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By Albert E. Ketler

Introduction – The introduction of computerized monitoring and control (M/c) equipment into the U.S. coal mining industry may prove to be of truly revolutionary proportions in the 801s.Many of you are aware that the British have developed and have been using such sophisticated M/C equipment for performing production and safety related tasks in their coal mines for nearly a decade. The benefits of M/C systems in the mining industry are usually separated into those which improve productivity, and hence make money for the company, and those which improve safety, and hence cost money. The economic benefits of M/C are startling for the production related functions such as for monitoring and controlling conveyor belts, de-watering pumps, electrical power distribution, and the like. It doesn't take much analysis to show that hundreds and even thousands of tons of coal don't get mined every time a belt shuts down or when power is out due to circuit breakers tripping for any number of reasons. A flood, caused by a malfunctioning pump which goes undetected for lack of feedback monitoring of pumping parameters, can destroy literally millions of dollars worth of mining equipment. The M/C system would be justified or not based on whether or not the productivity benefits balanced the cost within a timespan commensurate with the return on capital philosophy of the company. The safety related benefits are easily underestimated or ignored completely and the purpose of this paper is to under-score some of these benefits, as well as to review the application of M/C to the coal mining industry. The companies involved are Transmitton Ltd of England and Minetics Corp of Pittsburgh, Pennsylvania. Transmitton is probably the most experienced manufacturer of M/C equipment in the world having some 200 installations to its credit. Minetics is the marketing and manufacturing arm for Transmitton in the U.S.A. and is responsible for all aspects of distribution and service. Plans are underway for manufacturing of the Transmitton hardware for U.S. sales to be transplanted into U.S. subcontractors by 1981. Thus our coal mining industry will benefit from British technology, but without the delays and additional costs usually involved in international shipments.

Jan 1, 1981

By George W. Bain

The good work of the surveys supported by the different branches of the government needs little mention to geologists but is underappreciated by people at large. Geologists and engineers realize their usefulness and yet even from this group one hears occasionally an undercurrent of discontent about their work or the distribution of it. The very fact that discontent arises within and without this group and has drawn attention of legislative bodies of the country in the present time of stress means that a large number of people do not receive or do not realize that they receive benefit from these public works. This seems to be a clear indication that more than the relations between government surveys and the mining industry is involved and that if the mining industry is interested in continuation of the work of these surveys on the past scale they must consider the other survey divisions and their activity. Also, relations between government surveys and certain specialized types of mining have not been as close as they should be. I have been employed in almost the entire range of fields offered to geologists and have studied closely the feeling of people towards geological service. Recently it has been a pleasure to be closely associated with men who were as deeply interested in civic welfare and affairs of state as in the financial success of a large industry developing natural resources. Previously I had seen service in a national survey, a state survey, summer employment by a large mining company exploring new property and detailed geological work for a large corporation. Major responsibility as a college instructor has left me free to view each of these assignments in unprejudiced fashion and at the same time study the relation of government surveys to large natural resource industries, average industrial and construction work and service to nongeologists and laymen. Considerations Governing Geologic Public Service Three groups of people must be satisfied by the surveys if dissatisfaction is to be dispelled. First there is a large group of people who pay taxes to support the government activities and must receive some service

Jan 1, 1935

By J. Edgar Pew

As MOST of the oil production comes from leased-lands and not fee property, I shall refer to "leases" as covering the producing tracts. To produce oil, leases on land must first be obtained. Well-selected leases are all important. Not many years ago, the location for drilling for oil in wildcat territory was too frequently determined by the nearness, of adequate water and fuel supply, or with a view to cheapness of transportation. To some extent, the "creekology" theory is the result of the number of wildcat tests made near streams, to obtain water for operations. Now, an up-to-date operator will depend on his geologists for his location and, in many cases, will spend thousands of dollars to get water to it. The wisdom of following the geologist rather than the creek has been abundantly demonstrated in the past few years. In vast territories, where dry holes are spotted at intervals of a few miles or less. apart, and by reason of which these territories have been condemned for oil, the geologist is now finding many more spots that are producing large quantities of oil. No better tribute to the work of the geologist can be found than the surface and subsurface work being done in practically all parts of Oklahoma and the development had as a result of this, work. A land department is usually organized by placing in charge a man who is not only acquainted with the oil development, but who is a shrewd buyer, a first requisite for which should be unquestioned integrity. It takes a shrewd buyer to resist the persuasive lease broker, frequently backed by a geological picture from which the oil fairly drips. The geologist can help a lot by being absolutely honest when he makes these pictures; he will also thus strengthen his own cause. A geologist should interpret his own work and put his name behind his interpretation. If he does not he is liable to be misquoted and often discredited, as a result, by some overzealous lease broker giving an interpretation never intended by the geologist.

