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By Ralph A. Sherman, J. M. Pilcher

BY surface treatment of coal is meant the application of a material, either solid or liquid, to the surface of pieces of coal. The purposes of surface treatment are varied. They may be to identify or "trade- mark" the coal, to modify the burning characteristics, the coking tendencies, or the behavior of the ash, to prevent the freezing of wet coal, or to control the dust. The control of dust is the usual purpose of surface treatment. TRADE-MARKING COAL The application of color to the surface of coal for the purpose of identification and registration of the trade-mark has been practiced to some extent. In 1928, the Glen Alden Coal Co. began to color its coal and adopted the trade-mark, "Blue Coal." The Old Ben Coal Co. later followed a similar practice with "Green Coal." A commoner means of identification of coal has been the stenciling of designs or pasting labels on large lumps or in the distribution of small cardboard tags through the smaller sizes. The details of the method used to color coal have not been revealed. Usually all of the coal is not treated, because of the expense. Only enough pieces are colored to show clearly when distributed through the coal. The patent literature gives information on some of the methods proposed. Esselen and Weiss have patented the deposition of a coloring material in the valleys of the surface of the coal. Sperr covers the quenching of coke with water containing a pigment or dye that will deposit on the coke. He also suggests electroplating with copper or nickel. Glinsmann subjects the freshly fractured coal surface to the action of an alkali or alkali earth ferricyanide and a ferric salt. Barsky and Hanson specify a method for the application of the same chemicals covered by Glinsmann. COATINGS FOR IMPROVEMENT OF APPEARANCE As a purchaser often judges coal by its appearance, modification of the surface has been attempted from time to time, particularly of the surface of outcrop or stored coal, which has become covered with a brown film of iron oxides, but information is lacking as to the extent or success of the

Jan 1, 1950

By L. F. Mondolfo

An investigation of the relationship between properties of the elements and type of binary diagram formed was conducted. It was found that, for each type of equilibrium diagram, the factors for the size, valence, electronegativity, period, melting point, entropies of fusion, and sublimation calculated for each pair of elements cover a range of values. However, these factors show sufficient relationship to the equilibrium diagram so that the correlation of several of them can be used to predict the type of diagram formed, or at least limit the choice to only a few types. ThE goal of the metallurgist concerned with alloy development has always been to find a method that predicts the properties that can be obtained when a certain metal is added to another one. In most cases a qualitative predictiton of properties can be made if the equilibrium diagram is known. However, this means that for new metals the alloy development has to start with the experimental determination of the equilibrium diagrams. Because this determination is at least as complicated and time-consuming as the determination of the properties themselves, most alloy development has taken place by trial and error, and the study of the equilibrium diagrams has followed rather than preceded the creation of new alloys. Alloy structures and properties depend on the interaction between electrons and a complete knowledge of these interactions would permit prediction of structure and properties of alloys. Unfortunately direct measurement of these interactions is extremely difficult and somewhat doubtful and only properties that depend on them can be measured easily and with certainty. Study of the relationship between properties of the elements and equilibrium diagrams is not new. Besides the well known Hume-Rothery rule of the necessity of an atomic diameter fit within 15 pct for extensive miscibility in the solid, and the wide knowledge of the effect of such factors as size, electronegativity, electron-atom ratio on solid state features,"' work relating to liquid state and liquid-solid reactions can be found in the literature. Of particular interest is the work by Axon,3 who investigated the effect of size and melting point on a selected number of eutectic and monotectic dia-

