Hydrogen inhibition by using Cr(NO3)3·9H2O in the wet dust removal system for the treatment of aluminum dust

Abstract

Aluminum dust could react with water and produce hydrogen gas during its treatment process in a wet dust removal system, leading to a risk of hydrogen fire and explosion. In this work, in order to explore an effective method for inhibiting the production of hydrogen, inhibition experiments were carried out in an aluminum dust and water reaction tester using Cr(NO3)3·9H2O solution as the Hydrogen Inhibition Method (HIM). Scanning Electron Microscopy (SEM) was used to characterize the surface of aluminum particles before and after the experiments while the reaction products were analyzed by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive Spectroscopy (EDS). By using Cr(NO3)3·9H2O solution, the inhibition film was observed on the surface of aluminum particles after the experiments and the main components of the film were analyzed to be Al(OH)3 and Cr(OH)3, which could prevent contact between aluminum particles and water and thus prevent the reaction between them. Based on the shrinking core model, the physicochemical mechanism of the HIM method was identified. The proposed HIM using Cr(NO3)3·9H2O solution was validated to be very effective and could mitigate potential hydrogen fire and explosion accidents with a low cost.