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By THOMAS LEONBRD WATSON

INTRODUCTION. IN a paper read by title at the Washington meeting of the Institute, May, 1905,1 discussed at considerable length the geological relations, node of occurrence, and the genesis of the lead- and zinc-ores of the Virginia-Tennessee region. The present paper treats of the purely economic phases of the zinc-ores of the district; such as methods of mining the ores, their preparation and treatment. The Albemarle county mines and plant were discussed in the paper referred to above, and will not be considered here. METHODS OF MINING. Until very recently the mining of lead- and zinc-ores in Virginia was limited wholly to the surface belt of weathering. The mode of occurrence and the character of the ores to be mined were such as to demand the employment of methods used in mining secondary concentrated ores. Accordingly, a system similar to that practiced in mining brown iron-ores was employed, being modified to meet the changed conditions. Oxidized or Soft Ores.-Up to the present time practically all the ore mined in the Virginia district has been of the oxidized or soft type;-the silicate, calamine, and the carbonate, smith-sonite; largely the former, which has been localized and concentrated at only slight depths below the surface. Because of the extreme irregularity with which the limestone weathers when stripped of the overlying residual clay, it presents a roughened surface of large and small irregular "chimneys"

Mar 1, 1906

The Pueblo Viejo Mine, a 7, 250 mtpd (8,000 stpd) gold-silver cyanidation plant built by Rosario Dominicana S. A., was described in Volume I of this monograph. At the time of writing that volume, Pueblo Viejo had not yet gone on-stream and operating data or costs could not be presented. Since that time this information has been obtained and several interesting modifications and an expansion have been made to the plant. Because Pueblo Viejo is the largest open-pit gold mine in the world and one of the world's leading gold-silver operations with production of approximately 31 kg (1,000 oz) gold and 125 to 155 kg (4,000 to 5, 000 oz) silver per day, the authors have updated the previous data and flow sheet. The Dominican Government, which held a 4670 interest in Rosario Dominicana S. A., completed purchase of the mine to gain full control in 1979. Rosario Resources will continue to manage the mine, at least until the end of 1980. Gold was produced at Pueblo Viejo almost 500 years ago with initial production in the year 1505. Rosario Resources became interested in the property in 1969 and found surface oxidation had rendered the upper portion of the ore body amenable to direct cyanide treatment. The treatment of the underlying gold-bearing sulfide zone is still undergoing metallurgical studies. The ore is considered to be a laterite; and because there appeared to be few boulders in the ore zone, only a 400 m (16 in. ) square grizzly was initially installed ahead of the mills when the plant went on-stream in late 1974 at a design capacity of 7,250 mtpd (8,000 stpd). Operation also proved the ore to be harder than was originally anticipated. During 1967 a 1. 25 m by 1. 5 m (48 in. by 60 in. ) jaw crusher was installed to -feed the 1, 000 mt (1, 100 st) mill bin. Minus 200 mm (8 in.) crushed ore is fed directly to two 5.5 m by 1. 8 m (18 ft by 6 ft) semi-autogenous mills re-powered with 750 km (1,000 hp) motors and 50 mm (2 in.) grates. Each mill product is screened at 13 mm (1 /2 in.) by a vibrating screen. Screen oversize from each mill is combined on a single return belt equipped with a magnetic head pulley for grinding ball removal. The non-magnetic oversize is then split into two fractions for return to the primary mills. Originally, a minus 6 mm (1/4 in ) product was made on each screen and fed to a 300 kw (400 hp) 2.6 m by 3. 7 m (8-1/2 ft by 12 ft) regrind mill. During a plant expansion in 1978, an intermediate mill of 746 kw (1,000 hp) was installed to operate in open circuit on the combined primary mill

Jan 1, 1981

By Charles H. Fulton

The process of crushing ore in cyanide solution was first used at the Crown mine, New Zealand, in 1897, by Mr. F. R. W. Daw; and, two years later, Mr. John Hinton tried it experimentally at the old Dakota plant, Central City, South Dakota. To Mr. Hinton belongs the credit of introducing this important modification in the Black Hills, this being its first successful application in the U. S., and its results have been so satisfactory that it has become established as the proper manner in which to treat the dense oxidized siliceous ores of this district. Five mills are now crushing ore in cyanide solution, namely, the Horseshoe, 120 stamps (60 in operation); the Dakota, 30 stamps; the Maitland, 40 stamps; the Hidden Fortune, 60 stamps; the Lundberg, Dorr & Wilson, one 6-ft. Monadnock roller-mill; and several others intend to adopt this practice. The dry-crushing process still holds its place for the treatment of the more porous and open siliceous ores; and two mills continue to dry-crush dense siliceous ores. Character of the Ores. The occurrence of the ores of the Cambrian strata in the northern Black Hills has been frequently described.' In practice they are classified, according to their appearance, into " red " and " blue " ores, the former being oxidized and the latter unoxidized. At the present time, usually the red ores only are treated at the mills, although occasionally small quantities of blue ore, which have become intimately mixed with the red in mining, are included. Generally the extraction of values by the direct treatment of raw ore is from 70 to 75 per cent. for red ores, and from 25 to 50 per cent. for blue ores. The ores consist mainly of a siliceous matrix containing, as a +1SOUTH DAKOTA SCHOOL OF MINES, RAPID CITY, SO. DAK.

