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By J. W. Bolton

PRODUCTION of sound bronze castings is a matter of great practical interest to users and manufacturers of high-grade non-ferrous engineering specialties. Although there has been much excellent research in this field, there still remains some confusion regarding the fundamental principles underlying production of really sound bronze. The literature of the past 20 years on this subject indicates that the prevailing opinion of metallurgists and foundrymen has been that unsoundness in bronze is due generally to oxidation. The following references are typical.

Jan 1, 1929

By Eugene A. Stephenson

The writer apologizes for presenting this very elementary analysis of one aspect of proration, but a search of the literature failed to disclose any concrete illustrations of the effect of various proration formulas upon the allowable oil produced by tracts of different sizes. Many engineers have doubtless made somewhat similar calculations and are fully acquainted with the results. The various allocation formulas that are in use are based on one or more of the following factors: (1) wide-open well potential, (2) potential through an orifice, (3) uniform well allowable, (4) acreage, (5) sand thickness, (6) bottom-hole pressure, (7) productivity index, and (8) volumetric displacement. Of these, the unrestricted potential formula, or open-flow test, and the uniform well allowable are commonly regarded by engineers as those least likely to give each producer his proportionate share of the oil or gas, as represented either by acreage or by sand thickness, or both, except when the wells are located on tracts of large size. Unless the mechanical equipment that may be used during the potential test and the method of taking the test are both specified, the net result of the potential formula is to practically force the operators to use special equipment and adopt special procedures prior to and during the potential test, so as to secure the largest possible allowables. Much ingenuity and skill have been devoted to this,problem, but the general effect is to permit excessive allowables for very small tracts, and stimulate unnecessary drilling. It is interesting to compare some of the high yields from the Wilcox horizon at Oklahoma City with each other, as an illustration of the effect of an allocation factor based solely on potential (Table 5). One of the glaring instances is a well on a ½-acre lease, which had produced, as of September 1936, at the rate of almost 3,000,000 bbl. per acre. This is at least twice as many barrels as could have been present under the property if the reservoir had consisted of a tank of oil 200 ft, deep and 56 acre in area. Numerous combinations of acreage, potential, bottom-hole pressure, sand thickness, etc., have been proposed and are in use in various fields.

Jan 1, 1937

Primarily, 1961 was a year for widespread application of tools and techniques which have become operational in the past several years • • • Raising --Raise climbers and climber raising techniques have been improved; narrow veins as low as 55° dip are now being mined from climber raises. Climber modifications include: larger motors, tighter radius curves negotiated, improved lubrication and new methods of stowing the climber during a blast. Climber raises are now ventilated in several ways: a 12-in. diam flexible vent tube behind the climber rail; a 6-in. diam pipe behind the climber rail (with fan); or a 6 to 8-in. diam drill hole along the axis of the raise. In hot raises, these ventilating techniques have resulted in more rounds per shift. When driving raises from crosscut and lateral development, mucking machine loading of raise rock is preferred over slusher ramp loading for the following reasons: a) faster set-up and teardown of climber facilities; b) easier access for climber maintenance, repair and loading of raising supplies; c) area at the bottom of the raise can be kept cleaner. Both wide and narrow veins are mined from 7 x 7-ft climber raises at Butte and at Republic, Wash. At Republic, climber rollers have been modified to support increased weight when driving 55°dip raises • Drilling-The new largebore, short-stroke push feed drills are much faster drilling than previous models and are most satisfactory in hard ground. Although reports on maintenance studies of the new drills are not yet available, increased steel and bit wear and breakage, and increased drill maintenance are seen as potential problems. Mines in Montana and Idaho continue to test rubber-collared drill steel. The fabricating methods used are successful but advantages in increased steel life have yet to be proved. Underground applications of down-the-hole drills continue. Drilling speed and accuracy are reported as the outstanding advantages. Manufacturers are now hopeful of making drills which will operate in any direction. Present applications are for ventilation holes (to 8 in. diam) for climber raises, holes for hydraulic fill distribution, drain holes and "predrilled" raises. Good drilling accuracy has been reported to a depth of 200 ft. Cutting holes in drifting is seen as a future application

Jan 2, 1962

THE Council of the Geological Society of America has named its gold medal after R. A. F. Penrose, Jr., who recognized the need of such an award and supplied the endowment. The medal is to be awarded for achievement in pure science and may be given to a worker of any race or nation. Mr. Penrose, whose own professional work has been mainly in applied geology, had previously established a medal fund for the Society of Economic Geologists. This was awarded to T. C. Chamberlin at the meet-ing of that Society at Cornell University in 1924. The new medal is to be given on the recommendation of the G. S. A. Council, but not necessarily every year.