Jan 8, 1925

By Donald C. Barton

Geophysical methods of prospecting taken as a whole do not seem to offer much promise to a young man planning to enter them in the future. They have come to stay, to be sure, and they will continue in at least moderate use for a long time. Domestic use of those methods presumably is at a maximum at the present time. Geophysical prospecting is expensive; the effects of the law of diminishing returns in efficiency in finding prospects can already be recognized. Small oil companies, independent oil operators, and royalty buyers have been doing much geophysical work. But in face of the increasing costs of discovery of prospects and in face of the probably decreasing favorability of the prospects discovered, I expect to see a sharp drop in their use of geophysics within the next 10 years. The major oil companies and the larger small oil companies will continue to use geophysics indefinitely, but it seems doubtful whether the very extensive domestic campaigns of a few companies will be maintained for many years, certainly not for 10 years. The use of the geophysical methods in foreign countries has not yet reached its peak, and probaby will continue to increase for several years. That peak level of activity will probably be held for 10 years, although the site of maximum activity will shift from country to country; by the end of 25 years from now, I should expect the foreign use of the methods to have leveled off to one-fourth to one-half the peak level. Foreign service in geophysics does not seem to offer an attractive career, except for men of exceptional disposition. Young men just out of college, who are willing and who can afford to spend three or four years having a fling at adventure before settling down, will find it attractive, but when their tour of foreign service is over, they probably will have harder work finding a job than when they were seniors, and their foreign experience will count for little, except for further foreign service. A few men, mainly the higher men, will have headquarters at civilized or semi-civilized cities and towns or at permanent oil-company towns, and can

Jan 1, 1940

By G. S. Rice

With so tremendous a subject, an attempted review of the coal situation of the world in a short talk must necessarily be of a sketchy character. It is hardly necessary to tell a body of engineers that had it not been for nature's gift of coal the material side of modern civilization would never have reached its present status. On the other side, it is regrettable that it was a byproduct of coal, T. N. T., which made possible Germany's initial success in this war, because that country had an enormous development of manufacturing plants that could be immediately utilized to make this destructive agent: One sometimes hears the casual remark that when the coal of the world is exhausted we shall use electricity; but, of course, electricity is ordinarily only a means of transforming and transmitting energy derived from fuel or water power, and chiefly from coal. It is true, we have much undeveloped water power, but it is more or less remote from 'the, centers of industry; and when all shall have been developed it will not begin to supply the power requirements of the world. It is, however, reasonable to expect that before the world's supply of coal shall be exhausted, methods will have been discovered of harnessing other forces of nature, such as the tides, or the energy emanating from the sun. Petroleum and natural gas naturally come to mind, but the days of both, as fuel, appear to be numbered, although the products of petroleum, if economically used, doubtless will be available for internal-combustion engines, automobiles, trucks, and boats for a long time, provided the reckless use of crude petroleum as an ordinary fuel is stopped. The products of petroleum are too valuable to mankind for such waste to be permitted. The civilization of the world, therefore, appears to rest, and, so far as can be seen, will indefinitely continue to rest, upon coal. COal Resources of the World According to the compilation made by the geologists of the principal countries for the 12th International Geologic Congress, held in Canada

