Embodiment
The present invention prepares the method for high whiteness ball shaped nano barium sulfate, by following chemical reaction, realizes:
Ba
2++SO
4 2-→BaSO
4↓
S
2- X+1+H
2O
2+H
+→SO
4 2-+H
2O
Wherein the present invention reacts the method for the spherical barium sulfate so of the high whiteness of preparation with hydrated barta and ammonium sulfate, by following chemical reaction, realizes:
Ba(OH)
2+(NH
4)
2SO
4→BaSO
4↓+2NH
4OH
S
2- X+1+H
2O
2+H
+→SO
4 2-+H
2O
Specifically, the present invention is achieved through the following technical solutions:
The preparation method of ball shaped nano barium sulfate of the present invention comprises the steps:
(1) after barium hydroxide solution and ammoniumsulphate soln are processed respectively, with [Ba
2+]/[SO
4 2-] mol ratio is that 1.00/ (1.05~1.10) are carried out and flow successive reaction, carries out solid-liquid separation after reaction, obtains filter cake and filtrate; It is to be to filter at 30~35 ℃ in temperature that wherein said ammoniumsulphate soln is processed, and preferably with 0.5 μ m aperture accurate filter, filters; It is with 0.5 μ m aperture secondary filter that described ammoniumsulphate soln is processed; In wherein said barium hydroxide solution, barium ion concentration is 0.20~0.30mol/L, preferably 0.25~0.30mol/L; The concentration of ammoniumsulphate soln is 0.05~0.50mol/L, preferably 0.25~0.30mol/L; Wherein said and to flow barium hydroxide solution flow in successive reaction be 2000~6000L/h, preferably 4000~5000L/h; Ammoniumsulphate soln flow is at 2000~10000L/h scope, preferably 4000~6000L/h; Stirring velocity is 400~1500rpm, preferably 1000~1200rpm; Wherein said mother liquor adds after CaO, reclaims NH
3.
The equation reacting with barium hydroxide solution and ammoniumsulphate soln is as follows:
Ba(OH)
2+(NH
4)
2SO
4→BaSO
4↓+2NH
4OH
The object of this step is first to carry out after suitable processing containing hydrated barta and ammoniumsulphate soln, again with certain concentration and flow make the two and flow flow reactor in react, after carry out solid-liquid separation and obtain filter cake and mother liquor, mother liquor is reclaimed to ammonia after treatment.
(2) filter cake step (1) being obtained is distributed in water makes slip, adds sulfuric acid to adjust pH value of solution 2.5~3.0, after add hydrogen peroxide 70~75 ℃ of reactions, reaction finishes rear solid-liquid separation and obtains filter cake and filtrate; Wherein said to add the amount of hydrogen peroxide be that every cubic metre of slip adds 2-3 liter, preferably 2.5 liters; The time of wherein said reaction is 1-3 hour, preferably 2 hours.And
In this step, concrete reaction equation is as follows:
S
2- X+1+H
2O
2+H
+→SO
4 2-+H
2O
The object of this step is to react with the sulfur compound impurities being mixed with in barium sulfate under acidic conditions with hydrogen peroxide, negatively charged ion is wherein converted into sulfate radical, the metal ion that simultaneously metallic impurity elements such as ferrimanganic is converted into solubility makes it to enter in solution and separates by solid-liquid separation, remove the impurity being mixed with in barium sulfate, particularly affect the sulfocompound of color, to be converted into ionic condition and be dissolved in solution and be removed, by this step, make to obtain the feature that spherical barium sulfate has high whiteness.
(3) filter cake step (2) being obtained is distributed in water and forms slip, adds after ammonium sulfate, and adjusting pH is 6.5~7.5, preferably pass into ammonia and adjust pH, after at 75~80 ℃ of temperature, wash, solid-liquid separation obtains filter cake, filter cake obtains ball shaped nano barium sulfate product through evaporation, after drying; Wherein said washing time is 0.5-2 hour, is preferably 1 hour.
