CN102108445A - Method for removing fluorine and chlorine in zinc oxide fume dust - Google Patents

Method for removing fluorine and chlorine in zinc oxide fume dust Download PDF

Info

Publication number
CN102108445A
CN102108445A CN200910226711XA CN200910226711A CN102108445A CN 102108445 A CN102108445 A CN 102108445A CN 200910226711X A CN200910226711X A CN 200910226711XA CN 200910226711 A CN200910226711 A CN 200910226711A CN 102108445 A CN102108445 A CN 102108445A
Authority
CN
China
Prior art keywords
zinc oxide
alkali cleaning
fume dust
section
oxide fume
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
Application number
CN200910226711XA
Other languages
Chinese (zh)
Inventor
林文军
刘一宁
赵为上
廖贻鹏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhuzhou Smelter Group Co Ltd
Original Assignee
Zhuzhou Smelter Group Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Zhuzhou Smelter Group Co Ltd filed Critical Zhuzhou Smelter Group Co Ltd
Priority to CN200910226711XA priority Critical patent/CN102108445A/en
Publication of CN102108445A publication Critical patent/CN102108445A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Landscapes

  • Manufacture And Refinement Of Metals (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

The invention relates to a method for removing fluorine and chlorine in zinc oxide fume dust. The method is characterized by adopting Na2CO3 and NaOH to carry out alkaline cleaning on the zinc oxide fume dust by sections, uniformly mixing the zinc oxide fume dust with the solid Na2CO3, adding water and stirring the mixture at high speed to dissolve the mixture into solution with residues and filtering the solution with residues to obtain the first section alkali cleaning solution and alkali cleaning residues during the first section of alkaline cleaning; and adding the solid Na2CO3 and NaOH to the first section alkali cleaning solution, stirring and dissolving the mixture and adjusting the pH value and filtering the mixture to obtain the second section alkali cleaning solution and alkali cleaning residues during the second section of alkaline cleaning. The method has the following beneficial effects: the metals in ZnCl2, ZnF2 and PbCl2 form solid carbonate residues and the chlorine and fluorine are dissolved in the solution in the form of sodium salt, thus creating conditions for subsequently processing the residues and the solution respectively; and comprehensive recovery of zinc, cadmium, lead, thallium and indium can be realized through deep processing of the products in each stage.

