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By W. N. Tanner

THE wire-rope hoisting conditions at the mines of the Anaconda Copper Mining Co. in Butte, Mont., are very severe because of the conditions under which it is necessary to operate. A study was made, in the fall of 1919, for the purpose of changing these conditions in order to obtain longer rope and sheave life. There are at present in Butte, hoisting engines equipped with wire rope as follows: 9 main hoists using flat ropes. 7 main hoists using 1 ½ in. rope. 5 main hoists using 1 ¼ in. rope. 6 shafts using 1 1/8 in. rope. 2 chippy hoists using 1 ¼ in. rope. 9 chippy hoists using 1 1/8 in. rope. 15 shafts using 1 in. rope. 7 shafts using 7/8 in. rope. 1 shaft using ¾ in. rope. In addition, there are a number of sinking engines using 5/8 in., ¾ in., 7/8 in., and 1 in. (15.9, 19, 22, and 25 mm. rope.) The flat ropes run from ½ by 7 ½ in. (12.7 by 190.5 mm.) to ½ by 4 ½ in. (9.5 by 114 mm.) and are used on the older hoisting-engines, which are set comparatively close to the shaft. Because of swelling and moving ground at some of the shafts, these ropes present certain difficulties in operation that are more pronounced than with round ropes; they are, therefore, being superseded by round ropes as newer engines are being installed. They are, however, much more easily inspected and repaired than round ropes.

Jan 2, 1922

By Bhudeo N. Sinha, Paul Dean Proctor

Heavy metal contents in stream waters, sediments, and selected aquatic algae were determined for the upper Meramec River basin, Missouri, of 3905 km2 (1508 sq mi) area and site of the proposed and controversial Meramec dam and reservoir. Six distinct drainage areas within the basin are: (1) a lightly industrialized and farm area, (2) a primitive forested- ranch area, (3) an area which includes the Northern New Lead Belt, (4) the westward drainage of an old and extensive barite mining area, (5) the main trunk of the Meramec River, and (6) short north-divide tributaries of the Meramec River. Lower Paleozoic sediments rest nonconformably upon eroded and hilly Precambrian igneous basement. This locally rises as major inliers and also makes up the St. Francois Mountains to the east. Major lead, and lesser zinc, copper, cobalt, and nickel mineralization occurs in the buried Cambrian Bonneterre dolomite. Residual barite is present along the eastern fringe of the basin and is derived from the Potosi formation. Some 62 water samples, active stream sediments (AS), bank samples (BS), and 11 selected aquatic algae samples were collected in the various drainage areas and analyzed for copper, lead, zinc, cadmium, nickel, arsenic, and mercury contents. Heavy metals in water have a maximum range of 1-120 ppb (parts per billion), and this for zinc. The AS and BS sediments have orders of magnitude greater acid leachable metal contents in the -80 mesh fraction, with lead hawing the greatest range of 11-1028 ppm. Heavy metal content of stream-algae approaches that of the sediments in which they grow. Most anomalous heavy metal accumulations occur near mining and milling activities and in the streams draining such areas. Significant distortions of the primary dispersion pattern militate against geochemical exploration for hidden ore zones, but do demonstrate the mining, milling, and smelting activities of man, and sporadic mineral occurrences in younger horizons.

Jan 1, 1980

By Henry M. Howe

THE death of Sir Lowthian Bell removes almost the last of the group of heroic leaders who made their age and ours the Age of Steel-a group which his luster and the luster of his peers, Bessemer, Siemens and Tunner, made one of the most brilliant, perhaps even the most brilliant, in the annals of industry. Born on February 15th, 1816, in Newcastle-on-Tyne, he was the eldest son of Thomas Bell, an alderman of Newcastle, and of his wife Catherine Lowthian of Newbiggin, near Carlisle, in Cumberland, and was christened Isaac Lowthian, the name of his maternal grandfather. His father was born about 1788, and came in 1808 from Newbiggin to Newcastle, where he entered the office of the Cumbrian firm of Losh and Company, manufacturers of alkali and wrought-iron, at the Walker Iron and Alkali Works, at Walker, Dear Newcastle. Young Isaac Lowthian Bell was educated at Dr. Bruce's school in Newcastle, whence he went to Germany and Denmark, learning there German and Danish. On his return he studied at Edinburgh University, and then at the Sorboune in Paris. As a student he already showed the remarkable character and application which later gained him such distinction. After studying the manufacture of alkali near Marseilles, he returned, and when about twenty years old (A.D. 1836) was employed in his father's firm, then called Losh, Wilson, and Bell. After spending a year in their Newcastle offices, and after visiting the important iron-making districts of France, Germany, Poland, and Austria, he took charge of their rolling-mills at Walker, and profited so well by his opportunities, and especially by the teachings of his father and of Mr. John Vaughan (later one of the founders of the great firm of Bolckow, Vaughan & Co.), that he was made manager of the Walker works in or about

