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By Y. Dardel

Since the first determination of Dumas1 in 1880, many authors have tried to measure the solubility of hydrogen in solid aluminum, or at least the amount of dissolved gas in it. However, the interpretation of the results which have been obtained is still difficult. Sieverts? then Baukloh and Oesterlen,a during their gassing experiments could not determine any solubility of hydrogen in solid aluminum. On the other hand, Portevin, Chaudron and Moreq4 leaving the determination of the hydrogen solubility beyond the scope of their experiments, measured only the amount of gas that they could extract by high voltage positive ion bombardment and found up to 151 cm3 of gas per I00 g of metal. Winterhager,6 by repeated vacuum extraction during severe cold rolling, extracted up to 161 cm3 per 100 g. In both series of experiments, the extracted gas contained chiefly hydrogen with a small amount of nitrogen, carbon monoxide, carbon dioxide and methan. Later, Schmidt and von Schweinitze as well as Chaudron and Moreau7 showed the importance of the adsorbed layer of hydrogen, the extracted quantities being proportional to the surface and not to the weight of the sample, when its cleaning was not perfect. In earlier experiments, Steinhausers extracted from more massive samples nothing but a little amount (< 0. 5 cm3 per I00 g) of hydrogen, carbon monoxide and methane. Thus, according to these experiments the quantity of dissolved gas is probably very small and the effect of the surface could falsify the results of the extraction. However, owing to the care taken by Chaudron and his coworkers, it was clear that all the hydrogen extracted could not come from the superficial layer, or that the links which bound hydrogen to the surface were so strong that the usual method of cleaning could not destroy them. After the main parts of the experiments reported here had already been carried out, Eborall and Ransley9 published the results which they obtained with an analysor having an accuracy of 0.03 cm3 per I00 g, while that of the usual apparatus was only about 0.2 cm3 per I00 g. During all their experiments the adsorbed layer would have been a difficulty, for the value of the adsorbed hydrogen was approximately equal to that of the dissolved amount. Table i—Amount of Adsorbed and Dissolved Hydrogen (After Eborall and Ransley) Extraction Hz Adsorbed „ h2 dissolved Temperature Calculated Extraction OCcma 500 0.057 0.050 600 0.062 o.096 Since always keeping the same adsorbed layer is very difficult, an error in the correction for the adsorption can be made when using the apparatus of. Eborall and Ransley, as well as the earlier apparatus.

Jan 1, 1949

By M. A. Steinberg, J. Wulff, R. Kamm

In a previous paper1 from this laboratory, the development of a lead grid method for exploring the distribution of strain and density within metal powder compacts was described. In that work thin lead foil with rectangular holes cut at regular intervals was inserted with the powder fill, the arrangement pressed and then radiographed to permit measurement of the deformation of the lead grid. Densities at each grid element obtained in this manner were plotted as a function of the die dimensions. From such plots it was found that the densest part of a compact pressed from one side (the top) is at the top outer region and the least dense at the bottom outer region of the specimen. The axial density maximum occurs more often nearer the bottom than at the top. As a result of such exploratory measurements, it appeared reasonable to conclude that variations in density could be attributed in the main to die wall friction. Thus compacts of large diameter appeared relatively uniform in density except where the die fill had been uneven. Finally it was found that lubrication of the finely finished die cavity contributed more to magnitude and uniformity of density within the compact than interparticle lubrication. Since publication of the above results, it was found that circular-hole grids could be more accurately made and, when deformed within the powder, more readily measured and analyzed. Much of the former work was repeated and new results which include the effect of lubrication, compact height, pressure, speed of pressing and vacuum pressing are reported in the present paper. Circular-hole Grids and Analyses OF Radiographs Commercial lead sheet 0.008 in. in thickness was used in all the work reported. The 0.0938-in. diam holes were punched in the sheet on 1/8-in. centers to an accuracy of 0.001 in. The finished grid used contained eight or more holes in a row and from I to 24 rows. The lead sheet was clamped between two pairs of brass strips bolted to a small milling machine table which was itself bolted to a bench in correct position near a vise which held the punch. Travel of the lead grid in two dimensions was controlled by two steel lead screws calibrated in 0.001-in. divisions. A stripper plate was used on the punch to avoid distortion of the lead foil. A high carbon-high chromium (chrocar) one-piece steel die was used throughout the work. The die cavity was 1.125 in. in diam and the clearance between plungers and die wall was 0.001 in. The die was also used for pressing from both ends with two long plungers. Finally, lapping of die and plungers gave a surface whose rms value On an Abbot profilometer was 5 micro-in. The die walls and plungers were, except where otherwise noted, lubricated with a stearic acid suspension in benzene. This was put on in multiple layers and allowed to dry before filling the die.

