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By F. Milton Lewis, Edward S. Frohling

The information which is required for' a preliminary feasibility study and the additional information which is required for the final feasibility study on a new mineral deposit are discussed. The preliminary feasibility study is made from very little information and at a minimum cost to the owner. However, the outline for the preliminary report is similar to the one used in the final report. In this manuscript, it is assumed that the results from the preliminary study are favorable and the owner authorizes a final feasibility study by an outside engineering company. The type of organization for completing this final feasibility study is described. The final reports includes all information and data relative to this new mineral deposit. This information is presented so that it may be understood by financial people as well as by technical people.

Jan 1, 1978

By B. Ramaswami, Y. Nakada, U. F. Kocks

Compression tests were performed on single crystals of aluminum, silver, gold, and a Ag-10 pet Au alloy, with height-to-width ratios from 8:1 to 1:1. As this ratio decreased, so did the amount of easy glide until, for cubic specimens of all the pure materials, it was entirely absent. Heterogeneity of deformation is proposed to he a major contribution to the explanation of easy glide in slender specimens. For comparison, one single-crystal cube of zinc was tested and showed a behavior very similar to that in tension. Beyond easy glide, tension and compression curves are very similar. It is concluded that, in this range, neither grip effects nor orientation change influence the work-hardening characteristics to any significant extent. (121) and (100) crystals of all materials had similar stress-strain curves in tension and compression, except that the stress level of the flat portion of aluminum (109 crystals at high strains mas somewhat higher in compression. These results are at variance with previously proposed mechanisms of orientation dependence by both Hosford and Kocks. The compression tests themselves are described in detail and it is shown that they are essentially frictionless and produce single slip when the crystal is suitably oriented. DEFORMATION in uniaxial compression does not necessarily give the same result as deformation in uniaxial tension, essentially because the boundary conditions chosen are practically always different. 1) The shape and size of the specimens are usually different, and any genuine effect of size on work hardening should thus influence the result. 2) The grip constraints are usually different and can vary substantially for different kinds of tests. If the compression specimen is a thin plate and the friction on the platen is large, the grip contraints are more serious than in tension and lead, in the extreme, to uniaxial strain rather than uniaxial stress. If the specimen is roughly cubical and the friction is low, the specimen is less constrained than in tension inasmuch as displacements in the contact face are allowed. 3) The orientation change of single crystals is of opposite sign in tension and in compression; it is furthermore different in detail, because the relevant orientation in a squat specimen is the normal to the contact face, whereas that in a slender specimen is the generator of the side faces.' The considerable dependence of work hardening on the initial orientation in tension would suggest that the orientation change should also be very important. 4) Finally, localized deformation instabilities found in tension tests, such as necking and Lüders band propagation, are not possible in squat specimens. This is, for some investigations, a favorable consequence of the large grip influence. Even if one is not interested in any of the effects mentioned above, compression tests are often desirable just because the specimens needed are so much smaller and sturdier. For example, they have been very helpful in the investigation of latent hardening by means of alternate longitudinal and lateral compression of cubes,* and for testing

Jan 1, 1964

By T. C. King

AT the new Graham-Central Mill of Eagle-Picher, near Galena, Ill., material is simultaneously dewatered and introduced into the ball-mill scoop boxes by the use of variable-speed, 24-in. spiral classifiers. This arrangement has proved satisfactory in that the moisture content of the wet feed is reduced, thus allowing maintenance of density within the mills, and a constant feed at any desired rate to the mills is provided. In this mill the primary feed is wet crushed to minus ½ in. and preconcentrated by jigs to produce a bulk lead-zinc-iron concentrate and a waste tailing. The jig concentrate is then dewatered by a conventional dewatering classifier and stored in, bins ahead of the ball mills. Even though this material is well dewatered, the discharge at the bin bottom is sloppy because of the gradual drainage of the water from the surface of the particles. Conventional belt feeders with vertical cutoff gates are unsatisfactory because of the flushing characteristic of the wet sand.

