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By Emily Wortman-Wunder

As the 2012 president of the Society for Mining, Metallurgy, and Exploration, Inc., I am pleased to present the 2012 issue of the Transactions of the Society for Mining, Metallurgy, and Exploration, Vol. 332. A significant portion of the contribution that we make as a professional society is the publication of professional and technical papers that accelerate the advancement of scientific knowledge and enable the transfer of technology. Communication within the mining community is the key to a successful society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of AIME; those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2012 Transactions is the third Transactions to take advantage of new publication technologies. It is available solely as an online subscription. The new format better suits the way this material is used and, ultimately, better enables the transfer and dissemination of knowledge. The 2012 Transactions contains some of the most interesting research from the past year, including a paper on the uranium boom in Namibia, work on improving the safety of coal pillar extraction, ways to improve the optimization and efficiency of various mine activities and the newest research from the U.S. National Institute for Occupational Safety and Health (NIOSH). The 2012 Transactions consists of a total of 67 technical papers (550 pages, including index), including all 18 papers published in 2012 in the Technical Papers Section of Mining Engineering magazine (Vol. 64) and all 31 papers published in 2012 in Minerals & Metallurgical Processing (Vol. 29). Additionally, this volume contains 18 papers that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. All 67 technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our publications staff. As the 2012 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2012

By G. M. Savov

Copper recovery via Solvent Extraction (SX) process is a well-known technique, which is practiced commercially for approximately 40 years. The main advantages of the SX process are: an absence of using high temperatures (not more than 50oC), complete recycling of barren solutions, very high selectivity at removal and purification of metals, metal conversion to a form, suitable for easy subsequent recovery. Despite the wide acceptance of Solvent Extraction, it does have some shortcomings, namely SX employs large quantities of volatile organic substances. This leads to huge plant ?footprint? of SX circuits. The SX is very sensitive to low temperatures and quantity of total suspended solids in feed solutions and this causes bad phase disengagement times and therefore poor process performance. And most important ? low grade solutions (with copper concentrations below 1 gram per litre) are very unattractive for treatment via Solvent Extraction process, because capital costs for SX plants are not a direct function of copper tenor in the feed. The combined process with Ion Exchange (IX) and Solvent Extraction ? further called IX/SX by IONTECH Engineering was developed. This combination eliminates SX negative characteristics shown above. The key findings of the IX/SX process are; (1) recovery of copper from pregnant leach solutions with metal concentrations, varying on a broad range; (2) can be operate effectively with very low-graded copper pregnant leach solutions; (3) the construction of large ponds for pre-filtration of the pregnant leach solutions is not necessary; (4) working with turbid solutions and solutions containing large quantities of suspended solids; (5) winter operation without troubles; (6) strongly reduces organic losses; (7) technological approach lead to plant sizes reducing. This paper reviews the main stages of the combined IX/SX process, the applications for metal recovery and introduces projects where the process is applied. Key findings of the process are also presented. A comprehensive technical comparison between processes has been carried out. This paper also evaluates the advantages of using combined IX/SX technology as a purification and separation step in copper production process, with the aim of further increasing the overall copper recovery and to ensure that a suitable copper concentration in the advanced electrolyte is achieved. The implementation of a Ion Exchange (IX) process in the classic Solvent Extraction-Electrowinning process(SX/EW) is found to be beneficial for processing of pregnant leach solutions both from spent and new copper heaps and dumps, acid mine drainage and other industrial streams without any preconditioning as well as in terms of achieving improved recoveries and copper cathode quality.

Sep 1, 2012

By R. Dehghan, M. Zarei, A. Tohry, S. C. Chelgani

Typical depressants for selective reverse flotation of iron oxides from complex silicates do not generally show high levels of efficiency. Therefore, as a hot topic, there are several ongoing investigations in this area. The main aim of this paper is exploring the potential of using humic acid (HA) as a depressant in reverse cationic flotation of hematite from complex silicates. For such a process, the wettability and flotation behaviour of pure minerals (hematite and silicates) was investigated at pH 10 in the presence of HA and cationic collector. Adsorption mechanism of HA on these minerals was measured by zeta-potential and FTIR. Results of flotation tests showed that at the lower concentrations of HA, selective separation of silicates from hematite is beneficial, where the floatability of amphibole was higher than pyroxene. A higher separation efficiency of hematite through reverse flotation was observed in the presence of amphibole, in comparison with the presence of pyroxene. Wettability studies showed that HA has a significant effect on reducing the hydrophobicity of treated minerals with the collector. The adsorption, ZPC and FTIR test results indicated that HA was adsorbed on both silicates and hematite. However, the absorption intensity onto hematite was much higher than silicates. It was found that the adsorption mechanism of HA on hematite takes place through both strong H-bonding and ligand exchange. Keywords: Reverse cationic flotation, humic acid, iron oxide, complex silicates, surface adsorption

