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By Dharmil Patel, Michael J. Chow

"Construction progress is nearing completion at a Brownfield Site for a 100,000sf mixed-use 10 story building plus cellar for Silver Star Motors including a two-floor pre-owned Mercedes Benz showroom; high-end residential rental studios, 1, 2, and 3 bedroom apartments; and penthouses on the upper two floors. Excavation through impacted soil extended to 15ft depth. Project is approximately 7 ft north of a NYCT subway station, portions of the SOE are within inches of a 6ft diameter NYCDEP Sewer, and cellar extends below the depth of adjacent structures, requiring over 200 lf of underpinning.A complex series of earth retention systems was utilized consisting of underpinning, drilled-in soldier piles (micro-piles), timber/concrete lagging, soil anchors and inclined rakers supported by a partially constructed foundation mat. Foundation mat subgrade was approximately 4 ft below the groundwater level creating more challenges during underpinning and achieving suitable foundation subgrades. All construction was undertaken on a non-union basis.This paper describes the design, construction, and lessons learned for the multiple earth retention systems, Brownfield Remediation requirements, instrumentation, and monitoring used to manage complications of building adjacent to an active subway station, in close proximity to existing utilities, with underpinning and mat foundation installation below the water table.Results of the instrumentation program are summarized which utilized an AMTS, monitoring prisms on adjacent structures, automated seismographs, and manual NYCT surveys."

Jan 1, 2016

By Kenneth P. V. Lei

The Bureau of Mines investigated a silver-catalyzed oxidative procedure for leaching an arsenical copper sulfide concentrate containing 10 pct As and 32 pct Cu_ Currently, there are no environmentally safe means to treat arsenical copper concentrates in the United States. Leaching was conducted in a 2-L autoclave reactor. The effects of catalyst concentration, O2 pressure, temperature, and H2S04, Cu, As, and Fe concentrations in the leaching solution on extractions of metals from the concentrate were determined. The best leaching conditions for extracting 95 pet eu and As and less than 21 pct Fe were 260 g/L concentrate, 0.007 mol/L (1.0 g/L) AgCI, 3.0 mol/L (294 gIL) H2S04, 1000 C, 60 psig 02, and 6 h. Copper as CuS04-5H20 was recovered by crystallization from the pregnant solution. Arsenic, as AS203, was recovered from the copper mother liquor by solvent extraction, with tributyl phosphate, S02 reduction of As5+ to As3+ in the strip solution, and crystallization of the As3+. The silver catalyst was recovered by contacting the leached residue with a brine solution. A conceptual scheme is proposed for treating arsenical copper sulfide concentrates.

Jan 1, 1987

By E. T. Hunter

Surrounded by the 13,000-ft high peaks of the San Juan Mountains in southwestern Colo., the town of Silverton is the site of the extensive development operations initiated 20 months ago by Standard Metals Corp. Appropriately termed the Silverton Project, Standard's operation has now passed the half-way point in its program to reopen two mines that were once sizeable producers of copper, lead, and zinc ores.

Jan 1, 1961

By Dominique Vié

Standards methods covers the procedures for testing deep foundation to determine the force and velocity response to an impact of a pile driving hammer or similar device. The results of analysis generally include an assessment of pile integrity and the value of maximum dynamic stresses. But evaluation of static bearing capacity remains a matter of individual engineering judgment. A new 1D finite elements model has been developed for dynamic stresses and velocity analysis. Following an international benchmark of bearing capacity prediction organised by the Belgium Building Research Institute (BBRI), 12 piles in a site of fissured stiff tertiary clay tested in 1999, and 12 piles in a site of dense sand tested in 2001, comparison are proposed between analysis of dynamic tests and static tests results. A procedure is proposed to take in account the results of dynamic test for evaluation of bearing capacity.

