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By Peter Amelunxen, Javier del Río, Marcial Medina

El presente documento técnico tiene como objetivo mostrar las mejoras implementadas en la planta de cobre y molibdeno durante los primeros años de operación de Constancia, las cuales permitieron incrementar en forma sostenida los principales indicadores de producción. Se demuestra la optimización de cuatro principales indicadores: troughput, recuperación, disponibilidad y utilización. Los resultados obtenidos hasta el momento, que servirán como guía a nuevos proyectos mineros en construcción o en desarrollo, son el resultado de múltiples iniciativas de mejora y nuevas tecnologías implementadas principalmente en el año 2018.

Sep 20, 2019

A number of impending and actual pit wall failures have been observed and documented, which have been interpreted to initiate on newly generated structural features. This infers failure through intact rock. Failure mechanisms have been postulated resulting from circumferential stress, extensional strain and brittle flexure. These will be discussed in the context of the failures and the associated monitoring. The implications of failure initiating on ?unknown? features has a significant impact for deep open pit mines where designs are based on the expected structural regime. Being able to anticipate such failures is important for design. Equally important is management of such changes as they arise. In this context, monitoring using high resolution microseismic techniques will be discussed as a means of providing early warning of such failures.

Jan 1, 2006

By Nilo Ríos Q

Las inversiones mineras son importantes para renovar y dirigir los recursos de la firma. En ese sentido, las decisiones de asignación de fondos para inversiones, requiere de un análisis exhaustivo que evalúe los riesgos y la probabilidad de no lograr la tasa requerida de retorno de la inversión. Por ello, el presente texto señala una metodología para la evaluación de inversiones mineras en riesgo, a través de una revisión de los criterios de rentabilidad más aceptados y usados en inversiones mineras que enfatiza el criterio probalístico y señala los programas de computación disponibles para computadoras centrales y microcomputadoras.

Nov 8, 1984

By B B. Beamish

Long-hole directional drilling for in-seam exploration was introduced to New Zealand at Huntly West Mine in 1989. Following the success of this initial drilling program the Coal Corporation of New Zealand (CoaICorp) purchased its own drilling equipment and proceeded to adopt the technique with in-housetraining. From July 1991 to September 1992 a total of 15 455 metres was drilled at Huntly West Mine. During this period several modifications were made to the drilling technology to suit the ground conditions. The resulting interpretations of the drill information enabled reliable seam definition to be incorporated in mine planning. Since January 1993, the technique has been transferred to the Huntly East Mine to assist with seam definition for the planned development westwards under the Waikato River. The benefits of this drilling technique to coal mine planning are now well documented in Australia and New Zealand as well as other overseas countries. The possibilities of adapting the long-hole drilling technique to hard rock applications has been illustrated recently with successful cross-measure drilling at Huntly East Mine.

Jan 1, 1993

By T. Hadley, E. Catovic

"Northern Minerals Limited’s (ASX: NTU) flagship project is the Browns Range Rare Earth Project (the Project) located in Western Australia, consisting of a number of deposits with high value, heavy rare earth elements, in particular yttrium, terbium, and dysprosium. The deposits are dominated by xenotime mineralisation, which occurs within hydrothermal silicified and hematitic breccias. The Company delivered an initial JORC compliant resource estimate for the Project at the end of 2012 of 10,500 t of contained total rare earth oxides (TREO), which was increased to 28,084t of contained TREO in October 2013 and further enlarged to 47,997 t of contained TREO in February 2014. Concurrent with the growth of the Project resource base, significant progress has been made in developing the metallurgical process for the beneficiation and extraction of rare earth elements (REE’s) from the xenotime mineralisation. Development of the beneficiation circuit evaluated several process options and selected whole-ore flotation and magnetic separation, followed by flotation (hybrid circuit) as the two preferred flowsheets to pilot, following encouraging results on the bench of 83% and 86% recovery to a 20% TREO mineral concentrate respectively. Several downstream hydrometallurgical extraction flowsheets were evaluated. However, the following two preferred process flowsheets were ultimately selected for further detailed investigation during the prefeasibility study: 1. Sulphation bake, water leach, purification, oxalate precipitation, and/or calcination to produce a mixed RE oxide; 2. Sulphation bake, water leach, phosphate precipitation, caustic conversion, HCl leach, and oxalate precipitation to produce a mixed RE oxalate. Excellent heavy rare earth oxide (HREO) extractions (~ 90%) from beneficiation concentrates were achieved on the bench for both circuits, however flowsheet 1 was ultimately selected as the preferred flowsheet to pilot due to lower capital and operating cost. A mixed rare earth oxalate (42% TREO) or oxide (92% TREO) can be produced with low levels of Th and U of 3 ppm and 6 ppm respectively."

