Phosphate binder for casting

Abstract

The invention relates to a phosphate binder used for casting, which comprises the components by weight ratio: 45 to 55 percent of phosphoric acid, 33 to 45 percent of aluminium dihydrogen phosphate, 5 to 15 percent of boric acid and 6 to 12 percent of citric acid. The binder can also be mixedly matched with 0.5 to 2 percent of magnesium oxide curing agent by weight ratio. The binder adopts the phosphoric acid and the aluminium dihydrogen phosphate as a binder main body, and is added with the boric acid and citric acid for improving the bonding property, thus being one phosphate binder with good property used for casting. The binder has the advantages of low cost, little environmental pollution, high hot strength, good collapsibility and the like, can improve working environment to the utmost extent, and reduce production cost.

Description

technical field [0001] The invention relates to a phosphate binder for casting, which belongs to an inorganic binder. Background technique [0002] In the traditional foundry industry, because water glass is used as a binder to make water glass sand, it has the advantages of low cost, non-toxic and odorless, and simple sand configuration process. However, casting mold (core) sand made of water glass sand After the casting is poured, the residual strength is too high, which makes it very difficult to remove the sand from the casting, and the efficiency of sand removal is low. In order to improve the sand cleaning efficiency of castings, resin sand has tended to be used for production in the prior art. However, the price of the resin binder is high, and it is easy to produce a large amount of toxic organic gas after pouring, which seriously pollutes the operators and the air. It needs to be equipped with huge air purification equipment, and the investment cost of the equipmen...

AI Technical Summary

Problems solved by technology

This treatment method is not only costly, but also produces a large amount of toxic gas, which seriously affects human health, and the treated wastewater is discharged into the ground, seriously polluting the environment

Furthermore, this treatment method is likely to cause metal cracks in the casting, which affects the quality of the casting.

At the same time, the acid, alkali, and salt remaining in the inner cavity of the casting core during the sand cleaning process are easy to combine with other substances during the use of the casting, producing harmful substances, affecting the service life of the casting, and making the casting scrap