CN1031561C - Process for preparation of large grain ammonium sulfate - Google Patents
Process for preparation of large grain ammonium sulfate Download PDFInfo
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- CN1031561C CN1031561C CN90109065A CN90109065A CN1031561C CN 1031561 C CN1031561 C CN 1031561C CN 90109065 A CN90109065 A CN 90109065A CN 90109065 A CN90109065 A CN 90109065A CN 1031561 C CN1031561 C CN 1031561C
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/96—Methods for the preparation of sulfates in general
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
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Abstract
A preparation method for large-particle ammonium sulfate is provided, wherein the prepared byproduct ammonium sulfate of inner acyl amine is input into a crystallizing tank to conduct the concentrated crystallization, the ammonium sulfate crystal body is recovered from the pulp containing the crystallized ammonium sulfate through a segregating device, at least monitoring the blender current value, pulp concentration, crystal body content of ammonium sulfate in the pulp, as well as particle size distribution of ammonium sulfate crystal body in the pulp in the crystallizing tank, so as to increase/reduce the pulp amount discharged from the bottom part of the crystallizing tank, making the amount of ammonium sulfate crystal body left in the crystallizing tank repeatedly increase/reduce within a range between the upper limit and lower limit of the crystal body content of ammonium sulfate in the pre-determined crystallizing tank.
Description
The present invention relates to a kind of industrial production process of large-particle ammonium sulfate, wherein when preparing as lactan pay product and sulfuric acid oxime ammonium (the oxime ammonium sulfate) solution (ammoniumsulphate soln that oximation reaction produced) and/or the rearragement ammonium sulfate solution (ammoniumsulphate soln that the Beck-mann rearrangement reaction is produced) that obtain concentrate in the ammonium sulfate crystallization jar to be settled out ammonia sulfate crystal, crystal reclaims by this way: the hold-up and the residence time of coming ammonium sulfate crystallization in the crystallization control jar by the quantity that increases or reduce the slurry that contains the crystalline sulfuric acid ammonium (after this being called " end liquid ") of discharging from above-mentioned sulfuric acid amine crystallizer tank, monitor the particle size dispersion of mobile ammonia sulfate crystal in crystallizer simultaneously, if necessary, the end liquid that crystallizer is discharged is input to a tripping device (as sieve etc.) again, being divided into macrobead product and small-particle product, and then the small-particle product got back in the above-mentioned ammonium sulfate crystallization jar together with separated mother liquor is defeated.
In the method for the invention, (end liquid density is recorded by specific gravity hydrometer in variation by proofreading and correct end liquid density, and this specific gravity hydrometer is to be foundation with the agitator electric current that the current meter amount gets) and end liquid in the content (recording) of ammonia sulfate crystal by crystal-liquid surface meter, the end liquid quantity of being discharged by the ammonium sulfate crystallization pot bottom can increase or reduce automatically, thereby makes being prepared into stably to carry out continuously automatically of large-particle ammonium sulfate.
In addition, the large-particle ammonium sulfate that makes by the inventive method can be used for bulk blended fertilizer suitably with the preparation compound manure.
In recent years, be suitable for direct fertilising in order to prepare, the compound manure that contains nitrogen, phosphorus, three kinds of basal component of potassium, need so-called bulk blended fertilizer, wherein two or more granulo-fertilizer materials (as ammonium sulfate, ammonium chloride, Repone K, calcium superphosphate etc.) make physics in mode in bulk in any ratio and mix, but be used for blended particulate state ammonium sulfate in bulk often short supply owing to yielding poorly.
Be used for blended particulate state ammonium sulfate in bulk, require them to have little cubic block shape of uniform size, sphere or grain of rice shape, particle size is about 2 to 5 millimeters.
In the method for preparing particulate state ammonium sulfate of routine, the product ammoniumsulphate soln (sulfuric acid oxime ammonium solution or rearragement ammonium sulfate solution) of paying when being handle preparation hexanolactam obtains granular ammonium sulfate by a crystallizer.Usually use the growth form evaporative crystallizer, the tubular type of particularly ventilating (DTB, draft tmbe baffle) crystallizer is about weight concentration 40% above-mentioned ammoniumsulphate soln and is input in this crystallizer, concentrate this solution by evaporation, just make particulate state ammonium sulfate.That is to say, particulate state ammonium sulfate makes like this: ammonia sulfate crystal is able to normal growth owing to contacting with the crystalline fluidized-bed, the concentration that does not make simultaneously ammoniumsulphate soln greater than oversaturated degree to control the generation of new nucleus, make ammoniumsulphate soln maintain metastable state on the one hand, ammonia sulfate crystal is sorted out for again on the other hand the crystal fluidized-bed.
But, according to this method, though can obtain relatively homogeneous granules shape ammonium sulfate of size constantly, because the end liquid quantity of being discharged by the ammonium sulfate crystallization pot bottom in the operation etc. can remain unchanged in the whole time, but problem is that the size of crystal grain has only 1mm mostly, so they are not suitable for use in the ammonium sulphate grain of above-mentioned bulk blended fertilizer.