Jan 1, 1950

By Fred Witt, Milton Schwartz

ESTABLISHED methods for obtaining quantitative pole figures for flat sheets1"5 can be extended to apply to thin films on a substrate. The mode of scanning the sample is exactly the same as described in the references? but consideration is given to the fact that the scattered X-ray intensities are due to both the thin film and its substrate with appropriate attenuation factors. The purpose of this paper is to describe a method to obtain the scattered intensities from the film alone for subsequent pole-figure determinations. Fig. 1 shows the four possible general positions of the film (f) and its substrate (s) with respect to the incident X-ray beam (I,). In this paper it will be assumed that the plane of the sample is normal to the plane of the diffractometer. In the diagrams the line jV is the normal to the flat sample and the line P is the trace of the diffracting crystallographic planes in the plane of the diffractometer. The angle of tilt, a, is the positive acute angle measured from the line N to the line P; if this angle is measured clockwise then a is said to be in the positive a region; if this angle is measured counterclockwise then a is said to be in the negative a region. For the reflection cases, the total scattered intensity, at the proper Bragg angle for a particular set of planes, is due to that scattered by the film Vf) and that scattered by the substrate. The beam incident on

Jan 1, 1967

By B. T. Wykoff

This paper describes an important function of mining in Southeast Missouri. The practice is a necessary procedure to prevent disintegration of the pillars. Although the technique is peculiar to this district, it might have application in other mines using room and pillar method. CONSIDERING the subject alone, this paper would cover only a mechanical treatise of pillar roping. Because the St. Joseph Lead Co. originated the practice, it is proper to give a short introduction to the company. It is also proper to describe pillars and discuss their purpose to justify expending large sums of money to preserve them after the surrounding area has been thoroughly mined. Because the St. Joseph Lead Co. originated the practice of back pinning with wedge bolts, patch plates and channel irons, and the pouring of substitute pillars of concrete, these too, are mentioned. The Southeast Missouri Division of the St. Joseph Lead Co. is the largest lead producer in the United States. About 95 pct of the present producing mines are in St. Francois County, which begins 60 miles south of St. Louis. The entire lead ore production of this county, at the present time, is mined and milled by this company, treatment plant capacity being about 22,000 tons per day. This area is also the oldest, lead having been mined at Mine La Motte, in Madison County, in 1723. Estimated production of all the various companies that have mined here is about 7,000,000 short tons of pig lead. Method of Mining The lead occurs in the ore as galena. Galena is found either in the form of disseminated or solid streaks, of varying thickness. Ore stratum is the Bonne Terre dolomite, which is about 350 ft thick, but almost all the ore is in the lower 100 ft. Ore is mined by room and pillar method in open stopes. These stopes vary in height from 7 ft to 200 ft, depending on the thickness of the pay ore in that spot. Back, or roof, is supported entirely by pillars. In a majority of stopes, after the loose scales are mined down, the back has remained solid for many years (fig. 1). Under ideal conditions pillars are spaced to form an equilateral triangle and are as small and as far apart as the height of the stope and the character of the back will permit. They vary in diameter from 10 ft to 50 ft and are from 18 ft to 50 ft apart, measured from the outer edges. In general, the pillars are approximately 12 ft in diameter, and 25 ft apart. The spacing is very uncertain because of the vagaries of the ore trend, the desire to better support breaks in the back, and the attempt to spot out the thinner ore by not placing one in the core of the ore body. Use of Structural Steel Channels In stopes where the back is bad because the overlying formations are thin with wet, weak and shaly

Jan 1, 1951

By B. T. Wykoff

This paper describes an important function of mining in Southeast Missouri. The practice is a necessary procedure to prevent disintegration of the pillars. Although the technique is peculiar to this district, it might have application in other mines using room and pillar method. CONSIDERING the subject alone, this paper would cover only a mechanical treatise of pillar roping. Because the St. Joseph Lead Co. originated the practice, it is proper to give a short introduction to the company. It is also proper to describe pillars and discuss their purpose to justify expending large sums of money to preserve them after the surrounding area has been thoroughly mined. Because the St. Joseph Lead Co. originated the practice of back pinning with wedge bolts, patch plates and channel irons, and the pouring of substitute pillars of concrete, these too, are mentioned. The Southeast Missouri Division of the St. Joseph Lead Co. is the largest lead producer in the United States. About 95 pct of the present producing mines are in St. Francois County, which begins 60 miles south of St. Louis. The entire lead ore production of this county, at the present time, is mined and milled by this company, treatment plant capacity being about 22,000 tons per day. This area is also the oldest, lead having been mined at Mine La Motte, in Madison County, in 1723. Estimated production of all the various companies that have mined here is about 7,000,000 short tons of pig lead. Method of Mining The lead occurs in the ore as galena. Galena is found either in the form of disseminated or solid streaks, of varying thickness. Ore stratum is the Bonne Terre dolomite, which is about 350 ft thick, but almost all the ore is in the lower 100 ft. Ore is mined by room and pillar method in open stopes. These stopes vary in height from 7 ft to 200 ft, depending on the thickness of the pay ore in that spot. Back, or roof, is supported entirely by pillars. In a majority of stopes, after the loose scales are mined down, the back has remained solid for many years (fig. 1). Under ideal conditions pillars are spaced to form an equilateral triangle and are as small and as far apart as the height of the stope and the character of the back will permit. They vary in diameter from 10 ft to 50 ft and are from 18 ft to 50 ft apart, measured from the outer edges. In general, the pillars are approximately 12 ft in diameter, and 25 ft apart. The spacing is very uncertain because of the vagaries of the ore trend, the desire to better support breaks in the back, and the attempt to spot out the thinner ore by not placing one in the core of the ore body. Use of Structural Steel Channels In stopes where the back is bad because the overlying formations are thin with wet, weak and shaly

