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By J. C. Folinsbee, D. R. Derry

"The Property of Opemiska Copper Mines (Quebec) Ltd. is in Levy Township, Chibougamau district, west of Chibougamau and south of Opemiska Lake. The original find was made in 1929 by the late Leo Springer and associates of Prospectors Airways Ltd., following observation from the air of an area of dark rocks in newly burned-over country. Work on the ground discovered three veins of high-grade chalcopyrite in gabbro (No. l, No. 2, and ""North"") and, after several seasons of trenching and diamond drilling, financed by Ventures Ltd., a shaft was sunk in 1936. This work indicated about 280,000 tons of six per cent copper ore to a depth of 500 feet. During this period, the senior author carried out a reconnaissance geological survey over the whole property and surrounding claims, which showed that the veins were in the gabbro portion of a large composite basic sill that had been folded with the enclosing lavas. Owing to the low price of copper and lack of transport work was suspended and the property remained dormant until 1951.In that year the company was re-financed, the property prepared for production, and further exploratory drilling undertaken. The drilling, based on structural indications, located a new vein of which the only previous evidence had been some irregular stringers. This vein, No. 3, was traced by drilling for a length of 2,000 feet and the indicated reserves were thereby increased to about one million tons. An additional vein, No. 4, was intersected in several holes.With this encouragement, plans for production were confirmed, and operations commenced' at the beginning of 1954 on a scale of about 400 tons a day, concentrates being shipped by truck to St. Felicien and thence by rail to Noranda. In the first year of operation concentrates were re-covered carrying 14,047,210 pounds of copper, 76,714 ounces of silver, and 6,259 ounces of gold. The operation is under the direction of J. P. Millenbach, General Manager, with J. M. Thompson as Assistant General Manager and F. G. Cooke as General Superintendent on the property."

Jan 1, 1949

By Mathew Cook

Technological developments in Distributed Fiber Optic Sensing and improvements in both hardware and software have allowed fiber optic sensing systems to be deployed in a variety of applications such as pipeline leak detection, perimeter security monitoring, and power cable real time thermal rating. Recently, there has been a larger adoption of monitoring of conveyor belts in so called Conveyor Health Monitiring Systems (CHMS) within the mining and bulk material handling industries to identify idler conditions on an ongoing basis. Several attempts have been made to institute sensing capabilities into conveyors with mixed success. However, recent breakthroughs in modeling, installation methodology, and technology, as well as increased understanding of application and industry requirements, have allowed the technology to be deployed at both experimental and commercial scales. This paper summarizes the application conditions and requirements, design considerations, methodologies used, the outcomes achieved, the logistical and field considerations, and the future possibilities of the use of this technology in CHMS using Distributed Fiber Optic Sensing.

Feb 22, 2026

By I M. Platten, C J. S Sangster, Y Xie

The Cononish gold-silver deposit is a steep, relatively narrow quartz-vein system, with a current total mineral resource of 154 000 oz Au and 589 000 oz Ag. The northeast-southwest trending system was emplaced into late Proterozoic metasediments, and postdates metamorphism and associated Caledonian Orogenic foliations. Assay and mineralogical data show that gold and silver is spatially associated with sulfides in quartz. The main sulfide is pyrite, but galena, chalcopyrite and sphalerite occur in small amounts. Gold occurs as electrum, with minor native gold, and silver occurs additionally as tellurides and native metal. The gold/electrum is fine-grained, generally less than 100 microns in size. The main ore shoots plunge 45¦ south-west, have a 40 m to 80 m intersection with the existing underground development and extend between 40 m and 260 m down plunge. Small-scale sulfide-bearing domains within the vein carry the highest gold grades. They collectively define the ore shoots, where one or two, and rarely three, of the domains are present at an individual site in the vein. Discontinuity of individual domains, variation in domain thickness and internal heterogeneity results in short scale variation in grade across the structure. Geological mapping along a 1.2 km exploration adit has provided critical æconditioningÆ data to support resource evaluation based on development and relatively wide spaced drilling. In addition, it has provided an indication of potential challenges that could be encountered during production.