Jan 1, 1949

By A. L. Engel

Included in the program of the Rare and Precious Metals Station, Metallurgical Division, Bureau of Mines at Reno, Nev., are investigations of treatment methods for ores representative of various mining districts throughout the country. The samples received for this work may come from areas only recently explored or from newly discovered ore deposits in older mining districts. The present investigation deals with a case of the latter type, the. ample having come from a section that has a past record of considerable precious. metals production. The application of current treatment methods to this type of ore seems to offer excellent possibilities of satisfactory economic results. Definite identification of the silver mineral in this ore asthe chloride cerargyrite, AgCl, adds considerable interest to, the investigation, as in many cases where silver occurs in comparatively small amounts in an ore it is not possible to identify the particular mineral carrying the silver or else it is contained in or combined with other more common minerals. Cerargyrite is the "horn silver" of the bananza period and is mentioned in many accounts of pioneer mining of high-grade ores The occurrence of this mineral in finely disseminated form it a low-grade ore is believed to be unusual. The sample investigated was obtained from the&apos; Bullfrog District neat Beatty, southwest Nye County, Nevada. The ore contained 16.7 ounces of silver per ton of ore, 0.007 ounce gold, and 0.32 percent copper in a silicious gangue, with accessory minerals, including iron oxides and scorodite; the hydrous iron arsenate.

Jan 1, 1949

By J. B. Murdoch, John G. Jackson

The many mechanical, geological, and economic factors which influence the planning of a directional drilling program are thoroughly discussed and analyzed. It is demonstrated that the planning of a directionally drilled multiple-well artificial island location is a complicated undertaking and that it is imperative that complete planning and engineering analysis be undertaken before the program is started. Complete planning is profitable because all of the factors influencing the directional work are in general interrelated and many time compromises have to be made before a harmonious program results. The engineering control necessary to accomplish a complicated directional drilling program is outlined. Various means by which engineering control can be increased, such as cylinder drilling specifications, are given. A hypothetical example is developed for a complete offshore artificial island of ten wells to demonstrate the more important factors involved in the planning. Included with this example are special charts and tables which make more rapid the drafting of directional drilling proposals and maps. Introduction A petroleum engineer must consider many and varied factors when planning a long range directional drilling program for an offshore or inaccessible location on an oil structure. The basic principles of direc- tional drilling planning and operation must be reconciled with his company&apos;s drilling practices, and frequently special concessions to standard drilling and production practices should be made. The field techniques and tools used in directional drilling are well known and widely used, but the deliberate, careful planning of a complete directional program is in the main a recent innovation. This development, plus the increased demand for oil resources and the consequent exploitation of inaccessible structures and offshore locations, has placed this problem before many engineering departments for the first time. Directional drilling programs of a very complex and difficult nature have been successfully carried out in the Mid-Continent and Pacific Coast regions. The planning itself of a directional drilling project, however, has not had the careful analysis it deserves and we can reasonably expect widespread future progress along thesc lines. Data and experience gained in these programs by the directional drilling service companies and the oil producers have been studied with the objective of giving the engineer a better conception of the factors which govern the various steps in planning a series of directional wells. The newest engineering procedures are the result of recent careful analysis of years of directional drilling work accomplished under the supervision of directional drilling service companies working with the oil companies. The purpose of this paper is to illustrate

Jan 1, 1949

By Robert J. Hundhausen

The Young America lead-silver-zinc mine in Stevens County, Wash., was investigated by the Bureau of Mines during parts of 1946, 1947, and 1948. Results of the investigation are described herein. The mine is 1/4 mile northeast of Bossburg, Wash., the nearest railway station. An excellent paved highway (No. 22) connects Bossburg with Colville, Wash., 23 miles to the south. The property was located in October 1885. It is credited with a production of 2,178 tons of shipping ore since 1901. The shipping ore averaged 7 percent lead, 7.7 percent zinc, and 16.1 ounces silver per ton. The property is under lease and option to Walter E. Morris and Perry Leighton of Colville, Wash. The deposit crops out on a steep limestone bluff overlooking the Columbia River. The country rock is a highly metamorphosed, brecciated, marbleized limestone (Northport formation).

