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By H. J. Levinstein, H. J. Guggenheim

RbFeF3 is a transparent ferromagnet with a large faraday rotation which permits the direct observation of magnetic domain structures in bulk crystals. If the position of dislocations within the crystal were known a study of domain wall dislocation interactions would be possible. In this paper an etch pitting solution is described which gives a one-one correspondent between the etch pits and the dislocations intersecting the (100) surfaces of RbFeF3 crystals. In addition, RbFeF3 is shown to have sufficient plasticity so that known arrays of dislocaticms can be put into the crystal. It is concluded that RbFeF, is an ideal material for the investigation of domain wall dislocation interactions. THE influence of lattice defects on the motion of domain walls in ferromagnetic materials has been studied extensively both theoretically and experimentally.4 The experimental data obtained has been qualitative in nature due to the lack either of a quantitative knowledge of the magnetic domain array in the material or of the nature of the dislocation configuration in the material. At room temperature RbFeFJ has the cubic perovskite structure. It is ferromagnetic below 86°K.5,6 It is also transparent and has a large faraday rotation in the magnetic state.7 The domain structure of this material is observable in three dimensions in crystals which are millimeters in thickness.' Since RbFeF3 satisfies the requirements of having an easily visible three-dimensional magnetic domain structure, it was of interest to determine if the dislocation structure of the material could be determined and if the material was sufficiently plastic so that dislocations could be introduced into the as grown crystals. This is a report of the results of that investigation. EXPERIMENTAL PROCEDURE The crystals of RbFeFs used in this experiment were grown by a technique described elsewhere.5 In order to obtain flat strain-free surfaces, the samples were first cut to the crystal orientation desired and the surfaces were polished by employing standard metallographic techniques. The samples were then immersed in a solution of 1 to 3 g of KOH in 100 ml of water. This solution removes the damaged surface layers uniformly leaving a film on the surface of the sample. Etch pits are obtained by immersing the sample in an approximately 50-50 solution of 30 pct peroxide and concentrated acetic acid. The film formed during the KOH treatment turns deep red in color in the etching solution and flakes off the sample. The etching time required depends upon the pit size desired and

Jan 1, 1970

By J. M. Schopt

COAL petrology is the study of the lithologic composition and texture of coal and includes megascopic as well as microscopic differentiation. Coal petrography is a quantitative study, principally (but not exclusively) microscopical in nature. The distinction between coal petrologic and coal petro-graphic studies usually is not important, but it is important to recognize that these studies differ materially from other types of petrology that deal primarily with minerals. The petrologic entities* of coal are less clearly distinguished than most minerals and the basis of distinction is not always clearly expressed. The relation of coal petrology to geologic, mining, and technologic problems is most evident when results of coal petrologic studies can be stated quantitatively. The chemical and physical composition of coal and the determination of its quality and properties are continuing problems. The source of these problems lies in the heterogeneity of coal and in its almost complete insolubility in ordinary solvents at normal temperatures. The empirical and comparative character of standard chemical coal analytic values is one of the consequences resulting from heterogeneity and insolubility of coal. Nevertheless, these coal analytic methods are highly technical and diversified. Coal petrol.ogy employs a group of similar analytical methods which provide information about coal that the other methods cannot supply. The heterogeneity of coal is most clearly demonstrated by means of petrologic studies. The properties utilized in coal petrologic studies are related to texture (size, form, and association), hardness, light reflectance, and light absorption and transmission (color). Size relations are most evident but are commonly overlooked. Coal is classed chemically as a mixture, and chemical analyses thus show the composition of the sample as a whole. Geologically coal is an organic clastic deposit, derived from diverse plant fragments and particles having a size range comparable to that of a conglomerate or breccia. The mixture of different materials that compose coal, large and small, can be realized only by microscopic study. This is because the fundamental cellular units of plants, from which coal is formed, are microscopic in size. The kinds of altered plant particles and fragments in coal have specific differences in hardness, reflectance, and color that signify differences in composition. These differences must be taken into account in evaluating the aggregate properties of coal. Terminology and Texture Full discussion of terms applied by various petro-logists in analysis of coal is beyond the scope of this article. For convenience the simpler types of petrologic entities that are defined without reference to lithologic occurrence or texture will be called coal components. Fig. 1 lists reactive and relatively inert

