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Carbothermal Reduction and Nitridation of Ilmenite Concentrates and Chlorination of the Reduced Samples

Sep 13, 2010

By M. Scherbakov, W. Shi

Abrasion is an important mode of performance for any element of an engineered product that involves material contact for example, a conveyor belt cover. Abrasion resistance is considered to be one of the leading factors in belt cover design and improvement. Various types of abrasion testing are reviewed by and compared to actual belt applications. A new quantitative screening torsional abrasion test is developed by Goodyear to mimic a dynamic contact between belt cover and differently shaped stones of various weights dropped onto belt at any angle, velocity and height.

Jan 1, 2004

By Ignacio Humeres Valdivia, Alejandro Ferrada Vergara

In the latest years, the use of innovative blasting techniques has become more frequent in mines all over the world. Such techniques allow the miner to be more aggressive in the distribution of explosive energy into the rock mass, e.g., stretching blasting patterns to improve fragmentation. Considering the different rock mass conditions and more energetic blasting designs, misfired shot events have occurred. After cause investigation, initiators have shown evidences of deformation by impact and/or loaded boreholes have resulted in emulsion desensitization, both presumably affected by dynamic pressure.

Jan 1, 2015

By C. R. Boyd

It would be a quite congenial task to attempt to describe all that extraordinary mineral wealth which is now giving such prominence to the region from the James River to the Tennessee line: adjacent to the great lines of the Shenandoah Valley and the Norfolk and Western railways; but such a task would be impossible within the limits of any ordinary paper. Hence, in advance of the fifth edition of my book and map on the Resources of Southwest Virginia, I must restrict myself to a limited but most interesting subdivision of this remarkable mineral belt.

Jan 1, 1884

By E. H. Rennhack

THE presence of sufficient quantities of the inter- stitial elements, carbon, oxygen, and nitrogen is known to decrease sienificantly the room-temperature impact resistance of titanium. Hydrogen does not appear to affect impact strength unless present

Jan 1, 1959

By John Brulia

"Definition of On-Site Security: All mandatory and non-mandatory, deterrent and loss control measures undertaken by an authorized explosives business tokeep its stocks of explosive materials and precursors from: • (1) THEFT • (2) LOSS"

Jan 1, 2006

By Y. C. Kim

To generate a most profitable, ultimate pit limit is generally the first step in mine design. This paper presents a new graph theory oriented, optimum ultimate pit limit design algorithm which will maximize the total undiscounted net profit. This algorithm performs much better than the well known Lerchs-Grossmann algorithm, in terms of the reduction in computation time and computer memory requirements. This algorithm operates on many directed trees in a graph, where each vertex in a tree represents a block in the mine model. The formation of each directed tree is based more on the ore-waste support concept than the geometry constraints alone. The general procedures of the algorithm, programming considerations and two case study results are discussed in the paper.

Jan 1, 1992

By Richard L. Lewis

This is a discussion of the application of the zonal harmonic series to problems involving dipole sources in the vicinity of spherical boundaries. The application of a formal zonal-harmonic series solution to directly obtain numerical results involves two distinct problems: namely, the convergence of the series solution and the accurate calculation of the special functions involved in the series solution. Some interesting techniques will be introduced which help to improve the convergence properties of the series solution.

Jan 1, 1973

By Lama RD

The paper outlines the development in the control of dust in Australia over the last 20 years. Factors influencing dust make at the faces are discussed. The effect of high production systems is analysed. Changes in dust standards and results of dust sampling on longwalls and continuous miner panels are given. Research conducted on air curtains and water infusion on dust control on longwall faces is presented along with recommendations for future research. It is found that both dust curtains and water infusion can cut dust mak by 50" each when applied separately.

