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By L. Bombardieri, H. F. Mills

Iron King mine, producing gold-silver-lead-zinc-ore, is 10 miles east of Prescott, Ariz. At present the 1806 level is being developed. The echelon pat tern of ore deposit continues at depth but is less pronounced, and the orebody is now more or less continuous over 2600 ft of strike length, with widths 5 ft to as high as 26 ft where overlapping of lenses occurs in one section of the mine. Better continuity of ore at depth has encouraged systematic mining and improved plant facilities to offset higher operating costs. With favorable persistence of ore at depth, the three-compartment No. 6 hoisting shaft appeared inadequate to handle increased tonnage from greater depths, and in 1952, a four-compartment steel and concrete shaft was started. This is now at a depth of 1906 ft, and shaft pockets and loading cartridges are being installed on the 1806 level. Ore from the new shaft, hoisted in 5 ½ -ton Jeto bottom dump skips, is dumped into a 500-ton shaft bin, from which it is fed to a 16x30-in. gyratory crusher and conveyed 415 ft through an undersurface concrete gallery to the secondary crusher and conveying system supplying the 900-ton mill. Lead, zinc, and pyrite concentrates are floated, and the flotation tailings are cyanided after desliming. Waste from the new shaft is dumped into a 250-ton surge bin, fed from this bin to a 24-in. conveyor, and discharged into the glory hole above the block cave. The new shaft is served by a double-drum 400-hp hoist used for ore and waste; the No. 6 shaft conveys men and material.

Jul 1, 1956

By Charles H. Morgan

THE process of wire drawing depends upon the property which certain metals possess, termed ductility, 'which is defined in Brande's Dictionary of Science as a property in consequence of which metals may be drawn out at length without interrupting the continuity of their constituent parts. As defined by M. Tresca, it is the property of flowing when subjected to pressure, and is termed by him the "flow of solids," in his paper, read before the Academy of Sciences in Paris, November, 1865 * In the simple language of the wire shop, it is that quality in certain metals that permit, them to be drawn (or stretched) out through a tapering, hole in a metal block or die, the die being more dense and harder than the metal to be reduced. It is a fact well known to those skilled in the art, that to succeed in drawing iron or steel wire, it is of the utmost importance to have thorough lubrication, as a lack of it would caws abrasion of the wire, or of the walls of the tapering hole in the die or plate, and quickly put an end to the operation. In drawing coarse or large sizes of wire, say 2/10 inch diameter, the pressure upon the sides of the tapering hole, where the wire comes in contact with the die, is so great that an ordinary lubricant is squeezed out when the usual reductions in size are made, and abrasion takes place. In order to meet this difficulty, and secure proper lubrication, it has been' a common practice for years to apply a paste made of rye or wheaten flour, or lime, to the surface of the wire to be drawn, and when the paste is dry, to smear the wire with tallow or grease; the wire is then ready to be drawn, the dried paste serving to prevent the lubricant from being pressed out in the. process. Some years since, when Bessemer metal came largely into use as material for wire, "the writer found that its drawing required so much more power than iron wire, that he was led to institute a series of trials to ascertain the difference in power required. It was found that Bessemer wire required from 100 to 200 per cent. more power to make the same reduction in sizes than soft iron wire, the difference depending upon the amount of carbon and other chemical constitu- * Interesting experiments in the flow of metals have been made, by Messrs. Hoopes Townsend, of Philadelphia, in cold-punching iron, published and illustrated in the Journal of the Franklin Institute, of March, 1878, by Mr. David Townsend.

Jan 1, 1881

FRIENDS of the late Charles F. Rand presented in 1930 a sum of money from which the income is available to support various phases of the work of the Institute in which Mr. Rand was so deeply interested. At present the fund amounts to $10,400. The specific terms of the deed of gift are as follows: "The fund collected to establish a memorial to the late Charles F. Rand shall be placed in the custody of the Board of Directors of the American Institute of Mining and Metallurgical Engineers, to be set up as a trust to be known as the `Charles F. Rand Foundation,' the income of which shall each year be applied to a distinct purpose to be decided upon in that year by vote of the Board of Directors. This purpose shall be such as to promote the general welfare of the Institute and to constitute a permanent memorial of the usefulness of Mr. Rand, who for many years gave unstintingly of his time and talents in its service. "It shall be within the discretion of the Board of Directors to establish a medal to be known as the Charles F. Rand Memorial Medal to be awarded at such a time and under such rules as may be determined by the Board of Directors, for Distinguished Achievement in Mining Administration." The establishment of this medal was announced at the annual meeting in February, 1932, the term "mining" being defined in its broad sense to include metallurgy and petroleum. Robert Linton is chairman of the Charles F. Rand Foundation Award Committee.

