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By N. A. D. Parlee, I. D. Shah

THIS communication reports the results of some work done on the effect of gold, palladium, and platinum on the liquid-gas-solid equilibrium in the Ag-O system,1,2 see Fig. 1. Recently several investigators3, 4, 5 have reported the effects of gold, palladium, platinum, and copper on the solubility of oxygen in liquid silver. This communication represents only a portion of the work done here on the solubility of oxygen in liquid silver and liquid Ag-Au, Ag-Pd, and Ag-Pt alloyss—the greater part having already been reprted. The apparatus, materials, and procedures used were similar to those of earlier work.' l The main precautions observed in obtaining these freezing points at constant temperature and PO2 = 1 atm were as follows: 1) The points were approached very slowly from higher temperatures. 2) In the very near vicinity of the L-G-S equilibrium point precautions were taken to see that the melt was in equilibrium with oxygen at one atm. Equilibrium was considered to have been attained when no more absorption of oxygen was observed in the last 15 min at a fixed temperature. 3) In the case of these alloys, the freezing point of the melt at 1 atm of oxygen and the equilibrium amount of oxygen absorbed by the liquid "infinitesimally" above this point were determined by lowering the temperature in very, very small steps, equilibrating at

Jan 1, 1969

By Sidney A. Swensrud

The 24-in. crude-oil line. and- the 20-in. petroleum-products line, built as a war emergency by the United States Government and running from points in Texas to the New York-New Jersey-Philadelphia area, were constructed only because of the inability during the war to continue nor-inal ocean tanker movements from the Gulf Coast to the East Coast. The postwar disposition of these lines may be considered as one of the important problems of the postwar readjustments in the oil industry, if not the most important one. In the first place there appear to be many complications in keeping the lines in crude-oil or petroleum-products service. This conclusion was reached also in a study by T. E. Swigart, President of Shell Pipeline Corporation.' Since the lines are too largc for any one company to utilize, and since it appears likely that a surplus rather than a deficiency of tankers will exist after the war, most companies probably will feel that they can achieve lower costs and more satisfactoiy results from the resumption of tanker movements to the East Coast rather than by endeavoring to take over or utilize the capacity in the large pipe lines under some tariff-rate structure. As for using the lines for making deliveries to the middle west or central eastern areas, it would appear that when the war is over and normal transportation arrangements can be resumed, there will be no need of any extra capacity for such deliveries. Therefore, the War Emergency lines could be utilized for this purpose only if privately owned pipe lines and other transportation facilities were to be displaced. Against this rather unprepossessing prospect for use in petroleum or product service is the fact that at or near the source of the lines lie the greatest developed gas reserves in the world, for much of which there is at present no satisfactory market outlet; and at the other end of the lines lies one of the greatest concentrations of population in the world, which is not now served by natural gas. These who have been fortunate enough to use natural gas can have little doubt of its desirability as a domestic fuel. An analysis of the market potentialities and comparison with other areas where natural gas is being distributed, and where it has displaced manufactured gas, makes it seem clear beyond question that the full capacity of both of the large-diameter lines could be fully utilized in this service, and this without creating any undue drain upon the gas reserves of the nation. On the basis of an estimated capacity of roo to 120 billion cubic feet per year, the gas that might be marketed through these lines would amount to only 3 to 4 per cent of the total con-

Jan 1, 1944

By Sidney A. Swensrud

The 24-in. crude-oil line. and- the 20-in. petroleum-products line, built as a war emergency by the United States Government and running from points in Texas to the New York-New Jersey-Philadelphia area, were constructed only because of the inability during the war to continue nor-inal ocean tanker movements from the Gulf Coast to the East Coast. The postwar disposition of these lines may be considered as one of the important problems of the postwar readjustments in the oil industry, if not the most important one. In the first place there appear to be many complications in keeping the lines in crude-oil or petroleum-products service. This conclusion was reached also in a study by T. E. Swigart, President of Shell Pipeline Corporation.' Since the lines are too largc for any one company to utilize, and since it appears likely that a surplus rather than a deficiency of tankers will exist after the war, most companies probably will feel that they can achieve lower costs and more satisfactoiy results from the resumption of tanker movements to the East Coast rather than by endeavoring to take over or utilize the capacity in the large pipe lines under some tariff-rate structure. As for using the lines for making deliveries to the middle west or central eastern areas, it would appear that when the war is over and normal transportation arrangements can be resumed, there will be no need of any extra capacity for such deliveries. Therefore, the War Emergency lines could be utilized for this purpose only if privately owned pipe lines and other transportation facilities were to be displaced. Against this rather unprepossessing prospect for use in petroleum or product service is the fact that at or near the source of the lines lie the greatest developed gas reserves in the world, for much of which there is at present no satisfactory market outlet; and at the other end of the lines lies one of the greatest concentrations of population in the world, which is not now served by natural gas. These who have been fortunate enough to use natural gas can have little doubt of its desirability as a domestic fuel. An analysis of the market potentialities and comparison with other areas where natural gas is being distributed, and where it has displaced manufactured gas, makes it seem clear beyond question that the full capacity of both of the large-diameter lines could be fully utilized in this service, and this without creating any undue drain upon the gas reserves of the nation. On the basis of an estimated capacity of roo to 120 billion cubic feet per year, the gas that might be marketed through these lines would amount to only 3 to 4 per cent of the total con-

