CN103523808A - Method for producing chloride-free magnesium hydroxide flame retardant from magnesia - Google Patents
Method for producing chloride-free magnesium hydroxide flame retardant from magnesia Download PDFInfo
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- CN103523808A CN103523808A CN201310454055.5A CN201310454055A CN103523808A CN 103523808 A CN103523808 A CN 103523808A CN 201310454055 A CN201310454055 A CN 201310454055A CN 103523808 A CN103523808 A CN 103523808A
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Abstract
The invention relates to a method for producing a chloride-free magnesium hydroxide flame retardant from magnesia. The method comprises the following steps: with the magnesia as a raw material and concentrated sulfuric acid as an acidolysis solution, removing impurities through acid dissolution to obtain a pure magnesium sulfate solution; adding an alkaline precipitating agent; and reacting at room temperature to obtain magnesium hydroxide slurry; and performing high-pressure hydrothermal treatment on the magnesium hydroxide slurry to obtain flame-retardant magnesium hydroxide. The magnesium hydroxide prepared by the method has a regular hexagonal sheet structure, has the content of more than 99%, the Cl- content of 10-20ppm, and the specific surface area of 5-15m2/ g. The method is simple in operation, low in cost and high in added value; and the prepared magnesium hydroxide is relatively high in purity and very low in chloride ion content, and can be used as the flame retardant.
Description
Technical field
The present invention relates to a kind of processing method of being produced flame retardant of magnesium hydroxide by magnesia, particularly a kind of have high-purity preparation method without chlorine magnesium hydroxide, belongs to inorganic chemical technology technical field.
Background technology
Flame Retardant Magnesium Hydroxide be a kind of high filler loading capacity addition type inorganic combustion inhibitor and press down resist, can be widely used in the plastic, rubbers such as PP, PE, PVC, PS, ABS, PA, PC, have that nontoxic, tasteless, the non-volatile decomposition of good stability, temperature are high, the feature such as etching apparatus not.
China's magnesium resource is very abundant, and in salt lake, various magnesium salts reserves are huge, and magnesite reserves also account for No. 1 in the world.But due to production technology and production unit backwardness, can only produce inferior magnesium hydroxide products for a long time, added value is lower, there is no in the international market competitive power, and the most dependence on import of high-quality Flame Retardant Magnesium Hydroxide product, import price is up to 30000 yuan/ton.Therefore the flame retardant of magnesium hydroxide of, researching and producing high added value is all significant from economy and environmental angle.
At present, the producing and manufacturing technique of magnesium hydroxide has multiple, but is raw material mainly with the bittern of magnesium chloride or salt manufacturing by-product, adds alkaloids to make.In the magnesium hydroxide products making, because of the more difficult washing of chlorion, remove, affected the quality of Flame Retardant Magnesium Hydroxide.Therefore carry out that to take the magnesia that magnesite obtains after calcining be the research of raw material production high quality without chlorine flame retardant of magnesium hydroxide, just seem very necessary.Also can improve the exploitation degree of magnesite resource, improve product specification, increase added value simultaneously.
Summary of the invention
Magnesia can be called magnesia or light-magnesite powder again, and main component is magnesium oxide, the raw material of preparing mainly as a set of magnesium products.The object of the invention is to take the magnesia that magnesite obtains after calcining is raw material, produces high quality without chlorine flame retardant of magnesium hydroxide.This technical costs is cheap, and added value is high, and the magnesium hydroxide purity making is higher, and chloride ion content is very micro-, can be used as fire retardant and uses.
