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By F. C. Bond, J. T. Wang

H. J. Kamack (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.)—Rittinger's law usually is stated to the following effect: "The work (or energy) consumed in particle size reduction is proportional to the new surface area produced." The law has been stated substantially in this way by Taggart20 Berry21 Dalla Valle22 Coghill and DeVaney,23 Richards and Locke," Gross,25 and many others, and, according to Gaudin,26 was originally expressed by Rittinger in the same form. Consequently there can be little doubt that this is the understanding of the law among most workers in the field of particle size reduction. Bond and Wang, however, express the law in the form "the useful work accomplished . . . ." (italics theirs). The distinction is critical, for in the form used by Bond and Wang the law becomes, as they themselves remark "merely a more or less arbitrary definition of useful work," while in its usual sense the law expresses a physical hypothesis which has been verified experimentally within certain limitations. Considering the way the law has been used, it might be stated more explicitly as follows: "In a given machine operating under a given set of constant operating conditions, the work consumed in the particle size reduction of a given material is proportional to the new surface area produced." Or, as Coghill and deVaney have said,27 "the (Rittinger) law holds only when the tests being compared are made under analogous conditions." There are occasions when the law transcends these limitations; for example, the surface area produced per unit energy consumption for a given material in a ball mill does not vary much over a fairly wide range of operating conditions. But by and large, the surface area production per unit energy consumption will vary with the operating conditions, the type of machine, and the material. The essence of Rittinger's law is that the surface area production per unit energy consumption is independent of the particle size, and this has been verified experimentally by numerous workers for numerous materials, within certain limits. An important limitation is that when one grinds to very small particle sizes, agglomerative forces may tend to interfere with size reduction so that the surface area increases less rapidly than Rittinger's law would predict. Within such limitations, Rittinger's law can be regarded as empirically established. The law has, however, certain theoretical implications, and it seems to be chiefly against these that Bond and Wang direct their criticism. Solids are believed to possess surface energy which is proportional to surface area. Thus, Rittinger's law implies a proportionality between surface energy produced and mechanical energy expended (for a particular material in a particular machine). It does not imply that all or most of the mechanical energy is transformed into surface energy; in fact it is known that most of the mechanical energy is transformed into heat. Bond and Wang assert that most of this heat arises from the damping of elastic vibrations of stressed particles. This may possibly be true for crushing (with which they are chiefly concerned), although in grinding it is probable that much of the heat arises from friction between particles. However, the fact that the surface energy is small compared to the heat energy does not invalidate Rittinger's law, which implies merely that they are proportional. The authors also criticize Rittinger's law on the grounds that "this theory cannot be justified mathematically, since work is the product of force times distance, and the distance factor is ignored," and "energy input must be the product of force times distance, and the Rittinger theory completely ignores large variations in the distance (strain dimension or deformation) throughout which a force must act to produce breakage of different materials." However, the quantities force and distance as such are irrelevant to Rittinger's law, which considers energy input as an integral quantity. The fact that different materials require different forces and strains (hence, different amounts of energy) to break them is incontrovertible but again is irrelevant to Rittinger's law, which, as mentioned before, applies -only to a single material. Even in theory, it would not be expected that the surface area produced per unit energy consumption would be the same for different materials, because the surface energy per unit area is presumably specific to each material. Bond and Wang advance another argument of a

