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By Jürgen Antrekowitsch, Thomas Griessacher

"Heavy metal containing residues are typically hazardous wastes because on the one hand, a deposition gets more and more complicated and on the other hand, the large amounts of metals like Zn, Cu, Fe and Pb represent a significant value. Thus, a post-treatment of these materials with the recovery/recycling of the metals and stabilization of the waste is not only ecological but often also economical. The therefore typically applied recycling processes utilize pyrometallurgical steps, where carbon or carbon monoxide from fossil coal and coke is used as a reducing agent, which results in large amounts of CO2 emissions. An alternative option is the application of a hydrogen-rich gas emitted in biomass utilization processes as a carbon-neutral reducing agent. Investigations in a retort process which were done at different temperatures and times showed excellent results concerning the achievable reduction rates and final contents of the heavy metals for various residues.IntroductionNowadays heavy metal containing residues like electric arc furnace dust (EAFD), dust from cupola furnaces, waelz slag, etc. are declared as hazardous wastes in a growing number of countries due to the leachability of the heavy metals in these residues. For that reason it is no longer possible to landfill these materials or use them for road construction or disposal works. Some land filling activities, carried out until now, have only been realizable because of some process modifications or cost intensive post-treatment steps of these residues. But the disposal capacities for such materials are decreasing, therefore increasing the prices. The second point for the growing disposal limitations is the stringent environmental legislations and regulations, which restrict the number and amounts of materials which can be dumped [1 – 5].From the other point of view these heavy metal containing residues usually have high contents of zinc, lead, iron, etc., which represent a significant value and therefore a big potential to recover these metals. This is why in recent years the number of recycling processes and the amount of recycled heavy metal containing residues have continuously increased. These recycling processes have the target to recover the valuable metals from the residual materials in the form of a saleable product as well as the stabilization of the slag produced in these processes [5, 6]."

Jan 1, 2011

By A. B. Hooker

All state mining laws require that flame safety lamps be used in gassy mines; the laws of some States require that safety lamps be kept for emergencies at every coal mine, whether gassy or nongassy. The use of the flame safety lamp has been widespread because it is the only defice readily available for detecting both the presence of methane and deficiency of oxygen. This paper reports the results of an investigation by the Electrical Section, in cooperation with the Gas Section, of the Pittsburgh Experiment station relative to the behavior of permissible flame Safety lamps in mine atmospheres deficient in oxygen and the effects of methan5/ on the detection of oxygen deficiency.

Jan 1, 1937

By A. Ordoñez

El presente estudio refiere la metodología y los cálculos para resolver el problema del transporte del fluído en el sistema de bombeo, de forma que ayude al diseñador en la selección de números de plantas de bombeo, sistema de la tubería y los diámetros adecuados, así también se describe las características idóneas para las posibilidades de su operación. Las características técnicas y económicas son programadas en FORTRAN IV y se obtienen para cada alternativa los costos de inversión anual dol proyecto con los que se determina la solución óptima. Una vez obtenida la solución óptima para el sistema de bombeo, el diseñador evaluará un programa donde se determine los anclajes y la ubicación de válvulas de aire, considerando ciertas simplificaciones en la estructura que mejoren el análisis del sistema.

Nov 20, 1972

By O. C. Blade

This report on the properties of aviation gasolines and aviation jet fuels produced in the United States during 1953 was made under a co-operative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. Analytical data are presented for 101 samples of aviation gasoline which include, for the second time in this series of reports, data on some samples of grade 108/135 aviation fuel. Data also are given for 32 samples of aviation jet fuel. The analyses were made on samples typical of the manufacturers' production in their laboratories and the results sub-mitted to the Bureau of Mines for compilation. The products of 19 manufacturers of aviation gasolines and of 19 producers of aviation jet fuels are represented.

Jan 1, 1954

By A. V. S. Meyer

The Colloquium held at Iscor, Pretoria, on 28th June, 1988, had as its objective the need for Quality Management Systems in the industry. Case studies of how problems were identified and solved by the use of such systems were submitted.

Jan 1, 1988

By C. V. Jude

This U. S. Bureau of Mines (USBM) report presents results of stress analyses and field observations to investigate the effects of elevated trench drifts on the structural stability of rock mass zones surrounding a production draw drift in a mine utilizing a mechanized load-haul-dump (LHD) trench undercut panel caving system. A two-dimensional boundary-element mine stress model was developed to predict the locations and extent of damaged rock mass zones surrounding draw drifts where adjacent, parallel trench drifts are either elevated or not elevated above the LHD production draw drift level. A Mohr-Coulomb shear-failure criterion was obtained directly from in situ borehole shear test data. Hock-Brown shear-failure parameter values were computed from borehole-shear and triaxial test data. A procedure is described to estimate these parameters when a rock mass rating (RMR) value and triaxial data on intact samples exist, and no borehole shear test data exist Results indicate that trench drifts, elevated to the level equal to the height of the LHD production draw drift, would not minimize material damage nor significantly enhance the stability of rib and crown pillar zones surrounding production draw drifts in the mechanized LHD trench undercut caving panel investigated at this mine.