Sep 1, 1905

By C. D. Tedmon, D. P. Ferriss

THE yield stress, o of low-carbon steel has been shown to vary with the average grain diameter, d, according to the relation1-3 where o is taken to be the lower yield-point stress Of is the friction stress on an unlocked dislocation, and ky is a constant. The interpretation2,4 of ky in terms of dislocation theory relates this constant to the stress to unlock a source across a grain boundary. cottrel14 predicted that ky would increase with decreasing temperature. This was observed to be the case by Adams and coworkers5 in their investigation of niobium (columbium). However, petch6 and Backofen: both working with low-carbon steel, found ky insensitive to temperature. In his work with high-purity niobium, Johnson' found ky equal to zero. Evansg showed that k, was essentially zero for niobium containing nitrogen in an appreciable concentration range. The present experiments were designed to check this apparent anomaly in the value of ky in another Group V metal. Yield points were determined as a function of grain size at several temperatures for tantalum and a tantalum-tungsten alloy. The material used was double are-melted tantalum and a double are-melted alloy of 90 pct Ta and 10 pct tungsten (by weight), both obtained as unannealed, swaged rod. The impurity content of the materials is given in Table I. The tantalum was annealed at 1325"C. in a vacuum resistance furnace using a tantalum boat. The alloy was similarly annealed at 1660°C. Annealing times varied from 15 min to 2 hr, depending on the desired grain size. Nominal pressure in the furnace was 3 X 10~4 mm of Kg. Metallographic examination showed that the annealing treatment produced grain sizes ranging frorn 0.021 to 0.200 mm in the tantalum, and 0.060 to 0.160 mm in the alloy. Tensile bars were made by centerless grinding the annealed specimen;, and then electropolishing to remove all grinding marks. The specimens were than pulled :it 2 1/2 pct per rnin in an Instron testing machine. The tantalum specimens were tested at 77", 195", and 300°K. The alloy was tested at 300°K only. All specimens exhibited a yield-point phenomenon at all temperatures. Typical load-elongation curves at the three test temperatures are shown in Fig. 1. The lower yield stress is plotted as a function of (grain size) in Figs. 2 and 3 for tantalum and the 90 pct Ta-10 pct W alloy, respectfully. The position and slope of the curves was determined by least-

Jan 1, 1962

By J. M. Clark

(Wilkes-Barre Meeting, June, 1911.) For some years past, those interested in the development of the increasingly important mining industry of Canada, have urged the adoption by the Dominion Parliament of a federal mining-law, which would have the force and stability of statutory enactment. At present, placer-mining in the Yukon Territory, is governed by the Yukon Placer Mining Act. All other mining under federal jurisdiction is governed by 'Orders in Council and Ministerial Regulations. In the earlier stages of development, it is perhaps a matter of necessity that these important matters should be so dealt with; but it is now felt that the time has come when mining-rights in the extensive regions under federal control should be put on a permanent basis, -and that any changes required from time to time should be made only after full and open discussion in Parliament. A short sketch will suffice to indicate how vast and varied the interests affected really are. When the Dominion of Canada was constituted by the Imperial Statute known as the British North America Act of 1867 (which came into force by proclamation on July 1 of that year), it comprised only the present Provinces of Ontario, Quebec, Nova Scotia, and New Brunswick; but provision was made for the inclusion of Newfoundland, Prince Edward Island, British Columbia, Rupert's Land, and the North West Territories. Subsequently Rupert's Land and the North West Territories were acquired, the 'Crown Colonies of British Columbia and * SECRETARY'S NOTE.-Mr. Clark, an eminent Canadian lawyer, and joint author of the treatise on "The Law of Mines in Canada," has been requested by the Do¬minion Government to prepare a Federal mining-law, and presents this paper, by invitation of the Council, in order to obtain, if possible, useful suggestions from members of the Institute.-R. W. R.

Apr 1, 1911

By Frank Foote, E. R. Jette

Precision lattice-constant measurements have been widely used in the study of cubic solid solutions but as yet have been rarely applied to noncubic solid solutions. (See, however, references I and 2.) With the high precision at present attainable in the measurement of lattice constants, the X-ray method should be readily applicable to noncubic solid solutions. In the work reported here, hexagonal close-packed magnesium was used as the solvent and either lead, bismuth or gold as the solute. In the magnesium-lead and magnesium-bismuth systems the a and c lattice constants were determined as a function of composition, densities were calculated from these lattice-constant data, these theoretical densities were compared with those directly measured and the solid solubility limit was determined on quenched specimens over a considerable range of temperature. In the magnesium-gold system, the solid solubility is very small but we have obtained an indirect check on the solubility limit previously reported. Materials and Preparation oF the Alloys The magnesium used was obtained from the Aluminum Company of America and was 99.987 per cent pure. Impurities as reported On the label were: Fe, Al, 0'004 per cent; Si, 0.009 per cent; Zn, trace; Cu, Pb, nil. The bismuth was Merck's analytical grade, minimum purity 99.95 per cent. Maximum impurities as listed on the label were: Fe, 0.008 per cent; Pb, 0.010 per cent; Ag, 0.010 per cent; Cu, 0.005 per cent; Sn, 0.003 per cent; Sb, 0.00; As, 0.000; S, 0.01 per cent. The gold was purified by double precipitation with sulphur dioxide. The lattice constants of these three metals have been previously reported.3 The lead used was test lead, silver free and with a maximum of 0.10 per cent heavy metal impurities. The lattice constant 01 this lead has been measured and found to be 4.94057 ± 0.00016 at 25°C. The alloys were prepared by melting together weighed amounts of the constituent metals in magnesia-lined alundum crucibles under an atmosphere of hydrogen purified by passing over magnesium heated to 500°C. The magnesia lining prevented contamination 01 the alloys with aluminum. Vacuum melting could not be used because of the volatility of magnesium. A high-frequency induction furnace was used for the melting operation and the stirring action of the current resulted in thorough mixing of the constituents. The melts were allowed to freeze in the crucible, the ingots obtained weighed about 10 grams. An extremely thin white film formed on the surface of the melts, sometimes covering only a part of the exposed surface. The ingots were filed clean, placed in small iror crucibles with close-fitting lids and indi. vidually sealed into Pyrex glass tubes Before sealing off, the tubes were alter