Jan 1, 1952

By V. F. Hollister

The Queen Charlotte gold deposit (also known as the Specogna, Babe, or Cinola) was discovered in late 1970 by Efrem Specogna and Johnny Trico. They were prospecting along the trace of the Sandspit fault, and they sampled jarositic material that included veins from the fault zone. Their assays included some good gold values. They located the Babe Claims in 1971 and optioned them to Kennco Explorations Ltd. Kennco conducted stream sediment and soil geochem studies, geological mapping and drilling of 55.2 m (181 ft) in two drill holes. Kennco withdrew from the property, and by 1977, Cominco, Placer Development, Silver Standard, and Quintana Minerals had each successively worked on the deposit. Consolidated Cinola Mines bought the claims in 1977 and completed exploration of the deposit ultimately in a joint venture arrangement with Energy Reserves. Energy Reserves entered in late 1979, and by 1983, a total of 200 surface and 12 underground drill holes had been completed, totaling 28 600 m (93,832 ft). In addition, a 461.9 m (1515 ft) adit was driven in the ore body. Reserves published by Cinola aggregate 34 Mt (37 million st) of 1.7 g (0.060 oz) Au per tonne. All industry geologists working in the area agree that the Queen Charlotte gold is an epithermal gold deposit in porous volcaniclastic and clastic rocks that is genetically related to a Miocene-Pliocene rhyolite plug. The geologic description here follows the oral presentation made by G. G. Richards, J. S. Christie, and M. R. Wolfhard at a 1976 CIM meeting. Additional comments by the late C. S. Ney of Kennco Explorations are included with the Richards, Christie, and Wolfhard data to complete the geologic set- ting. The attached reprint by Champigny and Sinclair (1 980) provides additional data on the deposit. The Queen Charlotte (Babe, Specogna, or Cinola) gold deposit is located on Graham Island in the northern Charlotte Islands, at the fault boundary of the Skidegate plateau and the Charlotte lowlands. The Sandspit fault marks the physiographic boundary, and it is intruded by rhyolite porphyry at the deposit. Because displaced geochem anomalies, drain- age patterns, and topography suggest dextral and east side down movement for the fault, exposed east block rocks are younger than rocks west of the fault. The east block, which included the ore deposit, is a lowland largely masked by unconsolidated Pleistocene and Recent clastic rocks. Rocks west of the rhyolite plug, on the Skidegate plateau, are Cretaceous carbonaceous and calcareous shale unconformably overlain by a thin veneer of rhyolite tuff. The deposit is about 100 m (328 ft) above sea level. GEOLOGIC SETTING At the ore deposit, the Sandspit fault is a complex structure. However, lithologies on either side of the fault-controlled rhyolite porphyry plug are distinct. West of the rhyolite, the upper member of the Cretaceous Haida formation shale is the most common rock type. The member is composed of dark grey to black, poorly consolidated, and thinly bedded carbonaceous and calcareous shale. The sequence is silicified to an argillite or a hornfels near the rhyolite. West of the rhyolite porphyry plug, but not importantly involved in the mineralization, is a thin masking cover of rhyolite tuff. The tuff unconformably succeeds the cretaceous shale, but it is largely eroded in the mine area. East of the fault-controlled rhyolite porphyry plug is a thick section of conglomerate and sandstone of the Miocene- Pliocene Skonun formation. The ore body occurs within the coarse clastics, the rhyolite intrusive as the western boundary. Ore is entirely contained within the clastics. Original permeability of the clastic rocks was a major control for ore deposition and alteration, and for that reason, the Skonun formation is described in greater detail. The Skonun formation clastics unconformably overlie Haida shale. The Skonun is at least 300 m (984 ft) thick in the mine area, where it trends northerly and dips easterly 15º to 25º. The sequence is about 62 percent conglomerate, 3 1 percent coarse arkosic sandstone, and 7 percent interbedded siltstone and sandstone. Contacts between adjacent beds are generally sharp. Stratigraphic correlations between drill

Jan 1, 1985

By R. F. Sheldon

The discovery of the Carlin deposit was the result of discriminating geologic research and prospecting devoted to the objective of finding a gold deposit that could be mined by open pit methods. By the late 1950s, Newmont Mining Corp. was becoming increasingly concerned about the trend of rapidly rising underground mining costs unless bulk mining methods could be applied. The desirability of finding an open-pittable gold deposit was apparent. The attention of Newmont geologists was directed to Nevada by the publication of two papers: "Paleozoic rocks in North-central Nevada" (1958) and "Alinements of Mining Districts in North-central Nevada" (1960), both authored or co-authored by Ralph J. Roberts of the United States Geological Survey. John Livermore, geologist of Newmont Exploration Ltd., attended a talk given by Roberts in Ely, Nevada in the summer of 1961. These papers and the address by Roberts gave details concerning the Roberts Mountain overthrust, a 483 km (300-mile) long, shallowdipping fault which pushed clastic and volcanic rocks of early and middle Paleozoic age eastward over younger marine formations. Subsequent uplift and doming with consequent erosion had locally removed the upper plate strata exposing windows of lower plate carbonate rocks. Roberts noted that the principal mineral deposits of the region, including gold, were associated with these windows which exhibited a preferred alinement. In the summer and fall of 1961 Newmont's exploration geologists John Livermore and J. Alan Coope began a systematic examination of gold occurrences associated with these windows, aided by further discussion with geologists of the US Geological Survey. Attention was directed to the Lynn and Carlin windows, particularly to those formations lying immediately above and below the Roberts Mountain fault. It was appreciated at the time that many of the gold occurrences in the region were unusual in that no colours were obtained even when panning high grade samples. A large number of rock samples were collected and analysed using fire assaying procedures, and background values for gold were established. This systematic rock sampling resulted in the identification of a distinct area of anomalous gold values, and a block of claims was staked in late October, 1961. These claims, plus an adjoining optioned 32.4 ha (80 acres) of ground, cover the main area of the present Carlin gold mine. Prior to snowfall that winter, one of the bulldozed assessment pits required to establish a claim's discovery exposed 24 m (80 ft) of mineralization assaying 0.007 kg/t (0.22 oz per st) gold. In the spring of 1962 a program of trenching, sampling, and geological mapping followed by rotary drilling was underway. Other properties in the area were acquired. The generally undistinguished nature of the dolomitic siltstones and silty dolomitic limestones hosting the micron-sized gold particles, coupled with the lack of visually associated guide minerals, made identification of the gold bearing areas very difficult. The entire drill column had to be assayed to ensure that values were not overlooked, as very often sections that might be assumed to be waste turned out to be high grade. On September 10, 1962 a high grade intersection of 24 m (80 ft) assaying over 0.03 kg/t (1 oz per st) gold was encountered in the third hole drilled. An expanded program of both rotary and diamond drilling led to the further delineation of the ore body. By December 1963, the exploration program had established an initial reserve of 10 Mt (11 million st) grading 0.01 kg/t (0.32 oz per st) gold. A 1.8 kt/d (2,000 stpd) processing plant was constructed and the first gold bullion was poured in May, 1965, just two years and eight months after the discovery hole was drilled. REFERENCES Roberts, R.J., Holz, P.E., Gilluly, J., and Ferguson, H.G., 1958, "Paleozoic Rocks in North-central Nevada," Bulletin American Association of Petroleum Geologists, Vol. 42, No. 12. Roberts, R.J., 1960, "Alinements of Mining Districts in North-central Nevada," Professional Paper 400-B, US Geological Survey, Article 9.

