Silver removal from molten lead through zinc powder injection

Silver Crust Processing by Vacuum

“…Установлено, что за 24 ч при t = 1000 °С исходный образец СПЛ на ~94 % перешел в состав возгонов вместе с цинком, свинцом и частью серебра. В кубовом остатке в основном присутствуют, %: 67,97 Ag, 15…”

“…Драгоценные металлы (ДМ) из чернового свинца взаимодействуют с цинком с формированием тугоплавких интерметаллических соединений AuZn 3 и AgZn 3 , почти не растворимых в свинце. Как более легкие, эти соединения всплывают на поверхность, образуя серебристую пену (СП) [10][11][12][13][14][15][16][17].…”

“…At t ~ 800 °C, Р = 10 -1 mm Hg, zinc condensate was obtained containing, %: 99,85 Zn, 0,14 Pb. At t ~1000 °C, Р = 9•10 -3 mm Hg, zinc-lead concentrate (15,7 Zn; 83,6 Pb; 0,02 Ag), lead concentrate (86-87 Pb; 0,4-2,8 Zn; 0,04-0,12 Ag), silver concentrate (50-67 Ag; 0,1-5,3 Pb, 0,04-0,2 Zn). At t ~1200 °C, Р = 6,5•10 -3 mm Hg, lead concentrate (91-97 Pb, 0,6-1,7 Zn; 0,01-1,2 Ag) and silver concentrate (92 Ag, 1,4 Pb, 0,1 Zn) were obtained.…”

Experimental assessment of the gray cast iron production by inoculant injection

“…They found high effectiveness and stability, based on the silicon composition changes after performing the inoculation through pneumatic injection of the powdered inoculant by argon as a carrier gas into the liquid. Other works related to the powder injection technique are focused on the lead refining process [18][19][20]. The injection efficiency depends mainly on the flow patterns.…”

“…However, particle trajectories are very important as they establish the residence time, which represents the time required for the particles leaving the lance tip until they reach the liquid surface. As residence time increases, the injected particles will have more opportunity to react with the metal bath, and higher efficiencies are achieved [18,19]. The basic requirement for heterogeneous nucleation lies in the ability of the molten iron to wet the inoculant particles.…”