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By Theron Wasson

Discoveries in Michigan, which at the beginning of the year 1934 indicated possible new areas, did not develop into fields of market-breaking proportions. Hart, Oceana County, developed small production from the Traverse lime. Edmore, Montcalm County, proved a small area for oil from the Traverse. West Branch, Ogemaw County, previously reported as Ogemaw, had quite a drilling campaign but was somewhat disappointing because wells were small and erratic. During the year, 30 wells were completed at West Branch, and at the end of the year 15 others in and around this field were under way. At West Branch the Traverse lime, found at 1800 ft., has thin porous streaks near the top, which make small wells; the Dundee lime at 2800 ft. produces from a porous zone of varying thickness. Over the entire field the Dundee wells average 10 to 20 bbl. per day. Acid treatment has materially increased production from some Dundee wells in this field. About 3000 acres have been proved productive from the Traverse and Dundee. At the close of the year the well in Beaverton township, Gladwin County, is probably the most discussed of any in Michigan and may be opening a new field of some proportions. It had an initial production of 70 bbl. daily from the Dundee lime at 3830, which has decreased to 25 bbl. per day. Deeper drilling into the lime may increase production. During 1935 the area around this test will probably be the most active in the state. Structural conditions in Gladwin County, as in other parts of Central Michigan, are obscured by a thick mantle of glacial drift and it will take considerable drilling to outline subsurface conditions accurately. The most important new shallow gas area of the year is around Edmore in Mecosta and Montcalm counties. Eight wells have been drilled to the Michigan stray and the upper Marshall sand, having a combined initial production of 30 million cubic feet. These gas wells are scattered over so wide an area that an estimate of proven territory cannot be made until more drilling is done. At the present time no gas is being sold from Edmore.

Jan 1, 1935

By J. E. Powell

Introduction The disposal of mine tailings, development rock, and other unwanted refuse material underground in mines by using pneumatic conveying techniques has been undertaken in the coal industry for many years. Similar equipment has been utilized for backfilling hard rock mines and is currently being applied in a gold mine in South Africa where development rock is being stowed in the mined-out stopes to help reduce the incidence of rock outbursts. On a limited scale, pneumatic conveying has been applied for backfilling uranium mines and one particular mine in New Mexico, U.S.A., has used this technique for 8 years. Other uranium mines in this area are now considerinq the dry backfill technique to eliminate the problems associated with hydraulic fill. The need to backfill in uranium mines is primarily of importance to improve ventilation, stabilize the pillars and roof, and possibly to extract a larger percentage of the uranium ore. If this can be achieved by utilizing the tailings from the beneficiation plant and using rock from the development headings which in itself may be slightly radioactive, then a greater benefit can be derived. Backfill can be achieved with hydraulic fill methods by running slurry into the stopes and allowing the water to decant and return through the footwall development entries to sumps for pumping to the surface. However there are several disadvantages associated with this method in that water is percolating throough the mine workings; it is necessary to build bulk heads in flat lying deposits; it is difficult to fill right to the back; and the decanted water takes with it quantities of the finer sand particles which results in maintenance problems with the mine pumps. Pneumatic conveying can overcome these problems in that the voids can be completely filled with high degree of compaction, heavy bulk heads are not necessary, the development rock can be added to the pneumatic system for disposal underground so eliminating hoisting cost to the surface, and cement can be added to the wetted material. To

Jan 1, 1980

By H. W. Camp

The past year has had no revolutionary change in the process of petroleum refining, although there have been improvements and developments in practically every phase of operation, due largely, perhaps, to economic pressure. A few years ago, a Mid-Continent skimming plant using 35 gravity crude obtained 28 per cent. gasoline and naphtha; 9 per cent. kerosene, and the remaining yield gave gas oil and fuel oil. Figuring manufacturing cost, but not including sales, transportation, overhead and depreciation, the realization was $1.45 per bbl. of crude. Today, a thoroughly modern and up-to-date skimming plant, having all latest equipment, shows a realization of $1.74 per bbl. on the same basis. Thus it is evident that progressive developments have taken place in the last 2 or 3 years when potential earnings have been increased about 20 per cent. The average refiner is compelled to exert his utmost ingenuity in order to operate with a profitable margin. He has two factors to consider—recovery of maximum yields of profitable oils and the reduction of operating expenses. For the past 8 years, the margin between price of gasoline and cost of crude has grown narrower, constantly. Both these prices are determined by external conditions and not by the refiner himself, but the refiner might have been able to increase that margin had he more carefully controlled his output, limiting his production of light oils to current consumption. Be that as it may, this same economic pressure has given impetus to progress in improvements of primary distillation equipment, including stills, towers and heat-saving devices. A pipe still and bubble cap fractionating equipment can now replace a battery of shell stills, giving better yields, better control, elimination of rerunning and lowering of operating costs. The most recent pipe stills are being equipped either with radiant-heat furnaces or air-preheating systems and improved heat exchange equipment. These can be operated on a fuel consumption as low as 1 per cent. of the charge as compared to a fuel consumption of

