CN101311355B - Process for preparing calcium sulphate whiskers from ardealite - Google Patents
Process for preparing calcium sulphate whiskers from ardealite Download PDFInfo
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- CN101311355B CN101311355B CN2008100583245A CN200810058324A CN101311355B CN 101311355 B CN101311355 B CN 101311355B CN 2008100583245 A CN2008100583245 A CN 2008100583245A CN 200810058324 A CN200810058324 A CN 200810058324A CN 101311355 B CN101311355 B CN 101311355B
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- calcium sulfate
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Abstract
The invention relates to a method for preparing calcium sulphate crystal whisker by using phosphogypsum, which belongs to the technical field of phosphorous chemical preparation. Solid drogs phosphogypsum is used as raw material; after a synthetic reaction, filtering, heating and dissolving, thermal filtering and cooling crystallization for the raw material, the calcium sulphate crystal whisker product with the controllable diameter and length is prepared, the diameter of the crystal whisker is 1-4mum and the length of the crystal whisker is 50-200mum. The adoption of the solid drogs phosphogypsum for preparing the calcium sulphate crystal whisker reduces the production volume of natural plaster, saves resources, turns the waste into benefit, lowers the production cost of the calcium sulphate crystal whisker and improves added value of the product in the process of utilizing the phosphogypsum. The obtained calcium sulphate crystal whisker has excellent property, low cost and wide application.
Description
One, technical field:
The present invention relates to a kind of method of utilizing the solid slag preparing calcium sulphate whiskers from ardealite, belong to the phosphorous chemical industry preparing technical field.
Two, background technology:
Phosphogypsum is that Rock Phosphate (72Min BPL) and sulfuric acid react and the industrial residue that produces in the Wet-process Phosphoric Acid Production process; Phosphoric acid by calculating 1 ton of every production will produce 4～5 tons of phosphogypsums; Phosphogypsum annual quantity discharged in the whole world reaches more than 200,000,000 ton at present; But the utilization ratio of phosphogypsum does not surpass 10%, and the processing of phosphogypsum, disposal and comprehensive utilization have become a global difficult problem.China's phosphate fertilizer production ranks first in the world, and the phosphate fertilizer of production high density (like phosphorus ammonium, coarse whiting etc.) needs a large amount of phosphoric acid by wet processes, also can produce a large amount of phosphogypsum slags thereupon.Great majority are stored up or are toppled over, and the stacking of phosphogypsum not only takies a large amount of soils, expends a huge sum of money, and sour water leakage pollution water source, form secondary pollution.The main chemical compositions of phosphogypsum is identical with the plaster of paris, is sulphur, calcium and the gypsum resource with multiple potential use, but impurity such as the phosphorus that it contained, fluorine, organism, alkali metal constitute adverse influence to comprehensive utilization.Therefore, from the angle of the environment protection and the utilization of resources, the processing of phosphogypsum slag is extremely urgent with utilization.
At present; All phosphogypsum is decomposed a kind of important channel of system producing sulfuric acid and jointly cement as the phosphogypsum comprehensive utilization both at home and abroad; Both obtained these two kinds of staple products of sulfuric acid and cement, and can sulfuric acid be used for this enterprise phosphoric acid production, it is under-supply to remedy sulfuric acid; Can solve the outlet of phosphogypsum again, administer the pollution of phosphogypsum environment.But, big, the poor product quality of existing phosphogypsum system producing sulfuric acid and jointly cement industry investment, and its phosphogypsum decomposes to burn till in device of rotary kiln with cement clinker and accomplishes, because the technical problems that also exist are difficult to utilization and extention.
Whisker is meant a kind of fibrous single crystal that under artificial control condition, grows into, and has certain length-to-diameter ratio (generally greater than 10), and normal length is 2～300 μ m, and diameter is about 0.1～10 μ m.Whisker is because its special single crystal structure, thereby has complete profile and perfect internal structure, and intensity is high, and size is trickle, is that one type of important matrix material strengthens constituent element.
