CN103496801A - Electrolytic manganese chromium-containing wastewater treatment and hexavalent chromium recovery method - Google Patents
Electrolytic manganese chromium-containing wastewater treatment and hexavalent chromium recovery method Download PDFInfo
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- CN103496801A CN103496801A CN201310411442.0A CN201310411442A CN103496801A CN 103496801 A CN103496801 A CN 103496801A CN 201310411442 A CN201310411442 A CN 201310411442A CN 103496801 A CN103496801 A CN 103496801A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
The invention discloses an electrolytic manganese chromium-containing wastewater treatment and hexavalent chromium recovery method, relating to a method for recovering hexavalent chromium in wastewater. The method comprises the specific steps of performing multi-stage filtration on the electrolytic manganese wastewater containing hexavalent chromium, and then regulating a pH value; adsorbing Cr<6+> in the wastewater by utilizing an anion exchange resin column; removing a small amount of Cr<3+> and part of manganese in the wastewater by adopting a chemical precipitation method; regenerating anion exchange resin by utilizing a regeneration solution; adding sulfuric acid and water into the regeneration solution, regulating the pH value of the regeneration solution and the concentration of the Cr<6+>, and then reusing the regeneration solution for an electrolytic manganese workshop as a passivation solution. According to the method disclosed by the invention, hexavalent chromium ions in the wastewater are selectively adsorbed respectively by adopting an ion exchange method, the follow-up wastewater is treated by adopting a chemical precipitation method, and the concentration of the hexavalent chromium ions is close to zero, so that the purpose of changing harm to treasure is realized.
Description
[technical field]
The present invention relates to chromic recovery method in a kind of waste water, be specifically related to a kind of electrolytic manganese containing the chromic method for innocent treatment of hexavalent chromium wastewater, especially relate to a kind of spent ion exchange resin that makes chromic method is processed and reclaimed to the electrolytic manganese chromate waste water of the hexavalent chromium selective recovery utilization in waste water.
[background technology]
Known, manganese metal is mainly for the production of additive, reductor and the sweetening agent of superalloy, stainless steel, non-ferrous metal alloy and low-carbon high strength steel; Wherein the overwhelming majority is for the production of alumal, stainless steel and stainless steel electrode etc.; Manganese metal, as a kind of important metallurgy, chemical raw material, has been made larger contribution for the fast development of China's industry, has very important strategic position in national economy; Although domestic electrolytic manganese industry starting evening develop very soon, has become electrolytic manganese production, outlet and the consumption big country of maximum in the world at present; Pure manganese at home obtains mainly and makes by electrolytic process, and manganese carbonate ore be take as raw material, employing acidleach, double salt electrolysis process manganese processed in 95% above electrolytic manganese enterprise; Production technique restriction due to electrolytic manganese, can produce more Mn-bearing waste water in the production process of electrolytic manganese, this primary pollution source wherein is passivating wastewater, wash plate waste water, mill floor flushing waste water, filter cloth Cleaning Wastewater, sheet frame Cleaning Wastewater, clear groove waste water, slag storehouse percolate, plant area's rainwash, electrolyzer water coolant etc.That is to say processing wastewater 10 ~ 25 m that every production 1 t electrolytic manganese produces
3.126 of China existing electrolytic manganese enterprises, electrolytic manganese output has surpassed 1,000,000 t/a, and the waste water of generation is about 3.25 hundred million t/a.
Find Chinese patent: in the treatment process of chromate waste water in producing electrolytic manganese metal recycle " CN102424490A ", disclose following content in the existing document of retrieval; The chromate waste water of self-passivation groove adds potassium bichromate solution in the future, obtains mixed liquor A after mixing, by mixed liquor A, again sends into deactivation slot and recycles; When in chromate waste water, foreign matter content is more, chromate waste water need add electrolysis cathode liquid after Filter Press is removed impurity, and Cr6+ is reduced to Cr3+, after reacting completely, obtains mixed liquid B, with pump, mixed liquid B is sent into to the manganous sulfate leaching vat and recycles.The concentration of the described chromate waste water from deactivation slot is 5～9g/L.The concentration of described potassium bichromate solution is that in the described mixed liquor A of 30～35g/L, the concentration containing chromium is 13～17g/L.The present invention will not only solve the emission problem of chromate waste water containing the cycling utilization of wastewater of chromium, and save construction fund and processing cost, reduce the discharge amount of pollution to environment.
