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By Harold Vance

The Lafitte field, the largest oil reserve in South Louisiana, is in Jefferson Parish, some 25 miles due south of the City of New Orleans. The discovery well, The Texas Company's No. I, Louisiana Land and Exploration Co., in the southeast corner of sec. 19, T. 17 S., R. 24 E., was completed on May 15, 1935. The initial production of this well was 960 bbl. of 34.9º A.P.I, gravity oil per day, through 1/4-in. choke, with a tubing pressure of 1600 lb. per sq. in. Producing depth was 9558 to 9572 ft., the total depth being 9572 feet. The development of the field has been at the rate of three to eight new producing wells per year. Up to Jan. I, 1944, 60 producing wells and three dry holes had been drilled, while two of the original producing wells had been abandoned, Although the field is not unitized, The Texas Company was the sole operator in the field until the Lafitte Oil Co. completed its NO. I Jefferson Parish, near the center of the west line of the NW/4 sec. 20, T. I7 S., R. 24 E., on July 27, 1941. No additional wells have been drilled by the Lafitte Oil Company. Drilling and WeLl-completion Practices All drilling operations have been conducted with the steam-driven rotary equipment mounted on submersible barges. A canal is dug to the well location and the drilling unit is floated into position. The seacocks are then opened and the barge settles to the bottom. After the well is completed, seacocks are closed and water is pumped out of the barge. This procedure permits the barge, with drilling equipment still in place, to be floated and moved off the location. The conventional open-hole and the gun-perforation method of completing wells has been used in this field. Where possible, the initial completion is from the deepest 'sand and recompletions are made progressively up the hole, by plugging back with cement to the upper sand and gun-perforating opposite the new sand. The oil string usually is 7 5/8 in., 26 to 34-lb. casing. Three wells have been completed using 9 5/8-in. 44-lb casing set below 10.000 feet. Fig. I shows the completion and recom-pletion practices on one well in the field. This figure also shows the relative locations of the different producing sands as shown on the electric well log. Structure The structure is an elongated dome, cut by two north-south faults, which divides the field into three segments. The west segment is the highest structurally and contains most of the recoverable oil and gas. The center segment is less important and the east segment is of little value. Figs. 2, 4, 6, 8 and 10 are depth contour maps on top of the five main producing sands in the field. These maps show the relative size of the five reservoirs and the

Jan 1, 1945

By G. S. Hume

Production of petroleum and natural .gas increased in Canada in 1940 over the previous year. Alberta produced more than 97 per cent of the total Canadian production of 8,718,053 bbl. of oil, an increase for this province of nearly 12 per cent, whereas in Ontario and New Brunswick, where the production is relatively small, there was a slight decline. In Alberta the main producing field is Turner Valley, on the eastern edge of the foothills southwest of Calgary, and development continued in this field in 1940 with the completion of 36 wells, all of which obtained production. In the Red Coulce field, close to the International Boundary, near Coutts, no new wells were drilled and the seven producing wells showed a decline of 900 bbl. below the previous year. Also, in the Wainwright field of east central Alberta, four wells, yielding heavy crude oil, produced 4000 bbl. less oil than in 1939, owing possibly rather to discontinuous operation than to actual decline in potential yield. This decline was more than offset by production from a new field 40 miles northeast of Wainwright, at Borradaile, producing oil of 14" to I 5° A.P.1. There was a small increase in production during 1940 from the Del Bonita field, in southern Alberta, where the production is from two wells. The outstanding development of the year was the completion of Standard Oil Princess No. 2 well in the Steveville area, on the Plains 100 miles east of Calgary. This well was completed late in December with an initial flow1 of 520 bbl. of 26.3" A.P,I. oil, and 12,750 M cu. ft. of gas from the upper part of the Mississippian limestone. It has opened up a new field and given a further proof of the potentialities of the Southern Plains. The production of petroleum in Canada is shown in Table I. Since most of the yield comes from Alberta, the production is shown from the various fields in Table 2. The sale value of the petroleum produced in Canada in 1940 exceeded 11.1 million dollars, which is still somewhat less than the value of the natural gas production, shown in Table 3. Table i.—Production of Petroleum in Canada" Barrels Province 1939 1940 New Brunswick........ 20,101 21,161 Ontario............... 206,196 186,471 Alberta............... 7,595,000 8,493,237 Northwest Territories. . 17,013 8,493,23717.184 Total............... 7,838,310 8,718,053 Value............... $10,353,351 $11.113,000 0 Bureau of Statistics, Ottawa. Turner Valley, Alberta Turner Valley continues to be by far the largest producing field in Canada (details are given in Table 4), The limits of the Pr in- field are now Known. On the east the oil area is bounded by the gas cap, which in turn is cut off on its east side by a major overthrust fault; on the west, ii is defined by edge water at a level of 4roc

Jan 1, 1941

By L. S. Richardson, N. J. Grant

REACTIONS of oxygen and nitrogen at low pressures with titanium have recently been studied by a number of investigators.1-3 Gulbransen and Andrew' noted that the reaction with nitrogen followed the parabolic rate law whereas the reaction with oxygen deviated slightly from this law in the temperature range 300° to 800°C. In the work reported here, commercial titanium (75 A) was used as the test material. Cylinders 2.5 in. long and 0.25 in. in diameter were machined from heavier bar stock. The test pieces were given a metallographic finish, immersed for 30 min in cold concentrated HC1, washed in water, then acetone, and dried with lint-free cloth. Reaction rates were determined in a modified Sieverts type apparatus by measuring the decrease in gas pressure of the reacting gas contained in a constant volume. The amount of gas added could be measured in a calibrated gas burette to an accuracy of 0.01 mm. During the course of a run the temperature never varied by more than 10°C and then only for brief moments. After placing the specimen in the furnace, the system was first evacuated for 12 hr at room temperature, and then flushed with purified argon five times, adsorbed gases being discharged during this period from the glass system with a high frequency spark coil. The flushing and discharging were repeated at 400°C. This rather involved procedure was found necessary after a number of trial runs indicated extraneous effects traceable to the system. Reaction periods up to 2 hr were used, at initial gas pressures of 0.2 to 0.5 atm. Experimental Results Fig. 1 shows the decrease in oxygen pressure for tests at 0.5 atm at various temperatures as a function of the square root of the time. Deviations from linearity are minor and the parabolic rate law is obeyed. Fig. 2 shows the same plot for the nitrogen reaction. A definite deviation from linearity is noted; however, it is probable that the higher initial rates are caused by the presence of small amounts of oxygen contamination, the initial faster rate changing to the slower rate after about 5 to 10 min. Calculations of the rate constants were made on the basis of the latter portion of the curves. The parabolic rate law constants calculated from these curves are shown for oxygen and nitrogen in Fig. 3. In spite of some scatter the average curves are quite definite. Changes in gas pressure of the order of 20 pct did not result in a measurable change in the rate law constants. The activation energy for the oxygen reaction was calculated to be 47,400 cal per mol (above 700°C), which is not in agreement with the value quoted by Gulbransen and Andrew' for lower temperatures, their value being 26,000 cal below 600°C. The activation energy for the nitrogen reaction was calculated to be 45,400 cal per mol above about