(Calcium Sulfate Whisker CSW) is crystal whisker of gypsum again to calcium sulfate crystal whiskers, is CaSO
4Fibrous single crystal, the same branch with gypsum with anhydrous, Ban Shui and two water.Calcium sulfate crystal whiskers wherein anhydrous and half water has maximum strength and higher use value, thereby its research also has bigger economic worth with application.Compare with other whiskers, it also has the characteristics that production cost is lower and toxicity is minimum except having better enhancing and modification function.
At publication number is the preparation method who discloses a kind of non-metallic material calcium-sulfate whiskers among the CN 101029415A.This method is raw material and sulfuric acid reaction with the converter slag, and the converter slag granularity is 0.04～0.09mm, and sulfuric acid concentration is 10%～30%, and add-on is 4～7 times of converter slag weight, and the reaction times is 40～120min; Then the leach liquor behind converter slag and the sulfuric acid reaction is filtered, washs, obtain calcium sulfate.The calcium sulfate that obtains is mixed with clear water in solid-to-liquid ratio 0.2～0.8 ratio; With alkali (quicklime, Natural manganese dioxide, lime carbonate, sour magnesium, calcium hydroxide or Marinco H) adjustment pH value is 5～9; Is that 120 ℃～200 ℃, pressure are that 0.3～1MPa and mixing speed are controlled to be under 50 commentaries on classics/min～900 commentaries on classics/min conditions with the suspension of calcium sulfate after the modulation in temperature; Be 40min～120min time of drying, obtains calcium sulfate crystal whiskers.Adopt the rare pure and mild SULPHOSUCCINIC ACID ESTER of second to carry out surface-treated, dispersion calcium sulfate crystal whiskers, the consumption of properties-correcting agent is 0.5%～2%, finally obtains the calcium sulfate crystal whiskers product.
At publication number is to disclose a kind of Preparation methods of gypsum whiskers method among the CN 1955345A.This method is through at first synthetic crystallization director; The pre-treatment of technical grade quicklime elder generation, put into reactor drum 40 ℃～60 ℃ digestion, obtain lime slurry, the gained lime slurry is warming up to 40 ℃～110 ℃ in reactor drum; Add and the equimolar sulphuric acid soln of quicklime; Stirred 30～60 minutes, and in the process of reaction, added crystallization director, it is fully reacted.Be able to required calcium sulfate crystal whiskers product through filtration, washing, surface treatment and drying.
At publication number is the preparation technology who discloses a kind of calcium sulfate crystal whiskers material among the CN 1699638A; This technology is mixed gypsum and water by a certain percentage, processes slip, and above-mentioned slip is placed autoclave; The temperature and pressure and the reaction times of control reaction kettle; After question response was accomplished, drying under reduced pressure promptly got calcium sulfate crystal whiskers.
Do not see with the phosphogypsum to be the relevant report that raw material prepares calcium sulfate crystal whiskers up to now; With the phosphogypsum is that the calcium sulfate crystal whiskers that raw material prepares adds in the high molecular polymer; Can strengthen many performances such as polymkeric substance mechanical property, thermotolerance, be widely used at Aeronautics and Astronautics and numerous civilian industries field; If add in the plastic, rubber, can improve tensile strength, flexural strength, spring rate and the heat-drawn wire of matrix material; Also can replace asbestos to add abrasives, material of construction, lagging material to simultaneously; Can be used as reinforcing filler and be used for industries such as polymer matrix composites, sticker.Calcium sulfate crystal whiskers excellent property, cheap, environmental protection have wide application and market outlook.Utilize preparing calcium sulphate whiskers from ardealite, can make the solid waste phosphogypsum obtain the high-touch feature material.