Jan 1, 2009

By P. Tim Johnson

Relentless increases in demand for nickel and vanadium for uses such as steelmaking, catalysts and battery materials, plus the growing financial and environmental costs of their primary extraction, have led to much interest in potential secondary sources of these metals. The presence of such metals in heavy fuel oils, bitumen and related materials offers both opportunities and challenges for potential extraction methods, especially with the growing production and importance of metal-rich fossil fuels around the world. For several decades, Tetronics’ DC plasma smelting technology has been used for the recovery of metals such as nickel and chromium from stainless steel melt dusts and other wastes in compact, environmentally-friendly and efficient plants. This paper explores the suitability of DC plasma smelting as part of a wider flowsheet with feed preparation and aluminothermic reduction techniques for smaller-scale extraction operations based on this important niche secondary source of these key metals.

By J Lim, M Powell, P J. Scales

The current philosophy employed in the design of mineral processing plants effectively involves bolting together segmented unit operations both chosen and optimised from a product-centric perspective. In this context, integration of water saving technologies at an overall plant level becomes difficult and often only local water efficiency improvements are feasible. In general only limited benefit can be obtained from such add-on solutions. It is therefore proposed that to obtain significant savings in water consumption and reductions in the volume of discharged contaminated water in the mining process, the entire process along the mining and mineral processing chain should be addressed This paper explores aspects of the processes that may be modified to provide an integrated and combined step change saving in water consumption. It is also apparent from this study that taking a more holistic view of the process can provide significant benefits in energy savings and total cost of production, providing the potential of a substantial win-win outcome.

Jan 1, 2009

By H. Walqui, J. Drelich, J. Pletka, E. Luhta, E. Raber, J. Wieland, P. Boyd, N. Tervo, D. Herron, S. Boston

Mini-projects studying the flotation chemistry of paper de-inking were incorporated to an educational program at Michigan Technological University with support from the paper recycling industry. Interfacial activity of frothing agents, surfactants and polymers in de-inking flotation systems has been studied through flotation, atomic force microscopy, zeta potential, contact angle, surface tension, and froth stability measurements. These fundamental studies were developed to understand microscopic and molecular effects occurring in flotation of ink particles that may lead to improved designs in de-¬inking flotation processes. Fundamental studies indicate that ethoxylated alcohols are efficient frothing agents in flotation and can be used to clean the recovered paper from hydrophobic ink particles. Next, it was further supported in this research that the fatty acids activated by calcium ions act as collectors in flotation of ink particles. Finally, improvements in de-inking flotation are reported in laboratory tests involving aqueous solutions of polymeric flocculants.

Jan 1, 2001

By X. Gumede

A model is being developed to quantify the benefits for mining houses resulting from the reduction in greenhouse gas and energy consumption by the application of innovative blast designs in addition to direct financial benefits throughout the mine to mill value chain. The conversion from shock tube initiation systems to electronics and some changes to powder factor measured on an open pit mine had previously been used to show significant improvement on blast outputs. Benefits were realised on drilling, blasting, loading, hauling and beneficiation. Quantification of the relationship between powder factor and reduced greenhouse gasses is investigated in this study. The study has highlighted new data that must be recorded and hence some assumptions were made as to fuel consumption and the energy in crushing was obtained from the Bond work equation. The mine to mill projects in an open pit platinum mine and a quarry produced energy savings and reduced greenhouse gas emissions associated with the careful application of explosives and blast innovations. The less fines project showed an increased carbon footprint. The model provides a new insight into how project feasibility should be decided based on economic and environmental viability.

