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By P. A. Dimas

A new family of sulfide flotation collectors has been developed in our laboratory. These formulations are comprised of novel renewable materials combined with conventional reagents. The resulting diversity permits tunability of collector chemistry to meet a range of flotation problems. Several attributes of the new collectors are presented.

Jan 1, 2012

By Larry Schneider

I n the simplest application of a shock tube initiation system, the tubing acts as a “relay line” which passes a detonation signal from borehole to borehole. When the signal arrives at each borehole, it causes the detonator attached to it to fire. Such a single path constitutes a progressive series where each unit must function properly in order to activate the following units. Any application error, malfunction, or mistake in connecting any surface unit will stop the progression of the detonation signal through the system and result in a “cutoff” or misfire of the following charges.

Jan 1, 1995

By Tainan Ferreira Muniz

Visando atender à demanda de materiais de engenharia que apresentem elevada resistência ao desgaste sem prejudicar sua ductilidade, o presente artigo objetivou avaliar a influência dos tempos de cementação em meio sólido nas propriedades mecânicas de um aço baixo carbono submetido ao tratamento. Adotou-se diferentes tempos de estágio, a saber 6h, 11h e 24h, fixando-se a temperatura a 900ºC. Além disso, a fim de verificar a validade dos experimentos e compará-los às previsões teóricas, estimou-se, pela Lei de Fick, a profundidade da camada cementada. Métodos mais práticos, como a elaboração de perfis de dureza e a análise de microestruturas, reafirmaram as previsões e indicaram que a profundidade da camada cementada aumenta com o tempo de exposição das amostras à atmosfera adequada.

Oct 30, 2017

By P. Falcão Neves

A detailed analysis of the geomechanical behaviour in rock cutting with a diamond saw is provided to obtain a better understanding of the mechanisms involved in the process. The energy of elastic deformation (before failure) and plastic deformation (post failure) was determined in uniaxial compression tests as well as the energy consumed per unit volume in the cutting process. The test samples are White and Ruivina marbles from Borba - Vila Viçosa in Portugal. Correlations between total deformation specific energy and cutting specific energy, normal and tangential forces and diamond indentation are analysed, and some conclusions are presented.

Jan 1, 2012

By Ben E. Lindsly

The study of "bottom-hole' samples follow,-is in natural sequence the study of samples3 obtained under high pressures at the well heads of flowing wells. The principal object of this phase of gas-solubility research, started actively in January, 1530, was to gain a more accurate knowledge of the physical and chemical characteristics of the oil-gas mixtures that exist in natural reservoirs. In possession of actual data regarding the condition of the oil; the quantity of gas liberated from solution upon dimunition of pressure; and the relative volumetric proportions of gas to oil at various pressures throughout the flow string in a well, it should be possible to predict, with a fair degree of accuracy, what physical changes these mixtures would undergo throughout the life of a pool. Such information not only is important in designing flow strings in flowing wells but is important also in solving problems relating to pumping efficiency and the power required for pumping. Although certain fundamental rata Mere obtained in the stud of samples taken at the well head, "bottom-hole" samples are more representative of subsurface mixtures of oil and gas because they are obtained at reservoir temperatures, and before the oil has had the opportunity of intermingling with extraneous gas; that is, gas which either was not in solution originally, or which was liberated from solution at some higher pressure, and later became mired with the original undissolved gas.

