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By Todd S. Fayram

The Gordonsville Operation of Pasminco US Inc. along with the Center for Advanced Mineral and Metallurgical Processing (CAMP) at Montana Tech studied, developed and implemented a pilot scale hydrometallurgical facility for the industrial recovery of germanium and gallium. This paper describes the joint testing and engineering program that culminated in this successful process.

Jan 1, 2003

By Hong Yong Sohn

On the occasion of this symposium in my name, I reflect upon the contributions of my academic mentors and early associates who helped shape my professional career. I was fortunate to have these people around me during my graduate work and at the start of my professional career. In forming my view of the technical field and career, they represented academia, research institutions, industry, and different parts of the world.

Jan 1, 2006

By David M. Beckwith

Increased globalization and outsource manufacturing complicate the procurement and enforcement of intellectual property rights on a worldwide basis. Recent legislative and case law developments in the United States highlight the importance of a multinational intellectual property strategy. IP lawyers David Beckwith and John Hankins will discuss planning and pitfalls in this rapidly changing trans-border environment. Topics to be discussed include harmonization with international patent laws, protecting your technology and market space with a comprehensive approach to IP, and patent enforcement issues relating to import/export of products and components in the United States.

Jan 1, 2006

By Wenshan Zhang

This paper described the present status of China electrolytic manganese industrial production. Electrochemical reactions on cathode and anode, the major technological process, technical requirements on the production and technical index and quality control of the products and the ways of increasing current efficiency during Manganese electrolytic process have been expatiated.

Jan 1, 2006

By Pragna Bhakta

The use of microbes for sulfide oxidation was investigated as a potential treatment option for low-grade refractory gold ores at Newmont Mining Corporation. The resulting patented technology for heap biooxidation maximizes oxidation rate by distributing the microbial population on the ore before placement on a heap. This paper presents data on global oxidation rates based on oxygen uptake in a 50-kg column for sulfidic refractory ores from the Gold Quarry mine. The oxygen uptake data was converted to a global oxidation rate. The calculated global oxidation rate was used to determine heap cycling times for Newmont?s commercial heap biooxidation facility.

Jan 1, 2003

By B. J. Beaudry

Intermetallic compounds are frequently required in the form of thin sheets for magnetic refrigeration and other applications. Progress has been made in the preparation of thin sheets of brittle gadolinium intermetallic compounds by hot rolling of sheathed billets. The effect of fabrication procedures on the Curie temperature of GdPd and its heat capacity at low temperatures has been studied.

Jan 1, 1989

By Hans Hein

In its early stage of copper solvent extraction development, SX plants were designed in a series configuration and gradually the copper industry reduced staging and trains for keeping capital investments reasonably low. At a later date of its development, series parallel configuration was applied in some copper SX plants, particularly for increasing copper production at low copper tenor in pregnant leach solution. A gap between series and series parallel configuration had been observed for years. Conventional SX plants in series configuration frequently do not have the flexibility for maintaining designed or expected production level, whenever copper concentrations in pregnant leach solutions are getting low, whereas series parallel flow schemes almost require to double SX feed flows for achieving optimum results. A combined SX configuration breaks the gap and its application potentials are explained.

Jan 1, 2003

By A. V. Tarasov

Technology has been developed for production of elemental sulphur from off-gas from autogenous smelting processes based on reduction of sulphur dioxide with natural gas with subsequent treatment of reduced gas containing hydrogen sulfide by the Klaus method. This technology has been applied on a commercial scale at the copper smelter of the Norilsk Mining and Metallurgical Complex for treatment of off-gas from the Vanyukov smelting process (PV). In the course of further improvement of the technology a catalytic version of the process has been developed based on the use of a catalyst at the reduction stage, which permits a decrease in the natural gas requirement by 25% to 30%.