Jan 1, 2012

By John Sherbourne

Much valuable scientific research has been performed in recent years on the subject of phase behavior of hydrocarbons. ? 1-11 Engineers employed in petroleum production are interesting themselves in this work as well as in methods of applying the fundamental data available to the solution of their various problems. Recently a number of papers have been published in which applica-tions of phase behavior have been made to specific cases pertaining to critical phenomena.)12-16 Little effort, however, has been made in the literature to show the relation between changes occurring in the critical region and the more common phase behavior, therefore it is believed that a presentation of the fundamentals of phase behavior with reference to hydrocarbons is timely. Study of phase behavior is not new. In the metallurgical field, knowledge of heterogeneous equilibria has advanced tremendously, particularly with reference to solid-solid and solid-liquid behavior. Much is known about vapor-liquid equilibria too, but few engineers are familiar with this subject. ?

Jan 1, 1940

By Farid Mirahadi

Forecasting productivity of construction operations is a difficult but crucial task in planning construction projects. Over the past decades, many models have been developed to forecast productivity for different construction operations. Models made up of several functional relations and controlled by a specific number of control rules are more in line with human reasoning and logic. Neural-Network-Driven Fuzzy Reasoning (NNDFR) structure as one of these models shows a great performance for modeling datasets among which clear clusters are recognizable. Lack of the compatibility of conventional NNDFR with fuzzy clustering algorithms besides the insufficient attention paid to the optimization of number of clusters in this model, created a potential area for further research. The main contribution of the proposed model is to develop a modified NNDFR system to model construction data. To this end, Fuzzy C-Means (FCM) algorithm is substituted for K-means in NNDFR structure, and its parameters such as the number of clusters and weighting exponent are optimized through genetic algorithm. The proposed model is further verified through simulation of a construction operation in which several qualitative and quantitative factors are considered. Its implementation to the case study shows a considerable improvement of model performance with lower Mean Squared Error (MSE). The developed model assists researchers and practitioners in utilizing historical construction data to forecast productivity of construction operations with a high accuracy that could not be obtained by traditional techniques.

Aug 1, 2013

By L. Lorio, B. Hilscher, P. Nayak, N. Yoon

"Mining has been a staple to technological advancement ever since the dawn of time. By harnessing the different physical and chemical properties that each mining commodity brings to the table, more and more innovation is developed and manufactured. As these non-renewable resources continue to be extracted, the industry as a whole faces a challenge in finding the next economical deposit as well as declining grade at the current operations. By means of pre-concentration, ore sorting aims to separate the barren material from the valuable ore to reduce energy consumption and tailings generation, while increasing the feed grade, concentrate grade, mill recovery, and revenue. In addition, ore sorting allows the modification of deposit geometallurgy in order to allow the creation of an optimal mill feed. This paper evaluates the applicability and challenges of ore sorting by utilizing the results from four different mines, and reviews them in detail. The mines include one underground and three open pit mines that are precious metal operations. In order to understand the applicability of ore sorting in these operations, initial rock-by-rock test results and different types of assays (atomic adsorption [AA], inductively coupled plasma [ICP], and fire assay) are utilized. Using the assay results, the grade recovery curves for ore sorting are generated and they are further improved by using and developing an ore sorting algorithm, which is discussed in this paper. The application and evaluation of ore sorting in greenfield and brownfield properties will also be discussed. The state of the art ore sorting technologies for both rock-by-rock and bulk sorting are also reviewed in this paper. The future technologies on the horizon, including different combinations of sensors, are explained. The sorting technologies include X-ray transmission (XRT), X-ray fluorescence (XRF), colour, infrared, electromagnetic, and laser induced breakdown spectroscopy (LIBS)."

Jan 1, 2017

By M. L. Free

Laboratory scale extraction of metals from heterogeneous materials such as copper ores is often performed using fine material to increase kinetics and reduce sample size requirements and costs. In contrast, commercial extraction is usually accomplished using much larger material sizes than are used in laboratory settings. The large size difference between laboratory testing and commercial application materials makes it difficult to use laboratory test data to accurately predict performance for commercial material. One solution adopted widely in industry is the use of large test columns. Large test columns cost considerably more to set up and run and take much longer periods of time to evaluate than laboratory scale tests with small particles. Consequently, from a cost and data collection efficiency perspective, the development of accurate scale up methods offers significant potential for saving both time and money. This paper provides details for a new approach to correct for scale-up phenomena in heterogeneous material processing.