Jan 1, 1949

By J. H. Hamilton, J. R. Lewis, J. C. Nixon, C. L. Graverson

Recently there has been much speculation concerning the advantages of using oxygen enriched air or pure oxygen in pyrometallurgical processes. The advantage of using oxygen in the iron blast furnace and elsewhere in ferrous production metallurgy has been given careful consideration and, as a result, several experiments have been tried and a number of papers have recently appeared on this subject.1,2 The use of oxygen in nonferrous smelting likewise poses interesting problems, therefore any experimental data obtained in this area should likewise be of general interest.3 Ashcroft4 in 1933 claimed to have obtained improved results when copper concentrates were roasted in pure oxygen. However, his paper gives neither data nor experimental details. A few years ago a research program was started in this laboratory which had for its objective the determination of the mechanism of oxidation of metallic sulphides under varying conditions. To date we have studied the oxidation of galena,5 sphalerite, and chalcocite. It is a well known fact that copper sul-phde minerals are oxidized slowly by weathering agents, so that the sulphides of copper which find their way into a tailing pond are gradually changed into water-soluble and acid-soluble compounds. Commercially, the oxidation of copper sulphide minerals is accomplished by roasting them at elevated temperatures in air using a suitable (usually multiple hearth) roaster. Most copper smelters are equipped with such roasters. In this phase of the study we were especially interested in determining the effect of temperature on: (I) the air oxidation of chalcocite and (2) the oxidation of chalcocite using commercial oxygen. The amount of sulphur removed as sulphur dioxide, the percentages of water-soluble copper, and of acid-soluble copper were determined for the air oxidation tests. In the tests using commercial oxygen, the percentages of sulphur dioxide, water-soluble copper, acid-soluble copper, water-soluble sulphur and acid-soluble sulphur were determined. For these experiments the temperature was varied from 250 to 700°C. Experimental Preparalion of Chalcocite (Cu2S) Natural chalcocite is not pure, Minerals such as bornite, covellite, and chalcopy-rite may be present. It was decided, therefore, to prepare some chalcocite in our own laboratory. An intimate mixture of sulphur and hool divided metallic copper in the ratio of 4 g of copper to I g of sulphur was prepared. TO this was added a slight excess of

Jan 1, 1949

By C. E. White

History The Con-Rycon mine is situated in the Yellowknife mining district, North West Territories, 608 air miles north of Edmonton, Alberta. The earliest reported discovery of gold in the area was made in 1898 but no extensive exploration occurred until 1928. The birth of Yellowknife as a mining community took place in 1934 with the staking of the Rich group and subsequent shipping of 16 tons of high grade ore. The Giant group was also among the claims staked in 1934, and later staking showed a tendency to close the gap between these two properties. In the fall of 1935, the A.Y.E. claims, situated south of the Giant group, were staked to cover a discovery of the Geological Survey of Canada and, after general release of the Survey&apos;s information, the adjoining ground was staked. These claims included the Con, Negus, Meg, and Kam groups. In 1936 four lapsed claims were re-staked as the P and G group and later acquired by Rycon Mines, Limited, controlled by the Consolidated Mining and Smelting Company of Canada, Limited. The Con and various adjacent groups owned by Cominco are now operated with the Rycon under one management. Surface trenching on the Con property started in 1936 and, during the fall and winter of 1936-37, a 60- foot 5 ft. by 9 ft. inclined prospect shaft was sunk. The encouragement provided by the shaft and diamond drilling in 1937 led to the decision to establish a mining plant, and in August, 1938, the 100-ton cyanide mill produced its first brick- the first gold brick poured in the history of the North West Territories. In November, 1938, the mill was enlarged to a 175-ton capacity and operated at this rate until 1941, when refractory ore was encountered. This situation was met by the installation of flotation and roasting units and, at the same time, the milling capacity was increased to 300 tons daily. Labour shortages and Government restrictions forced a reduction of output and in 1943 milling was suspended while mine development continued on a reduced scale throughout the war years. The present full-scale of operations was resumed in 1946 and the total production to the end of 1948 amounted to 288,853 oz. gold and 72,347 oz. silver.