Jan 1, 1918

By J. H. Hensley

The mine of the Miami Copper Co. is in the Miami district, Gila County, Ariz., approximately 7 miles west of Globe. In 1906, the General Development Co. secured the ground now owned by the Miami Copper Co., and about a year later discovered ore in a prospect shaft at a depth of 220 ft. The Miami Copper Co. was organized in 1907, the claims held by the General Development Co. were transferred to it, and an active development campaign was inaugurated. The railroad was extended from Globe to Miami in 1909, a concentrating plant was constructed, and the company began producing early in 1911. The unit size of mineral tract in the district is the standard lode claim 600 ft. in width by 1500 ft. in length. Ownerships of land are held in fee. The geology of the district has been described by F. L. Ransome.' The formations of local importance are: The pre-Cambrian Pinal schist, which consists mainly of metamorphosed sedimentary rocks and is commonly of a thinly laminated sericitic variety; the diabase, which is thought to have been intruded in late Paleozoic or early Mesozoic times; the Schultze granite and granite porphyry, considered early Tertiary; the dacite of late Tertiary time; and the Gila conglomerate of early Quaternary. General Items Influencing Mining Methods The bodies of disseminated ore in the district are flat lying masses of irregular outline and variable thickness. As a rule, these masses lack definite boundaries; the orebody follows a curve along one of the main ridges, approximately 5500 ft. in length with a maximum width of 1600 ft. The minerals occur as finely divided and uniformly disseminated chal-cocite in the Pinal schist and Schultze granite. The typical overburden or capping is a barren rusty brown, very friable, highly siliceous, leached schist, or granite-porphyry. The topography of the district is fairly rugged and irregular; the altitude ranges from 3400 ft. above sea level, at the town of Miami, to 3900 ft. on the hills above the Miami orebody. The climate is mild; the mean annual temperature is 63.°F.

Jan 1, 1925

By J. F. Wolff

The iron formation of the Iron River, Crystal Falls, and Florence districts probably is not of one geologic age only but of at least two ages. The ores, therefore, are of different characteristics. But in general the geologic conditions that occasioned the development of the orebodies have been essentially the same throughout the district and the types and structures of the orebodies are very similar in different parts of the area. In general, the iron formation of this area has been folded into a series of close pitching synclines and anticlines; minor folds of many orders are included in the major folds. The pitching synclines have been particularly favorable places for the circulation of ground waters, which in such troughs have developed orebodies through the familiar process of leaching out the silica in the iron formation, oxidizing and concentrating ferrous iron compounds in the rocks. The iron formation of this area is interbedded with and has interbedded in it certain slate or slaty layers that, in addition to the foot wall of the iron formation proper, act as impervious layers in the pitching troughs, to direct and control the flow of underground waters. In most places, the entire iron formation in a structural trough is not altered into iron ore; the orebody may be lens-shaped and exhibit no folding in its layers, outline, or shape, but almost without exception such bodies have been developed in folds and because of the influence of folds, and structurally they occupy only one limb of a fold. Many orebodies occupy the entire trough of a minor fold and the structure of the fold can be traced throughout the orebody. Many definitely recognizable horizon markers in or associated with the iron formation occur in this district and serve as valuable guides to the engineer or geologist in exploring an orebody whether by drilling or underground mining development. Among such markers are the talc schist (an altered dolomite) and the Traders slate at the base of old Menominee iron formation proper, and the interbedded Brier slates and overlying Hanbury dates; and certain graphitic slates and gray-wackel in the Iron River and Crystal Falls area.

Jan 1, 1925

By Thomas M. Drown

I DESIRE to communicate to the Institute the results of a few analyses which bear on the condition of carbon in gray and white iron. These analyses were made in the course of an investigation, now in progress, of the chemical composition of "chilling" irons. It will be remembered that Bell says he found no material difference in the amount and condition of carbon in gray and white pig iron made at the Clarence furnace, in England, and he therefore refers the difference in color and appearance in these two varieties of iron to the size of the particles of graphite. I quote from his "Chemical Phenomena of Iron Smelting:" "The inference I would draw from the information afforded by these analyses is, that the condition of iron in respect to its so-called 'richness' is, within certain limits, entirely independent of its chemical constitution.. .. In the fluid state, I conceive the carbon, so taken up, confers upon the iron the property of fusion much below the temperature at which the pure metal melts, and the carbon itself may be regarded as dissolved in the iron. If, during the process of manufacture, the pig metal has been formed at a low temperature, consolidation, I imagine, takes place under such circumstances that the crystals are so minute, and the carbon which is separated assumes the uncombined or graphitic form in particles so minute as to be invisible, and, in consequence, the iron is white. If, on the other hand, the furnace is working at a very high temperature, the intensely heated iron crystallizes with large facets, upon which the extruded carbon assumes the condition of distinct plates or flakes. Should the temperature be less intense, these crystals are of smaller dimensions, and the separated carbon is less conspicuous, and, as the temperature of the furnace declines, the crystals decrease in size, as do the flakes of carbon, until both disappear in white iron.. .. Returning, then, to temperature as the cause of differences in quality of pig iron, the 'chilling' of gray metal, and its conversion into white, may be regarded as the effect of preventing, by rapid cooling, the formation