Jan 1, 1905

By D. B. Williams

For the first time in the history of the Venezuelan petroleum industry production exceeded 200 million barrels. The total production for all fields amounted to 205,430,869 bbl., which is more than 9 per cent of the world's 1939 total. This is an increase of over 15 million barrels or 8.0 per cent above the 1938 figure, which, compared with the slightly less than 2 per cent increase of the 1938 figure over 1937, shows the marked activity in Venezuela during the past year. The Maracaibo Lake fields are still the predominating factor in Venezuelan production, showing an increase of approximately 9½ million barrels over last year's figure and accounting for 71.8 per cent of Venezuela's total. Lagunillas continues to hold precedence as a single field, having yielded 47.1 per cent of the accumulative total and 39.4 per cent of 1939's total. This field showed an increase of slightly more than 3½ million barrels over 1938. Tia Juana, the second largest field, attained a record production, increasing its percentage of the Venezuelan total from 23.4 in 1938 to 23.7 in 1939. The La Rosa field, which includes Punta Benitez and Ambrosio, declined from 13.7 to 12.0 per cent; Bachaquero, the southernmost Lake field, which came into regular production at the end of 1938, contributed over 31/3 million barrels. Quiriquire, in eastern Venezuela, ousted La Rosa as the third largest producing field, and, although production increased by 11/3 milliorl barrels, percentage of the total declined from 13.2 to 12.9. Mene Grande, the oldest field, declined from 6.6 per cent in 1938 to 5.9 in 1939. Tem-blador produced for a whole year for the first time and yielded 3,647,867 bbl. The Colon district, in the Maracaibo Lake area, comprising the Tarra-Los Manueles fields, showed slight increases, as also did Cumarebo and Pedernales. Construction of the 16-in. pipe line from Oficina to Puerto La Cruz (Guanta), the longest line of this size in the world, was completed toward the end of the year and this new field in eastern Venezuela started shipping oil in December. This field is operated by the Mene Grande Oil Co. and was credited with a production of 2,347,625 bbl. in 1939. Jusepin field, some 25 miles southwest of Quiriquire in eastern Venezuela,

Jan 1, 1940

By D. B. Williams

For the first time in the history of the Venezuelan petroleum industry production exceeded 200 million barrels. The total production for all fields amounted to 205,430,869 bbl., which is more than 9 per cent of the world's 1939 total. This is an increase of over 15 million barrels or 8.0 per cent above the 1938 figure, which, compared with the slightly less than 2 per cent increase of the 1938 figure over 1937, shows the marked activity in Venezuela during the past year. The Maracaibo Lake fields are still the predominating factor in Venezuelan production, showing an increase of approximately 9½ million barrels over last year's figure and accounting for 71.8 per cent of Venezuela's total. Lagunillas continues to hold precedence as a single field, having yielded 47.1 per cent of the accumulative total and 39.4 per cent of 1939's total. This field showed an increase of slightly more than 3½ million barrels over 1938. Tia Juana, the second largest field, attained a record production, increasing its percentage of the Venezuelan total from 23.4 in 1938 to 23.7 in 1939. The La Rosa field, which includes Punta Benitez and Ambrosio, declined from 13.7 to 12.0 per cent; Bachaquero, the southernmost Lake field, which came into regular production at the end of 1938, contributed over 31/3 million barrels. Quiriquire, in eastern Venezuela, ousted La Rosa as the third largest producing field, and, although production increased by 11/3 milliorl barrels, percentage of the total declined from 13.2 to 12.9. Mene Grande, the oldest field, declined from 6.6 per cent in 1938 to 5.9 in 1939. Tem-blador produced for a whole year for the first time and yielded 3,647,867 bbl. The Colon district, in the Maracaibo Lake area, comprising the Tarra-Los Manueles fields, showed slight increases, as also did Cumarebo and Pedernales. Construction of the 16-in. pipe line from Oficina to Puerto La Cruz (Guanta), the longest line of this size in the world, was completed toward the end of the year and this new field in eastern Venezuela started shipping oil in December. This field is operated by the Mene Grande Oil Co. and was credited with a production of 2,347,625 bbl. in 1939. Jusepin field, some 25 miles southwest of Quiriquire in eastern Venezuela,

