CN100519445C - Method for processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation - Google Patents
Method for processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation Download PDFInfo
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- CN100519445C CN100519445C CNB2006101696970A CN200610169697A CN100519445C CN 100519445 C CN100519445 C CN 100519445C CN B2006101696970 A CNB2006101696970 A CN B2006101696970A CN 200610169697 A CN200610169697 A CN 200610169697A CN 100519445 C CN100519445 C CN 100519445C
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- precipitation
- waste water
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Abstract
The invention discloses a disposing method of cyanic waste water through chemical sediment-gamma-ray radiating method, which comprises the following steps: combining zinc salt sediment and gamma-ray decomposing cyanide method; adding zinc salt in the cyanic waste water; sedimenting and recycling most of cyanide; decomposing residual cyanide through gamma-ray to make waste water reach draining standard.
Description
Technical field
The invention belongs to nuclear technique and field of environment protection.Be particularly related to and from cyanide wastewater, reclaim the method for prussiate with a kind of processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation of Treatment of Cyanide-containing Wastewater.
Background technology
Cyanide gold-leaching is that gold smelting factory extracts generally a kind of method of employing of gold and silver institute.Not only toxicity is big to soak golden cyanide wastewater (cyanide barren solution), and the water yield is also big, the about 400m of medium scale cyanide plant generation every day
3Lean solution.Golden sustained development of enterprises is put forward in dealing with relationship to of cyanide barren solution.Lean solution generally contains the total cyanogen 0.5～8.0g/L of total cyanogen; Copper 0.4～2.4g/L; Zinc 0.2～2.0g/L and a small amount of gold and silver.The a considerable amount of copper minerals of some gold ore association, corresponding lean solution cupric are up to 8～10g/L, and total cyanogen is up to 15～22g/L.At present the processing of lean solution still there is not the ideal method.Most gold smelting factory carries out closed cycle or acidified precipitation copper removal-recycle after the neutralization with cyanide barren solution again, and utilizing prussiate wherein, but the impurities accumulation that causes of circulation has the leaching yield of gold and has a strong impact on for a long time; On the other hand, the lean solution circulation can cause the imbalance of the water yield, must discharge a part of waste water.Therefore needing to take out a part of cyanide barren solution handles.
The method of Treatment of Cyanide-containing Wastewater generally comprises and destroys the prussiate class and reclaim the prussiate class at present, but all has such or such shortcoming.Generally adopt destroy method to handle for the cyanide wastewater of lower concentration, as chlorine, hypochlorite oxidation method, this method is handled in the water of back residual a large amount of chlorine and can be produced CNCl severe toxicity gas, causes secondary pollution; Inco (air-SO
2Oxidation) method and hydrogen peroxide oxidation method all do not have the removal effect to thiocyanate-, and all need mantoquita to make catalyzer, consume non-ferrous metal, and cost is higher; Biological degradation method to waste water to contain cyanogen concentration, pH value and temperature requirement tight excessively.All destroy class methods all is pure consumptive.For the cyanide wastewater of middle and high concentration, the general method that reclaims that adopts is handled.These methods comprise: the acidization that (1) is traditional, and the total cyanogen concentration of processed waste water is generally total cyanogen 5～20mg/L, does not reach emission standard (total cyanogen 0.5mg/L); (2) ZnSO
4The precipitator method.The total cyanogen 20～40mg/L of processed waste water does not reach emission standard equally.(3) ion exchange resin absorption can make waste water reach emission standard, but resin elution, regenerated complicated operation, and resin is more expensive.
Summary of the invention
The purpose of this invention is to provide and from cyanide barren solution, reclaim the method for prussiate with a kind of processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation of processing cyanide barren solution.It is characterized in that adopt the art breading cyanide barren solution of zinc salt precipitation and gamma-ray irradiation degraded prussiate, its concrete processing step is as follows:
1) with the cyanide barren solution is feed liquid;
2) in cyanide barren solution, add the precipitation agent zinc salt and carry out precipitin reaction;
3) the whizzer centrifugation goes out clear liquid and precipitation, and filtering precipitate Zn (CN)
2
4). at Zn (CN)
2Add in the precipitation and account for Zn (CN)
2The cyanide barren solution pulp of precipitation volume 50% adds the vitriol oil or 50% dilute sulphuric acid again after the pulp, be acidified to pH=2, and the HCN of inflation stripping generation; Liquid is solution of zinc sulfate behind the stripping, with lime Ca (OH)
2PH is greater than 7 in adjusting, returns as precipitation agent to recycle;
5) with 10%NaOH solution or 10%Ca (OH)
2The HCN liquid that produces in the slurry absorption step 3 and 4;
6) with gamma-radiation to chemical precipitation after liquid carry out irradiation with further degraded prussiate, described zinc salt consumption is Zn
2+With total cyanogen+mol ratio=0.61～1.5, pH is 6.0-8.0.