Above-mentioned disclosure and traditional electrolytic manganese passivating technique are used potassium bichromate to carry out passivation, while cleaning negative plate, can make the part potassium bichromate enter waste water system; Electrolytic manganese chromate waste water complicated component and, containing the manganese of high level, pollution load is heavier, processing cost is very high, at present international, domestic, the improvement of electrolytic manganese chromate waste water mainly adopts reduction precipitation method, and its ultimate principle is to add reductive agent under acidic conditions in waste water, by Cr
6+be reduced into Cr
3+, and then add lime or sodium hydroxide, make it under alkaline condition, generate chromium hydroxide precipitation, thereby realize removing the purpose of chromium ion.
But the reduction precipitation method weak point is the most of metal ion in waste water all transforms into solid slag, Gu containing a large amount of manganese and chromium, belong to Hazardous wastes in slag, need secondary conveying to the qualification processed in units is arranged, in processing and transporting, inevitably environment is caused to very big harm; And these methods do not carry out reuse to chromium, the chromium slag refuse be delivered in environment is cumulative rises, has not only increased production cost but also increased the weight of the harm to environment.
[summary of the invention]
In order to overcome the deficiency in background technology, the invention discloses a kind of electrolytic manganese chromate waste water and process and reclaim chromic method, the present invention is by adopting the hexavalent chromium in ion exchange method difference selective adsorption waste water, follow-up waste water adopts chemical precipitation method to process, hexavalent chromium concentration is close to zero, realized that becoming harm is precious purpose, has significant environment, economic and social benefit.
In order to realize described goal of the invention, the present invention adopts following technical scheme:
Chromic method is processed and reclaimed to a kind of electrolytic manganese chromate waste water, and by reclaiming the sexavalent chrome in chromate waste water, water reuse in realization, obtain the non-wastewater discharge of whole system, and the chromic method of described recovery comprises the steps;
A, will to regulate pH after cascade filtration equipment filters containing the sexavalent chrome Electrolytic Manganese Wastewater be 3 left and right;
B, by under the condition that is 4BV/h at normal temperature and flow containing the sexavalent chrome Electrolytic Manganese Wastewater of previous step by anion-exchange resin column, make the Cr in anionite-exchange resin absorption waste water
6+;
C, the waste water that previous step is removed after sexavalent chrome adopt chemical precipitation method to remove a small amount of Cr in waste water
3+and part manganese, remove chrome waste water as the reuse of electrolytic manganese anolyte water;
D, in the waste water of previous step, utilize anionite-exchange resin absorption Cr
6+after reaching capacity, with sodium hydroxide, as regenerator, under the condition that is 1BV/h at flow, by exchange column, to anionite-exchange resin, utilize regenerated liquid to be regenerated;
Sodium chromate and sodium dichromate 99 that E, described regenerated liquid comprise high density, chromium ion concentration can reach 15g/L, adds sulfuric acid and water in regenerated liquid, regulates regenerated liquid pH and Cr
6+can again as passivating solution, be back to the electrolytic manganese workshop after concentration.
Described electrolytic manganese chromate waste water is processed and is reclaimed chromic method, at the cascade filtration equipment described in steps A, is horizontal flow type grit chamber, filter or mechanical filter.
Chromic method is processed and reclaimed to described electrolytic manganese chromate waste water, at the regulative mode described in steps A, is that water conservancy stirs and mechanical stirring.
Described electrolytic manganese chromate waste water is processed and is reclaimed chromic method, at the anionite-exchange resin described in step b, is the macroporous type weakly basic styrene type anion exchange resin.
Chromic method is processed and reclaimed to described electrolytic manganese chromate waste water, and described exchange column adopts the complete saturated series connection absorption of jack to jack adapter post, three post circulation exchange process of a resin column regeneration.
Chromic method is processed and reclaimed to described electrolytic manganese chromate waste water, and the described chemical precipitation method of step C adopts tube settler to be precipitated, the workshop reuse of settling tank clear liquid.
Described electrolytic manganese chromate waste water is processed and is reclaimed chromic method, and the regenerator described in steps d is 6wt% sodium hydroxide.
Owing to having adopted technique scheme, the present invention has following beneficial effect:
Chromic method is processed and reclaimed to electrolytic manganese chromate waste water of the present invention, the present invention is by adopting the hexavalent chromium in ion exchange method difference selective adsorption waste water, follow-up waste water adopts chemical precipitation method to process, after above-mentioned processing, hexavalent chromium concentration is close to zero, make the hexavalent chromium in former technique recycle, realized that becoming harm is precious purpose, the rate of recovery of hexavalent chromium >=99%, processed waste water hexavalent chromium concentration is close to zero, thereby effective improvement of waste water and the recycling of resource have been realized, in waste water, sexavalent chrome is far below the emission limit of national regulation, the present invention has realized the chromium Separation and Recovery in waste water, the rate of recovery reaches or approaches >=99%, effective improvement of waste water and the recycling of resource have been realized, further reduced the pollution treatment cost of enterprise and reduced environmental risk, there is significant environment, economic and social benefit.
