CN102020293B - Method for recovering reagent grade sodium nitrate from waste liquid generated in citric acid bismuth production - Google Patents
Method for recovering reagent grade sodium nitrate from waste liquid generated in citric acid bismuth production Download PDFInfo
- Publication number
- CN102020293B CN102020293B CN200910192425A CN200910192425A CN102020293B CN 102020293 B CN102020293 B CN 102020293B CN 200910192425 A CN200910192425 A CN 200910192425A CN 200910192425 A CN200910192425 A CN 200910192425A CN 102020293 B CN102020293 B CN 102020293B
- Authority
- CN
- China
- Prior art keywords
- waste liquid
- reagent grade
- sodium nitrate
- nitrate
- solution
- 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.)
- Active
Links
Abstract
The invention provides a method for recovering reagent grade sodium nitrate from waste liquid generated in a production process of citric acid bismuth prepared by the reaction of nitric acid bismuth solution with citric acid and sodium carbonate solution. The method comprises the following steps: heating and concentrating the collected waste liquid until the proportion of the heat solution is 1.15-1.20; adding 5-8% of ammonium nitrate into the waste liquid, wherein the molar ratio of the ammonium nitrate is equal to that of the sodium nitrite in the waste liquid; heating to microboil to remove the impurities of nitrite; adding calcium hydroxide to remove a small amount of residual citric acid in the reaction; adding the sodium carbonate to regulate the pH value of the waste liquid; preserving the temperature to remove the heavy metal impurities and excessive calcium; regulating the pH value of the filtrate by nitric acid; and concentrating and crystallizing to obtain the reagent grade sodium nitrate. The method for recovering the sodium nitrate is simple in operation and moderate in process condition, can be used for effectively removing various purities in the waste liquid; the comprehensive recovery rate is up to 75-85%; and the obtained product conforms to the analytically pure standard of GB/T 636-1992 chemical reagent. In the invention, the waste liquid is comprehensively processed and utilized to recover the reagent grade sodium nitrate, thus achieving the purposes of saving the energy, reducing the emission, lowering the environment pollution and lowering the production cost.
Description
Technical field
The present invention relates to a kind of working method of SODIUMNITRATE; Relate in particular to and a kind ofly produce the method that reclaims reagent grade sodium nitrate the waste liquid, more specifically relate to a kind of method by the waste liquid recovery reagent grade sodium nitrate that produces in bismuth nitrate solution and Hydrocerol A, the sodium carbonate solution prepared in reaction bismuth citrate production process from bismuth citrate.
Background technology
SODIUMNITRATE is a kind of water white transparency crystallization, white particle or powder, and odorless is distinguished the flavor of into little hardship, and is soluble in water in damp atmosphere part omitted moisture absorption, is slightly soluble in ethanol, methyl alcohol and glycerine.306.8 ℃ of the fusing points of SODIUMNITRATE when being heated to 380 ℃, are decomposed into Sodium Nitrite and oxygen.SODIUMNITRATE is a kind of strong oxidizer, also is a kind of important chemical material and analytical reagent, is mainly used in to make glass, dyestuff, medicine, gunpowder and food preservation, also is used for soil, chemical fertilizer analysis etc.
At present, the working method of domestic and international SODIUMNITRATE is concluded and is mainly contained: neutralisation, absorption process, double decomposition etc.Neutralisation adopts nitric acid and soda ash to be raw material, and is simple to operate, but cost is expensive, seldom adopts in the industry; Absorption process adopts soda ash solution to absorb the oxynitride in the nitric acid tail gas and get, and this method is utilized waste gas, and comprehensive utilization of resources can reduce environmental pollution, is generally to adopt both at home and abroad, but needs the support nitric plant and build; Double decomposition has nitrocalcite-sodium sulfate double decomposition, an ammonium nitrate-sodium hydrogencarbonate double decomposition, Sodium Tetraborate-nitric acid double decomposition etc.; Wherein obtain comparatively widespread use with nitrocalcite-sodium sulfate double decomposition; This method production cost is low; But often contain impurity such as higher sulfate radical and calcium ion, product purity is low.