Jan 1, 2014

By S Winter, G Klenowski

During longwall mining in the Bowen Basin, open tension cracks formed by overburden subsidence occur to a height of about 175 m above the mining horizon. Within this zone, water in aquifers or inundated workings will flow into the mine.At the Oaky Creek mines Aquila seam, open cut pits containing pit water overlie German Creek seam longwall panels at a height of about 105 m. The highly saline water is classified as contaminated and cannot be discharged off-site. Because alternative water storage facilities were not available, innovative water management solutions were needed to allow longwall mining to proceed without underground flooding.Computer modelling and underground inflow measurements have been completed to accurately determine inflow rates into longwall mines from overlying water sources at increasing overburden heights. Research work has also included determining cost-effective blanket treatment of final voids and reshaping spoil piles to minimise downward seepage.Ponded water overlying the Aquila low, Grasstree south and A6 pits required remedial works prior to longwall undermining to prevent flooding. In the Aquila low pit it was necessary to partition the pit and remove water overlying longwall 32. Two in-pit bridges were constructed by dozing and track compacting low wall spoil. The final void above the longwall panel was kept dry during undermining. Maximum recorded underground inflow rate was 30.0 L/s.The Grasstree south pit final void, part of the ramp and much of the spoil piles were inundated prior to undermining of 308 panel. A bridge and blanket were required to prevent ponding above the longwall. Maximum recorded inflow during undermining was 23.2 L/s.The pit A6 south final void, which contained dumped, saturated rejects and inundated highwall mining entries was undermined by longwall 36 at the Oaky No 1 underground mine. Because mapping of highwall entries was not available, the maximum calculated inflow rate of 73.0 L/s was based on all design entries being fully inundated. The actual inflow rate during longwall mining ranged up to 20.0 L/s.Water management improvements that have been implemented include greater use of contaminated pit water to wash coal, use of evaporation fans, and installation of a 6 ML/day reverse osmosis plant for water purification.CITATION:Klenowski, G and Winter, S, 2017. Inflows into longwall mines from inundated overlying workings, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 183–190 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By K. N. Panigrahi

India bestowed with 6000km of the coastal belt, contains some of the richest and largest placer deposits with a mixture of heavy minerals like ilmenite, rutile, leucoxene, zircon, monazite, sillimanite and garnet. Each of the minerals is having economic value due to its inherent characteristics for industrial use in fields of paints, metallurgy, refractory, abrasive and so on. The reserves of titanium bearing minerals (ilmenite, leucoxene, and rutile) in the country is around 378 million tonnes. More than 90% of the titanium based minerals produced worldwide are utilised for making value added products in the pigment industries. Approximately 8 million tonnes of monazite reserves are available in the country from which several rare earth elements like cerium, neodymium, lanthanum, yttrium etc. can be extracted for use in several industries. The country contains a deposit of about 20 million tonnes of zircon, which is used in foundries, refractories, ceramics and chemicals. India has a reserve of 107 million tonnes of garnet and 131 million tonnes of sillimanite required for the abrasive and refractory industries respectively. Keeping in view the multifarious uses, the beach sand minerals are being exploited to have the economic growth of the nation. Although the process adopted for the separations are simple, the equipment involved are specially designed because of the nature of the material of construction. Starting from the spirals to magnetic separators, all equipments are manufactured outside India, which is not only costly, but the availability also takes much time for fulfilling the import formalities. Unlike open cast mining, beach sand mining is a environment friendly mining because dredging is implemented to cut and pump the loose sand through a slurry pump causing less damage to the surface topography as both mining and backfilling takes place simultaneously. Therefore all out efforts are made to explore the beach sand placer deposits in an economic manner to emerge as a leader in the global mineral industries.

