The growing awareness of fertilisersʼ pivotal role in modern agriculture and food production has been driven by a parallel, rapid development of chemistry and the chemical industry. Corrosion is a worldwide crucial problem that strongly affects sulfuric, phosphoric, nitric, and hydrochloric; strong bases: soda ash, caustic soda, and ammonia; and salts of potassium and ammonia. All these chemicals are highly corrosive to steels and, under certain conditions, even to stainless steels; so that special stainless steels and high-cost nickel alloys may be required to avoid shutdowns resulting from corrosion problems. In the manufacture and handing of nitrogen fertilizer solutions, chromium-nickel stainless steels and aluminum alloys are satisfactorily resistant, but copper alloys and zinc are severely corroded. Corrosion in fertilizer plants may lead to contamination of products; loss of materials, equipment, and operating time; increase in maintenance expense; and environmental and even social problems. Granular fertilizer products and mixed fertilizers are transported by trucks, railways, and ships, in bags and in bulk, and they are stored in bins and warehouses. Corrosion of vehicles and storage structures may result from absorption of water by the fertilizers in humid climates and from wetting by rain. Agricultural machinery used for application of fertilizers in the field usually natural and industrial environments, in particular in the fertilizer industry (FI). The chemical nature and composition of a fertilizer determine its corrosion characteristics. Fertilizers may be acidic, neutral, or basic; their pH and hygroscopicity affect their corrosiveness in the presence of moisture. Corrosion problems occur in FI in four general areas: production, storage, transportation, and field application. Production of fertilizers involves use
of strong mineral acids: is fabricated of carbon steel which is protected by paint or organic coatings. These protective coatings may deteriorate from attack by acidic or basic fertilizers, and this leads to further corrosion of the unprotected areas of the steel equipment. The application of stainless steel for fabrication of critical parts of these machines avoids these problems. The corrosive characteristics of fertilizer intermediates and products are determined by simple and rapid laboratory tests that are based on accepted standards an techniques published by NACE, ASTM or equivalent European standards: BSI, DIN, AFNOR. The data obtained are useful in extending the life of equipment used in industrial operations. A sound knowledge of corrosion problems in the FI is necessary for the development of efficient, practicable methods for control and selection of materials of construction that will reduce the expense of maintenance of the equipment and facilities. Typical cases of corrosion management in the FI are
presented based on the authors experience and knowledge.
Michael Schorr*¹, Benjamin Valdez¹, Amir Eliezer ², Ricardo Salinas ¹
¹Institute of Engineering, Department of Materials, Minerals and Corrosion, University Autonomous of Baja California, CP. 21280, Mexicali, Baja California, Mexico. firstname.lastname@example.org, email@example.com, firstname.lastname@example.org
²The Authority for Research and Development, Sami Shamoon College of Engineering, Ber-Sheva, Israel. email@example.com