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By X. S. Yuan

With a demand for increasing energy efficiency and a need for improving bitumen recovery, a highly integrated solution for sustainable lease development of Aurora North of Syncrude has been proposed and implementation plans are underway. Flocculation and thickening technology as an important component of the integrated solution provides Syncrude an opportunity of rapid heat recovery from tailings and more flexible tailings closure and reclamation options. Flocculation of fine-particle suspensions by polymers is a non-equilibrium process whose performance is strongly influenced by physical and chemical variables. While polymeric flocculants are frequently used to establish the chemical conditions favorable for flocculation, the actual performance of a flocculation process generally depends more on the physical variables, such as the hydrodynamic conditions in mixing the flocculants and slurry. In order to study the effect of hydrodynamic conditions on flocculation of Syncrude fine tailings, a standardized laboratory test procedure called power flocculation has been developed in comparison with the conventional manual mixing methods. It is shown that the agitation speed and time in conditioning the flocculant solution and the slurry have a profound effect on the flocculation performances measured by initial settling rates, supernatant clarity and sediment density. It was found that the optimum bench test conditions for power flocculation of Aurora fine tailings with a sand-to-fine ratio (SFR) of about 1:1 are conditioning of the flocculant solution and the tailings slurry at 250 rev/min to 300 rev/min in 20 s to 40 s. The test results are inter-preted with a flocculant adsorption/redistribution kinetic model that helps understanding of the effect of hydrodynamic conditions on flocculant adsorption, floc formation and floc growth.

Jan 1, 2014

By Carl G. Schwenk

Rusk County is located in the northwestern portion of the state of Wisconsin, roughly 130 miles east of Minneapolis (Figure 1). The topography is generally flat with dairy farming the principal activity. Forest and swamp lands are common, as well as pasture and cultivated ground. Rusk County falls near the southern terminus of the Precambrian Shield and is covered by a thick layer of glacial drift. Outcrops are quite rare, but the few available exposures indicate that the subsurface is comprised of steeply dipping metamorphosed volcanics and sediments of Early Proterozoic age. A thin section of flatlying Cambrian sandstone is sometimes found directly under the glacial till. The depth to Precambrian basement has been recorded to be as great as 150 feet beneath the surface.

Jan 1, 1976

By R. Blosser

Phelps Dodge introduced a process improvement model known as Quest for Zero in 2001. In 2004, the focus of Quest for Zero shifted from corporate-led initiatives to projects led by site personnel. The Hydrometallurgical Division at Morenci focused on two (2) significant process improvements: reducing electrolyte bleed and organic losses. In September 2004, Morenci kicked off a bleed reduction project to reduce electrolyte bleed by 45%. By the end 2005, electrolyte bleed was reduced by 55% through understanding and reduction of variance. Significant process changes made during this time period include changes in acid-addition strategy, reduction of uncontrolled bleed, and optimization of bleed placement. In April 2005, the organic reduction project began with the goal of reducing losses by 15%. Operational improvements during this project included improved organic recovery systems, mixer speed optimization, and picket fence installation. By the end 2005, this project reduced organic losses by 35% and current losses are 48% lower than at the start of the project. These projects and smaller Questfor Zero projects have resulted in sustainable annualized savings of $13 million in Morenci hydrometallurgical operations. Through the use of Six Sigma tools, process variances can be controlled and reduced.

Jan 1, 2007

By Paul Thurlow, Richard K. Lipscombe

The measurement of deflection of designed diaphragm walls is critical for near real time information to assess wall and soil behaviour as the internal area is excavated in a controlled manner. Data enables the site team and designers to check performance of the design, which is linked to safeguarding the site and the external stakeholders.This paper documents the use of Shape Accel Arrays at the Tottenham Court Road Western Ticket Hall during excavation and propping within the diaphragm wall for the Crossrail project. It shows how the data obtained was used within the site settlement management plan to assist in the control of the works and the information used for Value Engineering purposes that benefitted the project.The use of Shape Accel Arrays for measuring the deflection of retaining walls is not commonplace in the UK construction industry, with the Tottenham Court Road Western Ticket Hall being one of the first times they have been used in such a way. A detailed analysis of the data obtained from the instruments has been undertaken, and compared to the results obtained from the manual inclinometers that were read next to the SAAs. The advantages of the relatively new SAAs have been discussed, as well as other applications of the instrument.