Bismuth citrate is a kind of medical material, is the main raw material of synthetic gastric mucosal protection medicine Bismuth Potassium Citrate (or being called Bismuth Potassium Citrate), and its working method is generally reacted and got by bismuth nitrate solution and Hydrocerol A, sodium carbonate solution.In the production process of bismuth citrate; The per kilogram product produces 2.5 liters of waste liquids approximately; This waste liquid is acid, and the pH value is about 2.0-2.5, mainly contains the SODIUMNITRATE of about 200-220g/L; In addition, generally also contain heavy metal ion impurities such as the remaining Hydrocerol A of a small amount of reaction, Sodium Nitrite and Bi, Pb, Cu in the waste liquid.If this waste liquid is directly discharged, not only polluted source breaks the ring ecotope, and can cause the wasting of resources.
Summary of the invention
For solving the problem of above existence, the purpose of this invention is to provide a kind of method of producing recovery reagent grade sodium nitrate the waste liquid from bismuth citrate.
For realizing above purpose, method of producing recovery reagent grade sodium nitrate the waste liquid from bismuth citrate of the present invention in turn includes the following steps:
(1) with the waste liquid that produces in the bismuth citrate production process of collecting, sampling detects the content of Sodium Nitrite in every liter of waste liquid;
(2) removing of Sodium Nitrite: get a certain amount of waste liquid; Calculate the wherein total amount of Sodium Nitrite; The waste liquid heating is concentrated into hot soln proportion 1.15-1.20, adds an ammonium nitrate, stirring and dissolving post-heating to little boiling; And keep little and boil and stir more than 2 hours at a slow speed, the amount of an ammonium nitrate with waste liquid in the mol ratios such as amount of Sodium Nitrite calculate and excessive 5-8% adds;
(3) removing of Hydrocerol A: in the waste liquid that step (2) was handled, adding calcium hydroxide to waste liquor PH value while stirring is 7-8, boils more than 15 minutes, and filtered while hot obtains clear liquid;
(4) removing of heavy metal ion: the filtrating with step (3) obtains, add yellow soda ash to pH value of solution >=11 while stirring, heated and boiled left standstill more than 2 hours 60-80 ℃ of insulation more than 15 minutes, filtered to obtain clear liquid;
(5) sodium nitrate condensing crystallizing: the filtrating that step (4) is obtained, regulating its pH with nitric acid is 4-6, to be concentrated into hot solution proportion be 1.45-1.50 in heating then; Concentrate is cooled to the abundant crystallization of room temperature; Get the crystallization centrifugation, wet article obtain the sodium nitrate product through drying;
Above-mentioned waste liquid is the waste liquid that produces in the production process by bismuth nitrate solution and Hydrocerol A, sodium carbonate solution prepared in reaction bismuth citrate.
For making SODIUMNITRATE obtain better yield, the mother liquor that mother liquor that above-mentioned steps (5) crystallisation by cooling process obtains and centrifugal process obtain is handled through step (4) and (5) again.
For calcium hydroxide is better disperseed in waste liquid, the calcium hydroxide of above-mentioned steps (3) adds in the waste liquid after with pure water furnishing emulsion again.
Because carbonate or subcarbonate that heavy metal ion forms are flocks mostly, in order to make the better cohesion of deposition, filter more thoroughly, after the solution of above-mentioned steps (4) boils, add an amount of gac and be incubated again and leave standstill.
For better remove carbonate excessive in the step (4) with the potential of hydrogen of product is met the requirements, in the above-mentioned steps (5), the preferred 4.5-5.5 of pH value of filtrate.
The drying temperature of above-mentioned steps (5) is 60-80 ℃, and be 5-6 hour time of drying.
For the excess amount of Ca (OH) of confirming that step (3) adds
2In calcium ion whether thoroughly remove, above-mentioned steps (4) is got the about 50ml of solution and is filtered after adding yellow soda ash, adding concentration expressed in percentage by weight to filtrating is 10% sodium carbonate solution 5ml, shakes up observation, limpid like the filtrating maintenance, then begins heated and boiled; Be muddy like filtrating, then continue to add yellow soda ash to solution.