Jan 1, 1944

By JESSE L. MAURY

ONE OF the most hopeful features of the current depression is the discussion which it has en- gendered of ways and means to counteract similar recurrences in the future. 1t is widely recognized that fruitful attack will be directed toward the steady employment of labor, through which the purchasing power of this preponderant class in society will be maintained. S. A, Lewisohn's article' has presented the major factors to be considered; the physical suffering and mental torture endured by those who are deprived of income through no fault of their own, the direct economic losses' sustained in the degradation of 'great, numbers of our population and the disintegration of efficient working forces, and the prime responsibility of owners and managers.

Jan 1, 1931

By Sherwin F. Kelly

PLAIN mining engineers usually avoid any gathering of geo¬physicists because of the incomprehensibility of their discussion to the uninitiated. This being so, gradients, gravity and gammas will be deferred to the end of this review, the first part of which will be devoted to what has been done in applying geophysics to the solution of real field problems. From the West, J. J. Jakosky reports that International Geophysics has had its activities fairly well 'divided between mining (both placer and lode), oil structural work, and clans-site and reservoir investigations. In oil exploration, electrical methods are used for depths down to 2500 ft., beyond which they utilize seismic methods. They find in their placer work that the many 'magnetic anomalies encountered in the bedrock of the Southwest render the electrical techniques more satisfactory, and with them they are obtaining thickness and tonnage of gravels, depth to and contour of the underlying bedrock as well as important structural features therein, and water-table elevations.

Jan 1, 1934

By Frank L. Nason

(New York meeting, February, 1912) IN the year 1904 an eminent Swedish geologist prepared a report on the iron-ore reserves of the world. His estimates follow: Countries. Tons. United States, 1,100,000,000 Great Britain, . 1,000,000,000 Germany, 2,200, 000, 000 Spain, 500,000,000 Russia and Finland, 1,500,000,000 France, 1.500, 000, 000 Sweden, . 1,000,000,000 Austria-Hungary, . 1,000,000,000 Other countries, 1,200,000,000 Total, . 10,000, 000, 000 The iron-ore allotted to the United States by the Swedish geologist is barely sufficient to last 20 years at the present rate of consumption. On the other hand (according to Edwin C. Eckel,1 from whom the above and following statistics are quoted), there is hardly need for worry on the part of our iron industries for the, next two centuries or more. Upon the basis of careful work by the U. S. Geological Survey, in which Mr. Eckel has taken an important part, the following estimates arc definitely, but by no means finally, given for the United States District. Tons. Lake Superior District, . . 1,500,000,000 to 2,000,000,000 Alabama, red hematite. . . 1,000,000,000 brown hematite, 725,000,000 Georgia, red hematite, 200,000,000 brown hematite, 125,000,000 Tennessee red hematite, . 6110,000,000 I brown hematite, 225,000,000 Virginia., red hematite, 50,000,000 brown hematite, 300,000,000 Total, . . 4,725,000,000 to :5,225,000,000

