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By Wm. D. Owsley, R. E. Moeller

In the petroleum industry, the process known as oil well cementing is the equivalent of pressure grouting in the mining and construction industries. The science of oil well cementing has been known and practiced for many years. At the present time it has been brought to a high degree of perfection in the handling of many different types of jobs, all of which are known as oil well cementing. In order to understand more easily these processes, we will discuss briefly several different types of oil well cementing jobs, the purposes for which they are performed, and the methods of their accomplishment. It is believed that some of .these procedures, in a modified form, can be applied to pressure grouting projects in general. Originally, oil well cementing consisted of placing a neat cement slurry about a steel casing set in a bore hole. Cement is used about these casings to protect them from the corrosive effects of ground waters, to protect the oil and gas zones from encroachment of undesired water from other levels, to prevent the blowing out of high pressure oil and gas zones from shallow levels, and to strengthen generally and support the casing being placed in the bore hole. After the bore hole is completed to the desired depth, casing is run into the well, pumps are attached to this casing and circulation of the mud fluid in the hole is established; this circulation being from the inside of the casing into the annulus about the casing, and thence back to the surface. Next, a cement slurry is mixed and pumped into the inside of the casing string, A plug, which acts as a piston within the casing, is placed above the cement slurry. This is to separate the top of the cement slurry from mud or water which is used to shove the cement down through the casing and out into the annulus. This plug further serves the purpose of shutting off against a baffle in the bottom end of the casing string, thus stopping the flow of cement out of the casing and leaving the shoe, or lower end of the casing, surrounded by cement and also filling the annulus there above. Casing strings cemented in the above described manner may vary in length from a few feet of large diameter pipe to very long lengths of smaller pipe. As of the present date the longest string of casing which has yet been cemented is some 16,600 ft deep. As a general rule, the deeper the well and the more cement slurry used, the higher the pressures which are required to place the slurry. In parts of West Texas, it is not uncommon to use 4000 sacks to cement a single string of casing in place. Machinery used to mix the cement and place it into the casing is mounted on heavy duty, powerfully equipped trucks which are capable of negotiating any type of highway or country roads. These trucks

Jan 1, 1949

By E. G. Bailey

PLANTS that normally burn coal now able too obtain a substantial increase over their normal supply for their greater power needs, and also additional tonnage for extra storage against the uncertainties of the future. Many plants previously burning oil or gas have already been converted to coal, and those which must yet change to coal will undoubtedly be able to obtain ample tonnage of coal of standard quality at reasonable prices. What a contrast this is to the conditions of 25 years ago, when the shortage of coal and transportation led to prices of $5 to $6 per ton at the mines, and degradation of quality, until the already overburdened railroads were called upon to haul 100,000 ton per day of extra ash alone. This was the result of a runaway market and the loading of gob, slate, and sub-quality coal amounting to an estimated increase in ash of 5 per cent of the total tonnage hauled. The problem of getting increased steam output from inferior coal caused unbelievable reductions in the low normal boiler efficiency of that time and untold labor in firing the hand- and stoker-fed furnaces of that day.

Jan 1, 1942

By James E. Lawver, James L. Wright

This paper discusses the design and calibration of a Faraday pail for measuring electric charge. The paper also shows that at least for two minerals, quartz and calcite, the phenomenon that Johnson termed "reversibility" can be explained in terms of the contact electrification between the minerals and the metal rotor of an electrostatic machine. Each year the free world produces about 13 million tons of mineral concentrates by electrical separation. However, despite the rather general acceptance of electrical concentration as an industrial process, research in this area has lagged far behind the efforts devoted to competitive processes such as froth flotation. The purpose of this paper is to describe the design and calibration of a Faraday ice pail for measuring charge density on mineral grains and to show some of its applications in the area of electrostatic and electrodynamic research. THE DESIGN AND CALIBRATION OF FARADAY PAILS FOR ABSOLUTE CHARGE MEASUREMENT The electric charge on mineral grains at a given time during an electrical concentration process is de- pendent on many factors and cannot, in general, be accurately calculated a priori. It is thus important to devise a method of measuring absolute charge. One method of measuring electric charge is to note the potential rise of an electrometer when charged particles drop into a Faraday pail. Two types of Faraday pail have been constructed and calibrated. The first type, Faraday Pail I (Fig. 1), is a vertical pail originally designed to measure the charge due to contact electrification between mineral grains and a metal rotor or due to conductive induction when mineral grains are passed over a rotating cylinder in the presence of an electric field. The second type, labeled Faraday Pail II (Fig. 2), is a horizontal pail designed to determine the charge distribution of mineral grains after they pass through the separating zone of the electrical concentrator shown in Fig. 4. The main advantage of the horizontal pail is its low head-room requirement and the long opening which enables the experimenter to sample the entire width of the stream of minerals being separated. The Faraday pails were calibrated in the following manner: A calibration head was constructed in the form of a hollow brass sphere that could be held in an insulated metal cylinder by vacuum (Fig. 1). The capacitance of the sphere was calculated by measuring the capacitance of the sphere and cylinder combined and that of the cylinder alone and subtracting the latter measurement from the former. The sphere was then charged to a known potential (V) and allowed to drop into the Faraday pail which was attached to a Keithley Model 610A electrometer. This instrument has an accuracy of 2% full scale and has

