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By Jacqueline A. McClaskey

The U.S. Bureau of Mines (USBM) Information and Analysis Directorate collects worldwide data on virtually every commercially important non fuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. The USBM's data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 329), which placed the collection of mineral statistics on an annual basis. The most recent authority for the USBM survey activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress). This act strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1993

By E. A. G. Colls

PART I.-GASES IN INDUSTRY INTRODUCTION THE part played by gases in industry can be considered from at least four distinct viewpoints, viz: (1) As air to support combustion and life and do various kinds of work (2) As fuel, or as essential to certain chemical processes (3) As sources of danger from explosion or fire ( 4) As hazards to man's health The present paper deals with gases only insofar as they are sources of danger, or are hazards to health. It may be noted, however, that, in point of tonnage, air is one of the most important materials handled in any industrial plant. In the operations of the Consolidated Mining and Smelting Company, for example, 138,000 tons of air are handled daily, the only material exceeding this figure being water. The United States Bureau of Mines has listed no fewer than seventy-four gases and vapours that, under certain conditions, may be considered as ex-plosive or dangerous (poisonous). The commonest and most important of these are as follows : Carbon monoxide Methane Acetylene Hydrogen Oxygen Hydrogen sulphide Benzol vapour Ammonia Petroleum vapour Carbon disulphide Hydrochloric acid gas Cyanogen Carbon oxysulphide Chlorine ` Fluorine (and fluorides) Acetone vapour Acetic acid vapour Water gas Natural gas Gasoline vapour Coal gas Producer gas Ether vapour Nitrogen oxides

Jan 1, 1940

By M. H. Chetrick

An important factor in the design and operation of a lignite-gasification plant is knowledge of the thermal requirements. These not only vary with different-size plants but also with the operating conditions for a plant of given capacity. Thermal data have been collected since 1945 from a commercial-scale lignite-gasification pilot plant operated by the Bureau of Mines at Grand Forks, N. Dak. The description and operation of this plant and a study of the gas-composition data have already been described in previous reports (1, 2, 3, 4, 5).2) / This investigation was made to review the thermal data taken in tests and to correlate them in terms of the fraction of undecomposed steam and the H2:CO ratio.

Jan 1, 1953

By Stephen D. Cramer

A nondestructive procedure for measuring electrodeposit porosity has been developed which records the location and number of deposit defects including pores, pits, and voids. The procedure involves the passage of an X-ray beam through the deposit-substrate system onto suitable film. The defects are recorded as images on the film. Variables studied included intensity and spectra of the X-ray beam, composition and thickness of deposit and substrate, film type and developing procedure, and limits for detecting defects. At an X-ray tube voltage of 40 kv, pores several mils thick were easily detected in copper-nickel specimens more than 20 mils thick. To illustrate the utility of the procedure, the effect of substrate oxidation and of current density on electrodeposit porosity was briefly studied.

Jan 1, 1970

By R. V. Ramani

Demands on available lands will continue to increase due to the projected increase in population and industrial expansion. Though there is an upper limit on the available lands, the multi-use nature of the lands will make it possible to meet these demands. However, this will not happen without adequate planning. Land uses can be broadly categorized as non-renewable and renewable. Lands with mineable resources can be dedicated at some point in time to the extraction of resources. Such a dedication, however long-term, is only temporary because of the non-renewable nature of the mineable resources. Implied here is that the land will be available before and after mining for other uses. Planning for such lands must have the objective that, as far as practicable, no non-renewable uses are pre-empted and no renewable uses are permanently destroyed. The primary aspects of this planning process will be addressed in this paper, These aspects include a discussion of planning responsibility, data needs and availability, the integration of mine planning and post-mining land use planning and a long-term plan for resource conservation and utilization. Minerals, together with agriculture and forestry products, are the primary sources of wealth. Therefore, to avoid land development that may pre-empt future mineral resource utilization, the local planning groups must be aware of the mineralization and mining potential. Much work needs to be done to identify and characterize the mineral resources. Even more work is needed in land use planning for lands with mineral deposits.