Jan 1, 1941

By Frank Foote, E. R. Jette

Precision lattice-constant measurements have been widely used in the study of cubic solid solutions but as yet have been rarely applied to noncubic solid solutions. (See, however, references I and 2.) With the high precision at present attainable in the measurement of lattice constants, the X-ray method should be readily applicable to noncubic solid solutions. In the work reported here, hexagonal close-packed magnesium was used as the solvent and either lead, bismuth or gold as the solute. In the magnesium-lead and magnesium-bismuth systems the a and c lattice constants were determined as a function of composition, densities were calculated from these lattice-constant data, these theoretical densities were compared with those directly measured and the solid solubility limit was determined on quenched specimens over a considerable range of temperature. In the magnesium-gold system, the solid solubility is very small but we have obtained an indirect check on the solubility limit previously reported. Materials and Preparation oF the Alloys The magnesium used was obtained from the Aluminum Company of America and was 99.987 per cent pure. Impurities as reported On the label were: Fe, Al, 0'004 per cent; Si, 0.009 per cent; Zn, trace; Cu, Pb, nil. The bismuth was Merck's analytical grade, minimum purity 99.95 per cent. Maximum impurities as listed on the label were: Fe, 0.008 per cent; Pb, 0.010 per cent; Ag, 0.010 per cent; Cu, 0.005 per cent; Sn, 0.003 per cent; Sb, 0.00; As, 0.000; S, 0.01 per cent. The gold was purified by double precipitation with sulphur dioxide. The lattice constants of these three metals have been previously reported.3 The lead used was test lead, silver free and with a maximum of 0.10 per cent heavy metal impurities. The lattice constant 01 this lead has been measured and found to be 4.94057 ± 0.00016 at 25°C. The alloys were prepared by melting together weighed amounts of the constituent metals in magnesia-lined alundum crucibles under an atmosphere of hydrogen purified by passing over magnesium heated to 500°C. The magnesia lining prevented contamination 01 the alloys with aluminum. Vacuum melting could not be used because of the volatility of magnesium. A high-frequency induction furnace was used for the melting operation and the stirring action of the current resulted in thorough mixing of the constituents. The melts were allowed to freeze in the crucible, the ingots obtained weighed about 10 grams. An extremely thin white film formed on the surface of the melts, sometimes covering only a part of the exposed surface. The ingots were filed clean, placed in small iror crucibles with close-fitting lids and indi. vidually sealed into Pyrex glass tubes Before sealing off, the tubes were alter

Jan 1, 1941

THE annual meeting of the Lake Superior Mining Institute was held on Sept. 7 and 8, Crystal Falls and Iron Mountain, Mich., being the principal centers of activity. Members of both institutes began assembling early, and by the evening of Sept. 6, some 60 had already arrived at Crystal Falls. The greater number arrived the following morning, however, and after the usual formalities of registration were attended to, the party were loaded into automobiles and set out on a tour of inspection of the mines near Iron River; some properties were passed through, and some were briefly visited to permit the inspection of any unusually interesting piece of equipment or detail of practice. The last stop of the morning was at the Caspian, Iron River, where the entire party was entertained at luncheon at the Caspian Club House. Both the food and the company were excellent, and as the weather was superlatively good (though the natives of the district modestly declared it was only ordinary autumn weather) the lunch was served on the lawn at the rear of the club, where the green turf, abundant flowers, and music by the band, added to the charm of good fellowship. The degree to which mining men have become addicted to golf was indicated by the large number of plus fours in evidence, whose wearers appeared just before lunch and disappeared immediately afterward.