Three, summary of the invention
The method that the purpose of this invention is to provide a kind of preparing calcium sulphate whiskers from ardealite; Use the solid slag phosphogypsum to be raw material; Preparing diameter of whiskers through synthetic reaction, filtration, heating for dissolving, heat filtering, crystallisation by cooling is 1～4 μ m; Length 50～200 μ m, the calcium sulfate crystal whiskers product of diameter and length controlled.
Fabricating technology route of the present invention is as shown in Figure 1, and it is accomplished according to the following steps:
(1) the raw material phosphogypsum being mixed with concentration expressed in percentage by weight is 5～15% slurries; Join in the synthesis reactor; It is 7.5～12 that adding pH adjustment agent makes the potential of hydrogen of solution, and controlled temperature is 90～200 ℃, evenly stirs 20～30min; Obtain calcium sulfate crystal whiskers first intermediates, said adjustment agent is sodium hydroxide or Pottasium Hydroxide;
(2) calcium sulfate crystal whiskers first intermediates are filtered, after the filtration weight in wet base per-cent is 30～45% filter residue, be calcium sulfate crystal whiskers second intermediates;
(3) heating for dissolving: it is 5%～20% slurries that second intermediates are mixed with weight percent concentration; Controlled temperature is 100～200 ℃; Evenly stir 20～30min; The additive magnesium nitrate powder that in the process that stirs, adds 0.15～0.2 times of raw material weight simultaneously is as the crystalline form growth substance, and the diameter and the length of control calcium sulfate crystal whiskers obtain calcium sulfate crystal whiskers the 3rd intermediates;
(4) the 3rd intermediates temperature remain on 80～150 ℃ and carry out heat filtering, and heat filtering gained filtrating is calcium sulfate crystal whiskers the 4th intermediates of water ratio 30～45%;
(5) crystallisation by cooling: the 4th intermediates are at room temperature cooled off, separate out crystal, treat that crystal all separates out; (in the water behind the no flocculence object); Stop going up cooling, the crystal that obtains is calcium sulfate crystal whiskers, cools off available cold water, frozen water or icy salt solution etc.; With the gained calcium sulfate crystal whiskers temperature is 150～310 ℃ dry 1～2 hour down, make water cut less than 0.3% calcium sulfate crystal whiskers product.
Major advantage of the present invention has:
(1) calcium sulfate crystal whiskers product diameter, length is even, quality is high;
(2) use the solid waste preparing calcium sulphate whiskers from ardealite, reduced the produced quantity of the plaster of paris, practiced thrift resource, reduced the production cost of calcium sulfate crystal whiskers simultaneously, improved phosphogypsum and utilized value-added content of product in the process;
(3) this technology does not have strict restriction for the composition of raw material phosphogypsum, and is applied widely, condition is wide;
(4) production technique environmentally safe, the calcium sulfate crystal whiskers excellent property of gained, with low cost, have multiple purposes widely.
Four, Fig. 1 is the preparing calcium sulphate whiskers from ardealite process flow sheet.
Five, embodiment
Embodiment 1: raw material phosphogypsum main chemical compositions weight percent is: CaO 35.36%, SO
247.12%, Fe
2O
33.01%, Al
2O
32.05%, P
2O
51.20%, F 0.06%, SiO
211.20%.It is 10% phosphogypsum slurries that phosphogypsum is mixed with weight percent concentration, joins in the synthesis reactor, adds pH adjustment agent sodium hydroxide; Make the potential of hydrogen of solution be adjusted into 9; Controlled temperature is 95 ℃, evenly stirs 25min, obtains calcium sulfate crystal whiskers first intermediates; First intermediates that utilize box filter that the front is prepared filter, and the weight in wet base per-cent that filters the gained filter residue is 32%, and this is calcium sulfate crystal whiskers second intermediates; It is 15% slurries that second intermediates are mixed with weight percent concentration; When temperature is 120 ℃; Evenly stir 25min; In the process that stirs, add 0.15 times of magnesium nitrate powder of raw material weight simultaneously as the crystalline form growth substance, the diameter and the length of control calcium sulfate crystal whiskers obtain calcium sulfate crystal whiskers the 3rd intermediates.Is to carry out heat filtering under 100 ℃ with the 3rd intermediates in temperature; Obtain weight in wet base per-cent and be 36% filtrating and be calcium sulfate crystal whiskers the 4th intermediates, cool off with frozen water, treat that crystal is all separated out after; Drying is 1.5 hours under temperature is 150 ℃, promptly obtains the calcium sulfate crystal whiskers product.With ESEM product is detected, the result shows that the diameter of calcium sulfate crystal whiskers is that 2～4 μ m and length are 100～200 μ m.This calcium sulfate crystal whiskers adopts Triple Pressed Stearic Acid as surface-modifying agent, carries out adding in the plastic, rubber after the surface-treated, can improve tensile strength, flexural strength and the spring rate of matrix material.
