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Method for regenerating sodium cyanide from solutions containing cyanogen and thiocyanate

A technology containing thiocyanate and thiocyanate, applied in cyanic acid/isocyanic acid, chemical instruments and methods, inorganic chemistry, etc., can solve the problems of regenerated cyanide, high power consumption, unsuitability and so on

Active Publication Date: 2005-11-23
CHANGCHUN GOLD RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] One is the process of regenerating cyanide from thiocyanate by using the ozone method. Its main principle is that the mixed liquid of ozone and air reacts with thiocyanate to generate CN when the pH is lower than 6. - , but ozone does not interact with CN under acidic conditions - Reaction to achieve the purpose of regenerating cyanide; this process is suitable for use in low concentration thiocyanate (SCN - It is not suitable for regeneration when the concentration of thiocyanate in the solution is high. One of the reasons is that the power consumption required for ozone generation is large (1kg of hydrogen peroxide requires 15-20kw) , and the second is that there is no mature technology for ultra-large hydrogen peroxide generators in China
[0006] The second is to use the electrochemical method to regenerate cyanide from the thiocyanate solution in the cyanidation process. Its main principle is that thiocyanate reacts electrochemically at the cathode of a special double-electrode electrolyzer to generate CN - To achieve the purpose of cyanide regeneration, but the method must be carried out under acidic medium to have the possibility of regeneration cyanide, and can only reclaim a part of cyanide, the reason is mainly CN - CNO is also produced in the electrochemical reaction at the cathode of the electrolyzer - , NH 3 and N 2 , has not yet been applied to industry and needs to be improved

Method used

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  • Method for regenerating sodium cyanide from solutions containing cyanogen and thiocyanate

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Experimental program
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Effect test

Embodiment 1

[0042] as attached figure 1As shown, the present embodiment is carried out according to several steps in the following order: wherein the barren solution to be treated is biological oxidation——a cyanidation plant in which the refractory concentrate is used as the cyanide nuclear material in the cyanidation process, because the gold in the concentrate , high silver grade, and relatively high content of associated minerals, so the consumption of sodium cyanide is also high in the cyanidation process. The composition of the barren solution is shown in Table 1:

[0043] composition

CNT

CN -

Cu

Pb

Zn

Concentration mg / l

5360.12

4423.4

31.67

0.23

630

composition

Fe

SCN -

As

Au

organic matter

Concentration mg / l

11.10

6366.08

6.00

0.10

6288

[0044] When pH = 2, the acidification of cyanide-occurrence and the oxidation of thiocyanate-occurrence a...

Embodiment 2

[0075]Carry out embodiment 1 repeatedly by the above-mentioned identical steps, but difference is, step 3 and step 4 carry out simultaneously, and each technical parameter is identical with step 3 and step 4 of embodiment 1; Its operating procedure is to add concentrated sulfuric acid to adjust pH earlier After the value is 2, add hydrogen peroxide in time to a concentration of 28kg / m 3 , then acidification, oxidation—aeration occurs—absorption takes place for 6 hours.

[0076] After embodiment 2 is processed by the above-mentioned method, the recovery rate of precious metals such as gold and silver reaches 95.02% in step 1, and in step 3 and step 4, the cyanide in the barren solution and regenerated sodium cyanide from thiocyanate The total recovery rate of cyanide is 81.51%. In step 5, the arsenic concentration after neutralization treatment is 0.16mg / l, which is lower than the industrial secondary discharge standard of 0.5mg / l. After the cyanide is advanced in step 6, The ...

Embodiment 3

[0078] Carry out embodiment 1 repeatedly by the same steps as described, but the difference is that the gas-liquid ratio in step 3 and step 4 is adjusted to 300, and other various technical parameters and steps are the same as embodiment 1, and the difference is that step 3 is carried out 2 hours, step 4 is also carried out for 2 hours.

[0079] After embodiment 3 is processed by the above method, in step 1, the recovery rate of precious metals such as gold and silver reaches 95.08%, and in step 3, the recovery rate of cyanide in the barren solution is 99.68%, and in step 4, from thiocyanic acid The regeneration rate of regenerated sodium cyanide in the salt is 86.76%, and the total recovery rate of cyanide is 94.81%. In step 5, the arsenic concentration after the neutralization treatment is 0.08mg / l, which is lower than the industrial secondary discharge standard of 0.5mg / l, in step 6, the total cyanide after advanced treatment of cyanide is 0.12, lower than the industrial s...

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Abstract

The invention relates to a method for regenerating sodium cyanide from solutions containing cyanogen and thiocyanate, which comprises the steps of reclaiming noble metal, pre-processing barren liquor, reclaiming cyanides in the barren liquor, regenerating sodium cyanide from sulfocyanate, arsenic disposing and returning filter liquor after advanced treatment of cyanides. The precious-metal recovery rate can reach 95%, the recovery ratio of cyanides in the barren liquor can reach over 99.5%.

Description

technical field [0001] The invention relates to a regeneration method for sodium cyanide, in particular to a method for regenerating sodium cyanide from a solution containing cyanide and thiocyanate. Background technique [0002] At present, the traditional equipment of the relatively mature acidification recovery method mainly includes acidification generation tower, sodium cyanide absorption tower, fan, lean liquid storage tank, lean liquid pump, sedimentation tank, acid mixer, sulfuric acid high tank, lye circulation tank, alkali Liquid circulation pump, submerged pump or metering pump, lean liquid heating device, etc.; the technical level of the acidification recovery method at home and abroad is basically the same, and the process is roughly divided into five parts, namely, wastewater preheating, acidification, HCN stripping (volatilization ), the absorption of HCN gas, the separation of sediment in wastewater and other devices; [0003] The sediment separation process...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01C3/14
Inventor 李哲浩朱军章陈民友
Owner CHANGCHUN GOLD RES INST
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