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NORTH AMERICA ALASKA Anchorage.-Strandberg, H. Tuck, R. Coal Creek.-Moore, E. G. Spencer, W. W. College.-Hance, J. H. Henricksen, R. Henton, H. M. Comet.-Albertson, F. E. Cordova.-O'Neill, W. A. Douglas.-Cahill, W. E. Fairbanks.-Crawford, J. D. Earling, R., B. Fowler. D. A.

Jan 1, 1937

By G. B. Gould

EVERY mathematical statement of a measure of anything (as distin-guished from a count) is followed by a qualification always implied if not explicity stated--that the statement is only an estimate, which may vary from absolute accuracy within certain limits, according to the accu-racy of the measuring instrument. This basic fact, so obvious to engineers, is not so well understood by many that make use of laboratory coal tests. The tolerances that must be allowed in measurements of coal quality are very important in both their commercial and engineering applica-tions-and the significance of these tolerances depends upon the use made of the laboratory coal test. Only in recent years has there been any intensive study of this ques-tion of tolerances as applied to measurements of coal quality. There is very little in our published literature on the subject, and what has been published is not, readily comprehended by those who sell coal, or buy coal and use it, unless they happen to have made a study of the subject them-selves. There is great need for more widespread understanding of what has been discovered and how it applies to the use of laboratory coal tests. What follows is an attempt to condense into a few pages the results of the major investigations so far reported, and to explain their meaning in simple nontechnical language, with the addition of some recent illustrative experiments.

Jan 1, 1937

An educated man is distinguished neither by his clothes nor by his knowledge; he is remarkable not for the things he says, but for the way he says them. You cannot even stand with him under an archway in the rain without finding him out. He may talk only of the weather. His words and his phrases alike my be simple. What distinguishes him is the arrangement of his words; however desultory his talk, it will be methodical; he has habituated himself to foreseeing the part to be played by each word he uses and the place to be taken by each sentence he utters. On the other hand, the uneducated man, though shrewd and well-informed, will relate facts and events as they recur to him, generally in disorder; in his effort to recollect and in his attempt to rectify forgetfulness he will pause irregularly, filling the intervals with meaningless phrases, such as "and then", "and so", or "said he to me", "said I to him"; and even the continuous parts of his story will be told confusedly-because he has not learned the proper use of words.* My own experience as an editor of technical manuscripts has taught me that the misuse of 'that' and 'which' is a fruitful cause of obscurity and confusion. The relative pronouns have distinct functions, and no writer can express himself clearly until he has learned to discriminate between these functions. For example : The engineers who refused to submit were discharged. The engineers, who refused to submit, were discharged. The engineers that refused to submit were discharged.

Jan 1, 1931

By R. T. Mishler

I wish to express my keen appreciation of the article on the above subject by Coe and C1evenger.l It has been doubly interesting to me, for the reason that the experience recorded and the principles evolved practically parallel the results of similar investigations made by myself and others at The Lucky Tiger Mine, El Tigre, Sonora, Mex. An outline of the work at El Tigre may aid in confirming the principles expressed by Coe and Clevenger. El Tigre has the unenviable distinction of possessing a slime with a much lower settling rate than any recorded in the article discussed. Under most favorable conditions the settling rate is about one-third that reported for the Liberty Bell mill, and one-tenth that reported for the Nipissing, Golden Cycle, and Presidio mills. This slow settling characteristic of Tigre ore has necessitated careful investigation of settling phenomena throughout the various evolutions of the plant. Previous Settling Investigation at Tigre During construction work at the mill, the metallurgical engineer in charge, D. L. H. Forbes, ran a series of experiments on settling. His tests proved that deep settling tanks were not ordinarily necessary. The use of tanks 2 or 3 ft. in depth was suggested.2 Later experiments demonstrated that the following principles of settling applied to Tigre pulp.3 1. In settling dilute pulp, settling rates are independent of pulp depth. 2. In settling thick pulp, settling rates are approximately proportional to pulp depth.4