Therefore, as being used for blended large-particle ammonium sulfate crystalline method in bulk from the ammoniumsulphate soln preparation, someone proposes to make the crystalline particle of being grown by the ammoniumsulphate soln evaporation in vacuum cyrsytalliser, guide in succession low temperature level successively from the high-temperature level, just obtain megacryst grain ammonia sulfate crystal later on through some steps; A kind of newer method, then the mealy crystal that obtains is guided to the high-temperature level in the low temperature level, because above-mentioned low temperature mealy crystal mixes with the ammoniumsulphate soln that is evaporating, solution becomes supersaturation by evaporation, these mealy crystals are just as the crystal product nucleus in the ammoniumsulphate soln, so, just can obtain the large-particle ammonium sulfate crystal with methods such as adverse current crystallization processs.
According to these methods, therefore the ammonia sulfate crystal of gained is round, is similar to spherically, preferentially is used for mixed compound fertilizer by the human consumer, but higher at fuel cost that dissolves step and re-crystallization step and maintenance cost, so macrobead crystalline production cost is also high.
On the other hand, also the someone proposes certain methods (Japanese patent application 109814/1981,109815/1981,109816/1981 etc.), wherein, in ammonium sulfate liquor, add nitric acid, ammonium nitrate preparing by crystallizer in the step of granular ammonium sulfate by ammonium sulfate liquor, thionamic acid, crystallization auxiliaries such as Ammonium sulfamate are with help crystallisation; Another kind method (Japanese patent laid-open publication gazette 20245/1982) is then used aluminium salt, and granulating auxiliary agents such as molysite are to produce granular ammonium sulfate; But when mass crystallization auxiliary agent or granulating auxiliary agent directly add in the ammoniumsulphate soln, or resulting ammonia sulfate crystal contains impurity (as thionamic acid, nitric nitrogen etc.), or described crystallization auxiliary or granulating auxiliary agent go bad because of decomposition, thereby its shortcoming is quality and economic problems when industrial implementation, not equal to be to be difficult to carry out.
Variety of issue in view of the big crystal grain ammonium sulfate ordinary method of preparation, people require to provide a kind of method of neither using crystallization auxiliary also not use the big crystal grain ammonium sulfate of preparation of granulating auxiliary agent consumingly, it is the method that a kind of preparation is applicable to the big crystal grain ammonium sulfate of bulk blended fertilizer, wherein conventional ammoniumsulphate soln is evaporated concentrate in crystallizer by improving, the method that sedimentary ammonium sulfate is reclaimed makes the ammonia sulfate crystal in the end liquid further generate big crystal grain again.
The purpose of this invention is to provide a kind of method that is suitable for the big crystal grain ammonium sulfate of industrial preparation, wherein when ammonia sulfate crystal in the ammonium sulfate crystallization jar during by the paying a product ammoniumsulphate soln and crystallize out of preparation lactan, can be suppressed at the generation of ammonium sulfate crystallization nuclear superfluous in this crystallizer, and prolong the residence time of ammonia sulfate crystal, ammonia sulfate crystal is generated big crystal grain as a result, thereby may obtain being applicable to bulk blended fertilizer easily, size evenly is about 2 to 5mm particulate state ammonium sulfate, and this ammonium sulfate crystalline making method can be carried out on convincing ground automatically.
Inventor of the present invention has done deep research, and purpose is to improve conventional method (wherein ammoniumsulphate soln concentrates by evaporation, again with sedimentary crystal recovery) and prepare big crystal grain ammonium sulfate in the ammonium sulfate crystallization jar; Discovery just needs to reduce the end liquid quantity of being discharged by the ammonium sulfate crystallization jar, to prolong the little residence time of crystal grain ammonia sulfate crystal in crystallizer in order to make big crystal grain ammonium sulfate; And by investigate increasing or reduce the end of discharging by the ammonium sulfate crystallization jar during liquid quantity, bottom liquid slurry concentration, end liquor ratio is heavy, agitator current value or the like each quantitative changeization, and the relation in the above-mentioned residence time between the variation of ammonia sulfate crystal particle size, notice that the bottom liquid slurry concentration in the ammonium sulfate crystallization jar rises in the above-mentioned residence time, further find to have between them the relation of almost determining; Therefore, survey the interior ammonia sulfate crystal content of ammonium sulfate crystallization jar if use specific gravity hydrometer and crystal-liquid surface meter simultaneously, and make the end liquid quantity of discharging suitably increase or reduce corresponding to it from crystallizer, so that the hold-up of ammonia sulfate crystal can be controlled, just can access megacryst grain ammonia sulfate crystal, the result has just finished the present invention.