Jan 1, 1982

By R. Hurman Eric

The dew-point technique of activity measurements take advantage of the volatility of a component in solution. The pressure of the volatile component over a sample is determined from observations of the temperature at which condensation of the vapor occurs. The method is applicable best when the vapor pressure of the components would differ by about two to three orders of magnitude. Experimentally, this is a closed system involving the use of evacuated and sealed transparent quartz sample probes. Furthermore reliable vapor pressure data of the volatile component is essential along with a specialized high temperature furnace capable of giving reproducible results. In this context, the vertical Dew-Point Furnace (DPF) was designed and built after elaborate trails until enough proficiency was gained for reproducible results. Over the years the DPF was modified and improved. The DPF developed was versatile and could easily be used for activity measurements in the isopiestic mode (another method of measuring activities of a volatile component in a solution). The necessary ancillary systems; namely evacuation-flushing-evacuation followed by sealing of quartz sample probes under vacuum were also perfected over the years. As and when necessary the dew-point technique was supplemented by classical equilibration-quenching method employed on the sealed quartz sample probes to reveal necessary phase equilibrium information. The following were studied utilizing the above technique: (i) Activities in CU2S-PbS and FeS-PbS binaries and CU2S-FeS- PbS ternary at 1200°C; (ii) Activities in Cu2S-SnS and FeS-SnS binaries and Cu2S-FeS-SnS ternary at I200°C; (iii) Phase equilibria and thermodynamic in Cu-Pb-S, Fe-Pb-S, Fe-Sn-S, Cu-Sn-S and Ag-Sn-S systems. Most recently the following systems have been tackled: (i) Phase equilibria and thermodynamics in the Ag-Pb-S and Sn-Pb-S systems; and (ii) Activities in Ag2S-FeS-CuzS-PbS quaternary at 1200°C.

Jan 1, 2003

By Gustavo De la Torre

Más allá de contar con las certificaciones ISO 9001, ISO 14001, Y OHSAS 18001, la planta concentradora de Cerro Lindo busca ser catalogada como un desempeño de categoría mundial, lo que implica usar la capacidad total del área (procesos, tecnología y talento humano) basado en un equipo de alta performance-EAR, y gestionar de forma sistemática seguridad, salud ocupacional, medio ambiente, costos, productividad, calidad y confiabilidad, además del proceso productivo. En el presente artículo se analiza información recopilada durante la fase de crecimiento, se presentan diferentes etapas en desarrollo y se describen los estudios realizados en la planta de beneficio, a nivel técnico y de gestión, con óptimos resultados de producción, eficiencia e indicadores metalúrgicos.

Apr 30, 2018

By V. V. Morozov, I. S. Barmin, A. V. Tugolukov, V. V. Polivanskaya

"It was presents the results of research on improving reagent regime and scheme of enrichment of slime classes of Apatite-Staffelite ores and tailings stockpile of Kovdorsky enrichment plant. It was investigated the regularities of flocculation in the processes of thickening and selective flotation apatite-bearing ores. It was established character of the influence of flotation reagents on the flocculation process. It was shown that the sodium silicate and soda ash have a stabilizing effect by thickening of sludges. Neonol and oleic acid have a coagulating or flocculating effect. It was tested the new regime flotation, involving an initial conditioning with using of reagent - dispersants before feeding the pulp into the flotation and subsequent conditioning with reagents having a coagulating effect. The flowsheet and reagent regime for enrichment of fine-grained tailings stockpiled was developed, which providing production of standard apatite concentrate and increasing the recovery of valuable components. There are presented results of the research of activities of strong organic surfactant on solubility of colloidal form fatty acid collector and aggregate stability of fine minerals in the process of thickening and flotation. Surfactants such as Neonol have been investigated for increasing the activity of the collectors. When using the process of thickening sludge fraction with flocculant Praestol 2540 and stadial conditioning of sludge were obtained concentrates containing up to 38.1% P2O5 at recovery. INTRODUCTION A feature of the Apatite-Staffelite ores of the Kovdorsky deposit is the presence of a large number of fine mineral particles and a reduced hardness of phosphate minerals (Beloborodov et al., 2010, Tugolukov et al., 2012). Formed in the ore-preparation process, sludges are lost with a discharge in the thickening operation. Sludge is characterized by an increased content of phosphorus pentoxide (P2O5). Losses of P2O5 at enrichment of the stale tailings of Kovdorsky GOK reach 14.0%. The high losses of P2O5 caused a profound study of the behavior of thin apatite classes under conditions of thickening and flotation."