Jan 1, 1918

ALABAMA Aldrich -Thomas, D A Altoona -Cain, J Anniston -Cowie, L K Walmsley, W N White, H E Ashland -Sturdevant, J C Bankhead -Connaway, M B Bessemer-Ball, E M McKenzie, W C, Jr Mitchell, F R Morgan, C Thompson, N E Birmingham -Abbott, C E Adams, J H

Jan 1, 1923

By F. R. Wadleigh

There are in commercial use today in the United States various classifications of coal, each based on one or more characteristics. The bases of these classifications may be described as follows: GeNeRaL Basis Examples 1. Geological By seams and basins (local). 2. Chemical By constituents, as determined by analysis—ash, volatilc, slilfur and hcating value. 3. Combustion Characteristics As frce-burning, smokeless, character of ash. 4. Carbonization Characteristics Coking, noncoking. 5. Physical Characteristics Splint, soft, hard, block. 6. Geographical States, Fields, Counties, Districts. 7. Sizes By dimension or name. 8. Company Names Producing or sales company names, as "C. C. B. Pocahontas," etc. 9. Trade Names, copyrighted or not 10. Uses Gas, steam, coking, locomotive, fuel, bunkers, etc. 11. Use Methods Stoker coal. 12. Pools (Tidewater Exchanges) Analyses Size Seams Railroads Uses Structure Districts There are also classifications founded on more than one basis, as follows: 1. Geographical and Geological. By locality of mines (State, District, County) and seam. Examples: Cambria County, Miller Seam, New River, Sewell Seam. 2. Geographical and Chemical. Alabama medium volatile. 3. Combustion Characteristics and Ash Content. Free-burning, red ash (anthra- cite). 4. Carbonization Characteristics and Analysis. Noncoking, high-volatile, low sulfur. 5. Physical and Carbonization Characteristics. Splint, noncoking. 6. Size and Use. ¾-in. gas coal; domestic sizes (prepared sizcs); stcam sizcs. 7. Company Name and Seam. Consolidation Co., Elkhorn. 8. Size and Analysis. Low-volatile run-of-mine; low-volatilc slack. 9. Sizes—size of screen and name. 6 by sin. lump. 10. Chemical and USP. High-volatile steam. 11. Geographical and Use. Youghiogheny gas. 12. District, Size and Use. Pittsburgh gas l¼-in. lump. ,

Jan 1, 1930

By Louis W. Huber

The Liberty tunnels extend through a very steep hill in Pittsburgh (locally called Mount Washington) for a distance of slightly over a mile. The two tunnels parallel each other and are 59 ft. apart, center to center (Fig. 1) They are for vehicular traffic, and in each there is ample space for two lines of vehicles. Northbound traffic, toward downtown Pitts- burgh, is confined to the east tunnel and southbound traffic to the west tunnel. The South Hills residential district is separated from downtown Pittsburgh by Mount Washington, a steeply rising escarpment south of and adjacent to the Monongahela River. The Mount Washington district immediately south of the Monongahela River has been reached, for many

