CN102345015A

CN102345015A - Method for removing thallium in process of producing refined cadmium with high-temperature dust generated by acid preparing system

Info

Publication number: CN102345015A
Application number: CN2011102860668A
Authority: CN
Inventors: 奚英洲; 程永强; 魏艳秋; 王铁成
Original assignee: HULUDAO ZINC INDUSTRY Co Ltd
Current assignee: HULUDAO ZINC INDUSTRY Co Ltd
Priority date: 2011-09-24
Filing date: 2011-09-24
Publication date: 2012-02-08
Anticipated expiration: 2031-09-24
Also published as: CN102345015B

Abstract

The invention provides a method for removing thallium in the process of producing refined cadmium with high-temperature dust generated by an acid preparing system. The method comprises the following steps of: carrying out neutral leaching on the high-temperature dust so as to obtain bottom flow; after carrying out high-acid leaching and water washing on the bottom flow, returning supernatant back for neutral leaching, and returning water washing slag back to a blasting furnace system for batching; oxidizing and removing iron from a medium leaching liquid by utilizing a blasting method; after removing iron, carrying out solid-liquid separation, and then returning filter slag back to a swirling furnace system for batching; removing thallium from filtrate with potassium chromate; carrying out solid-liquid separation again, wherein the obtained filter slag is used for extracting thallium; and carrying out primary replacement on the filtrate, and carrying out packing and smelting on produced sponge cadmium so as to obtain crude cadmium; carrying out secondary replacement on the liquid obtained after the primary replacement, and returning the produced secondary sponge cadmium to the leaching system for extracting zinc and cadmium; and entering a solution obtained after secondary replacement into a sewage treatment system for treatment. By applying the method provided by the invention, the efficiency of removing thallium can be improved, the losses of zinc and cadmium valuable metals are less, operation is simple, and filtration is easy. The method provided by the invention is suitable for application of removing thallium in the cadmium production process in a wet-process metallurgy industry.

Description

The high temperature dirt of acid making system output is produced the method for removing thallium in the pure cadmium process

Technical field

The invention belongs to nonferrous metallurgy hydrometallurgy field, what be specifically related to is that the high temperature dirt of acid making system output is produced the method for removing thallium in the pure cadmium process.

Background technology

It is that high temperature dirt with the acid making system output is raw material that high temperature dirt is produced pure cadmium, through leaching, purify, displacement, the melting of the group of pressure, rectifying and generate.High temperature dirt is one of byproduct of zinc smelting acid making system output, and main component is zinc and cadmium, also contains impurity such as thallium, arsenic.Because what scavenging process adopted is the air blast oxidation style, the oxidizing potential of oxygen is 1.23V in the air, and thallious oxidizing potential is 1.28V, and therefore, thallium can not be removed by dioxygen oxidation in this process.In the operation of displacement cadmium; Content for impurity thallium in the control sponge thing; The cadmium electrode current potential that utilizes the concentration difference of cadmium and thallium to cause more greatly is higher than the principle of thallium electropotential; Adopt method of replacement twice; At first evenly displace 90% cadmium amount lentamente; At this moment; Only have an appointment 15% thallium and cadmium together cemented out; Remaining thallium is along with displacement back solution gets into next step operation; Adopt twice replaced method that remaining cadmium and thallium are cemented out fully again, formation contains the higher intermediate material of thallium-secondary Spongy Cadmium.The secondary Spongy Cadmium is returning when soaking process, and thallium wherein enters into again in the production system, causes the accumulation of thallium in the cadmium production process.

Do not have the thallium operation of removing in the conventional wet processing process, cause thallium enrichment in thick cadmium production process, finally cause thus the pure cadmium of thick cadmium production to contain thallium and exceed standard, need return again and handle, waste great amount of manpower and material resources.

