CN115367770A - Method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride - Google Patents
Method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride Download PDFInfo
- Publication number
- CN115367770A CN115367770A CN202211115395.0A CN202211115395A CN115367770A CN 115367770 A CN115367770 A CN 115367770A CN 202211115395 A CN202211115395 A CN 202211115395A CN 115367770 A CN115367770 A CN 115367770A
- Authority
- CN
- China
- Prior art keywords
- ammonium chloride
- chloride
- solution
- solution containing
- ammonia
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/02—Preparation, purification or separation of ammonia
- C01C1/026—Preparation of ammonia from inorganic compounds
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B7/00—Halogens; Halogen acids
- C01B7/01—Chlorine; Hydrogen chloride
- C01B7/03—Preparation from chlorides
- C01B7/05—Preparation from ammonium chloride
- C01B7/055—Preparation of hydrogen chloride from ammonium chloride
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/46—Sulfates
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
The invention discloses a method for separating and recycling hydrogen chloride and ammonia and producing calcium sulfate as a byproduct by using ammonium chloride, which comprises the steps of mixing ammonium chloride solid or ammonium chloride solution with sulfuric acid solution and lime emulsion respectively to carry out thermal decomposition reaction to obtain hydrogen chloride, ammonia gas, solution containing ammonium sulfate and solution containing calcium chloride; mixing a solution containing ammonium sulfate and a solution containing calcium chloride for calcium precipitation reaction to obtain calcium sulfate and a solution containing ammonium chloride, and returning the solution containing ammonium chloride to react with a sulfuric acid solution when the pH value of the solution containing ammonium chloride is less than 7; and when the pH value of the solution containing ammonium chloride is more than or equal to 7, returning the solution to react with the lime emulsion. The method greatly reduces the equipment investment cost, has low production cost and simple process, can obtain high-purity hydrogen chloride gas and ammonia gas, has good separation effect, can also obtain high-quality calcium sulfate products, fully and comprehensively utilizes the ammonium chloride in the whole process, and realizes closed cycle of water.
Description
Technical Field
The invention relates to a method for separating and recovering hydrogen chloride and ammonia, in particular to a method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride, belonging to the field of chemical metallurgy.
Background
As is well known, NH 4 Cl is decomposed into HCl and NH by heating 3 Recombination of NH after cooling 4 And (4) Cl. To add NH to 4 HCl and NH released by Cl decomposition under heating 3 Separately, various methods have been tried, whichIncluding chemical chain decomposition and lime-sulfuric acid thermal decomposition. The chemical chain decomposition method comprises decomposing ammonium chloride in alkaline medium or acidic medium to separate and recover hydrochloric acid and ammonia water, for example, adding magnesium oxide or magnesium hydroxide into ammonium chloride, mixing, heating to-350 deg.C, and decomposing to give NH 3 Simultaneously, basic magnesium chloride is generated, then the obtained basic magnesium chloride is heated to 600 ℃ to release HCl, and magnesium oxide or magnesium hydroxide is obtained by regeneration and is returned to be continuously used as a decomposition medium of ammonium chloride; adding ammonium chloride into ammonium bisulfate melt, heating the ammonium chloride melt at 220-270 ℃ to decompose HCl released, converting the HCl into ammonium sulfate, and heating the ammonium sulfate to 290-350 ℃ to decompose NH released 3 And at the same time, regenerating to obtain ammonium bisulfate, and returning to be continuously used as a decomposition medium of ammonium chloride. Both methods seem to be designed to be elaborate, but again there are problems in practical applications: first, NH 4 Cl is easy to sublimate when heated, the existing alkaline medium or acidic medium chemical chain decomposition method is difficult to avoid the sublimation of ammonium chloride, and more than 10 percent of ammonium chloride is usually sublimated directly in the decomposition process; second, NH at elevated temperature 4 Cl has strong corrosivity to decomposition equipment, chlorine-resistant and acid-resistant equipment with the temperature of more than 200 ℃ is expensive to manufacture, basic magnesium chloride is heated to the temperature of 600 ℃ to be in a static decomposition efficiency, and dynamic decomposition equipment is not mature enough to manufacture; third, ammonium chloride is difficult to release chlorine completely in alkaline media, and difficult to release ammonia completely in acidic media. The lime-sulfuric acid thermal decomposition method is that solid ammonium chloride and lime are mixed and heated to 600 deg.C to release NH 3 And anhydrous calcium chloride is generated, the obtained anhydrous calcium chloride is mixed with concentrated sulfuric acid, and the obtained anhydrous calcium chloride is heated to 500 ℃ to force HCl to volatilize, and meanwhile, industrial gypsum is formed. The lime-sulfuric acid thermal decomposition method has the following disadvantages: 1) NH generated by pyrolysis 3 HCl gas contains a large amount of dust, and ammonia water and hydrochloric acid obtained by water absorption hardly reach industrial application standards; 2) The high-temperature operation environment is poor, the energy consumption is high, and the economic benefit is not calculated; 3) The quality of the produced industrial gypsum is poor, and a proper user is difficult to find.