Jan 1, 1969

By E. I. Larsen, E. F. Swazy, F. R. Hensel

Experience has indicated that hard bronzes are not suitable for bearing applications where high bearing loads and speeds are involved. It is the general practice to utilize softer materials for these purposes, such as copper, lead, silver, babbitt, lead-base alloys, and more recently aluminum-base alloys, preferably supported by a steel backing. It was the objective of the present investigation to study a new material produced by powder metallurgical methods susceptible to precipitation-hardening. Test MAteriaIs Preliminary tests were made with compacts containing copper, nickel and silicon in quantities sufficient to form 3 to 5 per cent nickel silicide. It mas found that this type of alloy was susceptible to the formation of a soft surface shell when sintered in tank hydrogen. The depth of the shell depended On the length of sintering time and sintering temperature, and varied in thickness from a few thousandths to as much as One eighth inch. This soft shell resulted from the preferential oxidation of silicon, thereby reducing the efficiency of age-hardening by the nickel silicide compound. The body of the sintered compacts below the soft shell could be precipitation-hardened to a hardness of 70 to 85 Rockwell B, by quenching from goo°C. and age-hardening at 450°C. A series of tests was made with various addition agents, in order to decrease the rate of preferential oxidation, and it was found that phosphorus was most beneficial in this respect. After considerable experimentation, the following nominal com-position was accepted as standard: 2.4 per cent nickel; 0.8 silicon; 0.3 phosphorus; balance copper. The physical propertties and certain bearing properties of this alloy are described in the present paper Preparation of Compacts Several methods of incorporating the hardening ingredient (nickel silicide) were studied. Compacts formed from copper, nickel and silicon powders were found to be inferior to those fabricated from prealloyed nickel silicide master alloys, because of the rapid oxidation of pure silicon during sintering. The use of a prealloyed nickel silicide hardener containing 25 per cent silicon and 75 per cent nickel could be further improved by preparing a master alloy, incorporating nickel, silicon, phosphorus and copper, having the following nominal composition~ 25 per cent nickel; 7 silicon; 3 phosphorus 64 copper. This alloy is brittle in the cast condition and can be readily powdered. Sintering Procedure The blended powders were pressed at '5 to 40 tons per sq' in., the pressure depending on the size and shape of the compacts. Sintering was carried out in hydrogen or cracked ammonia atmospheres at