The object of this step is to wash obtaining barium sulfate solid in step (2), the object that wherein adds ammonium sulfate in solution is that sulfate ion concentration is increased, utilize the common-ion effcet of barium sulfate, thereby the concentration of the barium ion while reducing balance in solution suppresses crystal growth, but general just by increasing wherein a kind of growth of crystal of control of the concentration barium sulfate of ion, and can not add two kinds of ions simultaneously, prevented the barium sulfate of the coated original generation of newly-generated vitriol; In this step, also acid ion is neutralized, and wash under neutral or near neutral condition, not only make the barium sulfate that obtains for neutral, and removed foreign ion that barium sulfate the adheres to content of the metallic element ions such as ferrimanganic that further improved purity drop.
More particularly, to prepare the method for high whiteness ball shaped nano barium sulfate as follows in the present invention:
By Ba (OH)
2solution temperature is adjusted to 30~35 ℃ of scopes, [Ba
2+] 0.20~0.30mol/L, preferably 0.25~0.30mol/L, filters stand-by with 0.5 μ m aperture accurate filter.
By (NH
4)
2sO
4solution is adjusted into 0.05~0.50mol/L scope, preferred 0.25~0.30mol/L, and under normal temperature, 0.5 μ m aperture secondary filter is stand-by.
Control synthesizer stirring velocity at 400~1500rpm scope, preferably 1000~1200rpm.
With constant flow pump, control barium hydroxide solution flow at 2000~6000L/h scope, preferably 4000~5000L/h.
With constant flow pump, control (NH
4)
2sO
4solution flow is at 2000~10000L/h scope, preferably 4000~6000L/h.
Control building-up reactions [Ba
2+]/[SO
4 2-] mol ratio is 1.00/(1.05~1.10) scope.
Building-up reactions slurry carries out solid-liquid separation, stripping recovery NH after the supplementary the addition of C aO of mother liquor
3, filter cake enters next-step operation:
Filter cake is placed in acid-resistant container, by material-water ratio, 1:6 adds deionized water, dispersed with stirring, add a small amount of sulfuric acid to adjust pH value of solution 2.5~3.0, in every cubic metre of slip 2-3, rise the preferably ratio of 2.5 liters and add technical grade hydrogen peroxide, chuck heat temperature raising, hierarchy of control temperature is 70~75 ℃ of scopes, stirring oxidation rinsing solid-liquid separation after 2 hours, filtrate is processed discharge, and filter cake enters next-step operation.
Filter cake is placed in washing pot, by material-water ratio, adds deionized water at 1: 6, dispersed with stirring adds appropriate (NH simultaneously
4)
2sO
4, make [SO in solution
4 2-] concentration reaches 0.05mol/L to suppress crystal growth, passes into NH
3adjust slip pH6.5~7.5 scope, chuck is warming up to 75~80 ℃ of scopes, and agitator treating is solid-liquid separation after 1 hour, and filtrate is processed discharge, and filter cake flash evaporation drying obtains spherical nano barium sulfate product.
Embodiment
When first, high whiteness ball shaped nano barium sulfate preparation process in embodiment below and product are analyzed, determinator and measuring method used is described as follows:
What about part measuring method in barium sulfate product analysis, use is standard SN/T 0480-1995(outlet barite analytical procedure) in measuring method;
Specifically, barium sulfate content is measured the method adopting in SN/T 0480.5-1995;
The measuring brightness instrument that the model that measuring brightness adopts Jinan MICHAEL DRAKE Instrument Ltd. to produce is DRK103A (adopt 200 mesh sieves, measure after 105 ℃ of oven dry) is measured according to disclosed method in SN/T 0480.12-1995;
200 mesh sieves: ASTM standard sieve;
Fineness (325 screen residue) adopts the method for SN/T 0480.2-1995 to measure;
325 mesh sieves: ASTM standard sieve;
The mensuration of product pattern: JSM-6490LV type scanning electronic microscope, NEC company system.
The particle size determination of primary particle: JSM-6490LV type scanning electronic microscope, NEC company system.
PH pH-value determination pH adopts PHS-3C type precision acidity meter, and by Shanghai, precision instrumentation company manufactures.
The device that flash distillation is used is the fast rotational flash dryer that the model of Changzhou sudden peal of thunder drying plant company limited manufacture is XZG.
Elemental analysis method: inductively coupled plasma (ICP) atomic emission spectrometry;
Atomic Absorption SpectrophotometerICP: IRIS Intrepid II XSP type inductively coupled plasma atomic emission spectrometer, U.S. power & light company system.
Technical grade hydrogen peroxide: mass percentage concentration is 27.5%, Jiangshan City, Zhejiang Province hydrogen peroxide company produces.
Constant flow pump: the east of a river, Suzhou precision instrument company limited.
Technical grade hydrated barta: Ba (OH)
2content>=98%.
Technical grade ammonium sulfate: (NH
4)
2sO
4content>=95%.
Step in following embodiment (1) and flow successive reaction can by routine and flow flow reactor and react, also can by shown in Fig. 2 and flow flow reactor and complete.
Embodiment 1
Shown in the process flow sheet of lower combination Fig. 1, illustrate that the present invention prepares the process of high whiteness ball shaped nano barium sulfate, by technical grade hydrated barta (Ba (OH)
2>=98%) add deionized water preparation baryta water, making barium ion concentration is 0.20mol/L, by this Ba (OH)
2solution temperature is adjusted into 30 ℃, with 0.4 μ m aperture accurate filter, filters stand-by.With technical grade ammonium sulfate ((NH
4)
2sO
4>=95%) preparation ammonium sulfate solution, wherein (NH
4)
2sO
4strength of solution is 0.05mol/L, under normal temperature, with 0.4 μ m aperture accurate filter, filters stand-by.Controlling and flowing continuous synthesizer stirring velocity is 400rpm, and with constant flow pump, controlling barium hydroxide solution flow is 2000L/h, with constant flow pump, controls (NH
4)
2sO
4solution flow is 8400L/h, controls building-up reactions [Ba
2+]/[SO
4 2-] mol ratio is 1.00/1.05, by the Ba after above-mentioned processing (OH)
2solution and (NH
4)
2sO
4solution is ejected into and flows in successive reaction equipment and react, and carries out solid-liquid separation and obtains filter cake and mother liquor, stripping recovery NH after the supplementary the addition of C aO of mother liquor in reaction process after continuous collection slurry
3, filter cake enters next-step operation;
Filter cake obtained in the previous step is placed in common acid-resistant container, by material-water ratio 1: the mass ratio of 5(slip and water) add deionized water to make slip, dispersed with stirring, add a small amount of sulfuric acid to adjust pH value of solution to 2.5, after in every cubic metre of slip, add the ratio of 2 liters of technical grade hydrogen peroxide to add hydrogen peroxide, chuck heat temperature raising, hierarchy of control temperature is 70 ℃, at this temperature, stir oxidation rinsing solid-liquid separation after 1 hour, filtrate is processed discharge, and filter cake enters next-step operation.
The filter cake that upper step is obtained is placed in washing pot, by material-water ratio, adds deionized water at 1: 5, and dispersed with stirring adds appropriate (NH simultaneously
4)
2sO
4make [SO in solution
4 2-] concentration reaches 0.04mol/L to suppress crystal growth, after pass into NH
3adjust slip pH to 6.5, chuck is warming up to 75 ℃, at this temperature agitator treating after 0.5 hour solid-liquid separation obtain filter cake and filtrate, filtrate is processed discharge, filter cake flash evaporation drying obtains spherical nano barium sulfate product 1
#, it is carried out to barium sulfate content, Mn content, Fe content, whiteness, fineness (325 screen residue), the mensuration of particle diameter and particle morphology is in Table 1.