Jan 1, 1928

By Ralph H. Sweetser

BENEFICIATION of iron ores from the blast-furnace point of view means more than the usual enrichment of the iron contents by the removal of a large part of the clay, carbonic acid gas, silica, or moisture of the natural ore; it includes all these, but it also embraces several other mechanical .processes made , necessary by the exacting requirements of present-day blast-furnace practice. The increasing use of iron- bearing by-products, to as much as a third or more of the total ore burden, has introduced still another series of processes for improving the blast-furnace ore burden. As we look back over the past three decades of blast- furnace practice 'in. this country, we see that many of the blast-furnace troubles were directly due to lack of proper preparation of the iron ore burden,, and we realize that beneficiation in one form or another would have remedied the trouble. This was particularly true in the smelting of magnetic iron ores, where run-of- mine ore included such big lumps of 'magnetite along with rich fines that the furnace operations were greatly retarded and control of the furnace such as is usual today, was completely unknown.

Jan 1, 1930

By Frank Foote, E. R. Jette

In recent years the constitution of the high-silver aluminum-silver alloys has been extensively investigated. Hansenl has reviewed the literature to 1935. More recently, Obinata and Hagiya,2 Hofmann and Volk,3 Taziri4 and Tishchenko5 have confirmed the general features of the phase diagram in the region around 25 atomic per cent aluminum. In this paper we present the results of high-precision measurements of lattice constants of the silver-rich alpha solid solution in the homogeneous range and the neighboring two-phase regions. These results are used to establish the nature of the solid solution, the identity of directly measured densities with those calculated from lattice constants and the homogeneity limits of the alpha solid solution with respect to three different neighboring phases. A study of the earlier investigations indicated that the last two subjects in particular required new and accurate data. Experimental Procedure Preparation of the Alloys.—The alloys were made from high-purity silver and aluminum. The silver was "Proof Silver," 99.999 per cent pure, supplied by the U. S. Metals Refining Co. The aluminum was 99.97 per cent pure (contained Si, 0.009 per cent; Fe, 0.0016 per cent; Cu, 0.004 per cent) and was supplied by the Aluminum Company of America. The lattice constants of these two materials have been reported by Jette and Foote.6 Weighed amounts of the two metals were placed in alundum crucibles and melted in vacuo in a high-frequency induction furnace. The melts were allowed to cool in the crucible, the ingots thus obtained weighed about 10 grams. These ingots were then filed clean, hamered, again cleaned and given a homogenizing anneal in vacuo of from 6 to 15 days at temperatures ranging from 500" to 695°C. The ingots were air-cooled from the annealing temperature. Lattice-constant Measurements.—Carefully prepared filings for X-ray analysis were sealed into evacuated quartz or Pyrex tubes and annealed for various periods of time at suitable temperatures. The furnaces used were vertical, rapid-quenching furnaces, the samples being quenched by crushing the sample tube under water by means of a heavy plunger. The general X-ray technique has been previously described6 The cameras were of the symmetrical, back-reflection, focussing type. Ka, radiation from a cobait-nickel alloy target was used. The wave-length values were taken from the second edition of Siegbaum's book.7 A correction for the index of refraction was applied and the lattice constants were calculated by the method of Cohen.8, 6 The lattice constants were calculated to a common temperature of 25°C., using the value of the linear expansion coefficient of pure silver as 18.9 X 10-6. Presumably the expansion coefficient for

Jan 1, 1941

By Frank Foote, E. R. Jette

In recent years the constitution of the high-silver aluminum-silver alloys has been extensively investigated. Hansenl has reviewed the literature to 1935. More recently, Obinata and Hagiya,2 Hofmann and Volk,3 Taziri4 and Tishchenko5 have confirmed the general features of the phase diagram in the region around 25 atomic per cent aluminum. In this paper we present the results of high-precision measurements of lattice constants of the silver-rich alpha solid solution in the homogeneous range and the neighboring two-phase regions. These results are used to establish the nature of the solid solution, the identity of directly measured densities with those calculated from lattice constants and the homogeneity limits of the alpha solid solution with respect to three different neighboring phases. A study of the earlier investigations indicated that the last two subjects in particular required new and accurate data. Experimental Procedure Preparation of the Alloys.—The alloys were made from high-purity silver and aluminum. The silver was "Proof Silver," 99.999 per cent pure, supplied by the U. S. Metals Refining Co. The aluminum was 99.97 per cent pure (contained Si, 0.009 per cent; Fe, 0.0016 per cent; Cu, 0.004 per cent) and was supplied by the Aluminum Company of America. The lattice constants of these two materials have been reported by Jette and Foote.6 Weighed amounts of the two metals were placed in alundum crucibles and melted in vacuo in a high-frequency induction furnace. The melts were allowed to cool in the crucible, the ingots thus obtained weighed about 10 grams. These ingots were then filed clean, hamered, again cleaned and given a homogenizing anneal in vacuo of from 6 to 15 days at temperatures ranging from 500" to 695°C. The ingots were air-cooled from the annealing temperature. Lattice-constant Measurements.—Carefully prepared filings for X-ray analysis were sealed into evacuated quartz or Pyrex tubes and annealed for various periods of time at suitable temperatures. The furnaces used were vertical, rapid-quenching furnaces, the samples being quenched by crushing the sample tube under water by means of a heavy plunger. The general X-ray technique has been previously described6 The cameras were of the symmetrical, back-reflection, focussing type. Ka, radiation from a cobait-nickel alloy target was used. The wave-length values were taken from the second edition of Siegbaum's book.7 A correction for the index of refraction was applied and the lattice constants were calculated by the method of Cohen.8, 6 The lattice constants were calculated to a common temperature of 25°C., using the value of the linear expansion coefficient of pure silver as 18.9 X 10-6. Presumably the expansion coefficient for