Jan 1, 2020

By E. Robert Ruhlman

["Phosphate rock" is a broad term applied to natural deposits of minerals valued chiefly for their phosphorus content. More specifically, phosphate rock may be defined as a natural rock containing one or more phosphate minerals, usually calcium phosphate, of sufficient purity and in sufficient quantity to permit its use directly, or after beneficiation, in the manufacture of phosphorus-bearing products. The grade or quality of phosphate rock is expressed either in terms of its phosphorus oxide (P20S) content or the equivalent in tricalcium phosphate (Ca3(P04)2). The trade name for tricalcium phosphate is bone phosphate of lime (B. P. L.).]

Jan 1, 1958

The deposit was discovered during systematic reconstruction of the geological history of glacial overburden, which averages 6 m in thickness over 80% of Sweden, by geochemical sampling and searching for small grains of eroded bedrock. The gold is mainly concentrated in and around high-grade quartz veins within a broad shear zone, though the correlation coefficient between quartz and gold in samples is not significant. Production from two pits, now connected, in the Central and Eastern orebodies has increased steadily from 1 238 kg Au in 1989 to 2 120 kg in 1994, the highest in Europe. The mine has adapted and improved its mining methods to achieve significant productivity increases and cost reductions. Most of the improvements have been achieved through a better understanding of the controls on mineralisation and of the implications of those controls for selective mining. Geostatistics has played an important role in the quantification of grade variability and gold occurrence. Better blasting and loading techniques have improved selectivity, grade control has been enhanced by a grade-control drilling programme, and significant improvements in mineral processing have been made

Dec 1, 1995

By OÆGrady P

Finite element analysis is becoming a routine component of design of longwall extractions, now superseding more traditional somewhat intuitive approaches. Finite element modelling is relatively inexpensive and provides an adequate degree of similitude to give satisfactory analysis. The physical modelling of two decades ago is now largely replaced by numerical methods of which finite element is the best known. Important data for finite element work are physical properties, including creep aspects, introducing the non-linearity of stress response.Various computer packages are available and some were used to model two specific UK examples, using both linear and non-linear approaches. It appears that non-linear approaches will yield most benefit. The use of materially non-linear analysis is merited by the greater similitude it provides between model output and real mine situations.

Jan 1, 1991

By C. W. Covington, H. C. Cook, J. F. Libsch

Sputtered aluminum thin films were prepared in each of two conventional bell-jar vacuum systems. One system utilized an inner "getter sputtering" enclosure; the second system was a standard diode sputterirlg arrangement. Consistent and repeatable film properties were obtained in both systems provided sufficient cleanup and presputter time was allowed. The various problems associated with aluminum sputtering are discussed, with pavticular attention to the vzinimization of film contamination by outgassing and oxidation. The growth and structure of the aluminum thin films were studied with the aid of electron wzicroscopy and related to deposition rate, substrate temperature, and film thickness. The resistivity of the films was correlated to film structure and surface roughness. Resistiuities as low as 3.5 microhm-cm (2.3 x bulk resistiuity) were measured for relatively thick films (20,000). THIS investigation was undertaken to explore the problems and film characteristics associated with the sputtering of aluminum. Earlier work reported on aluminum sputtering has stressed the contamination of both the cathode and film as well as abnormally low deposition rates.' Data on sputtering yields,3 however, indicate that aluminum sputtering could be practical. Recently, it was shown by Theuerer and Hauser3 that aluminum sputtering was feasible in a conventional oil-diffusion pumped vacuum system provided an inner "getter sputtering" enclosure was employed to minimize gaseous contamination. This technique employs the getter action of aluminum to produce extremely low reactive gas partial pressures in the deposition zone. Aluminum films have already found use in solid-state electronic devices such as transistors and integrated microcircuits. To the present time, most aluminum films have been prepared by evaporation due to the ease with which this metal can be evaporated. Controlled sputtering of aluminum offers a number of advantages over evaporation, however, such as 1) manufacturing compatibility with other metals which must be sputtered, 2) better control of process variables resulting in more repeatable and uniform films, 3) generally better adhesion resulting from higher-energy metal atoms, 4) built-in material supply for continuous operation, and 5) the ability to deposit alloys. The data presented in this paper are the result of two separate studies. One study utilized a small "getter sputtering" enclosure (System A) and was concerned with the structure and properties of thin aluminum films up to about 1600A thick. In this thickness range, study of the film structure was possible with transmission electron microscopy. The second study was conducted with a conventional diode sputtering apparatus (System B) and covered $ much wider range of film thickness up to about 34,000A. Emphasis was placed on developing techniques which would extend aluminum sputtering to an existing in-line continuous deposition process.4 I) EQUIPMENT AND PROCEDURE System A. Fig. 1 shows a schematic of the "getter sputtering" inner chamber used and Fig. 2 is a photograph of this chamber mounted on an 18-in. access ring of a standard liquid-nitrogen trapped bell-jar vacuum system. This chamber was designed after a similar system used by Theuerer and auser.3 The configuration allowed the glow to emanate in all directions from the cathode. Argon (99.99') was allowed to enter only at the top of the chamber such that most of the reactive gases entering with the argon were reacted with the aluminum vapor and deposited on the chilled walls of the chamber before reaching the deposition zone. Provision was also made as shown, Fig. 1, for heating and cooling the substrate from about 20" to 400°C. Two substrate materials were used: Corning 7059 glass (12 by 12 by 0.048 in.) and carbon films about