Jan 1, 1944

By J. H. Frye, R. M. Treco, J. W. Caum

IT has been suggested that: "Insofar as the hardening due to a solute depends upon the increase of lattice parameter produced by it, it is reasonable to suppose that this hardening might be related to the resistance which the pure solvent would offer to increase in its parameter."1 It was further suggested that this hypothesis might be examined by comparing the hardnesses of analogous silver and copper alloys, since the stress necessary to produce a given lattice expansion is quite different in the two metals. Suitable data 2,3,4 are now available on these alloys, and we shall proceed to an examination of the hypothesis quoted above. HARDNESS, LATTICE PARAMETER AND IONIC OVERLAP Increase in ultimate Meyer hardness has been plotted against increase in lattice parameter in Figs. I and 2, It is believed that most of the values are accurate within the limits indicated by the rectangles, These data are also presented in Table I. Ultimate Meyer hardness, Pu, is defined by the equation: [P" - D2] where L = load, D = diameter of an impression having the same diameter as the testing ball, which in this case is 4 mm. Increase in lattice parameter is defined as the difference between the lattice parameter of the solid solution and that of the pure solvent. The curves in Figs. I and 2 are based on equal solute concentration and an equal degree of plastic deformation pro¬duced by the testing ball. Hardnesses are corrected to a constant grain size for copper and silver alloys, respectively, and these two grain sizes are approximately equal. Furthermore, all solutes are from the same period of the B subgroup of the periodic table as their solvent. [ ] The question arises as to whether or not lattice parameter is the only factor controlling the hardness of these alloys. There

Jan 1, 1943

By C. Kremer Bain

UNDER present economic conditions the necessity of mechanizing the mines of our country has become a very important problem. More and more mines are looking toward increased or complete mechanization of their operations, so in the writer's opinion it is quite pertinent that some of the associated problems that accompany such a program be pointed out. The following generalization on attempting a comparatively slight change in mining methods at the Southeast Missouri properties of the St. Joseph Lead Co. is an attempt to point out to anyone faced with a mechanization program that much time and C. KREMER BAIN, Member AIME, is Assistant to General Manager, St. Joseph Lead Co., Bonne Terre, Mo. AIME Sun Francisco Meeting, February 1949. TP 2743 A. Discussion (2 copies) may be sent to Transactions AIME before March 31, 1950. Manuscript received Dec. 27, 1948; revision received Oct. 13, 1949. effort can be saved, and many headaches avoided, if company policy can be established whereby everyone in the organization from the top down is desirous of improvement and is working towards the common objective. Any changes in mining methods, machinery, and so on, must entah coordination of all the other phases of mining as they all have to mesh as accurately as a smooth running chain of gears if satisfactory results are to be obtained. The purpose of this paper is to point out some of the problems which :have to be surmounted when any mechanization program is attempted, rather than to go into the mechanical details and actual operating data of the equipment employed. After all, machines have to be adapted to best suit the local conditions, so no general formula can be given that would apply to other properties. Although St. Josepll Lead Co. has been mechani-cally-minded for a number of years, as shown by the fact that over 110 million tons have been loaded mechanically since 1922, any further mechanization or changes always present a problem. When our ore bodies were of great height and area the breaking and loading were developed to a high degree of efficiency according to known standards. But in recent years, when our ore bodies became smaller and more scattered, the amount of tonnage we were able to break was not sufficient to supply our shovels with enough rock to keep them working to capacity. Our first step in attempting to rectify this situation was to develop a technique of moving the shovels to the broken ore in various stopes, which sometimes entailed a move each shift. A shovel is not producing when being moved, so within the last two years we have been endeavoring to devise some means of getting more rock broken in these smaller stopes and it was then that we became interested in jumbo drilling. To illustrate the fact that mechanization is a process of a chain of developments rather than a stroke of genius can best be shown by a general summary of conditions and obstacles which were encountered in our present attempt to establish template drilling of a standardized round. Our first jumbo was more or less the conventional type with two machines mounted on a crossbar. This arrangement proved to be impractical to duplicate satisfactorily the regular routine of slabbing in a more or less radial pattern as carried out by column drilling. One machine was either too close to or too far from the face and there was another disadvantage in that one drillman was frequently delayed while waiting for his partner to bottom a hole. Our next step was to eliminate the crossbar so the machines could operate independently of each other, but we still encountered the same objections mentioned above except that one drillman was free to drill three holes instead of one in a vertical plane independently of his partner. Time studies while trying to adapt the jumbo to the regular slabbing practice as accomplished by column drilling, revealed that twice as much time was spent in maneuvering the jumbo into position and aligning the holes as was consumed in drilling.

