J. Burja, F. Tehovnik, F. Vode, B. Arh, Institute of Metals and Technology, Ljubljana, Slovenia In this chromium slags that form during melting of chromium alloyed steels are examined. During melting and oxidation of these steel grades a considerable amount of chromium is lost, and gained back with slag reduction. Laboratory experiments were performed to study the mechanism of chromium oxide re...

Title of dissertation: USE OF TARTARIC ACID AND ISOPROPYL ALCOHOL IN THE REDUCTION OF HEXAVALENT CHROMIUM AND APPLICATION TO CHROMIUM CONTAMINATED SOILS AND CHROMITE ORE PROCESSING RESIDUE Dominic A. Brose, Doctor of Philosophy, 2012 Dissertation directed by: Professor Bruce R. James Department of Environmental Science and Technology Although chromium (Cr) is a naturally occurring metal, in the...

Introduction: Komatiites provide several ways of assessing the chemical and thermal evolution of the mantle. Komatiitic liquids are produced from very high degrees of partial melting of the deep mantle, and erupted as extremely fluid lavas. Komatiites are important in the study of the early Earth because they are a significant constituent of the Archean crust. It has been proposed that komatiit...

Boninites are rare high magnesium andesites that often contain trace chromites. These chromites precipitate from primitive boninitic melts and thought to be carried the surface in continue crystallize a significant volume of silicate minerals. Such magmatic differentiation drives chromite out equilibrium with residual melt respect both divalent trivalent cation proportions. Diffusion then opera...

Abstract: In this paper solid state reduction of high carbon ferrochromium-chromite composite pellets in the temperature range of 900-1350°C was investigated. A two stage reduction mechanism is proposed. The first stage is likely to be controlled by the chemical reaction with activation energy of 127.2kJ/mol. In the second stage, solid state diffusion of carbon through the reaction product ...

Physicochemical patterns of complex reduction multicomponent charge have been studied in the absence liquid phases order to obtain spongy ligatures. The contained both simple oxides and oxide compounds. was conducted being realized at expense carbon gases (CO H2) as well with participation carbide phase, which formed during process. dependence phase composition products on initial ratios O/(C+H...

Cosmic-ray exposure ages of 480 million year old fossil meteorites found in Southern Sweden constrain delivery times of meteorites from a large collision in the asteroid belt. Chromite grains from seven meteorites from four stratigraphic layers define an exposure age gradient as expected if the meteorites originated from the well-known L-chondrite parent body break-up event. The very short deli...