For avoiding introducing other impurity, the nitric acid that yellow soda ash that the calcium hydroxide that an ammonium nitrate that above-mentioned steps (2) adds, step (3) add, step (4) add and step (5) add should be analytical pure.
Reagent grade sodium nitrate recovery method of the present invention, because waste liquid is rarer relatively, the concentration of various impurity in waste liquid is relatively low, therefore, step (2) should concentrate waste liquid earlier before removing Sodium Nitrite, is beneficial to remove better various impurity; Adopt an ammonium nitrate to remove nitrite anions, reaction formula is: NaNO
2+ NH
4NO
3=NaNO
3+ N
2↑+2H
2O, the product that obtains are SODIUMNITRATE, nitrogen G&W, and SODIUMNITRATE can reclaim by the SODIUMNITRATE in waste liquid, and nitrogen is removed through boiling to overflow, and can not pollute environment; And step (3) adds calcium hydroxide emulsion in waste liquid, and the pH value of control waste liquid, makes a spot of Hydrocerol A formation citrate of lime deposition in the waste liquid, and through removing by filter; Step (4) adds yellow soda ash in removing the filtrating of citrate; And the pH value of control solution; Not only can make the remaining calcium of heavy metal ion such as the contained Bi of solution, Pb, Cu and step (3) reaction form carbonate or subcarbonate deposition through removing by filter; And excessive an ammonium nitrate formation SODIUMNITRATE and ammonia that step (2) is added, ammonia is then overflowed after boiling insulation and is removed; Step (5) adopts nitric acid to regulate pH value of filtrate, in the excess of sodium carbonate of removing step (4) adding, also makes product SODIUMNITRATE meet its potential of hydrogen requirement, and can not introduce new ion.
Reagent grade sodium nitrate recovery method of the present invention, simple to operate, processing condition are gentle, can remove the various impurity in the waste liquid effectively, and comprehensive recovery reaches 75-85%, and the product that obtains meets GB/T 636-1992 chemical reagent analytical pure standard through check.The present invention has reclaimed reagent grade sodium nitrate through the treatment and comprehensive utilization to waste liquid, the purpose that reach energy-saving and emission-reduction, reduces environmental pollution and reduce production costs.
Embodiment
Be specific embodiment of the present invention below, these embodiment just produce from bismuth citrate the present invention and reclaim specifying of reagent grade sodium nitrate working method the waste liquid, are not in order to restriction protection scope of the present invention.
Embodiment 1
(1) produce in the waste liquid at the bismuth citrate of collecting, sampling detection SODIUMNITRATE and content of sodium nitrite are following:
SODIUMNITRATE: 215g/L
Sodium Nitrite: 0.06g/L
(2) get 1500 liters of above-mentioned waste liquids, divide inferior to heating in 1000 liters of stainless steel reaction pots to be concentrated into hot soln proportion 1.16-1.18 (surplus approximately 800-900 liter), add 110g AR level NH then
4NO
3(excessive about 5.4%), the stirring and dissolving post-heating also keeps little and boils and stirred 2 hours at a slow speed, nitrite is fully decomposed remove;
(3) with an amount of pure water with analytically pure Ca (OH)
2The furnishing emulsion, stir in the waste liquid that slowly adds above-mentioned processing down to its pH value be 7-8, heated and boiled is 15 minutes then, filtered while hot obtains clear liquid;
(4) above-mentioned filtrating under agitation to add AR grade anhydrous sodium carbonate to pH value of solution value be 11.0-11.5, get the about 50ml of solution and filter, filtrating adds 10% sodium carbonate solution 5ml; Shake up observation; It is limpid that filtrating keeps, and heated and boiled 15 minutes adds proper amount of active carbon then; Stir the back and left standstill 2 hours, filter and obtain clear liquid 60-80 ℃ of insulation;
(5) above-mentioned filtrating under agitation carefully to add AR level nitre acid for adjusting pH value be 4.5-5.0; Gradation adds in 500 liters of stainless steel concentrating pans then, and it is 1.46-1.48 that heating is concentrated into hot soln proportion, and liquid concentrator is placed the plastic tub crystallisation by cooling; Liquid concentrator is cooled to room temperature and makes abundant crystallization; Get the crystallization centrifuge dripping, wet article obtain SODIUMNITRATE product 170kg 60-80 ℃ of drying 5 hours;
(6) mother liquor that the mother liquor after the crystallization and centrifugal process is obtained merges, and handles through step (4)-(5) again, can obtain SODIUMNITRATE product 75kg again, reclaims SODIUMNITRATE product 245kg altogether, and comprehensive recovery is 76%.