Jan 1, 1940

By George D. Graffin

The first use of graphite is lost in the mists of time. It was used by primitive man to make drawings on the walls of caves and by the Egyptians to decorate pottery. As early as 1400 A.D. graphite crucibles were being made in the Haffnerzell district of Bavaria. Through the Middle Ages graphite was confused with other minerals, especially galena and molybdenite. Two common names that are still used for the mineral are "Plumbago," meaning leadlike, and "Black Lead." The latter name implied that graphite is either composed of lead or at least contains a large percentage of it. Gessner is credited with having recognized it as a separate mineral in 1565, but its composition was not determined until 1779, when Scheele demonstrated that graphite oxidized to carbon dioxide, thus proving its carbon constitution. In 1789, Werner named it "graphite" from the Greek word "graphein," meaning to write. The United States has long relied on foreign countries for its graphite supplies. This reliance has been due more to the lack of suitable domestic graphites than to any particular preference for buying minerals overseas. Ceylon (now Sri Lanka) graphites were imported as early as 1820, and Madagascar graphites have been imported since the properties on that island were opened up about a hundred years later. Mexico has long supplied the United States with most of its requirements for amorphous graphite. Physical Properties and Classification Graphite is found in laminated, flaky aggregates disseminated in schistose rocks. It also occurs in veins and exhibits a foliated or fibrous structure. Graphite is a black lustrous mineral that crystallizes in the hexagonal system, with rhombohedral symmetry. The crystals have tabular form and are six-sided; the faces are commonly striated. The flakes have perfect basal cleavage and are opaque. When well crystallized, the flakes have a black metallic luster while the amorphous material is black and earthy, with a microcrystalline compactness. The flakes feel greasy. Graphite is an excellent conductor of heat and electricity. It melts at approximately 3500°C and sublimes at about 4500°C. It is combustible in the presence of oxygen between 620° and 670°C, but is stable and chemically inert at ordinary temperatures.

Jan 1, 1975

By Robert E. Campbell

Mining geophysics in 1969 marked a year of growth and consolidation in the application of ground and airborne geophysical methods and techniques with a 20% rise in expenditures for world-wide exploration. Growth was determined by questionnaire survey of industry, geophysical contractors, universities and government agencies conducted by the Society of Exploration Geophysicists. Relative position of metlhods is shown in the accompanying table on page 87. Methods and Techniques Electromagnetic airborne and ground methods showed the largest gains in the utilization of VLF-EM instrumentation. The VLF-EM instrument is a directional radio receiver which is tuned to distant radio transmitters in the 15 to 25 kilohertz band range. It measures vertical real and imaginary components of the magnetic field vector, and is used in geological mapping and surveying for various types of conductors in the ground. Ground VLF-EM instruments, Ronka EM-16 and Radem, are manufactured by Geonics, Ltd., Toronto, Ont., and Crone Geophysics. Ltd., Port Credit. Ont.

Jan 1, 1970

By Arthur Phillips, C. H. Mathewson

During the past year considerable work dealing with the mechanical properties and microstructure following the anneal under uniform condi-tions of certain types of commercial rolled brass has been done in this laboratory. Since these experiments were conducted with the active cooperation of the Bridgeport Brass Co., involving free use of its product, and have thus furnished information which is characteristic of some of its special mixtures, full publication of the numerical relationships and comparative results encountered does not seem justifiable. Some of the more general features of this work are, however, available and it is our present purpose to use the material in question, along with some results of special tests, in discussing the characteristics of recrystallization as related to the degree of hardening by strain and the ordinary annealing variables. We desire to make acknowledgment of the many courtesies extended by Mr. Charles Ferry, Metallurgist of the Bridgeport Brass Co., and the value of his cooperation, which has greatly stimulated the study of brass in this laboratory. A clear and systematic presentation of the principal relations between temperature and time of anneal, the changing physical properties and microstructure and the degree of previous reduction by cold-rolling, was first made, in the case of rolled brass and copper, by the French engineer, C. Grard,' in 1909, although much fragmentary information of this general character had appeared earlier and the main facts involved were undoubtedly known to many brass specialists through their own private research. From this work, it appears that in the cartridge mixture (67 per cent. copper, 33 per cent. zinc) the properties imparted by cold-working within the limits, 13 to 75 per cent, reduction of area by rolling Original Area — Final Area 0.13 to 0.75), are not affected by anneal- Original Area " ing for a 50-min. period at any temperature below 200°C. At or in the