Disclosure of Invention
Aiming at the defects of low separation efficiency of hydrogen chloride and ammonia gas, poor product quality, high equipment requirement, high energy consumption and the like in the prior art, the invention aims to provide the method for separating and recovering the hydrogen chloride and the ammonia and producing the calcium sulfate as the byproduct by using the ammonium chloride.
In order to achieve the technical purpose, the invention provides a method for separating and recovering hydrogen chloride and ammonia and producing calcium sulfate as a byproduct by using ammonium chloride, which comprises the following steps:
1) Mixing ammonium chloride solid or ammonium chloride solution with sulfuric acid solution to perform thermal decomposition reaction I to obtain solution containing ammonium sulfate and hydrogen chloride gas;
2) Mixing ammonium chloride solid or ammonium chloride solution with lime emulsion to perform thermal decomposition reaction II to obtain solution containing calcium chloride and ammonia gas;
3) Mixing the solution containing ammonium sulfate and the solution containing calcium chloride for calcium precipitation reaction, performing solid-liquid separation to obtain calcium sulfate and the solution containing ammonium chloride, and returning the solution containing ammonium chloride to the thermal decomposition reaction I for recycling when the pH value of the solution containing ammonium chloride is less than 7; and when the pH value of the solution containing the ammonium chloride is more than or equal to 7, returning the solution containing the ammonium chloride to the thermal decomposition reaction II for recycling.
The main chemical reactions involved in the process of separating and recovering hydrogen chloride and ammonia and producing calcium sulfate as byproducts by using ammonium chloride are as follows:
2NH 4 Cl+H 2 SO 4 ＝Δ＝(NH 4 ) 2 SO 4 +2HCl↑ (1)
2NH 4 Cl+Ca(OH) 2 ＝Δ＝CaCl 2 +2NH 3 ↑ (2)
(NH 4 ) 2 SO 4 +CaCl 2 +2H 2 O＝2NH 4 Cl+CaSO 4 ·2H 2 O↓ (3)
wherein HCl and NH generated in the reaction process 3 Hydrochloric acid and ammonia water are respectively obtained through multi-stage countercurrent water absorption; washing the obtained calcium sulfate with water,And drying to obtain the high-purity calcium sulfate product. In the reaction process of the method, the hydrogen chloride gas and the ammonia gas obtained by the thermal decomposition of the ammonium chloride in the aqueous solution do not contain solid impurities, the separation efficiency is high, the thermal decomposition temperature is low, and the requirement on equipment is not high, wherein the ammonium sulfate solution and the calcium chloride solution are mixed, so that not only can a calcium sulfate product with high quality and high added value be obtained, but also Cl-ions and NH-ions in the solution 4 + The ions can be used for synthesizing the solution containing the ammonium chloride again, and the solution containing the ammonium chloride can be returned to be continuously used as a raw material for releasing the hydrogen chloride or the ammonia gas, so that the ammonium chloride is completely and comprehensively utilized, and the closed cycle of water in the process is realized.
