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By Hiram B. Woon

Uranium ore deposits in the Lisbon Valley area are in an arcuate belt, 15 miles long by one-half-mile wide, on the southwest flank of the Lisbon Valley anticline. They range in size from 500 to 1,500,000 tons and by mid-1965 had yielded 6,147,000 tons containing 48,530,000 pounds of U3O8. Ore bodies average 6 feet thick, are tabular, amoeba-shaped masses, concordant to the bedding, and are in the thickest, lowest sandstone unit of the Moss Back Member of the Chinle Formation of Triassic age. The host rock is predominantly a fluviatile, calcareous, fine-grained to conglomeratic sandstone. Uraninite, the principal ore mineral, fills the pores in the sandstone and partly replaces sand grains and fossil wood fragments. During Late Permian and Early Triassic time pre-Chinle Formations were arched to form the ancestral Permian anticline. Moss Back streams truncated Moenkopi and Cutler beds which capped the ancestral anticline and then covered it with fluviatile elastics, which were subsequently covered by thousands of feet of Triassic, Jurassic, and Cretaceous sediments. Uranium, probably derived from the Chinle Formation by diagenetic processes, was transported in connate ground waters, was moved by compaction or hydrostatic forces, and was deposited under reducing conditions. Uranium was emplaced around the crest of the ancestral anticline, prior to the Laramide orogeny. During the orogeny, the Tertiary-Lisbon valley anticline was super induced on the Permian anticline and, penecontemporaneous with uplift, was faulted parallel to its longitudinal axis. The Big Indian ore belt on the southwest flank footwall block was elevated to approximately its present position, and the northeast flank hanging wall block was elevated only slightly. An extension of the Big Indian ore belt around the northeast flank of the ancestral Permian anticline may exist in the Moss Back sandstone in the downthrown block northeast of the Lisbon Valley fault.

Jan 1, 1968

By Stewart, J. B.

THE property at which this work was done consists of a large deposit of potash salts occurring in massive beds of rock salt, overlain by 600 ft. of salt-impregnated shales and marls. It is in the Province of Cataluiia, Spain, about 45 miles from the railway station of Mauresa and about a mile south of Suria. In addition to sinking the shaft, the program of construction work laid out by the European owners (not Spaniards) included a single-track narrow-gage railroad from Mauresa to the mine; one large office building and several large shop buildings, all of brick and concrete with steel truss roofs; two extensive benches for the future recovery plant; and a large village of stone dwellings for employees. The pay-roll showed approximately 1200 to 1500 men employed. After two years' operation, ending early in the autumn of 1920, the shaft had been sunk 325 ft. and still had an equal distance to go to reach the potash; all tunnels for the railroad were done and the road-bed $0 per cent completed; only a little more than the foundations were completed for all the large buildings, and the excavations of the benches were about 75 per cent done-while only a fair start had been made upon the employees' village. This was the state of affairs when the European owners decided to offer this property under a one-year option to an American syndicate, providing that they agreed to carry on the entire building program and to sink the shaft as fast as was consistent with the quality of work which they demanded, for they wished the shaft to endure at least 200 years.

Jan 1, 1926

By E. R. Shorey

FLOTATION-Mill operator's have recognized that slimes are detri-mental to the flotation concentration of zinc ores. The, presence of primary slime in many of the Wisconsin ores is largely responsible for the failures experienced in treating these ores by flotation. These failures have discouraged the adoption-of the flotation process by opera-tors in the Wisconsin zinc district. The removal of slimes by decantation seemed to be the obvious way to meet the problem of treating slimy or' clayey ores by flotation. To facilitate the removal of slime, it was decided to mix the ore pulp with sodium silicate, which acts to deflocculate the pulp.1 Deflocculation causes slime suspension, making it possible to separate the slime from the sands by decantation.2 Since the literature contains little definite information on the use of sodium silicate to deflocculate ore pulps, a series of tests was conducted to obtain the necessary information. Tests to determine the settling rates of sand and slime in deflocculated pulps were conducted on a dolomite-marcasite-sphalerite ore ground to minus 80 mesh (175 microns) and mixed with water to form a pulp. The deflocculator3 was Mallinckrodt 40° to 42.5° Bé. liquid sodium silicate (Na20 + 3.25Si02). .By microscopic analysis the suspended slimes4 were found to be minus 15 microns (approximately 1000 mesh).