Jan 1, 2006

By O. C. Rojas

Improvements and modifications on lay out and process, from 1997 till 1998, are presented. Based on a Teniente Converter, started up 1993, a Strategic Development Plan was structured to increase the production efficiency and comply with the enviromental regulations, too. It considered the oxygen supplies to the Teniente Converter and Peirce Smith converters; reverberatory furnace shut down as a smelting unit; and the Teniente converter slag treatment through a combined process between a Slag Settler furnace and flotation. Also it included the off-gas handling and treatment.

Jan 1, 1999

By Theo Lehner

Nasty, according to the Collins Dictionary, comprises the adjectives: bad, critical, dangerous, dirty, odious, serious, severe, sickening, unpleasant etc. From this we may at first conclude that each individual smelter relying on its own specific business surrounding would have a special definition of its nasties. But common product standards and common metallurgy makes us experience common nasties. To get an idea of possible problem elements we start with the demands on the products: [ ]

Jan 1, 1994

By R. M. Luna-Sánchez

Electrochemical studies, particularly Evans? diagrams, have been employed in hydrometallurgy to simulate and explain the redox phenomena that take place at mineral and metal surfaces during operations such as leaching and cementation. However, despite their utility, in some cases, the combination of the cathodic and anodic branches, determined separately, does not reproduce the chemical environment present when both processes occur simultaneously on a specific surface. In the present paper, limitations of Evans? diagrams are analyzed through two examples: silver sulfide cyanidation and gold cementation on zinc. In both cases, the surface kinetics are sensitive to the local pH and cyanide levels. When the electrochemical oxidation of silver sulfide or the reduction of gold are performed in the absence of its corresponding redox reaction, the local pH obtained does not simulate the real situation and the combined reaction kinetics may be very different from those determined from the Evans? diagrams.

Jan 1, 2003

By Yasumasa Hattori

Fluid flow in a flash furnace concentrate burner was investigated quantitatively in order to improve burner performance. Computational fluid dynamics was utilized for researching fluid flow in a burner port mathematically then its results were reviewed in the commercial flash furnace burner and its calculation results were found to be in good agreement with the actual measurement results. Based on those results, a mathematical fluid flow model for the Sumitomo flash furnace concentrate burner has been developed so as, to improve premixing and combustion efficiency of concentrate in the reaction shaft.

Jan 1, 2002

By Qin Li

An highly active absorbent with oxidization based on fly ash, lime and additives was prepared. Experiments of simultaneous desulphurization and denitrification were carried out using fixture bed and duct injection. The influential factors for the absorptive capacity of the absorbent were studied. The absorptive capacities of 120.7mg for SO2 and 43.7 mg for NOx were achieved at a Ca/(S + N) molar ratio 1.2, respectively, corresponding removal efficiencies of 87% and 76%, while spent absorbent appeared in the form of dry powder. The optimal temperature and humidity of flue gas treated with this process were shown to be approximately 50\\176 and 5% respectively. The mechanism of removal for SO2 and NOx was investigated. In comparison with traditional dry FGD, this process appears to have lower cost, less complicated configuration and simpler disposal of used absorbent. The valuable references can be provided for industrial application by this process. The foreground of application will be vast in China and in the world.

Jan 1, 2006

By David A. Army

Many times, the maintenance professionals have been involved in changes to processes or systems. Often they rely on seat of the pants knowledge to determine whether or not they were successful. More often than not, once our attention has been turned to other endeavors, the initiative has floundered. This paper will describe those measures that can be most effectively used to track and manage the success of implementing an improved Work Management System. However, not only will the paper discuss traditional work indicators, it will also explain how to establish the behaviors in the work place that will ultimately ensure successful implementation. Combined with the discussion on indicators will be a discussion on how to tie them to bottom line results and display them in the form of a scorecard. Actual results will be discussed.