Embodiment 2
Technical grade hydrated barta is joined in deionized water and prepares baryta water, and wherein in barium hydroxide solution, barium ion concentration is 0.25mol/L, by this Ba (OH)
2solution temperature is adjusted into 33 ℃, with 0.5 μ m aperture accurate filter, filters stand-by.With the preparation of technical grade ammonium sulfate ammonium sulfate solution, wherein (NH
4)
2sO
4strength of solution is 0.25mol/L, under normal temperature, with 0.5 μ m aperture accurate filter, filters stand-by.The rotating speed of setting motor 12 is 1100rpm, setting barium hydroxide solution is 4000L/h with the flow of constant flow pump, the flow of setting ammoniumsulphate soln constant flow pump (not shown) used is 4200L/h, rear connection agitator motor power supply, connect the power supply of above-mentioned two constant flow pump (not shown) simultaneously, the baryta water that constant flow pump just configures is that 4000L/h is constantly by the first spray hole 7 by being located at that the first material inlet 2 of the bottom 16 of reactor body 1 joins in reactor body 1 according to flow, it is that 4200L/h is constantly injected to by the second spray hole 12 and flows in reaction chamber 4 according to flow that the ammonium sulfate solution of configuration is joined in reservoir 10 by the second material inlet 11, two kinds of solution moment contact hybrid reactions, control [Ba in synthetic reaction process
2+]/[SO
4 2-] mol ratio is 1.00/1.08.Reacted mixture is being located at and is being flowed under the effect of conical flow guiding cap 13 of reaction chamber bottom 17, constantly by the middle of current limiting plate 6, have metering hole 15 enter into stir chamber 5, the power that material provides by motor 14 in stir chamber 5 is uniformly mixed said mixture between agitating vane 8, be uniformly mixed in process, mixture after lower floor's blade stirring part mixture under the stopping of baffle plate 9 comes back in lower floor's blade and again stirs, part mixture continues to move upward, under the agitating vane effect of upper strata, continue to be stirred, mixture after upper strata agitating vane stirs is uniformly dispersed, in reaction process constantly by spraying in material outlet 3 slave units, after the slurry of collection ejection, carry out solid-liquid separation and obtain filter cake and mother liquor, stripping recovery NH after the supplementary the addition of C aO of mother liquor
3, filter cake enters next-step operation,
Filter cake obtained in the previous step is placed in acid-resistant container, by material-water ratio, add deionized water to make slip at 1: 6, dispersed with stirring, add a small amount of sulfuric acid to adjust pH value of solution to 2.7, after in every cubic metre of slip, add the ratio of 2.5 liters of technical grade hydrogen peroxide to add hydrogen peroxide, chuck heat temperature raising, hierarchy of control temperature is 70 ℃, at this temperature, stir oxidation rinsing solid-liquid separation after 2 hours, filtrate is processed discharge, and filter cake enters next-step operation.
The filter cake that upper step is obtained is placed in washing pot, by material-water ratio, adds deionized water at 1: 6, and dispersed with stirring adds appropriate (NH simultaneously
4)
2sO
4make [SO in solution
4 2-] concentration reaches 0.05mol/L to suppress crystal growth, after pass into NH
3adjust slip pH to 7.0, chuck is warming up to 73 ℃, at this temperature agitator treating after 1 hour solid-liquid separation obtain filter cake and filtrate, filtrate is processed discharge, filter cake flash evaporation drying obtains spherical nano barium sulfate product 2
#, it is carried out to barium sulfate content, Mn content, Fe content, whiteness, fineness (325 screen residue), the mensuration of particle diameter and particle morphology is in Table 1.