Jan 1, 1934

By George J. Young

(Cleveland Meeting, October, 1912.) I. GENERAL. THE recurrence of mine-fires in Nevada during the past decade is not only a matter of interest, but also one of considerable concern to engineers and mine-managers. The more important fires may he enumerated as follows: Forman Shaft fire., Gold Hill, April 21, 1903 ; shaft-house, machinery, and shaft, destroyed; loss estimated at $50,000.; Cause Unknown. Union Shaft fire, Virginia City, July 14, 1904; shaft-house, machinery, and shaft in part destroyed; loss estimated it $100,000; cause of fire stated as the careless throwing of a match in the rope-house. Sutro Tunnel fire, Virginia City, Jan. 27, 1909 ; 700 ft. of tunnel-timbering destroyed, and direct damage of $10,000; cause ' probably electric wires." Belcher Shaft fire, Gold Hill, Aug. 9, 1910; shaft-house destroyed, machinery ruined, and upper part of shaft damaged; damage, $25,000; no cause given. Belmont Mine fire, Tonopah, Feb. 23, 1911; fire started in winze ; 17 men killed. Giroux Mine fire, Kimberly, Aug. 23, 1911 ; fire originated iii shaft-station from unknown cause; 7 men killed, and $34,¬521 damage caused. (NOTE 1.-On June 11, 1912, some time after the present paper was written, a fire broke out in the pump-room on the 2475 station of the Ward shaft, Virginia City. This fire was caused by the short-circuiting and exploding of the starting-switch on No. 5 pump. The oil in the switch was scattered about and set fire to the timbers and laming of the pump-room. The pump-roan in charge notified the surface, and the * Professor of Mining and Metallurgy, Mackay School of Mines.

Oct 1, 1912

By Robert E. Sorenson

EXPLORATION for deep-seated orebodies in the Silver Belt area of the Coeur d'Alene mining district is complicated by meager surface expressions of diagnostic criteria, lack of knowledge of the significance of specific alteration phenomena, and the great expense involved in the exploration for ore shoots, the tops of which often occur near sea level elevation or below and as much as 4000 ft or more below the surface. Except for the early studies of Ransome and Calkins in 1903 and 1904,[1] little geological work was done in the Coeur d'Alene district for many years, and it is only during the last 15 to 20 years that complete and careful geological mapping has been applied to most of the mines in the area. Much early information, which now would prove invaluable, is lost in hundreds of miles of caved and inaccessible mine openings not mapped by mining geologists. In more recent years mining geology has become a tool of greater use in the district, and some measurable progress is being made in the accumulation of observations that are adding gradually to the knowledge of ore deposits in the district.

Jan 7, 1951

By Karl S. Hughes

ANY one of the mining engineers who spent three years under the benevolent and protective custody of the military forces of His Imperial Nipponese Majesty will admit that he has survived a most disagreeable experience, but our friends here in the States all demand that we tell them something about our thrilling adventure. Many of the younger men who were on Luzon in December 1941 joined up with the Army, either as civilian technical employees or through their reserve officer status. They served through the Bataan and Corregidor defense and had five months of thrills and hardship, if that is what constitutes adventure. Unfortunately, too many of them are not alive to tell their stories. But for most of us, our internment as alien civilians was just one long, drawn-out pain in the neck. Yes, we starved; yes, we contracted beriberi, dysentery, typhus, dengue, and for a while had no quinine to fight the ever-present malaria; but these things are not exciting, neither is the account of them interesting. Our contingent from Mindanao, 250 .in number including 25 mining men, went through one period of starvation at Davao. When the activity of the Allied fleet interfered with the importation of staple foodstuffs, and the natives stopped bringing fruit and vegetables into the market, the food situation became acute, and in December 1943, with stocks in sight and in prospect insufficient to provision their own soldiers, our custodians decided that we must be moved to Manila. The story of that ten-day voyage in an antiquated Jap freighter is too disgusting to tell, but hardly more adventurous than the account of a game of solitaire.

Jan 1, 1945

By O. W. Shimer, D. C. Helms, C. E. Brown

The early history and progress of anthracite stripping, from the first known operation at Summit Hill in 1821 through 1917, was covered in 1917 in a paper by J. B. Warriner,1 then chief engineer, now president of the Lehigh Navigation Coal Co., and stripping methods between 1917 and 1931 were the subject of a paper in 1931 by H. H. Otto,2 of the Hudson Coal Company. The present paper is confined to methods used today on pitching beds in the western middle and southern anthracite fields. The anthracite industry, not unlike other large industries, had been affected for more than a decade by the adverse economic conditions of the country. High development and operating costs and the competition of other fuels caused some collieries to be closed temporarily, while others were permanently abandoned. In order to obtain a larger tonnage at a lower development cost, a larger stripping program was put into effect by many companies. In 1932, stripping operations accounted for 3½ million tons, or 7 per cent of the total anthracite production of the year, and in the next 10 years this increased until more than double that amount, or over 14 per cent of the total production, was from stripping operations. These figures represent the total production of the entire anthracite region; unfortunately, the figures have not been separated from the different fields. There are some operations in the southern and middle western fields where the tonnage obtained from stripping amounts to more than 30 per cent of the total colliery production. Stripping operations on pitching beds present difficult problems. Owing to the various geological formations, a different situation is encountered in nearly every stripping pit; and because of the proximity of an overlying bed, it is very often necessary to load the entire overburden into trucks and haul it out of the pit to the dump area, although back filling and casting is done whenever possible. Beds in the areas described in this paper pitch from 20" to 90° and some are on the invert in many sharp folds and faults. Planning The more successful strippings have had adequate engineering analysis. Some work is being done without much preliminary planning, but many strippings would have failed completely if close supervision by the engineering department had not been maintained. Locations of stripping areas are determined as follows: I. By constructing cross sections over the areas and drilling sufficient diamond-drill or well drill holes to study the strata and to determine the location, thickness and pitch of the beds.

Jan 1, 1946

By O. W. Shimer, D. C. Helms, C. E. Brown

The early history and progress of anthracite stripping, from the first known operation at Summit Hill in 1821 through 1917, was covered in 1917 in a paper by J. B. Warriner,1 then chief engineer, now president of the Lehigh Navigation Coal Co., and stripping methods between 1917 and 1931 were the subject of a paper in 1931 by H. H. Otto,2 of the Hudson Coal Company. . The present paper is confined to methods used today on pitching beds in the western middle and southern anthracite fields. The anthracite industry, not unlike other large industries, had been affected for more than a decade by the adverse economic conditions of the country. High development and operating costs and the competition of other fuels caused some collieries to be closed temporarily, while others were permanently abandoned. In order to obtain a larger tonnage at a lower development cost, a larger stripping program was put into effect by many companies. In 1932, stripping operations accounted for 3½ million tons, or 7 per cent of the total anthracite production of the year, and in the next 10 years this increased until more than double that amount, or over 14 per cent of the total production, was from stripping operations. These figures represent the total production of the entire anthracite region; unfortunately, the figures have not been separated from the different fields. There are some operations in the southern and middle western fields where the tonnage obtained from stripping amounts to more than 30 per cent of the total colliery production. Stripping operations on pitching beds present difficult problems. Owing to the various geological formations, a different situation is encountered in nearly every stripping pit; and because of the proximity of an overlying bed, it is very often necessary to load the entire overburden into trucks and haul it out of the pit to the dump area, although back filling and casting is done whenever possible. Beds in the areas described in this paper pitch from 20" to 90 and some are on the invert in many sharp folds and faults. Planning The more successful strippings have had adequate engineering analysis. Some work is being done without much preliminary planning, but many strippings would have failed completely if close supervision by the engineering department had not been . maintained. Locations of stripping areas are determined as follows: I. By constructing cross sections over the areas and drilling sufficient diamond-drill or well drill holes to study the strata and to determine the location, thickness

Jan 1, 1944

By Young C. Kim, William C. Cassun

A proper economic analysis of pit slope design must reflect the trade-off between the benefits and the increased risk of slope failure inherent in steeper slope angles. This paper describes the results of a case study in which a newly developed probabilistic economic analysis procedure was applied to the selection of a pit slope design at a large porphyry copper mine in the southwestern U.S. The paper also demonstrates the availability of the required data such as the probability of failure schedule and cost of failure models, under "real-life" conditions.

Jan 1, 1978

By C. E. Sims, C. A. Zapffe

Many hundreds of publications have appeared during the past 78 years that treat the subject of hydrogen in iron and steel.l05 but conclusions regarding the functions of hydrogen in causing some important defects in steel are still unsatisfactory to many; and other hydrogen-caused phenomena yet remain to be identified with this gas. The most widely discussed of these defects is hydrogen embrittlement, but the conception, perhaps the popular one, that embrittlelnent is due to hydride formation aoes not conform to the known facts.l04 The true identity of hydrogen embrittlement seems instead to lie in a mosaic nature of metal crystals, which is a concept not Yet accepted by most metallurgists. A study of hydrogen embrittlement therefore provides new viewpoints in regard to the crystalline substructure of steel.

Jan 1, 1941

By Michael S. Roscoe

In order to more accurately predict longwall surface subsidence over the Pittsburgh No. 8 Coal in Eastern Ohio, North American Coal Corporation's Quarto Mining Company undertook or participated in several subsidence studies. Due to the changing roof geology and rapid variations in the amount of cover two separate areas were investigated at two different mines to determine the subsidence response if any to these changes. Data generated from these studies were compared with NCB derived,data for accuracy and then used to predict subsidence under houses, gas lines and other critical man made structures. The following report summarizes the results of these studies as well as the subsidence case histories of gas lines, transmission towers, houses and water wells. Problems that were encountered during both phases of this process (investigation and subsequent application) are also included.

F. C. HENDERSCHOTT,* New York, N. Y.-I am going to take, as the text of what I shall discuss, a portion of the second paragraph of Mr. Stanford's paper. It read as follows: "The most vital need of the management is for more brains. The logical course for an engineer ;in charge of an industrial organization is, therefore, to direct whatever forces may be at his command toward the development, training and guiding of-all the brains in his organization. This is easier said than done, for it involves the carrying on toward two objectives, the maximum of productive work and the development of the individuals, who perform it;" and the last sentence of the paper; "Industry has no greater asset than an intelligent workman." The United States of America, at the outbreak of the present war, had the best equipment of any nation in the world. That statement holds not only for our -shops and our transportation systems and our stores and our farms and our homes, but it holds generally.. There was no other nation in. the world that had so good equipment as the United States. There was no other nation in the world that could be called progressive that has such poorly trained workers as the United States. Even Norway, Denmark, Sweden and New Zealand ranked ahead of us. Now that is the, problem, generally speaking, and there was recognition of that fact, a growing recognition which-took form, and one of its forms was what we call the corporation school. Now obviously a corporation has no particular educational functions, but as is said in the closing sentence of Mr. Stanford's paper, or as is implied, an industrial institution is, after all, the reflection of the aggregate of the efficiency of the individuals who compose that organization. There is no way of getting away from that. If your individuals, from your president down, are efficient, if your individual has developed his brains, if he is a trained man, you have got an efficient organization, and if you haven't that condition, you have got weaknesses and your organization is no stronger than those weaknesses. I maintain that the same thing holds for a nation; .a nation is as efficient as the collective efficiency of the individuals who compose the nation, and no more so.

Jan 4, 1918

Fred. T. Greene, Rossland, B. C. (communication to the Secretary): At the beginning of his gaper, Mr. Herzig refers to an article of mine in the Engineering and Mining Journal of January 27, 1900. I would like to add that the method de-

Jan 1, 1901

THE fifth annual convention of coal-operating men, with the usual exposition of coal-mine equipment, was held at Cincinnati, May 7 to 11 inclusive, and was fully up to the high standard set by previous years. This spring meeting has come to be one of the most helpful services to industry performed by the Ameri-can Mining Congress and a center at which operators and engineers easily and quickly get into touch with the newest and best things in practice and equipment. Over 200 exhibitors showed this year and very little if anything that is new `failed to be shown. The ex-hibits were well arranged and adequate rather than elaborate. They attracted the careful attention of the members and guests of the Congress, admission being by badge rather than by ticket sold to, the general public. Eight sessions were held for reading and dis-cussion of technical papers, one for Management and

Jan 6, 1928

R. W. Raymond, New Pork, N. Y.:—I think Mr. Bache has put his finger on the chief source of the danger of dust-, or gas-and-dust, explosions in collieries. 1 mean the persistent determination of the miners' unions to increase their weekly wages by the excessive use of explosives. This would not be feasible if coal-miners were paid by the day; but this form of payment is, for many reasons, not economically practicable; and the universal practice is to pay for the winning of coal according to the quantity produced. If the miner, by using a large amount of powder, can throw down a large amount of coal without corresponding labor on his own part in undercutting and drilling, he will receive more money for less work, provided he is paid for everything—merchantable coal, worth-less dust, slate, and " bone "—resulting from such a method. My attention was called to this matter many years ago by an admirable report of Prof. W. B. Potter, a past- President of the Institute, on the conditions obtaining in this respect in the Illinois coal-field. It was made very clear in that report that considerations of danger to workmen or loyalty to employers could not be relied upon to prevent miners from employing this perilous and wasteful method of increasing their own immediate receipts. So far as I know, only three remedies have been attempted, namely: the enforcement of discipline as to the methods of mining; the refusal to pay for dust, etc., produced by the miners'methods; and restriction upon the use of explosives, effected by requiring the miner to purchase them from the employer, at a price so high as to make it unprofitable for him to use them in excess. All of these attempted remedies have encountered the bitter opposition of the miners' unions. The enforcement of discipline has become almost impossible, if discipline be (as it should be) understood to involve punishment for the violation of rules when no disaster has followed. I