Jan 1, 1949

By R. H. Nicholas

Shuttle cars have undeniably proved their worth as a means of transporting coal underground; however, several factors have arisen in connection with their possible improvement. This report .discusses the effect of shuttle cars that employ rough-tread and smooth-tread tires on mine roadbed, the amount of dust thrown into suspension by the use of such tire treads, and the service rendered by each type of tire. Involved, also, in this study are observations on the use of different amounts of calcium chloride on the haulageways.

Jan 1, 1949

By H. C. Cooke

"The Part of the Eastern Townships dealt with in this paper is shown in the accompanying figure. Each rectangle represents one of the topographic maps published by the Department of National Defence on a scale of one mile to one inch. Each sheet covers an area approximately 24 miles long and 17 miles wide, or slightly more than 400 square miles. The north-western part of the area figured, comprising the Upton, Aston, Becancour, and the two unnamed sheets, (Three Rivers and Yamaska), together with most of the Lyster, Drummondville, and St. Hyacinthe sheets, is largely covered by clays and sands deposited in interglacial and post-glacial time in the Champlain estuary, so that outcrops are widely scattered and in-formation is correspondingly sketchy. In the remainder of the area figured, comprising more than 4,000 square miles, outcrops are reasonably numerous and have been mapped on a scale of one mile to one inch, and the structure is moderately well understood.The Eastern Townships was an area of intense orogenic disturbance, apparently beginning late in the Cambrian or early in the Ordovician, and continuing till well on in the Devonian period. During this long period, which may have lasted for a hundred million years or more, the area was subjected from time to time to intense thrusts from the east and southeast. Each of these caused folding of the rocks, accompanied by faulting, raised parts of the area above sea-level, and presumably created ranges of mountains. Long periods of erosion cut away the mountains and reduced the area nearly to sea-level after which subsidence carried it below sea-level, and permitted further sediments to accumulate before the next thrust initiated the next cycle.The first of these movements, as stated, appears to have been in late Cambrian or early Ordovician time. The group of rocks known as Caldwell was folded and, south and east of the town of Asbestos, was thrown into great drag-folds before deposition of the next overlying series, termed the Beauceville, began. Unfortunately, the date of this orogeny is very imperfectly known, because both series of rocks have been so crushed and sheared that almost all fossil remains have been destroyed. Graptolites, found in one place in slates generally considered Beauceville, give that series a tentative Middle Ordovician age. In the Caldwell rocks, which underlie the Beauceville with great unconformity, no fossils whatever have yet been found. Thus, if the Beauceville rocks are correctly dated as mid-Ordovician, the best that can be said of the movement folding the Caldwell is that it took place at some time before Middle Ordovician."

Jan 1, 1949

By Charles Trotter

An instrument has recently been developed for determining the inclination and azimuthal direction of boreholes. This instrument is known as the Tro-Pari Instrument and is the invention of C. Trotter and G. Pajari of Sudbury, Ontario. Description The instrument is characterized by a unit mounted in gimbals and provided with a clockwork mechanism to clamp a compass to indicate azimuthal direction and simultaneously to clamp the unit in its plumb position to indicate inclination (Fig I). By means of a timing ring suitably calibrated in 5-min divisions, the unit may be set to lock after a lapse of time sufficient to allow the placing of the instrument at the desired point in the drill hole where readings are to be taken. The maximum time Lapse obtainable with the instrument designed for use in EX or AX size holes is I hr 30 min which is considered to be ample time to lower to the greatest depths that may be drilled with this size of equipment. Larger sizes could be developed for larger diameter holes such as BX and NX sizes or the larger oil-well sizes and a correspondingly greater time lapse could be provided for. Up to the present time only the EX-AX size has been built. Operation Assuming a borehole is to be surveyed at 1000-ft depth and assuming it will take 30 min to lower the instrument to this depth, the timing ring is rotated through seven divisions which represent a time lapse of 35 min (5-min leeway) and is then returned to its zero position. This operation imparts energy to a spring which drives the clockwork mechanism. Simultaneously the compass needle is freed to swing to its magnetic north-south position and the encased mechanism is freed to hang plumb within a semicircular portion of the frame which is graduated in degrees after the fashion of a protractor. This semicircular protractor portion has a V-shaped notch at each degree division of its inner periphery. The instrument, now in its free position, is inserted in a bronze container made to suit the size of hole to be surveyed (Fig 2). Soft rubber washers are provided within the container to prevent undue shock. The container is connected to the drill rods with three 5-ft lengths of brass or aluminum alloy rods separating it from the steel rods in order to prevent distortion of the magnetic field. The assembly is then lowered to the desired point where readings are to be taken and is allowed to remain at rest until a period of time has elapsed slightly in excess of the time for which the timing ring was set. In the example cited above, when the 35 min has elapsed the compass needle is locked in its north-south position and the protractor locking pin is extruded and locks in the V notch opposite its plumb position. The device may now be removed from the borehole and it will remain in this locked position in spite of jarring or shak-