Jan 1, 1946

By E. I. Larsen, E. F. Swazy, F. R. Hensel

Experience has indicated that hard bronzes are not suitable for bearing applications where high bearing loads and speeds are involved. It is the general practice to utilize softer materials for these purposes, such as copper, lead, silver, babbitt, lead-base alloys, and more recently aluminum-base alloys, preferably supported by a steel backing. It was the objective of the present investigation to study a new material produced by powder metallurgical methods susceptible to precipitation-hardening. Test MAteriaIs Preliminary tests were made with compacts containing copper, nickel and silicon in quantities sufficient to form 3 to 5 per cent nickel silicide. It mas found that this type of alloy was susceptible to the formation of a soft surface shell when sintered in tank hydrogen. The depth of the shell depended On the length of sintering time and sintering temperature, and varied in thickness from a few thousandths to as much as One eighth inch. This soft shell resulted from the preferential oxidation of silicon, thereby reducing the efficiency of age-hardening by the nickel silicide compound. The body of the sintered compacts below the soft shell could be precipitation-hardened to a hardness of 70 to 85 Rockwell B, by quenching from goo°C. and age-hardening at 450°C. A series of tests was made with various addition agents, in order to decrease the rate of preferential oxidation, and it was found that phosphorus was most beneficial in this respect. After considerable experimentation, the following nominal com-position was accepted as standard: 2.4 per cent nickel; 0.8 silicon; 0.3 phosphorus; balance copper. The physical propertties and certain bearing properties of this alloy are described in the present paper Preparation of Compacts Several methods of incorporating the hardening ingredient (nickel silicide) were studied. Compacts formed from copper, nickel and silicon powders were found to be inferior to those fabricated from prealloyed nickel silicide master alloys, because of the rapid oxidation of pure silicon during sintering. The use of a prealloyed nickel silicide hardener containing 25 per cent silicon and 75 per cent nickel could be further improved by preparing a master alloy, incorporating nickel, silicon, phosphorus and copper, having the following nominal composition~ 25 per cent nickel; 7 silicon; 3 phosphorus 64 copper. This alloy is brittle in the cast condition and can be readily powdered. Sintering Procedure The blended powders were pressed at '5 to 40 tons per sq' in., the pressure depending on the size and shape of the compacts. Sintering was carried out in hydrogen or cracked ammonia atmospheres at

Jan 1, 1946

By A. W. D. Hills

This paper describes the development of a generalized integral-Wofile method for the analysis of heat transfer dwing solidification. The method is extremely flexible, and can be applied to a wide range of situations. This flexibility has been achieved by characterizing the solid metal layer in terms of two parameters, and by developing two simultaneous nonlinear differential equations for these parameters in terms of the heat fluxes crossing the boundaries of the solid layer. The use of these equations is illustrated in a series of examples which involve the solidification of pure metals at zero superheat cooling under different conditions. The simplicity with which the method can be extended to treat more complicated jwoblems is illustrated in a further example which involves natwal convection effects in the liquid metal. ThE rate at which molten metal solidifies in an industrial casting process, and the structure of the cast product, are both controlled by the rate at which heat can be removed from the casting. A knowledge of heat transfer rates is thus essential to the control of the process and to the control of the structure and soundness of the final casting. Heat transfer rates during real solidification processes cannot be predicted by formal mathematical techniques, however, because nonlinear boundary conditions are involved. Approximate methods are normally used, and these have included electrical and hydraulic analogue techniques, finite difference methods, and the integral-profile method. Considerable effort has been devoted to the development of the first two techniques, but the integral-profile method has been used very little so far. This is unfortunate because the method is capable of providing relatively accurate solutions for the heat transfer equation during solidification without involving large amounts of computer time. A further advantage of the method is its flexibility, although this is not apparent from the integral-profile solutions that have been developed to date. These solutions have been derived for the solidification of molten metal at zero super-heat under cooling conditions involving either a constant heat flux from the cooled surface;' a constant heat transfer coefficient at the surface,'-3 or a specified variation in the surface temperature.4,5 A generalized integral-profile method is presented in this paper which can be used to predict unidirectional solidification rates under a very wide range of more realistic cooling conditions. The use of the method is illustrated in a series of problems involving pure metals, or skin forming alloys, solidifying at zero super-heat. However, the principal advantage that this method has over the previous integral-profile methods is the ease with which it can be extended to treat more complicated solidification problems. This is illustrated by considering a problem in which super-heat is liberated from the liquid metal by natural convection during the solidification process. In the final section of the paper the generalized method is compared with previous methods used to predict solidification rates and its extension to more complicated solidification problems is briefly discussed.