Description

The removal methods of fluorine chlorine in the zinc oxide fume dust
Technical field
The present invention relates to the recoverying and utilizing method of the cigarette ash that produced in a kind of metallic zinc smelting process, the removal methods of fluorine chlorine in the zinc oxide fume dust that is produced in particularly a kind of zinc hydrometallurgy process.
Background technology
Zinc hydrometallurgy is the conventional process that metallic zinc is smelted, and in the zinc hydrometallurgy process, zinc oxide fume dust is its a large amount of wastes that produce, for example the breeze leached mud is through Rotary Kiln volatilization output zinc oxide, the zinc oxide that produces handle through taking off F, Cl again, in this process, obtain a kind of flue dust, i.e. zinc oxide fume dust.Generally speaking, the valuable metal that contains recyclable utilization in these cigarette ashes, contain in the zinc oxide fume dust zinc 30～40%, leaded 10～20%, contain cadmium 3～8%, contain thallium 0.2～1.2%, zinc oxide fume dust per ton also contains the indium of 400～1500g, has very high recovery value.But because the fluorine cl content is generally respectively more than 2% and 3% in the zinc oxide fume dust, the fluorine cl content has a strong impact on the electrolysis of zinc than higher, and makes the comprehensive recovery of each valuable metal more complicated, remains in a lot of technical problems and need solve.At present, these zinc oxide fume dusts only adopt the method for preparing the zinc sulfate series product to reclaim zinc wherein in the prior art, and the rate of recovery of zinc is below 86%, and contained cadmium, lead and high value metals indium, thallium do not reclaim in the cigarette ashes such as zinc oxide fume dust, causes a large amount of losses of valuable metal resource.In the prior art, those skilled in the art once attempted the whole bag of tricks and reclaimed zinc, cadmium, plumbous, valuable metal such as indium and thallium, for eliminating the higher side effect that produces of fluorine cl content, direct alkali cleaning dechlorinating process was once adopted in this area, the fluorine chlorine decreasing ratio of this method is all below 80%, it is still very big that fluorine chlorine in the subsequent handling removes intractability, and cost is higher relatively, the economic feasibility that does not have industrial applications, zinc, the rate of recovery of cadmium and indium is respectively 86%, 80% and 75%, thallium does not reclaim, and comprehensive recovery is not high, leaded in the slag is about 35%, is unfavorable for continuing processing and reclaims plumbous.
Therefore, how the fluorine chlorine in the zinc oxide fume dust being removed, is a difficult problem that remains further exploration for the comprehensive valuable metals such as zinc, cadmium, lead, indium and thallium that reclaim in the zinc oxide fume dust create conditions.
Summary of the invention
The object of the present invention is to provide the removal methods of fluorine chlorine in a kind of zinc oxide fume dust, it can make, and removing of fluorine chlorine reaches respectively more than 92% and 95% in the zinc oxide fume dust, has the advantage that technology is simple, cost is low, for the valuable metal that further reclaims in the zinc hydride cigarette ash creates conditions.
Technical scheme of the present invention is:
The removal methods of fluorine chlorine in a kind of zinc oxide fume dust is characterized in that: it is to adopt Na 2CO 3With Na0H zinc oxide fume dust is carried out alkali cleaning, described alkali cleaning divides two stages to carry out, and elder generation is with zinc oxide fume dust and solid Na in first section alkali cleaning step 2CO 3After mixing, add the entry high-speed stirring again, make zinc oxide fume dust dissolving and and Na 2CO 3Reaction generates the zinc oxide fume dust solution that contains solid slag, filters and obtains first section alkaline wash and alkali cleaning slag; Second section alkali cleaning step is to add solid Na in first section alkali cleaning slag 2CO 3, stir and make solid Na 2CO 3Dissolve, add the pH value of NaOH regulator solution then, filter and obtain second section alkaline wash and alkali cleaning slag.
As to further improvement of the present invention, described Na 2CO 3The adding gross weight be to make contained F, Cl and Na in the zinc oxide fume dust by calculating 2CO 3Reaction generates NaF and the needed Na of NaCl 2CO 3Weight is determined; The Na that adds in described first section alkali cleaning 2CO 3Be 55～90% of gross weight, the Na that adds in described second section alkali cleaning 2CO 3Be 10～45% of total amount.
As to further improvement of the present invention, the Na that the weight of the NaOH that adds in described second section alkali cleaning adds by two sections alkali cleanings 2CO 3: the weight ratio of NaOH is calculating in 1: 1～4: 1.