Jan 1, 2018

By J. van Driel

NOx is a growing concern for acid plant operators due to recent legislation reducing the allowable stack limits, as well as continually more stringent requirements for product acid quality. NOx also causes a major problem during maintenance as NOx rich acid residues fume following exposure to moisture in the air. Until recently, the solution for NOx related issues was to treat the symptom, rather than the cause. NOx in product acid was treated using chemicals and the NOx in the plant stack was generally left untreated. As part of an environmentally driven change in concentrates, Budel Zink installed the first gas phase NOx destruction process to be incorporated into a commercial scale acid plant. Nitrogen oxides contained in the process gas are reduced selectively with ammonia over a catalyst to form nitrogen and water. As a result, the NOx reduction is in agreement with the permit requirements.

Jan 1, 2002

By J. Erik Loehr, Minh Uong, Andrew Z. Boeckmann, Sarah G. Myers

"The University of Missouri performed a lateral load test program involving 32 drilled shaft load tests for the Missouri Department of Transportation (MoDOT). Tests were performed at two MoDOT geotechnical research sites, and all shafts were founded in shale. Shafts were instrumented to measure the displacement of the shaft head, and the structural response of each shaft was interpreted from strain gage data and from ShapeAccelArray (SAA) data. The SAA is a chain of rigid segments with sensors that use MEMS (microelectromechanical systems) technology to measure the tilt of each segment/joint. The measuring principle of the SAA is therefore similar to that of an inclinometer. The SAA device was placed in a casing installed in the center of each test shaft to provide a continuous record of deflection along the length of the shaft throughout each test.Bending moment profiles were calculated from strain gage data and from SAA data. Interpretation of bending moments from measurements of strain (via strain gages) and displacement (via SAA) is a nontrivial exercise, primarily because the bending stiffness, EI, is nonlinear and greatly influenced by concrete cracking, which is difficult to predict. The procedure used for this work predicted values of bending stiffness along the length of the shaft as a function of the bending curvature, which was interpreted from the SAA data. Values for bending stiffness as a function of curvature were computed using Ensoft LPile v2012. Bending moment profiles from SAA data were typically similar to those from strain gage data. The SAA bending moment profiles were often “noisier” than the strain gage bending moment profiles, but the SAA bending moment profiles had more data points since the SAA chain was continuous from the top to the bottom of each shaft."

Jan 1, 2017

By George C. Gibbons

ALMOST everyone in any of the five counties embracing the great East Texas field depends heavily upon oil for his living whether or not he actually owns a well or piece of royalty himself. Oil is a natural resource that, when utilized, spreads its benefits over a vast area and into many channels. Depending then almost entirely upon agriculture: what is now known as the East Texas oil field a decade ago had a scattered farming population. For many of its people, tomatoes and other vegetable crops coupled with the old southern stand-by of cotton, furnished an adequate living and a small cash surplus. Some farm families on the red hills, however, were not far re- moved from the sowbelly and black- eyed peas, or cornpone and potlikker, standard of living. Kilgore of that day, was a village of less than 850 per- sons. Longview, with just over 5000, apparently had reached the limit of its growth. Tyler was an overgrown farming town of around 17,000 persons, de- pending largely upon the agricultural income of Smith County and surrounding territory for which it was a trading center.

Jan 1, 1941

By T. E. Sedysheva

The study of Co-rich manganese crusts has reached the level which allows to start prospecting works in the observable future, and furthermore, probably, exploitation of ore deposits. In this connection, among other goals, the necessity to analyze a distribution of ore bed parameters in details is quite urgent. Foremost, these are crust thicknesses in connection with landforms and elements of submarine mountains relief. This report is based on representative sampling made in course of research cruises run by SSC Yuzhmorgeologiya over guyots of the Magellan Seamounts. Crustal covers could overlie seafloor surfaces which are confined to a various landforms and elements of relief under the condition, that they are free of sediments. These are planed parts of a summit surfaces, edges, spurs, rectilinear parts of slopes, intermountain saddles and volcanic edifices. It is known, that crustal thicknesses are different at a various forms of relief [1]. We processed statistically the data around crustal thicknesses, which were sampled by dredging and submersible drilling (Tables 1, 2).

Jan 1, 2010

By A. Bilodeau

A new hydrometallurgical process for the production of refined gold and the recovery of palladium and platinum from silver anode slimes has recently been developed and installed at the, CCR Division of Noranda Inc. The process, which facilitates the production of gold of >99.99% purity in the face of increasing palladium receipts comprises; leaching silver anode slimes with hydrochloric acid and hydrogen peroxide at 95°C to solubilize gold, palladium, platinum and base metals while simultaneously rejecting silver as insoluble silver chloride; precipitating gold from the leach solu¬tion with sulphur dioxide gas in two stages to produce a first-stage high purity gold product and a second stage impure gold which is recycled to the leach; washing, melting and casting of the pure gold; precipitation of a palladium-platinum concentrate from the gold-free solution by reduction with sodium formate at pH 4 and 95°C; and neutralization of the palladium precipitation effluent to pH 10 with lime. The results of laboratory and pilot plant studies leading to the adop¬tion of this process are discussed, and data are presented for each of the unit operations. Details of the engineering of the commercial plant are given, and plant start-up experience is described.

Jan 1, 1987

By Robert Stefanko

The concept of disposing of liquid industrial wastes by deep-well injection is not a new one. Brines associated with crude oil long have been disposed of in this manner, with the additional benefit of aiding secondary oil recovery. More recently, with the expansion of nuclear energy, the lethal, highly radioactive wastes which are by-products of the fission process have created severe disposal problems. During the past ten years, a variety of industries have resorted to subsurface disposal, some of the details of which are given elsewhere (1,2). The list reveals wide variations in injection rate, pumping pressure, cost, and waste disposition. Included are successful installations in Western Pennsylvania.

Jan 1, 1969

By D. R. Mathews

Electrorefined vanadium was evaluated with respect to tensile properties and the effects of interstitial contaminants in the temperature range of 77° to 273° K. The yield strength of 18,500 psi and hardness of 63 diamond pyra-mid hardness (DPH) of electrorefined vanadium are approximately equal to that of iodide crystal bar vanadium. The ductile-brittle transition temperature was found to be below 77° K, but with 0.175 weight-percent oxygen or 0.10 weight-percent nitrogen, it increased to between 123° and 190° K. With carbon content up to 0.11 weight-percent, the transition temperature remained below 77° K. The yield strength of the interstitial-containing alloys can be expressed by: au = 7.5 + 480 (pct N) + 290 (pct 0) + 280 (pct C), where au is the upper yield stress in 1,000 psi at 273° K. Profuse deformation twinning occurred in the alloys tested at 77° K. However, twinning could be suppressed by dissolved oxygen or nitrogen in excess of 0.15 and 0.086 weight-percent, respectively. Carbon, even though present in excess of the solubility limit, did not affect twinning.