Jan 1, 1962

By George Enos

As the coating formed affects the corrosion rate, duplicate samples of eight non-ferrous alloys were placed in flowing mine water. The alloys tested were as-cast or as-rolled and machined or polished. The paper describes the tests and gives the corrosion losses and the appearance of the samples at the end of the test. AN IMPORTANT factor affecting the rate and nature of corrosion of metals and alloys is the film, or coating, formed on the surface; and this may accelerate or retard corrosive action once started. The formation of films and coatings is intimately associated with the chemical composition and physical constitution of both the metal and the corroding medium. A film or coating may be either the corrosion product resulting from oxidation; that is, an oxide or salt, or a deposition of suspended matter from the corroding media upon the surface of the metal, or a mixture of both. The coating may adhere tightly or loosely to the surface of the corroded metal. In short, a film or coating is the reaction product of the corroding medium and the metal, which adheres to the surface of the metal and with which may be intermingled material from the attacking media not concerned in the chemical reactions. As the, terms film and coating are used by different writers for very different things, distinction is made between the two, by the present writers, on the basis of thickness. Thus, a film is defined as a corrosion product or deposition, on the surface of a corroded metal, that is of such thickness that it cannot be measured by the metallurgical microscope. A coating, on the other hand, is of such thickness that it can be measured. If the resolving power of the 2 mm. (equivalent focal length) apochromatic oil immersion objective (N.A. 1.4) is taken as the limit of the microscope, the limiting resolution is two lines that are 0.0002-0.0004 mm. apart. It is thus possible to measure coatings that are greater than 0.0002-0.0004 mm. thick. This thickness is equivalent to 200,000-

Jan 7, 1924

[MINING AND EXPLORATION DIVISION Established as Mining, Geology and Geophysics Division, Sept. 27, 1949 Name changed February 19, 1958. Lyman H. Hart, Chairman Robert J. Lacy, Assistant Chairman Vice Chairmen: John C. Wangaard, Membership J. M. Ehrhorn, Program John G. Hall, Publications C. E. Nelson, Secretary American, Smelting and Refining Co. 120 Broadway New York 5, New York Editor, Rock-in-the-Box: J. W. Chandler.]

Jan 1, 1961

Samuel Thomas Wellman, of Cleveland, Ohio, prominent in the iron industry on the Great Lakes, died suddenly of heart disease at Kennebago, Me., July 11. He was on his way to the camps of the Megantic Fish and Game Association .of which he was a member, when stricken. He was one of the founders and directors of the Wellman-Seaver-Morgan Co., of Cleveland.

Jan 9, 1919

SECTION I Page Page Manuscript Closing Date, Febru- Forthcoming Meetings xxvii ary Meeting v . Library xxviii New York Section War Meeting on Membership xxxii Ferro-Alloys v Biographical Notices: Minutes of Meeting, Board of Robert Bell, by F. D. Adams. xlix Directors xvii H. J. Cantwell, by H. A. Members in Military Service xviii Wheeler 1 Personal xxiii Institute Committees Iii Employment xxv Officers and Directors Ix

Jan 11, 1917

LIMA, PERU Established May, 1952 (Official year begins in June) Luncheon meetings third Wednesday monthly Ernesto A Baertl, Chairman Arthur C Hall, Chairman-Elect Raymond R Beard, First Vice-Chairman Edgardo Portaro, Second Vice-Chairman Walter E King, Secretary-Treasurer Av Santa Cruz 331 San Isidro, Lima, Peru Alberto E Brazzini, Asst Treasurer Daniel M Rodriguez, Asst Secretary, '58, Section Delegate '58, Alternate Section Delegate

Jan 1, 1956

At the MBD Business Meeting held on March 1, 1971, the General Committee of the MBD Division voted unanimously to change the name and expand the role of the Fluo-Solids Separation Committee. The new committee is called the Environmental Control Committee. Such action was taken because of the importance of environmental control and the need for a more active role in this area by our Division.

Jan 1, 1971

William Kent, Montclair, N. J. (communication to the Secretary*):—The authors say, "The factor which determines the completeness of combustion of tlie volatile matter, after it has bee11 mixed with a certain amount of air, is the length of time the mixture is allowed to remain in the combustion-space; but this length of time depends on the extent of the space itself."