Jan 1, 2017

By Richard A. Thomas, Connor B. Brown, Thomas H. Dubaniewicz, Teresa Barone

Electric vehicles powered by lithium-ion (Li-ion) batteries are being developed by mining vehicle manufacturers as a replacement for diesel-powered vehicles. Explosion-proof (XP) enclosures are frequently employed to enclose electrical ignition sources in gaseous underground mines to prevent the spread of an internal methane-air explosion to a nearby explosive atmosphere. Due to thermal runaway (TR), Li-ion batteries have the potential to cause pressurized explosions in an enclosed structure. Past research has shown the potential for well-confined Li-ion cell TR to drive pressures beyond the conventional pressure specification for XP enclosures. Researchers at the National Institute for Occupational Safety and Health (NIOSH) used an Accelerating Rate Calorimeter (ARC) to induce thermal runaway of Lithium Titanate or Lithium Titanium Oxide (LTO) type 18650 cells enclosed within containers with various volumes and found an inverse power relationship between the TR pressure and available free space. The results were similar in magnitude to that of lithium iron phosphate (LFP) cells, which were used in prior testing. Temperatures, gas amounts, and TR pressure-rise rates were also recorded. The data indicate that with enough free space, the pressures can be lowered below the conventional pressure specification for XP enclosures.

Feb 1, 2024

By Seksak Asavavisithchai, Natthida Jareankieathbovorn, Areeya Srichaiyaperk

"Recycling of ADC12 alloy scraps for fabrication of open-cell aluminium foams has been conducted via pressure infiltration method of replication process. The scrap, up to 50 wt.%, was melted with pure aluminium billet, followed by infiltration in a replicated mold of polyethylene foam structure. Compared with the pure aluminium foam, the compressive strength and hardness are higher for the foams with recycled scraps. The increase in foam mechanical properties is due to the presence of Si hard phase in Al matrix. The strength and hardness of the foams also increase with increasing contents of the scraps.IntroductionRecently, open-cell metallic foams have been brought to considerable attention of many industries due to their superior properties; such as large surface area, high specific strength, thermal conductivity, high service temperature and excellent anti-microbial activity, that cannot be found in conventional materials [1, 2]. Typically, open-cell foams are used in functional applications for which a requirement of high strength materials is not demanded. Good examples of such applications include heat exchangers, bone-replacement implants, interconnects, catalyst supports, and sound insulators.Among all types of open-cell metallic foams, aluminium (Al) is the most widely used base metal, due to low material cost, low density, low melting temperature and good corrosion resistance. To improve mechanical properties of Al foam, modification of foam microstructure with addition of alloy elements or ceramic particles is commonly carried out [3, 4]. ADC12 alloy is a typical die-casting Al alloy with high content of silicon (Si) close to the eutectic point in Al-Si binary phase diagram. The alloy is extensively used in the casting industry, due to high wear and corrosion resistance, low coefficient of thermal expansion and excellent castability [5]. The mechanical properties of Al-Si alloy are strongly dependent of Si content."

Jan 1, 2012

By A. Luckita, A. Samtani, R. Barus, J. R. Donald, J. Syarifuddin

In conventional Rotary Kiln-Electric Furnace (RK-EF) laterite nickel processing, management of dust continues to be problematic. A more efficient processing of dust represents an opportunity for energy efficiency, increased production, and productivity. PT International Nickel Indonesia (PTI), together with Vale Base Metals Technology Development (VBMTD), has successfully developed and implemented a novel flowsheet enhancement that capitalizes on these opportunities. In the novel flowsheet, the dust recycle stream is moved forward in the RK-EF laterite nickel smelting process. The dust is injected into the kiln's main burner, as opposed to being recycled to the dryers. A similar treatment of dust is commonly practiced in the cement industry; however, application to nickel smelters has not been fully developed to date. This paper describes this dust insufflation technology, the process through which it was developed for laterite nickel processing, and summarizes the lessons learned. A key conclusion is that successful new technology development requires a multi-disciplinary team involving members from research and development, study management, engineering consulting firms, project implementation management, process technology and operations.

Jan 1, 2011

By Luis Alva Saldaña

"Actualmente el método para descubrimiento de nuevos procesos y la elaboración de nuevas técnicas se ha modernizado. En ese sentido, el presente artículo señala la invención de estos procesos y técnicas a través del estudio de la Termodinámica. Esta ciencia trata de las relaciones entre las diversas formas de la energía, mostrando cuantitativamente los efectos que experimenta el complejo materia-energía cuando en él se realizaalgún cambio. Por ello, es fácil observar que muchos laboratorios tanto de Europa como de los Estados Unidos de Norteamérica, realizan estudios no sólo para completar las tablas de propiedades termodinámicas de las sustancias químicas, ya existentes, sino también para revisar los datos que antes se tenían de éstas."

