CN115725919A - Method for controlling zinc in acid-containing wastewater in workpiece hot galvanizing process - Google Patents
Method for controlling zinc in acid-containing wastewater in workpiece hot galvanizing process Download PDFInfo
- Publication number
- CN115725919A CN115725919A CN202111021292.3A CN202111021292A CN115725919A CN 115725919 A CN115725919 A CN 115725919A CN 202111021292 A CN202111021292 A CN 202111021292A CN 115725919 A CN115725919 A CN 115725919A
- Authority
- CN
- China
- Prior art keywords
- zinc
- acid
- hot galvanizing
- workpiece
- wastewater
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910052725 zinc Inorganic materials 0.000 title claims abstract description 53
- 239000011701 zinc Substances 0.000 title claims abstract description 53
- 238000000034 method Methods 0.000 title claims abstract description 44
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 title claims abstract description 37
- 238000005246 galvanizing Methods 0.000 title claims abstract description 30
- 239000002351 wastewater Substances 0.000 title claims abstract description 27
- 239000002253 acid Substances 0.000 title claims abstract description 24
- 238000005554 pickling Methods 0.000 claims abstract description 19
- 239000002699 waste material Substances 0.000 claims abstract description 9
- 238000005238 degreasing Methods 0.000 claims abstract description 8
- 238000005406 washing Methods 0.000 claims abstract description 8
- 238000002161 passivation Methods 0.000 claims abstract description 7
- 238000007598 dipping method Methods 0.000 claims abstract description 6
- 238000007747 plating Methods 0.000 claims description 23
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 10
- 239000002244 precipitate Substances 0.000 claims description 6
- 229960004887 ferric hydroxide Drugs 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims description 3
- IEECXTSVVFWGSE-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Fe+3] IEECXTSVVFWGSE-UHFFFAOYSA-M 0.000 claims description 3
- 238000002791 soaking Methods 0.000 claims description 3
- QWPPOHNGKGFGJK-UHFFFAOYSA-N hypochlorous acid Chemical compound ClO QWPPOHNGKGFGJK-UHFFFAOYSA-N 0.000 claims description 2
- 239000013589 supplement Substances 0.000 claims description 2
- 239000007788 liquid Substances 0.000 abstract description 14
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 6
- 239000010410 layer Substances 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 235000005074 zinc chloride Nutrition 0.000 description 3
- 239000011592 zinc chloride Substances 0.000 description 3
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000002386 leaching Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000007605 air drying Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 235000019270 ammonium chloride Nutrition 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000012459 cleaning agent Substances 0.000 description 1
- 238000003618 dip coating Methods 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000005562 fading Methods 0.000 description 1
- 229910001448 ferrous ion Inorganic materials 0.000 description 1
- 239000002920 hazardous waste Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
Landscapes
- Chemically Coating (AREA)
Abstract
The invention discloses an acid-containing wastewater zinc control method for a hot galvanizing process of a workpiece, which comprises a degreasing step, an acid washing step, a pre-dipping step, a preheating step, a hot galvanizing step and a passivation step, wherein the acid washing step in the hot galvanizing process is different from a clamp used in the hot galvanizing step. By the mode, the method can cut off the way that zinc adhered to the surface of the clamp enters the pickling waste liquid during galvanization, reduce the zinc content in the acid liquid and reduce the treatment cost of the pickling waste liquid.
Description
Technical Field
The invention relates to the field of metal surface treatment, in particular to a method for controlling zinc in acid-containing wastewater in a workpiece hot galvanizing process.
Background
The steel tower structure needs to be galvanized on the surface before leaving a factory, surface corrosion is prevented in long-term use, the service life is influenced, but along with the improvement of the environmental protection requirement of China, the requirement on hazardous waste treatment is more and more strict, zinc-containing waste water generated in the hot galvanizing process has higher environmental hazard compared with the conventional pickling waste liquid, the treatment cost is higher, the whole process needs to be combed, the zinc content in the waste water discharged in the whole process flow is effectively reduced, the main generation way of high-zinc waste water is found through on-site combing to be that a layer of metal zinc can be synchronously plated on a clamp when a workpiece is subjected to hot galvanizing operation, after the workpiece is treated, the clamp can synchronously wash zinc on the surface layer of the clamp into a pickling tank in the pickling step when the next round of feeding is finished, and finally high-zinc waste liquid is formed.