Embodiment 3
By the technical grade hydrated barta preparation baryta water that is added to the water, wherein in barium hydroxide solution, barium ion concentration is 0.30mol/L, by this Ba (OH)
2solution temperature is adjusted into 32 ℃, with 0.6 μ m aperture accurate filter, filters stand-by.With the preparation of technical grade ammonium sulfate ammonium sulfate solution, wherein (NH
4)
2sO
4strength of solution is 0.50mol/L, under normal temperature, with 0.5 μ m aperture accurate filter, filters stand-by.Controlling and flowing continuous synthesizer stirring velocity is 1000rpm, and with constant flow pump, controlling barium hydroxide solution flow is 6000L/h, with constant flow pump, controls (NH
4)
2sO
4solution flow is 3960L/h, controls building-up reactions [Ba
2+]/[SO
4 2-] mol ratio is 1.00/1.06, by the Ba after above-mentioned processing (OH)
2solution and (NH
4)
2sO
4solution is ejected into and flows in flow reactor and react, and carries out solid-liquid separation and obtains filter cake and mother liquor, stripping recovery NH after the supplementary the addition of C aO of mother liquor in reaction process after continuous collection slurry
3, filter cake enters next-step operation;
Filter cake obtained in the previous step is placed in acid-resistant container, by material-water ratio, add deionized water to make slip at 1: 7, dispersed with stirring, add a small amount of sulfuric acid to adjust pH value of solution to 2.8, after in every cubic metre of slip, add the ratio of 2.3 liters of technical grade hydrogen peroxide to add hydrogen peroxide, chuck heat temperature raising, hierarchy of control temperature is 72 ℃, at this temperature, stir oxidation rinsing solid-liquid separation after 1.5 hours, filtrate is processed discharge, and filter cake enters next-step operation.
The filter cake that upper step is obtained is placed in washing pot, by material-water ratio, adds deionized water at 1: 6, and dispersed with stirring adds appropriate (NH simultaneously
4)
2sO
4make [SO in solution
4 2-] concentration reaches 0.06mol/L to suppress crystal growth, after pass into NH
3adjust slip pH to 6.8, chuck is warming up to 75 ℃, at this temperature agitator treating after 1.2 hours solid-liquid separation obtain filter cake and filtrate, filtrate is processed discharge, filter cake flash evaporation drying obtains spherical nano barium sulfate product 3
#, it is carried out to barium sulfate content, Mn content, Fe content, whiteness, fineness (325 screen residue), the mensuration of particle diameter and particle morphology is in Table 1.
Embodiment 4
Technical grade hydrated barta is joined in deionized water and prepares baryta water, and wherein in barium hydroxide solution, barium ion concentration is 0.30mol/L, by this Ba (OH)
2solution temperature is adjusted into 35 ℃, with 0.7 μ m aperture accurate filter, filters stand-by.With the preparation of technical grade ammonium sulfate ammonium sulfate solution, wherein (NH
4)
2sO
4strength of solution is 0.50mol/L, under normal temperature, with 0.7 μ m aperture accurate filter, filters stand-by.Controlling and flowing continuous synthesizer stirring velocity is 600rpm, and with constant flow pump, controlling barium hydroxide solution flow is 6000L/h, with constant flow pump, controls (NH
4)
2sO
4solution flow is 2000L/h, controls building-up reactions [Ba
2+]/[SO
4 2-] mol ratio is 1.00/1.07, by the Ba after above-mentioned processing (OH)
2solution and (NH
4)
2sO
4solution is ejected into and flows in flow reactor and react, and carries out solid-liquid separation and obtains filter cake and mother liquor, stripping recovery NH after the supplementary the addition of C aO of mother liquor in reaction process after continuous collection slurry
3, filter cake enters next-step operation;
Filter cake obtained in the previous step is placed in acid-resistant container, by material-water ratio, add deionized water to make slip at 1: 7, dispersed with stirring, add a small amount of sulfuric acid to adjust pH value of solution to 3.0, after in every cubic metre of slip, add the ratio of 3 liters of technical grade hydrogen peroxide to add hydrogen peroxide, chuck heat temperature raising, hierarchy of control temperature is 75 ℃, at this temperature, stir oxidation rinsing solid-liquid separation after 1.5 hours, filtrate is processed discharge, and filter cake enters next-step operation.
