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By Flavio Begazo, William A. Enrico

"Southern Peru Copper Corporation's Ilo Refinery, the largest in Peru, began operations in 1975 with a production capacity of 165,000 stpy. Southern Peru bought the Refinery from the state owned Minero Peru SA on June 1, 1994.The Refinery processes blister from Southern Peru's I/o Smelter. Blister copper is processed in an anode plant equipped with two 365 st tilting reverberatory furnaces, a 26 mold casting wheel and an anode press machine. Copper is electrorefined in a tank house equipped with 768 commercial cells, 44 stripper cells, and 40 liberator cells, utilizing two electrolyte circuits and a 21,000 Ampere rectifier.During 1989 through 1994 a program for improving productivity was carried out by increasing the number of cells and increasing current density to the total rectifier capacity. As a result, a capacity 215,000 stpy of refined copper, 2 million tr. oz silver and 6,000 tr. oz gold per year was achieved. In 1994 Southern Peru announced plans to increase capacity to 250,000 stpy of cathode with a US$ 18 million investment and a US$ 2 million investment in environmental improvement projects, as part of the purchase agreement with the Peruvian government.This paper outlines the scope of the SPCC lio Refinery modernization and environmental program. It describes the implementation of the Electrolytic Plant expansion based on instaliation of polymer concrete cells, a new rectifier, a new selenium roaster and a Precious Metal Plant upgrades."

Jan 1, 1997

By Gordon S. Farnham

THIS paper summarizes the results of investigations carried out at Sydney Mines, N.S., and at Ottawa, following the disaster at Princess colliery, December 6th, 1938. The Honourable Minister of Mines for Nova Scotia appointed A. E. Cameron special investigator to enquire into and report upon the cause of the rope failure. Public hearings were held in Sydney Mines and evidence taken from many witnesses. The site of the accident was examined in detail and investigations made of the rope layout and colliery practice. At the request of the special investigator, the Department of Mines and Resources, Ottawa, kindly undertook technical and scientific examination of the broken ends of the rope. These investigations were carried out in the Metallurgical Laboratories of the Department of Mines and Resources, under the supervision of G. S. Farnham, Metallurgist for the Department. Valuable assistance in interpretation of many features of the investigation was received from other sources. Acknowledgment is due to Messrs. Stuewe, McCall, and Gordon, and other members of the staff of the Dominion Steel & Coal Corporation; to Messrs. Morrison and Scott, and other members of District 26, United Mine Workers of America; and to Messrs. Timm, Parsons, Haycock, Haanell, and other members of the staff of the Department of Mines and Resources, Ottawa, for helpful ad vice and technical assistance in assembly of information, and preparation of material and interpretation of evidence obtained.

Jan 1, 1939

By O. M. Bishop

"SUMMARYAs a result of the increased demand for fluorspar during the war, the Bureau of Mines investigated numerous fluorspar properties in the southern Illinois field, which is centered in Rosiclare. Among these the J. J. Shelby 40-acre tract on the western edge of the district presented favorable factors that caused it to be chosen /or exploration.H. G. Spiller, formen lessee of the property, had explored the Shelby vein by means of an adit level and winze, and showed it to contain goad values in zinc and fluorspar at the depth explored. A diamond-drill hole with which Spiller explored the vein 78 feet southwest of the winze, however, failed to cut ore. After studying the field evidence, the Bureau concluded that the vein merited further exploration, particularly at a depth of about 440 feet, where the Fredonia limestone would form the foot-wall of the vein and the hanging wall would be the competent Cypress sandstone.Between October 17, 1944, and March 26, 1945, three diamond-drill holes were bored for a total inclined depth of 1,592 feet. Holes 1 and spaced approximately 500 feet apart, explored the vein at 440 feet 4 below the surface. The economic mineralization existed in the vein where cut. Hole 3 cut the fault at approximately 300 feet below the outcrop but failed to find any vein matter except stringers of calcite with small amounts of pyrite."