Jan 4, 1927

By E. N. Pennebaker

The concept of "unitization" comes from the petroleum industry. Of this, Campbell says: "Unitization is the process whereby the owners of adjoining properties pool their reserves and form a single unit for the operation of the properties. The revenue from operation of this unit is then divided in accordance with the basis established in the unit agreement. "The purpose of such an agreement is to produce the reserves more efficiently and thus to increase the profit to every participant."'

Jan 8, 1973

By Robert Mehl

IT is generally understood by workers in the field of the crystal struce ture of metallic alloys that terminal solid solutions are of two types, the substitutional and the interstitial. In reviewing the literature, the work of Weiss1 on the crystal structure of the alpha copper-tin alloys wa-encountered, in which a new type of terminal solid solution was proposed. In brief, Weiss' findings showed that the density of the alloys calculated from the side of the unit face-centered cube on the assumption of simple substitution-that is, with four atoms to the unit face-centered cell-was much higher than the density measured directly. It was suggested that the assumption of four atoms to the unit cube is not valid for these alloys, and that each unit cube contained less than four atoms; in other words, that one tin atom replaces more than one copper atom, leaving some atomic positions unoccupied. Such a structure, if verified, would have far-reaching significance in the study of the crystal structure of metallic alloys. It would indicate a complexity in terminal solid solutions not hitherto suspected and might encourage work leading to the discovery of other alloys of the same type, and perhaps to types intermediate between it and the two recognized types. It is of importance, therefore, to reinvestigate these alloys with respect to the type of solid-solution structure obtaining therein.

Jan 1, 1929

By Stanley M. Kaplan

As we all know, the electric-furnace operation consumes practically 100 pct cold steel scrap. This is in contrast to the operation of the open-hearth furnace, in which 40 pct or more of the charge may be hot metal. The problem of quality of scrap for the electric furnace is really twofold, and in the interest of simplification may be described under two headings: (I) physical specifications, (2) chemical composition. Shipment of electric-furnace scrap to meet required physical specifications is a relatively easy task. The scrap dealer is accustomed to preparing material to certain sizes and shapes. His employees readily execute orders when they are given in terms of length, width and thickness of the material to be loaded.

Jan 1, 1947

By T. A. Rickard

In a previous paper (ante, p. 411) some description was given of the occurrence of the auriferous alluvium, extensive deposits of which lie among the highlands of the province of Otago, New Zealand. The present paper will describe some of the methods by which that alluvium is exploited. The alluvial mining of New Zealand is not yet hindered by " debris legislation." The mines are for the most part situated in a country of little agricultural value, and large rivers with rapid currents act as tailings conveyors. In time, however, steps will have to be taken to restrict the discharge into the Clutha of the tailings which are slowly raising the river-bottom. The methods of California have been followed in Otago with such alterations as peculiar local conditions require. The distinctive feature of the alluvial mining of Otago is the prominence given to the hydraulic elevator. The all-important factor in this form of mining is the control of an abundant water-supply at a suitable height above the level where it is to be utilized; and in this respect the gold-fields of the south island of New Zealand are most favora-