Jan 1, 1967

By Sergio N. Monteiro, Artur C. Pereira, Foluke S. Assis, Henry A. Colorado

The fique fiber is an important natural fiber, originally from Colombia where it is used for sacks and crafts while its plant is used to contain slopes. However, few studies were realized with the fiber obtained from the fique plant leaf, its mechanical properties are superior in many aspects in comparison to some other lignocellulosic fibers. This work investigated the toughness behavior of polyester matrix composites reinforced with up to 30% in volume of a fabric made of fique fiber by means of Charpy impact tests. It was found that the addition of fique fabric results in a marked increase in the absorbed energy by the composites. Macroscopic observation of the post-impact specimens and SEM fracture analysis showed that transversal rupture through the fique fabric interface with the polyester matrix is the main mechanism for the remarkable toughness of these composites.

Mar 1, 2017

By J Mercuri, S Dunford, P Rothman, E Bartsch, J Snyder, D Newton, R Maron, D Cirulis

The purpose of a mineral comminution circuit with a ball mill running in closed-loop with a hydrocyclone classification cluster is to feed the downstream process with the target particle size. Maintaining the optimal particle size in the flotation feed can significantly improve plant cash flow. In particular, reducing the amount of coarse material is often a major challenge. Existing instrumentation to provide particle size measurement is considered standard equipment in most modern concentrator plants. However, availability is often very low, mainly owing to high maintenance requirements of the analyser and associated sampling system.CiDRA Minerals Processing has developed two novel and robust technologies that address this challenge by providing high reliability and very low maintenance systems for on-line measurement of coarse material in the overflow of individual hydrocyclones. The first system is non-invasive and measures pebbles and rocks greater than 6 mm. This paper focuses on the second system, which is a ruggedized wetted sensor design with no moving parts and provides a real-time trend of the desired target grind size parameter, such as percentage above 150 micron.Both systems have simple robust designs and measure in the primary overflow stream of the individual hydrocyclone. Individual hydrocyclone measurement enables identification of poor performing hydrocyclones in addition to providing a representative measurement of the whole hydrocyclone cluster. The systems do not require sampling and associated sample transfer piping circuits that are prone to plugging, thus avoiding high maintenance requirements.The wetted sensor will be described in detail along with its implementation in a robust control scheme in a major copper concentrator in North America. Plant data shows very high availability, achieved with very low maintenance, has enabled improved process control, thereby maintaining throughput and ball mill target power while reducing grind size.CITATION:Cirulis, D, Dunford, S, Snyder, J, Bartsch, E, Rothman, P, Maron, R, Newton, D, O’Keefe, C and Mercuri, J, 2015. Process optimisation using real-time tracking of coarse material in individual cyclone overflow streams, in Proceedings MetPlant 2015, pp 93–109 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By A. P. Chaves, D. Jose Neto, M. G. Bergerman, E. S. Mano

