CN105776303A - Production method of alpha-hemihydrate gypsum - Google Patents
Production method of alpha-hemihydrate gypsum Download PDFInfo
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- CN105776303A CN105776303A CN201610062945.5A CN201610062945A CN105776303A CN 105776303 A CN105776303 A CN 105776303A CN 201610062945 A CN201610062945 A CN 201610062945A CN 105776303 A CN105776303 A CN 105776303A
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- 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
- C01F11/466—Conversion of one form of calcium sulfate to another
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Abstract
A production method of an alpha-hemihydrate gypsum comprises the steps: (1) preparing a mixture of phosphoric acid and dihydrate phosphogypsum by adopting a conventional dihydrate method; (2) filtering the mixture by a filter, and separating the phosphoric acid and the dihydrate phosphogypsum; and transferring the phosphogypsum to a conversion tank, adding phosphoric acid and process water, fully mixing, introducing steam, adding concentrated sulfuric acid, carrying out a reaction, and making the dihydrate phosphogypsum converted into hemihydrate phosphogypsum; (3) after the reaction, filtering and separating a slurry containing the hemihydrate gypsum, and taking the filtered acid as a return acid for dihydrate wet-process phosphoric acid production; and washing the filter cake for two times, using the washed water in a dihydrate crystallization tank and in a hemihydrate crystallization tank for regulating the solid content, and thus obtaining water-containing hemihydrate gypsum; and (4) drying the water-containing hemihydrate gypsum to obtain the hemihydrate gypsum product. The method adopts a wet-process phosphoric acid production device to produce the alpha-hemihydrate gypsum, can make the by-product phosphogypsum fully utilized, alleviates the storage pressure of a slag yard, reduces pollution, is beneficial for enterprises to improve economic benefits, and is suitable for wet-process phosphoric acid production enterprises.
Description
Technical field
The present invention relates to phosphoric acid, be directed to Gypsum Fibrosum, particularly relate to the method by Wet-process Phosphoric Acid Production alpha semi-hydrated gypsum.
Background technology
It is known that the most general production method of phosphoric acid by wet process is " two water laws ", namely extracting ground phosphate rock with sulphuric acid and generate phosphoric acid by wet process and calcium sulphate dihydrate, calcium sulphate dihydrate is again dihydrate gypsum, and main component is calcium sulfate (CaSO4·2H2O).Owing to dihydrate gypsum crystalline particle is thicker, it is easy to filter and separate with phosphoric acid, so many producers all use " two water laws " to produce phosphoric acid by wet process.But, in Wet-process Phosphoric Acid Production process, the dihydrate gypsum of a large amount of by-products is but difficult with, and stacks only as solid refuse.Stacking dihydrate gypsum and do not only take up large-area soil, stockyard also needs to carry out Anti-seeping technology, produces a large amount of acid water pollution environment, necessarily expend great amount of investment during to prevent and raining.
Dihydrate gypsum is converted into alpha-semi water plaster stone (CaSO4·1/2H2O), directly utilize as plaster of Paris product, it is possible to decrease pollute, improve resource utilization, it is to avoid a process difficult problem for dihydrate gypsum.Through retrieval, the patent relating to a-semi-hydrated gypsum in Chinese patent database has No. ZL201210552488X " utilizing the method that high activity alpha semi-hydrated gypsum Binder Materials is prepared in chlor-alkali liquid waste processing ardealite reaction ", No. ZL2012105526071 " a kind of utilize Mud-slag modified ardealite for method that constant pressure hydro-thermal method prepares high-strength alpha-type semi-hydrated gypsum ", No. ZL2013100445299 " a kind of method that two water-half water Wet Processes of Phosphoric Acids produce phosphoric acid coproduction alpha-semi water plaster stone ", No. ZL2013104299003 " a kind of low cost prepares the method for alpha semi-hydrated gypsum and prepared alpha semi-hydrated gypsum and gypsum block " 4.The alpha-semi water plaster stone that prior art produces, compared with β-semi-hydrated gypsum, has intensity height, cost performance is superior, purposes is a wide feature, therefore ardealite transforms into novel gypsum building materials, is the approach solving ardealite problem.