Jan 1, 1929

By Chao Yang, Liguo Tian, Yan Yang

"The Jinfeng gold mine is one of the three gold mines that Eldorado Gold has in China and it is the second largest gold mine in China. The mine is located in a relatively remote and mountainous area in the southwestern Guizhou province. The orebody is similar to the Carlin type deposit in Nevada. The mill throughput was designed to treat 3,600 tones per day. The ore comes from open pit mining and underground mining, and is fed to one-stage jaw crushing. The crushed ore is stockpiled, reclaimed and then fed to the SABC grinding circuit. After classification with hydrocylones, the ore is floated, and the resultant concentrate is oxidized biologically in a process known as BIOX®. The oxidized concentrate is then washed in a CCD circuit and finally leached with cyanide in a CIL circuit for gold extraction. Jinfeng produces about 180,000 oz of gold per year.This paper introduces operations and modifications of SABC circuit over the past three years, and then describes some technical characteristic of the SAG mill and other circuits in the processing plant.Major modifications and improvements on the SABC circuit are described in the paper, including:1. Impacts of grinding ball and mill liner with respect to material selection, quality, hardness, manufacturing methods, and interactions between mill liner and grinding ball.2. Effect of milling operation parameters on milling efficiency.3. Impacts of SAG mill scats and modifications of grate size to improve mill throughput.4. Design and construction of a pebble crushing system, and recycle the crushed scats to the SAG mill to improve mill throughput.With the above-mentioned modifications, 20% increase over the design in mill throughput has been realized over the past three years, and operating cost has been significantly reduced. However, some issues still remain, and thus process modifications and technical innovations are still needed."

Jan 1, 2012

By Basil B. Zavoico

Production of crude oil in the U. S. S. R. during 1939 is estimated at, 226,111,000 bbl., as compared with 219,778,000 bbl. in 1938, an irlcreasc of 2.88 per cent but some 6.00 per cent under the planned output. During the past year a major readjustment took place in Russian oil fields, with the Grozny district falling into the third place, its former place having been taken by the fields of the Maikop-Kuban area of northwestern Caucasus. Production continued to grow in the Ural-Volg:t district and further large increases in this province in the coming years are certain. The drilling operations continued to be most unsatisfactory, falling far behind the plan, possibly as much as 25 per cent undvr the set objectives, and thereby interfering with the production plans, mora particularly since the Soviet oil industry is still based primarily upon the production from the naturally flowing wells without any proration whatsoever rather than upon stabilized production from either prorated oil wells or those operated with various mechanical lifts. The year 1939 started with the fulfillment of the drilling programs to the extent of about 90 per cent, but the situation rapidly deteriorated arid by the second half drilling programs were being fulfilled only to the extent of 60 per cent or less. Such breakdown in drilling operations was possibly due to poor equipment, which has not been able to stand increasing demands upon it, and this is substantiated by the rccent orders plaeed in the United States by the Soviet Government for some 60 drilling rigs of the latest design. Production Baku District.—-The fields of the Apshcbron Peninsula (Baku district) made a notable progrress during the past year and were able slightly to increase their production, to 166,000,000 bbt. as compared with 164,692,-000 bbl. during 1938. The c.rnphasis of production in the Baku district remained on the flowing wells, about 20 per cent of the total number of wells flowing about 70 per cent of production. During 1939 some 550 wells were complr.tcd in the Baku district with active rigs averaging

