CN101870494A - Method for recrystallizing and purifying desulphurized gypsum - Google Patents
Method for recrystallizing and purifying desulphurized gypsum Download PDFInfo
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- CN101870494A CN101870494A CN 201010201194 CN201010201194A CN101870494A CN 101870494 A CN101870494 A CN 101870494A CN 201010201194 CN201010201194 CN 201010201194 CN 201010201194 A CN201010201194 A CN 201010201194A CN 101870494 A CN101870494 A CN 101870494A
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Abstract
The invention provides a method for recrystallizing and purifying desulphurized gypsum, which mainly comprises the four steps of acid-washing, dissolution, crystallization and washing, and specifically comprises the following steps of: removing impurities, reacted with acids, in the desulphurized gypsum by the aid-washing, dissolving calcium sulphate in the desulphurized gypsum into the acid solution at a relatively higher temperature by utilizing the characteristic that the solubility of the calcium sulphate in the specific acid solution is remarkably changed with the temperature, performing solid-liquid separation to remove undissolved solid-phase impurities at the high temperature, performing cooling recrystallization and the solid-liquid separation on a liquid phase at a relatively lower temperature, and washing and drying a filter cake to obtain high-purity gypsum, wherein the liquid phase in the dissolution and recrystallization processes can be reused. Through the method provided by the invention, the gypsum with relatively higher purity and whiteness can be prepared by selecting a proper solid-to-liquid ratio, proper temperatures and proper acid concentration and performing dissolution and crystallization for a certain time, and the performance of the desulphurized gypsum is remarkably improved.
Description
Technical field
The present invention relates to a kind of method of recrystallizing and purifying desulphurized gypsum, belong to the technical field for preparing high purity plaster.
Background technology
Desulfurated plaster comprises the by product that produces in flue gas desulfurization (FGD) process, wherein calcium sulphate content higher (being higher than 70%), whiteness lower (whiteness is about 44%).Because these gypsum are by products in the commercial run, the restriction of industrial condition makes its impurity component complexity, and water content is higher, and particle is thin and particle diameter is concentrated, and grating is relatively poor, and whiteness is lower, for the desulfurated plaster recycling has caused obstacle.Though domestic plaster of paris content is bigger, but the Yangtze River Delta, area, Pearl River Delta plaster of paris scarcity of resources that industry is flourishing, and these industry are bigger than the developed regions sulphur dioxide emission, the desulfurated plaster aboundresources, and giving further to utilize provides real possibility.Desulfurated plaster does not promptly become trade waste if be not utilized, land occupation, contaminate environment, caused pollution for environment and society, simultaneously also caused burden to enterprise, if it is can the reasonable use desulfurated plaster, not only favourable to environment and society, also can reduce the heavy burdens, increase economic efficiency to enterprise.
Still do not have at present a kind of effective means can remove impurity in the desulfurated plaster, it is serious to cause desulfurated plaster to pile up, and how the reasonable use desulfurated plaster has become a problem demanding prompt solution.Impurity in the desulfurated plaster is complicated, and the ion of solubility is not only arranged, and some water-fast ash contents are also arranged, and causes whiteness low excessively, has reduced the hydrating capacity of gypsum, has had a strong impact on the application of industry by-product gypsum.The potential using value of desulfurated plaster is very big, in the building materials industry, produce the plaster of Paris, brushing gypsum, gypsum block, Thistle board, gypsum hollow plate, natural plane earth gypsum slurry, cement setting retarder etc., the agricultural aspect has report to be used to produce chemical fertilizer, salt affected soil improvement etc., and desulfurated plaster also can be used for producing added value height, the huge products of market potential such as high-strength semi-hydrated gypsum, calcium sulfate crystal whiskers after treatment.
Summary of the invention
The objective of the invention is to overcome the purification problem of desulfurated plaster now, improve the application performance of desulfurated plaster, expand its range of application, solve the environmental problem that causes owing to the desulfurated plaster bulk deposition and the purpose of social concern thereby reach.
The objective of the invention is to be achieved through the following technical solutions.
A kind of method of recrystallizing and purifying desulphurized gypsum, it is characterized in that this method comprises pickling, dissolving, crystallization, four steps of washing, with excessive acid elution desulfurated plaster, after solid-liquid separation, filter cake is mixed constant temperature and lasting stirring and dissolving under comparatively high temps with acid solution, carry out solid-liquid separation while hot and remove solid phase, with filtrate crystallisation by cooling under lesser temps, after solid-liquid separation, filter cake is washed, dried again then, promptly get high purity plaster.