Described stripping condition is pH value of solution=0.35,40～50 ℃ of temperature, and time 1h, vapour-liquid ratio are 1000, inflate 35 minutes.
Described precipitation agent zinc salt is zinc sulfate or zinc acetate.
Described gamma-radiation is by Co
60Produce, central duct dosage is 4.9GY/s.
Described gamma-radiation absorption dose is 125kGY～1010kGY, degraded volume G (total cyanogen)=0.07～0.14.
PH value in the described precipitin reaction generating process overflows its no HCN more than or equal to 7 from solution.
The present invention has following obvious advantage:
1. adopt zinc salt precipitation and gamma-radiation degraded prussiate novel process to handle cyanide barren solution, both recyclable most of valuable element cyanogen etc. can make water outlet reach emission standard (total cyanogen 0.5mg/L) again, thereby not only have an economic benefit but also environmental benefit is arranged.
2. energetic ray is handled cyanide barren solution efficient height, can handle multiple toxic pollutant simultaneously, does not produce secondary pollution, is a kind of usefulness height, new wastewater processing technology that degree of cleaning are high.
3. the zinc salt precipitation is strong to waste water adaptability with gamma-rays degraded prussiate novel process, can handle waste water such as gold mine cyaniding lean solution, cyanide electroplating brass waste water, cyanide electroplating copper waste water and solid sodium cyanide production.
Description of drawings
Fig. 1 is chemical precipitation-gamma-radiation irradiation-induced degradation Treatment of Cyanide-containing Wastewater process flow sheet.
Embodiment
The invention provides and from cyanide barren solution, reclaim the method for prussiate with a kind of processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation of processing cyanide barren solution.Be the art breading cyanide barren solution that adopts zinc salt precipitation and gamma-radiation irradiation-induced degradation prussiate, both recyclable most of valuable element cyanogen etc. can make water outlet reach emission standard (total cyanogen 0.5mg/L) again, thereby not only have an economic benefit but also environmental benefit is arranged.Its ultimate principle is described below:
Add precipitation agent zinc salt such as zinc sulfate in containing cyanide wastewater, then cryanide ion is converted into the zinc cyanide precipitation, and iron-cyano complex, copper-cyano complex also generate precipitation with the zinc sulfate reaction:
2NaCN+ZnSO
4＝Zn(CN)
2↓+Na
2SO
4
Na
2Cu(CN)
3+ZnSO
4＝Zn(CN)
2↓+CuCN↓+Na
2SO
4
Na
4Fe(CN)
6+2ZnSO
4＝Zn
2Fe(CN)
6↓+Na
2SO
4
More than the pH value of reaction generation is not overflowed from solution so almost there is HCN more than or equal to 7.To precipitate then and add H
2SO
4Acidifying, then Zn (CN)
4 2-Decompose and emit HCN:
Zn (CN)
2+ H
2SO
4=2HCN ↑+ZnSO
4, wherein sulfuric acid is the vitriol oil of thin up not.
Be acidified to pH=2 and inflate the HCN that stripping produces, hydrocyanic acid gas absorbs with sodium hydroxide solution:
HCN+NaOH＝H
2O+NaCN
Produce the high density sodium cyanide and return the use of cyanide gold-leaching system.Slurries behind the stripping HCN after filtration or centrifugation are isolated sour insoluble deposit C uCN and Zn
2Fe (CN)
6With clear liquid ZnSO
4Solution, ZnSO
4Solution can return prussiate in the precipitation next batch cyanide wastewater, promptly can be recycled.
With precipitable most of prussiate, wherein total cyanogen deposition rate 〉=94%, copper deposition rate 〉=95%, iron deposition rate 〉=94% removed of zinc salt; But thiocyanate ion seldom precipitates, and the waste water after the general zinc salt precipitation process does not reach emission standard, and also residual have some free cyanogen, complexing cyanogen, thiocyanate-even some organism are arranged, and still has certain toxicity.The present invention unites a kind of new green technology-gamma-radiation irradiation method and carries out the degree of depth except that the poison processing.Its ultimate principle is that waste water can produce a large amount of e during with gamma-radiation irradiation waste water
AqFree radicals such as (hydrated electron), H and OH, these particle activity are extremely strong, can cause chain reaction, and residual prussiate, thiocyanide and organism etc. are had intensive oxidation, Decomposition, may be reduction reaction also, make oxidations such as prussiate or be reduced into nontoxic N
2And CO
2Or product cyanate of low toxicity, methane amide, glycine etc.May there be following reaction mechanism in the radiolysis reaction of prussiate:
H+HCN→H
2CN
HCN
-+H
+→H
2CN
HCN
-+·CONH
2→HCONH
2+CN
-
2·CONH
2→HCNO+HCONH
2
·CONH
2+H
2CN→HCNO+H
2CNH
As seen the radiolysis reaction is complicated, and wherein glycine may be that hydrated electron forms HCN
-, produce by processes such as polymerization, hydrolysis again.