"More complex ore comminution and concentration operations have found increasing application in the mining industry due to lower grades and higher complexity of the available ores. An alternative to coping with the higher capital and operating costs of ore processing plants is the use of pre-concentration stages. They allow removing a significant mass of material with little or no content of the relevant mineral before the ore is fed into the processing plant, with the consequent reduction in the mass to be processed in downstream operations. Significant benefits arise out of the use of pre-concentration, such as higher contained metal output without the need to increase the grinding or flotation capacity, and longer mine life. The grade of marginal ores could be enhanced to a level that would make their exploration economically feasible, which would result in increasing exploitable reserves. Nevertheless, few studies to date have assessed the resulting impacts on ore grinding energy consumption and wear after the gangue is removed through pre-concentration operations. This study evaluated the energy consumption and wear of grinding circuits in Brazilian mining operations in which the feed has gone through a pre-concentration stage. Such assessment was based on different samples of sulfide and oxide ores. Laboratory tests were carried out to investigate the power consumption and wear of grinding circuits with and without a pre-concentration stage. Laboratory test results were used to simulate industrial grinding circuits based on both alternatives and illustrate the environmental and economic benefits of each one.INTRODUCTION Increasingly complex ore concentration operations in several stages have found broadening application in recent years in view of lower grades and higher complexity of the available ores. An alternative to coping with the higher capital and operating costs of ore processing plants is the use of pre-concentration stages. Different ore processing technologies can be used for that purpose, such as magnetic separation, density segregation, and separation methods based on high-tech sensors (ore sorting). Currently, the most common methods are gravimetric processes, in view of their low cost, particularly jigging and dense medium separation methods, such as the drum and cone separators manufactured by Western Machinery Company, Teska, Drewboy, Norwalt, Dynawhirlpool and Tri-flo, and dense medium cyclones (CAMPOS; LUZ; BRAGA, 2010). The use of dry ore sorters has also grown significantly in recent years (Jose Neto et al. 2017). The selection of the separator type depends essentially on the ore particle size, required flows, and operating density ranges. All these methods may even be used after preferential blasting in mining (Grigg & Delemontex, 2015)."

Jan 1, 2018

By O J. Restrepo Baena, S Nowosad, R Webber-Youngman, N Mojtabai, P Foster, A Binder, S Hazuria, erson, S Raval, L Liu

As the mining industry faces times of change, new challenges arise to ensure raw material supply for the younger and future generations. Different scenarios are currently shaping the way we mine and teach mining engineering. Led by an increasing demand for raw materials, net zero requirements for improving long-term operation performance, technological advancements such as automation and digitalisation, safety improvements, environmental considerations and a need for social acceptance, mining is pursuing to change and adapt to these requirements at a faster pace. Such changing times raise new concerns, one of the most relevant is the lower number of students interested or enrolling in mining engineering and related fields leaving mining engineering as one of the less preferred career options between the younger generations. Nonetheless, it is essential to continue addressing and supplying the skill sets that is suited to contemporary and future of the mining industry. To this end, globally, academia is currently undergoing several initiatives such as curricula updates and adaptation, up skilling, improving teaching practices and techniques, including e-learning techniques, enhancing industry-academia and inter-university collaboration, and much more

Sep 1, 2024

For the purposes of this discussion it is assumed that contributors should express the thoughts that arise from their personal experience. So wide is the range of mineral deposits, and so varied the methods employed in their discovery and development, that no two geologists are likely to have been impressed with the same applications of their science. The author's own personal experience has been, during recent years at least, very largely concerned with the broader aspects of the employment of scientific method and geological knowledge to the problems of exploration and exploitation, for the guidance of the general public and governmental authority rather than of mine executives and directors. The view-point thus reached is likely to differ in many respects from that of men who are much more intimately concerned with the mining problems of a single metal or a single mining field, and for this reason a statement may perhaps supplement those from others whose experience has been markedly different.It may well happen that, at some not distant date in the future, when systematic and comprehensive instruction in economic geology is embodied in the courses- prescribed for mining engineers during their years of training, the author's comments will be quitesuperfluous; but at the present time they appear to him to call for expression.The Need for Training of Mining Men in Economic Geology.Contact over a period of many years with mining men who have had different kinds of training and experience has been convincing that there is a general reluctance to acquire a full rational understanding of the geological factors involved in exploratory and developmental problems. The correction of this attitude is regarded as vital to the industry and it is necessary to insist that the outstanding requirement of the present day is the utilization of all branches of geological, investigation in the field and the laboratoryby men who have had systematic and specialized training in these matters. The science of geology is many-sided, but is, nevertheless, whole and essentially indivisible. No one can afford to disregard any fraction of its content 'or any of its methods of investigation.The greatest advances have been made in the understarnding of the occurrence of mineral deposits by those whose knowledge Qfbasal principles, has been soundest, whose endeavour has been to ascertain all their relationships in space and time, whose attention to detail of all kinds has been keenest, and at the same time, whose capability to distinguish between major and minor features has been most marked.With the passage of the years and the accumulation of data from many lands, it has been possible to build up a great body of information regarding the primary deposition and secondary alteration of mineral occurrences, which is of the utmost value in guiding thesearch for new deposits to take the place of those that become exhausted. This heritage is due not only to the efforts of gifted in...