Jul 1, 1912

By M. V. Lowry

This paper outlines the economic considerations that led to the recent installation of a thickener at St. Joseph LeadCo.'s Balmat, N.Y. mill. To incorporate storage of concentrates, they decided upon a single, unusually deep tank to be used for both storage and thickening. The abnormally high rake lift required was achieved by the novel feature of having the entire drive platform raise and lower. Initial operating problems are described along with the satisfactory solutions. Total costs for concentrate handling before and after installation of the storage thickeners are compared. In Northern New York State, the St. Joseph Lead Co. conducts a 2100 tpd zinc mining and milling operation at its Balmat Plant. Conventional crushing, grinding, and flotation is used to produce a zinc concentrate. For 32 years, from 1930 through 1962, the plant operated with the concentrates going directly from flotation to the filtering, drying, and loading facilities. All of the concentrate handling equipment, therefore, had to operate 24 hrs per day. It also had to accommodate wide fluctuations in tonnage, due to variations in the grade of ore. Many problems were thereby encountered in filtering and drying, but it was never concluded that the cost could be justified for installing a conventional, large diameter thickener. Finally, in 1963, they installed an unconventional thickener that is unusual in several respects. The tank depth is 16 ft instead of the normal 8 ft. The rakes are raised and lowered by having the main drive gear located on a movable platform. Automatic controls are programmed to raise the drive platform and rakes during one shift of storage. During the next two shifts of withdrawal, the controls are programmed to lower the drive platform and rakes. After three years of operating this unique storage-thickener, the conclusion is that a correct choice was made from several alternative schemes for storing concentrates. The various considerations involved in the final selection will here be analyzed, and the design features and installation details will be de- scribed. Operating problems and modifications made to the equipment will next be considered, and finally the effects upon filtering, drying, and loading will be reported. SELECTION CONSIDERATIONS Even without a thickener, concentrate handling had become reasonably efficient at the Balmat Mill by the year 1962. A tonnage that varied between 6 and 25 tph was being handled fairly satisfactorily. The filter cake moisture of 8%% seemed quite respectable, except that two large filters were usually in service. Three filters often had to be operated in order to prevent excessive filter overflow with consequent loss of values. This situation occurred when zinc concentrates from flotation exceeded 20 tph and when filter cloth blinding developed. Over the years, numerous small improvements had been effected, such as: selection of a filter cloth with better flow characteristics; addition of flocculant to the filter feed; and, in 1953, the smallest of three drum filters was replaced by a five disc, 8' 10" diam filter with a bottom agitator and snap blow. As another example of fairly efficient operation, the oil-fired dryer was doing a seemingly satisfactory job of further reducing the moisture content to an average of 3%. However, there were often considerable dust losses when the tonnage suddenly dropped off to 6 tph. At high tonnage rates, the resulting high moistures of 4% and 5% caused difficulties due to concentrates sticking and freezing in chutes leading to the box car loaders. (Drying of concentrates is justified because of the high freight rate for the long shipping distance to the company owned smelter at Josephtown, Pa. near Pittsburgh.) It was long realized that installation of a thickener would permit the subsequent steps of concentrate handling to proceed more smoothly and would alleviate the problems existing in the filtering, drying, and loading operations. It was also realized that even a slightly lower filter cake moisture could mean considerable savings in fuel oil. However, all these factors were never quite sufficient to warrant the expense of a thickener until three more considerations were added to the picture. First, the advent of flocculants meant that a thickener of relatively small area could now be considered. Secondly, a complete renovation of the zinc flotation circuit was made between 1957 and 1961. The

Jan 1, 1967

Jan 1, 1967

By Tegner C. Johnson

Just a few years ago, my company was referred to as the Marion Steam Shovel Company. Though we still make shovels, both two and eight-crawler types, the eight-crawler stripping shovel appears to have been replaced by the walking dragline for overburden removal and in some cases for the mineral as well. The walking dragline appeared in the coal fields in the early 1930's. It is popular because it can cope with overburden depths in excess of 100 ft and with blasted sedimentary rock, all at an O & O (ownership and operational) cost of ±10[c] per bank cu yd (bcy).

Jan 10, 1974

By F. G. Cottrell

(New York Meeting, February, 1912.) ABOUT a year and a half ago, at the San Francisco meeting of the American Chemical Society, in connection with the excursions to local smelting-works, I had occasion to show some lantern-slides illustrating the recent commercial development of electrical methods for precipitating the suspended matter from smelter-smoke, the underlying phenomena of which were clearly brought to the attention of the technical public by Sir Oliver Lodge as long ago as 1884. In the Journal of industrial and Engineering Chemistry, August, 1911, most of these views were reproduced, together with an account of the work from its beginning up to July, 1911. To-day I wish particularly to show you some of the further developments of the work since that time; but in order to make these clear they will be prefaced by a brief abstract of the article above referred to. The removal of suspended particles, front gases, by the aid of electric discharges is by no means a new idea. As early as 1824 we' find it suggested by Hohlfeld 1 as a means of suppressing ordinary smoke, and again a quarter of a, century later by Guitard.2 These suggestions, which do not seem to have stimulated any practical study of the question, were soon entirely forgotten, and only brought to light again by Sir Oliver Lodge,3 many years after he himself had independently rediscovered the same phenomena and brought them to public attention 4 in a lecture before the Liverpool Section of the So-

