Lost-wax casting, also called precision casting, is the process of casting a duplicate metal sculpture cast an original sculpture. The ceramic shell mould used in lost-wax casting usually consists of several layers formed with fine zircon and granular mullite particles using silica gel as a binder. However, it is a complicated and time-consuming process. Large amounts of waste moulds that need to be disposed and recycled become an environmental concern. In this study, waste shell sand from the recycled mould and calcium carbonate/metakaolin were used as raw materials to prepare geopolymer slurry and coating. The influence of mixing ratio and the SiO₂/K₂O modulus of the alkali solution on the setting time and green/fired strength were evaluated. Ceramic shells with one to four layers of geopolymer slurry and waste sand sprinkling were fabricated and tested for their permeability and green/fired strength. It was found that geopolymer shells had higher green/fired strength and better permeability than the original zircon/mullite shell. For foundry practice, metal casts were fabricated using recycled ceramic shell moulds with one to four layers of geopolymer coating. All cast results have their dimensions all within tolerance limitation and up to 13 h can be saved for the preparation of shell moulds.

中文翻译：

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熔模铸造中回收的壳粉和砂与土聚合物技术制造陶瓷模具

失蜡铸造，也称为精密铸造，是铸造重复的金属雕塑并铸造原始雕塑的过程。失蜡铸造中使用的陶瓷壳模具通常由几层组成，这些层由细的锆石和粒状莫来石颗粒组成，并使用硅胶作为粘合剂。但是，这是一个复杂且耗时的过程。需要处理和回收的大量废模已成为环境问题。在这项研究中，以再生模具中的废壳砂和碳酸钙/偏高岭土为原料制备地聚合物浆料和涂料。混合比和SiO ₂ / K _2的影响评价了碱溶液的O模量对凝固时间和生坯/烧成强度的影响。制作了具有一到四层地质聚合物浆料和撒落废砂的陶瓷壳，并测试了它们的渗透性和生火强度。发现地聚合物壳比原始的锆石/莫来石壳具有更高的生坯/烧结强度和更好的渗透性。对于铸造实践，使用具有一到四层地质聚合物涂层的回收陶瓷壳模制造金属铸件。所有铸造结果的尺寸均在公差范围内，准备壳模最多可节省13 h。