Synchronous Volatilization of Sn, Zn, and As, and Preparation of Direct Reduction Iron (DRI) from a Complex Iron Concentrate via CO Reduction

Volatilization behavior of SnO2 reduced under different CO–CO2 atmospheres at 975°C–1100°C

“…(Platteeuw and Meyer, 1956;Padilla and Sohn, 1979;Kim et al, 2011;Zhang et al, 2011;Cetinkaya et al, 2012;Zhang et al, 2012;Li et al, 2014). However, there is a big discrepancy between the results of reports.…”

Recovery and Purification of Tin from Tailings from the Penouta Sn–Ta–Nb Deposit

“…It should be noticed that Fe oxides have a significant effect on the reduction of the Sn oxides during the reduction process [26]. The equilibrium diagram for the gas phase of these Fe and Sn oxides under different CO-CO2 atmospheres [27][28][29] indicates that the reduction of the Fe oxides is inevitable, and therefore that the Fe content of the raw material is <15%; were it any higher, it would affect the reduction of SnO2. In addition, any tin metal could easily combine with metallic Fe to form an alloy, and thus cause the loss of the Sn.…”

“…In addition, any tin metal could easily combine with metallic Fe to form an alloy, and thus cause the loss of the Sn. Thus, the optimum conditions for melting the raw materials lie in the 700-1127 • C region, with a CO/(CO + CO 2 ) ratio of 7-17% [29] in which tin oxides are reduced to tin metal but the iron oxides are reduced only to FeO. This latter FeO can then combine with the CaO and quartz in the concentrate to form Fe-Ca-Si compounds in the slag.…”

Separation of Zinc from High Iron-Bearing Zinc Calcines by Reductive Roasting and Leaching

“…[23][24][25] However, in our early work using carbon as the reducing agent, the iron extraction of the roasted samples was so high that the selective leaching of zinc was difficult. 26 In the binary zinc ferrite-carbon system, the partial pressures of CO and CO 2 of the system in equilibrium with carbon are determined by the Boudouard Reaction, Reaction (8), and some of its thermodynamic data in the temperature range of 500-900°C are listed in Table II. C þ CO 2 ¼ 2CO:…”

“…Typical pyrometallurgical processes (including the Waelz process and the Ausmelt technology) use coal as a reducing agent for the reduction of zinc ferrite to metallic zinc and iron at 1100-1400°C, followed by the volatilization and recovery of the zinc as zinc oxide fumes and the discharge of metallic iron-containing residues from the ends of the rotary kilns. [6][7][8][9] Despite the high zinc and lead recoveries, the iron and other valuable metals are wasted and a large amount of fuel is consumed. In acid leaching processes, [10][11][12][13][14] zinc ferrite is dissolved under intensive leaching conditions (low pH and high leaching temperature).…”