Application of Ceramsite Sand in Lost Foam Casting Process

2026-06-01

Application of Ceramic Sand in Lost Foam Casting Process

Lost foam casting is a globally recognized near-net shaping process. It helps cut costs through integrated casting design and lightweight design. In the early stage of lost foam application, silica sand was the main raw sand. However, with the rapid development of lost foam casting technology, silica sand is restricted by poor refractoriness and high thermal expansion rate, leading to increasingly prominent application drawbacks, such as severe sand adhesion on casting surfaces, low surface precision and difficult sand cleaning.

SND ceramsite sand features high refractoriness, low thermal expansion, superior roundness and high reclamation rate. It can effectively eliminate defects like casting sand adhesion, making it an ideal raw sand for lost foam casting.

Properties of Ceramic Sand

Ceramic sand is produced via raw material inspection, grinding and homogenization, CNC batching, high-strength granulation, high-temperature sintering and precise grading.

Performance Comparison of Several Common Sands for Lost Foam Casting

Currently, the commonly used sands for lost foam casting include silica sand, pearl sand and ceramic sand. Their performance comparison is as follows:

1. Silica sand has a lower refractoriness than pearl sand and ceramic sand. It causes severe sand adhesion on local areas of castings (such as holes and grooves), making cleaning difficult. The sand adhesion problem is even more serious in the production of large steel castings.

2. The thermal expansion rate of silica sand is high, 10 times that of ceramic sand. At different temperatures, silica sand undergoes multiple crystal phase transformations, resulting in large volume changes.

3. Silica sand is prone to crushing and pulverization, leading to excessive dust in the workshop. This fails to meet environmental protection requirements, creates a poor working environment for workers, and results in a low recycling rate.

4. Compared with pearl sand, ceramic sand has three major advantages:

① High recycling rate. Ceramic sand grains feature high mechanical strength, a dense and solid structure without hollowness, low breakage rate, and high recycling efficiency.

In lost foam casting applications, due to the production process, pearl sand has a higher breakage rate and lower recycling cycles than ceramic sand. Therefore, the amount of new sand supplement required when using ceramic sand is less than that of pearl sand.

② Lower Cost. As ceramic sand has a lower bulk density than pearl sand, less sand is required in use, giving it a clear advantage in overall usage cost and a higher cost-performance ratio.

③ More Eco-friendly. Due to policy impacts, pearl sand faces rising market prices and unstable supply because of its poor production environment and high energy consumption. In contrast, ceramic sand is produced with greener processes, higher yield rates and lower energy consumption, making it the preferred choice for many foundry enterprises.

Summary

Ceramic sand, when applied to the lost foam casting process, can effectively reduce casting defects such as sand adhesion, helping enterprises lower their production and usage costs.