Jan 1, 1951

By N. Brown

IT has been observed that a hexagonal-close-packed crystal will undergo the same macroscopic displacements as an isotropic material if the basal plane is perpendicular to the axis of twist.&apos; Other orientations may produce both bending and twisting, but this analysis will be confined to pure torsion of a right circular cylinder. The z axis, the axis of twist, and the specimen axis are coincident. The displacements are given by Uq = rz, Ur = Uz = 0 [1] where 4 is the angle of twist per unit length. This requires rotational slip, as discussed by Frank&apos; and Wilman, which may be observed readily. The relative rotation of adjoining slip planes is simply produced by a movement of a planar grid of screw dislocations."." The screw dislocations are of the same sign and they move radially inward. For hexagonal-close-packed metals, the grid is hexagonal and the screw dislocations lie in the < 2110 > directions. The displacement of a point is the resultant of two displacements produced by intersecting screws sweeping over the point. The dislocations must pass over the point (r, o) in such a manner that its resultant displacement corresponds to the observed macroscopic displacement. If 6&apos; is measured from the [1010] direction, then for 0 < ? < ~/3, only the [1210] and 121101 type screw dislocations are needed to produce the required displacement. If n1 screws of type [1210] and n2 of type [2110] pass over a point, then, in order that Ur = 0 n, sin ? - n2 sin (/3 — 6&apos;) = 0. [2] If the tangential displacement is to be independent of 0, then n1 cos ? + n2cos (/3 —?) = N [3] where N is independent of ? and thus depends only on r. Nb is the tangential displacement where b is the Burgers vector. Since U? is a linear function of r, then N must be a linear function of r. If a2 is the outer radius and a, is the inner radius to which the plastic deformation has extended, then N = Nm2 r-a1 [4] This function meets the conditions that at

Jan 1, 1956

Lucien Eaton, Ishpeming, Mich. (communication to the Secretary *):—I began to use water Leyner drills at the Cliffs Shaft mine at Ishpeming, Mich., over four years ago, and now have over 20 in use. The ore in this mine is hard specular hematite, and is mined by the room-and-pillar system, the rooms being driven as breast stopes. For many years only 3 1/4-in. piston drills were used in the mine, each machine ordinarily being able to drill from 15 to 25 ft. of holes in a shift. In the hardest ground, however, it was often, impossible to drill more than 2 or 3 ft. in a shift. When water Leyner drills were used the footage drilled was materially increased, especially in the hardest ground, but it was found that in very hard ground the breakage of machine parts, and especially of drill steel, was very high. At this time round steel with lugs forged on the shanks was used, and most of the breakage occurred at or near the lugs. Many experiments were made in an endeavor to overcome this breakage, and it was finally decided to do away with the lugs altogether, and use hexagonal steel. Accordingly I designed a chuck to use hexagonal steel without luge, a tappet being interposed between the hammer and the shank of the&apos; drill steel. The design of this chuck of the proper size for the No. 18 Ingersoll-Leyner drill is shown in Fig. I. The different parts are also shown photographed in Fig. 2. A is the barrel of the chuck, which revolves inside the front head. It is made of machinery steel. B is the bushing which screws into the front end of the barrel A, and in which the drill steel fits loosely. This is turned down from a steel casting, the hexagonal hole being cast and then broached out to the proper size. It is case hardened inside. C is the tappet, which fits smoothly inside A just behind the bushing B. It is made of " N " temper Crescent tool steel and is carefully tempered. D is the tappet ring, which prevents the tappet from being pushed back too far by the