Jul 1, 1955

By Melissa S. Beauregard, Randall A. Pietersen

This study focuses on quantifying the effects of water infiltration on a full-scale energy pile system’s ability to meet the thermal demand of an HVAC system. Theoretically, an energy pile system should increase its thermal capacity after a rain event due to increased moisture content creating an increase in thermal conductivity of the surrounding soil matrix. The United States Air Force Academy has an energy pile research site consisting of 8 full-scale energy piles located below a shower facility. The local colluvium surrounding the piles allows for relatively high water infiltration during rain events. This study uses an 11kW Precision Geothermal Geocube to apply a thermal load on two single-loop piles. A weather station located south of the structure records atmospheric conditions. Results indicate that moderate rain events can caused up to a 23% increase in the system’s thermal exchange capacity. This change is due to the increase in moisture content near the surface, which penetrates to deeper soil layers with time. The time required for moisture to penetrate to greater depths and then dissipate in the soil matrix, explains why increased system performance is seen for over a week following the passing of a singular rain event. 1 INTRODUCTION With a “future-forward” focus, there is an ever-pressing economic and environmental need to use sustainable sources to meet growing energy needs. HVAC is typically responsible for 34% of the overall energy required by commercial buildings and 48% of the energy required by residential buildings (USEIA, 2009; USEIA, 2012). Energy piles are a low cost, sustainable technology that have been used to offset this energy demand incurred by a building’s space heating and air conditioning requirements. An energy pile consists of heat exchanging elements in a closed loop system integrated into a building foundation and connected to a ground source heat pump (GSHP). It is most common for these heat- exchanging elements to be constructed within a drilled shaft foundation due to both construction practices and geometric considerations. This system operates based on the principle that at a certain depth below ground (typically 4 meters) subterranean temperature remains constant at a value equal to the mean annual air temperature at a given location (Kavanaugh et al., 1997). This allows the soil to function as a heat sink for cooling operations and a heat source for heating operations when exchanged within this zone of relatively constant temperature. For the past 25 years, the implementation of energy pile technology in public, residential, and even large-scale architectural complexes has slowly expanded which has created an increase in research into the topic as a result (Brandl, 2006; Hamada, 2007; Sekine et al., 2007; Gao, 2008; Bourne-Webb, 2009; Stewart and McCartney, 2013; Murphy et al., 2014). When pile construction takes place beneath the groundwater table, soil is under fully saturated conditions, maximizing thermal exchange for a GSHP system. Under unsaturated conditions, however, changing moisture contents change thermal conductivity values in a soil, which affect a GSHP system’s ability to meet a thermal demand. The observational data presented in this paper apply to GSHP systems in unsaturated soil conditions.

Jan 1, 2019

By S. H. Ash, J. J. Forbes

Probably the newest thing in mining safety, or safety for mines, is the apparent dissatisfaction on the part of the mineral industries, as represented by both management and labor, and the general public of the Nation, with the safety record of the mining industry. This is reflected by published comments and papers in the technical press;l-9 in labor periodicals,10,11 in popular journals and periodicals,l2, 13 and in the daily press; also by discussions of the Safety Committees sponsored by the National Safety Council,9, 14-15 the American Mining Congress,l.l6 the American Institute of Mining and Metallurgical Engineers,2,4 the Mine Inspectors' Institute of Amerthe Coal Mining Institute of America,5 19 the American Standards Association, and others.20.21 Mining safety is a joint problem of management and the individual workman. Safety is not attained and will not be attained solely by laws, decrees, and commands because, if it could be done in this manner, acceptable mining safety would have been achieved long ago by the individual states in our Nation and by the nations abroad. The best safety performance is found at plants where management provides a safe environment for the workers; where supervision is efficient and super- visors, others concerned with promoting safety, and the individual worker know through training, experience, and personal contact the safe and unsafe practices of their field; and where the trained individual worker has become safety-minded by experience, quiet influence, unconscious suggestion, and personal guidance. Despite what may be said to the contrary, progress has been and is being made in mining safety. This is shown in Fig 1 to 4. It is beyond the scope of this paper to give possible reasons for the valleys and peaks in the fatal-injury rates. Some recent factors that appear to be contributing to the improvement in these rates are briefly discussed. Aside from mining equipment, "what's new in mining safety" for some mines has been in effect or was tried by others long ago. A safety pro- gram is a living thing; as such, it must be vitalized and continuously fed with enthusiasm, constructive action, and improvements. Because safety is concerned with human conduct, it is necessary to practice safety at all times; if not, it is soon forgotten, and accidents occur. Mining-safety Records The large employment and production concerned with anthracite contribute much to the mining-safety records of the mineral industry. Approximately 81,000 persons are. employed in this industry having mines concentrated in an area of 480 square miles in northeastern Pennsylvania. Because of the achievement of the anthracite industry in safety during 1948, the other branches of the mineral industry can profit by a study of what has been done to achieve that record. Where one mineral is produced by other large groups having methods of mining that are similar in many respects to the anthracite-mining methods, an achievement in such a large industry is important. Salient factors concerned with safetye in the anthracite industry are: no radical change has occurred in the mining-safety regulations pertaining to anthracite mines. Because anthracite mining is a branch of the coal-mining industry,