Jan 1, 1940

By J. D. A. Morrow

This discussion relates to the distribution of coal under the di , of the U. S. Fuel Administration beginning Apr. 1, 1918. At t' L a definite method of controlling and directing distribution was put int effect. Prior thereto, although some of the machinery utilized was in operation, especially in the few weeks immediately preceding' Apr. 1, distribution had not been effectively and comprehensively organized. The writer was called to the Fuel Administration by Dr. Garfield about the first of February, 1918, to assume general direction of the distribution of coal for the Fuel Administration, to develop the general plans, and to obtain practical men to assist in this work and in carrying through the program finally devised. A study of the situation and conferences with the Fuel Administrator and leading men in the business made it plain that it would be necessary to begin at the bottom, measure the undertaking, develop plans to meet the need thus shown, and build an organization to effect the distribution required. This work had to be done under war pressure in the midst of a bad coal shortage. The successful performance of such a task is always primarily a matter of putting competent men in the right places and giving them the power and opportunity to function properly together. In the Distribution Division of the U. S. Fuel Administration, the men who were chiefly responsible for whipping plans into practical form and then for carrying out these plans were A. W. Calloway, of Baltimore, President of the Davis Coal & Coke Co., who served as the Director of Bituminous Coal Distribution; S. Lovell Yerkes, of Birmingham, Alabama, Secretary of the Grider Coal Sales Agency, who assumed general charge of distribution while the new plans and organization were being perfected and then became the Assistant Director of Bituminous Coal Distribution; Warren S. Blauvelt, of Detroit, who was Director of Coke Distri. bution; A. S. Learoyd of New York, Director of Anthracite Distribution, in connection with the Anthracite Committee, consisting of Joseph P. Dickson, President of Dickson & Eddy, Chairman; S. D. Warriner, President of the Lehigh Coal & Navigation Co., and W. H. Richards,

Jan 1, 1920

By David B. Reger

The year 1935 was mostly quiet in West Virginia, and devoted to routine drilling in old pools and extensions. A notable exception to this general rule, however, was the further development and proving of a field of gas discovered in 1930 in the deep Oriskany sand (L. Dev.) in Kanawha County, as later discussed. No new pools of oil were found and little or no attempt was made to search for them. No new pools of gas were recorded but various extensions of old pools were made. There were no new pipe line extensions of consequence, either for oil or gas. Operating technology was much the same as in recent years, there having been some further advances in repressuring oil wells and in the use of acid for treating small wells in calcareous formations, and some change in the technique of shooting gas wells. Financially, there has been a full market for all crude oil produced and a fair market for gas. There have been occasional transfers of producing oil or gas properties, mainly between established companies. Most of the attempts made to finance mergers and new developments have failed largely because of difficulties encountered under the Federal securities act. This situation has prevented the normal turnover of properties by small operators who frequently desire to sell partly developed interests and then step out into new ventures. New Development In 1935 the State issued 569 permits for drilling and records the same number of completions. One trade journal records 533 completions and another 483. A running record kept by the writer accounts for 713 completions, with 156 oil wells, 417 gas wells and 140 dry holes (Table 3). Some of these completions may be old wells drilled to deeper sands. Some, apparently, have been drilled without legal permit. Extensions of Producing Areas Ritchie County has again led all others in new drilling, with 137 completions as compared to 74 in Calhoun and 61 in Cabell. This Ritchie County drilling was done mainly to extend or further develop old pools

Jan 1, 1936

By Alfred Fisher

CONSERVATION of mine timber is becoming in-creasingly important, and the consumer is en-couraged to use treated wood to permit longer life of mine timbers, and attempts are also made to substitute other material for wood. The great diffi-culty in substituting metal and concrete props for wood is the inability of these to give yielding resistance to roof pressure as wood supports do. In Europe, where mine timber costs are somewhat more important than in America, many designs of steel props have been tried, but have been unsuccessful, chiefly on account of inability to give yielding resistances. A metal pit prop that gives the desired effect has been extensively used in European mines and has caused a considerable reduction in accidents from falls of roof. Where mining operations have been sus-pended on account of strikes, conditions were found to be much better where such props were used instead of wood props, and machinery, which would have been destroyed by roof falls had wood props been used, was protected by the use of these yielding metal props. As this prop is adjustable, all the work of adjusting and transferring long props through narrow ways is done away with. It can also be drawn with greater ease and safety than wooden props; when properly used it is practically indestructible. European users have reported savings as against wooden props as high as 80 per cent. It gives audible warning of its working because the sliding action takes place in minute jerks. As the prop yields gradually to pressure its force is taken up by friction between the H sections, and this movement progressively increases the resistance of the prop to the increasing roof pressure. In the early development of the prop, it was designed with two steel members a and b of standard H steel sec-tions of equal dimensions provided with guide claws a' and b', held in frictional contact against each other by two differential wedges, f and g, and a floating link, e. In setting up the prop its two members are drawn out to the required length, the loose wedge, g, is then fitted into the space between the left-hand roller of the link d and the lower member of the prop b, and tapped suf-ficiently tight to prevent any relative movement of the two members from taking place prematurely. The prop is then raised to its intended position and secured in the usual way.

