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By R. C. Kadyk, C. J. Bise

High-voltage cable couplers are convenient and widely used accessories in modern coal-mine power distribution systems to help extend and retract power-feeder cables throughout a mine. Coupler design has tried to keep pace with the industry's desire to move to higher distribution levels, but the increase in recorded failures of 15-kV class couplers, which serve the 12.47-kV and above distribution levels, has inhibited this transition. Problems associated with the effects of partial discharge on high-voltage cable couplers are analyzed. The phenomenon of partial discharge is discussed, a testing standard is developed, and various coupler designs are subjected to its requirements. An analysis of test results and results based on field applications are provided.

Jan 1, 1985

By A. E. Weissenborn

Current knowledge of the substantial resources of zinc that exist in northwestern Washington is reviewed. These zinc-lead deposits are all associated with the Kootenay Arc, a narrow arcuate belt of folded and faulted rocks that dominates the regional structure of Stevens and Pend Oreille Counties and adjacent parts of British Columbia. The deposits of the Arc are only part of a major lead-zinc silver metallogenic province that includes the deposits of the Coeur d'Alene district and the famed Sullivan ore body of Kimberly, British Columbia. Most, but by no means all the zinc-lead deposits of the Kootenay Arc are in carbonate rocks. They occur in several stratigraphic units, and in different parts of the Arc are quite diverse in character. The deposits appear to have undergone a complex geologic history and have not necessarily all been formed at the same time or by the same geologic processes.

Jan 1, 1976

By E. T. Cox

WHILe engaged, in the year 1856, in determining the oil-bearing properties of some bituminous coals from Western Kentucky, by subjecting them to dry distillation in an iron retort, which held about a pint;, and to the neck of which were attached several bottles, for collecting the carbon oils, and washing and measuring the gas, I observed that there was a very great gain in the weight of coke thus made, over that obtained from the same coal when charred in a platinum crucible, as is usual in the laboratory for making the proximate analysis of coal. It was thought at the time that the increase of coke, by the former mode of treating the coal, was due to the pressure which the retarded gas exerted upon the solid carbon, and the possible fixing of a portion of the carbon from the volatile hydrocarbons. For the purpose of obtaining a more definite idea of the effects of pressure on the coking of coals, a series of experiments were made this spring under my direction, by my assistant, Dr. G. M. Levete. The results are highly instructive and full of interest, since they point out some peculiarities in the nature of bituminous coals which

By C. H. Jacoby

Since salt, sodium chloride, is an essential mineral to animals and humans alike, the delineation of the salt deposits of the world has been continuous from prehistoric times. As man explores deeper into the crust of the earth, particularly in search of petroleum, numerous new deposits of salt have been recorded. This paper deals with the factors that equate the current economic value of a salt deposit. The value of a salt deposit is not only determined by the chemical purity of the sodium chloride, but also the method of extraction to be used, the use of the product, and/or the use of the deposit. Salt is basically an inexpensive industrial commodity where large tonnages must be available to conduct a successful mining operation. Therefore, not only must the deposit contain these large tonnages, but also it must be accessible and transported as low cost freight to a large market. The geological environmental conditions surrounding the deposit must be such that it will be conducive to low cost mining operations. These conditions include not only the depth, size, shape, and internal structure of the deposit, but also the characteristics and extent of the overlying ground water.

Jan 1, 1973

By E. F. Evoy

The uranium deposit of Gunnar Mines Ltd. is on south shore of Crackingstone Peninsula in the Beaverlodge area of northern Saskatchewan. The property spans St. Mary's Channel, a narrow waterway separating the mainland from a group of islands in Lake Athabasca. The mine property, consisting of 12 claims and 7 fractions, was staked in July 1952 by A. O. Zeemel and W. J. Blair. Diamond drilling commenced in the fall of that year and continued until the spring of 1954. In that interval, some 70,000 ft of drilling outlined an orebody plunging from the surface south-ward to a depth of 1000 ft below the shore of St. Mary's Channel. The last 9000 ft of drilling was through lake ice, and when this was interrupted by spring breakup, sufficient ore reserves had been established to warrant the present operation. Surface drilling was therefore terminated.