Jan 1, 1916

By J. B. Coher, M. B. Bever

COLD work destroys long-range order, as was first observed by Dehlinger and Graf.1 Dahl2 showed that the mechanical disordering caused by cold work produces changes in those properties that are affected by long-range order. The existence of order has a marked effect on tile manner in which an alloy deforms and therefore on its mechanical properties.L' The relation between order and deformation behavior however, is only beginning to be understood. Seemann and G1ander4 suggested that cold work reduces an ordered alloy to a kind of gruel of antiphase domains. According to Cottrell,5 superdis-locations and pairs of dislocations in a slip plane connected by a strip of anti-phase domain boundary provide deformation mechanisms which do not change the state of order. In general, however, slip may be expected to produce new domain boundaries and destroy order if dislocations move on intersecting planes or cut through existing domain boundaries. The yield strength of an ordered alloy may pass through a maximum with decreasing domain size.5"7 The reduction of domain size resulting from cold work may, therefore, lead to a maximum in strength properties. Flinn8 suggests that dislocations can climb by short-range diffusion during deformation and thus can generate domain boundaries not only on slip planes, but also on other planes which will be those with the lowest domain-boundary energy. It has long been known that the rate of strain hardening of an alloy in the ordered state is larger than in the disordered state.3'9 Also the slip bands in ordered CU3, AU10 and Ni3Mn" are finer than in the disordered alloys. The stress which causes initial yielding in Cu,Au passes through a maximum with decreasing domain size.6'12 A maximum has also been observed in the hardness of ordered Ni3Mn as a function of strain.' These observations suggest, but do not prove, that domain size reduction occurs during deformation. According to Fisher13 slip destroys short-range order and thus the strength of an alloy is related to the degree of short-range order present. Rudman and Averbach14 and Averbach et a1.,15 demonstrated that cold work reduces short-range order in copper-gold and gold-silver alloys. Destruction of long-range and short-range order by cold work implies slip on an appreciable fraction of planes. Yielding of an alloy in which short-range order exists or antiphase domain boundaries are present should be discontinuous because the first dislocations moving across the slip plane meet with the largest resistance.5 Such discontinuous yielding has been observed in CU3AU6,16 and Cuzn.l7 This phenomenon, however, can also be explained by mechanisms not involving order.b The published investigations of the effects of cold work on alloys with long-range or short-range order have not been covered thoroughly in reviews of order-disorder phenomena. These investigations, therefore, will be listed here. They have been concerned with strength properties> 2,3,6,8,9,12,16-21 electrical resistivity,2,4,18,19,21-26: thermoelectric power, magnetic properties,2,18,21,26 and X-ray strain'1,2,14,15,27,28 The slip systems and the appearance of the microstructure after deformation in ordered and disordered alloys have also been investigated. 6.10.ll,l7,23,29,30 The alloys used in these investigations were copper-gold. 1-4,6,9,10,14,16,18 23-26,28,29 copper-zinc. L7. 19. 20,30 nickel-manganese,2 11,21 iron-aluminum. iron-nickel,' copper palladium,4,18,22 gold-silver.4,18,22 and palladium-silver-copper.4 In the work reported here. the changes in properties of polycrystalline Cu3Au were investigated as functions of strain in wire drawing and rolling. Specimens were heat treated before deformation

Jan 1, 1961

By Frederic L. Kadey

Perlite, as a volcanic glass, has been recognized since the Third Century, B.C. (Langford, 1978). The precise details of discovery often become lost in antiquity, and the variations among the stories pertaining to the more recent discovery of perlite as a material of commerce are no exception. Credit in the United States is given to a dentist who, while experimenting with tooth enamels about 1941, discovered that perlite-the rock-intumesced when subjected to heat. At about the same time it is reported that the chief geologist of Silver and Barytes Ores Mining Co. attempted to put out a picnic bonfire on the shores of Milos Island, Greece by throwing beach sand on it. The ensuing pyrotechnic display immediately conjured up in that man's mind the possibility of a new use for the volcanic rock that constituted most of the island. Very little was done with this discovery either here or abroad until after World War II. Today the name perlite is applied to both the hydrated volcanic glass, generally of rhyolitic composition, and to the lightweight aggregate that is produced from the expansion of the glass after it has been crushed and sized. Petrologically, it is defined as a glassy rhyolite that has a pearly luster and concentric, onionskin parting. Occurrences of perlite are restricted to several Tertiary to Quaternary age rhyolitic belts that trend in a generally north-south direction around the world. Commercially suitable deposits generally occur as domes of several hundred feet in height, although glassy zones in welded ash-flow tuffs and others associated with dikes and sills also have been reported. Mining is by ripping and blasting from open pits. Because of weight considerations, perlite usually is shipped to the local market area for subsequent expanding. In the United States, New Mexico leads in production with Arizona, California, Nevada, Idaho, and Colorado following in approximately that order. The principal use for expanded perlite is as a lightweight insulating aggregate in cryogenics, in plaster, concrete, and in loose fill insulation. Expanded perlite is also used in horticultural applications, and after subsequent milling and classification, as a filter aid. The United States is the world's largest producer and consumer of perlite. Table 1 shows the world production of perlite and Table 2 shows the perlite mined, processed, expanded, and sold or used by producers in the United States. Geology Composition and Morphology Any discussion of perlite must take into consideration its dual nomenclature, for it is known by the same name as both the naturally occurring rock and, after processing and expansion, as the lightweight aggregate of commercial significance. In its naturally occurring form, perlite is a rhyolitic glass that contains from 2 to 5% combined water. While perlite also can occur as andesitic or dacitic glass, these latter types are of negligible commercial significance. Table 3 lists the chemical composition of a few typical perlites (Anderson, et al., 1956; Langford, 1979). What sets perlite of commercial significance apart from other volcanic glasses is the fact that under the proper conditions of preparation-crushing and sizing-it will, when rapidly introduced into a flame of sufficient temperature, expand or "pop." All of the elements of composition contribute to the expansibility of the rock. The role of the combined water, however, is the most significant because it is believed not only to produce a fluxing effect in the softening of the highly siliceous glass prior to expansion, but it is also responsible for the explosive force of expansion through volatilization during heating. The current theory of the origin of the water in perlite is now less con-