Jan 1, 2010

By Deepak Malhotra, William F. Riggs, Edward C. Dowling

INTRODUCTION Mining companies are In the business of making an acceptable profit on their Investments, It became obvious in the recent recession that economic profitability/viability depends on being the lowest cost producer In order to compete on a global basis. The burden of achieving this objective falls on the mineral manager. He must strive to produce a salable product in an environmentally acceptable process while continuously Improving the profit margln.(1,2) Metal prices fluctuate on a regular basis. They directly Impact revenue and hence operating philosophy. The mineral engineer needs to develop an optimum operating strategy to meet his overall objectives, One would expect that, In the modem era of complex computer models, it would be easy to develop an economic model to maximize profits and/or cash flow. Discussions with mill managers Indicate that one mine/corporation's optimum operating strategy is not necessarily optimum for another. This paper approaches the problems from basics "Economics 101" and Illustrates the complexity of developing a universal model which can be applicable to all mines. Case examples are used to illustrate the need for better communication to avoid the basic economic fallacy “that optimization of segments leads to optimization of the whole system.” TECHNICAL MODELS Technical models are a prerequisite to the development of economic models because they provide the necessary Input data to these models, The flow of material from a mine through the sale of the finished product is shown In Figure 1. The ore Is mined and milled, and the concentrate can be stored for sale or smelted and refined In-house or at a toll facility. The finished product(s) are held In Inventory until sold either through existing contracts or in the spot market. [ ] Fairly reliable technical models have been developed for mining, milling and smelter operations. Mine plans are developed to provide a good Indication of the relationship between production and cut-off grade. It is easier to change surface mine plans than plans for underground mines. However, there are limits to maximum production that can be achieved with existing equipment. It Is possible that mine benches may not be developed to handle additional equipment, even If It was purchased to enhance production. More often than not, the cut-off grade Is lowered to Increase throughput goals.

Jan 1, 1993

By Reinhard Bott

The Companhia Mineira de Metais (Brazil) runs a Zn-recovery plant in Tres Marias, federal state Minas Gerais, Brazil. The Zn-production is about 65,000 t/a, This corresponds to a concentrate throughput of about 255,000 t/a with a Zncontent of about 29.5 % at an output of 85 %, The plant is run continuously 360 d/a and 24 h/d, respectively. From this it can be concluded that: Input: approx. 650 - 700 t/d ore-concentrate and approx. 29 t/h ore-concentrate, respectively.

Jan 1, 1990

By Paúl Urruchi

El Departamento de Perforación y Voladura de mina COMARSA, utiliza un nuevo tipo de emulsión a granel, que se sensibiliza in-situ por medio de gasificación al momento mismo de ser bombeada a los taladros. La emulsión del tipo agua en aceite, con buen balance de oxigeno y despliega una alta velocidad y presión de detonación. En este sentido, el presente texto señala las ventajas del uso de la emulsión gasificada como agente de voladura seguro -en tanto reacciona con una solución básica que lo sensibiliza químicamente, justo antes de su carguío a los taladros por medio del camión fabrica, así como agiliza las operaciones de voladura y de minado y reduce los costos de voladura.

Sep 14, 2009

By G. H. K. Pearse

Sulphur is derived from both 'voluntary' and 'involuntary' production. The former category includes sulphur obtained from elemental sulphur deposits and from pyrite and gypsumanhydrite deposits. Sulphur in the latter category is produced by pollution abatement at fossil Juel plants and from treatment of metallic sulphides. Canada is the world's largest sulphur exporter and third largest producer. Main resources of Canadian sulphur are sulphurous fossil fuels, metallic sulphides and native sulphur. Only the first two sources have produced sulphur in Canada 10 date; the first source accounts for over 85% of total Canadian production. Future sulphur sources will be derived increasingly through pollution abatement and decreasingly through voluntary production.

Jan 1, 1984

By E. G. Davis

The Bureau of Mines made laboratory-scale experiments to examine the technical possibilities of reclaiming manganese from slags produced by oxygen lancing of high-manganese pig iron. Ferromanganese was added to molten pig iron to yield a 4-to 5-percent manganese hot metal, which simulated a product obtainable from the blast furnace. This was injected with oxygen to reduce the metal to 1 percent or less manganese and form a slag containing about 40 percent manganese. The molten slag was water-quenched, treated with H2SO4) roasted at 660° C, and water-leached to give soluble manganese and iron sulfates. The sulfates were precipitated as hydroxides, converted to the oxide form, and smelted to produce a standard ferromanganese containing 74.6 percent Mn and 0.01 percent P. As an alternate method of manganese recovery, a manganese cell feed was prepared from the leach solutions and electrolytic manganese was produced. Direct smelting of the high-manganese slag resulted in 74.2 ferromanganese meeting ASTM specifications except for phosphorus content. The high phosphorus content of the metal and high slag-to-metal ratio obtained made this approach unattractive.

