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By Wm. O. Vanderburg

This paper describing the milling methods at the Hughesville concentrator of the St. Joseph Lead Co., Hughesville, Mont., is one of a series of similar papers being prepared by the U. S. Bureau of Mines on practices at the various mills in the United States. The writer expresses his thanks for the courtesies extended by the officials of the company while visiting the property and acknowledges the assistance and helpful suggestions given by R. H. Willcomb, general manager, and Carl Martin, mill superintendent, of the Hughesville Division f the St. Joseph Lead Co.; and E. D. Gardner, supervising engineer, U. S. Bureau f Mines, Southwest Experiment Station, Tucson, Ariz., in gathering and compiling the data herein presented.

Jan 1, 1931

By S. G. McAnally

This is one of a series of papers describing mining and crushing methods and costs at cement plant quarries throughout the United States and deals directly with the methods employed and costs obtained at the Reliance quarry of the Giant Portland Cement Co. at Egypt, Pa., although it is more or less descriptive of the methods used throughout the Lehigh Valley cement district. Systems of transportation vary according to local conditions, such as proximity to the mill, depth of quarry floor with relation to the mill level, etc. Methods of prospecting differ mainly in the type f drills used. Systems of storage, crushing, and grinding vary chiefly in the types of units. ACKNOWLEDGMENTS Most of the information regarding the early history of the Lehigh cement district was obtained from the History f the Portland Cement Industry of the United States, by Robert W. Lesley, the first president of the Portland Cement Association. The writer is indebted also to Charles Clader, Giant Portland Cement Co. quarry superintendent, for valuable information regarding present and past methods and equipment.

Jan 1, 1931

By R. S. Dean

A general survey of the metallurgical work of the U. S. Bureau of Mines has been given in an article in the Missouri School of Mines Alumnus, and a somewhat more detailed review of the bureau work on lead and zinc will be found in the Mining Congress Journal. C. C. Furnas has contributed one general mathematical article. Dean, R. S. U. S. Bureau of Mines. 4, 1930, pp. 7-8. Program of Metallurgical Investigations of the Missouri School of Mines Alumnus, vol. 4, No. Investigations of the U. S. Bureau of Mines on the Milling and Smelting of Lead and Zinc. Min. Cong. Jour., vol. 16, 1930, p. 799, 808. Furnas, C. c. Evaluation of the Modified Bessel Function of Am. Mathematical Monthly, vol. 37, the First Kind and Zeroth Order. No. 6, 1930, pp. 282-287.

Apr 1, 1931

By E. P. Youngman

The basic mining law of Netherland India is contained in N. I. Statute 1899 , No. 214 , as amended by N. I. Statute 1910 , No. 588 , and 1919 , No. 4 , which is quoted as the " Indian Mining Law, " the effective date of which was fixed as May 8 , 1907 , by proclamation dated October 12 , 1906. The Indian Mining Law was supplemented by Ordinance No. 38 , of 1930 , which was passed by the Volksraad on March 18 , 1930 , to become effective on October 1 , 1930 ( superseding an earlier ordinance entitled " Government Gazette , " 1906 , No. 434) . An important law with respect to American petroleum rights , Statute No. 23 , passed February 9 , 1928 , approving contracts between the Indian Government and the Netherland subsidiary of a large American oil company , is in the nature of a private law or of an enabling act ( see section of this paper entitled " Rights of Foreigners" ) . Statute 1930 , No. 348 , effective October 1 , 1930 , sets forth in minute detail conditions under which prospecting and mining permits may be granted. Statute 1930 , No. 341 , effective October 1 , 1930 , embodies the police regulations of the mining industry.

Jun 1, 1931

By ALICE V. Petar

Thallium is one of the rare metals that has come into commercial use within recent years . Its comparative scarcity , combined with a resemblance to the common metal lead , have retarded the development of uses for thallium . Although production is still measured in pounds rather than in tons , it is now finding application in a number of fields . Perhaps the earliest commercial use of thallium was as a constituent of optical glass of higher refractive power than similar glasses containing lead . One of the later applications to attract attention was the use of the oxysulphide in a sensitive electrical device similar to the selenium cell . The " Thalofide " cell , which was patented in 1919 , constituted for a time the most important outlet for thallium. During the next few years the limited use of thallium and its salts in other fields was insufficient to absorb an annual production of a few hundred pounds , and the price dropped from $ 16 or $18 per pound in 1922 to $ 5 per pound in 1924 . Beginning in 1925 several new uses were developed , especially as a poison for rodents and ants , and as a result the demand for thallium increased sufficiently to cause a recovery in price to the present level of from $12 to $15 per pound .