Jan 1, 1985

By L. W. Fagg

The purpose of this paper is to present in a convenient form data and examples necessary in making dynamometer card analyses; also to outline a procedure of well weighing. Many articles and papers have been written delving into the mathematical considerations relative to the shape and characteristics of dynamometer cards. However. it is recognized that there are too many unknown factors involved in such calculations to assure a workable degree of accuracy. For this reason the accepted procedure is to take dynamometer cards on wells in question rather than try to calculate the load curve. The polished rod dynamometer is now recognized as a necessary tool for measuring loads, torque, and horsepower. It is also used to determine pump action and trouble-shoot for any seemingly abnormal pumping condition. The apparently infinite variety of a = maximum load (height x scale constant) b = minimum load. Range of load is difference between maximum and minimum load speed—taken with stop watch stroke —measured at polished rod c = beginning of down stroke in direction of arrow. (End of up stroke) d = beginning of up stroke. (End of down stroke). Polished Rod Horsepower = (Area of card) x Scale const. x Stroke x Length x spm (Length of card) 33000x 12 1.35 1.35------x5300x 24 x 12 2.53 --------------------------= 2.06 23000x12 Appraximate Peak Torque: Upstroke = (2390) (12) (1) = 28,700 in. Ib Downstroke = (1 860) (12) (.866) = 19,300 in. Ib Counterbalance should be increased to make up stroke and down stroke peak torque equal. FIG. 1 dynamometer cards that can be obtained is one reason for the general lack of usage of the dynamometer as a control instrument rather than a means for making routine measurements of leads and horsepower. When it is considered that the dynamometer card is a record of the resultant of all forces acting on the polished rod at any particular instant during the pumping stroke. the problem is then one of breaking down this resultant into its various components. As a means of a quick review we shall consider the examples shown in Figs. 1 to 9: and Tables I and II and then proceed to the interpretation of variously shaped cards caused by some abnormal operating condition. In Table 11, when we were considering the factors involved in calculating the peak polished rod load, it can be seen that the factors involved greatly oversimplify the problem. Certain assumptions are made which may or may not he even close to the actual field conditions, such as the specific gravity of the fluid generally considered as one; that the crank has constant angular velocity; that the down-hole friction is zero; and that the fluid lift is from the pump. In the following examples we shall see what a variation in fluid weight and friction can do to the general shape and magnitude of the dynamometer card. (Figs. 10 to 22.) MAKING THE WELL STUDY It is obvious that it would be impractical to consider in detail all of these factors each time a well study is made, inasmuch as each well study job could conceivably be extended into a research project rather than serve the practical requirements of finding the answer to a specific problem. For this reason it is important that some objective be established previous to the time the well study is made. Load at TU = 3070 Ib Crank angle when polished rod is at position TU = ? ? = 30° Maximum counterbalance effect at polished rod = 2760 Ib Torque at TU = (Load at TU — Max. counterbalance effect-lbs) sin 0 x Length of Stroke 2 = (3070-2760) .5 x 24 = 1860 in. 15 2 Torque at TD = (Load at TD — Max. counterbalance effect-lbs) sin ? x Length of Stroke 2 = (530 - 2760) sin 330' x 24 = 13,400 in. Ib 2 Note: sin 0 from c to d on UPSTROKE will be positive value. sin 0 from c to d on DOWNSTROKE will be negative value Torque at c and d is zero because 0 is zero. FIG. 2 —APPROXIMATE METHOD FOR CALCUlATlNG TORQUE