Jan 1, 1970

By Chester A. Fulton

In Polk County, Florida, the mining of raw phosphates began some 50 years ago with dredging operations on the Peace River, and in other near-by places by removal of shallow overburden with negroes and wheelbarrows, or with mules and scrapers, and the excavation and screening of deposits found close to the surface. There were many individual operations of comparatively short life. Later steam shovels removed the overburden, and still later hydraulic methods were substituted for the steam shovel. Within the last 10 years large electrically operated draglines have almost entirely replaced hydraulic mining for overburden removal. The matrix is still mined by hydraulic giants and pumped to the washer or recovery plant. The many small operations have long since disappeared and the most desirable phosphate lands have gradually been acquired through purchase or merger by the seven companies that are operating in the field today. These companies are producing and selling about 2,000,000 long tons of phosphate per annum, or about two-thirds of what the industry likes to think is the normal output, with 1929 and 1930 in mind. To produce these 2,000,000 long tons of raw phosphate, they mine and treat about 1,000,000 tons of tailings from older and less efficient operations, about 11,000,000 tons of matrix, and remove from above this matrix some 22,000,000 tons of overburden. The mining practice that has made possible the excavation and handling of 34 million tons of material to win but 2 million tons of merchantable product, selling for probably an average of only $4 per long ton when dried, should be of interest to the mining profession, though little has been written of it. The Florida Pebble Field, as it has come to be known, comprises an area (Fig. 1) within a radius of about 18 to 20 miles centering around Mulberry in Polk County, a small town 30 miles east of Tampa, Florida's largest port on the Gulf coast. The geology1 of these phosphate pebble deposits may be described briefly. A fairly pure limestone was altered to a secondary apatite.

Jan 1, 1938

By Chester A. Fulton

In Polk County, Florida, the mining of raw phosphates began some 50 years ago with dredging operations on the Peace River, and in other near-by places by removal of shallow overburden with negroes and wheelbarrows, or with mules and scrapers, and the excavation and screening of deposits found close to the surface. There were many individual operations of comparatively short life. Later steam shovels removed the overburden, and still later hydraulic methods were substituted for the steam shovel. Within the last 10 years large electrically operated draglines have almost entirely replaced hydraulic mining for overburden removal. The matrix is still mined by hydraulic giants and pumped to the washer or recovery plant. The many small operations have long since disappeared and the most desirable phosphate lands have gradually been acquired through purchase or merger by the seven companies that are operating in the field today. These companies are producing and selling about 2,000,000 long tons of phosphate per annum, or about two-thirds of what the industry likes to think is the normal output, with 1929 and 1930 in mind. To produce these 2,000,000 long tons of raw phosphate, they mine and treat about 1,000,000 tons of tailings from older and less efficient operations, about 11,000,000 tons of matrix, and remove from above this matrix some 22,000,000 tons of overburden. The mining practice that has made possible the excavation and handling of 34 million tons of material to win but 2 million tons of merchantable product, selling for probably an average of only $4 per long ton when dried, should be of interest to the mining profession, though little has been written of it. The Florida Pebble Field, as it has come to be known, comprises an area (Fig. 1) within a radius of about 18 to 20 miles centering around Mulberry in Polk County, a small town 30 miles east of Tampa, Florida's largest port on the Gulf coast. The geology1 of these phosphate pebble deposits may be described briefly. A fairly pure limestone was altered to a secondary apatite.

Jan 1, 1938

By R. L. Frantz, R. W. Bouman

The authors investigated the comminution of quartz and limestone mixtures in a ball mill, showing that the distribution modulus of a comminuted material is the same whether it is ground separately or as part of a mixture. Analysis of the ground products indicates that quartz and limestone consume energy during ball milling in proportion to their mass fraction in the mixtures. Recently Schuhmann' made a significant contribution to comminution theory by proposing that complex comminution operations comprise the summation of many individual comminution events. By means of the single comminution event hypothesis, Schuhmann derived the Charles energy-size reduction relationship by considering that fragments of every particle crushed during a single impact have a size distribution characterized by the Schuhmann size distribution. In this paper, the size reduction of mixtures of solids in ball mills is analyzed by considering that size reduction occurs as many single comminution events. If a mixture of two materials is being ground in a ball mill, each successful impact of a ball with a particle of one material should yield an assembly of particles whose size distribution is characteristic of that material. Considering both materials to follow the Schuhmann size distribution equation, the size distribution of material 1 in the product is

Jan 1, 1962

By W. J. Keep

We have found that our graphic representations were, in some cases, not perfectly understood. In the tables by which we illustrate all our tests, the records appearing in the vertical columns between the rulings are the results of the tests of iron having the percentages and characteristics noted at the top of the column. The record is made by a short horizontal line in such vertical columns. It is located in horizontal spaces, which divide the table into units of measure, to indicate the value of the record. For example, in the upper part of Table VII. is recorded the transverse strength of the series of tests with white iron and aluminum, which were reported in our former paper. The numbers at the extreme top are the test-numbers. The fractional numbers below are the percentages

