CN109609970B - System and method for promoting recovery of potassium in urine wastewater through magnesium anode electro-corrosion - Google Patents
System and method for promoting recovery of potassium in urine wastewater through magnesium anode electro-corrosion Download PDFInfo
- Publication number
- CN109609970B CN109609970B CN201811592308.4A CN201811592308A CN109609970B CN 109609970 B CN109609970 B CN 109609970B CN 201811592308 A CN201811592308 A CN 201811592308A CN 109609970 B CN109609970 B CN 109609970B
- Authority
- CN
- China
- Prior art keywords
- magnesium
- potassium
- anode
- cathode
- reaction
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/18—Alkaline earth metal compounds or magnesium compounds
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B7/00—Fertilisers based essentially on alkali or ammonium orthophosphates
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B15/00—Operating or servicing cells
- C25B15/02—Process control or regulation
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Inorganic Chemistry (AREA)
- Automation & Control Theory (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
- Removal Of Specific Substances (AREA)
Abstract
Discloses a system and a method for promoting potassium recovery in urine wastewater by magnesium anode electro-corrosion, wherein the method comprises the following steps: (1) the system consists of a reaction tank, a magnesium anode, a conductive cathode and acid adding equipment, wherein the magnesium anode and the conductive cathode are connected through a direct current power supply, and a loop is formed between the anode and the cathode by using urine wastewater in the reaction tank; (2) the distance between the magnesium anode and the cathode is 5-500 mm; (3) the current density of the magnesium anode and the magnesium cathode is 0.1-50 mA/cm2(ii) a (4) In the electro-corrosion process, the pH value of the solution is controlled to be not higher than 11.5 by an acid adding device; (5) stopping current output at the lowest point of potassium concentration, terminating the reaction and harvesting the potassium magnesium phosphate precipitate. According to the method, a magnesium source is provided by utilizing magnesium anode electro-corrosion, the pH value is increased by cathode electrolysis, sodium magnesium phosphate co-crystallization can be effectively inhibited, so that potassium magnesium phosphate reaction crystallization is enhanced, the adding amount of the magnesium source, the phosphorus source and NaOH in the traditional potassium magnesium phosphate reaction crystallization method is reduced, the expected recovery efficiency of potassium is improved, the sodium content in a crystallization product is reduced, and the risk of salinization when the slow release fertilizer is applied is reduced.
Description
Technical Field
The invention belongs to the field of wastewater treatment and resource recovery in wastewater, and relates to a system and a method for promoting potassium recovery in urine wastewater by magnesium anode electro-corrosion.
Background
The background of the related art of the present invention will be described below, but the description does not necessarily constitute the prior art of the present invention.
China is a big agricultural country, and the shortage of potassium resources becomes a serious problem in the social and economic development of China. The global potassium ore is mainly concentrated in a few countries, the potassium fertilizer required by China is seriously imported, and the import rate of potassium reaches more than 70 percent for a long time. Potassium is listed as national economy prop mineral and key mineral species by the national soil resources department, and further, potassium is also listed as one of 9 mineral resources which are seriously in shortage for 2020 by the China mining union.
Human-excreted urine waste water is rich in potassium element, and potassium concentration in pure urine can reach 2g/L, also contains abundant phosphorus concentration in the urine simultaneously, adds the soluble magnesium salt and can realize the recovery of potassium in the urine waste water through potassium magnesium phosphate reaction crystallization method, and the reaction formula is as follows:
Mg2++K++PO4 3-+6H2O→MgKPO4·6H2O↓ (1)
the potassium magnesium phosphate crystal is an excellent composite slow release fertilizer, wherein the content of phosphate fertilizer and potash fertilizer is obviously superior to the quality standard of first-class products of the industry standard HG2598-94 of calcium magnesium phosphorus potash fertilizer. The estimation finds that the annual urine wastewater in China contains about 200 ten thousand tons of potash fertilizer (K)2Calculated by O), which is close to 30 percent of the annual potassium fertilizer application amount in China. Has important significance for searching non-ore potassium resources.