Jan 1, 1950

By R. Bakish, M. A. Badiali, N. W. Kirshenbaum

One pound of ultra pul-e molybdenum has been produced containing both metallic and nonmetallic impuvities close to or less than the limits of detection. various purification methods were investigated; althouglz the use of move than one purification step was consideved, it was found that a single, caefully-controlled sublimation of MoCl5 yielded a highly puvified product without prior treatment or recourse to repeated sublimation. Hydrogen reduction of MoC1, to metal was attempted at atmospheric pressure; however, reduced pressure was necessary to obtain substantial yields. The tubular deposits of metal were consolidated into bulk fovm by electron beam melting undev high vacuum yielding a very low gas content. Boblems involved in monitoring the puvity of these materials and analytical results obtained are also presented. THE pronounced effect of even trace amounts of impurities upon fundamental properties of materials is well known to metallurgists and solid-state physicists. Consequently, groups interested in basic studies of metals have in recent years immensely stimulated the preparation and production of numerous ultra-pure metals. Increased demand by scientists for these high purity materials has necessitated development of facilities to prepare them in significant quantities; the procedures reported here were devised to produce significant quantities of ultra-pure molybdenum. Previous work performed in the field of vapor phase purification and hydrogen reduction of several other refractory metal chlorides had demonstrated valuable techniques applicable to molybdenum.' Various purification and reduction steps were individually investigated. Those procedures which showed the most favorable results with respect both to attainment of high purity and to ease of operation were then incorporated in the process utilized to produce the metal.' STARTING MATERIALS It is well known that because of differences in volatility, chlorides may be separated by fractional distillation. It was presumed that distillation of molybdenum pentachloride offered a simple and straightforward method of purification due to its relatively low boiling point. Alternatively, sublimation of the solid chloride also appeared feasible since MoC15 has both a reasonably narrow temperature range in which it exists as a liquid (a property typical of refractory metal chlorides) and a low enthalpy of sublimation. Pertinent thermochemical data of MoC15 are given in Table I. It should be noted that this compound must be handled with care as it is extremely hygroscopic. Anhydrous MoC15 was obtained from the A Metal Climax Co. METHODS OF PURIFYING MOLYBDENUM PENTACHLORIDE Distillation. It was expected that distillation methods, while affording an efficient purification, would prove simple to control and would have a higher production rate than sublimation processes. Also considered was the possibility of effecting a high degree of purification by using both these volatilization methods in conjunction—possibly a distillation followed by sublimation of the solidified condensate. Distillation of MoC15 was investigated using a single stage distillation column packed with chemically resistant glass beads. Heating coils were wound around the column and collection tube (condenser). As-received MoCl5 was charged into a flask connected with the column using a side loading arm under an argon flow. After the column and condenser were brought to about 270" and 210°C, respectively, the apparatus was lowered until the flask was fully immersed in a constant temperature fused salt bath maintained at about 285 °C. Distillation was continued for about 10 or 15 min until 50 to 70 g of distillate had been collected. Analyses of these distillations indicated that several elements, e.g., Cu, Fe, Ni, Cr, and Mg, were lowered in quantity although not all were removed to the same extent. The occurrence of Na, B, Si, and A1 in the distillates appeared to be due to contamination, possibly from corrosion of the pyrex glass. An improved distillation system of larger capacity and longer distilling column was built. Improvements were effected in lowering the amounts of such impurities as B, Mn, Ni, Na, Mg, Cr, Cu, and Fe. These studies were pursued concomitantly with efforts to purify by sublimation; it was subsequently found that although improvements in purity were obtained by distillation, sublimation processes were simpler to control and effected a high degree of purity.

Jan 1, 1963

By Peter Beardmore, Michael B. Bever

The effects of the temperature of deformation and the degvee of deformation on the annealing spectrum of a Au-Ag alloy have been determined by vesistance measurements. Specimens were deformed in torsion at 4°, 78K and room temperature up to strains nd/l of about 1.0 and were isochronally annealed. Discrete annealing stages similar to those found for pure metals were observed. Stage A occurred below room temperature; the decrease in reszstance associated with this stage increased as the temperature of deformation was lowered or the strain was increased. Stage B manifested itself as an increase in resistance; this is attributed to the restoration of short-range order promoted by vacancy or vacancy aggregate migration. At temperatures above 48S0K, recrystallization or Stage C occurred. Stages A, B, and C in the annealzng curves of this alloy may be considered to correspond to Stages II, Ill, and V, respectively, in the terminology used to describe the annealing spectrum of pure metals. ThE annealing behavior after deformation below room temperature has been thoroughly investigated on pure metals, in particular gold and copper. The occurrence of several discrete stages in the annealing spectrum of these metals has been established, but the interpretation of some of these stages in terms of specific mechanisms is still controversial.' The annealing of alloys deformed below room temperature has been the subject of only a few investigations. In the investigation reported here, a Au-Ag alloy was annealed after deformation at and below room temperature. This continues a research program on the deformation and annealing behavior of Au-Ag alloys.2-8s EXPERIMENTAL PROCEDURE An alloy rod of composition 82.6 wt pct Au-17.4 pct Ag was reduced to wire, 0.0428 in. diam, by swaging and drawing. After a recrystallization treatment, the grain size was 0.031 mm, as obtained from the average linear intercept.7 The ends of wires about 6 in. long were flattened and sealed into short brass tubes with cold setting cement to form the grips of the torsion specimens. The equipment used for deformation has been described elsewhere.6 The specimens were deformed at room temperature, 78", and 4°K to various strains nd/l, where n is the number of turns, d the diameter of the specimen, and 1 its length between grips. The strain rate ?max was 0.1 min-' at the sur- face of the specimen except where noted otherwise. The specimens were annealed isochronally for 30 min at intervals of approximately 30°K from the temperature of deformation to approximately 800°K, except that after deformation at 4°K the lowest annealing temperature was 78°K. A potentiometric method was used to measure the resistance: all measurements were made at 78°K with the exception of some measurements at 4°K mentioned below. Data obtained with a single specimen yielded a complete annealing curve: in several cases duplicate specimens were used to confirm the reproducibility of the curves. Since the surfaces of the specimens were rough after deformation, their diameters could not be measured accurately. The resistance increments after deformation and annealing are therefore reported as percentages of the resistance of the same specimen measured after completion of the annealing, that is, after full recrystallization. The corresponding resistivity values can be calculated by obtaining the effective diameter of a deformed specimen from the ratio of its resistance after recrystallization to the true resistivity, which was determined with a smooth specimen of known dimensions. This method of calculation was used to obtain data shown in several of the figures. RESULTS AND DISCUSSION The isochronal annealing curves after deformation to various strains at 4", 78K, and room temperature are shown in Figs. 1, 2, and 3, respectively. The resistance increment of the as-deformed specimens as a function of strain is shown in Fig. 4. For the specimens deformed at 4°K. values measured at 78°K are plotted with the exception of those for the as-deformed