Jan 1, 1914

By J. C. Irvine

Meramec Mining Co., a joint venture by Bethlehem Steel Corp. and St. Joe Minerals Corp., is engaged in the mining, concentrating, and pelletizing of iron ore from the Pea Ridge mine near Sullivan, Mo., about 70 mi southwest of St. Louis. The orebody lies under about 1300 ft of sediments. It is tabular, about 2600 ft long and up to 600 ft thick, and lies in an approximate east-west delineation. The orebody dips about 80"s and is of unknown depth. The ore is primarily high grade magnetite with smaller zones of specular hematite. The Precambrian wall rock is rhyolite porphyry. The mine is serviced through two concrete-lined shafts, 19 ft 1 in. diam and 2500 ft deep. No. 1 shaft, equipped with an "A" type head-frame and conventional cylindrical drums, hoists men, materials, and waste rock; it is also the downcast air shaft. No. 2 shaft utilizes tower-mounted friction hoists to handle the two production skips, each with 24-ton counterweights, and a small man cage. The mine exhaust passes through this shaft. Ore is principally mined by sublevel stoping,

Jan 9, 1972

By George L. Reiter, George B. Clark

Commercial strip mining of coal was first begun in the state of Illinois in 1911.l The annual tonnage of coal produced from coal strip mines in the state was very small until 1924, when the strip mines shipped 1.68 pct of the total state shipping mine tonnage. Since then, strip mines have gradually come into their own by producing a sizable percentage of the coal produced in the state. Table 1 shows the coal tonnage shipped from both underground and strip coal mines in the state of Illinois for selected years. The table illustrates the major role that strip mines play in the state&apos;s coal industry. Today, strip mining is generally conducted in areas where the coal seams lie so close to the surface of earth that a stripping method of mining the coal seam is cheaper than an underground method. Strip mining not only recovers 100 pct of the coal deposit, but may also be used as a method of mining large acreages of coal abandoned by the closing of underground mines. Open cut or strip mining is a very highly mechanized method of producing coal and is carried on in three distinct and separate operations. The first of these is uncovering or exposing the coal seam so that the coal is made available for mining. The second operation is that of actually mining the coal. The third operation is the washing, crushing and grading of the coal according to the producer&apos;s market. Description of Shovel The Marion 5560 power shovel is used in the first of these three operations. The large electric-powered shovel works forward and back across the coal deposits, removing the overburden of dirt, rock, and clay in successive cuts of 30 to 60 ft deep and 40 to 80 ft wide. The shovel has a maximum cutting height of 95 ft, but around 60 ft is considered to be the maximum economical cutting height by the operators. The smaller the depth of cut, the more economically the shovel will operate until a minimum cut of 15 ft is reached, below which the efficiency decreases rapidly. The Marion shovel may be used in tandem stripping in excessive depths of overburden. The other type of excavating equipment used in the tandem team is generally a dragline with a long boom of about 180 ft. In tandem stripping, the dragline is used to remove the upper portion of the cut and to place it at a maximum dumping radius from the place of removal. The Marion 5560 power shovel is then used to remove the overburden left above the coal seam and to deposit it at the shovel&apos;s maximum dumping radius. The Marion 5560 power shovel is of gigantic proportions. It has a 102 ft 6 in. boom and 32 cu yd dipper and is

Jan 1, 1950

FREQUENTLY the careful engineer puts the word porphyry in quotation marks or precedes it with "so-called," when he writes of the Porphyry Copper mines. This is done by way of serving notice that he is aware that the term is not a precise one, though no one who is informed on the subject would in any event misinterpret it. The name originated from the fact that the rock containing the copper at Utah Copper, Morenci, Nevada Consolidated, and Braden-the first four to be developed-was in each instance known as porphyry. The term was convenient; and when Ray, Miami, and inspiration came along they fell into the Porphyry category even though the ore consisted essentially of a rock called schist instead of porphyry. The word is not inclusive enough; nor as a matter of fact is it sufficiently exclusive. Numerous copper deposits occur in porphyry rocks that are not Porphyry Coppers, paradoxical as it may seem. Desiring to be more accurate and at the same time to use a word that is in some degree descriptive, various engineers have adopted the expression "disseminated copper deposits." This alludes to the characteristic scattering of grains or specks of copper minerals more or less uniformly throughout the mass of the rock. Yet here again the implication is not entirely accurate, for the following reason: in some of the ores, the proportion of copper minerals "peppered" in the rock is small, compared with that which coats the walls of cracks and minute fissures; and that which is found as veinlets along planes of fracture. Many geologists have extended their interpretation of the term disseminated to include both types of mineral occurrence. One of the most striking features of the Porphyry ores is the intense shattering and fracturing that the rock underwent at some period or periods prior to the deposition of the copper

