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By H. Cui

Rapid technological development has caused an increase in the demand for rare earths. Ancylite, a strontium rare earth carbonate, is a potentially significant source of rare earths. In this research paper, essential aspects of the magnetic separation and flotation processes for Bear Lodge ore are presented. A flowsheet is proposed based on an optimization of the variables and flotation simulation. The economic feasibility of the proposed processing operation is analyzed.

By İsmail İnce

The existence of water is one of the most effective factors in deterioration of natural building stones. In the process of deterioration, capillary water absorption is the most significant procedure of water penetration into the building stones. Pyroclastic rocks have been widely utilized as building stone especially in historical buildings and monuments since ancient times in the Central Anatolia in Turkey. Nowadays, this type of rocks is used in the restoration of historical buildings as well as in the construction of modern buildings. Pyroclastic rocks are highly susceptible to deterioration process. Capillary rise has a significant influence on water penetration into building stones. Therefore, it is quite important to identify the factors affecting the values of capillarity, capillary rising speed, and capillary rise that define capillary water absorption in these rocks. To this end, pyroclastic rock samples in different textures were compiled from the Cappadocia region, in Central Anatolia. First, petrographic, mineralogical, geochemical, physical, and pore diameter distribution properties of the samples were determined in the laboratory. Then, capillarity values with capillary rise and capillary rise speeds dependent on time were established. Based on the data obtained, correlation coefficients between matrix percentage and capillary water absorption rate and capillary rise values of pyroclastic rocks were calculated and found to be as 0.850 and 0.891, respectively. Thus, the article proposes a new empirical equation to practically calculate the capillary rise value depending on the matrix percentage (MP) and median pore diameter (MPD) values.

Nov 30, 2020

By P. F. Berry

X-ray fluorescence analytical techniques are fairly well established in the mining and metallurgical industries. In recent years, instruments utilizing radioactive isotopes have been developed which, owing to their more compact size, greater reliability and independence of substantial power supplies, are often preferred to X-ray tube installations. Analyses can now readily be carried out in the field, on the factory floor and in otherwise difficult locations. This paper describes many examples of radioisotope X-ray fluorescence for the analysis of metallic minerals, finished metals and alloys and also for the continuous measurement of metallic coatings, such as tin and zinc, on steel. Radiation scatter techniques are also described for certain analyses and for thickness and density measurements.

Jan 1, 1967

By Frank H. Reed

This report is one of a series written by members of the Solid Fuels Mission to Germany describing wartime developments in the mining , preparation , and utilization of coal . This mission was organized early in 1945 under the auspices of the Technical Industrial Intelligence Committee , which cooperated with a counterpart British committee . The Solid Fuels Mission operated under the direction of a steering committee headed by Dr. C. J. Potter , Deputy Solid Fuels Administrator . The personnel of the mission consisted of H. F. Yancey, in charge , J. W. Buch, Thomas Fraser , L. L. Newman , and L. D. Schmidt of the Bureau of Mines ; H. H. Lowry , Director of the Coal Research Laboratory , Carnegie Institute of Technology; H. J. Rose , Vice - president and Director of Research , Bituminous Coal Research , Inc .; and F. H. Reed , Chief Chemist , Illinois State Geological Survey . Over 50 reports were written by the members of the Solid Fuels Mission . These , together with microfilms of supporting data obtained in the course of the investigations , are on file at the Bureau of Mines , Washington , D. C. , where they are available for public examination . The Office of the Publication Board in the Department of Commerce is prepared to furnish photolith copies , photostats , or microfilm reproduction of all declassified reports . A Bibliography of Scientific and Industrial Reports is issued weekly by the Department of Commerce , Office of the Publication Board , and is sold by the Superintendent of Documents , Government Printing Office , Washington 25 , D. C. , on a subscription basis . An initial payment of $ 10 will provide for approximately 9 months , and subscribers will be notified when additional remittance is necessary . All subscriptions will begin with volume 1 , No. 1 , unless ordered otherwise . The Bibliography, covers all materials and subjects and gives instructions for obtaining the desired items . The reports of the Solid Fuels Mission relate to the following general subjects : Mining methods in the Ruhr district of Germany , with special reference to mechanical cutting and loading equipment , pneumatic packing , and Diesel mine locomotives ; activities of industrial research laboratories supported by the German coal and coke industry ; coal preparation in western Europe ; low- temperature carbonization processes ; metallurgical coke from

