Kinetics of aluminum powder oxidation by water at 100°C

Abstract

The kinetics of aluminum powder oxidation by water at 100°С has been investigated using three types of aluminum powders. A "shrinking sphere" model was used for description of the experimental data at the initial reaction stage, whereas a "parabolic" diffusion equation was used at the second stage. Variation of the specific reactivity is discussed.

Porous Ceramic Matrix Al2O3/Al Composites as Supports and Precursors for Catalysts and Permeable Materials

“…Meanwhile, the rates of Al consumption at the second diffusion-controlled stage of hydrothermal oxidation were substantially different. For ASD-4 this rate was higher by two orders of magnitude (Tikhov et al, 2007). Therefore, the smallest hydroxide (oxide) particles were obtained for this PPM.…”

“…Quantitative estimates of the oxide content based on the earlier reported calibration curve (Tikhov et al, 2004) are shown in Table 1. The differences of the oxide content in cermets are mostly due to different reactivity of the used aluminum powders at the initial hydrothermal oxidation stage (Tikhov et al, 2007). Aluminum is practically not subjected to any oxidation during calcination in air at 550°C.…”

Modeling of the Bioleaching of Process Silver Pulp

“…There are many reports of systems that behave like the Yagi model and different modifications to this model have been proposed. It has been used to explain solid-liquid reactions under non-isothermal conditions [12], when the nucleus is porous [13,14], for different reaction orders [12], and considering a parabolic equation for the diffusion stage [15].…”

Metal Scrap to Hydrogen: Manufacture of Hydroreactive Solid Shapes via Combination of Ball Milling, Cold Pressing, and Spark Plasma Sintering

“…In the study [16], a first-order reaction model was used to approximate kinetic curves for aluminum powder, casing, and foil reacting with water under hydrothermal conditions. For commercial Al powders ('ASD-1', 'ASD-4', and 'PAP-2' grades) reacting with water at 100 • C, a 'shrinking sphere' equation was found to be applicable to the kinetics description at the initial stage, and the second stage was approximated using the parabolic diffusion equation [45]. For Al powder reacting with Na 2 SnO 3 (0.05 M), a similar 'shrinking sphere' model was used at the first stage, and the Ginstling-Brounshtein equation was employed for the second one [46].…”