The filter cake that upper step is obtained is placed in washing pot, by material-water ratio, adds deionized water at 1: 6, and dispersed with stirring adds appropriate (NH simultaneously
4)
2sO
4make [SO in solution
4 2-] concentration reaches 0.06mol/L to suppress crystal growth, after pass into NH
3adjust slip pH to 7.5, chuck is warming up to 80 ℃, at this temperature agitator treating after 1.5 hours solid-liquid separation obtain filter cake and filtrate, filtrate is processed discharge, filter cake flash evaporation drying obtains spherical nano barium sulfate product 4
#, it is carried out to barium sulfate content, Mn content, Fe content, whiteness, fineness (325 screen residue), the mensuration of particle diameter and particle morphology is in Table 1.
Embodiment 5
Technical grade hydrated barta is joined in deionized water and prepares baryta water, and wherein in barium hydroxide solution, barium ion concentration is 0.27mol/L, by this Ba (OH)
2solution temperature is adjusted into 33 ℃, with 0.5 μ m aperture accurate filter, filters stand-by.Ammonium sulfate preparation ammonium sulfate solution, wherein (NH with technical grade
4)
2sO
4strength of solution is 0.30mol/L, under normal temperature, with 0.6 μ m aperture accurate filter, filters stand-by.Controlling and flowing continuous synthesizer stirring velocity is 1000rpm, and with constant flow pump, controlling barium hydroxide solution flow is 5000L/h, with constant flow pump, controls (NH
4)
2sO
4solution flow is 10000L/h, controls building-up reactions [Ba
2+]/[SO
4 2-] mol ratio is 1.00/1.07, by the Ba after above-mentioned processing (OH)
2solution and (NH
4)
2sO
4solution is ejected into and flows in flow reactor and react, and carries out solid-liquid separation and obtains filter cake and mother liquor, stripping recovery NH after the supplementary the addition of C aO of mother liquor in reaction process after continuous collection slurry
3, filter cake enters next-step operation;
Filter cake obtained in the previous step is placed in acid-resistant container, by material-water ratio, add deionized water to make slip at 1: 6, dispersed with stirring, add a small amount of sulfuric acid to adjust pH value of solution to 2.9, after in every cubic metre of slip, add the ratio of 2.3 liters of technical grade hydrogen peroxide to add hydrogen peroxide, chuck heat temperature raising, hierarchy of control temperature is 72 ℃, at this temperature, stir oxidation rinsing solid-liquid separation after 2.5 hours, filtrate is processed discharge, and filter cake enters next-step operation.
The filter cake that upper step is obtained is placed in washing pot, by material-water ratio, adds deionized water at 1: 8, and dispersed with stirring adds appropriate (NH simultaneously
4)
2sO
4make [SO in solution
4 2-] concentration reaches 0.04mol/L to suppress crystal growth, after pass into NH
3adjust slip pH to 6.9, chuck is warming up to 78 ℃, at this temperature agitator treating after 1.5 hours solid-liquid separation obtain filter cake and filtrate, filtrate is processed discharge, filter cake flash evaporation drying obtains spherical nano barium sulfate product 5
#, it is carried out to barium sulfate content, Mn content, Fe content, whiteness, fineness (325 screen residue), the mensuration of particle diameter and particle morphology is in Table 1.