Jan 1, 1941

By V. V. Valleroy, A. J. Cornelius, B. T. Willman, G. W. Runberg, L. W. Powers

This paper reports the results of an investigation into the use of steam as a recovery agent. High oil recoveries by steam, as much as 100 per cent greater than by water flood, were demonstrated in laboratory linear cores. The principal mechanisms responsible for the additional oil have been identified as (1) thermal expansion of the oil, (2) viscosity reduction and (3) steam distillation. Although the first two also enhance recovery by hot water flood, they are effective with steam injection at lower volumes of produced fluids. Steam-zone residual oil saturation is independent of initial saturation. Recovery by steam is greater for lighter oils because they contain a greater fraction of steam-distillable components. Equations for the steam-zone advance in a radial homogeneous system are presented; these show the effect of reservoir parameters. The displacement in the hot liquid region moving ahead of the steam front can be estimated by a calculative procedure which is suggested. The method which takes account of the temperature gradient is applicable also to a regullar hot water flood. INTRODUCTION Considerable industry interest in the application of heat to petroleum reservoirs as a means of increasing oil recovery has been evident in the past few years. Three thermal methods which have attracted interest are (1) the injection of saturated steam, (2) the injection of hot water and (3) the injection of air into a formation to support combustion within the reservoir. Much has been published in recent years on underground burning, and there have been several papers on hot water injection. Although there are several early reports1,2 on steam injection, no recent experimental studies have been published on this recovery method. In our early thermal methods research, a marked improvement was found in oil recovery by steam injection compared with recovery by water injection in the same system. An investigation subsequently was undertaken to obtain quantitative information from which to evaluate steam injection as an oil recovery method. In addition, it was desired to investigate the recovery mechanism of hot water as compared with that of "cold" water and steam injection. An understanding of the mechanisms by which these processes operate would generally define favorable field conditions for their successful application. This paper reports the results of the laboratory study and suggests calculative approaches to estimate the field behavior of the steam-injection process. EXPERIMENTAL METHOD EQUIPMENT A schematic diagram of the equipment used for the displacement tests is shown in Fig. 1. Essentially, it consisted of a core with suitable means for recording temperatures, a feed system for injecting steam or cold or hot water, and a receiving train for condensing, cooling and measuring produced fluids. For the steam experiments, air-free saturated steam was piped from the boiler to the core face in insulated lines that were provided with steam traps and bleeds to remove any condensate formed in the lines due to heat losses. A 12-in. section of the line immediately ahead of

"Located in Madison River Canyon, about 14 miles by road from Norris, Mont. Built in 1907 by Madison River Power Co.DAM: Rock filled wooden crib structure, 183 ft. long, 34 ft. high or 44 ft. to top of flashboards.SPILLWAY: 140 ft. long, equipped with flashboards 10 ft. high.PIPE: One 10-foot and one 12-foot wood-stave pipe, 7,515 feet long.PRESSURE: One pressure chamber, 32 ft. high, 30 ft. wide and 81 ft.CHAMBER: long, built of concrete.PENSTOCKS: 4 9-foot steel penstocks about 200 ft. long, one for each wheel.WATER WHEELS: 4 double horizontal, center discharge, Sampson special 44-inch turbines, 3,600 h-p., at 100 ft. head. Speed 300 r. p. m„ direct connected to generators.GENERATORS: 4 G. E., W. C., 2,250 k-w., 4,000 volts, 300 r. p. m., 3 phase, 60 cycles, alternators, with exciters mounted on same shaft.TRANSFORMERS: 12 G. E., W. C., 900 k-w., 60 cycles. High tension voltage 23,100, 34,650, 46,200; low tension voltage 4,000, 3,800, 3,600. Now operating at 46,200, delta connected. They can be connected Y for 40,000, 60,000 or 80,000.OPERATION: This is the principal plant of the whole system and carries most of the load."

Jan 1, 1913

By Gerald Laswell

Jan 1, 1976

By C. F. Davan, C. T. Houseman

The news pages of MINING ENGINEERING and other trade publications have for the past two years carried a great many items about new developments in phosphate and potash, reflecting the surge in world consumption of these products as fertilizer. Today the question often arises concerning how much growth can be further anticipated by the phosphate and potash industries. To answer this question, a 15-year projection of world fertilizer consumption in terms of the three basic plant food nutrients-nitrogen, phosphate and potash-has been prepared. Two of these, phosphate and potash, are basic products of the mining industry. Nitrogen, once an important product of mining, is now mainly a chemical product. Another mineral, sulfur, although not a primary nutrient, depends on the fertilizer manufacturing industry for the bulk of its market. In crop year 1962-63, there began a startling in- crease in world fertilizer consumption. In that year, consumption increased by about 10% and in the following year by 10-12%.