[embodiment]
Explanation the present invention that can be detailed by the following examples, disclose purpose of the present invention and be intended to protect all technological improvements in the scope of the invention,
Chromic method is processed and reclaimed to electrolytic manganese chromate waste water of the present invention, and by reclaiming the sexavalent chrome in chromate waste water, water reuse in realization, obtain the non-wastewater discharge of whole system, and the chromic method of described recovery comprises the steps;
A, will after horizontal flow type grit chamber, filter or mechanical filter filter, use water conservancy to stir containing the sexavalent chrome Electrolytic Manganese Wastewater or mechanical stirring to regulate pH be 3 left and right;
B, by under the condition that is 4BV/h at normal temperature and flow containing the sexavalent chrome Electrolytic Manganese Wastewater of previous step by macroporous type weakly basic styrene type anion exchange resin post, make the Cr in anionite-exchange resin absorption waste water
6+;
C, the waste water that previous step is removed after sexavalent chrome adopt the chemical precipitation method of tube settler to be precipitated, and adopt and remove a small amount of Cr in waste water
3+and part manganese, remove chrome waste water as the reuse of electrolytic manganese anolyte water;
D, in the waste water of previous step, utilize anionite-exchange resin absorption Cr
6+after reaching capacity, with 6wt% sodium hydroxide, as regenerator, under the condition that is 1BV/h at flow, by the complete saturated series connection absorption of jack to jack adapter exchange column, three post circulation exchange process of a resin column regeneration, utilize regenerated liquid to be regenerated to anionite-exchange resin;
Sodium chromate and sodium dichromate 99 that E, described regenerated liquid comprise high density, chromium ion concentration can reach 15g/L, adds sulfuric acid and water in regenerated liquid, regulates regenerated liquid pH and Cr
6+can again as passivating solution, be back to the electrolytic manganese workshop after concentration.
Embodiment 1:
18mL anionite-exchange resin is packed in two exchange columns.It is 4 that the electrolytic manganese chromate waste water is regulated to pH, and with the flow of 4BV/h, by the dianion exchange column, single-column is processed the water yield can reach 143BV, Cr in raw wastewater
6+concentration is 440.1mg/L, Cr
3+concentration is 100.2mg/L.After anion exchange process, Cr
6+the concentration of concentration is far below 0.5mg/L, Cr
6+exchange capacity be 75mg/mL, clearance can reach 99.9%.PH to 8 is adjusted in the resin column water outlet, and after filtering, total Chromium in Waste concentration, far below 1mg/L, meets middle water reuse condition.After anion-exchange column absorption is saturated, the NaOH with 6% is regenerated by saturated column with the flow velocity of 1BV/h, Cr in the 2BV regenerated liquid
6+reaching peak concentration, is 24.8g/L, and mean concns is 16.9g/L, through acidification, can meet the passivation technology index request, can be used as passivating solution and uses, and realizes Cr
6+reuse.
Embodiment 2:
According to the operation steps in embodiment 1, the 110mL resin is packed in two exchange columns, Cr in raw wastewater
6+concentration is 1053.7mg/L, Cr
3+concentration is 327.2mg/L.Single-column is processed the water yield can reach 62BV, after anion exchange process, and Cr
6+the concentration of concentration is far below 0.5mg/L, and clearance can reach 99.85%.PH to 8 is adjusted in the resin column water outlet, and after filtering, total Chromium in Waste concentration, far below 1mg/L, meets middle water reuse condition.
Embodiment 3:
By anionite-exchange resin three the carbon steel exchange columns (Ф 1400 * 4500mm) that specification is identical of packing into, each exchange column dress 3.1m3 resin, under the condition that is 3 at pH by the electrolytic manganese chromate waste water, pass through anion-exchange column with the flow of 5BV/h, adopt the mode of 1,2 post series connection, continuously operation.Cr in raw wastewater
6+concentration is 165.6mg/L, Cr
3+concentration is 10.2mg/L, Cr after anion-exchange column is processed 5 days
6+concentration is lower than 0.01mg/L, and after precipitation process, total chromium concn is far below 0.5mg/L.
After 1 post absorption is saturated, the NaOH with 6% regenerates by resin column with the flow adverse current of 1BV/h.Cr in 2.5BV before regenerated liquid
6+concentration is 16.5g/L.Adding sulfuric acid adjustment pH is 6, Cr
6+concentration is the 11g/L(3wt% sodium dichromate 99), meet potroom passivating solution working conditions.Cr in 1.5BV after regenerated liquid
6+concentration is lower, and NaOH concentration is higher, as the next batch regenerated liquid.