However, in the conventional potassium magnesium phosphate reaction crystallization method, a large amount of NaOH is required to be added to adjust the pH value to be alkaline, which simultaneously causes the sodium magnesium phosphate reaction crystallization to occur, and the reaction is as follows:
Mg2++Na++PO4 3-+7H2O→MgNaPO4·7H2O↓ (2)
in order to realize the high-efficiency recovery of potassium, a magnesium source (MgCl) is required to be added simultaneously2) And a source of phosphorus (Na)2HPO4) And adjusting the pH value, wherein when the molar ratio of Mg to K to P is increased to 3.3 to 1 to 3, the potassium recovery rate can reach more than 90 percent, and the mass ratio of sodium magnesium phosphate to potassium magnesium phosphate in the crystallized product is about 2.2 to 1. On one hand, the co-crystallization reduces the expected recovery effect of potassium, greatly increases the adding amount of a magnesium source and a phosphorus source, and particularly needs a large amount of phosphorus source, so that the production cost is increased, and the feasibility of popularization and application of the method is reduced; on the other hand, the co-crystallization product contains a large amount of sodium, so that the content of the potash fertilizer is reduced, and soil salinization is easily caused when the co-crystallization product is directly used as a fertilizer.
Disclosure of Invention
The invention provides a system and a method for promoting potassium recovery in urine wastewater by magnesium anode galvanic corrosion, aiming at the problem of sodium magnesium phosphate co-crystallization in the traditional potassium magnesium phosphate reaction crystallization method.
The specific technical scheme is as follows:
(1) the system consists of a reaction tank, a magnesium anode, a conductive cathode and acid adding equipment, wherein the magnesium anode and the conductive cathode are connected through a direct current power supply, and a loop is formed between the anode and the cathode by using urine wastewater in the reaction tank;
(2) the distance between the magnesium anode and the cathode is 5-500 mm;
(3) the current density of the magnesium anode and the magnesium cathode is 0.1-50 mA/cm2；
(4) In the electro-corrosion process, the pH value of the solution is controlled to be not higher than 11.5 by an acid adding device;
(5) stopping current output at the lowest point of potassium concentration, terminating the reaction and harvesting the potassium magnesium phosphate precipitate.
The urine wastewater is completely or mostly ammonia nitrogen-removed urine wastewater.
The magnesium anode is made of magnesium metal materials such as pure magnesium or magnesium alloy.
The conductive cathode is made of conductive materials such as graphite or metal.
The acid adding equipment of the invention adds acid solution containing hydrochloric acid, sulfuric acid or phosphoric acid and the like.
The molar concentration of ammonia nitrogen in the urine wastewater is not higher than that of potassium.
The invention utilizes magnesium anode electroerosion to provide Mg2+The cathode simultaneously generates OH-The method can effectively inhibit sodium magnesium phosphate co-crystallization so as to strengthen potassium magnesium phosphate reaction crystallization, reduce the adding amount of a magnesium source, a phosphorus source and NaOH in the traditional potassium magnesium phosphate reaction crystallization method, improve the expected recovery efficiency of potassium, reduce the sodium content in a crystallization product and reduce the risk of salinization when the slow release fertilizer is applied.
Detailed Description
Exemplary embodiments of the present invention are described in detail below. The description of the exemplary embodiments is for purposes of illustration only and is not intended to limit the invention, its application, or uses.
The invention provides a system and a method for promoting potassium recovery in urine wastewater by magnesium anode electro-corrosion, which specifically comprise the following steps:
(1) the system consists of a reaction tank, a magnesium anode, a conductive cathode and acid adding equipment, wherein the magnesium anode and the conductive cathode are connected through a direct current power supply, and a loop is formed between the anode and the cathode by using urine wastewater in the reaction tank;
(2) the distance between the magnesium anode and the cathode is 5-500 mm;
(3) the current density of the magnesium anode and the magnesium cathode is 0.1-50 mA/cm2；
(4) In the electro-corrosion process, the pH value of the solution is controlled to be not higher than 11.5 by an acid adding device;
(5) stopping current output at the lowest point of potassium concentration, terminating the reaction and harvesting the potassium magnesium phosphate precipitate.
