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By A. B. Parsons

LAST YEAR (1934) saw the completion of a ten-year program of reconstruction and modernization of the world's largest lead- smelting plant, that of the ' Broken Hill Associated Smelters Proprietary, at Port Pirie, South Australia, which has a capacity for smelting and refining 220,000 (short) tons of lead per year. It deals with the entire output of lead concentrates from the famous Broken Hill district in Australia, being owned .jointly by the three leading companies: North Broken Hill, Broken Hill South, and the Zinc Corporation. These companies, together with the Sulphide Corporation, are credited with a production of 198,000 tons of lead in 1934. When one says regarding any metallurgical plant that modernization is "completed" he should add "for the moment." Development in the art of metallurgy and in the equipment used never ceases; that which seems close to the last word today is likely to be obsolete in a few years even in a process so well standardized as smelting and refining lead. However, the reconstruction at Port Pirie has altered the procedure materially. More im-

Jan 1, 1935

Jan 1, 1882

Jan 6, 1976

Jan 4, 1976

Scraper With over 40 pet more struck capacity than previous models, the new Caterpillar No. 90 scraper is designed to increase earthmoving production when used with D8 tractor power. This scraper moves dirt with the aid of a hard surfaced, reversible cutting edge. Material is carried in a flat, doublebottom bowl of high tensile steel. Operation is by means [ ] of a cable-control unit, which can be mounted on the rear of the tractor to provide for positive loading and ejection. Tapered roller bearings are installed at each axle. The scraper uses two 24.00 to 29 front tires and two 27.00 to 33 rear tires, all four of 24-ply rating. When loaded, the scraper distributes 60 pet of the weight on the rear tires. Circle No. 1

Jan 1, 1952

By G. B. WATERHOUSE

THE year 1929 was exceedingly busy and prosperous for the iron and steel industry in the United States. The lake shipments of ore were approximately 65,000,000 tons, steel ingots produced were about 57,000,000 tons. Plants were very active. operating for many months well over their rated capacity, slowing down during the last quarter following the severe break in the stock market. The ore tonnage mentioned above was the greatest ever shipped by lake from the Lake Superior region. The trend at the ore mines has been to supplement manual labor by mechanical appliances as much as possible. Mining methods have been greatly improved along the lines of safety as well as to increase the percentage of ore recovery. Crushing and grading of iron ores continued to gain in popularity inasmuch as remarkable blast-furnace operations and records were obtained with sizing and uniformity of raw materials. Progress was made along other lines. The Bradley process for the separation of manganese osicle and iron oside from siliceous manganiferous iron ore was cleuelopecl; also considerable work was clone on a process for the beneficiation of the Cuban laterite ores. Sintering of ores and concentrates increased in popularity. A new analytical method for the deter- mination of sulfur in iron ore was worked out which reduced the time required appreciably. The ore re- serves of the Lake Superior district continued to receive considerable attention and played an important part in the recent mergers which have taken place in the iron ancl steel industry.

Jan 1, 1930

By HUGH E. McKinstry

OPENING the sessions of the Mining Geology Committee, the program on postwar mineral controls drew a larger attendance than any other session of the entire meeting. In view of its general interest, the papers of this session, or a substantial portion of them, are printed elsewhere in this issue. Whether control of mineral resources can help to promote peace, how controls could be applied and to whom, are questions so far-reaching that naturally no pat answer was agreed upon. In fact the discussion took on something of the flavor of a debate between those who favor strict control and those who felt that attempting to ration nations in peacetime would defeat its own ends. Discussion from the floor emphasized the difficulties in administering any international control and the $64 question, that no one cared to answer, asked by a courageous young lady who was induced to mount the rostrum for the purpose, was whether the United Nations should exchange mineral controllers to police each other.