Jan 1, 1950

By Daniel P. Stare, Lucian P. Spiteri, Christopher M. Hallahan, James C. Myers

Buckeye Lake Dam was substantially remediated between 2015 and 2018 as a result of unacceptable dam safety performance. A permanent seepage cutoff, consisting primarily of a soil mixed cutoff wall (SMCW) with occasional sections of steel sheet piling, was constructed along the dam alignment. Closures were required at the terminus of the soil mix elements with existing structures or coffer cells, and at locations where new sheet piling was constructed parallel to the new soil mixed cutoff wall, creating a short circuit seepage path. The original proposed design to construct these closures included permeation grouting methods with chemical grouts. However, a combination of multiple chemical grout types, multiple grout pipes, and an extensive post-grouting verification program was required to ensure the design intent was achieved. After award of the project, the specialty grouting contractor elected to evaluate jet grouting as an alternative closure construction method. The advantages of the jet grouting option offered potential schedule and cost savings to the project as well as a superior product for seepage reduction, given the mixed soil conditions at the site. This paper presents an examination of the site conditions and project goals for the construction of the proposed closure elements for the rehabilitation of Buckeye Lake Dam. Descriptions of the original and alternative treatment methods are provided, with expected performance results. A description of the relative strengths and deficiencies of each method, as well as the feasibility and constructability of each method is provided. The implementation of the jet grouting program is presented, including a discussion of the design elements, quality control test methods, movement monitoring, and verification test methods. This paper also examines the risks associated with jet grouting and how those risks were mitigated during the grouting operations. HISTORY Buckeye Lake is situated approximately 28 miles east of Columbus, Ohio and is managed and operated by the Ohio Department of Natural Resources (ODNR) as part of the Ohio State Parks system. The lake is impounded by natural features that exist along the south and east banks of the reservoir, and by the embankment structure constructed along the north and west banks of the reservoir (see Fig. 1). The reservoir site was originally a natural swamp and the original purpose of the constructed dam and reservoir was to provide water to the Ohio and Erie Canal System. Several dam alignments and configurations were constructed during its early history; however, the original embankment is comprised of homogeneous earthen fill. The embankment is 15 ft (4.6 m) high and extends 4.1 miles (6.6 km) from the North Shore abutment along the east, continuing to the abutment at Lieb’s Island to the West. Several spillway and outlet structures exist along the embankment alignment. Most noteworthy are Seller’s Spillway and Amil Spillway. Fig. 2 is a Plan View of the embankment alignment and appurtenant structures at Buckeye Lake.

Jan 1, 2019

By Ashirbad Satapathy, Sanket Rawat, Ramanand Shukla, Ravi Kant Mittal

Bearing capacity factor (Nq) and Adhesion factor (α) are the key parameters for analyzing the load carrying capacity of pile foundations embedded in cohesionless and cohesive soils respectively. Numerous models are available in the form of charts or equations for the computation of these parameters and hence, have been adopted by most of the International and National standards. Indian Standard for the Design and Construction of Concrete Pile Foundations, IS 2911–Part 1 (2010), also makes use of charts detailed in its Annexure B. However, the sources of these charts have not been specified clearly, making it difficult to back-refer to the actual models to assess their basis for resolving any critical scenarios encountered during design. The present study aims at acquiring a distinct understanding of the development of these charts in order to bring more clarity to the design process of pile foundations. The given charts have been compared with various models specified in existing literature and international standards for the calculation of Nq and α for both driven and bored piles and hence, the basis of Indian Standard charts has been identified. Moreover, it is evident that the use of these charts complicates the process of automation of analysis and design of pile foundations as well as the associated optimization studies. Additionally, the manual entry of data especially, from the logarithmic graph of Nq, escalates the chances of error thus, making it a critical concern for design offices. Therefore, this paper also presents a non-linear regression model for Nq and α, developed using NCSS software for both driven and bored piles. Through multiple iterations, the value of coefficient of determination for Nq and α has been found to reach greater than 0.995. The developed equations can be simplistically used for both manual and automated analysis of pile foundations.