Jan 1, 2002

By Richard T. Stain

"In 2001, a pile trial site was established at Limelette in Belgium consisting of 25 displacement screw piles and 5 driven pre-cast piles. Interested parties were invited to participate in a pile prediction event, whereby they would submit predicted static load test behaviour in the form of load settlement plots. These predictions could be based on soil investigation results supplied by the organizers, or dynamic load test measurements.Following the submission deadline, the organisers released the results of static load tests for comparison.Of all the six participants, including Statnamic, the SIMBAT method was independently accredited with achieving the best predictions.This paper examines at the differences between SIMBAT and other systems, and presents the correlations from the Limelette trial.INTRODUCTIONThe Belgian Building Research Institute (BBRI) initiated an ambitious research programme involving the construction and testing of some 60 trial piles spread between two sites, a clay site at Sint Kateline Waver and a sandy site at the BBRI headquarters at Limelette. The project was financed largely by the Belgian Ministry of Economic affairs. (ref 1.) This paper refers only to the second site.At Limelette, six different types of displacement pile were installed: one driven pre-cast and five cast in place screw piles - Atlas, DeWaal, Fundex, Olivier and Omega. A detailed site investigation was carried out including in-situ and laboratory tests.An international pile capacity prediction event was publicised, participants being invited to predict static pile behaviour. Predictions could be based on:"

Jan 1, 2005

By Ángel Fernández

En Minera Coimolache se generan aproximadamente 700 t de residuos sólidos al año. El 50% de estos corresponde a residuos orgánicos, los que mediante fermentación anaeróbica con microorganismos eficaces son transformados en un plazo muy breve en bioabonos sólidos y líquidos (solución ecológica). Los microrganismos eficaces presentes en estos bioabonos han mejorado notablemente los procesos de siembra, incrementando hasta en un 361% la densidad poblacional de la misma. Por otro lado, dado que la actividad microbiana generada compite por el oxígeno del suelo reduciendo de forma colateral la generación de drenaje ácido de roca (el pH incrementó de 2.02 a 7.55 y se redujeron metales como el Fe, Pb, Cu y Zn), se ha obtenido una solución económica al emplear suelos abonados, como sustituto de la cal, para la cobertura de depósitos en proceso de cierre.

Jul 30, 2018

By Brosnan J. G

Simcoa Operations is the only silicon smelter in the region and since the plant was commissioned in late-1989, has progressed from supplying silicon metal to the secondary aluminium market to the current position of supplying in excess of 90 per cent of its production to the high quality chemical and primary aluminium markets. This position has been achieved through the unique advantage which Simcoa has developed within the industry, namely raw materials, people and Simcoa's ability to adopt and use modern technology. A quality culture was instilled into the workforce prior to commissioning which ultimately led to AS3902 qualification in 1992. Simcoa has continued its quality drive through the formation of 'Simcoa's Quality Leadership Process' which is planned to make Simcoa the best silicon producer in the world.

Jan 1, 1995

The Similkameen mine is located about 100 miles east of Vancouver, British Columbia, and ten miles west of Princeton, where the mine personnel live. Princeton was the first town in the British Columbia interior, originally the home of Cree and Blackfoot Indians and later settled by men of the Hudson's Bay Company, miners, cattlemen, and others looking for gold. After gold, there were coal mines and then copper mines . The Granby Consolidated Mining Company, Limited, operated the Copper Mountain ore bodies from 1926 to 1930 and from 1937 to 1957, mining 34 million tons of about 170 copper ore, mainly from underground. In 1966, Newmont Mining Corporation acquired the Ingerbelle property on the west side of the Similkameen River. Newmont then purchased the assets of Granby and formed Similkameen Mining Company to develop and operate the Ingerbelle and Copper Mountain ore bodies on both sides of the Similkameen River canyon. The Ingerbelle and Copper Mountain ore bodies lie within rocks composed of andesite tuffs, agglomerates, and argillites. Chalcopyrite mineralization occurs as a dissemination. Original ore reserves were estimated at approximately 75 million tons grading 0.52% copper. Mining is carried out on a three-shift, seven-day-week schedule at a rate of about 60,000 tons of ore and waste per day with four 10 cu yd P & H 1900 shovels which mine and load a fleet of 100-ton Lectra Haul trucks. Among the unique features of the design and construction of the Similkameen project was the construction of 4. 5 miles (7. 24 km) of new Trans-Provincial No. 3 highway by the company to the specifications of the British Columbia Department of Highways. The old highway traversed the Ingerbelle pit area. Along the relocated highway is a 4, 000 ft (1219 m) long berm which conceals the mine pit. This area has been replanted and now looks like the original forest scenery. Another interesting feature is that the tailings from the concentrator flow by gravity over a 1000 ft (34% m) suspension bridge, which crosses the Similkameen River canyon then passes through a tunnel to the dam site, a distance of 59,000 ft (17,980 m) to the cyclone station. When the Copper Mountain ore bodies are mined, the ore will be transported by belt conveyor on a second suspension bridge across the canyon to the Ingerbelle concentrator. After being loaded by the shovels into the 100-ton trucks, the ore is