As to further improvement of the present invention, dreggy weight ratio is 4: 1～6: 1 in described second section alkali cleaning gained solution and the solution, and temperature is 70～90 ℃, and the time is 1～1.5h, and the endpoint pH of described second section alkali cleaning is 9～12.
As to further improvement of the present invention, the stirring velocity of the fs in the described step 1 is 600～850r/min.
Reaction principle of the present invention is:
ZnCl 2+Na 2CO 3＝ZnCO 3↓+2NaCl
ZnF 2+Na 2CO 3＝ZnCO 3↓+2NaF
ZnCl 2+2NaOH＝Zn(OH) 2↓+2NaCl
ZnF 2+2NaOH＝Zn(OH) 2↓+2NaF
PbCl 2+Na 2CO 3＝PbCO 3+2NaCl
PbCl 2+2NaOH＝PbO↓+2NaCl+H 2O
Tl 2O+Na 2CO 3+H 2O＝Tl 2CO 3+2NaOH
Beneficial effect of the present invention is:
The present invention utilize contained valuable metal in the zinc oxide fume dust metal chloride, metal fluoride can with Na 2CO 3Principle with NaOH reacts makes ZnCl 2, ZnF 2, PbCl 2Deng the form formation solid slag of the metal in metal chloride, the metal fluoride with carbonate, chlorine, fluorine then are dissolved in the solution with the form of sodium salt, for condition has been created in the recovery of valuable metals such as Zn, Pb, thallium is dissolved in the solution, can from alkaline wash, reclaim thallium, for follow-up comprehensive recovery zinc, cadmium, lead, thallium and indium provide assurance.
The present invention removes required Na with fluorine chlorine in the zinc oxide fume dust 2CO 3The major part of theoretical weight joins in the zinc oxide fume dust in solid blended mode in first section alkali cleaning, by adding the mode of water high-speed stirring, accelerate the speed that combines and the degree of sodium ion and chlorion or fluorion, make most of alkali cleaning be reflected at the fs and finish, continue to add Na through second section again 2CO 3Handle with the NaOH alkali cleaning, the metal fluorochloride in the zinc oxide fume dust is reacted completely, make fluorine chlorine decreasing ratio respectively more than 92% and 95%.
The present invention has overcome that the fluorine chlorine because of the metal fluorochloride removes the problem that valuable metals such as zinc, cadmium, indium, thallium reclaim that thoroughly influence in the prior art, for the further above-mentioned valuable metal of recovery has been created condition.
Embodiment
Embodiment 1
Adopt the present invention that zinc oxide fume dust is comprehensively reclaimed, the zinc oxide fume dust composition is following weight per-cent Zn35.87%, F2.65%, Cl5.81%, In0.0468%, Tl0.28%, Cd3.13%, Cu0.12%, Fe1.47%, Pb15.35%, Co0.005%, Ni0.002%, As0.041%, Sb0.075%, carry out according to the following steps:
Step 1: calculate Na 2CO 3Add gross weight, calculate according to a conventional method and make contained F, Cl and Na in the pending zinc oxide fume dust 2CO 3Reaction generates NaF and the needed Na of NaCl 2CO 3Theoretical weight; Divide two stages to carry out alkali cleaning, elder generation is with zinc oxide fume dust and above-mentioned Na in first section alkali cleaning step 2CO 355% solid Na of theoretical weight 2CO 3After mixing, add the entry high-speed stirring again, stirring velocity is 600r/min, makes zinc oxide fume dust dissolving and and Na 2CO 3Reaction generates the zinc oxide fume dust solution that contains solid slag, filters and obtains first section alkaline wash and alkali cleaning slag; In second section alkali cleaning with above-mentioned Na 2CO 345% solid Na of theoretical weight 2CO 3Join in first section alkali cleaning slag the Na that the weight of the NaOH that adds in second section alkali cleaning adds by two sections alkali cleanings 2CO 3With the weight ratio of NaOH is to calculate at 4: 1, and the liquid-solid ratio of second section alkali cleaning is 4: 1, and temperature is 70 ℃, and the time is 1h, and keeps terminal point pH=9.The decreasing ratio of fluorine chlorine is respectively 92.35% and 95.68%.
Embodiment 2
Adopt the present invention that zinc oxide fume dust is comprehensively reclaimed, the component of zinc oxide fume dust is following weight per-cent Zn35.87%, F2.65%, Cl5.81%, In0.0468%, Tl0.28%, Cd3.13%, Cu0.12%, Fe1.47%, Pb15.35%, Co0.005%, Ni0.002%, As0.041%, Sb0.075%.
Carry out according to the following steps:
Step 1: calculate Na 2CO 3Add gross weight, calculate according to a conventional method and make contained F, Cl and Na in the zinc oxide fume dust 2CO 3Reaction generates NaF and the needed Na of NaCl 2CO 3Theoretical weight; Divide two stages to carry out alkali cleaning, elder generation is with zinc oxide fume dust and above-mentioned Na in first section alkali cleaning step 2CO 365% solid Na of theoretical weight 2CO 3After mixing, add the entry high-speed stirring again, stirring velocity is 700r/min, makes zinc oxide fume dust dissolving and and Na 2CO 3Reaction generates the zinc oxide fume dust solution that contains solid slag, filters and obtains first section alkaline wash and alkali cleaning slag; In second section alkali cleaning with above-mentioned Na 2CO 335% solid Na of theoretical weight 2CO 3Join in first section alkali cleaning slag the Na that the amount of the NaOH that adds in second section alkali cleaning adds by two sections alkali cleanings 2CO 3With the weight ratio of NaOH be 3: 1, liquid-solid ratio is 4: 1, temperature is 80 ℃, the time is 1.5h, and keeps terminal point pH=10.The decreasing ratio of fluorine chlorine reaches 93.62% and 96.79% respectively.