As a preferred scheme, in the step 1), ammonium chloride solid or ammonium chloride in ammonium chloride solution is mixed and reacted with sulfuric acid in sulfuric acid solution according to a molar ratio of 2.
As a preferable scheme, the concentration of the ammonium chloride solution in the thermal decomposition reaction I is 250-850 g/L.
As a preferable mode, the concentration of the sulfuric acid solution is not lower than 2.5mol/L.
As a preferred scheme, the conditions of the thermal decomposition reaction I are as follows: the temperature is 65-115 ℃ and the time is 1-3 h.
As a preferable scheme, in the step 2), ammonium chloride in the ammonium chloride solid or the ammonium chloride solution is mixed and reacted with calcium hydroxide in the lime emulsion according to a molar ratio of 2.
As a preferable scheme, the ammonium chloride in the ammonium chloride solution in the thermal decomposition reaction II is not less than 15wt%.
As a preferable scheme, the lime emulsion is prepared from quicklime and water according to a solid-liquid ratio of 1g: 1-4 mL. The quicklime can be replaced by calcium oxide.
As a preferred embodiment, the conditions of the thermal decomposition reaction ii are: the temperature is 75-125 ℃, and the time is 0.5-2.5 h.
As a preferred embodiment, SO in the solution containing ammonium sulfate 4 2- With Ca in solutions containing calcium chloride 2+ The molar ratio is 1.
As a preferred embodiment, the calcium precipitation reaction conditions are: the temperature is 25-115 ℃ and the time is 0.5-1 h.
In a preferred embodiment, the molar amount of ammonium chloride in the ammonium chloride solid or the ammonium chloride solution in the thermal decomposition reaction I and the thermal decomposition reaction II is the same. The equimolar ammonium chloride is respectively reacted with sulfuric acid and lime in aqueous solution for thermal decomposition to release hydrogen chloride gas or ammonia gas, so that the calcium chloride solution and the ammonium sulfate solution generated in the technical process can be well matched for producing calcium sulfate products all the time, and the closed circulation of water is realized.
Compared with the prior art, the invention has the following advantages and effects:
(1) The ammonium chloride is thermally decomposed in the aqueous solution to release the hydrogen chloride or the ammonia, so that the equipment investment cost is greatly reduced, the thermal decomposition temperature is low, the production cost is remarkably reduced, the process is simple, the operation is convenient, the obtained hydrogen chloride gas and the ammonia gas do not contain solid impurities, the quality of the obtained hydrochloric acid and the ammonia water is good after the hydrochloric acid and the ammonia water are respectively absorbed by water, and the separation efficiency is high.
(2) Ammonium chloride is skillfully mixed with ammonium sulfate solution and calcium chloride solution which are obtained by thermal decomposition of sulfuric acid and lime in aqueous solution respectively, so that not only can calcium sulfate products with high quality and high added value be obtained, but also Cl in the two solutions is enabled to be dissolved - Ions and NH 4 + The ions are recombined into the solution containing the ammonium chloride, and the solution containing the ammonium chloride can be recycled as a raw material for releasing the hydrogen chloride and the ammonia gas, so that the ammonium chloride is completely and comprehensively utilized, and the closed cycle of water in the process is realized.
Detailed Description
The invention will now be further described with reference to the following examples, which are intended to illustrate the invention but not to limit it further.