Employed acid is hydrochloric acid or nitric acid in the dissolution process of aforesaid method.The concentration of HCl is 1.5mol/L to 3.5mol/L in the hydrochloric acid soln, HNO in the salpeter solution
3Concentration be 1.5mol/L to 3.5mol/L.The mass ratio of desulfurated plaster and acid solution is 6: 100 to 9: 100 in the dissolution process.
In the aforesaid method in the desulfurated plaster calcium sulfate dissolved comparatively high temps be 80 ℃ to 100 ℃, the lesser temps of crystal of calcium sulfate is 10 ℃ to 30 ℃.Liquid phase in dissolving, the crystallisation process is reused.
Principle of the present invention is under the temperature conditions of higher, calcium sulfate in the desulfurated plaster fully is dissolved in the aqueous acid of specific concentrations, because the solubility with temperature of calcium sulfate in some acid solution is changed significantly, carry out solid-liquid separation while hot and remove the solid phase residue that is not dissolved in the acid solution, dissolved the temperature of the acid solution of calcium sulfate by reduction, be dissolved in the crystal of calcium sulfate precipitation in the acid solution when making comparatively high temps, obtain the higher gypsum of purity via solid-liquid separation, thereby reach the purpose of purification.According to method provided by the present invention, by the CONTROL PROCESS condition, as the concentration of slip ratio, temperature, acid, dissolving, crystallization certain hour can make purity, the higher gypsum of whiteness, have improved the application performance of desulfurated plaster.Remove impurity with acid-respons by pickling before purifying, the concentration that can guarantee to be used for the acid solution of recrystallization does not change substantially, thereby reuses acid solution, economizes in raw materials.Also can obstructed overpickling before the purification, if there is not acid cleaning process, when liquid phase is reusable, need to add a certain amount of acid with the concentration that keeps acid with preceding once consistent.
The present invention utilizes number acid that the solubility with temperature of calcium sulfate is changed tangible principle, is raw material with the desulfurated plaster, makes purity, the higher gypsum of whiteness by the CONTROL PROCESS condition.The acid solution that is used for recrystallization among the present invention can be repeatedly used, and consumption acids not substantially in the reaction process can be created good benefits in environment and social benefit, reduces business burden, increases enterprise income.By the present invention purify the back gained dihydrate gypsum, under comparatively high temps in air the heating can obtain the higher plaster of Paris of purity.
Description of drawings
Fig. 1 is an acid solution recrystallizing and purifying desulphurized gypsum schema
Embodiment
After now example of the present invention specifically being described in.
Embodiment 1: with the desulfurization gypsum in coal-fired power plant fragmentation, sieve with 80 mesh sieve, with the desulfurated plaster after the 100.00g fragmentation, salpeter solution with the 1mol/L of prior constant volume 1000mL is added in the 1000mL beaker simultaneously then, stir 4h, remove in the raw material impurity with nitric acid reaction, then with dry 12h in filter cake and the 60 ℃ of air dry ovens, broken then, take by weighing above-mentioned pickling, dried desulfurated plaster 35.00g, with 500mL, the salpeter solution of 2mol/L together is added in the 1000mL flask, is immersed in 95 ℃ of waters bath with thermostatic control with upper volume 2/3rds, and constant temperature also stirs 4h, after reaction is finished, suction filtration and remove the solid residue that is not dissolved in the salpeter solution while hot, filtrate is transferred in the 1000mL beaker, is positioned over crystallisation by cooling 18h in 15 ℃ of waters bath with thermostatic control.Suction filtration after crystallization is finished, filter cake is transferred in the 1000mL beaker washes, then filter cake dry 12h in 60 ℃ of baking ovens is promptly got high purity plaster product 18.88g.Desulfurated plaster raw material whiteness is 44.7%, and the back whiteness of purifying is 95.5%, product composition analysis in table 1.