Jun 1, 1948

By James T. Baxter

Underground mining of limestone is becoming increasingly attractive in Illinois. Most quarries are near rivers on the western and southern borders where competition for land use is intensive. Increasing demands for stone can be met by expanded mining with access by edits in existing quarries and by inclines and shafts at downdip sites. Geologic, hydrologic, and engineering conditions indicate that deep mines in the Ste. Genevieve, St. Louis, Salem, Ullin, and basal Burlington Limestones of Mississippian age and in the Moredock Limestone Member of the Dunleith Formation of Ordovician age are possible, but development will require prudent exploration and planning to ensure that the product will be of good quality.

Jan 1, 1978

By N. S. Dalal, X. Shi

"SUMMARYElectron spin resonance (ESR) measurements provide direct evidence for the involvement of the glutathionyl radical, as well as an isolable Cr(V)-glutathione intermediate in the Cr(VI) glutathione redox reactions. These results indicate a new mechanism for the reduction of Cr(VI) by glutathione in relationship to cellular environment and suggest that synergistic reactions of Cr(V) and GS· might be responsible for the (unexpected) increase in the Cr(VI)-induced DNA-strand breaks at high glutathione levels.INTRODUCTIONWhile the reduction of Cr(VI) by glutathione (GSH) is thought to be a critical' step in the pathogenesis of the Cr(VI)-exposure related carcinogenesis1- 4, the exact reduction mechanism is not yet understood. The following reaction steps have been suggested :(A) Initial step:Cr04 2- + GSH - GSCrOa - (1)(B) At high GSH levels:GSCroa- + GSH - Cr( IV) + GSSG (2)(C) At low GSH levels: GSC rO a - - Cr ( V ) + GS ·(3)Thus far, however, in these reactions, the GS· radical has eluded spectroscopic detection, while the evidence for the Cr(V) formation has been reported positives as well as negative2·. Her~ we present spin-trap ESR evidence for the formation of the GS· radical, and a definitive ESR detection of an isolable cr(V)-GSH intermediate in Cr(VI)-GSH reactions.MATERIALS. AND METHODSESR spectra were obtained at X-band (-9.7 GHz) using a Bruker ER200D ESR spectrometer. The magnetic field was calibrated with a self-tracking NMR Gaussmeter (Bruker, Model ER035M) and the microwave frequency was measured with a Hewlett-Packard (Model 5340A) frequency counter. The spin probes, a-(4-pyridyl-1-oxide) -N -tert-butylnitrone (4-POBN) and 5,5-dimethyl~1-pyrroline-1-ox1de (DMPO) were purchased from Aldrich, K2Cr201 from Fisher and used without further purification. All experiments were done at room temperature."

Jan 1, 1989

By Luciana Angelita Machado

Os rejeitos gerados na mineração de carvão, sob condições atmosféricas e a possível presença de bactérias acidofílicas proporcionam a oxidação primária do sulfeto de ferro, formando sulfatos e ácido sulfúrico. Com a redução do pH da água, ocorre a mobilização de metais contidos no material, gerando a drenagem ácida de mina (DAM). A DAM causa um impacto nocivo na qualidade da água superficial ou subterrânea. Uma das tecnologias de prevenção da geração da DAM consiste no método de aditivos alcalinos. Assim, o objetivo do presente trabalho foi avaliar o controle da DAM pela mistura de rejeito de carvão com escória de aciaria elétrica do forno panela. A metodologia utilizada baseou-se nos ensaios estáticos e ensaios cinéticos. Os resultados demonstram que o rejeito de carvão gera DAM. Contudo os problemas ambientais podem ser em grande parte resolvidos pela mistura do rejeito com a escória na proporção acima de 10:10. Os ensaios cinéticos demonstram que, nessa condição, ocorre aumento do pH e redução do potencial redox e sulfatos na água lixiviada. Desta forma, a disposição conjunta de escória de aciaria elétrica do forno panela com rejeito de carvão é uma alternativa viável para o controle da geração de DAM em minerações de carvão.

