Search Documents

By H. K. Shearer

Oil production in north Louisianat in 1939 was 25,249,640 bbl., a decrease of 11.2 per cent from 1938. The only important increases in production were in the Cotton Valley and Shreveport fields, but Caddo, Homer, Sligo and Zwolle also made slight gains. Greatest decreases were in the Lisbon and Rodessa fields. Xatural gas production of 313,333 million cu. ft. was an increase of 5.6 per cent over 1938. The increase was accounted for in the Monroe field, while all other fields showed only minor variations from the production of the previous year. Well completions in 1939, as compared with 1938, were as follows: The decline in number of completions was due entirely to lack of proved areas for drilling, and would have been greater except for a revival of interest in the old Caddo shallow field. A majority of the wells completed during the year were in various old, shallow fields, so the average depth of drilling was much less than in several preceding years, notwithstanding a few very deep tests. No new fields were discovered, the only wildcat well reported as a producer being a very small oil well in northwestern De Soto Parish, which is of no apparent commercial importance. Deep gas-distillate production in the Cotton Valley formation was opened at Lake Bistineau and Lisbon, and oil at Shongaloo, but all these wells were too small to encourage additional drilling. Extensions and Developments Caddo Field.—More active drilling was donc in the 36-year old Caddo field in 1939 than in any of the newer fields, with completion of 133 oil

Jan 1, 1940

By H. K. Shearer

Oil production in north Louisianat in 1939 was 25,249,640 bbl., a decrease of 11.2 per cent from 1938. The only important increases in production were in the Cotton Valley and Shreveport fields, but Caddo, Homer, Sligo and Zwolle also made slight gains. Greatest decreases were in the Lisbon and Rodessa fields. Xatural gas production of 313,333 million cu. ft. was an increase of 5.6 per cent over 1938. The increase was accounted for in the Monroe field, while all other fields showed only minor variations from the production of the previous year. Well completions in 1939, as compared with 1938, were as follows: The decline in number of completions was due entirely to lack of proved areas for drilling, and would have been greater except for a revival of interest in the old Caddo shallow field. A majority of the wells completed during the year were in various old, shallow fields, so the average depth of drilling was much less than in several preceding years, notwithstanding a few very deep tests. No new fields were discovered, the only wildcat well reported as a producer being a very small oil well in northwestern De Soto Parish, which is of no apparent commercial importance. Deep gas-distillate production in the Cotton Valley formation was opened at Lake Bistineau and Lisbon, and oil at Shongaloo, but all these wells were too small to encourage additional drilling. Extensions and Developments Caddo Field.—More active drilling was donc in the 36-year old Caddo field in 1939 than in any of the newer fields, with completion of 133 oil

Jan 1, 1940

By Stein Wennberg, Snorre Tessem

INTRODUCTION The mine is situated in the middle of Norway 150 km north of the town Trondheim. The iron ore deposits were discovered in 1906 and have been continuously mined since. The first owner was A/S Nordiske Grubekompagni. In 1912 Fosdalens Bergverks-Aktieselskab was established; since World War II it has been a wholly state-owned company. The location is advantageous, with mining facilities, ore dressing plant and stockpile situated near the northern head of the Trondheimsf jord. The iron ore always occurs in Ordovician lavas and sediments, now altered to greenschists, keratophyres and limestone. The ore bearing zone is 150 km long. The deposits consist of two parallel linear ore bodies lying one above the other in the same stratigraphic horizon which dips 70' to the south. The upper body is 50-100 m high, the lower one 250 m high, while the distance between the two bodies in the East mine varies between 20 and 60 m. The ore width varies between 5 and 8 m. The ore bodies strike WSW and plunge between 10' and 15" in this direction. To date continuous ore has either been worked or opened up along a total strike length of 10 km. Until 1969 all ore was mined in the western part of the deposit called the Western mine. In the spring of 1969 production started in a new mine, the Eastern mine. The ore bodies in this new mine are geologically the same as in the old mine, but they have been displaced 700 m downwards along a major fault in the Fosdalen valley.

Jan 1, 1981

By N. S. Kenny, A. A. Burr

THE purpose of this note is to present evidence that vacancies, which have been produced by quenching from a high temperature, alter the rate of strain-hardening of an hep single crystal. The majority of investigations of the effects of quenched-in vacancies on the yield stress of metals have been made using fee samples in the form of thin wires. However, there is an inherent disadvantage in using such wires to study the effects of vacancies on the rate of strain-hardening of metals because fee wires begin stage II slip either immediately upon yielding or very shortly thereafter. When stage II slip occurs, very rapid strain hardening also occurs, masking the effects of vacancies on the rate of hardening. In this investigation single crystals of magnesium hep were studied since magnesium has only one slip plane at low temperatures and has, therefore, an extensive easy glide region. In addition, the effect of both static and dynamic recovery on the rate of hardening were eliminated by testing in liquid nitrogen. Both forms of recovery occur in hep metals by dislocation climb, which is a diffusion controlled mechanism and is negligible at liquid nitrogen temperatures. Finally, the dependence of the strain-hardening rate on the crystal orientation was eliminated by using the equations of Schmid and Boas.' Variations in the strain-hardening rate could, therefore, be attributed to the presence of vacancies. Single crystals in the form of rods approximately 5 mm in diam and 6 cm long were grown by a modified Bridgman technique from commercial high-purity magnesium (99.97 pet) supplied by the Dow Chemical