Jan 1, 1949

By Kenneth M. Smith

The kaolin deposits of Aiken County, South Carolina (fig. 1), have been worked continuously since 1852. It has been long known that the deposits contain a high percentage of&apos; alumina and that large reserves exist. These facts led to the early selection of&apos; this area for examination in the search by the Bureau of Mines for high-alumina clays. An exploratory program was started by the Bureau, and drilling was carried on from. June 27, 1942, to October 31, 1942. The kaolin-bearing district occupies an area approximately 25 miles long and 11 miles wide, running northeast, with its center at Aiken, S. C. (fig. 1). Within this district, a triangular area bounded by Horse Creek, Silver Bluff Road, and Hamburg Road was roughly prospected by boring 43 machine and 12 hand holes. As a result of the data obtained, a final smaller area was chosen for more systematic prospecting. This area is bounded by Pine Log, Tewkesbury, Silver Bluff, and Craig Sawmill Roads and covers about 4,000 acres. Mineral exploration agreements covering 11,272 acres were signed by 35 property owners, and 11,956 feet was drilled in 200 holes on these properties.

Jan 1, 1949

By C. E. Sims, G. A. Moore, D. W. Williams

During the past several years the steel casting industry has made studies of heavy castings in which the test bar has been taken from heavy sections rather than from attached or separately cast coupons. It has been noted that the ductility properties of these heavy sections are often lower than those normally expected. Such lowered ductility is usually accompanied by a spotty test bar fracture and the ductility values often can be greatly improved if a low-temperature aging treatment is given to the casting. A loss of ductility of this type is considered "abnormal," since it is not accompanied by an increase of tensile strength or hardness, and "temporary" when the ductility can be restored by aging, The cure of such an abnormal condition represents a real improvement in the quality of the steel. Some hundreds of previous investigations, largely qualitative in nature, have established beyond reasonable doubt that hydrogen is normally present in newly manufactured steel and that this gas, in small amounts, can cause a temporary ab- normal loss of ductility. The commonly observed association of high gas content and low ductility has given strong evidence for the presumption that hydrogen, possibly assisted by other gases, is the primary cause of the low ductility observed. Accordingly, the Steel Founders&apos; Society of America has, since Nov. I, 1944, sponsored investigations at Battelle Memorial Institute whose primary objective is to obtain quantitative information on the relation of the amount of hydrogen and nitrogen in steel, together with associated methods of steelmaking and treatment, to low-ductility effects and porosity. In order that these investigations might proceed on a quantitative basis, hydrogen analyses of a precision considerably higher than any previously reported in the literature were necessary. &apos;The method chosen was selected entirely on the basis that it had the highest probability of freedom from uncontrollable errors and will be described in detail in another publication.&apos; Briefly, the method used consisted of the hot extraction of solid pieces of steel weighing from 45 to 50 g in a highly evacuated quartz tube maintained at 1050°C (1925°F) for a period of approximately 40 hr. The greatest precautions were taken to eliminate blanks and insure a sound gas-collection system. vacuum and temperature conditions were maintained automatically. Mercury-filled risers were used for the introduction of samples in order that the System could be degassed thoroughly in