Jan 1, 1957

By J. E. Gould, H. J. Hand

MANY independent studies are being made on slag-metal relationships in the open-hearth furnace, and these studies cannot help but result in an ultimate improvement in the quality of open-hearth steel of both the open and killed types In maintaining quality control at the National Tube Company's plant, emphasis has been placed on an evaluation of the iron oxide content of the steel in as quantitative a manner as possible, in order that the most desirable level of oxidation might be obtained for a given type of steel, and to secure a more precise basis for final deoxidation In the past, various methods were used for estimating FeO content of the metal at tap to ensure uniform and thorough deoxidation of killed steel, avoiding over-deoxidation to minimize the amount of inclusions present and to make as sound a steel as possible For the open-type steels, such control involves obtaining the necessary level of oxidation for the most suitable action of the steel in the molds to provide good surface quality and cross section for the specific grade involved While rapid analytical methods are available for determination of FeO in the liquid metal, such methods are still not sufficiently rapid for routine control on the open-hearth floor, nor do such analyses provide information as to what causes high or long FeO values The method of sampling can still be considered a problem in view of the variability encountered in taking simultaneous duplicate tests With the accurate rapid methods now available for determining carbon in the metal, estimating slag basicity and obtaining temperatures of liquid metal, it was believed possible to determine the influence of the various furnace reactions in establishing the state of oxidation at a given time Simultaneous slag and metal tests were used in this analysis, aided by statistical methods, to determine the factors that affect the metal FeO, and also to make a quantitative evaluation of these factors Data obtained are from actual furnace operations, the metal test being of the spoon, Herty type, and taken in duplicate. Metal temperatures were taken with the open-tube bath pyrometer developed by the Research Laboratory of the United States Steel Corporation This method of taking open-hearth metal temperature was invented by Collins and Oseland,1 and was developed into its present form by L 0 Sordahl,2 of the Research Laboratory The instrument and its mode of operation have been fully described by Sordahl and Sosman in three publications 3,4,5 Slag components were obtained by chemical analysis Data were taken from four 165-net-ton furnaces during the working period of the heat Recognizing that additions of ore affect the

Jan 1, 1942

By Howard Martens

HARDNESS behavior of commercial titanium alloys following various heat treating processes has been studied for some time. However, the hardness of such alloys following a definite measured cooling rate from the single phase region has not been reported. Therefore, a series of experiments was conducted on the three alloys: 150A, 130A, and 130B. The manufacturers gave the following compositions for these alloys: Ti 150A: 0.045 pct C, 0.069 pctN, 1.32 pct Fe, and 2.68 pct Cr; RC 130A: 0.13 pct C, and 7.9 pct Mn: RC 130B: 0.11 pct C, 3.5 pct Mn, and 3.2 pct Al. A method similar to that described by Greninger was used, and the cooling rate varied from 6" to 9200°F per sec. The cooling curves were recorded on a Speedomax or a recording oscillograph, and the hardness was measured on a Tukon hardness tester using a Knoop indentor with a 500 g load. The curves of Fig. 1 show the variation of the Knoop hardness with the cooling rate for these three alloys. The alloys 150A and 130B behave in a similar manner, as shown by the curves. In neither of these alloys was it; possible to retain the high temperature ß phases, even by the most rapid cooling rate. The slow cooling rates produced a typical ß structure in these two alloys. As the cooling was increased, these phalses became more finely dispersed and the hardness increased. This increase in hardness with cooling rate continued for the 150A alloy until a rate of approximately 1000°F per sec was reached. At this cooling rate, the structure showed the result of the dif-fusionless transformation of the ß solid solution to the supersaturated a solid solution which is referred as a'. At higher cooling rates, the structure showed no change and the hardness showed no great change, as indicated by the dotted portion of the curve in Fig. 1. The increase in hardness with cooling rate for the 130B alloy continued until a rate of approximately 300°F per sec was reached. At this rate the structure was produced and the maximum hardness was reached. Higher cooling rates caused no marked changes in hardness or structure. The alloy 130A behaved in a different manner, as shown by the curve of Fig. 1. The structure produced by the slow cooling rates was a typical a+ß structure, which became finely dispersed as the cooling rate increased. The hardness increased with cooling rate and reached a maximum at approximately 120°F per sec. At this maximum hardness, the structure showed the result of the decomposition of the ß phase into the ß + phase structure. As the cooling rate was increased, smaller amounts of the at phase were formed and the alloy became softer. For cooling rates of 3000°F per sec and above, the high temperature ß phase was retained and the hardness of the alloy did not change markedly. Acknowledgment This paper presents the results of one phase of research carried out at the Jet Propulsion Laboratory, California Institute of Technology, under Contract No. DA-04-495-0rd 18, sponsored by the Dept. of the Army, Ordnance Corps.

Jan 1, 1957

By P. W. Rainier

The Chivor emerald field is situated on the eastern slope of the Andes in the Department of Boyach, at an elevation of about 8000 ft. above sea level. It overlooks the Llanos (plains) of the Orinoco and is watered by many streams flowing into the Rio Meta, the Orinoco's largest tributary. The Rio Meta is navigable from the Orinoco to a point within about 50 miles of the Chivor district and may eventually prove to be the reasonable outlet for the future development of this part of the country. The topography of the district is extremely rugged and mountainous (Fig. I), the difference in elevation between two points on a mining claim 1 km. square being sometimes as much as 4000 ft. The ground is covered with dense forest growth and the available timber is suitable and sufficient for mining purposes, but it is becoming gradually depleted by Indian clearings as the country around the mines becomes settled. The many streams combined with the rough topography give good possibilities for hydroelectric power. The center of population nearest to Chivor is Bogoth, the capital of the republic and a city of some 300,000 inhabitants; the distance is two and one-half days' travel. The first stage of the journey from BogotB is accomplished by rail to Choconta, some 4 hr. travel. From Choconth the journey is made in the saddle, one night being spent in Guateque. The latter is a small town and the nearest post office to the mines, being some 10 hr. ride distant. The roads are mere bridle paths, in parts hazardous and almost impassable in the wet season. All supplies brought to the mines, other than those produced locally, are carried by pack mule; mule freight from Choconth costs 3 centavos1 per pound. The climate of the Chivor district is healthful and bracing. The wet season begins in March and concludes in November, the remaining months being dry. The annual precipitation is about 130 in. The temperature throughout the year is nearly constant, varying from about 45" F. to about 65" F. shade temperature. The rains are cold and unpleasant, and for the greater part of each day in the wet season the country is shrouded in dense mist. A fire can with comfort be kept burning in a living room all the year round. There are a few slight

Jan 1, 1931

By A. Gittens

In two recent papers stevens13,14 has compared the methods used by various investigators to calculate the contribution of grain boundary sliding to the total creep strain. In previous work Gittins15 has shown that the strain due to grain boundary sliding Egb may be estimated from the lateral, d, and vertical, v, displacements of a longitudinal marker line as it crosses a grain boundary. He obtained the formula, where nL is the number of grains per unit length measured on the specimens before creep, and \p and ?2 are, respectively, the angle between the grain boundary and the stress axis in the plane of the surface and normal to the surface (see Ref. 13, Fig. 1). The subscript L indicates that observations are made in a longitudinal direction parallel to the stress axis. It was generally found more convenient to measure the grain size of a specimen before creep; this was necessary to characterize the specimen. Stevens13,14 however prefers to define Egb in terms of NL, the number of grains per unit length after creep. Since nL - NL(l + €1) where cr is the total strain, Eq. 1 11 becomes The quantities d and ?, can be determined directly from the marker lines, while v and ?2 are found by sectioning normal to the surface. In the interior when symmetry considerations suggest that v = d and ?1 - ?2 the strain due to grain boundary sliding may be estimated from a suitable internal longitudinal marker line by the equation To determine cgb at the surface using either Eqs. |1| or [2] requires a large number of observations, particularly if many estimates of cgb are required, and also it is impossible to determine the variation of cgh with creep strain on the same specimen because the specimen must be sectioned to determine ?2. Gittins15 found that for a number of materials the sliding vectors d and v were related to each other so that provided one was measured the other could be estimated. Also during creep, grain boundaries tend to migrate to meet the surface at angles close to 90 deg,16 so that the term nL(v/tan?2)L was comparatively small when 4,- 90 deg. By determining the frequency distributions of ?2 on control specimens this term can be estimated without sectioning the creep specimen. In this way an empirical equation based on Eqs. |1| and |2| enables cgb to be determined with reasonable accuracy with fewer observations of the angles and sliding components. For B brass, the relationship between the sliding vectors indicated that ceb = 0.85nLVL . In Table I of Stevens paper this equation is stated to be incorrectly derived. However it should be pointed out that this is an empirical equation derived from Eq. |1|, based on a knowledge of the relationship between d and v and on the frequency distributions of ?1 and ?2 for a particular material under given experimental conditions. It was used only when these relationships were known, to reduce the number of observations required to estimate cb. Therefore the comment "derivation incorrect does not apply. Gittins did in fact make use of Eqs. |1| and 131. Author's Reply I must apologize to Dr. Gittins for the inadvertent misrepresentation of his work. Other slight errors in Table I have been pointed out to me. Langdon (No. 12 Table I), Gifkins (No. 7, Table I), and possibly other workers did not measure the number of boundaries per unit length after creep (A') but the corresponding quantity bejove creep (n). As Dr. Gittins points out, a completely analogous set of equations to those given in the paper can be derived by the same method: using the number of boundaries per unit length before instead of after creep. The basic equations corresponding to Eqs. [2] and 171 of the paper, from which all the others can be derived, are