Jan 1, 1951

By C. Kremer Bain

UNDER present economic conditions the necessity of mechanizing the mines of our country has become a very important problem. More and more mines are looking toward increased or complete mechanization of their operations, so in the writer's opinion it is quite pertinent that some of the associated problems that accompany such a program be pointed out. The following generalization on attempting a comparatively slight change in mining methods at the Southeast Missouri properties of the St. Joseph Lead Co. is an attempt to point out to anyone faced with a mechanization program that much time and C. KREMER BAIN, Member AIME, is Assistant to General Manager, St. Joseph Lead Co., Bonne Terre, Mo. AIME Sun Francisco Meeting, February 1949. TP 2743 A. Discussion (2 copies) may be sent to Transactions AIME before March 31, 1950. Manuscript received Dec. 27, 1948; revision received Oct. 13, 1949. effort can be saved, and many headaches avoided, if company policy can be established whereby everyone in the organization from the top down is desirous of improvement and is working towards the common objective. Any changes in mining methods, machinery, and so on, must entah coordination of all the other phases of mining as they all have to mesh as accurately as a smooth running chain of gears if satisfactory results are to be obtained. The purpose of this paper is to point out some of the problems which :have to be surmounted when any mechanization program is attempted, rather than to go into the mechanical details and actual operating data of the equipment employed. After all, machines have to be adapted to best suit the local conditions, so no general formula can be given that would apply to other properties. Although St. Josepll Lead Co. has been mechani-cally-minded for a number of years, as shown by the fact that over 110 million tons have been loaded mechanically since 1922, any further mechanization or changes always present a problem. When our ore bodies were of great height and area the breaking and loading were developed to a high degree of efficiency according to known standards. But in recent years, when our ore bodies became smaller and more scattered, the amount of tonnage we were able to break was not sufficient to supply our shovels with enough rock to keep them working to capacity. Our first step in attempting to rectify this situation was to develop a technique of moving the shovels to the broken ore in various stopes, which sometimes entailed a move each shift. A shovel is not producing when being moved, so within the last two years we have been endeavoring to devise some means of getting more rock broken in these smaller stopes and it was then that we became interested in jumbo drilling. To illustrate the fact that mechanization is a process of a chain of developments rather than a stroke of genius can best be shown by a general summary of conditions and obstacles which were encountered in our present attempt to establish template drilling of a standardized round. Our first jumbo was more or less the conventional type with two machines mounted on a crossbar. This arrangement proved to be impractical to duplicate satisfactorily the regular routine of slabbing in a more or less radial pattern as carried out by column drilling. One machine was either too close to or too far from the face and there was another disadvantage in that one drillman was frequently delayed while waiting for his partner to bottom a hole. Our next step was to eliminate the crossbar so the machines could operate independently of each other, but we still encountered the same objections mentioned above except that one drillman was free to drill three holes instead of one in a vertical plane independently of his partner. Time studies while trying to adapt the jumbo to the regular slabbing practice as accomplished by column drilling, revealed that twice as much time was spent in maneuvering the jumbo into position and aligning the holes as was consumed in drilling.

Jan 1, 1951

The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is .desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 6, 1917

By Shosei Serata

Conventional roof bolting may be giving ground to a new technique that utilizes only the ground itself to stabilize mine openings. This newly developed stress control technique (SCT) has initially been used in sedimentary ore bodies that are both overlain and underlain by weak strata. The technique is also suited to the design of production panels and main entry systems, and is readily adaptable to room and pillar as well as total- extraction mining, including both shortwall and longwall coal mining. In applications where the technique has been used, the requirements for roof bolting and floor renewal were virtually eliminated. The SCT comprises three basic methods and covers a wide range of problems associated with failing roofs and heaving floors in underground mines (see Table 1).