Jan 1, 1927

By N. S. Greensfelder

The firing of explosive charges by electricity dates back to 1745 when a Doctor Watson is said to have used an electric spark for igniting gunpowder. His method failed in practical application because, to ignite blasting powder, heat must be applied for a period longer than the duration of an electrostatic spark; Wheatstone found that this does not exceed 1/24000 sec. The usual result, therefore, of an electrical discharge in gunpowder is to scatter the grains, without igniting them. Benjamin Franklin partly overcame this difficulty by confining the powder and crushing grains that lay in the line of discharge. In 1822, after the primary cell had been discovered by Volta, Robert Hare, professor of chemistry at the University of Philadelphia, noticed the heating of a short piece of wire placed in the circuit of a voltaic battery. Later work by Oersted, Faraday, Wheatstone, and Henley resulted in the developmcnt of the magneto blasting machines. Fulminates of gold and silver are thought to have been discovcrcd by Cornelius Drebbel, about 1600. Pepys, in his diary for November 11, 1663, recounts a conversation with Doctor Allen, who told him about aurium fulminans "of which a grain ... put in a silver spoon and fired, will give a blow like a musquett and strike a hole through the silvel spoon downward, without the least force upward.'ll This fallacious belief that explosives act downwards only is still held by many who should know better. Fulminate of mercury was discovered by Howard in 1799. J. Shaw of Philadelphia is said to have invented a fulminate-of-mercury cap in 1814; his idea was later adopted by gunmakers in England and France. The principal advantages of mercury fulminate for use in detonators are the simplicity of exploding it and the great shock developed by its explosion.

Jan 1, 1923

By C. E. Shoenfelt

The year 1939 witnessed the rapid development of several of the more important Rocky Mountain oil and gas areas and the discovery of new oil and gas fields. As a further result of an active year, many oil fields had their productive limits greatly extended or responded to deeper drilling with oil production in lower horizons. In Colorado there was a substantial increase in refinery capacity, with three new units constructed. Its contribution to the crude-oil supply was an important extension of the producing area of a Western Slope field and a deeper oil-producing horizon in an old field east of the Front Range. Occurrences of gas were reported in two wells in northwestern Colorado, but severe winter weather prevented tests and the value of these discoveries cannot be determined at this time. Montana's northern fields were extended and a number of record wells were completed. The North Cut Bank area gives promise of wide expansion in 1940. The gas-producing area of Wyoming's Elk Basin field was extended into Montana on the north plunge of the anticline. The most important developments in Wyoming oil fields in 1939 were extensions to the producing area of Lance Creek and the discovery of a deeper pay in the Tensleep formation at Wertz dome. A new gas field at Horn Valley in the south central part of the state was the only new field discovered, but wildcatting was at low ebb in Wyoming in 1939. Colorado In Colorado, the year 1939 saw the completion of several interesting tests, but largely with negative results. Oil was discovered, however, in a deeper sand in the old Fort Collins field and the productive area of the Wilson Creek field was extended. Gas had been noted in two Western Slope wells, at Yellowjacket-Buford and at Trull, but their volumes had not been determined at the end of the year. Of principal interest, however, were the failures, descriptions of which will be given presently. One of these established a new depth record for Colorado.

Jan 1, 1940

By W. A. McCurdy, Joseph W. Leonard, William F. Lawrence

INTRODUCTION Utilization from the Point of View of the Preparation Engineer The primary interest of the coal preparation engineer is in process design, operation, and maintenance to produce an acceptable product that can be sold at the greatest possible profit. Because of emphasis upon these interests, attention to other potential values of coal is sometimes neglected. The intent of this chapter is to alert the preparation engineer to the utilization possibilities of the product as well as the tributary coal flow moving through a modern coal preparation plant. The basis for any unrealized potential derives directly from the coal seam itself. Most coal seams consist of coal bands and benches sandwiched together in layers that differ visually from each other in physical structure and luster. Randomly selected physical and chemical ranges determined from layers of coal in a single seam can easily differ by as much as 30 Hardgrove grindability indices, 0.30 of a specific gravity point, 20 percentage points of ash, 6 percentage points of dry volatile matter, and 10 percentage points of total su1fur.l Similar wide variations exist for calorific value, seam moisture content, and, undoubtedly, for any other conceivable coal test parameter that might be used for comparative purposes. These observations all point to the long-established fact that coal is not homogeneous, as conventional analytical methods might tend to indicate, but is instead a highly heterogeneous substance.

