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By A. S. Rhea

SALT-WATER disposal in the East Texas field by means of injection into the Woodbine sand is a relatively new procedure. The purpose of this paper is to present what has been accomplished to date in this field, with-out detailed discussion of other means of disposal, such as surface impound-ing for evaporation or release into surface streams. Subsurface disposal of salt water is still in an experimental stage in the East Texas field, and, though water can be injected into the Woodbine sand, the economic problem is not as yet solved. As past experience has been that fields producing from the Woodbine formation produce large quantities of salt water, it was assumed early in development of East Texas that it would be necessary to dispose of a tremendous quantity of salt water in the later periods of production. There has been a gradual increase in the amount of salt water pro-duced in the field, until at present it is about 200,000 bbl. per day from approximately 4400 wells. It is only natural to expect an increase in the number of wells producing water, as well as the amount of water produced in the future, and it has been estimated that if present practices con-tinue the production of salt water may ultimately be as much as 700,-000 bbl. per day. The Woodbine sand is found in the East Texas field at an average depth of 3650 ft. The oil-bearing portion of the sand lies between the depths of 3050 ft. below sea level, on the east edge of the field, and 3320 ft. below sea level on the west, which depth was the estimated original average oil-water contact. The Woodbine sand under the field has the form of a broad tilted wedge pinching out on the eastern side of the field and dipping gently into the East Texas Basin toward the west. The Woodbine sand in the East Texas field has an average porosity of approximately 25 per cent and is highly permeable, the average being about 1300 millidarcys.

Jan 1, 1940

By H. B. Treweek, V. R. Degner

Current mineral industry trends toward handling the high tonnages of lower grade ore and tailings retreat lead to a continuing need for large volume flotation cells. The benefits which accompany the larger cell flotation circuit include reduced capital cost, less mill floor space, reduced operational complexity, and less maintenance, provided the metallurgical performance and solids suspension capability of the cell are not compromised. This study reviews development considerations pertinent to large mechanical air induction type flotation cells from the standpoint of cell internal hydrodynamic characteristics and metallurgical performance. While the importance of process related factors such as chemical usage, pH control, solids size and loading, and circuit arrangement cannot be denied, this study will emphasize the relationship of cell size (volume), mechanism geometry (impeller diameter), and mechanism operating conditions (rotor speed and submergence), to air transfer, liquid circulation, liquid "rise velocity" and mechanism power draw. Specific hydraulic performance maps for large capacity 300 and 500 cu ft flotation cells will be reviewed in terms of the relationship between the operational variables and the air and liquid flow conditions within the cell. Metallurgical results, obtained under plant operating conditions for 300 and 500 cu ft cells, are included to illustrate the metallurgical performance similarity of flotation cells which follow hydrodynamic scale-up criteria set forth in this investigation.

Jan 1, 1976

By E. H. Ahrens

This paper deals with the responsibilities of an operating geologists and the relationship of operations to exploration. It should be of interest to those soon to enter the profession, those new to mining geology and as a review to more experienced geologists. Subjects discussed include detailed geologic mapping, sampling, core logging, assaying, selection of proper map scale, posting geological and assay data, section preparation, identification of ore controls, delineation of development drill targets and geologic hazards, models and the very important topic of salesmanship. Methods and ideas, proven valid in vein, pyrometasomatic replacement and porphyry copper deposits are presented. Hopefully, these will smooth the path for new members of our profession.

Jan 1, 1984

By A. Ahmadieh, J. E. Dorn, Jack Mitchell

A detailed investigation of the disloccrtion mechanisms controlling prismatic, slip in a solid solutions of magnesium containing up to 15.9 at. pel Li revealed that low-temperature prismatic slip is controlled by the Peicrl's mechanism for all alloy compositions. At higher temperatures slip in the 7.9 at. pet Li alloy was found to follow the diclates of the cross-slip mechanism from basal to prism planes, while the higlier-lilhium alloys exhibited an athermal dejormation process which might be due COARSE-GRAINED polycrystalline aggregates of distilled magnesium exhibit very limited ductility at low temperatures.' The ductility of polycrystalline magnesium, however, is much improved by solid-solution additions in excess of about 8 at. pct to shot-range ordering. The major effect of lithium additions on the low-temperature Shear] stress. for prismatic slip appears to be due to its efftct in lowering the Peierl's stress whereas (1 increase in the shear stress with increased lithium conlent at higher temperatures might he due to short-range order strengthening. Additions rip to 7.9 (at. pel Li appear to have only minor effects on the slackiug-jaidt energy. Li.2 Although the relative amounts of basal slip and twinning are not materially altered by such alloying, a substantial change takes place in the relative amounts of prismatic slip. Whereas prismatic slip is negligible and limited to regions of high stress concentrations in the vicinity of the grain boundaries in pure magnesium, extensive prismatic slip over entire grains occurs in the higher lithium content alloys. Furthermore, as the lithium content is increased above 8 at. pct, the flow stress for polycrystalline aggregates decreases. Comparison of the single-crystal data on pure magnesium for basal slip by Sheely and Nash3 and those for prismatic slip by Flynn, Mote, and Dorn4 indicates that the critical resolved shear stress for prismatic slip is much above that for basal slip.

