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By Malcolm C. Bridges, Ian A. Goddard

INTRODUCTION Mount Isa mine is a major producer of both copper and lead-zinc- silver ores. During the 1975/76 year, 4.3 million tonnes of copper ore were extracted at an average grade of 3.4%, and 2.4 million tonnes of lead-zinc-silver ore at average grades of 7.0%, 6.7% and 173 grams per tonnes respectively. Systematic lead-zinc mining has continued for just over 45 years and copper mining for just over 30 years. Virtually all mining is underground. The composite and somewhat schematic longitudinal section of Figure 1 shows the overall distribution of ore at the Mount Isa mine. The mine can be roughly divided into two parts about a central shaft complex: to the north there is predominantly lead-zinc ore and to the south there is copper ore. Underground operations are serviced by three shafts in the central shaft complex (P61, R62 andU62) and another to the south in the copper mining area (X41). Mining is spread over a total strike length of 2.9 km and extends to a depth of 960 m. Currently, lead-zinc ore is being extracted between 15 and 11 levels and is hauled to the central ore-hoisting shaft on 13 and 15 levels. Copper ore is being extracted between19 and 13 levels and is hauled to the central shafts on 19 level. The principal lead-zinc mining methods used now, as they have been over the last ten years, are sublevel open stoping and cut-and- fill stoping, with about equal tonnages of ore from each (Figure 2). Since about 1970, there have been several interesting developments in lead-zinc mining methods and procedures, principally: • the development of an effective method for the recovery of pillars between open stopes and • the evolution of safer and more productive cut-and- fill methods. During this period also, the focus of mining has moved 120 m deeper

Jan 1, 1977

By David B. Scott

When mining operations were first instituted in the mines of the Miami Copper Co., at Miami, Ariz., the relatively hard character of the ground in the western section of the property made it seem advisable to use a wide shrinkage stope and pillar system. The system as finally evolved was applied to the mining of 2,300,000 tons of ore by the use of stopes and pillars each 50 ft. in width. Development, mining and extraction of this reserve has been continuously in progress since 1910, and the final stages of extraction are now reached. A complete survey of all phases of this system can therefore be made. Modification in working methods was obviously necessary, and the system to be described is believed to be typical of the best features. Development The preliminary work had three main objectives: The opening of a haulage level, the construction of a drawing-off level, and the driving of sublevels for use in stoping. In addition to these, some extra sublevel drifting was necessary to determine exactly the boundaries of the orebody, the general outline having been determined by churn drilling. This development was based on the requirements of stopes 50 ft. wide, with pillars 50 ft. wide between each stope. The length of these units varied from 200 to 500 ft.. Haulage Level The tramming level was 50 ft. below the floor of the stopes, and the tramming lines were run parallel with the long axis of the stopes. These lines were also beneath the middle of the stopes and pillars. Each line therefore served one stope or one pillar, this arrangement making it possible to load along an entire stope without switching or uncoupling. This advantage is apparent principally during the process of stoping when rapid drawing of excess broken ore is desirable. Furthermore, the arrangement of the drawing-off level chutes at 25-ft. intervals, as shown

Jan 1, 1917

By A. M. Gaudin, D. W. Fuerstenau

IN concentration of certain ores by soap flotation, prevention of quartz flotation is desired; the contrary is true in treatment of some oxide iron ores. Experimental study of the flotation of quartz goes back at least a quarter of a century.' Clean quartz does not float with fatty acids or soaps but does float when activated by one of many metallic salts. Control of pH is important. Broadly speaking the problem of quartz flotation has been approached from the empirical side, as was the related topic of flocculation or dispersion of quartz suspensions.' Empirical studies indicated the existence of critical relationships between the additions of collector and activator. These additions were not stoichiometric for the formation of soaps of the activator cation.