Jun 1, 1931

By E. P. Youngman

Before the World War the use of zirconium and its compounds was largely experimental and confined almost wholly to Germany and Austria . Occasionally small lots of zirconium ore had been produced in the United States ( 1,000 pounds in 1869 , 26 tons in 1883 , and 3,000 pounds in 1903 ) and used (with monazite ) in the manufacture of various lighting devices , especially incandescent gas mantles ; but it was not until 1906 that the discovery of the natural zirconium oxide in large quantities near Sao Paulo , Brazil , first gave promise that a zirconium industry eventually might be developed . Edward Rietz , who worked the Brazilian deposits , interested German chemists in extending the use of zirconium , and by 1911 trade journals were listing German firms as manufacturers of compounds or products derived therefrom . For a time zirconia was one of the various oxides used in the Nernst lamp . It was used also for crucibles and hearths as refractory material ; in the manufacture of chemical utensils ; in enamels ; in the place of bismuth subnitrate for defining Röntgenray pictures of the stomach ; as a pigment ; in medicine ; and in a number of other ways . The Germans were credited also with producing a remarkable zirconium steel , which , it was claimed , was much superior to other alloy steels . During the World War the United States Government investigated the possibilities of zirconium , as well as those of other steel -hardening elements , and a large automobile manufacturer actually purchased a substantial quantity of ore with the purpose of employing zirconium in automobile steels . Immediately after the armistice the Government ceased its investigations ; but despite the difficulties experienced by various investigators in reaching concordant results , interest in the use of zirconium as a steel -hardening agent , as well as in other uses of the element and its compounds , continued . In 1918 the Foote Mineral Co. , which had been interested in zirconium for several years , was exploiting the deposit in Brazil formerly worked by the Germans and was supplying zirconia in the form of ore , brick , and cement for refractory and other purposes . About the same time the Electro Metallurgical Co. , which before the entrance of the United States into the war was experimenting with zirconium alloys , supplied in tonnage quantities the demand for these alloys . In 1919 it was reported that American manufacturers , after several years of research, were producing in commercial quantities pure zirconium oxide , which was finding a place in the manufacture of small refractory articles , scorifying dishes , crucibles , tubes , and one- piece furnace linings . In 1920 the lowering of the price of zirconium metal powder ( because of improved metallurgical methods ) promised the production of the metal on a semicommercial scale . In 1924 the Titanium Alloy Manufacturing Co. introduced a new opacifying agent , " Opax , " made from zircon . A year or two later some of the large pottery manufacturers became interested in the use of zirconium oxide as an opacifying agent , the increased production of titanium pigments having resulted in the production of zirconium as a by-product at a price that could compete with tin oxide . In 1928 it was reported that the industrial use of zirconium oxide was increasing steadily in the manufacture of brick , crucibles , and other refractory products , such as high- temperature cements . However , the reluctance of producers to install additional and more suitable

Jun 1, 1931

By E. P. Youngman

Zirconium, formerly distinctly a rare element, is rapidly becom- ing of rather extensive commercial importance. Economic features of the zirconium industry, together with general information regarding the metal and its compounds, are discussed in a separate paper, to which this paper is a supplement. In addition to giving a brief discussion of the four or five de- posits that so far have proved to be commercial sources of the element, this circular summarizes available data (including some hitherto unpub lished material from the files of the Bureau of Mines) upon other occur- rences, including many of scientific interest only, of the two commercial. minerals, zircon and baddeleyite, and also data upon some of the minor minerals, such as eudyalite and cyrtolite, which have attracted addition- al interest in recent years because they are frequently richer in hafnium than the more common zirconium minerals.

