フェライトスラグ中への鉛精鉱の吹込み溶錬に関する基礎的研究

抄録

The problem to be solved in a direct lead smelting process is the considerable lead losses in dust and slag. The dissolution of lead in ferrite slag is approximately 10 times lower than that in silicate slag, affording a possibility to produce low sulfur bullion with high lead recovery by changing the slag from a silicate to a ferrite type and by using oxygen enriched air to decrease the dust loss. To investigate the usability of the proposed new process by use of ferrite slag and oxygen, an apparatus with a laboratory scale was constructed in this study to make lead bullion by injecting PbS reagents or concentrates and oxygen gas onto a layer of calcium ferrite slag.
The lead content of the produced calcium ferrite slag was quite low, being at most 5% at the sulfur content of bullion of 2%. On the other hand, the dissolution of lead in the iron silicate slag was extremely high, amounting to about 40% at the same sulfur content of bullion. The lead loss as chemical dust decreased considerably with increasing oxygen concentration of input gas, resulting in the high recovery of lead as bullion.