Jan 1, 1965

By M. M. Fine

This report presents the results of laboratory mineral-dressing investigations by the Bureau of Mines of 14 individual or composite character samples from deposits in the Batesville manganese district. It will be noted that some concentrates have met or approached analytical specifications for metallurgical manganese ore although great variations in both physical and chemical composition from once deposit to another make each a new problem. In most cases it is evident that a substantial loss of manganese has occurred in the various slime and tailing products. An important aspect of this work is the research being conducted on manganese-bearing limestones. Recent reconnaissance indicates that this resource constitutes one of the major domestic reserves of manganese. Laboratory study has shown that ferrograde concentrates can be recovered from samples of manganese-bearing limestones from two properties. Research on samples from other areas is still underway.

Jan 1, 1957

By A. H. G. Mitchell

Gold-poor and gold-rich porphyry and epithermal gold-silver deposits of Caenozoic and Cretaceous age in the western Pacific and central and eastern Europe are confined to predominantly andesitic continental margins and island arcs. The arc volcanic rocks overlie a complex non-oceanic basement of stacked nappes, the uppermost of which is often ophiolitic. The emplacement of ophiolite triggered a reversal of tectonic polarity, subduction and arc magmatism. Andesitic volcanism and the formation of a strato-volcano were followed by the ascent of magma and porphyry copper mineralisation. Regional propylitic alteration came from convecting, predominantly meteoric fluids. Magmatic degassing caused advanced argillic alteration. This is commonly unmineralised in perched water tables, but may sometimes host high sulphidation gold or enargite gold at deeper levels within the propylitic zone. The onset of extensional stress after the andesitic volcanism allowed meteoric water to circulate to depths of 5 km or more, with consequent cooling of an ascending magma body at depth and the development of low sulphidation epithermal gold mineralisation near and immediately above the sub-volcanic basement surface. All andesitic arcs are mineralised. Regional controls on their ore potential include the level of erosion and geological features in the basement that focus the ascent of fluids. Differences between the mineralisation of the European and the western Pacific arcs may reflect the presence of older, more granitic basements in many of the European arcs.

Jan 12, 1992

By R. W. Armstrong, P. C. Jindal

The hardness dependence on grain size for polycrys-talline cartridge brass and a leaded brass has been measured by Brine11 and Rockwell B testing. In each case, the hardness, H, depends on the average grain diameter, 1, according to: H =Ho + kHl-1/2 where Ho and kH are experimental constants. Diamond pyramid hardness values have also been measured as a function of the indentation size and grain size to give additional information on the nature of the hardness test and the dependence of hardness on micro-structure. The hardness of polycrystalline brass depends on its grain size. Bassett and Davis' demonstrated this as early as 1919 by making Brinell hardness measurements on cartridge brass. Since then, the hardness of this type of material has been measured as a function of grain size by making Rockwell,2'3 Vickers,4 and Brinell5 tests. he hardness dependence on grain size has also been measured for other materials. Angus and summers6 investigated the grain size dependence of the Brinell hardness of polycrystalline copper and a Cu-4.5 pct Sn bronze. In other studies, nickel,? Armco iron,Big an Fe-0.07 pct C alloy,I0 and an 0.39 pct C-12.45 pct Cr stainless steel" have been investigated. In some of the preceding cases, the hardness results have been analyzed to show that the hardness varies with the average grain diameter, 1, according to an l-l\4, l-1/4 or I-2 dependence,11-13 The studies of the influence of grain size on hardness have not been based on any theoretical model. This may be because the hardness of a material is itself a complicated property. However, attempts have been made to correlate, experimentally and theoretically, the hardness of a material with its unidirectional stress-strain behavior.14-l6 On this basis, Hall" proposed that the polycrystal hardness dependence on grain size might follow directly from the Hall-Petch18,19 relation for the grain size dependence of the yield stress. Thus, the hardness-grain size relation was given as: H = Ho + kHl-1/2 [1] where Ho and kH were taken as experimental constants. The relation was applied to the measurements on brass,' copper,6 bronze,= and Armco iron.' More recently, this relation was shown by Armstrong and jindal20 to adequately describe the measurements on cartridge brass made by Bassett and Davis' and Babyak and Rhines.5 In this case, the relationship was taken a step further by independently relating the values of Ho and kH to the values of oyand ky, previously reported by Armstrong, Codd, Douthwaite, and petch21 from measurements of the yield stress dependence on grain size for this type of material. In the present investigation, new Brinell and Rockwell B hardness measurements have been made as a function of grain size for a cartridge brass and a leaded brass. In addition, diamond pyramid hardness values were measured as a function of the indentation size. All these results are applied to a further analysis of the hardness dependence on grain size. MATERIALS AND EXPERIMENTAL METHODS Cartridge brass and a leaded brass were selected for this investigation for two main reasons: it was anticipated 1) that these materials could be cold-worked and recrystallized to a wide range in grain size and 2) that the results to be obtained on these typical industrial materials could be usefully compared with previous investigations. The chemical analyses of the actual materials which were employed are given in Table I. The as-received 1/2- and 3/4-in.-thick plates were given various reductions in thickness by cold rolling. The rolled material was heat-treated at various temperatures between 330" and 850°C for differing time periods from 5 min to 9 hr to achieve a variation in the average grain diameter between 0.0339 and 0.000543 cm.22 During heat treatment, the brass was protected from zinc loss by packing it in chips or foils of the same composition material. Reasonably equi-axed grain structures were obtained in each case. The metallurgical grain sizes of the specimens were determined from measurements of the average linear intercept on a random line. Annealing twin interfaces were not counted along with grain boundaries. The