Jan 1, 1962

By L. H. Morris, M. Mordecai

The emission of firedamp from the strata surrounding active workings of longwall coal faces normally follows a cyclic pattern associated with the mining operations being carried out on the face. Mining a coal seam disturbs the uniform distribution of overburden weight such that the working is enveloped by a region of high stress, both above and below the seam, advancing with the coal face. There is a decrease in stress as the strata is relaxed following the passage of the face (1). The paper describes experimental results obtained during the initial investigations of a study intended to examine the permeability of samples of coal measure strata under various triaxial stress conditions. Several investigators have studied the effect of stress on the permeability of rock, usually in the field of oil reservoir engineering. Two general lines of approach are evident. One used by among others Fatt and Davies (2), McLatchie et a1 (31, Brace et al (4) and Gunther (5) was to subject a rock sample to hydrostatic pressure. Gas or water would be passed through a sealed core mounted inside a high pressure hydraulic bomb. The second approach, favoured by Wilhelmi and Somerton (6) and also by Gray et a1 (7) was to employ a so-called 'triaxial' state of stress. Here radial confining pressure and axial stress are applied independently. The permeability is measured in the direction of the axial load. With the exception of Gunther who tested coals and Brace et a1 who tested a granite, the rocks used have been sandstones with permeabilities generally appreciably higher than British coal measure rocks.

Jan 1, 1971

By A. D. Hoagland

The Flat Gap mine is located on Copper Ridge in the Appalachian Valley of East Tennessee. Large zinc orebodies occupy zones of solution and collapse breccias in Lower Ordovician Kingsport limestone and dolomite. The principal ore mineral is sphalerite and the principal gangue is dolomite. The ore-bearing horizons are considerably more than 95% covered by thick residual clay. Geochemical prospecting under these conditions is an effective exploration technique which played an important role in the discovery and exploration of the Flat Gap mine. The Flat Gap mine, an important zinc deposit of the Appalachian type, is located in the Copper Ridge Belt in the Valley of Tennessee approximately 30 miles northeast of the Mascot-Jefferson City zinc district (Fig. 1). The ore is found in large stratigraphically linked deposits in solution and collapse breccias of the Kingsport, Longview and, to a minor extent, Mascot formations of Lower Ordovician age. The principal ore mineral is sphalerite and the principal gangue minerals are dolcrmite and accessory pyrite. There is local minor galena and very rare barite and fluorite. The ore-bearing horizons are covered by about 20 to 100 ft or more of residual clay except where active streams have exposed bedrock. Considerably less than 5% of the favorable host rocks are exposed in outcrop, and this nearly complete soil cover creates a serious obstacle to exploration. Comprehensive surveys of the base metal content of soils furnish a useful substitute for outcrop geology, and under favorable conditions, this technique is a very valuable prospecting tool. The analysis is carried out by a titrametric dithizone method modified after the procedure described by E. B. Sandell.' This method detects