Jan 1, 1955

By Leo H. Glanville

UNTIL 1934, natural ventilation was depended upon in the mine of the Climax Molybdenum Co. at Climax, Colorado. In that year a 7-ft. axial-flow, low-pressure fan was installed as an exhausting unit. In 1936, three more fans of the same kind were installed, all as exhausting units, with a total capacity of 115,000 cu. ft. per min., and since then fans and sprays have been added as required. ATMOSPHERIC CONDITIONS Adverse atmospheric conditions at this elevation of 11,500 ft. account in part for difficulty in maintaining adequate ventilation throughout the mine. Barometric pressures range from 18.99 to 20.01 in. of mercury; the normal average being 19.70 in. Air weight is 0.051 lb. per cu. ft., and humidity is low-about a 30 per cent yearly average. This makes the use of mechanical humidity aids mandatory the year around to prevent excessive dryness of the mine workings and the resultant dust hazard. The yearly temperature range is from minus 24° to 95°F.; typically, in February 1942 the mean low was minus 3.25°F. and the mean high, 21.3°F. In August the mean low was 34.8°F.; the mean high, 64.26°F. Even during the summer month air filtration through the openings of the cave area is 32°F., owing to accumulation of snow in the glory hole and in part to glacial ice, which, combined with a rock temperature of 39°F. on the upper levels (elevation 11,945 ft.) and 42°F. on the main haulage level (elevation 11,490 ft.), makes it difficult to maintain a comfortable working temperature. The one advantage in ventilation of mine workings at the altitude of the Climax mine is that the power required to circulate a given air volume is 32 per cent less than would be required at sea level. PROBLEMS Since 1936 the mine management has studied intensively plans for providing adequate ventilation for the entire mine for its expected life. As the ore breaks into large pieces, much secondary blasting is necessary, therefore there is a considerable amount of smoke, gas and dust, which requires circulation of a large amount of air to remove the contamination. It is undesirable to use haulage drifts and manways as air passages because some would be passageways for contaminated air also, and there would be undesirable high velocities in some drifts. High velocities and large volumes of subfreezing air dry out the passageways through which they pass, and thus increase the amount of dust. Regulating doors in haulage drifts are difficult of upkeep and interfere with production. It was decided as a general principle to distribute fresh air to each working place at low velocities and low pressures and to remove contaminated air as soon as possible with a minimum of travel through working places.

Jan 1, 1943

By G. S. Hume

Production of petroleum and natural .gas increased in Canada in 1940 over the previous year. Alberta produced more than 97 per cent of the total Canadian production of 8,718,053 bbl. of oil, an increase for this province of nearly 12 per cent, whereas in Ontario and New Brunswick, where the production is relatively small, there was a slight decline. In Alberta the main producing field is Turner Valley, on the eastern edge of the foothills southwest of Calgary, and development continued in this field in 1940 with the completion of 36 wells, all of which obtained production. In the Red Coulce field, close to the International Boundary, near Coutts, no new wells were drilled and the seven producing wells showed a decline of 900 bbl. below the previous year. Also, in the Wainwright field of east central Alberta, four wells, yielding heavy crude oil, produced 4000 bbl. less oil than in 1939, owing possibly rather to discontinuous operation than to actual decline in potential yield. This decline was more than offset by production from a new field 40 miles northeast of Wainwright, at Borradaile, producing oil of 14" to I 5° A.P.1. There was a small increase in production during 1940 from the Del Bonita field, in southern Alberta, where the production is from two wells. The outstanding development of the year was the completion of Standard Oil Princess No. 2 well in the Steveville area, on the Plains 100 miles east of Calgary. This well was completed late in December with an initial flow1 of 520 bbl. of 26.3" A.P,I. oil, and 12,750 M cu. ft. of gas from the upper part of the Mississippian limestone. It has opened up a new field and given a further proof of the potentialities of the Southern Plains. The production of petroleum in Canada is shown in Table I. Since most of the yield comes from Alberta, the production is shown from the various fields in Table 2. The sale value of the petroleum produced in Canada in 1940 exceeded 11.1 million dollars, which is still somewhat less than the value of the natural gas production, shown in Table 3. Table i.—Production of Petroleum in Canada" Barrels Province 1939 1940 New Brunswick........ 20,101 21,161 Ontario............... 206,196 186,471 Alberta............... 7,595,000 8,493,237 Northwest Territories. . 17,013 8,493,23717.184 Total............... 7,838,310 8,718,053 Value............... $10,353,351 $11.113,000 0 Bureau of Statistics, Ottawa. Turner Valley, Alberta Turner Valley continues to be by far the largest producing field in Canada (details are given in Table 4), The limits of the Pr in- field are now Known. On the east the oil area is bounded by the gas cap, which in turn is cut off on its east side by a major overthrust fault; on the west, ii is defined by edge water at a level of 4roc