In the time of 1 column regeneration, the absorption of can connecting of 2,3 posts.3 posts like this recycle.
It is 7.5-8.5 that pH is adjusted in the water outlet of dianion exchange column, and after precipitation process, effluent reuse is in workshop.
Part not in the detailed description of the invention is prior art.
Claims (7)
1. chromic method is processed and reclaimed to an electrolytic manganese chromate waste water, and by reclaiming the sexavalent chrome in chromate waste water, water reuse in realization, obtain the non-wastewater discharge of whole system, and it is characterized in that: the chromic method of described recovery comprises the steps;
A, will to regulate pH after cascade filtration equipment filters containing the sexavalent chrome Electrolytic Manganese Wastewater be 3 left and right;
B, by under the condition that is 4BV/h at normal temperature and flow containing the sexavalent chrome Electrolytic Manganese Wastewater of previous step by anion-exchange resin column, make the Cr in anionite-exchange resin absorption waste water
6+;
C, the waste water that previous step is removed after sexavalent chrome adopt chemical precipitation method to remove a small amount of Cr in waste water
3+and part manganese, remove chrome waste water as the reuse of electrolytic manganese anolyte water;
D, in the waste water of previous step, utilize anionite-exchange resin absorption Cr
6+after reaching capacity, with sodium hydroxide, as regenerator, under the condition that is 1BV/h at flow, by exchange column, to anionite-exchange resin, utilize regenerated liquid to be regenerated;
Sodium chromate and sodium dichromate 99 that E, described regenerated liquid comprise high density, chromium ion concentration can reach 15g/L, adds sulfuric acid and water in regenerated liquid, regulates regenerated liquid pH and Cr
6+can again as passivating solution, be back to the electrolytic manganese workshop after concentration.
2. electrolytic manganese chromate waste water according to claim 1 is processed and is reclaimed chromic method, it is characterized in that: at the cascade filtration equipment described in steps A, be horizontal flow type grit chamber, filter or mechanical filter.
3. electrolytic manganese chromate waste water according to claim 1 is processed and is reclaimed chromic method, it is characterized in that: at the regulative mode described in steps A, be that water conservancy stirs and mechanical stirring.
4. electrolytic manganese chromate waste water according to claim 1 is processed and is reclaimed chromic method, it is characterized in that: at the anionite-exchange resin described in step b, be the macroporous type weakly basic styrene type anion exchange resin.
5. electrolytic manganese chromate waste water according to claim 1 is processed and reclaimed chromic method, it is characterized in that: described exchange column adopts the complete saturated series connection absorption of jack to jack adapter post, three post circulation exchange process of a resin column regeneration.
6. electrolytic manganese chromate waste water according to claim 1 is processed and reclaimed chromic method, it is characterized in that: the described chemical precipitation method of step C adopts tube settler to be precipitated, the workshop reuse of settling tank clear liquid.
7. electrolytic manganese chromate waste water according to claim 1 is processed and is reclaimed chromic method, and it is characterized in that: the regenerator described in steps d is 6wt% sodium hydroxide.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104007226A (en) * | 2014-05-04 | 2014-08-27 | 华南理工大学 | Method for measuring zinc content in hexavalent-chromium passivating solution for hot galvanizing |
| CN105621734A (en) * | 2015-10-30 | 2016-06-01 | 无锡市嘉邦电力管道厂 | Comprehensive electroplating wastewater treatment process |
| CN107311380A (en) * | 2017-08-18 | 2017-11-03 | 舒城联科环境科技有限公司 | A kind of method that utilization absolute ethyl alcohol reclaims sodium chromate in chromium system regenerated liquid |
| CN111547892A (en) * | 2020-05-22 | 2020-08-18 | 贵州大龙汇成新材料有限公司 | Treatment method of ammonia nitrogen wastewater in manganese chemical industry |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104007226A (en) * | 2014-05-04 | 2014-08-27 | 华南理工大学 | Method for measuring zinc content in hexavalent-chromium passivating solution for hot galvanizing |
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| CN107311380A (en) * | 2017-08-18 | 2017-11-03 | 舒城联科环境科技有限公司 | A kind of method that utilization absolute ethyl alcohol reclaims sodium chromate in chromium system regenerated liquid |
| CN111547892A (en) * | 2020-05-22 | 2020-08-18 | 贵州大龙汇成新材料有限公司 | Treatment method of ammonia nitrogen wastewater in manganese chemical industry |
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