Accretion Growth at the Tuyeres of a Peirce-Smith Copper Converter

Abstract

AbstractIn copper converting, accretions form at the tip of the tuyeres, and may block the air flow which then necessitates punching. In this study, observations have been made of accretions in a Peirce–Smith converter at the Inco Copper Cliff Smelter by viewing through the mouth when the vessel was rolled out of the stack. In addition, a mathematical model, based on heat and mass transfer, has been developed to predict the size and shape of accretions as a function of several variables: blast pressure, blast flow rate, oxygen enrichment, stage of the converting cycle, bath superheat and bath composition. Thus it has been found that accretion formation is most pronounced during the slagmaking stage, particularly toward its completion, and early in the coppermaking blow. Increasing the air flow rate or decreasing the bath superheat enhances accretion growth. With increasing oxygen enrichment of the blast, the size of the accretion diminishes until at about 36% O2, the tuyere line is virtually exposed. Rais...