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By E. S. Bardwell

TWENTY years ago, W. T. Burns, in his paper presented at the Butte Meeting of the Institute, discussed the general scheme then in use in the electrolytic copper refinery of the Anaconda Copper Mining. Co. at Great Falls, Mont., for removing impurities from tank-room electrolyte and controlling its acid content. Since then marked changes have taken place in copper-refinery practice at Great Falls. The electrolytic copper refinery in use in 1913 has been replaced by a new and entirely modern plant capable of producing up to 27,000,000 lb. of cathode copper per month. With the building of the new plant in 1916, the treatment of converter anodes was discontinued. At first the substitution of refined anodes for converter anodes resulted in a decrease in the impurity content of the anodes, but as time went on, changes in metallurgical practices at the smelter resulted in substantial increases in the impurity content of the anodes. The leaching of the silver slime to remove copper before shipment to Raritan for treatment further added to the purification problem. The fact that the scheme of purifying electrolyte which Mr. Burns described in his paper' has proved adequate for our needs under a wide variation of conditions speaks well for its essential soundness.

Jan 1, 1933

By G. A. Alers, F. Borik

Rolled sheet products are elastically anisotropic and a large number of measurements of Young's modulus and rigidity modulus are necessary to completely specify their elastic properties. This paper describes and uses a simple measurement technique to obtain the nine elements of the elastic modulus tensor from which all the elastic The elastic properties of a polycrystalline material are usually specified by giving the Young's modulus E and the rigidity modulus G. Unfortunately, these two moduli by themselves are insufficient to completely specify the elastic properties because the rolling process introduces a preferred orientation which makes the material properties can be deduced. In particular, the variation of Young's modulus and the rigidity modulus in the principal planes of a sheet of ausformed steel were deduced. Furthermore, the variation of Young's modulus in the rolling plane was compared with direct measurements. anisotropic. This anisotropy makes E and G functions of the orientation of the test specimen in the sheet so that a complete description of the elasticity requires many measurements on a large number of specimens. A more fundamental approach to the problem is to consider the sheet as a single crystal and measure the elements of its elastic modulus tensor. Although this appears formidable, there have been developed recently high-frequency ultrasonic techniques which yield these tensor elements directly. The symmetry of a rolled sheet is such that it behaves elastically as if it were an orthorhombic

Jan 1, 1965

By T. F. Witherbee

AS the forms of blown-out furnaces are of much interest to ironmasters and metallurgists, the manner of taking the accompanying sections of the Cedar Point stack is here given. The diagrams show the original and also the final shape of the furnace after a two years and twelve days' blast,, during which the following solid materials passed through it, viz.: Coal, 41,000 tons; ore, 57,000 tons; limestone, 30,000; total, 125,000 gross tons. Product, 411/4 tons per day Bessemer pig iron. The apparatus used in taking the sections was a modification of that proposed by Mr. Frank Firmstone,* and consisted of a sliding rule, to follow around the circumference of the stack, which rule was connected by a string to a segment of a circle of 24 inches radius. The segment was carried by an arm which connected it to a huh as a centre, 2 inches in diameter. A second string was wound around the hub, and communicated motion to a pencil-carrier, the pencil of which marked out on paper the exact outline, and reduced it to a scale of & inch to the foot. The whole machine was made in about three hours, with the facilities of a carpenter's shop, and gave in operation every irregularity of the lining. The sections were taken at salient points, by lowering a hanging staging on which the apparatus was placed. Tracings from the paper of the machine were made, and, as in this case several copies were required, the tracings were glued on to thin sheets of basswood, and patterns carefully sawed out with a bracket saw.

Jan 1, 1879

By S. H. Cathcart

Price, production and drilling operations exceeded any year since 1930. A top price for crude of $2.55 was maintained from May 1 to November 6 and increased activity about coincides with that period. The average crude price for the year was: Bradford, $2.46; Kane-Butler, $2.34; Southwest Pennsylvania, $2.13. Production for the year exceeded 15 million barrels, an increase of about 2 million barrels over 1933. That this increase was more than justified by market demand is indicated by a reduction of 892,000 bbl. in stocks for the year. Two classes of data appear on Table 1, which are differentiated by footnote references. Where possible the .figures were obtained from individuals and companies that, from long acquaintance and varied contacts, are most capable of supplying an estimate where an estimate is necessary. The remaining data represent a rather careful compilation from all available published records (see p. 378). Drilling operations and production as summarized by the Oil City Derrick are as shown on Table 2.

Jan 1, 1935

By G. Reed Marchant

In 1967 the US Congress passed the "Clean Air Act." This act was amended in 1970. As a result it soon became obvious that American industries were going to have to make significant changes in their methods of operation to be able to comply with quickly developing federal regulations. One of the first regulations developed was on sulfur dioxide. For this reason, the nonferrous smelting industry was immediately affected by these new regulations. This is true because the smelting process produces sulfur dioxide as a natural product of combustion when the sulfur-bearing ore is oxidized to purify the metal. The federal government's approach for setting standards included public hearings at which government, industry, and private citizens were allowed to make comments. For this reason, it was apparent to Kennecott's Metal Mining Div. that it was desirable to make a maximum effort in working with the agency to see that correct input was provided at the hearings to assist the government in setting fair and realistic standards. It was also obvious that more complete monitoring would be required. It soon became apparent that the efforts required input from many levels of the corporation from the chief executive to the plant operators. In order to accomplish both the administrative and the technical needs, an organization was needed that could respond quickly to these needs, obtain information from diverse sources, and bring it to focus in an organized approach to the problem.

Jan 1, 1979

By T. W. Watson, D. R. Flynn

,Measurements are reported for the thermal conductivity of four heat-resistant alloys which were measured at the National Bureau of Standards. Data are given for two samples of AISI Type 316 stainless steel covering a combined temperature range from -150° to + 800°C. The thermal conductivities of three samples of AISI Type 347 were measured over the temperature range from -150° to +150C. Thermal conductivity values are given for Carpenter 20 stainless steel from 100" to 800" C. Data are given for Inconel 702, in both the solution-annealed and the age-hardened condition, over the temperature range from -150" to +800C. SINCE 1958 the National Bureau of Standards, at the request of other government agencies or private laboratories, has carried out measurements of the thermal conductivity of a number of metals and alloys. This paper presents available thermal conductivity data obtained in this way on samples of four heat-resistant alloys. The data presented for Carpenter 20* stainless steel are, to the best of our knowledge, the only thermal conductivity values which have been reported for this alloy to date. Although thermal conductivity values for AISI stainless steels 316 and 347 have been reported by previous investigators, the present data are believed to be of particular interest because, for each alloy, the effect on thermal conductivity of small changes in chemical composition can be observed. The data on Inconel 702' are of interest, not only for

Jan 1, 1969

By Thomas M. Turner

Open pit mining, always a demanding task, faces two relatively new problems today: (1) availability of equipment and (2) environmental restrictions. The modern dredge offers relief in both problem areas. Delivery on a major dredge might run 18 to 24 months rather than 60 months; and lowering of the water table is precluded, thus minimizing environmental objections. In addition, a lower first cost and potentially increased efficiency may offer real advantages to the miner who is forced away from his traditional mining methods. What are the objections to the use of a dredge in open pit mining? Perhaps first and foremost is the natural reluctance to change from a successful operation. Who can blame the miner who has developed expertise in the use of the dragline if he is reluctant to change to a new mining technique that requires new and different skills? A part of the same problem is the miners' desire to control the excavation visually in order to delineate sharply between overburden and matrix. This problem can be alleviated significantly by utilizing good boring data and a positive acquisition cutter. In the final analysis, however, if the miner is prohibited from dewatering the area, either he mines the deposit by dredge or not at all. There is little doubt that when the decision is made to remove overburden and/or matrix by dredge, the problems of delineating between overburden and matrix, creation of slimes, and development of mining plans to minimize double handling etc., will be addressed and solved. There are two broad categories of dredges: mechanical and hydraulic.

Jan 1, 1976

By Philip U. Santacroce, James H. Meinholz

INTRODUCTION The Milwaukee Metropolitan Sewerage District (MMSD), is a special purpose sub-regional agency that provides collection and treatment services for sanitary wastewater for an area of 420 square miles (1088 km2) in 27 municipalities in the Milwaukee, Wisconsin metropolitan area. During its almost 75 years of existence, it has constructed 464 km of intercepting sewers, the majority in tunnel, and two sub-regional secondary wastewater treatment plants. The present program, the $1.7 billion Milwaukee Water Pollution Abatement Program, was started in 1977 and developed from ongoing internal planning, the Federal Clean Water Act and court judgments. Elements of the Program include improvement and expansion of the two treatment plants; rehabilitation of older in-place sewers; building new interceptors and relief sewers and providing capacity for high volume storage in approximately 32 km of deep, large diameter rock tunnels; reducing combined sewer overflow; and disposal/utilization of the solids that remain after the treatment process. The construction phase of the Program accounts for $1,105,900,000 within 335 separate construction contracts, 211 let to date, and covers a span of 15 years, starting in 1979 and running through 1994. Conveyance System construction cost is estimated to be $650,000,000 or about 60 percent of the total. Through December 1986, in terms of dollars, the total construction program is about 38 percent complete with Conveyance at 34 percent complete.

Jan 1, 1987

Environmental and public concerns and the banned use of cyanide for the recovery of gold in some parts of the world have heightened the search for an alternative lixiviant to cyanide. Thiosulfate appears to be the most promising alternative to cyanide due to thiosulfate being non-toxic, relatively cheap compared to cyanide and generally gold recoveries are similar to those of cyanide. The most widely researched thiosulfate process is one where copper ions and ammonia are added to the solution. This paper reviews the leaching of gold in thiosulfate solutions and the contributions of the research at Monash University to the understanding of the gold oxidation reaction in thiosulfate solutions, the solution chemistry when copper ions, ammonia and oxygen are present, the influence of the changing solution chemistry on the gold leach kinetics, and the application of thiosulfate in the leaching of gold from ores. It is clearly shown that the gold oxidation rate is hindered in thiosulfate solutions. In the presence of copper ions the gold oxidation rate though is significantly enhanced and thus is why copper(II) is more effective than other oxidants in the thiosulfate leach system. The copper-ammonia-thiosulfate leach solution chemistry is shown to be very complex, especially in the presence of oxygen as the rate of thiosulfate oxidation increases and the majority of the copper ions are not maintained in the copper(II) oxidation state. The thiosulfate oxidation rate must also be maintained low as an intermediate thiosulfate oxidation product hinders gold leaching. In optimising the recovery of gold from ores with copper-ammonia-thiosulfate leach solutions it is important to evaluate and minimise any negative effect an ore may have on the leach solution chemistry and hence gold leaching.

Jan 1, 2003

The resignation of Herbert Hoover, Director General of Relief in Europe, from his post as Chairman of the Board of Directors of the Food Administration Grain Corporation, in which capacity he had served for nearly two years; and the reorganization of the corporation under the name of the United States Grain Corporation, with Julius Barnes, United States Wheat Director, as its new head, took place at the annual meeting of the stockholders, held in New York, July 1. This action on the hart of Mr. Hoover is believed to be one of the first steps in his intended withdrawal from public service upon the conclusion of the war service of the various departments of the Food Administration, or as soon as they shall have been absorbed by other agencies. The Grain Corporation has been, for the past two years, a vast collection and distribution agency. Its function has been to assist in supplying to the Allies and the American Army and Navy large quantities of wheat, wheat flout, and other foods, with very little disturbance of American prices, and with such an even control of American distribution that reserves from one crop to another have been brought down to the lowest possible compass and without the dvelopment of actual scarcity anywhere in the United States. In the year just past, it carried on all the buying and the shipping for, the Belgian Relief Commission, until the commission retired on May 1 and the Belgian Government itself undertook its own overseas supplies. During the twenty-two months of its existence the corporation had disbursed $3,500,000,000 and collected an equal amount, selling for over-seas shipments commodities valued at $1,800,000,000, at an operating expense of about $3,250,000, or one-sixth of 1 per cent. During this time it has not lost a single dollar through fire loss.