Apr 1, 1947

By Daniel G. DiCanio

This report describes a computer-based model for estimating the tangible costs of injuries and deaths from work-related accidents in underground coal mines. The study undertook to identify and quantify the elements of accident costs, including field visits to coal mines, insurance carriers, and public agencies. The mathematical models developed for each tangible element of accident cost are presented in Volume I of the report. A listing of the computer programs which comprise the model and instructions for using the programs are presented in Volume II. Statistical distributions of mining family characteristics, data on 95 miners killed in underground accidents, and other basic data used to develop the model are presented in Volume III. Application of the model to a data base of 9,286 accidents which occured in underground bituminous coal mines during 1974 yielded a total of $56,900,000 in tangible costs to industry, mining families, and public agencies. Loss of income to the families of miners injured or killed in these accidents accounted for 47 percent of the total.

Jan 1, 1976

By William Brundan

INTRODUCTION The Srisailam Left Bank Canal (SLBC) Tunnel Scheme is part of the Alimineti Madhava Reddy Project in Andhra Pradesh, South India. This scheme has been planned since 1983 and will provide irrigation facilities to drought-ridden areas in Andhra Pradesh. Water will be transferred from the Srisailam Reservoir during the monsoon months to 0.3 million acres of farmland and will also provide drinking water to villages en-route. The paper will address the design and onsite assembly of the Robbins Double Shield TBMs for Tunnel-1 of the SLBC tunnel scheme from planning to start-up of the machines. Also, it will provide a current status of the project and describe the advantages of a site assembly. Problems encountered to date and the solutions adopted will also be described. The project comprises over 50 km of tunnels and involves construction of the world?s longest tunnel without intermediate access. The TBM tunnels at 43.9 km in length and 10.0 m diameter will cross the Amrabad plateau, containing a wild life sanctuary and India?s largest tiger reserve, the Rajiv Gandhi. Jaiprakash elected to excavate the tunnel using two tunnel boring machines, rather than by drill and blast, in order to alleviate surface disturbances to environment and the tiger reserve, wild life sanctuary, and protected forestry areas. The Project was awarded to the Main Contractor Jaiprakash Associates Ltd with The Robbins Company as the Tunnel Boring Machine (TBM) supplier in August 2005. The Robbins Company supplied the TBMs along with two continuous conveyor systems and all spares and consumables to complete the tunnel excavation.

? Hollow Stem Auger ? Drill Bits ? Leads/Torque Arm ? Hydraulic Gearbox ? Hydraulic Power Unit ? Grout Pump ? Crawler Crane

Jan 1, 2002

By S. V. Cherty

The utilization of natural gas in non-ferrous industries during smelting and refining stages of copper , aluminum, zinc and lead was studied. The total amount of nonelectrical energy consumed in the production of zinc, copper, lead and aluminium, are 96.5% ,93%,92%, and 6 % respectively. It is calculated that 9.45 wt %of air of stoichiometric amount can be substituted by natural gas to the total air input in the nonelectrical energy utilization processes. The results showed that the non electrical energy may be substituted to an amount of 71 % ,52 % ,35 % ,32 % ,and 26% ,in the production of lead, aluminium (plates, foils) copper, aluminium, zinc, respectivelly. Similar calculations are carried out in terms of energy in Btu for the total production of non-ferrous metals in the U.S. It shows that 51.866~106 millions of Btu of nonelectrical energy can be substituted by 54.58~106 cu. ft of natural gas. Finally, the substitution of non electrical energy in terms of equivalent coal energy is discussed. 1t is shown that total non electrical energy is equal to 1.852 million tones of coal .If this 1.852 million tones of coal is replaced by natural gas, a total savings of 22.14 million dollars are achieved. The total or partial substitution of coal by the natural gas in the existing industrial processes and modification of redesigning the processes is discussed.