Jan 1, 1893

By Wilford Stork

CERTAIN influences of oxygen on iron have been known for many years and it has always been considered one of the worst enemies of the iron and steel founders. Nobody had a good word for it, hence little was done to make use of this oxygen. In all the fields of foundry practice, the desideratum was "melt without oxidation of the metal." In the consideration of the influence of oxygen on cast iron, we must not confuse this condition with oxidized iron caused by poor melting conditions, due to a high bed, heavy charges, low coke ratio, excessive melting rate, high blast, or poor charging. It is admitted that oxygen absorbed by iron melted under these conditions has a deleterious effect on the properties of the iron. The writer has had experience both in the melting under such poor conditions and in remedying these bad conditions and considers the product far inferior to iron melted under normal conditions. As stated by Dr. Richard Moldenke,1 such iron has a higher melting point and high combined carbon, is sluggish, and contains slags and oxides in solution in the liquid, causing slag inclusions and gas occlusions, thus producing defective castings. This oxidized condition cannot be counteracted or removed by any of the known deoxidizers; it can be remedied only by proper melting conditions. Such iron is really burned, whereas the iron considered in this paper was melted under normal conditions with moderate blast, correct bed height, light charges of iron, and low coke consumption and is not in this category at all. In 1914, the late J. E. Johnson, Jr., startled the metallurgists of the world when he published his results on the advantages of oxygen on cast iron.2 His work is so convincing and so logical, in spite of the common and well-established notions on the subject, that nobody has been able to refute a single argument. Such an eminent authority on iron and steel metallurgy as Prof. H. M. Howe has accepted the work in all its details in his latest book3 The work of J. E. Johnson, Jr., has revolutionized

Jan 6, 1919

By John V. Beall

Many months ago, the ME staff began thinking about what to put on the February cover of the Centennial Commemorative issue. We have considered photographs of mines, equipment, symbolic artwork and various collages. Our theme is "the next 100 years in mining" and the cover ideally should convey a related message or idea. All of us are convinced that there are many exciting technical changes that will be coming. But even so, we decided that, in our opinion, the engineer is the most vital factor. For this reason we chose to put a man on the cover of this issue. At first it was going to be the face of a man with whom each member could conceivably identify himself. It was one of the Bobs on our staff (we have four) who came up with the thought that since it's the future we are talking about, we should have a young man's or a student's face. Of course we firmed up our idea at the ninth hour, and it was too late to canvass the mining schools. However, by a stroke of luck, we were rapping with a group of University of Arizona students on the terrace of the Pioneer Hotel on December 7, 1970, and met Dave Bolles.

Jan 1, 1971

By J. E. Willson, N. K. Bohidar

An evaluation of internal stress distribution based on photoelastic studies and destructive testing of simulation models shows that pillar failure is a function of the internal stress distribution, and that stability can be changed by altering the internal stress pattern. Induced stresses in three-dimensional epoxy disks subjected to uniaxial forces were evaluated by photoelastic studies. Stress profiles across different sections perpendicular to the loading direction revealed two maxima for each profile. Based on the stress distribution for the entire column, an attempt was made to explain pillar spalling and the hour glass pattern of failure in a mine pillar. For maximum stability and optimum design of mine pillars, it is necessary to consider the external forces, the nature and distribution of induced stresses and the characteristics of the pillar material as determined in the laboratory. This paper summarizes the research done by N. K. Bohidarl and Ben L. seegrniller2 as partial fulfilment of the requirement for Master of Science degree in Mining Engineering, University of Utah. It is an evaluation of a study to determine the stress distribution in short columns in order that regions of high stress concentration in mine pillars may be found and their effect on pillar failure be ascertained. The ratios of the dimensions of the columns studied are representative of those found in mines located in flat-bedded deposits. The weight of the overburden generally constitutes the major external force. This force is calculated by taking into account specific weight and thickness of the cover. Determination of the distribution of this force on pillars may often require a complex analytical study. There have been many investigations of the strength

Jan 1, 1968

By Walter Crafts

Structural steels containing chromium have become widely used in the last 20 years. In the earlier part of this period the major applications were in chromium-molybdenum aircraft tubing and similar special high-strength steels. During the past 10 years there has been a notable expansion in the use of chromium-bearing steel for structural purposes when welding was utilized for fabrication. The chromium-bearing steels introduced by Saklatwallal (chromium-copper), Kinzel2 (chromium-manganese-silicon), and Schultz3 (chromium-copper) are being extensively used at the present time. General Effects of Chromium Chromium is so widely known for its carbide-forming tendency that its capacity to stabilize oxygen, nitrogen, and phosphorus is often overlooked. In low-carbon steels of the structural type these so-called secondary characteristics become more prominent. For this reason also, chromium in structural steel is definitely a toughening agent. As the carbon content is increased, the more widely known hardening effect becomes more evident. In low-carbon steels chromium increases the notched-bar impact strength substantially. This property persists at subzero temperatures and is utilized for low-temperature service in chromium-copper steel.4 Chromium also reduces any tendency to strain-aging embrittlement. In addition to improving the toughness of steels with the usual impurities, chromium has the specific property of counteracting the brittleness induced by high phosphorus.5,6 In steels low in carbon and alloys, chromium has an almost negligible effect on tensile strength, and a hardening influence is noticeable only in the stronger steels. The ductility of welds adjacent to the base plate is also improved by chromium, both in the range of foolproof welding steels having strengths of less than 80,000 lb. per sq. in. as well as in the higher strength steels.

Jan 1, 1939

By Walter Crafts

Structural steels containing chromium have become widely used in the last 20 years. In the earlier part of this period the major applications were in chromium-molybdenum aircraft tubing and similar special high-strength steels. During the past 10 years there has been a notable expansion in the use of chromium-bearing steel for structural purposes when welding was utilized for fabrication. The chromium-bearing steels introduced by Saklatwallal (chromium-copper), Kinzel2 (chromium-manganese-silicon), and Schultz3 (chromium-copper) are being extensively used at the present time. General Effects of Chromium Chromium is so widely known for its carbide-forming tendency that its capacity to stabilize oxygen, nitrogen, and phosphorus is often overlooked. In low-carbon steels of the structural type these so-called secondary characteristics become more prominent. For this reason also, chromium in structural steel is definitely a toughening agent. As the carbon content is increased, the more widely known hardening effect becomes more evident. In low-carbon steels chromium increases the notched-bar impact strength substantially. This property persists at subzero temperatures and is utilized for low-temperature service in chromium-copper steel.4 Chromium also reduces any tendency to strain-aging embrittlement. In addition to improving the toughness of steels with the usual impurities, chromium has the specific property of counteracting the brittleness induced by high phosphorus.5,6 In steels low in carbon and alloys, chromium has an almost negligible effect on tensile strength, and a hardening influence is noticeable only in the stronger steels. The ductility of welds adjacent to the base plate is also improved by chromium, both in the range of foolproof welding steels having strengths of less than 80,000 lb. per sq. in. as well as in the higher strength steels.

Jan 1, 1939

By Alec M. Crowell, Thomas D. Bailey

Although natural gas was first discovered in Northwest Arkansas in 1887, . near Fort Smith, Sebastian County, the literature contains very little information on the region, which is separated distinctly from the oil area of Southern Arkansas. For that reason this brief and concise report is a summary of developments from discovery to the present time. Northwest Arkansas produced 5,736,-ooo,ooo cu. ft. of natural gas during 1942, the trend of production having been generally upward over the past five years, as is shown in Fig. I. Since 1904 a reserve of 237 billion cubic feet of natural gas has been discovered in Northwest Arkansas, of which approximately 162 billion cubic feet have been expended, leaving a reserve of approximately 75 billion cubic feet available as of Jan. 1, 1943. A prolific new field discovered in Pope County Oct. 23, 1942, will add to the reserve of the region materially. Per well reserves, over-all, are unusually high because of the practice of multiple completion. As yet no commercial deposits of oil have been discovered in Northwest Arkansas. but the gas deposits have proved of immense value industrially, principally in the processing of zinc ore mined in the local area as well as that imported from distant states. With the war, new interest in the exploitation of the metallic ores of the region lends new significance to the gas reserves tabulated herein. Geological Discussion The region covered in this report comprises the Arkansas Valley from Pope County weslward to the Arkansas-Oklahoma state line as shown in Fig. 2. This valley is a westward trending structural trough with sharp-topped ridges and mesa-like mountains rising above the valley's undulating surface. It is bounded on the north by the Ozark Highlands and on the south by the Ouachita Mountains. The sedimentary beds of the Arkansas Valley are composed mainly of noniossil-iferous shales and sandstones. The rocks contain a high content of carbonaceous material and many coal beds are found in the region. The Gxed carbon ratios (ratio of fixed carbon to volatile combustible matter of surface coals) are very high and average about 80 per cent over the region covered in this report. Little or no calcareous material is present. Rocks of the Arkansas Valley are sharply folded, and igneous intrusive rocks cut the sedimentary beds at a few places. The Arkansas Geological Survey' made a detailed reconnaissance survey of the Arkansas Valley province in 1927, the purpose being to delineate the major structural features (Fig. 3) and to point out the possibilities of discovering addi. tional gas deposits. More than fifty anticlines were mapped as a result of this survey. The information gained by this