Jan 1, 1979

By C. W. Davis, R. S. Dean

The purification of iron ores by means of hand magnets dates back more than 100 years. The first record in the United States Patent Office of a machine for the magnetic separation of ores shows that on Feb. 20, 1849, U.S. Patent 6121 was issued to Ransom Cook for improvement in electromagnetic ore separators. The patent covered the use of a revolving cylinder, or drum, with poles of electromagnets in its periphery for the purpose of separating magnetic oxide of iron from substances with which it might be associated, by causing the electrornagnets when revolving as component parts of the cylinder to be successively charged to take up the ore and discharged to part with it. Since this patent was issued the science and technique of magnetism have advanced more than most other fields of endeavor. The development of electrical machinery has required and obtained better and better magnetic materials, and the science of applied magnetism is as completely and satisfactorily developed as any branch of physics. Nevertheless, the patent of Ransom Cook, issued in 1849, comes close to covering everything that is now being applied in magnetic separation. The cynic may conclude that this proves the uselessness of modern science and may point in confirmation to flotation, which has grown in a few years, practically without benefit of science, to be the most versatile and useful of concentration methods. On more careful study, however, it appears that an accurate determination of the magnetic properties of minerals and their amenability to control by mechanical and heat treatments has not heretofore been made. The first essential, therefore, in the design of improved magnetic separators has been missing. In spite of this hiatus in scientific data inventors have been busy, and patents are on file covering mineral separations by means of nearly all known magneto-mechanical effects. Because of a lack of knowledge of mineral properties, most of these inventions never worked well enough to find commercial use. The Metallurgical Division

Jan 1, 1935

By N. S. Greensfelder

The firing of explosive charges by electricity dates back to 1745 when a Doctor Watson is said to have used an electric spark for igniting gunpowder. His method failed in practical application because, to ignite blasting powder, heat must be applied for a period longer than the duration of an electrostatic spark; Wheatstone found that this does not exceed 1/24000 sec. The usual result, therefore, of an electrical discharge in gunpowder is to scatter the grains, without igniting them. Benjamin Franklin partly overcame this difficulty by confining the powder and crushing grains that lay in the line of discharge. In 1822, after the primary cell had been discovered by Volta, Robert Hare, professor of chemistry at the University of Philadelphia, noticed the heating of a short piece of wire placed in the circuit of a voltaic battery. Later work by Oersted, Faraday, Wheatstone, and Henley resulted in the developmcnt of the magneto blasting machines. Fulminates of gold and silver are thought to have been discovcrcd by Cornelius Drebbel, about 1600. Pepys, in his diary for November 11, 1663, recounts a conversation with Doctor Allen, who told him about aurium fulminans "of which a grain ... put in a silver spoon and fired, will give a blow like a musquett and strike a hole through the silvel spoon downward, without the least force upward.'ll This fallacious belief that explosives act downwards only is still held by many who should know better. Fulminate of mercury was discovered by Howard in 1799. J. Shaw of Philadelphia is said to have invented a fulminate-of-mercury cap in 1814; his idea was later adopted by gunmakers in England and France. The principal advantages of mercury fulminate for use in detonators are the simplicity of exploding it and the great shock developed by its explosion.

Jan 1, 1923

THAT the march of civilization has synchronized with progress in the art of utilizing minerals is a proposition that needs no proof. It is a truism. Historians conveniently divide the time that the earth has been inhabited into the Stone Age, the Bronze (more accurately the Copper) Age, and the Iron Age. As archeologists are not entirely in accord as to dates, and as a few centuries make no difference whatever to this particular story, it may be approximated that the Age of Copper began about 8000 years B.C. and that it gave place to the Age of Iron about 1000 years B.C. The logic of this succession-stone, copper, iron-lies in the fact that copper first displaced stone, then iron displaced copper as the standard material out of which the utensils, implements, and weapons, the utilitarian articles of antiquity, were made. After the advent of iron, the mining and smelting of copper continued. Copper and bronze found use particularly in objects of artistic and ornamental nature; but the superior qualities of iron for many purposes were recognized. Useful manufactures of those days consisted principally of knives, hammers, chisels, spear-heads, arrow-heads, and battle-axes. First these were made of stone, then of copper and bronze, then of iron-particularly as there was plenty of iron ore, and the metallurgy was comparatively easy of accomplishment. Of course, the periods of transition dragged slowly. Definite as were the three Ages dominated by the mineral substance from which they get their names, ten or fifteen centuries probably elapsed from the time the first iron was smelted in a small charcoal furnace until it became the accepted material from which to shape a battle-axe. Contrast this with the pace of modern progress. In a brief span, half a dozen more or less deserving candidates for the distinction of having their name

Jan 1, 1933

By J. E. Tiffany, S. S. Lubelsky

For blasting in coal mines the U. S. Bureau of Mines recommends that permissible explosives be used exclusively, that these shall be fired electrically, and that where feasible the working place shall be cut or sheared. These recommendations are made to promote safety and prevent mine explosions. Although permissible explosives are not flameless, their lower flame temperature and shorter duration of flanie make their use safer than that of nonpermissible explosives. Mixtures of air with both methane and bituminous coal dust, which are liable to occur in coal mines, may be ignited by coming in contact with any type of flame or spark of sufficient temperature and duration or by the firing of a blast. In a working place where a blast is to be fired, in addition to the use of permissible explosives, adequate ventilation for the dilution and removal of accumulations or outbursts of flammable gas should be provided. Bituminous coal mines should be rock-dusted as a means of rendering the coal dust harmless The efficient use of permissible explosives depends upon the proper preparation of the working place, standardized drilling, the strength characteristics of the explosive, and the use of a proper weight of charge. Experienced shotfirers should load, tamp and fire all holes. The major part of the information and data here presented is based on the results of efficiency tests made in large producing mines of Pennsylvania and Illinois. Bureau of Mines Report of Investigations, Serial No. 2697, describes how a standard method of blasting was worked out and put into operation in a mine in southern Illinois.' This paper contains a description of the methods worked out subsequently in another mine in that district. Descriptions of tests in two Pennsylvania mines are given in Bulletins 11 and 19 of the Carnegie Institute of Technology.2 These tests

Jan 1, 1928

By C. E. Shoenfelt

The year 1939 witnessed the rapid development of several of the more important Rocky Mountain oil and gas areas and the discovery of new oil and gas fields. As a further result of an active year, many oil fields had their productive limits greatly extended or responded to deeper drilling with oil production in lower horizons. In Colorado there was a substantial increase in refinery capacity, with three new units constructed. Its contribution to the crude-oil supply was an important extension of the producing area of a Western Slope field and a deeper oil-producing horizon in an old field east of the Front Range. Occurrences of gas were reported in two wells in northwestern Colorado, but severe winter weather prevented tests and the value of these discoveries cannot be determined at this time. Montana's northern fields were extended and a number of record wells were completed. The North Cut Bank area gives promise of wide expansion in 1940. The gas-producing area of Wyoming's Elk Basin field was extended into Montana on the north plunge of the anticline. The most important developments in Wyoming oil fields in 1939 were extensions to the producing area of Lance Creek and the discovery of a deeper pay in the Tensleep formation at Wertz dome. A new gas field at Horn Valley in the south central part of the state was the only new field discovered, but wildcatting was at low ebb in Wyoming in 1939. Colorado In Colorado, the year 1939 saw the completion of several interesting tests, but largely with negative results. Oil was discovered, however, in a deeper sand in the old Fort Collins field and the productive area of the Wilson Creek field was extended. Gas had been noted in two Western Slope wells, at Yellowjacket-Buford and at Trull, but their volumes had not been determined at the end of the year. Of principal interest, however, were the failures, descriptions of which will be given presently. One of these established a new depth record for Colorado.