Jan 1, 1955

By R. G. Garlick, M. Garfinkle

It was observed for several bcc metal crystals that the Knoop hardness anisotropy was dependent essentially on the direction of the lung axis of the indentor alone and not on the plane of indentation. The generality of this observation was tested for an fcc md an hcp metal and an ionic crystal. For cubic crystals, this observation was valid; for the hcp structure, however, the planes of indentation did have an effect on the hardness anisotropy, although this was not nearly as significant as the direction of indentation. Because the direction of indentation is the only significant crystal-lographic parameter necessary to describe the hardness anisotropy, it is possible to represent the anisotropy of single crystals on the standard stereographic triangle. THE commonly observed1, 2 periodic variation of indentation hardness with crystallographic direction on the high-symmetry planes of various single crystals has been inadequately related to the physical or mechanical properties of the crystals examined. In fact, the hardness anisotropy curves for the various planes of a particular metal crystal, as is illustrated in Fig. 1, are uncorrelated and appear in the literature3, 4 as unrelated observations. Attempts to correlate hardness anisotropy curves with specific physical properties can be generally divided into either mechanistic or nonmechanistic approaches. A nonmechanistic approach would be to devise a mathematical expression that could describe the various hardness anisotropy curves. Such a relation could then be compared with the known anisotropy of various physical properties to determine which contribute to the observed hardness anisotropy. No such mathematical expression has been found in the literature.

Jan 1, 1969

By W. C. McClain

In the design of underground excavations, rock mechanics considerations are nearly always based on an elastic behavior of rock. Most rocks do exhibit a certain amount of elasticity, and the application of principles and concepts of elasticity to rock mechanics problems has been largely responsible for progress in the field over the past 10 or 15 years. NO doubt the theory of elasticity will remain the most useful analytical tool available for both the design of underground openings and the interpretation of phenomenological data. Dr. Cook's analysis of rock behavior based on energy considerations represents a significant new approach to mining rock mechanics problems. Although the foundations of this analysis are somewhat broader and more general than elastic analysis, the development and applications are grounded almost entirely in the theory of elasticity. It has long been known1,2 that all rocks, even granites and dense limestones, exhibit nonlinear time-dependent strain properties to a greater or lesser degree. Creep strain (that is, deformation under constant stress) in salt, potash, and trona can be several orders of magnitude greater than instantaneous elastic strain. Design of underground workings in these materials must incorporate provisions for these strains and must therefore go considerably beyond elastic analysis. Some of the principles of underground design in highly plastic materials will be discussed in this paper. Since all rocks, especially when highly fractured, exhibit a certain amount of creep-type strain, these concepts should be at least recognized in any rock mechanics problem. The discussion will be illustrated largely, but not entirely, by examples drawn from

Jan 1, 1967

By P. W. George

The rapid increase in cost of discovering new orebodies by churn drilling in the Tri-State district has led to some attempts to lessen the expense by using geophysical methods. Electrical prospecting was tried three or four years ago, but no successful results were recorded. In 1926, the Federal Mining and Smelting Co. engaged the North American Exploration Co., of Houston, Texas, to make some tests with the torsion balance. At first, it was thought that the most favorable conditions for discovery of ore deposits with the torsion balance would be in locations where the ore was known to occur at rather shallow depths, therefore the first trial was made at Ducnweg, east of Joplin, where some zinc ore had been developed at a depth of 130 ft. The gravity gradients at 61 stations on a tract of about seventeen acres indicated plainly one large zone of maximum gravity and a smaller narrow zone of minimum gravity. Fourteen churn-drill holes, half of which struck ore, show that all the ore found was located outside the zones of maximum and minimum gravity. In the zone of maximum gravity the limestone beds were closest to the surface, and the first chert beds encountered were at the greatest depth. The results (shown in Table 1) indicated that the gravity of the limestone was greater than the gravity of the fractured chert together with its orebodies, and probably also greater than the bouldery soil and clay on top of the limestone. A cross-section of the Duenweg lease is shown in Fig. 1.