Jan 1, 1890

By P. Rama Rao, D. H. Sastry, T. R. Anantharaman

Deformation (a) and twin (a') stacking-fault densities in cold - wor ked filings of fcc silver alloys containing 2, 4, and 6 wt pct Sb have been estimated from Debye-Scherrer peak shifts and asymmetries, respectively. Evidence has been obtained for a possible strain-induced transformation in a two-phase alloy containing 9.0 zut pct Sb. Using Fourier analysis of X-ray line profiles, the effective particle sizes and root mean square strains have been determined for the three fcc alloys in the cold-worked condition. The values of the compound fault probability 0.5a + a') evaluated from peak shifts and asymmetries are in reasonable apeement with those derived from peak broadening. COLD work of fcc metals may produce both deformation and twin (also called growth) stacking faults, which can be detected and quantitatively estimated by X-ray diffraction techniques.' In addition to peak broadening, deformation faults produce a shift in peak positions and twin faults an asymmetry of the Debye-Scherrer reflections. Besides stacking faults, a reduction in the size of coherently diffracting domains and distortion within these also broaden the powder reflections of deformed fcc metals and alloys. Fourier analysis' of peak shapes provides quantitative infor- mation about the effective domain sizes, lattice strains, and also the compound fault probability (1.5a + a'), where a and a' represent deformation-and growth-fault density, respectively. The Paterson method2 for determination of a from peak shifts, the warren3 or wagner4 method for evaluation of a' from peak asymmetries, and the Fourier analysis for quantitative estimates of all the contributory causes of peak broadening have, in the course of the last decade, been extensively applied to obtain data for a number of deformed fcc metals and alloys. One of the useful results of earlier measurements of a in several solid solutions is a correlation between a and the solute valence as well as electron concentration per atom (p) in alloy systems based on a particular solvent. The work of Smallman and westmacott5 on Cu-Zn, Cu-A1, and Cu-Sn, of Foley, Cahn, and ~aynor' on Cu-Si and Cu-Ge, and of Rama Rao and Anantharaman7 on Cu-Si and Cu-Sb has revealed a common trend in the increase of a with p and also a with valency of the solute. Cahn and Davies' and Ad-ler and wagnerg have observed similar trends for silver alloys containing cadmium, indium, and tin. Data on a for silver alloys with a pentavalent solute element are not, however, available. It is primarily to fill this need that the present investigation on Ag-Sb alloys was undertaken. Utilizing the Patersonand Warren methods, values of a and a', respectively, have been determined in three silver alloys containing 2, 4, and 6 wt pct Sb. By Fourier analysis of the broadening of Debye-Scherrer peaks, effective particle sizes, lattice strains, and the compound fault probability (1.5a +a') have also been evaluated.

Jan 1, 1967

By O. P. Dolph

SPANIARDS were probably the first to mine the rich surface ore in the veins cutting the rhyolite capping that outcrops on the hills of La Mazata, oil the Allyones side of the Magdalena valley in Jalisco, Mexico, although the name comes from a word of Indian origin meaning "deer". The camp is about 12 km. west of Magdalena, a town on the Southern Pacific Railroad, and about 17 km. north of Etzatlán, on the Mexican National Railroad, at an elevation of 4500 ft. The climate is subtropical with no extremes of heat or cold, the rainy season beginning in June and ending in October.