Jan 8, 1927

The cables brought the news last spring that the Institute had lost by death one of its most distinguished foreign members, Hjalmar Sjogren of Stockholm. For thirty-one years, Professor Sjogren had been one of our number. He was elected in 1891, joining the Institute at the time he was in the United States, in attendance at the Fifth International Geological Congress, which was held in Washington in the late summer of that year. Professor Sjogren was once more in America in 1906 and again in 1913, and on both of those visits his friends in New York had the welcome opportunity of extending courtesies to him. He was thus well known to a wide circle in our membership. His keen interest in the geology of iron ores brought him in touch with the many Americans who have studied them and who have been active in the important productive districts which he visited. Our Transactions contain (Vol. XXXVIII) one very important paper of seventy pages on the Geological Relations of the Scandinavian Iron Ores, which he contributed. Sten Anders Hjalmar Sjogren, to give his full baptismal name, was born June 13, 1856, and was the son of Anton Sjogren, a mining engineer, at the time in charge of the iron mines at Persberg, in the east and west iron-ore belt of central Sweden, about 160 miles west from Stockholm. The Persberg orebodies yielded magnetite and specular hematite from schists, with which limestones. were interstratified as well as the peculiar Swedish rocks called "halleflinte." The mines were also well known to collectors and students of minerals. While Hjalmar Sjogren was yet a lad, his father was advanced to the superintendency of a number of famous mining localities in this same district of Wermland. Paisberg, famous for its native lead, was one; and two others, Langban and Nordmarken, were among the most prolific sources of interesting minerals in all Sweden. In several localities, the pre-Cambrian limestones had obviously experienced the recrystallizing influences of intrusive igneous rocks and had been charged with the so-called "contact" minerals, which have found their way to the museums of the world. Anton Sjogren, the father, was a keen mineralogist and Hjalmar, the son, grew up in a favorable environment for receiving training and enthusiasms of the same sort. One is not surprised, therefore, to find Hjalmar Sjogren, in the long run, turning to mineralogy and geology as his final career.

Jan 1, 1923

By Northcutt Ely

A year ago the petroleum code was in effect, and Congress had before it bills with powerful backing designed to extend and put on a permanent basis the Federal authority impliedly recognized in the petroleum code. Those men in the industry who were convinced of the unconstitutionality of Federal regulation, who believed in conservation, and who were seeking accomplishment of a conservation compact among the oil-producing states, were at that time encountering difficulties in bringing about such an agreement. Since then there has been a shift in the center of gravity. Today, by virtue of the Supreme Court's Schechter case decision, the petroleum code is not in existence, the industry is not operating under an oil administrator, and the Federal-control bills are not on Congress' calendar. In view of what the Supreme Court has said in the Schechter case and the Hoosac Mills case about the local character of mining and manufacturing, the problem today is not whether the Federal Government or the State Governments ought to regulate oil production, but how effective we can make the devices that are available to us under the constitution for the conservation of the nation's oil resources. The interstate oil conservation compact ratified during the past year by Texas, Oklahoma, Kansas, New Mexico, Colorado and Illinois, approved by Congress, but not yet in effect in California, is the mechanism now at work. Interstate Oil Conservation Compact What is this interstate compact? The basic theory is simple and logical. It has four elements to it. The first point is that in order to effect the maximum recovery of our oil arid gas reserves it is necessary for some governmental authority to regulate the way in which those resources are taken out of the ground, so that the reservoir energy is efficiently used, and used equitably by the various owners of the pool. Second, that the state, as distinguished from the national government, possesses the police power necessary to protect the public interest and to protect the correlative rights of the common owners of the oil pool. Third, that the state governments ought to cooperate with each other through an interstate advisory commission so that orderly production in one state is

