Materials for water-cooled cooling fingers for furnace refractories

摘要

Current copper smelting is characterized by high intensity and productivity. However, this has led to increasing demands on refractories resulting in possible shortening of the service life of furnace linings. To counteract this, it has become common to embed water-cooled copper cooling elements within refractory walls to promote solidification of a thin slag layer onto the refractory surface. However, failures still occur and it is not fully understood why these cooling elements at times fail in protecting the refractory lining. High temperature oxidation rates of copper, nickel-plated copper and copper-aluminum alloys are presented. Immersion tests of laboratory scale cooling elements with various protective means, have been carried out in molten matte and slag. The results show that the addition of 3 to 4 wt% aluminum to copper decreases the high temperature oxidation rate by 4 orders of magnitude. However, due to a significant drop in thermal conductivity, the ability to extract heat is compromised, leading to failure when immersed in molten matte.