Recovery of copper, antimony and lead tin from crude tin electrolysis anode slime

July 02, 2023


  Rough tin electrolytic anode mud treatment process

Recycling copper :
(1) in the anode mud after drying reverberatory furnace, oxidizing roasting, copper → CuO, tin → SnO 2 at a temperature of 700 ~ 750 ℃, and volatile part of arsenic, antimony.
(2) baking for 40 to 60 mesh sand, 5% to 7% dilute sulfuric acid leaching of copper, the liquid: solid = 2: 1, stirred for 2h, the leaching temperature is 80 ~ 90 ℃. Copper enters the solution as CuSO 4 . After leaching, the liquid contains copper 4.5 to 6 .5g /L ; the leaching residue component (%) is: 0.2 to 0.4Cu, 32 to 45Sn , 6 to 15Bi , 21 to 26Pb .
(3) replacing the copper-containing solution to obtain an iron powder with copper powder.
Recycling bismuth:
(1) a dilute sulfuric acid leach residue after the copper, with 8% to 10% diluted hydrochloric acid leaching liquid: solid = 2: 1, the leaching temperature is 90 ~ 95 ℃, stirred for 2 ~ 3H, bismuth into solution was BiCl 3 , the leachate contains 铋 40 ～ 50g The leaching rate of /Lo 铋 is generally 70 %.
( 2 ) The hydrazine-containing solution is hydrolyzed to obtain a BiOCl precipitate. The volume ratio of the water added to the hydrazine solution is 8 to 10 : 1 . The mixture was hydrolyzed and stirred, and allowed to stand for 24 hours after hydrolysis . The obtained BiOCl precipitate contains 65% to 72% Bi , which can be used as a raw material for producing electrolytic ruthenium.
( 3 ) The steps and technical conditions for producing electrolytic ruthenium from BiOCl :
The BiOCl precipitate is slowly added to 10 % to 12 % hydrochloric acid to dissolve into BiCl 3 : liquid: solid = 3 : 1 , and stirred at room temperature, a small amount of potassium chlorate may be added to ensure complete dissolution of the hydrazine. Adding glue at the end of dissolution 0.2g /L and sulfuric acid 3g /L to speed up clarification and lead removal.
The crude BiCl 3 solution is replaced with an iron plate to obtain a sponge crucible; an iron plate can also be used as a cathode and an anode to control current density. 110A /m 2 , allowing the electrowinning and displacement to occur simultaneously, accelerating the formation of the sponge.
The sponge crucible is melt cast into a rough anode. The sponge is covered with caustic soda or caustic potash at 35 0 ~ 400 °C The temperature of the molten bismuth into crude, and then cast into anodes which component (%) is: 9 7 ~ 99Bi, 0.1Sn, 0. 8 ~ 1.3Cu, 0.8Pb, 0.05Fe.
Rough electrolytic refining: using HCl-BiC1 3 electrolyte (hydrochloric acid 16 0 ~ 165g /L , Bi 3+ 11 0 ～ 150g /L) , cathode current density 90A /m 2 , electrolyte temperature 1 5 ~ 30 °C The same name 50mm The cathode is purely ruthenium and the periphery is coated with paraffin. The cathode deposits are dense and fine. After casting into ingots, the composition (%) is: 99.95Bi , 0.001Sn , 0.002Cu , 0.002Pb , 0.001Fe , 0.001As , 0.002Sb .
( 4 ) The direct yield of the whole process is 78 % to 81 %.
Recycling lead and tin:
(1) hydrochloric acid residue of the secondary component (%) after leaching bismuth: 4 0 ~ 48Sn, 22 ~ 28Pb, 1 ~ 2Bi. Reverberatory furnace smelting reduction with tin, lead, bismuth, reduced to metal. The ratio of smelting ingredients is: secondary filter residue 100kg , Pulverized coal 1 0 ~ 12kg, sodium carbonate 4 ~ 5kg Limestone 3kg Fluorite 3kg . The melting temperature is 120 0 to 1300 °C, and the produced alloy contains 45 % to 55 % Sn , 40 % to 47 % Pb , and 4 % to 6% Bi . This alloy has a low tin grade and a high lead content and is a coarse solder.
( 2 ) Rough solder electrolytic refining. Silicon hydrofluoric acid electrolyte, the component (g · L -1) was: total acid 16 0 ~ 180, Sn 2+ 15 , Pb 2+ 10, HBF 4 12 ~ 15, gelatin 0.15, β - naphthol 0.15. The conditions controlled during electrolysis are: current density 6 5 to 70 A · m -2 , electrolyte temperature 3 2 ~ 36 °C , Cell voltage 0. 2 ~ 0.35V. The obtained cathode deposit has a smooth surface and contains 55 % to 60 % Sn and 40 % to 45 % Pb as qualified solder.
Impurities such as antimony and arsenic remain in the anode slime. This anode mud is the raw material for the tadpole.

Extruded Desulfurization Extruded Activated Carbon

Extruded Desulfurization Extruded Activated Carbon,Carbon Activated,Bulk Activated Carbon,Activated Carbon For Waste Gas

Shanxi Xinhui Activated Carbon Co.,Ltd. , https://www.shanxixinhuicarbon.com