Jan 1, 1983

By Frank T. Sisco

The discovery of phosphorous is usually credited to the German alchemist Brand, in 1669, and the element was rediscovered the next year by Boyle in England. IT was more than 100 years later, however, before its presence was detected in high-carbon iron produced in early blast furnaces. In 1781 the German chemist Meyer published the results of his investigation on the ?white earth? that he had found in cast iron made from bog ores. This white earth was metallic in appearance, it was extremely brittle, it was readily fusible, and it was not attracted by magnet. Meyer noted that cast iron containing this white earth was more fusible than other cast iron, and he was sure that he had discovered a new metal ? for which he proposed the name Wassereisen, or the Latin term Hydrosiderum. Two years later the distinguished Swedish Chemist Bergmann made the same discovery, finding a ?white calx? in cast iron, which he also mistakenly considered to be a new metal, and for which he proposed the Siderum.

Jan 1, 1944

By AIME AIME

The XCVIIth meeting of the Institute for the reading and discussion of papers will be held at Spokane, Wash., beginning Monday, Sept. 27, 1909, as already announced in Special Circulars of May 8 and Aug. 14, 1909, and in the Bulletins for June, July, and August. The meeting will be preceded by a tour through Yellow stone Park and visits to Butte and Anaconda, and will be followed by visits to the Coeur d'Alene district, to the Alaska-Yukon-Pacific Exposition at Seattle, to the mining- and smelting-plants near Salt Lake, and to the iron- and lead- and zinc-plants at Pueblo. The special train for the party' will leave Chicago, September 16, and return about October 12. Details of the itinerary are given later in this announcement. The Secretary of the Spokane Local Committee is Lyndon K. Armstrong, 615 Hyde Block, Spokane, Wash., to whom should be addressed all inquiries concerning local matters. The control of the papers and proceedings will remain in charge of the Institute office, as usual. It is greatly to be desired, both in behalf of the Institute and in recognition of the many courtesies to be extended on the trip, that the excursion party be made larger. Exceptional facilities to visit the many mines and smelters have been freely provided; and members are requested to make all reasonable effort to attend the meeting at Spokane and participate in the excursions. For those who cannot join in the entire trip, it may be possible to provide special Pullman accommodations after leaving Yellowstone Park. In order to make the necessary arrangement, however, the names of members and guests contemplating this partial trip should be sent at once to Theodore Dwight, 29 West 39th Street, New York City. The general cost of the trip per member will be $300, which includes transportation, berth, and meals for the entire trip from

Sep 1, 1909

By Wm. R. Webster

THIS is a contribution for the proposed new discussion on the physics of steel. The former discussion on the subject started with the consideration of five papers presented at the Chicago meeting in 1893, and continued for several years. The Suggested Lines of Discussion, prepared by Doctor Howe, covered a wide field and added greatly to the success of the work. Naturally, the first step in a new discussion will be to remodel and bring up to date the old Suggested Lines of Discussion so as to embody all the important advances in the metallurgy of steel that have a bearing on the physics of steel and keep the papers and discussions within the field of work undertaken. This paper will be devoted to the practical application, in rolling steel, of the effects of carbon, phosphorus, and manganese on its tensile strength, with some suggestions on further research work. Dr. J. E. Stead, in his paper Influence of Some Elements on the Mechanical Properties of Steel,1 gave a complete review of all that had been done during the past thirty years. He gave full credit to all investigators who worked on these lines, also their results, with his views on same, and in many cases his own results. All of this data and much new valuable information were put in convenient shape for reference and study. To do this required a great deal of work, which is fully appreciated by the steel manufacturers and investigators. The variations in the values given by the different investigators for the increase of the tensile strength of steel for each 0.01 per cent. of carbon, phosphorus, and manganese were largely due to the steels they worked on, the large or small variations in the amount of the elements present, and the omission to take into consideration all the factors, from the blast furnace through to finished rolled material, that affect the character of the steel. For instance, a poorly made dirty steel requires considerably more carbon to give the same ultimate strength than a well-made clean steel with the same phosphorus and manganese content.