Jan 1, 1944

By W. B. Tucker

UNUSUAL interest has recently centered in the Mojave mining district of California, owing to new discoveries of gold ore at the Silver Queen mine, and subsequently at other neighboring proper- ties. These finds have proved that opportunities exist for the prospector even in old mining districts, where careful search may still be rewarded. The Mojave district is characterized by a group of small hills centering around Soledad Butte, four to six miles southwest of Mojave, in Kern County. This butte is 1250 ft. higher than the surrounding desert and 4000 ft. above sea level. Four miles west of Soledad Mountain are the so-called Middle Buttes, a group of flat-topped hills. Gold was first discovered in the district in 1894, and the following productive mines developed: Queen

Jan 1, 1936

By Michael J. Messel

OF the various minerals that occur in fibrous form known as asbestos, chrysotile is the variety most in demand for commercial uses, and, last year, over 683,000 tons of the various grades were produced in Canada and United States, exclusive of African and Russian production, which figures are uncertain. Production has not been able to keep up with the increased demand, and an acute shortage exists. Canada, Russia, and Africa are still the most important producers. However, Russia consumes most of its production at home and exports very little. The United States consumes over 60 pct of the total production and produces only about 4 pct of the total from deposits in Vermont and small quantities from Arizona. This paper will review mainly, some of the more recent developments concerned with the extraction and processing of this fibrous mineral for various industrial uses, such as textiles, insulation, building materials and brake linings.

Jan 1, 1949

By Donald L. Katz

THE Oklahoma City Wilcox sand, discovered on March 26, 1930, has produced 394 million barrels of crude oil and 819 billion cubic feet of natural gas as of July 1, 1941. The 100,000-bbl. wells, pressures of 2600 lb. per sq. in., and flows of "Wilcox" sand caused exciting moments in the early life of the field. Today the reservoir is substantially at atmospheric pressure and produces 75,000 bbl. of crude oil daily through 466 pumping wells. Early estimates of the initial crude-oil content of the "Wilcox" sand' indicated that about 600 million barrels of crude oil would remain after the pumping wells ceased to produce economically. The Oklahoma City Wilcox Secondary Recovery Association was organized in March 1939, to study the possibilities of recovering a portion of this oil. Only a very brief summary of the information available can be presented in a paper of this nature. Some simplification and generalizations are necessary to give the over-all picture in so short a space and statements made may not apply to a specific well or small area. Since the area under consideration by the Association is that north of the south line of section 22-11-3, some information will be presented for areas A, B, C, r, 2, 3 and part of 4 of Fig. 2, and some will be for the entire Wilcox zone west of the fault. This paper is essentially an abstract of an engineering report made by A. D. Small, B. T. Murphree, M. C. Sons and the author for the Oklahoma City. Wilcox Secondary Recovery Association on Sept. 5;.1940. Some information is taken from a report to the Association by C. V. Sidwell on March 1, 1940, and some data are from a recent report by A. D. Small. It gives a brief history of the Wilcox zone, estimates of the initial oil contents of the reservoir, present conditions in the reservoir, and probable results from several programs of "secondary recovery." HISTORY OF WILCOX ZONE The Wilcox sand lies on the flank of the general structure, as shown by cross section of Fig. 12.1 .4 and areal map of Fig. 2. The sand is of Ordivician age and is composed of well assorted, rounded' sand grains with no apparent cementing material. The loose texture of the sand is shown by the enormous quantities of sand production from the wells and from the soft cores. The productive sand varies from zero thickness on the east to 220 ft. maximum and to zero thickness on the west because of water. The development of the pool4 was dependent upon drilling restrictions within the city limits, which accounts for the spacing of drilling operations listed in Table I by years. In 1931, areas I through 7 of Fig. 2 were open for drilling with the exception of some west-edge properties, and all wells drilled before Feb. I, 1935, were in this portion of the field. Nearly all wells drilled from 1933 to 1937 were in areas A, B and C. Since 1939, the newly drilled wells have gradually enlarged the producing area toward the west in the northern portion.