Summary of the invention
It is desirable to provide the production method of a kind of alpha semi-hydrated gypsum, utilize existing dihydrate wet phosphoric acid technique, be transformed into two water-half water wet method phosphoric acid manufacture process, phosphogypsum dihydrate transformed into semi-hydrated gypsum, with the hang-up overcoming ardealite to utilize simultaneously.
The alpha semi-hydrated gypsum production method that inventor provides comprises the steps:
(1) produce Wet Phosphoric Acid Plant by conventional two water laws, extraction tank adds ground phosphate rock and sulphuric acid, so as to carry out extractive reaction, produce the compound of phosphoric acid and phosphogypsum dihydrate；
(2) filter compound with filter, phosphoric acid is separated with ardealite；Ardealite before washing on filter being moved to conversion tank, is simultaneously introduced phosphoric acid and fresh water (FW), makes material be sufficiently mixed and pass into steam in conversion tank, and add concentrated sulphuric acid, slip carries out conversion reaction, makes phosphogypsum dihydrate be converted into half water ardealite；
(3), after conversion reaction completes, the slip containing semi-hydrated gypsum enters filter plant and is filtered separating, and filter acid returns acid as what dihydrate wet phosphoric acid produced；Filter cake water performs twice at washing, reclaims phosphorus therein and ensures the quality of semi-hydrated gypsum；Wash water regulates solid content for two water crystallization grooves with for semihydrate crystal groove, and the filter cake after washing is moisture semi-hydrated gypsum；
(4) moisture semi-hydrated gypsum is dried, namely obtain semi-hydrated gypsum product.
In above-mentioned (2nd) step, the technic index of described conversion reaction is: it is 20%～21% that slip solid content controls, SO in slip4 2-Concentration: 14.0%～16.7%, liquid-solid ratio controls P in 3.5: 1 filter acids2O5Content controls 17%～20%, response time 2h, and reaction temperature controls at 92 DEG C～106 DEG C.
In above-mentioned (3rd) step, P in described filter acid2O5Concentration is 15%～20%.
In above-mentioned (4th) step, described dry be adopt the hot air drying 2h of 260 DEG C, the quality of described semi-hydrated gypsum product is homogeneous, canescence, and crystallization is elongated needle-like, and wherein the molten phosphorus content of Chinese holly is 0.07%～0.14%.
Inventors have noted that: the 1. solid content of reaction slurry and SO4 2-Concentration is proportional, and solid content controls 20.5%, filter acid SO4 2-Concentration is comparatively suitable about 14%；2. slip solid content and filter acid P2O5Concentration substantially tends to the relation of direct ratio, and the solid content of reaction slurry is unsuitable excessive, as when 25%, time sulphuric acid joins a certain amount of, slip can become viscous rapidly, and experiment proves that slip solid content controls react smoothly about 21%, filter acid P2O5Concentration is 15%～20%；The viscosity of slip can be played mitigation by higher stirring intensity, it is ensured that reaction is normally carried out.3. filter acid SO4 2-Concentration and the molten phosphorus content of semi-hydrated gypsum Chinese holly are inverse relation, i.e. wherein SO4 2-Concentration is more high, and the molten phosphorus content of semi-hydrated gypsum Chinese holly is more low.
Inventor points out again: alpha-semi water plaster stone product should keep dry, it is prevented that it is converted into β-semi-hydrated gypsum.
The production method of the alpha semi-hydrated gypsum of the present invention is by transforming dihydrate wet phosphoric acid process units, and to technic index optimization, reach to produce the purpose of alpha semi-hydrated gypsum, the side-product ardealite that can make Wet-process Phosphoric Acid Production is fully utilized, thus alleviating storing up pressure and reducing the pollution to environment of slag field.The inventive method improves the phosphrus reagent of phosphoric acid system, makes full use of the wash water of filtration washing, is conducive to the economic benefit of enterprise, it is easy to operation, with practical value.Suitable in Wet-process Phosphoric Acid Production enterprise.