Nov 1, 2022

By C. I. Walker

Field tests at a number of large mineral processing operations have been undertaken to better understand the wear life impact of different aspects of pump design, materials of construction and maintenance procedures. Data are presented for wear rates, and typical result variability is explored. To improve the availability of pumping equipment in a milling circuit it is not only important to improve the wear life, but also reduce the variability in the wear life of components so that the incidence of premature failure is lessened. Localised gouging wear due to flow separation and turbulent eddy formation is often the point at which part-holing occurs. A number of improvements to the design of pump impeller and throatbush (suction side liners) to reduce the localised gouging wear are outlined. Also, results are presented on the use of composite materials (mix of metal, rubber and ceramic) for throatbush materials to protect specific areas against wear.

Jan 1, 2012

By Volker Vogt, Wolfgang Sand, Eberhard Gock

"It was discovered that the selective activity of bacteria during the extraction of raw material concentrates by means of flotation could also be achieved with extracellular polymeric substances (EPS) excreted by bacteria. EPS, which is extracted by means of centrifuging bacterial cultures, can help to significantly reduce the use of cyanides, approximately 200,000 t/a of which are used for ore dressing today.The bacterium used was Acidithiobacillus ferrooxidans. In order to identify the bandwidth of the oxidation activity, 20 bacterial strains of the strain collection of the University of Hamburg were attracted to iron(II) sulfate and pyrite under defined conditions. All strains oxidized iron(II) sulfate ten times faster than pyrite.EPS has so far been derived from four strains. In general, EPS extracts are divided into a hydrophilic and a hydrophobic fraction. The hydrophilic fraction is composed of e.g. fucose, rhamnose and glucose; fatty acids such as dodecanoic acid, hexadecanoic acid, octadecanoic acid and nonadecanoic acid were found in the hydrophobic fraction.Pure mineral phases and mineral mixtures were used for the flotation tests. As opposed to current knowledge, the results were reproducible with technical flotation machines."

Jan 1, 2003

By Natasa Mitevska, Predrag Djordjevic, Zivan Zivkovic

This paper presents the results of an experimental investigation into the distribution of copper in the slag of an industrial reverberatory furnace sulfide concentrates smelting process in the copper smelter RTB Bor (Serbia). The influence of copper content in the matte, the temperature and the height of the slag on the content of copper in the slag was determined as Cuoxide, Cusulfide and Cutotal and was based on possible mechanisms for the loss of copper in a silicate slag from the smelting of sulfide copper concentrates. The greatest quantity of copper in the silicate slag was found in the form of matte particles, which were captured in the slag as a result of the “flotation” of SO2 gas which was formed by magnetite reduction with FeS at the slag–matte interphase boundary.

By Jack L. Henry, Davis E. Traut, L. R. Penner

The Bureau of Mines conducted solvent extraction batch tests to evaluate the usefulness of neodecanoic acid ( NDA) for extracting Co 3+ from ammoniacal leach liquors high in ammonium sulfate . This work is an outgrowth of previous Bureau research in which technology was devised for the recovery of cobalt , nickel , and byproduct copper from domestic laterites . The previously devised technology uses an oxidative ammoniacal sulfate leach to treat the laterite , and nickel and copper are then recovered from the leach solution by solvent extraction and electrowinning . This report deals with the subsequent solvent extraction of cobalt from the nickel - copper raffinate solution . The results showed that about 70 pct of the contained Co 3+ can be extracted batchwise at pH 8 using NDA ( a 10 - carbon - chain highly branched carboxylic acid ) . However , NDA had a solubility of approximately 0.6 to 0.8 g / L in aqueous raffinate following extraction , and this high solubility makes it impractical for use with alkaline solutions that are low in cobalt . In addition , the extracted cobalt species ( predominately cobaltic hexammine ) is not amenable to the electrolytic recovery of cobalt metal because of its extreme stability . This fundamental prob-