Summary of the invention

In order in the pure cadmium production process, to remove thallium, the high temperature dirt that the present invention proposes a kind of acid making system output is produced the method for removing thallium in the pure cadmium process.This method makes it to remove thallium with the thallium precipitin reaction through adding potassiumchromate in the solution after deironing.Not only solve pure cadmium and contained the problem that thallium exceeds standard, and the removing the thallium slag and can further reclaim the extraction thallium of output.

The scheme that technical solution problem of the present invention is adopted is:

High temperature dirt with the acid making system output; In per 100 kilograms of high temperature dirt; Contain 15～25 kilograms of Zn, contain 5～10 kilograms of Cd, contain 20～40 kilograms of Pb; Contain 2～4 kilograms of Ti; Contain 7～10 kilograms of S, carry out neutrality as raw material and leach, the underflow that obtains is after peracid leaches and washes; Supernatant liquor returns neutral the leaching, and the washing slag returns blast furnace system batching; Middle immersion liquid utilizes the alternated blasting iron removal by oxidation; Carry out solid-liquid separation after the deironing, filter residue returns whirlpool furnace system batching, and filtrating uses potassiumchromate to remove thallium; And then carry out solid-liquid separation; Filter residue is used to extract thallium, filtrates through once displacement, and the Spongy Cadmium of output gets thick cadmium after the melting of the group of pressure; Thick cadmium is through getting pure cadmium after the rectifying; A displaced liquid is through twice replaced, and the secondary Spongy Cadmium of output returns the leaching system and extracts zinc and cadmium, and twice replaced back liquid gets into Sewage treatment systems and handles.

Positively effect, the application of the inventive method can improve except that thallium efficient, and the loss of zinc, cadmium valuable metal is little, easy and simple to handle, filter easily.Remove the application of thallium in the suitable hydrometallurgy industry cadmium production process.

Description of drawings

Fig. 1 is a flow chart of the present invention

Among the figure, 1. neutral the leaching, 2. peracid leaches, 3. washing, 4. air blast deironing, 5. press filtration after the deironing 6. removes thallium, 7. removes press filtration behind the thallium, 8. once displacement, the 9. group of pressure, 10. rectifying, 11. is twice replaced.

Embodiment

Describe with reference to the accompanying drawings:

The high temperature dirt of acid making system output is put in the dilute acid soln, leached 1 operation through neutrality and carry out neutrality leaching, the underflow of immersion liquid and lower floor in the acquisition; Underflow mixes with high concentrated acid; Leach 2 operations through peracid and obtain high acid leaching liquor; Supernatant liquor wherein is transported to the neutral operation that leaches; And the underflow of lower floor is washed through washing 3 operations; The supernatant liquor that washing obtains is carried back the neutral operation that leaches, and the washing slag that the washing back is produced is put in the blast furnace; Neutral middle immersion liquid of leaching through air blast deironing 4 operation deironing after; Carry out press filtration through 5 operations of press filtration after the deironing; Filter residue is transported in the whirlpool stove, and adds potassiumchromate in the filtrating, through removing thallium 6 operations; Remove thallium; Potassiumchromate and thallium react, and make thallium form throw out, and process is except that press filtration 7 operations behind the thallium; Obtain filter residue and filtrating, filter residue is used to carry the thallium raw material; The resulting filtrating of press filtration is replaced through once replacing 8 operations after removing thallium, obtains Spongy Cadmium and displaced liquid, carries out melting, the thick cadmium of acquisition after the melting after wherein a Spongy Cadmium is pressed into group through the group's of pressure 9 operations; Thick cadmium obtains the pure cadmium product after rectifying 10 operations; Displaced liquid obtains the secondary Spongy Cadmium through the replacement Treatment of twice replaced 11 operations, returns to leach and carries in zinc and the cadmium operation, and twice replaced back liquid gets into sewage disposal device, handles.

The concrete operations that remove thallium are: will carry out solid-liquid separation except that the solution of intact iron, filtrating is incorporated in another purification tank, is warmed to 60～70 ℃, and adjustment solution pH value 2～4 is extraordinarily gone into potassiumchromate by 3～5 of thallium-containing quantity in the solution, stirs 30～50min, solid-liquid separation.Filter residue is produced thallium in order to reclaim, and filtrating is produced cadmium in order to displacement.