Accompanying drawing explanation
Fig. 1 is present invention process schematic process flow diagram.
Detailed description of the invention
The method that following example are used for further illustrating the present invention
320g, 350g, 360g, 390g, 400g, 500g dihydrate gypsum is mixed with 850g phosphoric acid respectively, and it is separately added into 95g, 105g, 104g, 115g, 120g, 150g concentrated sulphuric acid according to a small amount of repeatedly principle, it is 3.5: 1 that liquid-solid ratio controls, period carries out concentrated sulphuric acid container washing with suitable fresh water (FW), ensure the quality that concentrated sulphuric acid adds, maintain stablizing of solid content simultaneously as evaporation moisturizing.Slip 92 DEG C～106 DEG C, mix and blend when carry out conversion reaction 2h；Control solid content 20%～21%.
Conversion reaction complete after slip be easily separated filtration, obtain P2O5Mass fraction is the filter acid of 15.74%～19.87%, produces returning of reactive tank as dihydrate wet phosphoric acid sour for regulating pulp density；
Semi-hydrated gypsum after filtration through one washing, two wash, wash water regulates solid content for two water crystallization grooves with for semihydrate crystal groove, and the filter cake after washing is moisture semi-hydrated gypsum；Moisture semi-hydrated gypsum is used260DEG C hot air drying 2 hours, the semi-hydrated gypsum product obtained is rendered as homogeneous, canescence, and crystallization is the semi-hydrated gypsum of elongated needle-like, and the molten phosphorus of Gypsum Fibrosum Chinese holly is below 0.14%.
Claims (4)
1. the production method of an alpha semi-hydrated gypsum, it is characterised in that comprise the steps:
(1) produce Wet Phosphoric Acid Plant by conventional two water laws, extraction tank adds ground phosphate rock and sulphuric acid, so as to carry out extractive reaction, produce the compound of phosphoric acid and phosphogypsum dihydrate；
Filter compound with filter, phosphoric acid is separated with phosphogypsum dihydrate；Ardealite before washing on filter being moved to conversion tank, is simultaneously introduced phosphoric acid and fresh water (FW), makes material be sufficiently mixed and pass into steam in conversion tank, and add concentrated sulphuric acid, slip carries out conversion reaction, makes phosphogypsum dihydrate be converted into half water ardealite；
After conversion reaction completes, the slip containing semi-hydrated gypsum enters filter plant and is filtered separating, and filter acid returns acid as what dihydrate wet phosphoric acid produced；Filter cake water performs twice at washing, reclaims phosphorus therein and ensures the quality of semi-hydrated gypsum；Wash water regulates solid content for two water crystallization grooves with for semihydrate crystal groove, and the filter cake after washing is moisture semi-hydrated gypsum；
Moisture semi-hydrated gypsum is dried, namely obtains semi-hydrated gypsum product.
2. the method for claim 1, it is characterised in that described in (2nd) step, the technic index of conversion reaction is: it is 20%～21% that slip solid content controls, SO in slip4 2-Concentration: 14.0%～16.7%, liquid-solid ratio controls P in 3.5: 1 filter acids2O5Content controls 17%～20%, response time 2h, and reaction temperature controls at 92 DEG C～106 DEG C.
3. the method for claim 1, it is characterised in that in (3rd) step, P in described filter acid2O5Concentration is 15%～20%.