Jan 12, 1965

By Emby Kaye

It is the purpose of this paper to outline briefly some of the considerations that enter into the economics of so-called recycling, the generic designation of the relatively recently developed process by which a condensate† is separated from gas-distillate gas at high pressure and the residual gas returned to the reservoir. This subject necessarily embraces not only a discussion of factors that should be considered in projecting a recycling operation, such as estimating reserves, investment and operating costs, but also a comparison of condensate with other types of petroleum. The place of condensate in its relation to the total supply of crude oil is pointed out as well as certain logical methods of product disposal. The cost of drilling wells and lease maintenance is not pertinent to this discussion because income and revenue are in this paper confined to that retained by the plant or plant operator for supplying processing facilities for the gas. Before the development of recycling a great many gas-distillate gas fields in Louisiana and Texas provided no income to their owners. When gas was sold from these reservoirs it was accompanied by irretrievable losses of condensate in the formation. The understanding of the func- tion of retrograde condensation resulted in the introduction of a new commercial petroleum recovery process for these hitherto unexploited fields and now permits the conditioning of this type of wet gas field for the sale of dry gas therefrom without waste. Some Economic Factors The study of a gas-distillate field for possible exploitation necessarily involves the critical appraisal of a number of elements, chief of which will be discussed here: (I) estimate of distillate in place, (2) estimate of distillate that can be brought to the surface, (3) available market, (4) costs. The considerations affecting the estimating of distillate reserves in place are in the main subject to the same errors as are involved in determining dry gas reserves. Determinable data including acreage, sand thickness, reservoir pressure, reservoir temperature, porosity and connate water provide the basis for calculating the volume of gas in place. Ample allowance must be made for connate water, which may occupy from 20 to 35 per cent of the pore space of the sand. The factor of supercom-pressibility is to a considerable extent nullified by the reservoir temperature. It has been considered well advised to allow this factor to serve as a cushion. With the gas reserves calculated, it remains only to assay the distillate content of the gas. Those familiar with the handling of "wet" gas at high pressure readily appreci-ate the variables in sampling gas from

Jan 1, 1942

By Emby Kaye

It is the purpose of this paper to outline briefly some of the considerations that enter into the economics of so-called recycling, the generic designation of the relatively recently developed process by which a condensate† is separated from gas-distillate gas at high pressure and the residual gas returned to the reservoir. This subject necessarily embraces not only a discussion of factors that should be considered in projecting a recycling operation, such as estimating reserves, investment and operating costs, but also a comparison of condensate with other types of petroleum. The place of condensate in its relation to the total supply of crude oil is pointed out as well as certain logical methods of product disposal. The cost of drilling wells and lease maintenance is not pertinent to this discussion because income and revenue are in this paper confined to that retained by the plant or plant operator for supplying processing facilities for the gas. Before the development of recycling a great many gas-distillate gas fields in Louisiana and Texas provided no income to their owners. When gas was sold from these reservoirs it was accompanied by irretrievable losses of condensate in the formation. The understanding of the func- tion of retrograde condensation resulted in the introduction of a new commercial petroleum recovery process for these hitherto unexploited fields and now permits the conditioning of this type of wet gas field for the sale of dry gas therefrom without waste. Some Economic Factors The study of a gas-distillate field for possible exploitation necessarily involves the critical appraisal of a number of elements, chief of which will be discussed here: (I) estimate of distillate in place, (2) estimate of distillate that can be brought to the surface, (3) available market, (4) costs. The considerations affecting the estimating of distillate reserves in place are in the main subject to the same errors as are involved in determining dry gas reserves. Determinable data including acreage, sand thickness, reservoir pressure, reservoir temperature, porosity and connate water provide the basis for calculating the volume of gas in place. Ample allowance must be made for connate water, which may occupy from 20 to 35 per cent of the pore space of the sand. The factor of supercom-pressibility is to a considerable extent nullified by the reservoir temperature. It has been considered well advised to allow this factor to serve as a cushion. With the gas reserves calculated, it remains only to assay the distillate content of the gas. Those familiar with the handling of "wet" gas at high pressure readily appreci-ate the variables in sampling gas from

