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By Eder Salazar

El presente texto describe la optimización de la productividad en la empresa minera a través de la mejora contínua en la cadena de valor en SMEBSAA, los siete pasos de la calidad, proceso de mina, planta, soporte y la cuantiificación de dicha mejora en la cadena de valor en SMEBSAA. Asimismo, la implementación de los diversos sistemas de gestión refuerzan los resultados, siendo el Sistema de costeo basado en actividades el gran agrupador de toda la información de los módulos: Logístico, Control Patrimonial, Orden de Servicio, Planillas y Contabilidad.

Sep 12, 2005

By Sigurd L. Lamhauge, Karl Gunnar Holter, Svein E. Kristiansen

An innovative sprayable waterproofing membrane in combination with the traditional Nordic method of waterproofing with polyethylene foam sheets was used for the waterproofing of the tunnel. The sprayable membrane was integrated in the final sprayed concrete lining in a sandwich structure, hence constituting a composite water-proof lining based on sprayed concrete. The spray able membrane was applied in areas with small to moderate water ingresses, making up approximately 50% of the total area requiring waterproofing in the tunnel. State-of-the-art application technology with a computerized spraying robot was used. A consistent application of the required thickness at a high speed was thereby achieved.

Jan 1, 2007

By Moorrees C, Koh P. T, Tsambourakis G

Calcination of samples from the Savage River region of Thsmania containing varying magnesite/dolomite ratios under conditions optimized for the magnesite component, followed by carbonic acid leaching at elevated pressures, leads to leachates of varying composition. For a 3 per cent solids slurry leached at 15.5°C and 700 k Pa carbon dioxide, the leachates have magnesium concentrations in the range 0.71 - 13.2 g/litre. The corresponding magnesium extraction data are 12.5 - 86.4 per cent. The variation in leachate composition would be unacceptable in terms of continuous processing, so that a feed of "constant" composition is essential. Selective mining and physical beneficiation to remove the bulk of the dolomite do not appear to be practical. It is concluded that the most appropriate method of feed preparation is to carry out extensive blending of the magnesite/dolomite ore and the resultant calcine.

Jan 1, 1987

By B. Tanda

A process has been developed at Curtin University whereby glycine is used in an alkaline environment to leach gold, silver and copper from their ores, concentrates, process intermediates and wastes. Copper mineralisation investigated includes various oxides, sulfides and native copper. The leach process utilises an oxidising environment such as oxygen. Glycine is a non-toxic, non-volatile, edible, low cost reagent which is produced in large industrial quantities for use in several industries. Glycine and its copper and precious metals complexes are stable over wide pH, Eh and temperature ranges. Other than losses in leach residues, the glycine is recovered and recycled for leaching. Iron dissolution is insignificant in the pregnant leach solution. Iron in pyrite remains unaffected, whereas iron associated with base metal sulfides (e.g. chalcopyrite and bornite) is converted to a readily filterable iron hydroxide. Efficient separation of copper by solvent extraction and conventional electrowinning has been shown to be feasible for a number of organic extractants, whereas gold and silver glycinates adsorb very well onto carbon allowing CIP/CIL/CIC (carbon-in-column) based processes. The process is ideal for ores containing acid-consuming gangue, concentrates with high arsenic or halide contents and for copper-gold ores with significant sulfide mineralisation. The process eliminates many of the problems associated with the processing of copper-gold-silver ores, such as elemental sulfur formation, silica gels, unwanted metal co-dissolution, and jarosite precipitation. The reagents used and process residues are much safer and environmentally benign than conventional process options. The processing technology can be applied to in-situ, heap and vat, or agitated tank leaching at temperatures ranging from ambient to below 100?C at atmospheric pressure and is currently being commercialised. This paper will focus on copper leaching and recovery and iron rejection from a chalcopyrite flotation concentrate.

Jan 1, 2016

THE science of topography deals with the various natural and physical features of the earth's surface. These features are determined by the manifold constructive and destructive processes of nature, and their many diverse forms and characteristicsare dependent primarily upon geologic structure. Thus it is that a close relationship exists between the rocks of a region and the topographic features of the lJountry wherein they occur. Again, the existence of all sorts of mineral wealth is dependentupon the nature of the rocks, and their extension is directly connected with the topographic features represented upon the enclosing land-area.In studying any district with a view to deciphering its geological structure, to locating any mineral deposits it may contain, and to ascertaining, so far as a surface-examination may show, their probable and economic possibilities, it is therefore ofprimary importance to have at hand a correct topographical map of the area under investigation.GENERAL REMARKSThe actual amount of topographic detail shown will depend upon the money and time available for topographic surveying and upon the scale upon which the final map is to be produced...

Jan 1, 1912

By H. W. J. P. Neomagus, R. K. K. Mbaya, J. R. Bunt, N. T. Leokaoke, N. W. Makgobelele

Silicon Smelters consumes more than 80000 t/a of wood-derived charcoal as carbonaceous reductant in the production of silicon metal. More than 10% of this material is discarded as fines (<6 mm) generated due to abrasion during processing. Charcoal fine residues (<650 μm) and polyvinyl alcohol (PVA) binder were used in this study to produce mechanically strong charcoal briquettes for metallurgical application as carbonaceous reductant. The PVA binder was added in mass percentages of 1, 3, and 5 wt% to the charcoal fines. The compressive strength, abrasion resistance index (ARI), drop shatter resistance (SRI), and water resistance index (WRI) were measured as functions of curing for up to 7 days under atmospheric conditions, and the results compared with metallurgical grade coarse charcoal. The ash content of the produced briquettes was found to be high (6.6–8.0%) compared with the coarse charcoal (1–3%). The 3 and 5 wt% PVA-bound briquettes were found to be the strongest, with compressive strengths of 40 and 115 kg/cm2 respectively, with WRI values of 75 and 73% respectively. The produced briquettes were found to have lower ARI and SRI values compared to the coarse charcoal. Future work should include beneficiation of the fine charcoal discards prior to briquetting, and an increase in binder addition to above 6 wt% to improve the ARI and SRIn.

May 1, 2021

By D. K. Steele

An 18-in-diam column water elutriator was designed, tested, and operated by the Bureau of Mines for recovering nonferrous mixed metals from automobile shredder rejects. The waver elutriator separated metals from nonmetals contained in shredded nonmagnetic rejects. The unit was constructed and integrated into a local automobile shredding operation. Nonmagnetic rejects from the automobile shredder were fed onto the surface of a column of rising water. Dense materials fell through the rising water and were collected as a sink product at the bottom of the column; medium-density materials were removed as an intermediate product in a water flow through a discharge port located between the overflow and sink; and light materials were immediately carried out in the overflowing water at the top of the column as a float product. Nearly 99 pct of the mixed metals were recovered from the nonmagnetic rejects as a 70-pct-metal concentrate. Other operating conditions yielded a 93.7-pct-pure-metal product resulting in a 93.1-pct metal recovery. Float rejects are combustibles, light plastics, foam rubber, and minimal amounts of coated and uncoated copper wire. The middling discharge contained mainly medium-density rubber, plastics, glass, rock, coated and uncoated copper wire, and frequently some thin-sheet stainless steel and wrought aluminum. Maximum metal recovery in the operating program was achieved using a water velocity of 52 fpm (650 gpm). Maximum purity was obtained with a velocity of 88 fpm (1,100 gpm). .Water was recycled through a 12,000-gal baffled clarifying tank. Entrainment water losses with the float and middling rejects averaged 50 gpt of reject feed. Records maintained by the shredder operator show a 34-pct increase in nonmagnetic metals recovery during a 1-yr operation of the water elutriator as compared to recoveries from a previously used air classification system.

Jan 1, 1983

By Brian Maroney

In this paper an overview of the California Department of Transportation&apos;s (CALTRANS) bridge design criteria is presented. Special emphasis is focused upon seismic design and retrofit criteria. Topics include earthquake load definitions, foundation and structure type selection, structural earthquake analysis, and structure behavioral requirements.

Jan 1, 1993

By James L. Eirls

Tracor MBA under a contract to U.S. DOI Bureau of Mines designed, developed, fabricated and demonstrated a conveyor belt service machine. It is self-contained, battery powered, rubber tired and capable of handling, storing and transporting conveyor belting, wire rope and associated structures for sectional conveyor belts. While moving the tail section to its next position the machine discharges the belting, wire rope and belt structures. The belting is elevated and separated to provide for the insertion of the structures with minimum expended effort. A hydraulic system provides the power for steering, braking, winding or unwinding under controlled tension the belting and wire rope, operating a load-bed slat conveyor, raising, lowering and locking connection hitches and powering external hydraulic tools. Also, a pneumatic system is available to operate air impact tools. The service machine, with its present components can function in coal seams as thin as 48 inches, double wind conveyor belting 42 inches wide, 400 feet long, load or unload 3/4" wire rope on two separate reels and is controlled by two operators. A complete belt move using this machine requires only four workers. Successful underground demonstrations were conducted in coal mines located in West Virginia and Kentucky.