By Thomas M. Drown

I DESIRE to communicate to the Institute the results of a few analyses which bear on the condition of carbon in gray and white iron. These analyses were made in the course of an investigation, now in progress, of the chemical composition of "chilling" irons. It will be remembered that Bell says he found no material difference in the amount and condition of carbon in gray and white pig iron made at the Clarence furnace, in England, and he therefore refers the difference in color and appearance in these two varieties of iron to the size of the particles of graphite. I quote from his "Chemical Phenomena of Iron Smelting:" "The inference I would draw from the information afforded by these analyses is, that the condition of iron in respect to its so-called `richness' is, within certain limits, entirely independent of its chemical constitution... . In the fluid state, I conceive the carbon, so taken up, confers upon the iron the property of fusion much below the temperature at which the pure metal melts, and the carbon itself may be regarded as dissolved in the iron. If, during the process of manufacture, the pig metal has been formed at a low temperature, consolidation, I imagine, takes place under such circumstances that the crystals are so minute, and the carbon which is separated assumes the uncombined or graphitic form in particles so minute as to be invisible, and, in consequence, the iron is white. If, on the other hand, the furnace is working at a very high temperature, the intensely heated iron crystallizes with large facets, upon which the extruded carbon assumes the condition of distinct plates or flakes. Should the temperature be less intense, these crystals are of smaller dimensions, and the separated carbon is less conspicuous, and, as the temperature of the furnace declines, the crystals decrease in size, as do the flakes of carbon, until both disappear in white iron. . . . Returning, then, to temperature as the cause of differences in quality of pig iron, the `chilling' of gray metal, and its conversion into white, may be regarded as the effect of preventing, by rapid cooling, the formation

Jan 1, 1875

By George C. Stone

The stack gases from regenerative furnaces lare very seldom utilized for the production of steam. If the temperature of the gases is not higher than 300" C. (572" F.) there is no economy in their use for this purpose, as the amount of available heat is very small and the temperature is so little above that of the steam that the interchange is too slow. With higher temperatures of the waste gases, however, good results can be obtained. At the plant of the New Jersey Zinc Co. (of Pa.) at Palmerton there are a number of return tubular boilers, each 6 ft. in diameter and 20 ft. long, with 96 3.5-in. tubes, which are heated by the waste gases from the spelter furnaces. These furnaces have continuous regenerators heating the air only and the stack gases reach the boilers at a temperature of about 450". The gas producers for one of these furnaces require 14 tons of anthracite (a mixture of Nos. 2 and 3 buckwheat), and the waste heat from the furnace gives a little more than 42 h.p. in steam. The boilers are not well adapted for the purpose, as they are much too large for the amount of heat going to them and the area of the tubes is not sufficient to take the gas from two furnaces without causing an objectionable amount of back pressure. The plant was built without any idea of using waste-heat boilers, and it was impossible to place the latter as close to the furnaces as they should be. Furnace and boiler are connected by an underground brick flue in which the temperature of the gas drops about 100°, losing 40 per cent. of its available heat. If the boilers were close to the furnaces the horse power of each would be 70 instead of 42. Even under these unfavorable conditions the boilers have been very advantageous, as one boiler easily supplies the steam necessary for two batteries of producers. With such low gas temperatures the heating surface of the boilers is, of course, not as efficient and the flue areas need to be considerably larger than for coal firing.