Jan 1, 1993

By The DY125-33(Leg 2) Science Parties, Chuanshun Li, Xuefa Shi, Bing Li

"The slow-spreading Mid-Atlantic Ridge (MAR), with a length of ~1.26*104km (Bird, 2003), is the longest mid-ocean ridge on this plant. Separated by the large, left-stepping Equatorial fracture zones, it then be divided into two approximately equal-length parts: Northern Mid-Atlantic Ridge (NMAR, ~6292km) with an average spreading rate of 24mm/yr, and Southern Mid-Atlantic Ridge (SMAR, ~6332km) of 33mm/yr (calculated from PB2002 model, Bird, 2003). Previous works (e.g. Fouquet 1997, Hannington et al., 2011) suggest that slow-spreading ridge could support hydrothermal activities and further favorable for the development of extensive seafloor massive sulfide deposits (SMS). Unlike the NMAR for which large part has been explored for SMS (Hannington et al., 2011; Beaulieu et al., 2015), the SMAR is amongst the least hydrothermal explored spreading ridges until now (Haase et al., 2005, Beaulieu et al., 2015), though both of them show significant similarities in terms of spreading rate, ridge morphology, segmentation, etc. (Macdonald et al., 2001, Sandwell et al., 2014, Tucholke et al., 2008).Before this work, several hydrothermal cruises had been to SMAR since British and German programs starting in 2002, some hydrothermal fields, along with systematic geophysical data, were newly investigated, and types of geologic setting that can host hydrothermal activity were firstly identified (e.g. German et al., 2008; Haase et al.,2005; Haase et al.,2009; Devey et al.,2010; Schmidt et al.,2011).."

Jan 1, 2017

By G. E. Erdman

The total attitude of the industrial minerals producing company is a most important factor in how they regard quality control, technical support for their customers, and procedures used in mining their minerals products. This philosophy of the producing organization directs their action along certain courses. For instance, one producer might see itself as a mining company with its major goal mining efficiency to make it exceedingly price competitive in the market place. Another producer might see itself as a wide spectrum multi-mineral producer that furnishes a reputation for a complete line of products. Another producer might see itself as a specialist in one specific industrial mineral and bet its whole bankroll on providing the very best of quality with the goal of becoming the largest producer of the mineral commodity. Each perception can have a different impact upon the producer's operations and its regard for quality control. Minerals Being Produced The specific markets being served will have their own influence on how mineral product quality is regarded. Ceramic raw materials, for instance, have a very low tolerance for iron which is the cause of low fired color. Thus, industrial minerals for use in glass and ceramic markets must be won from deposits with a very low iron content. A high iron silica sand might be sold to a manufacturer of good old beer bottles. That is a solution to one particular quality facet, but eliminates selling to a significant market in clear glass, porcelain enamel, ceramics whiteware bodies and hobby glazes. Thus, there is a need for sound research in the industries expected to be served before the product is brought to market.

Jan 1, 1987

By K. Yoo

Cuprous oxide is one of the oldest antifouling agents and also acts as red pigment in these paints. In printed circuit board manufacturing industries, waste etchant contains a substantial amount of copper ion. In the present study, a process was suggested for recovering cuprous oxides from the waste etchant and optimum conditions were investigated to recover the cuprous oxides. The process consists of two steps: in first step, Cu powder is added into wastewater solution, and cupric ions re-duce into cuprous ions (Cu+Cu2+?2Cu+), where cuprous ions precipitate as cuprous chloride; In second step, cuprous oxide is synthesized by adding NaOH into cuprous chloride solution (2CuCl+2NaOH?Cu2O+NaCl+H2O). Optimum conditions were investigated to recover cuprous oxide in the processes. When copper powder was added into wastewater with copper ions, Cu concentration decreased from 15.6% to 2.6% and ORP decreased from 620 mV to -59.9 mV. This result shows that cupric ions reduced into cuprous ions. XRD data indicated that the precipitate was cuprous chloride powder. Using the cuprous chloride recovered and NaOH solution, cuprous oxide was synthesized. To investigate the optimum condition, various NaOH solutions were added into water with CuCl, and then pH, ORP, Cu concentration, Cu contents in precipitates were analysed. XRD data showed that main component of precipitates was cuprous oxide.