Jan 1, 2005

By Fernando Altamirano

"En el presente trabajo técnico justificaremos la necesidad de implementar un Centro de Entrenamiento en Emergencias a nivel nacional, se expondrán los objetivos y beneficios, los tópicos de emergencia que se deben considerar de acuerdo la realidad del país, así como la inversión prevista.En el País la cultura de seguridad está en formación, por lo que vamos a esperar ocurran emergencias con mayor frecuencia, y debemos estar preparados para afrontarlas."

Sep 1, 2017

By Américo Pérez

La política ambiental de Centromin Perú S.A. promueve el aprovechamiento de los recursos minerales sin comprometer la capacidad de las futuras generaciones para satisfacer sus necesidades y desarrollo. En ese sentido, los objetivos de la empresa comprenden la protección de la salud y seguridad pública, la prevención del medio ambiente a largo plazo y el uso productivo de las áreas afectadas, retornándolas a su estado inicial. Por ello, el presente trabajo señala los avances en la resolución de los pasivos ambientales de la ex unidad de Casapalca y el Programa de Adecuación Ambiental de la unidad de Morococha, en actual operación.

Sep 13, 2001

The changes in layout and design over 48 years, from the first crushing and shiploading plant installed at Whyalla in 1915, up to the present plant being built at Koolan Island, Yampi Sound may be summarized as follows.1. Smaller motors and lower power consumption have resulted froma. oil lubrication, where practicable, in place of grease,b. a high pressure "oil-lift" device to reduce starting torque in crushers with white metal bearings, andc. roller bearings in place of white metal.2. Short centre drives with pivot-based motors permit controlled loads on bearings and a reduction in size of crusher houses and motor rooms.3. Dust proofing and pressurising of crusher houses and motor rooms reduces working temperatures and improves cleanliness.4. Variable speed pan feeders give improved plant control, with the use of one man only, and remove the need for large surge bins between crushing stages.5. The use of diesel quarry trucks to dump ore through a "drive over"tip results in faster truck cycles.6. Elevated cylindrical silos with air operated chutes, replace long horizontal storage bins with multiple manually operated side discharge chutes for loading rail cars, and give faster and more accurate truck loading. The silos are charged by belt conveyors with automatic distributors.7. Increased shipping bin capacity (40,000 tons at Whyalla and 6O,OOO tons being built at Koolan Island) caters for the bigger vessels now in use and envisaged for the future. Automatic travelling distributors deliver ore to the bins in layers to ensure, maximum mixing and a more uniform grade for blast furnaces.INTRODUCTIONThe Broken Hill Proprietary Company Ltd has six major crushing plants in Australia at its principal sources of raw material. These are at Iron Knob bench G, Iron Knob scree ore plant, Iron Baron, and Cockatoo Island, all of which are ironstone operations. The other two plants are at Rapid Bay, a limestone quarry, and at Ardrossan, which is the Company's only source of dolomite.

Jan 1, 1963

By Barbara Mazzini Loureiro

As placas de circuito impresso (PCI) são materiais heterogêneos e sua composição pode variar em função do ano de fabricação, tecnologia empregada, propósito de utilização, legislações vigentes e país de origem, entre outros. Essas características interferem diretamente no valor econômico agregado a estes resíduos, pois dependem da composição dos mesmos, de tal maneira que as empresas recicladoras tomam como base essas informações no momento da aquisição da sucata. Assim, a classificação e caracterização de PCIs é de suma importância para o mercado de reciclagem de resíduos eletroeletrônicos. A fim de alcançar este objetivo foi realizada cominuição em moinho de facas utilizando grelhas com abertura de 9, 6 e 3mm. A etapa de caracterização incluiu ensaios de digestão em água régia, perda ao fogo, análises química quantitativa por ICP-OES e MEV/EDS. Verificou-se que o lote de PCI estudado possui 39,5% de material cerâmico, 34,5% polimérico e 26 % metálico. A porcentagem em massa de cobre na placa é de 14,28%, de ferro 3,73%, de ouro 0,012% e de estanho 1,29%. O lote não é lead free e é multilayer com quatro camadas de cobre.

Aug 8, 2018

By José Vergara, José Espinoza

El objetivo principal de la técnica de precorte es generar un plano de debilidad que permita disminuir las vibraciones y gases producidos por las voladuras de producción, de modo que la calidad final del talud no sea vea deteriorada. Mientras que los modelos teóricos suponen limitaciones para diseñar la tronadura para el caso de un macizo rocoso fracturado, los modelos numéricos, aun cuando son complejos en su arquitectura, son una gran herramienta para analizar el comportamiento dinámico que se genera dentro del macizo rocoso al momento de desarrollar la detonación de los explosivos. Este trabajo tiene como objetivo mostrar los resultados obtenidos al aplicar programación en elementos finitos con programa Elfen, en diseños de precorte en roca fracturada.

Sep 20, 2019

By Julio Bustamante, Angel Ríos, David Velazco

Antamina es un complejo minero polimetálico que produce concentrados de cobre, zinc, molibdeno, plata y plomo. En Antamina, la perforación de los sondajes diamantinos es realizada por los Socios Estratégicos. Posteriormente, se realiza la descripción de la geología en el área del Core Shack, adonde llegan las cajas de testigos. La información de las leyes está compuesta por análisis de plasma de acoplamiento inductivo (ICP), espectroscopia de absorción atómica (AA) y análisis volumétrico (Volumetría). El trabajo de recopilación de información de los sondajes por parte del equipo de perforación era muy laborioso y rutinario. Para evitar demoras y errores en la visualización y análisis de la trayectoria de los sondajes, se implementó la automatización de la trayectoria de la perforación en tiempo real.

Sep 30, 2022

By Boden A

A procedure was developed for recovering metal values from copper-smelter fume. The fume is first leached to neutrality with dilute sulphuric acid to obtain a solution of zinc sulphate containing a low level of impurities. The tailings from this leach are treated with hydrochloric acid in two stages, in which tin and zinc are quantitatively leached and recovered as a tin concentrate and a zinc sulphatelzinc chloride solution.About 80 per cent of the lead sulphate is converted into lead chloride, which can be recovered as a pure product.Data on the effect of temperature, acid concentration, aeration, and solid/liquid ratios on the hydrochloric acid leach are presented, and the fate of the most important metals during the recovery process is described. Alternative treatments of the tailings from the neutral sulphuric acid leach were briefly investigated.

Jan 1, 1977

By S. Kouniali

Experience with knowledge-based systems for Layout planning and roadway support dimensioning is on hand in European coal mining since 1985. The systems SOUT (support choice and dimensioning, 1989), SOUT 2, PLANANK (planning of bolt-support), EXOS (layout planning diagnosis. 1994), Sout 3 (1995) have been developed in close cooperation by CdF1. INERIS2. EMN3 (France) and RAG 4, DMT5, TH - Aachen6 (Germany); ISLSP (Integrated Software for Layout and support planning) development is in progress (completion scheduled for July 1996). This new software technology in combination with conventional programming systems. numerical models and existing databases turned out to be suited for setting-up an intelligent decision aid for layout and roadway support planning. The system enhances reliability of planning and optimises the safety-to-cost ratio for ? deformation forecast for roadways in seam and surrounding rocks, consideration of the general position of the roadway in the rock mass (zones of increased pressure, position of operating and mined panels). ? support dimensioning ? yielding arches, rigid arches, porch sets, rigid rings, yielding rings and bolting / shotcreting for drifts ? yielding arches, rigid arches and porch sets for roadways in seam ? bolt support for gateroads (assessment of exclusion criteria and calculation of the bolting pattern) ? bolting of face-end zones (feasibility and safety assessment, stability guarantee).

Jan 1, 1996

By M. E. Silva, V. B. Medrano

Los proyectos de Pecoy y Tororume son dos nuevos descubrimientos de sistemas tipo pórfido Cu-Mo, con créditos en oro y plata localizados, en la región Arequipa. Además de los cuerpos intrusivos mineralizados, Granito Porfirítico (Pecoy) y Granodiorita Equigranular (Tororume), se tienen importantes cuerpos de brecha hidrotermal en ambos, principalmente en Pecoy, donde los sondajes ejecutados confirman extensiones verticales en las brechas de hasta 800 metros. La alteración hidrotermal más importante es la potásica con biotita secundaria, a la cual se asocia mayormente la mineralización de sulfuros primarios de cobre y molibdeno.

May 1, 2008

By Max Moya Bendezú

"El presente texto analiza algunos problemas inherentes a la fabricación de barrenos integrales, así como presenta una posible solución a los mismos. Los barrenos de perforación con collarines de jebe no han dado buenos resultados en Morococha. Sin embargo, su implantación en otras áreas de las minas de la compañía, como perforación podrá representar ahorros considerables en este renglón del costo total de producción. La principal causa de falla de los collarines de jebe es el recalentamiento que estos sufren por impacto y vibración al punto que descompone el jebe causando su prematuro deslizamiento. En ese sentido, los collarines de jebe solo son exitososcuando son usados con máquinas más ligeras que las empleadas en el presente experimento o cuando las presiones de aire no sean mayores de 65 o 70 libras por pulgada cuadrada. "

Sep 1, 1968

By I. Trinidad, A. Alván

Este resumen proporciona los resultados de los estudios sobre sedimentología, litogeoquímica y estratigrafía de secuencias realizados en rocas jurásicas del Grupo Yura en Tacna (Puente, Cachíos, Labra, Gramadal y Hualhuani Fms). Los resultados revelan que Puente, Cachíos y Labra Fms consisten en facies de serpenteo fluvial depositadas en entornos de alta sinuosidad, mientras que Hualhuani Fm consiste en trenzar facies fluviales. El apilamiento del Grupo Yura refleja su naturaleza programática y regresiva (meandros al trenzado), siendo clave para comprender su potencial económico mediante la caracterización y predicción de sus facies en el subsuelo.

May 1, 2008

By C. -T. Mutale, A. S. Tuling

Titanium can exist in three different oxidation states. Its oxides are numerous and in presence of iron and oxygen, iron-titanium oxide compounds can also form. Some of the oxides are non-stoichiometric, making the determination of the thermodynamic properties of titanium and its oxides in molten steel and in slag difficult. Therefore, for the assessment of titanium activity in molten steel using the electrochemical measurements of oxygen partial pressure, the identification of oxides in equilibrium with titanium is important. This paper reports on an investigation of solid titanium oxide inclusions, which have been identified by combining different methods of analysis on quenched samples. These samples were taken from a Fe-Ti-melt at 1600°C, quenched in cold water then mounted and polished for optical microscopy. The oxide inclusions were analysed using transmission electron microscopy (TEM) with energy dispersive spectroscopy (EDS). Both single crystal and polycrystalline diffraction patterns were used to identify the oxides by comparing the d spacings with those in the ICDD X-Ray Diffraction (XRD) database. XRD was used to analyse the oxide particles on the top of slow cooled samples. It was found in the TEM study that the similarity of the diffraction patterns of the various phases meant that unique identification was difficult to achieve in some of the diffraction patterns. However, TiO, Ti2O3, Ti3O5, Ti4O7were identified in quenched samples, while TiO2, FeO.TiO2and iron oxides were seen in slow cooled samples. It was also confirmed that the type of oxides is related to titanium content of the samples. Keywords: Titanium, Titanium Oxides, Iron, TEM, XRD, thermodynamic.

Jan 1, 2004

By Brian Fulcher

The Arrowhead Tunnels Project represents the final portion of a 70 km (44-mile) long water conveyance facility that will bring up to 28 m3/sec (1,000 ft 3/sec) of water into Southern California. The 13 km (8-mile) tunnelling project is well underway and consists of two, 5.8 m (19-ft) diameter TBM bores through extremely variable geological conditions. An extensive and essential pre-excavation drilling and grouting program was performed in all reaches of the Arrowhead Tunnels Project, located north of San Bernardino, CA. This program supported the advance of two hybrid hard rock TBMs though extremely challenging ground conditions under substantial ground cover and up to 27 bar (900 ft) of ground water pressure. The well known San Andreas Fault lies nearby and has greatly influenced the local geological conditions. This paper will describe the means, methods and materials used throughout the numerous phases of the pre-excavation grouting program. It will also describe many versatile, flexible and innovative drilling and grouting methods and equipment systems utilized to improve performance, save time and costs in constantly changing geological conditions. Considerable lessons learned have been learned while overcoming some extremely formidable ground conditions and safely advancing the tunnels.

Jan 1, 2008