Jan 1, 1933

By Yoshio Mitarai, Takeshi Nagatome, Yosuke Tanaka

"This paper describes an application of lightweight soil in a deep water area to stabilize an existing quay wall at the Port of Tokyo. Super Geo Material, abbreviated SGM, is a type of lightweight soil, which consists of dredged cohesive soil, cement and air foam, and is applied in coastal development work, such as port and airport construction. This paper reports a SGM construction project at the Port of Tokyo by using a SGM special plant vessel, which was deployed for the Tokyo International Airport (TIA) Expansion Project in order to achieve large-scale and rapid construction. The key issue in SGM construction is quality control. One key quality issue is control of the mix proportion of SGM in consideration of volumetric changes due to air foam-breaking during pumping and air foam shrinkage due to water pressure when SGM is placed in deep water. A smart technique for placing SGM is also necessary to prevent quality deterioration when SGM is placed in deep water, for example, increased bulk density and decreased shear strength due to water absorption. This paper introduces an actual case of SGM construction with a particular focus on quality control of SGM during construction.INTRODUCTIONSuper Geo Material, abbreviated SGM, is a lightweight stabilized soil which is used in coastal development work in Japan (CDIT 2008). SGM is applied as a backfilling material behind existing quaywalls or above underground structures in order to reduce earth pressure on the existing structure and improve seismic resistance. SGM has been applied in many coastal development projects. In particular, SGM was used at the Tokyo International Airport (TIA) Expansion Project (Haneda Airport) as the backfilling material at a quay wall at the joint between the reclaimed area and pier part in a new runway (Nagatome et al. 2010a & 2010b, Yamatoya et al. 2010, Mitarai et al. 2011). In this project, large-scale and rapid SGM construction was implemented by the special SGM plant vessels within 6 months under the condition of limited construction period.This paper introduces a new SGM construction project at the Port of Tokyo in 2011. This project employed the special SGM plant vessel, “Ryujin Mark II”, to achieve large-scale and rapid construction within a limited period. SGM was also placed in a deep water zone at the maximum water depth of approximately 15 m. Thus, quality control of SGM was a key issue for meeting project requirements. This paper describes the actual SGM construction in the Tokyo Bay area and quality control techniques for SGM, considering volume changes due to pumping and placement below water."

Jan 1, 2015

By M. H. Moys, J. A. Finch, A. R. Laplante

"A detailed review of ball milling circuit control practices in industry has been carried out. Based on fundamental process performance objectives, a standard system for base-level control of most ball mill installations is presented. This system is simple, inexpensive, and provides the major economic benefits available from contemporary automatic control technology.Value Analysis of Grinding OperationsValue analysis (or engineering, or management), originally developed by Lawrence D. Miles of the General Electric Company (1), focuses on the identification of value (product or process worth versus cost) and provides a systematic procedure for its improvement. A recent research and development project involving the application of the principles of value engineering to grinding operations has provided a basic technoeconomic model of grinding processes (2). The functional objectives of the ball milling process and the means to achieve value based grinding circuit control originate from this study.The Need for Grinding Circuit ControlThe economic effectiveness of a process is determined by the quality or value of the product and the related processing costs. If the inputs (both the raw feed and the applied processing work) are absolutely constant, the product characteristics and the process efficiency will be determined only by the engineering design. The need for and degree of process control is therefore determined by the nature of variations or upsets in the process inputs, and the extent to which these effect product value and operating costs."

Jan 1, 1988

By Clinton C. Knox

To demonstrate the feasibility of unwatering ore reserves previously indicated in the virgin Melrose zinc-lead field in Kansas and Oklahoma, the Bureau of Mines .carried through a pumping project on the Park Walton farm in 1943. Due to success of the undertaking, attention was turned to exploration of other indicated ore deposits and promising areas within that part of the field benefited by .the drainage project, By the middle of 1946, four private mining companies were active in the field; and a considerable output of lead and zinc concentrate had been obtained from the new Park Walton mine and mill. The Park Walton Ore deposit was unwatered by installing deep-well pumps in three holes previously drilled by the lessee. Pumping was continued by the Bureau of Mines at a rate of 2,500 to 1,000 g.p.m. for about 6 months; during this time the local static artesian water-level, originally averaging 108 feet below the surface in the old drill holes was lowered to the 316-foot level, which justified beginning the initial shaft sinking and mine developments. In all, about 750,000,000 gallons of water was pumped by the Bureau of Mines at an operating cost averaging $0.024 per 1,000 gallons.

Jan 1, 1948

The University of New South Wales (UNSW Australia) has been a world leader in the development of innovative virtual reality technologies over the last 15 years. AVIE (Advanced Visualisation and Interactive Environment) was developed by iCinema as a collaborative venture between UNSW?s Faculties of Engineering and the College of Fine Arts. This is the world?s first 360°-surround, virtual reality (VR) stereo projection theatre system. The School of Mining Engineering at UNSW Australia has developed 18 different virtual reality modules aimed at mine safety training and mining engineering education. These modules are being regularly used in both the mining industry and the university. The School of Mining Engineering is continuously involved in the development of different modules. Research is also currently being conducted on the implementation of other technologies into this environment. Artificial intelligence (AI) and fuzzy logic are tools that the authors would like to consider implementing in future module development. This paper will review current research in both these areas and consider options for applying these technologies.