The mechanism of degradation of metal-cyano complex is: metal-cyano complex and CN
-There is balance between the ion, CN
-After ion is degraded by the way, balance is constantly moved right, thus degraded metal-cyano complex.For example:
The degraded of thiocyanate ion is SCN
-Formed CN by the oxidation of OH free radical institute
-Ion, CN then
-Ion is degraded by the way.
Therefore under certain irradiation dose condition, can degrade prussiate quickly and efficiently and make water outlet contain total cyanogen concentration qualified discharge standard.
Embodiment 1
Feed liquid is the true cyanide barren solution of Hebei gold mine, and its composition is as follows: total cyanogen 0.770g/L, Cu0.030g/L, Zn 0.246g/L, CN
-0.560g/L, SCN
-0.141g/L, Fe 0.029g/L, pH=11.9. processing technological flow such as Fig. 1.
At first remove and reclaimed most of cyanogen with the zinc sulfate precipitation.
After in cyanide barren solution, having dropped into zinc salts such as zinc sulfate or zinc acetate, Zn
2+Rapidly and the OH in the lean solution
-, CN
-, zinc cyanogen complex ion, copper cyanogen complex ion, [Fe (CN)
6]
4-Produce white flocks Deng prussiate by above-mentioned reaction.These reactions are carried out very soon, and 1～3min finishes substantially under suitable stirring.Go out clear liquid and precipitation with the whizzer centrifugation then.The zinc salt optimum amount is Zn
2+With total cyanogen mol ratio=1.5, pH is 6.5～8.0, and this moment, residual cyanogen concentration maintained about 40ppm, and the cyanogen deposition rate is 94.7%, iron 1.8mg/L, the about 150mg/L of thiocyanate.
The Zn that centrifugation is come out (CN)
2In the precipitation, adding accounts for Zn (CN)
250% cyanide wastewater pulp of precipitation volume adds 50% vitriol oil again after the pulp, be acidified to pH=2, and inflation stripping HCN, with 10%NaOH solution or 10%Ca (OH)
2Slurry absorbs HCN.The stripping condition is pH value of solution=0.35,40～50 ℃ of temperature, and time 1h, vapour-liquid ratio are 1000, inflate to make total cyanogen concentration reduce to 26.1mg/L by 7340mg/L in 35 minutes, the stripping rate reaches 99.64%.
Liquid is solution of zinc sulfate behind the stripping, returns as precipitation agent to preset value with lime adjusting pH to recycle.Solution of zinc sulfate can be repeatedly multiplexing.
Use gamma-radiation (Co at last
60Central duct dosage 4.9GY/s) liquid after the chemical precipitation is carried out irradiation with further degraded prussiate.The order that single contaminant degradation difficulty is increased is: NaCN＜Zn-CN＜Cu-CN＜NaSCN.The result of irradiation-induced degradation shows that making the cyanide barren solution degraded gamma-radiation absorption dose up to standard that contains total cyanogen 26mg/L is 125kGY, degraded volume G (total cyanogen)=0.07.After lean solution is removed cyanogen through the zinc salt precipitation, contain the thiocyanate ion of 150mg/L, dosage 125kGy can make and fall thiocyanate ion degraded 69%.
Embodiment 2
Feed liquid is the true cyanide barren solution of Shandong gold mine, and its composition is as follows: total cyanogen 8.38g/L, Cu 2.40g/L, Zn 1.88g/L, CN
-4.3g/L, Fe0.94g/L, pH=12.5.Processing technological flow is seen Fig. 1.
At first remove and reclaimed most of cyanogen with the zinc sulfate precipitation.
After in cyanide barren solution, having dropped into zinc salts such as zinc sulfate or zinc acetate, Z
n 2+Rapidly and the OH in the lean solution
-, CN
-, zinc cyanogen complex ion, copper cyanogen complex ion, [Fe (CN)
6]
4-Produce white flocks Deng prussiate by above-mentioned reaction.These reactions are carried out very soon, and 1-3min finishes substantially under suitable stirring.Go out clear liquid and precipitation with filtration or whizzer centrifugation then.
The result shows that the zinc salt optimum amount is Zn
2+With total cyanogen mol ratio=0.61, pH is 6.0-8.0, and this moment, residual cyanogen concentration maintained about 421ppm, and the cyanogen deposition rate is 95%; The iron deposition rate is 92%, and the copper deposition rate is 93.5%, residual concentration copper 66mg/l, iron 75mg/L.
