Treatment method and application of inorganic binder reclaimed sand

Abstract

The invention relates to a treatment method and application of inorganic binder reclaimed sand. The method comprises the following steps of: uniformly stirring the inorganic binder reclaimed sand, a sintering agent and water, standing for reaction, and performing heating treatment to obtain the treated inorganic binder reclaimed sand. The reclaimed sand treated by the method provided by the invention thoroughly gets rid of the situation that the inorganic binder reclaimed sand can only be used in inorganic type manufacturing materials, realizes the production of organic resin sand, and greatlyexpands the recycling channels of different types of waste sand; and by adopting the method provided by the invention, the process requirements on the regeneration of the inorganic binder used sand can be reduced, the used sand can be used for completely replacing new sand by simple treatment, and the refractoriness, bonding strength and other properties of the reclaimed sand treated by the method provided by the invention can be improved by more than 20% in comparison with the new sand.

Description

technical field [0001] The invention belongs to the technical field of recycling old foundry sand, and in particular relates to a treatment method and application of inorganic binder regenerated sand. Background technique [0002] my country's silica sand resources are limited, and the recycling of foundry waste sand to improve the regeneration process of foundry old sand, replacing new sand and recycling is an urgent requirement and inevitable trend to realize energy saving and emission reduction of enterprises and green production of my country's foundry industry. [0003] Common casting molding materials include: inorganic binder sodium silicate sand, organic phenolic resin sand, etc. There are many regeneration processes for foundry used sand, such as mechanical regeneration, thermal regeneration or wet regeneration, or the combination of the above regeneration processes. Certain properties of regenerated sand cannot completely replace new sand. The main reasons are as f...

AI Technical Summary

Problems solved by technology

[0004] (1) Mechanical regeneration destroys the smoothness of the sand surface, thereby reducing the fluidity of the sand, the strength of the resin coating, and affecting the compactness of core making and molding;

[0005] (2) In the sand gully area, there are residual substances (bentonite, paint, carbonized resin film, etc.), which affect the refractoriness of reclaimed sand and reduce the quality of reclaimed sand. A certain amount of new sand must be mixed in before it can be used;

[0006] (3) For the old sand with silicate inorganic binder, these residual silicates will be adsorbed in the gully area of ​​the sand and can hardly be removed

[0007] Since the activity of silicate is reversible, it will recover its activity after absorbing moisture. When producing hot core phenolic resin coated sand, it is necessary to add the aqueous solution of curing agent urotropine, and use the waste heat of the sand to evaporate the water. , and the residual silicate in the reclaimed sand will absorb this part of the water, increase the water content of the coated sand, and also affect the cross-linking reaction between the organic phenolic resin and the curing agent, thereby reducing the performance of the coated sand

[0008] At present, regenerated sand with inorganic binder cannot be used in the production of coated sand, regenerated sand can only be used in the sand system with inorganic binder, and a certain amount of new sand must be added

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