Jan 1, 1933

By C. M. Young

WHEREVER salt is extracted from the ground as an artificial brine produced by pumping down fresh water to dissolve the salt, subsidence of the overburden is a possibility, though apparently few cases of such subsidence have been noted and detailed records are wanting. This description is intended as a record of subsidence that may permit the forcasting of similar occurrences in other cases; the data were supplied largely by R. B. Lee, city engineer of Hutchinson, Kans. About eleven years ago, ground movement occurred at a neighboring salt plant, when the surface assumed the form of a shallow funnel. Movement was probably due to a flow of sand into a well through a poor seal or a broken casing. The salt deposit increases in thickness from the east until at Hutchinson, where the subsidence occurred, it is about 310 ft. think. The interbedded layers of shale vary in thickness from mere traces to about 7 ft. While knowledge of the shale content of the beds is not exact, the log of a shaft 3 miles east of Hutchinson indicates that shale forms about 25 per cent. of the total thickness. This shaft does not reach the bottom of the salt by about 60 ft., but there is no reason to think that the lower part of the bed is different from the upper. Logs of wells sunk to the bottom are not sufficiently detailed to be of much value. Above the salt is the shale of the well-known Red Beds. The thickness of this is variable, principally because of its eroded surface, but at the mine it is 340 ft. This shale is variable in character and strength, but contains no strong members of limestone or sandstone. If the support is removed, very probably it will subside. The Arkansas River flows across the salt district and Hutchinson is situated on the flood plain. Between the top soil, which is about 8 ft. thick, and the shale is 60 to 100 ft. of water-bearing sand and gravel.

Jan 2, 1926

By V. J. Sikora, T. S. Hutchinson

This paper presents a method for making a water-rlrive ana1gsis without prior knowledge of aquifer geometry and uniformity using a standard desk calculator. Although it is necessary to know the initial oil in place to use this method, this is a minor limitation to the scope of (he method since in most reservoirs it is possible to obtain reasonably accurate volumetric oil-in-place estimates. An equation is developed which relates pressure at the water-oil contact to the water influx rate as a function of time by a factor called the resistance function. The resistance function introduces the composite effect of the aquifer geometry and flow resistance disrribution. It is pointed out that the characteristic shape of this function makes it possible to start with on approximation of the function and successively improve the approximation until the correct resistance function curve is obtained. In this fashion water-drive estimates can be made without the limitation of assuming simplifed aquifer shapes and flow distributions. This is the novel feature of this development. Methods are given for extrapolating the final curve to calculate future aquifer behavior. Equations are developed for adjusting the pressures and water influx rates where it appears that possible errors in these quantities make it difficult or impossible to obtain a useuble resistance function curve without this adjustment. Application of the pressure build-up analysis techiiique to estimate. some of the aquifer properties is also presented INTRODUCTION A great many oil pools are the result of oil accumulation in some type of trap in an otherwise large and continuous porous stratum. The void space of this stratum outside of the oil pool itself is filled with water or brine. In analyzing performance of the oil pool surrounded by this water aquifer, it is quite necessary. in most cases, to include behavior of the water. When the pressure at any point in a fluid system is lowered, such as by opening a well in an oil sand, fluids in the immediate neighborhood of this point will begin flowing towards this lower pressure sink. As pressure in this area drops due to flow towards the sink, fluids from farther out will start to flow towards the lower pressure. As more and more fluid is removed from the system, the distance from the sink or well within which flow is occurring will continually increase; that is, thc region of disturbance will grow. If some rigid boundary such as a fault is reached by the disturbance, this area will cease to grow; but if some movable boundary is reached, such as a water-oil contact, the area will grow on out into the water, although rate of growth may and almost always does change. The relation between amount of pressure drop and amount of fluid flowing at any point and at any time in an aquifer depends on such factors as compressibility and viscosity of the fluids, the porosity and permeability of the rock, geometry of the whole system and withdrawal rate or pressure drop. With these factors known, it is theoretically possible to calculate the pressure-flow behavior of the system, However, in practice true solutions to the problem are next to impossible due to complexity of reservoir systems. A number of approximate methods of solution have been developed based on various simplifying assumptions. One frequent assumption is that the water-oil contact can be located and equations defining oil reservoir and aquifer solved separately by assigning values to various parameters so as to match past pressure and production history. Usually the properties of the aquifer are not known, since few, if any, wells are drilled through the aquifer; but the water influx and the pressure at the reservoir boundary are known over some time. If it can now be assumed that the aquifer is circular, pie-shaped, or linear, and that it has uniform properties, it is possible to fit a theoretical dimensionless curve to the past aquifer performance history and therefore calculate future water drive. These theoretical curves are available in the literature,1,2,3 Of course, the assumption of uniform aquifer properties is almost always somewhat in error. Fortunately, however, moderate variations from the average have little effect on behavior of the system; and, hence, the best fit of a theoretical curve is frequently satisfactory. In other cases variations in aquifer properties and geometry are large enough that none of the available theoretical curves will give an acceptable fit of the data. In these cases, methods of fitting the data with various electrical analyzers have been developed.1,2&apos; It is the purpose of this paper to present an approach