Example 1
Adding 500g of ammonium chloride into a three-neck baked cake containing 600mL of water, heating and stirring, adding 468g of 98% concentrated sulfuric acid, stirring at 105 ℃ for 1h, obtaining an ammonium sulfate solution after HCl in the ammonium chloride is completely volatilized, and volatilizing HCl gasAbsorbing with three-stage counter-current water to obtain 35% hydrochloric acid reaching the quality standard of superior product in synthetic hydrochloric acid specified in national standard GB 320-2006, adding 500g ammonium chloride into 300mL water-containing three-neck baked cake, heating and stirring, adding lime milk prepared from 262g CaO content quick lime and 300mL water, stirring at 115 deg.C for 1.5h, and waiting for NH therein 3 Evaporating completely, filtering the residual evaporating liquid to obtain calcium chloride solution, evaporating NH 3 The gas is absorbed by multistage countercurrent water, the obtained 20% ammonia water reaches the quality standard of industrial ammonia water specified by the national standard HG/T5353-2018, then the obtained ammonium sulfate solution is mixed with the calcium chloride solution, calcium sulfate is precipitated by stirring for 1h at 90 ℃, the solution is filtered and washed while the solution is hot to obtain 650mL of solution containing 500g of ammonium chloride and 950.6g of calcium sulfate dihydrate filter cake with the pH value of 6.5, the ammonium chloride solution is returned to be continuously used as a raw material for releasing hydrogen chloride, the obtained filter cake is dehydrated for 2h at 250 ℃, anhydrous calcium sulfate with the purity of 99.6% is obtained, and the quality of the anhydrous calcium sulfate reaches the quality standard of food additive calcium sulfate specified by the national standard GB 1892-2007.
Example 2
650mL of solution containing 500g of ammonium chloride obtained in example 1 is added into 1000mL of three-necked baked cake, heating and stirring are carried out, 98% concentrated sulfuric acid 468g is then added, stirring is carried out for 1.5h at 92-112 ℃, HCl in the solution is completely volatilized to obtain ammonium sulfate solution, the volatilized HCl gas is absorbed by three-stage countercurrent water, the obtained 31% hydrochloric acid reaches the quality standard of superior products in synthetic hydrochloric acid specified in national standard GB 320-2006, simultaneously 500g of ammonium chloride is added into the three-necked baked cake containing 250mL of water, heating and stirring are carried out, then lime milk prepared by 262g of analytically pure calcium oxide and 275mL of washing water obtained in example 1 is added, stirring is carried out for 2h at 105 ℃, NH in the lime milk is carried out 3 Evaporating completely, filtering the residual evaporating liquid to obtain calcium chloride solution, evaporating NH 3 The gas is absorbed by multistage countercurrent water, the obtained 21 percent ammonia water reaches the quality standard of industrial ammonia water specified by the national standard HG/T5353-2018, then the obtained ammonium sulfate solution is mixed with the calcium chloride solution, the mixture is stirred at 117 ℃ for 0.5h to precipitate calcium sulfate, the calcium sulfate is filtered and washed when the mixture is hot to obtain 635mL of solution containing 500g of ammonium chloride and 798.1g of calcium sulfate hemihydrate filter cake, the ammonium chloride solution is returned to be continuously used for releasingNH 3 And (3) drying the obtained filter cake for 2h at 120 ℃ to obtain calcium sulfate hemihydrate with the purity of 99.7%, wherein the quality of the calcium sulfate hemihydrate reaches the quality standard of calcium sulfate as a food additive specified in national standard GB 1892-2007.
Example 3
635mL of the solution containing 500g of ammonium chloride obtained in example 2 was added to 1000mL of a three-necked sesame seed cake, heated and stirred, then quicklime with a CaO content of 262g and 300mL of the lime milk prepared from the washing water obtained in example 2 were added, and the mixture was stirred at 90 to 120 ℃ for 1 hour until NH was formed therein 3 Evaporating completely, filtering the residual evaporating liquid to obtain calcium chloride solution, evaporating NH 3 Absorbing the gas by multistage countercurrent water to obtain 20.5% ammonia water which reaches the quality standard of industrial ammonia water specified in national standard HG/T5353-2018, simultaneously adding 500g of ammonium chloride into a three-neck baked cake containing 400mL of water, heating and stirring, and then adding H 2 SO 4 Stirring for 1.5h at 98-107 ℃ until HCl in the 10mol/L sulfuric acid solution is completely volatilized to obtain an ammonium sulfate solution, absorbing the volatilized HCl gas by three-stage countercurrent water, enabling the obtained 33% hydrochloric acid to reach the quality standard of superior products in the synthetic hydrochloric acid specified in the national standard GB 320-2006, then mixing the obtained ammonium sulfate solution with a calcium chloride solution, stirring for 0.5h at 87 ℃ to precipitate calcium sulfate, filtering and washing while hot to obtain a solution 646mL containing 500g of ammonium chloride and a dihydrate calcium sulfate filter cake 956.2g with the pH of 6.3, returning the ammonium chloride solution to be continuously used as a raw material for releasing hydrogen chloride, and drying the obtained filter cake for 2.5h at 80 ℃ to obtain the dihydrate calcium sulfate with the purity of 99.3%, wherein the quality of the dihydrate calcium sulfate reaches the quality standard of a food additive specified in the national standard GB 1892-2007.