Under the action of DC power supply, urine waste water is used as electrolyte, a loop is formed between the magnesium anode and the conductive cathode, magnesium corrosion occurs at the anode, and the product is producedRaw Mg2+Cathode producing OH-And (3) forming a supersaturated solution to induce potassium-magnesium phosphate reaction crystallization, and taking the molar concentration of phosphorus in the common deamination urine wastewater into consideration to be lower than that of potassium, adding a phosphoric acid solution by using an acid adding device, wherein the pH value can be controlled to be not higher than 11.5 while adding phosphorus. Compared with the traditional potassium magnesium phosphate reaction crystallization method, the magnesium anode electro-corrosion method does not introduce sodium impurities, weakens the sodium magnesium phosphate co-crystallization capacity, strengthens the potassium magnesium phosphate reaction crystallization, reduces the addition of a magnesium source and a phosphorus source, and promotes the recovery of potassium resources in urine wastewater.
On the basis of a large number of experimental researches, the proper distance between the magnesium anode and the conductive cathode is determined to be 5-500 mm, when the distance is too large, the resistance is increased, the voltage is increased, the energy consumption is large, the distance is too small, and although the energy consumption is low, short circuit is easily caused. Meanwhile, the proper current density is determined through experimental research, the current density is too high, the magnesium corrosion and pH rising speed are high, the reaction finishing time is not easy to determine, and the recovery of potassium is not facilitated; if the current density is too low, the reaction rate is too slow, which increases the processing cost. Particularly, the pH value is required to be controlled to be not higher than 11.5 in the process, and the reaction crystallization of the potassium phosphate and the magnesium phosphate is inhibited, so that magnesium hydroxide crystals are easily generated, and the recovery of potassium is not facilitated.
In the invention, the urine wastewater is completely or mostly ammonia nitrogen-removed urine wastewater. Preferably, the molar concentration of ammonia nitrogen in the urine wastewater is not higher than that of potassium.
The present invention will be further described with reference to the following examples. These examples are merely illustrative of preferred embodiments of the present invention and the scope of the present invention should not be construed as being limited to these examples.
Example 1:
(1) the method comprises a reaction tank, a magnesium anode, a conductive cathode and a direct current power supply; the size of the reaction tank is 100 multiplied by 70 multiplied by 210 mm;
(2) the magnesium anode is made of pure magnesium plate, the magnesium content is more than 99 percent, and the size of the magnesium anode is 200 multiplied by 50 multiplied by 10 mm;
(3) the conductive cathode is made of a pure magnesium plate, the magnesium content is more than 99%, and the size of the cathode is 200 multiplied by 50 multiplied by 10 mm;
(4) adding 800mL of deamination pretreated urine wastewater into a reaction tank, wherein the concentration of potassium ions is 410 mg/L;
(5) the acid adding device is a burette, and the acid solution is 1M hydrochloric acid solution;
(6) the distance between the magnesium anode and the cathode is 20 mm;
(7) controlling the current density of the magnesium anode to be 20mA/cm2 through the output of a direct current power supply;
(8) monitoring the change of the pH value of the solution in the reaction process, and controlling the pH value of the solution to be not higher than 11.2 by using an acid adding device;
(9) when the reaction is carried out for 6min, the direct-current power supply is closed, the recovery rate of potassium is 23 percent, and the recovery rate of phosphorus is 69 percent; the mass ratio of sodium magnesium phosphate to potassium magnesium phosphate was 0.77.