Jan 1, 2014

By Y. Obara, A. Sato

"Limestone is one of the most important mineral resources, and in Japan it is only one mineral which can be fully supplied by the domestic product. Generally limestone mines in Japan located at mountainous regions, and the combination between bench-cut method and the carry-out system using vertical shaft is widely used in the domestic mines. During mining operations, the occurrence of the blockage in the vertical shafts is very serious problem. Once the blockage in the shafts is occurred, a lot of works and dangerous procedures are necessary to solve the problems. It is thought that blockage is influenced by the cohesion and friction coefficient due to clay minerals thrown into the vertical shafts, however, the quantitative and precise reason is not revealed yet.In this study, the process of blockage occurrence was simulated by 2-Dimensional Discrete Element Method (DEM). In the 2D-DEM analysis, discontinuous circular particles are generated, and the individual movement of each particle is calculated by forward difference method. In the analysis, several typical ore distributions are applied, and the DEM analysis was conducted under the various combinations of cohesion and friction coefficient. From analytical results, it was found that the friction coefficient strongly influences to the occurrence of blockage and there were a threshold values which blockage does not occur. Several kinds of shaft shape were also simulated towards different ore size distributions, and those influences to the blockage occurrence were also discussed."

Jan 1, 2015

By E. Viljamaa

In this research, earlier developed information integration method and novel web technologies are applied to intensify infrastructure construction process control. The applied method uses semantic methods to integrate scattered information that is later on exploited by process management using state-of-the-art web technologies. The applied method and web technologies not only improve the process management situation awareness by integrated up-todate multi-source process data but also provide platform independent access and visualization tool for process data. Utilization of such technologies potentially lead on cost savings, make processes safer and also more environmentally friendly. The integration method also enables intelligent queries to the integrated data making possible to use machine based inferring to the data.

Aug 1, 2013

By J. D. T. Steyl, C. A. Biley

"The chemistry of electrolyte systems containing iron remains generally poorly understood despite their prevalence in many natural and industrial processes, particularly in hydrometallurgy. These systems are typically challenging to study and model due to their affinity for complex formation and precipitation even at low pH. Recent developments in the hydrometallurgical processing of nickel laterites at Anglo American have called for a deeper understanding of the fundamental chemistry of the Fe2(SO4)3–FeSO4–H2SO4–H2O system. This paper details the development of an internally consistent, Pitzer ion-interaction model of this system, with explicit recognition of important contact ion pairs (CIPs). The primary application of this model is a thermodynamic framework for the interpretation of kinetic processes occurring during iron(III) reduction with SO2. Adopting a rigorous thermodynamic basis for the system chemistry facilitates the formulation of simple rate expressions that are capable of inherently capturing complex effects. While the iron(III) reduction case study remains the focus of this work, the developments have more universal applications and the thermodynamic speciation model can be extended into other systems containing acidic ferric sulfate.INTRODUCTIONIron is present in nearly all hydrometallurgical refining circuits typically as both a necessary and unwanted impurity and needs to be removed and disposed in a safe and efficient manner. This is generally performed by precipitation to form a range of solids such as hematite, goethite or jarosite. Numerous studies in the open literature have focussed on the removal of iron from refractory gold sulfide ore (Berezowsky & Weir, 1989; Berezowsky et al., 1991) and zinc pressure leaching (Buban, 1999; Ismael, 2003), and PGM matte sulfide circuits (Dutrizac & Monhemius, 1986). Moreover, since ferric iron is a strong oxidizing agent, it has been used extensively as a leaching agent for sulfide minerals (Dreisinger, 2006). Given the outlook of challenging economic conditions, declining ore grades and increasing levels of impurities, effective iron management is going to become increasingly critical to all hydrometallurgical processes.Against this background, and considering the widespread importance of acidic iron sulfate systems throughout natural and industrial processes, it is unexpected that the knowledge of the fundamental solution chemistry of these systems contains such significant gaps, particularly at the conditions typically found in hydrometallurgical applications. Existing literature describing the measurement and modelling of solution speciation in these systems have highlighted their significant chemical complexity (Magini & Caminiti, 1977; Magini, 1979; Lee & Tavlarides, 1985; Stipp, 1990; Papangelakis et al., 1994; Gil et al., 1995; Majzlan & Myneni, 2005; Kormanyos et al., 2008; Yue et al., 2014). Partially responsible for the lack of quantitative speciation measurements is the strong tendency of ferric to hydrolyse at even low pH (Flynn, 1984), complicating the laboratory study of such systems. Moreover, the large number of aqueous species that may co-exist simultaneously makes the study of individual species and the modelling of the numerous interactions between these species extremely difficult (Dry & Bryson, 1988; Stipp, 1990; Majzlan & Myeni, 2005; Kobylin et al., 2007)."