Jan 1, 1968

By Ernest Gayford

THIS is a nontechnical paper on flotation, subdivided under three general headings: (1) Definition of flotation; (2) what flotation is now doing in Utah; and (3) what is the future of flotation? . DEFINITION T. A. Rickard defines flotation1 as "the act or state of floating," from the French flottaison, water-line and fitter, to float. The dictionary defines flotation as "the science of floating bodies." The flotation process is a method of concentrating ores by frothing. Weinig and Palmer 2 define flotation as follows: What is the flotation process? Briefly, it consists in the agitation of finely divided ore in water containing bubbles of air or gas, a small amount of oil and, usually, other reagents, soluble and insoluble; under these conditions the small parti- cles of native metals, sulfides, arsenides, antimonides, selenides and tellurides show a tendency to attach themselves to the 6lms of the bubbles, and are thus carried to the surface of the water. The oxidized gangue minerals, such as quartz, feldspar, limestone, hematite, etc., show much less affinity for the bubbles, are easily wetted by the water, and either remain in suspension in the water, or sink to the bottom of the vessel. If the bubbles are sufficiently stable they can be removed, carrying their load of sulfide-mineral particles with them. Thus there can be effected a separation of the two classes of minerals from each other, assuming that the grinding has been sufficient to unlock all of the particles of different composition. The separation does not depend upon differences in specific gravity of the various minerals; in fact, the sulfides are usually heavier than the oxides, and some of the heaviest sulfide minerals are the easiest to float. A particle of mineral may be so large, however, that its weight will counteract its affinity for the film of the bubble. In most cases the ore must be fine enough to pass a screen having at least 48 meshes to the linear inch. Taggart defines flotation as follows : Flotation is a method of wet concentration of ores in which separation of mineral from gangue is effected by causing the mineral to float at or above the surface of a body of liquid pulp while the gangue becomes or remains submerged. The method

Jan 1, 1928

Jan 1, 1970

By J. B. Goddard

In situ leaching of uranium by aqueous ammonium carbonate containing oxygen or hydrogen peroxide as oxidant results in the partial dissolution of sulfides. While some of the sulfide sulfur is oxidized to sulfate, a considerable portion is oxidized only to thiosulfate and polythionates. Polythionates poison the ion exchange resin used to extract uranium. At the Palangana operation in south Texas, the trithionate ion (S3062-) was found by infrared spectrometry to be the major resin poison. Treatment of ion exchange feed solutions with hydrogen peroxide only resulted in partial conversion of reduced sulfur species to sulfate. Trithionate conversion was particularly slow. Poisoning of the resin also occurred from the ammonium chloride eluant, which built up trithionate because of recycling. This was essentially eliminated by chlorinating the eluant before yellow cake precipitation.

Jan 1, 1986

By J. D. Wright

INTRODUCTION The Endako deposit was first explored in 1926, but development waited until the early nineteen sixties. It first came under the control of Placer Development in 1963, and early in 1964 a decision to bring it into production was reached. The deposit is located near the geographic center of British Columbia, and is served by an east-west communication system including a paved highway, mainline railway and good telephone, teletype, and computer facilities. The plant area is shown in Figure 1. The operation is known as the Endako Mines Division of Canex Placer Limited of Vancouver. First production was achieved in June, 1965, at a nominal rate of 10,000 tons per day, but it soon was closer to 15,000 tons per day. In 1967, two new grinding and flotation, sections brought capacity to the present rate of approximately 27,000 tons per day. With mill heads of around 0.15 percent MoS2, production is about 14,000,000 pounds of molybdenum per year. A flowsheet of the operation is given in Figure 2. A legend for this flowsheet is given in Table 1. Published ore reserves are estimated at 214,500,000 tons at an average grade of 0.143 percent MoS2. PRIMARY CRUSHING The 85 or 100-ton haulage trucks dump over a grizzly into a 42 inch x 65 inch C.A.C. (Canadian Allis Chalmers) gyratory crusher. The

Jan 1, 1976

By Charles F. Herbert

In February of this year at the Washington, D.C., hearings of the Interior Department on the Alaska pipeline, the author was amazed to hear speaker after speaker oppose not only pipline construction but any development whatsoever in the State of Alaska. In one case, a man objected to development in Alaska because his neighbor in Maryland had cut down some shade trees. Another man recited at length from the poems of Robert W. Service. While it seemed inconceivable that such thoughtless opposition should have any effect, a check with the offices of some congressmen showed that mail was largely against any development of Alaska. In the barrage of words and redundant phrases directed against Alaska, it is difficult to find a thought worthy of study. Fortunately, there is a statutory guide towards resolution of the problem of development versus non- development. This law, the Environ- mental Protection Act of 1969, has indeed given much of industry the jitters; copper smelters see no way to comply with the new sulfur- emission standards, the Alaska Department of Highways estimates that the Act has nearly doubled the cost of planning and engineering for highway construction. In spite of these and many other troubles and costs, the Act provides a sound legal basis for defeating nihilistic emotions and, since Alaska is relatively undeveloped, adoption of environmental safeguards will be simpler than correcting longstanding abuses.

Jan 1, 1971

By W. A. Sweet

The furnace I am now about to describe was designed to obtain and maintain very high temperature. Knowing the cost of the gas furnace that was in successful operation here and abroad, I approached the subject with some misgivings as to my ability to attain anything like success, or even to reach a point of advancement. There seemed to be a field for a furnace of moderate cost for small mills, or where a particular heat was wanted, but the work was not enough to warrant the outlay necessary to build any gas furnace yet brought before the public. The section, Plate V, represents the furnace as I now build it for

By Otto Henry

THE purpose of this investigation was to determine the equilibrium diagram of the lithium-magnesium pair as a first step in studying the possible usefulness of these alloys as ultra-light structural materials. REVIEW OF THE LITERATURE The behavior of lithium towards magnesium was first investigated by Masing and Tammann.(I)? In order to prevent oxidation the alloys were made in iron tubes under an atmosphere of hydrogen; temperatures were measured with a glass-protected thermocouple. These investigators found that lithium and magnesium form two series of solid solutions separated by a miscibility gap between 85 and 95 per cent magnesium; that the alloys with 81 and 95 per cent magnesium showed a homogeneous structure under microscopic examination, while the alloy with 89 per cent magnesium contained two distinguishable crystallites; that the curve indicating the beginning of crystallization rises from the melting point of lithium to that of magnesium; and that no compounds of lithium and magnesium are formed. The equilibrium diagram was not plotted because no definite data were obtained for determining the solidus and the posi-tion of the miscibility gap in the solid state. The difficulties encountered in this investigation were: (1) that it was necessary to heat them as high as the melting point of magnesium in order to obtain homogeneous melts; at such temperatures the alloys attacked the glass protecting the thermo-couple; and (2) that at temperatures above 400° C. the lithium united

Jan 1, 1934

By Ernest Gayford

This is a nontechnical paper on flotation, subdivided under three general headings: (I) Definition of flotation; (2) what flotation is now doing in Utah; and (3) what is the future of flotation? Definition T. A. Rickard defines flotation' as "the act or state of floating," from the French flottaison, water-line and flotter, to float. The dictionary defines flotation as "the science of floating bodies." The flotation process is a method of concentrating ores by frothing. Weinig and Palmer,2 define flotation as follows: What is the flotation process? Briefly, it consists in the agitation of finely divided ore in water containing bubbles of air or gas, a small amount of oil and, usually, other reagents, soluble and insoluble; under these conditions the small particles of native metals, sulfides, arsenides, antimonides, selenides and tellurides show a tendency to attach themselves to the films of the bubbles, and are thus carried to the surface of the water. The oxidized gangue minerals, such as quartz, feldspar, limestone, hematite, etc., show much less affinity for the bubbles, are easily wetted by the water, and either remain in suspension in the water, or sink to the bottom of the vessel. If the bubbles are sufficiently stable they can be removed, carrying their load of sulfide-mineral particles with them. Thus there can be effected a separation of the two classes of minerals from each other, assuming that the grinding has been sufficient to unlock all of the particles of different composition. The separation does not depend upon differences in specific gravity of the various minerals; in fact, the sulfides are usually heavier than the oxides, and some of the heaviest sulfide minerals are the easiest to float. A particle of mineral may be so large, however, that its weight will counteract its affinity for the film of the bubble. In most cases the ore must be fine enough to pass a screen having at least 48 meshes to the linear inch. Taggart3 defines flotation as follows: Flotation is a method of wet concentration of ores in which separation of mineral from gangue is effected by causing the mineral to float at or above the surface of a body of liquid pulp while the gangue becomes or remains submerged. The method

Jan 1, 1928

By Bruce A. Kennedy

This is an opportune time to examine the disposition of practical rock mechanics in the mining industry. The rock mechanics world has put on steam with publication of a number of books and the organization of a large number of symposia and teaching seminars. SME has just published Stability ill Open Pit Mining. proceedings of a conference held In November 1970 in Vancouver, R.C. R book entitled Planning Open Pit Mines covering the entire range of open pit mining with emphasis on slope stability has just been published by the South African Institute of Mining and Metallurgy. The Thirteenth Symposium on Rock Mechanics was held at the University of Illinois. Urbana-Champaign, during the last week of August. The University of British Columbia's Division of Continuing Education is holding a symposium and specialty seminars on stability in open pit mining during the first week in November. A tremendous planning effort has started to organize the Tl3ii.d Congress of the International Society of Rock Mechanics in Denver in 1974. This meeting is held every four years in the country of origin of the president of the Society. This third congress comes to the U.S.A. with Leonard Obert of the 17. S Bureau of Mines as president of the Society. The previous two were held in Lisbon. Portugal and Belgrade. Yugoslavia.

Jan 1, 1971

By W. L. Chu

It was observed that chromized coatings on low carbon steel could be embrittled by cooling slowly through the 475°C range. A higher chromium coating was more susceptible to embrittlement than a lower chromium coating. Coating structure and composition could be correlated with the chromizing process and prior carbon content of the steel. IT was recently observed that during the fabrication of rectangular tubings made with chromized thin gage 1010 steel, a high percentage of these parts were fractured readily in a brittle manner under the light impact-forming load employed. Ensuing investigation indicated the cause for such brittle failures to be the so-called 475°C embrittlement of the chromized coatings. The experimental work and results are briefly reported. Rectangular tube sections of normalized AISI C1010 steel, which had a cross-section of 0.5x1.5 in. and a wall thickness of 0.030 in., were chromized to yield coatings having several ranges of thickness, varying from 0.0005 to 0.002 in. Essentially, the chromizing process is similar to that described by Samuel and Lockington,' which consists of heating the parts in a sealed container at about 955°C for 4 hr in intimate contact with a chromizing mixture* samples in a hydraulic press, and the other employed a simple beam bending test of the flat sides of the tubing walls. Neither, however, was able to differentiate the relative brittleness of samples known to include both the brittle and tough types, since the impact-brittle samples were found to deform readily in a manner similar to the tough ones. Both the tough and brittle samples were studied by reflection microscopy. Observation showed that the microstructures of the steel cores were similar in content and distribution of inclusions as well as in the ferritic grain size. Results of Filar micrometer measurements showed that coating thicknesses+ of the brittle samples averaged 0.0007 in., whereas those of the tough samples averaged 0.0016 in. The micrographs of Fig. 2 illustrate the structural differences between coatings of both types of samples. By dissolving the steel cores in nitric acid, coatings of both the brittle and tough samples were isolated. Simple bending tests showed that coatings of the brittle samples cracked readily at about 90" bend, whereas those of the tough samples could be bent nearly 180° without cracking. The coatings as well as the steel cores were analyzed for carbon and

Jan 1, 1956

By Alfred F. Brainerd

Some fifty years ago, iron-ore was discovered near the town of Sheldon, Franklin County, Vermont, in a vein out-cropping on a knoll near Black Creek, which empties into the Missisquoi River a couple of miles away. A short time after this discovery, the owners, Mr. TV. 0. Gadcomb and Hon. Lawrence Brainerd, both of St. Albans, commenced mining (mostly by open cut), and also erected a Catalan forge, from which iron blooms were produced, most of which were worked into bar-iron and used in the neighborhood of the forge, while some were shipped by Lake Champlain to Troy, Albany and New York. But by reason of the lack of any railroad connections, and an insufficient demand for the blooms, this forge was subsequently abandoned, and the material used in its construction removed to other places. Mr. Keith, of Sheldon, used for many years a mixture of this ore with bog-ore from Swanton, in a charcoal blast-furnace, the product of which he consumed partly in his own foundry, shipping, however, a considerable amount to Troy and New York. Accurate data as to this enterprise are not at hand. The same vein has since been traced for some 20 miles, and some prospecting has been done 011 its outcrops at Berkshire, Enosburg and a few miles east of St. Albans; but the vein being small, only a few car-loads of ore were taken out from these places. The commencement of the St. Albans Iron and Steel Works in 1872, and the erection in 1877 of a ten-ton Siemens open-hearth furnace for the manufacture of steel rails, opened a new use for this ore. The furnace-charge consisted of pig-iron, old mils, steel scrap, and magnetic iron ore, added towards the close of the heat. The ore

Jan 1, 1885

By William R. Barton

It is generally conceded as axiomatic that the aggregate producer and the average urban resident have mutually incompatible goals. The producer wants to be near his mass market and the average resident wants him as far away as possible. The traditional economic decision to mine local material to avoid transportation costs is increasingly challenged by zoning and planning bodies and by citizens' groups. This conflict generated much written and spoken word and offered opportunity for great flights of rhetoric. The pressure on the producer also has forced re¬appraisal of the need for the classic confrontation with indications that much of the conflict is more apparent than substantive. In New England several factors combine to increase complexity of the siting problem. It is a region of high land values and population density. Due to the proximity of metropolitan areas, even rural communities have experienced a prolif¬eration of environmental groups with concomitant enthusiastic regional planning and critical watch over land use. In New England where there is little public understanding of the necessity for, and the realities of, mineral production a sophisticated approach to aggregate production site location is required.

Jan 1, 1975

By J. R. Schneider

INTRODUCTION Landowners in Texas for many years have freely granted, reserved and leased "oil, gas and other minerals" or interests therein. In recent years we have witnessed much litigation concerning what sub- stances should be included as "other minerals" within the phrase "oil, gas and other minerals," and this question has received the attention of numerous legal scholars. At the South Texas Uranium Seminar held in Corpus Christi, Texas, in September, 1978, Mr. William R. Dodson presented a paper dealing with this very subject and entitled "Uranium - Mineral or Surface? Who Owns It?" In his paper, Mr. Dodson reported on two recent Texas Supreme Court decisions, Acker v. a, 464 S.W.2d 348 (Tex. 1971) and Reed v. Wylie, 554 S.W.2d 169 (Tex. 1977). which held that the particular substance in question in each case is not a mineral within the phrase "oil, gas and other minerals" if substantial quantities of the substance lie so near the surface that production will entail the stripping away and substantial destruction of the surface. Since that time another chapter has been written in the Texas saga of "When is a Mineral not a Mineral?" and it is the intent of this paper to present an update of the Texas law. A review of the early Texas cases so ably covered by Mr. Dodson in his paper will not be repeated, except as is necessary to illustrate the evolution of the legal doc- trine which has been so aptly named "The Surface Destruction Test". BACKGROUND In order to appreciate the genesis of the problem, one must consider that oil and gas production commenced in Texas many years ago, Spindletop came in in 1901. As oil and gas became more valuable, land- owners with considerable frequency sold interest in the oil, gas and mineral estates in their lands, and reserved interest in the oil, gas and mineral estates in their lands when they disposed of their property. Due to the oil and gas background, and perhaps be- cause oil and gas was paramount in the minds of the parties, the traditional language employed in these grants and reservations was "oil, gas and other minerals" or variations thereof. There are literally hundreds of instruments employing this language constituting a link in the chains of title to thous- ands of acres of Texas land. In addition, there are thousands of acres of Texas land held by oil, gas and mineral leases, the primary terms of which have been perpetuated by production, containing similar language in their granting clauses. The severance of the mineral estate from the surface estate results in two separate and distinct estates, each having all of the incidents and attributes of an estate in land. with the surface estate being the serviant estate, and the mineral estate being the dominant estate and having certain easements in the surface estate to explore. produce and remove the minerals. Harris v. Currie. 176 S.W.2d 302, 305 (Tex. 1943). As observed by the court in the Harris case, this is because a grant or reservation of minerals would be wholly worthless if the grantee or reservor co~lld rwt enter upon the land in order to explore for and extract the minerals granted or reserved. Although the Texas law has recognized that an oil and gas lessee has the right to use so much of the surface as is reasonably necessary to produce the minerals. Warren Petroleum Corporation v. Monzingo, 304 S.W.2d 362, 363 (Tex. 1957), recent decisions of the Court have qualified this doctrine. In Getty Oil Company v. Jones. 470 S.W.2d 618 (Tex. 1971). Getty's pumpine, units were interfering with ones self-propelled sprinkler system utilized for irrigating the premises, and Jones sought to require Getty to install the-pumping units in cellars so that the sprinkler system could pass over them. In an effort to accommodate both the surface estate and the mineral estate, the court held (page 622) "...where there is an existing use by the surface owner which would otherwise be precluded or impaired, and where under the established practices in the industry there are alternatives available to the lessee whereby the minerals can be recovered, the rules of reasonable usage of the surface may require the adoption of an alternative by the lessee". Bearing in mind that the "reasonable use doctrine" grew up in the oil and gas industry involving sub- stances which can be produced by methods that do not destroy or deplete the surface estate, the question presented is whether the Texas courts will extend this doctrine to situations where claimants of "other minerals" seek to produce shallow deposits of iron ore, coal, lignite and uranium by surface mining methods which do destroy or deplete the surface estate? The surface destruction test has answered this question in the negative, at least as to iron. coal and lignite. However, the multitude of mineral estates in Texas which have been created by a grant. reservation or lease of "oil, gas and other minerals" will, doubtlessly, continue to fuel the fires of litigation. EARLY TEXAS DECISIONS In view of the evolution of the Surface Destruc- tion Test, an exhaustive review of the early Texas

Jan 1, 1980

By W. H. Emmons

Most mineral deposits change as they are followed downward on their dips. Some of these changes are due to primary arrangement; different ores were precipitated at different depths when the deposits were formed. Other changes are due to weathering or secondary enrichment. The chief changes resulting from weathering, in the main, are understood and standard changes are recognized. The processes are relatively simple. They take place at ordinary temperatures and pressures and can be duplicated in the laboratories. Moreover, there are thousands of deposits available for study, because the processes take place near the surface where the development of mines is begun. The changes due to primary arrangement of the deposits of the metals are not so well understood. Deposition has taken place at higher temperatures and our knowledge of the chemistry of the processes leaves much to he desired. Very few experimental data are available. The deposits, moreover, offer fewer examples because many mines are not developed to depths where the changes can be studied and a change to unprofitable material usually results in stopping work. Most students of ore deposits now accept, as confirmed, the hypothesis that nearly all lodes and related deposits were formed by solutions originating in intrusive igneous masses. Outward from these masses, the deposits at many places are grouped in zones and the arrangement noted from the intrusions outward are commonly the reverse of the changes noted from the surface downward in a single lode. A study of the changes in groups of deposits, from the parent intrusion outward, will throw light on the changes to be expected in a single lode downward. Recause the changes in series of deposits from the intrusive outward may all be observed near the surface, where more data are available, it is possible to increase the number of examples many fold and to apply the statisttical method of study with greater confidence of avoiding error. It is not everywhere possible to identify the parent igneous body to which a group of ore deposits are related. Several kinds of criteria are available; certain groups are superior to others. By applying the

Jan 1, 1924