Jan 1, 1940

By J. B. Scuffham, G. Eggett, W. R. Hopkins

With solvent extraction now being accepted as a major method for recovering copper from leach liquors, the authors' company decided that in tankhouse design full advantage was not being taken of the benefits available from sol- vent extraction produced electrolytes. Consequently, a major development program was undertaken to examine means of operating such tankhouses with current densities in excess of current electrowinning practice. Techniques investigated included high circulation of liquors, current reversal and the application of ultrasonics. At the same time there was a necessity for improving the quality of cathodes produced from electrolytes of high free acid content. The application of anodes which are capable of reducing or eliminating the lead content of cathodes is described in the paper. The other problem area in eletrowinning from solvent extraction produced electrolytes is the production of a higher degree of acid mist. Techniques for alleviating this problem are described bearing in mind their possible effects on the solvent extraction section of the plant.

Jan 1, 1973

Although copper production established a new record, lead and zinc registered gains, and iron production held steady, the mixed trend in metallic and nonmetallic mining and generally lower prices in 1961 resulted in a net decline in the total value of domestic mineral production. According to preliminary estimates from the U.S. Bureau of Mines, the value of metals produced in this country during the year was approximately $1.9 billion, a decrease of $117 million from 1960; the value of nonmetallics was about $3.7 billion, a $14 million decrease. The following report of mining and mineral developments during 1961 is based on USBM and industry sources. Aluminum Output Dips from 1960 Record Government reports indicate that the domestic primary aluminum industry produced approximately 1,880,000 tons, equivalent to 77% of this nation's capacity. This production is about 6% below the 1960 record output of 2,014,498 tons. Shipments of primary metal ingot slightly exceeded the quantity produced.

Jan 2, 1962

By Donald J. Drinkwater, M. C. Fuerstenau

Many important contributions to the more fundamental aspects of mineral processing have been made this past year. Mular1 researched the flotation characteristics of pure zinc oxide and also samples that had been doped with Al+++ and Cu++. Correlation of the response of pure zinc oxide to oleate flotation with a calculated zpc (from solution equilibrium) suggests that adsorption of oleate ion is coulombic in nature. Doping the sample with Al+++ (which will make the ZnO more n-type) had a marked effect on the maximum value of pH at which 50% recovery was obtained at constant collector addition. That is, when 0.5 mole percent Al+++ was added, the pH for 50% recovery was reduced by about four units. Treatment with Cu++ was found to have little effect on the flotation response of zinc oxide, even for additions of one mole percent. Since the zero points of charge of the Al+++ doped powders were not measured, it was not possible to correlate flotation data of these samples directly with charge phenomena.

Jan 2, 1966

By Joseph Pogue

THE writer visited the Muzo emerald mines in July, 1915, and spent six days in their study. This paper embodies the results of his observations, plus information personally communicated by Robert Scheibe, FIG. 1.-SKETCH MAP SHOWING APPROXIMATE LOCATIONS OF ALL IMPORTANT EMERALD MINES AND PROSPECTS IN COLOMBIA. (Data in part supplied by Robert Scheibe, July, 1915.) Professor of Geology in the Mining Academy of Berlin, who at the time of the visit was completing a detailed field investigation of nearly a year's duration of the emerald deposits of Colombia. An elaborate account of this valuable work may be expected at a future date from the pen of Professor Scheibe.

Jan 5, 1916

By Albert Sauveur

(New York Meeting, February, 1913.) IT is delightful to read a technical paper like that of J. E. Johnson, The Effect of High Carbon on the Quality of Charcoal-Iron, presented in October, 1912, at the Cleveland meeting of the American Institute of Mining Engineers.1 The clear, simple, and straightforward manner in which he describes his experiments and results makes you feel as if you had been, so to speak, at his elbow during the course of his investigations, while his method of procedure is so rational that you can fairly anticipate each step in the logical sequence of the tests performed. The following notes suggested by Mr. Johnson's paper are presented here in the hope that they may help, if only a mite, towards the final solution of a problem of considerable scientific and industrial importance.

Jan 3, 1913