Jan 1, 1941

By Oscar A. Glaeser

MINE VENTILATION is an important factor in mine maintenance as well as having direct bearing on labor efficiency. Effective ventilation systems are costly, especially those for the deeper mines, but with intelligent direction the worth of a system is usually greater than its cost. In most mines using mechanical ventilation, and practically all deep mines, it has been found beneficial to equipment, timber, and the ground, to run the fan or fans continuously even though production has been curtailed or entirely suspended. Therefore, economies in ventilation may be overlooked when general cost reductions are necessary. The operating costs of a well-designed ventilation system should be capable of reduction during periods of curtailed or suspended operations. A mine that is ventilated by splits, or that can be sectionized, can reduce its fan-power costs considerably, and provisional divisions can sometimes be made in other mines, in which the air is ordinarily coursed through all the workings, without harmful effects.

Jan 1, 1932

By Robert J. Linney

In the latter part of the year 1943, it was decided to experiment with diamond-drill blast holes in the Old Bed magnetite mine at the Mineville mines of the Republic Steel Corporation, in sections of the ore body where vertical dimensions were large and where development for sublevel bench stopes had already been done. Other possibilities of application for this drilling method were in the reclamation of old floors and pillars in the pitching folds of the Lower Old Bed ore body and in the reclamation of large vertical pillars in the "21" Bonanza-Joker ore body. The cross sections and views of the two ore bodies will show the conditions to which the diamond-drill method has been applied. The Lower Old Bed magnetite ore body is lenticular and dips approximately 30° toward the southwest and strikes generally southeast and northwest. An intensely folded structure, which pitches generally on an axis approximately at right angles to the strike, is continuous from the uppermost old workings down to the present bottom of the mine, and probably continues with depth. On successively lower levels this folded structure becomes greater in vertical dimensions and the two folds are closer together in a horizontal dimension. As shown in Fig. I, this folded structure gives to parts of the ore body considerable vertical dimensions, which provide areas that were developed for sublevel bench stoping above a slushing drift, as shown in Fig. 2. It was in one of these previously devel-oped sublevel bench stopes, No. 26 on the 1185-ft. level, that the diamond-drill blast-hole method was applied for mining the upper sublevel. The lower sublevel was underhand-bench-drilled to the finger raises of the scram drift below. The roof of this stoping area began to break and spall on the lower sublevel, causing the roof to become inclined. Along the hanging wall of the stope this reached an elevation about half way between the two sublevels. A smooth schistose seam in the hanging wall causes the ore to break away freely. Therefore, if bench mining had been carried on in the upper sublevel, a dangerous condition of poorly supported benches would have resulted. When the drillers were slashing across the sublevel te footwall and hanging wall to make a bench, spdlling roof of the opening below would probably have carried away part of the bench, and would have left a dangerous place in which to continue underhand benching. A 6 by 8-ft. raise had been driven between the lower stope and the upper sublevel about 200 ft. from a manway. It was decided to use this raise for a starting cut and to arrange holes as shown in Fig 3, so that a slot would be opened across the ore body between the footwall and hanging wall. This slot would then be used for the purpose of breaking into the ore, by blasting vertical rings of holes drilled at right angles to the axis of the pitching folds as nearly as possible. Layouts of this slot drilling and the rings adjacent are