Jan 1, 1970

By C. E. Hottman, R. K. Johnson

Fluid pressure within the pore space of shales can be determined by using data obtained from both acoustic and resistivity logs. The method involves establishing relationships between the common logarithm of shale transit time or shale resistivity and depth for hydrostatic-pres-sure formations. On a plot of transit time vs depth, a linear relationship is generally observed, whereas on a plot of resistivity vs depth, a nonlinear trend exists. Divergence of observed transit time or resistivity values from those obtained from established normal compaction trends rinder hydrostatic pressure conditions is a measure of the pore fluid pressure in the shale and, thus, in adjacent isolated permeable formations. This relationship has been empirically established with actual pressure measurements in adjacent permeable formations. The use of these data and this method permits the interpretation of fluid pres.rure from acoustic and resistivity measurements with an accuracy of approximately 0.04 psilft, or about 400 psi at 10,000 ft. The standard deviation for the resistivity method is 0.022 psi/ft, and for the acoustic method 0.020 psi/ft. Knowledge of the first occurrence of overpressures, and of the precise pressure-depth relationship in a geologic province, enab1es improvements in drilling techniques, casing progroms, completion methods and reservoir evalzmtions. INTRODUCTION CENKRAL STATEMENT Operators engaged in the search for and production of hydrocarbon reserves in Tertiary basins are more and more frequently confronted with complications associated with over pressured (abnormally high fluid pressure) formations. This is particularly true in the Texas-Louisiana Gulf Coast area. The problems associated with these formations are of direct concern to the combined activities of all phases of operations, i.e., geophysical, drilling, geological and petroleum engineering.' - Knowledge of the pressure distribution of a given area of operations would greatly reduce the magnitude of many of these complexities and in some cases would completely eliminate specific problems. his pape; presents techniques developed for estimating formation pressures from interpretations of acoustic and electric log data. Specifically: the acoustical and electrical properties of shales, reflected by conventional acoustic and electrical surveys, can be used to infer certain reservoir properties, such as formation pressure, at any level in a well. It has been possible to develop these techniques because of a firm understanding of the basic principles that govern and apply to such overpressured provinces. NORMAL PRESSUKES Normal pressures refer to formation pressures which are approximately equal to the hydrostatic head of a column of water of equal depth. If the formations were opened to the atmosphere, a column of water from the ground surface to the subsurface formation depth would balance the formation pressure. On the Gulf Coast, the shallow, predominantly sand formations contain fluids which are under hydrostatic pressure. These formations are said to be normally pressured or to have a normal pressure gradient.* Experience has shown that the normal pressure gradient on the Gulf Coast is approximately 0.465 psi/ft of depth. OVERPRESSURES Formations with pressures higher than hydrostatic are encountered at varying depths in many areas. These formations are referred to as being abnormally pressured, abnormally high pressured, or overpressured. Formation pressures up to twice the hydrostatic pressure have been observed. These formations require extreme care and much expense to drill and to exploit. COMPACTION-FLUID PRESSURE RELATIONS THEORY The generation of overpressured formations in Tertiary sections of the Gulf Coast and several other Tertiary sedimentary basins is, in general terms, considered to be primarily the result of compaction phenomena.' This portion of the paper presents a brief review of the theory which associates compaction and fluid pressure relations, and should thus provide the necessary background for an understanding of the techniques presented. See Hubbert and Rubey' for a more comprehensive treatment of this subject. The theory of the consolidation of a water-saturated clay' has been well established by workers in soil mechanics. The concept is explained by a model with perforated metal plates separated by metal springs and water and enclosed in a cylindrical tube. Fig. 1 is a schematic representation of such a model (see Ref. 5, Fig. 27, page 74). The springs simulate communication between clay particles, and the plates simulate the clay particles. Mano-

Jan 1, 1966

By J. W. Freeman, E. E. Reynolds, A. E. White

Fram a study of 63 systematic alloy modifications it was found that molybdenum, tungsten, and columbium, added individually or simultaneously, and increases in chromium cause major improvements in 1200°F rupture strengths of Cr-Ni-Co-Fe base alloys. Rupture strengths were a function of the effect of composition modifications on both the inherent creep resistance and the amount of deformation the alloy would tolerate before fracture. THIS paper describes the results of an investigation of a series of alloys with systematic variations of the chemical composition of the following basic alloy: C, 0.15: Mn, 1.7; Si, 0.5; Cr, 20.0; NI, 20.0: Co, 20.0: Mo, 3.0; W, 2.0; Cb, 1.0; N, 0.12; Fe, 32.0 pct. The 62 modifications of this alloy were produced under conditions which minimized all factors influencing properties at high temperatures except composition. Melting, fabrication, and heat treatment were carefully maintained constant. Stress-rupture properties at 1200°F were used as the primary criteria of evaluation of the alloy. The objective of the study was to obtain data for determining the fundamental role of the influence of alloying elements on properties of heat-resistant alloys at high temperatures. In addition the results should be useful in determining optimum chemical compositions, the sensitivity of properties to variations in composition, and the degree to which alloy content could be reduced while retaining worthwhile properties. It is difficult or impossible to develop correlations between properties at high temperatures and systematic variations in chemical composition from published data for wrought heat-resistant alloys developed for gas turbines.' ' The main reason for this is the extreme dependence of the properties on conditions of treatment of the alloys." In most cases variation in final treatments between alloys so influences the properties that the influence of chemical composition is obscured. In addition it is recognized Table I. Basic Alloy and Some Modifications Used Basic AllOy, Variations in Element Pct Composition, Pct C 0.15 0.08. 0.40. 0.60 Mn 1.1 0.03,0.25.0.50,1.0,2.5 S1 0.50 1.2, 1.6 Cr 20.0 10, 30 Ni 20.0 0, 10,30 Co 20.0 0. 10, 30 MO 3.0 0. 1.2.3, 5, 7 W 2.0 0, 1, 5, 1 Cb 1.0 0.2,4,6 N 0.12 0.004, 0.08, 0.18 Fe 32.0 that variations exist between heats of the same alloy which are related to melting practice and that there is a strong possibility that conditions of hot working influence response to final treatments. The development of heat-resistant alloys has been based on the gradual accumulation of data roughly related to composition from extensive testing programs. There is every reason to believe that in most cases the optimum compositions have been achieved by this procedure in the alloys commercially available. There are, however, very little data showing the influence of systematic variations of composition free from the influence of other factors, particularly for alloys of the type investigated. Several investigators of cast alloys have demonstrated compositional effects, notably Grant,1-6 Epremian,t Guy,8 and Harder and Gow.9 Sykes10 eviewed the work on the wrought alloy Rex 78 and the systematic variations of carbon, copper, molybdenum, and cobalt leading to the development of the stronger Rex 337A alloy. From the papers by Wilson11 and Henry12 it is possible to deduce the beneficial effect of substituting cobalt for iron in 0.45 pct C-20 pct Cr-20 pct Ni-4 pct Mo-4 pct W- 4 pct Cb alloys. Wilson mentioned but did not present the extensive compositional studies involved in developing these alloys. Binder" showed optimum properties for 3, 2, and I pct, respectively, for molybdenum, tungsten, and columbium in 20 pct Cr-20 pct Ni-20 pct Co-30 pct Fe alloys for limited systematic variations of these

Jan 1, 1953

By F. G. Miller

Earlier studies of the mechanism of flotation showed that coal flotation products are contaminated by composite coal and mineral particles. The mineral matter of these particles has the dual effect of increasing the specific gravity and decreasing the coal surface of the particle available for bubble attachment. The present study showed that these particles are more loosely held in the froth column than the high grade coal particles, especially in the coarser sizes. Consequently, it is possible in the laboratory to produce a secondary concentration of the product by sprinkling the froth product with water to wash these loosely held particles from the froth during formation and recovery. To improve coal flotation, Bethlehem Steel Corp.'s research department has been working on a number of related problems based on both physical and chemical factors. The ideal is of course full understanding of the interrelated effects of both sets of factors. However, detailed studies1 of each physical factor have produced immediately usable results in commercial coal flotation and are providing the basis for our current work on the effect of chemical factors. Since these detailed studies provided the basis for the present investigation of froth sprinkling, their key results are highlighted here. For example, for a highly floatable bituminous coal, particle floatability was shown to be directly related to the percentage of coal surface available for bubble attachment and inversely related to particle mass. The data also underscored that in a given size range the addition of mineral matter to a particle makes flotation more difficult both by adding to the mass of the particle and by decreasing the amount of coal surface available for bubble attachment. Size also affects particle floatability in that as the size of particles of a given specific gravity increases, mass increases and the ratio between coal surface area and mass of the particle decreases. Flotation tests showed that any recovery of the coarsest particles in a coal feed is accompanied by progressively higher recovery of finer and finer particles. Consequently, fine high-specific-gravity particles are recovered with the coarse good coal. As a result, when the entire 14 mesh x 0 size range is processed by froth flotation, the good coarse coal is contaminated with high-specific-gravity fines. It is the small quantities of these fines that must be rejected from the froth product if flotation efficiency is to be increased above its present level. These principles and findings, together with work by Professor V. I. Klassen,' led to the froth sprinkling investigation reported in this paper. Working with Russian coals, Klassen had shown that froth sprinkling washes loosely held refuse particles from the froth and compensates for the water lost in the upper froth layers and increases its stability. As a result, the coal particles are retained in the froth and the loss of coarse coal from the froth is prevented. Decreases in ash of 0.1% to 1.5% were reported by Klassen. Working with a 28 mesh x 0 American coal, the author of the present paper found that single-stage flotation coupled with froth sprinkling produced a product comparable to that obtained by the more expensive method of roughing and cleaning.3 The investigation reported in the present paper expanded study of the effect of froth sprinkling to include each of the standard size fractions of a bituminous coal. The main findings are as follows: (1) For those size fractions between 48 mesh and 150 mesh, froth sprinkling produces a marked reduction in both sulfur and ash. In the case of those sizes coarser than 48 mesh, while this reduction is not as significant, the additional benefit of shorter retention time is still a plus for froth sprinkling. Furthermore, when froth sprinkling is coupled with normal fast flotation, the product purity approaches that obtained by starvation reagent feeding, i.e., gradual feeding of flotation reagent to float the recoverable coal from the pulp slowly in several increments. The specific results for these two size groups are: (a) 14 x 48 Mesh. By using froth sprinkling with fast flotation, product sulfur can be reduced to a level

