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By R. F. Slack, J. C. Draper, J. A. Younkins

In 1959, the Duquesne Light Co. was faced with the problem of moving more than 40 million tons of bituminous coal in Greene County, Pa. The coal had to travel a distance of about 4 ½ miles from a new mine portal in Rocky Run Valley to the company preparation plant and loading facilities on the Monongahela River. After careful study of this immense transport problem, Duquesne decided that the belt conveyor system described in the following pages offered the best solution. This system, now in operation, is probably one of the four or five longest permanent overland conveyor systems in existence. The general layout of the entire system is shown in Fig. I. A detailed description of the salient features of the system is presented below. THE MINE The valley of Rocky Run where the system begins is very, very narrow and very steep. It was chosen as the site of Duquesne's new mine portal because it was the only place on this particular property where the Sewickley coal seam cropped out. The valley also had two other advantages. First, it fronted on a state road and, second, it offered a site where some 4 million gallons of water could be stored for use in dust-allaying sprays needed in the mine. The company elected to construct a drift mine in the valley because this would require neither the hoisting time of a shaft mine nor the walking time of a slope mine. As part of the mine construction project, the valley was leveled by relocating its stream and filling its center with material cut from each side.

Jan 11, 1966

The first discovery of gold in Montana is credited to François Finlay, a half-breed, from the Red River country, in Canada; he went to California during the early days and learned there how to wash the gold from placer deposits; then, on his return, he crossed Montana and found gold on the western slope of the Rocky Mountains, on Gold creek, a minor tributary of the Hell Gate river, in what is now Deer Lodge county. That was in 1852.* Finlay did not find enough gold to induce him to continue at work, but six years later a group of miners, led by the brothers James Stuart and Granville Stuart prospected on this same creek, obtaining about ten cents to the pan. They, however, were harassed by the Blackfeet Indians, and they were also handicapped by lack of proper tools; so they too desisted from further operations. Two years later, in 1860, Henry Thomas started to work on Gold creek with three sluice-boxes hewn out of green timber that he cut on the spot. With this simple apparatus he won from $1.50 to $2.00 per day. This may be considered the fist instance of systematic mining in Montana. Meanwhile the Stuarts went to Fort Bridger, in southwestern Wyoming, where they remained as traders until 1861, when, again lured by the gleam of gold, they returned to the valley of the Deer Lodge and resumed prospecting, using 10 sluice-boxes that were brought from Walla Walla, in Washington, 425 miles distant. In the summer of 1862 they were joined by many others, chiefly from Colorado, in consequence of an exchange of

Jan 1, 1932

By H. C. Howarth

This paper gives observations on ground movement and subsidence resulting from pillar drawing in the Lick Run section of Montour No. 10 mine of the Pittsburgh Coal Co. adjacent to solid coal owned by the U. S. Bureau of Mines at its Experimental mine in Snowden Township, Allegheny County, Pennsylvania. The investigation was planned by George S. Rice, chief mining engineer of the Bureau, who arranged the necessary cooperation with Dr. L. E. Young, vice president of the Pittsburgh Coal Co. Engineers of that company placed permanent monuments on the surface to establish the boundaries of the coal owned by the Bureau and to furnish fixed points to which all levels were referred. Engineers of the Experimental mine staff then covered the ground under observation with a checkerwork of monuments made of oak pegs set into the ground at 50-ft. intervals in two directions at right angles to each other. The level of these pegs was determined first from Dec. 16 to 30, 1929; again from May 25 to June 5, 1930, and finally from July 7 to 15, 1931. Observations were then discontinued because work had been stopped temporarily in this part on Montour 10 mine. General Conditions Fig. 1 is a plan of the part of the area under observation with which this paper deals. The mine is developed on a room and pillar system known locally as half advancing and half retreating. As Nos. 35 and 36 butt entries were advanced, rooms were driven from No. 36 and drawing of the room pillars followed their completion. When the entries reached the boundary, rooms were started from No. 35 butt beginning at that point, and all remaining pillars were drawn as rapidly as possible. The rib lines of Jan. 9 and June 13, 1930, were surveyed a week to 10 days after the first and second sets of levels were run, and there was some advance in that period. The rib line of July 15, 1931, agrees in time

