The metal surface effects produced with various blasting abrasives can range from deep cutting to gentle scouring of the surface. Important factors to consider in selecting an abrasive include: type of surface to be cleaned, shape of the structure, type of material to be removed, surface finish desired, profile, breakdown rate of the abrasive, reclamation of the abrasive, hazards associated with the use of the abrasive. The types of available abrasives vary from one part of the country or the world to another. The general categories are: steel shot, metal grit and mineral abrasives. Naturally occurring ores includes; sand, garnet, ilmenite and white sand are probably the most commonly used for blast cleaning of metallic surfaces before applying protective painting. This study covers the specification and the quality of some nonmetallic ores (sand, garnet, ilmenite, white sand), utilized as abrasive materials used in the blast cleaning of metal surface such as petroleum construction projects, ships, hulls and tanks to remove rust, scale, old paint and marine growth, also to provide the required anchor “profile” necessary for bonding of paint layers with metal substrate. The study program shall compare between the physical, chemical and mechanical properties of Egyptian, Indian, Chinese and Austrian ores to demonstrate the complete figure for the proper abrasive media can achieve the standard metal surface preparation before applying protective coatings in the oil, gas, petrochemical construction projects. The evaluation techniques to evaluate the quality of the various nonmetallic abrasive ores incorporated laboratory and field testing including physical properties (specific gravity, moisture content, pH value, Particle size distribution, free flow, Conductivity, oil content, Hardness), chemical analysis and field particle testing. The study indicates that the GMA Australia garnet, Egyptian Garnet, China and Indian garnet gives a very good result for steel surfaces cleaning, profile, no dust contamination and very low level of slat contamination in comparison with other non metallic ores.
Loading....