Features of vertical lance operation in direct-flow mode

Autogenous processing modes implemented in special pyrometalurgical plants are widely used to intensify the processes of pyrometallurgical processing of heavy non-ferrous metal raw materials. One of the actively implemented smelting technologies in the world is the process using TSL in Ausmelt® and ISASMELT™ furnaces. Top-Submerged Lance (TSL) maintains its durability by ensuring the formation of the skull layer on the lance body when blowing an oxygen-air mixture (OAM) into the melt through a vertical pipe of a special design. The practice of implementing these processes has shown the theoretical and actual possibility of using air blast both with swirling (TSL) and without swirling of the air blast flow. Feeding natural gas into the central part of the air blast without swirling affects the overall swirl of the swirling flows when blowing the melt in the furnace. The melting process parameters change significantly from the standard operation mode of the TSL when organizing a direct-flow mode of blast mixtures for all coherent jets. In order to analyze the distinctive features of direct-flow and swirling jets with more detail, the main parameters of blast mixtures when flowing from the lance and their mutual influence on the flame characteristics are shown. To determine the parameters of a vertical lance and its process features, a calculation and evaluation method for direct-flow jets for a blast mixture in a vertical melting furnace is proposed. When the blast mixture of air and oxygen blows straight with different ratios, the mathematical means are presented to estimate the diameter of the blast funnel and the depth of its penetration into the melt. With regard to the hardware design of Ausmelt® and ISASMELT™ furnaces equipped with direct-flow lances, a model for the formation of melt circulation zones in the inner hearth and their influence on the process parameters of melting is shown.