... Φ12.5mm, Φ14.4mm, Φ17mm, Φ20mm, Φ25mm, Φ32mm, Φ38mm, Φ42mm, Φ50mm, Φ100mm and other dimensions protective sleeve of the crystallizing dish ... shortcomings of being oxidized for the common graphite protective sleeve, but also the defect of being preheated and explode ... convenient, but also difficult to damage the protective sleeve. Protective sleeve and inner liner usde for oxygen-free copper producing ...