Jan 1, 1962

By R. W. Gould, B. G. LeFevre, A. G. Guy

The resistivity anomaly known as the K state was studied in Ni-Mo alloys containing 10.5 and 14.0 at. pct Mo. Both these alloys exhibit a large K effect which depends on the mechanical and thermal treatment. On the basis of X-ray diffuse scattering studies which were correlated with resistivity measurements, it appears that the K state in dilute Ni-Mo alloys can be associated with changes in the degree of short-range order within the a phase. An interesting phenomenon that has received much attention in recent years is the K state. The K state is marked by anomalous changes in some of the physical properties of certain alloys without the occurrence of observable microscopic structural changes. One of the early pieces of work in this area was by Thomas' who studied alloys of Ni-Cr, Ni-Cu, Ni-Cu-Zn, Fe-A1, Fe-Si, and Ni-A1. Upon annealing specimens which had been previously cold-worked or quenched from an elevated temperature he found an anomalous increase in resistivity over a certain temperature range. He also found that specimens which had been appropriately annealed to develop the K state showed a decrease in resistivity upon subsequent cold working. These effects are opposite to those found in normal alloys. Although the resistivity anomaly has been rather arbitrarily taken as the "definition" of the K state, there are several other interesting effects which accompany the resistivity increase. In Ni-Cr alloys,2, 3 for example, it was found that the hardness increases with increasing resistivity. It was also found that specimens which have been treated to develop the K state can be cold-worked for as much as an 80 pct reduction of area without an increase in the hardness. In Fe-A1 and Fe-Si alloys4 the K state is accompanied by an increase in flow stress and by a lattice contraction. In Ni-A1 alloys,5 specimens which have been treated to develop the K state also show an increase in elastic modulus. In Ag-Pd alloys6 the increased resistivity observed on annealing a cold-worked specimen is accompanied by an increase in the thermoelectric power and an increase in the Hall coefficient. The explanations of the K state phenomena are varied and depend upon the particular alloy in question. Several theories have been advanced to explain the increased conductivity with cold work on the basis of changes in the electronic configuration of the alloy as a result of local lattice distortions.7"9 Most investigators, however, believe that some type of local order in the solid solution, either short-range order (SRO) or clustering, is responsible for this effect. Theories concerning the relationship between ordering and the K state have for the most part been speculative, since there is little direct X-ray evidence that can be correlated with the above property changes. Much of the previous work on the K state was done in the Ni-Cr system where the small difference in the X-ray atomic scattering factors of the components nickel and chromium makes it very difficult to use X-ray diffuse-scattering measurements to determine the role of local order. In the Ni-A1 system, however, Starke et al.10 succeeded in detecting a connection between local order and the K state. It was found that a small but measurable K effect correlated with increasing SRO in the nickel-rich a phase. The manner in which local order might increase the resistivity of K state alloys is not completely clear. Since most of the known K state alloys contain at least one transition element, significance has frequently been attached to the presence of an unfilled d shell. It has been suggested that during the formation of the K state the number of conduction electrons decreases as a result of the transfer of s electrons to the d shell where they are more tightly bound.1'11'12 Koster and Rocholl13 have proposed that SRO can cause an increase in resistivity for alloy systems in which the number and mobility of charge carriers are reduced when the percent solute is increased. According to this hypothesis, the local environment of a given solvent atom changes in the same manner with increasing percent solute as it does with an increasing degree of SRO; hence the change in physical properties should tend in the same direction. In this hypothesis, SRO is considered only in a statistical sense, and the increased resistivity of the K state is attributed to a change in the mean distribution of electrons and holes in the s and d states as a result of SRO. From the work of Chen and Nicholson on Ag-Pd alloys,6 it appears that the K state can occur in systems for which the d shell is completely filled. These investigators explained the increased resistivity by picturing the SRO as small domains of some form of long-range order (LRO). According to ~ibson,'~ the number of effective electrons can be reduced by the creation of a new Brillouin zone boundary near the Fermi surface of an alloy as a result of the changing crystallographic symmetry that accompanies the formation of a superlattice. This idea may be expressed in terms of the superzone concept.15 In the present work the role of local order in the formation of the K state in Ni-Mo alloys was investigated. The principal tools used in this study were X-ray diffuse scattering and electrical resistivity measurements; however, these data were supplemented by electron microscopic and field-ion microscopic data. The purpose of the work was to determine whether or not the K state in Ni-Mo alloys can indeed be attributed to the formation of SRO as has been proposed by previous investigators.

Jan 1, 1969

By Blamey Stevens

My previous paper is entitled, The Laws of Igneous Ernanation Pressure. The present paper lays no claim to the exactitude and completeness of a law, since it is of a provisional nature and may be disregarded when experiments have established a basis for more exact reasoning. The general physical states in which aqueous emanations may occur are first considered. The possible physical couditions under which the mineral elements may occur in emanations are then discussed, and a classification of deposits, dependent on emanation, is proposed. A system of scientific experimental investigation is outlined, and it is shown that the physical and chemical properties of emanation may be exactly determined thereby. The investigation is urged as feasible and simple, and not necessarily requiring large and costly apparatus. It is the only step necessary to make possible the formulation of a complete set of laws of igneous emanation. Process of Emanation. In a rising column, magma ranges in temperature from 900° to 1,200°C. Exhalation must begin at some fairly great depth. What this depth may be we can only surmise, since no experimental evidence is available. Exhalation, however, continues as the magma flows upward, until at another level the occluded gases have all escaped. This depth is probably upward of 5,000 ft. (See Fig. 1.) All exhalations must come from between these two levels. As the whole emanation is the sum of the exhalations and residues, the residues must come from below the uppermost level. They will be most abundant when coming from those parts of the intrusion which have solidified below the lower level.

Jan 1, 1913

By William P. Prof. Blake

WHEN we consider the efforts made in Europe to promote the physical and moral well-being of the working classes, the question is suggested whether in this country, where, theoretically, every man is peculiarly the arbiter of his own destiny, we may not be too prone to expect every man to take care of himself, and neglect to make those provisions for the welfare of the employed, demanded alike by enlightened economy and humanity. In the older countries, where the disproportion between capital and labor is greater, and the working classes are more dependent, their welfare largely occupies the attention of employers. The subject is involved in the problem of the just relations of capital and labor, and we are rapidly approaching the time, if we have not already reached it, when a generous paternal interest in the welfare of the employed should be more generally manifested. It is a subject which is of special importance to mine-owners and engineers in this country, especially to those located in the coal regions. My own attention has been particularly directed to it by a visit made to the Hassard collieries, a few miles from Liege, Belgium, under the direction of M. Andrimont. This celebrated engineer has established a comfortable home for the miners near the mouth of the shaft of the mine. It has been highly successful and beneficent in its results, and may to a great degree be regarded as a, model for such undertakings. It is known as "Hotel Louise," this being the name of Madame d'Andrimont, who laid the corner-stone of the building April 4th, 1871. The structure is of brick, upon three sides of a square, and