Product meets GB/T 636-1992 chemical reagent analytical pure standard through check.
Embodiment 2
(1) produce in the waste liquid at the bismuth citrate of collecting, sampling detection SODIUMNITRATE and content of sodium nitrite are following:
SODIUMNITRATE: 207g/L
Sodium Nitrite: 0.07g/L
(2) get 1500 liters of above-mentioned waste liquids, divide inferior to heating in 1000 liters of stainless steel reaction pots to be concentrated into hot soln proportion 1.18-1.20 (surplus approximately 800-900 liter), add 130g AR level NH then
4NO
3(excessive about 6.8%), the stirring and dissolving post-heating also keeps little and boils and stirred 2.5 hours at a slow speed, nitrite is fully decomposed remove;
(3) with an amount of pure water with analytically pure Ca (OH)
2The furnishing emulsion, stir in the waste liquid that slowly adds above-mentioned processing down to its pH value be 7-8, heated and boiled is 20 minutes then, filtered while hot obtains clear liquid;
(4) above-mentioned filtrating under agitation to add AR grade anhydrous sodium carbonate to pH value of solution value be 11.5-12.0, get the about 50ml of solution and filter, filtrating adds 10% sodium carbonate solution 5ml; Shake up observation; It is limpid that filtrating keeps, and heated and boiled 25 minutes adds proper amount of active carbon then; Stir the back and left standstill 2 hours, filter and obtain clear liquid 60-80 ℃ of insulation;
(5) above-mentioned filtrating under agitation carefully to add AR level nitre acid for adjusting pH value be 4.5-5.0; Gradation adds in 500 liters of stainless steel concentrating pans then, and it is 1.48-1.50 that heating is concentrated into hot soln proportion, and liquid concentrator is placed the plastic tub crystallisation by cooling; Liquid concentrator is cooled to room temperature and makes abundant crystallization; Get the crystallization centrifuge dripping, wet article obtain SODIUMNITRATE product 175kg 60-80 ℃ of drying 6 hours;
(6) mother liquor that the mother liquor after the crystallization and centrifugal process is obtained merges, and handles through step (4)-(5) again, can obtain SODIUMNITRATE product 77kg again, reclaims SODIUMNITRATE product 252kg altogether, and comprehensive recovery is 81%.
Product meets GB/T 636-1992 chemical reagent analytical pure standard through check.
Claims (8)
1. produce the method that reclaims reagent grade sodium nitrate the waste liquid from bismuth citrate for one kind, in turn include the following steps:
(1) with the waste liquid that produces in the bismuth citrate production process of collecting, sampling detects the content of Sodium Nitrite in every liter of waste liquid;
(2) removing of Sodium Nitrite: get a certain amount of waste liquid; Calculate the wherein total amount of Sodium Nitrite; The waste liquid heating is concentrated into hot soln proportion 1.15-1.20, adds an ammonium nitrate, stirring and dissolving post-heating to little boiling; And keep little and boil and stir more than 2 hours at a slow speed, the amount of an ammonium nitrate with waste liquid in the mol ratios such as amount of Sodium Nitrite calculate and excessive 5-8% adds;
(3) removing of Hydrocerol A: in the waste liquid that step (2) was handled, adding calcium hydroxide to waste liquor PH value while stirring is 7-8, boils more than 15 minutes, and filtered while hot obtains clear liquid;
(4) removing of heavy metal ion: the filtrating with step (3) obtains, add yellow soda ash to pH value of solution >=11 while stirring, heated and boiled left standstill more than 2 hours 60-80 ℃ of insulation more than 15 minutes, filtered to obtain clear liquid;
(5) sodium nitrate condensing crystallizing: the filtrating that step (4) is obtained, regulating its pH with nitric acid is 4-6, to be concentrated into hot solution proportion be 1.45-1.50 in heating then; Concentrate is cooled to the abundant crystallization of room temperature; Get the crystallization centrifugation, wet article obtain the sodium nitrate product through drying;
Above-mentioned waste liquid is the waste liquid that produces in the production process by bismuth nitrate solution and Hydrocerol A, sodium carbonate solution prepared in reaction bismuth citrate.
