Hachinohe Smelting Company Limited operates a zinc-lead smelter based on the Imperial Smelting Process producing 112,000 t/y of zinc and 40,000 t/y of lead. In 2017, we celebrated the 50th anniversary of the establishment of the company.
Raw materials for the smelter comprise a variety of zinc and lead sulfide concentrates, and secondary oxide materials. The secondary materials are treated either in the sinter plant or in the hot briquetting plant. In the smelting furnace, zinc is reduced to zinc vapor and caught by molten lead. Lead and slag are flow out from below the furnace. In addition to zinc and lead, precious metals can be recovered advantageously, which dissolved in crude lead and copper dross. Moreover, this process is particularly resistant to impurity elements such as chlorine and fluorine, which are not good at electrolytic smelting.
In this presentation, we will report on recent improvements in our plant.