Jan 1, 1875

By William P. Blake

When we consider the efforts made in Europe to promote the physical and moral well-being of the working classes, the question is suggested whether in this country, where, theoretically, every man is peculiarly the arbiter of his own destiny, we may not be too prone to expect every man to take care of himself, and neglect to make those provisions for the welfare of the employed, demanded alike by enlightened economy and humanity. In the older countries, where the disproportion between capital and labor is greater, and the working classes are more dependent, their welfare largely occupies the attention of employers. The subject is involved in the problem of the just relations of capital and labor, and we are rapidly approaching the time, if we have not already reached it, when a generous paternal interest in the welfare of the employed should be more generally manifested. It is a subject which is of special importance to mine-owners and engineers in this country, especially to those located in the coal regions. My own attention has been particularly directed to it by a visit made to the Hassard collieries, a few miles from Liège, Belgium, under the direction of M. Andrimont. This celebrated engineer has established a comfortable home for the miners near the mouth of the shaft of the mine. It has been highly successful and beneficent in its results, and may to a great degree be regarded as a model for such undertakings. It is known as ((Hotel Louise," this being the name of Madame d' Andrimont, who laid the corner-stone of the building April 4th, 1871. The structure is of brick, upon three sides of a square, and

THE Leadville tunnel, a Bureau of Mines project designed to unseal Colorado's rich but flooded lead, zinc, and manganese mines, is still being advanced, although the work is encountering severe difficulties. Work on the tunnel, begun in 1943, was dropped for lack of funds in 1945, and started again last September. The tunnel is one of the nation's toughest mining jobs. Fifty firms and individuals, who were asked to bid on the job of continuing be- yond the 6600-ft mark, didn't even answer. The work was finally taken over by the Utah Construction Co. of Salt Lake City. Since last September, the face has been moved 1000 ft closer to the flooded Leadville district mines, and to the hoped-for length of 17.300 ft. Some apparent success has already been noted, with an unusual decline in the water level in some major mine shafts reported this winter.

Jan 5, 1951

By W. L. McMorris, A. H. Brisse

IN the last several years the coal industry has intensified its effort to solve the growing problem of cleaning and recovering fine mesh coals. On one hand these has been increasing civic pressure for cleaner streams, and on the other hand there has been increasing production of fine mesh coal, resulting directly from adoption of the modern mining methods so essential to the economy of the coal mining industry. Cleaning fine coal with the same precision possible with coarser coals is a difficult task, and for coals finer than 200 mesh it has been impractical. Furthermore, the inclusion of —200 mesh material in the final product markedly increases costs of de-watering and thermal drying, which are necessary steps if coal is to meet market requirements. Consequently these extreme fines have generally been wasted. As a result, problems have been created in many districts because there has not been enough area for adequate settling basins. Wasting of coal in the -200 mesh slimes may account for a loss in washer yield equivalent to 2.0 to 2.5 pct of the raw coal input. With rising mining costs the value of such a loss is constantly increasing and a need for a better solution to the fines problem becomes more pressing every day. From an operating viewpoint, also, continuous removal of extreme fines from the washing plant circuit permits good water clarification practice, improving significantly the overall cleaning efficiency. The obvious desirability of recovering a commercially acceptable coal from washery slimes prompted U. S. Steel Corp. to investigate the merits of the Convertol process developed in Germany." Although this process has been used commercially in Europe for some time, little if any consideration has been given to its possible adoption in the U. S. until very recently. Fundamentals of the Convertol Process: In the Convertol process, droplets of dispersed oil are brought into intimate contact with the solids suspended in the coal slurry to be treated. This contact causes oil to displace the water on the surface of the coal by preferential wetting, or phase inversion, after which the coal particles are allowed to agglomerate in a manner permitting their re- moval from the slurry by centrifugal filtration. The clay and other particles of mineral matter suspended in the slurry do not have the affinity for oil the coal particles have. Consequently the oil treatment is preferential to coal to the extent that more than 95 pct of the oil used reports with the clean coal recovered. Figs. 1 through 3 will clarify the steps involved in the process. Fig. 1 shows the suspended material in the slurry to be treated, which is a thickened product containing 40 to 45 pct solids. Oil is now injected into the slurry under vigorous agitation to produce good oil to coal contact conditions, which result in preferential oiling of the coal particles. These coal particles are then permitted to agglomerate by gentle stirring in a conditioner to form flocs, as shown in Fig. 2. At this point in the process the agglomerated oiled coal can be washed and partially dewatered on a vibrating screen, as shown in Fig. 3. Finally, the washed flocculate can be further dewatered in a high-speed screen basket centrifuge or in a solid bowl centrifuge. Commercial Application of the Convertol Process in Germany: The original Convertol process was developed by Bergwerksverband zur Verwertung von Schutzrechten der Kohlentechnik, G.m.b.H., a German research organization controlled by the Coal Operators Assn. of the Ruhr Valley. The process as reduced to commercial practice in Germany' is shown in Fig. 4. In this process a thickened slurry (40 to 45 pct solids) mixed with a predetermined percentage of oil is fed from a surge tank to the phase inversion mill. After the phase inversion step, the slurry is usually discharged directly to a highspeed screen centrifuge. From 3 to 10 pct oil is used, depending on type of oil, size consist of coal to be recovered, and operating temperature. The top size of fine coal cleaned in Germany by the Convertol process is limited by the size of the openings in the centrifuge screen basket. Any mineral matter coarser than the basket opening, which is generally 60 to 80 mesh, must remain with the oiled coal. If the coal fines have been effectively cleaned down to about 80 mesh, the cleaning performance of the process is practically unaffected by the presence of coarse coal particles. However, since recovery of coal much coarser than 80 mesh is mow economical by conventional methods, it normally becomes more costly to allow substantial percentages of this coarse coal in Convertol process feed. Where the general plant layout does not permit effective cleaning of coal sizes down to 80 mesh or lower. there is some justification for a coarser Con-

