Example of wet processing of é“‹ä¸çŸ¿
First, Southwest factory using FeCl 3 bismuth leaching in mine. The raw materials used are shown in Table 1, and the process flow used is shown in Fig. 1.
Table 1 é“‹ä¸çŸ¿æˆåˆ†(%)
Fig.1 Flow chart of the process of picking up the wetness method
(1) Process technical conditions and indicators1, three ferric chloride leaching. Leachate composition: Fe 3 + 30 ~ 35 g / l, HCl 20 ~ 30 g / l; liquid to solid ratio: 4: 1; mechanical stirring, room temperature leaching: leaching time: 4 hours.
The leaching slag contains less than 0.3% bismuth; the leaching rate of bismuth is higher than 98%.
2, iron powder replacement sponge é“‹. Iron filings consumption: 0.45 ~ 0.5 kg / kg é“‹; after replacement, the liquid contains less than 0.5 g / liter.
3. Ferric chloride regeneration
(1) Chlorine gas oxidation method. The chlorine is allowed to flow for 2 hours, and the regenerant contains Fe 3 + higher than 35 g/liter.
(2) Diaphragm electrolysis method. The electrolyte solution contains HCl 40-50 g/L, Bi 3 + 40-70 g/L: anolyte contains Fe 2 + 30-40 g/L: cell voltage 2～2.3 V; current density is 200～ 300A / m 2 ; electrolyte temperature 55 ~ 60 ° C; cycle is 8 hours; pole distance 100 ~ 120 mm; both the cathode and anode are made of graphite plate, both are 0.3 m 2 ; the anode diaphragm cover is made of microporous plastic plate; The post-product fluid contains 10 g/L.
The enthalpy efficiency is 90% to 95%; the chlorination rate of Fe 2 + is 95% to 98%.
4, sponge sputum casting. After washing the filter sponge bismuth, bismuth-containing 64% -69%, 6% to 8% iron, melting, solid base was added to the pot about 200 kg, heated after being melted, a sponge bismuth, such as bismuth-containing copper sponge High, you can mix the appropriate amount of sulfur powder in it and refill the pot.
The consumption of crude alkali per ton is 0.55~0.65 tons, and the consumption of sulfur is 0.07~0.09 tons. The crude sputum contains 97% to 98.5%, and the direct recovery of hydrazine is 95% to 96%.
After the alkali residue is taken out, the solid alkali is recovered by water immersion, and the leaching residue can be recovered by the beneficiation or smelting method.
(2) Equipment
1. Leaching equipment . 2 m 3 steel tank, inner lining cavity, bottom lining ceramic tile, mechanically stirred leaching tank two, one for leaching of ferric chloride; one for leaching solution plus new bismuth mine reduction.
2. Replacement equipment. The displacement reaction was carried out in a leaching tank.
3. Recycling equipment
(1) Chlorine gas oxidation equipment. The sealed rubber-lined steel tank has a diameter of 1 m and a height of 1.6 m. The three steel tanks are connected in series, and the chlorine gas pipe is a circular porous plastic pipe, which is inserted from the top, and the exhaust gas is absorbed by water and then emptied.
(2) Diaphragm electrolysis equipment. The electric accumulator is welded with a 10 mm thick plastic plate. The internal dimensions are 1400×500×570 mm. The bottom is tapered, and the anode and cathode are connected in parallel. The trough and the trough are connected in series and then connected in parallel.
(4) Casting equipment. Cast steel pot.
Second, East China factory was semi-industrial test case of bismuth sulfide concentrate with ferric chloride leach more gold. The materials used are listed in Table 2.
Table 2 Chemical composition of antimony sulfide concentrate (%)
The process flow is shown in Figure 2.
Figure 2 Process flow of FeCl 3 leaching strontium sulfide concentrate
It can be seen from Fig. 1 that the strontium sulfide concentrate is leached with ferric chloride and hydrochloric acid, similar to the leaching of the strontium ore, mainly through four processes, namely, leaching of ferric chloride, iron filings, chlorine regeneration and sponge casting.
(1) Process technical conditions and indicators
1. Leaching of ferric chloride. Leaching temperature 98-106 ° C; leaching time 2 hours; concentrate particle size - 200 mesh accounted for more than 90%: Fe 2 + concentration 70-90 g / liter: liquid-solid ratio: from 3:1 to 2:1; leaching acidity : HCl 20 ~ 30 g / liter: liquid impurity content after leaching: Cu 2.5 ~ 3 g / liter, Pb 1 ~ 1.7 g / liter, Ag 0.1 ~ 0.4 g / liter, Fe 2.5 ~ 3 g / liter.
The leaching rate is higher than 99%; the leaching slag contains Bi less than 0.3%; the silver extraction rate is higher than 98%; the leaching slag contains silver 17-260 g/ton; the lead leaching rate is higher than 95%; the slag rate is 40%-60 %.
2. Iron filings replacement. Normal temperature replacement: replacement time 4 to 6 hours: control pH 0.4 to 0.6; iron filing coefficient of 1.5 or so.
The replacement rate is higher than 98%; the silver substitution rate is higher than 98%; the replacement liquid contains about 0.3 g/liter.
3. Chlorine regeneration. 2 hours of chlorine, the solution containing Fe 3 + less than 2 g / liter before regeneration, Fe 2 + ~ 95 g / liter after regeneration at room temperature; spray cold water outside the reaction tank to facilitate the reaction, because 2FeCl 2 +Cl 2 = 2FeCl 3 is an exothermic reaction.
4, sponge sputum casting. Feeding ratio: crushed alkali: sponge 铋 0.6 to 0.7:1: slowly heated to 650 ° C for 8 hours.
(2) Equipment
1. Leaching equipment. φ850 mm composite coating tank leaching, a titanium material serpentine heater, a stirrer; mill 550 × 550: acid pump 1 / 2BA-6 acid pump fiberglass, titanium shaft.
2. Replacement equipment. Φ850 mm displacement groove, 1 m high; acid-resistant pump φ100 plastic pump; ceramic filter 150 liters.
3. Regeneration equipment. 150, 350 liters of regenerative reaction tanks; vacuum pump SZ-2 water ring type; water jacket cooler 600 liters.
4. Melting and casting equipment. One φ1200 mm casting pot.
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