CO2 hardened silicate-bonded sand additive agent and formative technology thereof

Abstract

The invention discloses a CO2 hard sodium silicate sand additive; wherein, the mass proportion of each component is: 1 to 5 percent of PEO, 10 to 35 percent of starch sugar, 25 to 50 percent of carbonate and 25 to 40 percent of water; the molecular weight of the PEO is 1*10<5> to 9*10<5>. The starch sugar is selected from dextrose, maltose or malt extract; the carbonate is selected from chalk, limestone or calcium carbonate. The invention also provides a sanding mixing technique of casting sand mixture which uses the CO2 hard sodium silicate sand additive. The CO2 hard sodium silicate sand additive of the invention can effectively reduce the content of the sodium silicate sand in the sand mixture as well as maintains higher sand mixture intensity and better old sand collapsihility. The sodium silicate sand prepared by using the additive is not sensitive to the overblowing of CO2, is easy to control the hard technique and has the higher humidity resistance.

Description

technical field [0001] The invention relates to an additive for casting molding materials, especially a CO 2 Additive for hardened water glass sand. The invention also relates to a water glass sand molding process. Background technique [0002] CO 2 Hardened water glass sand has simple process, good operability and high production efficiency. Compared with clay sand, the core strength is higher, and compared with resin sand, the core yield is better, and the pollution to the environment is relatively much smaller. But ordinary CO 2 The main disadvantage of hardened water glass sand is: the addition of water glass is more (accounting for 7% to 9% of the sand weight), which makes the collapse performance of the old sand worse; 2 Hardening is easy to form "overblowing", which reduces the strength of the core; the storage stability of the core sand is greatly affected by the ambient humidity. [0003] In order to improve the performance of water glass sand, Chinese patent Z...

AI Technical Summary

Problems solved by technology

But ordinary CO 2 The main disadvantage of hardened water glass sand is: the addition of water glass is more (accounting for 7% to 9% of the sand weight), which makes the collapse performance of the old sand worse; 2 Hardening is easy to form "overblowing", which reduces the strength of the core; the storage stability of the core sand is greatly affected by the ambient humidity

[0003] In order to improve the performance of water glass sand, Chinese patent ZL94110887.2 discloses a lignin disintegrating agent and its application. Since lignin can only improve the disintegration performance of water glass sand at 300-500°C, it is necessary to add additional lignin in actual use. Inorganic matter, so the operation of sand mixing operation has been increased; Chinese patent ZL200410035418.2 discloses a kind of foundry sand adhesive agent, although the collapsibility of water glass sand is improved by combining organic disintegrating agent and inorganic disintegrating agent, but its The amount added to the molding sand is 6% to 8% of the sand weight, and the absolute water glass content is still as high as 5.7% to 7.8%. Difficulty; In addition, the existing technology for CO 2 There is no good solution to the problems of overblowing and core moisture absorption

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