Jan 1, 1911

By P. Payson

EMBRITTLEMENT of hard-tempered martensite (500°F embrittlement) appears to be coincident with the beginning of the third stage of tempering. During the first stage, primary martensite of steels containing over 0.25 pct C decomposes to a mixture of c carbide and martensite of appreciably constant carbon content close to 0.25 pct.' During the third stage of tempering, cementite forms. In steels with

Jan 1, 1955

By Walter E. Heinrichs

The following is a condensed version of an open letter addressed to Bil Gilbert of Sports Illustrated: Your article, "When a Law Fights a Law, Sports Illustrated. April 26, 1971, betrays considerable unfamiliarity with the subjects of ecology, social science, mining law and history. In a magazine as widely circulated as Sports Illustrated, an article of such a slanted nature misleads the general public.

Jan 1, 1971

By A. C. Backeberg

There is no South African code for the design of reinforced concrete headframes, and all those erected have been designed on a uniform basis which, up to the present, has tended to be conservative. With certain exceptions designs have generally conformed with British Standard Code of Practice C.P. 114. In the design of reinforced concrete headframes the following loads are taken into account:

Jan 11, 1961

By K. H. Nimerick, B. E. Scott, F. J. Beafore

A unique freeze conditioning agent (FCA) which functions by forming structurally weak ice rather than suppressing the freezing point of water has been successful in alleviating frozen coal problems. Frozen coal treated with FCA has been quickly unloaded at temperatures below -17.8°C (O°F). Other applications of FCA include deicing: conveyor belts, idler, idler arms, and other moving parts that have been impeded by ice.

Jan 9, 1979

H. A. SCHWARTZ, ? Indianapolis, Inc. (written discussion§).-Re-ferring to the very interesting paper on the graphitization of white cast iron, the writer desires to present certain facts and conclusions, entirely, in harmony with those of the authors but which may he not without interest as furnishing additional evidence upon the same subject. The graphitization of white cast iron, being the basis of malleable

Jan 10, 1919

By D. H. R. Price

This paper presents two tentative models of the use of a notional metal in a country like Britian, which have been developed using the System Dynamics modelling method. Computer simulations have been carried out using one of the models. These show the effect on the recycling of the notional metal of a wide range of possible future values of world market price and demand for the metal.

Jan 1, 1977

By Swapan Bhattacharya

United States federal and state regulatory authorities require underground mine operators to adopt adequate measures to minimize material damage to the surface caused by mine subsidence. This paper presents an approach to define and determine the extent of material damage due to subsidence from underground coal mining. The basic steps involved in the development of adequate criteria have been enumerated together with the approaches and methodologies used.

Jan 1, 1984

By E. J. Rapperport, C. S. Hartley

I TTRIUM is a close-packed-hexagonal metal with a c/a ratio of 1.5712.1 This low c/a value prompted a cursory examination of the deformation modes to obtain more data on the deformation characteristics of hcp metals with subideal c/a ratios. The chemical analysis of the arc-melted stock from which the specimen was cut is given below in Table I.

Jan 1, 1960

By Sam F. Harrison

Most hydraulic system malfunctions make their presence known by sending out warnings that are loud and clear to the initiated mechanic, according to Aeroquip Corp. service engineers. To detect problems in many systems, they suggest that the use of four senses-sight, smell, hearing and touch-and a knowledge of how to interpret the information gathered are all that's needed to identify hydraulic malfunctions.

Jan 3, 1978

By K. H. Nimerick, B. E. Scott, F. J. Beafore

A unique freeze conditioning agent (FCA) which functions by forming structurally weak ice rather than suppressing the freezing point of water has been successful in alleviating frozen coal problems. Frozen coal treated with FCA has been quickly unloaded at temperatures below -17.8OC (O°F). Other applications of FCA include deicing: conveyor belts, idler, idler arms, and other moving parts that have been impeded by ice.

Jan 1, 1980

By Richard E. Chism

The dry methods of assaying mercury-ores and other combinations of mercury all rest upon the volatility of this metal as a beginning. After the separation of the mercury in the form of vapor from the matrix upon which the assay is performed, the mercurial vapors are either condensed upon cold surfaces or received upon a gold plate into which the mercury is absorbed.

Jan 1, 1899