Jan 1, 1983

By J. D. Morgan

The US economy continued to grow steadily in 1988, reaching an annual rate of $5 trillion in the last quarter (US trillion = 1012). The value of domestically processed mineral-based materi¬als rose 20% to $300 billion (US billion 109). The value of metals produced from US ores rose 40% to more than $10 billion, industrial minerals rose 6%&apos; to $20 billion, and recycled scrap more than doubled to $10 billion. Increasing economic activity stimulated metal prices. Yearly lows and highs were 95 cents and $1.68 for copper, 52 cents, and $1.30 for aluminum, 34 cents and 42 cents for lead, and 43 cents and 75 cents for zinc. A number of mining and metal companies experienced significantly increased profitability. Consumer demand strongly affects mining because the US economy is relatively saturated with long-lived products. Consumer, mortgage, and Federal debt continued to rise. About 246 million US citizens already possess 170 million licensed motor vehicles and 100 million dwelling units. New car production remained at the 1987 level of 7.1 million units. Truck and bus production, however, rose 7% to 4.1 million units. New housing starts fell 7% to 1.5 million units. Imports supplied a significant proportion of total US consumption of several important mineral materials. By year-end, imports of crude and refined petroleum exceeded domestic crude oil production. Such imports cost $42 billion. Imports of nonfuel mineral-based materials were valued at $44 billion and exports at $35 billion. The US and Canada-the world&apos;s two largest trading partners-consummated a historic free trade agreement. In February, President Reagan transferred responsibility for stockpiling strategic and critical materials to the Secretary of Defense. And, in July, the GSA group that bought, stored, rotated, and sold stockpiled materials was transferred to the Defense Department&apos;s Defense Logistics Agency. Concern about apartheid in South Africa continued, resulting in increasing attention to chromium, manganese, platinum-group metals, cobalt, vanadium, and gold. The Defense Production Act, authorizing priorities and allocations, supply expansions, voluntary agreements, and the National Defense Executive Reserve, was amended to include provisions for averting harm to national security from foreign takeovers. The DPAct, in effect through September 1989, is now up for further extension. Under the Act, the US Bureau of Mines maintains the Emergency Minerals Administration. During the year, consultations were held with Canada to strengthen the North American Defense Industrial Base. Coal production, 60% from open pits, rose 5% to 870 Mt (960 million st). Nearly four-fifths was burned to generate 57% of US electricity. Exports included 56 Mt (62 million st) of metallur- gical coal and 29 Mt (32 million st) of steam coal, with a total value of $4 billion. Domestic petroleum produc¬tion fell 2% to 574 hm3 (3.6 billion bbl). Uranium mining, including recovery from phosphates, was unchanged at 5.9 kt (6500 st). Nonfuel minerals Major metals Raw steel production-a major con¬sumer of many minerals-rose 14% to 92 Mt (102 million st). Domestic iron ore production rose 25% to 59 Mt (65 million st), about 96% pelletized. Net imports rose 37% to 16 Mt (18 million st). Raw steelmaking capacity of 102 Mt (112 million st) was unchanged. Voluntary Restraint Agreements with 21 steel exporting nations limited im¬port penetration to about 20% of the domestic market. Domestic producers of bulk ferroal¬loys of chromium, manganese, and sili¬con operated at about 75% of capacity. The US mined no manganese or chro-

Jan 1, 1989

By B B. Du, Y N. Lu, L X. Wang, S L. Wu

The cohesive zone in the blast furnace is largely affected by the softening and melting behaviour of ferrous burden because of its vital role in the blast furnace process. The Visual High Temperature Methodology (VHTM) has been given to study the softening and melting behaviour of sinter, two kinds of lump ores and acid pellet intuitively. Before softening, both two kinds of lump ore swelled and more serious for lump ore B because of its denser structure than lump ore A. The softening and melting temperature intervals are different from one another and this phenomenon contributed to the gas permeability of ore layer in the cohesive zone since the ‘ore window’ has formed. Besides, the softening and melting behaviour of mixed burdens have been studied, where it has been found that the softening and melting characteristics of mixed burden A (consisting of sinter and lump ore A) is better than mixed burden B (consisting of sinter and lump ore B) and mixed burden C (consisting of sinter and acid pellet) despite the poorest characteristics of lump ore A. The reason is that the high temperature interactivity between lump ore A and sinter is much better than lump ore B and acid pellet. The high temperature interactivity is mainly influenced by the chemical compositions, porosity and contact condition. This paper provides a new research method for the softening and melting behaviour of iron ore and an important technical basis for the optimisation of blast furnace burden.CITATION:Wang, L X, Wu, S L, Lu, Y N and Du, B B, 2017. The softening and melting behaviour of single and mixed iron ore burdens, in Proceedings Iron Ore 2017, pp 605–610 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By E. H. Rose

This paper, describing the concentrator practice of the Moctezuma Copper Co., is one of a series being prepared by the Bureau of Mines. The Nacozari concentrator of the Moctezuma Copper Co. (the Mexican subsidiary of the Phelps Dodge Corporation) is located about 75 miles south of Douglas, Ariz., in the Moctezuma District of the State of Sonora. Nacozari is the southern terminus of the Nacozari Railroad, ever which all concentrate is transported to Douglas for smelting.