Jan 1, 1959

BRANCH COUNCILS MINING BRANCH R M Foose, Chairman (Industrial Minerals) Carroll A Garner (Coal) J V Beall, Eastern Secretary A B Cunmins (Industrial Minerals) R E O'Brien, Western Secretary E D Gardner (Mining, Geology, and Geophysics) Carroll F Hardy (Coal) Philip J Shenon (Mining, Geology, and Geophysics) R E Byler (Minerals Beneficiation) A C. Callen (Mineral Industry Education) Grover J Bolt (Minerals Beneficiation) R J Lund (Mineral Economics)

Jan 1, 1951

By J. D. Miller, J. E. Sepulveda

Tar sand deposits in the state of Utah contain more than 25 billion bbl of in-place bitumen. Although 30 times smaller than the well-known Athabasca tar sands, Utah tar sands do represent a significant domestic energy resource comparable to the national crude oil reserves (31.3 billion bbl). Based upon a detailed analysis of the physical and chemical properties of both the bitumen and the sand, a hot-water separation process for Utah tar sands is currently being developed in our laboratories at the University of Utah. This process involves intense agitation of the tar sand in a hot caustic solution and subsequent separation of the bitumen by a modified froth flotation technique. Experimental results with an Asphalt Ridge, Utah, tar sand sample indicated that percent solids and caustic concentration were the two most important variables controlling the performance of the digestion stage. These variables were identified by means of an experimental factorial design, in which coefficients of separation greater than 0.90 were realized. Although preliminary in nature, the experimental evidence' gathered in this investigation seems to indicate that a hot-water separation process for Utah tar sands would allow for the efficient utilization of this important energy resource. The projected increase in the ever-widening gap between the domestic energy demand and the domestic energy supply for the next few years has motivated renewed interest in energy sources other than petroleum, such as tar sands, oil shale and coal. Although a number of research programs on the exploitation of national coal and oil shale resources have already been completed, very few programs have been initiated on the processing of tar sand resources in the United States. In recognition of their significance as a domestic energy resource, investigators at the University of Utah have designed an extensive research program on Utah tar sands. An important phase of this program, and the main subject of this publication, is the development of a hot-water process for the recovery of bitumen from Utah tar sands, as a preliminary step toward the production of synthetic fuels and petrochemicals. The term "tar sand" refers to a consolidated mixture of bitumen (tar) and sand. The sand in tar sand is mostly a-quartz as determined from X-ray diffraction patterns. Alternate names for "tar sands" are "oil sands" and "bituminous sands." The latter is technically correct and in that sense provides an adequate description. Tar sand deposits occur throughout the world, often in the same geographical areas as petroleum deposits. Significantly large tar sand deposits have been identified and mapped in Canada, Venezuela and, the United States. By far, the largest deposit is the Athabasca tar sands in the Province of Alberta, Canada. According to the Alberta Energy Resources Conservation Board (AERCB),2,3 proved reserves of crude in-place bitumen in the Athabasca region amount to almost 900 billion bbl. To date, this is the only tar sand deposit in the world being mined and processed for the recovery of petroleum products. Great Canadian Oil Sands, Ltd. (GCOS) produces 20 million bbl of synthetic crude oil per year. Another plant being constructed by Syncrude Canada, Ltd. is expected to produce in excess of 40 million bbl of synthetic crude oil per year. According to the Utah Geological and Mineral Survey (UGMS), tar sand deposits in the state of Utah contain more than 25 billion bbl of bitumen in place, which represent almost 95% of the total mapped resources in the United States.4 The extent of Utah tar sand reserves seems small compared to the enormous potential of Canadian tar sands. Nevertheless, Utah tar sand reserves do represent a significant energy resource comparable to the United States crude oil proved reserves of 31.3 billion bbl in 1976.5 Tar sands in Utah occur in 51 deposits along the eastern side of the state.4 However, only six out of these 51 deposits are worthy of any practical consideration (Fig. 1). As indicated in Table 1, Tar Sand Triangle is the largest deposit in the state and contains about half of the total mapped resources. Information regarding the grade or bitumen content of Utah deposits is still very limited. The bitumen content varies significantly from deposit to deposit, as well as within a given deposit. In any event, the information available6-8 seems to indicate that Utah deposits are not as rich in bitumen as the vast Canadian deposits which average 12 to 13% by weight.9 Although many occurrences of bitumen saturation up to 17% by weight have been detected in the northeastern part of the state (Asphalt Ridge and P. R. Spring), the average for reserves in Utah may well be less than 10% by weight. Separation Technology As in any other mining problem, there are two basic approaches to the recovery of bitumen from tar sands. In one