Jul 30, 2018

By C Roche, G M. Mudd

The Morobe Province of central Papua New Guinea (PNG) has been mined for gold for nearly a century, although it is only in the past decade that large-scale modern mining commenced. The Hidden Valley gold-silver project began construction in mid-2006 and production by August 2009, and is located in the mountains above Wau in the headwaters of the Watut River. The mine is owned and operated by the Morobe Mining Joint Venture (MMJV), which also owns the Wafi-Golpu project, comprising the Wafi gold deposit and Golpu copper-gold deposit, situated in the Watut River Valley. Together they represent a potential mine of the scale of Ok Tedi or Bougainville or bigger. The MMJV is owned in equal shares by Newcrest Mining from Australia and Harmony Gold from South Africa. Although Hidden Valley was the first large-scale mine in PNG to engineer and build a tailings storage facility, poor environmental management during construction and early operations led to significant erosion of waste rock and sedimentation impacts throughout the ~200 km length of the Watut River. Since then, substantial efforts have been made to improve environmental management, especially waste rock placement and storage and water quality management. While the impacts from the Hidden Valley project appear to be reducing, the saga has heightened concerns by many along the Watut River and across PNG about ongoing impacts from mining.This paper presents the results of an ongoing project in the Morobe Province conducted by the Mineral Policy Institute examining the historical, current and future impacts of mining, including community views, social and environmental impacts and the monitoring and regulation of mining. Overall, there is a clear need to more fully integrate social and environmental issues into life-of-mine planning and go above and beyond regulatory requirements. In this way, some of the lessons learnt – by the community, MMJV and government – can be incorporated before, during and long after mining.CITATION:Mudd, G M and Roche, C, ?2014. Mining in Morobe, Papua New Guinea – impacts, assurance and self-determination, in Proceedings Life-of-Mine 2014 , pp 313–336 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By W. G. Hatch

Introduction In November, 1927, a paper was presented at the Annual Meeting of the British Columbia Division by H. A. Pearse(l), in which he described the milling practice at Britannia and set forth the metallurgical results which were being obtained at that time. In the intervening four years, various changes and additions have been made in equipment and practice, which have resulted in marked improvements in efficiency and costs. These changes and their effects are discussed in the present paper. During the past few years two major changes have been made in plant equipment. The first of these was the. elimination of an intermediate crushing stage by discarding two gyratory crushers in favour of two Symons cone crushers. The latter installation-now effects in one stage a greater reduction than was formerly accomplished in two, that is, by the gyratories together with a set of rolls. The second important change in equipment took place when the original M.S. flotation machines were replaced by six Forrester pneumatic machines, so that now the flotation department consists entirely of machines of this type. A number of minor changes and some further additions to equipment have also been effective in raising plant capacity and concentrate grade, while making noticeable reductions in tailing losses and costs of ore treatment.

Jan 1, 1932

By Michael L. Sorokin

The behaviour of cobalt during processing of nickel raw material is analysed within the Ni-Co-Fe-S-O-SiO2 system using the computer model. For this purpose the thermodynamic parameters for "three-suffix" Margules's equations in Co-Fe-S and Co-Fe¬Ni-O-S1O2 systems were computed! Phase and iso-activity diagrams for Co-Fe-S system, and phase diagrams for the systems Co-O, Co-Fe-O, Co-Ni-O, C-oO=SiO2 and Co-Fe-O¬SiO2 are calculated using the developed computer programs and identified parameters. The diagrams are used to analyze cobalt behaviour at smelting and converting.

Jan 1, 1995

By C. I. Garcia, G. Zhou, W. Gao, A. J. DeArdo

The development of X-100 and X-120 linepipe steels was investigated using a series of low-carbon Mo-Nb-B steels. The laboratory steels were vacuum melted and processed using advanced thermomechanical processing (TMP) philosophies. Prior to the laboratory hot-rolling experiments, the grain coarsening temperature, the conventional T95 and T5 start-stop recrystallization temperatures and the transformation behavior of y were studied using a computer-controlled high temperature deformation MTS-458 and a Theta-IV High Speed dilatometer systems. The results from these experiments provided the guidelines for the design of the laboratory hot-rolling TMP processing experiments. The mechanical properties of the experimental steels showed yield strengths in the range 700-850 MPa and CVN impact properties of over 80 J at -20°C. The best balance of mechanical properties was obtained by using CCR+DQ+Tempering treatments. The major microstructural features responsible for the observed mechanical properties in order of importance were: a) substructural refinement associated with lower bainite, b) dislocation strengthening, c) fine recrystallized ferrite, and d) small amounts of retained austenite. Fine Nb(C,N) precipitates formed in ferrite were observed, however their contribution to the strength was minimum. Most of the Nb(C,N) precipitation took place in austenite. This precipitation was used to exert microstructural control of austenite during hot rolling. The physical metallurgy and optimum TMP to achieve the mechanical properties are detailed in this paper.

Jan 1, 2005

By K Ehrig, V Liebezeit, Y Li, B Pewkliang, M Smith, E Macmillan

Pre-concentration of low grade ores via the rejection of low/no value materials based on fragment size is the subject of many published papers and studies over the past decade. However, the possibility of upgrading should not limited to low grade ores given the high cost of capital, energy, water, reagents, and ultimately tailings storage across the mining industry. Mining and processing facilities at Olympic Dam consist of an: 1) underground mine where ore is extracted via sublevel open stoping and 2) integrated processing plant located on the surface which produces Cu-cathode, Au-Ag bullion and uranium oxide concentrate. Blasted ore is trucked/trained to underground crushers which produce an ore feed with a product size P80 = -145 mm. Crushed ore is then hoisted to the surface and delivered to the ROM pads via an overland conveyor. The typical copper grade of mill feed is approximately 2 wt%. A rapid assessment of the potential to upgrade Olympic Dam mill feed prior to the ROM pads via rejection of low value materials based on fragment size was completed using existing data. Three separate datasets were utilised to assess the deportment of Cu, U, Au across size ranges of 200 mm down to sub-8 m. Cumulative grade vs cumulative mass distribution graphs for each element were produced. This data clearly demonstrates that Cu, U, Au grades remain constant down to ~212 m, which happens to be the liberation size of the sulfides. Hence, no potential to upgrade the ore stream via rejection of +200 mm - to ~212 m sized materials prior to milling. Mineralisation within the Olympic Dam Fe-oxide Cu-U-Au-Ag deposit (IOCG) occurs as disseminated sulfide grains within granite- to hematite-rich breccias. The typical sulfide grain size is sub-200 m that supports the outcomes of the grade deportment by fragment size study.

Nov 10, 2020

By Dermot M. Winters, Brent T. Wahlquist, C. Y. Chen

The enactment of the Surface Mining Control and Reclamation Act (SMCRA) in August 1977 addressed subsidence resulting from underground mines, in addition to creating the requirements for reclamation of surface coal mines. Subsidence control regulations pursuant to SMCRA were initially promulgated in March 1979. Several revisions have since been made. In addition, due to court challenges some regulations have been remanded and others are still on appeal. In the meantime the Secretary has agreed to initiate rulemaking on some issues. It is yet to be determined how the prohibition of certain areas from surface coal mining operations under Section 522(e) of the Act applies to subsidence. This presentation discusses the status of the regulations and issues related to or affecting the subsidence regulations.

Jan 1, 1986

By R. A. Busch

Sludge ponds of fine coal, fine soil, and water created behind large piles of coarse coal waste can present hazardous conditions; this is a Bureau of Mines report of the subsurface physical property data developed on the fine coal waste materials that make up the core areas of two typical coal waste impoundments. These data will help define more completely the engineering properties of this problem area of the structures. Additional calorific, chemical, and mineralogical data were obtained on the coal waste materials to determine possible uses or development of byproducts. The possibility of extracting alumina from coal ash was also investigated.

Jan 1, 1975

ABSTRACTFor the binary system copper-lead two relationsEquation 1andEquation 2have been derived for the activities of copper and lead at compositions and absolute temperatures within the liquid region of the phase diagram.These relations give, with greater accuracy than is given by previously published relations, the activity-composition temperature variations for all regions of the phase diagram of interest to metallurgists.These relations are essentially simple forms of the Margules equations but with linear temperature dependence applied to their coefficients. This has been done in such a manner that a phase diagram obtained from these relations agrees well with the data available for this system. The methods of obtaining the relations and constructing a phase diagram from them are both given in detail. The enthalpies and entropies of mixing are compared with those derived by other methods.

Jan 1, 1971

By The Staff, Explosives Research Center

The principal activities of the Bureau of Mines Explosives Research Center from July 1, 1962, to June 30, 1963, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1963; in general, the research reported in these publications antedates the report period.

Jun 24, 1964

By Zvonimir Ester

The course of motorway tunnel under construction was set only 2 m away from the main motorway. The thickness of the tunnel overburden rock was 9 m. During the tunnel construction the traffic on the motorway was not supposed to be interrupted. The tunneling was carried out by NATM with classical drilling of blastholes and by blasting.

Jan 1, 1998

By Dino Kartofilis, Rick Deschamps, Giovanni (John) Bonita

"Anew condominium complex in Arlington, Va., presented some formidable constraints. One was the requirement for a permanent retaining wall to support a 48.5-ft (15-m) cut and an existing 16- story building on top of the slope. Another was the adjacent property owners’ refusal to allow tieback anchors to encroach on their property. The General Contractor (GC) proposed an innovative design incorporating vertical concrete load-bearing elements (LBEs) supported by post-tensioned tiedowns. The owner accepted and the project was successfully completed in 2007.The original designer had proposed a system that included a temporary, raked soldier pile and lagging wall and a permanent cantilever retaining wall with a large piled footing. The system was potentially costly and its constructability questionable.The GC then asked for a design-build alternative to reduce costs and enhance the schedule. The first idea was a diaphragm wall with vertically anchored T-sections. However, configuring a crane to excavate perpendicular sections using grab equipment seemed impossible. There were also utilities approximately 25 ft (9 m) from the existing building, two tiered retaining walls down the slope and a large swimming pool at the base. However, the GC was committed to providing a stable bench 20 ft (6 m) wide along the wall alignment to support the crane.The design evolved to single bite panels using diaphragm wall technology, commonly called LBEs, or barrettes, when they carry vertical loads. For this project, 44 LBEs were horizontally spaced at 9 ft (2.75 m) on center, oriented perpendicular to the wall, extending into bedrock and anchored vertically on the upslope side to resist overturning moments. They were essentially large soldier piles that provided both temporary and permanent support of excavation.An unusual formal agreement was established with the GC to complete the work based on pricing, and prior to completion of final design. This arrangement allowed for an exchange of ideas that increased project efficiencies and lowered costs — without the fear that design concepts would be “shopped” to competitors."

Jan 1, 2009

By E. J. Lintner

This paper is one of a series being prepared by the United States Bureau of Mines describing clay mining, crushing and grinding methods, and costs at various clay-mining operations throughout the United States. These papers are designed to disseminate technical information regarding methods used. The cost tabulations represent local operating expenditures only and not total production costs. Although the publication of total production costs might not be advisable in some instances, yet a knowledge of operating costs is essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to-this distinction between total and operating costs in order that no misunderstanding of the cost tabulations shall ensue. The following report deals specifically with the methods employed by the Dennison Sewer Pipe Co., Dennison, Tuscarawas County, Ohio.

Jan 1, 1936

By André de Albuquerque Vicente

O valor do PREN da liga pode levar a uma previsão equivocada da resistência à corrosão por pite pois, caso haja um desbalanceamento das frações volumétricas da ferrita d e da austenita, as composições químicas das fases poderão ser muito diferentes daquela da liga. Neste caso o PREN de uma das fases pode ficar abaixo do PREN da liga. Caracterizou-se três chapas de aços inoxidáveis duplex laminados com diferentes PRENs: UNS S32304 (Lean Duplex), UNS S31803 (Duplex) e UNS S32750 (Super Duplex). Várias técnicas complementares de análise microestrutural foram utilizadas, tais como de espectrometria de emissão ótica, microscopia óptica e microscopia eletrônica de varredura com EDS acoplado. Realizaram-se análises metalográficas quantitativas para a determinação das frações volumétricas de ferrita d e da austenita e análises químicas semi-quantitativas das fases presentes utilizando-se um MEV com EDS acoplado.

Oct 30, 2017