Jun 1, 1931

By Paul M. Tyler

Hafnium appears to be among the more abundant of the newly discovered elements . Though quite widely distributed in nature , its compounds chemically so resembled those of zirconium , its sister element , that it escaped detection until 1923 , when Coster and Hevesy announced the discovery of the element , to which they gave the name of " hafnium " , from Hafniae , the Latin name for Copenhagen , where their research work was performed . Hafnium has so far been found only as a minor constituent of zirconium minerals . Zirconium as an element was discovered more than 140 years ago , but only a few unimportant uses were found for the metal or its compounds until some 18 years ago ; it is still classed among the rarer commercial metals . It is not surprising , therefore , that hafnium has not yet found a definite place for itself in industry . Nevertheless it has commanded a considerable interest among scientists ; and in 1930 some 70 grams of perfectly pure oxide of hafnium were prepared in Europe . A commercial future for hafnium is already glimpsed in the radio industry , and its high melting point and electronic emissivity have already led to the taking out of patents for its use in radio tubes and incandescent electric lamp filaments and for the cathode surfaces of devices such as X- ray tubes and rectifiers .

Apr 1, 1931

By I. AITKENS

The basic mining law of Cuba is contained in the basic Spanish mining decree having the effect of law December 29 , 1868. This legislation has remained substantially unchanged , with the exception of a few minor administrative changes made by the present Government . These changes provide for the register of mines , oil wells , and operations of such nature , and also provide for the keeping of records showing the value of minerals taken out . By Royal decree of April 17 , 1883 , the law of mines enacted for the Peninsula ( Spain ) on July 6 , 1859 , and the General Bases of December 29 , 1868 , were declared in force in Cuba . In order to encourage the mining of iron org , in 1883 the Crow of Spain issued a royal decree to the following effect.

Jul 1, 1931

By IRENE AITKENS

The emerald is the most costly of all gems , due to the scarcity of flawless stones . This fact gave rise to the ancient axiom , " As rare as an emerald without a flaw . The finer gems not only command the highest prices at all times , but when flawless are considered the most highly prized of all gem stones . George F. Kunz divides emeralds into two distinct classes : " Exceptional specimens , " which bring as much as $ 6,000 a carat ; and " fine- quality specimens , " which bring about $ 1,000 a carat .

Jul 1, 1931

By Arthur Crowfoot

This paper describing t o concentrating practice of the Phelps Dodge Corporation, Morenci Branch, at Morenci, Ariz., is one of a series of articles on concentrating methods and posts being prepared by the Bureau of Mines. The Morenci concentrator, locally known as No. 6 concentrator, treats 5,000 dry tons of ore per 24-hour day by primary tabling followed by two stages of flotation treatment, at 48-mesh size and 65-mush size respectively.

Jan 1, 1931

By W. R. Moorehead

This paper, describing the mining methods and colt at the New Indria quicksilver mine, is one of a series of similar papers being prepared by the Bureau of Mines on various mines in the United States. The New Idria mine lies at an elevation of 3,500 to 4,200 feet in the Coast Range of San Benito County, Calif. The property is accessible by automobile stages from Gilroy or Hollister via Tres Pinos. Tres Pinos, 65 miles northwest of the mine, is the nearest railroad point.

Jan 1, 1931

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

The chief object of the Electrical Section of the United States Bureau of Mines is the study of causes and means of preventing accidents resulting from the use of electricity in mines . A large part of this work for the last 20 years has been the inspection and testing of mining equipment under the provisions of schedules which give the minimum requirements considered essential for the safety of equipment intended for use at or near the working faces of dusty or gassy mines . During the first few years of this work , particular attention was paid to the explosionproof features of the various accessories such as motors , controllers , and other parts . The knowledge of the essentials necessary for safe designs of enclosures has since been augmented by field experience and by data obtained in testing a large number and variety of designs . With our present knowledge it would seem that a disproportionate stress was placed on making the various enclosures explosionproof , but not enough thought was given to the danger from wiring and connections outside of explosionproof enclosures . The list of equipment that has met minimum requirements for safety and has been approved as permissible by the Bureau of Mines includes storage - battery locomotives , power trucks , drills , loading machines , conveyors , cutting machines , room hoists , pumps , concrete mixers , and rock-dusting machines . The wiring on some of the machines is comparatively simple and sometimes , except for the trailing cable , may be entirely within the explosionproof enclosures . In general , there is outside wiring between enclosures , and on the larger machines the wiring may be extensive and complicated . In considering the safety of wiring for mining machinery , attention must be given the severe service and unfavorable surroundings imposed by mining conditions . Some of the matters that require consideration are : ground . The lack of care of the exterior wiring to be expected in the average mine . The lack of adequate periodic inspection of the wiring . The absence of adequate facilities for satisfactory inspection and repairs under- The severe conditions of moisture , dirt , mechanical injury , and low voltage encountered in mining service .