Embodiment 2: raw material phosphogypsum main chemical compositions % is: CaO=37%, SO
2=50.17%, Fe
2O
3=0.1%, Al
2O
3=0.59%, P
2O
5=1.01%, F=0.01%, SiO
2=11.12%.It is 12% phosphogypsum slurries that phosphogypsum is mixed with weight percent concentration; Join in the synthesis reactor, add pH adjustment agent Pottasium Hydroxide, make the potential of hydrogen of solution be adjusted into 10; And when temperature is 95～100 ℃, evenly stir 30min, obtain calcium sulfate crystal whiskers first intermediates; First intermediates that utilize centrifugal filter that the front is prepared filter, and the weight in wet base per-cent that filters the gained filter residue is 43%, is calcium sulfate crystal whiskers second intermediates; It is 16% slurries that these second intermediates are mixed with weight percent concentration; When temperature is 140 ℃; Evenly stir 30min; In the process that stirs, add 0.2 times of magnesium nitrate powder of raw material weight simultaneously as the crystalline form growth substance, the diameter and the length of control calcium sulfate crystal whiskers obtain calcium sulfate crystal whiskers the 3rd intermediates.The 3rd intermediates are carried out heat filtering when temperature is 100 ℃ after; Obtaining weight in wet base per-cent is that 35% filtrating is calcium sulfate crystal whiskers the 4th intermediates; Cool off with frozen water; After treating that crystal is all separated out, be 200 ℃ of down dry dryings down 1.5 hours, promptly obtain the calcium sulfate crystal whiskers product in temperature.With ESEM product is detected, the result shows that the diameter of calcium sulfate crystal whiskers is that 1～4 μ m and length are 50～150 μ m.This calcium sulfate crystal whiskers adopts blast furnace slag as surface-modifying agent, carry out surface-treated after, add in the high molecular polymer, can strengthen polymkeric substance mechanical property and thermotolerance.
Claims (2)
1. the method for a preparing calcium sulphate whiskers from ardealite, it is characterized in that: it is accomplished according to the following steps:
1) the raw material phosphogypsum being mixed with concentration expressed in percentage by weight is 5～15% slurries; Join in the synthesis reactor, it is 7.5～12 that adding pH adjustment agent makes the potential of hydrogen of solution, and controlled temperature is 90～200 ℃; Evenly stir 20～30min, obtain calcium sulfate crystal whiskers first intermediates;
2) calcium sulfate crystal whiskers first intermediates are filtered, after the filtration weight in wet base per-cent is 30～45% filter residue, be calcium sulfate crystal whiskers second intermediates;
3) heating for dissolving: it is 5%～20% slurries that second intermediates are mixed with weight percent concentration; Controlled temperature is 100～200 ℃; Evenly stir 20～30min; The additive magnesium nitrate powder that in the process that stirs, adds 0.15～0.2 times of raw material weight simultaneously is as the crystalline form growth substance, and the diameter and the length of control calcium sulfate crystal whiskers obtain calcium sulfate crystal whiskers the 3rd intermediates;
4) the 3rd intermediates temperature remains on 80～150 ℃ and carries out heat filtering, and heat filtering gained filtrating is calcium sulfate crystal whiskers the 4th intermediates of water ratio 30～45%;
5) the 4th intermediates are at room temperature cooled off; Separate out crystal, treat that crystal all separates out, the crystal that obtains is calcium sulfate crystal whiskers; With the gained calcium sulfate crystal whiskers temperature is 150～310 ℃ dry 1～2 hour down, make water cut less than 0.3% calcium sulfate crystal whiskers product.