Jul 1, 1912

By E. A. Anderson, P. W. Ramsey, E. J. Boyle

Only a few zinc-rich alloys are in commercial use today, and these depend largely upon solid solution effects for their desirable properties. Typical examples are rolled alloys containing about 1 Per cent of copper, with Or without additions of elements such as magnesium, and die-casting alloys containing about 4 Per cent of aluminum with small amounts of magnesium and sometimes copper." A number of elements are capable of forming alloys with zinc, Which do not enter into solid solution except in limited degree. The Present Paper considers One such system, zinc-titanium, in which alloys having potentially useful properties in the rolled form were found. Zinc-titanium System The zinc-rich portion of the zinc-titanium diagram, as determined by standard methods in this laboratory,3 is shown in Fig. I. The portion of the diagram of significance in the present work extends from 0 to about 0.5 per cent titanium. Gebhardt4 places the eutectic at 0.45 per cent, but the evidence in favor 01 the composition given in Fig. I is considerable. The solid solubility of titanium in zinc is very low indeed and possibly places these alloys in a somewhat different category from the commercial alloys previously mentioned. Alloy Preparation All of the alloys used in this work were prepared with titanium metal of 98.9 per cent purity. In most cases high-purity zinc (99.99 per cent) was used but sufficient work was done later to show that zinc of about high-grade composition would yield approximately equal results. Best practice in alloy manufacture seemed to be to prepare a zinc-titanium hardener by adding about 4 per cent of titanium metal to molten zinc and holding under a boric acid cover, with frequent stirrings, at 750°C, until the titanium had dissolved. The desired titanium content could readily be obtained in the final alloy by adding the calculated amount 01 this hardener. The alloys proved to be quite stable in composition, unless overheated, and, with reasonable temperature control, required no cover or flux to prevent loss of titanium content by oxidatioll, Hot-rollig Tests Three alloys containing, by analysis, 0.05, 0.12, and 0.23 per cent titanium were selected for preliminary study. Slab cross sections a a marked grain refinement* (Fig. 2) in the two alloys of highest titanium content. Cast unalloyed zinc has a columnar grain structure similar to that shown for the alloy of lowest titanium content but without the scatter of small equiaxed grains at the center.

Jan 1, 1944

By P. W. Ramsey, E. J. Boyle, E. A. Anderson

Only a few zinc-rich alloys are in commercial use today, and these depend largely upon solid solution effects for their desirable properties. Typical examples are rolled alloys containing about 1 Per cent of copper, with Or without additions of elements such as magnesium, and die-casting alloys containing about 4 Per cent of aluminum with small amounts of magnesium and sometimes copper." A number of elements are capable of forming alloys with zinc, Which do not enter into solid solution except in limited degree. The Present Paper considers One such system, zinc-titanium, in which alloys having potentially useful properties in the rolled form were found. Zinc-titanium System The zinc-rich portion of the zinc-titanium diagram, as determined by standard methods in this laboratory,3 is shown in Fig. I. The portion of the diagram of significance in the present work extends from 0 to about 0.5 per cent titanium. Gebhardt4 places the eutectic at 0.45 per cent, but the evidence in favor 01 the composition given in Fig. I is considerable. The solid solubility of titanium in zinc is very low indeed and possibly places these alloys in a somewhat different category from the commercial alloys previously mentioned. Alloy Preparation All of the alloys used in this work were prepared with titanium metal of 98.9 per cent purity. In most cases high-purity zinc (99.99 per cent) was used but sufficient work was done later to show that zinc of about high-grade composition would yield approximately equal results. Best practice in alloy manufacture seemed to be to prepare a zinc-titanium hardener by adding about 4 per cent of titanium metal to molten zinc and holding under a boric acid cover, with frequent stirrings, at 750°C, until the titanium had dissolved. The desired titanium content could readily be obtained in the final alloy by adding the calculated amount 01 this hardener. The alloys proved to be quite stable in composition, unless overheated, and, with reasonable temperature control, required no cover or flux to prevent loss of titanium content by oxidatioll, Hot-rollig Tests Three alloys containing, by analysis, 0.05, 0.12, and 0.23 per cent titanium were selected for preliminary study. Slab cross sections a a marked grain refinement* (Fig. 2) in the two alloys of highest titanium content. Cast unalloyed zinc has a columnar grain structure similar to that shown for the alloy of lowest titanium content but without the scatter of small equiaxed grains at the center.