Jan 1, 1914

By T. Glen Heslop, Dennis H. Laubscher

INTRODUCTION In all cave mining operations waste is drawn mixed in the ore, hauled, hoisted and milled. This waste usually contains some mineral which partly covers some of the costs of mining and milling it, but it still re- presents a loss of profits as the production rate from the mine is matched to the mill capacity - every tonne of waste milled replaces a tonne of profitable ore. Draw control aims to reduce the amount of waste drawn and to increase the amount of ore recovered. It is also used to regulate the grade of ore flowing to the mill and in block cave blocks to prevent potential stress build- up on the major apexes above grizzly drifts. This paper summarises what has been learnt about draw control in the forty years that cave mining methods have been used in the three largest underground chrysotile asbestos mines in the southern hemisphere. The four mining methods to which draw control has been applied are: a. Block caving. b. Shrinkage with overburden caving. c. Sublevel caving. d. Open stoping. Open stoping has been included because on a number of occasions severe falls from the back and side of these open stopes have occurred. Without full records of where and when ore is blasted, when and how much ore has been drawn from each of the drawpoints, it would be impossible to analyse the migration of ore and fallen waste in the stope. Several problems peculiar to chrysotile asbestos ore bodies affect the practice of draw control. Heterogeneous fragmentation, cavities, side pressures and the interaction of stresses in the caved ore affect the migration of ore under draw. Fibre is normally not developed uniformly throughout the ore bodies, values vary from place to place but there is usually a general decrease upwards and the hangingwall contact is an economic limit. The immediate hangingwall rock frequently looks like the ore body hostrock and is difficult to recognise in a drawpoint, and cannot be used as the marker for stopping draw. During caving or shrinkage, a large proportion of fibre becomes detached from the host rock and re- ports in the fines, which migrate differently to the larger rocks. The fines are not sticky, and flow easily if loose and dry, but compacted, the fibre and rock fines con- solidate the ore. During draw the proportion of fines in the ore varies considerably, as fines either flow relatively freely between the large rocks or become trapped and compacted above large rocks or hangups. This creates a large sampling error in drawpoint grade assessments, whether done visually or by bulk sampling, unless the assessments are done frequently. The method of draw control used is to regulate the draw rate in an attempt to lower the ore-waste interface as evenly as possible, and to finally stop working the drawpoint when a calculated tonnage has been drawn.

Jan 1, 1981

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Jan 1, 1907

By C. D. Rubert, W. J. Parton

A flotation plant was placed in operation in 1945 at the Tamaqua colliery of the Lehigh Navigation Coal Co. Inc., to recover fine anthracite which is discharged from the cleaning plant with the washery water.‡ In addition to the recovery plant, facilities were provided for the complete clarification of the washery water, recirculation of this clarified water for breaker use, and disposal of the refuse solids in a waste impounding dam. Fig I shows a view of the settling tanks and the flotation plant. Flow Diagram The flow diagram for the complete recovery project is given in Fig 2. All the waste water from the cleaning plant is collected in a sump A outside the breaker structure, from which a 7000 gpm pump B delivers it through a 16 in. line to a 75-ft diam hydroseparator C. The hydroseparator, acting as a classifier, is set to give a separation at approximately 200-mesh. The minus 200-mesh overflow is discharged by gravity into the 180-ft thickener D for final settling of the solids. The classifier underflow sludge is pumped to the flotation plant by a 6-in. quadruplex diaphragm pump E. A 10-ft diam hydroseparator F is used to make a second classification on the sludge solids at approximately 28-mesh. The underflow from this classifier containing the coarse particles is elevated by a 6-in. diaphragm pump G and is discharged on two 4- by 6-ft vibrating screens II. These screens are dressed with approximately 28-mesh cloth. Screen oversize product flows directly to the centrifuge that dewaters the cleaned froth. The screen underflow and the overflow from the 10-ft classifier flow to the flotation circuit. The flotation feed is conditioned in a 12 by 12-ft agitator tank J at a pulp density of I:2.33 (30 pct solids). Reagents are fed to the circuit by reagent feeder I. The conditioned pulp is then diluted to a pulp density of approximately I: 5 (18 pct solids) and is fed to two banks of four 100-cu ft froth flotation cells K for primary coal recovery and cleaning. Additional reagents from reagent distributor L are added to the feed weir-box of Nos. 2, 3, and 4 cells of each bank of flotation machines. Clean coal removed from these cells flows directly to the clean-coal sump. Dilute tailings from the primary cells is re-thickened in a 30-ft diam thickener M and is then retreated in a scavenger circuit for final recovery of coal. The scavenger circuit consists of a 6- by 6-ft agitator tank N and two banks of four 24-cu ft froth flotation cells 0. Coal froth from these cells flows to the dewatering equipment and the tailings flows to a vertical refuse pump which delivers it to the 180-ft diam waste thickener D. Dewatering of the coal products is accomplished in a 54- by 72-in Bird centrifugal filter P. The cake product is dropped onto a conveyor and is loaded