Claims (10)
1. A method for separating and recovering hydrogen chloride and ammonia and producing calcium sulfate as a byproduct by using ammonium chloride is characterized by comprising the following steps of: the method comprises the following steps:
1) Mixing ammonium chloride solid or ammonium chloride solution with sulfuric acid solution to perform thermal decomposition reaction I to obtain solution containing ammonium sulfate and hydrogen chloride gas;
2) Mixing ammonium chloride solid or ammonium chloride solution with lime emulsion to perform thermal decomposition reaction II to obtain solution containing calcium chloride and ammonia gas;
3) Mixing the solution containing ammonium sulfate and the solution containing calcium chloride for calcium precipitation reaction, performing solid-liquid separation to obtain calcium sulfate and the solution containing ammonium chloride, and returning the solution containing ammonium chloride to the thermal decomposition reaction I for recycling when the pH value of the solution containing ammonium chloride is less than 7; and when the pH value of the solution containing the ammonium chloride is more than or equal to 7, returning the solution containing the ammonium chloride to the thermal decomposition reaction II for recycling.
2. The method for separating and recovering hydrogen chloride and ammonia and producing calcium sulfate as a byproduct by using ammonium chloride according to claim 1, wherein the method comprises the following steps:
the concentration of the ammonium chloride solution in the thermal decomposition reaction I is 250-850 g/L;
the concentration of the sulfuric acid solution is not lower than 2.5mol/L.
3. The method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride according to claim 1 or 2, wherein: ammonium chloride in the ammonium chloride solid or ammonium chloride solution reacts with sulfuric acid in the sulfuric acid solution in a molar ratio of 2.
4. The method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride according to claim 1 or 2, wherein: the conditions of the thermal decomposition reaction I are as follows: the temperature is 65-115 ℃ and the time is 1-3 h.
5. The method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride according to claim 1, wherein:
the ammonium chloride in the ammonium chloride solution in the thermal decomposition reaction II is not less than 15wt%;
the lime emulsion is prepared from quicklime and water according to a solid-liquid ratio of 1g: 1-4 mL.
6. The method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride according to claim 1 or 5, wherein: and (3) reacting ammonium chloride in the ammonium chloride solid or the ammonium chloride solution with calcium hydroxide in the lime emulsion according to a molar ratio of 2.
7. The method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride according to claim 1 or 5, wherein: the conditions of the thermal decomposition reaction II are as follows: the temperature is 75-125 ℃, and the time is 0.5-2.5 h.
8. The method for separating and recovering hydrogen chloride and ammonia and producing calcium sulfate as a byproduct by using ammonium chloride according to claim 1, wherein the method comprises the following steps: SO in the solution containing ammonium sulfate 4 2- With Ca in solutions containing calcium chloride 2+ Reacting according to an equimolar ratio.
9. The method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride according to claim 1 or 8, wherein: the conditions of the calcium precipitation reaction are as follows: the temperature is 25-115 ℃ and the time is 0.5-1 h.
