Erosion-corrosion and corrosion wear evaluation of materials in potash brine

Abstract

Potash plants handle very corrosive raw materials and several corrosive intermediates and by-products. Several corrosion problems are encountered during potash production due to the prevalent conditions of high pressures and temperatures, high fluid velocities, abrasion, erosion, and the presence of very corrosive chemicals and by-products. The corrosion wear of materials results in severe corrosion damage and other forms of degradation. Corrosion wear is defined as the degradation of materials in which corrosion and wear mechanisms persist together and often interact. The wear action may remove the corroded surface layers to leave fresh metal surfaces exposed to corrosive environments so that total materials losses are much greater than that of each process taken alone. Erosion-corrosion is a conjoint action involving corrosion and erosion in the presence of a moving corrosive fluid, leading to the accelerated loss of material. In the present study, the corrosion wear and erosion-corrosion resistance of select commercially available metallic alloys, ceramics, polymers, and glass fiber reinforced polymer composites (GFRP) in hot potash brine environments were determined using a modified slurry tester and a reciprocating test apparatus, respectively. Experiments were conducted at room temperature and 85°C. The evaluation methods employed included weight loss analysis, optical microscopy, and scanning electron microscopy (SEM). Although all the polymer-based materials gained weight by absorbing potash brine during the early stages of the experiment, the overall results show that GFRP (A-series and P-series), high density polyethylene (HDPE), and Ferralium 255 have excellent erosion-corrosion and corrosion wear resistance in potash brine. Note:Missing: Page 93