The invention provides a kind of method for preparing big crystal grain ammonium sulfate, in this method, in the byproduct of ammonium sulfate solution input ammonium sulfate crystallization jar with the preparation lactan, it is concentrated in jar and precipitate, then end liquid is discharged from the bottom of this crystallizer, utilize tripping device reclaim(ed) sulfuric acid ammonium crystal from this end liquid slurry, the feature of this method is that the ammonium sulfate crystallization jar is equipped with an agitator at least, be used for containing in the agitated crystallizer slurry (end liquid) of crystalline sulfuric acid ammonium, an amperometer is used for measuring the electric current of this agitator, a specific gravity hydrometer is used for measuring the slurry concentration of end liquid, crystal-liquid surface meter is used for measuring the ammonia sulfate crystal content in the end liquid, and the feature of this method also is to monitor at least the current value of above-mentioned agitator in this ammonium sulfate crystallization jar, the slurry concentration of end liquid, ammonia sulfate crystal content in the end liquid, the sour ammonium crystalline particle size distribution of stream from the end liquid that discharge the crystallizer tank bottom, the upper limit of ammonia sulfate crystal content in the crystallizer is taken as equals ammonia sulfate crystal and just in time be generated to diameter crystalline hold-up in jar when maximum, and crystal to grow up be to prolong the residence time of little crystal grain ammonia sulfate crystal in jar to suppress the result that the superfluous nuclei of crystallization produce simultaneously in end liquid, on the other hand, with the lower limit of crystalline content be taken as the ammonium sulfate crystallization dyskaryosis ground that equals new in reaching the end liquid of hypersaturated state before producing jar in the crystal hold-up, increase or reduce the quantity of the end liquid of discharging, just make the quantity of staying the ammonia sulfate crystal in the jar in above-mentioned jar, increase in the scope between ammonia sulfate crystal upper content limit and the lower limit repeatedly and reduce by the crystallizer bottom.
Fig. 1 is that the schema that the present invention prepares the large-particle ammonium sulfate method is implemented in expression.
Fig. 2 represents the disappearance along with the time, the variation of density in the crystallizer, the variation of crystallizer agitator current value, the variation of heater temperature difference, the variation of the end liquid quantity of from crystallizer, discharging, and the variation of the ammonia sulfate crystal product particle size dispersion that reclaims by centrifuge separator among the embodiment 1.
Referring to accompanying drawing, preparation method of the present invention will be explained as follows in detail:
The summary of the inventive method is shown in Fig. 1
(A) crystallisation step of ammonium sulfate
Above-mentioned sulfuric acid oxime ammonium solution or rearragement ammonium sulfate solution (ammoniumsulphate soln) are joined in ammonium sulfate crystallization jar 1 and/or 2, in each jar, water vapor is discharged, above-mentioned ammoniumsulphate soln is concentrated and be settled out ammonia sulfate crystal by evaporation under the pressure of high temperature and reduction.When liquid slurry at the bottom of the ammonium sulfate is discharged from ammonium sulfate crystallization jar 1 and/or 2 bottoms, recited abovely by evaporation ammoniumsulphate soln is concentrated to prevent that this bottom liquid slurry concentration is elevated to greater than remaining on metastable oversaturated degree, simultaneously, the quantity of the end liquid of discharging maintains lower value, and inhibition produces the superfluous nuclei of crystallization, make the residence time of small-particle ammonia sulfate crystal in crystallizer prolong, and make this ammonia sulfate crystal grow to its limit.Then, by above-mentioned " growing to the ultimate ammonia sulfate crystal " discharged, and the discharge quantity of increase end liquid, crystalline content in the crystallizer is reduced, and after the hypersaturated state that remaining ammonia sulfate crystal can keep taking place in the end liquid in each crystallizer, the output of end liquid reduces again, and the small-particle ammonia sulfate crystal is grown up, thereby repeats so-called periodic Control operation.
(B) separating step of ammonium sulfate
Will be from the bottom of ammonium sulfate crystallization jar 1 and/or 2 end liquid that discharge, that contain " being allowed to grow to the ultimate ammonia sulfate crystal ", be input to centrifuge separator 5 and/or 6 by gravitation tank 3 and/or 4, in these tripping devices, " growing to the ultimate ammonia sulfate crystal " is that the large-particle ammonium sulfate crystal is by Separation and Recovery from end liquid, defeated again ammonium sulfate crystallization jar 1 and/or 2 got back to of separated mother liquor of containing the small-particle ammonia sulfate crystal simultaneously, make the end liquid that is concentrated in each crystallizer thinning, and carry out the crystallization of ammonium sulfate therein.
The operation of above steps among the preparation method of the present invention will be described in more detail below.
Crystallisation step about ammonium sulfate: in the present invention crystallisation step preferably have first crystallizer 1 and=crystallizer, couple together as shown in Figure 1, embodiment is as follows: (A-1) is input to first crystallizer 1 with the rearragement ammonium sulfate solution that obtains in the sulfuric acid oxime ammonium solution that obtains in the oximate step (step that promptly prepare cyclohexanone-oxime under the condition that ammonia exists by pimelinketone and oxammonium sulfate reaction) and/or the lactan rearrangement step (promptly the cyclohexanone-oxime that is subjected to the Beckmann rearrangement by neutralizing with ammonia under the condition that sulfuric acid exists prepares the step of hexanolactam) through piping 9 and well heater 10, wherein sulfuric acid oxime ammonium solution and/or rearragement ammonium sulfate solution concentrate under the pressure of high temperature and reduction, then, when allowing part of sulfuric acid ammonium crystal settling, (a) end liquid is discharged by the bottom of above-mentioned first crystallizer 1 by pipeline 17, and is delivered to follow-up separation ammonium sulfate crystalline step; (b) partly " first end liquid that contains a small amount of ammonia sulfate crystal " (after this being called " first end liquid ", is the end liquid of non-suspension) overflowed by the first crystallizer top, and discharges by circulating line 14, inputs to second crystallizer 2 by pipeline 11 again; (c) high-temperature gas of being emitted by above-mentioned first crystallizer 1 top (as water vapor etc.) is transported to heat exchanger (vaporizer effect evaporator) 13 by pipeline 12, heating " second end liquid that contains a small amount of ammonia sulfate crystal " (after this is called " second end liquid ", be the end liquid of non-suspension), this second end liquid is overflowed by the top of second crystallizer, drain into circulating line 15, be heated then; After this, (A-2) fails next first end liquid (liquid at the bottom of the non-suspension) 2 li of second crystallizers from first crystallizer 1, pressure in high temperature and reduction concentrates down, allowing the sedimentary while of ammonia sulfate crystal, (a) end liquid is discharged from the bottom of this second crystallizer 2 by pipeline 18, be transported to follow-up separation ammonium sulfate crystalline step resembling in first crystallizer; (b) second end of the part liquid (liquid at the bottom of the non-suspension) in above-mentioned second crystallizer 2 is discharged by pipeline 29 by circulating line 15, in the case, (c) high-temperature gas of being emitted by this second crystallizer top (as water vapor etc.) preferably is disposed to vacuum fan (not shown on the figure) by pipeline 16.