Jan 1, 1943

By Thomas D. Bailey, Alec M. Crowell

Although natural gas was first discovered in Northwest Arkansas in 1887, . near Fort Smith, Sebastian County, the literature contains very little information on the region, which is separated distinctly from the oil area of Southern Arkansas. For that reason this brief and concise report is a summary of developments from discovery to the present time. Northwest Arkansas produced 5,736,-ooo,ooo cu. ft. of natural gas during 1942, the trend of production having been generally upward over the past five years, as is shown in Fig. I. Since 1904 a reserve of 237 billion cubic feet of natural gas has been discovered in Northwest Arkansas, of which approximately 162 billion cubic feet have been expended, leaving a reserve of approximately 75 billion cubic feet available as of Jan. 1, 1943. A prolific new field discovered in Pope County Oct. 23, 1942, will add to the reserve of the region materially. Per well reserves, over-all, are unusually high because of the practice of multiple completion. As yet no commercial deposits of oil have been discovered in Northwest Arkansas. but the gas deposits have proved of immense value industrially, principally in the processing of zinc ore mined in the local area as well as that imported from distant states. With the war, new interest in the exploitation of the metallic ores of the region lends new significance to the gas reserves tabulated herein. Geological Discussion The region covered in this report comprises the Arkansas Valley from Pope County weslward to the Arkansas-Oklahoma state line as shown in Fig. 2. This valley is a westward trending structural trough with sharp-topped ridges and mesa-like mountains rising above the valley's undulating surface. It is bounded on the north by the Ozark Highlands and on the south by the Ouachita Mountains. The sedimentary beds of the Arkansas Valley are composed mainly of noniossil-iferous shales and sandstones. The rocks contain a high content of carbonaceous material and many coal beds are found in the region. The Gxed carbon ratios (ratio of fixed carbon to volatile combustible matter of surface coals) are very high and average about 80 per cent over the region covered in this report. Little or no calcareous material is present. Rocks of the Arkansas Valley are sharply folded, and igneous intrusive rocks cut the sedimentary beds at a few places. The Arkansas Geological Survey' made a detailed reconnaissance survey of the Arkansas Valley province in 1927, the purpose being to delineate the major structural features (Fig. 3) and to point out the possibilities of discovering addi. tional gas deposits. More than fifty anticlines were mapped as a result of this survey. The information gained by this

Jan 1, 1943

By H. K. Shearer

Oil production in north Louisiana in 1938 was 28,442,910 bbl., a decrease of 225,160 bbl., or less than 1 per cent, from 1937. The principal increases were at Cotton Valley, Lisbon and Zwolle. The greatest decrease was at Rodessa, with small normal declines in production of the old settled fields. Natural gas production from gas wells declined 15.9 per cent from 1937, but casinghead gas increased, so the decline in total production was only 6.9 per cent. Decline in completions was due to lack of proven areas for drilling, as well as price and marketing difficulties; and wildcat activity mas also less than in 1937. The increase in number of dry holes was due chiefly to shallow drilling in the old Caddo and Zwolle fields. Most important events in 1938 were the discovery of the Shreveport deep oil and gas field, extension of the Logansport gas-distillate field into Louisiana, development of oil production in the Bodeaw zone on the flanks of Cotton Valley, opening of deep gas-distillate production at Shongaloo, and completion of one well in a deeper horizon at Bluc Lake (Zwolle field). Geological Notes The deep drilling done in 1938 did not cause any important changes in geological correlation and nomenclature of the formations below the Upper or Gulf Cretaceous. The stratigraphic section of the Lower Cretaceous and deeper beds, with names used in the accompanying tables, as approved a year ago by the Shreveport Geological Society, is as follows:

Jan 1, 1939

By H. K. Shearer

Oil production in north Louisiana in 1938 was 28,442,910 bbl., a decrease of 225,160 bbl., or less than 1 per cent, from 1937. The principal increases were at Cotton Valley, Lisbon and Zwolle. The greatest decrease was at Rodessa, with small normal declines in production of the old settled fields. Natural gas production from gas wells declined 15.9 per cent from 1937, but casinghead gas increased, so the decline in total production was only 6.9 per cent. Decline in completions was due to lack of proven areas for drilling, as well as price and marketing difficulties; and wildcat activity mas also less than in 1937. The increase in number of dry holes was due chiefly to shallow drilling in the old Caddo and Zwolle fields. Most important events in 1938 were the discovery of the Shreveport deep oil and gas field, extension of the Logansport gas-distillate field into Louisiana, development of oil production in the Bodeaw zone on the flanks of Cotton Valley, opening of deep gas-distillate production at Shongaloo, and completion of one well in a deeper horizon at Bluc Lake (Zwolle field). Geological Notes The deep drilling done in 1938 did not cause any important changes in geological correlation and nomenclature of the formations below the Upper or Gulf Cretaceous. The stratigraphic section of the Lower Cretaceous and deeper beds, with names used in the accompanying tables, as approved a year ago by the Shreveport Geological Society, is as follows:

Jan 1, 1939

By R. D. Satterley

The Sherwood mine is an iron-ore mine owned and operated by the Inland Steel CO. in the Iron River district of the Menominee Range in Michigan. The property consists of an 80-acre tract in the village of Mineral Hills, about a mile north of the city of Iron River. The Ore mined is a reddish brown, nonbessemer hematite and limonite. The ore bodies lie in a large syncline having an east-west strike and are associated with a rock structure that is folded in a complex manner. The two 40-acre tracts run north and south and the shaft is at about the center of the north forty. The shaft is 1286 ft. deep, with the principal operating level at a depth of 1000 ft. from surface. A new level at a depth of 1200 ft. is in process of development. The ore body at the 1000 ft. level is east and west at approximately the line between the north and south forties and at this elevation is from 50 to 250 ft. wide and extends above the level at varying heights of from 50 to 250 feet. The 1000-ft. haulage drift extends south from the shaft, through the east-west ore body to the slates on the south side of the body. The ore body was intercepted in the drifting at about goo ft. from the shaft and was about 200 ft. wide at that point. A crosscut was extended to the east and west property lines along the south boundary of the ore body. This east-west ore body is laid out in areas go ft. wide for stoping with pillars 40 ft. wide. With this plan a stope is approximately 80 by 200 ft. and has a pillar on both sides that is approximately 40 by 200 ft. The ore has a height of from 50 to 250 ft. above the elevation of the level, therefore the height of the stopes varies in accordance with the height of the ore body at each location. From the crosscut, two main raises, each 6 by 7 ft., are put up into each 80 ft. stope area (Fig. 1). One of the main raises serves as a manway and the other as an ore raise, through which the ore is transferred from the stope to the tramming equipment. The original layout as for scraping of the ore from under the stopes into the ore raises. The ore raise is put halfway (east and west) along the 80-ft. stope area and usually is in iron formation. The manway and ore raise are on approximately 15-ft. centers. These main raises are Put up to a height of from 22 to 30 ft. above the level floor, then from the toll of the ore raise a scraper drift (8 X 8 ft.) is driven across the width of the ore body, which is in the neighborhood of 200 ft. From the scraper drift, mill raises are put up at 12½-ft. centers, staggered on opposite sides of the drift, and these are extended 23 ft. above the elevation of the scraper-drift floor. The sublevel connecting the top of these mill raises is called a mill "sub." Other sublevels are developed parallel to the scraper and mill subs at 25-ft. vertical intervals above the mill sub. The mill sub and the other subs above the mill sub are known as sublevels or dog drifts, and are 4 ft. wide and 6 ft. high. These dog drifts

Jan 1, 1946

Jan 1, 1967

By W. G. Woolf, A. Y. Bethune

Filtration of hot (60°C) supersaturated zinc sulphate solution (sp gr 1.540) from slimy leach residues at the electrolytic zinc plant of Sullivan Mining Co., Kellogg, Idaho, is described. Separation of liquids and solids in the finished leach is by Burt filters modified to meet conditions of high-acid, high-density process for electrolytic zinc. Operating characteristics of the Burt filter on this pulp are presented.

Jan 5, 1950