CN1193933C - Method for producing magnesium hydroxide and its aqueous suspension - Google Patents

Method for producing magnesium hydroxide and its aqueous suspension Download PDF

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Publication number
CN1193933C
CN1193933C CNB001353608A CN00135360A CN1193933C CN 1193933 C CN1193933 C CN 1193933C CN B001353608 A CNB001353608 A CN B001353608A CN 00135360 A CN00135360 A CN 00135360A CN 1193933 C CN1193933 C CN 1193933C
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magnesium hydroxide
water
magnesia
acid
hydration
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CN1309087A (en
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樋口胜
樋口彰彦
镰本实
河原久夫
清水江平
井上章
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DAICEL ABOSHI INDUSTRIAL Co Ltd
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DAICEL ABOSHI INDUSTRIAL Co Ltd
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Abstract

The present invention relates to a method for producing magnesium hydroxide and its aqueous suspension, calcined magnesia is subjected to dry mixing or dry kneading, while wetting 100 pts.wt. of the magnesia with <=25 pts.wt. (e.g. 0.1 to 20 pts.wt.) of water. Thereafter, the resulting magnesia is subjected to aging at 70 to 150 deg.C in the presence of 0.1 to 20 pts.wt. of water based on 100 pts.wt. of the hydration product, expressed in terms of its solid content, to produce granular magnesium hydroxide. Water in a vapor or liquid state can be added to magnesia, and also, a catalyst for accelerating the hydration reaction and a dispersant for improving dispersibility of the calcined magnesia are optionally added to the system used. Granular magnesium hydroxide can be simply and efficiently produced by hydrating magnesia, and accordingly, the storage cost, transfer cost and transportation cost of magnesium hydroxide are reduced.

Description

The manufacture method of magnesium hydroxide aqeous suspension
Female case of the present invention be submitted on August 11st, 1997, application number is 97117352.4, denomination of invention is divided an application for " preparation method's of magnesium hydroxide and aqeous suspension thereof ".
Technical field
The manufacture method of the powder shape magnesium hydroxide that the additive that the present invention relates to use as neutralizing agent and sweetening agent, fertilizer, heavy oil combustion, pulp cooking agent etc. are useful, the powder shape magnesium hydroxide that makes with this method and the manufacture method that contains the aqeous suspension of this magnesium hydroxide.
Background technology
The normal magnesium hydroxide that uses in the neutralization of stack desulfurization and waste water etc.Always, this magnesium hydroxide makes by making magnesium chloride and slaked lime reaction in the seawater.But this method is because the Mg content in the seawater is micro-, so manufacturing process's complexity, and although the concentration of hydrogeneous magnesian water paste is 30 (weight) %, it is full-bodied, therefore, is difficult to high densityization, and its manufacturing and transportation cost are also high.
On the other hand, make magnesium oxide hydration (digestion) also can obtain magnesium hydroxide, but slow because of its speed of response, must react at high temperature more than 100 ℃ with above under the non-pressurized high pressure with autoclave.In order to address this problem, open in the flat 3-252311 communique the spy and to propose magnisite burnt till and obtain the method for the hydration of light-burned magnesia, open in the flat 6-206722 communique the spy again and disclose, carrying out the case of wet attrition while in the presence of alkaline aqueous medium, light-burned magnesia is carried out the method for hydration.
In this method, when the occasion of use magnesium hydroxide aqeous suspension in stack desulfurization and waste water etc. and in the operation, carry out smoothly and efficient neutralizing treatment in order to make reaction, the particle diameter of magnesium hydroxide is diminished.Yet when particle diameter is little, the viscosity of slurry is just high; On the other hand, in order to reduce viscosity, the particle diameter that make magnesium hydroxide become big but in and efficient just low, generate throw out simultaneously easily.Moreover its viscosity of suspension that magnesium hydroxide concentration is high significantly rises, and is difficult to shift and transportation, and operability is also low.
The water paste that makes with aforesaid method shifts and the cost of conveying in order to lower, and removes a large amount of moisture content from this water paste, and it also is possible obtaining powder shape magnesium hydroxide.Yet,, in the hydration operation by above-mentioned light-burned magnesia in aqueous medium, from the water paste that generates, remove a large amount of moisture content operations and necessitate in order to obtain powder shape magnesium hydroxide.For this reason, the energy in a large number simultaneously, is difficult to easy and obtains powder shape magnesium hydroxide effectively.
And, because the ratio of magnesium hydroxide is great, so keep the dispersion stabilization of this aqeous suspension between being difficult to for a long time, just, when prolonged preservation magnesium hydroxide aqeous suspension, it is mobile poor, and throw out solidifies densely and generates the hard block thing that is difficult to redispersion.
For viscosity stability and the flowability that improves water paste, open in the flat 6-115930 communique the spy and to have announced, by magnesium hydroxide, anionic property macromolecule dispersing agent and mixing of water-soluble alkali metal salts and prepare the method for the water paste of magnesium hydroxide.Opening in the flat 6-191832 communique the spy and to disclose, is in the warm water solution of anion surfactant of principal constituent at an alkali metal salt that contains lipid acid, adds light-burned magnesia; Heat digestion simultaneously, thus the method for modulation sensitization magnesium hydroxide.In Czechoslovakia's patent 236626 communiques, also disclose, in the presence of tensio-active agent, made magnesia carry out the manufacture method of the magnesium hydroxide of hydration for improving speed of response.Yet in these methods,, also must from water paste, remove a large amount of moisture content in order to make powder shape magnesium hydroxide.And, be accompanied by removing of moisture content, water paste or high viscosityization, perhaps consolidated block and can not stirring, thus make that the lock out operation and the drying operation of powder shape (solid state) magnesium hydroxide are complicated.Therefore, to make powder shape magnesium hydroxide effectively in a large number be difficult industrial.
In the public clear 47-22942 communique of spy, disclose, when unslaked lime, magnesium oxide or their mixture are digested with digestion machine and water reaction, in order to promote water infiltration coarse fragment.Before the reaction beginning, make the decompression of digestion machine in advance and begin the digestion method that decompression operation is ended in the back in reaction.The concrete grammar of being put down in writing in the document is, injects 1.2 times water, 75 grams of theoretical amount in the coarse fragment of the 200 gram unslaked limes that reduce pressure in the digestion machine, ends decompression operation and digests.Yet in the method, not only decompression operation is necessary, and is applicable in the digestion of magnesia and can not stirs, and therefore, to make powder shape magnesium hydroxide effectively be difficult industrial.And when with light-burned magnesia etc. during as the magnesia source, the magnesia composition of remained unreacted is difficult to improve hydration rate.In addition, when the unreacted magnesia is residual, generate the hard block thing in the slurry of preserving, simultaneously, owing to condense, its redispersibility is just poor.
Summary of the invention
Therefore, the object of the invention is to provide a kind of method of simple and effective manufacturing powder shape magnesium hydroxide.
Another purpose of the present invention provides the method that a kind of simple and effective manufacturing has the powder shape magnesium hydroxide of hyperhydrated rate.
Another purpose of the present invention provides and is reducing preservation, useful powder shape magnesium hydroxide and manufacture method thereof on transfer and the transportation cost.
Still a further object of the present invention provides the method for preparing powder shape magnesium hydroxide from the solid magnesia with the hyperhydrated rate.
Another object of the present invention provides that to be used for preparing be powder shape and water dispersible and high useful powder shape magnesium hydroxide and the manufacture method thereof of water paste of storage stability.
Even still a further object of the present invention provides the generation that can suppress unreacted magnesia composition and generates the manufacture method that block also can improve the powder shape magnesium hydroxide of its redispersibility.
Still a further object of the present invention provides the method that can obtain the magnesium hydroxide aqeous suspension with easy operation.
The present inventor is research for achieving the above object and attentively, found that, in the presence of less water, when the powder shape magnesia that keeps flowability is carried out dry type mixing or dry grinding, produces hydration reaction expeditiously, generates powder shape magnesium hydroxide expeditiously; When this resultant was carried out slaking in the presence of moisture content, the powder shape magnesium hydroxide that hydration efficiency is greatly improved generated efficiently; When in dry type mixing system or dry grinding system, adding catalyzer and/or dispersion agent, can further improve hydration efficiency and water dispersible, thereby finish the present invention.
Embodiment
Just, in the inventive method, in the presence of moisture content, carry out hydration by dry type mixing or dry grinding and make powder shape magnesium hydroxide.In this method, also can in the presence of moisture content, carry out slaking after being preferably in hydration.The usage quantity of water with can guarantee dry type and mix or the dry grinding system in magnesia mobile and do not damage hydration reaction and be advisable.The inventive method is for example can (1) moistening with the following water of 25 weight parts with per 100 weight part magnesias; Magnesium oxide powder is carried out dry type mix or dry grinding, obtain powder shape magnesium hydroxide, also can (2) form continuous gas phase in the solid gap; Make the reaction of magnesia and water, and obtain magnesium hydroxide.
Can use light-burned magnesia as above-mentioned magnesia, its form can be that piece material, coarse crushing thing and micro mist mince.And in hydration systems or aging system, water can be by (1) gaseous state or liquid state; Perhaps by (2) aqueous slurry or moisture block and make an addition to magnesia or by dry type mix or the hydration resultant of dry grinding gained in.Hydration reaction also can be carried out having in the presence of catalyzer and/or the dispersion agent.
Slaking (also claiming afterreaction) can be undertaken by being incubated under (about 70-150 °) temperature more than 70 ℃ at (a), and (b) water-content can remain on being mixed or the hydration resultant of dry grinding gained is about the 0.1-20 weight part by dry type with per 100 weight parts of solid component meter in maturing process.
The present invention also provides the powder shape magnesium hydroxide with the aforesaid way gained.And, also comprise among the present invention, by the prepared powder shape of aforesaid method magnesium hydroxide is scattered in the water, to prepare the method for magnesium hydroxide aqeous suspension.Also can in the presence of dispersion agent, powder shape magnesium hydroxide be scattered in the aqueous medium in this method.
Also have, this specification sheets what is called " dry type is mixed or dry grinding " is meant: though contain moisture content, the powder body is mixed or grinding.Again, among powder granulous magnesium hydroxide manufacture method, " moisture content " in dry type mixing system or dry grinding system or the amount of " water " are not contain because moisture content and evaporation or the evaporable moisture content that reaction is consumed, it means it is the free-water deal that exists in the reactive system, and it is to raw material magnesia (weight) % content.
[magnesia]
Be not limited to the hard burned magnesia that natural product magnesite (periclasite) is at high temperature burnt till especially as above-mentioned magnesia used in the present invention, but mostly use be with natural product magnesite about temperature 550-1500 ℃, more fortunately about 650-1300 ℃, be more preferably the light-burned magnesia that about 800-1200 ℃, burns till.Use is burnt till the light-burned magnesia of gained in this temperature, can obtain the magnesium hydroxide (active hydrogen magnesium oxide) that its activity significantly improves.
Above-mentioned magnesia so long as may powderization just, there is no particular restriction, for example, magnesia can be by mixing or grinding and fragmentation or ground block (the not block of the light-burned magnesia of Fen Suiing), meal minces and micro mist minces.For example largest particle diameter 10-200mm (for example 10-100mm), average particulate diameter are the light-burned magnesia of 3～60mm (for example 3-40mm) scope as above-mentioned spendable block, particle diameter as the coarse crushing thing mainly is that for example the largest particle diameter is 0.1-10mm (for example 0.5-10mm) scope, and average particulate diameter is 0.1-3mm (a for example 0.5-3mm scope).And, mince as micro mist and can use largest particle diameter 1-3000 μ m (being preferably 1-1000mm, for example the 40-100 mu m range), the light-burned magnesia of average particulate diameter 1-300 μ m (for example 10-70 μ m) scope.
In light-burned magnesia preferably, contain by coarse crushing gained powder body and block, powder body (for example below its largest particle diameter 3000 μ m, average particulate diameter 0.1-300 μ m, better be 1-200 μ m, be more preferably the powder body of 2-200 μ m).
[dry type hydration]
In the presence of water, the hydration by dry type mixing or dry grinding is with preparation powder shape magnesium hydroxide with above-mentioned magnesia.Just, feature of the present invention is: add moisture content to dry type mixing system or dry grinding system in not damaging mobile scope, the water-content of reactive system is maintained in the specified range; And make the magnesia hydration.For this reason, among the present invention, water-content all has a significant impact for the even flowability and the hydration reaction of married operation or grinding operation and magnesia.
In reaction process, the water-content of being kept in reactive system is advisable not damage dry type mixing or grinding, its flowability and hydration reaction, for example the magnesia for 100 weight parts adds (but in fact not comprising 0) below 25 weight parts, better 0.1-20 weight part scope (as 0.2～15 weight part), under 0.2-10 weight part, most of situation, be the scope of 0.3～15 weight part (as 0.4～7.5 weight part) better.When the water-content of per 100 weight part magnesias is surpassed 25 weight parts, then mix and stirs just difficulty, be difficult in uniform mixing system or grinding system, generating magnesium hydroxide expeditiously.Also have, be accompanied by the carrying out of reaction and generate magnesium hydroxide, the magnesia amount reduces, so above-mentioned water-content is the amount with respect to the raw material magnesia as described above.
Moreover, when water-content less than 10 weight parts of reactive system in per 100 weight part magnesias, then can keep mixing uniformly or stirring system,, form wet mixing or stirring system along with the increase of water-content, when surpassing 25 weight parts, the stirring power of mixing or stirring system increases sharp, is easy to produce and rolls the sound that makes a sound, simultaneously, on agitating vane and wall, be difficult to carry out hydration reaction equably.And, when adding excessive moisture content, mix or stirring system becomes pulpous state, not that dry type is mixed or dry grinding system and always the hydration reaction of becoming.
Based on a spot of like this water is present in the reactive system, can in the gap of solid magnesia, form continuous gas phase; And make the reaction of magnesia and water and carry out hydration.Just, in the inventive method, the filling morphology of powder body, liquids and gases is mixed in following three kinds of modes or is ground and react: (a) gentle mutually continuously, almost non-existent (Dry) state of doing of liquid phase of solid phase; (b) solid phase is gentle mutually continuously and the discontinuous swing of liquid phase (Pendular) state; (c) solid phase, gas phase and liquid phase successive rope-1 (FunicularI) state.Such filling morphology from apparent be to constitute dry or the mixing (mixing) that parches or (mulling) system of grinding (" mixing mix technology) " second edition, Japanese powder industry can compile Nikkan Kogyo Shimbun's distribution on April 30th, 1986)., when using this mixing or grinding system, can mix equably or grind for this reason, but install also summary with little stirring power; Simultaneously because grain refined due to grinding, because of spheroidizing due to the moisture content, can make the even particle size distributionization of the magnesium hydroxide that is generated.
As long as the moisture content amount in reactive system is remained in the above-mentioned scope, water can be supplied with or interpolation magnesia by gaseous state (steam) or liquid (drop etc.).Because water is with splashing into and method such as spraying, to mixing or grinding system can be continuously or supply in turn; Also can supply with discontinuously.Moreover water is that additional form is supplied with because hydration reaction consumes moisture content mostly.The supply of water becomes according to temperature of reaction, but normally per 100 weight part magnesias supply with the 10-100 weight part/hour, better be the 20-80 weight part/hour, be more preferably the 25-75 weight part/hour.Also have, the measured value that the adjustment of water-content is not only surveyed by aquametry apparatus also can be adjusted based on being accompanied by the stirring power value that mixes or grind.
And, water also can be from the moisture content that coexists as the concurrent (slurry and block etc.) in the reactive system, for example, under above-mentioned magnesia and the situation to non-reacted water paste of water and block (for example water paste and the block of magnesium chloride in the seawater and slaked lime reaction gained magnesium hydroxide (seawater magnesia)) coexistence, the water that is consumed in the above-mentioned magnesia reaction also can be from water paste and block in reaction system.During with such slurry and block supply or interpolation moisture content, can make reactive system be easy to form evenly.And, all wts once can be added slurry and block; Also can add continuously or discontinuously.The water ratio of slurry and block there is no specific limited, for example, 10-90 (weight) %, better is 20-80 (weight) % scope.In this method, can also can carry out the drying of slurry and block simultaneously with the moisture content in slurry and the block by removing with the reaction of magnesia.
The use total amount of water is according to variations such as the composition of magnesia and ratio thereof, magnesian content, purity, and usually per 100 weight part magnesias use the 40-55 weight part, better are the 41-55 weight parts, are more preferably 43-52 weight part scope.
Above-mentioned hydration reaction can be carried out under the suitable condition that does not damage the reaction of magnesia and water, and for example, temperature can better be 50-130 ℃ (for example, 60-120 ℃) at 30-150 ℃, is more preferably under 70-110 ℃ (80-110 ℃) and carries out.Temperature of reaction is as being lower than 30 ℃, and then hydration reaction speed is slow; As surpassing 150 ℃, then thermolysis takes place in part sometimes, and hydration rate descends.Again, reaction pressure be for example the 1-10 normal atmosphere, better be the 1-5 normal atmosphere, be more preferably the 1-2 normal atmosphere, also can react smoothly at normal pressure.Moreover temperature of reaction can be used conventional process for example indirect heating and cooling and control.
[catalyzer]
Above-mentioned hydration reaction also can successfully be carried out in the presence of the catalyzer not having, but for the promoting digestion reaction, should carry out dry type mixing or dry grinding in the presence of catalyzer.Catalyzer also can directly add in the magnesia; Also can be used as mixed solution interpolation with water.Again, usually, the catalyzer (acetate etc.) that gasifies under water-soluble catalyst (acetate, magnesium acetate etc.) and the temperature of reaction is general as using with the mixed solution of water.
In above-mentioned catalyzer, for example contain habitual acid or its salt: (A) organic acid and salt thereof; (B) acid phosphoric acid ester or acid sulfate or their salt; (C) mineral acid or its salt and (D) alkali metal hydroxide.
In above-mentioned (A) organic acid, contain organic acid of (A1) simple function and the organic acid that (A2) has 2 above functional groups.
(A1) organic acid of simple function has for example aliphatics monocarboxylic acids (for example, the aliphatics monocarboxylic acid of 1-4 carbon atom) such as formic acid, acetate, propionic acid, butyric acid, isopropylformic acid, valeric acid, vinylformic acid, Ba Dousuan; The halogenation aliphatics monocarboxylic acid (for example, the halogenation aliphatics monocarboxylic acid of 1-4 carbon atom) of Monochloro Acetic Acid, dichloro acetic acid, trichoroacetic acid(TCA) etc.; Encircle penta carboxylic acid, ester ring type carboxylic acids such as cyclohexane carboxylic (for example, the ester ring type monocarboxylic acid of 4-10 carbon atom); Phenylformic acid, aromatic series monocarboxylic acids such as toluic acid (for example, the aromatic series monocarboxylic acid of 7-15 carbon atom); The alkylsulphonic acid (for example, the alkylsulphonic acid of 1-10 carbon atom) of methylsulfonic acid, trifluoromethanesulfonic acid, ethyl sulfonic acid etc.; Phenylsulfonic acid, the aryl sulfonic acid of tosic acid, naphthene sulfonic acid etc. (for example, the aryl sulfonic acid of 6-20 carbon atom) etc.
The monocarboxylic acid that in gratifying (A1) simple function carboxylic acid, contains representative examples of saturated aliphatic, the aliphatic monocarboxylic acid of halogenation.Alkylsulphonic acid, aryl sulfonic acid etc.Preferably water-soluble monocarboxylic acid (for example, the aliphatics monocarboxylic acid of the carbon atom of the 1-4 with halogen atom of formic acid, acetate, Monochloro Acetic Acid, dichloro acetic acid, propionic acid, butyric acid etc.), particularly preferably be the aliphatics monocarboxylic acid (particularly acetate etc.) of 1-3 carbon atom with halogen atom.
(A2) have and be included in the functional group that also has when having a carboxyl at least more than 1 in the organic acid of 2 above functional groups () organic acid for example: carboxyl, hydroxyl, sulfydryl, alkoxyl group, alkyl thio-base, carbonyl, thiocarbonyl, amino, amide group, cyano group etc., the big multipotency of this organic acid forms inner complex.
The organic acid example that above-mentioned (A2) has 2 above functional groups has, for example polycarboxylic acid, hydroxycarboxylic acid, alkoxyl group carboxylic acid, oxo carboxylic acid, aminocarboxylic acid etc.
As for example having of polycarboxylic acid: propanedioic acid, succsinic acid, hexanodioic acid, aliphatics polycarboxylic acids such as toxilic acid are (for example: the aliphatics polycarboxylic acid of 2-12 carbon atom); Aromatic series such as phthalic acid, iso-phthalic acid polycarboxylic acid (for example: the aromatic series polycarboxylic acid of 8-15 carbon atom).Comprise propanedioic acid, the aliphatics polycarboxylic acid of 2-8 such as a hexanodioic acid carbon atom (particularly dicarboxylic acid) in the preferred polycarboxylic acid; Carbonatomss such as phthalic acid are the aromatic series polycarboxylic acid (particularly dicarboxylic acid) of 8-12 etc.
As for example having of hydroxycarboxylic acid: the aliphatic hydroxyl carboxylic acid (for example: carbonatoms is the aliphatic hydroxyl carboxylic acid of 2-12) of oxyacetic acid, lactic acid, R-Glyceric acid, oxysuccinic acid, tartrate, citric acid, glyconic acid etc.; Whitfield's ointment, the aromatic hydroxy-carboxylic of gallamic acid etc. (for example: carbonatoms is the aromatic hydroxy-carboxylic of 7-15) etc.Comprise tartrate in the preferred hydroxycarboxylic acid, glyconic acid etc. have the hydroxycarboxylic acid (for example: the carbonatoms with 2-6 hydroxyl is the aliphatic hydroxyl carboxylic acid of 2-12) of 2 above hydroxyls etc.
In the alkoxyl group carboxylic acid, for example comprise: aliphatics such as methoxyacetic acid, ethoxyacetic acid, anisic acid or aromatic alkoxyl group carboxylic acid (for example: carbonatoms is the alkoxyl group carboxylic acid of 2-15) etc.For example have in oxo carboxylic acid: carbonatomss such as oxoethanoic acid, pyruvic acid, etheric acid, oxaloacetic acid are 2-12, and preferably carbonatoms is the oxo carboxylic acid of 2-10.For example have in the aminocarboxylic acid that carbonatomss such as glycine, L-Ala, leucine, L-glutamic acid, ethylenediamine tetraacetic acid (EDTA) are 2-15, be preferably the aminocarboxylic acid that carbonatoms is 2-10.
(B) for example have in acid phosphoric acid ester: monoethyl phosphate, diethyl phosphoric acid, mono phosphoric acid ester butyl ester, mono phosphoric acid ester dodecyl ester, carbonatomss such as phosphoric acid one phenylester, phytinic acid are 1-15, preferably carbonatoms is the monobasic of 1-10 or polynary acid phosphoric acid ester etc.In preferred phosphoric acid ester, contain polynary acid phosphoric acid esters such as phytinic acid.(B) carbonatomss such as methyl sulfate, Ethyl Sulfate, sulfuric acid mono, sulfuric acid list dodecyl ester being arranged in the acid sulfate is 1-15, monobasic that preferred carbonatoms is 1-10 or polynary acid sulfate etc.The big multipotency of polynary acid phosphoric acid ester or polynary acid sulfate forms inner complex.
In above-mentioned (C) mineral acid for example hydrochloric acid is arranged, hypochlorous acid, bromine hydracid, sulfuric acid, sulfurous acid, thionamic acid, nitric acid.Nitrous acid, phosphoric acid, phosphorous acid, Tripyrophosphoric acid (for example, tetra-sodium, triphosphoric acid, three METHAPHOSPHORIC ACID, tetramethyl phosphoric acid etc.), carbonic acid etc.In these mineral acids, generally use hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, carbonic acid etc.; The mineral acid (tripolyphosphate etc.) that Tripyrophosphoric acid etc. can form inner complex also uses.
Salt as above-mentioned acid has: an alkali metal salts such as lithium salts, sodium salt, sylvite; Alkaline earth salt such as magnesium salts, calcium salt; The metal-salt of periodictable 3-15 family (for example; The metal-salt, particularly zinc etc. of periodictable such as manganese, zinc 7 families or 12 families); The salt of ammonia, amine (for example: Trimethylamine 99, triethylamine, diethanolamine, trolamine, dimethylaminoethanol, morpholine etc.) or alkaline nitrogen-containing heterocycle compound (pyridine etc.) etc.
Preferably have in (A) organic acid salt: an alkali metal salt of sodium etc. (for example: monocarboxylic acid an alkali metal salts such as sodium acetate; Hydroxycarboxylic acid an alkali metal salts such as gluconic acid sodium salt; The aminocarboxylic acid an alkali metal salts of disodium ethylene diamine tetraacetate etc. etc.), the alkali earth metal salt of magnesium salts etc. (for example: the monocarboxylic acid alkali earth metal salt of magnesium acetate etc.; Hydroxycarboxylic acid alkali earth metal salts such as magnesium tartrate etc.) etc.
Also have, preferred (C) inorganic acid salt has: sodium-chlor, Repone K, Sodium Bromide.Alkali metal halides such as Potassium Bromide; The alkaline-earth metal halogenide of calcium chloride, magnesium chloride, magnesium bromide etc.; The ammonium halide of ammonium chloride, brometo de amonio etc.; Sodium sulfate, the alkali metal sulfates of vitriolate of tartar etc.; Alkaline-earth metal vitriol such as sal epsom; The ferric sulfate of ferric sulphate etc.; Tai-Ace S 150; Zinc sulfate; Ammonium sulfate; Basic metal sulfurous acid (hydrogen) salt of sodium bisulfite, S-WAT, Potassium hydrogen sulfite etc.; Alkaline-earth metal sulfurous acid (hydrogen) salt of calcium bisulfite, magnesium bisulfite etc.; The alkaline-earth metal nitrate of alkali-metal nitrate such as SODIUMNITRATE, saltpetre, nitrocalcite, magnesium nitrate etc.; The iron nitrate of nitric acid high ferro etc.; Aluminum nitrate; Zinc nitrate; Ammonium nitrate; The alkali metal phosphate of sodium phosphate, potassiumphosphate etc.; Alkaline-earth metal phosphoric acid salt such as trimagnesium phosphate; Ammonium phosphate; The alkali metal polyphosphates of trisodium phosphate, tripoly phosphate sodium STPP, Potassium tripolyphosphate etc.; The alkaline-earth metal polyphosphate of magnesium pyrophosphate, tripolyphosphate magnesium etc.; Basic metal carbonic acid (hydrogen) salt such as yellow soda ash, sodium bicarbonate, salt of wormwood; The alkaline earth metals carbonate of magnesiumcarbonate etc. etc.
Have in the alkali metal hydroxide of above-mentioned (D): lithium hydroxide, sodium hydroxide, potassium hydroxide etc., preferred alkali metal hydroxide is a sodium hydroxide.
In addition,, it seems, use for example organic acid or its salt (particularly acetate and salt thereof) and alkali metal hydroxide usually from the viewpoint of industry, economy etc. as catalyzer.When organic acid and alkali metal hydroxide used together, also available organic acid an alkali metal salt (for example sodium acetate etc.) replaced above-mentioned two kinds of compositions.
These catalyzer can use separately.Also can be of the same race more than two kinds or xenogeneic is sour or salt is used in combination.Sometimes be used in combination above-mentioned more than two kinds acid or improve hydration rate during salt significantly.For example: will be selected from (1) (A1) organic acid or its salt of simple function; (2) organic acid or its salt of 2 above functional groups (A2) are arranged; (B) acid phosphoric acid ester or acid sulfate or their salt; And (C) the composition combination in mineral acid or its salt and when using as catalyzer, not only can promote hydration reaction, and when making the magnesium hydroxide slurry, also can suppress the high viscosityization of suspension in the water paste, simultaneously, the redispersibility of the block of generation also can improve.
In addition, use at least a and (D) alkali metal hydroxide combination in the above-mentioned sour composition (A)-(C), when perhaps using an alkali metal salt of (A)-(C) dispersiveness of powder shape magnesium hydroxide in water improved; Simultaneously, can prevent the consolidated block of slurry.
The usage quantity of catalyzer can be according to the kind of employed catalyzer, can keep that dry type is mixed or the broad range of dry grinding system in select, for example per 100 weight part magnesias are the 0.01-20 weight part normally, 0.1-15 weight part preferably, be more preferably about 0.5-10 weight part, general many at about 1-15 weight part (particularly 2-15 weight part).Along with the increase of catalyzer usage quantity, though be that dry type is mixed or the dry grinding system, its hydration rate also can be greatly improved.Again, along with the raising of hydration rate, the dispersion stabilization that the powder shape magnesium hydroxide that generated is scattered in the water also improves, and the cake mass that generates is soft and be easy to redispersion.
In addition, when using when a plurality of catalyst components of combination, the ratio of each catalyst component will suitably be selected.For example (A1) simple function organic acid composition, (2) (A2) have an organic acid composition of 2 above functional groups by (1); (B) acid phosphoric acid ester or acid sulfate composition; And (C) when selected various compositions are used in combination in the mineral acid composition, the usage quantity of above-mentioned (A1) organic acid composition is for for example, per 100 weight part magnesias are 0.01-15 weight part (better preferred 0.02-10 weight parts, be more preferably the 0.05-5 weight part), above-mentioned (A2), (B) and (C) in the usage quantity of selected composition for example be, per 100 weight part magnesias are that the 0.01-15 weight part (better is the 0.02-10 weight part, is more preferably the 0.05-5 weight part.
[dispersion agent]
The inventive method also can be in the presence of dispersion agent, carries out dry type mixing or dry grinding and generates magnesium hydroxide from magnesia.
Dispersion agent is no matter molecular surface active agent or polymeric surface active agent all can use.In low-molecular-weight surfactant, have: fatty acid alkali metal salt (carbonatoms is metal alkylide salt, ammonium salt, amine salt of the higher fatty acid of 10-30 etc.), alkylbenzene sulfonate.Alpha-olefin sulphonate, sucrose fatty ester etc.Preferred dispersing agent is a polymeric surface active agent, when using polymeric surface active agent, when making powder shape magnesium hydroxide form water paste, keeps high dispersion stability and storage stability; Even the magnesium hydroxide aqeous suspension of high density also can lowering viscousity.
The molecular weight of polymeric surface active agent is for example 1 * 10 3More than (for example 1 * 10 3-1 * 10 6), preferably 1 * 10 3-1 * 10 5, be more preferably 2 * 10 3-1 * 10 5The polymerization degree of selection polymeric surface active agent will be in the flowability without detriment to the magnesium hydroxide aqeous suspension.Under the dispersed condition, for example the viscosity of pbz polymer tensio-active agent 1 (weight) the % aqueous solution under 25 ℃ is 1.2-1000cps (centipoise), preferably 1.5-500cps, be more preferably about 1.8-200cps.
Comprise anion surfactant and nonionogenic tenside in the above-mentioned polymeric surface active agent.For example have as anion surfactant: 1. have the polymeric carboxylic of carboxyl or the carboxylic acid type anion surfactant of its salt at intramolecularly; 2. intramolecularly has the sulfonic acid type anion surfactant of sulfonic macromolecule sulfonic acid or its salt; 3. intramolecularly has the acid polymer sulfuric ester of acid sulfate base or the sulfuric acid type anion surfactant of its salt; 4. intramolecularly has the phosphatic type anion surfactant of polymer phosphoric acid, polymer phosphorous acid or their salt of acid phosphatase ester group or acid phosphorous acid ester group.Also have the acidic groups of above-mentioned carboxylic acid, sulfonic group, acid sulfate base, acid phosphatase ester group, acid phosphorous acid ester group etc. or their salt, abbreviate " anionic property base " as.
1. the carboxylic acid type anion surfactant comprises synthetic macromolecule carboxylic acid and natural or semi-synthetic polymeric carboxylic.As above-mentioned synthetic macromolecule carboxylic acid for example unsaturated carboxylic acid or its salt such as vinylformic acid, methacrylic acid, toxilic acid, fumaric acid, methylene-succinic acid, Ba Dousuan are arranged; Perhaps use homopolymer and the multipolymer of acid anhydrides as monomer component.
But for example have: (methyl) acrylate of (methyl) methyl acrylate, (methyl) ethyl propenoate, (methyl) propyl acrylate, (methyl) butyl acrylate, (methyl) Octyl acrylate, (methyl) propylene ester 2-(ethyl hexyl) ester etc. as polymerizable monomer with the unsaturated carboxylic acid copolymerization; The styrenic monomers of vinylbenzene, Vinyl toluene, alpha-methyl styrene etc.; The vinyl ester of vinyl acetate, vinyl propionate etc. is a monomer; The monomer of vinyl ether such as methylvinylether, ethyl vinyl ether, propyl vinyl ether, isopropyl-ethylene base ether, butyl vinyl ether, IVE system etc.
Concrete example as the synthetic macromolecule carboxylic acid for example has: polyacrylic acid, polymethyl acrylic acid, (methyl) acrylate-(methyl) acrylic copolymer, vinyl ether-copolymers of unsaturated carboxylic acids are (for example: butyl vinyl ether-Maleic Acid, Anhydrous multipolymer etc.), poly-Ba Dousuan, vinylbenzene-(methyl) acrylic copolymer, vinylbenzene-Maleic Acid, Anhydrous multipolymer etc.
The acid number of above-mentioned synthetic macromolecule carboxylic acid in the water-soluble scope that has is, 30-800KOHmg/g for example is preferably about 50-500KOHmg/g.
As having of above-mentioned natural or semi-synthetic polymeric carboxylic: alginic acid, carboxymethyl cellulose, hydroxyl carboxymethyl cellulose, carboxymethylated starch, gum arabic, tragacanth gum, pectin, hyaluronic acid glue etc. have the polyose of carboxyl etc.
2. for example having as the sulfonic acid type anion surfactant: beta-naphthalenesulfonic-acid formaldehyde condensation compound, trimeric cyanamide sulfonic formaldehyde condensation compound, triazine sulfonic formaldehyde condensation compound, polyvinyl sulfonic acid, polystyrolsulfon acid, lignosulfonic acid etc.
3. as the having of sulfuric acid type anion surfactant, for example, sulfation polyvinyl alcohol, sulfate cellulose, OK a karaoke club Ji Nan (カ ラ ギ-Na Application), agar, chondroitin sulphuric acid etc.4. for example having in the phosphatic type anion surfactant: phosphoric acid polyvinyl alcohol, phosphorylated cotton, phosphorous acid Mierocrystalline cellulose etc.
Also have, above-mentioned anion surfactant can be used as salt and uses.For example have as salt: an alkali metal salts such as sodium salt, sylvite; Alkali earth metal salts such as magnesium salts, calcium salt, barium salt; The metal-salt of periodictables such as zinc salt 12 families; The salt of ammonia, amine (Trimethylamine 99, triethylamine, diethanolamine, trolamine, Deanol, morpholine etc.) or alkaline nitrogen-containing heterocycle compound (pyridine etc.); The quaternary ammonium salt of Tetrylammonium, tri methyl benzyl ammonium etc. etc.Salt is the salt of an alkali metal salt, ammonia or amine, above-mentioned quaternary ammonium salt etc. preferably.When intramolecularly had a plurality of acidic groups, the counterion of each acidic groups can be identical, also can be different.
In above-mentioned anion surfactant, anion surfactant of carboxylic acid type, sulfonic acid type, sulfuric acid type etc. preferably, particularly, carboxylic acid type anion surfactant (natural or semi-synthetic polymeric carboxylic or their salt that the polyose with carboxyl etc. of carboxymethyl cellulose, alginic acid etc. is wherein also arranged) has high lowering viscousity effect to water paste.Again, sulfonic acid type anion surfactant and sulfuric acid type anion surfactant also have the effect of the hardization that suppresses the block that generates when preserving the magnesium hydroxide water paste over a long time when having above-mentioned lowering viscousity effect.
Above-mentioned anion surfactant has an anionic property base at least at intramolecularly, is preferably the polyanion polymeric surface active agent of above-mentioned anionic property base more than 2 (for example 2-10000, better be 4-1000).When intramolecularly had a plurality of anionic property base, above-mentioned anionic property base can be identical, also can be different.
For example have as above-mentioned nonionogenic tenside: the affixture of affixture, fatty acid cane sugar ester and the oxyethane of alkyl polyoxyethylene ether, alkyl phenyl Soxylat A 25-7, alkyl-carbonyl oxo polyoxyethylene, polyol esters of fatty acids and oxyethane etc., polyoxyethylene block copolymer etc.In nonionogenic tenside, polyoxyethylene block copolymer (ethylene oxide-propylene oxide block copolymer etc.) is big to the lowering viscousity effect of water paste.
These dispersion agents can be used in combination by one or two or more kinds, also can be used in combination polymeric surface active agent and low molecular weight surfactants.When particularly above-mentioned 1. carboxylic acid type anion surfactant and above-mentioned 2. sulfonic acid type or sulfuric acid type anion surfactant being used in combination, can not only have high dispersion stability and can have storage stability water paste, owing to prolonged preservation generates sedimentary block, the block that is generated also is soft, be easy to redispersion with vibration, stirring etc., redispersibility is significantly improved.
The usage quantity of dispersion agent is 0.001-15 weight parts to the magnesia of per 100 weight parts, and preferably the 0.005-10 weight part is more preferably the 0.01-5 weight part, generally uses the 0.03-2.5 weight part (for example: the scope 0.05-2 weight part).
Will be 1. carboxylic acid type anion surfactant and 2. sulfonic acid type or when 3. the sulfuric acid type anion surfactant makes up, both ratios be for example the former/latter=0.1-20 (weight ratio), 0.5-15 (weight ratio) preferably is more preferably the scope of 1-10 (weight ratio).
Moreover, when the magnesium hydroxide content concn height in water paste, for example: during 65 weight % above (65-75 weight %), add the paucidisperse agent and can not make the water paste viscosity degradation.In this case, the magnesium hydroxide that the content of above-mentioned dispersion agent, particularly polymeric surface active agent is preferably per 100 weight parts is the 1-10 weight part, better is the 3-10 weight part, is more preferably 5-10 weight part scope.
Dry type is mixed or dry grinding can use the mixing machine of stirrer and kneading machine, pressurization kneader, the muller of interior mixing machine (banbury mixers) etc., in addition, can utilize habitual digestion machine, for example: spiral, Ke Laicier (Kritzer) formula, Sha Fuer (Schaffer) formula, overflow type, Stuart class grace formula (Startband), Wo Musi but your (Warmestelle) formula, Anthony Heald (Schilde) formula, be subjected to normal pressures digestion machines such as upright uncommon (Erich) formula, kennedy (Kennedy) formula; Woodville (Woodville) formula, Cauer pine (Corson) formula.The pressurization digestion machine of lucky damp lime formula etc. etc.
[slaking]
In the inventive method, by above-mentioned dry type mixing or dry grinding and after the hydration, also the hydration resultant that is generated can be carried out slaking in the presence of moisture content.Owing to adopt this curing step, when can further improve hydration rate, also be soft even in water paste, generate block, and the redispersibility height of this block.Therefore, when as required its compressed moulding, as fertilizer sources etc. being utilized, its crumbliness is improved.Just, when using light-burned magnesia and magnesia source, reason such as inhomogeneous owing to raw material and firing condition, also there is the magnesia composition that has little time hydration reaction, even this magnesia composition mixes through dry type or dry grinding still as the unreacted magnesia and residual, it becomes to improving the obstacle of hydration rate.Again, mix or during the water paste of the hydration resultant that dry grinding generated when preserving through dry type, sometimes generate the hard block thing, because agglomerative is former thereby redispersibility is reduced, to this, when will be because of dry type is mixed or dry grinding generated hydration resultant slaking, unreacted magnesia composition be just almost no longer residual, just can address the above problem.
Slaking is to carry out in the presence of moisture content, the moisture content amount that maturing process is in reactive system to be kept is with under the hydration reaction condition of not damaging above-mentioned hydration resultant, carry out that dry type same as described above is mixed or dry grinding to keep the having powder shape form of flowability or the scope of wet system is advisable.Water-content in the maturing process is with solid component meter, per 100 weight parts mix or the hydration resultant of dry grinding (for example: the 0.1-25 weight part), 0.1-20 weight part preferably is below 25 weight parts through dry type, be more preferably the 0.5-15 weight part, particularly 1-15 weight part (especially 5-12 weight part) scope.
Moreover, identical with the hydration of above-mentioned dry type mixing or dry grinding, above-mentioned moisture content also can derive from the moisture content of the concurrent (slurry and block etc.) that coexists in aging system, just, to coexist by above-mentioned dry type is mixed and dry grinding is generated hydration resultant with to nonreactive water paste of water and block (for example :) in the aging system, in the presence of the moisture content of water paste and block, carry out slaking by the water paste and the block of magnesium chloride in the seawater and slaked lime reaction gained magnesium hydroxide (seawater magnesium oxide).When using this slurry and block slaking, form uniform aging system easily.Mix identical with above-mentioned dry type with dry grinding.Slurry and block can all be measured once and to add, also serially or the compartment of terrain add, there is no particular restriction to the water ratio of slurry and block, for example 10-90 (weight) %, preferably in 20-80 (weight) the % scope.In this method, the moisture content in slurry and the block is removed by reacting with unreacted magnesia composition, also can carry out the drying of slurry and block simultaneously.
Slaking can by under the temperature that does not hinder hydration reaction for example more than 70 ℃ (for example, 70-150 ℃, particularly 75-150 ℃), be incubated under preferably 80-120 ℃ (for example: 90-120 ℃) scope, again, with the initial stage temperature of slaking (for example: 70-90 ℃ of scope) compare, (for example: 90-120 ℃ of scope) also be fine improve latter temperature.
Curing time can preferably be selected in the scope of 1-48 hour degree according to curing temperature etc. from for example 1-60 hour.
Can supply with or add by gaseous state (steam) or liquid (drop etc.) magnesia moisture content, also available splash into and method such as spraying is supplied with continuously or one by one also can be supplied with discontinuously.Again, moisture content also replenishes because the moisture content amount that hydration reaction consumed is supplied with serially or on schedule.
As required, slaking also can mix with above-mentioned dry type or dry grinding carries out simultaneously.Again, slaking also can be added in above-mentioned hydration resultant under the situation of catalyzer and/or dispersion agent and carries out.The usage quantity of catalyzer and dispersion agent can suitably be selected from above-mentioned scope.
Slaking can above-mentioned dry type mix or the dry grinding system in carry out, the mixing tank that also can use non-style of opening is (for example: the steel basin that cooling tube is arranged) and container (for example autoclave) and carrying out.
After this slaking operation, as required, a small amount of remaining moisture content can be removed, just can obtain powder granulous magnesium hydroxide.
[magnesium hydroxide]
The powder shape magnesium hydroxide that makes like this can make it have suitable particle diameter and size-grade distribution by purposes, and its median size for example is: 0.1-1000 μ m (for example 1-1000 μ m), and preferably 2-100 μ m (for example 3-75 μ m) (for example is more preferably 3-30 μ m; 5-20 μ m) scope.In size-grade distribution, magnesium hydroxide is not limited to single size-grade distribution peak, and the size-grade distribution peak more than 2 is arranged.
The hydration rate of the powder shape magnesium hydroxide that is generated (for example: be 85-100% 85-100%), better, be more preferably the 90-100% scope is generally 80-100 by reaction conditions etc. and decide.The powder shape magnesium hydroxide that is generated is the water dispersible height not only, and compares its storage property with water paste always, and conveying property and transitivity are all high.Therefore, powder shape magnesium hydroxide can be easy to carry out water pasteization at the scene with the such simple operations of mixed/stirred, of great use, can realize that cost reduces significantly simultaneously in the modulation water paste.Particularly, the powder shape magnesium hydroxide that hydration rate is high, for example, hydration rate is the powder shape magnesium hydroxide of 90-100% (preferably 92-100%) scope, even be modulated into non-dispersant water paste, also can present high dispersion stabilization, simultaneously, even the generation block is also redispersible with simple operations such as vibration, stirrings.
In addition, contain above-mentioned dispersant system or do not contain in the dispersant system, through dry type mixing or dry grinding, when carrying out slaking on demand, the also available dispersion agent of the powder shape magnesium hydroxide that is generated is handled; In the presence of dispersion agent, the powder shape magnesium hydroxide that is generated can be scattered in the water.In processing or the dispersion, the usage quantity of dispersion agent can suitably be selected from the scope that is equivalent to the total usage quantity of above-mentioned dispersion agent like this.
Gained powder shape magnesium hydroxide, can pulverize as required, granulation, screening and the operation sequence of classification etc., therefore, of many uses, for example can suitably be used for neutralization, stack desulfurization, fertilizer, and as combustion additive, the pulp cooking agent of heavy oil, the additive of plastics additive, tinting material, preparation etc.Powder granulous magnesium hydroxide also can be used in the fertilizer that is configured as tablet etc., as purposes such as neutralizing agents, utilizes it high-dispersedly to can be used for modulating water paste (aqeous suspension).
[magnesium hydroxide aqeous suspension]
Powder shape magnesium hydroxide is scattered in adjustable hydrogen manufacturing magnesium oxide aqeous suspension in the aqueous medium.With powder shape magnesium hydroxide as described above, also can in the presence of no dispersion agent, be scattered in the aqueous medium, but, when in the presence of above-mentioned dispersion agent is arranged, being scattered in powder shape magnesium hydroxide in the water, can obtain the high water paste of dispersion stabilization (aqeous suspension) really.
To powder shape magnesium hydroxide, there is no particular restriction for the interpolation order of water and dispersion agent, for example, in the aqeous suspension of magnesium hydroxide, can add dispersion agent (preferably polymeric surface active agent), in powder shape magnesium hydroxide, also can add the mixed solution of water and dispersion agent; Add water again after also powder shape magnesium hydroxide can being handled with dispersion agent; And, also mentioned component can be mixed simultaneously and magnesium hydroxide is scattered in the water.Above-mentioned dispersion, mixing can be undertaken by conventional processes such as stirring, vibration, ultrasonic irradiations.
Above-mentioned dispersion, married operation also can be forced to stir to powder shape magnesium hydroxide under shear action.Under force stirring, disperse, during mixing,, also be easy to make the block redispersion but pass through restir because the prolonged preservation of gained magnesium hydroxide aqeous suspension makes its solids component and water sepn.And, forcing dispersion under the stirring, mix the gained aqeous suspension and have the concentration height but the low characteristic of viscosity.Particularly, when using the polymeric surface active agent as dispersion agent, can suppress the rising of viscosity and the generation of hard block thing, though can obtain preserving the magnesium hydroxide aqeous suspension that also can be easy to redispersion between can be long-term.
Above-mentioned pressure is stirred can use various mixing and blending machines, and the rotation number of the stirrer with agitating vane is increased; Perhaps carry out methods such as strong shear action carries out with stirrers such as homogenizer and super mixing machines.Circumferential speed in force stirring is for example more than 300m/ minute, preferably 350-5000m/ minute scope.Churning time can be selected according to the mode of circumferential speed and mixing and stirring system, and for example, circumferential speed is more than 30 minutes when being 400m/ minute, preferably more than 1 hour, is more preferably 2-20 hour scope; When circumferential speed was 1000m/ minute, (better being 5 minutes-1 hour scope) was just much of that more than 3 minutes.
Because powder shape magnesium hydroxide is dispersed high, the content of the magnesium hydroxide in aqeous suspension can be selected in broad range, 10-85 (weight) % (for example 15-80 (weight) %) for example, better be 30-75 (weight) % (for example 35-70 (weight) %), be more preferably 35-70 (weight) % scope.
The magnesium hydroxide aqeous suspension of gained has the high and high density of dispersion stabilization but viscosity is hanged down such characteristic like this.Therefore, can reduce transportation storage cost significantly by high densityization.Again, because the flowability of water paste is also high, so the storage of slurry, operability such as the logical conveying of pipe improve.And, because dispersion stabilization and dilution stability height, so can modulate the magnesium hydroxide aqeous suspension of desired concentration easily.
Moreover the viscosity of magnesium hydroxide aqeous suspension under 25 ℃ is 5-2500cps for example, better is 10-2000cps, is more preferably the 20-1500cps scope.
Among the present invention, mix or dry grinding, carry out the such simple operations of slaking in case of necessity keeping predetermined water-content to carry out dry type simultaneously, can be easy and make powder shape magnesium hydroxide efficiently.In addition, owing to can obtain magnesium hydroxide, reduce the cost of preserving, shifting and carry with the powder shape.And, use simple operations as described above, just can be from the solid magnesia with hyperhydrated efficiency system amyloplastid shape magnesium hydroxide.And, owing to suppress the generation of unreacted magnesia composition,, also can improve redispersibility though generate block.Moreover the property height even powder shape moisture content looses can make water paste (aqeous suspension) so powder shape magnesium hydroxide is scattered in simple operations such in the water.
The present invention is described in more detail by the following examples.
Viscosity in an embodiment is the value shown in the time of 25 ℃, and " % " represents with (weight) %.
" hydration rate " measured with following method, just, with test portion (magnesium hydroxide) after being dried to constant under 150 ℃, make micro mist broken with mortar, burn till at 600 ℃ with electric furnace, up to constant, from trying to achieve the magnesium hydroxide amount, calculate hydration rate again because of weight due to burning till reduces.
" in and time " is with pulverizing, and screening is added in the 200 gram 2N-sulfuric acid, up to reaching the required time of pH6 by 200 purpose test portions, 12.70 grams.
Moreover the mensuration of " water-content " is carried out according to stirring power (galvanometric pin extent of vibration) in the reactive system.Just, try to achieve water-content and stir relation between the power with pilot study, when galvanometric pin did not vibrate, water-content was in 15 (weight) below the %; When galvanometric pin has some when vibration, water-content is in 18 (weight) below the %; When rheometer vibrated, water-content was 25 (weight) %, utilizes this to concern to come the water-content of assaying reaction system.
" water-content " of reactive system can be surveyed its weight by behind the test portion chilling stopped reaction that reactive system is got, and with methyl alcohol it cleaned, at 150 ℃ of dry back gravimetries.Calculate and draw by the weight minimizing.
" dried up rate " is that suspension is put into cylindrical container up to predetermined height, places after 6 days, and isolating water layer height is to the ratio (%) of total height.
" block state " is with container vibration 50 times, presses following benchmark evaluation:
Excellent: cake mass is soft, and all blocks are all redispersible;
Very: cake mass is soft, only deposits not dispersive block slightly at container bottom;
Can: cake mass is soft, at container bottom not dispersive block is arranged on a small quantity;
Can not: cake mass is hard, at container bottom not dispersive block is arranged in a large number.
Embodiment 1
Use the kneader (internal capacity 3L) of stainless steel, this kneader, there are 2 Z type agitating vanes in portion, at an upper portion thereof two dropping funnels are housed within it, the chuck of reflux cooler and thermometer, light-burned magnesia (by 330 mesh sieve holes) 1000 grams are added in this kneader, 60 ℃ of heating down.Light-burned magnesia is stirred under 75rpm, with 500 gram water, divide in 6 hours, to splash into for 6 times with above-mentioned two dropping funnels., began through 45 minutes the time from splashing in 18 (weight) below the % at this water-content that splashes into the reactive system in the process, temperature rises to 75 ℃ in it, and top temperature reaches 87 ℃.After dripping termination, continue 1 hour postcooling of heating, the water-content that obtains the goods benchmark is 4.4%, the magnesium hydroxide of hydration rate 79.7%.
Embodiment 2
Except replacing the light-burned magnesia (by 330 mesh sieve holes) with light-burned magnesia (by 120 mesh sieve holes), to react with quadrat method by embodiment 1, temperature of reaction is up to 78 ℃.The water-content that obtains the goods benchmark is 4.8%, and hydration rate is 83.1% magnesium hydroxide.
Embodiment 3
Light-burned magnesia (by 120 mesh sieve holes) 1000 is restrained under 85 ℃ of stirrings, the mixing solutions of 20 gram acetate and 480 gram water was splashed in 1 hour, restir 2 hours, in addition all react by embodiment 1 same procedure, the water-content that obtains the goods benchmark is 5.5%, hydration rate is 99.5% magnesium hydroxide, also have, at the water-content of the reactive system of the process of dropping in 15 (weight) below the %.Gained powder shape magnesium hydroxide is scattered in the water, when being modulated into the aqeous suspension of 50 (weight) %, its viscosity is 65cps (being 130cps after 6 days), pH9.9, dried up rate 3%, generates block hardly, again, aqeous suspension used in and the time be 110 seconds.
Embodiment 4
Light-burned magnesia (by 350 mesh sieve holes) 1000 is restrained under 75 ℃ of stirrings, the mixing solutions of 30 gram acetate and 470 gram water was splashed into during 2 hours, restir 1 hour, in addition all react by embodiment 1 same procedure, the water-content that obtains the goods benchmark is 7.7%, the magnesium hydroxide of hydration rate 89.7%, again, the reactive system water-content in the dropping process is in 15 (weight) below the %.
Embodiment 5
Light-burned magnesia (by 120 mesh sieve holes) 1000 is restrained under 88 ℃ of stirrings, the mixing solutions of 50 gram acetate and 450 gram water was dripped during 1 hour, restir 1 hour, in addition all react by embodiment 1 same procedure, the water-content that obtains the goods benchmark is 2.2%, the magnesium hydroxide of hydration rate 99.4%.Again, the water-content of the reactive system in the process of splashing into is in 15 (weight) below the %.
The powder shape magnesium hydroxide of gained is scattered in the water, and when being modulated into the aqeous suspension of 50 (weight) %, its viscosity 13000cps (37500cps after 6 days), pH9.9, dried up rate are 0%, do not generate block.Again, gained powder shape magnesium hydroxide is scattered in the water, when being modulated into the aqeous suspension of 37 (weight) %, its viscosity is 240cps (1600cps after 6 days), pH9.8, dried up rate 6.8%, does not generate block.
Embodiment 6
Light-burned magnesia (by 330 mesh sieve holes) 1000 is restrained under 86 ℃ of stirrings, the mixing solutions of 50 gram acetate and 450 gram water was splashed into during 1 hour, restir 1 hour, in addition all react by embodiment 1 same procedure, the water-content that obtains the goods benchmark is 3.5%, hydration rate is 96.1% magnesium hydroxide, again, the water-content of the reactive system in the process of splashing into is in 15 (weight) below the %.
Gained powder shape magnesium hydroxide is scattered in the water, and when being modulated into 50 (weight) % aqeous suspension, its viscosity 11000cps (29000cps after 6 days), pH9.9, dried up rate are 0%, do not generate block.Again, gained powder shape magnesium hydroxide is scattered in the water, when being modulated to the aqeous suspension of 37 (weight) %, its viscosity 220cps (840cps after 6 days), pH9.9, dried up rate are 5.5, do not generate the cake block.
Embodiment 7
Except light-burned magnesia (by 330 mesh sieve holes) 1000 is restrained under 88 ℃ of stirrings, the mixing solutions of 120 gram acetate and 400 gram water was splashed in 1 hour semiduation, beyond the restir 1 hour half, all react by embodiment 1 same procedure, obtain the magnesium hydroxide of water-content 5.3%, hydration rate 96.8%, again, the water-content of the reactive system in the process of splashing into is in 15 (weight) below the %.
Embodiment 8
Except light-burned magnesia (by 330 mesh sieve holes) 1000 is restrained under 96 ℃ of stirrings, the mixing solutions of 50 gram sodium hydroxide and 500 gram water was splashed in 1 hour 30 minute phase, outside the restir 3 hours 30 minutes, all react by embodiment 1 same procedure, make the water-content 5.6% of goods benchmark, the magnesium hydroxide of hydration rate 88.0, again, the water-content of the reactive system in the process of splashing into is in 18 (weight) below the %.
Embodiment 9
Except light-burned magnesia (by 330 mesh sieve holes) 1000 is restrained under 90 ℃ of stirrings, the mixing solutions of 10 gram sulfuric acid and 500 gram water was splashed in 1 hour 30 minute phase, beyond the restir 2 hours 30 minutes, all react by embodiment 1 same procedure, obtain the water-content 5.9% of goods benchmark, the magnesium hydroxide of hydration rate 84.5%, again, the water-content of the reactive system in the process of splashing into is in 18 (weight) below the %.
Gained powder shape magnesium hydroxide is scattered in the water, and when being modulated into 50 (weight) % aqeous suspension, its viscosity is that 35cps (35cps after six days), pH are 11.2.
Embodiment 10
Except light-burned magnesia (by 330 mesh sieve holes) 1000 is restrained under 85 ℃ of stirrings, with 75.3 gram magnesium acetates. the mixing solutions of four Heshuis and 475 gram water splashed into during 2 hours, outside the restir 1 hour, all react by embodiment 1 same procedure, obtain the water-content 5.6% of goods benchmark, the magnesium hydroxide of hydration rate 94.2%, again, the water-content of the reactive system in the process of splashing into is in 15 (weight) below the %.
Gained powder shape magnesium hydroxide is scattered in the water, and when being modulated into the aqueous suspensions of 50 (weight) %, its viscosity 7000cps (88000cps after 6 days), pH are 10.0, dried up rate is 0%, do not generate block.Again, gained powder shape magnesium hydroxide is scattered in the water, when being modulated into the water suspending agent of 37 (weight) %, its viscosity 660cps (1140cps after 6 days), pH are 9.9, dried up rate 4.2%, do not generate block.
Embodiment 11
Except light-burned magnesia (by 330 mesh sieve holes) 1000 grams are stirred down at 84 ℃, with 10 gram acetate, 1 gram sodium polyacrylate (trade(brand)name Polymast-D-45, Bai Dong KCC system, 1% viscosity: 3cps) mixing solutionss with 500 gram water splashed into during three hours, beyond the restir 1 hour, all react by embodiment 1 same procedure, the water-content that obtains the goods benchmark is 5.7%, and hydration rate is 96.2% magnesium hydroxide.Again, the water-content in the reactive system in the process of splashing into is in 15 (weight) below the %.
Embodiment 12
Except light-burned magnesia (by 120 mesh sieve holes) 1000 is restrained under 80 ℃ of stirrings, with 10 sodium hydroxide, 1 gram Xylo-Mucine (trade(brand)name CMC1120, Dicel chemical industrial company system, 1% viscosity: 11cps) and the mixing solutions of 500 gram water, divide five times, splash at bihorium, restir all reacts by embodiment 1 same procedure beyond 3 hours 30 minutes, the water-content 5.0%, the hydration rate that obtain the goods benchmark are 89.0% magnesium hydroxide, again, the water-content of the reactive system in the process of splashing into is that 15 (weight) are below the %.
Embodiment 13
Use has two opening for feeds, and the drying machine of chuck and 4 agitating vanes (internal capacity is 200L), vacuum pump also are docile and obedient the cyclonic separator that preface inserts, the device of bag filter and condenser.In above-mentioned drying machine, add light-burned magnesia (by 120 mesh sieve holes) 50kg, 40 ℃ heat after, when light-burned magnesia is stirred, to contain 1kg acetic acid water solution 25kg added during 30 minutes, the water-content that is determined at the reactive system in this interpolation process is that 5.0 (weight) are below the %, though top temperature reaches 101 ℃, does not generate the acetate stink.After above-mentioned acetic acid aqueous solution added, will remain moisture content and take out, the water 3.2kg that obtains discharging with vacuum pump.The water-content of gained magnesium hydroxide 68.5kg (goods benchmark) is 3.4%, hydration rate 95.9%.
Gained powder shape magnesium hydroxide is scattered in the water, and when being modulated into 50 (weight) % aqeous suspension, its viscosity 7800cps (6700cps after 6 days), pH9.9, dried up rate are 0%, do not generate block.Again, gained powder shape magnesium hydroxide is scattered in the water, when being modulated into the aqeous suspension of 37 (weight) %, its viscosity is that 520cps (being 1960cps after 6 days), pH9.9, dried up rate are 1.5%, does not generate block.
Embodiment 14
The about 10kg usefulness of water paste (slurry concentration is 35 (weight) %) of the magnesium hydroxide that will be obtained by the reaction of the magnesium chloride in the seawater and slaked lime has the suction filter filtration under diminished pressure of filter paper (5A), obtain the block (A) of magnesium hydroxide, the water content of this block (A) is 39.2 (weight) %, hydration rate 93.3%.
Use the kneader among the embodiment 1, and make moisture content in the block (A) and the reaction of light-burned magnesia and obtain Powdered magnesium hydroxide.In kneader, add light-burned magnesia (by 120 mesh sieve holes) 887 grams and grind, during 45 minutes, add the block (A) that a little is added with 25.6 gram acetate in advance, when adding block (A) in the time of about 30 minutes, internal temperature surpasses 100 ℃, and seeing has water vapour to take place.After adding end of a period, continue to grind after 1 hour, cool to room temperature obtains loose Powdered magnesium hydroxide (water-content of goods benchmark is 0.9 (weight) %, hydration rate 93.3%) again.
Embodiment 15
Except the block (A) with the foregoing description 14 unclamps, place in the air at room temperature, make its water evaporates, obtaining water-content is the block (B) of 29.5 (weight) %.Use 1000 gram these blocks (B), 23.3 gram acetate, 636 gram light-burned magnesias (by 120 mesh sieve holes), all react by embodiment 14 same procedure, the top temperature of reaction reaches 80 ℃.The water-content of the goods benchmark of the Powdered magnesium hydroxide that gained is loose is 7.6 (weight) %, hydration rate 89.0%.
Add 292.8 gram water in gained magnesium hydroxide 200 grams, stir down, adjust to pH13.1, obtain the aqeous suspension of 37.5 (weight) % with sodium hydroxide.The viscosity of this aqeous suspension after one day is that 670cps (being 680cps after 6 days), the dried up rate after 6 days are 14.7%, generates block hardly.Again, this suspension used in and the time be 60 seconds.
Comparative example 1
Except that 500g water once added, other reacted by embodiment 1 same procedure, began through after 10 minutes from interpolation, and internal temperature rises to 63 ℃, chugs simultaneously.On wall, agitating vane, there is mixture to adhere to again, generates block simultaneously, so that can not stir.In addition, the water-content of the top layer part of block be 0.6%, hydration rate 63.9%.
Embodiment 16
In being equipped with mixing machine rotation mixer, liquid distributor, that concrete mortar is used (inner capacities is 90 liters), add light-burned magnesia (by 330 mesh sieve holes, below be referred to as light-burned magnesia A), 30kg, stir down, spray 3 liters in 9 liters of 3.3 (weight) %NaOH aqueous solution that are heated to 80 ℃.Owing to after reaction heat makes internal temperature reach 80 ℃ (after 40 minutes), during about 20 minutes remaining 6 liters of NaOH solution are slowly sprayed, mixing system is carried out the dry type mixing or is ground under wet condition again.Owing to hot gas is sent in reaction, the temperature of content reaches 160 ℃, and, during 40 minutes, 6.7 liters in the water that is heated to 80 ℃ is added with spray pattern, finish in reaction beginning its reaction in back 2 hours, its internal temperature is 85 ℃.Being mixed or the water-content that grinds the resultant of reaction that is generated is about 5 (weight) % by dry type, when the hydration rate of assaying reaction resultant, is 86.8%.
Take out a part of resultant of reaction, by following mode slaking.The water that in resultant of reaction, adds 80 ℃, so that its water-content is adjusted to 10 (weight) %, in insulation still (80 ℃), place after 16 hours, again water-content is adjusted to 10 (weight) %, 95 ℃ heated 6 hours after, residual moisture content is removed with the drying machine evaporation, and the moisture content of the powder shape magnesium hydroxide that generates is 0.8 (weight) %, and hydration rate is 92.5%.Moreover, in the insulating process in the insulation still,, reaction heat reaches (80-110 ℃ of degree) more than 80 ℃ owing to making temperature, and in 95 ℃ heat-processed, temperature is 95-105 ℃.Again, in above-mentioned light-burned magnesia A the amount of the possible effective constituent of hydration (magnesium oxide and calcium oxide) being arranged is 94.4%.For this reason, substantial hydration rate (correction value) is 98.0% (92.5/94.4 * 100) after the slaking.The magnesium hydroxide of gained, with the pulverizer that 0.2mm φ sieve is housed (Nara's formula pulverizer, the M-4 type) pulverizes, adjust to by behind the 100 purpose particles, be dispersed in the water, be modulated to 37.5% aqeous suspension, the pH of aqeous suspension is 11.8, viscosity after 6 days is 20cps, dried up rate 45%, and block is in good condition.
With homogenizer above-mentioned aqeous suspension was handled 5 minutes under 800rpm, the characteristic of gained aqeous suspension is again: pH is that the viscosity after 11.8,6 days is 24cps, and dried up rate is 51%, and the state of block is " excellent ".The results are shown in table 1.
Embodiment 17
Other is identical with embodiment 16 except not carrying out slaking operation, and the resultant of reaction pulverizing being generated through dry type mixing or grinding is modulated into aqeous suspension, and the pH of this aqeous suspension is that the viscosity after 12.1,6 days is 22cps, and is dried up from being 50%.And, the state of block be " can not ".
Embodiment 18-embodiment 37
Use following material, carry out dry type by embodiment 16 same procedure and mix or dry grinding, the slaking of hydration resultant.
[by the dry type hydration due to dry type mixing or the dry grinding]
1. light-burned magnesia
A: by 330 mesh sieve holes, the possible active constituent content of hydration is 94.4%
B: maximum diameter is 3mm, and mean diameter is 800 μ m, and the possible effective one-tenth content of hydration is 95.5%
2. additive
NaOH:3.3 (weight) the % aqueous solution
CMC: sodium carboxymethyl-cellulose (CMC1120, Dai Saier chemical industrial company system, 1% viscosity: 0.2 (weight) % aqueous solution 11cps)
Acetate: 4.0 (weight) % aqueous solution
[curing step]
Acetate: 4.0 (weight) % aqueous solution
CMC: sodium carboxymethyl-cellulose (CMC1120 Dai Saier chemical industrial company system, 1% viscosity: 1.0 (weight) % aqueous solution 11cps)
Acid S-WAT: 4.0 (weight) % aqueous solution
Sodium polyacrylate: polyacrylic acid yellow soda ash (Polymast-D-45, Bai Dong KCC system, 1% viscosity: 2.0 (weight) % aqueous solution 3cps)
Seawater magnesia block; The about 10kg of water paste (slurry concentration is 35 (weight) %) of magnesium chloride in the seawater and slaked lime reaction gained magnesium hydroxide is used the block (water-content 39.2 (weight) %, hydration rate 93.3%) of the suction filter filtration under diminished pressure gained magnesium hydroxide that has filter paper (5A)
Moreover, in curing step, when slaking begins, water-content is adjusted to 10 weight %, insulation is after 16 hours, with additive all addings in heating of predetermined amount in the insulation still.Moisture content when heating is at beginning and every 10 (weight) % that was adjusted to through 6 hours thereafter of heating.
Again, in embodiment 35, use used mixing tank in the foregoing description 16, in curing step, will stir by hydrated reactant and the seawater magnesia block that dry type is mixed or dry grinding generated; In the seawater magnesia moisture content in the presence of, slaking under preset temperature obtains Powdered magnesium hydroxide.In the curing step of using this seawater magnesia block, with hydrated reactant 41.6kg (the solids component 40kg that dry type is mixed or dry grinding generated, moisture content 1.6kg) and seawater magnesia block 8.8kg (solids component 5.4kg, moisture content 3.4kg) mixes (water content 10 (weight) %), 80 ℃ of following slakings 16 hours, at slaking thing of gained 2000 grams (solids component 1970 grams, moisture content 30 grams) add seawater magnesia block 582 grams (solids component 354 grams in, moisture content 228 grams), make water-content remain on 10 (weight) %, 95 ℃ of slakings 6 hours, again at gained post cure thing 2100 grams (solids component 2029 grams, moisture content 71 grams) add seawater magnesia block 476 grams (solids component 289 grams in, moisture content 87 grams), water-content is adjusted to 10 (weight) %, 95 ℃ of following slakings 6 hours.
Again gained powder shape magnesium hydroxide is scattered in the water, is modulated into 37.5% aqeous suspension.Measured the characteristic that has and do not have the aqeous suspension of homogenizer (8000rpm, 5 minutes) processing.
The results are shown in table 1-table 5.
From table as can be known, because slaking can improve hydration rate greatly, make the block softening simultaneously, the redispersibility of block also improves.
Table 1
Embodiment 16 Embodiment 18 Embodiment 19 Embodiment 20 Embodiment 21
The kind of raw material magnesia A (330 order) A (330 order) A (330 order) A (330 order) B (3mm)
Water inventory (part)/magnesia (100 parts) 52 50 50 50 47
The kind of additive NaOH CMC CMC CMC NaOH
Addition (part)/magnesia (100 parts) 0.1 0.01 0.01 0.01 0.1
Water-content after the hydration (%) 4.7 0.4 0.4 0.4 4.3
The hydration rate of dry type hydration (%) 86.8 86.9 86.9 86.9 85.8
More than 80 ℃, after the slaking in 16 hours, at the curing time more than 90 ℃ (hr) 6 6 6 6 6
Water-content in the hydration resultant (%) 10 10 10 10 10
The kind of additive - - Acetate Acetate -
Addition (part)/hydrated reactant (100 parts) - - 0.1 0.2 -
Water-content after the slaking (%) 0.8 0.8 0.6 0.6 0.8
Hydration rate after the slaking (%) 92.5 92.2 93.6 94.0 95.7
Calibrated hydration rate (%) 98.0 97.7 99.2 99.6 100.2
Water paste Homogenizer is handled Do not have Do not have Do not have Do not have Do not have
pH 11.8 10.8 10.3 9.6 11.9
Viscosity after 1 day (cps) 15 10 8 7 9
Viscosity after 6 days (cps) 16 10 7 7 10
Dried up rate (%) 46 48 49 45 46
The block state Very Very Very Very Excellent
Water paste Homogenizer is handled Have Have Have Have Have
pH 11.8 10.7 10.2 9.6 11.9
Viscosity after 1 day (cps) 24 14 13 11 18
Viscosity after 6 days (cps) 31 14 13 11 22
Dried up rate (%) 51 52 53 48 45
The block state Excellent Can Can Very Excellent
Table 2
Embodiment 22 Embodiment 23 Embodiment 24 Embodiment 25 Embodiment 26
The kind of raw material magnesia B (3mm) B (3mm) B (3mm) A (330 order) A (330 order)
Water inventory (part)/magnesia (100 parts) 47 50 50 47 47
The kind of additive NaOH - - - -
Addition (part)/magnesia (100 parts) 0.1 - - - -
Water-content after the hydration (%) 4.3 4.9 4.9 4.6 4.6
The hydration rate of dry type hydration (%) 85.8 74.5 74.5 63.0 63.0
More than 80 ℃, after the slaking in 16 hours, at the curing time more than 90 ℃ (hr) 6 12 12 18 18
Water-content in the hydration resultant (%) 10 10 10 10 10
The kind of additive CMC - CMC - Acetate
Addition (part)/hydrated reactant (100 parts) 0.01 - 0.01 - 0.1
Water-content after the slaking (%) 0.5 1.0 0.7 0.7 1.0
Hydration rate after the slaking (%) 95.1 94.6 96.3 89.4 92.1
Calibrated hydration rate (%) 99.6 99.0 100.8 94.7 97.6
Water paste Homogenizer is handled Do not have Do not have Do not have Do not have Do not have
pH 11.9 10.8 10.5 10.7 10.1
Viscosity after 1 day (cps) 9 25 63 8 16
Viscosity after 6 days (cps) 9 25 70 13 16
Dried up rate (%) 47 40 32 50 47
The block state Excellent Excellent Excellent Very Excellent
