REUSE OF DUSTS FROM CAST IRON CASTINGS PRODUCTION IN FOUNDRY

Abstract

In the production process of cast iron and steel castings, a large amount of waste is generated. Each stage of production of castings generates a certain type or types of waste. The largest volume of waste is the used molding compound, followed by slags from melting processes and dust, the creation of which is copied by the entire foundry process. Dust waste is generated from the beginning to the end of the production cycle in the foundry. Finishing operations represent, in addition to a large source of noise, a large source of dust waste. They are primarily dusts from blasting and grinding of castings. These dusts are characterized by a high proportion of metallic iron. This contribution deals with the treatment and subsequent use of dusts from blasting cast iron and steel castings. In the first stage, the dust is treated by magnetic separation, during which the magnetic (metallic) part is separated from the non-magnetic (nonmetallic) part. The non-magnetic part of the dust was added to the bentonite molding mixture, while the influence of the amount of dust in the mixture on the mechanical properties of the newly prepared molding mixture was monitored. The magnetic part, which mainly contained metallic iron, was used in the production of pellets, which were added to the metal charge intended for the production of cast iron. The effect of the amount of pellets in the charge on the quality of the cast iron determined by the mechanical properties and structure of the cast iron was observed. When the proportion of pellets in the charge was up to 6%, the mechanical properties of the cast iron did not deteriorate.