Jan 5, 1976

By J. M. Dumore

If in a vertical, downward miscible displacement, the transition zone between the displacing and displaced fluids is neglected, a criterion for stable displacement can be obtained by considering a small hypothetical protrusion of one of the fluids into the other. This criterion leads to the definition of the well-known critical rate, uc = kg p/p. The consideration is further extended by taking into account the transition zone that develops as a result of diffusion and mixing. A generalization of the previous criterion leads to the definition of another characteristic rate, the stable rate, which in actual miscible drives will be less than the critical rate. In such drives, the entire transition zone is stable at rates less than the stable rate. At rates between the stable and critical rates, the displacement is only partly stable, i.e. part of the transition zone adjacent to the displaced fluid is in an unstable position. From that part of the transition zone viscous lingers will develop. At rates greater than the critical rate the entire displacement is unstable and viscous lingers will develop more strongly. Results of laboratory experiments are in agreement with the expected behavior based on the theoretically deduced stability of the displacement. INTRODUCTION The simplest form of miscible drive in an oil-bearing formation is the injection of a fluid that is completely miscible* with the oil under reservoir conditions. In general, such a fluid, a solvent for example, is less dense and less viscous than the oil present in the formation. If it is injected into a horizontal homogeneous layer, gravitational forces will lead to the formation of a gravity tongue of solvent in the upper part of the layer and the adverse solvent-oil viscosity ratio will cause viscous fingers to develop. If, however, the solvent is injected up-structure into ,a dipping layer, gravity has a favorable effect, because it tends to keep the less dense solvent up-structure. Tongue formation and viscous fingering are consequently reduced and it is even possible that they will be suppressed completely. Viscous fingering and gravity tonguing are the consequences of the instability of the displacement. A stable displacement cannot result in growing viscous fingers and/or growing gravity tongues. Since large amounts of oil can be bypassed if there is viscous fingering and/or gravity tonguing, the stability of a miscible drive is very important with respect to the recovery efficiency of the drive. The stability is of particular importance in miscible-slug drives, as it determines how quickly the miscible slug between the displaced and displacing fluids will be distorted and broken up, after which the drive is no longer completely miscible. Stability is thus a most important factor in determining the success of a miscible drive, and it is considered that the aspects of stability considered in this paper will make a useful contribution to existing theories. Consideration is given only to vertical downward displacements, in which no gravity tongues can develop and which are therefore simpler than downward displacements in sloping layers. THEORY CRITERION FOR STABLE DISPLACEMENT Let us consider a vertical column of a homogeneous permeable medium saturated with oil. A solvent less dense and less viscous than the oil is injected at the top of the column at a constant rate; in the column the velocities of oil and solvent are assumed to be uniform. Diffusion and mixing of oil and solvent will at first be neglected, i.e. we assume that solvent and oil are divided by a sharp interface. An additional assumption is that the interface is horizontal. Continuity of pressures exists at the interface, because no capillary forces are present between the two miscible fluids. Consequently, at the interface (Z = I)):** Ps = Po - P-where Ps is the pressure at the solvent side and

Jan 1, 1965

By J. Chipman, N. J. Grant, R. Rocca

D. E. Babcock (Republic Steel Corp., Youngstown, Ohio)—With reference to eqs 7 and 8, at what temperature do they apply John Chipman (authors' reply)—That was 1600°C. Dr. Babcock—You have l x 10-4 as the component for the lime and 1 or 4x10-. Now, is it by dividing one into the other you get the 400? That is assuming equivalent activity on the part of oxygen, sulphur, and magnesia. Dr. Chipman—Yes, they are calculated for 1600. Now, the first one for CaO was calculated before we had a glimpse of Dr. Rosenqvist's paper." If you take his calculation you get 14,000 cal which is very good agreement, but our calculation would be superseded by Dr. Rosenqvist's new data. Dr. Babcock—The state you assume those to be in is the liquid state, as near as you can measure? Dr. Chipman—Naturally it is based on the solid CaS, but if you add the effect of fusion on both sides it just about balances out, so the ratio would be about the same. B. M. Larsen (U. S. Steel Co., Kearny, N. J.)—If we knew the activity of sulphur in the slag instead of merely the percentage, we might be able to find some conflicting factors that balance one another out, and find that the FeO or oxygen pressure effect is really present over the whole range. Dr. Chipman—I am fairly sure we would. The activity of sulphur in the slag and the activity of CaO in the slag, if we just knew those quantities, would enable us to save a lot of this computation and assumption and all the approximations we are doing now. Mr. Larsen—Two other points perhaps should be included: 1—an independent effect of manganese in helping the desulphurization; and 2—the number of mols of constituents or number of mols of ions or whatever there is in the slag could vary with these compositions in such a way that you get dilution effects. Dr. Chipman—You can figure all that in if you want to and it might improve the degree of approximation a little bit. Maybe enough to justify the labor of calculation, inaybe not, but we did not do it. L. S. Darken (U. S. Steel Co., Kearny, N. J.)—The authors have tackled a very complicated problem in trying to tie together in one picture the desulphurizing problem over the wide range of basicity and oxidation level from that of the open hearth to that of the blast furnace. At the present state of our knowledge of slags such an ambitious undertaking necessarily involves the adoption of numerous hypotheses. Their formulation (eq 11) for the higher FeO range