Example 2:
(1) the method comprises a reaction tank, a magnesium anode, a conductive cathode and a direct current power supply; the size of the reaction tank is 100 multiplied by 70 multiplied by 210 mm;
(2) the magnesium anode is made of pure magnesium plate, the magnesium content is more than 99 percent, and the size of the magnesium anode is 200 multiplied by 50 multiplied by 10 mm;
(3) the conductive cathode is made of a pure magnesium plate, the magnesium content is more than 99%, and the size of the cathode is 200 multiplied by 50 multiplied by 10 mm;
(4) adding 800mL of deamination pretreated urine wastewater into a reaction tank, wherein the concentration of potassium ions is 410 mg/L;
(5) the acid adding device is a burette, and the acid solution is 1M hydrochloric acid solution;
(6) the distance between the magnesium anode and the cathode is 30 mm;
(7) controlling the current density of the magnesium anode to be 20mA/cm2 through the output of a direct current power supply;
(8) monitoring the change of the pH value of the solution in the reaction process, and controlling the pH value of the solution to be not higher than 11.2 by using an acid adding device;
(9) when the reaction is carried out for 9min, the direct-current power supply is closed, the recovery rate of potassium is 25 percent, and the recovery rate of phosphorus is 61 percent; the mass ratio of sodium magnesium phosphate to potassium magnesium phosphate was 0.44.
Example 3:
(1) the method comprises a reaction tank, a magnesium anode, a conductive cathode and a direct current power supply; the size of the reaction tank is 100 multiplied by 70 multiplied by 210 mm;
(2) the magnesium anode is made of pure magnesium plate, the magnesium content is more than 99 percent, and the size of the magnesium anode is 200 multiplied by 50 multiplied by 10 mm;
(3) the conductive cathode is made of a pure magnesium plate, the magnesium content is more than 99%, and the size of the cathode is 200 multiplied by 50 multiplied by 10 mm;
(4) adding 800mL of deamination pretreated urine wastewater into a reaction tank, wherein the concentration of potassium ions is 410 mg/L;
(5) the acid adding device is a burette, and the acid solution is 1M hydrochloric acid solution;
(6) the distance between the magnesium anode and the cathode is 20 mm;
(7) controlling the current density of the magnesium anode to be 5mA/cm2 through the output of a direct current power supply;
(8) monitoring the change of the pH value of the solution in the reaction process, and controlling the pH value of the solution to be not higher than 11.2 by using an acid adding device;
(9) when the reaction is carried out for 15min, the direct-current power supply is closed, the recovery rate of potassium is 16 percent, and the recovery rate of phosphorus is 45 percent; the mass ratio of sodium magnesium phosphate to potassium magnesium phosphate was 0.66.
Example 4:
(1) the method comprises a reaction tank, a magnesium anode, a conductive cathode and a direct current power supply; the size of the reaction tank is 100 multiplied by 70 multiplied by 210 mm;
(2) the magnesium anode is made of pure magnesium plate, the magnesium content is more than 99 percent, and the size of the magnesium anode is 200 multiplied by 50 multiplied by 10 mm;
(3) the conductive cathode is made of a pure magnesium plate, the magnesium content is more than 99%, and the size of the cathode is 200 multiplied by 50 multiplied by 10 mm;
(4) adding 800mL of deamination pretreated urine wastewater into a reaction tank, wherein the concentration of potassium ions is 2050 mg/L;
(5) the acid adding device is a burette, and the acid solution is 1M hydrochloric acid solution;
(6) the distance between the magnesium anode and the cathode is 20 mm;
(7) controlling the current density of the magnesium anode to be 20mA/cm2 through the output of a direct current power supply;
(8) monitoring the change of the pH value of the solution in the reaction process, and controlling the pH value of the solution to be not higher than 11.2 by using an acid adding device;
(9) when the reaction is carried out for 15min, the direct-current power supply is closed, the recovery rate of potassium is 23 percent, and the recovery rate of phosphorus is 38 percent; the mass ratio of sodium magnesium phosphate to potassium magnesium phosphate is 0.
