Recycling of bismuth oxides

OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 23 No. 3 2021 Ta b l e 2 Bismuth oxide melting products at a temperature of 1,150 ºС Product, Q-ty, g Experiment No. 3: Content (β), % / Distribution (ε) of the component, % Bi Pb Zn Sb As Sn Alloy 67.3 7.06/89.0 81.64/99.0 0.03/0.4 1.15/32.2 ‒ 0.17/7.2 Slag 44.8 0.06/0.5 1.81/1.0 6.72/46.9 1.24/23.1 1.55/39.9 1.17/33.6 Dust 20.8 2.69/10.5 ‒ 16.29/52.8 5.16/44.7 5.03/60.1 4.43/59.1 Product, Q-ty, g Experiment No 4: Content (β), % / Distribution (ε) of the component, % Bi Pb Zn Sb As Sn Alloy 68.3 7.32/93.6 80.55/99.7 0.02/0.2 1.07/30.4 ‒ ‒ Slag 91.3 0.08/1.4 1.23/2.0 3.31/47.0 0.61/23.1 0.65/34.1 0.46/27.2 Dust 36.4 0.73/5.0 ‒ 3.39/52.7 3.07/46.5 3.15/65.9 3.12/72.8 Fig. 1. Diffractograms of bismuth lead: a – experiment 4; b – experiment 3 ; 1 – Pb, 2 – PbS 3.9–7.4 MgO; 2.5–6.3 CaO, which receive, %: 0.5–1.4 Bi; 1.5–2.0 Pb; ~47 Zn; 23 Sb; 34.1–39.9 As; 27.8–34.4 Sn. The phase composition of the slag (Experiments 3 and 4) is shown in Fig. 2. The amount of fluxes (Na 2 CO 3 , SiO 2 ) and reducing agent (graphite) taken in mass ratios (Table 3) was varied to streamline the reduction smelting operations of bismuth oxides. The amount of fluxes was taken on the basis of preliminary calculation of compositions slags in the binary system of Na 2 O–SiO 2 , which allows predicting the melting temperature of the latter. The calcula- tion was carried out in two alternatives based on possible yield of both meta- and ortho-silicates of sodium,