In the present invention, above-mentioned sulfuric acid oxime ammonium solution that obtains by the oximate step and/or the rearragement ammonium sulfate solution that obtains by rearrangement step, be advisable to be heated to 30-150 ℃ (being more preferably 50-120 ℃, preferably 70-100 ℃), be input to first crystallizer 1 then by well heater 10.
In addition, in this first crystallizer 1, end liquid temp is advisable with 50-120 ℃ approximately, is more preferably 70-100 ℃, and internal pressure is advisable with 10-700torr, is more preferably 50-500torr; And in second crystallizer 2, end liquid temp is advisable with 30-120 ℃, is more preferably 40-80 ℃, and internal pressure is advisable with 10-300torr approximately, is more preferably 20-100torr.
The heat control of supplying with end liquid in each crystallizer is as follows: every kind of end liquid is discharged from by being spilled over to circulating line 14 and 15, when it being cycled through each crystallizer by circulating pump (not shown on the figure), use well heater 10 and heat exchanger 13 to come to each end liquid heat supply, be pulled away owing to vaporization heat but then, when having a large amount of water vapors or other material to be vaporized in the crystallizer, suitably controlling these two kinds of heats just can the maintenance heat balance.
In above-mentioned ammonium sulfate crystallization step, spissated bottom liquid concentration weight percent is about 40-60% in the ammonium sulfate crystallization jar, and preferably 45-55%.
And in the present invention, why to be discharged to second end of part liquid (liquid at the bottom of the non-suspension) outside the system from circulating line by pipeline 29, its reason is the impurities accumulation of intention prevention organism and so on or concentrates in the end liquid of first and second crystallizers, preferably second end liquid of part is discharged as ammonium sulphate waste liquor, again the equipment of handling by wet oxidation or activity sludge treatmenting equipment or the like and it is removed.
In the present invention, as mentioned above, by the end liquid quantity of discharging in each crystallizer, increase or reduce with some cycles corresponding to bottom liquid slurry concentration (that is proportion of end liquid) changes, and when the new nuclei of crystallization produce unusually in suppressing each crystallizer, the small-particle crystalline residence time is extended in jar, makes them grow to the limit.Like this, feature of the present invention is " a kind of periodic Control process ", in other words, is " a kind of piston-flow system ", and wherein the ammonia sulfate crystal content in each crystallizer increases repeatedly in the scope of upper and lower bound or reduces.
Therefore, in the present invention, the end liquid quantity that control is discharged by each crystallizer bottom is most important, and output increased according to the cycle and the amplitude that reduces is big more, the output of big crystal grain ammonia sulfate crystal is just high more, but when the ammonium sulfate concentrations in the end liquid had surpassed the boundary of supersaturation solubleness, end liquid played pendulum, and the balance of operation just is easy to destroy.If but output increases and the amplitude that reduces is very little, though can guarantee the safety of operating, the problem of generation is that large-particle ammonium sulfate crystalline output reduces.Therefore, the big within the possible range side of amplitude control that significantly above-mentioned output is increased and reduces during operation, to increase large-particle ammonium sulfate crystalline output, the balance of operating in this possible range can be kept according to certain cycle.For this purpose, remain in the quantity of ammonia sulfate crystal in each crystallizer, being preferably in increases repeatedly in the scope between jar interior ammonia sulfate crystal upper content limit and the lower limit or reduces.
The increase and the minimizing of above-mentioned end liquid quantity of discharging from each crystallizer bottom, preferably carry out by the open and close time of regulating " automatic switch valve " (on figure, not drawing), this valve is fitted together with the end liquid discharge line that is connected crystallizer and gravitation tank, can replace or repeats to do open and close operation.Certainly, this increase and the minimizing of end liquid output, the time length that is not limited to regulate the operation of " automatic switch valve " open and close, for example, also can replace with a control valve " automatic switch valve ' ', the big I of the valve openings of this control valve is done suitably control.