Jan 1, 1978

By Julian Wills

The Candrill was developed with Soredem as a one-operator rockdrill for Canadian narrow vein mining. It provides the benefits of increased drilling rates, lower noise and vibration, mass reduction of 20% and system cost saving. The Candrill is to be commercialised at the end of 2001 together with a stoper drill through Parts Headquarters, Novatek's Canadian agent. The Candrill or pneumatic drills may be further exploited using a simple mechanised drilling system to further reduce operator labour, improve drilling speeds by up to 50% and to enhance drilling accuracy. Novatek's drilling system for simple mechanisation in gold and platinum mines is integrated with roof supports, can operate in stope widths as low as 800 mm and has resulted in labour savings of 50%, improved advances per blast of 20 to 50% and improved operator safety and ergonomics.

Oct 1, 2001

By T. W. Camm

The Bureau of Mines conducts studies of the economic impacts of regulations on federal lands. These studies are part of the Bureau Potential Supply Analysis (PSA) program. To meet the needs of these studies, a methodology was developed to estimate operating and capital costs for a mineral deposit given its tonnage, grade, and depth. The format for the cost models in this study was developed at the Bureau's Western Field Operations Center (WFOC), Spokane, W. A., for studies of known and undiscovered resources on Federal lands. These cost models are described in a Bureau publication by Camm (1991).

Jan 1, 1993

By E Beltran, S Ngunz, F Orrante, F van Zyl, M Westcott

"The primary control objective of the project is to achieve milling optimisation by ensuring that the energy available for rock breakage is used as efficiently as possible. This is achieved by increasing the level of mill filing until a process constraint is reached. Stable operation against this limiting constraint is then maintained to ensure long-term optimised operation.Semi-autogenous grinding (SAG) mill control optimisation presents a number of challenges. SAG mills have multiple inputs that are used to control multiple outputs (MIMO process). Secondly, the SAG mill loading process is a ‘high inertia’ process that can be approximated as an integrating process. This means that it is open-loop unstable. The hybrid control strategy presented implements an advanced ‘load stabiliser’, which transforms this integrator process into a more manageable first order process, which can be steered stably against the constraints. This SGS hybrid Expert control strategy implemented on both SAG mills at the Porgera concentrator therefore consists of two integrated parts responsible for:stabilising the mill load to a targetdriving the mill load target to the maximum determined by the process constraints (eg maximum power draw) to maximise efficiency and throughput. A comparative study is done between the operation of the plant for a period of a month before and a month after the implementation of this strategy. The results indicated a significant improvement in the SAG mills’ stability and operation as well as a reduction of overload situations leading to a loss of throughput.Citation:Ngunz, S, van Zyl, F, Orrante, F, Beltran, E, Westcott, M and Wilson, S, 2016. Simplified Hybrid Semi-autogenous Grinding Mill Control - Explanation and Practical Results at the Porgera Concentrator, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 313–320 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By Hubert Law, Dan A. Brown, Kyle M. Rollins

"Soil mixing and jet grouting provide a means to significantly increase the lateral resistance of pile group foundations with relatively little investment of time, effort, and expense compared to the cost for additional piles necessary to produce the same increased resistance. Comparative field testing conducted on full-scale pile groups before and after treatment of small soil volumes showed significant improvement in lateral resistance. The lateral resistance of the pile group increased by 60% due to soil mixing and by 180% due to jet grouting. To provide additional understanding regarding the influence of the soil mix strength, depth of improvement and width of improvement, a series of parametric studies were performed using a 3D finite element model. This set of “virtual load tests” was then combined with the results from the actual field tests to help develop a simplified model to account for observed behavior. In general, the testing and analysis indicate the pile group and the surrounding improved soil block generally act as an equivalent “super pile”. The passive force, side shear and base shear on the improved soil surrounding the pile group itself increased lateral resistance. This increase in resistance from the soil block can be added to the lateral resistance of the pile group.INTRODUCTIONThe lateral resistance of pile groups is often critical to the design of bridges and high-rise structures subject to seismic, wind, wave and landslide forces. Typically, when analyses indicate that the lateral resistance of a foundation is inadequate, additional piles, drilled shafts or micro-piles are added to increase the lateral resistance. Furthermore, an expanded pile cap or connecting beam is often required to structurally connect the new piles to the existing pile group. While this approach provides the required lateral resistance, it may also be relatively expensive and time consuming. An alternative approach is to use soil improvement techniques to increase the strength and stiffness of the surrounding soil and thereby increase the lateral resistance of the pile group. The improved zone could potentially be relatively shallow because the lateral resistance of piles is typically transferred within 5 to 10 pile diameters. For example, the soil around the periphery of the foundation could be relatively easily improved for an existing foundation as illustrated in Fig. 1(a) using a variety of soil improvement techniques. Alternatively, the soil under the foundation could be improved for a new foundation or even for an existing foundation with a technique such as jet grouting (see Fig. 1(b)). Improving the soil under the foundation would have the potential for producing greater increases in lateral resistance because the improvement would reach interior piles. In addition, the process of creating a cemented “soilcrete” zone around pile foundations could potentially produce a zone which would behave like a reinforced “superpile” with increased structural stiffness."

Jan 1, 2015

By Amanda R. Parry, Chris R. Pray

Predicting and modeling the soil structure interaction of laterally loaded piles with significant unbraced lengths is one of the challenges faced in designing many waterfront structures. Designers often rely on pile specific design software to calculate forces in an embedded pile and then couple that with either a structural design software to capture the behavior of the rest of the structure or use potentially overly conservative assumptions to omit modelling the piles entirely. Given that some projects have hundreds of piles coupled with hundreds of loading conditions, the shuttling of results from the structural analysis software into the pile analysis software can become cumbersome, difficult to track and manage, and prone to user input errors. An alternative approach recently used on two large marine infrastructure projects consisted of calibrating a structural analysis software to replicate the resultant outputs from a software developed specifically for pile analysis. This calibration was done using thoughtfully placed springs along a pile modeled in the structural analysis software to replicate the soil-structure interaction of the piles. The focus of this paper will be on the methodology used to calibrate the two software programs and an evaluation of the results which showed close agreement. Based on the two case studies, calibrating a generic finite element analysis software via this method should be considered as a reasonable and time saving design approach for pile-supported structures.

Sep 8, 2021

By C Young

The identification of Critical Risks, their associated Critical Controls, and the implementation of processes to ensure their ongoing management can be difficult and resource intensive. Answering the following Critical Risk Management related questions can be challenging: • What is a Critical Risk? • What is a Bow-tie Analysis and when should it be used? • What is Critical Control? • How is the effectiveness of a Critical Control assured, and how is this measured? • Who is responsible for managing Critical Controls? • What are the implications if a Critical Control is not effective? It appears that in the mining industry’s efforts to implement the Critical Control Management Process outlined by the International Council on Mining and Metals (ICMM), instead of embedding an integrated, well understood, value adding process, we have instead created a resource hungry monster that is poorly understood by numerous layers of the organisation.

May 5, 2022

By P Paredes, T Leaño, D Gajardo, C Tramón, S Peñaloza

The definition of an ore handling system and its consequent layout design is of crucial importance in cave mining projects. It not only represents the main driver in the production capacity and reliability of the mining system, it is also a fundamental variable in the footprint’s development time and cost.In recent decades, load-haul-dump (LHD) tramming distance optimisation through the allocation of several orepasses inside the footprint has been the most common practice in ore handling system layout definition at Codelco’s operations. Today, the improvement of existing technology, such as higher-capacity LHDs and jaw-gyratory crushers, and intensive preconditioning techniques to improve fragmentation allow the conceptualisation of simple and highly productive ore handling system layouts for wide caving areas that avoid the complexity and high cost of developing numerous orepasses inside the footprint.The initial macroblocks of the Chuquicamata underground mine project (PMCHS) consider an ore handling system layout in which LHDs dump into orepasses located inside the footprint area. The ore is then transferred into crusher chambers located below the production level, where it is crushed by jaw crushers and then conveyed to surface. In an effort to reduce development time and costs, a new ore handling system layout for the PMCHS experimental macroblocks was engineered using improved technologies and techniques in a simpler mining system. This paper compares the new ore handling system layout for the project’s experimental macroblocks with the traditional LHD-orepass layout in terms of production capacity, reliability, development time and cost.CITATION:Paredes, P, Gajardo, D, Leaño, T, Peñaloza, S and Tramón, C, 2016. Simplifying the ore handling system through the use of current technology at Chuquicamata underground mine project, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 571–584 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By G Williams

Discussing equipment, systems of work, the need for updated programmes of local seismic exploration, and developments within the South Wales coalfield.

Jan 1, 1993

By D. R. Nagaraj

Secondary Ion Mass Spectroscopy (SIMS) was used to study copper ion adsorption, and its effect on subsequent sulfide collector adsorption, on pyrite and pyroxene minerals under flotation related conditions. Copper was found to adsorb on both of these minerals and cause enhanced sulfide collector adsorption. The distribution and depth profile of copper and collector on these mineral surfaces were obtained by using SIMS in the imaging mode. The results of this study have provided a valuable insight to understanding pyrite and gangue flotation observed frequently in operating plants.

Jan 1, 1995

By D. Brady

The need for onsite gas monitoring during, or following, a major incident at an underground coal mine has long been recognised. Recommendations from inquiries following Queensland mine disasters have included ?qualified persons and equipment for rapid analysis of gas samples be available in times of emergency? and that ?this may be accomplished by either mobile laboratories or laboratories established in each mining locality.? Following the Moura No. 2 disaster, the Queensland Government allocated funds to Simtars for a mobile laboratory to respond should such a disaster occur again in the future. This vehicle was commissioned in 1997 and has been used at many mine sites under a wide range of scenarios. Simtars, armed with over ten years of operational experience with this mobile laboratory, has taken an active role in the design and construction of a modernised replacement unit. With a twenty point tube bundle system and ultrafast gas chromatograph the result is, arguably, the best equipped mobile gas analysis laboratory for mine emergency response in the world. This paper outlines the features of the new laboratory, its capabilities and the philosophy behind the design and inclusions.

Jan 1, 2012

By Víctor Cobeña

El presente trabajo señala el desarrollo de la simulación de disparos por computadora -en tanto está diseñado para solucionar problemas de voladuras en las minas, canteras y obras civiles. El programa elimina el costo invertido en los métodos convencionales de "ensayo y error" de pruebas de campo y optimiza las operaciones de voladuras.

Jan 1, 1987

By J. D. Miller, C. L. Lin, J. Dong

Nano clay mineral particles such as kaolinite — with primary particles typically smaller than 2 μm in size — can cause significant problems in flotation processes and tailings disposal, including the processing of Florida phosphate rock and Canadian oil sands. In this study, the consolidated state of flocculated kaolinite sediment was examined, and high-resolution X-ray microtomography (HRXMT) was applied to describe the structure of the consolidated sediment. Using this tomographic information, the complex geometry of the channel network structure for the consolidated flocs was established for the first time. With the establishment of the experimental channel network structure, permeabilities were estimated by flow simulation using the Lattice Boltzmann method. Results for kaolinite sediment with and without polymer are compared and discussed. Results for flocculated kaolinite sediment in a gravitational field are also presented and discussed. The results show that as polymer dosage increases, the permeability of flocculated kaolinite sediment increases, and as suspension pH increases, the permeability of flocculated kaolinite sediment decreases.