Jan 1, 1952

By R. P. Thomas

Secondary fertilizer minerals are the mineral materials used to supply directly and indirectly the secondary and trace plant food nutrient needs of a fertilizer. Since few soils contain sufficient availability of all plant nutrients for their proper growth, man has prepared mixtures of plant food materials to correct these nutrient deficiencies. These mixtures or fertilizers, when added correctly to a soil, make it possible for abundant and economic crop growth. Many kinds of materials are used as sources of these needed nutrients. They come from natural and synthetic materials and minerals including many beneficiated byproduct compounds. A fertilizer consists largely of carriers of one or more of the three major plant foods, namely nitrogen (N), phosphorus-phosphorus pentoxide (P2O5) and potassium-potash (K2O). Many other nutrients are just as essential for plant growth as the three major plant foods. In fact, the efficient use of fertilizers today depends upon an adequate supply of all these other nutrients. Since these additional materials are usually removed from the soil by plants and supplied in fertilizer in less quantities than the major nutrients, they are called secondary and minor nutrients. In the early days these special nutrients were contained as impurities in the primary nutrient carriers. Today, fertilizers are made primarily from concentrated and synthetic materials which carry very few of these other essential nutrients. Consequently, many secondary and trace nutrient carriers, as salts, byproduct compounds and even minerals have to be added to fertilizers. Secondary Nutrient Carriers The secondary plant foods in fertilizer are next to the major nutrients in abundance. They are calcium, magnesium, sulfur, chlorine, silicon and sodium. Although many of these elements are added to a fertilizer as part of the major nutrient carriers, they are also added in special carriers. The large tonnage of these secondary nutrient carriers used in fertilizers represents only a small percentage of the total production of these materials. A fertilizer producer thinks in terms of materials which supply nutrients instead of minerals. Therefore, these materials will be discussed by elements. CALCIUM Soils need calcium to supply the nutrient needs of plants and maintain the desired physical and biological conditions in the soil. The available calcium is usually 40 to 80 pct of the exchangeable bases. (These bases are ones which can be displaced by other cations and determined quantitatively. They are then expressed as milliequivalents per hundred grams of soil-me.) Direct applications of lime materials such as burnt, ground or hydrated limes are the important sources of calcium for the soil. Most crops, especially legumes, have a high requirement for calcium. The average farmer does not use enough lime to maintain the proper level of available calcium. Hence, it is necessary for many fertilizers to contain soluble calcium materials for efficient use of the major nutrients. The following major nutrient carriers supply some calcium: calcium nitrate, ammonium nitrate mixtures and cyanamid, and many of the phosphates. Both synthetic and natural gypsum are used in fertilizer production. Some crops such as peanuts require a large amount of soluble calcium. Gypsum is the important supplier of this soluble calcium. It is not applied with the fertilizer

Jan 1, 1960

By Graham Swan, Ove Alm

In-situ fracture toughness experiments have been performed with a scanning electron-microscope. The rock, Stripa granite, was loaded both in tension and three-point bending using the same size notched plates. Observations, which included crack extension measurements as a function of load, are presented in the form of R-curves. The data does not sup- port the proposition that R-curves can be regarded as independent of specimen configuration for this granite. Typically crack extension was seen to begin at loads of 70-80 % failure load. Tensile specimens showed considerably greater sub-critical crack growth than the bend specimens. Evaluation of the approximate fracture toughness Km for both specimen types produced as expected erroneously low estimates Of KIC, being worst in the case of the tensile specimen. Some crack extension data for Stripa granite using the indirect methods of compliance calibration, fluorescent dye penetrant and acoustic emission are compared. In a material such as Stripa granite it is considered that no single method is without its limitations.