10. The method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride according to claim 1, wherein: the molar amount of ammonium chloride in the ammonium chloride solid or the ammonium chloride solution in the thermal decomposition reaction I and the thermal decomposition reaction II is the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211115395.0A CN115367770A (en) | 2022-09-14 | 2022-09-14 | Method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211115395.0A CN115367770A (en) | 2022-09-14 | 2022-09-14 | Method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115367770A true CN115367770A (en) | 2022-11-22 |
Family
ID=84071234
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211115395.0A Pending CN115367770A (en) | 2022-09-14 | 2022-09-14 | Method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115367770A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1689965A (en) * | 2004-04-20 | 2005-11-02 | 赵国学 | Technique for producing ammonium sulfate and hydrochloric acid using ammonium chloride and sulphuric acid |
| CN107473447A (en) * | 2017-09-26 | 2017-12-15 | 赣州逸豪优美科实业有限公司 | A kind of method of calcium method recycling treatment acidic high-strength ammonium sulfate waste water |
-
2022
- 2022-09-14 CN CN202211115395.0A patent/CN115367770A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1689965A (en) * | 2004-04-20 | 2005-11-02 | 赵国学 | Technique for producing ammonium sulfate and hydrochloric acid using ammonium chloride and sulphuric acid |
| CN107473447A (en) * | 2017-09-26 | 2017-12-15 | 赣州逸豪优美科实业有限公司 | A kind of method of calcium method recycling treatment acidic high-strength ammonium sulfate waste water |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3970528A (en) | Process for the purification of electrolysis brine | |
| CN112875726B (en) | Method for preparing sodium bicarbonate and calcium sulfate dihydrate by comprehensively utilizing sodium sulfate | |
| CN108373140A (en) | A method of removing fluorine from sulfate liquor | |
| CN112093814B (en) | Method for preparing aluminum oxide by utilizing aluminum ash slag-free method | |
| CN110699756B (en) | Method for preparing alpha-type gypsum whisker by using ammonia-soda waste liquid | |
| CN104120271A (en) | Clean production technique of vanadium oxide by vanadium slag carbocholine leaching-hydrogen reduction process | |
| CN113651342A (en) | Method for producing lithium product by processing lepidolite through nitric acid atmospheric pressure method | |
| CN109336177B (en) | Method for cleanly producing high-purity vanadium pentoxide by using hydrogen peroxide and ammonia water | |
| CN115432724A (en) | Resourceful treatment method of waste ammonium magnesium salt | |
| CN1156394C (en) | Method for producing fluoride and silicon dioxide | |
| WO2006111057A1 (en) | A method for comprehensively using of the raw material in wet-processing phosphorite and producing nano calcium carbonate with high purity and microsphere shape at the same time | |
| CN1234596C (en) | Process for preparing fluorine compound and SiO2 from sodium fluosilicate | |
| CN110844926A (en) | Production method of high-purity magnesium sulfite | |
| CN115367770A (en) | Method for separating and recovering hydrogen chloride and ammonia and by-producing calcium sulfate by using ammonium chloride | |
| CN116102211A (en) | Method for treating synthesis wastewater of battery anode material precursor | |
| CN113044857B (en) | Production process for preparing high-purity sodium cyanide or potassium cyanide with high yield | |
| CN109809442B (en) | System and method for producing magnesium hydroxide and light calcium carbonate by purifying ash in calcium carbide furnace | |
| CN111394598A (en) | Method for extracting magnesium and co-producing calcium sulfate from magnesium-containing carbonate ore | |
| CN114455561A (en) | Comprehensive utilization process of hot galvanizing pickling wastewater and method for preparing battery-grade iron phosphate | |
| JPH05501396A (en) | Method for continuous production of chemical fertilizer salts with strontium derivatives and gypsum derivatives | |
| US3954952A (en) | Continuous chemical process for the manufacture of sodium and potassium peroxydisulfate | |
| CN111847384B (en) | Preparation method of anhydrous hydrogen fluoride | |
| US2801155A (en) | Method of producing magnesium hydroxide from dolomite by means of nitric acid | |
| CN115417435B (en) | Process for producing ammonium sulfate closed cycle lithium carbonate | |
| CN114477249B (en) | Method for preparing high-purity magnesium hydroxide and calcium sulfate by adopting calcium carbide furnace purification ash |
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 |