By James F. Howe

EveRy engineer and user of wire rope is desirous of information that will enable him to determine whether the performance of any particular piece of rope is satisfactory, and what conditions can be changed so as to increase the life of a rope. In most cases, it is far from easy to analyze the conditions of service and tell which is the greatest factor in determining the life of wire rope. If we start on a layout for an entirely new rope system, the task of making conditions satisfactory is simplified so far as the engineering details are concerned; but if the plant requiring wire rope is in operation, any change is likely to involve the expenditure of considerable money to replace and change over machinery that must be kept in constant operation, because a large monetary loss will result from a shutdown for even a few days. Often wire rope is kept operating under bad conditions, as the user thinks that it is cheaper and quicker to replace the rope than to make alterations in the hoisting machinery. A typical case is a metal mine operating in what is now almost the center of a large mining city, where it owns a few acres of mineral rights. It was expected that the shaft would go to a depth of 1000 ft. (305 m.), so a moderate-sized rope, about 1 1/4in. (31.7 mm.), was used on a 6-ft. drum with a 7-ft. head-frame sheave and rather short lead from drum to head sheave. This mine has gone deeper each year until it is now 2500 ft. deep and the rope speed has been increased from 1500 ft. per min. to over 3000 ft. The original rope just filled the drum in one layer, now it overwinds three layers. The original ropes were probably 6 X 19 crucible steel and lasted from 12 to 18 mo.; now, the highest grade plow steel is used, yet the average service is only about 6 mo. The cause is not hard to find. If the engineers had known at the outset what would be done with this hoist, the design would have been very different. Conditions at this mine, from a wire-rope standpoint, have gradually become worse and it is difficult to see how rope service on this hoist can be compared with the service of previous years with any fairness to the wire-

Jan 1, 1923

By James F. Howe

EveRy engineer and user of wire rope is desirous of information that will enable him to determine whether the performance of any particular piece of rope is satisfactory, and what conditions can be changed so as to increase the life of a rope. In most cases, it is far from easy to analyze the conditions of service and tell which is the greatest factor in determining the life of wire rope. If we start on a layout for an entirely new rope system, the task of making conditions satisfactory is simplified so far as the engineering details are concerned; but if the plant requiring wire rope is in operation, any change is likely to involve the expenditure of considerable money to replace and change over machinery that must be kept in constant operation, because a large monetary loss will result from a shutdown for even a few days. Often wire rope is kept operating under bad conditions, as the user thinks that it is cheaper and quicker to replace the rope than to make alterations in the hoisting machinery. A typical case is a metal mine operating in what is now almost the center of a large mining city, where it owns a few acres of mineral rights. It was expected that the shaft would go to a depth of 1000 ft. (305 m.), so a moderate-sized rope, about 1 1/4in. (31.7 mm.), was used on a 6-ft. drum with a 7-ft. head-frame sheave and rather short lead from drum to head sheave. This mine has gone deeper each year until it is now 2500 ft. deep and the rope speed has been increased from 1500 ft. per min. to over 3000 ft. The original rope just filled the drum in one layer, now it overwinds three layers. The original ropes were probably 6 X 19 crucible steel and lasted from 12 to 18 mo.; now, the highest grade plow steel is used, yet the average service is only about 6 mo. The cause is not hard to find. If the engineers had known at the outset what would be done with this hoist, the design would have been very different. Conditions at this mine, from a wire-rope standpoint, have gradually become worse and it is difficult to see how rope service on this hoist can be compared with the service of previous years with any fairness to the wire-