Jan 3, 1921

By Rodney G. Ravenscroft

Leasing is not a new phenomenon. Experts have identified its origins as early as biblical times. It is a method of finance that has grown rapidly and is now used in most countries, including those of South East Asia, South America, the Middle East and even the People's Republic of China. Internationally, the leasing world divides fairly easily into two groups and this is determined, by and large, according to whether a country has Anglo-Saxon origins or not. Most of the Anglo-Saxon countries have seen tax-oriented leasing become a sophisticated means of financing the acquisition of large and costly items of equipment and large projects. Countries such as France, Spain and Japan have a highly developed leasing industry but it is not tax-oriented. This paper will not address leasing of this kind. LEASING - THE CONCEPT Wide acceptance of leasing as an alternative for financing capital equipment has grown with the recognition by the users of equipment that it is use and not ownership that generates profits. Whilst this seems obvious, memories of repossession of assets during the Depression and attitudes towards leasing as "last resort financing" have raised strong philosophical resistance that has only recently begun to be overturned. A financial lease is a commitment by way of contract between a user of equipment (lessee) and a financial owner (lessor) under which the lessee makes a series of payments in return for use of the equipment. The lessee is acquiring economic value associated with ownership but not ownership of the equipment itself - that remains with the lessor. A lease is a method of financing the use of an asset; other methods finance the assets themselves. It is the taxation aspects that then become important. The lessee is giving up some or all of the taxation benefits of ownership such as depreciation and investment tax credits. The lessor claims these benefits, as he is entitled to do as owner, and takes them into consideration when determining the level of lease payments that are necessary to generate his required rate of return. These lease payments are, of course, lower than they would have been without those taxation benefits. The lease payments themselves are fully tax deductible. This is tax shelter leasing. The lessor is acquiring taxation deductions that are applied fully and immediately against his other taxable income so as to reduce the amount of tax he is to pay to the revenue authorities. It is this concept that makes financial leasing work. Governments provide incentives by way of tax concessions to encourage capital investment. Governments presume that prudent capital investment will offer employment opportunities, generate sales and streamline economic activity. These, in turn, will lead to the collection of government revenue. It makes no difference at all whether these incentives are claimed by a commercial or industrial owner/user or by a financial owner who makes equipment available for use by industry. Rather, the issue is to ensure that if an incentive is available, it is used so as to achieve its desired results. No greater or lesser incentive is available for leasing and leasing does not misuse the taxation aspects of equipment ownership. The critical issue is whether the full value

Jan 1, 1985

By W. Irwin Moyer

Two methods for the rapid valuation of oil properties are in common use. The one best known and most widely used is the "per barrel" value, based on the present daily production of the well, without regard to its past performance or the history of the sand or pool from which it produces. The second method is the "time to pay out," or the length of time required for a well to place itself upon the credit side of the ledger, from which time the returns from its production (less the operating expenses) will be clear profit. The time basis for valuation is also commonly used in the appraisal of an undeveloped lease. In most oil fields, it is not thought good business to invest in production that will not pay out in at least 4 to 5 years. Nearly all buyers (except in certain regions of very persistent production like the deep-sand territory of the Appalachian field) expect wells to pay out in considerably less time than this. Like the barrel per day price, the time necessary for a well to pay out has been determined for each field, so that one frequently hears a field or district referred to as having a certain time to pay out. This is considered the norm for that field or district and the buyer and seller base their value, to greater or less extent, on their belief in the accuracy of this time. The writer long ago became convinced of the inaccuracy of the barrel per day method, except when greatly modified for local conditions, such as the age of the wells, their economic limit, operating conditions in the field, the future price of oil, and the persistence of the sand as a producer. When so modified, this method becomes more of an analytic or predicted probable yield valuation. While the appraiser may not go through each step in a valuation based on future returnable revenue, his knowledge of the field and the local conditions surrounding his leases make it possible for him to estimate a fair sales value that, in many cases, will be a close approximation to the truth. This is quite different from the commonly understood barrel per day value, in that the conditions surrounding the sale of one lease or property at a fair market value may

