Recovering cesium from hard zinc and zinc slag

I. Overview

Shaoguan smelter into the germanium-containing plant material to about 0.0048%, the production process using an ISP zinc and lead metals, about 55% of the feed crude into the germanium and zinc. In the rectification process, about 40% of the bismuth in the crude zinc enters the lead tower hard zinc, 40% enters the B ton tower hard zinc, and the rest is mostly in the zinc slag of the blast furnace.

Hard zinc is obtained by distillation to obtain zinc powder and slag. The zinc slag is leached-tannin-sinked to obtain the bismuth concentrate (the immersion liquid is treated to obtain zinc sulfate heptahydrate).

The ruthenium containing product is subjected to chlorine leaching-distillation to prepare ruthenium tetrachloride, and finally it is hydrolyzed to ruthenium dioxide. The ruthenium dioxide is reduced to obtain a metal ruthenium.

The total recovery rate from lead-zinc concentrate to metal lanthanum is 33% to 55%.

The process diagram of hard zinc treatment is shown in Figure 1. The process flow of zinc slag treatment is shown in Figure 2. The production process of cerium oxide and metal ruthenium is shown in Figure 3.

Figure 1 Hard zinc treatment process

Figure 2 Zinc slag treatment process

Figure 3 Ceria production process

Second, raw materials

(a) hard zinc composition

Hard zinc is a multi-component alloy mainly composed of zinc and lead, and contains a small amount of elements such as Fe, As, and Ge. The hard zinc components are shown in Table 1.

Table 1 Hard zinc composition, %

(2) Zinc slag composition

Zinc slag is used to produce zinc sulphate and recover hydrazine. Its composition (%) is: Ge0.088, Zn76.70, Pb2.57, As0.299, Fe0.22.

Third, technical operating conditions

Hard zinc is treated with a muffle furnace and a power frequency induction furnace. The technical operating conditions for the production of these two furnaces, tannins and cerium oxide are as follows:

(a) muffle furnace

(2) Power frequency induction furnace

(3) Tannin sinking

Silicone: é”— (35 ~ 40): 1 (leaching solution containing é”— 0.10 ~ 0.25g / L)

Starting acid pH 2.5~3.0

Temperature 60 ° C

Stirring time 5min

(4) Tannin roasting

Temperature about 550 ° C

Time 3~5h/disk

The atmosphere can be fully oxidized

(5) Production of cerium oxide

Leaching-distillation

Liquid to solid ratio 8:1

Acid pH 1

FeCl ₃ added amount 0.1 to 0.3 times the amount of material

Stirring speed 80r/min

Chlorine content 50kg material chlorine 3kg

Leaching temperature 60~70°C

Distillation maximum temperature 115 ° C

Distillation residue containing CaCl ₂ 300g / L, HCl 2 ~ 2.5g / L

Residual liquid neutralization

Initial temperature 60 ° C

Final temperature <90°C

Final acid pH 4.5~5.0

hydrolysis

Radon tetrachloride input amount 1600ml / barrel

Antimony tetrachloride: water 1:6.5 (volume)

The addition rate of antimony tetrachloride is 20~30ml/min

Hydrolysis tank temperature <0 °C

Drying temperature 140～160°C

Drying time 6~8h

Fourth, product yield and composition

(a) muffle furnace

Daily processing capacity 2.4～3.6t/(furnace·d)

Nissan zinc powder 1.4~2.2t/(furnace·d)

Containing bismuth lead Zn15%, Pb70%, Ge1.2%. About 20% of the amount of hard zinc

Zinc slag Zn75%, Pb8%. For the production of zinc sulfate

(2) Power frequency electric furnace

The output of zinc powder is 500kg/(台·d), and the yield is about 70%.

The slag residue contains ～3.0～4.0kg/(台·d), and the yield is about 7.5%.

Crude lead Pb>75%, Zn1.8%, Ge<1.1%, yield about 12%

High arsenic slag composition Zn4.62%, Pb21.8%, As12.4%, Fe10.93%

(3) Production of crude cerium oxide

Tannin é”— coarse ore Ge<5% As<1% (wet slag: Ge<2% As<0.2% H ₂ O<80%)

Crude ceria white powder Ge≥65% As<1.0%

V. Main technical and economic indicators

Fire kiln (2.7m ² , 3.55m ² )

Zinc recovery rate 95.5%

Direct zinc yield 75.5%

Gas consumption unit 3800m ³ /t hard zinc

Water consumption 120t/t hard zinc

Power frequency electric furnace (190kW/380V)

Zinc recovery rate 95.0%

Direct zinc yield 83%

é”—Recovery rate 95%

Straight yield 75%

Hard zinc single consumption 1.181t/t zinc powder

Crude cerium oxide production

Zinc recovery in zinc slag 92%

The recovery rate of zinc slag is 50.5%

The recovery rate of arsenic in high arsenic slag is 90.25% (to GeO ₂ )

Six, the main equipment examples

The main equipment of the 韶 é”— é”— workshop is two muffle furnaces with an area of ​​2.7m ² and 3.55m ² , one 190kW/380V power frequency induction furnace; the rest are small equipment in the wet process workshop.