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BUMPS in No. 2 Mine, Springhill, N. S., furnished the main feature for discussion at the morning meeting* on Ground Movement and Subsidence on Feb. 18. Walter Herd, the author of the paper by which the discussion was introduced, not being well, was unable to be present. The paper was presented by T. L. McCall, who laid stress on the presence of sand- stone as the cause of bumps, on the value of retreating longwall in eliminating such phenomena at the coal face and on the advantage of wide headings with packs on either side, leaving space behind them for any coal that bumps might dislodge. George S. Rice, who presided, referred to his visits to the Nova Scotia mines and said that bumps usually occurred only where the coal was thick and strong and the roof and floor both more than usually hard. If any of the three were weak, bumps were not likely to occur. In the Nova Scotia mine, to which Mr. Herd referred, there was no material for packwalls and for this reason as well as for safety he had been convinced that long- wall retreating with a small percentage of pack walling was the most feasible plan.

Jan 1, 1929

By R. J. Stevens

The Roan Antelope Smelter commenced operations in October, 1931. As originally designed, its equipment consisted of one reverberatory furnace, 120 X 25 ft, two Peirce-Smith converters 12 X 20 ft, and one straight line casting machine. Since that time the following additions have been made: One reverberatory furnace 120 ft X 28 ft ('934) One reverberatory furnace 95 ft X 28 ft (1943) Two 12 X 20 ft Peirce-Smith converters (1934 and 1938) One 13 X 30 ft holding furnace (1938) One straight line casting machine and 2 ladle tilting quadrants (1934) The metallurgy of the smelting process is comparatively simple. However, there are several features of operation which are uncommon to most copper smelters: (I) The high grade of concentrate treated; this has always been about 50 pct copper. (2) The high flux burden on the charge. This is necessary because of the deficiency of bases in the concentrate and the high alumina content of the concentrate. (3) The frequent necessity of adding coal to the furnace charge to control the matte grade. (4) The high grade of matte produced. This has led to unusual converter problems. From the commencement of operations, the ore mined has come from the Roan Basin orebody. The concentrate produced from this ore consists mainly of chalcocite and shale with small proportions of other copper minerals. As mining operations extend to the Roan Extension orebody, the proportions of bornite and chalcopyrite in the concentrate will increase with a corresponding decrease in the copper content of the concentrate. Because of the concentrate grade the capacity of the reverberatory furnaces in terms of tons of copper produced per ton of coal burned is high. This ratio is usually over 2.2, and on especially favourable runs has reached 2.6. Reference to Table I shows that the iron content of the concentrate is unusually low. Only part of this iron is available for slag formation, the balance going to the matte. To make up this deficiency in bases, limerock is added to the furnace charge. This flux ensures a slag that is of the correct silicate degree, is suficiently fluid, of low specific gravity, and it counteracts the thickening effect of the alumina present. An ample supply of flux is obtainable from Ndola, 22 miles distant by rail. Although the reverberatory slag has a high copper content, the slag fall is low and the copper loss in the slag now rarely exceeds 1.0 pct of the total copper charged. The blister copper shipped is of such purity that only one fire refining operation has been necessary to produce a wirebar with properties comparable to electrolytic copper. Bismuth has always been the most troublesome impurity and consequently the problem of its control in the finished product has been of prime importance. Practically none is removed in the reverberatory furnace. The bulk of the elimina-

Jan 1, 1949

By T. Egleston

THE works of the Ore Knob Copper Company are situated in the county of Ashe in the northwestern part of the State of North Carolina, about ten miles from the Virginia line, at an elevation of 4600 feet above the sea. The nearest railroad station is at Marion, Smythe County, Virginia, about forty-five miles distant. The roads from the railroad to the works have been constructed by the company for the transportation of their material, and are very hilly, and in certain seasons of the year in bad repair. Transportation is therefore always limited and never easy, although it is done by contract at a very low price. The main difficulty with the transportation is not so much its cost as the fact that it puts a limit to the production of the works. These unfavorable conditions make it necessary for the owners of the mine to smelt their ores and to send to market nothing except the metal, which alone will bear the cost of transportation. The mine was opened previous to 1860, but has only been worked systematically during the last five or six years. The vein is a fissure vein from ten to twenty feet in thickness in the gneiss of the

Jan 1, 1882

By T. Egleston

The works of the Ore Knob Copper Company are situated in the county of Ashe in the northwestern part of the State of North Carolina, about ten miles from the Virginia line, at an elevation of 4600 feet above the sea. The nearest railroad station is at Marion, Smythe County, Virginia, about forty-five miles distant. The roads from the railroad to the works have been constructed by the company for the transportation of their material, and are very hilly, and in certain seasons of the year in bad repair. Transportation is therefore always limited and never easy, although it is done by contract at a very low price. The main difficulty with the transportation is not so much its cost as the fact that it puts a limit to the production of the works. These unfavorable conditions make it necessary for the owners of the mine to smelt their ores and to send to market nothing except the metal, which alone will bear the cost of transportation. The mine was opened previous to 1860, but has only been worked systematically during the last five or six years. The vein is a fissure vein from ten to twenty feet in thickness in the gneiss of the

Jan 1, 1882

By H. F. Kendall, J. H. Ffolliott

MANY papers and reports have been devoted to the geology and ore deposits of the Ducktown district, Tennessee, especially the complete report by W. H. Emmons and F. B. Laney, published as Professional Paper 139, by the U. S. Geological Survey. The present paper discusses the work of the geological organization of the Tennessee Copper Co., which is based on the field work of the above paper and the consulting work of W. H. Emmons. The Ducktown basin lies in the southeastern corner of Tennessee and extends a short distance into Georgia and North Carolina. All productive mines are contained in an area of 15 sq. mi. in the center of this basin, which is an undulating plateau at an elevation of 1650 to 1800 ft. above sea level. It is surrounded by the relatively high mountains of the southern Appalachian region. The rocks are of early Cambrian age. Deposition of the ores probably took place during the latter part of the Paleozoic era. The ore deposits are rudely tabular to lens-shaped bodies of massive sulfide, varying from a few feet to over 200 ft. in width. In general they all strike northeast and dip southeast at angles from 45° to 70°. Locally, where affected by folding and faulting, the variations in dip may be even greater. The lodes usually are parallel at distances of from one-half to one mile measured normal to the strike. The deposits are a replacement of a fairly continuous bed or a series of disconnected limestone lenses, highly folded and somewhat faulted, which probably represent the same stratigraphic horizon.

Jan 1, 1933

Jan 1, 1931

By A. F. Taggart

THE following notes represent significant excerpts from a mass of records of experimental work done in the ore-dressing laboratory at the Columbia School of Mines during the years 1926 to 1928-inclusive. CLASSIFICATION OF EXPERIMENTAL WORK The experiments performed may be grouped for purposes of description under the following general -headings: I. Collecting agents. a. A method for quantifying collecting effect. b. Coating with undissolved collecting agents (oils) c. Action of dissolved collecting agents. II. Frothing agents. a. A method for quantifying frothing effect. b. Relation between frothing effect and chemical composition. III. Inorganic reagents. a. Methods of studying the effects of these reagents. b. Effect on slime dispersion. c. Effect on sulfides. SUMMARY OF THE ORIGINS OF PRESENT-DAY FLOTATION PRACTICE The first practicable, foolproof method of froth flotation was described in U. S. patent 835120, issued in 1906 to Sulman, Picard and Ballot, and in the equivalent patents in other countries. A number of less simple methods of producing the same result had been described previously in patent publications and otherwise.1 The reagents specified in all of these early patents were "oils" and, in addition, some inorganic substance, usually an acid. The quantities of reagents recommended and added were enormous when' compared with those used today.

Jan 1, 1929

By D. E. Wolfson, D. A. Reynolds, F. W. Smith

IN 1948 the U. S. Bureau of Mines began a three-phase program to evaluate the extent and quality of U. S. coking coal: 1) a factual appraisal of known recoverable reserves in beds of mineable thickness, 2) a study of preparation characteristics, and 3) a study of carbonization properties. A previous paper presented the methods used in assessing reserves.' Although this investigation is only partly completed, data on coking properties of the Pittsburgh district coals are now available. The results are presented in this article. When coals are selected for manufacture of metallurgical coke more factors must be considered than for any other major use, as no basic industry requires coal of such high quality and uniformity. This is particularly true in the Pittsburgh district, where blast furnace practice is based on use of cokes from high quality coals. Although it is true that inferior coals are carbonized in other industrial areas, both here and abroad, the Pittsburgh coals are the best economically obtainable in the required tonnages, even though they are not the most desirable for metallurgical use. In the general evaluation of suitability of coals for coke making, particular attention is given to: 1) reserve, 2) ash and sulfur content, 3) inherent properties of forming strong, well fused coke, 4) expanding characteristics, and 5) blending properties. Items 1 and 2 are covered in detail in the first two phases of the survey, and coking behavior is considered in items 3 through 5. Problems is Coal Evaluation: Although not all coal beds of immediate or potential use to the coking industry in the Pittsburgh area have been tested for their coking properties, enough tests have been made to permit certain generalized statements. Virtually all the coals that will be used in this district are from the Appalachian region, and except for high oxygen coals from outcrops or stripping operations, they are coking coals. Hence the evaluation problem is not so much that of distinguishing between coking and noncoking coals as attempting to measure quantitatively differences in the coking and expanding properties of the better coking coals. Quantitative differentiation between good coking coals, is complex, since differences in their coking abilities are frequently of about the same magnitude as the precision of the test. Small-scale tests are generally unsuitable for measuring these slight differences, and there has been gradual acceptance of pilot-scale tests. Test Methods Employed: All the data reported here were obtained in two units known as the Bureau of Mines-American Gas Association (BM-AGA) carbonization apparatus and the sole-heated expansion oven. The BM-AGA unit, which consists essentially of a cylindrical steel retort about 18 in. diam and 26 in. high, carbonizes enough coal (180 lb) to allow evaluation of the coke by standard methods of the American Society for Testing Materials. The BM-AGA carbonization procedure and methods of testing the gas, liquid, and solid products have been described.' Expanding characteristics of the coals were determined in the sole-heated expansion oven," wherein the coal charge, heated from the bottom only, is carbonized under a constant applied force and the linear expansion or contraction is measured. Although results in this oven have never been quantitatively correlated with the expansion behavior of coals in conventional slot ovens, they are useful in assessing expansion behavior. In this report discussion will be confined to results obtained from these pilot-scale units, although the following data are available for most coals: proximate and ultimate analyses, free swelling index, agglutinating value, and plasticity. Sources of Coals Tested: In selection of coals for coke manufacture, economic considerations are as important as quality, and each coke plant balances these two factors to meet requirements of the most satisfactory coke at lowest price. Although these economic factors may in some instances outbalance small differences in coke quality, they are usually specific to each coke plant and cannot be given in any general statement. Recognizing that coal and plant operating costs are beyond the scope of the survey, the USBM evaluates the coking quality of various coals without regard to their competitive economic status. For the purpose of this article, coals of interest to the Pittsburgh district are arbitrarily defined as

Jan 1, 1958

By Otis M. Clarke

The Eufaula bauxite-kaolin district in southeastern Alabama is an important source of raw material for the refractory industries in the United States. At the present time, five companies are mining and processing bauxite and kaolin from this district and a sixth company is holding substantial reserves. Mining operations are expanding, but finding new ore reserves is a major problem. The Geological Survey of Alabama sponsored geologic research in the Eufaula district to: (1) investigate the

Jan 1, 1973

By Donivan L. Gordon, Fred H. Dorheim

Often, as viewed by the public and many in the mining industry, abandoned limestone and gypsum quarries offer a simple, economic solution to the twofold problem of solid-waste disposal and land reclamation. In a state where about 75% of the existing quarries are in hydrologic connection with carbonate aquifiers the rationale for considering the storage of solid waste in them must be critically examined. Consistent with the requirements of water resources protection, criteria are suggested to evaluate the potentiality of using abandoned limestone and gypsum quarries as sanitary landfill sites.

Jan 1, 1975

By P. D. Merica

ALUMINUM and its alloys have been the subject of much investigation, during recent years, in the course of which the principal features of the constitution of most of the binary alloy systems with aluminum have been determined. Except in the case of a few metals-silicon, bismuth, cadmium, lead, zinc, and tin-an aluminum-rich compound is formed in each binary system, which forms a eutectic with the aluminum or its solid solution with this compound. Thus such compounds as FeAl3, CuAl2, Mg4Al3, and NiAl3 are formed, which are found in aluminum-rich alloys of their respective series as eutectics with the aluminum solid solution. These compounds are, in all cases, hard and brittle and their presence affects profoundly the physical properties of the alloys in which they occur. Within the zinc-aluminum system a compound, Al2Zn3, is formed that decomposes at lower temperatures. Silicon and tin each form a simple eutectiferous series with aluminum; bismuth, lead, and cadmium are only partly miscible in the liquid state with it. The extent of the solubility in aluminum, in solid solution, of these compounds or of the elements themselves, in the case of those series

Jan 7, 1919

By Nestor Torres-Acuña, Fathi Habashi

Metallic copper of purity equal to commercial electrolytic copper is deposited during the anodic dissolution of technically available white metal, Cu2S, in m acidic solution of' copper(II) sulfate as electrolyte and copper sheets as cathodes. The process may be applied on commercial scale since it has the advantage of by passing the converting and poling steps, decreasing pollution problems due to SO, and recovering the sulfur of the white metal in the elemental form. The anodic dissolution is believed to take place in three steps: The working conditions that lead to 98 pct cathodic current efficiency are: 30 gpl Cu2+ and 100 gpl H2SO4 in electrolyte, current density 1.0 amp per sq dm, and tetnperature of bath 40°C'. DURING the smelting of copper, nickel, lead, and zinc sulfide ores, large amounts of sulfur dioxide are produced. Because the release of this gas in the atmosphere causes pollution problems, many attempts were made in the past for its recovery either in liquified form or processed to sulfuric acid. Although these two forms of sulfur are the usual forms that are consumed by the chemical and metallurgical industries, their storage and transport usually raise economic problems. It was realized, long ago, that a process by which sulfur can be recovered directly in the elemental form would be most attractive. Elemental sulfur is easily stored and transported, and is readily converted to SO2, H2S, or H2SO4 when needed. Processes aimed to recover the metals from their sulfide ores, and at the same time by-product sulfur in the elemental form, were recently reviewed.' As early as 1882, Marchese2 patented a process in which a matte having the composition: Cu 15, Pb 14, Fe 41, and S 25 pct was electrolyzed. According to cohen3 the process was applied on a pilot scale by the Aktiengesellschaft fur Bergbau-, Blei-, und Zinkhiitten-betriebe at Stolberg, Rheinland, Germany. The process was unsuccessful, however, owing to the contamination of the electrolyte during electrolysis. Studies in this field were reported by Bernfeld4 and Egli.5 Borchers et a1.6-8 developed the process further by using white metal (Cu 78.2 pct, S 19.6 pct) instead of the matte, and a pilot plant was operated by the Mansfeldschen Kupferschiefer Co. at Eisleben, German~.~ It appears, however, that the process never went into commercial operation. Further studies in this direction were carried out by Russian workers.10-23 The International Nickel Co. of Canada erected a pilot plant at Port Colborne in 1951 to apply the process to nickel matte which is essentially pure nickel sulfide."'- 26 Full-scale plant went into operation at the Thompson Refinery in Manitoba in 1964.27 In this method nickel sulfide matte is melted and cast into anodes analyzing 76 pct Ni and 20 pct S with small amounts of copper, cobalt, and iron. These anodes are then electrolyzed in an aqueous solution of NiS04 at pH 4. Further work on this method was reported in the literature.28-31 In this paper, experiments on the anodic dissolution of white metal in aqueous copper sulfate solution are reported. EXPERIMENTAL White metal, Table I, obtained from The Anaconda Co., was cast in form of anodes 10 by 7.5 by 1 cm, Fig. 1. The anodes are mechanically strong and do not break easily; when polished they gave a shiny gray metallic appearance. From the chemical composition shown in Table I, it can be seen that the atomic ratio Cu:S corresponds approximately to the formula CU2.06S. The copper in excess to the formula Cu2S is most probably present as a separate phase since metallic copper could be seen under the microscope, Fig. 2. Fig. 3 shows the X-ray diffraction pattern of white metal which matches fairly well with that of reagent-grade Cu2S.

Jan 1, 1969

New York Meets first Wednesday after first Tuesday of each month. DAVID H.-BROWNE, Chairman, JOHN H. JANEWAY, Vice-Chairman. F. E. PIERCE, Secretary, 35 Nassau St., New York, N. Y. P. A. MOSMAN, Treasurer. LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. HENRY L. SMYTH, Chairman. . ALFRED C. LANE, Vice-Chairman. HENRY A. WENTWORTH, Secretary-Treasurer, 60 India St., Boston, Mass. ROBERT H. RICHARDS, ALBERT SAUVEUR. Columbia Holds four sessions during year. Annual meeting in September or October. FRANK A. ROSS, Chairman. RUSH J. WHITE, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P O. Drawer 2154, Spokane, Wash. FREDERIC KEFFER, FRANCIS A. THOMSON.

Jan 11, 1915

By E. M. MacKevett

The only source of uranium ore in Alaska that has been mined commercially is the Ross-Adams de- posit, a gently inclined, fusiform orebody in alkali granite in which uranothorite and uranoan thorianlte are the chief ore minerals. In mode of occurrence, apparent genetic association with the granite, and to a lesser extent in mineralogy, this type of deposit is uncommon. The mine is in the southern part of Prince of Wales Island (Fig. 1) at an altitude of about 950 ft on the southeast flank of Bokan Mountain. A steep unpaved road 1 ¾ miles long leads to the dock on the West Arm of Kendrick Bay, which can be reached by boat or seaplane from Ketchikan, some 35 miles to the northeast.

Jan 9, 1959

By V. T. BERNER

THIS apparatus was designed primarily to meet the demand for a quick, efficient stopping to seal off the burning area temporarily during a mine fire, but it can be used in any circumstance where an immediate brattice is required for ventilation control. In using the old style brattice, mine-rescue workers have found it difficult, in smoke-laden drifts and stopes, to erect an effective stopping with wooden frame and canvas. Stulls must first be cut to the proper length, the canvas tacked in place, and the numerous irregularities of the walls and back must be caulked. This operation requires the employment of axes, saws, and hammers, which cannot easily and safely be handled in dense smoke. The fire fighters have often been forced to abandon their brattice, unfinished, because of the rapid approach of the fire, or because of the exhausted sup- ply of oxygen in their breathing apparatus. It is neces-

Jan 1, 1930

By Gopalan Ramadorai

Tailings water from primary flotation concentrators usually contains minor amounts of pollutants such as heavy metals, cyanide and solubilized molybdenum, which are solubilized in the flotation process. A review of various techniques to reduce pollutants to acceptable levels is presented. Generally, molybdenite ores are processed by conventional size-reduction techniques, followed by flotation to produce a metallurgical-grade concentrate of 88% to 92% MoS2. Reagents commonly used in the milling process include: vapor oil (collector); pine oil, MIBC (frother); Dowfroth 250 (water-soluble frother); lime (rougher pH control); and sodium cyanide (Fe and Cu depressor). For lead depression, Nokes reagent is stage-added to the regrind mills and cleaners. Flocculant is added to obtain clear overflows in the intermediate thickeners.

Jan 9, 1978

By Stanley J. LeFond

Jan 1, 1985

The Library of the above-named Societies is open from 9 A.M to 10 P. M. except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should he made as definite as possible so that the information received may he what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 6, 1918

By Neil Donnell, O&apos

MODERN mine maps are largely a product of evolution. The first mine maps used in the west were old composite maps with all the levels plotted on the same sheet. The composite was widely used and occasionally is seen even now. This type of underground map had serious limitations. One was the development of an indecipherable complex of workings around steep shafts. The other limitation was that of size; often when a working passed the limit of the sheet no map was made of it. These old maps have been superseded by the single level maps, laid out in squares or rectangles which can be expanded indefinitely in all directions. This produces a system capable of unlimited expansion in three dimensions, with all the detail of every working clearly marked and legible. A good set of mine maps should be laid out in blocks, all blocks of equal size. Each block should be limited by plane coordinates without overlap on bounding map quadrangles. At all times the direction of North should be indicated as an aid in remembering bearings of underground workings. It is desirable that all maps of whatever scale be plotted on sheets of uniform size. In fact, it is possible to make nearly all underground maps, surface maps and sections on sheets of the same size.

Jan 9, 1950

By John L. Watson

A conceptual model (MAGSEP) is described to simulate the beneficiation characteristics of a drum magnetic separator in terms of the probability of an individual grain being recovered in the magnetic concentrate. This probability is determined as a function of particle magnetic composition and magnetic field strength and is modified by particle size and the separator operating conditions. The model predicts the size, magnetic grade and distributions of magnetic and gangue minerals in the concentrate and tailings produced by the drum separator. The configuration of the magnetic concentration circuit may be altered to permit single or double drum units in parallel or series operation. The characteristics of the feed material, in terms of a magnetic parameter, are essential in permitting the determination of individual grain recovery probabilities upon which the model is based. Thus the model requires input data relating to the distribution of composite grains in terms of magnetic grade and particle size. To illustrate the use of the conceptual model an example is given for the beneficiation of New Zealand iron sands.

Jan 1, 1984