Jan 1, 1929

By Don H. Baker

THE need for new or improved refractory materials has caused metal phosphides to be given renewed scrutiny. Some metal phosphides show high-temperature inertness, are exceptionally hard, and exhibit a marked resistance to chemical attack. Various metal phosphides have been prepared for study by direct combination of the elements,'-' by reaction of metal or metal compounds with phosphine or phosphorus trichloride,'"' by thermal decomposition of a metallic phosphate or phosphite,"-'8 and by molten salt electrolysis.19 Electrolytic preparation of phosphides of titanium, manganese, and chromium from their oxides is reported in this paper. An externally heated 3-in.-ID by 6-in.-deep graphite cell, that served as the anode as well as a container for the electrolyte, was used in these investigations, and a suspended, centrally positioned graphite rod served as the cathode. A closely fitting silicon carbide furnace liner minimized atmospheric oxidation of the crucible. Electrolyses were performed for predetermined periods and current settings. Preliminary research had indicated the more efficient current and potential settings that could be used. Upon completion of the deposition period, the deposit was hot-stripped from the cathode. The mass of crystalline deposit, plus occluded and adhering salt, was crushed to minus 10 mesh and hot-leached in dilute hydrochloric acid. The leached crystalline material was water-washed, dried, and sampled for analysis. Products were identified by X-ray diffraction and standard analytical procedures. Electrochemical studies were initiated to establish the optimum conditions necessary to produce manganese phosphide (MnP), titanium phosphide (Tip), and chromium phosphide (CrP). Among the factors studied were the operating temperature, the imposed current, and the electrolyte system. If the temperature, or imposed current, was too high, deposition of phosphorus resulted, and if either were too low, partially reduced lower oxides were deposited. The operating conditions established for repetitive high-quality production of metal phosphides of the MP structure are presented in Table I. The metal phosphide crystals varied in size, but all had a definite metallic appearance. Typical are the crystals of CrP shown in Fig. 1. Evaluation data and analysis of the crystals are presented in Table 11. Efforts to measure resistivity of these three compounds over the temperature ranges of 250o to 400°K were hampered by the small physical size of the crys-

Jan 1, 1968

By B. C. Allen

Surface free energy and surface self-diffusion of solid molybdenum were studied in the temperature range 1600" to 2400°C using pressure-sintered bi-crystals. Comparison of groove angles formed in various surfaces perpendicular to the grain boundary indicate a maximum of 1 pct variation in surface free energy with crystallographic mientation. This anisotropy tends to decrease with increasing temperature. The surface diffusion of the bicrystals is equivalent to that of sheet with a mild (100) Preferred orientation. Anomalously low values found for bi-crystals with surface orientations of (OOl), (012), and (011) are rationalized in terms of anisotropy in surface free energy. THE effect of crystallographic orientation on surface free energy1,' and surface self-diffusion3,4 has been primarily studied in fcc metals. The object of this work was to study the effect of orientation on surface diffusion and surface free energy of bcc molybdenum using pressure-sintered bicrystals. EXPERIMENTAL WORK Materials and Crystal Preparation. Arc-melted molybdenum rod was obtained commercially and electron beam zone refined at 50 cm per hr at 10- 5 torr to form single crystals about 8 cm long and 0.65 cm diam. Three crystals were prepared with axial orientations about 1 deg from [001.], [011], and. [111]. To reduce the carbon content, the crystals were annealed 2 hr in 1.4 atm flowing wet hydrogen at 2050°C. Then the oxygen content was reduced by annealing for 2 hr in -30°C dewpoint hydrogen at 2020°C. The resulting impurity analysis is given in Table I. Bicrystal Preparation. The single crystal rods were cut into transverse slices with a thin silicon carbide abrasive wheel to produce specimens about 0.6 cm long. They were mounted in epoxy and surrounded by stainless steel washers. Cutting in half was done longitudinally at various angles to known crystallographic planes containing the cylinder axis according to Fig. 1. To reduce surface deformation resulting from the cutoff wheel and thus reduce parasitic grain boundary formation on subsequent annealing, about 0.003 cm was manually ground off each cut surface with 600 grit paper. Care was taken to keep the surface flat. After removal from the mounts, one half was generally ro-tated 180 deg with respect to the other to give a po- tential symmetrical tilt grain boundary between the two halves. In the other cases when low misorienta-tion angles were desired, the crystals were not rotated. On the basis of symmetry, sufficient bicrystals were prepared to cover the entire range of misorientations for symmetrical tilt boundaries. The misorientations, +, ranged from 0 to 45, 0 to 90, and 0 to 60 deg for [001], [011], and [111] bicrystals, respectively. One [Ill] twist bicrystal was prepared from 2 single crystal discs rotated 17 deg relative to each other. Each specimen consisted of two pieces which were placed in a cylindrical tantalum can. Sharp edges were rounded and the fit was made as snug as possible to reduce subsequent deformation during bonding. The assembly and crystals generally were vicuum outgassed at 900" or 1700°C and then electron beam welded in the can at l x 10-4 torr. After being leak checked, the samples were placed in an autoclave and hydrostatically gas-pressure bonded5 in four batches under helium at 10,000 to 18,000 psi at 1650°C for 3 hr. Satisfactory bonds were obtained in many cases, and most of the crystals bonded after two exposures. The results did not appear to be affected by the various pressures used, preannealing conditions, crystal orientation, or time-pressure-temperature route taken to the final bonding condition. After bonding, the tantalum cans were selectively removed in cold concentrated HF. Measurements indicated overall deformation was under 1 pct. The bicrystals were metallographically ground and polished flat and perpendicular to the axis. Examination showed the boundaries were straight and almost free of parasitic grains caused by extraneous local deformation. Annealing. In preparation for thermal grooving, the bicrystals were cleaned and annealed by outgassing at 10-5 torr at 1900°C and heating at 2300°C under 1 atm 99.996 Ar for 0.5 hr. The crystals were held in a closed 4-deck box made of molybdenum sheet, and were heated in a Ta-1OW resistance furnace. The ar-

Jan 1, 1970

By George W. Maynard

At the Pittsburg meeting of the Institute, May, 1879, I made the first announcement in America of the results obtained by Sidney Gilchrist Thomas and Percy C. Gilchrist, in their efforts to eliminate phosphorus in the manufacture of steel in the Bessemer converter and the open-hearth furnace.' The first published statement in an American newspaper was a reprint of the first Thomas-Gilchrist paper,which I sent to J. C. Bayles, at that time the editor. At the suggestion of many friends who were present at the Pittsburg meeting, and others who are cognizant of the beginnings of the process in the United States, and for the information of the younger generation of the iron and steel fraternity, I have thought it eminently proper that the history of the process in detail should be given where I made the first announcement and where the process has had its largest development. During my residence in England, from April, 1873, to February, 1879, and as a member of the Iron and Steel Institute since 1874, I was present at many of its meetings during those years. At nearly every meeting the burden of discussion was the question of the use of pig-iron containing phosphorus in the manufacture of steel by the Bessemer or the open-hearth process. In my biographical notice of Thomas: read at the New york meeting of the Institute, February, 1885, I show. that the working-out of the process was not a hap-hazard or accidental inspiration, but the culmination of many years of investigation of experiments and theories which had been carried on aid advanced by chemists and metallurgists at home and abroad.

Jan 1, 1911

By Gerald A. Munson, Fremont F. Clarke

DURING recent years the use of lithium has expanded greatly in industrial, chemical, and metallurgical fields, while at the same time modernized methods of mining and refining lithium have increased production. Technical literature includes many papers describing the geology and mineralogy of lithium deposits. Mining and beneficiating problems, however, have not been thoroughly described. Published reports have failed to emphasize that one of the chief reasons lithium minerals were not extensively mined until recently is the difficulty of beneficiation. Four lithium minerals of pegmatites and the lithium-sodium-phosphate byproduct from the brines at Searles Lake, Calif., have been sources of lithium. Among the pegmatite minerals, only spodu-mene and petaline are known to occur in deposits large enough to support large tonnage operations. Spodumene, a lithium-aluminum-silicate, is the principal lithium mineral mined in the U. S. Lithium Corp. of America, during its rapid development and growth, has successfully employed three different methods of concentration: 1) hand sorting, 2) Heavy Media separation, and 3) froth flotation. Each method, though economic in its sphere, is becoming outdated as extractive techniques improve. The most recent development has taken place at Lithium Corp.'s new operation in North Carolina, where the extractive process yields lithium compounds directly from mined rock without an intervening concentrating step. Until 1954 Lithium Corp. mined only in the southern part of the Black Hills of South Dakota, where the various types of lithium-bearing pegmatite could be used to develop untried processes of beneficiation. Concentrates from these operations are shipped to the corporation's chemical plant in St. Louis Park, Minn., where actual extraction of lithium and production of commercial compounds takes place. Nature of Deposits The geology of the southern Black Hills pegmatite deposits is admirably presented by a U. S. Geological Survey publication.' Only the factors pertinent to exploitation need be mentioned here. Lithium Corp. has been interested primarily in three deposits, the Edison, the Mateen, and the Longview-Beecher No. 2. The history of these deposits dates back to the mining boom of 1880 to 1900 in the Black Hills, when most of the deposits were prospected for tin by the ill-fated Harney Peak Tin Mining Co. The three deposits described here, however, lay idle and unwanted until Lithium Corp. opened the Edison mine in 1943 and the Mateen and Longview-Beecher No. 2 in 1951. Edison Deposit: The Edison deposit is about a mile southeast of Keystone, S. D., on the northeastern flank of the Harney Peak uplift. The deposit consists of no less than four and probably at least six separate pegmatites that coalesce in a central mass from which the individual pegmatites finger outward and downward in complexly folded schist and gneiss beds of the country rock.

