Reduction of Lead-Rich Slags with Coke in the Lead Blast Furnace

摘要

The reduction of lead-rich slag with metallurgical coke is one of the major reactions in the dripping zone of the lead blast furnace. However, because the conditions of this zone are hard to replicate in a laboratory experiment, previous studies have been limited to simplified reaction geometries. In this work, an experimental study is performed in a laboratory-scale set-up that more closely resembles the conditions inside the dripping zone of the lead blast furnace. A synthetic, lead-rich, PbO-SiO_2-CaO-Fe_2O_3 slag, is molten on top of a small-scale metallurgical coke bed with a total bed diameter of 35 mm, by heating for 15-60min at temperatures of 1200-1300 °C. A multitude of particles, including lead-depleted slag, lead, and iron, were found on the coke surfaces. This illustrates the occurrence of the direct reduction reaction. The importance of coke surface morphology for reactivity with slag is emphasised, as the majority of reduced particles are found in pores and surface depressions.