Jan 1, 1965

By CorrOa de Araujo A, Salum MJG

The treatment of mining and metallurgical liquid effluents is becoming, everyday, a necessity felt by these industries. Physical-chemical and chemical methods for treating such effluents are generally necessary whenever heavy-metals and other toxic compounds such as cyanide are present. The present paper discusses the use of precipitate flotation as an alternative physical- chemical method that can be applied for the treatment of effluents containing heavy-metals (mainly zinc and cadmium) and cyanide. Examples of laboratorial scale applications on real effluents are given. In both cases precipitate flotation was able to reduce the concentration of toxic components of the effluents at a very high removal rate, generating a solid waste that can either be disposed, re-used or recycled. A cationic collector - dodecylamine hydrochloride - demonstrated to be the best choice of surfactant for the two systems investigated. Sodium sulphide and dithizone were selected for the precipitation of the zinc bearing effluent whereas a copper salt was preferentially used for precipitating cyanide in a form adequate for its recycling envisaging the use of an AVR (acidification - volatilisation - regeneration) technique.

Jan 1, 1993

By Sumit Kumar Biswas, Moyukh De, Sibapriya Mukherjee

"The piles often are also subjected to lateral (horizontal) forces and moments. In fact, there are some structures where the primary function of piles is to transfer lateral loads to the ground. Proper analysis of laterally loaded piles is very important to the geotechnical and civil engineering profession.In the present investigation an experimental study has been carried out with free head short model cast iron hollow piles of outer diameter of 24 mm and L/d ratios of 8, 10, and 15. The experimental results have been supplemented by numerical techniques using PLAXIS-3D Foundation version 2.1 software. The results have been found to agree reasonably well with the experimental results. Further finite difference approach has been adoptedto reduce the computational time and to calculate the coefficient of modulus of subgrade reaction (?h) from the load- deflection data obtained from PLAXIS output at different pile depths. The parametric study has been extended for the non-dimensional form defined as flexibility ratio (F.R.),where ?h, L, Ep and Ip are the coefficient of modulus of sub-grade reaction, the embeddedlength of model pile, elastic modulus of pile material and the moment of inertia of model pile about the central axis respectively).The variation of coefficient of horizontal modulus of sub-grade reaction (?h) has been studied with respect to the following parameters for homogeneous soil system: relative density andL/d ratio. It has been found that the logarithm of flexibility ratio increases with increase inrelative density and increase inL/d Ratio. The values of ?h obtained by the proposed method have been, found to be close to the numerical results.As output of this research, graphs have been generated in respect of different parametric variations to gain an insight into behavior of piles under lateral load for short piles."

Jan 1, 2015

By Shengli Wu, Laixin Wang, Minyin Kou, Xinliang Liu, Weidong Zhuang, Yujue Wang

COREX process has obvious advantages in environment protection but still has some disadvantages, for example, it has a higher sulfur content of hot metal than blast furnace. In this paper, the thermodynamics and dynamics of desulfurization have been investigated to obtain the main operation parameters related to the mass fraction of sulfur in the hot metal. In addition, statistical analyses have been carried out to study the relationship between operating parameters and sulfur content of COREX hot metal based on actual plant data. It has been found that the mass fraction of sulfur in hot metal is significantly influenced by the C content in hot metal, MgO/Al2O3 in slag, the concentration of MgO in slag, the temperature of hot metal and binary basicity (R2).A linear model has been developed and subsequently used for reducing the mass fraction of sulfur in hot metal, improve the quality of hot metal and contribute to low carbon ironmaking.

Jan 1, 2016

By Barun Gorain, Aparup Chattopadhyay

"Many double refractory gold deposits are characterized by the dominance of ""invisible gold"" (sub-microscopic gold) as solid solution or as colloidal-sized particles in different sulfides and other phases. These deposits are mainly composed of silicates and carbonates with moderate clay and mica content and with minor amount of sulfides and organic carbonaceous matters. The presence of highly preg-robbing and finely disseminated carbonaceous matter adversely affects gold recovery in leach circuits. Characterization of carbonaceous matters, commonly known as TCM and quantification of gold associated within these carbonaceous matters along with different sulfide and oxide phases is highly complex and challenging. Studies were initiated on various complex ore deposits and also on samples representing various process streams. This paper presents the development of a systematic approach to gold deportment studies using state-of-the-art mineralogy characterization techniques for quantification of invisible and visible metal contents in various species. The relevance of this mineralogy characterization to metallurgy will also be discussed in this paper."

Jan 1, 2014