Jan 1, 1946

By H. E. Montgomery

Engineering trends for some years have been toward higher temperatures, both in process work and in steam generation. Progress in design has been dependent upon the development and evaluation of suitable alloys. Elementary knowledge of the limitations of copper-base alloys indicate their unsuitability for the higher ranges of operating temperatures; say, for steam to 950°F. Emphasis upon the more severe conditions perhaps is a reason why more complete evaluations have not been made for copper-base alloys over their range of suitability. However, the few studies made show clearly the need for more accurate evaluations. Some copper-base alloys long looked upon favorably because of superior room-temperature properties are not as desirable as some others perhaps not so "strong" and "hard," as measured by usual acceptance tests. Load-carrying capacity and structural stability arc two important factors. Structural stability as influenced by temperature, by presence of corrosive media, or by the effects of stress itself, frequently is a limiting factor. An early reference to creep properties of the cast copper-base alloys is that of Brown1 (Admiralty gun metal, Cu 87.5, Sn 10.1, Zn 2.3 and Pb 0.08). His tests were similar to present-day stress-rupture tests without measurement of creep elongrttion. Loading was in steps with usually 24 hr. between steps, and continued until failure. He advocated a "useful strength value" of 61/2 tons (I4,560 Ib.) per sq. in. at 572°F. (300°C.). A specimen broken in 1/2 hr. at 572°F. had a strength of 21 tons (26,880 Ib.) per sq. in. The strength values as determined by 1/2-hr. tests and those by the longer stress-rupturc start to differentiate at 392°F. (200°C). This is the temperature at which time at load began to play an important part. Bolton, Price and Hebemann2 give creep curves on 88-10-2 (A.S.T.M. B-60, CU 88, Sn 10, Zn 2) and steam or valve bronze (A.S.T.M. B-6I, Cu 87.50, Sn 6.00, Zn 3.75, Pb 1.70) at 500°F. Direct comparison of the two alloys under 7500 lb. per sq. in. stress showed the steam bronze (A.S.T.M. B-61) superior in creep strength to the 88-10-2 (A.S.T.M. B-60). The steam bronze shows no creep after 700 hr. (1540-hr. test). The 88-10-2 shows a rate of about 7.0 per cent in 100,000 hr. over the last 700 hr. of the test. Creep curves on the steam bronze are also given at the same temperature (500°F.) with loads of 6500 lb. per sq. in. and 8000 lb. per sq. in. These indicate "creep strengths" (creep rate within I per cent in 100,000 hr.) in excess of 8000 lb. per sq, in. for this alloy. It was found that higher percentages of tin are detrimental to creep resistance. This is caused by the presence of or formation during test of considerable alpha-delta eutectoid in the higher tin alloys. Bolton also states that the high

Jan 1, 1945

By Robert J. Linney

IN the latter part of the year 1943, it was decided to experiment with diamond-drill blast holes in the Old Bed magnetite mine at the Mineville mines of the Republic Steel Corporation, in sections of the ore body where vertical dimensions were large and where development for sublevel bench stopes had already been done. Other possibilities of application for this drilling method were in the reclamation of old floors and pillars in the pitching folds of the Lower Old Bed ore body and in the reclamation of large vertical pillars in the " 21 " Bonanza-Joker ore body. The cross sections and views of the two ore bodies will show the conditions to which the diamond-drill method has been applied. The Lower Old Bed magnetite ore body is lenticular and dips approximately 30° toward the southwest and strikes generally southeast and northwest. An intensely folded structure, which pitches generally on an axis approximately at right angles to the strike, is continuous from the uppermost old workings down to the present bottom of the mine, and probably continues with depth. On successively lower levels this folded structure becomes greater in vertical dimensions and the two folds are closer together in a horizontal dimension. As shown in Fig. 1, this folded structure gives to parts of the ore body considerable vertical dimensions, which provide areas that were developed for sublevel bench stoping above a slushing drift, as shown in Fig. 2. It was in one of these previously developed sublevel bench stopes, No. 26 on the 1185-ft. level, that the diamond-drill blast-hole method was applied for mining the upper sublevel. The lower sublevel was underhand-bench-drilled to the finger raises of the scram drift below. The roof of this stoping area began to break and spall on the lower sublevel, causing the roof to become inclined. Along the hanging wall of the stope this reached an elevation about half way between the two sublevels. A smooth schistose seam in the hanging wall causes the ore to break away freely. Therefore, if bench mining had been carried on in the upper sublevel, a dangerous condition of poorly supported benches would have resulted. When the drillers were slashing across the sublevel to footwall and hanging wall to make a bench, spalling roof of the opening below would probably have carried away part of the bench, and would have left a dangerous place in which to continue underhand benching. A 6 by 8-ft. raise had been driven between the lower stope and the upper sublevel about 200 ft. from a manway. It was decided to use this raise for a starting cut and to arrange holes as shown in Fig. 3, so that a slot would be opened across the ore body between the footwall and hanging wall. This slot would then be used for the purpose of breaking into the ore; by blasting vertical rings of holes drilled at right angles to the axis of the pitching folds as nearly as possible. Layouts of this slot drilling and the rings adjacent are