Jan 1, 1941

By D. V. Carter, D. C. Williams

Four oil discoveries were made in east and east central Texas during 1940, three of which represented new fields. In the Chapel Hill field, Smith County, oil was found where formerly only gas and distillate were produced. The three oil fields discovered are: Hawkins, Wood County; Pittsburg, Camp County; and Tehuacana, Limestone County. Important extensions were made to the following fields: Bazette, Navarro County; Long Lake, Anderson and Leon Counties; Cayuga, Anderson, Freestone and Henderson Counties; Opelika, Henderson County; and Talco, Titus and Franklin Counties. At the close of the year 54 oil and gas fields were producing in the district. There were 13 other fields, 11 oil and 2 gas, which have been abandoned. The East Texas field led the district in the number of completions for the year. During the year about 622 wells (oil and distillate wells included) were completed and 80 wildcats were drilled. Production and Proration During the year 170,424,685 bbl. of oil (distillate production included) were produced in the district—a decrease of 2.6 per cent from the 175,053,729 bbl. (distillate production included) during the preceding year. The district's production for the year 1938 was 182,369,484 bhl. As usual, most of the district's annual production was in the East Texas field, which produced 139,095,694 bbl. (distillate production in- cluded) during 1940, or 81.6 per cent of the total oil produced as compared with 141,333,317 bbl. (80.7 per cent) for 1939. The December estimated daily average production in the district was 424,565 bbl. The district accounted for 34.9 per cent of the state's annual production, compared to 36.7 pcr cent of the state's 1939 production. The decrease in production for 1940 may be attributed to changes made in proration schedules. Any material changes in the district's annual production may be considered for the most part as a reflection of proration-schedule changes affecting the East Texas field, since it is by far the most important field in the area. The entire state was subject to 71 shutdown days for the year; the East Texas field to 131; and the Rodessa field (Cass County, Texas, portion) to 5 days. No important changes were made in field rules and regulations during the year regarding the allocation of oil in individual fields in this district. Discoveries The Hawkins field is in southeastern Wood County in and principally north of the town of Hawkins. Development to date indicates that the field is somewhat of an elongated anticline trending slightly east of north and the proved oil area appears at this time to cover approximately 4000 acres. The oil production has been secured from the Woodbine sand, Upper Cretaceous; a considerable quantity of gas has been encountered in the Sub-Clarksville formation (Eagleford shale) in the higher part of the structure. It appears that a free gas

Jan 1, 1941

By D. C. Williams, D. V. Carter

Four oil discoveries were made in east and east central Texas during 1940, three of which represented new fields. In the Chapel Hill field, Smith County, oil was found where formerly only gas and distillate were produced. The three oil fields discovered are: Hawkins, Wood County; Pittsburg, Camp County; and Tehuacana, Limestone County. Important extensions were made to the following fields: Bazette, Navarro County; Long Lake, Anderson and Leon Counties; Cayuga, Anderson, Freestone and Henderson Counties; Opelika, Henderson County; and Talco, Titus and Franklin Counties. At the close of the year 54 oil and gas fields were producing in the district. There were 13 other fields, 11 oil and 2 gas, which have been abandoned. The East Texas field led the district in the number of completions for the year. During the year about 622 wells (oil and distillate wells included) were completed and 80 wildcats were drilled. Production and Proration During the year 170,424,685 bbl. of oil (distillate production included) were produced in the district—a decrease of 2.6 per cent from the 175,053,729 bbl. (distillate production included) during the preceding year. The district's production for the year 1938 was 182,369,484 bhl. As usual, most of the district's annual production was in the East Texas field, which produced 139,095,694 bbl. (distillate production in- cluded) during 1940, or 81.6 per cent of the total oil produced as compared with 141,333,317 bbl. (80.7 per cent) for 1939. The December estimated daily average production in the district was 424,565 bbl. The district accounted for 34.9 per cent of the state's annual production, compared to 36.7 pcr cent of the state's 1939 production. The decrease in production for 1940 may be attributed to changes made in proration schedules. Any material changes in the district's annual production may be considered for the most part as a reflection of proration-schedule changes affecting the East Texas field, since it is by far the most important field in the area. The entire state was subject to 71 shutdown days for the year; the East Texas field to 131; and the Rodessa field (Cass County, Texas, portion) to 5 days. No important changes were made in field rules and regulations during the year regarding the allocation of oil in individual fields in this district. Discoveries The Hawkins field is in southeastern Wood County in and principally north of the town of Hawkins. Development to date indicates that the field is somewhat of an elongated anticline trending slightly east of north and the proved oil area appears at this time to cover approximately 4000 acres. The oil production has been secured from the Woodbine sand, Upper Cretaceous; a considerable quantity of gas has been encountered in the Sub-Clarksville formation (Eagleford shale) in the higher part of the structure. It appears that a free gas

Jan 1, 1941

By J. A. Morgan, R. E. Lund, D. E. Warnes

The design, operation, and performance of an integrated pilot plant for recovering zinc and copper from a complex sulfide ore are described. Metallurqical processing comprised selective sulfate roasting in a fluid bed, leaching in a weak sulfuric acid solution, recovering copper by cementation with scrap iron, air oxidation to remove soluble iron, more-or-less conventional Purification for removal of impurities deleterious to zinc electrolysis, recovering zinc by electrolyzing solutions, and recycling spent electrolyte to the sulfating roaster. The effects of several feed preparation and roasting variables on the sulfation response of zinc, copper, and iron are set forth, together with the electrolyzing characteristics of the zinc solutions. SEVERAL years ago, St. Joseph Lead Co. undertook a research program to develop procedures for winning values from a complex ore. The deposit was a massive sulfide ore body containing upwards of 65 pct pyrite. Gangue, composed principally of quartz, calcite, dolomite, and alumina, comprised only 10 to 20 pct of the mineralized zones. Zinc, lead, and copper values were variable, but averaged about 6.7 pct Zn, 2.6 pct Pb, and 0.4 pct Cu. Early in the exploratory test work, it was established that the intimate physical association of the minerals in the ore made beneficiation by conventional flotation procedures difficult. Accordingly, in addition to a comprehensive program to investigate physical methods of ore beneficiation, a research program was established to develop a direct metallurgical method for processing the ore. After surveying a number of potential methods for recovery of both metal and sulfur values, effort was concentrated on the development of a sulfate roasting process. It is the pilot-plant development of the sulfate roasting-solution purification—electrolyzing procedures which forms the subject of the present paper. PREPILOT PLANT INVESTIGATIONS From a thermodynamic viewpoint, it is feasible to sulfate selectively a host of metals, including Zn, Cu, Pb, Cd, Ni, and Co, in an iron sulfide ore without sulfating iron. Of course, a number of conditions such as roasting temperature and gas composition must be controlled. In addition, as first disclosed by Hybinette,' an alkali metal salt is frequently beneficial in promoting the sulfation reactions. The application of fluid bed roasting to the sulfate roasting of nonferrous metals was pioneered by Stephens of Battelle Memorial Institute.' Subsequently, Falconbridge Nickel Mines, Ltd. developed an unique process for selectively sulfating and recovering nickel, copper, and cobalt from their nickeliferous pyrrhotite, which recently has been described in an excellent paper by Thornhill.3 One of the unique features of the Falconbridge process is that the feed is introduced into the fluidized roasting furnace in a manner such that the feed slurry is broken up into droplets and the droplets lose their moisture before contacting the surface of the fluidized bed. The dried droplets do not tend to cake or fuse, but rather remain as discrete agglomerates of concentrate particles and roast without significant degradation. St. Joseph, aware that Battelle Memorial Institute had participated in the development of the Falconbridge process, obtained permission from Falcon-