Jan 1, 1934

THE first mention of the mining and use of coal in the Pittsburgh district refers to the mine under Duquesne Heights that furnished coal for the garrison at the fort at Pittsburgh in 1760. Coal had been dug and used as fuel just outside of Brownsville, Fayette county, in 1759, but this was not a regular mine as the opening was in an outcropping. Maps of Ohio in 1770 showed "Cole Mines" at various points. The Penns purchased all the coal south of Kittanning in southwestern Pennsylvania from the Chiefs of the Six Nations for a reported price of $10,000. During the Revolution, coal from Herron Hill, Minersville, and Coal Hill, all within the present city limits, was used in Pittsburgh. There is today one custom pit opened in Coal Hill (Duquesne Heights). The first steam engine was set up in Pittsburgh in 1794 and used coal as fuel. The first mine in the Youghiogheny gas district was opened in 1796. In 1803, the first shipment of coal by water was made from Pittsburgh down the Ohio river and landed at Philadelphia, where it sold for approximately $9.50 per ton. The mines along the Monongahela were naturally the first to be opened. With the completion of locks and dams in 1844, permitting slack-water navigation, the industry began to thrive. The No. 8 field of Ohio and the Fairmont region of northern West Virginia were opened in the period 1840 to 1855. From that time on there has been a continuous development of the coal resources of this district, until at present-productive capacity is enough to supply 30 per cent. of the country's needs of bituminous coal. The original method of working the Pittsburgh seam was to drive under cover at some .easily accessible point on the outcrop with a single entry, usually 1 1/2 yd. wide. Rooms or gangways were turned to the

Jan 10, 1926

By Alan D. Smith

Mine roof fall characteristics of 250 falls in 5 different room-and-pillar coal mines, located in Pike, Martin, and Floyd counties, were investigated to determine the relationship of selected parameters associated with roof failure and the assumed condition of the mine roof before failure. The selected parameters used in the study included: presence of cracks and water before the occurrence of fall, sloughing of coal ribs, floor heave condition, type of roof support (resin or mechanical anchor bolts), distance to coal face, and time of occurrence of fall after initial coal extraction. In addition, research hypotheses, utilizing multiple linear regression techniques, were generated to test the relationship among the selected parameters and mine roof condition. The results indicated that the vast majority of falls portrayed some presence of water before the actual fall, occurred in less than 30 weeks after initial coal excavation, located usually greater than 30 meters from nearest coal face, gave evidence of cracks in mine roof before occurrence of fall, generally portrayed a good roof condition before the fall, showed presence of sloughing of coal ribs, and gave no occurrence of floor heave before occurrence of fall. In terms of the characteristics of the original support systems in the mine roof falls studied, most roofs were either supported by mechanical-anchor bolts or resin or full-column bolts; very rarely did the roof appear to fail if supported by posts or cribs. A detail inspection of the hypothesis and model comparison results gave supporting evidence that the condition of the roof is not dependent on the usual indicators of potential failure, such as presence of cracks and moisture. In fact, in most cases of mine roof failure, the immediate roof condition was rated as good or better, which gives little or no indication of pending failure and collapse. Hence, a combination of factors that are not easily accessible to measurement, are the dominant factors in the determination of roof fall-potential areas.

Jan 1, 1984

By G. D. Jermain

The Bureau of Mines investigated the Gypsum-Camel deposit on Iyoukeen Cove Chichagof Island, Southeastern Alaska, from April 21 to August 26, 1948, as A part of the United States Department of the Interior program for developing an Alaskan construction industry. As gypsum is one of the components necessary for the manufacture of cement and one of the raw materials for plaster and plaster-board products, it is desirable to locate and develop a readily accessible deposit of gypsum in Alaska. In 1928, B. D. Stewart of the Territorial Department of Mines surveyed the gypsum deposits at Iyoukeen Cove, and during the summer of 1946 George M. Flint, Jr., and Edward H. Cobb of the Federal Geological Survey examined and mapped the old workings at Gypsum Creek and the prospect at Iyoukeen Cove. Both the Territorial Department of Mines and the Federal Geological Survey recommended the Gypsum-Camel prospect as warranting a diamond-drilling program by the Bureau of Mines. The Bureau of Mines project consisted of cleaning out and sampling, the old underground workings and diamond drilling from the surface to ascertain the lateral extensions of the deposit.

Jan 1, 1952

By M. J. Ankeny, J. J. Forbes

"One of the main functions of the U. S. Bureau of Mines, as authorized by Congress, is to investigate safety and health conditions, to disseminate information regarding safe and unsafe practices in mining, and to aid in improving safety and health conditions of mining communities and in promoting the welfare of the miner. Among several methods of reaching the miner and interesting him in safety work, perhaps the most effective is through the 11 mine safety stations and 11 railroad cars known as mine rescue, or more correctly, mine safety cars.Frequently, the Bureau of Mines receives requests for information regarding the purpose, equipment, personnel, and construction of its safety cars used in the field service. It is the intention of this circular to present to the mining public in particular, and to the public in general, some definite information regarding these safety cars and their functions.The cars are operated throughout the mining fields of the United States and are headquartered as follows (see fig. 1): Car 1, Reno, Nev.; Car 2, Raton, N. M.; Car 3, Pittsburgh, Pa.; Car 4, Terre Haute, Ind.; Car 5, Pineville, Ky.; Car 6, Pittsburg, Kans.; Car 7, Huntington, W. Va.; Car 8, Duluth, Minn.; Car 9, Butte, Mont.; Car 10, Des Moines, Iowa; Car 11, Anchorage, Alaska.One of the most important purposes of the U. S. Bureau of Mines safety cars is to render service at mine fires and explosions where human life is endangered. State mine inspectors and other interested persons are supplied with itineraries of the car operating in their districts from time to time, so that they may know at all times where the car can be found in case of emergency. When these disasters occur the car may be reached direct or through its field headquarters, and upon receiving word of a mine disaster, or request for assistance, it immediately proceeds to the scene of trouble. Frequently a special locomotive is supplied by the railroads and in many instances the movement of the car is given the right of way over all other railway traffic. Upon reaching the destination, the facilities and personnel of the car are immediately available for rescue and recovery operations.Following most mine disasters a thorough investigation is made by engineers of the Bureau of Mines, and a confidential report is submitted to the operator. The information gained in this manner from a large number of mine fires and explosions, together with the knowledge gained from the experimental work carried on at the Experimental mine of the bureau at Bruceton, Pa., serves as a basis upon which the bureau is able to recommend preventive measures whereby similar occurrences may be averted. The bureau car is often used as headquarters for the investigating engineer when such an examination is being made."

Mar 1, 1931

By H. Mogollón

El presente texto señala el proceso de fabricación del alambre y cobre en la Cerro de Pasco Corporation, así como los métodos adecuados para su elaboración. Bajo el amparo de la ley 13270 de promoción industrial nace la Compañía Industrial del Centro, subsidiaria de dicha corporación, y responsable no solo de la producción de barras y alambrón de cobre, sino de la producción de ácido sulfúrico en La Oroya. Actualmente, esta producción se ajusta a 90 toneladas métricas de alambrón redondo de cobre refinado con un diimetro nominal de 7,9375 mil metros. Sin embargo, esta pueda ampliarse hasta un máxlmo de 145 toneladas métricas a través de cambios menores en el equipo auxiliar.

Nov 20, 1967

The introduction consists of back-ground information, of an historical and statistical nature, relating to the Thompson mine. The geological presentation is based on illustrations that are intended to provide a progressively closer look at the ore occurrence. The illustrations consist of an index map, a geological map of a 15-by 85-mile area including the Thompson mine, a series of four maps dealing with the geophysics and geology of a 6-by 4\f.j-mile area at Thompson, a mine level plan and corresponding section, two sto11e 11lans and corresponding sections, and photo-graphs and photomicrogra11hs of the various one types. T HE Thompson mine is located about 400 miles due north of Winnipeg. The ore deposit was dis-covered in February, 1956. Five years later on March 25, 1961, the Thompson production facilities were officially dedicated with the shearing of the first nickel produced at the Thompson refinery. Full production, at an annual rate of more than 75,000,000 lbs. of refined nickel, was attained later in the year.

Jan 1, 1963

By T. G. Pedro, Q. Gonzalo, R. E. Roberto

Anionic surfactants, such as oleic acid and sodium oleate (OLE), and cationic surfactants, such as dodecyl amine-hydrochloride (DDA), are used as flotation collectors of spodumene. However, recovery is poor even if activating ions are used because gangue minerals are also activated. Some reports demonstrate that OLE/DDA mixtures act as a selective collector to enhance spodumene recovery. From mostly macroscopic tests, it has been argued that anionic OLE and cationic DDA form electroneutral complexes, which are adsorbed on the mineral surface through chemisorption; however, no molecular evidence has been presented. Therefore, the adsorption mechanisms of the collector mixtures remain mostly unknown. It seems necessary to first study the behaviour of these surfactants confined in salt solutions, to determine auto-associations when they are pure and cross-associations when mixed, the transition from monomers to micelles, and the structure of the micelles and the effects of pH, temperature and concentration. In this paper, ab initio calculations are first used to determine the surface charge distribution of OLE and DDA separately. Then molecular dynamics simulations are used to determine the conformation, aggregation, and diffusion of these pure and mixed surfactants in freshwater and saltwater with the ionic strength of seawater in a pH range. In particular, it is interesting to determine the various associations that result in mixtures of both surfactants and the impact of alkali and alkaline earth metal cations on the structures formedp. Cations influence the order of the structure and orientation of water dipoles, reducing the mobility of water, ions, and surfactant molecules. This knowledge is critical to improve the molecular understanding of the adsorption mechanisms on minerals. Keywords: Computer simulation, molecular dynamics, flotation, collectors, saltwater

Jan 1, 2020

By C. D. Hunter, I. B. Browning, Ralph Thomas

Production of oil in Kentucky during 1938 was 5,566,154 bbl., showing a substantial increase over that of the year 1937; while in the gas areas development was somewhat retarded although deliveries were similar to those of 1937. In eastern Kentucky there was an oil increase during 1938 of over 150,000 bbl. above that of 1937. No new pools were developed and the increase was almost entirely due to the installation and expansion of secondary recovery methods and to the further development of the Maxon and Big Lime, Mississippian pools in Floyd and Martin Counties. With this development eastern Kentucky reached a level near that of 12 years previous, when the development of several large producing areas had just been completed. In eastern Kentucky during 1938 not over 50 gas wells were completed. Although the pipe-line deliveries were approximately the same as during 1937, development was retarded because of an excess of gas already developed and the intensive development of the Oriskany fields in West Virginia. In western Kentucky, in the part of the Illinois Basin lying in the state and known in Kentucky as the Western Coal Basin, the increase was due to the discovery of a number of new pools, the largest and the one producing the biggest wells being known as the Birk City pool. In fact, the discovery of this pool with the McClosky "sand" (St. Genevieve limestone) as the producing formation was in a large measure responsible for the increased activity, which in turn brought the discovery of the other areas. The discovery well in this pool is the C. T. Blackwell, which came in flowing 1000 bbl. daily from the McClosky sand at a depth of 1870 ft., drilled in April 22, 1938. This discovery, coming at a time when the major companies and many others were conducting an intensive leasing campaign and making extensive subsurface and geophysical surveys in the deeper part of the basin, resulted in renewed activity over the entire area and brought much new drilling. It also brought to Kentucky for

Jan 1, 1939

By C. E. Reistle, G. L. Nye

The East Texas field is in Smith, Rusk, Gregg, Upshur and Cherokee counties, Texas. The discovery well was completed Sept. 8, 1930, near the eastern limit of the field. Within less than one year the new field became the dominant factor in the world production of crude oil. On Aug. 16, 1931, eleven months after completion of the discovery well, there were 1644 wells in the field, and the average daily production was 584,475 bbl. Since that time the number of wells has increased to 8195 on Oct. 1, 1933, and the field has produced 385,979,691 bbl. of oil. The geology of the East Texas field has been discussed by Lahee,1 Levorsen,2 Minor and Hanna3 and others, and it will not be discussed in detail here. The field is a structure of the monocline type on the westward dipping homocline between the Sabine uplift and the East Texas geosyncline. Production is obtained from the Woodbine group, which has been truncated and then sealed by the Austin chalk, which rests unconformably upon it. The oil-saturated part of the sand lies bettween a sub-sea depth of 3050 ft. on the east side of the field, where the Woodbine sand stops and the Austin chalk rests directly upon older formations, and a sub-sea depth of 3320 ft., which was the average depth of the water table in the sand at the time the field was discovered. The field is about 40 miles long and has an average width of approximately 4 1/2 miles. The area within the proven limits of the field is close to 116,580 acres and the normal Woodbine water underlies nearly 62,000 acres on the western side of the field at the present time. The field is unusual in several respects: (1) the tremendous size of the reservoir system and the quantity of oil in place; (2) the large area of the oil and water contact, which makes water movement possible into the oil-bearing part of the structure; (3) the absence of free gas within the main producing sand of the field. Changes in the reservoir pressure during the production history of the field have been greatly affected by

Jan 1, 1934

By C. D. Hunter, I. B. Browning, Ralph Thomas

Production of oil in Kentucky during 1938 was 5,566,154 bbl., showing a substantial increase over that of the year 1937; while in the gas areas development was somewhat retarded although deliveries were similar to those of 1937. In eastern Kentucky there was an oil increase during 1938 of over 150,000 bbl. above that of 1937. No new pools were developed and the increase was almost entirely due to the installation and expansion of secondary recovery methods and to the further development of the Maxon and Big Lime, Mississippian pools in Floyd and Martin Counties. With this development eastern Kentucky reached a level near that of 12 years previous, when the development of several large producing areas had just been completed. In eastern Kentucky during 1938 not over 50 gas wells were completed. Although the pipe-line deliveries were approximately the same as during 1937, development was retarded because of an excess of gas already developed and the intensive development of the Oriskany fields in West Virginia. In western Kentucky, in the part of the Illinois Basin lying in the state and known in Kentucky as the Western Coal Basin, the increase was due to the discovery of a number of new pools, the largest and the one producing the biggest wells being known as the Birk City pool. In fact, the discovery of this pool with the McClosky "sand" (St. Genevieve limestone) as the producing formation was in a large measure responsible for the increased activity, which in turn brought the discovery of the other areas. The discovery well in this pool is the C. T. Blackwell, which came in flowing 1000 bbl. daily from the McClosky sand at a depth of 1870 ft., drilled in April 22, 1938. This discovery, coming at a time when the major companies and many others were conducting an intensive leasing campaign and making extensive subsurface and geophysical surveys in the deeper part of the basin, resulted in renewed activity over the entire area and brought much new drilling. It also brought to Kentucky for

Jan 1, 1939

By Frank R. Hunter

Introduction Scope of Work This paper represents the results of an investigation of the presence, amounts, and degree of concentration of heavy minerals found in the pulp of the phosphate flotation plant at Peace Valley, Fla., which is operated by the International Minerals and chemical Corporation of Chicago. In this paper, heavy minerals are those, excepting collophane, that sink in acetylene tetrabromide with a specific gravity of 2.95. Percentages of heavy minerals at several points of the flowsheet and the species of minerals have been determined. Some information as to the screen size of the minerals has been acquired. Previous Work All previous published reports or investigations of the deposits of heavy minerals in Florida have been limited to present beach sands. The mining operations conducted by the Humphreys Gold Corp. about seven miles east of Jacksonville along an ancient shore line have been described in trade journals, but descriptions of the minerals have been lacking. Commercial grades of ilmenite, zircon, and rutile are produced on a large scale. Papers have been published on heavy minerals found on the Florida beaches.1-6 Location "International's" Peace Valley flotation plant is in south-central Polk County, Fla. about eight miles south of Bartow and along the Atlantic Coast Line Railroad. The mine surrounds the plant and includes about 1500 acres of the phosphatic lands in this area. Geology General Setting All of the rock underlying the area is almost horizontal. The oldest bed exposed is part of the Hawthorn phosphatic limestone of Miocene age. This outcrops in the stream bed of the Peace River about one mile east of the plant. Elsewhere the Hawthorn is covered except where it has been exposed by mining operations. The Bone Valley formation of Pliocene age, which is the phosphatic stratum extensively mined in this area, unconforma-bly overlies the Hawthorn. Resting unconformably upon the Bone Valley formation are Pleistocene (?) terrace deposits of unconsolidated quartz sand which comprise the overburden of the phosphate ore. Stratigraphy Hawthorn formation: "Bedrock" of the pebble phosphate deposits is a cream to white colored, sandy, dense limestone containing varying amounts of small grains and nodules of collophane. The upper surface of the formation is undulating and irregular showing evidence of former

Jan 1, 1949

By C. H. Hitchcock

A brief resiclence in Virginia hasenabled me to examine some of its crystalline strata, and a few hints, concerning their correspondence with similar rocks elsewhere, may be of service to those who are studying them. In comparing the crystalline rocks of Virginin and New England, we may first recall the similarity of their geographical position. They constitute a continuous belt, being traceable through the Highlands of New York and yew Jersey, Southeastern Pennsylvania, in the counties of Bucks, Montgomery, Philadelphia, Delaware, and Chester, and Marylund. Thus the Green Mountains of Vermont and the White Mountains of New Hampshire seen] to be topographically continuous with the Blue Ridge and Midland districts of Virginia. This tract of country has been termed the Atlantic area in distinction from the Appalachian territory, whose eastern limit is the great, Lower Silurian limestone valley extending from the St. Lawrence and Champlain valleys to Alabama. The Appalachian formations were studied by the brothers Rogers, forty years since, and found to refit, unconformably upon the western flank of the Blue Ridge, the oldest of the series adjoining the gneisses, followed westerly by the other Palseozoic members in a regular ascending order, to which numercial designations were applied—Number 1 being the Cambrian, Number 2 the Lower Silurian Iimeqtones, etc?. In Vermont the same conclusion Was presented in the State reports: the Green Mountains were said to possess the anticlinal structure, and to underlie the quartzites and limestones. Inasmuch as this Atlantic area is' topgraphically continuous from the Middle to the Northern States, and is unconformably overlaid upon the west side by the same succession of strata, the presumption ii very strong that the history of bath sections has been the same, and that the entire area is of Eozoic age. Cross sections, in both districts, illustrate the existence of gigantic overturns, causing the strata of 'the Appalachian region to dip to wards the Atlantic gneisses. To the beginner it would appearthat tile Silurian group must dip beneath the crystallines, and hence many of the geologists in the beginning of the study of the stratigraphy of this easters border of the continent believed that