Jan 1, 1930

By Martin D. Conyac

A 1984 Bureau of Mines investigation identified ho mineral resources in the Wilderness Study Area (WSA). However, four prospects in the WSA contain anomalous amounts of copper and silver minerals; one had traces of gold. Stratabound copper-silver occurrences appear to be prevalent. Quartz veins in the WSA locally contain trace gold, and one mine adjacent to the area produced some gold in the late 1800&apos;s. The WSA is underlain principally by Precambrian and early to middle Paleozoic quartzites, argillites, dolomites and limestones that have been complicated by faulting, generally tilted northeastward, and thrust southeastward over sequences of late Paleozoic sedimentary rocks. The stratabound copper-silver occurrences and gold-quartz veins are in Precambrian and Cambrian rocks in the western part of the WSA, as are similar deposits regionally. Sand and gravel, and limestone are abundant, but plentiful resources of these commodities are nearer established markets. In November 1983 there were 5 small groups of current claims oh the WSA boundary; none are patented claims. Probably less than 35 claims have been located within the WSA, mostly in the northwestern portion; hut over 100 claims have been located outside, near the northwestern boundary. Oil and gas leases nearly surround the boundary and 6 extend up to 1 mile into the study area. There has been no recorded mineral production from within the WSA. From 3 to 5 miles to the west, several lode nines in the Johnnie district have produced several million dollars worth of gold from quartz veins, and some silver and lead from galena-calcite veins. These veins generally trend northeasterly and dip northwesterly and probably do hot extend into the study area.

Jan 1, 1985

By J. A. Finch, Zhenghe Xu

The competitive adsorption of xanthates on sulphide minerals in a binary mineral system (pentlandite and pyrrhotite) was studied using the pseudo-in-situ technique of attenuated total-reflectance FTIR spectroscopy. The minerals were placed in the same collector solutions, either separated by a glass wall or in direct contact with each other before magnetic separation and separate analysis. The effect of mineral interaction on xanthate adsorption was clearly demonstrated spectroscopically for the first time. At low concentrations of xanthate, its adsorption on pentlandite was activated by physical contact with pyrrhotite; the effect may be attributed to the enhancement of electron transfer through electrical contact between the two minerals. The results emphasise the need for caution in extrapolating results obtained from single-mineral studies to flotation practice

Jun 18, 1905

By Vincent Joannes, Marine Lasne, Luca Brenelli, Colin Serridge, Inge van Baardwijk, Martin Stanley, Anthony Fisher, Mary Ellen Bruce, Tony Suckling, Pedro Avellanosa

"Abstract The European Federation of Foundation Contractors (EFFC) and Deep Foundations Institute (DFI) developed a sector-specific carbon accounting methodology and associated “carbon calculator” for foundations and geotechnical works. The EFFC-DFI Carbon Calculator is believed to be one of the construction industry’s first collaboratively produced carbon calculator tools for European and international countries based on verifiable and standardized data. It is intended that the tool be adopted internationally and become the open-source industry standard for ground works. A detailed methodological guide is provided with the calculator (Lemaignan and Wilmotte, 2013). This guide explains the background of the standards, accounting methodologies, emission sources and factors that were used as the bases for the tool development and includes detailed guidance on use of the calculator.Drivers for DevelopmentFoundation contractors anticipate project cost and carbon emissions will become inextricably linked in response to the climbing price of fossil fuels and carbon intensive materials as resources become scarce. Low carbon solutions will therefore become more competitive options. Also with high profile construction projects having low carbon/carbon neutrality as requirements, sustainability in the foundations industry also becomes a market issue.This carbon calculator will be used to lead the industry and shape the expectations of commissioning organisations by providing insight into the carbon cost of their projects. Commissioning organizations are encouraged to be aware of the carbon impact of projects and to also facilitate a fair and accurate way of comparing footprints to provide a level playing field for foundation contractors."

