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By J. Philip Bromberg

Any effectuation of a viable program of air pollution control will' require a basic understanding of the chemistry of atmospheric processes, the fate and migration of SO2, and the ultimate health effects of the sulfur oxides themselves. The migration and ultimate fate of Sop discharged into the atmosphere will be discussed with particular emphasis on the various conflicting views and how these relate to our present emission control regulations. Our present lack of knowledge is a severe detriment, and consideration will be given to those particular areas where future research may best be directed to provide the answers to a number of perplexing questions.

Jan 1, 1976

By J. A. Fellows, Earnshaw Cook, Howard S. Avery

HEAT-RESISTANT alloys of the higher nickel and chromium ranges have been empirically developed through the practical experience of the past two decades to a position of significant industrial importance. Few quantitative metallurgical data have been published, however, that could be related directly to engineering specifications and design. Inadequate information led to the inauguration, in 1934, of a research directed toward a better understanding of the properties and performance of these steels at temperatures between 1400° and 2000°F. Investigation was concentrated upon the 26 per cent Cr:12 per cent Ni type, which owes its extensive application to an excellent combination of economy, strength and surface stability at elevated temperatures. The requirements of the oil-refining industry have been prominent in influencing the scope and evolution of the program. Creep strength at the maximum allowable deformation ranges has been employed to evaluate the merits of these alloys. Permissible elongation rates vary from 1.0 per cent in one million hours for turbine blades to 1.o per cent in ten thousand hours for tube supports and heating-furnace equipment. Throughout this paper, the limiting creep stress (L.C.S.) for a given temperature has been defined as the stress that will produce a uniform elongation rate (stage II) of one per cent in ten thousand hours as extrapolated from rates per hour or tests of less than two thousand hours duration. Certain current specifications require a minimum L.C.S. of 1600 lb. per sq. in. at 1800°F., of 3600 lb. per sq. in. at 1400°F., and include a tensile acceptance test at room temperature, after aging for 24 hr. at 1400°F., as a measure of embrittlement in service. An elongation of 4 per cent is considered satisfactory for general use, while a minimum of 9 per cent is prescribed on occasion. Many differences of opinion concerning the properties and performance of these alloys appear to result from their sensitivity to unappreciated variations of chemical analyses which, for example, may change their L.C.S. from 3500 to 350 lb. per sq. in. at 1800°F. Within broad chemical limits, it is possible to balance the six or more important elements present to attain desirable properties with a number of different combinations. One method for adjusting the composition has been described under the sponsorship of the Alloy Casting Institute,1 in which, by maintaining a substantially austenitic* alloy, optimum creep strength and minimum tendency to embrittle after aging are expected. Unless, however, the limits are undesirably dose, it has not been possible to ensure a moderate range of strength and of ductility by any chemical specification alone. There is a definite need

Jan 1, 1942

By Pedro Jorge Walburga Keglevich de Buzin

A produção siderúrgica em usinas semi-integradas gera resíduos de processo, dentre os quais pó de aciaria elétrica (PAE). A presença de zinco e os custos crescentes para a disposição deste resíduo são fatores de motivação para sua reciclagem ou incorporação em outros materiais. Entretanto, fatores como o teor de zinco e as espécies minerais existentes, têm influência no processamento do PAE. Adicionalmente, a presença de outros elementos como o chumbo, cromo e o cloro muitas vezes afetam de modo determinante os processos de reciclagem ou aproveitamento. Neste estudo, após análise, são feitas considerações acerca da influência da composição do PAE em processos piro e hidrometalúrgicos de reciclagem. Complementando o trabalho, são feitas simulações sobre o possível comportamento de algumas espécies químicas do PAE em processos de reciclagem, com auxílio da ferramenta termodinâmica computacional FactSage.

Aug 7, 2018

By M. M. Neale

The pottery department has been aptly described as the "heart of the zinc plant," md every operator of a horizontal-retort plant is acquainted with the fact that good retort practice is the keystone of the smelting process. Since retorts and condensers are clay products, it is obvious that improvements in other branches of the ceramic industry should be observed for possible adoption in the pottery process for zinc smelting. Deaeration of clay bodies is one of the improvements that have become fully, established in many brick and pottery plants. Our investigation of a number of these installations always yielded the same answer—improved practice. Improvement in workability, elimination of laminations, less porosity, greater wet and dry strength, were among the claims put forth for this process. All of these features are exceedingly desirable characteristics in the manufacture of a zinc retort. A preliminary test, which involved truck transportation of deaired slugs over a relatively long distance, did show the value of many of these characteristics in forming the retort. Results from the standpoint of , longer retort life in the smelting furnace were not outstanding. The idea lay dormant for several years but was revived again in 1940, when it was decided to make whatever changes were necessary in the equipment for pottery manufacture to fully demonstrate the process. A number of the manu- facturers of machinery for clay work were asked to submit proposals, and the plan finally adopted was extremely simple and economical. Machine FOR DeaeRRATING Selection of the ''Straight-line'' principle for conversion of the "Wettengel" pug mill to a ''vacuum-extrusion" machine preserved some usable parts of the original equipment, such as the drive mechanism, and main shaft. The converted machine consists of a feed hopper, a compression and shredding zone, a vacuum chamber, and an extrusion barrel, as shown in Fig. I. In operation the clay mix travels from the feed hopper into the compression zone, where it is compressed and finally forced around the tapered cone into the vacuum chamber. As it enters this chamber the clay body is shredded into thin plates, for exFosure to the vacuum. The shredder consists of a hub mounted on the main shaft, to which are bolted segmental sections, each of which carries shredder knives. The compression zone and extrusion barrel function as seals for the vacuum chamber and the shredded clay mix is agitated thoroughly during its exposure to the vacuum. A vacuum pump, equipped with a 3-hp. motor, is attached to this chamber, and maintains 25 to 26 in. vacuum during operation of the mill. Changes in Practice Prior to the adoption of the deaeration process, our standard pottery practice called for double mixing in the combination 7

Jan 1, 1944

By Gustavo Coqui Barbosa

Neste trabalho, foi desenvolvido um modelo de elementos finitos para simular o primeiro passe da laminação a quente do trem acabador de tiras de aço C-Mn. O comportamento desse aço é definido por equações constitutivas que descrevem os mecanismos de encruamento e recristalização acoplados aos campos de tensões, deformações e temperatura. Foi implementada uma sub-rotina em linguagem FORTRAN disponível no programa de elementos finitos ABAQUS/Standard. O modelo foi estabelecido no estado plano de deformação por meio de elementos finitos com acoplamento dos campos de temperatura e deformação para o cilindro de trabalho e tira. As dimensões e condições de processo foram obtidas a partir de dados industriais do laminador de tiras a quente da CSN. O modelo prevê as distribuições de temperaturas e valor de carga de laminação em boa concordância com as medidas industriais. Os resultados do modelo evidenciam que há ocorrência de recristalização dinâmica durante o primeiro passe e, apontam que em determinadas regiões da tira a fração recristalizada dinamicamente chega a 100%. A análise de sensibilidade dos parâmetros do modelo foi feita para determinar o seu impacto nos resultados das simulações, notadamente na força de laminação e no tamanho de grão austenítico final.

Jul 30, 2018

PRESIDENT HERBERT HOOVER, STANFORD UNIVERSITY; CAL. PAST PRESIDENTS SIDNEY J. JENNINGS NEW YORK, N. Y. HORACE V. WINCHELL MINNEAPOLIS, MINN. FIRST VICE-PRESIDENT EDWIN LUDLOW, NEW YORK, N. Y. TREASURER GEORGE D. BARRON NEW YORK, N. Y.

Jan 1, 1923

By E. You

The concentrator at Kennecott Utah Copper currently has 4 lines with a configuration of one SAG mill feeding two ball mills. The slurry that reports to each ball mill will vary resulting in an unequal load of material. This configuration contains two separate sumps that receive material from a distribution box relying solely on natural slurry flow to feed each sump. The unequal split to each mill results in one mill receiving a greater amount of material. This will result in the equipment on one mill reaching limitations that may affect product quality and the operation of the equipment near maximum. The parallel mill in this condition will often have additional capacity that can be used but cannot be utilized due to the unequal split. The major consequences of this issue result in reduced throughputs and metal recovery. To resolve this condition an advanced control strategy was implemented to control the split in April of 2002 using equipment that was in place.