Jan 1, 1910

By C. H. Brehaut, W. N. Taylor, R. S. Douglas, H. A. Shannon

THE name for this new method of mining is derived from a composition of Horizontal, Radial, Diamond, and the drilling is from raises. This method, worked out at Copper Mountain, B.C., is believed to be distinct in many features from other known methods. GEOLOGY The ore deposits of Copper Mountain are related to the Copper Mountain stock, which is an ideal example of the magmatic differentiation in that it grades from a basic gabbro at the border to an almost pure orthoclase-pegmatite core. The "contact" ore bodies lie along the contact of the gabbro and an older complex of volcanics and sediment termed the "Wolfe Creek" formation. These older rocks, collectively referred to as greenstone, had been fractured prior to the intrusion of the stock and were highly metamorphosed during the intrusion. The "outlying" ore bodies are somewhat different in character, though a similar structural pattern prevails. It is believed that a deep-seated magma of which the Copper Mountain stock is a part has given off solutions that caused a partial granitization of some of the volcanics. Mining problems are caused further by the presence of a series of soft barren dikes intersecting a great many of the ore bodies, which are about 30 ft. wide, strike north-south, and dip at a high angle to the east; and are further increased by the presence of four major faults, with a great many minor faults running at acute angles from them. Fault zones average 8 ft. in width, and consist of gouge and breccia. They strike northeast and dip steeply to the northwest. The faults cut through the ore zones and the dikes, and continue on into the gabbro. The general mine structure with two types of ore bodies, bounded by weak walls and intersected by several series of soft barren dikes and major faults, indicated that a method of mining should be devised that would remove the ore at low cost with the least disturbance of the waste walls and dikes. THEORETICAL ESTIMATE OF STOPING WITH THE DIAMOND DRILL After consideration of various methods, the most suitable one appeared to be horizontal drilling to break the ore in a manner similar to shrinkage stoping. Drilling vertical holes or rings from a bench and breaking to an open slot was eliminated because the weak walls of ore, dike or waste would not permit this type of opening. It was then decided to drill either horizontal radial holes from a raise or parallel holes from a slot cut across the ore body. After discussion, the latter method was believed unsuitable, for the following reasons:

Jan 1, 1945

By W. F., Dietrich

THIS paper deals with the- methods of mining the high-grade clays of California. Although the majority of the clay pits in the state are operated on a scale that is small by comparison with most metal mines, this very fact results in a diversity of methods and gives rise to problems of selection of the method best suited to given conditions. Two or three operators in California produce approximately 500 tons per day of a single kind of clay from a single pit. About five varieties of clay are mined on a scale of 200 to 400 tons per day; not over fifteen varieties are mined on a? scale of 50 to 200 tons per day; and more than 50 varieties are mined at a rate of less than 50 tons per day. It is the aim of this paper to delimit, insofar as the data at hand permit, the conditions and scale of operations that favor the selection of each dominant method of mining that is actually being applied at California properties. Details of the occurrence and utilization of the clays of California have been given in a recent bulletin and are not considered here.

Sep 1, 1928

A. Scott Reid, London, Eng. (communication to the Secretary*) :—As a constructor of several glass mine-models, .I have read with much interest the description of the model of the Montana-Toriopah mine-workings by Edmund D. North.

Jan 1, 1910

By Barry S. Epstein

Financing the acquisition of a going coal mine operation has not had the exposure other finance-oriented projects have had. Therefore, C.I.T. feels that coal mining people and financial people should improve their understanding of the factors involved in this important type of acquisition. The discussion consists of two major subjects: analysis of the acquisition of the property, and sources and terms of funding the acquisition. Source and Terms of Funding There is a need to keep the competent medium-sized independent operator in the coal business, especially in these times of energy shortage. The creation of a resale market for coal mines encourages new investment in the coal mining business by medium-sized operators and their financial backers. Who provides debt and equity financing to acquire going coal mine operations and on what terms?

Jan 9, 1975

By Earl R. Parker, Ralph Hultgren

DURING the past year publications in physical metallurgy have not been abundant when compared with the output of prewar years. Nevertheless, some noteworthy contributions have been made to the literature. Because of the necessity for war production, much of the metallurgical effort has been directed towards the solution of problems of production processes. The limited amount of time devoted to other problems is reflected in the small number of papers devoted to nonapplied research, though a few excellent contributions have been made to the fundamentals as will become evident in the following pages. Results of many of the government-sponsored research investigations have been released to the public and are being published in the technical journals. Many more of these papers may be expected to appear in the 1946 publications.. Public distribution of information obtained in the course of these investigations should be of great value to American industries in the postwar era. Continued activity in research of all kinds is apparently assured because of intense

Jan 1, 1946