Embodiment 2: filtrate 500mL among the embodiment 1 is recycled, be added to simultaneously in the 1000mL flask with desulfurated plaster after the 35.01g pickling, then flask 2/3rds is immersed in 95 ℃ of waters bath with thermostatic control with upper volume, constant temperature also stirs 4h.After reaction is finished, suction filtration and remove the solid residue that is not dissolved in the salpeter solution while hot, filtrate is transferred in the 1000mL beaker, is positioned over crystallisation by cooling 18h in 15 ℃ of waters bath with thermostatic control.Suction filtration after crystallization is finished, filter cake is transferred in the 1000mL beaker washes, then filter cake dry 12h in 60 ℃ of baking ovens is promptly got high purity plaster product 15.55g.The back whiteness of purifying is 92.4%, product composition analysis in table 1.
Embodiment 3: take by weighing as the prepared recrystallization purification back desulfurated plaster 35.00g of step among the embodiment 1 and carry out the purification of desulfurated plaster secondary recrystallization, salpeter solution with the 2mol/L of prior constant volume 500mL is added in the 1000mL flask simultaneously then, then flask 2/3rds is immersed in 95 ℃ of waters bath with thermostatic control with upper volume, constant temperature also stirs 4h.After reaction is finished, suction filtration while hot, filtrate is transferred in the 1000mL beaker, places 15 ℃ of thermostat water bath crystallisation by cooling 18h.Suction filtration after crystallization is finished, filter cake is transferred in the 1000mL beaker washes, then filter cake dry 12h in 60 ℃ of baking ovens is promptly got high purity plaster product 17.42g.One time recrystallization desulfurated plaster whiteness is 95.5%, and whiteness was 95.1% after the secondary recrystallization desulfurated plaster was purified, product composition analysis in table 1.
Table 1 desulfurated plaster and product composition analysis/wt.%
| The sample classification | ??CaO | ??SO 3 | ??MgO | ??Na 2O | ??K 2O | ??SiO 2 | ??Fe 2O 3 | ??Al 2O 3 | ??TiO 2 | ??Cl |
| Desulfurated plaster | ??25.27 | ??40.34 | ??0.98 | ??0.00 | ??0.03 | ??1.69 | ??0.18 | ??0.34 | ??0.02 | ??0.00 |
| Embodiment 1 | ??32.44 | ??47.72 | ??0.93 | ??0.00 | ??0.00 | ??0.00 | ??0.03 | ??0.00 | ??0.00 | ??0.00 |
| Embodiment 2 | ??31.26 | ??46.27 | ??0.94 | ??0.00 | ??0.00 | ??0.00 | ??0.04 | ??0.00 | ??0.00 | ??0.00 |
| Embodiment 3 | ??25.87 | ??42.83 | ??0.92 | ??0.00 | ??0.00 | ??0.00 | ??0.03 | ??0.00 | ??0.00 | ??0.00 |
Claims (6)
1. the method for a recrystallizing and purifying desulphurized gypsum, it is characterized in that this method comprises pickling, dissolving, crystallization, four steps of washing, with excessive acid elution desulfurated plaster, after solid-liquid separation, filter cake is mixed constant temperature and lasting stirring and dissolving under comparatively high temps with acid solution, carry out solid-liquid separation while hot and remove solid phase, with filtrate crystallisation by cooling under lesser temps, after solid-liquid separation, filter cake is washed, dried again then, promptly get high purity plaster.
2. press claims 1 described method, it is characterized in that employed acid is hydrochloric acid or nitric acid in the dissolution process.
3. press claims 2 described methods, it is characterized in that the concentration of HCl in the hydrochloric acid soln is 1.5mol/L to 3.5mol/L, HNO in the salpeter solution
3Concentration be 1.5mol/L to 3.5mol/L.
4. press claims 1 described method, it is characterized in that calcium sulfate dissolved comparatively high temps is 80 ℃ to 100 ℃ in the desulfurated plaster, the lesser temps of crystal of calcium sulfate is 10 ℃ to 30 ℃.
5. press claims 1 described method, it is characterized in that the mass ratio of desulfurated plaster and acid solution is 6: 100 to 9: 100 in the dissolution process.
6. press claims 1 described method, it is characterized in that dissolving, the liquid phase in the crystallisation process reuses.