Jan 1, 1938

By L. R. Duncan, O. M. Wicken

Magnesium, the eighth most abundant element in the earth's crust, is found widely distributed in a variety of minerals. Among the more commercially important ones are magnesite (MgCO,), brucite (Mg[OH],) , dolomite (CaMg[CO,],), and the salts magnesium sulfate and chloride often found in natural brines. Among other commercially important magnesium-containing minerals are olivine ([MgFe],- SiO,) , talc (H,Mg,[SiO,],) , and serpentine (H,Mg,Si,O,) . These are valuable because of desirable characteristics given them by the magnesium content and its placement in the particular crystal structure. These minerals are the raw materials for a host of products including magnesium metal and several grades of magnesia or magnesia- containing materials for refractories, fluxes, fillers, insulation, cements, decolorants, fertilizers, and chemicals. Considering only those minerals valued for their magnesia or magnesium content, over 85% of the material tonnages are processed to be used as refractories. Dolomite, which is used in enormous tonnages for its physical properties in construction, has an important use as a refractory raw material in its own right and, after calcination, as a precipitant for magnesium hydroxide, which is an intermediate for the production of magnesia or magnesium metal. Magnesia from the reaction of calcined dolomite (or limestone) with sea-water or magnesium-containing brines has supplanted much of the production of magnesia from mined magnesite, particularly in the United States. The best known of the minerals directly and widely exploited for magnesia content is magnesite, one of the calcite group of rhombo- hedral carbonates which includes calcite (Ca- CO,) , siderite (FeCO,) , and rhodocrosite (MnCO,) among others. The members of this group enter into a wide range of substitutional solid solutions when the positive ions have similar radii. The radii of magnesium and iron ions are within 6% of each other; hence, magnesite and siderite form a complete series of which breunnerite (ferroan magnesite) is a well-known end member. However, the radius of calcium ion is 36% larger than that of magnesium ion, and only limited substitution exists at each end of the MgC0,-Cam, series. Dolomite is not a member of the calcite group, but results when calcium and magnesium ions alternate in equal number in an ordered structure among carbonate ions. The result of these relationships is that calcite and dolomite, often found intermixed with magnesite, occur commonly as identifiable crystal entities which can often be separated to a varying degree from the magnesite by various beneficiation techniques. Magnesite, when pure, contains 47.8% MgO and 52.2% CO,. The pure mineral is sometimes, but rarely, found as transparent crystals resembling calcite, but, preponderantly, magnesite contains variable amounts of the carbonates, oxides, and silicates of iron, calcium, manganese, and aluminum. Magnesite may be either crystalline or "amorphous" (cryptocrystalline). The crystalline form has a hardness of 3.5 to 4.0. The color may range from white to black with shades of yellqw, blue, red, or gray. The color is not a fundamentally significant indicator of purity, but in a given deposit, an experienced person can often roughly grade magnesite by assessing color and crystallinity. The crystalline form of magnesite occurs in

Jan 1, 1975

By Philip D. Wilson

AS thin most important and vital component of an airplane aluminum hay rapidly become the heart and tome- of the war program. Its production ham increased amt will continue to increase, in comparison with its pre-war position further than that of any of lie other important critical metals except magnesium. Compared with the 1939 production of tons of primary ingot coming from four plants, all owned by the Aluminum Company of America the 1942 figures are more than three timer as large. Including, recoverable scrap and contracted ingot from Canada the 191,, supply of aluminum for the United States will be over siren times dial of 1939- A substantial part of this increase has been achieved during the past year as total production in 1941 was only some 307,500 tons. During 1942 six great new ingot plants sponsored and owned by the Government have come into production and three others are nearing completion.