Embodiment 3
Adopt the present invention that zinc oxide fume dust is comprehensively reclaimed, the component of zinc oxide fume dust is following weight per-cent Zn35.87%, F2.65%, Cl5.81%, In0.0468%, Tl0.28%, Cd3.13%, Cu0.12%, Fe1.47%, Pb15j5%, Co0.005%, Ni0.002%, As0.041%, Sb0.075%.
Carry out according to the following steps:
Step 1: calculate Na 2CO 3Add gross weight, calculate according to a conventional method and make contained F, Cl and Na in the zinc oxide fume dust 2CO 3Reaction generates NaF and the needed Na of NaCl 2CO 3Theoretical weight; Divide two stages to carry out alkali cleaning, in first section alkali cleaning step earlier with zinc oxide fume dust with above-mentioned Na 2CO 375% solid Na of theoretical weight 2CO 3After mixing, add the entry high-speed stirring again, stirring velocity is 750r/min, makes zinc oxide fume dust dissolving and and Na 2CO 3Reaction generates the zinc oxide fume dust solution that contains solid slag, filters and obtains first section alkaline wash and alkali cleaning slag; In second section alkali cleaning with above-mentioned Na 2CO 325% solid Na of theoretical weight 2CO 3Join in first section alkali cleaning slag the Na that the amount of the NaOH that adds in second section alkali cleaning adds by two sections alkali cleanings 2CO 3With the weight ratio of NaOH be 3: 1, liquid-solid ratio is 5: 1, temperature is 80 ℃, the time is 1.5h, and keeps terminal point pH=10.The decreasing ratio of fluorine chlorine reaches 92.78% and 96.10% respectively.
Embodiment 4
Adopt the present invention that the multiple hearth furnace zinc oxide fume dust is comprehensively reclaimed, the component of zinc oxide fume dust is following weight per-cent Zn35.87%, F2.65%, Cl5.81%, In0.0468%, Tl0.28%, Cd3.13%, Cu0.12%, Fe1.47%, Pb15.35%, Co0.005%, Ni0.002%, As0.041%, Sb0.075%.
Carry out according to the following steps:
Step 1: calculate Na 2CO 3Add gross weight, calculate according to a conventional method and make contained F, Cl and Na in the zinc oxide fume dust 2CO 3Reaction generates NaF and the needed Na of NaCl 2CO 3Theoretical weight; Divide two stages to carry out alkali cleaning, in first section alkali cleaning step earlier with zinc oxide fume dust with above-mentioned Na 2CO 385% solid Na of theoretical weight 2CO 3After mixing, add the entry high-speed stirring again, stirring velocity is 800r/min, makes zinc oxide fume dust dissolving and and Na 2CO 3Reaction generates the zinc oxide fume dust solution that contains solid slag, filters and obtains first section alkaline wash and alkali cleaning slag; In second section alkali cleaning with above-mentioned Na 2CO 315% solid Na of theoretical weight 2CO 3Join in first section alkali cleaning slag the Na that the amount of the NaOH that adds in second section alkali cleaning adds by two sections alkali cleanings 2CO 3With the weight ratio of NaOH be 2: 1, liquid-solid ratio is 5: 1, temperature is 85 ℃, the time is 1.5h, and keeps terminal point pH=11.The decreasing ratio of fluorine chlorine reaches 94.84% and 97.72% respectively.
Embodiment 5
Adopt the present invention that the multiple hearth furnace zinc oxide fume dust is comprehensively reclaimed, the component of zinc oxide fume dust is following weight per-cent Zn35.87%, F2.65%, Cl5.81%, In0.0468%, Tl0.28%, Cd3.13%, Cu0.12%, Fe1.47%, Pb15.35%, Co0.005%, Ni0.002%, As0.041%, Sb0.075%.
Carry out according to the following steps:
Step 1: calculate Na 2CO 3Add gross weight, calculate according to a conventional method and make contained F, Cl and Na in the zinc oxide fume dust 2CO 3Reaction generates NaF and the needed Na of NaCl 2CO 3Theoretical weight; Divide two stages to carry out alkali cleaning, in first section alkali cleaning step earlier with zinc oxide fume dust with above-mentioned Na 2CO 390% solid Na of theoretical weight 2CO 3After mixing, add the entry high-speed stirring again, stirring velocity is 850r/min, makes zinc oxide fume dust dissolving and and Na 2CO 3Reaction generates the zinc oxide fume dust solution that contains solid slag, filters and obtains first section alkaline wash and alkali cleaning slag; In second section alkali cleaning with above-mentioned Na 2CO 310% solid Na of theoretical weight 2CO 3Join in first section alkali cleaning slag the Na that the amount of the NaOH that adds in second section alkali cleaning adds by two sections alkali cleanings 2CO 3With the weight ratio of NaOH be 1: 1, liquid-solid ratio is 6: 1, temperature is 90 ℃, the time is 1.5h, and keeps terminal point pH=12.The decreasing ratio of fluorine chlorine reaches 96.15% and 99.06% respectively.

