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By D. J. Coolidge, H. L. Sheakley

THIS paper does not deal with all sands used in the glass industry in Missouri; it covers only that used in the plate-glass factory at Crystal City. However, it is probably safe to say that other sands, pro- [ ] duced throughout the state for this purpose, are of identical nature. The glass sand used in Missouri is commonly called the St. Peter deposit, which is ascribed to the Ordovician Rock series in the form of sandstone. This St. Peter deposit, aside from a few small outliers, covers a large area of eastern Missouri. It forms, through a broad curve, the northeast margin of the typical Ozark region between Cape Girardeau on the southeast and Mineola, Montgomery County, on the northwest. The belt is extremely irregular, varying from one to ten miles in width; its length is 150 miles in a straight line. [ ] The outcrop near the entrance to the Crystal City mine appears in the form of a sandstone bluff approximately 30 ft. high, running along Plattin Creek (Fig. , I). Above the sand rock an overburden of Joachim limestone appears, which, thickens to nearly 300 ft. and forms the hill commonly called Buck Knob. Test holes, where drilled at various points and the drillers' log indicate that the St. Peter deposit ranges in thickness from 63 to 71 feet. PROPERTIES OT THE ST. PETER SAND From an analysis of the glass sands of the St. Peter formation in Missouri, the follow-

Jan 1, 1942

By E. P. Youngman

This paper presents one of a series of digests of foreign mining legislation and court decisions that is being prepared in advance of a general report relative, to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the mining laws of British Guiana has been prepared from the best available sources in Washington and is, released subject to amplification and correction, if necessary, by United States foreign-service officials. INTRODUCTION The sources of information available in the preparation of this paper are the following: 1. The Crown lands ordinance, No. 32 of 1903, September 26, 1903.

Jan 1, 1934

By D. A. Lindsey

Gravel lithology affects the quality of aggregate because different rock types in gravel have different physical and chemical properties. The lithologic composition of alluvial gravel reflects the composition of its source terrane and the variable effects of weathering and transport on each rock type. This report discusses lithologic controls on aggregate quality in the mountain-front environment of the Colorado Front Range. Lithologic controls on aggregate quality of gravels were evaluated using pebble count data. Gravel lithology along the Front Range shows both temporal and regional variation. The principal variable in gravel lithology is quartz plus quartzite, of which quartzite is commonly more abundant. Large quantities of metaquartzite derived from the mountain front southwest of Boulder, Colo., were dispersed northeastward during deposition of the oldest Front Range gravels. Average quartz plus quartzite is greatest in the oldest gravels. Aggregate quality is probably enhanced by large quantities of quartzite. Abundant volcanic rocks in gravel may enhance aggregate quantity, but such occurrences are local in extent. Abundant sedimentary rocks in gravel, mainly sandstone near the mountain front, may decrease aggregate quality.

Jan 1, 2002

By V. F. Parry

This report is the first substantial description of the carbonizing process and the details of experimental work conducted at the Denver laboratories under a coopeative agreement between the Bureau of Mines and the Texas Power & Light Co. It presents the results of tests on several Texas lignites and other typical western coals that have been processed in the first pilot plant operated at Denver. Investigations on drying fine coal in the entrained and fluidized state have been under way at Bureau of Mines Denver laboratories for several years. Reports on this work were published in 1949 and 19505/ describing the theory and practice of re-moving inherent moisture from the lower -rank coals. The investigation did not include a study of the removal of surface moisture from fine fuel. Private industry in Canada became interested in the possibilities of drying fine coal, employing the closed-circuit system and techniques recommended by the Bureau. Large, commercial-scale drying units were built by a Canadian company, which successfully demonstrated that surface moisture could be removed from fine coal at high efficiency and capacity ill drying units similar in design to those developed by the Bureau.