Jan 1, 2014

By Seokwon Jeon, Ho-Young Jeong

"Various numerical methods have been tried to estimate the cutting forces of a TBM disc cutter. In this study, SPH/FEM coupled method was newly employed to improve the traditional FEM analysis. The disc cutter and rock were modeled by Lagrange and SPH codes, respectively. The numerical cutting test was carried out for representative Korean rocks with different cutting conditions. The results show that the cutting forces obtained from numerical simulation had a good agreement with those from LCM tests, and that applying SPH method to rock cutting model has advantages and improvement compared to traditional FEM method. Erosion criterion and erosion limit were not required to simulate the rock fragmentation process, and the cutting forces from the numerical simulation was more stable and accurate. The results indicate that the numerical simulation can be successfully used to estimate cutting performance of a TBM. 1. INTRODUCTION Various numerical studies have been carried out to accurately simulate the limitations of linear cutting machine (LCM) tests. Numerical modelling methods have advantages comparing with full scale tests in terms of cost and time involved. Many numerical methods have been used to simulate rock cutting process by different cutting tools and the studies are summarized in Table 1.In 2D simulations listed in Table 1, because they do not take account of rolling force and horizontal rolling mechanism of a disc cutter, indenter was selected as cutting tool in their modelling. For these reason, 2D modelling is not suitable for rock cutting modelling using a disc cutter. In contrast, 3D numerical models can take account of the indentation process by thrust force and penetration processes controlled by rolling force."

Jan 1, 2016

By Guy Chevalier

The QCM Mount-Wright mine and concentrator complex produces about 14 M tonnes of iron concentrate annually. Approximately 9.5 M tonnes of this concentrate are used to produce iron ore pellets at four different silica grades: Three for blast furnace operations and one for direct reduction furnaces. The paper presents the scientific approach that led to the realization of two projects where the acquisition of new process equipment led to an improved pellet plant iron recovery, a better flexibility and to lower operating costs as well as to the production of fine iron ore concentrate from the Port-Cartier tailings pond. Typical 4.8 % SiO2 concentrate is processed to achieve required pellet silica content. This is obtained with the aid of hindered settlers or hydraulic classifiers, screens, whims and, lately, spirals. The increasing demand for low silica iron ore products resulted in a greater need for upgrading. The Pellet Plant upgrading capacity being limited, more and more iron units were lost. Base on test works results and economic evaluations, QCM engineers figured out a way to increase efficiently their upgrading plant capacity and go back in the pond gather what has been lost in recent years of operation.

May 1, 2007

By A. W. Khair, S. J. Jung

"IntroductionIn a typical incremental loading test, the AE activity increases rapidly in the initial stage of the loading. It is associated with initial closure under compression of favorably oriented cracks already present, together with sliding of crack faces against each other /1/. After the initial stage, crack closure and movement largely cease and the AE activity drops to a barely detectable level /2/. In the final stage of loading test, cracking associated with the onset of inelastic deformation' occurs, and the rate of AE rapidly increases /3/ indicating an increase in the •number of events associated with higher number of microcracks. To understand better primary fragmentation process, Anderson and Ruzzi conducted tests to identify a practical method of monitoring fracture development in rock, as caused by an excavation tool /4/. They proved that a relationship existed between the AE activity, generated during fracturing and the amount of fracture surface area created.A process of fragmentation, demonstrated by conical bits acting orthogonal to the flat surface of block of coal specimen with and without lateral confining pressure is presented here. The monitoring of AE during the fracturing process of rock/coal has been a very useful indirect method in studying fracture mechanism.Specimen PreparationLarge blocks of Waynesburg coal were obtained from a surface mine. These blocks were then out and molded to approximate dimensions of 25.4 x 25.4 x 15.2 'an (10 x 10 x 6 in.). These specimens were instrumented with three strain gages in a 45 degree rosette. One was mounted parallel to the bedding plane direction, another was tinted at an angle of 45 degree from the bedding plane direction and the third was mounted perpendicular to the bedding .plane direction. Each of the three strain gages were set 5.1 an (2 in.) away from the impact point.Typical Test ProcedureIn a typical experiment, the specimen was placed in the confining chamber.Predetermined equivalent in-situ stresses were applied to the specimen by using two sets of hydraulic cylinders. Two 1 in. thick steel plates ware positioned between the sample and the hydraulic cylinders in order to distribute the pressure uniformly over the whole surface of the specimen. The LVDT null position was adjusted with respect to the coal face. After setting the LVDT, the bit and associated weight was lifted to a predetermined height (equivalent to a predetermined kinetic energy) by a win. The three strain gages were balanced using the signal conditioner and the output was recorded by a 6 channel strip chart recorder. The experimental set-up is shown in Figure 1."

Jan 1, 1989

By Danilson Gonçalves de Melo e Silva

O balanço de energia realizado em um forno de aquecimento de tarugos apresentou rendimento de 53%. A maior perda energética estava relacionada ao sistema de refrigeração dos skids, cujo valor calculado foi de 18%. Objetivando minimizar tais perdas, estudou-se a utilização de um novo tipo de revestimento refratário para esta região. O fabricante de refratários apresentou uma estimativa de ganho de 62%. Desta forma, a VBR planejou um teste para validar a eficiência do refratário proposto. Neste teste, o produto foi instalado em uma viga auxiliar. Esta viga foi instrumentada, e foram registrados dados de vazão, pressão e temperatura do fluido de refrigeração (água). Objetivando comparar estes valores com o material convencional anteriormente instalado, outra viga com as mesmas características (dimensões e posição no forno) também foi instrumentada. Posteriormente, foram feitos os balanços de energia em cada viga para quantificação das perdas de energia térmica. Os resultados encontrados mostram uma redução de 92% da perda térmica relacionada ao sistema de refrigeração dos skids. Considerando a eficiência do forno de 53% e a redução de 92% da perda térmica, estima-se uma economia de R$ 1.200.000 por ano.

Sep 25, 2017

By Alan Morris

SEASON cracking of brass has received wide attention and there is a wealth of technical literature on the subject. Its causes are fairly well understood and means for its prevention are inexpensive and effective, .so that the frequency of failures from this source has diminished of recent years. But its sister phenomenon, the failure of annealed brass by reason of applied tensile stress plus a certain type of corrosion, has received less attention, though it has been responsible for occasional more or less troublesome cases of cracking of brass in service. The work described in the following pages was undertaken about two years ago to determine the relative resistance of various commercial brass mixtures to stress-corrosion cracking, and to learn something of the controlling factors. By stress-corrosion cracking we mean the cracking of brass free- from internal stresses by reason of applied tensile stress and simultaneous attack by certain corrosive agents. Rogers,1 in discussing a paper by Hatfield and Thirkell, says : "He had also applied a solution of mercuric salt to tensile test pieces of brass whilst they were under stress in the testing machine. At very moderate stresses such test pieces cracked, and very readily broke." Moore, Beckinsale and Mallinson2 subjected test pieces to simultane-us corrosion and tensile stress. In order to determine the minimum stress detectable in brass by the mercurous nitrate test, tensile samples were placed under stress and treated with mercurous nitrate solution. They found that brass stressed below a minimum did not crack.

Jan 1, 1930

By Adilson Rodrigues da Costa

Os cilindros usados em laminadores a quente, especialmente os cilindros de trabalho são submetidos a altas taxas de desgaste da superfície durante a laminação. Após a campanha de laminação os cilindros devem ser enviados para uma retifica de cilindros para remover a camada danificada. Para este processo de retifica, são utilizadas rebolos com alta eficiência de corte e alta resistência. O objetivo foi analisar os resíduos metálicos e as partículas abrasivas do rebolo após a retificação dos cilindros e, correlacionar com o desempenho obtido com dois tipos diferentes de rebolos, sendo assim capaz de definir um rebolo com melhor desempenho e menor custo operacional.

Jul 30, 2018

By V. A. Shea-Albin

Sandstone escarpments surrounding western coal-bearing plateaus serve as critical habitat for animal species. Effects of mining subsidence on escarpment stability are not well documented; therefore, regulatory agencies may limit extraction of coal reserves underlying escarpments. Because millions of tons of this coal exist on Federal Lands, associated public revenues from Federal royalties, and valuable coal reserves, risk being lost. The U. S. Bureau of Mines is using numerical modeling techniques to analyze effects of subsidence on escarpment stability. Finite element models that incorporate bedding plane slip, gob formation, and movement along joints simulate escarpment subsidence observed in the field.

Jan 1, 1994

By Irwan Halim, Young Jin Park

A new tunnel lining was designed for rehabilitation of the existing unlined Weehawken Tunnel in New Jersey. Structural assessment using beam spring models was performed for the lining design as a drained structure at the invert with a waterproofing umbrella. Empirical Federal Highway Administration (FHWA) guideline was typically adopted for estimating hydrostatic pressure, which recommends full hydrostatic pressure at the crown and ten or twenty-five percent gradual reduction from the initial pressure toward the invert. Finite element seepage analyses were conducted for the actual conditions based on anticipated drainage behind the lining and impact on the structural design. Considerations will be provided on the existing guideline for estimating hydrostatic pressures.

Dec 1, 2022

Idaho Bureau of Mines and Geology, University of Idaho, Moscow, Ida. John W. Finch, Director. A list of publications will be sent upon application. A series of Bulletins and Pamphlets have been issued by the Bureau to date since 1920 Of the Bulletins, six are out of print, and a charge is made for eight. Each of the Bulletins, in the main, treats of the geology and resources of a particular district in Idaho, as follows (only available Bulletins listed): Bulletin 1, South central Idaho (1920), 15 cents, 7, North central Idaho (1924), 50 cents, 8, Bonneville, Bingham and Caribou counties (1924), 50 cents, 9, Boise Basin (1924), 50 cents; 10, Boundary County (1926), 50 cents; 11, Region about Silver City (1926), 50 cents; 12, Clark Fork district (1930), 50 cents, 14, Eastern Cassia County (1931), 50 cents, Press Bulletin 15, Teton County (1927), Bulletin 16, Melon Valley near Buhl (1927); 17, Concerning land slips near Whitebird, Idaho (1928) The 37 Pamphlets are issued free of cost, and each treats, also, in the main of the geology and resources of a particular district in Idaho Nos 1, 2, 3, 4, 5, 7, 8, 10, 17, 18, 20, 22, 25, 26, 30 and 35 are out of print Of those available, attention may be called to Pamphlet 6, Reported platinum occurrences near Coeur d' Alene (1925), 11, Bruneau River Basin, 12, Power and Oneida

Jan 1, 1933

By J. C. Bradley

THE relation of annealing temperature to conductivity of copper wire has been determined.1 Conductivity hard was 98.26 per cent. After a 10-min. heating at 200° C. it was 98.69. By annealing 10 min. at 300° C. a large increase, to 100.93, occurred. Maximum conductivity, 101.15, was attained after a 500° C. anneal; thereafter it decreased to 100.53 after a 950° C. anneal. If copper is gassed the decrease is much more than this. MATERIAL AND METHOD The work was done on high grade electrolytic copper, 99.942 per cent. copper-plus silver, silver 0.0008 per cent. It was hot-rolled to 3 in., then cold drawn to 0.080 in. The wire was cut into 25 5-ft. lengths and numbered 1 to 25 as cut. Four samples were tested hard. The others were wound into 5-in. diameter coils. For the 100° C. heating a coil was put into water, the water brought to boiling, and the wire kept at this temperature for 10 min. For the higher temperatures the coils were placed in envelopes of sheet copper, a little water added, and the envelopes sealed by folding over the edges twice, and hammering them together. This kept the air out very well. The envelope and wire were brought to the desired temperature; this was maintained for 10 min., then the whole was water-quenched.

Jan 1, 1927