Jan 1, 1944

By F. R. Morral

INDUSTRY has yet to find a universal solution to the problem of engineer personnel selection. Today, the choice of the right man for the right job is even more pressing than ever before. The age of the hard apprenticeship seems to have passed. In its place one finds the interviewer who must determine through personal contact and evaluation of college grades whether a graduate engineer will fit into his company's scheme. The problem, as it is constituted today, may be broken into four parts: Need for better use of human resources (there is a shortage of engineers, scientists, and skilled workers), productivity with higher efficiency, encouragement of personal pride in work performed, and employee's happiness on the job and away from it.

Jan 4, 1953

By John G. Hall

The pumping operations at the Chief mine have been unique in the respect that for many years the entire flow of water into the mine has been disposed of by pumping into natural underground " caverns" or "sinks." Volumes up to 4000 gpm have been pumped into these caverns with no apparent tendency for the caverns to fill with water, and it has never been proven that any of the water returns to the mine workings. Major pumping operations have been carried on during two periods, the first from 1918 to 1927, and the second from 1942 to the present time.

Jan 1, 1949

By Arnulf Muan, D. P. Masse

PHASE relations in the system CoO-SiO2 have been determined as a basis for further investigations of thermodynamic properties of olivine solid solutions involving Co2SiO4 as a component. Previous data on the system CoO-SiO2 are incomplete or uncertain. Biltz and Lemke1 determined the melting point of cobalt orthosilicate as 1345°C , but Asanti and Kohlmeyer2 have later found a considerably higher temperature, 1420°C. The latter authors also studied melting relations of one mixture on the CO side and two mixtures on the SiO2 side of the orthosilicate composition and sketched a tentative phase diagram for a limited composition range of the system. However, no phase identification was carried out, and the authors left unanswered the question of the possible existence of a stable meta-silicate phase. Greig3 showed that a 90 wt pct SiO2-10 wt pct Co mixture at 1725°C consists of two immiscible liquid phases. The quenching technique was used in the present investigation. Mixtures of high-purity cobalt oxide ("Fisher Certified") and dehydrated silicic acid ("Baker Analyzed") were equilibrated in air atmosphere. The samples were then quenched to room temperature and the phases present were identified by microscopic and X-ray examination. The samples were kept in small envelopes made from thin (0.0004 in.) platinum foil. Thermodynamic data which have become available recently for Pt-Co alloys4 were used to check that the losses of COO from the oxide samples by alloying of cobalt with platinum in the present investigation were too small to change significantly the compositions of the oxide material during the equilibration. A vertical tube furnace with an 80 pct Pt 20 pct Rh resistance winding was used in runs up to 1510°C. Temperatures in these runs were measured with a Pt vs 90 pct Pt 10 pct Rh thermocouple calibrated against the melting point of diopside (CaMgSi2O6, 1391.5?C). The given temperatures as measured by this technique are estimated to be accurate to *5°C. Quench runs at temperatures above 1650°C were made with a modified Roberts and Morey5 strip furnace, using strip resistors composed of a 60 pct Pt-40 pct Rh alloy. Temperatures were measured with an optical pyrometer which was calibrated against the liquidus temperature of a mixture composed of 10 wt pct CaO, 90 wt pct SiO2 (1707°C). The temperatures measured with this technique have an estimated accuracy of +15°C. The results are shown graphically in Fig. 1. Only one intermediate phase, the orthosilicate Co2SiO4 with olivine-type structure, is stable in addition to the end members cobalt oxide and silica. The melting point of the orthosilicate was found to be 1415" ± 5°C. The metastilicate CoSiO3 is not stable at the temperatures of the present investigation. The two eutectic points in the system CoO-SiO2 where COO plus olivine, and olivine plus silica, coexist with liquid were found to be 72 wt pct COO and 1407°C and 63 wt pct COO and 1381°C, respectively. The melting point of cobalt oxide in air was taken as 1745?C, based on the previous data of Aukrust and Muan.6 Within limits of error (+ 5?C), identical eutectic temperatures to those determined in air were found when two representative mixtures were equilibrated at 1 atm O2 pressure and in an atmosphere of 84 vol pct CO2, 16 vol pct H2. This suggests that changes in oxidation state of cobalt in the condensed phases are not significant as far as their effect on the phase relations are concerned. This inference was substantiated by failure to detect7 any "excess oxygen" (i.e., oxygen in excess of that contained in Co2SiO4) in a sample of orthosilicate composition equilibrated in air 10°C above the liquidus temperature and subsequently quenched to room temperature. This work was carried out as part of a research program sponsored by the U.S. Atomic Energy Commission under Contract No. AT(30-1)-2781.