Jan 1, 1949

By F. J. Longworth

For a number of years an intensive study has been made to improve the blast-furnace practice at Copperhill not only as to costs but to provide a good grade of gas for the acid plants. This study, took us back to the fundamentals of successful pyrite smelting; namely, a blast furnace working on a clean sulfide ore, free from fines, and the use of quartz high in silica as a flux. In 1919, the quality of the flux was improved and its effect on the metallurgy was very marked. To improve the practice further, it was necessary to work out some method of treatment for the sulfide fines and the siliceous and refractory ores, other than in the blast furnace. A series of milling tests indicated that these products could be successfully treated by differential flotation, and in 1922 plans were made and a flotation plant built. It was estimated that the flotation plant would deliver to the smelter 40 to 50 tons of concentrates per day; the problem was what to do with these concentrates. It was out of the question to attempt to smelt them in a blast furnace because of the dust losses and, because our practice demands a charge free from fines for satisfactory operation. There is no custom smelter in the vicinity to which concentrates may be sold, pending the time when the tonnage will be sufficient to warrant roasters and a reverbatory furnace. Sintering and nodulizing were investigated but neither method fitted into our scheme of metallurgy. A close study of the converter practice was then made to see if some method could not be evolved to smelt this tonnage of concentrates in a converter without preliminary treatment. At that time, the converter installation consisted of two 12-ft. Great Falls converters, which were handling 12 to 14 per cent. matte. The heat balance of the converters working with 12 to 14 per cent. matte was more than sufficient to smelt the contemplated tonnage of concentrates but the mechanical difficulties. of feeding fines into the Great Falls converter made the use of this type of converter impractical.

Jan 9, 1924

By John Henry Harden

IT appears that in the earlier days of anthracite coal mining, 1824-25, the Lehigh region mined 76 per cent. of all the coal sent to market. During the same period Wyoming sent 12 and 5 per cent. respectively, whilst the Schuylkill sent 11 and 18 per cent., the number of tons marketed being in those days very small indeed. In the year 1828 the Schuylkill region mined over one-half of all the coal sent to market, and continued to do so for thirty years (with the exception of the year 1831), until 1858 ; since that date the pro¬duction has declined very steadily in comparison with the other regions, until, in 1876, it was only 34 per cent. Wyoming, in the year 1820, was mining 40 per cent., but the production of all the regions was very small ; in six years it declined to 5 per cent., increased to 34 per cent. in 1831, declined to 10 per cent. in 1838. Since which time the increase has been gradual, until 1873-75 Wyoming produced over 50 per cent. of all the anthracite coal sent to market. In 1867 the production exceeded that of Schuylkill, and has continued to do so since that time. In the year 1876, during the existence of the " coal combination," Wyoming lost 9 per cent. ; during the same time Lehigh gained 7 and Schuylkill 2 per cent. over their relative production of the preceding year, the decrease of Wyoming being two and a half million tons, the increase of the Lehigh one million, the decrease of the Schuylkill nearly three-quarters of a million. The extraordinary production of the Lehigh region at a time of decreased demand and in opposition to an agreement with the other regions to limit the supply to the supposed demand was the cause of the disagreement which ultimately broke up the combination of the great coal-producing and carrying companies. The Lehigh region produced very steadily, from 1829 to 1854, an average of about 22 per cent. of the whole production. From 1854