Jan 1, 1953

By Jhon Espinoza

El distrito minero de Yanacocha es un depósito epitermal de alta sulfuración emplazado en rocas volcánicas terciarias aflorantes en el Norte del Perú. Los ensambles de alteración hidrotermal son típicos a un yacimiento ácido-sulfato: silicificación, argílica avanzada y argílica, las características tectónicas y petrológicas hacen indicar varios eventos de mineralización de oro diseminado ligados a procesos intrusivos y extrusivos en un contexto de flow domes complex. Asismismo se reconocieron varios depósitos como: Carachugo, Maqui Maqui, San José y Yanacocha, los cuales están actualmente en proceso de minado. En ese sentido, el presente texto señala a la minera Yanacocha como un distrito que utiliza el software en creado por Newmont Technical and Scientific System, el cual está diseñado especialmente para el modelamiento geológico en un ambiente tri-dimensional que permite construir y revisar secciones interpretativas de estos depósitos en cualquier dirección, así como es posible una navegación real y rotación del yacimiento en pantalla.

May 25, 1998

By A. Baldwin

This report describes the engineering feasibility and economic advantages of a unique new mining machine using cutting bits that take a constant-depth linear cut in the coal face. The studies show that this innovative new cutting concept, being developed by the Bureau of Mines, can be designed into the basic continuous mining machine. The resulting miner would be attractive to mine owners because coal could be mined with minimum generation of airborne respirable dust, substantial increases in productivity, and elimination of methane ignition due to cutting.

Jan 1, 1977

Recent improvements are described in several techniques for ground control in underground mining. Promising methods for analysis and mitigation of rockbursts are discussed. Methods of assessing damage to underground excavations from repetitive seismic loading are reviewed. Analysis of mining-induced surface subsidence is discussed.

Jan 1, 1989

By Kathryn C. Sole, Owen Tinkler

"Although the first large-scale application of copper recovery by solvent extraction (SX) took place in Zambia in the early 1970s, it is only in the last decade that this technology has become widely employed in this part of the world and is now a mainstay unit operation in most copper hydrometallurgical flowsheets. The mineralogy of the ores in the African Copper Belt, and hence the characteristics of the African leach liquors, differ significantly from those in Chile and the south-western USA, where copper SX has had a long and successful history. These differences provide operators, metallurgists, reagent vendors and engineers with many challenges: new approaches are needed to adapt this technology for successful implementation in this region. This paper examines typical operating practice in the African Copper Belt, discusses differences compared with other parts of the world and looks at some of the challenges and opportunities presented by these flowsheets. INTRODUCTION Following the success of the Rancher’s Bluebird and Bagdad solvent extraction and electrowinning (SX–EW) operations in Arizona in the late 1960s, the Tailings Leach Plant at Chingola, Zambia became the first large-scale copper SX plant in the world, commissioned in 1974. Despite the equipment design now being outdated, this plant still continues to operate successfully, indicating the versatility and adaptability of this technology. Today, there are some 75 copper SX operations worldwide with cathode production above 10 kt/a. The top ten producers currently account for some 40% of the global 4.3 Mt/a SX–EW copper production. South America (predominantly Chile and Peru) is the largest copper cathode-producing region, with annual production of some 2 Mt. The Central African Copper Belt (Zambia and the Democratic Republic of Congo (DRC)) is second, with cathode production of 1.2 Mt/a and North America (USA and Mexico) third, producing close to 0.8 Mt/a Cu (Cytec data, 2014). The remaining 0.35 Mt/a comes from all other regions combined (referred to as “Rest-of-World”). Current and future operations in Zambia and the DRC are summarised in Figure 1. The industry in this region is characterised by a large number of small (3 to 20 kt/a) plants, mainly Chinese-owned, and a few very large (>200 kt/a) operations, owned by major multinational corporations. This paper examines typical operating practice in the African Copper Belt, discusses the differences compared with other parts of the world and looks at some of the challenges presented by the conditions, as well as innovations in flowsheets, reagents and operating conditions that have been introduced in these circuits."