Jan 1, 2007

By Ronald Damen, Dion Denes

"Friction fatigue is the loss of soil-pile friction around the shaft area of the pile. It has been observed during impact driving of piles, and has been modelled to a limited degree using physical scale models. This paper proposes the use of high strain dynamic pile testing to assess and quantify friction fatigue in impact driven piles. The method is applied to two case studies: one on a project off the north-west coast of Australia and one on a South Pacific Island. On both sites calcareous sand layers are present. Pile Driving Analyzer (PDA) monitoring has been conducted during impact driving of steel piles, which allowed for assessment of shaft resistance development both with depth and with progressive driving, by use of wave equation signal matching. Lessons are drawn from the case studies to improve future observations.INTRODUCTIONFriction fatigue is the loss of soil-pile friction around the shaft area of the pile, under cyclic loading or during pile driving. The phenomenon has been frequently observed in some non-silica sands, such as pumice sands and calcareous sands and has been the subject of academic study.The occurrence of friction fatigue impacts the driving behaviour of piles and the shaft friction component of the ultimate geotechnical strength (Rd,ug). If potential friction fatigue is not recognised in the design phase of a project, required pile toe levels can be significantly underestimated. This could lead to extra cost and delays, or, if no adequate pile verification is conducted, to geotechnical failure or underperformance of piles. This is especially true in remote locations, such as Pacific islands, where calcareous material is often present.A better understanding of the phenomenon would aid both pile design and driveability assessment. This paper proposes the use of high strain dynamic pile testing to assess and quantify the effect of friction fatigue from impact driving. Two case studies are presented in which high strain dynamic testing has been conducted on driven piles in calcareous sands to illustrate the method.BACKGROUNDFriction fatigueThe geotechnical strength of piles is composed of the resistance to static loading by the base of the pile and the shear resistance between the shaft of the pile and the adjacent soil. The latter is often referred to as the shaft resistance or shaft friction.During impact pile driving, a decrease in shaft resistance is often observed. Although this phenomenon is also observed during vibratory pile installation, this paper deals predominantly with impact driving. This decrease in material strength from the tip of the pile influences the shaft resistance and may be either temporary or permanent. Temporary reduction in shaft resistance is common in cohesive soils and is thought to be caused by excess pore water pressure, which has insufficient time to dissipate. This phenomenon, commonly referred to as set up, is observed to a significantly lesser extent in non-cohesive materials such as clean sands (Rausche et al., 2004)."

Jan 1, 1900

By B. L. Razzaboni, P. Bolsaitis

"The formation of reactive oxygen species resulting from the interaction of silica dust particles with red blood cell membranes was investigated; particularly, the effect of surface hydroxyl (silanol) group concentration on the rate of formation of such reactive oxygen species was investigated. The rate of formation was measured indirectly through the effect of catalase, a hemoprotein peroxidase, on silica-induced hemolysis. It was found that the addition of exogenous catalase to erythrocytes markedly reduces the hemolysis caused by silica particles. Furthermore, the amount of catalase required for deactivation of silica per unit area of particle surface is lower for fumed silica particles and calcined crystalline particles than for uncalcined, crystalline silica, suggesting a correlation between the concentration of OH groups at the silica particle surface and its potential for generation of H2O 2• The addition of albumin, a copper chelator, also decreases hemolysis. These results suggest that the hemolysis caused by silica particles is at least partly related to the formation of H2O2 at the particle surface and its subsequent reaction with Cu+ ions. The relationship between the concentration of surface silanol groups on the silica surface and the amount of catalase required to decrease hemolysis may also provide a method for testing potential fibrogenicity of respirable dusts. IntroductionReactive hydroxyl groups on silica surfaces are known to be cytotoxic and are believed to play a major role in silicosis (1-9). It has been proposed that this cytotoxicity results from hydrogen bonding to cell membranes and a resulting increase in membrane fluidity and permeability (4). Surface hydroxyl groups on silica surfaces have also been shown to interact with carbonyl oxygens in cell membranes (1,5). An extensive study by Nolan et al. (6) of the relationship between the negative surface charge resulting from ionized silanol groups and the hemolytic activity of crystalline a-quartz (Min-U-Sil) has shown a positive correlation between hemolytic activity and the surface concentration of silanol groups. These authors demonstrated that the hydrogen bonding of polyvinyl-N-oxide (PVPNO) with silanol groups, as well as the bonding of metal cations to the ionized sm- groups, results in significant decreases in hemolytic activity. Furthermore, it has been found that the complete removal of surface hydroxyl groups from the surface of respirable silica particles nearly eliminates the hemolytic potential of silica (7), suggesting that hydroxyl groups might be involved in other cytotoxic processes associated with silica-induced lung injury. Reactive oxygen species have been .implicated in cellular damage caused by respirable silica particles. Evidence for the presence .of oxygen radical species (02, OH°, H2O2) generated by silica, especially on freshly formed surfaces, has been produced by various investigators. Kalbanev et al. (8) detected H2O 2 in aqueous suspensions of quartz. Electron spin resonance and spin trapping by Shi et al. (9) confirmed the presence of OH"" radicals in aqueous suspensions of quartz, and Gulumian and van Wyk (10) suggested that both glass and quartz produce hydroxyl radicals in the presence of H2O 2 • Gabor et al. (11) detected the presence of malondialdehydereactive lipid peroxides (i.e., lipid-0°) in cultures of macrophages and respirable silica particles using the thiobarbituric acid (TBA) reaction test. Will (12), however, reported that iron enhances the TBA value of peroxidized lipids, and Scheulen and Kappus (19) found that catalase augmented malondialdehyde formation, thereby increasing the TBA values."

Jan 1, 1990

By Robert F. Hauck

This chapter discusses a new technology for computer control in open-pit mine operations: the real time automatic dispatching of manually driven trucks to shovels. The monitoring of truck activity is accomplished by detection of local radio signals. Computer-operated directives are communicated to drivers by remote controlled digital display units inside the truck cab. The production objective is to maximize tonnage in a cost effective manner. The problem is formulated in the appendix and the solution method is briefly described. Side conditions such as maintaining delivered ore grade aims, balancing waste to ore volumes to keep within stripping ratio tolerances, and meeting production rate requirements temporarily established for certain shovels are also discussed. Experience with a developed event- to-event simulator applied to analyses of several North American mining operations using this technique is summarized. Complete systems employing this technology are now under- going installation at mine sites in Canada and the United States.

Jan 1, 1979

By C. W. Smith

The U.S. Bureau of Mines conducted research to determine the effect of ground water control on the dewatering of phosphatic clay wastes. Two storage impoundments were constructed. One impoundment was surrounded on three sides with a series of well points (shallow vertical wells) to lower the ambient water table and the second impoundment served as a control. Ground water was pumped from the area surrounding the test impoundment for a period of 490 days. A constant pumping rate of 60 gal/min resulted in a water table drawdown of 13 ft, approximating the bottom of the impoundment. At the end of the test period percent solids in the test impoundment was 35 pct, while in the control impoundment percent solids was only 26.8 pct. Percent solids of greater than 30 pct is required for capping and final reclamation using fertile overburden.

Jan 1, 1989

By E. Stemn

Incident investigation is of utmost importance in most high-risk industries. This study was undertaken to study the content of past investigation reports to determine the effectiveness of the incident investigations. The study uses a semi-quantitative method to assess the effectiveness of incident investigations in the Ghanaian mining industry by evaluating the quality of past investigation reports. The assessment tool consists of 5 elements with several indicators and rating scales for assessing the quality of an investigation report as a measure of the effectiveness of the investigation. The method was applied to 304 investigation reports of 3 Ghanaian large-scale gold mines, and the results correlated with incidence rates of the mines to determine if any relationship existed. The results showed that the mines differ significantly in the quality of their investigation reports, suggesting differences in the effectiveness of their investigations. In addition, the incidence rates of the mines negatively correlated with some elements of the assessment tool. In general, the method was found useful and revealed areas where improvement is needed. INTRODUCTION The importance of learning from incidents is well documented in the literature. For instance, some scholars regard learning from incidents as important for improving safety [1,2]. Thus, many organisations spend considerable resources in identifying lessons from incidents and subsequently on the process of improvement that follows the identification of lessons. It is therefore important for such organisations to determine the effectiveness of their learning from incidents processes, in order to identify specific areas where improvements are needed, so that interventions can be as specific as possible. The learning from incidents process models the plan-act-check-do approach of management systems, often consisting of four major stages, namely; data collection and incident analysis, planning interventions, implementing interventions and follow-ups and evaluation [3,2]. The investigating and analysis of incidents have been regarded as one of the vital stages of the learning process since it is the stage where lessons are identified [3,2,4]. It has also been noted elsewhere in the literature that results of the previous stage of the learning process are important for the next stage [3]. For example, ineffective incident analyses could result in the planning of ineffective remedial measures. One of the primary aims of incident investigations is to identify lessons from previous incidents which when implemented can prevent future recurrences or minimise the effects of future incidents. There is thus the need for organisations to assess the quality of their investigations periodically since it is one of the means they adopt to improve safety and the quality of remedial measures to some extent depends on the effectiveness of the investigations. Although previous studies [5,2] have assessed the effectiveness of the learning process, and some aspects of the learning process, such as incidents reporting, there is less focus on the effectiveness of incident investigations. The research described in this paper was therefore conducted to contribute to this gap, focusing more closely on incident investigation reports.

Jan 1, 2019

By S. C. Tadolini, P. Mills

"INTRODUCTION This research produced a shotcrete formulation that extends beyond stabilization and can be used to restore the structural integrity of damaged infrastructure. The primary challenge was to develop a shotcrete or gunite with structural strength within a few minutes to prevent parasitic loading and allow ingress into damaged structures within a few minutes of the mix formulation being applied. This also applies to mining conditions where rapid support of progressive failures can minimize failure. An additional benefit was the discovery that the product had extremely high adhesion properties in addition to high flexural strengths. The approach to product design was the development of “single bag” dry mixes that are entirely self-contained, can be rapidly transported anywhere in the field or underground, and be deployed using simple equipment. Dry mix eliminates issues relevant to high shear water mixing, as water is added in the form of a mist at the point of delivery; thus low W/C can be achieved. However, as there is no onsite powder mixing, the product must have a high degree of inherent homogeneity. A commercial version of this material is currently offered as Minova’s Tekcrete Fast® product which has been successfully deployed in the mining industry and is currently being used in civil, construction and tunneling operations. The material can rapidly stabilize unstable ground in metal/nonmetal and coal mines. This paper described the technology development, product testing results and applications in mining and civil applications. BACKGROUND The original development of this product was to complete rapid stabilization of shock damaged structures, which falls outside the purview of normal construction and mining practices, due to the critical time issue and the nature of the damaged structure. The stabilization of damaged structures requires materials and equipment that can be rapidly deployed to place materials that have very rapid strength development. These materials need to be placeable at a distance to provide some degree of safety to the responders. In addition, the materials must be able to adhere to structural surfaces that have not been specially prepared and conditioned, and may also be highly fractured, dusty, wet, and quite possibly hot or extremely cold. The technology for the rapid delivery of large volumes of cementitious materials to vertical or even overhead surfaces currently exists. Pneumatic delivery (shotcreting) has been used in construction for over 100 years (American Shotcrete Association, 2014). Shotcreting has played a major role in structures like the Washington D.C. Metro subway system and been used in underground mining applications routinely to serve as part of the primary and secondary support system when used in conjunction with traditional roof bolts. Numerous rapid setting cements are commercially available. They are used for rapid repair of surfaces such as bridge decks, pavements, and commercial floors, as well as structural repairs of vertical and overhead surfaces. Few of these products are specifically marketed for use in shotcrete applications. The majority of rapid setting cements are based on, or at least contain, Portland cement as a principle component. Other components are added that help provide early strength, such as high alumina cement (HAC), organic polymers, chemical accelerators (which can also be added during concrete batching), and calcium sulfate hemihydrate (e.g. gypsum plaster) (Lea, 1971). Cementitious mortars prepared with some of these cements can achieve compressive strengths of 6.8 – 13.8 MPa (1,000-2,000 psi) within 1 hour. However, Portland cement mortar and concrete typically require many weeks of proper curing to reach significant levels of their ultimate strengths, even when used with set accelerators. Also, high early strengths require the use of large proportions of Portland cement in the concrete mix, which can lead to high heat evolutio"

Jan 1, 2017

By R. H. McCorkell

Measurements of radon in air and aqueous solutions can be affected by leakage from vessels in which samples and standards are kept and by absorption and later release of radon by the materials of these vessels. The author had received various oral communications concerning the se processes : e.g ., that natural rubber and greases absorb large amounts of radon, whereas silicone rubber and grease do not; and that radon is readily lost from polyethylene bottles and that inverting glass bottles containing aqueous samples reduced radon loss from them . However, the results of actual tests and quantitative data showing these effects were not available. For this reason, it was necessary to make numerous measurements of the leakage and absorption of radon in the course of designing apparatus and methods for measuring radium and radon concentrations. It was thought that the data obtained might be of use to others, and consequently they are compiled in the present note .

Jan 1, 1980

By J. Rao Mokka

Extensive exploration has resulted in delineation of a massive sulfide district on the north flank of the east-central Alaska range. The district covers approximately 400 square miles and contains numerous stratiform; transported and some replacement type sulfide deposits ranging in size from less than 1 million tons to 20 million tons. Five types of ores were sampled for the study. Mineralogical analysis revealed that the minerals are too fine grained for conventional grinding and beneficiation. Hydrometallurgical studies were con-ducted using ferric chloride as a lixiviant. Ore microscopic studies as well as electron microprobe analyses of minerals in the raw samples and leach residues explained the low recoveries for certain elements as well as sources of impurities that need to be eliminated from the process streams.

Jan 1, 1991

By Samantha Moodley, Rauf Hurman Eric, Cevat Kucukkaragoz, Aditya Kale

"Two titania slags, rutile and synthetic rutile were chlorinated with petroleum coke and CO in a small bubbling fluidized bed reactor. The study aims to identify differences in chlorination mechanism, compare conversion rates, blowover and the chlorination of impurities for the various titania feedstocks at different temperatures.Chlorination rates were highest at 1000ºC; rutile chlorination significantly increases as temperature increases from 800ºC to 1000ºC. At 1000ºC, synthetic rutile had the highest chlorination conversion rate; this was followed by Slag B which in turn was more reactive than Slag A and rutile. The mechanism for slag, synthetic rutile (SR) and rutile chlorination differs. Synthetic rutile feed is porous, providing a larger surface area for the chlorination reaction, hence the highest conversion rates was attained. Titania slag becomes porous with the initial chlorination of FeO and MnO whilst rutile remains solid. As the porosity of slag particles increases so does its tendency to be elutriated. Ti2O3 is oxidized within the early stages of chlorination during the chlorination of FeO and MnO. Ti2O3 not oxidized is then rapidly chlorinated.IntroductionTitanium dioxide (TiO2) is the most common compound of titanium, about 95 - 98% of extracted titanium minerals is processed into TiO2 white pigment [1]. Two processing routes exist for the production of TiO2 pigments, i.e., sulphate and chloride based processes. In the chloride process, titania feedstock is fed to a fluidized bed reactor together with reductant and chlorine gas. A temperature of 1000 - 1300ºC is maintained in the reaction zone and apart from silica, zirconia, uranium and thorium, virtually all the metal oxides in the feed are converted to their respective chlorides [2]. Chlorine is recovered and recycled back to the reactor."

Jan 1, 2012