The upper limit of ammonia sulfate crystal content in the crystallizer, be to prolong the small-particle residence time of ammonia sulfate crystal in jar, be suppressed at simultaneously under the condition that produces the superfluous nuclei of crystallization in the end liquid, ammonia sulfate crystal is just in time grown up and is engraved in crystalline hold-up in the crystallizer for the moment to maximum that of diameter, and wish constantly at this, ammonia sulfate crystal in the end liquid arrives than overflowing the low slightly position of water level, surpasses above-mentioned first end liquid of this water level (liquid at the bottom of the non-suspension) and second end liquid (liquid at the bottom of the non-suspension) and just is drained in circulating line 14 and 15 respectively.Also wish simultaneously the affirmation of this position, measure (preferably tuning-fork type crystal-liquid surface meter) with tuning-fork type, floating or electromagnetic type crystal-liquid surface meter and carry out, or, detect by an unaided eye and carry out by a viewing window.
And the lower limit of ammonia sulfate crystal content in the crystallizer, be that ammonium sulfate concentrations has surpassed the supersaturation solubility curve in end liquid, end liquid reaches unsteady state and has destroyed hypersaturated state, thereby the new nuclei of crystallization of ammonium sulfate produce unusually this constantly before the hold-up of ammonia sulfate crystal in the crystallizer, this lower limit is wished by knowing end liquid density in advance, slurry concentration in the end liquid, mutual relationship in the variation of each amount such as the current value of agitator and the end liquid between the variation of ammonia sulfate crystal particle size dispersion is determined, for example, the end liquid variable density state that records by the specific gravity hydrometer with differential pressure type specific gravity hydrometer and so on is determined.
But the lower limit of ammonia sulfate crystal content is quite difficult in the decision crystallizer, and therefore in real work, near the actually operating such lower limit is preferably carried out in the following manner.Promptly at first increase the output of end liquid in the crystallizer, and in making jar " grow to the ultimate ammonia sulfate crystal ' ' reduce gradually.Then, reduce the output of end liquid in the crystallizer, wait for that the small-particle ammonia sulfate crystal flows out in the middle of being clipped in the large-particle ammonium sulfate crystal that remains in the jar together, at this moment, the selection of time of operation is most important.If late, will produce many crystallites suddenly, that is to say the new nuclei of crystallization because plane of crystal is not enough and produce singularly and adopt.Therefore, in order to prevent this situation, ammonium sulfate crystallization jar 1 and 2 moves in the following manner: when eliminating the superfluous nuclei of crystallization, (this part end liquid is to overflow from crystallizer 1 and 2 tops to reduce the quantity of liquid at the bottom of the outside circulation, and respectively by circulating line 14, well heater 10, recycle pump (not drawing on the figure) and circulating line 15, heat exchanger 13, recycle pump (not drawing on the figure) returns the bottom of crystallizer 1 and 2 again), and the temperature head of well heater 10 front and back and the temperature head of heat exchanger 13 front and back are improved about 1-5 ℃, be more preferably 2-3 ℃ (with comparing before the minimizing of end liquid output in the crystallizer).
In addition, if ammonia sulfate crystal content surpasses the above-mentioned upper limit in the crystallizer, the end liquid that contains a large amount of ammonia sulfate crystals will be spilt into circulating line 14 and 15 by the top of this crystallizer, at this moment will be because of various troubles take place no longer can steady running, thermal equilibrium around crystallizer is destroyed, because in by heat supplieds such as well heater 10 and heat exchangers 13, taken away vaporization heat when a large amount of water vapors etc. are vaporized in crystallizer; The load of recycle pump (not shown) increases singularly; The perhaps carrier pipe that links to each other with 15 with circulating line 14, pH exploring tube etc. are blocked or the like by ammonia sulfate crystal.
On the other hand, if ammonia sulfate crystal content is lower than above-mentioned lower limit in the crystallizer, the nuclei of crystallization generate singularly with as described above in the end liquid, even therefore at this moment carve by reducing end liquid output and prolong the residence time of ammonia sulfate crystal in crystallizer, ammonia sulfate crystal also no longer can fully be grown, and in the final analysis, this need be by increasing end liquid in the crystallizer output remain in the quantity of the ammonia sulfate crystal in the jar with minimizing, and the ammonia sulfate crystal that generates is singularly discharged together in company with end liquid.Therefore, these situations do not wish to take place.
And, also can be as described above among the present invention by pipeline 30 and heat exchanger 13 and above-mentioned sulfuric acid oxime ammonium and/or rearragement ammonium sulfate are transported in second crystallizer 2.Separating step about ammonia sulfate crystal.
In this step, as shown in Figure 1, discharge by the first ammonium sulfate crystallization jar, contain " grow to the ultimate ammonia sulfate crystal ' ' end liquid; be imported in the two-stage tripping device; it comprises a gravitation tank and a centrifuge separator; in this device, utilize sieve that " growing to the ultimate ammonia sulfate crystal " (being the large-particle ammonium sulfate crystal) and small-particle ammonia sulfate crystal are separated, promptly from this end liquid, reclaim the large-particle ammonium sulfate crystal that obtains.On the other hand, for those small-particle ammonia sulfate crystals, then preferably they are sent back in separately the crystallizer as seed crystal together with the mother liquor after separating again, and make them be grown to serve as big crystal grain.