Jan 1, 1970

By N. Plint, E. T. Pinkney

Copper segregation developments within the Anglo American Group are described with particular reference to the work of the TORCO Project Team. Some radical differences have been adopted in the mechan-ical approach as compared with methods used by previous workers. Most important among these are the following: (1) The heating unit is a fluidized-bed roaster. (2) A moving bed segregation chamber is used in which a packed bed of heated ore, to which reagents have been added, moves slowly downwards under gravity and is discharged at a controlled rate by means of a suitable valve mechanism. (3) The quantities of reagents used (sodium chloride and some form of carbon) are only a small fraction of those recommended by other investigators. (4) Retention times of only 2 min have been satisfactory for the complete segregation of many types of ore. Project TORCO is the code name given by Anglo American Corp. of South Africa, Ltd., to the investigation undertaken in Zambia to develop a plant capable of treating large tonnages of refractory copper-bearing ores by the segregation process. The process has now been under investigation for six years (1960-66) and during that period work has progressed from bench-scale laboratory tests through small-scale pilot-plant work to a 500-tpd commercial pilot unit. Test work has been carried out mainly on the ores of the Zambian Copperbelt and results have been encouraging. Recoveries on the order of 90% have been obtained on all Copperbelt ores tested with high concentrate grades. PRELIMINARY INVESTIGATION Laboratory scale segregation test work on Nchanga banded sandstone ore and oxidized ore from Kansan-shi was originally conducted by Professor Maurice Rey. SociCtC Miniere et Mktallurgique de Pefiarroya, in 1957. Both ores responded favorably to the process. In November, 1960, the consulting engineers of Anglo American Corp. of South Africa, Ltd., initiated preliminary investigations on the application of the segregation process to Copperbelt ores. In early laboratory work, samples were heated in a closed, externally heated tube furnace for one hour at temperatures ranging from 800 to 830°C. The free moisture content of the ore feed was 4% and reagent additions were 0.5% salt and 1.0% coal. Both salt and coal were pre-crushed to -48 mesh Tyler.* All samples except an ore from the Bancroft mine responded well to the process and recoveries of over 90% were obtained. The presence of dolomite was responsible for the relatively poor recoveries from the Bancroft ore, as tests on one of the other ores with additions of calcite or dolomite confirmed. Recoveries dropped from 94 to 45% Grades of all the rougher flotation concentrates produced were low at 10-15% copper. The laboratory investigation was then followed up on a pilot-plant scale. An attempt was made to carry out the segregation process in a coal-fired 5-ft-diam fluidized-bed roaster. The feed consisted of a banded sandstone from Nchanga to which 0.5% sodium chloride had been added. Reducing conditions were maintained in the roaster by the addition of coal in excess of that required for heating the feed. The excess coal and added salt constituted the segregation reagents and the temperature of the bed was held at approximately 750°C. Recoveries of copper and grades of concentrates were low. The reasons for lack of success were: (1) The reaction is a gaseous one and a fluidized-bed roaster is therefore unsuitable as a segregation unit. (2) Coal in excess of that required for heating was introduced into the fluidized bed and under these conditions some of the copper would be reduced in situ. The term "reduced in situ" is used here to describe any copper mineral reduced to the metallic state in its original site within the ore particles. If this copper is to be recovered by subsequent froth flotation it must first be liberated from the gangue by grinding or some other method which, in practice, is usually not feasible on ores of this type.

Jan 1, 1969

By GEORGE D. RAMSAY

WHEN the Ironton blast furnace of the Columbia Steel , Co. was first put into operation the iron ore was mined frol11 the deposit near Iron Springs, Utah. This is principally a hematite with 12 to 20 per cent of magnetite finely disseminated throughout the ore. It varies from a fairly soft broken rock structure to that which is hard and compact. In the broken form it will weigh about 150 lb. per cu. ft., and in place the density is approximately 250 lb. per cu. ft. The first ore received for the blast furnace was crushed so as to pass through approximately a 4-in. square opening screen. A typical screen test of this ore is shown in Table 1.

Jan 1, 1935

By ALEXANDER S. CORSUN

THE main orebody in the Hecla mine, Burke, Ida- ho, occurs along a nearly vertical shear zone in the Burke quartzite, with a substantial gouge and lamprophyre dike occurring in an irregular manner throughout the lode. The veins range from 3 to 40 ft. wide and dip from 70 deg. to 90 deg. There is 110 definite line of demarcation between the lode and the wall rock. Stringers of ore are often found in the wall rock for irregular distances. Horizontal but irregular quartz stringers are also found running into the walls and positions of the wall have a tendency to break to the quartz stringers and the accompanying gouge, which causes indefinite, uneven and extremely heavy side and top pressures.