2. method of producing recovery reagent grade sodium nitrate the waste liquid from bismuth citrate according to claim 1 is characterized in that: the mother liquor that mother liquor that said step (5) crystallisation by cooling process obtains and centrifugal process obtain, handle through step (4) and (5) again.
3. according to claim 1 and 2ly produce the method that reclaims reagent grade sodium nitrate the waste liquid from bismuth citrate, it is characterized in that: the calcium hydroxide in the said step (3) adds in the waste liquid after with pure water furnishing emulsion again.
4. according to claim 1 and 2ly produce the method that reclaims reagent grade sodium nitrate the waste liquid, it is characterized in that: after the solution of said step (4) boils, add an amount of gac and be incubated again and leave standstill from bismuth citrate.
5. method of producing recovery reagent grade sodium nitrate the waste liquid from bismuth citrate according to claim 1 and 2 is characterized in that: in the said step (5), and the preferred 4.5-5.5 of pH value of filtrate.
6. method of producing recovery reagent grade sodium nitrate the waste liquid according to claim 1 and 2 from bismuth citrate; It is characterized in that: said step (4) is after adding yellow soda ash; Get solution 50ml and filter, add 10% sodium carbonate solution 5ml, shake up observation to filtrating; As the maintenance of filtrating is limpid, then begins heated and boiled; Be muddy like filtrating, then continue to add yellow soda ash to solution.
7. method of producing recovery reagent grade sodium nitrate the waste liquid according to claim 1 and 2 from bismuth citrate, it is characterized in that: the drying temperature of said step (5) is 60-80 ℃, be 5-6 hour time of drying.
8. method of producing recovery reagent grade sodium nitrate the waste liquid from bismuth citrate according to claim 1 and 2 is characterized in that: the nitric acid that yellow soda ash that the calcium hydroxide that an ammonium nitrate that said step (2) adds, step (3) add, step (4) add and step (5) add is analytical pure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910192425A CN102020293B (en) | 2009-09-11 | 2009-09-11 | Method for recovering reagent grade sodium nitrate from waste liquid generated in citric acid bismuth production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910192425A CN102020293B (en) | 2009-09-11 | 2009-09-11 | Method for recovering reagent grade sodium nitrate from waste liquid generated in citric acid bismuth production |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102020293A CN102020293A (en) | 2011-04-20 |
| CN102020293B true CN102020293B (en) | 2012-09-05 |
Family
ID=43862123
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910192425A Active CN102020293B (en) | 2009-09-11 | 2009-09-11 | Method for recovering reagent grade sodium nitrate from waste liquid generated in citric acid bismuth production |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102020293B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102502715B (en) * | 2011-11-09 | 2013-09-25 | 广东光华科技股份有限公司 | Method for reclaiming reagent-grade anhydrous sodium sulfate from basic nickel carbonate production waste liquor |
| CN103332667A (en) * | 2013-06-28 | 2013-10-02 | 安徽嘉联生物科技有限公司 | Method for treating foreign matters in potassium dihydrogen phosphate production process |
| CN104445293A (en) * | 2014-12-22 | 2015-03-25 | 长沙鑫本化工有限公司 | Method for recycling waste potassium nitrate generated in glass toughening into potassium nitrate reagent |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1036936A (en) * | 1988-04-18 | 1989-11-08 | 王文生 | The production method of SODIUMNITRATE |
| CN1095359A (en) * | 1994-05-24 | 1994-11-23 | 韩蔚田 | The technology of preparing sodium nitrate by solid phase conversion and metathesis |
-