Jan 1, 1965

By Wittenau, E.

OPERATION of a pilot mill of 100 tons' daily capacity during 1930 and 1931 proved that the copper minerals of the Colorado and Clay sections of the Morenci ore body could be successfully concentrated by the flotation process. Economic conditions caused postponement of further testing work until late in 1938 when the former No. 6 Concentrator at Morenci was converted into an experimental mill of 1500 tons' daily capacity which was known as the Test Concentrator. The Test Concentrator began continuous operation on April 3. 1939, using such crushing and grinding equipment of the No. 6 Concentrator as was appropriate. Modern classifiers and certain flotation machines were installed and later other types of flotation machines, a large grate-type grinding mill. mechanical screens, a short-head cone crusher, and a disk filter were added to the test equipment. Operation was uninterrupted until Dec. 31, 1941.

Jan 1, 1942

By Rudolf Gahl

Page Tests Conducted in Small Test Mill................... 577 Demonstration Tests Conducted by Minerals Separation Co....... 577 Flotation Tcsts Conducted by Inspiration Co............. 577 Sampling of Orebody........................ 578 Other Results Obtained in Small Test Mill.............. 580 Tests Conducted in Large Test Mill................... 580 Flow Sheet............................. 580 Discussion of the Value of Preliminary Table Treatment......582 Callow Flotation Installation..................... 585 Flinn-Towne ~nstallation...................... 587 Cole-Bergman Installation...................... 588 Methods Followed in Competitive Tests................ 590 Advantage of Pneumatic Flotation Machines.............. 591 Pneumatic Machines of Minerals Separation Co............. 591 Float Skimming Device......................; 594 Experimental Inspiration Flotation Machine.............. 596 Arrangement of Callow Cells in Series ................ 598 Variations of Flow Sheet....................... 599 Coal Tar as Flotation Agent..................... 600 Experience with Primary Slime.................... 602 Influence of Iron on Flotation..................... 605 Influence of Chemicals on Primary Slime............... 607 Fineness of Crushing Desired.................... 607 Operation of Large Concentrator..................... 608 Flow Sheet of Callow Sections.................... 608 Flow Sheet of Inspiration Sections.................• 609 Inspiration Flotation Machine of Steel Construction.......... 610 Minerals Separation Section..................... 613 Filter Plant............................ 613 Results Obtained in Commercial Concentrator............... 616 Tonnage............................... 616 Air and Power Consumption...................... 616 Floor Space............................ 617 Water Consumption......................... 617 Recovery............................. 618 Oil Consumption.......................... 618 Operating Costs for Flotation..................... 620 Discussion of Results Obtained.................... 620 Prospects for Futurc Development of the Flotation Process......... 621 Porous-Bottom Experiments..................... 622 Raising the Grade of Concentrates.................. 624 Recovering Carbonates by Flotation................. 624 Recovery of Silicates by Flotation.................. 627 General Theory......................... 628 Conclusion............................... 630