Disclosure of Invention
The invention mainly solves the technical problem of providing a hot galvanizing process which can reduce the zinc content in pickling waste liquid generated in the hot galvanizing process.
In order to solve the technical problems, the invention adopts a technical scheme that: the method comprises a degreasing step, an acid washing step, a pre-soaking step, a preheating step, a hot-dip plating step and a passivation step, wherein the acid washing step in the hot-dip plating process is different from a clamp used in the hot-dip plating step.
In a preferred embodiment of the present invention, the pre-dipping step, the pre-heating step, the hot-dipping step and the passivating step are carried out using the same jig.
In a preferred embodiment of the invention, the hot galvanizing process further comprises a workpiece zinc removal and back plating step, wherein the workpiece zinc removal and back plating step forms high-zinc wastewater which is separated from the wastewater formed in the pickling step.
In a preferred embodiment of the invention, a hydrochloric acid solution is used as a back plating solution in the step of de-zincing and back plating the workpiece.
In a preferred embodiment of the invention, the high-zinc wastewater is used for removing Fe 2+ The ion is used as a presoaking supplement.
In a preferred embodiment of the invention, the high-zinc wastewater is used for removing Fe 2+ The method comprises the following steps: firstly adding the high-zinc wastewaterHypochlorous acid, then the pH value of the solution is adjusted to be 2~4, ferric hydroxide precipitate is formed, and finally the precipitate is removed in a filtering mode to obtain the pre-soaking supplementary liquid.
The beneficial effects of the invention are: the hot galvanizing process is integrally carded to find that the zinc fading of the pickling of the clamp in the hot galvanizing process is the main forming reason of the high zinc wastewater, so that the way of the zinc element entering the pickling tank is effectively cut off by using different clamps in the pickling and hot galvanizing steps, and the generation of the high zinc wastewater is effectively reduced.
Detailed Description
The following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention, and to clearly and unequivocally define the scope of the present invention.
The embodiment of the invention comprises the following steps:
a zinc control method for acid-containing wastewater in a workpiece hot galvanizing process comprises the following steps:
(1) Degreasing step
Putting a workpiece into a degreasing pool by using a special feeding clamp, and cleaning and degreasing the workpiece by using an alkali liquor or water-based metal degreasing cleaning agent at 40-80 ℃ to reach a position where the surface of the workpiece can be soaked by water;
(2) Acid pickling
Then transferring the workpiece from the degreasing tank to a pickling tank by using a feeding clamp for pickling to remove a surface oxide layer, wherein the pickling solution is a hydrochloric acid solution with the concentration of 20%, 5g/L of urotropine corrosion inhibitor is added into the hydrochloric acid solution to prevent the matrix from being excessively corroded in pickling to cause poor adhesion of a coating or incomplete peeling of a zinc layer, and after the pickling is finished, taking the feeding clamp down from the workpiece by using a secondary hanging mode and clamping by using a special galvanized clamp;
(3) Pre-impregnation
The galvanized fixture sends the pickled workpiece into the plating assistant agent for presoaking so as to keep the workpiece to have certain activity before dip plating and avoid secondary oxidation. 100-150gL ammonium chloride, 150-180g/L zinc chloride and a small amount of an explosion-proof agent are added into the plating assistant agent. The presoaking temperature is 70 to 80 ℃;
(4) Hot dip coating
And (3) sending the workpiece into an oven for drying by using a galvanizing clamp, preheating to 100-120 ℃, removing water, sending into a zinc pool for dip plating according to the process requirements, controlling the temperature of a zinc liquid, the dip plating time and the extraction speed of the workpiece, and improving the uniformity and the adhesive force of the plating layer.