Jan 1, 1988

DR. E. E. SOUTHARD,* Boston, Mass.-As Director of a Psychopathic Hospital, I am a sort of "voice in the wilderness" speaking to mining engineers. I suppose that I am here because Major Gilbreth had prevailed upon me to speak on a kindred topic before the mechanical engineers at the annual meeting of their Institute. You might wonder why a psychopathic hospital, a state institution for the first care of mental cases and especially for incipient, acute and curable cases, should have any part or lot in the industrial problem. We have obvious contacts in our institution with the retarded and exceptional children of the schools, with the defective and non-defective

Jan 4, 1918

By H. M. Howe

The tenacity with which a bad name adheres to a process is well illustrated by the prevalent belief in the irregularity of the product of the Bessemer converter. We have been lately told by an eloquent member that lack of uniformity is the name of Bessemer steel, and that uniform soft steel can only be made in the Clapp-Griffiths Bessemer converter. Yet I believe that, however irregular the percentage of carbon in Bessemer steel may have been formerly, to-day it is well-nigh completely under control. Indeed, the results of a large number of analyses that I' have studied go to show that the

Jan 1, 1887

By T. W. Healy, D. R. Dixon

The mechanism of activation of ZnS by metal ions and the subsequent flotation induced by xanthate has been considered as a surface redox reaction. By ultraviolet (UV) irradiation of ZnS suspensions, the normally inert ZnS is caused to react with xanthate in the absence of activator. By similar UV irradiation, the rate of adsorption-exchange of activator ions at the ZnS-H2O interface is also increased. Mechanisms of these reactions are proposed and compared to current electrochemical and semiconducting models of sulfide flotation.

Jan 1, 1976

By Moto Goto

PT Smelting, located in Gresik, East Java, is the first copper smelter and refinery in Indonesia. Since the first charging concentrate in December 1998, many equipment troubles have been systematically eliminated, and the present operation is smooth and has accomplished the design capacity of 200,000 tonnes per year of LME, grade-A copper cathode. This paper describes troubles and countermeasures, which were experienced until now.

Jan 1, 2002

By G. A. Vissac

The drying of fine coal involves special techniques, which are discussed and analyzed. Types of dryers employing these techniques are described. Calculations are presented for new methods of deal ing with the entrained dust that is always present in fine coal drying operations.

Jan 10, 1953

Jan 1, 1930

Jan 1, 1927

By R. O. Burt

The economics of recovering slimes by gravity concentration, except in a few highly specialized cases, was hampered by the lack of suit- able high capacity equipment. However, in the last decade increasing cost of power and reagents, coupled with the development of high capacity units, has led to a reappraisal of the benefits of slime gravity concentration. This paper seeks to analyze the merits of gravity concentration, and the constraints placed upon it by the laws of motion. It traces the recent developments of unit processes, and their application to a wide range of minerals. The economics of gravity concentration are also discussed.

Jan 1, 1980

By Andrew Balint, Peter Cammack

When coal is irradiated by the X-rays emitted from a plutonium 238 isotope, the radiation absorbed by elements of low atomic number (carbon and hydrogen) is lower than that absorbed by elements of high atomic number (silicon, aluminium, iron) which form the ash in coal. The differences are reproducible and readily measurable, and this paper describes how this technique is used to determine the ash content of coal and to optimize measurement accuracy. Uses of the output signal are given with an example of a simple control circuit, and the advantages of instantaneous ash measurement are highlighted in terms of operational convenience and profit.

Jan 1, 1977

By Charles E. Joachim

Railroad and blast induced vibrations were measured in the vicinity of the proposed Big Bend Cutoff. Peak horizontal and vertical particle velocity relations were developed using least squares regression analysis. The dominant frequencies of these data are in the range of 30 to 50 hz. Therefore, allowable charge weight per 30 msec delay curves were generated for buildings (2 in./sec) and unlined tunnels (8 in./sec). A blasting contour map is presented for this site.

Jan 1, 1984

By D T. Froedge

This paper is a presentation of a coyote shot at the Oriskany Sand Quarry of the Pennsylvania Glass Sand Corporation, Berkeley Springs, West Virginia.

Jan 1, 1982