Jan 1, 1922

By N. De Nevers

A calculation method has been developed for carbonated water flooding. This method takes into account the effects of oil viscosity reduction and oil swelling, due to carbon dioxide transferred to the reservoir oil from the carbonated flood water. It shows the effect of changes in carbonation pressure and carbonated water slug size. The method is based on a Buckley-Leverett-type linear flow model. The mathematical approach is similar to that developed by Welge, et al, for enriched gas drives. However, it contains a very important advance over the previous papers in its solution to the problem of injection of a "slug" of carbonated water rather than continuous injection of fluid of constant composition. The method also shows the chromatographic nature of the transport of Co 2 in a carbonated water flood. Sample calculations indicate that viscosity reduction is the most important source of incremental oil recovery. Swelling contributes to a lesser extent. Raising the carbonation pressure increases recovery, but this effect diminishes as pressure is increased. increasing the slug size also increases recovery, but again this effect diminishes as slug size is increased. INTRODUCTION In recent years there has been considerable interest in carbonated water flooding as a secondary recovery method. Several carbonated waterflood field tests are now in progress.1'3 Yet there is no published method for predicting the results of a carbonated water flood. This paper presents a method for predicting the oil recovery for ; carbonated water flood. In a carbonated water flood. a carbonated water slug is injected into the reservoir. Then this slug is driven forward by injecting plain water behind it. The field operator must choose the carbonated water slug size and the CO2:water ratio in the slug. The calculation method presented here shows the effects of both slug size and CO2:water ratio on oil recovery. The calculation assumes that the addition of carbon dioxide to flood water increases the oil recovery by two mechanisms: 1. Carbon dioxide transfers from the flood water to the oil, thereby reducing the viscosity of the oil. At the lower viscosity, the oil flows more readily and is more easily swept out by flood water. 2. The carbon dioxide which transfers to the oil phase causes the oil phase to swell. Assume that the residual oil saturation (volume per cent of pore space) is the same whether the oil is carbonated or not. Then the same volume will contain less stock tank oil if it is carbonated, due to oil swelling. The plain water driving the carbonated water slug forward will strip the CO2 out of this residual oil., causing this oil to shrink. This swelling-followed-by-shrinking leaves behind a lower residual oil saturation than would have been left behind by a plain water flood. Since some oils swell to almost twice their original volume at reasonable CO2 pressures, this effect may be large. Two additional benefits sometimes claimed for carbonated water flooding are: 1. Adding CO2 to flood water greatly increases the water injectivity in some cases.1 (Injectivity = BPD of water injected/ft of sand x differential bottom-hole pressure, psi.) CO2 forms a weak acid in water; injecting carbonated water is, therefore, somewhat like acid treating. If a formation responds to acid treating, it will probably have a higher injectivity for carbonated water than for plain water. Although the increased injectivity increases the profitability of a carbonated water flood over a plain water flood, it does not change the production curve based on total fluid injected. Therefore, the method presented here does not show any effect of increased injectivity. 2. It is claimed in one patent4 that carbon dioxide will react with some constituents of the oil to form detergents. These detergents are expected to increase the oil recovery. There is little data available to support this idea. The calculation method presented here takes no credit for extra oil recovery due to the formation of any such detergents.

Jan 1, 1965

By Thos Gibson

THE object of taxation is the raising of a revenue. Unless a tax accomplishes this, it is a failure. The right to take for public purposes a part of the moneys obtained from the carrying on of private enterprises is an attribute possessed only by a lawful government, and may indeed he called the supreme attribute of government. In free, democratic communities this power must of necessity rest upon the consent of the governed. Power implies obligation, hence it is obviously the duty of a government, in framing a system of taxation, to provide one which, while effective in producing a revenue, is also just and impartial. It will be conceded that mines and mining property ought to bear a fair share of the public expenditure. The question is, upon what basis taxation should proceed. Two separate taxing principles are usually contended for: Taxation should be proportionate to the benefits received by the person or property taxed; taxation should be based on ability to pay. A third is sometimes added, taxation should have reference to the extent and value of the natural resources enjoyed. As applied to mining taxation, it is pointed out by those who support the first mentioned basis that, mines being usually situated in rocky and hence sparsely peopled regions, mining companies are frequently obliged to construct roads, railways, telegraph and telephone lines, schools, water and sewerage systems, and many other amenities and conveniences of civilization, the cost of which in regions better suited for agriculture and consequently more thickly populated, has either been defrayed locally, or can be spread over a sufficiently large taxable group of people to materially lighten the financial burden on the mine. The mining com¬pany, it is argued, having made these outlays, should receive credit for, them and be relieved of taxation to a corresponding extent. There may be some force in this contention, but the situation is capable of relief without attempting to place taxation upon so unworkable a basis as the value of benefits received. Who is to be the judge of these benefits, and how are they to be valued? The very existence of a mining company and its ability to carry on business in peace and security, depend on the prevalence of law and order, which is a result of good government. The state provides protection against violence, and courts of law for