Jan 1, 1956

By H. C. Juvkam-Wold

The aquifer depressurization system uses a number of wells surrounding a mine shaft to reduce the aquifer pressure in the vicinity of the shaft. The effect of various parameters such as number of wells, wellbore diameter, time, and well location is discussed. It is concluded that, with a properly designed depressurization system, the aquifer pressure and the water inflow rate to the shaft may be reduced to less than 15% of their potential values in the absence of wells.

Jan 1, 1983

By Jerry A. Selvaggi, Richard B. Jacob

The High Gradient Magnetic Separator (HGMS), also known as the High Gradient Magnetic Filter (HGMF), is an effective device utilized in magnetic separation. This method of separation is gaining popularity in the separation of submicron material containing feebly magnetics. The most common use of this type of separator is in the removal of iron stained particles to improve the brightness of kaolin clay. Potential areas for use of this magnet include: (1) desulfurization of coal (2) the clean-up of mill effluent (3) removal of fine particulate matter from municipal and indus¬trial waste (4) desulfurization of oil Design, operation, and applications of this separator are further dis¬cussed in papers by R. R. Oder (1975), and R. R. Oder and B. I. Horst (1975). This device is a system composed of an iron enclosure of high per¬mability material housing a set of electrical coils, a canister en¬closing a magnetic matrix (stainless steel wool), an electric power supply and a hydraulic system to maintain specified operating tempera¬ture conditions. See Figure 1.

Jan 1, 1984

A mine in the mountains of southeastern British Columbia is fast earning a reputation as the safest metal mining operation of all time. Already officially proclaimed as the safest mine in Canada, the H.B. mine of The Consolidated Mining and Smelting Co. of Canada (Cominco) continues to advance its safety performance far in the lead of average accident frequencies in mines across the country. Official recognition came its way again this spring when the Cominco mine was awarded the John T. Ryan trophy for the fourth time in the last five years. This award is emblematic of top national safety performance of a metal mining operation. The H.B. mine is its only four-time winner. The Ryan award is based on a frequency of accidents involving lost time of more than six days. In each of the years that the H.B. has won the award-1958, 1959, 1961 and 1962-its frequency was zero, with no accidents involving a time loss of more. than six days

Jan 12, 1963

By Hisaaki Takada, Atsushi Yoshida, Kazuo Satoh, Norikazu Nanko, Naoshichi Higashi

Kamioka Mine of Mitsui Mining & Smelting Co., Ltd. is the largest lead-zinc mine in Japan and is composed of two mines, Tochibora Mine and Mozumi Mine, which have daily production rates of 5,200 metric tons and 1,800 metric tons of crude ore respectively. In the mines, there are many massive pyro-metasomatic deposits which have been derived from the replacement of limestone. The deposits are composed of skarn minerals which mainly contain hedenberite. The country rock is generally hard and fine-grained gneiss. These deposits have been mined by means of the sublevel stoping method, induced block caving method and sublevel caving method at Tochibora Mine and mainly by the cut and fill method at Mozumi Mine. Since the 19601s, the trackless mining system has been introduced successfully into both mines, and is still promoted to be applied over wider areas. The underground hauling system is simplified remark- ably and much improved by adopting trackless ramps to the existing vertical and horizontal underground framework. Moreover, through the combination of the trackless mining system with the mining methods stated above, a notable increase in efficiency has been achieved. This is due to the high performance of the introduced machinery, reductions in man power of miscellaneous jobs, and also has enabled a highly efficient performance through its mobility. In addition, as it becomes possible to realize a flexible development to meet the irregularly shaped deposits and also becomes much easier to recover the remaining pillars by secondary mining, the extraction rate of ore has been improved considerably. With the introduction of the trackless mining system, the development method has been changed, thus former hand-hold leg-drills are now mostly re- placed by jumbo-type drills. Repair shops for Load-Haul-Dump machines also have been provided with an established service system. Reinforcement and rearrangement of the ventilation system has been carried out.

