Association of Foundrymen of St. Petersburg and Leningrad Region (St. Petersburg, Russia):

S. S. Tkachenko, Dr. Eng., Prof., e-mail: spblenal@mail.ru
G. A. Kolodiy

South Ural State University (Chelyabinsk, Russia):
L. G. Znamensky, Dr. Eng., Prof., Chair of foundry production

Plant of Special Chemistry (Chelyabinsk, Russia):
A. A. Ermolenko, Leading Specialist

The well-known molding technology based on an inorganic binder is presented, which almost completely eliminates environmental risks while improving technological parameters and maintaining economic viability. Referring to the history of the development of molding technologies, the authors clarify the reasons by virtue of which modern foundry production uses organic binders, when there are inorganic ones that are not inferior to them. The technology is described in the form of a comparison of the technological parameters of the most well-known inorganic binders - aluminoboronphosphate concentrate (ABPC) with common processes that use organic resins as binders. The most important characteristics of the mixtures are compared and the advantages of the mixture with the inorganic binder are highlighted, such as: undemanding quality of the sand; possibility of using the waste mixture after mechanical regeneration; possibility of using universal equipment; possibility of preparing the mixture at low temperatures; lack of adhesion of the mixture to a pattern equipment; high strength of molds and cores; low gas evolution; high gas permeability; high refractoriness; high non-stick properties; minimum labor intensity of the mold knock-out and cleaning of castings; high quality castings; almost complete absence of harmful emissions. It is noted that the high performance characteristics of the ABPC allow to use it in other types of casting, other than mold boxes on the base of cold-hardening mixtures. Known technologies for the use of the ABPC for preparation of suspensions for investment casting, as well as for preparation on its basis of anti-stick paints for lost foam casting. The analysis of the operational characteristics of the technology formulates a conclusion about the existence of an objective need to develop the casting process using ABPC-based cold-hardening mixtures and its widespread use in domestic enterprises as an alternative to the «borrowed» cold-hardening mixtures based on organic binders.

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