Jan 1, 1949

By McHenry Mosier

The Anson Bette manganese mine, with two prominent manganese-bearing outcrops in schist, has attracted considerable attention for its variety of manganese minerals and its possibilities as a potential source of manganese. Little mining was done prior to 1925, when the present owner acquired the property, and operations since that date have been intermittent. Mine workings are open cuts with a maximum depth of 35 feet. The two outcropping ore deposits are irregular, pipelike bodies about 500 feet apart. As nothing was known of the grade or extent of mineralization in depth, four holes totaling 1,072.5 feet of bore Were diamond-drilled by the Bureau of Mines in the summer of 1943, with the results shown in figures 3 to 6. In.1945 a geophysical survey was run to map the magnetic anomalies in the manganese-bearing belt as a means of determining the locations of manganese deposits. Positive correlation of magnetite and manganese ore was not obtained.

Jan 1, 1949

By J. R. Thoenen

Occurrences of titanium, zircon, and other heavy minerals are widespread in Florida. Deposits concentrated as "heavy sands" by wave and wind action have been mined an or near Atlantic coastal beaches since 1916. An important inland concentration at Trail Ridge; .believed, to have formed along an ancient share line, was disclosed by preliminary investigations (1947) by the Bureau of Mines. This report describes investigations to determine the extent and grade of "heavy-sand" concentrations in other inland stabilized dune areas in the central and northeastern parts of the peninsular region of the State (fig. 1). Portions of the central highlands south of Trail Ridge and terraces and dunes in the coastal lowlands region, east and northeast of the ridge were investigated. Holes were drilled in 10 areas (see table 1 and fig. 2) along State and County roads and on private property. They were spaced 250 to 2,000 feet. apart to obtain a cross-sectional picture of "heavy-sand" content in the dune areas. These sections were generally placed in east-west directions normal to the general trend Of the peninsula to intercept one or more of the ancient shore lines in the various areas (figs. 3 to 13, incl.). A total of 433 drive piped and 333 jet holes were drilled, and 7,293 bulk and core samples were taken. Intermediate holes were placed at closer intervals when field analysis indicated 1 percent or more of heavy minerals present. All of the holes drilled and the analysis of samples that contain 1 percent or more of heavy minerals are listed in table 2. Profiles (figs. 14 to 20, inclusive) show the more favorable concentrations, which are irregular in outline and erratic in mineral content. The highest concentrations averaged 1.0 to more than 2.0 percent heavy-mineral content, but a few individual hole samples exceeded 3.0 percent in grade.

Jan 1, 1949

By J. B. Bassett, E. S. Rowland

The experimental work reported herein firas inspired by the publication of a paper by Grange and stewart, in which it was suggested that at low chromium contents the effect of this element on the Ma point was greater than at higher chromium contents, It was argued that, if a small increase of chromium in solution in austenite caused a sharp lowering of the M, point, it might lead to an explanation of occasional unsolved stress cracking of SAE 52100 during heat treatment. Commercial hardening is carried out at temperatures of incomplete solution, leaving carbides available to enrich the austenite during any inadvertent increase in temperature, such enrichment of the austenite in chromium content would lower the M, point nearer room temperature where cracking is more likely to occur. According, it was decided to investigate the effect of chromium, in quantities between o and 2 pet, on the M, point of commercial steels. Fig I summarizes the data available on chromium steels. For purposes of comparison, the M, temperature values were corrected by means of the Grange and Stewart formulas to (I) Hypoeutectoid compositions: 0.50 pct carbon and 0.80 pct manganese (z) Hsereutectoid compos-sition&apos;: 1." pet carbon and O.35 pct manganese. Only the steels having compositions reasonably close to these corrected values were included, because large adjustments inevitably introduce increased error such as are experienced in using the formula. The straight lines of Fig I were drawn by the authors. These data obviously do not settle the question Of the effect Of chromium On the Md Oint, particularly at low chromium contents. While it is fairly well established that chromium causes the M, to be lowered when present in quantities of I pet Or more, Grange and Stewart1 have suggested that in small amounts (less than 1 pet) it is more effective in lowering the Ma point, while Klier and Troiano2 have suggested that in small amounts it is less effective in lowering the Ma point. Payson and Savage3 concur with Klier and Troiano and further suggest that the effect is not linear at these concentrations. Rose and Fischer4 report that small amounts of chromium actually raise the Ma point of a 0.20 carbon steel. Material Two series of 35 Ib induction heats were melted for this work, the analyses of which are given in Table I. One series was aimed at 0.50 pct carbon and 0.80 pct manganese with chromium additions in 0,25 pet increments from o to 1.5 pct with a single heat at 2.0 pct Cr. This series was considered necessary because the commercial heat treatment of SAE 52100 does not generally introduce more than about 0.60 pct carbon in solution in the austenite. The high