Jan 1, 1962

By Nicholas J. Grant, W. Michael Yim

The creep-rupture properties of nickel, in as-prestrained or prestrain-polygonized condition, were studied at 1300°F and 4000 psi, and also at 700°F and 26,000 psi. An improvement of strength was noted in both the as -prestrained and the prestrain-polygonized tests at each temperature. The as-prestrained tests, however, showed superior creep resistance to the prestrain-polygonized ones. From the results of X-ray and etch-pit studies, the strengthc gain was interpreted in terms of dislocation density and the stability of preformed substructures. COLD work is known to improve the strength properties of metals at low temperatures. At high temperatures, however, the strength improvement is often lost if gross structural changes, such as re-crystallization, take place prior to or during the test. Even in the absence of recrystallization, a prestrained metal may undergo structural changes— polygonization and the formation of well-defined subgrains—which importantly effect the resultant properties. The relationship between substructure and creep properties has received considerable attention in recent years. The work of wood1 indicated that the creep strength of aluminum and its alloys was closely related to the subgrain size. Hazlett and Hansen,2 and Ancker, Hazlett, and parker,3 working with nickel and nickel alloys, had shown that small amounts of prestrain at room temperature followed by a recovery anneal at 800°C (1470°F) improved the strength at both low and high temperatures. The strength gain was attributed to an increase in the number of subgrain boundaries as a result of the prestrain-polygonization treatment. More recently Coldren and Freeman4 studied the effect of substructures on the creep rate of nickel at 1550°F. Their conclusions indicated that the substructure size as measured by the number of boundaries was the factor that controlled the creep rate. In addition, the perfection of the subgrain boundary has been indicated to have an important role on the strength.' On the other hand, there are data which disagree with the above observations. Grant, Chaudhuri, Silver, and Ganow6 found no creep strength improvement by a prestraining treatment. In reviewing the role of subgrains on high-temperature creep, Shepard and Dorn7 concluded that the contribution of the subgrains to high-temperature creep strength was a minor one. Guard,8 in a recent study on poly-gonized nickel, has cast doubt on the validity of the postulate that subgrain size controls the creep rate. In the majority of the previous studies, the subgrain boundaries have been singled out as the most important factor in determining creep strength; however, there is no firm theoretical ground for the postulate that the subgrain boundaries act as effective barriers to dislocation motion.B910 Little effort has been directed toward the study of the relationship between creep strength and other structural variables, such as dislocation density, lattice strain,

Jan 1, 1963

By E. R. Johnson

The copper concentrator of the Braden Copper Co. is at Sewell, Chile, on the westem flank of the main Cordillera of the Andes, at an air distance of approximately 50 miles southeast of Santiago, the capital of Chile. The region is mountainous and space is at a premium because of the rough terrain and the danger of snowslides. The ore, a porphyry copper, is mined by a block-caving method in the El Teniente mine. It is hauled to the crushing plant, a distance of 2.6 miles, through a tunnel because of the severe climatic conditions. The usual large, coarsely set, primary reduction machines found in many ore-treating plants are not required because of the mining method employed and the limiting 12-in. spacing of the grizzlies at the head of each ore pass in the mine. It is the purpose of this paper to describe the numerous improvements made in the crushing section of this large flotation concentrator during the past I5 years to increase the efficiency of the plant and to raise the daily output from around 20,000 to 30,000 tons. The reader should keep in mind that all changes were made within the existing building because of the limited space and the high cost of the heavy mill construction required to withstand the snow loads. The present plant, as well as the former, operates on a 24-hr, 7 days a week basis. The crushing plant commenced operations at its present site in 1921, the main equipment being No. 7½ gyratories, followed by 48-in. horizontal Symons disk crushers. Fines were removed by I-in. stationary grizzlies ahead of each unit. In 1924 a third stage of crushing was provided by the addition of 55½-in. rolls in open circuit. During 1925, the Symons disks were replaced by 73½-in. rolls. All the rolls were changed to closed circuit, with elevators and screens to give a final product of 9 pct plus 3-mesh. The flowsheet of a typical crushing section of this period is shown in Fig I. The ore was withdrawn from a common bill serving the five crushing sections in the plant by means of any number up to six 36-in. wide-apron feeders, which discharged onto a common conveyor belt. This conveyor was equipped with a magnetic head pulley and the crusher attendant was stationed near the discharge end to pick out pieces of mine timber that might be in the ore. The ore was discharged over a 13/4-in. spaced bar grizzly and the oversize of this grizzly was crushed by a No. 7½ McCully gyratory crusher set at 13/4-in. opening on the closed side. The grizzly undersize joined the gyratory discharge and was conveyed to a set of 73½ by 20-in. Garfield rolls set at I in. These rolls operated in closed circuit with a bucket elevator and two vibrating screens placed in parallel.