The present invention is achieved through the following technical solutions:
By magnesia, produce the method without chlorine flame retardant of magnesium hydroxide, comprise the steps:
(1) take magnesia as raw material, add water in reactor, magnesia, drips 98% vitriol oil and carries out acidolysis reaction;
(2) acid hydrolysis solution step (1) being obtained is placed in water bath with thermostatic control, in 80～95 ℃ of insulation reaction 0.5-3h;
(3) in the slurry obtaining in step (2), add a kind of oxygenant and neutralizing agent, regulating pH value is 6.5～7.5, and insulation is filtered, and obtains pure Adlerika;
(4) it is 10～60g/L that Adlerika step (3) being obtained is configured to concentration, adds alkaline precipitating agent, carries out precipitin reaction 0.5-2h at 20-95 ℃;
(5) by the slurries filtration after precipitin reaction, washing, gained filter cake is put into aqueous solution dispersed with stirring, makes solid content and be 10% suspension;
(6) suspension of being prepared by step (5) proceeds in autoclave, stirs, and hydrothermal temperature is 150-220 ℃, carries out hydrothermal modification 0.5-10h;
(7) by the slurries filtration after hydrothermal modification, and be 1:(1-10 by the mass ratio of filter cake and water) wash, refilter, the dry not magnesium hydroxide of chloride ion-containing that obtains.
Mass ratio 2.5～the 3.5:1.0 of 98% vitriol oil and magnesia in above-mentioned steps (1), the mass ratio 8～20:1.0 of water and magnesia
In above-mentioned steps (3), oxygenant is any in sodium peroxide, clorox, hydrogen peroxide; Neutralizing agent is any in calcium hydroxide, sodium hydroxide, magnesia.
In above-mentioned steps (3), the mass ratio of oxygenant and raw material magnesia is 0.001～0.03:1
Alkaline precipitating agent described in above-mentioned steps (4) is any in potassium hydroxide, sodium hydroxide.
The quality that the alkaline precipitating agent that adds quality and calculate than the chemical equilibrium formula of reacting with alkaline precipitating agent by sal epsom of alkaline precipitating agent described in above-mentioned steps (4) should add is excessive.Excessive mass percent is 0.1～5%.
In above-mentioned steps (6), mixing speed is 10～200 revs/min.
The present invention does raw material with magnesia, and 98% vitriol oil is done acid hydrolysis solution, through the molten removal of impurities of acid, makes pure Adlerika, then adds alkaline precipitating agent, through normal-temperature reaction, makes magnesium hydroxide slurry.Magnesium hydroxide slurry through high pressure water thermal treatment, obtains Flame Retardant Magnesium Hydroxide again.This technological operation is simple, with low cost, and added value is high.The magnesium hydroxide making by this method is regular hexagonal flake structure, and its content reaches more than 99%, Cl
-content at 10～20ppm, specific surface area 5～15m
2/ g.
Accompanying drawing explanation
Fig. 1 produces the technical process without chlorine flame retardant of magnesium hydroxide by magnesia.
Embodiment
The present invention produces technical process without chlorine flame retardant of magnesium hydroxide as Fig. 1 by magnesia, and its technological process comprises the following steps:
(1) magnesia obtaining 800～850 ℃ of calcinings with magnesite (grade is greater than 85%), granularity is at 325 orders, the raw material of preparing for magnesium hydroxide products.In reactor, add water, magnesia, and 98% vitriol oil is slowly added in reactor with 10～30g/min.Mass ratio 2.5～the 3.5:1.0 of 98% vitriol oil and magnesia, the mass ratio 8～20:1.0 of water and magnesia
After (2) 98% vitriol oils dropwise, acid hydrolysis solution is placed in to water bath with thermostatic control, in 80～95 ℃ of insulated and stirred reaction 05-3h.
(3) in the feed liquid after insulation reaction, add a kind of oxygenant (sodium peroxide, clorox or hydrogen peroxide), and add gradually a kind of neutralizing agent (calcium hydroxide, sodium hydroxide or magnesia), to regulate the pH value of feed liquid to reach 6.5～7.5, insulation is filtered, and obtains pure Adlerika.The mass ratio of oxygenant and raw material magnesia is 0.001～0.03:1
(4) Adlerika making being configured to concentration is 10～60g/L, add alkaline precipitating agent (potassium hydroxide or sodium hydroxide), the quality that the alkaline precipitating agent that adds quality and calculate than the chemical equilibrium formula of reacting with alkaline precipitating agent by sal epsom of alkaline precipitating agent should add is excessive.Excessive mass percent is 0.1～5%.Then at 20-95 ℃, carry out precipitin reaction 0.5-2h.