Jan 8, 1919

By Dennis L. Murr, James E. Wennen

"The through-put and energy efficiency of an autogenous (AG) grinding mill are adversely affected by variability in rock size and rock competency. This applies to both fully autogenous and semi-autogenous (SAG) grinding circuits. In this paper we focus on an approach to overcome the problem of inconsistent mill through-put related to variability in mill feed size and rock competency. The focus is on ores containing hard, competent rock. This approach consists of preparing feed to an autogenous mill that contains 20% coarse media rock and 80% of material crushed to pass 37 mm. Results of pilot-scale testing for two iron-ores will be presented to show that a 10% to 12% reduction in unit energy consumption is possible with prepared feed, compared with feeding the mill with conventional primary crusher discharge.INTRODUCTIONIn the past 30 years or so, autogenous grinding and semi-autogenous grinding have been the comminution technologies of choice for most mining and mineral processing operations. These technologies saved both capital and operating expenses associated with the installation and operation of multi-stage crushing and screening plants required for conventional rod mill – ball mill circuits. However, SAG and AG are inherently inefficient in terms of energy consumption, especially for very hard ores. In cases of hard ore, changing characteristics of rock fed to the mills causes wide fluctuations in mill capacity, which contributes to the inefficiency. Rising electric power costs make this the most expensive unit operation used in the extraction of valuable minerals from an ore. The objective of the concept discussed here is to reduce the energy consumption in AG grinding for hard ore and eliminate the use of large-diameter steel grinding balls that are required for SAG grinding"

Jan 1, 2012

By E. C. Bennett

"INRTODUCTIONVarious methods of making leakage tests have been tried during a study of losses in the transmission of natural gas. This work has been carried on by the Bureau of Mines in cooperation with the Natural Gas Association of America. Results of torts show that the ""shut-in -pressure-drop"" method described by Rawlins is the most accurate and reliable; therefore its use is recommended. This paper describes a graphic method for computing the rote of leakage from the fall in pressure and change in temperature determined by the ""shut -in pressure-drop"" method of testing.METHOD OF MEASURING PRESSURE DROPThe gas is ""shut in"" line to be tested and is not allowed to escape except through existing leaks. The leakage causes the pressure in the line to fall. The charge in pressure is obtained with a dead weight gage. Approximate results may also be obtained from readings on a good spring test gage. Numerous tests show that the dead weight gage is more sensitive to small changes in pressure than spring gages.The temperature of the gas in the line is observed simultaneously with each pressure reading. Temperature changes affect the pressure exerted by a given quality of gas ""shut in a line, end since the rate of leakage from a closed system is directly proportional to the rate of pressure drop, fluctuations in temperature must be considered."

May 1, 1926

By Kyle L. Murrell

Along the southeast United States coast, clayey silt and silty clay marine formations may cause pile installation and integrity problems. More specifically, excess pore pressures which develop in these soils during driving can cause high displacement piles to rebound or ?bounce?. Bounce is defined as a large (¾-in. to more than 1-in.) downward pile displacement during the hammer blow with little to no net displacement at the end of the blow. Pile bounce can generate damaging tension stresses and result in inefficient pile installation. A case history is presented where pile bounce was observed during the installation of 20-in. square ?high displacement? prestressed concrete piles which support a new ferry terminal in coastal North Carolina. High-strain dynamic pile testing was performed during test pile installation to evaluate driving stresses, pile capacities, and hammer performance. During and after installation of numerous production piles, circumferential cracking was observed on some of the piles. Additional high-strain dynamic pile testing was performed on two piles installed with a hammer having a heavier ram than the initial hammer. The new driving system generated lower tension stresses and installed the 20-in. piles more efficiently. Low-strain integrity testing was performed on the piles to qualitatively assess the cracks and locate any unidentified cracks. The low-strain testing was performed on piles installed at least a week prior to testing and on piles installed immediately prior to testing. When low-strain testing was performed immediately after pile installation before dissipation of excess pore pressures, pile integrity could be evaluated to depths of at least 12 pile diameters deeper than when performed weeks after installation.

Jan 1, 2008

External pressures are being exerted on busi- ness, and especially the mining and energy in- dustries, as never before. These pressures are burdensome, they emerge in unique forms, and they constitute an entirely new operating environ- ment for business. They pose one of the signi- ficant challenges to senior management today. To cope with these pressures-which we have termed the new public realities-we must deal more effectively with the media, the public, and government. However, before examining methods for improvement, it is essential to understand the nature of these new public realities and par- ticularly their determinants-the underlying eco- nomic, sociological, political, and international events and trends which have shaped them. Previously the productive element of society had only to concern itself with what might be termed `conventional realities' : the costs of labour, equipment, and land, as well as marketing and distribution factors.

Jan 1, 1978

By M. K. Gangal, E. D. Dainty

The paper describes the use of portable aerosol monitors in determining real-time concentrations of diesel soot and respirable total dust in dieselized mines. The field studies were conducted in a simulated diesel environment in the laboratory where no other type of dust was present, and in four underground mines with multi-diesel machine operations. Two packages for the real-time monitoring of diesel soot were prepared which included two types of aerosol monitors: a Miniram, model PDM-3, and a Sibata, model PDS-1. These monitors utilize the principle of light-scattering to measure the airborne mass concentration in the environment. The monitoring device results were compared against the Time-Weighted-Average (TWA) values produced by the gravimetric filter sampling method, permitting calibration factors to be determined for each field test. Both instrument packages provided comparable results. The instrument calibration factors varied for different tests, which may be due to different material composition, particle size distribution, density and shape of the aerosols. This approach for real-time determination of diesel soot is found to be simple, inexpensive and easy to use. More field tests for diesel soot determination and further research on size distribution of particulates in dieselized mines are required.

Jan 1, 1989

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members) The following is a partial list of members and guests who called at Institute headquarters during the period May 10,1917, to June 10, 1917. F. J. Anderson, Cali, Colombia. W. F. Jahn, Kirkland Lake, Ont., Canada. George J. Bancroft, Denver, Colo. W. McA. Johnson, Hartford, Conn. W. F. B. Berger, Denver, Colo. J. E. Jopling, Marquette, Mich. F. J. Brulé, Toronto, Ont., Canada. William Kelley, Vulcan, Mich. J. Murray Clark, Toronto, Ont., Canada. H. M. LaFollette, La Follette, Tenn. Will L. Clark, Jerome, Ariz.. Dorsey A. Lyon, Washington, D. C. G. H. Clevenger, Palo Alto, Cal. James F. Magee, Lancaster, Pa. Paul S. Couldrey, Sound Beach, Conn. M. Ortin, Nijni-Novgorod, Russia. C. W. Crispell, Kingston, N. Y. - C. H. Palmer, Jr., Los Angeles, Cal. George A. Easley, La Paz, Bolivia. Edison S. Pettis, ?Mill Valley, Cal. Bancroft Gore, Butte, Mont. Mortimer A. Sears, Paintsville, Ky. John B. Guernsey, Roanoke, Va. W. J. Uren, Houghton, Mich. Rush M. Hess, St. Louis, Mo. C. E. Visel, New Haven, Conn. E. Hibbert, Nickelton, Ont., Canada. Percy E. Barbour, has resigned his position as managing editor of the Engineering & Mining Journal, to accept the appointment of Deputy Superintendent of the New York State Troopers, with headquarters at Albany, N. Y., with the rank of captain.. He has also been commissioned as captain in the 22nd Regiment, N: Y. N. G., having been formerly 1st Lieutenant.

Jan 7, 1917

This paper summarises some observations regarding the way SAG and AG mills work based on the last ten years of pilot plant operation, grinding circuit design and operational reviews for various projects in Australia and overseas. The main purpose is to promote discussion on key factors influencing breakage in a SAG mill. The focus of the paper is on two questions: ? How do mill lifters and liners really work and have an effect on grinding? ? How does the mill charge composition impact on grinding performance? The focus of the paper is on observations of mill behaviour in both pilot plant trials and plant operation, particularly on Cadia ore. DEM, by others, and JKSimMet modelling of SAG mill performance have greatly assisted in forming the ideas expressed in the paper and both are valuable tools in developing our understanding of the comminution process. Put in the `extreme' form the major observations and conclusions expressed in this paper are that: ? the main purpose of mill lifters is to reduce mill liner wear and not to promote rock breakage; ? the often promoted theory that balls impacting the ?toe of the charge? is a dominant form of breakage is incorrect; and ? fines production in a SAG mill is primarily a function of the rock load mass, with a secondary dependence on ball load for any given circuit configuration.

Jan 1, 2007

By C Hertle, B Goebel, R Fabre

The mining industry maintains a ælove-hateÆ relationship with water. Dewatering, aquifer, water disposal, irrigation, process water, tailings water, run-off water, seepage, leachate and sumps are all terms that are used on a daily basis in the mining industry, highlighting the numerous water usages on site and their associated quality. According to the Australian Bureau of Statistics (2001), each year the mining industry consumes over 530 000 ML of water. The increasing recognition of water as a limited and valuable commodity, and the associated environmental concerns with the management of water disposal to the environment has led the industry into improving on-site water management. Progressively, water balance models and water reuse strategies are being developed, incorporating more sophisticated water treatment processes. By way of example, membrane technologies, once restricted to industries such as the pharmaceutical industry or the drinking water industry, are now entering the mining world with the aim of producing clean water of suitable quality for ore processing or for advanced treatment prior to release to the environment. This paper will provide a review of the threats and opportunities linked to water use and recovery/reuse in the mining industry in Australia. It will open with an overview of current water usage and associated quality for various mineral industries and continue with identifying the threats and limitations associated with the quality of available water. It will then present how newly developed water treatment technologies and assessment tools can be incorporated into the system to enhance the recovery and reuse of water on site, reduce the risks associated with securing long-term water supply and further improve production, environment and safety (health risk control).

Jan 1, 2006

By Balesh W. Konda, Andrew B. Cecala

Face ignitions occurring during longwall mining are increasing each year and are expected to continue to increase as deeper and gassier seams are mined. Effective methane monitoring strategies are needed to supplement techniques developed either to control the ignition sources or to dilute the gas to an acceptable concentration. Present monitoring strategies do not always detect dangerous concentrations as rapidly as they should. In a number of instances, dangerous concentrations have been observed at the shearer, but are diluted to acceptable levels when measured at the tailgate monitoring location. To effectively monitor and control methane concentrations, methane liberation and emission patterns must be identified. This need has led to a joint research effort between the Canada Centre for Mineral and Energy Technology and the United States Bureau of Mines. By combining the knowledge and experience of both organizations, the methane hazard facing underground longwall operations can be addressed more effectively. A comprehensive plan was developed to monitor methane levels throughout the panel and for an entire longwall mining cycle. In June-July 1986, a case study was performed at the Cape Breton Development Corporation's Lingan colliery in Sydney, Nova Scotia. This initial study was performed on two advancing longwall panels. Methane concentrations and flow patterns from this study are described in this report. A similar study is planned on a retreating longwall panel.

Jan 1, 1987

By Katsunori Okaya, Gjergj Dodbiba, Hiroyuki Ono, Toyohisa Fujita, Seiji Matsuo

"In an attempt to raise the copper grade of Printed Circuit board (PCB) by removing other components, carbonization treatment was investigated. The crushed PCB without surface-mounted parts was carbonized under nitrogen atmosphere. After screening, the char was classified by size into oversized pieces, undersized pieces and powder. The copper foil and glass fiber pieces were liberated and collected in undersized fraction. The liberation of copper foil from the oversized pieces was also investigated. The copper foil was liberated easily from glass fiber by stamping treatment. Liberation rate of copper foil was high at high carbonized temperature. The experimental results indicated that 90% of oversized char was liberated and the copper foil recovery from PCB carbonized at 1073K was 110kg/t. The copper recovery from char powder by flotation was also investigated. 15% of the copper grade and 80 % of the copper recovery were obtained, whereas the removal rate of silicon was 55%.IntroductionWaste Electrical and Electronic Equipments (WEEEs) should be recycled because they have many kinds of valuable materials and most WEEEs include Printed Circuit Boards (PCBs). In Japan, about 30 km2 per year of Printed Circuit board (PCB) has been produced [1], PCBs are normally separated from WEEEs and picked up by hand and sold to non-ferrous metal market because PCBs include high grade of copper and other precious metal such as gold, silver and palladium [2]. However, PCB also has impurities such as silicon, aluminum and calcium which are slag materials in non-ferrous smelting process, and other harmful elements such as lead, bromine and antimony. Low grade PCBs are sold after removal of invaluable parts or sometimes land filled without any treatment"

Jan 1, 2011