Example 5:
(1) the method comprises a reaction tank, a magnesium anode, a conductive cathode and a direct current power supply; the size of the reaction tank is 100 multiplied by 70 multiplied by 210 mm;
(2) the magnesium anode is made of pure magnesium plate, the magnesium content is more than 99 percent, and the size of the magnesium anode is 200 multiplied by 50 multiplied by 10 mm;
(3) the conductive cathode is made of a pure magnesium plate, the magnesium content is more than 99%, and the size of the cathode is 200 multiplied by 50 multiplied by 10 mm;
(4) adding 800mL of deamination pretreated urine wastewater into a reaction tank, wherein the concentration of potassium ions is 410 mg/L;
(5) the acid adding device is a burette, and the acid solution is 1M hydrochloric acid solution;
(6) the distance between the magnesium anode and the cathode is 20 mm;
(7) controlling the current density of the magnesium anode to be 5mA/cm2 through the output of a direct current power supply;
(8) monitoring the pH value change of the solution in the reaction process, and controlling the pH value of the solution to be 10.8-11.0 by using acid adding equipment after the reaction is carried out for 12 min;
(9) when the reaction is carried out for 30min, the direct-current power supply is closed, the recovery rate of potassium is 38 percent, and the recovery rate of phosphorus is 96 percent; the mass ratio of sodium magnesium phosphate to potassium magnesium phosphate was 0.49.
Claims (6)
1. A system for promoting potassium recovery in urine wastewater through magnesium anode electro-corrosion is characterized in that:
1) the system consists of a reaction tank, a magnesium anode, a conductive cathode and acid adding equipment, wherein the magnesium anode and the conductive cathode are connected through a direct current power supply, and a loop is formed between the anode and the cathode by using urine wastewater in the reaction tank; the urine wastewater is completely or mostly ammonia nitrogen-removed urine wastewater;
2) the distance between the magnesium anode and the cathode is 5-500 mm;
3) the current density of the magnesium anode and the magnesium cathode is 0.1 to c50mA/cm2；
4) And in the electro-corrosion process, the pH value of the solution is controlled to be not higher than 11.5 by an acid adding device.
2. The system of claim 1, wherein: the magnesium anode is made of pure magnesium or magnesium alloy.
3. The system of claim 1, wherein: the conductive cathode is made of graphite or metal.
4. The system of claim 1, wherein: the acid adding equipment adds acid solution containing hydrochloric acid, sulfuric acid or phosphoric acid.
5. The system of claim 1, wherein: the molar concentration of ammonia nitrogen in the urine wastewater is not higher than that of potassium.
6. A method for promoting the recovery of potassium from urine wastewater by using the system of any one of claims 1 to 5, comprising the steps of:
1) adding urine wastewater into a reaction tank;
2) controlling the current density of the magnesium anode through the output of a direct current power supply;
3) monitoring the change of the pH value of the solution in the reaction process, and controlling the pH value of the solution by an acid adding device;
4) stopping current output at the lowest point of potassium concentration, terminating the reaction and harvesting the potassium magnesium phosphate precipitate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811592308.4A CN109609970B (en) | 2018-12-21 | 2018-12-21 | System and method for promoting recovery of potassium in urine wastewater through magnesium anode electro-corrosion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811592308.4A CN109609970B (en) | 2018-12-21 | 2018-12-21 | System and method for promoting recovery of potassium in urine wastewater through magnesium anode electro-corrosion |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109609970A CN109609970A (en) | 2019-04-12 |
| CN109609970B true CN109609970B (en) | 2021-02-26 |
Family
