Preparation of Direct Reduction Sponge Iron (DRI) Using Pyrite Cinder Containing Nonferrous Metals

摘要

Pyrite cinder is a solid waste generated by the sulfuric acid industry and is considered environmentally hazardous. It contains abundant iron, such as Fe_(2)O_(3) and Fe_(3)O_(4), and nonferrous metals, such as zinc, lead and copper. In order to try and recycle this material as a source of Fe units, preparation of direct reduction iron (DRI) using pyrite cinder was investigated by coal-based grate rotary kiln process. This process includes chloridizing and reduction roasting. The results show that 97?% lead was removed after the chloridizing process. Copper was only detached in chloridizing process with the removal rate of 78.49?%. Furthermore, the removal of zinc was carried out in both chloridizing and reduction process, and the removal rate of 96.76?% was achieved after reduction roasting. The final product representing a metallization degree of 93.36?% with compressive strength of 1,198?N/pellet was obtained after the oxidized pellets were reduced at 1,050?°C for 80 min.