Jan 1, 1882

THE Institute assembled on Tuesday evening, October 24th, in the hall of the Franklin Institute, Mr. Frank Firmstone, VicePresident, in the chair. Mr. J. Price Wetherill, of Tremont, Pa., read a paper on An Outline of Anthracite Coal Mining in Schuylkill County, Pa. The paper was discussed by Messrs. Coxe, Rothwell, Heinrich, Harden, and Symons. The second session was held on Thursday evening. Mr. A. L. Holley, Chairman of the International Committee, appointed by the Institute to consider the nomenclature of iron and steel, offered the following report of the committee, signed by all the members: WHEREAS, The recent production of soft, cast, malleable compounds of iron by the Bessemer, the Siemens-Martin, and the crucible steel processes appears to demand a new nomenclature of iron compounds, for the following reasons: 1st. The term "steel," by which these soft products are commercially and professionally designated in England and in the United States, does not completely distinguish them from previously existing "steel which would harden and temper. 2d. A nomenclature recognized in all languages seems desirable, as well for commercial as for scientific purposes, especially as lawsuits, already commenced, depend on the meaning of the term " steel." 3d. Although homogeneity, due to fusion, is usually recognized, and is by this committee recognized as the most definite characteristic of both hard and soft steel, this quality may be equally well expressed in other terms, thus leaving the old term, " steel," to define the malleable compounds of iron, which will harden and temper. Therefore, resolved, That this committee recommends the following nomenclature : 1. That all malleable compounds of iron with its ordinary ingredients, which are aggregated from pasty masses, or from piles, or from any forms of iron not in a fluid state, and which will not sensibly harden and temper, and which generally resemble what is called " wrought iron," shall be called Weld Iron (German, Schweisseisen; French, fer soudé). 2. That such compounds, when they will from any cause harden and temper, and which resemble what is now called puddled steel," shall be called Weld Steel (German, Schweiss stahl; French, acier soudé).

THE Institute assembled on Tuesday evening, October 24th, in the hall of the Franklin Institute, Mr. Frank Firmstone, Vice-President, in the chair. Mr.. J. Price Wetherill, of Tremont, Pa., read a paper on An Outline of Anthracite Coal Mining in Schuylkill County, Pa. The paper was discussed by Messrs. Coxe, Rothwell, Heinrich, Harden, and Symons. The second session was held on Thursday evening. Mr. A. L. Holley, Chairman of the International Committee, appointed by the Institute to consider the nomenclature of iron and steel, offered the following report of the committee, signed by all the members: WHEREAS, The recent production of soft, cast, malleable compounds of iron by the Bessemer, the Siemens-Martin, and the crucible steel processes appears to demand a new nomenclature of iron compounds, for the following reasons : 1st. The term "steel," by which these soft products are commercially and professionally designated in England and in the United States, does not completely distinguish them from previously existing "steel" which would harden and temper. 2d. A nomenclature recognized in all languages seems desirable, as well for commercial as for scientific purposes, especially as lawsuits, already commenced, depend on the meaning of the term "steel." 3d. Although homogeneity, due to fusion, is usually recognized, and is by this committee recognized as the most definite characteristic of both bard and soft steel, this quality may be equally well expressed in other terms, thus leaving the old term, "steel," to define the malleable compounds of iron, which will harden and temper. Therefore, resolved, That this committee recommends the following nomenclature : 1. That all malleable compounds of iron with its ordinary ingredients, which are aggregated from pasty masses, or from piles, or from any forms of iron not in a fluid state, and which will not sensibly harden and temper, and which generally resemble what is called " wrought iron," shall be called WELD IRON (German, Sehweisseisen; French, fer soudé) 2. That such compounds, when they will from any cause harden and temper, and which resemble what is now called "puddled steel," shall be called WELD STEEL (German, Schweiss stahl; French, acier soudé).

Jan 1, 1877

Discussion of the paper of C. M. YOUNG, presented at the St. Louis meeting, October, 1917, and printed in Bulletin No. 129, September, 1917, pp. 1369 to 1384. CARL SCHOLZ, Chicago, Ill.-Mr. Young was kind enough to' allude to the development of a mine in which I am now engaged. Several months ago the Burlington Railroad decided to open a mine in the field Which they own in Franklin County containing some 15,000 acres .(6070 ha.) of coal, ranging in thickness from 8 to 12 ft. (2 to 3.6 m.). This proposition in itself is attractive to any mining engineer, but with the backing of a large company I saw an opportunity to do some novel work in the construction line, and for several months I have been investigating and working on the problem of developing what I hope will be the largest and best equipped mine in the State of Illinois. The shaft will be sunk at a place where the coal lies at a depth of 600 ft. (182 m.) and conditions both of the surface and of the coal are ideal in every way; the seam is almost level, and we had only 7 ft. (2 m.) of surface clay to go through. We are going to hoist by skips in order to reduce the rope speed. I believe that is a long step in the direction of economy, because we not only double the output of the mine by hoisting the contents of two cars atone time, but we reduce the proportion of dead weight. In our case there will be 20 tons of coal and 18,000 lb. of skip, or 55 per cent. net and 45 per cent. tare. That, of course, necessitates less than half the rope speed for the same tonnage, and we all know that speed means power and power means cost. Skip hoisting permits the use of solid-end gate cars, which is an advantage. The cost of these cars will be in the neighborhood of $250 apiece; They are well built, with roller-bearing wheels of the most up-to-date type, spring draw-bars, and refinements of-that character which are necessary to move the loads most advantageously.

Jan 1, 1918

By Fred Wise

THE Getchell mine, a comparatively recent gold discovery, is in the old Potosi mining district, Humboldt County, Nevada. All ore is mined from open pits using Diesel shovels and gasoline trucks. Two types of ore are mined, oxide and sulphide. Oxide ores are siliceous or shaly; sulphide ores either gougy, siliceous or shaly. In mining, the sulphide ore is segregated into hard and gougy ore, because the gouge must be dried before it can be crushed, The oxide ore is not segregated. GENERAL METALLURGY The oxide ore is the leached outcrop that overlies the sulphide ore body. All of the iron and arsenic sulphides found in the sulphide ores have been thoroughly oxi-dized, The sulphur and arsenic have been leached out while the iron is present as hematite and limonite. The oxide ore is amenable to direct cyanidation, and although no visible free gold is present it is released at a comparatively coarse grind. The sulphide ore is more refractory, since the gold is all of micron size and some of it is locked in fine sulphides. It has been established microscopically that the free gold is coated with an impervious shell, which is probably some form of iron compound. The sulphide ores contain from 1.5 to 2 per cent of arsenic, which is present as orpiment and realgar with minor amounts of arsenopyrite. The orpiment and realgar are of a later mineralization than the gold and are barren. Roasting and washing of the sulphide ore prior to cyanidation is necessary to eliminate the arsenic, to alter the gold coating from an insoluble form to a soluble form, and to release the gold associated with the fine sulphides. Washing the ground calcine in weak sulphuric acid, trona, or hot water are beneficial in the order named, but to date the water is the best from an economic standpoint. Metallurgical tests as well as plant practice indicate that a certain amount of gold cannot be recovered even by going beyond economic practices, On this basis metallurgical results are viewed in the light of an optimum tailing rather than a per-centage of extraction.

Jan 1, 1940

By Edwin A. Sperry

The use of steam-stamps in the crushing of ore for the purpose of amalgamation has been very limited, and little has been written on the subject. As the writer has been operating a mill of this kind during the past year, it is possible that he may be able to present a few points in regard to mill-practice in this line which will be of interest. The mill herein referred to contains two Tremain steamstamps, a more detailed description of which will be given below. A bond and lease had been taken on a property on Cross mountain, Gunnison county, Colo., and the parties operating wished to prospect it thoroughly and did not wish to ship out the ore, owing to high freight-rates. They looked around to find some mill that would answer the purpose and not be too expensive. The steam-stamp in question was finally decided on, and the writer was employed to erect and operate it. The economy of construction was demonstrated at the outset. The stamps were dropping within ten days from the time that the machinery was unloaded on the ground. A large portion of this period was consumed in waiting for supplies and fittings which should have been on the ground at the Hame time with the machinery. Ore.—The ore to be treated was a mixture of white, porous quartz, with the decomposed and undecomposed oxides of iron and manganese in varying proportions, from the pure white quartz to solid pieces of the oxides. It appeared to be the product of replacement in a soft dolomite at or near the line of contact with a dike of porphyry. On careful examination with the aid of a microscope it was found that the gold was in the form of an extremely thin film over the surfaces of the quartz, making only a bronzy-yellow coating, quite readily distinguished from the film of iron oxide, which was also present. Mill.—The mill was constructed on the usual plan, with the ore-bin above and against the hill, which was cut into for the

Jan 1, 1897