Apr 1, 1931

By E. P. Youngman

From a scientific point of view , the zircon is by far the most remarkable of the gem stones , and a satisfactory solution of the problems offered by its characters and constitution has not yet been made . 3 Three distinct forms have been recognized , differing in specific gravity , hardness , optical properties , behavior when heated , and color.4 ( See section of this paper entitled "Description and Properties . " ) Zircon as a gem stone has not been as well known as its properties warrant . It is one of the most brilliant of the precious stones (having a high refractive index) . The colorless zircon rivals the diamond in brilliance and fire play to such an extent that a judgment based entirely upon optical inspection might be erroneous . In the opinion of gem authorities , the colored stones likewise have much merit . The blue zircon ( " Starlite" ) was so named by Kunz because of its resemblance to a " star twinkling in the night . " Another gem authority describes the leaf- green stone as one possessing a restful beauty , the red stone as having a certain ( though somber) grandeur , and the golden-yellow stone as being unsurpassed in magnificence . The slowness with which the zircon , a stone frequently mentioned in ancient literature , has come into use in modern jewelery may be owing to the fact that authorities differ as to whether the colorless and the blue zircons are found as such in nature or are treated stones . Any treated stone , although the material of which it is composed may be essentially genuine , has been considered a deception . However , according to Kunz , " Starlite is now sold over the entire world ; never has anything been so well introduced. "7 Dr. Foshag, mineral curator of the United States National Museum, states that the first allotment of zircons to enter the United States was obtained in 1921 from Siam ( through France ) for scientific or museum purposes and that four or five years later the stones were adopted by the jewelers of this country . Retail jewelers are displaying the colorless type and the blue stones , especially , in finger rings , necklaces , and like ornaments . Fine crystals have been used somewhat extensively in jewelling watches and as supports for the edges of fine balances . At one time zircons were though to be appropriate in mourning jewelery .

Jul 1, 1931

By Paul M. Tyler

Bismuth is a useful metal and rather an uncommon one . The element probably constitutes much less than one-millionth part of the earth's crust , but the potential supply - to no small extent as a by-product of the production of lead and copper with which it is associated in nature has tended for many decades to exceed the demand. A single mine in Bolivia could readily flood the world's markets , and considerable quantities of bismuth are allowed to escape recovery at many smelting plants .

Jul 1, 1931

By D. L. Forrester

This paper, describing the milling practice of the Old Dominion Co., is one of a series being prepared by the: United Staten Bureau of Mines. ACKNOWLEDGMENT In the preparation f this paper, acknowledgment is made of the valuable service rendered by R. S. Allen, metallurgist of the Old Dominion Co. T. G. Chapman, one f the consulting engineers of the Bureau of Mines, assisted in arranging the paper for publication.

Jan 1, 1931

By H. Herbert Hughes

Iceland spar is a variety of calcite ( calcium carbonate ) characterized by its purity , transparency , and perfection of crystalline structure . It takes its name from the country in which it was discovered . The actual demand for it is small , but the supplies of high - grade optical spar are so meager that the search for it has become international in its scope . Iceland spar is a scientific necessity , for without it research precision and technology would be hampered considerably . The earliest students of mineralogy were familiar with calcite , but the transparent variety was not discovered until early in the seventeenth century , when crystals of it were found in the bed of a stream in Iceland . It received little attention until 1669 , when Erasmus Bartholinus first recognized its powers of double refraction . The results of his investigation were published in a book , " Experimenta Crystalli Islandici , " which appeared in 1670. The law governing the action of the rerracted rays was discovered by Christian Huygens eight years later . The polarization of light rays in passing through Iceland spar was discovered in 1809 by Etienne Louis Malus , a French physicist , who published a paper describing the phenomenon . His work was closely followed by that of William Nicol , who in 1828 designed the Nicol prism which is still used as the source of polarized light in most optical instruments .