Jan 1, 1982

By John S. Brock

INTRODUCTION The Oxford Dictionary says that the word "promoter" has usually been used in an opprobrious sense since at least 1876. This popular image of mining promoters is of cigar-chomping shysters and Brooklyn-Bridge vendors, improving their standard of living with the aid of funds raised through the sale of stock to little old ladies. It is unfortunate that mining promoters are considered crooks until they can prove their integrity and honesty by finding a mine. A common rule of thumb states that for every 1,000 prospects, 100 come to be drilled, and one becomes a mine. However, it is also a statistic that there have been mining promotions, where money raised has gone elsewhere than into the ground; Junior exploration companies can be handy vehicles for unscrupulous financial activity. One must remember though that every stock exchange has had its share of sound mining promotions that, because of the one in 1,000 odds, have failed for legitimate reasons. The promoter must be able to rationalize the worth of a mineral discovery which, on an industry- average basis, probably cost more to find than the discounted value of its net return, which return is not an assured percentage of invested capital, and furthermore, is ultimately from a wasting asset. So, it is easy to understand why the promoter must constantly justify the credibility of his operation to his grubstakers during the course of the "five phases of exploration," those being (1) euphoria, (2) disillusionment, (3) search for the guilty, (4) punishment for the innocent, and (5) distinction for the uninvolved. The promoter with the exploration organization that does not have the benefit of positive cash flow, by definition for the sake of this article, works for a promotional outfit, a Junior Company, that must raise its exploration budget from a variety of sources. Promotion, as discussed here, will not entirely refer to the formation and operation of a joint- stock company but rather to the overall methods of raising risk capital for mineral exploration ventures from outside sources. THE NECESSITY OF PROMOTION In Canada, the publicly financed Junior Company has had an enviable record of mine-finding success. In the Province of British Columbia alone, the discovery of fifteen out of twenty-four mines has been as a result of the activity of the Junior Company (B. C. & Yukon Chamber of Mines, 1977). In the Province of Ontario, one research study indicated that between 1951 and 1974 the 'Juniors' spent only 28 percent of the total exploration funds but were responsible for 62 percent of all economic discoveries (Freyman, 1978). The reasons for the success of the Juniors are tied to a variety of factors, the main one being personal initiative based on incentive. In other words, the principals, or their employees have 'a piece of the action.' The smaller companies can operate faster and more efficiently than their larger counterparts. The Junior Company is also destined to take some bigger risks, the 'long shots,' many of which efforts by virtue of the Junior's perseverance coupled with a touch of 'ore is where you find it' philosophy, result in major discoveries. The individuals, syndicates, private and publicly financed Junior Companies, because of high costs of exploration and development, cannot hope to finance most mineral prospects all the way to production. Exceptions do exist, those being the lower capital cost, small, high-grade deposits. Private investors and publicly financed Junior companies, therefore, can usually afford to finance most exploration through the initial drill-testing stage. The major resource company will enter a mining deal with a Junior Company usually by way of option or joint venture agreement, and will finance to production to earn an equity in the prospect or the Junior Company or both. The conventional lending institutions, banks and government agencies, will usually only participate through loaning a portion of capital

Jan 1, 1985

By J. C. Irvine

The down-the-hole drill is becoming a more common tool in today's underground mining scene. New drilling capabilities and efficiencies are being derived as experience is gained. Ancillary equipment and bits are becoming increasingly important parts of the concept. This paper describes some presently used units; underground down-the-hole drilling units.

Jan 1, 1978

By R. B. Gilmore

It has been the custom of the Railroad Commission of Texas to hold hearings each month with respect to existence and imminence of waste of oil and gas in Texas and its prevention, and to issue orders restricting the production of oil to the reasonable market demands and allocating production to the various fields in Texas. The practice of designating the actual days during the month on which wells are to be shut down was discontinued in the order for November 1942, and orders issued thereafter contain only the number of shut-in and producing days for the month. Orders issued by the Railroad Commission are divided into two main subdivisions, the first a general shutdown order of all oil wells in the various fields in Texas, and second, the exception of certain fields to this general order. Table I shows the producing days for all of the fields in Texas for 1944 under the first of these classifications : The fields that have producing schedules varying from the general order may be divided roughly into three subdivisions, as follows: Table 2 shows the producing days for certain fields that were prorated as a group throughout 1944. Other fields which were occasionally included with this group were also prorated under the general order and by special orders. The producing days for these irregular fields are shown in Table 4. In Table 3 are listed fields that were exempted from any shutdown days during December 1944, the majority retaining this exception throughout 1944. Certain fields included in the general order were added to this group on the first day of the month shown.