2. the method for preparing calcium sulphate whiskers from ardealite according to claim 1, it is characterized in that: described adjustment agent is sodium hydroxide or Pottasium Hydroxide.
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| CN101311355B true CN101311355B (en) | 2012-05-02 |
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| CN101550602B (en) * | 2009-05-19 | 2011-10-05 | 武汉科技大学 | CaSO4 crystal whisker with desulfurized gypsum as raw material and preparing method |
| CN101792932B (en) * | 2009-11-16 | 2012-04-18 | 瓮福（集团）有限责任公司 | Method for preparing ultra-fine calcium sulfate crystal whisker by using phosphogypsum |
| CN101736403B (en) * | 2009-12-14 | 2012-05-30 | 昆明理工大学 | Method for preparing calcium sulfate crystal whiskers by using impurity-containing gypsum as raw material |
| CN101823749B (en) * | 2010-04-30 | 2012-01-04 | 汪晋强 | Method for co-production of calcined gypsum in preparation of anhydrous calcium chloride by phosphogypsum |
| CN102115142A (en) * | 2010-12-31 | 2011-07-06 | 张胜勇 | Method for producing industrial calcium sulfate by producing ardealite |
| CN102180507B (en) * | 2011-03-24 | 2013-04-17 | 昆明安雅达建材科技有限公司 | Method for preparing high-crystallinity gypsum |
| CN102383179B (en) * | 2011-10-09 | 2015-09-09 | 昆明理工大学 | A kind of method that industrial waste acid and phosphogypsum fully utilize |
| CN102534801A (en) * | 2012-02-23 | 2012-07-04 | 云南民族大学 | Method for improving quality of calcium sulfate whiskers |
| CN102677177B (en) * | 2012-04-13 | 2015-08-26 | 昆明理工大学 | A kind of preparation method of high length-diameter ratio hemihydrate calcium sulfate crystal whisker |
| CN102776569A (en) * | 2012-07-09 | 2012-11-14 | 泰山医学院 | Method for preparing calcium sulfate crystal whiskers by using natural gypsum |
| CN102925956B (en) * | 2012-11-26 | 2014-12-03 | 武汉科技大学 | Method for preparing calcium sulfate hemihydrate whiskers by taking ardealite as main raw material |
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| CN111188087B (en) * | 2015-01-07 | 2021-10-26 | 西南科技大学 | Method for preparing calcium sulfate whisker from phosphogypsum |
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| CN107557870A (en) * | 2017-09-08 | 2018-01-09 | 云南磷化集团有限公司 | A kind of method with preparing calcium sulphate whiskers from ardealite |
| CN110541188B (en) * | 2019-10-18 | 2021-02-05 | 郑州中科新兴产业技术研究院 | Method for preparing calcium sulfate hemihydrate crystal whisker with high length-diameter ratio by using calcium sulfate dihydrate |
| CN113512761A (en) * | 2021-07-09 | 2021-10-19 | 浙江钙宝新材料有限公司 | Method for purifying industrial solid waste gypsum and preparing calcium sulfate whisker |
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| CN115305574B (en) * | 2022-07-21 | 2023-09-19 | 武汉理工大学 | Method for rapidly preparing whisker by using phosphogypsum and saline |
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