crisoles

Crisoles are crucibles—refractory vessels used to contain materials at high temperatures during heating, melting, calcination, or chemical reactions. The term crisoles is the Spanish plural of crisol, and in English the corresponding term is crucibles; nonetheless, crisoles may appear in multilingual or historical texts. They are essential in laboratories, metalworking, and materials research for processing substances that must be heated beyond the tolerance of ordinary containers.

Most crisoles are made from ceramic or carbon-based materials chosen for high melting points and chemical compatibility. Common options include porcelain, fused silica, alumina (aluminum oxide), magnesia (magnesium oxide), zirconia, and graphite or clay-graphite compounds. Porcelain and quartz are relatively inexpensive and inert to many oxidizing melts, while alumina and magnesia crucibles withstand higher temperatures and more aggressive melts. Graphite crucibles offer excellent thermal conductivity and stability under reducing conditions but may react with certain metals and oxidize in air, making clay-graphite composites a common cost-effective alternative.

Typical applications include melting and alloying metals, preparing ceramic or glass frits, digestion of ash and residues, and various chemical synthesis steps that require containment at high temperatures. The choice of crucible depends on temperature, chemical compatibility, and desired lifetime; some melts can attack or contaminate the container, limiting reuse. Safety considerations include handling hot crucibles with tongs, using appropriate furnace atmospheres, and inspecting for cracks before reuse.