Hydrogen, which can be produced due to the accumulation of aluminum dust that reacts with water in wet dust removal systems, is a fire and explosion hazard. To reduce hydrogen production, sodium tungstate is used in hydrogen inhibition experiments to inhibit the reaction between aluminum dust and water. The purity of the aluminum powder was 95.15%, analyzed with X-ray fluorescence spectrometry (XRF). Each of the hydrogen inhibition experiments lasted for 12 h. In addition, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface morphology and composition of particles before and after the experiments. There was nearly no hydrogen produced when the concentration of the sodium tungstate solution reached 100 g/L. The results show that a protective coating containing W element was formed on the surface of the aluminum particles after the reaction with sodium tungstate, and the coating prevented the aluminum particles from contacting with water.

Confined space operations are inherently dangerous, leading to frequent accidents with serious consequences. This study utilizes an improved Human Factors Analysis and Classification System (HFACS) model to analyze the human factors contributing to confined space accidents, employing both chi-square tests and grey correlation analysis. The integration of these two analytical methods is essential for providing a comprehensive understanding of the causal relationships among human factors, thereby enabling more robust and validated conclusions. Initially, we identified human factors associated with confined space accidents based on the traditional HFACS model and the unique characteristics of confined space operations, resulting in the identification of 5 primary risk factors and 17 secondary risk factors. Subsequently, we employed chi-square tests and grey correlation analysis to examine the causal relationships among these human factors. The combined results of these methods reveal significant influence relationships within the HFACS model levels pertinent to confined space accidents, identifying 11 significant causal relationships and three paths of accident development. The primary aim of the statistical and correlation analyses is to identify and validate the significant causal relationships among the identified human factors, thereby enhancing our understanding of their impact on confined space accidents. The findings of this research are instrumental in reducing the risk of confined space accidents within enterprises, ultimately ensuring the safe and sustainable operation of production processes.