Inertization of aluminum powder for industrial reuse avoiding its oxidation. Coating processes without interferences in subsequent applications

• Published in: Powder technology 2015-12, Vol.286, p.212-217
• Main Authors: Salazar Mardones, G., Arnáiz García, F.J., Pedrosa Saez, M.R., Blasco González, M.V., García Ruiz, J.J.
• Format: Article
• Language: English
• Subjects: Aggregates; Aluminum powder; Inertization; Passivating; Pelletising; Reuse
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2015.08.006

The objective of this work is to develop a simple, potentially cost-effective technique to preserve the properties of aluminum powder, reducing its explosivity. Inertization of aluminum powder with protective coatings was carried out employing different chemical agents and conditions with the aim of achieving a valid method for the stabilization of aluminum powders in water. When hydrophobic, antioxidant or tensoactive agents are employed, coating is proposed as a suitable process to avoid aluminum hydroxide production. This behavior increases the possibilities for reuse of waste aluminum powder. The methodology for determining the efficiency of the inertization process of aluminum powder was based on comparing the content of aluminum, treated and untreated, after aggressive oxidation conditions or simulating real storage conditions. Anhydrous lanolin and green linseed oil gave good aggregates when stirred with aluminum powder. Pelletizing was applied as possible method of inertization. However, the existence of easier and cheaper protection systems make their implementation difficult. The final product obtained when the most efficient method was employed (covering the powder by mixing with waterglass) was validated in industrial application, affirming the possibility for reuse of the residual aluminum powder. Waterglass and citric acid were the best inertizing agents in the different tests and showed good results in industrial validation. The focus of this work is the inertization of aluminum powder. To achieve the objective different agents and methods were employed. As a result of this work, two inertizing agents were chosen, because they showed good results in different tests and in industrial validation. [Display omitted] •Inertization of waste aluminum powder•Addition of reagents to intertize and pelletize avoiding aluminum oxidation•Type and concentration of reagents employed for aluminum powder protection•Waterglass and citric acid give the best results as aluminum inertizing agents.