Jan 1, 1945

By Eugene McAuliffe

SINCE 1917, the bituminous coal industry has surged, violently at times, across the nation's social, industrial and economic foreground. To-day a silent, yet more active, force is working within the industry, and the movement now taking place, if allowed to continue, will cause serious consequences when coal is again wanted at the rate of 550,000,000 tons annually instead of at the rate of 400,000,000 tons, the apparent requirement for 1921. I refer to the shift of tonnage from the highly unionized fields of Pennsylvania, Ohio, Indiana and Illinois to the non-union fields of Pennsylvania, West Virginia, Alabama and certain western states, and to the so-called union fields in Kentucky and Colorado, on which the union saddle rests lightly. This movement, in the absence of the usual winter transportation shortage, is taking place rapidly and will be accentuated if, as is probable, work is suspended in the union mines on March 31 next. This drift of tonnage has been made possible by the unit wage reductions in the non-union fields and by the modification of the so-called conditions that have been saddled on all mines wherever the United Mine Workers have gained a foothold; these changes permitted the first reduction in mine cost, which made possible the securance of contracts; better running time assisted in making further reductions, and the transfer of ton-nage served to increase the unit cost in the field from which it was transferred. This situation not only opposes the highly unionized operation but brings about a transfer of traffic from the roads serving such mines to those that serve in a primary or secondary manner the more favored localities. The net result is evidenced in (a) the migration of union labor to the non-union mines; (b) the deteriora-tion and decadence of union properties; (c) the neces-sary curtailment in the purchase of new equipment and in the maintenance of existing equipment and track facilities on the part of the carriers serving the union fields. This, in turn, when business is restored to normal or to the point above normal that invariably follows an adverse swing of-the business pendulum, will cause (d) a shortage of coal and coal transportation facilities; (e) an era of coal speculative debauchery with exorbitant prices and serious deflection in the matter of quality; (f) a period of labor unrest followed by de-mands for increased wage rates supplemented by a marked loss in individual efficiency, with, resultant strikes, business unrest, and the pressure of new eco-nomic theories. In 1918, the labor status with respect to relative tonnage produced was approximately as follows: pro-duced in highly organized fields, 62 per cent.; produced in partly organized fields, 21 per cent.; produced in unorganized fields, 17 per cent. During the strike of November and December, 1919, the mines that remained at work attained 35 per cento of the nominal production of soft coal, a situation made possible by the migration of union labor to non-union mines and the concentration of the nation's coal trans-portation facilities on the rails of the carriers serving the non-union fields. The history of the efforts made by the carriers to untangle the car scrambling which took place during this period and which sent the self clearing battleship type of car into western territory where it could not be readily unloaded, and the western gondola type of car to New England and the seaboard, is yet painfully recalled. -This confusion proved a serious factor in the coal car shortage that continued throughout the following year. We are drifting toward a similar situation now, propelled by economic forces rather than by a sudden strike.

Jan 1, 1922

By W. D. Forgeng, R. E. Grace

The rate of copper corrosion in liquid lead was studied as a function of flow rate and temperature in a closed isothermal loop system between 350" and 500°C. Kinetic data were interpreted with the Nernst-Brunner equation and the Chilton-Colbum mass transfer analogy to heat transfer. Over the range of temperatures and flow rates employed the solution rate constant varied from 2 x 10-3 to 20 x 10-3 cm per sec. The rate constant was found to vary with the 0.76 power of the Reynolds number in the range 7500 < Re < 40,000. The results of this investigation indicate that the Cu-Pb corrosion process is controlled largely by diffusion across a boundary layer. particularly at the higher temperatures. The effective boundary layer for diffusion is found to be approximately three to four times smaller than the momentum boundary layer. CORROSION by liquid metals has long been a problem during melting, static containment, and casting. Recently, considerable emphasis has been placed on the understanding of liquid metal corrosion mechanisms in an effort to prevent mass transfer and eventual failure in liquid metal heat exchangers and in liquid-metal-fueled nuclear reactors. The present investigation was conducted to determine the relationships which exist between corrosion kinetics and hydrodynamic conditions in an isothermal loop containing a simple liquid metal-solid metal corrosion system. The Cu-Pb system was chosen for its simplicity and ease in handling. Previous isothermal Cu-Pb corrosion studies1-3 have been conducted in both static and dynamic systems but not under conditions which allow easy "scale-up" to engineering systems, such as liquid metal heat exchangers. On the other hand, most liquid metal loops which have been used to evaluate mass transfer rates4 have been driven with temperature gradients under conditions of natural convection and unknown flow rates. The primary contributions of this research are twofold: 1) to evaluate the design of a simple isothermal loop corrosion system and 2) to investigate liquid metal corrosion behavior under well-defined hydrodynamic conditions. MATERIALS AND EXPERIMENTAL WORK The apparatus used to measure the Cu-Pb corrosion rates is shown schematically in Fig. 1. The loop system consisted of 1) a reservoir made of Type 316 stainless steel containing a centrifugal pump and 2) stainless-steel tubing containing a removable copper test section. The copper test section was OFHC hard-drawn tubing, 11.0 0.05 cm in length and 0.775 ±0.005 cm ID. A Type 316 stainless-steel venturi meter* was inserted in place of the copper test sec- tion in order to determine the lead velocity as a function of pump speed at each temperature. The Cu-Pb system was chosen for this study because the solubility of copper in liquid lead is large enough to measure accurately but small enough that the diameter of the copper tubing was not changed significantly by corrosion. There are no intermediate phases formed in the system, and the solid solubility of lead in copper is vanishingly small so that back-diffusion cannot occur. Molten lead (corroding grade; 99.94+ pct Pb, 0.0015 max pct Cu) was charged from an auxiliary melting furnace into the system under an argon cover to minimize oxidation. The lead was then maintained at constant temperature by a stirred molten salt bath in which the loop was immersed to a depth just above the lead level in the reservoir, Fig. 1. The total volume of lead in the system was 320 2 cu cm.