May 1, 1956

By Ralph Sherman

IN these days of intense competition for the domestic fuel market much is heard of the low efficiencies with which solid fuels, and most particularly bituminous coal, are burned in domestic heating equipment. In contrast to the every-day operating efficiencies of 85 and 90 per cent in large, central, electric-generating stations, efficiencies of 50 per cent and lower are cited for the hand-fired home furnace. Just as the miles per gallon of gasoline is only one of the factors that determine the cost of operation of an automobile, so the thermal efficiency is only one factor in the cost of domestic or other heating. The purpose of this paper is to analyze the total costs of domestic heating by various fuels and types of equipment, to determine the relative importance of efficiency and other factors, and to discuss what this signifies relative to the future of the use of fuels in the home.

Jan 1, 1933

By V. H. Wilhelm

Greater stabilization in the petroleum industry was effected during 1934 through stricter compliance with curtailment measures and the establishment of the Pacific Coast Petroleum Agency. Various estimates of individual, company and state reserves revealed the fact that they were inadequate to sustain the present rate of production over a lengthy period, therefore drilling operations were increased during the year both in proved and wildcat territory. This greater activity resulted in the addition to reserves at Mountain View, Mount Poso and Edison in Kern County, Santa Barbara in Santa Barbara County and Playa del Rey in Los Angeles County. Additional reserves were also established in the Long Beach and Santa Fe Springs fields, in Los Angeles County, due to operators being successful in isolating small prolific sand bodies, formerly disregarded during the flush production periods.

Jan 1, 1935

By P. H. Mell

CAN the auriferous slate deposits of the Southern mining region ever be successfully worked? is a question that has been often asked me by persons seeking investments in Southern mines. As the subject is one that has given me much thought during the past few years, I have decided to present my conclusions to the members of the Institute for their consideration. Those who have had the opportunity of exploring the region mentioned above, will readily recall to mind numerous localities, to which their attention was directed by would-be miners, as "rich and desirable properties," in which there were but few quartz seams running in every direction through fine-grained talcose slate. Most of the gold in sued formations was always found disseminated through the slate, and but a small percentage contained in the quartz. Such are the deposits I propose to discuss in this paper. Of course there are many excellent quartz mines in the South that are paying the owners good profits, and many more to my knowledge, that are not being worked for obvious reasons. But it is out of the question to suppose that these slate deposits can be practically

Jan 1, 1881

By Yoshinao Nakada

In many experiments involving electropolishing such as electropolishing during deformation and electrothinning of deformed metals for electron microscopy, it is usually assumed that the specimen temperature is the same as the temperature of the polishing bath. In order to test this assumption, the interior temperature of aluminum single and polycrystals was measured while they were being electropolished. Specimens were 1/4 by 1/4 by 6 in. and were of 99.99 pct purity. A small hole 1 in. deep was drilled axially at one end of the specimen so that a copper-constantan thermocouple could be inserted. The electropolishing solution was 4 parts methanol (reagent grade) and 1 part perchloric acid (70 pct). The electropolishing was performed using an apparatus shown in Fig. 1. The electropolishing solution was stirred by a motor-driven stirrer and was cooled to —5°C with a mixture of methanol and dry ice. Electrolyte temperature was measured and remained at -5°C during the electropolishing. Current density of 0.3 amp per sq. cm was used. When the current was turned on, after about a 5-sec delay, the temperature began to rise rapidly until it reached 65°C. In order to determine whether the temperature measured was localized, the thermal expansion of the specimen was meas-