Claims (5)

1. the removal methods of fluorine chlorine in the zinc oxide fume dust, it is characterized in that: it is to adopt Na 2CO 3With NaOH zinc oxide fume dust is carried out alkali cleaning, described alkali cleaning divides two stages to carry out, and elder generation is with zinc oxide fume dust and solid Na in first section alkali cleaning step 2CO 3After mixing, add the entry high-speed stirring again, make zinc oxide fume dust dissolving and and Na 2CO 3Reaction generates the zinc oxide fume dust solution that contains solid slag, filters and obtains first section alkaline wash and alkali cleaning slag; Second section alkali cleaning step is to add solid Na in first section alkali cleaning slag 2CO 3, stir and make solid Na 2CO 3Dissolve, add the pH value of NaOH regulator solution then, filter and obtain second section alkaline wash and alkali cleaning slag.
2. the removal methods of fluorine chlorine in the zinc oxide fume dust according to claim 1 is characterized in that: described Na 2CO 3The adding gross weight be to make contained F, Cl and Na in the zinc oxide fume dust by calculating 2CO 3Reaction generates NaF and the needed Na of NaCl 2CO 3Weight is determined; The Na that adds in described first section alkali cleaning 2CO 3Be 55～90% of gross weight, the Na that adds in described second section alkali cleaning 2CO 3Be 10～45% of total amount.
3. the removal methods of fluorine chlorine in the zinc oxide fume dust according to claim 1 and 2 is characterized in that: the Na that the weight of the NaOH that adds in described second section alkali cleaning adds by two sections alkali cleanings 2CO 3With the weight ratio of NaOH is to calculate in 1: 1～4: 1.
4. the removal methods of fluorine chlorine in the zinc oxide fume dust according to claim 3, it is characterized in that: dreggy weight ratio is 4: 1～6: 1 in described second section alkali cleaning gained solution and the solution, temperature is 70～90 ℃, time is 1～1.5h, and the endpoint pH of described second section alkali cleaning is 9～12.
5. the removal methods of fluorine chlorine in the zinc oxide fume dust according to claim 3 is characterized in that: the stirring velocity of the fs in the described step 1 is 600～850r/min.
CN200910226711XA 2009-12-23 2009-12-23 Method for removing fluorine and chlorine in zinc oxide fume dust Pending CN102108445A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN200910226711XA CN102108445A (en) 2009-12-23 2009-12-23 Method for removing fluorine and chlorine in zinc oxide fume dust