(5) Passivation of
After the galvanization is finished, the workpiece is led out from a zinc pool by a galvanization clamp, is finished, the residual zinc liquid on the surface is removed, and is put into a passivation pool for passivation treatment, and a passivator in the passivation pool is a chromium-free passivator to reduce heavy metal pollution;
(6) Cooling down
And finally, sending the passivated workpiece into a cooling pool by a galvanized fixture, cooling to 30-50 ℃, taking out and air-drying to obtain a finished product, taking out the workpiece by the galvanized fixture, transferring to an acid washing position, and repeating the next round of steps.
In the process, if part of the workpiece coating is found to be unqualified by inspection, the workpiece needs to be subjected to zinc removal and plating returning, in the step of the zinc removal and plating returning of the workpiece, the workpiece is placed into hydrochloric acid plating returning solution with the concentration of 10-15% by a zinc plating clamp to be subjected to zinc removal and plating returning, a surface zinc layer is removed, and high-zinc wastewater formed by the plating returning is placed in a special high-zinc storage tank and is separated from the wastewater formed in the step of acid washing.
Since the high-zinc waste liquid contains zinc chloride and one of the main components of the pre-leaching liquid is also zinc chloride, the high-zinc waste liquid can be used as a raw material of the pre-leaching liquid by removing ferrous ions in the high-zinc waste liquid. The specific treatment method comprises the following steps: firstly, hypochlorous acid is added into the high-zinc wastewater, then the pH value of the solution is regulated to be 2~4, ferric hydroxide precipitate is formed, and finally the precipitate in the solution is removed in a filtering mode.
By the mode, on one hand, the way that the clamp carries zinc to pollute the pickling solution is effectively cut off, the zinc content in the pickling solution is reduced, and the acid solution treatment difficulty is reduced, on the other hand, the high-zinc acid solution formed in the process of back plating and de-zincing can be comprehensively utilized, the usage amount of the upper-product medicines and the comprehensive treatment cost are further reduced, and the environment applicability of the process is obviously improved.
The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent structures or equivalent processes performed by the present invention or directly or indirectly applied to other related technical fields are also included in the scope of the present invention.
Claims (6)
1. A zinc control method for an acid-containing wastewater of a workpiece hot galvanizing process comprises a degreasing step, an acid washing step, a pre-dipping step, a preheating step, a hot dipping step and a passivation step, and is characterized in that: the acid washing step in the hot galvanizing process is different from a clamp used in the hot galvanizing step.
2. The method for controlling zinc in acid-containing wastewater in a hot galvanizing process of workpieces as set forth in claim 1, wherein the same jigs are used in the pre-dipping step, the preheating step, the hot galvanizing step and the passivating step.
3. The method for controlling zinc in acid wastewater in a hot galvanizing process for workpieces as claimed in claim 1, wherein the hot galvanizing process further comprises a workpiece de-galvanizing back-plating step, and the high zinc wastewater formed in the workpiece de-galvanizing back-plating step is separated from the wastewater formed in the pickling step.
4. The method for controlling zinc in acid-containing wastewater in a workpiece hot galvanizing process according to claim 3, wherein a hydrochloric acid solution is used as a back plating solution in the step of de-galvanizing the workpiece.
5. The method for controlling zinc in acid-containing wastewater in workpiece hot galvanizing process according to claim 3, wherein the high-zinc wastewater is used for removing Fe 2+ Ionized to be used as a presoaking supplement.