Jan 1, 1965

By W. L. Austin

AT the Steptoe metallurgical plant, where ore of the Nevada Consolidated Copper Co. is beneficiated, a small copper-leaching annex has been in operation treating flue dust from roasting-furnace dust chambers, together with a siliceous oxidized ore. This leaching plant was designed to obviate smelting low-grade siliceous flue dust, which interfered with the operation of the reverberatories by forming a blanket on the charge The major portion of the copper content of the flue dust accumulating in the upper chambers of the. roaster flue, and at the stack, is water soluble, and also contains much free sulphuric acid and soluble sulphate It was found that sufficient acid could be obtained by mixing this material with water to provide a lixiviant for leaching the siliceous copper o mentioned. This was the sole source of the lixiviant used in the operatic to be described. An analysis of the flue dust showed it to be composed as follows: Per Cent. Copper 3.00 SiO2 23.41 Fe : 4.08 CaO + MgO : 2:72 Al203 6.07 Free H2SO4 19.94 S03 combined as sulphate 25.10 H2O combined With the sulphates 10.67 0 2.50 Total 97.49 Copper soluble in dilute H2SO4 2,56

Jan 7, 1914

By L. S. Castleman, L. L. Seigle

IN a recently reported investigation, J. B. Clark and F. N. Rhines1 used a diffusion couple technique to determine the number of intermetallic phases which should be present in the Al-Mg equilibrium phase diagram. Their method was an application of the following generally accepted principle. If a diffusion couple made up of two metals is annealed at a given temperature for a long time, all the phases of the binary system which exist under equilibrium conditions at the diffusion temperature will form intermetallic layers. It is important that the diffusion temperature be high enough and the diffusion time be long enough to permit the nuclea-tion of all thermodynamically stable phases at the interface of the couples and their growth to observable thicknesses. These simple time-temperature criteria are at times difficult to satisfy, and it is the purpose of this note to point out a situation in which this is the case. The authors are currently studying diffusion bonding in the Al-Ni system." It is well established

Jan 1, 1958

By E. V. Manlapig, David J. Spottiswood

In recent years great advances in the automatic control of flotation plants have been made, mainly due to the development of reliable sensing instruments to monitor process performance and the development of an adequate understanding of system responses to process disturbances. Some of the control strategies used in flotation plants which apply computer control are presented here. These schemes, which involve the control of collector; depressant, frother, and air and pulp level, are analyzed with respect to their control objectives, control variables, and the instrumentation involved. The knowledge gained in understanding these strategies may be applied in the dew and implementation of control system in other concentrators.

Jan 1, 1981

By Robert M. Rudio

Montana is leading the way in the field of mined-land reclamation with new laws and new ideas. The Montana Department of State Lands is combining new legislation and practical application techniques to all mining operations in the state. Road building, stream relocations, or settling systems can be designed to meet the environmental problems. Mineral exploration now requires a new and closer look at drill site locations, road gradients, and exploration tools. The problems and costs of land rehabilitation must be thoroughly understood by the exploration geologist in order to satisfactorily conduct exploration in Montana.

Jan 1, 1975

In one of the largest dredging projects of its kind, Lake Asbestos of Quebec Ltd. is stripping overlying mud and sand from the bed of a lake to reach asbestos orebodies 70 to 200 ft below surface. Black Lake, about two miles long by half a mile wide, was almost overlooked in the search for asbestos in Quebec's ore-rich eastern townships-a search that has been underway there ever since the first asbestos was mined in 1877. Not until 1948 was the Black Lake mineral discovered. Four years later careful exploration was carried out by American Smelting & Refining Co., parent firm of Lake Asbestos. The search involved more than 75,000 ft of diamond drilling and about 5000 ft of underground work. ASARCO, in its first asbestos mining project, decided to proceed with a dredging and draining program to prepare for open pit mining.

Oct 1, 1956

By W. E. C. Eustis

During the last year I had occasion, on behalf of our New York copper works, to send to various chemists samples, intended to he accurate, of material which we were buying and selling, and I was astonished to find what differences were reported. After talking over the probable reasons for this with a number of chemists and metallurgists, it was suggested that it would be of real use and some scientific interest to send samples to the different chemists, and take such care in making up the samples that we could feel sure that each chemist had as nearly identical a sample as it was possible to make. After some consideration it was determined to send a mixture which should carry about 50 per cent. copper, and

Jan 1, 1883

By Dale A. Augenstein, S. C. Sun

A primary concern in the solution of any solid waste disposal problem is the characterization of the material. In the past, available methodology for the determination of coal refuse characteristics has been severely limited by the inseparable combination of organic and inorganic matter of which the refuse is comprised. The recent development of an electronic, low temperature asher which removes the organic material without alteration of the inorganic constituents has opened new areas of coal and coal refuse research. This study deals with the development of methodology for the characterization of Pennsylvania anthracite refuse through utilization of the low temperature asher. Seven samples of anthracite refuse were examined for verification of the methodology developed and information concerning the characteristics of the refuse.

Jan 1, 1975

By H. Baldauf, H. Schubert

The structure of flotation reagents is important for their adsorption on mineral surfaces and thus for their flotation effectiveness. The influence of the structure of organic depressants on the flotation of fluorite and barite with anionic and cationic collectors was investigated using a modified Hallimond microflotation cell. In addition, adsorption, desorption, and electrokinetic results were employed to further elucidate the role and the correlation of the structural parameters for adsorption and the depressing effect. As hydrophilic reagents, different aliphatic and aromatic compounds capable of forming chelates with alkaline earth materials were used. For the depressing effect, the kind, number, and position of the polar groups in the molecule, as well as the structure of the reagent films play decisive roles.

Jan 1, 1980

By J. W. Robinson

The Jersey mine, owned by Canadian Exploration Ltd., has produced nearly five million tons of lead- zinc ore from a flat-lying replacement orebody. A room and pillar method of trackless mining has been used, leaving a checkerboard pattern of 40-ft wide panels, with the hanging wall supported by pillars from 20 to 40 ft in diameter. About 35% of the remaining ore reserve is tied up in pillars. The pillars in the north end of the mine are smaller than the pillars in the south end and each contains about 500 to 1000 tons of ore. The larger pillars in the south end contain from 2000 to 8000 tons of ore each. The pillars vary from 15 to 60 ft high, depending on the thickness of the orebody at any given point. They are irregularly shaped, and from 20 to 40 ft in diameter.

Jan 12, 1963

Open pit operators have found the dropball crane a great aid in cutting costs and hazards of secondary breakage. But a common problem in using the unit has been with the shock absorbing connection from the cable to the dropball itself. Blair Limestone Div. of Jones & Laughlin Steel Corp. has come up with a new connector to solve this problem and to save the time usually lost in frequent replacement of the cable slings, chains, or old tires hitherto used at this point. J&L personnel solved the problem by combining three ideas from other dropball crane owners. Their unit consists of two long U-bolts running through a heavy spring originally made for use on a vibrating screen. Heavy duty swivels attached to the bent ends of the U-bolts provide attachment points for the crane cable and the special chain to the dropball. Connection at the dropball is by an eyelet welded directly into the mass of steel, and a special alloy chain is connected to this with a clevis.

Nov 1, 1955

By Ramachandra Rao

THE occurrence of copper ores at Garimenapenta, 14 59 min 30 sec N Lat., 79 33 min 10 sec E Long., in Nellore district, Madras State, India, has been examined and investigated on numerous occasions during the past two centuries.' No tangible orebody was ever located as a result of all the ex- tensive trenching and shafting done in the area by various agencies. However, during 1933 Messrs. Piepmeyer & Co., a German firm engaged by one of the leaseholders of the area, carried out an electrical survey using inductive methods.' On the basis of certain strong indications found in their survey, they recommended that the prospect be proved by drilling or shafting. But for want of financial backing no further work was carried out. When the Madras government more recently proposed investigation, Dr. Krishnan, then Supt. Geologist of the Madras Circle, urged that before further costly ventures were carried out a test geo-

Jan 1, 1954