Reclamation method of used sodium silicate sand

Abstract

The invention provides a reclamation method of used sodium silicate sand. The reclamation method comprises the following steps of: placing the used sodium silicate sand which is well crushed and screened into a closed or semi-closed container, introducing high-temperature water vapor at the temperature of 100 DEG C and above into the container for steaming and showering the used sodium silicate sand, steaming and showering for above 15 minutes, filtering out treatment fluid generated by steaming and showering from the bottom of the container, then taking the sodium silicate sand out of the container, and drying to get reclaimed sodium silicate sand. According to the reclamation method disclosed by the invention, sodium oxide in the used sodium silicate sand can be effectively removed so that the content of the sodium oxide is lower than 0.25%; and furthermore, a gel film in the sand can be effectively removed and the film removal rate can be up to above 90%. The performances of the reclaimed sodium silicate sand approach and even exceed those of new sand, so that the reclaimed sodium silicate sand can completely meet the using requirements of cast-molding. Moreover, the water consumption in the treatment process is very low, which is only 1 / 10-1 / 5 of the quantity of the treated sand, and the treatment fluid can also be comprehensively utilized, so that the reclamation method has the advantages of resource conservation, greenness and environmental protection, and is further conductive to realizing cyclic economy.

Description

technical field [0001] The invention relates to a high-quality and high-efficiency regeneration method of used water glass sand. Background technique [0002] The production of steel castings by water glass sand molding has the advantages of simple process, low cost, non-toxic, tasteless, and abundant sources. It is the most promising green molding material in the 21st century. However, it is difficult to regenerate old sand, and it is difficult to break due to poor collapsibility. Over the years, used water glass sand has been regenerated by dry, wet, and chemical methods. Due to the unique properties of used water glass sand, the quality of regenerated water glass sand Poor, old sand collapsibility significantly decreased and other defects. [0003] At present, there are mainly two types of regeneration treatment methods for used water glass sand, dry and wet, the essence of which is to remove the residues on the surface of used water glass sand, especially the Na 2 O in...

AI Technical Summary

Problems solved by technology

However, it is still not solved in the recycling process of sodium silicate old sand, Na 2 The accumulation of O will still deteriorate the high temperature performance of water glass type (core) sand

[0009] It can be seen that due to the toughness of the binder on the surface of the old water glass sand, dry regeneration is difficult, low in efficiency, and poor in effect, and wet regeneration can only remove the water-soluble part of the sand

However, the old water glass sand contains a water-insoluble adhesive film, which cannot be completely regenerated by wet method.

Thereby up to now, the regeneration of sodium silicate old sand has not been satisfactory solution and regeneration equipment