6. The method for controlling zinc in acid-containing wastewater in workpiece hot galvanizing process according to claim 3, wherein Fe is removed from the high-zinc wastewater 2+ The method comprises the following steps: firstly, adding hypochlorous acid into the high-zinc waste waterAnd (3) adjusting the pH value of the solution to 2~4 to form ferric hydroxide precipitate, and finally removing the precipitate in a filtering mode to obtain the pre-soaking supplementary solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111021292.3A CN115725919A (en) | 2021-09-01 | 2021-09-01 | Method for controlling zinc in acid-containing wastewater in workpiece hot galvanizing process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111021292.3A CN115725919A (en) | 2021-09-01 | 2021-09-01 | Method for controlling zinc in acid-containing wastewater in workpiece hot galvanizing process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115725919A true CN115725919A (en) | 2023-03-03 |
Family
ID=85292111
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111021292.3A Pending CN115725919A (en) | 2021-09-01 | 2021-09-01 | Method for controlling zinc in acid-containing wastewater in workpiece hot galvanizing process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115725919A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108796412A (en) * | 2018-05-29 | 2018-11-13 | 徐州瑞马智能技术有限公司 | Facilitate the internal circulation method in the workshop and hanger that are recycled in galvanizing tooling hanger |
| CN110129703A (en) * | 2019-06-25 | 2019-08-16 | 中电建成都铁塔有限公司 | A kind of hot dip galvanizing process and hot dip liquid system for iron tower construction member |
| CN112251697A (en) * | 2020-10-23 | 2021-01-22 | 徐州瑞马智能技术有限公司 | Side-in end-out type scaffold hot galvanizing device |
| CN113186476A (en) * | 2021-04-30 | 2021-07-30 | 山东时风（集团）有限责任公司 | Hot galvanizing process method for coil-type scaffold |
-
2021
- 2021-09-01 CN CN202111021292.3A patent/CN115725919A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108796412A (en) * | 2018-05-29 | 2018-11-13 | 徐州瑞马智能技术有限公司 | Facilitate the internal circulation method in the workshop and hanger that are recycled in galvanizing tooling hanger |
| CN110129703A (en) * | 2019-06-25 | 2019-08-16 | 中电建成都铁塔有限公司 | A kind of hot dip galvanizing process and hot dip liquid system for iron tower construction member |
| CN112251697A (en) * | 2020-10-23 | 2021-01-22 | 徐州瑞马智能技术有限公司 | Side-in end-out type scaffold hot galvanizing device |
| CN113186476A (en) * | 2021-04-30 | 2021-07-30 | 山东时风（集团）有限责任公司 | Hot galvanizing process method for coil-type scaffold |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101215682B (en) | Non-poaching-water common hot-dip galvanizing technique | |
| CN108149179B (en) | Hot galvanizing production process for fastener | |
| CN107740085B (en) | A kind of composite coloured passivating solution of environment-friendly type and preparation method thereof | |
| CN108914168A (en) | A kind of sheet metal surface treatment process | |
| CN113186476B (en) | Hot galvanizing process method for coil-type scaffold | |
| CN104328371A (en) | Hot dip galvanizing technique for implementing corrosion resistance and rust resistance of steel tube | |
| CN104498925B (en) | A kind of metal surface treating liquid and application based on polyfunctional group alkyl phosphate | |
| CN105648378A (en) | Antirust heat treatment technology for spare parts | |
| CN110863149A (en) | Hot-dip galvanized steel pipe and manufacturing method thereof | |
| CN107574430A (en) | A kind of silicate bright blue passivation liquid and preparation method thereof | |
| CN107740022B (en) | A kind of hot-dip aluminum zinc magnesium alloy fluxing agent | |
| CN115725919A (en) | Method for controlling zinc in acid-containing wastewater in workpiece hot galvanizing process | |
| CN101392360A (en) | Hot-dipped aluminum technique method of heavy duty automobile exhaust tube | |
| CN103266326A (en) | Wire rope pickling method | |
| CN111074188A (en) | Hot galvanizing processing technology | |
| CN109440042A (en) | A kind of galvanized method of the scattered component of steel tower | |
| CN112695312A (en) | Molybdenum-zirconium type phosphorus-free passivator, metal part and surface passivation treatment method thereof | |
| CN106637169A (en) | Novel carbon steel water-supply equipment pretreatment process | |
| KR100436597B1 (en) | Method for plating with molten aluminum | |
| CN104195485B (en) | On-line automatic pretreatment process for steel pipe hot-dip galvanizing | |
| KR100676523B1 (en) | Preprocessing method for hot-dip aluminizing | |
| CN109385649A (en) | A kind of crisp acid cyanideless electro-plating zinc technology method of low hydrogen | |
| CN114369780A (en) | Hot galvanizing process for power iron accessory and photovoltaic solar bracket | |
| CN116479356A (en) | Hot galvanizing process | |
| CN116607094A (en) | Production process of galvanized iron wire |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |