Alkaline phenolic resin old sand and regeneration method thereof

Abstract

The invention relates to a regeneration method of alkaline phenolic resin old sand. The regeneration method comprises the following steps of 1, adding 0.2-2% by mass of powder into alkaline phenolic resin old sand, carrying out mixing to obtain a uniform mixture, heating the mixture to a temperature of 600-800 DEG C, and carrying out hot method regeneration for 30-60min, and 2, screening the regenerative sand subjected to hot method regeneration to remove impurities of the regenerative sand so that the alkaline phenolic resin regenerative sand is obtained. The powder is high-valence carbonate or sulfite. The powder can be easily decomposed at a high temperature and form a corresponding oxide, the oxide is added into the regenerative sand and improves mold core strength and obviously improves regeneration effects, and the treated regenerative sand has obviously reduced acid demand value, pH value and loss on ignition, can replace original sand and can satisfy heating core and cooling core conditions. The regeneration method improves regenerative sand quality, reduces environmental pollution caused by old sand and has an important meaning for saving a casting enterprise molding material cost.

Description

technical field [0001] The invention belongs to the field of material regeneration and relates to regeneration of old sand, in particular to an alkaline phenolic resin used sand and a regeneration method thereof. Background technique [0002] The characteristics of the old alkaline phenolic resin sand are the same as those of the ester-hardened water glass old sand. It has always been considered as the old sand that is difficult to regenerate and reuse, and it has not been solved well so far because: ⅠEster-hardened alkaline phenolic resin old sand The resin film on the surface of the sand grains has a certain toughness at room temperature, especially when the water content in it is >1.0%, it is difficult to obtain an ideal regeneration effect by dry mechanical regeneration; Ⅱ. Ester hardened alkaline phenolic resin on the surface of old sand grains A certain amount of organic ester remains in the resin film, which can shorten the usable time of the regenerated sand, redu...

AI Technical Summary

Problems solved by technology

However, the addition of additives cannot remove the resin film and residual ester. At the same time, adding this additive has a certain acidity. Long-term use will corrode equipment and cause harm to human health.

Therefore, this method of chemical regeneration is difficult to be promoted.

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