Jan 1, 1977

By T. Egleston

The treatment of the residues from the manufacture of sulphuric acid which contain small amounts of copper, silver and gold, has attracted considerable attention in Europe. They are successfully treated in several works on the continent, and in as many as twenty establishments in different parts of England. As the process must sooner or later attract attention in this country, I have put together my notes made in three of the most important establishments in Europe. These are the works at Hemixem near Antwerp, of Duisbourg in Westphalia, and of Oker in the Hartz. In the last works only, the ores are produced in the vicinity of the place where they are treated. The works at Duisbourg treat ores which come from the Rio Tinto mines in Spain, which often contain considerable quantities of arsenic. They are roasted in a number of different works along the Rhine for the manufacture of sulphuric acid. They are brought by boat and are landed at the works by steam-cranes. They are carried at once by a double-inclined plane worked by steam to the storagehouses to be kept, until treated. The wagons, after being weighed, are dumped. The ore is assayed at once, the assay-sample being taken from the boat while the ores are being discharged. They are all fine, and contain two to eight per cent. of copper and about sixty per cent. of iron, and a small amount of silver and gold. Their average composition is given below:

Jan 1, 1886

By Ralph V. Higgins

This paper concerns the magnitude of the amount of supersaturation that occurs in an underground reservoir during the flow of oil and gas to wells and to the amount of undersaturation that occurs during repres-suring of an oil reservoir where some effective permeability to gas exists. The study is based on earlier laboratory findings of other investigators on the rate of diffusion of gas in oil as a function of the depth of oil. Utilizing these relationships and the principles of reservoir mechanics, a quantitative estimate of undersaturation and super-saturation was calculated. The results showed that the diffusion of the gas is rapid enough that for all practical purposes no supersaturation exists during the flow of oil to wells or undersaturation during repressuring in reservoir sands having some effective permeability to gas. The reason diffusion of the gas virtually keeps the oil saturated is the long time required in radial flow for oil to reach the well and the slow rate at which pressure in reservoirs is increased during repressuring. INTRODUCTION Knowledge of the phase relationships during flow of gas and oil in an underground reservoir is essential to operating the reservoir in the most efficient manner. In material-balance calculations and in fluid-flow studies, the oil is assumed to contain all the gas that it will dissolve at given temperature and pressure. Pressure-volume-temperature relationships are normally obtained in the laboratory using "bottom-hole" or combined samples of the reservoir fluids. In such laboratory determinations equilibrium is obtained between the oil and gas in the pressure cells by mechanical agitation. During the flow of oil and gas in reservoirs, however, no comparable agitation occurs to mix thoroughly these fluids to aid in effecting equilibrium between the two phases. During repressuring of a partly depleted underground reservoir, the gas is usually injected into the reservoir faster than the oil can absorb it; consequently, the oil is undersaturated. On the other hand, as the oil flows through the reservoir to the wells during producing operations the pressure decreases faster than the gas in solution can diffuse through the oil to the gas phase. The oil therefore is supersaturated with gas. Where the oil is undersaturated, gas diffuses away from the gas-oil interface, and where it is supersaturated the gas diffuses toward the interface. In either case the gas moves from a higher to a lower saturation. This report contains the results of a study of the factors influencing the degree of nonequilibrium of the phase relations of oil and gas in porous mediums during the flow of oil through reservoirs to wells and also during the injection of gas into partially depleted sands. Data from an underground reservoir are presented and the degree of supersaturation during the flow of the oil through the reservoir to the well is approximated. Also data from another reservoir are used and the degree of undersaturation during the repressuring operation is calculated. In addition, the flow rates of oil in laboratory experiments and in underground reservoirs are compared, as data from the laboratory are often used to interpret events in the reservoir, and the rates of flow influence appreciably the degree of nonequilibrium. Much of the contents of this report was prepared in 1943; but, because of other activities during and since the war, the manuscript was left untouched until 1952, when it was decided to include an estimate of the amount of undersaturation during repressuring as well as supersaturation during flow.