The example of a detail operations is as follows: (a) will be by first crystallizer 1 (or second crystallizer 2) bottom through pipeline 17 (or pipeline 18) end liquid that discharge, that contain " growing to the ultimate ammonia sulfate crystal ", be delivered to first gravitation tank 3 (or second gravitation tank 4) (first end liquid utilizes 7, the second end of mateiral pump liquid to utilize mateiral pump 8) by pipeline 19 (or pipeline 20); (b) utilize be contained in first gravitation tank 3 (or second gravitation tank 4) ingress " sieve with the chassis that is contained in its below ' ', the large-particle ammonium sulfate crystal in this end liquid and the small-particle ammonia sulfate crystal is separated from one another comes; (c) get back to first crystallizer 1 (or second crystallizer 2) failing by above-mentioned chassis through piping 21 (or pipeline 22) together with the mother liquor after separating by the small-particle ammonium sulfate of above-mentioned sieve; (d) during this period not " the large-particle ammonium sulfate crystal that contains liquid of the less end " by above-mentioned sieve overflow by the edge of this sieve, run down into the bottom of above-mentioned first gravitation tank 3 (or second gravitation tank 4), simultaneously part of sulfuric acid oxime ammonium solution and/or rearragement ammonium sulfate solution are passed to this bottom by pipeline 9 and 27 (or 28), whereby above-mentioned " the large-particle ammonium sulfate crystal that contains liquid of the less end " dilution are become suspension liquid; (e) discharged this suspension liquid by the bottom of first gravitation tank 3 (or second gravitation tank 4) then, by pipeline 23 (or pipeline 24) input first centrifuge separator 5 (or second centrifuge separator 6), large-particle ammonium sulfate crystal and small-particle ammonia sulfate crystal are separated therein; And (f) when sending back in above-mentioned first crystallizer 1 (or second crystallizer 2) by pipeline 25 (or pipeline 26) together with the mother liquor after separating, preferably the large-particle ammonium sulfate crystal is sent to product warehouse (not shown) as product with the travelling belt (not shown) to the small-particle ammonia sulfate crystal.
In the present invention, be input to the sulfuric acid oxime ammonium solution and/or the rearragement ammonium sulfate solution of above-mentioned gravitation tank 3 and 4 bottoms, diluted " the large-particle ammonium sulfate crystal that contains liquid of the less end ", made the large-particle ammonium sulfate crystal that accumulates in above-mentioned gravitation tank 3 and 4 bottoms may be in fluidized state.This just can be used to prevent to connect the obstruction of the pipeline 23 (or managing 24) of each gravitation tank and each centrifuge separator.Therefore, the sulfuric acid oxime ammonium solution and/or the rearragement ammonium sulfate solution supply that are passed to gravitation tank 3 and 4 bottoms are advisable with 30-70%, are more preferably 40-60% (overall supplies with this sulfuric acid oxime ammonium solution and/or rearragement ammonium sulfate solution is as the criterion).
And, the present invention's used sieve in above-mentioned gravitation tank and centrifuge separator, its size is respectively 10-14 orders and 12-16 orders.
Be appreciated that from the above mentioned, in the present invention because the ammonium sulfate crystallization step is to move under by the control of determining the cycle, discharge and be transported to the ammonia sulfate crystal of separating step in succession from each crystallizer bottom, the skew of certain amplitude also takes place in its particle size dispersion according to this cycle.Therefore, the crystalline particle diameter is along with the disappearance of time roughly becomes the large size stage equably by the small size stage.When becoming small size during the stage by the large size stage, the small-particle crystal that generates in next cycle begins to mix with the macrobead crystal, along with the macrobead crystal becomes fewer and feweri, the small-particle crystal increases gradually, last these small-particle crystal are grown to serve as big crystal grain equably, and this process is repeated again.
So by the ammonia sulfate crystal that above-mentioned each centrifuge separator reclaims, the increase of its grain-size can be significantly improved by the method in the above-mentioned ammonium sulfate separating step; Be sent to the product warehouse but work as ammonium sulphate crystal products from each centrifuge separator, they mix there mutually, and it is quite big that the amplitude of particle size dispersion just becomes.
Therefore, in the present invention, when production is used for the large-particle ammonium sulfate crystal of bulk blended fertilizer, preferably the ammonium sulfate in the product warehouse is sieved, to reclaim the uniform large-particle ammonium sulfate crystal of size.
And, in the present invention as can be known by the above, the variation of each amount such as the end liquid density in each crystallizer, the slurry concentration of end liquid, the current value of agitator, and in the end liquid between the variation of ammonia sulfate crystal particle size distribution, exist definite mutual relationship, therefore by obtaining this mutual relationship in advance, use crystal-liquid surface meter and specific gravity hydrometer to measure crystalline content and end liquid density (measuring apparatus is contained in the place part of end liquid) automatically respectively, the change state of crystalline content of being surveyed and end liquid density is judged by operating mechanism.Operating mechanism is according to the result of gained, and the control device to the automatic switch valve that is contained in end liquid discharge tube sends the opening and closing instruction immediately, to regulate the time that this automatic switch valve opens and closes.By the end liquid quantity that such adjusting is discharged by each crystallizer, the preparation of large-particle ammonium sulfate just can be stablized by automatic operation and be carried out.