Jan 1, 2007

By C. WIFLARD HAYES

(New Haven Meeting, February, 1909.) I DESIRE to make it perfectly clear at the outset that I fully realize the hazardous nature of any attempt to estimate the quantity of iron-ore or any other mineral in the ground. I should not have had the temerity to venture upon an inventory of the iron-ore supplies of the United States except for the requirements of the Conservation Commission. During the preparation of this inventory I have been impressed by the wide diversity in estimates of those best qualified to. hold an opinion, and I am therefore prepared in advance for criticism of my figures. Inasmuch as this report was prepared in large part for unprofessional readers, I considered it necessary to classify and describe the commercial iron-ores in a somewhat elementary manner, in order to explain the reasons for the large element of uncertainty in the estimates. I have therefore given a chemical and a geological classification of iron-ores, which place the commercial deposits in six classes: (1) magmatic segregations in basic igneous rocks; (2) contact-deposits formed in connection with igneous intrusions; (3) concentration-deposits; (4) replacement-deposits; (5) bedded-deposits, and (6) gossan-deposits. The iron-ores are further distinguished under two classes available and not available. This classification is in large measure arbitrary, and it, is evident that it will vary front time to time. In the available class are placed those ores which can be worked at a profit under conditions essentially as they exist at present. Since it depends wholly on the question of costs, the various factors which affect cost will determine the classification of any particular deposit. Actual production, * Abstract of Report prepared for the Conservation Commission. t Chief Geologist, United States Geological Survey. .

Apr 1, 1909

By Franklin H. Sharp, Kenneth L. Clifford

During the last few years the New Lead Belt of Southeastern Missouri has become the main source of lead in the United States. It also produces significant amounts of zinc, copper and silver. The mines are located on a narrow, mineralized trend extending southward from Viburnum, MG. for about 35 miles. The ore occurs as replacement deposits in the Bonneterre lime- stone formation which is about 1000 ft below the surface. In most of the mines, enough water is produced to supply the milling requirements without any reuse. There are dry areas, however, and at least two mills must rely on water reclaimed from their tailings lake to augment the mine water. These mills have no choice but to utilize recycled mill water.

Jan 7, 1973

By William Gleason

The mining industry is at a crossroads. Currently, there is an estimated $25 billion worth of projects around the world that have been stopped as the consequence of a dispute or disagreement with their communities, the government or some other stakeholder. Anglo American chief executive officer Mark Cutifani is one who sees the mining industry in need of change and on Dec. 12, he gave the keynote address for the launch the Kellogg Innovation Network?s Mining Company of the Future Initiative?s Development Partner Framework (DPF). The launch was held at the Ford Foundation building in New York City. The DPF seeks to inspire and support the mining industry to adopt a new way of thinking and a new approach to how it secures, nurtures and revitalizes its social license to operate. Working with a diverse group of people from faith-based organizations, nongovernmental organizations (NGO) and other stakeholders, Cutifani often had the rather uncomfortable position of representing the mining industry in a room full of people who are far from the industry?s biggest fans.

By John J. Collins

[CONTENTS PAGE Purpose and scopeI Core samplingI Sludge sampling.....7 Combining core and sludge assays13 Deviation and surveying of drill holes17 Conclusions24 Acknowledgments25 Bibliography25] PURPOSE AND SCOPE The purpose of this paper is to review a few of the problems involved in the interpretation of diamond-drill core and sludge samples, with the hope that it will stimulate discussion and bring forth some of the information on the subject that has been accumulated by various organizations. The release of these data would benefit the mining industry as a whole. Particularly valuable would be the details of drilling programs that have been tested by actual mining operations, as most of the available published material is unsupported by production records. The scope of this paper is limited to a few of the commonest problems of interpreting diamond-drill core and sludge samples and the deviation of holes. It does not include the description of routine operations performed by the drillers, nor the estimation of ore reserves. The methods of calculating reserves have been described 25,26,31,32.50,65 but more information is needed on the results shown by actual mining operations. CORE SAMPLING The accuracy of diamond-drill-hole sampling depends in large measure on the percentage of core recovery. As a general rule, the longer the run, the poorer is the recovery. Although the longer runs allow cheaper drilling costs, the determining factor should be the percentage of recovery desired. The problem is one of balancing accuracy against costs. Holes of larger diameter may show improved recovery, except as Joralemon* points out that there are some conditions in which small holes give better core recovery than large holes. This is particularly true, he says, in rocks like shattered quartzite, where larger core tends to break in angular fragments and grind up, while the diameter of smaller core is less than the distance between joint planes and grinding is not so serious. In a large measure the length of the sample run should depend on the type of deposit. Favorable drilling may allow uniform sample runs of 5 ft., 10 ft., or perhaps 20 ft. In veins or beds of relatively narrow widths and changing characteristics, however, the ore zone may be overrun and ground in a core barrel full of waste rock. Generally it is desirable to break the sample at a change in the rock or ore. Such a change, often indicated by a color change in the sludge water, should be a signal for the driller to make a "dry" block and to pull out that run regardless of the length. Such a procedure permits the segregation of waste from ore samples so