Jan 1, 1877

By J. Blodget Britton

IN the Journal of the Franklin Institute for May, 1870, there is published a description of a Colorimeter, together with a modification of the method proposed by Professor Eggertz, for determining combined carbon in iron and steel. An instrument of the kind there described, but of a little higher range, though in other respects not differing materially from the one originally made and used in the Iron-Masters' Laboratory, I now submit to your inspection ; and I propose, also, to make some determinations with it for the purpose of showing how quickly they may be made, and enabling you to form some judgment of what reliance can be placed in the results. Professor Eggertz proposed only a single standard, and the solution to be tested should be diluted to exactly correspond in color with that of the standard, and the per cent. of carbon calculated after carefully noting and making allowance for the measures of water used in diluting. In practice, difficulty was found in bringing the color of the normal solution down to the exact shade of the standard ; also other difficulties were met with in conducting the process, causing delay and interfering with the accuracy of the results. To materially overcome these, and after numerous attempts, an instrument such as is now before you suggested itself to me; and also I concluded to use a larger quantity of metal than directed by Eggertz, and, in addition, to filter the solution from its insoluble matter before making the comparison ; and, more recently, to use an acid of just such strength as would completely dissolve the metal without the application of heat. Experimenting with these changes from the original method I obtained reasonably good results. The instrument, you will observe, consists of a series of tubes, sixteen in number, two and a half inches long, and about half an inch in diameter, standing upright, and securely fastened in a light, portable, walnut-wood frame, but separated one from the other so as to allow just sufficient space between to place for comparison the tube containing the solution to be tested. The tubes are filled with

Jan 1, 1873

By Walter Miller

The broad picture of petroleum refining engineering during 1934 continued to show a tendency in the direction of highly specialized processing improvements, particularly in manufacture of lubricating oil. The slowing up of the trend toward higher octane products in non-premium gasoline noticed in 1933 was definitely established as a fact by 1934 development, with just a slight indication of recession. No outstanding engineering achievements can be credited to 1934 in refinery cracking, unless the completion and successful operation of the 30,000-bbl. crude capacity combination cracking and skimming unit at Texas City, Texas, and a 20,000-bbl. similar unit in the East can be listed as such. Development and improvement was largely a continuation of previous lines of endeavor. Such trend as there is shows a continnation in the direction of very large integrated skimming and cracking units. A lessening of the cost of ethyl lead, coupled with the reaching of the octane number "ceiling," kept the subject of "reforming" low-octane gasoline into high-octane products pretty well in the background. Considerable interest, however, was shown during the year in cracking and polymerizing of refinery gases into high-octane motor fuel. The commercial development and application of this activity was greater in 1934 than during any previous year. Fair yields of gasoline of satisfactory stability and high antiknock value were reported, ranging from 2 to 8 gal. per 1000 cu. ft. of fixed refinery gas, yields varying with both the nature of refinery gas treated and processing methods. Assuming economic feasibility, regarding which there is still difference of opinion, gas polymerization offers the industry a possible outlet for its gases more in keeping with its basic chemical composition and value. The increased interest of railroads and heavy-duty truck and tractor manufacturers served to focus more attention on diesel fuels. The publicity given the Union Pacific diesel train, the Burlington "Zephyr" and others operated on special diesel fuels served to revive the intimations and fears of several years ago as to the ultimate replacement of the gasoline motor by diesel engines in even the passenger car field. How-

Jan 1, 1935

By A. H. Taitt

The original basis for the search for oil in Great Britain was described last year.t During 1937 the exploratory drilling by the D'Arcy Exploration Company, Ltd. has been continued. Three wells have been completed in the south of England and a fourth is nearing completion. In addition, test wells are now being drilled in Scotland and East Yorkshire. Southern England The test well on the Portsdown structure, which at the end of 1936 was drilling in the Lower Lias at 5792 ft., entered the Triassic at 6540 ft. and was completed in that formation at a depth of 6556 ft., without encountering further indications of petroleum. The Henfield well encountered the Lias at a depth of approximately 4090 ft., and after drilling 800 ft. of an argillaceous development of that formation entered a series of marls, breccias and conglomeratic limestones of the Carboniferous. Drilling was suspended at a depth of 5105 ft., in the latter formation. The consistently impermeable nature of the strata encountered in the Portsdown and Henfield test wells focused attention on the desirability of obtaining shore-line conditions of the Jurassic. With this end in view the Kingsclere anticline, a few miles south of Newbury in Berkshire, was selected for a next test. The Kingsclere well has now reached a depth of 5032 ft. in the Lower Lias and has encountered a full development of the Jurassic. With the exception of the Portland sand, which has a slightly greater porosity, and the Corallian, in which relatively great thicknesses of impervious limestone were met, conditions of sedimentation have been found to be comparable with those of the earlier wells. Small traces of petroleum have been found in cuttings and cores, but formation tests carried out at frequent intervals have yielded no flow of oil. In order to test the Corallian, from which series an outcropping oil sand had been found, a test well was drilled in a near-by anticline at Poxwell in Dorset. The Poxwell well started in the Portland beds and entered the Corallian at 995 ft. The sands at the horizon of the out-