Jan 1, 1930

By E. M. Norris

THE Western phosphate deposits extend over a large area in the Rocky Mountain region, comprising portions of south central Montana, southeastern Idaho, northeastern Utah, and southwestern Wyoming. A limited acreage of these deposits passed into private ownership prior to Dec. 9, 1908, at which time 7000 sq. mi. of land in these phosphate fields was withdrawn from public entry by direction of the Secretary of the Interior. Under the Act of Feb. 25, 1920 (41 Stat. 437) title to all phosphate lands in the public domain was reserved to the United States with provisions for leasing portions to citizens, corporations, states, etc. The above act, in effect, created by law a Western phosphate reserve of approximately 2,269,055 acres.

Jan 1, 1944

By M. C. LYNN

RECENT completion of a $40,000 lubricating oil plant will make it possible for students in the School of Petroleum Engineering at the University of Oklahoma to carry out on a large scale the entire process of refining crude oil, from the time it is received in tank cars and pumped through the 1/4-mile University pipe line to storage tanks on the campus until the various products appear in finished form. This plant is part of a $100,000 expansion program which this school has been carrying out during the past year. Two years ago the Oklahoma State Legislature appropriated $50,000 for the School to use in improving its laboratory facilities. A few months later a $30,000 PWA grant was ob-

Jan 1, 1937

By Charles Will Wright

THE HIGHLY SPECIALIZED heavy air transport services to mining regions, such as exist in the New Guinea gold fields and in northern Canada, have been even more essential in the development of mines in Peru. Few nations have been con- fronted with greater natural obstacles to transport than has Peru, and without the plane it would have been impossible to get the machinery and supplies for the construction of power plants and mills to many of these interior mines, situated as they are over high mountain ranges, with muleback the principal means of transportation. As the mines within a district become important producers and warrant the expenditure, the mule trail is being replaced by automobile roads to connect with the railway stations and with the airports.

Jan 1, 1940

By Louis Moyd

In the preparation of illustrations to accompany reports of investigations concerning particle shapes of various natural and manufactured materials proposed for use as fine aggretates in concrete structures, it was found that stereoscopic views of such materials presented the information much more effectively than the usual two-dimensional photographs. With the whole-hearted cooperation of the Photographic Section, a technique was developed in the petrographic laboratory of the Concrete Research Division, U.S. Corps of Engineers, at Clinton, Miss., for simple and rapid preparation of paired stereoscopic photographs and micrographs. The method requires only equipment which is usually part of the general stock of any laboratory, and it is adaptable for all purposes in which three-dimensional views would be found superior to ordinary photographs.

Jan 1, 1949

By AIME AIME

FRANK T. SISCO is a native of Lawrence, Kansas. He received his earlier education in Clinton, Iowa and his university training at the University of Illinois. His experience in the steel industry has included service in the chemical, testing, and metallurgical departments of the Illinois Steel Co., of South Chicago; the Hess Steel Corp., of Baltimore; the IJ. S. Naval Ordnance Plant at Charleston, W. Va.; and the American Steel and Wire Co., Waukegan, Ill. He severed for seven years as chief of the metallurgical laboratories of the U. S. Army Air Corps at Wright Field, Dayton, before coming to New York in 1930 to become metallurgist and editor of the Alloys of Iron Research, the position he now holds.

Jan 1, 1940

By AIME AIME

M ALBERTSON is research engineer for the Shell Petroleum COT. He joined the Roxana Petroleum Corp. (later the Shell) in 1920, at Hanger, Texas, became district geologist at Shreveport, and after two years was transferred to the production department, where he has been for the past fifteen years. His jobs have ranged from a modest field engineer up to assistant production manager. During this time hc has successively resided in Texas, Louisiana, Missouri, Louisiana, Oklahoma, Missouri, Texas, The Hague (Holland), and Texas. II? the Yates Pool, Texas, in 1929, "Al" initiated' the tubing of wells under pressure to control gas-oil ratios, particularly at restricted rates of flow. This led to the compulsory tubing of all oil wells drilled in the State

Jan 1, 1937

By AIME AIME

THOUGH Frank Wardlaw was born in the East- at Schroon Lake, N. Y., on July 14, 1887-and was educated in New York City-Columbia, E.M., 1916 he has spent his entire professional life in the West, and is still there, as assistant general manager of the Inspiration Consolidated Copper Co., in Arizona. His first jobs were as miner and surveyor for the Utah Consolidated Mining Co., at Bingham, where he worked under A. S. Winther, now general manager of Inspiration's adjoining big neighbor, the Miami Copper Co. After rising to the position of chief engineer and geologist, Mr. Ward- law left Utah Consolidated to go to Chile for two years with the Braden Copper Co. Then he returned to his

Jan 1, 1940

By AIME AIME

NOTWITHSTANDING the metropolitan appearance of M. L. Haider, the present Chairman of the Petroleum Division, he is not a native New Yorker, but was born at Mandan, N. Dak., Oct. 1, 1904. He began his travels at an early stage in life and after attending the University of Southern California for two years he spent two additional years at Stanford University and was graduated in 1927. After a few months as an analytical chemist for the Portland Cement Co. he became research engineer in the natural gasoline department of the Richfield Oil Co. where he remained for approximately two years before taking a position with the Carter Oil Co. in Oklahoma. He was chief engineer for this company for three years before being trans-

Jan 1, 1945