Jan 1, 1942

By Fred D. DeVaney

DURING the past few years a radically new process for the magnetic roasting of iron ores has been investigated and developed by Pickands Mather & Co. and the Erie Mining Co. in the Erie laboratory at Hibbing, Minn. This process, originally devised by Dr. P. H. Royster of Washington, D. C., involves the use of a roasting technique quite different from older methods. It has now been demonstrated that iron-bearing materials can be roasted as effectively as by any previously known method, and at a much lower cost. The increasing shortage of highgrade iron ores in this country has accelerated the search for new methods that would permit low grade materials to be utilized. The concept of magnetically roasting low grade nonmagnetic ores such as the oxidized taconites and then separating such material magnetically has always had considerable appeal. The magnetic concentration idea is attractive because of the sharpness of the separations and cheapness of the method. Heretofore, however, the equipment and the processes available for the magnetizing-roasting -step have left much to be desired. The customary equipment available for reduction roasting has been: 1-multiple hearth furnaces, 2-rotary kilns, and 3-shaft type kilns. In addition, it is understood that some work has been done in magnetically roasting fine ores by a process using the FluoSolids principle, but little information on this process is available. The multiple hearth kiln has been used the most but first costs and operating costs have been high because of low capacity, high maintenance, and poor gas utilization. Magnetic roasting can be done in a rotary kiln, but the radiation losses are high and the conversion to magnetite is usually unsatisfactory because of poor contact between the gases and the solids. Of the shaft-type furnaces, probably the most efficient yet developed is that designed by E. W. Davis of the Minnesota Mines Experiment Station. This furnace was operated at Cooley, Minn., during 1934-1937 but was abandoned in 1937 because the operation was uneconomic. Heretofore the basic concept behind most magnetic roasting processes has been the idea of heating iron ore to a temperature of 800° to 1100 °F in a strong reducing atmosphere, preferably either carbon monoxide or hydrogen. Temperatures under 800°F were undesirable since excessive roasting time was required. Temperatures over 1100°F were avoided because of the danger of converting part of the iron to ferrous oxide which is nonmagnetic. In the new roasting process, the operation is carried on in a shaft furnace using a controlled atmosphere containing a low percentage of reducing gas. The temperature in the roasting zone is considerably higher than with the usual reducing gas and this speeds up the reduction time. Portions of the spent furnace gases are cooled and recirculated and this together with the good contact between ore and gas makes for high reducing gas utilization. High heat economy is secured by recuperating heat from the roasted ore by passing the cold reducing gases countercurrent to flow of ore. The heat transfer principle is similar to that employed in a pebble stove and to that used in the Erie Mining Co. furnace at Aurora, Minn., for pelletizing fine magnetite concentrates derived from taconite. The theory of controlled atmosphere during the roasting operation can best be appreciated by inspecting the equilibrium diagram of the Fe-C-O system shown in Fig. 1. An inspection of this diagram shows that in certain areas magnetite, Fe3O4, is the only stable form of iron. A further inspection of this table shows that if the proper ratio is maintained between carbon dioxide to carbon monoxide, such a gas will be reducing with respect to hematite, Fe2O3, and will be oxidizing with respect to both ferrous oxide, FeO, and iron, Fe. It should be kept in mind that the formation of ferrous oxide in a roasting operation is harmful, since this oxide is nonmagnetic; if it forms in any quantity, it will cause substantial loss of iron in the ensuing magnetic separation step. If a ratio of approximately three parts carbon dioxide to one of carbon monoxide is maintained, the resulting operation can be carried on at a relatively high temperature without fear of over-reduction. Specifically, most of the tests in the Erie furnace have been made at a temperature of 1500° to 1600°F, with an entrant gas containing approximately 5 pct carbon monoxide and 15 pct carbon dioxide, with the remainder largely nitrogen. It should be remembered that the ratios of carbon monoxide to carbon dioxide shown in Fig. 1 hold even though the bulk of the gas is an inert gas such as nitrogen. It may surprise many to learn that a gas containing as low as 3 pct carbon monoxide, and 12 pct carbon dioxide with the remainder nitrogen is an extremely effective reducing gas in the 1000° to 1600°F temperature range. The reducing gas is not limited to carbon monoxide, and mixtures of hydrogen and carbon monoxide may be used effectively, provided that a similar ratio is maintained between the reducing gases and carbon dioxide and water vapor. For a more detailed explanation of the theory involved, the reader is referred to U. S. patents 2,528,552 and 2,528,553. From a safety standpoint, the weak reducing gas used in the furnace offers an advantage. Its composition is such that it is well below the limits of explosion should air enter a hot furnace. This condition is not true with the usual reducing furnace, in which a gas rich in carbon monoxide or hydrogen is used. The general furnace design and method of operation may best be understood by an inspection of

Jan 1, 1952

By S. A. Montague

Mica can claim a considerably greater importance than would be assumed from its comparatively small dollar volume, which came to about $37,000,000 for the United States industry as a whole in 1957. Mica is one of the strategic minerals. We must depend on imports from distant sources for virtually all of our requirements of high grade block and all of our mica splittings. Mica is essential and indispensable for vacuum tubes and high-performance condensers, two electronic components which are vital military necessities besides being nearly indispensable to civilization today. Composition and Properties Mica is the general name for a group of some nine different minerals, two of which, muscovite and phlogopite, are the minerals used by the mica industry as its raw material. Several of the other varieties are commercially useful-vermiculite, * used for heat insulation in expanded form, and lepidolite, used as an ore of lithium while the others-biotite, roscoelite lepidomelane, paragonite and zinnwaldite have little or no commercial importance. Biotite frequently occurs as an undesirable impurity in muscovite. Table 1 lists various properties and other data concerning muscovite and phlogopite. Chemically, mica is a complex silicate of sodium, potassium and aluminum. Most varieties of muscovite are higher in sodium, and of phlogopite in magnesium. There are no important uses of mica where the chemical analysis is important, except that in some uses of ground mica, the content of iron oxide present as an impurity must be kept to a very low limit. Muscovite occurs in a range of color from the so-called India "ruby" which is more closely a pinkish brown, to light and dark green, with numerous other intermediate shades. Ruby color is usually preferred by industry, especially in the better qualities. When split very thin the color in most [ ] micas disappears. Muscovite mica is frequently found containing black and red "stain" as a homogeneous part of the books or sheets. In most cases this stain or impurity is magnetite