Jan 1, 1936

By V. R. Garfias, R. V. Whetzel

It has been repeatedly questioned whether estimates of oil reserves are of any practical value, as the greater number of such calculations previously made have subsequently been proved to be grossly inaccurate. But even admitting partial justification for such statements, it must be evident that some idea, however approximate, of the available reserves of essential minerals—petroleum included—is of vital importance in mapping their development and the future trend of the related industries, particularly if it is kept constantly in mind that these estimates are not only never intended as a final word but must continually be subject to revision in accordance with the changes in their component factors. The value of these estimates, therefore, hinges on the clear understanding of what is meant by reserves and that the figures can only apply within the limited time when the controlling factors remain unchanged. It should be understood, further, that while estimates of possible and probable oil deposits are as a rule but idle conjectures, appraisals of proven oil reserves can undoubtedly be made with an ever-increasing degree of accuracy. And it is with this in mind that in the present study the endeavor has been to estimate only the world's proven oil reserves and to leave out of consideration the questionable volume of the probable and possible oil reserves. Such a survey presupposes further a clear distinction between the known amount of oil underground in proven fields at any one time, and the proven reserves: the portion that can be economically brought to the surface and made available for utilization. Only a fraction of the petroleum stored underground in proven fields— usually associated with natural gas—is or can be economically brought to the surface, and not all of the oik brought to the surface is economically utilized; also, although practically all the natural gas can be economically recovered and utilized, in actual practice a large part of the total volume that reaches the mouth of the well is wantonly blown into the air and wasted. It is thus estimated that in the United States only some 25 per cent of the petroleum stored underground in proven fields is actually brought to the surface; and in actual practice close to 25 per cent of the total gas produced is now absolutely wasted. And the dissipation of this

Jan 1, 1936

The stabilization of a gravel road with soil is a method of treatment developed in recent years by the United States Bureau of Public Roads for the purpose of binding the constituents together better, and maintaining a more durable surface. The process consists in adding to the gravel or crushed stone and sand, a soil mortar, so-called, of fine sand, silt and clay, mixed in the proper proportions. The coarse gravel and sand supply structural strength and hardness; the fine sand adds embedment support to the coarse sand; the silt acts as a filler to prevent the granular particles from rocking; while the clay serves not only as a binder but also provides pores minute enough to cause connecting moisture films which are supposed to have high cohesive properties'. It will be recognized that the clay is an important ingredient both when wet and dry, and should not show excessive expansion when wet, nor correspondingly high shrinkage in drying, as otherwise there is danger of unseating the nonplastie particles. Such a stabilized road, although an improvement on one with a floating surface, will in course of time be subject to wear, and become dusty when the clay dries out and breaks up. It has been found that if some salts are added to the road mixture they tend to maintain the soil moisture and prevent dustiness of the road or raveling of the road surface. In addition to this, it is claimed that these dissolved salts cause a thinning of the moisture films on the particles, thus permitting greater compaction of the road mixture, and thereby increasing its density. This fact can be proved by noting the increased compaction which a road mixture shows when certain salts are added to the soil water. Since certain chemical substances such as sodium chloride are electrolytes, the question arises whether they cannot have wine effect on the qualities of the clay in the soil mortar, and perhaps improve them. In view of the fact that certain salts seem to exert a favorable effeet on the road mixture it is desirable that they he held in the road soil as long a time as possible.