In the method for the invention, be that ammoniumsulphate soln is input in the ammonium sulfate crystallization jar, and in jar, concentrate.When ammonia sulfate crystal is precipitated out and be recovered, this ammoniumsulphate soln concentrates by evaporation, in order to avoid the slurry concentration of end liquid is elevated to more than the supersaturation solubility curve, and by end liquid output in the crystallizer is maintained low level, suppress to produce the superfluous nuclei of crystallization simultaneously, prolong the residence time of ammonia sulfate crystal in this crystallizer, so that the small-particle ammonia sulfate crystal grows to the limit.Then, increase end liquid output, to reduce the crystalline content in the crystallizer, keep after this state, the ammonia sulfate crystal that just remains in this jar is said, can keep the hypersaturated state in the end liquid, reduce end liquid output once more, grow in succession to impel the small-particle ammonia sulfate crystal.Like this, by repeating the operation of so-called periodic Control, just can obtain being applicable to bulk blended fertilizer easily, particle size is about 2-5 millimeters, large-particle ammonium sulfate crystal of uniform size.
To be described more specifically method of the present invention in the following embodiments, but this embodiment and do not mean that and limit method of the present invention by any way.
Embodiment
In step shown in Figure 1, quantity and ammonium sulfate concentrations such as the listed sulfuric acid oxime ammonium solution of table 1 are input to first crystallizer 1 (with second crystallizer 2).In multiple periodic Control process, this sulfuric acid oxime ammonium solution is concentrated to be settled out ammonia sulfate crystal.Secondly, the end liquid of being discharged by first crystallizer 1 (with second crystallizer 2) bottom is transported to first centrifuge separator 5 (with second centrifuge separator 6) by first gravitation tank 3 (with second gravitation tank 4), therein large-particle ammonium sulfate crystal and small-particle ammonia sulfate crystal is separated.Then the large-particle ammonium sulfate crystal is regained, the mother liquor that will contain the small-particle ammonia sulfate crystal simultaneously is defeated back into row recirculation, carries out the crystallization of ammonium sulfate; So just can make the large-particle ammonium sulfate crystal continuously, wherein the particle of sieve mesh 12+ accounts for more than 80% of weight, and output is about 4200 tons/month (seeing table 1 for details).
In addition, the operational cycle of first crystallizer 1 (with second crystallizer 2), promptly the ammonium sulfate product particle diameter that is reclaimed by first centrifuge separator 5 (and second centrifuge separator 6) reaches the moment of peak value and reaches perdurability between moment of next peak value, approximately is 24 hours.
And, the density of end liquid in the crystallizer, the current value of agitator in the crystallizer, the temperature head of well heater, the end liquid quantity of being discharged by crystallizer, and the changing conditions of the particle size dispersion of the ammonium sulfate product that is reclaimed by centrifuge separator all are illustrated among Fig. 2; The mean particle size of ammonia sulfate crystal distributes and then lists at table 1 in each cycle.Fig. 2 " end liquid quantity of discharging by crystallizer ' " valve " in ' one hurdle, be meant to be contained in end liquid is displaced into automatic switch valve on the pipeline of gravitation tank by crystallizer.This valve opens or closes at a certain time interval, and the turn-off time is held constant at 90 seconds.
Comparative Examples
In step shown in Figure 1, quantity and ammonium sulfate concentrations such as the listed sulfuric acid oxime ammonium solution of table 1 are input to first crystallizer 1 (with second crystallizer 2), this sulfuric acid oxime ammonium solution is concentrated therein, and ammonia sulfate crystal is precipitated out.Then, end liquid is discharged with certain quantity and certain ammonium sulfate concentrations all the time by the bottom of first crystallizer 1 (with second crystallizer 2), be transported to first centrifuge separator 5 (with second centrifuge separator 6) by first gravitation tank 3 (with second gravitation tank 4), therein large-particle ammonium sulfate crystal and small-particle ammonia sulfate crystal are separated, simultaneously defeated above-mentioned first crystallizer 1 (with second crystallizer 2) of getting back to of the mother liquor recirculation that contains the small-particle ammonia sulfate crystal.Like this, just realize the crystallization of ammonium sulfate, the particle that can make sieve mesh 12+ continuously accounts for the ammonia sulfate crystal of weight about 10-40%, and output is about 400 tons/month (seeing table 1 for details).In addition, table 1 has also been listed the current value of agitator in the crystallizer and the mean particle size of the ammonium sulfate product that reclaimed by centrifuge separator distributes.