Jan 1, 1923

By B. Otto Pixler

Mud-analysis logging provides identification of the fluid content of formations drilled by the rotary method and permits the accurate correlation of oil and gas shows with the depth. Mud-analysis logging eliminates much coring and has an especially important application in drilling programs when coring is particularly hazardous or the electric log is difficult to interpret correctly. An appreciation of the factors that influence the results of the mud analysis, such as rate of penetration, mud properties, coring, and characteristics of reservoir rock as related to the "flushing effect," permits a better understanding of the mud-analysis log. Recent studies of the relationship of the two gas readings obtained by the gas-detector instrument have proved significant. The difference between the total combustible gas reading and the higher molecular weight gas reading indicates the presence of methane. With few exceptions, zones not showing an increase of methane probably can be condemned. Mud-analysis logging furnishes valuable information, which generally cannot be obtained by other methods. Introduction Logging by mud analysis of wells drilled with rotary tools is a direct method of locating oil-and-gas-bearing formations. The use of this method of logging has increased each year until now more than 20 field units are being used in 13 oil-producing states and in some foreign countries. Several papers1-9 have been published in the petroleum trade journals describing in detail the equipment and the application of mud-analysis logging. This paper will discuss briefly the method and review its application and some of the late developments. Method As the drilling of a well progresses, the drilling bit dislodges and disintegrates a cylindrical section of the formation. If oil or gas is contained in the pore spaces of the cylinder, some of the contents of these porous spaces will be entrained in the drilling fluid. In wall logging by mud analysis, the mud is continuously examined for oil and gas on its return to the surface, and the results are correlated back to the actual depth of the hole at the time the mud was clearing the eyes of the bit. The test for gas is made by diverting a portion of the circulating mud from the flow line to a separator or gas trap, where the mud is thoroughly mixed with air and a portion of the gas entrained in the mud is removed. A stream of air is drawn coun-tercurrent to the flow of mud in the gas trap, thus materially assisting the separation of the gas from the mud. The air-gas mixture is then drawn into a "hot-wire" gas-detector instrument where the percentage of the combustible gas is determined. The presence of oil in the formation drilled is detected by a physical examination of the drilling mud under ultraviolet light. A sample of the mud is treated to reduce the surface tension and gel strength, after which it is placed in a viewing box. This box is so constructed that all external light is excluded and so that the sample may be subjected selectively to either ultra-

Jan 1, 1946

By B. Otto Pixler

Mud-analysis logging provides identification of the fluid content of formations drilled by the rotary method and permits the accurate correlation of oil and gas shows with the depth. Mud-analysis logging eliminates much coring and has an especially important application in drilling programs when coring is particularly hazardous or the electric log is difficult to interpret correctly. An appreciation of the factors that influence the results of the mud analysis, such as rate of penetration, mud properties, coring, and characteristics of reservoir rock as related to the "flushing effect," permits a better understanding of the mud-analysis log. Recent studies of the relationship of the two gas readings obtained by the gas-detector instrument have proved significant. The difference between the total combustible gas reading and the higher molecular weight gas reading indicates the presence of methane. With few exceptions, zones not showing an increase of methane probably can be condemned. Mud-analysis logging furnishes valuable information, which generally cannot be obtained by other methods. Introduction Logging by mud analysis of wells drilled with rotary tools is a direct method of locating oil-and-gas-bearing formations. The use of this method of logging has increased each year until now more than 20 field units are being used in 13 oil-producing states and in some foreign countries. Several papers1-9 have been published in the petroleum trade journals describing in detail the equipment and the application of mud-analysis logging. This paper will discuss briefly the method and review its application and some of the late developments. Method As the drilling of a well progresses, the drilling bit dislodges and disintegrates a cylindrical section of the formation. If oil or gas is contained in the pore spaces of the cylinder, some of the contents of these porous spaces will be entrained in the drilling fluid. In wall logging by mud analysis, the mud is continuously examined for oil and gas on its return to the surface, and the results are correlated back to the actual depth of the hole at the time the mud was clearing the eyes of the bit. The test for gas is made by diverting a portion of the circulating mud from the flow line to a separator or gas trap, where the mud is thoroughly mixed with air and a portion of the gas entrained in the mud is removed. A stream of air is drawn coun-tercurrent to the flow of mud in the gas trap, thus materially assisting the separation of the gas from the mud. The air-gas mixture is then drawn into a "hot-wire" gas-detector instrument where the percentage of the combustible gas is determined. The presence of oil in the formation drilled is detected by a physical examination of the drilling mud under ultraviolet light. A sample of the mud is treated to reduce the surface tension and gel strength, after which it is placed in a viewing box. This box is so constructed that all external light is excluded and so that the sample may be subjected selectively to either ultra-