Jan 1, 1943

By J. P. Sheehan, W. R. Hibbard, M. Baeyertz

This paper deals with molybdenum modifications of 5140 steel that have the same hardenability but a better tolerance for phosphorus than the AISI-SAE 5140 grade. Lack of toughness in steels with higher than normal phosphorus contents is well known to metallurgists. This problem is troublesome even within normal phosphorus ranges, if the heat treatment or the design of the part or the service is critical. Under such unfavorable conditions and also in the case of phosphorus contents toward the upper side of the commercial range, the use of molybdenum to replace a part of the chromium in 5140 steel provides a factor of safety. The toughness of steel is variously exhibited in different mechanical tests; broadly the term is applied to the capacity of the steel to deform prior to fracture. Defined in this way, toughness is considered to be an inherent quality that depends upon the composition and structure of the steel, and also upon its temperature during deformation and fracture in the test. In the present state of our knowledge, the type of mechanical test needs to be included in any discussion of toughness, because the revelation of this quality in steel depends on the stress state and rate of stressing imposed by the test. In comparing the toughness of one steel with another by laboratory testing, it has long been customary to use notched tests that impose severe constmint to deformation, and then to test over a range of temperatures to obtain the so-called transition. At temperatures above the transition, the steel fails after considerable deformation and absorption of energy. Below the transition, less energy is absorbed as the steel fails largely by cleavage. The transition range itself is characterized by a more or less abrupt change in energy absorption and type of fracture. The conventional V-notch Charpy impact test has been used exclusively in the work covered by this report. For the steels under study, rather sharp transitions are obtained with this test, at testing temperatures that are easily obtained in the laboratory. The position of the transition on the testing temperature scale provides a rather sensitive index of the toughness of the steel, when the steels under study are similar in character as they are in this work. Turning to the metallurgical reasons for the greater toughness of one steel as compared to another, the authors propose to limit the discussion to the small field under study. Only one structural state is considered, tempered martensite of a hardness of about 28 Rockwell C or 269 Brinell. The study deals first with the loss of toughness in AISI-SAE 5140 steel caused by increasing the phosphorus content from about 0.020 to 0.040 pct. A second part of the work deals with counteracting this loss in toughness by replacing a part of the chromium by molybdenum. A series of molybdenum modifications was studied, in each of which the chromium was reduced sufficiently to duplicate the hardenability of 5140 steel. Phosphorus affects the toughness of steel in two ways. An inherent lack of toughness of phosphorus-bearing ferrite as compared to low phosphorus ferrite has often been noted. Jolivet and Vidall have shown that phosphorus has the same effect in tempered martensite in chromium steels. The other well known effect of phosphorus is to make steel susceptible to temper embrittlement. Temper brittleness is a loss in toughness brought about by tempering steel within a limited temperature interval somewhat below the A1 temperature. In most of the standard AISI-SAE alloy steels, this temperature interval is approximately 850-1100°F. Either of these types of loss in toughness is easily followed by the shift in the transition temperature obtained with the notched-bar impact test. The data to be presented show the beneficial effect of substituting molybdenum for a part of the chromium in 5140 steel with either moderate (0.020 pct) or high (0.040 pct) phosphorus contents. Both the inherent lack of toughness of phosphorus-bearing steel and temper brittleness are counteracted by this use of molybdenum. The work of Jolivet and Vidal mentioned above shows the detrimental effect of phosphorus on the toughness of tempered martensite in the absence of temper embrittlement, as well as the temper brittleness caused by phosphorus. They used two steels, essentially 0.25 pct C-1.4 pct Cr, with 0.044 and 0.013 pct P, respectively. The nonembrittled state was obtained by quenching in oil from 1610°F, then tempering for one hour at 1200°F and quenching in water. In this state the transition temperature range of the low phosphorus steel in the notched-bar impact test was below that of the steel with 0.044 pct P. An additional treatment of 24 hr at 975°F (that is, in the embrittling range) caused both steels to lose toughness, but the high phosphorus steel showed the greater embrittlement. Recently Hollomon2 has published a comprehensive survey and bibliography of the literature on temper brittleness, to which the reader is re-

Jan 1, 1950

By Joseph E. Pogue

NEW economic forces are at work in the petroleum industry.. In order to visualize these forces and clearly see their bearing on the producer, refiner and marketer, it is necessary to see in perspective the economic evolution of the business. For several decades prior to 1913 the outstanding feature of the petroleum industry was a trend toward integration, culminating in a huge combine, the Standard Oil Co. An important aspect of this integrative trend, however, was its concentration on the combination aid control of refining and marketing, leaving crude oil production, for the most part, to the exigencies. of small-unit competition. It is a noteworthy coincidence that during this era the law of oil and gas was formulated and applied, whereby these substances had to be reduced to possession to establish ownership; and the forces of competition in crude oil production were thereby intensified. It was to the interest of an industry, safeguarded in its control of manufacturing and markets, to have supply stimulated by legal convention as well as by individual initiative in order that the growing demand could be met without interruption. And so over-production of crude oil during this era was no handicap, but rather an aid, to the progress of the industry.

Jan 1, 1929

By T. Reed Woodbridge

The object of this paper is to bring to notice a method in use at the Cedar Point laboratory of Witherbees, Sherman & Co., for determining the phosphorus in the ore mined at Mineville, N. Y. This ore is magnetite, with a gangue containing crystals of apatite. In 1886, Mr. H. F. Dawes, then head chemist at the works, suggested that as all the phosphorus seemed to be in the apatite, it could be obtained in solution by dilute nitric acid. After some experimenting the following method was adopted, and has proved invaluable for rapidity and ease; half a dozen determinations requiring very little more time or trouble than one. From + to 10 grammes of ore are weighed into a 150 c.c. beaker; 50 C.C. hot water and 10 c.c. strong nitric acid are added; the beaker is covered and the contents are boiled for 1/2 hour (10 minutes sometimes proves sufficient; but 4 hour is safer). The bumping which ensues if more than & gramme is used need cause no trouble. The hot solution is filtered into a 250 C.C. beaker. The filtration and washing (with hot water) proceed rapidly, as the magnetite itself is but slightly acted upon. After the addition of 15 C.C. ammonia and 15 c.c. nitric acid, the solution is cooled to 45' C., and from 15 to 40 C.C. of molybdic acid solution is added and stirred vigorously. In 5 minutes the precipitate will be down, and the determination can be finished by any good method. At Cedar Point the method more commonly used is weighing as yellow salt. Good washed filter-paper is used, No. 0 Swedish being preferred; and dozen 3 1/2-inch filters are numbered and dried and weighed at 110°C. These are always kept in stock. The yellow salt is filtered on one of these, washed with dilute nitric acid (2 per cent. by volume); dried for 1 hour at 110' C., and then weighed, 1.63 per cent. of weight being calculated as phosphorus. The filters vary in the two weighings from