2009
- 2009-09-11 CN CN200910192425A patent/CN102020293B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1036936A (en) * | 1988-04-18 | 1989-11-08 | 王文生 | The production method of SODIUMNITRATE |
| CN1095359A (en) * | 1994-05-24 | 1994-11-23 | 韩蔚田 | The technology of preparing sodium nitrate by solid phase conversion and metathesis |
Non-Patent Citations (2)
| Title |
|---|
| JP特开平6-242294A 1994.09.02 |
| 李宝林等.硝酸钠生产方法的研究进展.《现代化工》.1995,(第4期),21-23. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102020293A (en) | 2011-04-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2018113478A1 (en) | Method for producing lithium hydroxide monohydrate using lithium carbonate as raw material | |
| CN104003443B (en) | A kind of method adding JZPD capsule ammonium meta-vanadate | |
| CN104003362A (en) | Production method of dipotassium phosphate | |
| CN101560120B (en) | Method for producing compound fertilizer by wet method for decomposing potassium feldspar | |
| CN101439867B (en) | Method for extracting potassium carbonate from cabo and refining carbon | |
| CN104477943A (en) | Method for preparing potassium sulfate | |
| CN1318297C (en) | Potash feldspar wet method decomposition and production process | |
| CN102260801B (en) | Clean conversion method of stone coal | |
| CN104744175A (en) | Method for producing nitrogen-phosphorus-potassium mixed fertilizer by utilizing phosphorus-potassium associated ore | |
| CN103539165A (en) | Method for producing potassium sulfate by utilizing insoluble rocks containing potassium | |
| CN101708835B (en) | Production method of high-purity zinc phosphate | |
| CN102020293B (en) | Method for recovering reagent grade sodium nitrate from waste liquid generated in citric acid bismuth production | |
| CN105692575B (en) | A kind of Application way of rock phosphate in powder | |
| CN101671087B (en) | Method for recovering reagent grade sodium nitrate from waste liquid of bismuth subnitrate production | |
| CN110817827A (en) | Method for preparing food-grade monopotassium phosphate by using industrial wet-process purified phosphoric acid | |
| CN101857212B (en) | Method for preparing food-grade monoammonium phosphate from wet-process phosphoric acid | |
| CN106976851B (en) | A method of ferric phosphate and ammonium polyphosphate fertilizer are prepared using phosphatization slag | |
| CN103993179A (en) | Method for recovering germanium from germanium-silicon alloy | |
| CN108640162B (en) | Alkali circulation iron-containing solid waste iron oxide pigment production equipment system | |
| CN1234596C (en) | Process for preparing fluorine compound and SiO2 from sodium fluosilicate | |
| CN110817824A (en) | Method for preparing food-grade disodium hydrogen phosphate by using wet-process diluted phosphoric acid | |
| CN1091395A (en) | The method of soda production from sodium sulfate | |
| CN110817825A (en) | Method for preparing food-grade sodium dihydrogen phosphate by using wet-process diluted phosphoric acid | |
| CN109775740B (en) | Treatment method for by-product single cryolite in production of organic silicon | |
| CN104944397B (en) | A kind of technique that potassium dihydrogen phosphate is prepared by purification of wet process phosphoric acid low cost |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: GUANGDONG GUANGHUA SCIENCE AND TECHNOLOGY CO., LTD Free format text: FORMER NAME: GUANGHAU CHEMICAL CO., LTD., GUANGDONG |
|
| CP01 | Change in the name or title of a patent holder |
Address after: 515031 Shantou University Road, Guangdong, No. 295 Patentee after: Guangdong Guanghua Science and Technology Co., Ltd. Patentee after: Guangzhou Jinhuada Chemical Reagent Co., Ltd. Address before: 515031 Shantou University Road, Guangdong, No. 295 Patentee before: Guanghau Chemical Co., Ltd., Guangdong Patentee before: Guangzhou Jinhuada Chemical Reagent Co., Ltd. |