Jan 1, 1966

By A. B. Hooker

All State mining laws require that flame safety lamps be used in gassy mines; the laws of some States require that safety lamps be kept for emergencies at every coal mine, whether gassy or nongassy. The use of the flame safety lamp has been widespread because it is the only defice readily available for detecting both the presence of methane and deficiency of oxygen. This paper reports the results of an investigation by the Electrical Section, in cooperation with the Gas Section, of the Pittsburgh Experiment Sta¬tion relative to the behavior of permissible flame safety lamps in mine atmospheres deficient in oxygen and the effects of methane5 on the detection of Oxygen deficiency.

Jan 1, 1937

By M. N. Abdusalyamova

The Republic of Tajikistan has large mercury-antimony deposit. The Republic takes the second place in the countries of the CIS by having antimony recourses or the fourth place in the world. Recently, on the mine bottom horizons the resources of gold were found. Gold in the data ore is submitted as nanosize particles. Results of ores enrichment of bottom horizons of Djijikrut deposit are obtained by a method of flotation. The flow sheet includes the rougher flotation, two scavenging flotation and two cleaner flotation. As a result of enrichment of ore, the mercury-antimony concentrate with the contents of 51.5% of antimony and recovery 90.3% from ore with the content of mercury of 3.5% was received. The investigation of thallium, selenium, and tellurium distributions on products of enrichment was carried out. The most effective reagents are a mixture of oksafore and butyl xanthogenate. While applying this mixture of reagents it is possible to refuse of the use of activator - nitrate lead. The behavior of gold is in details investigated during enrichment. To collective flotation concentrate is extracted only 30% of gold. The basic quantity of gold concentrates in tailings of flotation and is not taken by existing traditional methods. The alternative innovative technology of gold extraction was created. Various methods of roasting of a collective mercury - antimony concentrate oxidizing and reducing are investigated. Vacuum distillation of concentrate allocation in serial sublimates mercury and antimony was designed. In the received calcine concentrates gold. At additional roasting of a calcine up to 900°? concentration of gold makes 30.6 g/t. The offered innovational technology in a complex allows to process ores and concentrates unique mercury-antimony?gold bearing raw material. Keywords: ore, concentrate, flotation, cyanidation, roasting, mercury, antimony, gold

Sep 1, 2012

By R. O. Dannenberg

The Bureau of Mines conducted laboratory investigations with the objective of developing an alternative process for recovering cobalt and copper from complex sulfide concentrates. Processes currently used depend largely upon precipitation techniques to remove impurities and recover cobalt from sulfate liquors prepared by oxidative pressure leaching of the sulfide concentrates. The Bureau conducted bench-scale research on a process for treating cobaltite concentrates, comprising (1) oxidative pressure leaching, (2) jarosite precipitation followed by H202 oxidation and pH control to remove iron and arsenic, (3) copper solvent extraction with a mixed hydroxyoxime-amine extractant, (4) copper electrowinning from recirculating acidic strip liquor, (5) selective cobalt extraction from copper solvent extraction raffinate with a phosphinic acid extractant, and (6) electrowinning of cobalt from a recirculating weak acid strip liquor. Overall cobalt and copper recoveries were 91.7 and 84.1 pct, respectively. Electrowon products assayed 99.8 pct Co and 99.89 pct Cu.

Jan 1, 1987

By W. D. Eddy

Topaz is a fluorine-bearing aluminosilicate mineral of the kyanite-sillimanite group. The formula has been given as Al2SiO4(F,OH)2, [Al(F, OH)]2SiO4, or 2Al2O3?2Al(F, OH)3SiO2. Topaz is generally considered a semiprecious-to-precious gem mineral, but it is a fairly common minor constituent of granites. In 1937 the U.s. Geological Survey reported an occurrence of massive topaz in the 3 Brewer gold mine, Chesterfield County, S.C. Over the next 8 years considerable research was done on topaz to establish its properties and to determine possible end uses The first reported shipment of ore was in 1939 Peak production was reached in 194412, and output then began declining until the mine closed in 194913? During World War II topaz was used in refractories, as a flux in steel mills, and in the manufacture of borosilicate glass 14. The main advantage of using topaz over kyanite and sillimanite in refractory use was that calcined topaz converted to over 95 percent mullite (3A1203 .2Si02) while calcined kyanite or sillimanite contained only 88 percent mullite15. However, a major draw-back to utilization of topaz is the evolution of fluorides during calcination. In 1973 the Geological Survey reported that topaz occurred in probable commercial quantities in at least two domestic locationsl6: the Brewer area of South Carolina and a location in Colorado. The literature also indicated that progress had been made in controlling fluorine-bearing fumes. This research has progressed to the state where valuable fluorine compounds are being recovered on a commercial scale 17. Thus, a major obstacle to utilization of topaz appears to have been resolved. The Bureau of Mines under its program of advancing minerals technology initiated a project to study techniques for the concentration of topaz from disseminated materials. The objective of the study was to determine those techniques that would be used to produce topaz concentrates that could be utilized as a source of fluorine and mullite.