Jan 1, 1969

THE Institute assembled on Tuesday evening, October 24th, in the hall of the Franklin Institute, Mr. Frank Firmstone, VicePresident, in the chair. Mr. J. Price Wetherill, of Tremont, Pa., read a paper on An Outline of Anthracite Coal Mining in Schuylkill County, Pa. The paper was discussed by Messrs. Coxe, Rothwell, Heinrich, Harden, and Symons. The second session was held on Thursday evening. Mr. A. L. Holley, Chairman of the International Committee, appointed by the Institute to consider the nomenclature of iron and steel, offered the following report of the committee, signed by all the members: WHEREAS, The recent production of soft, cast, malleable compounds of iron by the Bessemer, the Siemens-Martin, and the crucible steel processes appears to demand a new nomenclature of iron compounds, for the following reasons: 1st. The term "steel," by which these soft products are commercially and professionally designated in England and in the United States, does not completely distinguish them from previously existing "steel which would harden and temper. 2d. A nomenclature recognized in all languages seems desirable, as well for commercial as for scientific purposes, especially as lawsuits, already commenced, depend on the meaning of the term " steel." 3d. Although homogeneity, due to fusion, is usually recognized, and is by this committee recognized as the most definite characteristic of both hard and soft steel, this quality may be equally well expressed in other terms, thus leaving the old term, " steel," to define the malleable compounds of iron, which will harden and temper. Therefore, resolved, That this committee recommends the following nomenclature : 1. That all malleable compounds of iron with its ordinary ingredients, which are aggregated from pasty masses, or from piles, or from any forms of iron not in a fluid state, and which will not sensibly harden and temper, and which generally resemble what is called " wrought iron," shall be called Weld Iron (German, Schweisseisen; French, fer soudé). 2. That such compounds, when they will from any cause harden and temper, and which resemble what is now called puddled steel," shall be called Weld Steel (German, Schweiss stahl; French, acier soudé).

By E. M. Frizzell

Introduction In 1956, the first mobile crusher was installed in a limestone quarry in Hover, Germany. These early mobile crushers solved the problem of wet and soft ground conditions that did not permit the use of haulage trucks due to the high cost of building and maintaining the haulage roads. Quarry operators also wanted to take advantage of continuous belt conveyor haulage systems and the resulting cost savings. European mines, particularly the coalfields, are in soft materials that allow use of bucket wheel excavators and their following continuous haulage system of belt conveyors. Quarry operators, with this background knowledge of belt conveyors in mining, easily accepted the conveyor concept, once in-pit mobile crushing solved the problem of size reduction of mine-run-rock required for conveyor application. Four years after the initial mobile crusher installation, the first report published on the subject appeared in the December 1960 issue of Mining Engineer (Kochanowsky, 1960). With this early background and basis for direction, mobile in-pit crushing and conveying have increased to more than 74 installations. The capacity, type of crusher, and material being processed appear in Table 1. These data in Table 1 indicate that experience to data has been heavily influenced by limestone installations of less than 1 kt/h (1102 stph). Most of these installations were directly fed by a mine face excavator because of the limestone quarry ground conditions. Crusher Configurations Crushers systems developed to date have varying mobility capabilities. These range from fully mobile units that are used continuously in this mode to fixed, permanently located in-pit crushers. The following terms are presented to help distinguish the range of mobility within the configurations of "mobile" crusher systems planned or now in use. Mobile Crusher The crusher works at the mine face, is directly fed by an excavator, and moves in unison with the excavator on its own transport mechanism as the mining progresses. An example is the unit delivered in 1976 to Yamama Cement Co. in Reyadh, Saudi Arabia.

Jan 1, 1986

By T. V. Subrahmanyam, A. P. Rao

The adsorption behavior of chalcopyrite has been studied at different xanthate concentrations and flow rates in a column apparatus with potassium ethyl xanthate as the collector. Based upon the experiment results an equation of the type: 1/F = K3 + m3C + k2/t.Cm2.fm1 is proposed to account for the experimental data. Among copper minerals an early study on chalcocite by Gaudin and Schuman (Taggart, 1951) is well known for its research on the kinetics of the reaction by conventional method of mass balance between the products of reaction and xanthate consumed. The results were interpreted by the concept of ion exchange adsorption. Szeglowski (1977) conducted measurements on the adsorption of potassium ethyl xanthate on copper polarized to various potentials, the adsorption being measured by radio-tracer techniques. The adsorption in the range -1800 to 700 mv was found to be a reversible physical adsorption. The potential range in which the primary electrode process could lead to surface coverage with a minimum number of product layers was evaluated. The adsorption density of xanthate on sulfide surface was found to be related to the concentration of xanthate in solution and concentration of depressants as: [ ]

Jan 1, 1983