Jul 1, 1931

By D. Harrington

Along with other phases of mining , the ventilation of metal mines has been affected by the business depression of 1930. As might be expected , some of the results are favorable , and some are distinctly disadvantageous to progress . Probably the worst effect of the recession of mining activity is that , as usual , one of the first departments of almost any industrial establishment ( and this is especially true of mining ) to be curtailed is that which concerns what might be called welfare work , such as safety , health , etc. , and ventilation : in consequence , a number of men who were employed mainly on ventilation work in metal mines are now out of employment and their former duties either are being handled by others as only part of a crowded routine or are being allowed to lapse . On the bright side of the picture is the following paragraph from a letter by the ventilation and sarety engineer of the United Verde Copper Co. , Jerome , Ariz . , indicating that money and effort expended on ventilation during " flush " times give results which aid in money savings when depression comes : The desirability of absolute control over the ventilation system has again been demonstrated at this mine . Under full operation we have been using approximately 500 hp . to drive our big fan . Under curtailed operations we naturally do not require as much air , so by sending the air only where needed and airing out all other places periodically to keep timber , etc. , in good condition we have been able to economize in the quantity of air required . The fan speed has been reduced and the power dropped to 300 hp . , thus effecting a material saving in the power bill , and still maintaining an efficient ventilating system . "

Jul 1, 1931

By J. D. Tolman

In view of present interest in a revival of gold mining enterprises, papers dealing with the development of small gold properties are apropos. The present paper deals with the operation of a small gold property in the exploration and development stage, mining and milling 25 tons of ore daily, and indicates what may he expected in the way of mining costs under northern climatic conditions, by practicing rigid economy, at a property where disproportionate overhead costs are unavoidable bacause of the small rate of production. The output of this prospect is treated in a small amalgamation plant which has been described in a previous circular.. HISTORY Prospecting in the district was begun in 1909, and by 1911 the adjoining mines, Hollinger and McIntyre, were in operation. Actual work was begun on the Rochester claim in July, 1922, and carried on through 1924. The property was closed until 1928 when the present company took it over, together with the other holdings of the Canadel Mining Co. A small mill was started as a pilot plant on March 24, 1929, and is still in operation.

Jan 1, 1931

By I. AITKENS

The precious stones rubies and sapphires are transparent varieties of the mineral corundum . Essentially they are aluminum oxide , but the aluminum is often replaced. by small amounts of chromium , titanium , or iron . The chromium is said to give a red color , titanium a blue , and iron a yellow . True rubies range from rose to a somewhat purplish red and are sometimes termed " oriental rubies " to distinguish them from spinel rubies , stones of inferior hardness , density , and value . " Oriental rubies " are very rare , and the so-called " pigeon's blood" variety is the most valuable . Sapphires normally range in color from palest blue to deepest indigo , but actually all precious varieties of corundum of any other color than red are called sapphires . The most esteemed tint is like that of the blue cornflower . Colorless corundum of gem quality is called white sapphire ; the yellow variety is described either as yellow or as golden sapphire ; and the pale pink is classed as pink sapphire . The word " oriental " is also used as a prefix in naming varieties of corumdum of less popular colors . For instance , oriental emerald is used for green corundum, oriental topaz for yellow , and oriental amethyst for violet to purple varieties . The chief physical characteristics of rubies and sapphires are hardness , adamantine luster , and moderately high specific gravity ( 3.9 to 4.1) . Next to the diamond, corundum is the hardest of all minerals ; in fact , the sapphire is number 9 on Moh's scale , ranking between the topaz and the diamond. Rubies crystallize in 6-sided prisms terminated by flat faces and other varieties of corundum with twelve inclined faces , six above and six below , meeting in a girdle . Corundum is doubly refractive , with a direction of single refraction running parallel to the edge of the prism . The refractive indexes are very constant, the ordinary index ranging from 1.766 to 1.774 and the extraordinary index from 1.757 to 1.765. The double refraction always remains the same.

Aug 1, 1931