Abstract

ROGEL-RAMIREZ, Alejandro de la Cruz  and  ZAMORA-PLATA, José Antonio. Development of a steelmaking slag-based coating for solar water heating application. Ing. invest. y tecnol. [online]. 2023, vol.24, n.4, 2013.  Epub Nov 28, 2023. ISSN 2594-0732.  https://doi.org/10.22201/fi.25940732e.2023.24.4.026.

Along with iron and steel production, large amount of slag is generated (30-45 % and 10-20 %, respectively). The black steelmaking slag is produced in BOFS (Basic Oxygen Furnace Slag, mostly in México) and EAFS (Electric Arc Furnace Slag). The objective of this study is the construction of solar water heating systems by using industrial wastes. This work describes the testing of an affordable steelmaking slag based coating, for solar thermal energy capture. The coating was elaborated by mixing BOFS particles with size ranging from 5 to 25 µm (95 %), copper filing (1mm x 3mm), and natural adhesive. Firstly, the study was conducted on a copper tube (3/4”, ID) filled with stationary water and fitted with thermometer, using a polycarbonate tube (1 ¼” ID) as transparent cover. The highest temperature reached was 64°C. The effects characteristics of the coating layer, including size and mass concentration of particles and coating thickness on thermal behavior were studied. The formulation was streamlined on results and the process was repeated until optimal results were achieved (5 % mass of copper). Then, a flat plate solar water heating collector was constructed (0.5 m2) with thermotank of 30-liter capacity. The highest temperature of solar water heating system was 65°C. Taking into account that commercial flat plate collectors manufacturers claim heating in 45-65°C range, the new affordable paint competes with the commercial solar thermal energy coating. The new steelmaking slag based coating can be used, e.g., in solar water heating collectors (low temperature), heating air for space thermal conditioning and materials drying.

Keywords : Basic Oxygen Furnace Slag; BOFS based coating; solar water heating collectors; thermal performance; materials drying.