Jan 1, 1949

By B. W. Dyer

In 1924, the Crescent Eagle Oil Co., while drilling the salt section of the Paradox formation in Grand County, Utah, encountered a salt that did not appear to be sodium chloride. This salt was analyzed and showed the presence of potash minerals, both sylvite (KCl) and carnallite (KMgC12.6H2O). Because of the high potash content of the sample, there was considerable speculation: (I) as to whether the hole had been salted, and (2), if not, the extent, richness, and the depth at which the deposit occurred. The discovery caused a large amount of activity in the area. During the next few years, 68 potash prospecting permits were issued by the Government, 24 under the Act of 1917 and 44 under the Act of Feb. 7, 1927, each including about four sections of land. Several holes, all shallow, were drilled for potash. A number of holes were drilled for oil into the salt horizon and the cuttings collected at the oil wells were examined petrographically and chemically. The shallow test holes were not sufficiently deep to reach the potash horizon and revealed nothing of value, but several of the oil test holes gave some indication of where potash might be found. Location and Geology of Deposits The potassium and magnesium salts have been found in various places from the Denver and Rio Grande Western Railroad tracks about seven miles west of Thompsons, in eastern Utah, to Cane Creek, a tributary of the Colorado River— a distance north and south of about 35 miles. In this locality, there appear to be five separate deposits: the Crescent Eagle area, which is in T. 22 S., R. 19 E.; the Salt Valley area, in the vicinity of the north-south line of T. 23 S., between R. 20 E. and R. 21 E.; the Seven Mile area, in the eastern part of T. 25 S., R. 20 E.; the Cane Creek area, on the Colorado River, in T. 26 S. and T. 27 S., R. 20 E. and R. 21 E.; and the Salt Wash area, in T. 22 S. and T. 23 S., R. 16 E. and R. 17 E. (Fig. I.) The Crescent Eagle and Salt Valley areas are in the Salt Valley anticline, some of the wells being in the fault graben and others outside. Structurally, the Salt Valley anticline is very complex, and can be described in general terms as a northwesterly plunging collapsed anticline about 15 miles long. In the Crescent Eagle area, the valley graben is about 1 1/2 mile wide and the salt probably forms a plug, the apex of which is in the vicinity of the Crescent Eagle well. Owing to the complex structure, there has been every opportunity for flowage in the salt to cause local thinning or thickening of beds. The regular succession of formations in the general area* is: Cretaceous Mancos Dakota Jurassic Morrison Summerville Entrada Carmel

Jan 1, 1948

By B. W. Dyer

In 1924, the Crescent Eagle Oil Co., while drilling the salt section of the Paradox formation in Grand County, Utah, encountered a salt that did not appear to be sodium chloride. This salt was analyzed and showed the presence of potash minerals, both sylvite (KCl) and carnallite (KMgC12.6H2O). Because of the high potash content of the sample, there was considerable speculation: (I) as to whether the hole had been salted, and (2), if not, the extent, richness, and the depth at which the deposit occurred. The discovery caused a large amount of activity in the area. During the next few years, 68 potash prospecting permits were issued by the Government, 24 under the Act of 1917 and 44 under the Act of Feb. 7, 1927, each including about four sections of land. Several holes, all shallow, were drilled for potash. A number of holes were drilled for oil into the salt horizon and the cuttings collected at the oil wells were examined petrographically and chemically. The shallow test holes were not sufficiently deep to reach the potash horizon and revealed nothing of value, but several of the oil test holes gave some indication of where potash might be found. Location and Geology of Deposits The potassium and magnesium salts have been found in various places from the Denver and Rio Grande Western Railroad tracks about seven miles west of Thompsons, in eastern Utah, to Cane Creek, a tributary of the Colorado River— a distance north and south of about 35 miles. In this locality, there appear to be five separate deposits: the Crescent Eagle area, which is in T. 22 S., R. 19 E.; the Salt Valley area, in the vicinity of the north-south line of T. 23 S., between R. 20 E. and R. 21 E.; the Seven Mile area, in the eastern part of T. 25 S., R. 20 E.; the Cane Creek area, on the Colorado River, in T. 26 S. and T. 27 S., R. 20 E. and R. 21 E.; and the Salt Wash area, in T. 22 S. and T. 23 S., R. 16 E. and R. 17 E. (Fig. I.) The Crescent Eagle and Salt Valley areas are in the Salt Valley anticline, some of the wells being in the fault graben and others outside. Structurally, the Salt Valley anticline is very complex, and can be described in general terms as a northwesterly plunging collapsed anticline about 15 miles long. In the Crescent Eagle area, the valley graben is about 1 1/2 mile wide and the salt probably forms a plug, the apex of which is in the vicinity of the Crescent Eagle well. Owing to the complex structure, there has been every opportunity for flowage in the salt to cause local thinning or thickening of beds. The regular succession of formations in the general area* is: Cretaceous Mancos Dakota Jurassic Morrison Summerville Entrada Carmel