Jan 4, 1919

By Thos. W. Gibson

The object of taxation is the raising of a revenue. Unless a tax accomplishes this, it is a failure. The right to take for public purposes a part of the moneys obtained from the carrying on of private enterprises is an attribute possessed only by a lawful government, and may indeed be called the supreme attribute of government. In free, democratic communities this power must of necessity rest upon the consent of the governed. Power implies obligation, hence it is obviously the duty of a government, in framing a system of taxation, to provide one which, while effective in producing a revenue, is also just and impartial. • It will be conceded that mines and mining property ought to bear a fair share of the public expenditure. The question is, upon what basis taxation should proceed. Two separate taxing principles are usually contended for: Taxation should be proportionate to the benefits received by the person or property taxed; taxation should be based on ability to pay. A third is sometimes added, taxation should have reference to the extent and value of the natural resources enjoyed. As applied to mining taxation, it is pointed out by those who support the fist mentioned basis that, mines being usually situated in rocky and hence sparsely peopled regions, mining companies are frequently obliged to construct roads, railways, telegraph and telephone lines, schools, water and sewerage systems, and many other amenities and conveniencea of civilization the cost of which in regions better suited for agriculture, and consequently more thickly populated, has either been defrayed locally, or can be spread over a sufficiently large taxable group of people to materially lighten the financial burden on the mine. The mining company, it is argued, having made these outlays, should receive credit for them and be relieved of taxation to a corresponding extent. There may be some force in this contention, but the situation is capable of relief without attempting to place taxation upon so unworkable a basis as the value of benefits received. Who is to be the judge of these benefits, and how are they to be valued? The very existence of a mining company and its ability to carry on business in peace and security depeind on the prevalence of law and order, which is a result of good government. The state provides protection against violence, and courts of law for

Jan 1, 1920

The editorial expenses for the preparation of the manuscript of the second edition, as for the first, were provided by grants of the Engineering Foundation and the Open Hearth Steel Committee of the Iron and Steel Division, AIME ; the Seeley W. Mudd Memorial Fund again sponsored the publication of this volume. The companies and research or educational institutions with which the authors, reviewers, and editors are connected also contributed much to the writing and editing of this book through their generous donations of time and travel and office expenses. And finally, the authors and others have given countless hours of their own time with no recompense but the satisfaction of a job well done. In order to give credit to the companies or educational institutions which made it possible for the members of the Editorial Board to devote considerable time to the revision of this book, the names of these members and their affiliations are recorded here as follows W. O. Philbrook, Carnegie Institute of Technology M. B. Bever, Massachusetts Institute of Technology H. B. Emerick, Jones and Laughlin Steel Corporation B. M. Larsen, United States Steel Company A number of individuals suggested desirable changes in the book before rewriting was started. Almost all manuscripts were gone over critically by reviewers, and the resulting criticisms led to the correction of errors and omissions and greatly contributed to the accuracy and completeness of the text. Other people have supplied additional data or illustrations or assisted in other ways. While some of these contributors must remain anonymous because they are not known to the Editors, the cooperation of the following individuals is gratefully acknowledged: R. D. Allen, Republic Steel Corporation, Chicago Isadore Amdur, Massachusetts Institute of Technology Mary Baeyertz, Armour Research Foundation S. P. Bahmer, Republic Steel Corporation, Massillon E. C. Bain and Associates, United States Steel Company, Pittsburgh C. W. Briggs, Steel Founders' Society of America H. W. Briske, Wisconsin Steel Works

Jan 1, 1951

By V. C. Smith

Reliable and detailed statistical data available for Kentucky, Ohio and West Virginia are the most meager and unsatisfactory of any of the producing states. Detailed histories and statistics are available for only a few pools. The antiquity of these pools, loose nomenclature, particularly where several names are applied to the same pool or various parts of the pool or a new namsed when the pool was rediscovered, made the collection of accurat historical and statistical data almost impossible. So many of the data reported are unreliable that a breakdown by pools or even by counties, until more accurate information is available, would lead to gross errors. Rather than perpetuate inaccuracies, we have endeavored to go to original sources wherever possible, sift these and provide data that may serve as an incentive and basis for future work. The necessity for accurate information is thoroughly recognized by the operators, particularly because of the effect of recent government regulations and request? for data in connection with the preparation of the various codes a pending legislation. Producers, both major operating companies and individuals, . freely given their time and assistance in the compilation of these data. Valuable information was obtained from tax records, rate cases, statistics published by the oil and gas publications and the Bureau of Mines. So many individuals cooperated in the preparation of these data that individual credit cannot be given. Undoubtedly many errors will be found. Some of the data are open to controversy, and many have been omitted in the hope that new information of a more reliable character may become available. Other omissions are due to an inability to contact the proper individuals, many of whom are no longer connected with this industry. Pennsylvania grade crude sold in 1933 for the lowest price since 1895. Gas production could not find sufficient new markets to fill the void left by industrial stagnation. In the gas industry, where the market price is fixed by contract, uncertainty persisted because of impending legislative action affecting both taxes and utility rates. As a result of these factors and a lack of new money, drilling was restricted to a new low. The lifting of proration toward the end of the year in the Pennsylvania

Jan 1, 1934