Jan 1, 2006

By Rudolf Keller

In the electrolysis of neodymium oxide from a molten fluoride electrolyte, anode effects may occur at the carbon anodes, interfering with smooth cell operation. In laboratory experiments, we attempted to circumvent this problem by selecting electrolytes with a high oxide concentration, possibly at relatively low rare earth content, but cathodic deposition was not satisfactory. A regime at higher cell voltage was discovered to yield good cell performance, but evolution of considerable amounts of fluorocarbon compounds suggested that a reactive treatment of the off-gases would be necessary for environmental acceptability. Subsequent experimentation at low cell voltage revealed conditions for satisfactory operation without occurrence of anode effects and without formation of any CF4 or C2F8.

Jan 1, 1997

By M. F. Chambers

Neodymium metal was electrowon from a molten-chloride electrolyte at 650° C using a molten-metal cathode. A 50 mol pct NdC13-50 mol pct KC1 mixture served as the electrolyte. Binary metal alloys of 'Mg with Zn and Mg with Cd were used as molten cathodes. Under the best conditions, current efficiencies were 90 pct with a Mg-Zn cathode and 80 pct with a Mg-Cd cathode. Vacuum distillation was performed at 1,100° C for 30 min under a vacuum of 10-3 to separate the cathode metals from the neodymium. Neodymium metal of 99.9+ pct purity was recovered from the Mg-Cd alloy cathode. Almost 2 pct zinc remained in the neodymium recovered from the Mg-Zn alloy.

Jan 1, 1989

By Corby Anderson

The efficient separation of palladium from the transition metals copper, nickel and iron can be effected by passing a leach solution of these metals through a column of the silica polyamine composite material, WP-1, patented by Purity Systems Inc (PSI), Assignee, University of Montana with exclusive license to PSI. The separation can be done at the intrinsic pH of a nitrogen species catalyzed (NSC) oxidative pressure leach solution (~0) and stripping of the palladium from the composite can be effected with hydrochloric acid/ammonium chloride solutions at 50oC. Batch capacities of the composite for palladium are ~ 1.8 mmol/g resin. The possibilities for isolating the metal from the strip are discussed. Given the proven longevity and rapid capture kinetics of the polyamine composites, this new approach should prove to be an economically viable alternative to the multi-step concentration processes practiced in the PGM industry to date.

Jan 1, 2003

By B. C. Curson

A comprehensive simulation of .the gas handling system in BHP Copper's San Manuel smelter was developed using AFT Fathom software, with the objective of minimizing SO2 emissions while maximizing smelter throughput. Once verified with plant data, the simulation quickly revealed' the complex interactions occurring between individual converters and the flash furnace. The increased understanding provided by the simulation allowed novel, counter-intuitive control strategies to be developed and tested successfully.

Jan 1, 1999

By P. Barrios

The copper refinery of Atlantic Copper was modernised and converted to the Isa permanent cathode system in 1995. The technology installed has proved to be an excellent platform for the development of operational improvements. During the years it has been working, the progressive assimilation of the new technology has been achieved and the level of operator knowledge has allowed design production to be reached and surpassed by more than 10%. At the same time, modifications to the work programmes, using existing equipment, have permitted the incorporation of new cells and the achievement of annual production levels of 250,000 tonnes and a productivity of 0.43 t/man-hour.

Jan 1, 1999

By C. Allen

A series of zinc chloride electrowinning tests was carried out in a laboratory scale cell to evaluate the effect of temperature, current density, electrolyte composition, gas sparging and additives on the performance of the cell with respect to current efficiency, voltage, specific energy consumption and deposit morphology. The anode material was DSA for chlorine evolution and the cathode was made of aluminum. At 400 A/m2 current density, a current efficiency of 90.9%, a voltage of 3.4 V and an energy consumption of 2.78 kWh/kg were observed. Air sparging was found beneficial but was not pursued for health and safety reasons. Various additives in the same chemical family as tetrabutyl ammonium chloride (TBAC1) were tested. Both TBAC1 and tetrabutyl ammonium bromide were found to be equally effective. Attempts to carry out the electrolysis at 1200 A/m2 were not as successful.

Jan 1, 2000