Jan 1, 1938

By Walter A. English, Ralph Arnold

Though production began in Canada only a short time after the discovery of oil in the United States, it has never attained large proportions, and if we were to judge entirely by the past the reserves of Canada would be put at a very low figure. There are only two areas from which oil is marketed at the present time; one, the old district around Petrolia in southern Ontario, and the other is the small Sheep Creek field near Calgary in Alberta. The former district has produced between 200,000 and 800,000 bbl. annually for the past 40 years, recent figures being near the minimum amount. Sheep Creek has produced about 12,000 bbl. annually for the past five years. The known reserves in proved territory in each of these fields are exceedingly small, when considered in terms of world reserves. The chief hope of Canada for reserves of considerable magnitude lies in the western provinces. Sedimentary rocks similar to those in the productive fields of the United States occupy thousands of square miles in the western provinces, so that it seems likely that somewhere within this great area the peculiar conditions necessary for the presence of oil pools will be found. Prospecting is being carried on energetically by several large companies, as well as by many independents. The Dominion Government, which controls most of the public lands, is pursuing a fairly liberal policy toward the prospector, which should stimulate wild-catting, although the province of British Columbia, which controls public lands within t.hat province, is at present unwilling to give adequate encouragement to make wildcatting attractive. As there is really no assurance that any productive pools will be found in western Canada, the estimates of reserves are subject to a wide possibility of error. In making estimates, the various areas within which geologic conditions are more or less uniform are discussed separately; the estimates given for each area are not given with the idea that there is a reasonable probability of their eventually proving to be correct. It is hoped that an average of these estimates, taken together with those made for other undeveloped countries, will give a correct total of reserves

Jan 1, 1923

By Joseph C. Kieffer

The Duquesne property of the Callahan Zinc-Lead Co. is about 20 miles east of Nogales, in southern Arizona. One mine is near the mill, but most of the mill feed is hauled in by truck from a number of small mines. The same sulphides are found in all the ores, in general, but the amounts vary considerably. All ores contain silver, copper, lead and zinc minerals but one mine ships ore high in silver and lead and low in copper and zinc; while another mine ships ore high in copper and zinc, and low in silver and lead. The common sulphides are galena, carrying most of the silver; chalcopyrite; sphalerite, carrying iron in solid solution; and pyrite, in a gangue consisting of limestone, quartz and garnet. Mineralization is fairly coarse. At the present grind of about 66 per cent minus 200 mesh most of the sulphides are liberated A small amount of chalcopyrite is locked up with the sphalerite and cannot be liberated at an economic grind, and the copper carried into the zinc concentrate with the sphalerite accounts for the comparatively poor recovery of copper in the copper-lead concentrate. Production oF Two Concentrates The milling problem, which was complicated by the extreme variation in the grade of the feed, was first attacked with the idea of producing a silver-copper-lead con- centrate and a zinc concentrate, both with satisfactory grades and recoveries. By February 1941, it was felt that these objectives had been attained, when the grades of the various products and the recoveries were as shown in Table I. A rough outline of the flowsheet and reagents used is as follows: Minus ¾-in. feed to a 7-ft. by 36-in. Hardinge ball mill working in closed circuit with a 36-in. Wemco classifier. The classifier overflow passes to the second cell of an 8-cell bank of No. 18 Special Denver Sub-A flotation machines (volume, 22.5 cu. ft. per cell). A rougher concentrate is removed from the second to the fifth cells inclusive, and returned to the first cell, which is the cleaner. A scavenger concentrate is removed from the sixth, seventh, and eighth cells, and returned to the third cell. Consump-

Jan 1, 1943