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Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102352528A (en) * | 2011-09-30 | 2012-02-15 | 瓮福（集团）有限责任公司 | Method for extracting phosphorite co-production gypsum whisker by utilizing nitric acid |
| CN102352535A (en) * | 2011-09-22 | 2012-02-15 | 东莞上海大学纳米技术研究院 | Method for preparing calcium sulfate crystal whiskers from desulfurized gypsum under normal pressure |
| CN102616825A (en) * | 2012-04-17 | 2012-08-01 | 河南城建学院 | Purification process of desulfurization gypsum and gypsum raw materials purified through process |
| CN103074667A (en) * | 2013-01-30 | 2013-05-01 | 湘潭大学 | Method for preparing calcium sulfate whisker through recrystallization |
| CN103588237A (en) * | 2013-11-19 | 2014-02-19 | 河北工业大学 | Decoloring and purifying method for flue gas desulfurization gypsum |
| CN103628142A (en) * | 2013-11-01 | 2014-03-12 | 贵州开磷（集团）有限责任公司 | Method for preparing phosphogypsum whiskers by secondary crystallization |
| CN104528798A (en) * | 2014-12-16 | 2015-04-22 | 中国科学院青海盐湖研究所 | Method for purifying low-grade natural gypsum or gypsum tailings by recrystallization |
| CN104846440A (en) * | 2015-05-29 | 2015-08-19 | 昆明冶金研究院 | Method for preparing high-purity calcium sulfate dihydrate crystal whisker by using metallurgic flue gas desulfurization gypsum recrystallization process |
| CN105950178A (en) * | 2016-06-27 | 2016-09-21 | 聂超 | Composite improved formula for saline-alkali soil |
| CN104496237B (en) * | 2014-12-01 | 2016-09-28 | 路德环境科技股份有限公司 | A kind of method of power plant desulfurization gypsum remove impurity |
| CN109280979A (en) * | 2017-07-19 | 2019-01-29 | 北新集团建材股份有限公司 | A method of preparing semi-hydrated gypsum whisker |
| CN109280959A (en) * | 2017-07-19 | 2019-01-29 | 北新集团建材股份有限公司 | A method of semi-hydrated gypsum fiber is prepared by desulfurized gypsum |
| CN109574060A (en) * | 2018-12-19 | 2019-04-05 | 天津渤化永利化工股份有限公司 | A kind of method of desulfurized gypsum removal of impurities decoloration |
| CN110395919A (en) * | 2019-08-09 | 2019-11-01 | 中国科学院沈阳应用生态研究所 | A kind of method that the gypsum resourceization containing arsenic is handled and the application for handling the low arsenic gypsum of gained |
| CN110903045A (en) * | 2019-12-09 | 2020-03-24 | 汪文杰 | Industrial waste residue natural stone imitation paste and preparation method and application thereof |
| CN113149037A (en) * | 2021-05-25 | 2021-07-23 | 天津渤化永利化工股份有限公司 | Method for preparing potassium sulfate by utilizing desulfurized gypsum |
| CN113603128A (en) * | 2021-09-08 | 2021-11-05 | 西南科技大学 | Method for preparing various calcium sulfate powder from industrial byproduct gypsum and calcium sulfate powder |
| CN114247556A (en) * | 2021-12-23 | 2022-03-29 | 四川轻化工大学 | Phase change purification method for industrial byproduct gypsum and phase change purified gypsum |
| CN114775059A (en) * | 2022-06-20 | 2022-07-22 | 国能龙源环保有限公司 | System and method for preparing gypsum whiskers by comprehensively utilizing concentrated salt wastewater and gypsum whiskers |
| CN116102048A (en) * | 2023-03-14 | 2023-05-12 | 贵州大学 | Method for preparing cement retarder by deeply removing phosphate impurities from phosphogypsum |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1323742A (en) * | 2000-05-12 | 2001-11-28 | 吉野石膏株式会社 | Method for producing high purity plaster |
-
2010
- 2010-06-12 CN CN 201010201194 patent/CN101870494A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1323742A (en) * | 2000-05-12 | 2001-11-28 | 吉野石膏株式会社 | Method for producing high purity plaster |
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| CN102352535B (en) * | 2011-09-22 | 2014-01-29 | 东莞上海大学纳米技术研究院 | Method for preparing calcium sulfate crystal whiskers from desulfurized gypsum under normal pressure |