Jan 1, 1979

By R. V. Higgins

This paper presents a computer method to obtain the shape factors and equal cell volumes of the channels for any well spacing pattern from a potentiometric model. By using this program the authors have processed the data for the seven-spot, direct line-drive and the staggered line-drive patterns. The data for the five-spot pattern had been previously processed by a noncomputer method and are included for completeness. The shape factors and volumes for the channels are presented in tables for those who want to use them to process data using their own permeability relationships and viscosities of their reservoir oils. The authors have used the data and sets of representative permeability curves to process sample calculationr of waterflood performances. The comparison of the calculated results shows that the influence of well spacing is small. The permeabilities of the reservoir rock to oil and water had a greater influence on oil recovery for a given pore-volume throughput of water than the well spacing pattern. The more water-wet the reservoir rock, the better the possibility of permeabilities which are conducive to good recovery. The viscosity of the reservoir oil also influences the recovery more than the well spacing pattern. The reduction in the percentage recovery of oil with increase in viscosity of the reservoir oils is small when oil viscosities are in the range of 0.1 to 3. Above this range the reductions in recoveries are extensive. Sample comparisons of the time required for different patterns to recover the oil are presented. Results of an example calculation are given to show the effect of the permeability profile on recovery. INTRODUCTION The effect of well spacing pattern on the recovery of oil when flooding with either gas or water has been studied by many investigators. Muskat et al.1 presented an analysis using conductivity, sweep efficiency and unit mobility to the time of breakthrough. Dyes et al.2 used experimental techniques (X-ray shadowgraphs) and different mobility ratios. They presented quantitatively the relationship between mobility and sweep efficiency at and after breakthrough. Hauber3 presented a method to predict waterflood performance for arbitrary well spacing patterns and mobility ratios. Craig et al.,4 using techniques similar to Dyes et al. to determine sweep efficiency for a five-spot pattern, added the use of relative permeability curves at breakthrough and thereafter. Douglas et al.5 sed rela- tive permeabilities and continuously changing saturations throughout the entire five-spot flood pattern. In obtaining their solutions they used finite-difierence equations. Hig-gins and Leighton6,7 also used relative permeabilities and continuously changing saturations throughout the pattern before and after breakthrough. They employed techniques that process a flood-pattern calculation on the computer in about one minute. The methods of Douglas et al. and Higgins and Leighton both checked closely the laboratory results for a wide range of mobility ratios. This paper presents some sample performances calculated by the Higgins and Leighton method that show the effect on recovery of different permeabilities and viscosities using the seven-spot, the line-drive and the staggered line-drive, as well as the fivespot flood pattern. No previous paper has presented these data using different permeability curves and continuously changing saturations throughout the flood patterns. The paper also presents (1) the results and analyses of the flood-pattern prediction, (2) the computer techniques for determining the shape factors and volumes from the potentiometric models for the foregoing flood patterns, and (3) the shape factors and volumes of the channels of the flood pattern in the event reservoir engineers may like to process waterflood calculations using their own permeability curves and reservoir oils. DESCRIPTION OF METHOD VOLUMES AND SHAPE FACTORS The use of channels taken from a potentiometric model (see Fig. 1) to aid in calculating the performances of water floods of nonlinear patterns has been thoroughly explained in the literature.0,7 Therefore, very little theory, discussion, or proof regarding this phase will be repeated in this paper. The computer method presented in this paper to calculate the volumes and the shape factors of the channels of potentiometric models employs the trapezoidal rule for the volumes and the Pythagorean theorem (the hypotenuse equals the square root of the sum of the squares of the two sides of a right triangle) for the shape factors. In calculating the volume of a channel, the area of each cell in the channel is determined and then multiplied by the thickness to obtain the volume. In determining the areas of the cells, trapezoids are constructed whose vertical sides are spaced Ax apart, as shown in Fig. 2. The length of the sides is the difference between an ordinate cut off by the top and bottom of the cell — usually equipo-tentials. The coordinates of the points along an equipo-tential or streamline are obtained by Lagrange's8 equation of interpolation for which the constants are coordinate points at the intersections. Three intersections for con-