Jan 1, 1938

By John Oxenford

There are currently two operators producing oil from the surface-mineable portions of Alberta?s oil sands (Syncrude Canada Ltd. and Suncor Inc.) and two other companies are proposing to enter the industry (Albian Sands in 2002 and True North in 2004). Tailings from the two current oil sands plants contain approximately 220 000 tonnes per year of recoverable TiO2 and approximately 80 000 tonnes per year of recoverable zircon. This represents approximately 6% of the world?s TiO 2 consumption and approximately 9% of the world?s zircon production. With the commissioning of plants by Albian Sands and True North, and the announced expansion of plants by Syncrude and Suncor, it is expected that these tonnages could quadruple in the next ten years. All of these operators have at least 50 years of reserves even at these expanded production rates. The occurrence of heavy minerals in Alberta?s oil sands has long been known and is well documented in the literature. There have been a number of attempts to produce market-grade products from this resource and the results of this work have been quite mixed. Typically, researchers have used the normal mineral dressing techniques of the industry and have found the mineral assemblage does not respond to these techniques all that well. This has led to the widelyheld suspicion that there must be some difficult metallurgical problems associated with this resource. There are three main problem areas that have created difficulties for previous researchers: 1) The bitumen coating on the sand grains; 2) Secondary mineralization such as pyrite, siderite and calcite 3) A high proportion of aluminosilicates (approximately 25%) that have the same gravity, electrostatic and magnetic properties as other minerals in the heavy mineral suite. Recent work by Lakefield Research shows that these problems can be largely overcome with some novel approaches. The bitumen can be removed by washing with a solvent in the presence of a demulsifier. The pyrite can be removed by flotation. And the titanium and zircon minerals can be separated by selective flotation followed by conventional electrostatic and magnetic separation.

May 1, 2001

Industry has a very special request to make. Environmental issues must not be allowed to become a factor of competition so that nations or individual industries can gain economic advantages for themselves by encroaching unduly upon the environment. An international harmonisation of the demands imposed on specific industries and industrial plants where discharges are concerned is therefore essential. The same applies to any to any action contemplated against noxious products. An important step towards that goal is no doubt represented by the United Nations Conference on the Environment scheduled for 1972. Conclusions: Australia must recognise its responsibilities in an inter- national movement to control pollution. It must react on a national scale to a problem which is threatening our whole national environment. To gather, collate and coordinate the information needed to ensure policies which strike a balance between conservation and development, we must look towards the Commonwealth to coordinate the activities of its own instrumentalities and those State and independent bodies working in the area. Financial aid must be provided to stimulate research and later to ensure that environmental protection policies are observed. These policies will be founded on social economic theories which will be both practical and sound, The United Nations conference on the Environment is scheduled for 1972 and in this is the opportunity for international cooperation. Cooperation in the field of controlling legislation and the collection of much needed data. There is an imperative need to assemble facts for world use - an international know-how bank which acquires the most sophisticated technology of process design and waste purification. Arising out of this Conference, is it too much to expect that there could be established an international authority for environmental control, whose activities are governed on a multi-national basis? Such an organisation would have as its primary concern the collection and classification of official regulations, as well as the sheer collation of data to permit economic evaluation of the costs of conservation of the environment. There is an international scope with different factors involved, including industrial technology: in other words, the concrete measures taken against industrial pollutants ought to be more or less identical for similar industries irrespectives of the countries in which they operate. The assembling of an international common foundation of knowledge is imperative so as to acquire the most sophisticated technology of process design and waste purification available for all who are interested.

Jan 1, 1971

By Richard McCaffery

THIS paper considers certain aspects of the acid Bessemer process, particularly in its relations to the duplex process-that combination in which the pig iron is first desiliconized and decarburized in acid Bessemer converters and then dephosphorized in basic open-hearth furnaces. The acid Bessemer process employs an acid-lined converter and produces an acid slag. The blow is usually thought to eliminate the silicon and manganese as oxides and then to burn off the carbon as carbon monoxide. On account, however, of the relatively large amount of metallic iron present in the converter, compared with the relatively small amount of the impurities it is desired to oxidize, the first reaction in the converter probably is the formation of iron oxide, which dissolves in the bath and acts as an oxygen carrier for the silicon and carbon. As soon as iron oxide is dissolved throughout the bath, the oxidation of silicon commences; but in the early stages of the blow the mass law would indicate that iron oxide must form first, and this oxide probably increases up to some saturation point. The molten metal in the converter from the early stages of the blow right through to its completion remains basic, while the slag produced is siliceous. This fact is shown by the corrosion of the acid bottom and the tuyeres, which is greatest at the tuyere orifice where oxidation is most active and where there is the most iron oxide. Why does this acid bottom corrode? Because it is attacked by a base. The thought, therefore, suggests itself, why not make the bottoms of basic or neutral material?1 As the converter slag is acid, those parts of the converter coming in contact with the slag should be acid; but those parts of the converter that are in contact with the molten metal saturated with metallic oxides should be basic or neutral. Bessemer operators have for some time tacitly admitted this condition, for the blast pressures have steadily increased with the object of keeping the metal in suspension, and so preventing bottom corrosion; if the molten metal were not basic, it would not attack an acid bottom. In addition, the tuyeres are bunched together at the middle of the bottom and a clear space is left around the outside of the bottom; if tuyeres are placed too near the side walls the