Jan 1, 1946

By C. F. Dietz

WHEN thinking of industrial relations, we must not confine the term to what is ordinarily called "welfare work;" viz., organizing baseball teams, departmental parties, athletic contests, and such things. These are all of interest but not very helpful in solving the problems of industry. We must think of industrial relations as that understanding developed between workers and management that permits of harmonious progress because of a mutual understanding of each other&apos;s problems. Most of the industrial unrest, discontent, mistrust, or antagonism is due to misunderstanding; and that misunderstanding is the direct result of not having taken the workers into our confidence. If they are merely cogs in a machine, employed to do certain things, and have no interest in anything but the receipt of the pay envelope, we cannot expect intelligent harmonious progress. There are still some people who think that the interests of management, or capital invested in a business, and the interests of the worker are diametrically opposed. That is an unfortunate belief; the interests are identical. If the worker does not understand what his part of the work represents, what the management&apos;s part represents, and what the invested capital&apos;s part represents, he is bound to have a misconception, of the matter and will think only in terms of the pay envelope. The methods used for producing a better understanding between workers and management do not much matter so long as the end is attained. Some plants prefer shop committees; others attempt to work through the foremen in the various departments; others, by personal contact-between the management and the men, especially if a shop is small. It does not really matter how the end is attained as long as the object is accomplished. The best type of industrial relations can probably be attained when the mystery is taken out of industry-when the workers understand what they. are a part of, what their function is, what they are contributing. They should also understand something of fundamental economics-that it is not just a question of getting all they can and giving just as little as possible but that their contribution makes for expansion, progress, and permanence, and opens a field of activity for themselves that other-wise would probably be blocked.

Jan 6, 1925

Zinc is just now a very important metal. Its use in cartridges and shrapnel brass are in the public eye. But its uses after the war are no less important. Brass as an engineering material for electrical machin-ery, journal bearings, and plumbing fixtures takes fully 50 per cent. of the production, and its use in these lines would have been increased in the last few years but for the price. Its use for barbed wire is probably more in war time than in peace. In the composition of paints, it is becoming more and more necessary. One of the forms of pigment, litho- pone, is the base of nearly all interior wall paints; of all the sanitary enamels for bath-rooms and bath-tubs, and is now in great demand. Zinc oxide is also increasing in use for paint, and for manufacture of linoleum. When we realize that this district-Missouri, Oklahoma, Kansas and Arkansas-produces now over one-third of the zinc ore of the world, it is at once seen that a meeting where the geology, mining, concentration

Jan 6, 1917

The Telfer Project, one of the world&apos;s newest gold mines, is located about 300 km (190 miles) northeast of the Mt. Newman iron ore project in the northern part of Western Australia. The first mineral claims were staked in 1972; and by mid-1975 ore reserves of 3. 8 million mt (4. 19 million st) of 9.6 g per mt (0. 28 oz per st) ore had been indicated. It is interesting to note that Newmont spent more than 10 years and A$10 million in Australia for extensive mineral exploration before finding the Telfer deposit, and then spent approximately A$3 million in exploration and feasibility engineering on Telfer. Including this A$3 million, a total of A$27 million was spent to complete construction of the mine, village, gold treatment plant and associated roads, airport, water and services. Over 50% of the capital cost is in the metallurgical facility, or approximately A$10, 000 per ton per day. All economically significant gold mineralization at Telfer occurs in a series of layered quartz-limonite reefs in which the former pyrite has been oxidized to limonite to a depth of 100 m (330 ft). The most important gold reef occurs at the base of the siltstone-shale horizon within the enclosing sandstone dome -like structure. At the Main Dome structure the dipping ore horizons will be mined to a vertical depth of about 60 m (200 ft) by open-cut methods. The waste-to-ore ratio is approximately 12:1. Eventually 44 million mt (48. 5 million st) of ore and waste will be mined. Mining of the waste is by contract; however, the ore and a thin layer of waste is company-mined. Dilution from mining the geological ore reserve is about 10%. The ore is completely oxidized and the gold occurs free within the reef, material as discrete particles of varying but mainly fine grain size. Most of the gold is "free milling"; that is, over 50% of the gold is coarse enough to be recoverable by gravity concentration. Two duplex mineral jigs receive the two cyclone underflows from the grinding circuit. The rougher jig concentrate is up-graded on a continuous strake from which the concentrate is tabled to produce a final free gold product. Jig tailings are returned to the ball mill and the concentrates are amalgamated. Gold amalgam is pressed, retorted, and melted into gold bars. The gravity gold recovery circuit is the same as was used in many of the gold mills in California in the 1930s.

Jan 1, 1981