Jan 1, 1977

By Leandro Gusmão da Silva

Neste trabalho, foram estudados os efeitos da irradiação de uma superfície polida do aço inoxidável tipo ASTM F138 com laser de pulsos ultracurtos. As irradiações foram realizadas variando-se a velocidade de varredura do laser, ou seja, a taxa de sobreposição espacial de pulsos. Foi observado que após a irradiação houve uma visível mudança na coloração da amostra. Também foi verificado que com o aumento da taxa de sobreposição de pulsos a superfície tendeu a tornar-se preta, ou seja, absorvedora de luz. Com essa técnica, pode-se realizar marcações com alto contraste sem que haja formação de camadas de óxidos, nitretos ou alterações microestruturais no metal, o que é importante para um material com a precisão que um implante exige.

Aug 17, 2017

By H. J. Hager, B. W. Gandrud, G. D. Coe

"INTRODUCTION The reduction of washery losses of marketable coal is a phase of coal preparation important to many of the Alabama coal producers. The problem has wide scope, and this report deals with but one of its several aspects. The investigation on which this report is based was made by the Southern Experiment Station of the Bureau of Mines with the cooperation of the Alabama By-products Corporation and the University of Alabama. The Alabama Byproducts Corporation provided samples of table middlings from its Colta washery on the Mary Lee bed at Flat Creek, Ala.PRACTICE AT THE COLTA WASHYAt Colta run-of-mine coal is crushed in a hammer mill in closed circuit with 5/16-inch square-mesh vibrating screens and tabled without classification on eight rectangular-deck wet tables. The coal is more friable than the bone normally present, and hence the bone is concentrated in the coarser sizes. An unclassified feed of this character can not be tabled with high efficiency to low ash content because of the sizing action of a concentrating table, which is such that when the tables are adjusted to exclude the coarse bone from the washed coal, a large amount of fine coal is lost in the middlings. At the time this investigation was undertaken there was no market outlet for middlings, with the result that middling products had to be discarded with the refuse."

May 1, 1939

By Thomas E. Ricketts

Occidental Oil Shale, Inc. constructed two commercial-sized modified in situ (MIS) retorts, Retorts 7 and 8, at its Logan Wash Oil Shale Mine in February and April 1981, respectively. One of the primary objectives of this two-retort program was to examine large-scale blasting reproducibility for commercial-sized retorts. The blast design used 545 blastholes and 550,000 pounds of explosive in ANFO equivalent per retort. Each retort was blasted using millisecond delay blasting caps tied into a single round. The blasts resulted in rubble beds very close to one another and to predicted results obtained using newly developed limited void blasting technology. The heights of the remaining void rooms over the beds after blasting were within 0.3 feet of one another. This excellent reproducibility is brought into true perspective when compared to the scale of the rubble beds which were 230 feet high with volumes of over six million cubic feet each.

Jan 1, 1984

By Alvin M. Cummings

During the period from June to September 1943, the Bureau of Mines undertook an investigation of the Vial mine, near the village of Linden I in Iowa County, Wis., as part of a general investigation of the zinc-producing area of southwestern Wisconsin. The work was done when every effort was being made to increase the production of metals important to the Nation's war program. The Bureau completed 29 churn-drill holes aggregating 3,348 feet of bore in areas immediately north and west of the old Vial mine, which had been worked intermittently between 1908 and 1939. The drilling supplemented a previous drilling program by the lessees and disclosed the presence of two significant zones of mineralization.

Jan 1, 1948

By F. Kongoli

Viscosity is an important parameter of copper smelting and converting processes. It affects the settling of matte or metal droplets in the slag, distribution of elements etc, Despite this importance, confusion exists on the viscosity of copper smelting slags as a result of disagreements found among the measured viscosity data of several authors especially in the slags of high ferric iron content and close to magnetite precipitation. In this work a critical review of the existing data on the viscosity of copper smelting slags has been first carried out and the effect of oxygen potential on the viscosity of copper smelting slags has been clarified through a coupled quantification of viscosity and liquidus temperature. The confusion in the literature has been clarified and the importance of the relation between the viscosity and the liquidus temperature is discussed,

Jan 1, 2003