Water paste Homogenizer is handled Have Have Have Have Have
pH 11.8 10.7 10.5 10.7 10.1
Viscosity after 1 day (cps) 21 41 63 8 16
Viscosity after 6 days (cps) 24 45 70 13 16
Dried up rate (%) 48 48 32 50 47
The block state Excellent Excellent Excellent Very Excellent
Table 3
Embodiment 27 Embodiment 28 Embodiment 29 Embodiment 30 Embodiment 31
Kind water-content (part) magnesia (100 parts) of raw material magnesia A (330 order) 47 A (330 order) 47 A (330 order) 47 A (330 order) 47 B (3mm) 53
The kind of additive - - - - NaOH
Addition (part)/magnesia (100 parts) - - - - 0.1
Water-content after the hydration (%) 4.6 4.6 4.6 4.6 4.2
The hydration rate of dry type hydration (%) 63.0 63.0 63.0 63.0 77.6
More than 80 ℃, after the slaking in 16 hours, at the curing time more than 90 ℃ (hr) 18 18 18 18 12
Water-content in the hydration resultant (%) 10 10 10 10 10
The kind of additive NaOH NaOH Acid S-WAT Acid S-WAT -
Addition (part)/hydrated reactant (100 parts) 0.1 0.2 0.1 0.2 -
Water-content after the slaking (%) 1.0 1.0 0.6 0.7 0.5
Hydration rate after the slaking (%) 87.9 88.0 90.0 90.0 98.2
Calibrated hydration rate (%) 93.1 93.2 95.3 95.3 102.8
Water paste Homogenizer is handled Do not have - Do not have - Do not have
pH 11.1 11.9 10.6 10.2 12.5
Viscosity after 1 day (cps) 8 9 9 7 203
Viscosity after 6 days (cps) 11 8 11 8 203
Dried up rate (%) 51 44 53 46 30
The block state Can Very - Excellent Excellent
Water paste Homogenizer is handled Have Have Have Have Have
pH 11.1 11.8 10.6 10.2 12.5
Viscosity after 1 day (cps) 8 14 9 13 200
Viscosity after 6 days (cps) 11 15 11 14 200
Dried up rate (%) 51 50 53 51 30
The block state Can Very - Very Excellent
Table 4
Embodiment 32 Embodiment 33 Embodiment 34 Embodiment 35
The kind of raw material magnesia A (330 order) A (330 order) B (3mm) B (3mm)
Water-content (part)/magnesia (100 parts) 53 53 50 50
The kind of additive NaOH NaOH - -
Addition (part)/magnesia (100 parts) 0.1 0.1 - -
Water-content after the hydration (%) 3.1 3.1 4.9 4.9
The hydration rate of dry type hydration (%) 64.9 64.9 74.5 74.5
More than 80 ℃, after the slaking in 16 hours, at the curing time more than 90 ℃ (hr) 18 18 12 12
Water-content in the hydration resultant (%) 10 10 10 10
The kind of additive - Sodium polyacrylate Sodium polyacrylate Seawater magnesia block
Addition (part)/hydrated reactant (100 parts) - 0.02 0.02 55.0
Water-content after the slaking (%) 0.6 0.9 0.7 0.7
Hydration rate after the slaking (%) 93.4 92.7 97.1 93.3
Calibrated hydration rate (%) 97.8 97.1 101.6 98.0
Water paste Homogenizer is handled Do not have Do not have Do not have Do not have
pH 12.1 12.3 10.7 11.0
Viscosity after 1 day (cps) 62 28 34 55
Viscosity after 6 days (cps) 81 33 28 63
Dried up rate (%) 28 40 40 28
The block state Excellent Excellent Excellent Very
Water paste Homogenizer is handled Have Have Have Have
pH 12.1 12.2 10.6 10.9
Viscosity after 1 day (cps) 62 48 58 176
Viscosity after 6 days (cps) 81 66 60 184
Dried up rate (%) 28 37 33 25
The block state Excellent Excellent Excellent Excellent
Table 5
Embodiment 36 Embodiment 37
The kind of raw material magnesia A (330 order) B(3mm)
Water-content (part)/magnesia (100 parts) 48 48
The kind of additive Acetate Acetate
Addition (part)/magnesia (100 parts) 0.01 0.01
Reaction times 1.5 1.5
Be up to Da Wendu (℃) 120 130
Water-content after the hydration (%) 4.1 3.5
The hydration rate of dry type hydration (%) 89.3 90.8
More than 80 ℃, after the slaking in 16 hours, at the curing time more than 90 ℃ (hr) 6 6
Water-content in the hydration resultant (%) 10 10
The kind of additive - -
Addition (part)/hydrated reactant (100 parts) - -
Water-content after the slaking (%) 0.3 0.2
Hydration rate after the slaking (%) 92.4 96.8
Calibrated hydration rate (%) 97.9 101.3
Water paste Homogenizer is handled Do not have Do not have
pH 10.3 10.4
Viscosity after 1 day (cps) 12 12
Viscosity after 6 days (cps) 14 14
Dried up rate (%) 45 42
The block state Excellent Excellent

Claims (16)

1. the manufacture method of magnesium hydroxide aqeous suspension, it is characterized in that, in hydro-combination process, magnesia to per 100 weight parts, total usage quantity of water is the 40-55 weight part, in the presence of moisture, magnesia is carried out dry type mixing or dry grinding and makes hydration, thereby generate powder shape magnesium hydroxide, the magnesium hydroxide of the gained ratio with 10-85% weight is scattered in the water.
2. according to the manufacture method of the described magnesium hydroxide aqeous suspension of claim 1, it is characterized in that, after the magnesia hydration, further in the presence of moisture content, carry out slaking.
3. according to the manufacture method of the described magnesium hydroxide aqeous suspension of claim 1, it is characterized in that, moistening continuously to per 100 weight part magnesias with the water of 0.1-25 weight part, and the magnesium oxide powder plastochondria is carried out dry type mix or dry grinding.
4. according to the manufacture method of the described magnesium hydroxide aqeous suspension of claim 1, it is characterized in that, make to form continuous gas phase in the solid gap, and make magnesia and water reaction.
5. according to the manufacture method of the described magnesium hydroxide aqeous suspension of claim 1, it is characterized in that described magnesia is light-burned magnesia.
6. according to the manufacture method of the described magnesium hydroxide aqeous suspension of claim 1, it is characterized in that magnesia is that bulk, coarse crushing thing or micro mist mince.
7. according to the manufacture method of claim 1 or 2 described magnesium hydroxide aqeous suspensioies, it is characterized in that, thus mix at magnesia or by dry type or dry grinding gained hydration resultant in add gaseous state or liquid water carries out hydration or slaking.
8. according to the manufacture method of the described magnesium hydroxide aqeous suspension of claim 1, it is characterized in that,, in dry type mixing system or dry grinding system, add water the water yield of per 100 weight part magnesias maintenance 0.1-20 weight part.
9. according to the manufacture method of the described magnesium hydroxide aqeous suspension of claim 1, it is characterized in that, make under temperature 30-150 ℃ and pressure 1-10 normal atmosphere and react.
10. according to the manufacture method of the described magnesium hydroxide aqeous suspension of claim 1, it is characterized in that, in the presence of catalyzer, carry out dry type and mix or dry grinding.
11. the manufacture method according to the described magnesium hydroxide aqeous suspension of claim 10 is characterized in that, the magnesia of per 100 weight parts is used the catalyzer of 0.01-20 weight part.
12. the manufacture method according to the described magnesium hydroxide aqeous suspension of claim 1 is characterized in that, carries out dry type and mix or dry grinding in the presence of dispersion agent.
13. the manufacture method of described according to Claim 8 magnesium hydroxide aqeous suspension is characterized in that, the light-burned magnesia of per 100 weight parts is kept the water-content of 0.2-15 weight part, and light-burned magnesia is carried out dry type mixing or dry grinding and carries out hydration.
14. the manufacture method according to the described magnesium hydroxide aqeous suspension of claim 2 is characterized in that, insulation is so that slaking under 70-150 ℃ of temperature.
15. the manufacture method according to the described magnesium hydroxide aqeous suspension of claim 2 is characterized in that, to being mixed or dry grinding gained hydration resultant keeps the water-content of 0.1-20 weight part by dry type of per 100 weight parts of solid component meter, and carries out slaking.
16. the manufacture method according to the described magnesium hydroxide aqeous suspension of claim 1 is characterized in that, in the presence of dispersion agent, powder shape magnesium hydroxide is scattered in the water.
CNB001353608A 1996-08-12 1997-08-11 Method for producing magnesium hydroxide and its aqueous suspension Expired - Fee Related CN1193933C (en)

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JP4745713B2 (en) * 2005-04-28 2011-08-10 タテホ化学工業株式会社 Magnesium hydroxide particles, method for producing the same, and resin composition containing the same
JP5052780B2 (en) * 2005-11-15 2012-10-17 宇部マテリアルズ株式会社 Method for producing magnesium hydroxide fine particle dispersion
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CN101905896B (en) * 2009-06-05 2012-04-25 北京化工大学 Method for preparing magnesium hydroxide from brucite ore
CN102303879B (en) * 2011-07-29 2013-06-19 武汉工程大学 Method for preparing magnesium hydroxide by utilizing light calcined dolomite
JP5654429B2 (en) * 2011-10-03 2015-01-14 帝人エンジニアリング株式会社 Method for producing magnesium oxide composition, magnesium oxide composition, neutralizing agent for desulfurization, flue gas desulfurization method, and flue gas desulfurization apparatus
KR101462369B1 (en) * 2014-04-08 2014-11-14 허재수 Mg(oh)_2 manufacturing method
CN104925838B (en) * 2015-07-15 2016-12-28 后英集团海城市高新技术产品有限公司 A kind of efficient oxidation magnesium prepares magnesium hydroxide technique
CN105776258B (en) * 2016-04-25 2016-12-28 辽宁洁镁科技有限公司 A kind of method using Preparation of Magnesium Hydroxide Using Magnesium Oxide
CN105924023B (en) * 2016-04-25 2017-05-03 辽宁洁镁科技有限公司 Preparation method for magnesium oxide raw material and magnesium hydroxide with low particle size by using low-grade magnesite
CN109290340B (en) * 2018-09-13 2021-03-23 捷艾悉环保科技（上海）有限公司 Garbage deodorizing and purifying agent, preparation method thereof and garbage deodorizing method
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CN109574049B (en) * 2019-01-23 2021-09-21 大连海事大学 Hydration synthesis method of magnesium hydroxide slurry with controllable dissolution rate
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