Jan 1, 1948

By Charles Wert

THE diffusion and precipitation of carbon and nitrogen in a iron have previously been investigated using the internal friction as a measuring tool.' Most of this work has been done on rather pure iron; no effect was observed which would indicate that either of these phenomena is affected by the rather small amounts of impurity found in these samples of iron. Fastz observed, however, that both the diffusion rate and the aging properties of nitrogen in iron were sensibly changed by the addition of Vz pet Mn. The diffusion rate at a given temperature is reduced and the nucleation of nitrides is apparently changed somewhat. He observed no such changes for carbon in this alloy. Later Dijkstra and Sladek" extended these observations on nitrogen to other alloys of iron. They found that metals other than manganese also influence the behavior of nitrogen in iron; chromium, molybdenum and especially vanadium affect the diffusion and precipitation of nitrogen even more than manganese does. Their results have been verified in all essential details by this author, who finds in addition that small additions of nickel have about the same effect on the diffusion of nitrogen as the same amount of manganese. The present work was undertaken to study the effect on carbon in iron of these alloying elements. The alloys used had two sources. The material used as a "standard" (designated Fe in this paper) in the measurements was some iron supplied by J. K. Stanley, of Westinghouse Electric Corp., who reported 0.01 pct 0, as the only major impurity. He also made up an alloy of 0.26 pct Ni and one of 0.9 pct Mo using this same iron as a base. They were supplied by him in 2 lb billets, which were sawed into rods and cold formed into 0.030 in. wires for measurement. The alloys of chromium, manganese, and vanadium were prepared by the metallurgy section of the Institute for the Study of Metals, University of Chicago, by adding these metals in turn to vacuum melts of National Research Corp. iron. The small castings prepared in this way were also cold formed into 0.030 in. wires. After these wires had been prepared they were decarburized for 30 min at 730°C in wet Hz. After this treatment, no trace of carbon (as measured by internal friction) could be found. All specimens were then carburized for about 15 min at 710°C and water quenched. By this treatment the internal friction at 40°C was raised to a Q-' ~ 0.015. The diffusion of carbon in these alloys was studied by observing the shape and position of the internal friction peak at 0.9 cycles per sec. These measurements were made using a torsional pendulum in a manner described earlier.' The data are plotted in Fig. 1. It is seen that there is no apparent difference in internal friction between the various alloys. This is in marked distinction to the broadening and shift-

Jan 1, 1953

By B. W. Dyer

IN 1924, the Crescent Eagle Oil Co., while drilling the salt section of the Paradox formation in Grand County, Utah, encountered a salt that did not appear to be sodium chloride. This salt was analyzed and showed the presence of potash minerals, both sylvite (KC1) and carnallite (KMgC12.6H20). Because of the high potash content of the sample, there was considerable speculation: (I) as to whether the hole had been salted, and (2), if not, the extent, richness, and the depth at which the deposit occurred. The discovery caused a large amount of activity in the area. During the next few years, 68 potash prospecting permits were issued by the Government, 24 under the Act of 1917 and 44 under the Act of Feb. 7, 1927, each including about four sections of land. Several holes, all shallow, were drilled for potash. A number of holes were drilled for oil into the salt horizon and the cuttings collected at the oil wells were examined petrographically and chemically. The shallow test holes were not sufficiently deep to reach the potash horizon and revealed nothing of value, but several of the oil test holes gave some indication of where potash might be found. LOCATION AND GEOLOGY OF DEPOSITS The potassium and magnesium salts have been found in various places from the Denver and Rio Grande Western Railroad tracks about seven miles west of Thompsons, in eastern Utah, to Cane Creek, a tributary of the Colorado Rivera distance north and south of about 35 miles. In this locality, there appear to be five separate deposits: the Crescent Eagle area, which is in T. 22 S., R. 19 E.; the Salt Valley area, in the vicinity of the north-south line of T. 23 S., between R. 20 E. and R. 21 E.; the Seven Mile area, in the eastern part of T. 25 S., R. 2o E.; the Cane Creek area, on the Colorado River, in T. 26 S. and T. 27 S., R. 2o E. and R. 21 E.; and the Salt Wash area, in T. 22 S. and T. 23 S., R. 16 E. and R. 17 E. (Fig. I.) The Crescent Eagle and Salt Valley areas are in the Salt Valley anticline, some of the wells being in the fault graben and others outside. Structurally, the Salt Valley anticline is very complex, and can be described in general terms as a northwesterly plunging collapsed anticline about 15 miles long. In the Crescent Eagle area, the valley graben is about 1 mile wide and the salt probably forms a plug, the apex of which is in the vicinity of the Crescent Eagle well. Owing to the complex structure, there has been every opportunity for flowage in the salt to cause local thinning or thickening of beds. The regular succession of formations in the general area* is: [Cretaceous Mancos Dakota Jurassic Morrison Summerville Entrada Carmel]

Jan 1, 1945

By W. I. Duvall, L. D. Sadwin

Three explosives with different detonation characteristics were tested by studying their cratering ability in a granite-gneiss. The strain wave generating characteristics of these explosives were also studied in the same rock medium. Correlations between the relative performance of three explosives as evaluated by crater studies and other methods of evaluation are indicated. Numerous test methods have been employed to evaluate the output performance of explosives; for example, the underwater explosion method, the airblast method and the ballistic pendulum method.'*' For blasting applications, the study of explosion produced craters and explosion generated strain waves are the most meaningful. This laboratory has employed these techniques extensively for many years and has shown that the detonation properties of explosives and their ability to generate strain waves in rock are related and that the amplitude and shape of the strain wave is related to some of the crater parameters such as slab thickness and fly rock velocity.3'11 However, a good comparison between the relative performance of explosives as determined by the crater and strain wave methods had not been made. The purpose of this investigation was to determine if the relative performance of three explosives as determined by the crater method shows a correlation with the relative performance as determined by the strain wave method. If a good correlation exists between these two sets of relative performance, it should then be possible to relate the detonation properties of an explosive to its ability to break rock in a crater test. In most commercial blasting operations, the diameter of the blast hole remains constant even though the type of explosive may change. In general, it is the explosive volume rather than the weight which remains constant when two or more explosives of different density are compared. Therefore all tests in this investigation were conducted on a constant volume basis rather than on a constant weight basis. TEST SITE AND ROCK PROPERTIES The tests described in this paper were conducted at a granite quarry owned and operated by the Consolidated Quarries Div. of the Georgia Marble Co. at Lithonia, Ga. The tests were performed in an area where the exposed rock surface was nearly horizontal and where the general rock mass had few joints or faults. The rock has an apparent sp gr of 2.6 and a longitudinal propagation velocity of 18,000 fps. The characteristic impedance of Lithonia granite gneiss is 53(lb - sec/in3). EXPERIMENTAL PROCEDURE There are many parameters which must be considered in the study of explosion-produced craters. The role played by each variable in the explosive-rock-crater system can be determined by experimental techniques in which one parameter is varied while others are maintained constant. In this investigation, the crater geometry was studied as the depth was varied for each of three explosives. The explosive volume and rock-type were held constant for all crater tests. The experimental arrangement used in performing the crater tests is illustrated schematically in Fig. 1.