4. the method for claim 1, it is characterised in that in (4th) step, described dry be adopt the hot air drying 2h of 260 DEG C, the quality of described semi-hydrated gypsum product is homogeneous, canescence, crystallization is elongated needle-like, and wherein the molten phosphorus content of Chinese holly is 0.07%～0.14%.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107619060A (en) * | 2017-09-13 | 2018-01-23 | 重庆工商大学 | A kind of semi-hydrated gypsum nano wire, preparation method and applications |
| CN108117287A (en) * | 2017-12-26 | 2018-06-05 | 安徽森科新材料有限公司 | The ardealite producing building land plaster of half water law of half water law of phosphoric acid by wet process and two water |
| CN108314342A (en) * | 2018-04-28 | 2018-07-24 | 贵州大学 | A kind of method that phosphogypsum dihydrate prepares alpha type high-strength gypsum |
| CN109112635A (en) * | 2018-08-10 | 2019-01-01 | 瓮福化工科技有限公司 | A method of quickly preparing semi-hydrated gypsum whisker and anhydrous gypsum whisker using ardealite |
| CN111003723A (en) * | 2019-12-18 | 2020-04-14 | 武汉工程大学 | Method for preparing α -hemihydrate gypsum by using chemical gypsum and α -hemihydrate gypsum prepared by using method |
| CN112919520A (en) * | 2021-03-02 | 2021-06-08 | 金正大生态工程集团股份有限公司 | Deep dephosphorization method for phosphogypsum |
| CN115974437A (en) * | 2022-12-28 | 2023-04-18 | 四川国泰民安科技有限公司 | Efficient ardealite processing system |
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| CN105253867A (en) * | 2015-09-18 | 2016-01-20 | 金正大生态工程集团股份有限公司 | Production method for by-product alpha-hemihydrate gypsum of wet-process phosphoric acid |
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| CN101792932A (en) * | 2009-11-16 | 2010-08-04 | 瓮福（集团）有限责任公司 | Method for preparing ultra-fine calcium sulfate crystal whisker by using phosphogypsum |
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| CN103508689A (en) * | 2013-09-18 | 2014-01-15 | 武汉理工大学 | Method for preparing alpha semi-hydrated gypsum at low cost and prepared alpha semi-hydrated gypsum and gypsum block |
| CN104310823A (en) * | 2014-09-26 | 2015-01-28 | 青岛精益信电子技术有限公司 | Phosphogypsum modifying method |
| CN105174760A (en) * | 2015-09-18 | 2015-12-23 | 金正大生态工程集团股份有限公司 | Method for preparing alpha semi-hydrated gypsum from dihydrate gypsum |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107619060A (en) * | 2017-09-13 | 2018-01-23 | 重庆工商大学 | A kind of semi-hydrated gypsum nano wire, preparation method and applications |
| CN108117287A (en) * | 2017-12-26 | 2018-06-05 | 安徽森科新材料有限公司 | The ardealite producing building land plaster of half water law of half water law of phosphoric acid by wet process and two water |
| CN108314342A (en) * | 2018-04-28 | 2018-07-24 | 贵州大学 | A kind of method that phosphogypsum dihydrate prepares alpha type high-strength gypsum |
| CN108314342B (en) * | 2018-04-28 | 2020-09-18 | 贵州大学 | Method for preparing alpha-type high-strength gypsum from dihydrate phosphogypsum |
| CN109112635A (en) * | 2018-08-10 | 2019-01-01 | 瓮福化工科技有限公司 | A method of quickly preparing semi-hydrated gypsum whisker and anhydrous gypsum whisker using ardealite |
| CN111003723A (en) * | 2019-12-18 | 2020-04-14 | 武汉工程大学 | Method for preparing α -hemihydrate gypsum by using chemical gypsum and α -hemihydrate gypsum prepared by using method |
| CN111003723B (en) * | 2019-12-18 | 2021-06-15 | 武汉工程大学 | Method for preparing alpha-semi-hydrated gypsum by using chemical gypsum and alpha-semi-hydrated gypsum prepared by same |
| CN112919520A (en) * | 2021-03-02 | 2021-06-08 | 金正大生态工程集团股份有限公司 | Deep dephosphorization method for phosphogypsum |
| CN115974437A (en) * | 2022-12-28 | 2023-04-18 | 四川国泰民安科技有限公司 | Efficient ardealite processing system |
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