. A built-in ratcheting mechanism provided rotation and a hand-cranked screw provided feed thrust. As the industrial revolution proceeded into the twentieth century, the demand for raw materials stimulated refinements of all recovery machinery, including rock drills. As drills became heavier and more powerful, a mounting (or carrier) had to be provided to move the drill from hole to hole. This resulted in the development of the wagon drill (Figure 3). Propelled by muscle power, the wagon drill was for years the standard tool of the surface drilling industry (Figure 4). As drills penetrated faster and as labor increased in cost, the time consumed in nondrilling peripheral operations had to be

Jan 1, 1977

By T. M. Yegulalp

A new explanation of the scale dependency of the strength properties of rock is presented based on the theory of extremes. A review of past work on specimen size strength relationship is followed by an introduction to the fundamentals of the underlying theory of extremes and its relationship to the scale effect on the statistical properties of the strength distribution. It is shown that the weakest link theory is directly related to extremal statistics and properties of strength distributions of rock can be derived as a function of the specimen size. Three sets of Brazilian test data are used to demonstrate the use of this approach.

Jan 1, 1992

By G. R. Doubek

Dual Tube Reverse Circulation (DTRC) drilling has been extensively used for collecting groundwater information for the dewatering program at Amax Gold Inc. Sleeper Mine. This paper presents a discuss ion of the types of data which can be collected from DTRC drilling, as well as the effect submergence has on the data. A simple low-cost method of injection testing has been developed using DTRC equipment, allowing quantitative data to be obtained from exploration or test holes. Potential yields can be determined for each drill location, allowing siting and design of production wells to be optimized.

Jan 1, 1992

By J. S. Aronofsky

The areas are identified where the techniques of operations research have been applied in the petroleum industry. Particular emphasis is given to the linear program models that have been used for solving management problems. Of the entire gamut of applications for linear programming, attention is focused on the models that represent underground reservoirs. Such models could be used to help schedule drilling rig operations and to schedule oil production. A framework is established for placing the model for underground reservoirs in the proper perspective along with the models which represent other facets of the oil business. One of the remarkable phenomena of this century is the rapid growth in the size and' complexity of human organizations. The mere size of modern business means that administrative decisions can affect vast quantities of capital and large number of people. Mistakes can be tremendously costly, and a single wrong decision can require years for rectification. Moreover, the pace of modern business is such that decisions are required more rapidly than ever before; the mere postponement of action can give a decided advantage to a competitor. It is not surprising that the increase in difficulty of decision making has been followed by efforts to put this activity on a more objective basis. The growing science of operations research, which relies heavily on the methods that have proved so successful in the physical sciences, is one aspect of these efforts.

Jan 1, 1962

By David R. Cole

Before discussing some of the specific public relations issues in Colorado mining, I would like to define public relations, identify the "publics," review Colorado's population profile, and outline Colorado's mining history. Public Relations In describing public relations, a definition which is frequently quoted appeared in the PUBLIC RELATIONS NEWS, and is as follows: "The Management function which evaluates public attitudes, identifies the policies and procedures of an individual or organization with the public interest, and executes a program of action to earn public understanding and acceptance..' As you can see, this covers a "multitude of sins."

Jan 1, 1975

By R. B. Taylor

The Esmeralda mine is located about three miles west of the town of Parral, in the State of Chihuahua, Northern Mexico, and about 400 miles south of El Paso, Texas. The area is serviced by the Interamerican Highway and a branch line of the National Railways of Mexico. The Parral district is quite typical of the semidesert of Northern Mexico, lying near the western margin of the Chihuahua basin and range province known in Mexico as the ?Mesa Central? In the immediate mine area, low rounded hills and rolling plans slope toward the Parral River. Surface elevation at the mine is 5,800 feet. The Esmeralda vein outcrops strongly, but was too low grade to be of interest to the Spaniards, The first claims were staked in 1897 and limited exploration work to a depth of 550 feet was carried out prior to 1912, at which time work was suspended. The Eagle-Picher Company acquired the property in 1944 and by surface diamond drilling outlined an orebody to a depth of 800 feet, Minas de Iguala, S. A, de C.V., one of Eagle-Picher?s totally owned subsidiary companies in Mexico, then unwatered the old workings, developed the mine, installed a modern differential flotation plant and started production lage in 1948. To the present, more than two and ahalf million tons of ore have been mined and milled producing lead and zinc concentrates.

Jan 1, 1958