Jan 1, 1946

By Priscila Alves da Silva Machado

A busca por pesquisas que provem soluções e inovações que utilizam parte de tais resíduos vem ganhando grande destaque. O poli (tereftalato de etileno) é um polímero termoplástico, e é o material base para produção de embalagens plásticas que são comercializadas mundialmente. Sabe-se que é de grande volume os resíduos sólidos provenientes de tais embalagens plásticas. Com o objetivo de solucionar um problema ambiental e verificar a viabilidade técnica, foram fabricados em proporções de 0%, 5%, 10% e 15% m/m, materiais compósitos de base cimentícias reforçados com fibras de poli (tereftalato de etileno) provenientes de resíduos de garrafas plásticas (PET), posteriormente amostras passaram por caracterizações mecânicas. Destacou-se um aumento das resistências a compressão axial e diametral do material produzido com fabricação de adição de poli(tereftalato de etileno). Tais resultados referente a resistência foram positivos, propondo assim a utilização do polímero na composição de novos compósitos.

Oct 30, 2017

By Webster Smith

El presente texto describe la historiografía del cobre en el mundo. El cobre fue el primer metal usado ampliamente por el hombre. Posteriormente, las propiedades de resistencia de corrosión del cobre, bronce y latón hizo que estos metales permanecieran no solo como decorativos, sino como funcionales durante la Edad Media hasta nuestros días. Ya en el siglo XIX, Gran Bretaña fue el mayor productor del metal rojo. Pero nuevas minas se abrieron en EE. UU, Chile y Africa, hasta que en 1911 la producción mundial de cobre fundido excedió a un millón de tonelada por año. Con el avance de la Revolución Industrial, se descubrieron nuevos e importantes usos para el cobre, así como producir numerosas y nuevas aleaciones. Actualmente, se produce más de cinco millones de toneladas de cobre y este metal desempeña una parte vital y progresiva en muchas ramas de la tecnología moderna.

Nov 1, 1967

By E. N. Gilje

"IntroductionDURING the past five years, over two miles of shaft sinking have been completed at Falconbridge. As sinking has continued, we have improved our equipment and technique with a resulting increase in efficiency. Throughout this period, all sinking has been done by contracting firms, under our direction and to our equipment specifications, with highly satisfactory results. Since 1949, Riddell shaft mucking machines have been successfully used in conjunction with the •benching method of sinking. Our most recent practice can best be illustrated by describing the method used in sinking No. 1 shaft at the Fecunis Lake mine.No. 1 Shaft, Fecunis Lake MineNo. 1 shaft, consisting of six compartments and measuring 13 ft. 11 l/2 in. by 19 ft. 9 3/8 in., outside timber (Figure 1), will be sunk to a depth of 4,170 feet. It was designed to accommodate two 10-ft.diam. Koepe hoists."

Jan 1, 1955

By B. Csoke

As opposed to large household appliances, in the processing of which dissambling has an important role, this possibility is pushed into the background as the size decreases. The practicable solution is physical liberation of the used small electronic household devices (by comminution) and separation of the liberated components according to their physical properties. In the first phase of the experimental work the structural/material composition of the typical products (mixer, kitchen robot, hair dryer, coffee machine, iron, bread toaster, vacuum cleaner, oil fryer) was determined. In the second phase a physical liberability test for each appliance using a rotary shear/shredder for crushing and a hammer shredder for milling was carried out. In the third phase the experimental separability tests using an air classifier and a shaking air table, as well as an eddy-current and an electrostatic separator were performed. In the present paper the results obtained using the air classifier and the electrostatic separator, are reported. To follow the life of a grain a new methodological procedure was elaborated. The particle size fractions after comminution were sorted into material fractions (copper, aluminium, plastics, etc.), then separated, and finally the recovery of the material components in the products were determined. Furthermore, the joint separability was investigated from two points of view: 1) for grain fractions and 2) for each waste appliance. According to the tests carried out so far, it was established that it is reasonable to form appliance groups by selection (e.g. mixer, iron, bread toaster and similar appliances form the first group, while the sandwich oven,

Jan 1, 2014

By A. N. Shen

Fe3A1 intermetallics are potential inexpensive candidate for hot applications. In this project, torsion tests on hot-rolled and annealed Fe3A1 (Fe-15.5A1-5.8Cr-1.0Nb¬0.05C) were carried out over the ranges 750-950°C and 0.01~1s-1 . The experimental results showed that when peak stress op>90MPa (LogZ>16s-1 , Z: temperature-compensated strain rate), specimens cracked at randomly low strains. Optical microscopy exhibited original elongated grains and many grain boundary cracks associated with segregation. With op<40MPa (LogZ<16s-&apos;), specimens deformed with low random op but considerably high fracture strains; slowly propagating cracks may explain the reduced flow stress. Optical microscopy showed both elongated grains and equiaxed subgrains with some indications of geometric dynamic recrystallization (gDRX) and of static recrystallization (SRX). Compression tests gave higher stress with little effect of the preexisting cracks. The activation energy Quw of current material in satisfactory torsion and compression tests is about 10% higher than previously published. Fe3A1 has body-centered cubic structure in the experimental range, so it was compared with ferritic stainless steel 434C (Fe- 16.55Cr-0.96Mo-0.21Ni). Constitutive constants and restoration mechanism are compared between these materials. While Fe3A1 is hardly a light metal, it is considerably lighter than most steels. Furthermore, like the other body centered cubic metals (BCC) (a-Fe, ß-Ti, ß-Zr and ß-brass), it exhibits a high degree of dynamic recovery (DRV) like Al alloys, producing easier hot workability than that of austentic stainless steels.

Jan 1, 2007

President-Mrs Robert D Coombs, 375 Paramus Road, Paramus, N J First Vice-President-Mrs Howard R Norsworthy, 333 East 53 Street, New York 22, N Y Second Vice-President-Mrs Arthur Notman, Circle Road, Dongan Hills, Staten Island 4, New York Third Viee-President-Mrs David Eugene Park, 30 Sutton Place, New York 22, N Y Fourth Vice-President-Mrs Cony T Brown, 211 East Abeyta Avenue, Socorro, New Mexico Fifth Viee-President-Mrs J A Carpenter, 245 University Terrace, Reno, Nevada Recording Secretary-Mrs W McG Peirce, 7 Lexington Avenue, New York 10, N Y Asst Recording Secretary-Mrs Arnold H Miller, 601 West 115 Street, New York 25, New York Corresponding Secretary-Mrs Theodore Nagel, 76 Remsen Street, Brooklyn 1, New York Treasurer-Mrs Robert W Rowen, 116 East 68 Street, New York 21, N Y Assistant Treasurer-Mrs Samuel H Dolbear, 11 Broadway, New York 4, N Y Assistant Treasurer-Mrs H A Kursell, 12 Murray Hill Road, Scarsdale, New York

Jan 1, 1955

By Xiaolong Lin, Yuanbo Zhang, Guanghui Li, Zhizhong Li, Zhiwei Peng, Tao Jiang, Yan Zhang, Yutian Ma

Pyrometallurgical processes for recovering platinum group metals (PGMs) from spent catalyst have been the focus of current research for many years. They suffer from high energy consumption, large trapping agent consumption and huge slag production. Because of versatility of PGMs-containing spent catalysts, comprehensive recovery of valuable metals from these catalysts from an experimental point of view remains a challenge. In this study, thermodynamic analysis of pyrometallurgical smelting process in the presence of various additives for ef ficient recovery of PGMs was performed. It showed that addition of sodium salts would promote the migration and separation of the precious metals from carrier of the spent catalyst. By replacing calcium oxide with sodium carbonate and sodium borate, the smelting temperature could be reduced by more than 200 °C, which agreed well with the experimental findings.

Mar 1, 2018

By M. Bugdayci, Onuralp Yucel, K. C. Tasyurek

This paper is a contribution to the theory and quantitative understanding of the processes for the production of magnesium, calcium and strontium metals by metallothermic process. In the present study, effect of reductant type was investigated. Thermodynamic simulation of system was made by Fact Sage 6.4 program. In order to produce magnesium metal, effects of reductants “FeSi, Al, Si and CaC2” were investigated. To understand Calcium-oxide reduction system, effects of Al and CaF2 addition were investigated for different temperatures. In the last simulations, SrO reduction parameters were simulated. Al used as main reductant and BaO, CaO, CaC2 were added to green mixture as a functional additive. Finally probable phases and minimum reduction temperatures are determined.

Mar 1, 2018

By Donald J. Reining

The California Surface Mining and Reclamation Act (SMARA) is the nation&apos;s first legislation establishing a statewide mineral resource policy governing mining activities that recognizes regional needs and retains local autonomy. The Southern California Rock Products Association supported this proposed legislation. It was through our efforts that SMARA was passed in 1975. The local planning and zoning processes, which are so critical to the mining industry, have been significantly improved with implementation of SMARA. Recognition of the importance of the mining industry is now being developed by the State Mining and Geology Board and the California Division of Mines and Geology (CDMG).

Jan 1, 1984