The Zn that centrifugation is come out (CN)
2Add in the precipitation and account for Zn (CN)
2The lean solution pulp of precipitation volume adds the vitriol oil or 50% dilute sulphuric acid and inflates stripping HCN, with 10%NaOH solution or 10%Ca (OH)
2Slurry absorbs HCN.In pH value of solution=0.2, temperature 40-50 ℃, vapour-liquid ratio is a stripping 1 hour under 360 the condition, can make total cyanogen concentration reduce to 82mg/L by 26029mg/L, and total cyanogen stripping rate reaches 99.7%.Liquid is solution of zinc sulfate behind the stripping, returns as precipitation agent with lime adjusting pH to 2-4 to recycle.Solution of zinc sulfate can be repeatedly multiplexing.
Use gamma-radiation (Co then
60, central duct dosage 4.9GY/s) and liquid after the chemical precipitation is carried out irradiation with further degraded prussiate.The order that single contaminant degradation difficulty is increased is: NaCN＜Zn-CN＜Cu-CN＜NaSCN.The result of irradiation-induced degradation shows that making the post precipitation liquid degraded gamma-radiation absorption dose up to standard that contains total cyanogen 421mg/L is 1010kGY, degraded volume G (total cyanogen)=0.14.
Claims (7)
1. the method for a processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation is characterized in that, adopts the art breading cyanide barren solution of zinc salt precipitation and gamma-radiation irradiation-induced degradation prussiate, and its concrete processing step is as follows:
1) with the cyanide barren solution is feed liquid;
2) in cyanide barren solution, add the precipitation agent zinc salt and carry out precipitin reaction;
3) the whizzer centrifugation goes out clear liquid and precipitation, and filtering precipitate Zn (CN)
2
4) at Zn (CN)
2In the precipitation, adding accounts for Zn (CN)
2The cyanide barren solution pulp of precipitation volume 50% adds the vitriol oil or 50% dilute sulphuric acid again after the pulp, be acidified to pH=2, and the HCN of inflation stripping generation; Liquid is solution of zinc sulfate behind the stripping, with lime Ca (OH)
2PH is greater than 7 in adjusting, returns as precipitation agent to recycle;
5) with 10%NaOH solution or 10%Ca (OH)
2The slurry absorption step 3) and 4) in HCN;
6) with gamma-radiation to chemical precipitation after liquid carry out irradiation with further degraded prussiate.
2. according to the method for the described processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation of claim 1, it is characterized in that described zinc salt consumption is Zn
2+With total cyanogen mol ratio=0.61～1.5, pH is 6.0-8.0.
3. according to the method for the described processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation of claim 1, it is characterized in that described stripping condition is pH value of solution=0.35,40～50 ℃ of temperature, time 1h, vapour-liquid ratio are 1000, inflate 35 minutes.
4. according to the method for the described processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation of claim 1, it is characterized in that described precipitation agent zinc salt is zinc sulfate or zinc acetate.
5. according to the method for the described processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation of claim 1, it is characterized in that described gamma-radiation is by Co
60Produce, central duct dosage is 4.9GY/s.
6. according to the method for the described processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation of claim 1, it is characterized in that described gamma-radiation absorption dose is 125kGY～1010kGY, degraded volume G (total cyanogen)=0.07～0.14.
7. according to the method for the described processing cyanogens-containing waste water using chemical precipitation and gamma ray irradiation of claim 1, it is characterized in that the pH value in the described precipitin reaction generating process overflows its no HCN more than or equal to 7 from solution.
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| CN100519445C true CN100519445C (en) | 2009-07-29 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103304052A (en) * | 2013-05-28 | 2013-09-18 | 西安建筑科技大学 | Treatment method of gold extraction cyaniding wastewater containing copper and iron ions with high concentration |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102491487B (en) * | 2011-11-29 | 2014-04-16 | 华东理工大学 | Depth processing method of cyanogen-containing waste water |
| CN104291356A (en) * | 2014-09-10 | 2015-01-21 | 杭州青化社化工有限公司 | Preparation method of zinc cyanide |
| CN104900295B (en) * | 2015-05-28 | 2018-04-20 | 官爱平 | Irradiation apparatus and its method for fluid processing |
| CN106977029B (en) * | 2017-05-17 | 2022-11-04 | 重庆哈工拓普科技有限公司 | Cyanide gold extraction wastewater treatment and cyclic utilization system based on sonochemistry is compound |
-
2006
- 2006-12-27 CN CNB2006101696970A patent/CN100519445C/en not_active Expired - Fee Related
Non-Patent Citations (4)
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| γ-辐照法处理有机废水的研究. 清华大学核能所六室辐照组.水处理技术，第10卷第3期. 1984 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103304052A (en) * | 2013-05-28 | 2013-09-18 | 西安建筑科技大学 | Treatment method of gold extraction cyaniding wastewater containing copper and iron ions with high concentration |
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