Jan 1, 1955

There are not many data about early coal production in Kentucky, but some legislative reports, early geological studies and occasional newspaper articles have left some figures. The earliest production with any authentic record is that of Lee County, the coal being boated down the Kentucky River to Frankfort. While never a large producer, this county has the longest record in the State. Production is recorded in several of the western coal counties in 1820, and in several others a few years later. The early production in Greenup County was for the iron furnaces operating there. Clay County had a large salt output in the early days and this required a large output, for those days, of coal; the amount of fuel is based on the quantity of salt. It will be noticed that several counties on the Ohio River produced considerable quantities of coal before the Civil War, much of it being consumed by the river steamers. Since the end of the war, these counties have never occupied the relatively important position they had prior to that time. All of the coal produced in the eastern mountain counties moved out of them by water before the war, and during that struggle nearly all mining was stopped. The growth of the railroads after the war greatly reduced the river traffic from these counties, and in some cases it was never renewed. The coal shipped from Lawrence County prior to 1861 all moved by water; after that date there was no production excepting for local use until 1879, and since that time, all shipments have been by rail. Some of the early railroad reports have been helpful in reporting shipments, but for the early years very few of them can be found, and after about 1879 the quantities reported cannot be identified as to origin. Pres. J. B. Hill, Louisville and Nashville Railroad, furnished all of the data available for his line. Sources of data are shown on Table 61; other figures are estimated. A list of early Kentucky mines is given in Table 13.

Jan 1, 1942

By Arthur Braid

The war has caused an increasing scarcity of phosphorus and its well known alloys with copper and tin. At the same time, the production of brass and bronze, nickel-silver, cupro-nickel, and other non-ferrous alloys, has considerably increased. The manufacturers of these products had therefore to secure other materials which would serve their purpose; principally that of a deoxidizer, which could be obtained promptly and regularly. Fortunately these materials, pure carbon-free manganese metal and manganese-copper alloy, were not hard to find—in fact, they were never lost. Manganese in various forms has been used in Europe for more than a century; in this country, however, when manganese was first used, and indeed for a long time thereafter, it was consumed mainly in the manufacture of manganese-bronze. Many foundrymen at that time used manganese-copper with the same freedom as phosphor-copper. Although iron enters into the composition of certain grades of bronze, it is very detrimental to non-ferrous mixtures in general; consequently ferromanganese is not applicable, and therefore pure manganese metal, or the alloy of manganese and copper, technically free from iron and other impurities, is now being generally used. The following are the principal elements having an affinity for oxygen: 1, Sodium. 2, Potassium. 3, Calcium. 4, Strontium. 5, Barium. 6, Magnesium. 7, Aluminum, 8, Phosphorus. 9, Silicon. 10, Manganese. 11, Iron. 12, Zinc. 13, Lead. Each metal has its natural flux, or deoxidizer, in the form of a metal or non-metal which will alloy with it, and has a strong affinity for oxygen. For example, phosphorus, as is well known, acts very beneficially in copper alloys that contain tin. Within the last few years, and particularly since the war began, the .great value of mangancse in nickel alloys has been demonstrated, and one by one the manufacturers of these products have adopted its use. While manganese has not so strong an affinity for oxygen as magnesium, aluminum, or silicon, it is nevertheless sufficiently powerful to reduce any oxide of nickel, copper, or zinc that may be present in the nickel alloy to be purified.

Jan 1, 1919

By A. Werenfels

No PETROLEUM, in commercial quantities, is found in France except the small production of the Pechelbronn field (Fig. 1) in Alsace, which produced 75,000 tons in 1923; therefore the test of the petroleum prospects of the Limagne is most interesting. Under the superintendence of M. Termier, chief engineer of the French mines, a well near Crouelle (Fig. 2) was drilled in 1921 to a depth of 856.3 m. (2808 ft.); at different depths favorable showings were encountered. The well, however, was abandoned because of drilling difficulties. A second one is now being drilled near the same place.

Jan 1, 1925

By C. Gutiérrez

Flotation and adsorption studies of ilmenite with technical oleic acid, pure oleic acid, and mixtures of each of them with n-hexadecane have been conducted. From them it is concluded that the depression of ilmenite caused by a too long conditioning time is due to adsorption of the collector onto the fines produced by attrition in the conditioning cell, and that fuel oil is necessary for economic flotation of non-deslimed ilmenite ore. This beneficial effect of fuel oil is attributed to van der Waals forces, of the hydro-carbon chains.

Jan 1, 1978