Jan 1, 2015

By Diego Berti Salvaro

A morfologia, dimensões e composição química de tribocamadas são fortemente dependentes das pressões e temperaturas existentes no contato e oriundas das reações das superfícies entre si, com a atmosfera, com os lubrificantes e contaminantes presentes no contato. No presente artigo foi analisada a formação de tribocamadas em pares DLCaço inoxidável testados por 180, 500, 1000 e 2500 horas em atmosfera de gás refrigerante R134a sem a presença de óleo lubrificante. A caracterização foi realizada por microscopia eletrônica de varredura espectroscopia de energia dispersiva (MEV-EDS) (morfologia e composição química) e interferometria ótica de luz branca (dimensões). Nas análises por MEV-EDS foram identificadas tribocamadas que se apresentaram mais pronunciadas nas superfícies do aço inoxidável sendo as mesmas oriundas de transferências mútuas entre os pares tribológicos bem como oxidação. A espessura das tribocamadas, por sua vez variou de 100 a 500 nm. Os resultados revelam que as tribocamadas são quimicamente estáveis e que suas espessuras não variam significativamente após mil horas de ensaio.

Aug 16, 2017

By Tony Peglas, Harry Asche, Eva Wood

The North-South Bypass Tunnel is a new $AUD1.5 billion underground traffic route in Queensland, Australia, a project of the Brisbane City Council. The tunnel is approximately 5.2 km long, bypassing the Central Business District, and is adjacent to and below major buildings and services. Road tunnel alignment issues include the complex southern connections to the Pacific Motorway and the design of ramps to the east and the north. A review of road tunnel alignment criteria and accident data for Australian and overseas tunnels, similar to the proposed NSBT, are discussed. The key findings of this review lead to a rationalization of the traditional tunnel cross sectional width allocation. The road alignment design elements adopted for the NSBT are also discussed. The NSBT route crosses beneath the Brisbane River. Geotechnical investigations and hydrogeological modelling are described. The crossing has a fundamental impact on the alignment and the tunnelling methods. The tunnelling methods to be adopted and the tunnel support are described. The geotechnical investigations and hydrogeology analysis culminate in the selection of a single shielded TBM for the reference design. These outcomes are related to complex issues of hydrogeology and contaminated groundwater. These are discussed in detail.

Jan 1, 2005

By Keet B. A, Waid J. S

The Gippsland Basin is one of Australia's most important producers of petroleum products. An inevitable byproduct of the production, refinement and transport of the millions of barrels of oil is thousands of tonnes of waste. These wastes are generated from the wellhead through to the petrol bowser and range from oily brines and coal tars to oil and petrol contaminated soils. The vast majority of these wastes are of a relatively low toxicity and most importantly are carbon-based and biodegradable. Current disposal practices tend to ignore the latter characteristic and inappropriate and/or expensive waste disposal solutions such as landfilling (tipping), incineration or ocean outfalls are the result. A very cost effective and environmentally friendly alternative is land treatment of such wastes. Landfarming, as it is called, has been successfully practiced in Europe for over a decade. Essential features of the system are: ò Application of a predetermined quantity of biodegradable waste in liquid, sludge or highly contaminated soil form, to pre-ploughed soil with concurrent addition of nutrients (N, P and trace elements) and lime to encourage bacterial activity. ò Harmless bacteria already present within the soil break down the carbon-based compounds into carbon dioxide, water and waste heat, WHILE concurrently generating new cells. The breakdown occurs over a period of weeks to months and continues with time with the extremely low levels of the more difficult waste types being the last to disappear. ò Further waste is applied to the soil at regular intervals. The treatment area may be dedicated to landfarming or may be used alternatively for agricultural purposes. Application rates vary but may be as high as 800 tonnes per hectare per year for wastes such as refinery sludges.

Jan 1, 1992

By Stephen D. Cramer

The Bureau of Mines conducted a study in which the magnetic fraction of urban refuse was used as melting stock in the preparation of high-strength, low-alloy and carbon steel. Product steels, made from incinerated steel can scrap, nonincinerated-nondetinned steel can scrap, nonincinerated-detinned steel can scrap, and dilutions of these scraps with No. 1 heavy melting scrap, were used in continuing tests in industrial, rural, and marine environments to determine the effect of residual elements and atmospheric pollutants on their atmospheric corrosion resistance. The respective commercial steels were exposed at the same time to establish baseline corrosion data for the test sites. Weight-loss data are reported for atmospheric exposures of 0.5, 1.0, 1.5, and 3.8 years. The marine environment was the most corrosive; the industrial environment was the least corrosive. The atmospheric corrosion resistance of the carbon steel was improved 25 pct by using incinerated scrap and nonin-cinerated-nondetinned scrap in the steelmaking process. In no case was the atmospheric corrosion resistance of carbon steel degraded by using the magnetic fraction of urban refuse as melting stock. The presence of sulfur in the corrosion film was the most important factor affecting the corrosion resistance of the steels. With increasing sulfur concentration, the rate of the corrosion reaction was reduced and the corrosion film became more protective. The residual elements in the product steels most responsible for improving corrosion resistance were copper and tin. These elements tended to increase the concentration of sulfur in the corrosion film. At the levels present in the product steels, Cr, Ni, and Pb had no observable effect on the corrosion resistance of the steels.