Embodiment

Solution carries out press filtration after the deironing, and 30m will filtrate ³Be driven in another purification tank main component (g/L) Cd 14, Zn 72, TL 0.8, As 0.02, Cu 0.05, Pb 0.02, pH value 5.0.Solution is heated to 70 ℃, and adjustment pH value of solution value 3 adds potassiumchromate 96kg, stirs 40min, press filtration.Filtrate component (g/L) Cd 14.4, Zn 72.1, TL 0.009, As 0.0008, Cu 0.046, Pb 0.001.Filter residue composition quality per-cent is: TL 15.4, Cd 0.01, Zn 0.2, Pb 0.38, Cu 0.001, As 0.41.Above-mentioned filtrating is replaced Spongy Cadmium chemical ingredients mass percent: Cd 90.58, TL 0.06, Zn 2.01, Pb 0.07, Cu 0.32, As 0.005.

Through practical application, adopt the inventive method in wet production cadmium process, to remove thallium and have following characteristics:

1, remove thallium efficient height, the decreasing ratio of thallium can reach more than 95%, but also impurity such as arsenic remaining after the deironing, lead further can be removed.

2, the loss of zinc, cadmium valuable metal is less than 0.1%.

3, easy and simple to handle, solid-state potassiumchromate directly joins in the purification tank, stirs 30-50min and gets final product.

4, because thallium is to remove with throw out rather than hydroxide form, therefore, filter more or less freely.

5, do not need to increase in addition facility investment.

Claims

1. the high temperature dirt of acid making system output is produced the method for removing thallium in the pure cadmium process, it is characterized in that: high temperature dirt is put in the dilute acid soln, leached (1) operation through neutrality and carry out neutrality leaching, the underflow of immersion liquid and lower floor in the acquisition; Underflow mixes with high concentrated acid; Leach (2) operation through peracid and obtain high acid leaching liquor; Supernatant liquor wherein is transported to the neutral operation that leaches; And the underflow of lower floor is washed through washing (3) operation; The supernatant liquor that washing obtains is carried back the neutral operation that leaches, and the washing slag that the washing back is produced is put in the blast furnace; Neutral middle immersion liquid of leaching through air blast deironing (4) operation deironing after; Carry out press filtration through press filtration after the deironing (5) operation; Filter residue is transported in the whirlpool stove, and adds potassiumchromate in the filtrating, through removing thallium (6) operation; Remove thallium; Potassiumchromate and thallium react, and make thallium form throw out, and process is except that press filtration (7) operation behind the thallium; Obtain filter residue and filtrating, filter residue is as the raw material of carrying thallium; Remove behind the thallium the resulting filtrating of press filtration and replace through displacement (8) operation once, obtains Spongy Cadmium and displaced liquid, wherein Spongy Cadmium carries out melting, the thick cadmium of acquisition after the melting after being pressed into through the group's of pressure (9) operation; Thick cadmium obtains the pure cadmium product after rectifying (10) operation; Displaced liquid obtains the secondary Spongy Cadmium through the replacement Treatment of twice replaced (11) operation, returns to leach and carries in zinc and the cadmium operation, and twice replaced back liquid gets into sewage disposal device, handles.

2. the high temperature dirt of acid making system output according to claim 1 is produced the method for removing thallium in the pure cadmium process; It is characterized in that raw material is in per 100 kilograms of high temperature dirt of acid making system output; Contain 15～25 kilograms of Zn; Contain 5～10 kilograms of Cd; Contain 20～40 kilograms of Pb; Contain 2～4 kilograms of Ti, contain 7～10 kilograms of S.

3. the high temperature dirt of acid making system output according to claim 1 is produced the method for removing thallium in the pure cadmium process, it is characterized in that the technical qualification of production process control are: 60～70 ℃ of temperature, and pH2～4, the add-on of potassiumchromate is 3～5 times of thallium-containing quantity in the solution.