Jan 1, 1965

By Zárate G. E.

Practical and statistical considerations concerned with the sampling, sample preparation and chemical analysis of precious metal ores are reviewed. The principal requirements related with the characteristics of sample cutter, sample preparation, equipment and methods are discussed. The main errors introduced in the different stages of the sampling systems are defined. The application of statistical techniques to evaluate these errors to determine the ore grade variation and to design the number of increments needed to get an accurate assay are presented. Finally, results obtained with the application of this method to gold and silver ores are analyzed and some recommendations are given.

Jan 1, 1984

By J. F. Elliott

PRESENT knowledge of the usual metallurgical slags indicates that they are, for the most part, rather complex in behavior and as yet there is no ready means for describing, in a simple manner, the behavior of any one of them. One of the best known slag systems is the iron oxide-silica-lime ternary which is the basic "solvent" in a number of important metallurgical refining operations, the basic open hearth being one of the most important. In this operation, the slag dissolves such components as sulphur, phosphorus, manganese oxide, and magnesia. Considerable study of this slag system and the behavior of these additions has been carried out in the past by a number of authors, as has been summarized in several critical reviews.','2 However, except for determination of the activity of iron oxide, only a limited amount of effort has been directed towards developing, from these data, an understanding of the general behavior of the basic solvent. Reported here are the results from a series of calculations based on data from the literature which permit a semiquantitative evaluation of the activities of iron oxide, silica, and lime (plus magnesia) in the ternary system at 1600°C. The preliminary results, which were reported briefly at a symposium held by AIME in 1953, have been revised and are completed. The steps in the calculation are as follows:* I—establish the activity curves and the curve of the excess molar free energy of mixing at 1600°C for each of the binary systems, 2—construct the activity surface of iron oxide for the ternary from the data on the binary systems and information available in the literature for the ternary area, 3—determine the surface of excess molar free energy of mixing for the ternary system from the activity surface of iron oxide and from the molar curves obtained for the binary system, and 4—differentiate the ternary surface of the molar excess free energy of mixing to obtain the ternary surfaces for the logarithm of the activity coefficients for silica and lime (log rslo, and log rc.~). Si0,-Fe,O: Schuhmann and Ensio have measured the activity of iron oxide in simple iron oxide-silica slags when in equilibrium with y iron. Their data recalculated to 1600°C are shown in Fig. 1. Also included is a point representing a measurement by Gokcen and Chipmana of the activity of iron oxide at 1600°C at the point of saturation with solid silica. For convenience and in accordance with other treatments,' the calculations are based on the hypothetical component, FelO, which is obtained by converting all the analyzed iron in the slag to FeO. In spite of Schuhmann and Ensio's conclusion that the activity of iron oxide in the system does not vary with temperature over the experimental range of 1258" to 1407"C, the data are corrected to 1600°C assuming that temperature does have an effect. It was felt to be most reasonable to assume that the term log rr.10 is a linear function of the reciprocal of the temperature. Reyu has indicated that an effect of temperature on the activities in this system is to be expected from the Schuhmann and Ensio data. In essence, the correction consists of multiplying the experimental value of log rf,,o by the ratio of the experimental temperature in Kelvin to 1873°K. The magnitude of the correction is not large, being approximately 11.5 pct of the experimental value of log rve10. A very minor correction was necessary to compensate for the fact that the slags were in equilibrium with y iron in the experiment, while at steel-making temperatures they would be in equilibrium with liquid iron. Data for the correction were obtained from Darken and Gurry. The standard states established are pure liquid iron oxide (FelO) in equilibrium with pure liquid iron (with the appropriate amount of oxygen in solution) and pure liquid silica. The method of plotting in Fig. 1 is convenient for the calculation of the activity of liquid silica and permits a reasonable extrapolation for the activity of Fe,O in the ranges where no experimental data are available. The uncertainty in the extrapolation to infinity at one terminal where Nvelo = 1 for the usual Gibbs-Duhem integration is reduced considerably by this method. The region of two coexisting liquid phases is estimated to range from 1.8 to 41.7 mol pct Fe,O. The nature of the activity curve for the single-phase region indicates that the activity of iron oxide across the two-phase region is very close to 0.39. Computation of the function log ~F,,o/(1— NF,,o)' for this region (dashed line) in conjunction with the curve through the adjusted experimental data indicate the best probable value of 0.382 for alPe,o in the two-phase area. The line from 0 to 0.018 Nf~~o is obtained by assuming that the component follows Henry's law. In this range, the value for log rveto is 2.59. Appropriate mathematical manipulation of the plotted linet yields the activity curves for the The curve AF", the excess molar free energy of mixing (actual minus ideal), as shown in Fig. 3 is also computed from Fig. 1. This curve is required for subsequent calculations. CaO-Fe,O: The phase diagram for the lime-iron oxide system when in equilibrium with liquid iron is not well known but there appears to be no intermediate compound present. This fact as well as the activity values for Fe,O extrapolated to the CaO-Fe,O binary from Taylor and Chipman' tend to indicate somewhat negative deviations from ideality for the activity curves for the two components. Strong indication of this is evident in Fig. 1 where are plotted the points computed from the estimated activities of Fe,O for the binary system.' It appears that the best line through the data is a horizontal straight line. Because of the general indication of the slight negative departure from ideality, the line is extrapolated horizontally to NF~,o = 0. It is con-

Jan 1, 1956

By C. W. Dunham

FROM the primary gyratory crushing plant, described in MacLeod's article, ore is delivered to a large storage or surge bin from which it is carried by two transverse conveyors to the secondary crushing plant. The bin has a useful drawoff of about 13,000 tons, this being slightly over one half of the initial daily capacity of the Morenci Reduction Works. This arrangement provides sufficient storage to permit intermittent operation of the primary and secondary crushing plants without too close a coordination between the two.