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN200910226711XA CN102108445A (en) 2009-12-23 2009-12-23 Method for removing fluorine and chlorine in zinc oxide fume dust

Publications (1)

Publication Number Publication Date
CN102108445A true CN102108445A (en) 2011-06-29

Family

ID=44172731

Family Applications (1)

Application Number Title Priority Date Filing Date
CN200910226711XA Pending CN102108445A (en) 2009-12-23 2009-12-23 Method for removing fluorine and chlorine in zinc oxide fume dust

Country Status (1)

Country Link
CN (1) CN102108445A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105188968A (en) * 2013-03-22 2015-12-23 新日铁住金不锈钢株式会社 Dust cleaning device and dust cleaning method
CN107227466A (en) * 2017-06-26 2017-10-03 郴州市金贵银业股份有限公司 A kind of method that chlorine oxygen copper dechlorination carries copper
JP7415629B2 (en) 2020-02-07 2024-01-17 住友金属鉱山株式会社 Method for producing zinc oxide ore

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105188968A (en) * 2013-03-22 2015-12-23 新日铁住金不锈钢株式会社 Dust cleaning device and dust cleaning method
CN105188968B (en) * 2013-03-22 2017-05-10 新日铁住金不锈钢株式会社 dust cleaning device and dust cleaning method
CN107227466A (en) * 2017-06-26 2017-10-03 郴州市金贵银业股份有限公司 A kind of method that chlorine oxygen copper dechlorination carries copper
JP7415629B2 (en) 2020-02-07 2024-01-17 住友金属鉱山株式会社 Method for producing zinc oxide ore

Similar Documents

Publication Publication Date Title
CN101818254B (en) Comprehensive recovery method of zinc oxide fume dust
CN108118157B (en) Wiring board burns the recovery method of cigarette ash pretreatment and bromine
CN102286759B (en) Method for preparing electrodeposited zinc from high-fluorine high-chlorine secondary zinc oxide powder
CN103757420B (en) Method for recovering lead and silver from zinc leaching residues
CN102286665A (en) Comprehensive recovery method for complicated materials containing arsenic and valuable metal slag dust
US9828654B2 (en) Method for directly recovering lead oxide used for a lead-acid battery cathode from waste lead paste
CN105293564A (en) Method for recycling zinc-containing dust ash in steel plant
CN105734299A (en) Method for comprehensively recovering valuable metals through oxygen pressure treatment of tin anode mud
CN102206750A (en) Method for recovering lead from lead-containing material by matching leaching-electrowinning method
CN103305695A (en) Method for preparing nano-lead dioxide powder from waste lead paste by wet process
CN105617596A (en) Wet-process harmless treatment method for electrolytic bath overhaul residue
CN112941312B (en) Comprehensive recovery process for antimony and arsenic smelting alkaline residue
CN101062783A (en) Environment-friendly type technique for vanadium extraction of stone coal
CN102108445A (en) Method for removing fluorine and chlorine in zinc oxide fume dust
CN103667735B (en) A kind of method of waste lead battery lead recovery
CN108486379A (en) The efficient separation method of arsenic and alkali in a kind of arsenic alkaline slag
CN102828033A (en) Method for recycling electrolytic zinc acid leaching slag
JP2005246226A (en) Treating method for fly ash
CN102826586A (en) Method for producing high purity nanometer zinc oxide by using steel plant dust
CN102826588B (en) Method for producing high-purity nanometer zinc oxide by using ammonia process decarburization of steel plant dust
CN102849782B (en) Method for producing high-purity zinc oxide by steel mill smoke dust ash ammonia method decarburization
Nakamura et al. Basic consideration on EAF dust treatment using hydrometallurgical processes
CN102849781B (en) Method for producing high-purity zinc oxide through fume ash in steel works
US5810946A (en) Method for the production of galvanizing fluxes and flux feedstocks
CN102826589B (en) Method for producing high purity nanometer zinc oxide by using ammonia process of steel plant dust

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C02 Deemed withdrawal of patent application after publication (patent law 2001)
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20110629