Jan 1, 2016

By Garry Keizer

The Cortez gold mine is located in Lander County, NR, about 130 km (80 miles) southwest of Elko. Cortez Gold Mines (CGM) is a joint venture between Placer Dome US Inc. (60% operator) and Kennecott Corp. (40%). The claims that supply oxide and refractory ore feed to the Cortez milling facility are located in both Lander and Eureka counties. These include the Cortez and Horse Canyon deposits, all operated by the joint venture. Other deposits outside the CGM claim area include Fire Creek, Buckhorn, Gold Bar and Tonkin Springs. These deposits all occur along the Battle Mountain-Eureka Trend. History Mining in the Cortez district began in 1862 with the discovery of high-grade silver ores. Grades in the hundreds of ounces per ton occurred in an area 7 km (4.5 miles) southeast of the current CGM mill site. Underground mining through the Garrison and Arctic tunnels provided the bulk of the ore production between 1864 and 1895. To a lesser extent, the Mill Canyon area also supplied ore until 1930.

Jan 1, 1993

By Javier Támara

Para aumentar la productividad de la empresa minera es necesario conocer el sistema de aire -en tanto se prioriza los intereses de los clientes, y así se puede suplir todos los componentes necesarios para garantizar una máxima eficiencia y confiabilidad del sistema completo de aire comprimido que va desde el filtro de admisión hasta el punto de uso. En ese sentido, el presente texto describe las estrategias para realizar Solucionazing en ahorro energético y así aumentar la produtividad de los sistemas de aire.

Aug 25, 2002

By D. M. Ziebarth

"Normal sequence of operations to develop a new underground mine is: construct and outfit headframe for shaft sinking, sink shaft, construct and outfit shaft sump, develop shaft station and shaft bottom steel. In an effort to reduce the overall project schedule, an innovative plan was developed to install service shaft steel below station level, prior to the completion of the shaft sinking effort. To better evaluate the construction of this substantial steel tower, a preliminary constructability evaluation was conducted, including the best method of supporting the main tower; from the bottom, middle or top of the tower. The design criteria and plan involved: •,Develop access from existing service shaft, 25 km underground •,Use of materials to maximize strength while minimizing corrosion exposure •,Estimating the location of the shaft centerline •,Over excavating the station and shaft below station to allow future shaft steel repositioning •,Designing the tower steel for modular installation •,Incorporate commissioning considerations, such as suspension of the cheese weights during steel installation •,Provision for covered stair access to shaft bottom •,Enclosed shaft envelope with open panels to allow visibility and ventilation The design approach was innovative and this paper will describe the design principles and challenges encountered while providing insight into the solutions developed and implemented; especially the modular construction and installation methodology. INTRODUCTION In an effort to expand the mining operations, a plan was developed to construct a new service shaft closer to the new mine workings and convert the existing service shaft to a production shaft at the Potash Corporation of Saskatchewan Inc. (PCS now Nutrien) Rocanville Potash mine in southeast Saskatchewan. The new service shaft required a multi roped friction hoist operating a cage / counterweight, rope guided conveyances to support the operational requirements. The service shaft is an integral part of the mining infrastructure as it provides access to the underground workings, transport personnel and materials underground for operation and maintenance of the mine. The shaft also allows for services required for safe operation of the underground mine, power supply, controls, communication, dewatering and fresh water supply."

Jan 1, 2019

By W. L. Zeigler

This paper describing the milling practice of the Hecla Mining Co. is one of a series being prepared by the United States Bureau of Mines. The concentrator of the Hecla Mining Co., which utilizes combined gravity and flotation methods, is located at Gem, Shoshone County, Idaho, about 2 miles south of the Hecla mine at Burke. It has a maximum capacity of 900 tons per day and all ore treated is drawn from the company's Hecla mine. Milling ore for 1910 contained 9.7 per cent of lead, 1.2 per cent of zinc, and 4.77 ounces of silver per ton.

Jan 1, 1932

By A. Kale

A chlorination pilot plant having capacity to produce 5?10 kg/hr of titanium tetrachloride is in operation at the chlorination facility in Mintek. The bubbling fluid bed chlorination plant can be operated in batch and/or continuous process to study the chlorination kinetics of various feedstocks. The chlorination of titaniferrous ores to produce titanium tetrachloride (TiCl4) was carried out during the commissioning of the pilot plant and also as part of the titanium programme carried out at Mintek. TiCl4 is a basic raw material for producing commercial titanium dioxide pigment and titanium metal. This paper discusses the challenges faced during the commissioning and operation of the chlorination pilot plant. It also discusses the effect on the auxiliary facilities and instrumentation as a result of the harsh operating conditions of +1000°C and use of corrosive gases like chlorine and titanium tetrachloride. It discusses the effect of physico-chemical properties of the titanium tetrachloride and iron chlorides. The effect on the chlorinator refractory lining due to heating and cooling of the chlorinator is also discussed. Besides the special provisions made during the design of the chlorinator, this paper also discusses the operational experience and possible solutions to be implemented in future. Keywords Fluid bed chlorination, titanium ore chlorination, titanium tetrachloride (TiCl4) production using fluid bed technology.

Jan 1, 2011

By Timothy L. Roberts

For many years practicing geotechnical and structural engineers in Texas and Louisiana were reluctant to include augered cast-in-place (ACIP) piles as a viable deep foundation alternate. Three primary concerns were the lack of a final driving resistance to confirm adequate capacity, the inability to inspect ACIP piles prior to installation, and the fact that pile integrity is highly dependent on the skill of the ACIP pile contractor's field personnel. The Deep Foundations Institute (DFI) Committee on Augered Cast-In-Place Piles has responded to these quality control concerns by establishing standards of practice for ACIP pile installation and ACIP pile inspection. Regional areas of the country have different subsurface soil and rock conditions and many times this will influence local installation and inspection requirements. The best way structural and geotechnical engineers can address quality control concerns is to be familiar with the DFI standards of practice, to know the special requirements for a particular project site, and to incorporate them into a well-written ACIP pile specification. The purposes of this paper are to: 1) review the main fundamentals of a successful quality control program, 2) describe how these fundamentals can be applied to the installation of ACIP piles, and 3) add personal experiences from ACIP pile projects in Texas and Louisiana. Nondestructive test methods are frequently used as a quality control tool to evaluate questionable piles. An additional brief discussion of two nondestructive test methods is presented to complete the paper.

Jan 1, 1998

East Otago gold deposits are hosted in Otago Schist that is the metamorphosed equivalent of Permian-Triassic Torlesse terrane greywackes. Relatively undeformed Torlesse sequences in Canterbury have <l m - 50 m bedding, with c. 500 m - l km and c. three kilometre scale units, typically either: 1) thick-bedded, massive, sandstones; 2) thin-bedded sandstone-argillite flysch; or 3) siltstone- or argillite-dominated units. Such lithological layering in Otago was intensely folded, deformed, and overprinted by metamorphic fabrics during Jurassic-Cretaceous regional metamorphism. Although primary sedimentary structures can no longer be recognised, a æghostÆ lithological variation is still present in Otago represented by psammitic (sand-derived), interlayered (sandstone-siltstone derived) and pelitic (siltstone-mudstone derived) schist. Lithological æunitsÆ in the schist are typically either 20 100 m or c.1 - 2 km thick, and are oblique to faults and shears hosting gold mineralisation at Macraes, Barewood, Nenthom, and Oturehua. Lithological variations and folds in lithological units are important in the along-strike distribution of gold in these deposits, and in the development of relatively high-grade pods and shoots at l00 m - 1.5 km scales. Ramps, flats and step-overs (known to be locally important for controlling mineralisation) are commonly located at lithological boundaries, presumably by local refraction of faults or shear zones as they propagated through folded stratigraphy. The various lithologies have also responded differently to deformation, causing variations in permeability that affected the penetration of mineralising fluids. Mapping lithological variations in barren host-rocks, either directly+ by fieldwork or indirectly by aerial geophysics, is a key to understanding and predicting the distribution of gold at mine and deposit scales.

Jan 1, 2001

By Ian MacKenzie

Over the past twelve years, professionals such as architects, engineers, accountants, and attorneys have not had to pay a great deal of attention to GST. The fees charged to clients (outputs) have not been subject to GST, but they have had to pay GST on al purchases of materials and taxable services relating to their activities.

Jan 1, 1990