Jan 1, 1942

The Ural Mountains, which were formerly the dividing line between Asia and Siberia, area chain of low mountains, the highest peaks reaching only a little over 5000 ft. The country has been much eroded and the mountains now appear as rounded hills. In the central and northern parts turf swamps abound. The range is covered with forests except at the extreme southern end. The trees are mostly pine. Birch grows on cut-over areas, but never to large size. The rivers are small or the fall is slight, so no large water powers are available. A series of rivers with a north and south course, and which are navigable for long distances, furnish cheap transportation during the summer months. Railroad communications are very insufficient. The first active exploitation of the mineral wealth was initiated by Peter the Great, who sought iron and copper for use in his wars against the Swedes. He selected a blacksmith named Demidoff to supervise operations and gave him rights to most of the Ural and to the Altai. The Nijni Tagil Estates are still in the possession of the Demidoff family. The original large grant was subsequently subdivided through inheritance and marriage, but the Ural is still a country of very large estates, some of them held as leases only and some of them by actual ownership.

Jan 6, 1919

By E. J. Roberts

F. C. Bond (Allis-Chalmers Mfg. Corp., Milwaukee) —This paper considers comminution as a first order process, with the reduction rate depending directly upon the amount of oversize material present. The data show that other factors should be taken into account, and it is possible that in time these may be evaluated as simultaneous or consecutive reactions: Development of the theory of comminution has been retarded for many years by the assumption that surface area measurements constitute the sine qua non of the work done in crushing and grinding, and it is encouraging to note the belated growth of other ideas. In the Abstract the term "net power" should be changed to "net energy." Throughout the paper the term "hp per ton" should be changed to "hp hrs per ton", or "hp hr t." The term "Probability Theory" in the title does not seem appropriate, since it is not clear how the probability theory is used in developing the ideas in the paper. There seems to be a contradiction between the large calculated advantages of closed circuit operation and the statement following that the closed circuit test results showed no significant change in grinding behavior, when compared with the batch grind curves. Tables I and II show that between 75 pct and 50 pct solids the energy input required decreases with increasing moisture content and may indicate the advisability of grinding at higher dilutions in certain cases. The calculation of the hp-hr per ton factor indicates an input in the laboratory mill of only 7.32 gross hp per ton of balls; this casts some doubt upon the accuracy of the factor used, since the power input in commercial mills at 80 pct critical speed is customarily much higher. The tests show that within fairly wide limits the amount of ore in the laboratory mill may be varied and a product of constant fineness obtained, provided that the grinding time is varied in the same proportion. This has often been assumed, and confirmation by actual testing is of value. The Cavg corrections for differences between the plant and laboratory size distributions do not seem very satisfactory, since in many cases the plant/laboratory ratio is farther from unity after correction than before. The following equation has been derived from the data in Table VI: Relative Energy (log new ball diam in in. + 0.410) Input = --------------—--------------- from which the relative energy inputs for balls of different sizes can be calculated and compared. The relative energy input is unity for balls of 2.715 in. diam. The equation indicates that the work accomplished by a ton of grinding balls per unit of energy input is roughly proportional to the square root of the total ball surface area; provided, of course, that the balls are sufficiently large to break the material. The data in support of this statement are admittedly meager, but are fairly consistent when plotted. The relative grindability values listed in Table VI for 200 mesh multiplied by 4/5 apparently correspond approximately to the A-C grindability at 200 mesh.' It would seem that for open circuit tests comparable accuracy could be obtained much more simply by the old method' of plotting the test grind, extending the mesh grinds to the left of zero time if necessary, and determining from the plot the equivalent time required to grind from the plant feed size to the plant product size, using the average of several mesh sizes. The en- ergy input value of one time interval could be determined by tests on materials of known grinding resistance, and this multiplied by the interval required should give the desired energy input value. The relative grindabilities would be the relative time intervals required for a specified feed and product size. When the plotted mesh size lines of a homogeneous material are extended to the left beyond zero time they meet at one point at zero pct passing. The horizontal distance of this point from zero time indicates the equivalent energy input required to prepare the mill feed. The author's results show that the closed circuit grinding tests give about the same K values as open circuit tests, from which he concludes that open circuit tests are satisfactory in many cases. The value of the closed circuit test is its ability accurately to predict energy requirements in closed circuit grinding for both homogeneous and heterogeneous materials. If the material is homogeneous, the open circuit test gives satisfactory results; but if the material contains appreciable fractions of hard and soft grinding ore, the open circuit tests will not be accurate because of the accumulation of hard grinding material in the circulating load. Since in most cases it is not possible to determine a priori whether the material contains hard and soft fractions, the closed circuit tests are preferable and more reliable. B. S. Crocker (Lake Shore Mines, Ontario)—Dr. Roberts probability theory of grinding is very similar to our log pct reduced vs. log tonnage method of plotting and evaluating grinding tests at Lake Shore. However, although we both seem to start at the same point we finish with different end results. Shortly after publishing our grinding paper (referred to by Dr. Roberts) in 1939, we did pursue the subject of the "constant pct reduction in the pct +28 micron material for each constant interval of time. We ran innumerable tonnage tests on the plant ball mills, rod mills, tube mills with 11/4 and 3/4 balls, and lastly pebble mills, with tonnage variations from 180 tons per day to 950 tons per day. We found that when we plotted the log of the tonnage against the log of the pct reduced of any reliable mesh, we had a straight line up until 90 pct of the mesh is reduced. We have also tested this in our 12-in. laboratory mill with the same results. We have used this method of evaluating grinds for the past 8 years and developed the recent four stage pebble plant on this basis. By pct reduced we mean the percentage of any given mesh that is reduced in one pass through a mill at a given tonnage (or time). For example, if the feed to a rod mill is 90 pct +35 mesh and the discharge at 500 tons per day is 54 pct +35, the pct reduced is 90 — 54/90 = 40 pct. If the feed had been 80 pct +35 the discharge would have been 48 pct +35 or pct re- duced 80-48/80 = 40 pct as long as the tonnage re- mained constant at 500 tons per day. Thus we can easily correct for normal variation of mill feeds. This log — log relationship derived from the tonnage tests of all our operating mills has proved of tremendous help in checking laboratory work and in designing alternate layouts or new plants. The difference between the log — log and the semi-log plot is only shown up when the extremes in tonnages are plotted. When the relationship between the pct reduced and the tonnage was first investigated, we used semilog

Jan 1, 1952