| CN102352535A (en) * | 2011-09-22 | 2012-02-15 | 东莞上海大学纳米技术研究院 | Method for preparing calcium sulfate crystal whiskers from desulfurized gypsum under normal pressure |
| CN102352528A (en) * | 2011-09-30 | 2012-02-15 | 瓮福（集团）有限责任公司 | Method for extracting phosphorite co-production gypsum whisker by utilizing nitric acid |
| CN102352528B (en) * | 2011-09-30 | 2013-09-11 | 瓮福（集团）有限责任公司 | Method for extracting phosphorite co-production gypsum whisker by utilizing nitric acid |
| CN102616825A (en) * | 2012-04-17 | 2012-08-01 | 河南城建学院 | Purification process of desulfurization gypsum and gypsum raw materials purified through process |
| CN103074667B (en) * | 2013-01-30 | 2015-06-24 | 湘潭大学 | Method for preparing calcium sulfate whisker through recrystallization |
| CN103074667A (en) * | 2013-01-30 | 2013-05-01 | 湘潭大学 | Method for preparing calcium sulfate whisker through recrystallization |
| CN103628142A (en) * | 2013-11-01 | 2014-03-12 | 贵州开磷（集团）有限责任公司 | Method for preparing phosphogypsum whiskers by secondary crystallization |
| CN103628142B (en) * | 2013-11-01 | 2015-12-30 | 贵州开磷集团股份有限公司 | A kind of secondary crystal prepares the method for ester exchange at phosphorus |
| CN103588237A (en) * | 2013-11-19 | 2014-02-19 | 河北工业大学 | Decoloring and purifying method for flue gas desulfurization gypsum |
| CN104496237B (en) * | 2014-12-01 | 2016-09-28 | 路德环境科技股份有限公司 | A kind of method of power plant desulfurization gypsum remove impurity |
| CN104528798A (en) * | 2014-12-16 | 2015-04-22 | 中国科学院青海盐湖研究所 | Method for purifying low-grade natural gypsum or gypsum tailings by recrystallization |
| CN104846440A (en) * | 2015-05-29 | 2015-08-19 | 昆明冶金研究院 | Method for preparing high-purity calcium sulfate dihydrate crystal whisker by using metallurgic flue gas desulfurization gypsum recrystallization process |
| CN105950178A (en) * | 2016-06-27 | 2016-09-21 | 聂超 | Composite improved formula for saline-alkali soil |
| CN109280979A (en) * | 2017-07-19 | 2019-01-29 | 北新集团建材股份有限公司 | A method of preparing semi-hydrated gypsum whisker |
| CN109280959A (en) * | 2017-07-19 | 2019-01-29 | 北新集团建材股份有限公司 | A method of semi-hydrated gypsum fiber is prepared by desulfurized gypsum |
| CN109574060A (en) * | 2018-12-19 | 2019-04-05 | 天津渤化永利化工股份有限公司 | A kind of method of desulfurized gypsum removal of impurities decoloration |
| CN110395919A (en) * | 2019-08-09 | 2019-11-01 | 中国科学院沈阳应用生态研究所 | A kind of method that the gypsum resourceization containing arsenic is handled and the application for handling the low arsenic gypsum of gained |
| CN110903045A (en) * | 2019-12-09 | 2020-03-24 | 汪文杰 | Industrial waste residue natural stone imitation paste and preparation method and application thereof |
| CN110903045B (en) * | 2019-12-09 | 2021-10-19 | 汪文杰 | Industrial waste residue natural stone imitation paste and preparation method and application thereof |
| CN113149037A (en) * | 2021-05-25 | 2021-07-23 | 天津渤化永利化工股份有限公司 | Method for preparing potassium sulfate by utilizing desulfurized gypsum |
| CN113603128A (en) * | 2021-09-08 | 2021-11-05 | 西南科技大学 | Method for preparing various calcium sulfate powder from industrial byproduct gypsum and calcium sulfate powder |
| CN114247556A (en) * | 2021-12-23 | 2022-03-29 | 四川轻化工大学 | Phase change purification method for industrial byproduct gypsum and phase change purified gypsum |
| CN114775059A (en) * | 2022-06-20 | 2022-07-22 | 国能龙源环保有限公司 | System and method for preparing gypsum whiskers by comprehensively utilizing concentrated salt wastewater and gypsum whiskers |
| CN116102048A (en) * | 2023-03-14 | 2023-05-12 | 贵州大学 | Method for preparing cement retarder by deeply removing phosphate impurities from phosphogypsum |
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Open date: 20101027 |