Jan 1, 2014

By S. P. Holt

The Salt Chuck mine is on the east bank of the Salt Chuck, a salt-water inlet at the head of Kasaan Bay, Prince Edward Island, Southeestern Alaska. The deposit was worked at intervals from 1905 until. 1941. Early ship-ments of hand-sorted ore are reported to have assayed about 4 percent copper, 0.15 ounce gold, and 0.15 ounce silver. The total mine production up to 1941 is reported to have been 326,000 tons containing 6,200,000 pounds of copper. During December 1942 the Bureau of Mines cut a 15-foot channel sample on the surface and channel samples from headings on the 300-foot level. In July 1943 a development project was started. Thirteen diamond-drill holes totaling 1,550 linear feet were drilled from underground stations on the 200- foot and 300-foot levels.

Jan 1, 1948

By George L. Richert

The Minas de Matahambre is situated on the north coast of Cuba, in the Province of Pinar del Rio, approximately 150 miles west of Havana. This nine is the only producer of copper in Cuba, and has been worked for the past 15 years. In 1921 the property was affiliated with The American Metal Co., Ltd., and has been worked by them since that time under the direction of Mr. D. D. Homer, General Manager. Extracts from P. D. Wilson&apos;s ?Preliminary report on the geology at Minas de Matahambre? have been freely used in this report.

Jan 1, 1929

By Richard D. Hagni

Although the economically important uranium minerals are difficult to recognize under the ore microscope, they can be identified by a combination of qualitative and quantitative techniques. Useful quantitative techniques include indentation hardness, percent reflectance, spectral reflectance curves, and color coordinates. The latter two properties are especially distinctive for the primary urahlferous minerals uraninite, coffinite, brannerlte, and davidite. Together with the quantitative properties of indentation hardness and reflectance, the character and color of internal reflections are distinctive for many of the secondary uranium minerals. Ore microscopic techniques also provide an excellent means for determining the intergrowths of these minerals with other ore and gangue minerals. Such intergrowths are important to an understanding of the genesis of uranium deposits, and they may be important to uranium extractions.

Jan 1, 1981

By A. H. Onur

Many factors govern the size and shape of an open pit, and these must be properly understood and used in the short and long-term planning of any open pit and quarrying operation. The importance of each factor will depend on the particular project, but the geology, grade, and localization of mineralization, extent of the deposit, topography, property boundaries, production rates, bench height, pit slopes, road grades, mining costs, and cut-off grades are key elements of open pits. This paper discusses the work done on the above parameters in order to provide an optimal production plan for a limestone quarry and clay deposits that provide raw material for a cement factory in Turkey. Soke cement factory has 1 400 000 tons of clinker capacity and is located on the western part of Turkey, in the province of Aydin. It is one of the largest facilities in the cement sector in terms of capacity, and it has a large advantage over facilities because the location of the factory was chosen to obtain the raw materials necessary for cement production within very short distances. However, the old reserves that supplied limestone to the factory had been reported to have run out, and therefore new limestone reserves in the same province have been investigated over the years by experienced geologists. From surface samples, high MgO content was reported in the neighbourhood of limestone formations with high dolomatization; hence, other alternatives were taken into consideration. One alternative with better chemical composition had been found 24 km away from the factory, but the haulage cost of limestone was unacceptable for the factory due to high diesel prices in Turkey. The maximum allowable MgO content in the pre-mix feed to a rotating furnace is 2.5% MgO content in pre-mix from both limestone and clay deposits. The clay deposits belonging to the cement factory have higher MgO content than the limestone deposit, and therefore this quality problem was taken into consideration first, instead of transporting material from 24 km away. This study gives the details of work done to evaluate both the clay and limestone deposits, statistical analysis performed on core samples taken from drill holes, mathematical modelling for both sites, and most importantly of all, in-pit homogenization work that reduced the pre-mix MgO content. As a result of this study, the profitable limestone quantity has been improved in order to serve the cement factory over a projected 25 additional years without using any material from the close deposit.

Jan 1, 2008

By Nick Barton

When the Q-system was launched in 1974, the name referred to rock mass classification, with focus on tunnel and cavern support selection. Besides empirical design of support, the Q-value, or its normalized value Qc, has been found to correlate with seismic P-wave velocity, with deformation modulus, and with deformation. The Q-system provides temporary or permanent support for road, rail, and mine roadway tunnels and for caverns for various uses. It also gives relative cost and time for tunnel construction for a complete range of rock qualities. There are also indications that Q has captured important elements of the cohesive and frictional strength of rock masses, with Qc resembling the product of rock mass cohesion and rock mass friction coefficient.

Jan 5, 2007