Jan 1, 1917

By AIME AIME

The following financial report of the Treasurer of the United Engineering Society is published for the information of members NEW YORK, February 15, 190S. To the Board of' Trustees, United Engineering Society I beg to submit herewith the report of the Treasurer as of December 31, 1907. Your attention is called to the fact that the resources and liabilities, receipts and disbursements statements cover all the financial transactions of the United Engineering Society from its organization up to December 31, 1907. The income and expenses of operating the building during the whole operating period from December 1 to December 31, 1907, somewhat in excess of twelve months, are given. Included in the expenses, amounting in all to $52,647.11, will be found an item entitled "Building Equipment (construction account)." The expenditures under this item were not made for the operating expenses of the building, they represent a construction account, properly speaking, covering expenditures for furnishings and equipment of the building. The Founders' Agreement specifically provides for this class of expenditure under the provision that the Founder Societies shall each be liable for a charge not to exceed $200,000 of principal, which shall include the land and building completed and ready for occupancy, together with the " furnishings, equipment and personal property therein." Certain details of equipment are yet to be supplied, and it. is proposed in the near future to call upon the Founder Societies for an assessment on their respective land and building funds to cover this item of building equipment. Such action would enable the item of $10,039.85 to be transferred to the income account and reduce correspondingly the assessment

Mar 1, 1908

Frank Clemes Smith, Deadwood, 8. D. (communication to the Secretary): The reading of Mr. Chance's interesting paper suggests a few ideas relative to his discussion of certain Black Hills gold-ores. Mr. Chance refers to his examination, in 1897, of " the (Carboniferous) limestone plateau-country which encircles the central area of the Black Hills," and says that " it had been generally assumed that the mineralization of this formation was confined to the northern area;" further, that he "found, however, a general mineralization, extending in zones or belts throughout the region," and that the ores, being more or less specially

Jan 1, 1900

By W. Bradley, R. G. Hall

This paper will attempt to show how a metallurgical problem at one California quicksilver mine was solved, and how the solution was applied successfully at another mine. The pronouns "we" and "our," as used below, refer '0 the Bradley 'lining Co. of San Francisco. The term "concurrent firing" for the purpose of this paper can be defined as feeding and firing a a kiln at the same end—that is, of course, the upper end' This is as opposed to "countercurrent firing," the orthodox method, in which a kiln is fed at the upper and fired at the lower end. The terms "quicksilver" and "mercury" are used interchangeably. Early References The earliest work on nonferrous metallurgy, we believe, was The Pirotechnia of Vannocio Biringuccio,l its first edition having been printed in Italy in 1540. Quoting from its chapter entitled "Concerning Quicksilver and Its Ore": Quicksilver ... is one of the gods and has divine strength in itself, and also, to the annoyance of the alchemists, it is winged. Hence, when it sees that it is in gravest danger, it loosens itself from . . . every bond . . . and fies away into the heavens, escaping from the hands of those who crucify it. Almost laughing, it leaves all its adversaries mocked and scorned, with their phials and filters empty . . . How thorough a job, under certain conditions, it can do of mocking its adversaries and leaving their phials and filters empty, was found out four centuries later at the Sulphur Bank mine, on the east shore of Clear Lake, in Lake county, California, The other mine mentioned in the title is the Reed, in Yolo County, California, 35 miles by road southeast of Sulphur Bank, Reed and Sulphur Bank ranked respectively Nth and seventh in U. S. production in 1943. The earliest direct reference we can find to furnacing troubles at these mines was by Thomas Egleston in 1890.2 Speaking of Sulphur Bank, Egleston says: of there is more sulphur than cinnabar in the ore, which is a detriment to both . . . making the sulphur impure, and rendering the cinnabar difficult to work on account of the soot. In some of the early . . . furnaces the accumulation of soot from the excess of sulphur has been known to penetrate as far as the fan blower at the end of the . . . condensers, and completely prevent its revolution. In order to get rid of the inconvenience of this accumulation . . . , as well as to get a commercial value from the sulphur, it (the sulphur) is now separated by steam and sold. It is claimed that the sulphur alone pays all the expenses of ... the mine. The mine was first worked for sulphur, and the cinnabar it contained was considered to be an inconvenience, and was carefully picked out and thrown away, as its richness and value were not

Jan 1, 1949