Jan 1, 1960

By D. G. Wilder

D.G. Wilder I found the suggestion that the amount of displacement of a fault can be numerically related to the thickness of gouge or breccia to be both intuitively satisfying and intriguing. I have long agreed that there is some type of relationship between the amount of gouge and the amount of displacement of faults. I congratulate the author for developing a numerical relationship between them. However, I am concerned that the limits for applying this relationship be fully understood. An underlying assumption in this approach is that there is either a uniform thickness of gouge or breccia along a given fault or the thickness does not vary widely. Since it is not always possible to confirm this, the displacements derived by this method should be viewed with caution unless significant fault extent can be observed. At the Nevada Test Site, in drifts constructed in granite for test emplacement of spent nuclear reactor fuel, we found a fault with 0.3 to 0.4 m (12 to 16 in.) of clay gouge. Within a few meters of this location, the fault had no clay gouge, but rather consisted of a highly fractured zone with significantly altered rock and some slickensides. Based on Fig. 1, the 0.3 to 0.4 m (12 to 16 in.) thickness of gouge would indicate a displacement in excess of 30 m (98 ft). However, no gouge thickness would indicate essentially no displacement. Based on a quartz vein that terminated on the fault, and is not identified nearby, an estimated displacement of more than a few meters was made. This estimate is consistent with that obtained using the regression line proposed in the paper if the 0.3 to 0.4 m (12 to 16 in.) thickness for the gouge is used. However, using the regression curves with zero thickness would not yield results consistent with what was observed in the field. Therefore, it is important to recognize that the suggested procedure would properly yield a range of probable displacements. ? *Work performed under the auspices of the US Department of Energy by the Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. Reply by E.C. Robertson It is certainly true that the t (thickness) of gg-bx (gouge and breccia) on a fault does vary along the fault. My observations have been that near the termination of a fault, the displacement d is small and the t is also small, whereas the maximum d and t will usually be found in the central part of the fault. The information on gg-bx and t of the fault found in granite in the NTS tunnel by Mr. Wilder could be interpreted somewhat differently than he does. He speaks of the fault changing within a few meters from 0.3 to 0.4 m (12 to 16 in.) of clay gg to "a highly fractured zone with significantly altered rock and some slickensides," but no gg. The highly fractured rock may be taken to be bx, rock not so finely ground as gg but still crushed by the fault movement, equivalent to the gg in my usage, and probably occupying about the same t. Mr. Wilder's estimates for the fault in the NTS tunnel for t of 0.3 to 0.4 m (12 to 16 in.) and for d of a quartz vein, in excess of "a few meters," would place the point on the low side of the central trend line in my Fig. 1, at the lower limit. There is, of course, a problem with determining d using displacement of only one planar surface. It would be greater or lesser depending on the rake of the movement. Finally, estimating the d of a fault from its t should be made with awareness of our present uncertainties, as pointed out by Mr. Wilder. Although the central trend line in my Fig. 1 has a ratio of d/t of 100, I have put the limiting ratios at 10 and 1000. Understanding of the values of the ratio will be improved only with collection of more data, for which the discussion of Mr. Wilder is much appreciated. ? G.C. Waterman E.C. Robertson's paper provides significant information to a geologist attempting to deduce fault offset by noting the products of structural dislocation. However, considerable mapping in underground and open-pit mines, and examination of structures produced in different geological settings, have convinced me that gouge and breccia thickness are controlled by geological conditions and fault movement. The following paragraphs suggest geological variables that control them. 1. Depth of Loading A near-surface fault resulting from tensional stress has more breccia/gouge than is produced by a similar stress at considerable depth. A deep-loaded compressional stress may produce a linear zone of schist, or structural dislocation may occur along an earlier formed belt of schist. Such "shear zones" are common in Canadian mines in precambrian rocks. In neither case can offset be directly deduced by an analysis of the minimal gouge/breccia in the shistose rocks. At greater depth, stress may be partially to wholly relieved by flowage. I vividly recall first noting the regional "Midas Thrust" in the Lark mine, Bingham Mining District, UT (where we called the structure the North Fault). My recorded notes, as I remember them, showed a narrow gouge streak separated the "Jordan" and "Commercial" limestone units from impure, muddy limestone beds of uncertain stratigraphic position. The visible structure did not indicate the great importance of this premineral fault

Jan 1, 1985