Abstract

Foundries using organic binders like alkaline phenolic show interest in the use of inorganic binders like sodium silicate in core making and mould process. The cost of dumping waste sand from alkaline phenolic plants are more as they contain more toxic gases as compared to those of inorganic sodium silicate plants. Foundries are looking into saving cost by possibly using their already existing reclaimed sand from alkaline phenolic plant in new plants using sodium silicate. This research initiated to assist an alkaline phenolic foundry decision to use their already available reclaim sand in the new sodium silicate plant planned to build. A process for preparing foundry cores or moulds, sands and chemical resins used made available. The chemical binders consisted of inorganic binder of Alkaline phenolic and an organic binder of sodium silicates with their catalysts. Sand materials consisted of new silica sand and reclaimed sand from foundry alkaline phenolic moulding plant. Core prepared by mixing sand with each binder and allowing them to cure at room temperature. Alkaline phenolic at a 1, 5% binder addition to sand and 20% to binder of catalyst addition. For Sodium silicate testing completed at 3% binder addition to sand and 10% to binder of catalyst. The curing time of 1 hour, 4 hours and 24 hours. The results showed that alkaline phenolic developed higher bending strength with new silica sand with strength of up to 32 N/cm² than with reclaimed and 20:80 new to reclaimed sand mixture which only reach the bending strength of 15 N/cm². Alkaline phenolic developed higher Tensile strength of 25 N/cm² with reclaimed sand and 20:80 new to reclaimed sand with 20 N/cm² than with new sand reaching only five N/cm². In conclusion, new sand can develop strength with both alkaline phenolic and sodium silicate binders. It is difficult to develop strength with sodium silicate binder when using reclaimed sand. Based on this research it not recommended the use of Reclaimed sand from alkaline phenolic plant on the new sodium silicate plant.

Key words

Sodium silicate, Alkaline phenolic, Self-hardening/ no bake, Curing time, Core