SOUTHERN JOURNAL OF SCIENCES

Editorial note.

Background: Aluminum stands out for being a light, corrosion-resistant, and recyclable metal, achieving wide coverage in the market. When incorporated into alloying elements, it is possible to acquire other desirable characteristics. Alloy 6063, intended for architectural purposes, has aesthetic, structural, and strength functions. Anodized finishing is performed through an electrolytic process, ensuring a more resistant aluminum oxide film than that formed naturally. For decorative purposes, the anodic film coloration can be performed by several methodologies, in this case, for the coloration by organic adsorption, with the use of aniline, and the electrolytic coloration, composed of tin sulfate salts, both for obtaining the black color. Aim: Compare of two different staining methods on the surface of anodized profiles of aluminum alloy 6063. Methods: Profile samples were collected and tests were carried out to measure the thickness of the anodic layer, immersion tests with 3,5 percent sodium chloride, for 1000 hours, and neutral saline mist, for 600 hours. Results and Discussion: Both methodologies proved to be resistant to immersion tests with sodium chloride, as well as with neutral saline mist, and these tests are quite aggressive and provide corrosion of the material when not well treated. Corrosion points were only seen at the intersections performed, and in the rest of thearea, no points were detected. Conclusions: The result of both methodologies was positive, considering tht there was no corrosion in the tested samples, except in the intersections performed, as well as the maintenance of the color in both tested methodologies, which was not expected in the literature. For future work, it is suggested to deepen the study to perform electrochemical impedance spectroscopy tests for exaluate the strength of the anodic film and perform anodizing with the same parameters, however, with different anilines to analyze their behavior.

The ore beneficiation process uses little technology, but mining companies have high economic performance. As an energy source, firewood plays a fundamental role due to its simple storage, low cost, great availability of forests, and lack of processing. Thus, the present work aims to analyze the consumption of firewood as fuel and possible improvements in the process for the production of lime in terms of harnessing raw materials and costs. Calcium oxide is obtained from the thermal decomposition of calcium and magnesium carbonates obtained from dolomitic deposits of limestone (CaCO₃ : CaMgCO₃). After CaO extraction, it is subjected to a calcination process, removing carbon dioxide (CO₂) in ovens that work at temperatures between 900 and 1200°C. The source of energy applied to the calcination furnaces in the analyzed area is wood. The wood has a calorific value between 2,250 and 2,700 Kcal/Kg, but the moisture content responsible for the thermal variation must be considered. The firewood burning process was carried out in a ravine type oven where the temperature at which operators are exposed to heat was evaluated. The results indicated that the cooking time dropped by 20% as the amount of wood is fed into the oven. This increase represents a significant gain in lime production, thus leading to a higher profit for the company.