Jan 1, 1945

By Herbert J. French

ALLOY steels have become essential to industry in meeting the rigid requirements on materials imposed by our, advanced technology. In comparison with the total ingot capacity of the steel industry, the volume of alloy steels is relatively small although for many years annual alloy-ingot tonnage has, been in seven figures. However, the monetary value of the alloy-steel production is exceedingly high and the benefits derived from the products are relatively great. The trend in total ingot production since 1932 has been generally upward with only two major interruptions. That of the year 1938 was due to a decrease in general business activity whereas that of 1946 resulted largely from work stoppages. Traditionally, the tonnage of alloy-steel ingots produced was in the neighborhood of 5 to

Jan 1, 1948

By AIME AIME

ON the headwaters of the Hudson Riser, in a sparsely populated area of the north woods at Tahawus, N. Y., thirty miles from the nearest railroad, is the Maclntyre property of National Lead Co. Operations involve the mining and processing of titaniferous iron ore to produce ilmenite concentrate, and magnetite concentrate containing vanadium, for use in the production of iron, titanium, and vanadium in the war program. Accordingly, Maclntyre at present is classed as a war plant. More than 3000 long tons of ore is ruined daily by opencut methods and treated in an ore concentrating plant.

Jan 1, 1943

By Bieniawski, Z. T.

The importance of understanding the phenomena associated with rock fracture has long been fully appreciated in rock mechanics. This is clearly apparent from the special attention paid to rock fracture in the comprehensive papers published within the past four years. These papers present a picture of how the knowledge of brittle fracture of rock was gradually enriched and also show that what was often taken for granted three or four years ago is no longer considered as valid today.

Jan 1, 1972

By D. L. Katz

The Oklahoma City Wilcox sand, discovered on March 26, 1930, has produced 394 million barrels of crude oil and 819 billion cubic feet of natural gas as of July I, 1941. The 100,000-bbl. wells, pressures of 2600 lb. per sq. in., and flows of "Wilcox" sand caused exciting moments in the early life of the field. Today the reservoir is substantially at atmospheric pressure and produccs 75,000 bbl. of crude oil daily through 466 pumping wells. Early estimates of the initial crude-oil content of the "Wilcox" sand1 indicated that about 600 million barrels of crude oil would remain after the pumping wells ceased to produce economically. The Oklahoma City Wilcox Secondary Recovery Association was organized in March 1939, to study the possibilities of recovering a portion of this oil. Only a very brief summary of the information available can be presented in a paper of this nature. Some simplifications and generalizations are necessary to give the over-all picture in SO short a space and statements made may not apply to a specific well or small area. Since the area under consideration by the Association is that north of the south line of section 22-11-3, some information will be presented for areas A, B, C, 1, 2, 3 and part of 4 of Fig. 2, and some will be for the entire Wilcox zone west of the fault. This paper is essentially an abstract of an engineering report made by A. D. Small, B. T. Murphree, M. C. Sons and the author for the Oklahoma City Wilcox Secondary Recovery Association on Sept. 5, 1940. Some information is taken from a report to the Association by C. V. Sidwell on March I, 1940, and some data are from a recent report by A. D. Small. It gives a brief history of the Wilcox zone, estimates of the initial oil contents of the reservoir, present conditions in the reservoir, and probable results from several programs of "secondary recovery." History of Wilcox Zone The Wilcox sand lies on the flank of the general structure, as shown by cross section of Fig. I2,3,4 and areal map of Fig. 2. The sand is of Ordovician age and is composed of well assorted, rounded sand grains with no apparent cementing material. The loose texture of the sand is shown by the enormous quantities of sand production from the wells and from the soft cores. The productive sand varies from zero thickness on the east to 220 ft. maximum and to zero thickness on the west because of water. The development of the pool4 as dependent upon drilling restrictions within the city limits, which accounts for the spacing of drilling operations listed in Table I by years. In 1931, areas I through 7 of Fig. 2 were open for drilling with the exception of some west-edge properties, and all wells drilled before Feb. I, 1935, were in this portion of the field. Nearly all wells drilled from 1933 to 1037 were in areas A, B and C. Since 1939, the newly drilled wells have gradually enlarged the producing area toward the west in the northern portion.