Table 1
Embodiment 1 Comparative Examples 1
Treatment capacity ammonium sulfate concentrations treatment capacity ammonium sulfate concentrations
(m
3/ month) (weight %) (m
3/ month) (weight %) sulfuric acid oxime ammonium solution 8,460 41 7,920 41 ammonium sulphate crystal products 4, the mean particle size distribution (1) of 240 tons/month 3,980 tons/month agitator current values 26-30 (peace) 23-25 (peace) ammonium sulphate crystal products
5 orders, 8.3 weight %
5-7 orders, 32.6 weight %
7-9 orders, 26.9 weight %, 0.5-7.2 weight %
9-12 orders, 18.8 weight %, 12.5-26.4 weight %
12-16 orders, 9.8 weight %, 27.2-40.8 weight %
16-24 orders, 2.8 weight %, 19.4-38.3 weight %
One month mean value of 24 orders, 0.8 weight %, 10.5-23.0 weight % (1) expression
Claims (2)
1. method for preparing large-particle ammonium sulfate, this method is input to the ammonium sulfate crystallization jar to the by product ammoniumsulphate soln of preparation lactan, allow it in jar, concentrate while stirring with agitator, separate out ammonium sulfate crystallization, the slurry that will contain the crystalline sulfuric acid ammonium is again discharged from the bottom of above-mentioned ammonium sulfate crystallization jar, utilizes tripping device reclaim(ed) sulfuric acid ammonium crystal from this slurry; This method is characterised in that its employed ammonium sulfate crystallization is canned rheometer, specific gravity hydrometer and a crystalloid fluid body interface meter, the size-grade distribution of ammonium sulfate crystallization in the slurry that in preparation process, monitors the content of ammonia sulfate crystal in the concentration, this slurry of the current value of agitator, above-mentioned slurry and discharge by the crystallizer bottom, and repeatedly increase or reduce the hold-up and the residence time of coming ammonium sulfate crystallization in the crystallization control jar from the slurry quantity that contains ammonium sulfate of ammonium sulfate crystallization pot bottom discharge, make ammonia sulfate crystal be generated big crystal grain;
Reduce the output of crystalline sulfuric acid ammonium slurry, suppress the generation of superfluous ammonium sulfate crystallization nuclear in the slurry in the ammonium sulfate crystallization jar, prolong small-particle hold-up and the residence time of ammonia sulfate crystal in jar, make the ammonia sulfate crystal in jar interior slurry grow to maximum diameter;
When the ammonia sulfate crystal in the slurry in the jar reaches maximum diameter, increase the quantity of the slurry of discharging from the bottom, reduce jar an interior sulfuric acid amine crystalline hold-up and a residence time; Then
Before the moment that generates in a large number, reduce the quantity of the slurry of discharging, to increase the hold-up of ammonia sulfate crystal in the crystallizer from the bottom with being right after ammonium sulfate crystallization dyskaryosis new in the slurry of hypersaturated state in crystallizer.
2. the method for preparing large-particle ammonium sulfate as claimed in claim 1, it is characterized in that large-particle ammonium sulfate crystal and small-particle ammonia sulfate crystal by discharge at the bottom of the ammonium sulfate crystallization jar, come they separated from one another coming with a tripping device, thus the large-particle ammonium sulfate crystal is regained, the small-particle ammonia sulfate crystal is then got back to the ammonium sulfate crystallization jar together with the mother liquor after separating is defeated, to impel the crystal further growth.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP287785/1989 | 1989-11-07 | ||
| JP1287785A JPH0764553B2 (en) | 1989-11-07 | 1989-11-07 | Manufacturing method of large ammonium sulfate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1051711A CN1051711A (en) | 1991-05-29 |
| CN1031561C true CN1031561C (en) | 1996-04-17 |
Family
ID=17721712
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN90109065A Expired - Fee Related CN1031561C (en) | 1989-11-07 | 1990-11-07 | Process for preparation of large grain ammonium sulfate |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPH0764553B2 (en) |
| KR (1) | KR0152084B1 (en) |
| CN (1) | CN1031561C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101522276B (en) * | 2006-07-28 | 2013-08-14 | 帝斯曼知识产权资产管理有限公司 | Process for continuous production of large crystal products |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003298888A (en) * | 2002-04-02 | 2003-10-17 | Konica Corp | Method of manufacturing image pickup device |
| WO2014040858A1 (en) | 2012-09-11 | 2014-03-20 | Dsm Ip Assets B.V. | Process for initiating an ammonium sulfate crystallization process |
| CN102897795B (en) * | 2012-11-12 | 2015-02-25 | 中国石油化工股份有限公司 | Production method of large granular ammonium sulfate crystal |
| CN103739312A (en) * | 2013-12-19 | 2014-04-23 | 瓮福（集团）有限责任公司 | Production method for improving nitrogen of granular ammonium sulfate |
| CN110759752A (en) * | 2019-11-07 | 2020-02-07 | 李文娟 | Process for preparing granular ammonium sulfate |
| CN111408157B (en) * | 2020-04-14 | 2021-09-14 | 中石化南京工程有限公司 | Ammonium sulfate crystallization method and device thereof |
| CN111530119B (en) * | 2020-04-14 | 2021-09-14 | 中石化南京工程有限公司 | Tandem ammonium sulfate crystallization method and device thereof |
| CN115520879B (en) * | 2021-06-24 | 2024-03-26 | 中国石油化工股份有限公司 | Method and device for continuously preparing granular ammonium sulfate by heterogeneous seed crystal |
-
1989
- 1989-11-07 JP JP1287785A patent/JPH0764553B2/en not_active Expired - Fee Related
-
1990
- 1990-11-07 CN CN90109065A patent/CN1031561C/en not_active Expired - Fee Related
- 1990-11-07 KR KR1019900017959A patent/KR0152084B1/en not_active IP Right Cessation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101522276B (en) * | 2006-07-28 | 2013-08-14 | 帝斯曼知识产权资产管理有限公司 | Process for continuous production of large crystal products |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0764553B2 (en) | 1995-07-12 |
| KR910009561A (en) | 1991-06-28 |
| KR0152084B1 (en) | 1998-10-15 |
| JPH03150217A (en) | 1991-06-26 |
| CN1051711A (en) | 1991-05-29 |
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