Preparation and Evaluation of Rust Removal Solution for Anticorrosive Properties

Abstract

The deterioration of metal surface especially iron due to oxidation or other chemical reactions results in the formation of rust. Rust consists of hydrated iron (III) oxide (Fe2.O3. nH2O), which is generated when iron, is in contact with both moisture and oxygen. The formation of rust causes enormous loss to the economy of the country and compromises the integrity of the structures. Therefore, there is a need to develop solutions which can remove rust from metallic surfaces. The objective of this study was to prepare some rust removal formulations using selected reagents and to evaluate their rust removal properties. The formulations were prepared using compositions of different low molecular weight organic acids (LMWOs) at room temperature. Formulation one contained citric acid, sulphamic acid, and iron sulphate whereas, formulation two was composed of acetic acid, sulphamic acid, and iron sulphate. Formulation three contained hydroxyacetic acid, sulphamic acid, and iron sulphate. Formulation four was composed of oxalic acid, sulphamic acid, and iron sulphate, whereas formulation five was composed of extracted citric acid, sulphamic acid, and iron sulphate. The study established that the % rust removal for formulation one was in the range of 35- 63%, 71-85%, and 77-92%, after 30 minutes, 60 minutes, and 90 minutes respectively. The percentage of the rust removed by formulation two ranged from 38-60%, 60-87% and 73- 79%, after 30 minutes, 60 minutes and 90 minutes, respectively. The percentage rust removal by formulation three was 62-77%, 78-81% and 55-88% while for formulation four the range was 14-29%, 32-63% and 11-21% and for formulation five the range was 0.3-66%, 0-1.6 % and 0.7-1.9 % after 30, 60, and 90 minutes respectively. The study showed that at room temperature after 30 minutes the percentage rust removal was in the following order: Formulation 3 with a mean of 81%, followed by formulation 1 at 47.6%, then formulation 2 at 42.4%. This was followed by formulation 5 and 4 at 22.7% and 22.5% respectively.FTIR analysis was conducted on the composition of all formulations before and after the reaction with the rusted metal surface to establish the functional groups involved in the process of rusting. The FTIR study showed that the peaks produced by formulations had some peaks disappear, others shifting from original positions. Based on the study, the prepared formulations indicated the ability to remove rust from the rusted nails of this project. The amount of removed rust depended on the nature of the formulation. Formulation one gave the optimum rust removal property at room temperature.