Jan 1, 1942

By D. L. Katz

The Oklahoma City Wilcox sand, discovered on March 26, 1930, has produced 394 million barrels of crude oil and 819 billion cubic feet of natural gas as of July I, 1941. The 100,000-bbl. wells, pressures of 2600 lb. per sq. in., and flows of "Wilcox" sand caused exciting moments in the early life of the field. Today the reservoir is substantially at atmospheric pressure and produccs 75,000 bbl. of crude oil daily through 466 pumping wells. Early estimates of the initial crude-oil content of the "Wilcox" sand1 indicated that about 600 million barrels of crude oil would remain after the pumping wells ceased to produce economically. The Oklahoma City Wilcox Secondary Recovery Association was organized in March 1939, to study the possibilities of recovering a portion of this oil. Only a very brief summary of the information available can be presented in a paper of this nature. Some simplifications and generalizations are necessary to give the over-all picture in SO short a space and statements made may not apply to a specific well or small area. Since the area under consideration by the Association is that north of the south line of section 22-11-3, some information will be presented for areas A, B, C, 1, 2, 3 and part of 4 of Fig. 2, and some will be for the entire Wilcox zone west of the fault. This paper is essentially an abstract of an engineering report made by A. D. Small, B. T. Murphree, M. C. Sons and the author for the Oklahoma City Wilcox Secondary Recovery Association on Sept. 5, 1940. Some information is taken from a report to the Association by C. V. Sidwell on March I, 1940, and some data are from a recent report by A. D. Small. It gives a brief history of the Wilcox zone, estimates of the initial oil contents of the reservoir, present conditions in the reservoir, and probable results from several programs of "secondary recovery." History of Wilcox Zone The Wilcox sand lies on the flank of the general structure, as shown by cross section of Fig. I2,3,4 and areal map of Fig. 2. The sand is of Ordovician age and is composed of well assorted, rounded sand grains with no apparent cementing material. The loose texture of the sand is shown by the enormous quantities of sand production from the wells and from the soft cores. The productive sand varies from zero thickness on the east to 220 ft. maximum and to zero thickness on the west because of water. The development of the pool4 as dependent upon drilling restrictions within the city limits, which accounts for the spacing of drilling operations listed in Table I by years. In 1931, areas I through 7 of Fig. 2 were open for drilling with the exception of some west-edge properties, and all wells drilled before Feb. I, 1935, were in this portion of the field. Nearly all wells drilled from 1933 to 1037 were in areas A, B and C. Since 1939, the newly drilled wells have gradually enlarged the producing area toward the west in the northern portion.

Jan 1, 1942

Shovel To further increase the efficiency in the production of their foundry sand, the American Silica Sand Co. has purchased a new and improved shovel that will be used for loading trucks at their Reynolds Pit. The [ ] new shovel will greatly facilitate winter mining operations and make possible larger winter shipments of the company's foundry sand. The Reynolds Pit is one of three sand pits in the Ottawa district owned by American Silica which produce sand that is refined for foundry use. Circle No. 1 Electric Switches The Crane Electric Co. has just announced the production of their R-1000, a new rotating limit switch designed to control the travel of any rotating device requiring interruption or establishment of electrical current after a predetermined number of revolutions. It is useful for machinery, lifts, and other power equipment. The switch is presented in a finished case, 16 gage, reinforced, with walls of sufficient strength to hold the entire mechanism and all the parts in accurate alignment. The worm gear combination has a 60 to 1 ratio, sufficient for most industrial uses. The number of revolutions can still be increased by using various combinations of driving sprockets, either on the shaft of the switch, or on the sprocket of the unit controlled by the switch itself. Circle No. 2

Jan 1, 1952