Jan 1, 1889

By T. E. Kihlgren

SYSTEMATIC data are presented on the relation of composition of nickel silvers to color, tarnish resistance, hardness and liquidus temperatures, for alloys containing up to 30 per cent nickel and 50 per cent zinc, further modified at certain nickel and zinc contents by 0 to 8 per cent of tin and 0 to 10 per cent of lead. Attention has also been directed, using a still more limited range of alloys, toward a study of tensile properties and such casting properties and characteristics as fluidity, shrinkage and pressure tightness. In some of these, rather broad ranges of composition are dealt with; in others, it has been expedient to focus attention on the Federal Specification 20 per cent nickel silver casting alloy, WWP-541. INTRODUCTION The demand for an alloy essentially white in color, which could be cast and worked by simple methods and which possessed strength and corrosion-resisting properties superior to the usual brasses, led to the discovery and early use of cupronickel alloys containing zinc, and some-times tin, lead and other metals. This type of alloy was generally known as German silver until the war, when the term "Nickel Silver" became generally accepted. The element principally responsible for the white color of the alloy and for its strength and corrosion resistance is nickel, which may constitute from 8 to 30 per cent of the alloy. The functions of the other elements will be described later. The manifold uses of nickel silver are largely due to its color, corrosion resistance, ease of casting, fabrication, joining and rather moderate cost. In many instances the alloy is finished by grinding and polishing while in others it may be finished with a silver or nickel plus chromium plate. Electroplates

Jan 1, 1935

By H. J. Oberson, J. H. Brown

Comminution devices such as rod or ball mills are characteristically nonselective in their operation in that all material fed to a mill is ground to some extent. This is unfortunate when the object of comminution is liberation, for not only is energy expended in breaking pure gangue particles wasted, but, since gangue is frequently the predominant phase, the opportunity for such loss is great. Ideally, in this application a comminuting device should develop fracture only in locked particles. In the present investigation an attempt was made to use the large density difference which may exist between minerals to prevent comminution of one while grinding the other. EXPERIMENTAL MATERIALS AND EQUIPMENT The two minerals used in this work were -8-mesh galena and -8+ 20-mesh quartz. All tests were made on 2000-g charges containing 50 pct by weight of each mineral. Heavy media suspensions consisted of -100-mesh ferrosilicon in water. For grinding, a laboratory mill 10 in. diam by 12 in. long was filled to about 30 pct of its volume with either a ball or a rod charge. The balls ranged in size from 3/8 to 1 1/8 in. in diam; the rods ranged from 5/8 to 1 1/4 in. diam by 11 in. long. EXPERIMENTAL PROCEDURE In all tests employing heavy media, the ground pulps were treated as follows: 1) After recovering the ground charge from the mill but before drying, the pulp was wet screened on 200 mesh. 2) After drying the + 200-mesh product from step 1, the ferrosilicon was removed magnetically. 3) The nonmagnetic quartz and galena product from step 2 was sized on 10-mesh through 200-mesh screens. 4) The mineralogical composition of each screen fraction was determined by measuring its specific gravity. The specific gravity was related to the weight of galena in the fraction through the relationship

Jan 1, 1961

By AIME AIME

STEADY advance has been made in the art of lead smelting and refining during the year. The bringing of natural gas to the Salt Lake valley has led to its adaptation to lead smelting operations. The Tooele plant of the Anaconda Copper Mining Co. has put into practice the high blast pressure and constant volume for lead blast furnaces, which we understand was first advanced by John F. Austin. It would appear that within limits, capacity is nearly proportional to the volume of air. If the charge is dense, a constant pressure, as in the old practice. did not get much air through the charge and the furnace slowed up. The constant volume idea makes the charge smelt at the same rate as if the charge were porous. The cost of a little additional power insures capacity operation at all times.

Jan 1, 1932