Problems and development direction of sand casting binder

With the progress of science and technology, green sand casting technology has made great progress, but there are some problems in both less polluting inorganic binder for sand casting and low-cost non emission old sand recycling technology.

Sodium silicate binder is more and more used in sand mold casting, but sodium silicate sand also has some problems, such as poor collapsibility of old sand, difficult regeneration and reuse, and alkaline sewage reuse of wet reclaimed sodium silicate sand, which restrict the development of sodium silicate sand. With the development of ester hardened sodium silicate sand technology, the problems of collapsibility and recycling of used sodium silicate sand have been solved, but there is still a long way to completely solve the problem of recycling used sodium silicate sand. In recent years, the application of microwave hardening technology to sodium silicate sand casting has further reduced the amount of sodium silicate in sodium silicate sand and improved the collapsibility and recycling of sodium silicate sand. The development of microwave hardening sodium silicate sand technology has made another big step towards green casting of sodium silicate sand.

The regeneration and reuse technology of single used foundry sand is relatively mature, but the regeneration and reuse technology of mixed waste sand commonly existing in enterprises is not mature. The old sand regeneration and reuse technology with low cost, high quality and no secondary emission is still an important development direction for the resource regeneration and utilization of cast waste sand in the future.

At present, sand casting is still the main way of casting production in China. The low-cost regeneration and reuse of waste sand in sand casting and the harmless emission of sand casting tail gas all put forward higher requirements for sand casting binder. The sustainable development of foundry industry and the green and clean production mode in the 21st century proposed by the state urge foundry workers to design, develop and use safe and pollution-free green foundry binder. The development and production application of new green casting binder has important practical significance for accelerating the clean process of sand casting production and the renewal of traditional products, eradicating environmental pollution in sand casting production from the source, reducing production cost and improving casting output.