Jan 1, 1949

By Paul T. Allsman, E. W. Newman

Trenching, sampling, and core drilling in Stillwater and Sweetgrass Counties, Mont., by the Bureau of Mines have delimited over 5,000,000 tons of chromite ore containing more than 20 per cent chromic oxide. The Benbow and Mouat-Sampson mines have been developed and are fully equipped for mining and milling 500 tons and 2000 tons a day, respectively. Introduction The Montana chromite deposits were the first to be explored under the Strategic Minerals Act of 1939. In June of that year, the Bureau of Mines started exploration by trenching, test pitting, sampling and diamond drilling, and completed the project in March 1943. The U. S. Geological Survey cooperated by mapping the geology and logging the cores. The project was to determine the extent and grade of the chromite ore and to indicate sufficient reserves to justify development and exploitation of the deposits for the national emergency. Exploration has indicated that the district contains the largest and most important reserve of chromite ore in the United States. The Benbow and Mouat-Sampson mines have been developed and a 500-ton concentrating mill has been constructed on the Benhow property and a 2000-ton mill on the Mouat-Sampson property. Concentrates were produced from the Benbow mill three months after the attack on Pearl Harbor, when the nation&apos;s major chromite supplies from foreign sources were cut off. History It has been known for 50 to 60 years that some chromite deposits existed in an east-west belt along the north escarpment of the Beartooth Mountains about 25 miles north of Yellowstone Park, but nothing was known of their size and extent until the war demand of 1917 and 1918 stimulated the search. In those years two properties in the Stillwater region were actively developed, but no shipments were made. The Benbow property was located in 1918 by a local group. The property comprised seven claims along the strike at the east end of the belt. An adit was driven several hundred feet on the Eclipse claim. The seven claims were sold to the Chromium Products Corporation of Livingston, Mont., and were subsequently patented. In 1929, an eastern group obtained an option, installed some equipment, and erected several log cabins. The "crash" in the market in 1929 caused the operators to drop their lease, and the property remained inactive until 1939, when the Bureau of Mines began its exploration. Fourteen claims were located on the Boulder River in 1918 and subsequently patented by the U. S. Chrome Corporation.

Jan 1, 1949

By Lawrence B. Wright

The Republic district, Washington, is of new interest because of the discovery of new gold-silver ore within a unique structural pattern. The camp was revived in 1937 fol1owing installation of a plant to treat low-grade disseminated ore at Knob Hill and further stimulation followed discovery of "cross vein" breccia ores in 1939. Previous writers 1-2 ascribed the quartz veins to a latite porphyry stock, but are in disagreement as to its precise location and extent. This study leads to the conclusion that the ores have a more profound parentage linked to a broad system of thrust faults and folds, the mechanical origin of which is related to a southward trending (Sanpoil) syncline connecting with the Lewis and Clark zone of shift described by Billingsley and Locke3 in 1939. The Republic anticliue and a cross anticline recumbent against Cretaceous granodiorite. and involving some 4000 ft of Eocene andesite flows and early Miocene lake beds, localize the ores, mainly along the east flank, in a series of openings simulating drag folds and steeper than the folded flows. These broad structural features no doubt reach deeply into the basement rocks, where at appropriate crossings and junctions it is suggested that heat effects gave rise to ore-making materials, including, in this instance, intrusive breccias that later were mineralized, and comprising the broader bodies of new ores. The breccia ore is seen crosscutting the earlier narrow quartz veins with a welding of the two at junction areas by a second surge of ore minerals. The ore mined and developed since 1937 equals district production from 1896 to 1937 The ores are typified by cherty quartz, adularia and some barite, with fine pyrite and marcasite, polybasite, pyrargyrite, tetrahedrite and gold. Selenium is present, possibly with gold, as a normal selenide. The disseminated ores, as well as the vein and breccia ores, are localized principally in one 500-ft flow (Knob Hill andesite), which has been traced around the crest of the low northward-plunging Republic anticline. The gold-silver ratio in the earlier narrow veins is about I to 4 and in the disseminated and breccia ores, I to 7. The latter higher silver ratio is deemed to reflect the character of the second surge of mineralization. Sills and dikes of the Columbia River (Miocene) basalt cut the folded structure and ore, thus placing the mineralization in the middle Miocene. Introduction The Republic district of north central Washington is of new interest because of the discovery, development and extraction of new gold-silver ore; also, because of a unique local structural pattern believed to be integral with the broader tectonic mechanism of the continental framework. This district had 40 years of modest rating following its discovery in 1896. Its narrow ore bodies, complex mineralogy. and early inadequate metallurgy, together with the apparent bottoming of ore near 1000 ft, limited production to 300,000 oz of gold and 1,000,000 oz silver between 1897 and 1914. The camp was then reduced to lease Life until 1937, when the gold price increase of 1933 to $35 per ounce