ID=66011581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811592308.4A Active CN109609970B (en) | 2018-12-21 | 2018-12-21 | System and method for promoting recovery of potassium in urine wastewater through magnesium anode electro-corrosion |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109609970B (en) |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005034138A1 (en) * | 2005-07-19 | 2007-01-25 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Reactor for recovering magnesium ammonium phosphate and process for recovering magnesium ammonium phosphate from manure or ammonia-containing waste gases |
| CN102229506B (en) * | 2011-04-08 | 2013-09-04 | 清华大学 | Method for recovering phosphorus and potassium from urine effluent and producing slow-release composite fertilizer of phosphorus and potassium |
| US9194049B2 (en) * | 2012-07-23 | 2015-11-24 | E2Metrix Inc. | Method for simultaneous elimination of orthophosphate and ammonium using electrolytic process |
| CN105668717B (en) * | 2016-04-12 | 2019-01-01 | 景德镇陶瓷大学 | A kind of ammonium magnesium phosphate-electroxidation integrated device and its synchronous denitrification and dephosphorization method |
| CN105883982B (en) * | 2016-04-22 | 2017-04-12 | 浙江大学 | Device and method for recycling nitrogen and phosphorus of wastewater |
| CN106146153B (en) * | 2016-07-01 | 2017-06-20 | 北京国环清华环境工程设计研究院有限公司 | Potassium and the method for manufacturing carbon-base slow release type composite fertilizer are extracted from urine waste water |
| CN107487814A (en) * | 2017-08-21 | 2017-12-19 | 吉林大学 | A kind of electrochemical method of high ammonia nitrogen and high phosphorized waste water recycling |
-
2018
- 2018-12-21 CN CN201811592308.4A patent/CN109609970B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109609970A (en) | 2019-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108675403B (en) | Method for recovering nitrogen and phosphorus in sewage through electrochemical struvite crystallization | |
| CN104018186B (en) | A kind of recovery method of CIGS | |
| CN105132720B (en) | Method for recovering rare earth in ion adsorption type rare earth ore leaching solution through fractional precipitation | |
| CN110240182A (en) | The recycling processing method of rich lithium aluminium electrolyte | |
| CN107487814A (en) | A kind of electrochemical method of high ammonia nitrogen and high phosphorized waste water recycling | |
| Govindan et al. | Electrochemical recovery of H2 and nutrients (N, P) from synthetic source separate urine water | |
| CN100560758C (en) | Method for recycling indium from waste mercury-free alkaline zinc-manganese dioxide battery | |
| CN108101185B (en) | Phosphorus removing agent containing molybdenum and application thereof | |
| CN107265425B (en) | The method for preparing lithium phosphate using pelite containing lithium | |
| CN109609970B (en) | System and method for promoting recovery of potassium in urine wastewater through magnesium anode electro-corrosion | |
| CN103350991B (en) | Ferrous ammonium phosphate sustained-release fertilizer synthesis method | |
| CN112838289B (en) | Method for recovering lithium and ferrous phosphate from lithium iron phosphate positive electrode material | |
| CN109504861A (en) | A kind of method of remaining lithium in circulation and stress hydro-thermal legal system electrode material reaction mother liquor | |
| CN102107891A (en) | Method for treating free ammonia during sodium bicarbonate production and application | |
| CN110316747B (en) | Method for comprehensively recovering lithium and phosphorus from lithium phosphate | |
| CN104817154A (en) | Method for recovering ammonia nitrogen in wastewater | |
| CN118080545A (en) | Fly ash treatment and utilization method with zero waste liquid discharge | |
| CN109179801B (en) | Treatment method of trivalent chromium electroplating waste liquid | |
| CN111302552A (en) | Landfill leachate concentrated solution resource utilization system and method | |
| CN110642317A (en) | Sodium sulfate wastewater resource utilization method | |
| CN113247921B (en) | Combined denitration process for chlor-alkali and sodium chlorate | |
| CN108033535A (en) | A kind of method of the phosphorus removed based on Corrosion Behaviors of Magnesium Alloys in sewage | |
| CN103803631B (en) | The cupric micro-etching solution of circuit board etching is utilized to produce the method for copper sulfate | |
| CN1100722C (en) | Process for precipitating B and Li in bittern at same time | |
| CN102021601B (en) | Electrolytic method for mixed liquor of dilute waste hydrochloric acid |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |