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By W. Kunda

Silver nitrate solution is a very common product in hydrometallurgical processes involving the treatment of various silver bearing materials. Silver is recovered by electrolysis. The alternative method for the recovery of silver from aqueous solutions is the precipitation by hydrogen at elevated temperature and pressure. A previous study by the authors revealed the feasibility of this technique for the silver ammine sulfate system. Further study showed different behavior for silver in the silver ammine nitrate system and a systematic study was initiated to establish the optimum conditions for the process. The study showed that the process can be controlled by (1) composition of the feed solution, (2) temperature and (3) hydrogen pressure. The recovered silver product was in the form of very fine powder.

Jan 1, 1989

By F. Lowell Lawrance

JOHN SMITH, citizen of the U.S.A., has become so accustomed to reading that Congress has appropriated billions of dollars to pay war costs. that he no longer is impressed by relatively small figures, such as several hundred thousand or a few million, in connection with Government departments.

Jan 1, 1944

By Nathan C. Rockwood

WHILE mining engineers have been searching in far corners of the country and of the world for hidden wealth there has grown up around us in nearly every city great wealth-producing mines calling for the investment of hundreds of millions of dollars and yielding products now sold for over half a billion dollars yearly-largely unknown and almost wholly neglected by mining engineers. But this neglect is explainable and excusable. They are industries of very recent origin-practically the growth of the last 25 years. They are in a very large measure the result of tremendous developments in engineering construction and the rapidly expanding use of portland cement concrete for structures of every description. Concrete as a material of construction is going through an evolution very much as did cast iron and other metals used in engineering; and this phase of the industry should appeal to the imagination of metallurgical engineers. At first iron was iron-a material of uncertain properties, owing both to small differences in chemical composition and in methods of manufacture. By successive steps iron was studied and knowledge of its properties developed-the striking effects of very small percentages of other minerals and of various heat-treatments.

Jan 1, 1924

By J. -C. Sztuke, M. Cao

ABSTRACT The correlations between froth recovery of coal and air recovery were investigated using a hybrid mechanical flotation column. The particle slurry was fed onto the surface of air-water two phase froths to carry out the tests. Froth recovery was taken as the recovery of particles into the froth product, whereas air recovery was determined by the froth height method. The relationships between froth recovery and air recovery were nearly linear, with greater slopes for more hydrophobic particles. Inside the froth phase, the particles were stratified, with hydrophobic particles concentrated in the upper region and hydrophilic particles in the lower region.

Jan 1, 2013

By J. Gotor, C. Frias, E. Delgado

The Iberian Pyrite Belt (IPB) is one of the world's largest reserves of primary sulphides containing base metals (Cu, Zn, Pb), precious metals and some special metals such as indium. Estimated resources are over 1,500 million tonnes of volcanogenic massive sulphide ores. From 1980´s Europe lives the decline in its mines mainly motivated by the low price of the metals. One aspect that contributed equally to this was the ecological disaster produced by the discharge of more than seven million tonnes from the tailings dam of Boliden-Apirsa (Aznalcollar) in 1998. Today the situation is different; the companies present in the IPB have given evidence that it is possible to reconcile mining projects and care on the environment, and the regional authorities are opening a public tender to re-start Aznalcollar mine. A new challenging era has been started at this Spanish/Portuguese mining area. This paper presents the results and preliminary economics of a project devoted to IPB primary sulphides processing through different technology approach, e.g. conventional selective flotation against bulk flotation or mixed metals flotation combined with hydrometallurgical processing.

Jan 1, 2014

This appendix contains the list of equipment, their corresponding number and their specifications with the quotations from the vendors/ manufacturers who can supply this equipment. The listings are arranged by process plant areas.

Jan 1, 1979

By J. T. Ryan

FIGURES for the first 11 months of 1935 indicate that the total coal production of the United States for 1935 will be approximately 416,000,000 tons, or almost identical with the production figures for 1934. Bituminous production will show a gain of about six million tons, and anthracite production a loss of about the same tonnage, compared with the previous year. This does not take into account so-called "bootleg" anthracite coal amounting to approximately 5,000,000 tons. Twenty-nine years ago, in 1906, the production of coal was almost identical with this year's production. At that time, 626,000 men were employed in producing this tonnage, which took a toll of 2138 lives from accidents. In 1935, approximately 540,000 men were required to produce the same tonnage with an estimated loss of 1155 lives. This shows definite safety advancement in the industry, but even so accidents are still costing an average of 3c. a ton more than they should.

Jan 1, 1936

By J. Abrahams, A. Nesbitt

Over the past half-century, researchers have commented on the complexities of ion-exchange processes, but have been forced to use gross assumptions to simplify the associated mathematics sufficiently for mathematical models to be of practical use, given the available computational power. This paper reviews the development of increasingly complex models as computational power has increased over the past half-century, from the direct application of Fick's Law in 1947, through to today's models requiring finiteelement methods. The assumptions required for and the associated limitations of the various models are presented and the associated computational complexities are discussed. A case study is presented in which a continuous loss of capacity in an acid resin was observed over about sixty cycles of loading and elution. Resin poisoning does not explain this observation. This paper presents the capacity loss data, speculates on possible causes of the phenomenon, discusses why conventional kinetic and equilibrium mechanisms cannot explain it and concludes that the need to develop a more rigorous model is apparent. The significance of this observation is that standard tests done for a new resin application could significantly overestimate the commercial performance of the resin concerned, highlighting the importance of computer simulation in this field of process engineering.

Jan 1, 2005

By H. Z. Kuyumcu

Associated with the development of a novel microbiological oxidation process for the conditioning of iron hydroxide slurries from ferrous mine waters, there is a realistic chance to make the contained iron available for a material utilization. The transformation of ferrous into ferric compounds is coupled with the precipitation of iron hydroxisulphate mostly in terms of the mineral Schwert-mannite. The further treatment of the iron hydroxisulphate has to be aimed on the processing for product recovery and product refinement. For many potential applications, e.g. in the ceramic industry, the pigment industry or for metallurgical applications, the removal of sulphate is essential. For the dehydration of the iron hydroxisulphate and the sulphate removal, microwave heating technology is a beneficial method. In contrast to conventional thermal heating processes the supply of energy in microwave application takes place directly within the material through the dissipation of electromagnetic energy, i.e. no heating medium is needed. It is a volumetric heating process regardless of the surface of the material. The rapid and targeted energy supply and the good controllability of microwave heating systems are advantages which have led to a wide variety of applications in industrial processes. Among the diverse use for heating of temperature-sensitive, chemical and pharmaceutical products as well as foodstuffs the number of applications also in mineral and solid processing increases. At the Department for Mechanical Process Engineering and Solids Processing of the Technical University Berlin the use of microwave technology for the treatment of iron hydroxisulphates has been investigated systematically within the framework of a cooperative research project. The paper at hand shows results from material conversion tests subject to a variation of the relevant process parameters. The reaction products are characterized and the process is compared with the conventional heating in a rotary kiln.

Jan 1, 2014

By Arístides Sotomayor

El presente texto señala la importancia del oro a nivel financiero y minero ya que los inversionistas suelen utilizar este metal para obtener ganancias debido al mínimo riesgo existente en la pérdida de su valor comparado con otras divisas. Así, se estima que en el Perú, existen 480 unidades mineras de oro, de las cuales 28 concentran cerca del 90% de la producción nacional, como la Minera Yanacocha, Minera Barrick, Compañía de Minas Buenaventura, Consorcio Minero Horizonte, Aruntani y Aurífera Retamas. Entre las dos regiones que producen mayor cantidad de oro está: Cajamarca y La Libertad ( 38%) y la tercera región es Arequipa, seguida por Madre de Dios (9%).

May 1, 2016

By William R. Barton

Dimension stones, with their almost infinite variety, have a broad range of properties and uses. Natural stone was beyond doubt the first mineral commodity used by man. Today dimension stone has widened to encompass building exteriors and interiors, decorative and ornamental modes, statuary, monuments, paving, curbing, flagging, roofing, and miscellaneous categories such as blackboards, surface plates, and honestones. For many purposes, it competes with greater or less success with alternate materials such as concrete, metal, brick, plastic, or glass. The almost ubiquitous geographic distribution of stone resources is the basis for a dimension stone producer industry in almost every State and in almost every land. In the United States, alone, dimension stone sold or used by quarries is valued at 2 million to 3 million dollars annually. Mining, finishing, transportation, and use technology have been modernized, resulting in a broader spectrum of stone products and new adaptions in use. Increased efficiencies also have been reflected in costs and prices and, coupled with gains that should be realized from current research, auger well for continued vitality of the ancient and honorable dimension stone craft.

Jan 1, 1968

COUNCIL OF ECONOMICS OF AIME Formerly Mineral Economics Division Established as a Division December 15, 1948 Established as a Council February 26, 1957 Douglas Donald, Chairman Sheldon Wimpfen, Vice-Chairman (Mining) A J Phillips, Vice-Chairman (Metals) E Connaughton, Vice-Chairman (Petroleum) J S Vanick, Contact AIME Director A H Lindley, Jr Secretary-Treasurer Lehman Brothers 1 William Street New York 4, N Y COUNCIL OF EDUCATION Formerly Mineral Industry Education Division Established as a Division January 15, 1932 Established as a Council February 26, 1957 L E Shaffer, Chairman J D Forrester, Vice-Chairman O Cutler Shepard, Past Chairman , Contact AIME Director

Jan 1, 1959

By DR. SAMUEL B. CHRISTY

? THE man is always greater than his work.? The training of the men who are to develop the mineral resources of the world is the most important problem connected with mining engineering. It becomes ever more important to civilization as the mineral wealth of the earth approaches exhaustion. I have therefore decided to consider a few of the more important problems arising in the training of the mining engineer, and especially those arising in America. THE PECULIAR NATURE OF MINERAL WEALTH. Mining and Agriculture are the two fundamental arts. Without the latter our existence would be precarious; without the former, our civilization impossible. Agriculture furnishes that regular supply of food and raiment which leads to the growth of large communities in which cultivated leisure first becomes possible; while raining furnishes the metallic thread from which is woven that complex fabric we call civilization. But in these two arts the conditions for success are widely different. Most of the crops that the farmer reaps may be harvested year after year, and the proper fertilizers being added, he may continue the annual harvest indefinitely, while, as a result of cultivation, his farm becomes yearly more valuable. But the crop the miner reaps can be harvested but once in the history of the race. Our mineral wealth has taken unknown ages to mature in the bosom of the earth. The ripened fruit can be plucked but once. There are no fertilizers for worked out mines. It never pays to work over a mine that has been

Sep 1, 1905

By H. D. Hunt

This paper which describes the milling practice of the Miami Copper Co. is one of a series being prepared by the United States Bureau of Mines. LOCATION The mine, concentrator, and other surface plants of the Miami Copper Co. are located near the town of Miami in the Globe-Miami mining district of Gila County, Ariz.

Jan 1, 1932

By Dave Kay, Young-Suk Song

To meet the needs of South Korea's rapidly expanding economy, a large number of infrastructure projects are under way to improve transportation efficiency within the nation. These projects include high-speed rail links between major population centres and improvements to the road network. Being densely populated and geographically mountainous, infrastructure development in Korea requires a significant amount of tunnelling. Owing to the predominantly hard granitic nature of rock, drill and blast is the preferred method of tunnel advance. The Korean tunneller, however, faces the same pressures as those of his international counterpart in that both cost and production targets need to be achieved while meeting expectations of both community and regulator.

Jan 1, 2005

By D. K. Uko

In the stretch-bend or bending-under-tension test, a strip is rigidly clamped and restrained at each end and bent by central transverse loading using a radiused punch: The strip deflection at failure has been used as a measure of formability for high-strength low-alloy (HSLA) steels by other investigators. In this work, a detailed study is made of strains developing during stretch bending of an 80,000-lbf/ in 2 (552 MPa) yield stress steel using different punch radii. It is shown that toward the end of the process, the bending strains at both the inner and outer surfaces are tensile and suddenly increase at a rapid and approximately equal rate. The strain ratio in the failure region departs significantly from plane strain , even using a large width-to-thickness ratio of about 10. The effective fracture strains appear to be independent of bend ratio (punch radius/thickness) and significantly below the fracture s train in simple tension. Metallographic and tensile data were obtained for the subject material and, for one bend ratio, the effects on stretch-bend parameters of annealing both on this material and a. carbon steel were compared.

Jan 1, 1977

By Arne M. Myrvang

Rock stress measurements have been carried out by the Mining Department, the Norw. Institute of Technology (NTH) since 1964. Before that time rock stress measurements were carried out at a few locations by the Swedish professor Hast as early as 1958. From the very beginning the NTH engagement in the rock stress measuring field has been very practically aimed, and we have all the time enjoyed a very good cooperation with the Norwegian mining industry. At a very early stage the industry realized that proper measurements with proper equipment could be a very valuable practical tool. Hence the industry also was willing to grant considerable funds for the education of experts and development of measuring techniques. Since 1964 measurements have been carried out in the great majority of Norwegian mines. During the last years a large number of measurements have also been carried out in connection with hydro-electric power plants, road tunnels etc.

Jan 1, 1981

By D. Harrington

This paper is a revision of Information Circular 7380, by D. Harrington and J. H. East, Jr., published in 1946, entitled ?Safe Storage, Handling, and Use of Commercial Explosives in Metal Mines, Nonmetallic Mines, and Quarries.? Issued soon after the close of World War II, this earlier circular described the unprecedented increase in the production and use of commercial explosives during the war as a result of expanded industry and the tremendous demand f or metals and minerals. In the years following World War II, the production and use of commercial explosives in the United States have continued to rise. Hence, the Bureau of Mines presents these revised figures through 1952. In rewriting this Wormation circular, most of the text prepared by Harrington and East has been retained, with newer statistical information compiled by Seth T. Reese, Accident Analysis Branch, and V. E. Wrenn, of the same branch.

Jan 1, 1954

By K. Muralidharan, P. R. Rao, M. Momayez, K. A. Runge

The evolution of trapped geothermal heat in hot underground mine along with emission of toxic gases and dust during mine activity makes the mine environment unfavorable is hazardous to worker’s health. This imposes significant demand on cooling and ventilation systems. As a result, substantial costs are incurred while implementing environmental regulation processes to dissipate the heat and provide comfortable working conditions. Thus, as an alternative, the development of cost effective materials to act as efficient thermal insulators is on the rise. Thermal conductivity is an important property that is a direct measure of a material’s ability to facilitate/deter heat flow. In addition to their superior chemical resistance, adequate mechanical strength, abrasion and fire retardant as well as environmental benefits in comparison to existing building materials such as ordinary Portland cement, aluminosilicate based geopolymers are now gaining widespread interest as promising thermally insulating and sustainable materials. This paper begins with an overview of geopolymers, transitioning into a discussion of recent developments in the field of geopolymer development as a thermally insulating material broadly classified into: filled geopolymers and porous geopolymers resulting in structures with enhanced ability to impede heat flow.

May 9, 2020

By W. D. Sinclair

"Between 1934 and 1956, nearly 31 million grams of gold were produced in the Matachewan area from deposits on properties belonging to Young-Davidson Mines Limited and Matachewan Consolidated Mines Limited. In 1979, production from these properties was renewed by Pamour Porcupine Mines Limited.Most of the gold produced has come from relatively lowgrade deposits (3.4 gl t or less) that occur in an east-trending belt of dykes and irregular bodies of trachytic syenite. Although small by comparison, these deposits have some of the characteristics of porphyry copper-molybdenum deposits. The mineralized syenite contains up to 5 per cent disseminated pyrite and is highly fractured and cut by quartz and quartzcarbonate veinlets. Gold occurs as native gold along fractures, in quartz veinlets and as minute inclusions in pyrite. Minor chalcopyrite and trace amounts of scheelite, molybdenite and galena are also present. Mineralization was accompanied by potassic alteration, consisting mainly of potassium feldspar.Some gold was also produced from small, but higher-grade, deposits in volcanic rocks. These deposits occur near the syenite-hosted deposits and consist of quartz veins and stringers mineralized .with pyrite and gold. Minor gold is present in some low-grade, porphyry-type copper-molybdenum occurrences and, locally, in large, isolated quartz veins.Lead isotope analyses suggest that the gold deposits were formed at about 2700 Ma and were locally remobilized at approximately 2400 Ma, following the Kenoran orogeny. The deposits appear to be genetically related to felsic magmas emplaced in an epizonal environment and deposited from hydrothermal solutions relatively concentrated in S and K20."

Jan 1, 1982