Jan 1, 1949

THE Bergbüchlein and Probierbüchlein occupy a unique position in the literature of mining and metallurgy, for, they are the first printed books on any aspect of the two related professions. The first printed book on any subject has an allure that may not be entirely warranted by the strict historical significance of its contents. Among the books of the first century of printing there are very few that contain information that was new at the time of publication. Much&apos; of what they recorded had been previously circulated in manuscript form. Printed books are nevertheless of great value because they mark the time when the author&apos;s words, free from errors-or at least with the same errors-became available to large numbers, of readers, who thus could easily and cheaply acquire a common background for their future work. Moreover, though there is occasionally some doubt as to the exact year of publication&apos;(as in the case of the present works), it is generally easier to date a printed work than a manuscript, and thus to provide a fixed coördinate in history. The Bergbüchlein, "The Little Book on Ores," is the first printed work in the field of mining. It is an introduction to mining geology, which means that it was not addressed to the practicing expert but was intended to rouse the interest of beginners in the various aspects of a future vocation. It touches on the theories of the generation of ores, introduces and defines some of the most frequently encountered technical terms of the profession, and indicates what knowledge and tools are required for successful prospecting and mining. It also describes the ores of the seven most important metals. For those parts that deal with theory the author accepted uncritically the traditional teachings of the alchemists and the astrologers; his hints on where to find promising ores are based partly on superstition; but, there is enough factual,

Jan 1, 1949

By E. J. Matson

The Little Castle Creek chromite deposit was examined in February and May 1941, respectively, by W. O. Vandenburg and O. H. Metzger, engineers of the Bureau of Mines. The Federal Geological Survey started a magnetometer survey of the area in November 1940 and completed its work during April and May 1941. Field work by the Bureau of Mines was conducted during May and June 1941. The purpose of the Bureau of Mines investigation was to search for a continuation of the chromite mineralization. The property at one time was the largest chromite producer in California.

Jan 1, 1949

By G. L. Oldright

The first Report of Investigations of the present series (No. 4562) was on the fundamental properties of lead compounds, and the manner in which they set limits to the richness of lead products treated in the usual sintering-blast furnace units. These properties of the compounds were emphasized, as&apos; it was desired, also, to learn the limitations of smelting the same compounds in present ore hearth practice; the hearth has a competitor in these "usual" units, even with the rich lead feeds best adapted for the hearths. Operating conditions that were followed in older metallurgical processes, when rich products, were treated, were outlined. The second report of the series (R. I. 4563) was on the development of the ore hearths of the types now used in the Tri-State from the viewpoint of the features, functions, and dimensions of the earlier hearths that had been most changed. Experimental data, for both well and poorly desulfurized charges being considered, were given to show the relative changes in the sizes and compositions of the charges after they were added to the ore (Scotch) hearths. A general picture was given of the charge column and of the conditions prevailing there when the operation was satisfactory. In this third paper, the composition of the gases prevailing in the charge column at various elevations will be correlated with what has been learned of the nature of the charge column in order to trace the steps of operation by which lead sulfide is converted into metallic lead. The metallurgical factors that govern operation and the lines along which improvements may be made will be noted.

Jan 1, 1949