Jan 8, 1920

By Saba Mohan

This study presents results based on the Pile Installation Demonstration Project (PIDP) that was conducted as a part of the East Span San Francisco-Oakland Bay Bridge Seismic Safety Project. For the three full-scale pile installations, two different high-energy hydraulic hammers were selected for the installation. However, these hammers may not have sufficient energy to drive these large diameter piles at their ultimate capacity following long-term set-up. Nevertheless, these hammers were selected because, soil plug behavior, the generation of excess pore pressures and remolding of soil during driving were expected to reduce the shaft and end bearing resistance, and therefore reduce the energy required to drive these piles to design penetration. Data collected during continuous installation driving and after a series of re-strikes at different set-up times ranging from 1 to 33 days were used as input data for CAPWAP. These results were used to estimate the soil resistance along the pile length and at the toe of the pile, and the soil pile set-up behavior. Validity of the procedures used to predict the soil resistance to driving and predicted blow counts were verified with the field observed blow counts and the energy that was delivered to the pile. Based on combined CAPWAP analyses, the soil pile set-up with time was estimated and compared with results of other methods currently available in the literature for predicting the soil pile set-up rate.

Jan 1, 2002

By Maxwell Adams

Considerable interest has recently been developed in sage-brush oil because of its possible utilization as a flotation agent in the mining industry. A list of some of its physical properties, together with the method used in its extraction, may prove of interest at this time. Something over a year ago, a study of the essential oils in desert plants was begun in the Chemical Laboratory of the University of Nevada. None of the oils so far studied possess properties of special interest to engineers, except the oil of sage, Artemisia tridentata, which has exceptional power as a flotation agent. This plant, known as common sage brush, also called black sage, is widely distributed over the semi-arid West, being found quite generally on most of the dry plains and mountains west of Missouri. The method of extracting the oil followed in these experiments is very simple. The leaves, twigs and small branches are placed in an airtight drum, having a capacity of about 27 cu. ft. Steam is admitted through a number of ,small openings at the bottom of the retort, and the pressure maintained at 20 to 25 lb. per sq. in. for 3 hr. The escape of the steam from the retort is regulated by allowing it to pass through a stop-cock into a condenser. The water in the receiver is drawn off from time to time and the oil, which is insoluble and floats upon the water, is thus collected. At the end of 2 hr. most of the oil has been driven out, though traces continue to come over for a much longer time. By raising the pressure, the time required could probably be shortened and the yield increased, but the lack of laboratory equipment has prevented the carrying out of this experiment. The stock wood, bark and branches contain no oil, the distribution of the oil being limited to the leaves and young shoots. There is a seasonal variation in the amount of oil contained. Samples collected on different dates gave the following amount of oil: May 1, 0.42 per cent.; May 27, 0.6 per cent.; June 30, 0.72 per cent.; Aug. 1, 0.9 per cent.; Sept. 10, 1.0 per cent. The increase appears fairly constant from early spring, when the leaves first appear, until light frosts occur in the autumn. When the plant is air-dried there is some loss of oil, as the following data will show: Two 100-lb. samples were collected at the same time. One was distilled when green; the other was air dried for

Jan 1, 1917

By T. H. Brien, O&apos

At nearly all of the copper smelters in the Southwest, at some time, calculations have been made having in view the economy of replacing fuel oil with pulverized coal as a heat-producing medium for smelting operations This matter has been, and is more so now than at any time heretofore, of very great importance. Due to the intensive development of oil-producing areas of the world and the tremendous use of fuel oil for many purposes, it seems that before many years the supply of oil will become so small as to prohibit its use for such operations as smelting. This may be caused by prohibitive prices, or even by government decree as a conservation measure. In the event that the use of fuel oil becomes out of the question, the copper companies have just two alternatives: the use of pulverized coal or electricity. The copper companies of the Southwest produced an average of 808,400,000 pounds of copper per year for the war years of 1916, 1917 and 1918. This figure is, of course, a higher one than has prevailed since the war, but at the present time nearly all of the mines and smelters are getting back to capacity. There is no doubt whatever that the consumption of copper is going to increase, perhaps for the next ten years. This means that more copper mines will be discovered and developed, and that the mines which are now producing will be called upon for a greater production. This all tends to show that the mine manager who is looking ahead must develop some substitute for fuel oil in the event of its use becoming prohibitive, and all indications seem to point in that direction. The only coal which is commercially available to the smelters in the district under discussion must come from Colorado and New Mexico. These coals are high in ash and volatile matter and comparatively low in calorific value. The proximity of the smelter to the coal mines is a large factor in determining which fuel is more economical. Most of the smelters within two or three hundred miles of the coal mines find it more profitable to burn coal, while those at greater distance find that the higher freight charges on the coal make the use of oil more economical.

Jan 1, 1923

By Pierre J. Goossens

The coastal Cordillera around the Panama basin is made up of a Cu-rich tholeiitic volcanic belt representing either immature, late Mesozoic, island arc, or oceanic ridge. The same belt is exposed (uplifted) along the western slope of the Cordillera Occidental of Ecuador and Colombia. Ni-lateritic, Cr-podiform, and Pt-(Au) placer deposits are formed there after or within ultramafic bodies of oceanic association. Younger calc-alkaline igneous activity provided the mechanism for porphyry copper and associated ore formation. This Cu (+Mo) mineralization occurs along a narrow belt exposed by the erosion of the volcanic cap. Ag-Pb-Zn(-Au) and Hg volcanogenic mineralizations occur within the calc-alkaline belt, but slightly eastward and only above the copper belt. To the east and in the Venezuelan Andes, Paleozoic and older sediments, volcanics, and metamorphics contain volcanogenic massive sulfide, Pb-Zn, Au, and Cu sedimentary and vein deposits, and sedimentary iron ore and phosphate. The Cenozoic Cu, Ni-Pt-Cr and a portion of Ag-Pb-Zn, Hg, and Au mineralizations occur within or just above the oceanic basement whereas the eastern- most Cenozoic Ag-Pb-Zn mineralizations occur within and above a pre-Cenozoic sialic basement. This continental crust is the northern extension of the Peru-Chilean Andes where no oceanic crust has been preserved, however. Cenozoic metallogeny and subduction relationships are unclear in the Northern Andes. Yet strong structural volcanogenic ore controls exists apparently due to deep strike-slip movement between two plates.

Jan 1, 1977

By Persifor Frazer

These properties, owned by Mr. William A. Butcher, of Philadelphia, are in the Panuco Mountain, which lies about thirty miles southwest of the town of Candela. It is a granite which penetrates the surrounding limestones and contains the famous copper-mine to which it gives its name. This mine, which is the property of a company in Philadelphia, has long been known to produce gold as well as copper from almost all its parts; and in corroboration of this be it said, that the undersigned has washed gold from a number of places where the works of the mine or natural sections had exposed the decomposed granite to view in the state of kaolin. It is well known that these junction- or contact-planes between two different formations are often the lodging-places of much freemilling gold, which through fissures are sometimes carried long distances perpendicular to the strata and into the interior of the formation. The structure of the Panuco Mountain, with its outlying spurs and adjacent foot-hills, forms a most instructive and unusual study. At a rough guess the area covered by this mountain will equal, perhaps, twenty-five to thirty square miles ; but its singular feature is the intimate welding together of two formations into one topographical unit. The lines of division between the granite and the calcareous sandstone are of such complicated character that they could not be mapped on a small scale. Unlike the majority of such contacts, the divisions between formations are not always marked in the Panuco Mountain by gulches, valleys, and streams (or the dry beds of the latter), but in the portion of the mountain which lies south of the Panuco copper mine, the lines of junction of these formations cross the gulches and promontories, and, in some instances, cannot be traced by any such topographical features. The house of the Panuco copper mine is 3742 feet above oceanlevel (by rough barometric observation), and the gold-mine about to be described is 235 feet above this, and about two miles distant,

Jan 1, 1886