Jan 1, 1965

On an average of at least once a year there comes to the attention of the Institute Headquarters the activities of some individual who represents himself as a member of the Institute, and by a hard-luck story or other means secures loans or advances of money which are never returned. On one or two occasions the Institute has been able to secure the arrest and conviction of these frauds. Recently some individual has been operating in California and defrauded several members of the Institute. He is described as a man of 5 ft. 7 or 8 in. height, decidedly slim, and his weight is about 140 lb. His hair and mustache are gray, eyes blue or gray and he claims to be near-sighted. He is also said to have had a keen, furtive, "Hang-dog" look and claims to have been raised in Bethlehem, Pa. He speaks with a German accent. If a man answering this description presents himself before any members and claims to be a member of the Institute it will be to the good of the profession if he can be caught making fraudulent representations and placed where his ability to defraud will be under control. The most effective means of apprehending persons of this character is the very prompt notification to Institute Headquarters of any persons claiming to be members of the Institute in hard luck. If such persons are asked to supply their signature or photograph or both to be, forwarded to Institute Headquarters for identification this will serve as an excellent check on their operations. Reluctance to comply with such a request is in itself a suspicious circumstance.

Jan 9, 1919

By H. I. Aaronson, H. A. Domian, G. M. Pound

Zener's two-parameter theory of the y a reaction in Fe-X alloys is extended to encornpass austenite-stabilizing as well as fewite-stabilizing elements, and is then cottzbitzed with statistical thermodynamic theories of Fe-C alloys to permit development of a ther-modynamic description of the proeutectoid fewite reaction in Fe-C-X alloys. Equilibrium tielines are calculated for tile a + y rep'on from experimental data and frort extrapolations of the y/y +a equilibrium surface. Sectzovs of the y/y + 0 surface are calculaled for the tzetastable sstuation LYL u-kich alloyrtg eleitzents do not partition betzseen azrstenite andfer-rite. The finding that the metastable y/a + y curves Lie close to their equilibriuwz counterparts when X = Si, .Vo, Co, Al, and Cu but well below them when X = A/ln or Ari pr-elides a thermodunamic explanation for the expcri1?7e?ztally obserted absence of partition during the proeutec toid ferrite reartlon in the fortner alloys and for the occurrence of partition at hzgher ternperatures in the latter alloys. Cotarison ofno- patitzoa free-energy changes and y/y i a curr,es in Fe-C-X alloys with the equilibrium 11al1es of these quantities in Fe-C alloys furnishes additional qualitative insight into the irqluence of allojling elements upon the kinetics of the proeutectoicl ferrite reaction. THE introduction of a substitutional alloying element, X, appreciably complicates calculation of the thermodynamics of the formation of proeutectoid ferrite from austenite. As noted in the preceding paper,' the positional entropy of the interstitial species is the principal component of the free energy of an interstitial solid solution with which theory has so far been able to deal. One would expect, however, that other components of the free energy of this type of solid solution may be significantly altered by the addition of a substitutional alloying element. Even if the assumptions are made, by analogy to the case of Fe-C alloys,' that changes in the positional entropy of carbon represent a significant part of the thermodynamic effects of an alloying element, and that the remaining effects can be taken into account by fitting the equations developed on this basis to experimental data on Fe-C-X phase diagrams or on the activities of carbon in alloyed austenite and ferrite, the experimental information available on either of these quantities is not yet sufficiently accurate or extensive, respectively, to make such an approach useful. An attempt made by Zener on the former basis to explain the effects of alloying elements on the thermodynamics of Fe-C alloys in terms of a temperature-independent "free-energy change" (actually enthalpy hane') required to transfer 1 mole of an alloying element from austenite to ferrite, in which the "free-energy change" was determined by fitting the theoretical relationships developed to Fe-C-X phase diagrams, thus proved inadequate in part because of deficiencies in the available ternary-phase-diagram data.= Other difficulties of a more fundamental nature, however, also indicated the desirability of a different approach to the problem.3y4y6 zener6 subsequently proposed that the free-energy change associated with y — a transformation in pure iron can be decomposed into magnetic and nonmagnetic components. Alloying elements were assumed to affect those components separately. One parameter was used to describe the quantitative effect exerted on each component. These parameters were evaluated from Ms (martensite-start) temperature data and from other experimental information usually either readily available or measurable with acceptable accuracy. Zener applied this treatment only to the calculation of Fe-X phase diagrams in which X is a ferrite-stabilizing element. In the present study, this treatment is extended to include austenite-stabilizing elements, and then combined with treatments previously considered for Fe-C alloys1 to permit calculation of the thermodynamic quantities of interest in the austenite - proeutectoid ferrite transformation in Fe-C-X alloys, where a number of representative, and commonly used alloying elements are chosen for X, including Si, Mn, Co, Mo, Al, Cr, and Cu. The results are used to explain important features of the partition of alloying elements between austenite and proeutectoid ferrite, as reported in a companion paper7 on the basis of electron-probe analysis, and to provide some additional understanding of the influence of alloying elements upon the kinetics of nucleation and growth of proeutectoid ferrite. Portions of this treatment6 have been clarified in the course of a review by Kaufman and Cohen.3 The consolidated summary of these developments with which this section is begun provides a basis for further clarification of the treatment, from which extension to include austenite- as well as ferrite-stabilizing elements is a natural consequence. The division of the free-energy change associated with the 7 - a transformation in pure iron, into two independent components is formally stated as:

Jan 1, 1967

By F. C. Miller

THE metallurgical fuel of Colorado, Utah, and New Mexico has been a very tardy member in the caravan of western industrial progress. The history of western coke has naturally been closely related to the development of the metallurgy of iron and steel and the precious metals, in the State of Colorado. It was at Leadville, with a population of 300 in 1877, that the Sentinel was published by Richard S. Allen. The Sentinel gave very full accounts of the various mineral discoveries at the new town of Leadville, which found their, way to the more widely circulated journals of the East, and attracted the attention of many people. At the close of 1878, a census showed a total of 5040 persons. The first smelter was established in 1877, at Malta, two miles from Leadville, by A. R. Meyer, but was not successful. It was succeeded by the Harrison Reduction Works, in 1878. The La Plata began with one furnace in June, 1878, and in 1879 had four furnaces in active operation. These furnaces used charcoal for fuel, and, because of hot tops, suffered a tremendous loss in lead and silver. This difficulty was overcome by the erection of 50 single-bank 10-ft. beehive ovens at Crested Butte, Colo., in 1880. The slack coal sent to these ovens was very pure, and yielded a coke carrying as little as 4.5 per cent. ash. Among the pioneers in the Leadville district were Grant, Eddy, James, Billings, Eiler, and Dickson. To these men the West owes the present expansion of its mining industry, and the erection of metallurgical processes for the treatment of precious metals.

Jan 8, 1918

Because common salt, sodium chloride, is necessary to all animal and much plant life, it is probably the most widely used of all mineral commodities, except for water. Nevertheless, of the total salt consumed, only 7% is used for food, including animal food. Two-thirds of the total is used as chemical raw material, principally for making such basic chemicals as chlorine, caustic soda, and soda ash. Other uses are for road thawing (16%) and water softening. Some 162.5 million tons of salt were used, worldwide, in 1972 (Table 15.4F.1). Production is from bedded salt deposits, salt domes, and evaporation of brines, including solar evaporation of seawater. Production is worldwide from at least 20 countries, of which the United States, China, USSR, the United Kingdom, and West Germany are the leaders. Consumption increases about 7 % annually. Reserves are plentiful: Other important sodium salts are soda ash (sodium carbonate) and salt cake (sodium sulfate). Soda ash comes mainly from the Solvay process (70% ) , which uses salt, limestone, and ammonia as raw materials. A large and growing portion of United States production is from mining large bedded deposits of trona, a natural hydrated sodium carbonate and bicarbonate found in Wyoming, and from brine evaporation in California. Soda ash is used for glassmaking, phenol, soap, detergents, and bleaches. Half of the United States salt cake used is a byproduct from rayon manufacturing. The other half comes from brines and playa lakes in California, Texas, and Wyoming. Salt cake is used mainly for papermaking. ACKNOWLEDGMENT Appreciation is expressed to William B. Dickson, president, Salt Institute. [ ]

Jan 1, 1976

By William Hall

THE product obtained by roasting stibnite is likely to contain some unoxidized antimony trisulphide and a mixture of antimony trioxide and antimony tetroxide. It was desired to determine, as accurately as possible, the condition of the antimony as well as the total quantity present. Attempts were made to separate the trisulphide and the two oxides by methods based upon their varying solubilities in different solvents, but no satisfactory results were obtained in this way. It was found, however, that by determining the total antimony content, the antimony present as trioxide, and the antimony present as trisulphide, a good idea of the chemical composition of the roasted product could be obtained. The total antimony was determined by dissolving the sample in concentrated hydrochloric acid, reducing the antimony entirely to the trivalent condition by means of hydriodic acid and eventually titrating the antimony back to the pentavalent condition by means of iodine in the presence of sodium bicarbonate.' The details of the procedure are as follows: Weigh out 0.25 gram of the roasted product into a trapped flask (Fig. 1), add 4 grams of powdered tartaric acid, 2 grams of potassium iodide and 40 c.c. of concentrated hydrochloric acid. Boil the solution gently for 5 min. and then cool to room temperature by shaking the flask while holding it under running water. Then, very carefully discharge the iodine color by the cautious addition of 0.05-normal sodium thiosulphate solution, adding a little starch toward the last. Nearly neutralize the acid with ammonia solution, but leave the solution distinctly acid. Pour the slightly acid solution into 200 c.c. of water con-

Jan 1, 1916