(5) by the slurries filtration after precipitin reaction, washing, gained filter cake is put into aqueous solution dispersed with stirring, makes solid content and be 10% suspension.
(6) above-mentioned suspension is proceeded in autoclave, setting rotating speed is 10～200 revs/min, and hydrothermal temperature is 150-220 ℃, carries out hydrothermal modification 0.5-10h;
(7) by the slurries filtration after hydrothermal modification, and be 1:(1-10 by the mass ratio of filter cake and water) wash, refilter, dry to obtain crystal formation be regular hexagonal flake structure, magnesium hydroxide content reaches more than 99%, Cl
-content at 10～20ppm, specific surface area is 5～15m
2the product of/g.
Embodiment:
Embodiment 1
Under normal temperature, in reactor, add 1600g water, 200g magnesia, and the 500g98% vitriol oil is slowly added in reactor, 98% vitriol oil drop rate is 10g/min, after 98% vitriol oil dropwises, acid hydrolysis solution is placed in to water bath with thermostatic control, in 80 ℃ of insulated and stirred reaction 0.5h.In feed liquid after insulation reaction, add 0.2g sodium peroxide, and add gradually calcium hydroxide, to regulate the pH value of feed liquid to reach 6.5, insulation is filtered, and obtains pure Adlerika.The Adlerika making is reconfigured as to the solution that concentration is 60g/L, gets 1L Adlerika, add the potassium hydroxide solution 500mL of 2mol/L, at 20 ℃, carry out precipitin reaction 0.5h.By the slurries filtration after precipitin reaction, washing, gained filter cake is put into aqueous solution dispersed with stirring, makes solid content and be 10% suspension.Above-mentioned suspension is proceeded in autoclave, setting mixing speed is 10 revs/min, hydrothermal temperature is 150 ℃, carry out hydrothermal modification 10h, by the slurries filtration after hydrothermal modification, and be that 1:1 washs 2 times by the mass ratio of filter cake and water, refilter, dry to obtain magnesium hydroxide content be 99.48%, Cl
-content be 20ppm, specific surface area is 15m
2the product of/g.
Embodiment 2
Under normal temperature, in reactor, add 4000g water, 200g magnesia, and the 700g98% vitriol oil is slowly added in reactor, 98% vitriol oil drop rate is 30g/min, after 98% vitriol oil dropwises, acid hydrolysis solution is placed in to water bath with thermostatic control, in 95 ℃ of insulated and stirred reaction 3h.In feed liquid after insulation reaction, add 6g hydrogen peroxide, and add gradually sodium hydroxide, to regulate the pH value of feed liquid to reach 7.5, insulation is filtered, and obtains pure Adlerika.The Adlerika making is reconfigured as to the solution that concentration is 10g/L, gets 2L Adlerika, add the sodium hydroxide solution 125mL of 4mol/L, at 95 ℃, carry out precipitin reaction 2h.By the slurries filtration after precipitin reaction, washing, gained filter cake is put into aqueous solution dispersed with stirring, makes solid content and be 10% suspension.Above-mentioned suspension is proceeded in autoclave, setting mixing speed is 200 revs/min, hydrothermal temperature is 220 ℃, carry out hydrothermal modification 0.5h, by the slurries filtration after hydrothermal modification, and be that 1:10 washs 2 times by the mass ratio of filter cake and water, refilter, dry to obtain magnesium hydroxide content be 99.02%, Cl
-content be 10ppm, specific surface area is 5m
2the product of/g.
Embodiment 3
Under normal temperature, in reactor, add 2400g water, 200g magnesia, and the 600g98% vitriol oil is slowly added in reactor, 98% vitriol oil drop rate is 20g/min, after 98% vitriol oil dropwises, acid hydrolysis solution is placed in to water bath with thermostatic control, in 90 ℃ of insulated and stirred reaction 2h.In feed liquid after insulation reaction, add 2g clorox, and add gradually magnesia, to regulate the pH value of feed liquid to reach 7, insulation is filtered, and obtains pure Adlerika.The Adlerika making is reconfigured as to the solution that concentration is 45g/L, gets 1L Adlerika, add the potassium hydroxide solution 383mL of 2mol/L, at 60 ℃, carry out precipitin reaction 1h.By the slurries filtration after precipitin reaction, washing, gained filter cake is put into aqueous solution dispersed with stirring, makes solid content and be 10% suspension.Above-mentioned suspension is proceeded in autoclave, and setting mixing speed is 100 revs/min, and hydrothermal temperature is 170 ℃, carry out hydrothermal modification 4h, and be that 1:10 washs 2 times by the mass ratio of filter cake and water, refilter, dry to obtain magnesium hydroxide content be 99.12%, Cl
-content be 15ppm, specific surface area is 10m
2the product of/g.
Embodiment 4
Under normal temperature, in reactor, add 3200g water, 200g magnesia, and the 500g98% vitriol oil is slowly added in reactor, 98% vitriol oil drop rate is 15g/min, after 98% vitriol oil dropwises, acid hydrolysis solution is placed in to water bath with thermostatic control, in 85 ℃ of insulated and stirred reaction 1.5h.In feed liquid after insulation reaction, add 4g hydrogen peroxide, and add gradually calcium hydroxide, to regulate the pH value of feed liquid to reach 7, insulation is filtered, and obtains pure Adlerika.The Adlerika making is reconfigured as to the solution that concentration is 30g/L, gets 2L Adlerika, add the sodium hydroxide solution 258mL of 4mol/L, at 70 ℃, carry out precipitin reaction 1.5h.By the slurries filtration after precipitin reaction, washing, gained filter cake is put into aqueous solution dispersed with stirring, makes solid content and be 10% suspension.Above-mentioned suspension is proceeded in autoclave, and setting mixing speed is 120 revs/min, and hydrothermal temperature is 200 ℃, carry out hydrothermal modification 6h, and be that 1:10 washs 2 times by the mass ratio of filter cake and water, refilter, dry to obtain magnesium hydroxide content be 99.24%, Cl
-content be 18ppm, specific surface area is 13m
2the product of/g.
Embodiment 5
Under normal temperature, in reactor, add 2000g water, 200g magnesia, and the 600g98% vitriol oil is slowly added in reactor, 98% vitriol oil drop rate is 15g/min, after 98% vitriol oil dropwises, acid hydrolysis solution is placed in to water bath with thermostatic control, in 85 ℃ of insulated and stirred reaction 1.5h.In feed liquid after insulation reaction, add 0.2g sodium peroxide, and add gradually sodium hydroxide, to regulate the pH value of feed liquid to reach 7.5, insulation is filtered, and obtains pure Adlerika.The Adlerika making is reconfigured as to the solution that concentration is 35g/L, gets 1L Adlerika, add the potassium hydroxide solution 292mL of 2mol/L, at 80 ℃, carry out precipitin reaction 1.5h.By the slurries filtration after precipitin reaction, washing, gained filter cake is put into aqueous solution dispersed with stirring, makes solid content and be 10% suspension.Above-mentioned suspension is proceeded in autoclave, and setting mixing speed is 160 revs/min, and hydrothermal temperature is 150 ℃, carry out hydrothermal modification 8h, and be that 1:10 washs 2 times by the mass ratio of filter cake and water, refilter, dry to obtain magnesium hydroxide content be 99.36%, Cl
-content be 16ppm, specific surface area is 12m
2the product of/g.
Embodiment 6
Under normal temperature, in reactor, add 2800g water, 200g magnesia, and the 700g98% vitriol oil is slowly added in reactor, 98% vitriol oil drop rate is 20g/min, after 98% vitriol oil dropwises, acid hydrolysis solution is placed in to water bath with thermostatic control, in 90 ℃ of insulated and stirred reaction 1h.In feed liquid after insulation reaction, add 2g clorox, and add gradually magnesia, to regulate the pH value of feed liquid to reach 6.5, insulation is filtered, and obtains pure Adlerika.The Adlerika making is reconfigured as to the solution that concentration is 50g/L, gets 2L Adlerika, add the sodium hydroxide solution 433mL of 4mol/L, at 80 ℃, carry out precipitin reaction 0.5h.By the slurries filtration after precipitin reaction, washing, gained filter cake is put into aqueous solution dispersed with stirring, makes solid content and be 10% suspension.Above-mentioned suspension is proceeded in autoclave, and setting mixing speed is 70 revs/min, and hydrothermal temperature is 160 ℃, carry out hydrothermal modification 2h, and be that 1:10 washs 2 times by the mass ratio of filter cake and water, refilter, dry to obtain magnesium hydroxide content be 99.18%, Cl
-content be 14ppm, specific surface area is 14m
2the product of/g.
Claims (7)
1. by magnesia, produce the method without chlorine flame retardant of magnesium hydroxide, comprise the steps:
(1) take magnesia as raw material, add water in reactor, magnesia, drips 98% vitriol oil and carries out acidolysis reaction;
(2) acid hydrolysis solution step (1) being obtained is placed in water bath with thermostatic control, in 80～95 ℃ of insulation reaction 0.5-3h;
(3) in the slurry obtaining in step (2), add oxygenant and neutralizing agent, regulating pH value is 6.5～7.5, and insulation is filtered, and obtains Adlerika;
(4) it is 10～60g/L that Adlerika step (3) being obtained is configured to concentration, adds alkaline precipitating agent, carries out precipitin reaction 0.5-2h at 20-95 ℃;
(5) by the slurries filtration after precipitin reaction, washing, gained filter cake is put into aqueous solution dispersed with stirring, makes solid content and be 10% suspension;
(6) suspension of being prepared by step (5) proceeds in autoclave, stirs, and hydrothermal temperature is 150-220 ℃, carries out hydrothermal modification 0.5-10h;
(7) by the slurries filtration after hydrothermal modification, and be 1:(1-10 by the mass ratio of filter cake and water) wash, refilter, dry obtaining without chlorine magnesium hydroxide.
2. the method for claim 1, is characterized in that the mass ratio 2.5～3.5:1.0 of 98% vitriol oil and magnesia in described step (1), the mass ratio 8～20:1.0 of water and magnesia.
3. the method for claim 1, is characterized in that the middle oxygenant of described step (3) is any in sodium peroxide, clorox, hydrogen peroxide; Neutralizing agent is any in calcium hydroxide, sodium hydroxide, magnesia.
4. the method for claim 1, is characterized in that the mass ratio of the middle oxygenant of described step (3) and raw material magnesia is 0.001～0.03:1.
5. the method for claim 1, is characterized in that the alkaline precipitating agent described in described step (4) is any in potassium hydroxide, sodium hydroxide.
6. the method for claim 1, is characterized in that the described excessive alkaline precipitating agent that adds of step (4).
7. the method for claim 1, is characterized in that in described step (6), mixing speed is 10～200 revs/min.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105984890A (en) * | 2015-02-26 | 2016-10-05 | 宝山钢铁股份有限公司 | Method for producing flame retardant grade magnesium hydrate from oriented silicon steel magnesium oxide waste |
| CN111017968A (en) * | 2019-12-27 | 2020-04-17 | 河北邢台冶金镁业有限公司 | Method for preparing pure magnesium sulfate by using light burned bitter soil as raw material without adding any impurity removing agent |
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| CN1884633A (en) * | 2006-05-31 | 2006-12-27 | 东北大学 | Method for magnesium hydroxide whisker using giobertite as material |
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2013
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105984890A (en) * | 2015-02-26 | 2016-10-05 | 宝山钢铁股份有限公司 | Method for producing flame retardant grade magnesium hydrate from oriented silicon steel magnesium oxide waste |
| CN105984890B (en) * | 2015-02-26 | 2017-11-28 | 宝山钢铁股份有限公司 | The method that orientation silicon steel magnesia discarded object produces flame-proof magnesium hydroxide |
| CN111017968A (en) * | 2019-12-27 | 2020-04-17 | 河北邢台冶金镁业有限公司 | Method for preparing pure magnesium sulfate by using light burned bitter soil as raw material without adding any impurity removing agent |
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Application publication date: 20140122 |