Jan 1, 1965

By V. F. Malone

IRON ore reserves of Lone Star Steel Co. cover 56,000 acres in the north basin of the East Texas geosynclinal area near Daingerfield. Ore is almost wholly restricted to the Weches formation of middle Eocene Age. Its resistance to erosion has created the hilly topography of the East Texas area. The ore deposits, in the upper portion of the hills, are usually overlain with residual sand and clay overburden less than 15 ft thick. The ore formation consists of inter- bedded shallow ocean sediments ranging from pure greensand to fine-grained sands and clays containing a maximum of 70 pct limonite, or siderite, and varying from 2 to 100 ft thick. The iron in this ore originated as iron silicate or greensand in the ocean sediments, and the ore mineral siderite was formed when meteoric waters redeposited the iron under reducing conditions as a carbonate. With weathering and progressive erosion much of this siderite was later oxidized and altered to limonite - yellow to dark brown hydrous iron oxides formed into nodules up to 18 in., embedded in a sandy clay and weathered greensand matrix. Beneath the water table the siderite zone consists of interbedded shale and greensands with thin ledges and nodules of siderite. Lone Star Steel Co. has proven a 75-year supply of ore, and exploration of reserves and acquisition of new property is not complete.

Jan 5, 1957

By G. B. Clark

Dynamic rock mechanic as it pertains to blasting has involved several areas of active research effort. Among the important problems which have been the subject of research are wave mechanics in rocks, mechanisms of rock breakage, cratering, applications of similitude, energy partitioning of explosives, coupling, and other related factors. In some of these areas many problems have received fairly complete answers, while in others, investigations have raised new questions while attempting to answer existing ones. The slabbing mechanism explains many of the phenomena observed in blasting, but is hot the complete answer to observed breakage and fragmentation phenomena. There is currently a gap between coupling experimental results and theory. Applications of similitude to open pit blasting have been made unnecessarily complicated. Basic scaling laws for large true and apparent craters have not been derived for either chemical or nuclear explosives. There are few useful data and little developed theory on the partitioning of energy of explosives in all types of blasting. No suitable mathematical model has been developed which will describe the stress waves in rock which are responsible for rock breakage: Significant progress has been and is being made in these areas of research, however. ELASTIC AND NONELASTIC WAVES Complete solutions for spherical wave equations in viscoelastic media are not available in the literature. Equations for certain viscoelastic models do show limited promise, however, of being applicable to rock masses, particularly for pulse type phenomena. Seismic investigations, blasting operations, the design of protective underground structures, and the evaluation of other explosive effects in solids would be greatly bene-

Jan 1, 1967

By J. A. Herbst, R. Mackelprang, J. D. Miller

Droplet size distributions were determined by stabilizing in gelatin and measurement of the distributions by means of computerized image analysis Several variables that affect droplet sizes were studied and the resulting size distributions were modeled via a population balance equation Key parameters in the model were related to the physical properties and operating conditions of the systems examined using a multiple linear approach

Jan 1, 1981

By Howbert Van Dyne

THE Presidio mine of The American Metal Co. is situated in the "Big Bend" region, some 45 miles over state highway south of Marfa, a station on the Southern Pacific R.R. It lies 20 miles by road north of the Mexican border, in semidesert surroundings typical of this general section of the United States and the adjoining part of Mexico. All supplies are hauled in by truck from Marfa under contract. The concentrates and precipitates produced by the mill are carried by the same trucks to Marfa, from whence they are shipped, respectively, to the El Paso and Selby plants.

Jan 1, 1930

By K. R. Weller

The Ardlethan Tin Ltd. concentrator typically recovers 55% of the tin in a gravity concentrate at 51% grade from fresh ore assaying 0.5% Sn. Coarse gravity concentration is performed in a complex circuit involving Reichert cones, spirals, shaking tables and two regrind mills. The paper describes how flow and size-by-size sample data from a steady-state survey were used to construct a computer model of the plant involving 46 process streams. The data reduction involved a computer- aided mass balancing technique, recovery-size modelling of gravity concentrators and the use of a mineral dressing flowsheet simulator. The model was used to simulate possible rearrangements of the available equipment. Early simulations indicated that improved performance could be obtained by using spirals to-treat cone middlings or tailings rather than cone concentrates. A test spiral rig was used at Ardlethan to determine typical performances for all cone product streams and the results were incorporated in new simulations. A revised circuit was recommended and implemented by Ardlethan Tin as far as physical restraints within the plant would allow. Production figures show that a substantial increase in tin recovery and 10-15% increase in milling rate were achieved following the circuit changes, and these improvements were sustained over a six month period.

Jan 1, 1984

By William Braden

IT is obvious that the choice of the method to be employed in the handling of blast-furnace slags and mattes depends upon local facilities and conditions which may indicate as advisable some particular plan. As a result of the variety of such conditions hardly any two smelters use identically the same method, though they be located only a few hundred feet apart. For instance, of the several plants in Leadville, Colorado, each has a more or less distinctive system. The same is true of Salt Lake City and vicinity. In view of this it is evident that the existing diversity of practice cannot be accepted, prima facia, as evidence

Jan 1, 1897

By Norbert R. Morgenstern

INTRODUCTION An understanding of the role of water in controlling the stability of rock masses is central for a rational approach to the subject. The presence of water can hinder mining opera- tions in two ways: 1. excessive discharge 2. excessive pressure It should be noted that if the rock mass is very tight, excessive pressures can exist without large discharges. Alternatively, if abundant water is available and the rock mass is open, then substantial discharges can occur under quite small pressures. The problems associated with excessive discharge are usually well understood by the mining engineer. Vehicle mobility is inhibited, some areas are flooded and hence become inaccessible; at best, a costly nuisance exists. The methods of solving these problems are also well-known to mining engineers. They generally involve tapping the source of the excessive discharge and channeling it away in such a manner that any hindrance to the mining operation is minimized. The effects of water pressure on the stability of rock masses are less obvious and the following will be devoted solely to this aspect of the problem. The manner in which water pressures enter into the consideration of stability is made clear by an understanding of the concept of effective stress. THE CONCEPT OF EFFECTIVE STRESS The simplest mechanical model for the problem of rock slope stability consists of a rough, rigid block sliding down an inclined plane under the influence of gravity. This is illustrated in [Fig. 1]. The down-slope component of the weight of the block tends to produce movement which is resisted by the shearing force generated by friction along the base of the block. The shear stress per unit area inducing movement is

Jan 1, 1971

By R. W. Brauchli

During the last few years the compila-tion of formation logs from rotary well cuttings has become common practice among petroleum geologists. This meth-od has undoubtedly furnished a great amount of information valuable for both scientific and commercial purposes. How-ever, in spite of its great usefulness it has certain drawbacks, principally in the contamination of cuttings by cavings. In extreme cases this contamination can reach such proportions that it is next to impossible to draw conclusions with any degree of certainty as to the nature of the formations penetrated by the drill. This difficulty was frequently encoun-tered during the development of the Okla-homa City Field. In many cases where Wilcox sand-the most prolific sand of this field-was drilled, the samples con-sisted almost entirely of shale cavings with only traces of sand. In order to obtain more reliable knowl-edge of the formations encountered while drilling it is therefore necessary to resort to more coring, and above all to improve our present methods of coring. With this in mind a study has been made of the results of coring in the Oklahoma City Field, and the present article is mainly confined to a statistical analysis of the relation between recovery, diameter of cores and drill pipe, length of cores and a few other factors. Most of the coring in the Oklahoma City Field was done during the early part of, the development. A total of around 18,000 feet or 0.3 per cent of the total footage drilled before February, 1932, has been cored, and about 80 per bent of the cores were taken in the Simpson formation at a depth below 6,000 feet.

Jan 1, 1933

By James Pollock

SUMMARY THE possibility of colloidal deposition of cinnabar has been neglected. In opalite deposits cinnabar exists in particles within or near the colloidal size range. Colloidal processes have been admitted to be operative in hot springs and low-temperature deposits similar to most cinnabar deposits. Mercuric sulphide sols are stable to elevated temperature and pressure, and in nature probably are chiefly affected by the electrolytes in solution, dilution of colloid, and presence of protective colloids as silica. The stability of mercuric sulphide sols to electrolyte is measured, and shown to be greatly increased by dilution and by the protective action of silica. Mercuric sulphide sols follow the Schulze-Hardy valency rule, therefore the precipitating power of complex mixtures of electrolytes can be computed roughly. The stability of mercuric sulphide sols is shown to be greater than the equivalent precipitating power of the electrolytes in a hot spring depositing mercuric sulphide. It is concluded that finely divided or earthy types of cinnabar are colloidally deposited. POSSIBILITY OF COLLODIAL DEPOSITION While colloidal solution has been suggested as a means of transport for a number of minerals, such as the sulphides of antimony, arsenic, and iron, it has been neglected in connection with mercury. This is surprising because there exists positive evidence that cinnabar is present in certain deposits in particles of colloidal or near colloidal size. Colloidal transport could result from either the rapid dilution or neutralization of alkaline sulphide solution bearing mercury coming in contact with deep ground waters, or from colloidal solution near the original source and subsequent flow to the point of deposition unchanged. That the dilution of a mercuric alkaline sulphide solution will precipitate mercury sulphide in colloidal form has been demonstrated a number of times and is easily confirmed. The dilution hydrolyzes the alkaline sulphide Na2S to the corresponding hydroxide and hydrosulphide NaOH and NaHS, and the diminution of the concentration of alkaline sulphide reduces the solubility. It is not the contention of this writer that colloidal deposition is the mode of transport of mercuric sulphide in all mercury deposits, but that the stability of a mercuric sulphide sol, as demonstrated below, in waters that are similar to those that have deposited mercuric sulphide necessitates consideration of this possibility in many deposits, especially those of the hot-spring and so-called opalite type. EVIDENCE OF COLLOIDAL DEPOSITION Ross1 has shown that most deposits of quicksilver are formed at low temperatures and pressures, and probably by solutions that have relatively simple chemical compositions. In most cases the solutions are probably similar to those observed in hot springs, and in two instances-at Steamboat Springs, Nevada, and Sulphur Bank, California-hot springs have been reported by Becker as actually depositing cinnabar.2 Opalite deposits were believed by early investigators to be surface phenomena

Jan 1, 1944

By J. C. Wynn

This paper outlines research conducted by the US Geological Survey on the geophysical signatures of chromite. Results of the chromite study highlight the importance of a laboratory research Phase (petrophysical and petrographic studies) at the beginning of work on a new commodity; a realistic ore deposition model to serve as a conceptual framework, and the necessity to continually test, refine, and modify it during the study; and indirect geologic/geochemical indicators, secondary associations, and the use of multiple physical properties. The keystone to the success of the study is frequent and substantive dialogue among geologists, geophysicists, and geochemists.

Jan 1, 1984

By E. J. Yoder, N. B. Aughenbaugh, R. B. Johnson

Mineral aggregates experience degradation during field and laboratory compaction. Reduction in the aggregate size is accomplished by abrasion of the particle edges and fracturing of individual pieces which have become overstressed. Little is known of the factors that govern the amount of breakdown experienced for a given situation. A field study was made of the factors affecting aggregate breakdown under compaction using three carbonate aggregates of different physical properties. The preliminary results indicate that rock type, compactive effort, gradation, and thickness of compactive layer are factors which exert the greatest influence. Mineral aggregates experience a mechanical breakdown of some of the aggregate pieces into smaller fragments during any compaction process, whether in the field or laboratory. This phenomenon occurs as abrasion of the sharp edges during movement and reorientation of the particles in densifying and/or as granulation and fracturing of those pieces which have become overstressed. Two types of aggregate breakdown occur in the field. These may be classed in a general category of aggregate degradation.* One occurs during the con- * Aggregate degradation has been defined in many different ways. For this paper it is considered as any breakdown of larger particles into smaller ones, whether mechanical or chemical. struction period and is related to the densification of the aggregate body from a loose state to a relatively dense mass by heavy compaction equipment. This type is almost entirely a mechanical action. The other occurs after the construction period when the roadway has been put into use. This in-service breakdown is; a different phenomenon from the breakdown during construction in the sense that it combines mechanical with chemical changes. Time becomes an important consideration that may cause subordinate factors in construction degradation to develop into principal ones for in-service breakdown. Breakdown of aggregates in service has been extensively studied by investigators from the northwestern

Jan 1, 1962

By W. J. Sharwood

(San Francisco Meeting, September. 1915) THE assay or estimation of the total gold content of an ore presents little difficulty, when circumstances permit of securing a thoroughly representative sample. The general practice has been fairly standardized, and such errors as occur in the results obtained are for the most part attributable to the methods of sampling rather than to those of assaying, while duplicate assays made by skilled workers usually agree closely. When it is a question of estimating the "free" or amalgamable gold of an ore, as opposed to the total gold, there is but little uniformity in the methods employed by different workers, and often equally little in the results obtained when duplicate determinations are attempted, no satisfactory standard method having been generally adopted. The methods in use are of two general types-"panning" and "amalgamation."

Jan 8, 1915

By Ronald D. Hill, Roger C. Wilmoth

The neutralization of acid mine drainage is becoming a common practice in the eastern United States. Over 200 plants are now in operation. Lime is the neutralizing agent utilized in most treatment plants; however, limestone may have an economic and practical advantage. Current research efforts of the Federal Water Quality Administration, both inhouse and through grants, to develop and demonstrate the use of limestone are reported. In essence, a state-of-the-art review is presented.

Jan 1, 1972

By Jules E. Jenkins

IN the past quarter century the seismograph has played an increasingly important role in evaluating vibratory effects transmitted to adjacent communities by industrial blasting operations. In this period research has advanced through two major phases—from falling pin seismometers to three-component recording seismographs. The initial phase of this research is now regarded as the era of recording, during which the seismograph merely recorded occasional events. It has emerged from this stage into the era of control and analysis and in this later period has been recognized as a full-fledged industrial tool. Although the falling pin machines of earlier years indicated probable amplitudes of industrial blasting vibrations, they gave no reliable measure of such displacements, nor did they provide essential information concerning direction or frequency of motion. The first contribution of the three-component recording seismograph was the weight-for-distance formula developed by the U. S. Bureau of Mines. This empirical formula enabled users of commercial explosives to determine beforehand the probable vibratory effects of a blast when the weight of the explosives charge and the distance from the shot point were known. This formula has withstood the test of time and is still applicable for blasts detonated by instantaneous methods. The second major contribution of the three-component recording seismograph followed the introduction in 1945 of short period or millisecond delay detonation. This might be described as a two-stage contribution, the first of which revealed a 50 pct reduction in the vibration magnitude when millisecond detonation was used rather than instantaneous discharge. This second part of this double contribution led to the discovery of the vibration dip phenomena, see Fig. 1. In Fig. 1 the horizontal coordinates indicate the displacements amplitude in inches, and the vertical coordinates, the explosive weight in pounds. The top curve is that of the U. S. Bureau of Mines for instantaneous detonation. Its curvature conforms to the two-thirds power of the explosive weight as provided in the weight-for-distance formula; hence the vibratory effects increase in proportion to an increase in the explosive charge. If the other curves shown below are temporarily disregarded, it may be considered that the entire area below this top curve represents both useful and waste energy. As mentioned previously, when millisecond delay detonation was first investigated it was found that in general the U. S. Bureau of Mines curve could be decreased by about 50 pct, or to the position of the middle curve. At the outset it was assumed that this curve would likewise increase in some proportion to the explosive charge, as did the top curve, that is, the curve would indicate a continuous upswing. As seismographic data accumulated this assumption was found to be erroneous in part. It was discovered that

Jan 1, 1957

By Harold Rabling

The following notes are taken from results obtained on a standard 25-ft. Hancock jig1 tested during regular operation in the Bonne Terre mill of the St. Joseph Lead Co. The object of the tests was to determine the conditions for most effective work, and the nature of products that could be made. The material treated was sized between 9-mm. and 2-mm. round-hole screens, and was constant throughout the experiments. Three products were made, concentrates from the first three hutches, middlings from the fourth and fifth, and tailing from the sixth. The middlings were crushed in one pair of Allis-Chalmers Style B, 30 by 14-in. rolls, and elevated with the original ore to the 2-mm. screens, oversize of which formed the jig feed. While this arrangement was very simple, it gave rise to undesirable crowding of the circuit. Table 1 shows tonnage and assay values of the jig feed and products at the beginning of the experiments, and brings out the excessively large amount of middlings, comprising 63.3 per cent. of the total material fed to the jig. The rolls, being heavily overloaded, did very little crushing, a screen analysis of the product showing that only 27 per cent., or 128 tons, was crushed fine enough to pass to the tables. The remaining 347 tons returned to the jig with 400 tons of original ore. At .times, this overcrowding became much worse, and the tonnage in circuit grew to enormous proportions. It became imperative

Jan 1, 1918

By Kichizo Niwa, Toshio Yokokawa, Mitsuo Shimoji, Yoshihiko Watanabe, Satoshi Kado

A LTHOUGH a systematic research on diffusion in liquid metals has not been carried out, partial studies have been developed by various workers in several systems. A few recent papers among them have shown that this line of approach is quite useful for understanding the structure of the liquid state. Furthermore, it has been found in kinetic

Jan 1, 1958