Novel chemical regeneration method for used sand of sodium silicate

Abstract

The invention discloses a novel chemical regeneration method for used sand of sodium silicate, and belongs to the field of resource recycling in the casting industry. According to the invention, a two-component reagent composed of calcium oxide and distilled water, an emulsion composed of sucrose and calcium oxide, a calcium chloride aqueous solution and the like are used for regeneration treatment of used sand; samples are prepared from regenerated sand which is obtained by mixing reagents into used sand to be subjected to sealing and standing for 0-24 hours, sample preparation performances including instant strength, final strength, collapsibility and sodium carbonate content of the reclaimed sand are tested, and performances of the regenerated sand are compared with those of new sand and the used sand after the test is completed. The various performance indexes are comprehensively considered, and in the regeneration methods, the performance indexes of the regenerated sand obtained by regenerating for 12 hours by utilizing (calcium oxide + distilled water) are best; compared with new sand, the instant strength is improved by 60%; the final strength is improved by 154%; the collapsibility is slightly poorer than that of new sand and is superior to that of old sand; the content of sodium carbonate is reduced by 1.38% compared with used sand, and the use requirement is met.

Description

technical field [0001] The invention belongs to the field of resource recovery and utilization in the foundry industry, and in particular relates to a novel chemical regeneration method for used water glass sand. Background technique [0002] As a big foundry country, my country needs to transform into a powerful foundry country in the new era, which requires more attention to environmental protection and energy conservation. Water glass old sand is divided into two types, ester hardened old sand and CO 2 Hardened old sand, considering the wide use of water glass sand in the foundry industry, in order to avoid the destruction of the environment and waste of resources caused by the random disposal of used old sand, it is necessary to regenerate the old sand. Under today's technology, there are a variety of regeneration schemes including physical and chemical forms, such as dry regeneration, wet regeneration, composite regeneration and chemical regeneration, etc. These techno...

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Problems solved by technology

Under today's technology, there are a variety of regeneration schemes including physical and chemical forms, such as dry regeneration, wet regeneration, composite regeneration and chemical regeneration, etc. These technologies have their own advantages and disadvantages, dry and wet regeneration At present, there have been sufficient researches. The dry regeneration operation is simple and easy to implement, but the reusability and stripping rate are low; the wet regeneration effect is good, but it requires a large amount of water, which makes sewage treatment difficult; and in chemical regeneration In terms of technology, there are few researches at home and abroad. The current main achievement is that the strength of regenerated sand obtained by using sodium hydroxide for regeneration treatment has been greatly improved, but the continuous accumulation of regenerated sand alkalinity (mainly sodium carbonate and sodium acetate) will cause Affect the performance of reclaimed sand, and the direct discharge of waste sand will pollute the environment

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