Jan 1, 1950

By Gilberson Mendonça Storck de Melo

O desenvolvimento de placas de aços API necessita de preparação adequada das etapas produtivas na aciaria, de maneira a garantir tanto o atendimento aos requisitos do cliente que irá laminá-las, como as condições da última edição da norma API 5L. Este trabalho contém as premissas e as ações tomadas para o desenvolvimento do processo, desde o vazamento até o processo de lingotamento, sempre com foco na qualidade da placa lingotada. Finalmente, serão mostrados os resultados de desempenho das placas, submetidas às premissas e condições de desenvolvimento, nos laminadores dos clientes.

Aug 8, 2018

By W. P. Yant, H. C. Fowler

"INTRODUCTIONHydrogen sulphide is probably the most toxic gas associated with crude oil. Hydrocarbon (petroleum) vapors themselves are harmful to the human system, but hydrogen sulphide, when present, is usually more important from the standpoint of health and safety. These conclusions were reached in an investigation of the toxic gases encountered in the transportation end refining of high-sulphur petroleum. The results of that investigation are presented in Bureau of Mines Bulletin 23l. although the writers of Bulletin 231 paid no direct attention to the production of oil in the field, they attributed to hydrogen sulphide reports of accidents caused by gas in the oil fields of Mexico.During the development of oil fields in Texas, a ""poison gas"" was encountered that constituted a decided health and safety hazard. The present report discusses an investigation of this gas made in July, 1926.The major portion of the investigation was conducted in the Panhandle field of Texas, but the study also includes the Big Lake and McCamey fields.Scope of WorkThe work undertaken in each field included:Examination of the gas-coming from representative wells at various locations in the field; also analyses of the gas-air mixtures to which the workmen were or might be exposed.Observation of symptoms of poisoning and severity of these symptoms."

Oct 1, 1926

By F. Roelofse, D. Grobler, and M. Purchase, C. Gauert, E. Kotze

Scandium is an important industrial metal for which demand is projected to increase in the future. Although many Sc deposits are secondary, Sc is scavenged by clinopyroxene during fractional crystallization of primary, mafic-ultramafic magmas. Sc may thus occur in sub-economic concentrations in mafic-ultramafic intrusions. In this work, we present new data on the concentration of Sc in the Bushveld Complex (BC) of South Africa. The eastern and western limbs of the BC are considered to be largely pristine, primary magmatic deposits, whereas the northern limb shows evidence of largescale, localized crustal contamination. Samples from the primary magmatic cumulates of the eastern limb, from the mineralized Flatreef of the northern limb, and from the crustal-contaminated Footwall Assimilation Zone (FAZ) of the Flatreef were analysed for Sc. Despite the FAZ containing abundant clinopyroxene, interpreted to have recrystallized from the original cumulates in the presence of melted sedimentary rocks, no significant differences are seen in the concentration of Sc compared to other cumulate rocks of the BC containing less-abundant clinopyroxene. The concentration of Sc in the analysed samples is mainly controlled by mineralogy, with anorthosites, chromitites, and harzburgites containing under 20 ppm, and norites and pyroxenites containing 20–40 ppm. The parapyroxenites of the FAZ are less enriched in Sc than expected, suggesting that Sc may have been lost during alteration and recrystallization.

Sep 1, 2022

By Harold B. Ewoldt

The Appalachian Ores Co., Sweetsprings, W. Va. was a small but persistent producer of manganese ore for several years prior to 1942. Most of the ore mined was hard, nodular psilomelane, with some pyrolusite and, wad, occurring in clay. The Bureau of Mines started an investigation of the area in January 1942 and completed the work in May 1942. Twenty-four churn-drill holes were bored, aggregating 2,084 feet. A total of 420 feet of test pits was sunk on selected drill holes to check the churn-drill sampling. Twelve drifts and crosscuts aggregating 139 feet were driven from the bottom of test pits to investigate concentrations of manganese nodules. Three hundred sixty-six churn-drill samples and 102 other samples were sent to Bureau laboratories for analyses. Beneficiation tests were conducted in the Burp.au of Mines laboratory in Rolla, Mo. Results of testing 10 samples indicated that approximately 80 percent of the material in crude ore could be discarded by log washing. Gravity tests indicated 'that 55 percent of the total manganese in the crude ore was recoverable as a gravity concentrate averaging 34.6 percent manganese.

Jan 1, 1949

By E. L. Litchfield

Spark ignition of combustible-gas mixtures is a relatively old subject of investigation and has been treated both experimentally and analytically by many people. Elements of static and current electricity are almost always present in mining and industrial operations, and the spark can be an extremely efficient source of ignition. Thus the practical interest of such problems as the "intrinsic safety" of electrical apparatus is obvious. Ignition and quenching phenomena are the primary laboratory representatives of combustion phenomena that are dynamically nonsteady, and such nonsteady phenomena playa considerable part both in industrial processes and in safety matters, although they are of less immediate practical interest. Considerable effort has been expended by the Federal Bureau of Mines in investigations of spark ignition.5 6 7 8/ Primarily, this work has established the significance of several of the parameters involved. Although the

Jan 1, 1959

By K J. Riihioja, E Nozawa

SmartTag is a radio frequency identification (RFID) based technology designed to allow tracking of ore from its source through blasting, run-of-mine (ROM) pads, crushers, intermediate stockpiles and finally into the concentrator. This paper presents current developments and the future direction of the SmartTagÖ ore tracking system, as well as presenting some case studies. Successful applications of the SmartTag system have encouraged development to allow the system to be used in a wider variety of plants, in particular plants with finer crushing and screening stages. This presented Metso with a number of technological challenges, including RFID tag and antenna design. By reducing the traditional RFID tag diameter from 60 mm to 20 mm the RFID tags can now successfully pass through a secondary crusher. The new smaller RFID tags (referred to as mini RFID tags) have been used in some Process Integration and Optimisation projects with very promising results. The results indicate that the miniature RFID tags have a higher survivability to blasting and through secondary crushing stages. Extending ore tracking further through the process allows more reliable linking of spatial data with time based process performance. Metso is looking at developing even smaller micro RFID tags, and is also investigating other applications for the SmartTag system, including ore tracking from the original source to the final destination (ie from the mine, through the plant and ports to the customer).

Sep 26, 2011

By A. S. Rao

In the original roast-leach-electrowin (RLE) circuit at the Chambishi Cobalt Plant, commissioned in 1978, the separation of nickel and zinc from cobalt in aqueous streams was achieved by successive stages of precipitation using lime. However, this technique was not able to meet the increasingly stringent metal quality requirements of customers whilst maintaining acceptable process recoveries. Intensive process development work was carried out and, in July 1988, an ion exchange circuit for nickel removal was commissioned using DOW XFS 4195 resin and for the first time Z.C.C.M. produced high purity cobalt metal containing less than 0.10% nickel. Following further work, a solvent extraction circuit for zinc removal, using DZEHPA, was commissioned in February 1991 in order to enhance cobalt recovery by reducing co-precipitated cobalt losses. This paper outlines the process development, design, commissioning and subsequent operation of these nickel ion exchange and zinc solvent extraction circuits.

Jan 1, 1993

By Melinda J. Hummel, Zachary T. Smith, Nathaniel Witter, Nina F. Carney

The revitalization of Pittsburgh’s historic Strip District has led to the redevelopment of existing properties and the development of new properties. At one time, the Strip was home to wholesale market products. Now, the historical warehouse buildings are being converted to multi-use residential and commercial properties. One such property, 1600 Smallman Street, consisted of 1 to 6-story connected buildings that housed night clubs, retail shops, and office space. The lower story portion of the building, on the southwest side of the property, was torn down to make room for a new 5-story- parking garage with street level retail space. The remaining 6-story-building, on the northeast, was gutted to be renovated into high-end condominiums, keeping the exterior historical building facade.