Bulletin, Issue 244

Front Cover
U.S. Government Printing Office, 1927

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Page 71 - ... sizes of finished products made from optical fluorite 421 INTRODUCTION Fluorite, or fluorspar as it is commonly called, is a mineral of rather limited occurrence, used in bulk in this country in the manufacture of steel, hydrofluoric acid, enamels, glazes, and for a few other purposes. In addition, clear, colorless, or faintly colored specimens, such as occur rather sparingly in some localities along with the crude material, are suitable for the manufacture of certain types of lenses and prisms...
Page 58 - The chemical reactions which occur when fluorspar is used as a flux are not well understood, and authorities differ not only as to the chemical reactions but also as to the role fluorspar plays in smelting and the nature of the results obtained.
Page 157 - Isolated crystals of galena and ehalybite are not uncommon, although, as mentioned previously, these are usually concentrated in the center of the vein. Pyrites Is rare, and in contrast with the Derbyshire and Kentucky deposits there is an entire absence of barytes. The only other accessory mineral of any importance is calcite, which is never abundant and in most of the veins is quite a rarity. While most of the veins can be depended on to carry fluorspar steadily for long distances (in some cases...
Page 159 - In a matrix of fluorspar, quarts;, and caleite, with galena and a little blende. On the northwest flank of Rotherhope Fell the vein is traceable for at least 2 miles, and to the northeast runs across the South Tyne River to join the Dowpot vein. The fluor is of good quality, but is closely intergrown with the other minerals, so that pure lump is an exception. The best level for spar is at the Whin Sill, here found under the Single Post limestone ; the Scar limestone is also a good producer. The main...
Page 71 - ... western Kentucky, but centering in Hardin County, Illinois, the availability for optical use of the product from this region has heretofore been neglected, and the United States has been dependent upon foreign sources for its material, which came largely through the hands of German optical dealers.3 In connection with a recent geological survey of the fluorspar deposits of southern Illinois, the State Geological Survey with this application in mind has determined the presence of optical fluorite...
Page 159 - Co. had several of these waste heaps hand picked for "lump" spar, and many thousand tons were taken away, but a much greater ituirmnt still remains untouched. The spar is mostly in small blue "lump" and "snivel." and is hard and clear. It was used for fluxing purposes. Certain layers in these waste heaps consist almost wholly of fluor "gravel...
Page 59 - The chief purpose of the fluorspar is to render the slag sufficiently fluid so as to hasten the transfer of heat from the flame to the steel beneath the slag, which reduces the time or duration of the heat, and that the slag may flow from the furnace without difficulty at tapping.
Page 156 - It must tie added, however, that the surface waste heaps which have been the mainstay of the Derbyshire output for the last six years have now been well picked over and are no longer of serious account for future supplies.
Page 129 - This inclined adit tunnel showed no ore to a point about 10 feet above the Gila River or 50 feet below the main workings, which was as far as it could be examined on account of accumulated mine seepage. The winze was...
Page 173 - Fohs, FJ, Fluorspar deposits of Kentucky, with notes on production, mining, and technology of the mineral: Kentucky Geol. Survey, Bull. 9, 296 pp., 1907.

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