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JOM: The Journal of The Minerals, Metals & Materials Society (TMS) (v.54, #4)
In the final analysis by James J. Robinson (pp. 4-4).
Postage stamps: A convergence of metallurgy, art, and history by Fathi Habashi (pp. 10-12).
Postage stamps have been used around the world to commemorate, in miniature, significant events and people, including those of importance in the history of metals and mineral production. From the presence of gold artifacts in an ancient Egyptian tomb to the role of uranium in nuclear power, stamps have captured the evolution of metallurgical processes. This article highlights some of those stamps.
TMS hot topic symposium examines WTC collapse and building engineering by Toni Grobstein Maréchaux (pp. 13-16).
Tools for optimizing Cu electrodeposition: Modeling and reagent addition monitoring by Norbert L. Piret (pp. 17-18).
Using CollaMat to measure glue in copper electrolyte by Peter Stantke (pp. 19-22).
The development of the CollaMat glue measuring system started at Norddeutsche Affinerie (NA) in 1986. Since 1989, CollaMat has been used for continuous glue measuring in NA’s copper tankhouse. In addition, the system is used under license worldwide in ten tankhouses. This paper provides an overview of basic CollaMat investigations in the laboratory as well as NA experiences in the production plant.
Applying the haring cell to monitor glue addition by James E. Hoffmann (pp. 24-27).
Haring Cell technology, as embodied in the Flowing Haring Cell, provides a simple, reliable, inexpensive, and accurate method for the monitoring of cathode polarization. Sampling size is large and continuous at 1 liter per minute, providing instantaneous response to changes in glue concentration. The cathode polarization can be readily used in a feedback loop to control glue addition to ensure a constant value of cathode polarization.
Current density limitation and diffusion boundary layer calculation using CFD method by A. Filzwieser; K. Hein; G. Mori (pp. 28-31).
The knowledge of limiting current density and thickness of diffusion boundary layer is particularly important in improving space-time-yield of electrolysis and especially of high current-density electrolysis. Both natural and forced convection of electrolyte flow are considered in the presented computational fluid dynamics model for calculation of these values. Natural convection is modeled by implementation of a source term at the cathode surface for copper concentration according to Faraday’s law, which allows calculation of electrolyte density for each volume cell of the grid. Forced convection is considered as flow of electrolyte through the cell generated by electrolyte inlet and outlet. By variation of current density, the limiting current density can be calculated with a copperion concentration of zero at the cathode surface after reaching the steady-state conditions in electrolyte. Time dependency of diffusion boundary layer thickness is shown for a chosen cell geometry. Literature data and measured and calculated values of both quantities are in good agreement.
Using polyethylene glycols as alternative inhibitors in copper electrorefining by Michael Stelter; Hartmut Bombach; Nikolay Nesterov (pp. 32-36).
Polyethylene glycols (PEGs) with well-defined molecular weight ranges are interesting alternative additives for copper electrorefining. In comparison to glue, PEGs offer high thermal stability and slow chemical decomposition at higher temperatures, with high cathodic polarization. Thosefactors are advantages for an optimized process control in copper electrorefining. Investigations into cathodic polarization as a function of molecular weight and concentration at 500 A/m2, and also into the half-life of PEGs, were conducted in typical copper electrolyte.
Evaluating and monitoring nucleation and growth in copper foil by Ye-Kun Lee; Thomas J. O’Keefe (pp. 37-41).
The electrodeposition of copper foil for use in electronic materials applications is a complex and demanding process. The specific aspects of producing and controlling the structure-property-performance requirements of the foil are important because of the stringent demands placed on their use in printed circuit boards and similar products. In this paper, a brief review of the electrodeposition process for raw copper foil is presented. Since electrolyte additives play such a significant role in the copper-depositionprocess, the effects of two essential additives, chloride ion and an organic (e.g., glue or gelatine), on the foil are described. Also, the influence of other operating parameters on the initial nucleation, growth, and subsequent electrocrystallization are discussed. Selected characterization methods, such as polarization and scanning electron micrography techniques, are described as a means of monitoring the process, but universally accepted methods of evaluating and controlling the additives and foil quality during electrolysis are still being sought.
Producing bismuth trioxide and its application in fire assaying by Zack Kelly; Funsho Ojebuoboh (pp. 42-45).
Bismuth trioxide (Bi2O3) is the prevalent commercial oxide of bismuth. A precursor to the preparation of other compounds of bismuth, including the chemical reagents, bismuth trioxide has specialized uses in optical glass, flame-retardant paper, and, increasingly, in glaze formulations where it substitutes for lead oxides. In the last decade, bismuth trioxide has also become a key ingredient in flux formulations used by mineral analysts in fire assaying. The production of bismuth trioxide generally begins with the minor metal bismuth. This paper describes bismuth trioxide production and the properties and basis for its use in environmentally sound fire assaying.
Upcoming editorial topics (pp. 46-46).
Voices of innovation celebrates engineers by Kelly Roncone (pp. 60-60).