Jan 1, 1970

By F. Roemer, D. Goldmann, T. Elwert

Tantalum is an important minor metal for the production of high performance capacitors. Approximately 60% of the annual tantalum production is used in this application. Despite its high price of 298 US$/kg (average price 2010–2014), at the moment, no recycling from end-of-life products takes place. In the established recycling processes of waste electrical and electronic equipment (WEEE), tantalum is lost in the slags of copper smelting, where it is highly diluted. An economic recovery is not possible at that point. Although tantalum must therefore be extracted from the WEEE stream before it enters smelting, no industrial recycling processes exist. The main reasons are its low concentration in the WEEE stream, lack of information about tantalum bearing devices, technical difficulties of extraction, and conflicts of interests regarding the recycling of other valuable metals in WEEE. In this paper, the results of a cooperation research project are presented. The aforementioned challenges are addressed and a novel tantalum recycling process is developed. Small pilot scale experiments show that a mechanical processing route can produce marketable tantalum-concentrates of 30% tantalum with yields between 60 and 70%. This is reached through a manual pre-sorting of potentially tantalum bearing products followed by a combination of an optimized comminution, sieving, air classifying, eddy-current (EC), and two stage magnetic separation. Key to the implementation of this process was a detailed survey of the tantalum concentrations in different products carried out by the industrial partner.

Jan 1, 2016

By Ruddle R. W.

The slags produced in copper smelting are largely composed of silica and ferrous oxide and may therefore be regarded as essentially ferrous silicates. A fair amount of information is available on the constitutions of the liquid slags used in copper smelting and, in this connection, the large volume of work being carried out on steelmaking slags should be helpful. Constitutional diagrams are available for most of the principal systems involved (SiO2-FeO; SiO2-FeO-Al2O 3; SiO2-FeO-CaO; SiO2-FeO- MgO; and SiO2-FeO-CaO-Al2O3) and these show that additions of Al2O3 and CaO reduce the freezing points of SiO2-FeO slags but that additions of MgO increase the freezing point. A certain amount of information is available on the thermodynamics of slags, but much further work on this subject is required. Modern theories of the constitution of liquid slags deny the existence of molecular compounds but consider that liquid slags are mixtures of various ions such as, Fe2+. O2- and SiO4(4-). Little appears to be known of the reactions between matte and minor constituents dissolved in the slag

Jan 1, 1953