Jan 1, 1980

By J. J. deBarbadillo

This Bureau of Mines report describes a process for recovering chromium and other metals from superalloy scrap. Laboratory-scale experiments were conducted to test a complex flowsheet utilizing a wide range of extractive metallurgical operations. The novel basis for the process is the fonnation of a sulfide matte in which chromium is concentrated in a discrete chromium sulfide phase. Mineral processing and hydrometallurgical procedures are used to separate chromium sulfide from the other matte constituents. The products of the process are a chromium-nickel alloy suitable for reuse in the superalloy industry, electrolytic nickel, electrolytic cobalt, and iron-molybdenum residue. Recovery of the principal elements contained in the scrap is chromium--93 percent, nickel--99 percent, cobalt--96 percent, and molybdenum--92 percent.

Jan 1, 1981

By P. Mokwena

Paper written on project work carried out in partial fulfilment of BSc (Hons) in Chemical Engineering Diamond synthesis has attracted a great deal of interest because of its exceptional properties and various applications. In this study, the chemical catalytic vapour deposition (CCVD) method was used to synthesize diamond films using acetylene as carbon source and hydrogen as carrier gas at a temperature of 1000°C, and their thermodynamic stability was studied. Photographic analysis revealed that these products are diamond films, Ramman spectroscopy confirmed that they are graphitic while confocal laser scanning microscopic image analyses proved that these diamonds films have structural defects due to iron impurity from the catalyst precursor. The quantity of diamonds films produced is also proportional to the acetylene to hydrogen ratio but these films are larger in size at lower acetylene to hydrogen ratio. Thermogravimetric analyses showed that transformation of these materials begins at 25°C but could not be used to determine if a temperature range below 25°C exists. The stability of these CCVD-synthesized diamonds also increases below 25°C when stored at different temperatures.

Jan 1, 2007

By Yuri Sáenz

El presente trabajo señala la efectividad del uso del material triturado como elemento de confinamiento de energía (taco) para el control de una voladura a tajo abierto, siempre que se utilice una nueva técnica en el carguío del explosivo. El objetivo de este método evita eyecciones, mantiene la misma fragmentación y el menor consumo de explosivos en el uso del material zarandeado y su aplicación es válida para taladros secos como los que presentan agua en su interior.

Oct 21, 2015

By J. B. Cheatham, M. D. Biggs

This paper presents a systematic method for determining the forces on a simplified roller bit. The kinematics of an actual roller bit drilling in rock is complex; nevertheless, it is desirable to obtain an accurate analytical model.. As a preliminary study, the roller bit is represented here by a simple two-dimensional bit and the rock by a Coulomb plastic material. Results from previous work, plus additional assumptions, are incorporated into a computer program to determine the forces required to move the bit in a specified manner. Example problems are worked by use of this program. By studying similar drilling problems and by supporting laboratory work, one could eventually obtain an accurate analytical model for drilling by an actual roller bit. This could lead to the compilation of a catalog of results that, in turn, would allow selection of the optimum drill bit for any given situation. INTRODUCTION

Jan 1, 1970

By Gilberto Yanarico Apaza

A través de estudios electrocinéticas, electroquímicos, y de flotación, se ha confirmado que la flotación de arsenopirita, ocurre debido a la formación de dixantogenato isopropílico, por la oxidación del colector en la superficie del mineral. Este fenómeno se promueve en condiciones ácidas, lo que no es nuestro caso; Sin embargo, se evita la flotación en condiciones alcalinas donde se forman hidróxidos de fierro y arseniatos en la superficie de arsenopirita y variedades de minerales de arsénico.

Sep 1, 2017

By F. Albayrak

This report is a study of the impact of Federal laws and regulations on the domestic supply of metallic and nonmetallic minerals. The study was confined to pertinent environmental legislation and the recently enacted Federal Mine Safety and Health Act of 1977. Emphasized were the legal requirements placed on individual selected mineral industries, and the economic impact of these requirements. A certain amount of attention was also directed to the particular environmental and health and safety problems generated by selected mineral industries. The study also pinpointed a list of major problem areas having significant impact on the domestic mineral supply.

Jan 1, 1978

Copper waste dump leaching is growing in importance because of the.large tonnages (up to 250,000 ton/day) of low grade waste rock available from open cut mining of copper deposits and proof that controlled leaching of copper from such dumps can be profitable.Overburden or waste rock, ranging in size from large boulders to fines, is dumped as cheaply as possible on sloping sites. Copper is leached from the dumps by applying up to 12,000 gal/min of leach solution (a combination of spent solution from cementation and make-up water) to the top of the dumps by various techniques.Efliuent from the dumps is sent to a cementation plant for copper recovery.Factors which may be controlled, either directly or indirectly, to give a controlled copper content in the dump efliuent (usually 1-2 g/l.) are the cycle of operations (i.e. the alternate wetting and drying periods), thevolume of solution applied to the dump, pH, Fe2+ and Fe3+ content or redox potential, oxygen content, bacteria and their necessary nutrients, and temperature.Dissolution of oxide copper minerals appears to be mainly a function of acid concentration. Copper sulphide minerals need oxidation for dissolution to occur and this is accomplished by a combination of oxygen,ferric ion, and bacteria. Oxidation of pyrite, oxidation of Fe2+ to Fe3 +, and hydrolysis of Fe3+ are of some importance in leaching practice. The presence of gangue carbonate minerals is detrimental.Physical factors connected with penetration of solution into large rocks are important and the treatment of an individual dump usually extends over a period of many years. Recovery of copper from solution is usually achieved by cementation with iron (usually in the form of crumpled cans) but the use of sponge iron is becoming more important. Iron consumption varies from 1 to 4 lbiron per pound of copper. Preconcentration of the copper in the efliuent solution by solvent extraction followed by electrolysis may become a useful method.Application of dump leaching techniques to metals other than copper depends on finding an economic method of recovering the metal from solution...

Jan 1, 1967

By J L. Mauk

The Gladstone Hill area hosts epithermal veins similar to those at Martha Hill, which is less than one kilometre away. There are several vein types in the Gladstone Hill area including (1) pyrite-marcasite, (2) quartz, (3) base metal sulfide, and (4) calcite. Pyrite veinlets formed first, whereas the quartz and carbonate veins formed later. The base metal sulfide vein occurs at depth and is predominantly comprised of quartz and chlorite intimately intergrown with pyrite, sphalerite, galena, and rare chalcopyrite. Platy calcite and massive calcite veinlets were the last vein types to form. Several vein textures occur in the Gladstone Hill area, including colloform and crustiform banding, lattice-bladed, zonal, comb, massive and feathery textures. Crustiform banded veins are the dominant texture and contain variable gold-silver grades. Colloform banded veins consist of ubiquitous quartz and minor chalcedony with gold grades as high as 60 g/t. The lattice-bladed texture forms from the deposition of calcite, which has been replaced in many samples by quartz, indicating that boiling and later cooling has taken place. Unreplaced platy calcite only occurs at deeper levels (>300 m). Zonal and comb textures are preserved in quartz and late-stage amethyst veins. Feathery textures within quartz are commonly associated with breccias and some colloform banding, and with significant Au-Ag grades.   The homogenisation temperatures (Th) of primary and secondary inclusions in quartz, amethyst and platy calcite range from 166 to 274¦C, with salinities <1.3 wt% NaCI equiv. The presence of vapor-dominated inclusions and primary fluid inclusions in platy calcite suggests that boiling occurred intermittently throughout deposition. The veins formed under a relatively flat lying paleowater table that occurred 280 - 300 m above sea level. The fluids involved in vein formation were alkali chloride in composition and low in CO2.

Jan 1, 2001