Embodiment 6
Technical grade hydrated barta is joined in deionized water and prepares baryta water, and wherein in barium hydroxide solution, barium ion concentration is 0.25mol/L, by this Ba (OH)
2solution temperature is adjusted into 32 ℃, with 0.7 μ m aperture accurate filter, filters stand-by.Ammonium sulfate preparation ammonium sulfate solution, wherein (NH with technical grade
4)
2sO
4strength of solution is 0.05mol/L, under normal temperature, with 0.5 μ m aperture accurate filter, filters stand-by.Controlling and flowing continuous synthesizer stirring velocity is 400rpm, and with constant flow pump, controlling barium hydroxide solution flow is 4000L/h, with constant flow pump, controls (NH
4)
2sO
4solution flow is 2000L/h, controls building-up reactions [Ba
2+]/[SO
4 2-] mol ratio is 1.00/1.06, by the Ba after above-mentioned processing (OH)
2solution and (NH
4)
2sO
4solution is ejected into and flows in flow reactor and react, and carries out solid-liquid separation and obtains filter cake and mother liquor, stripping recovery NH after the supplementary the addition of C aO of mother liquor in reaction process after continuous collection slurry
3, filter cake enters next-step operation;
Filter cake obtained in the previous step is placed in acid-resistant container, by material-water ratio 1:6, add deionized water to make slip, dispersed with stirring, add a small amount of sulfuric acid to adjust pH value of solution to 2.8, after in every cubic metre of slip, add the ratio of 2.5 liters of technical grade hydrogen peroxide to add hydrogen peroxide, chuck heat temperature raising, hierarchy of control temperature is 70 ℃, at this temperature, stir oxidation rinsing solid-liquid separation after 1 hour, filtrate is processed discharge, and filter cake enters next-step operation.
The filter cake that upper step is obtained is placed in washing pot, by material-water ratio, adds deionized water at 1: 6, and dispersed with stirring adds appropriate (NH simultaneously
4)
2sO
4make [SO in solution
4 2-] concentration reaches 0.05mol/L to suppress crystal growth, after pass into NH
3adjust slip pH to 7.0, chuck is warming up to 78 ℃, at this temperature agitator treating after 1 hour solid-liquid separation obtain filter cake and filtrate, filtrate is processed discharge, filter cake flash evaporation drying obtains spherical nano barium sulfate product 6
#, it is carried out to barium sulfate content, Mn content, Fe content, whiteness, fineness (325 screen residue), the mensuration of particle diameter and particle morphology is in Table 1.
Embodiment 7
Technical grade hydrated barta is joined in deionized water and prepares baryta water, and wherein in barium hydroxide solution, barium ion concentration is 0.25mol/L, by this Ba (OH)
2solution temperature is adjusted into 32 ℃, with 0.7 μ m aperture accurate filter, filters stand-by.Ammonium sulfate preparation ammonium sulfate solution, wherein (NH with technical grade
4)
2sO
4strength of solution is 0.05mol/L, under normal temperature, with 0.5 μ m aperture accurate filter, filters stand-by.Controlling and flowing continuous synthesizer stirring velocity is 400rpm, and with constant flow pump, controlling barium hydroxide solution flow is 4000L/h, with constant flow pump, controls (NH
4)
2sO
4solution flow is 6000L/h, controls building-up reactions [Ba
2+]/[SO
4 2-] mol ratio is 1.00/1.06, by the Ba after above-mentioned processing (OH)
2solution and (NH
4)
2sO
4solution is ejected into and flows in flow reactor and react, and carries out solid-liquid separation and obtains filter cake and mother liquor, stripping recovery NH after the supplementary the addition of C aO of mother liquor in reaction process after continuous collection slurry
3, filter cake enters next-step operation;
Filter cake obtained in the previous step is placed in acid-resistant container, by material-water ratio, add deionized water to make slip at 1: 6, dispersed with stirring, add a small amount of sulfuric acid to adjust pH value of solution to 2.8, after in every cubic metre of slip, add the ratio of 2.5 liters of technical grade hydrogen peroxide to add hydrogen peroxide, chuck heat temperature raising, hierarchy of control temperature is 70 ℃, at this temperature, stir oxidation rinsing solid-liquid separation after 1 hour, filtrate is processed discharge, and filter cake enters next-step operation.
The filter cake that upper step is obtained is placed in washing pot, by material-water ratio, adds deionized water at 1: 6, and dispersed with stirring adds appropriate (NH simultaneously
4)
2sO
4make [SO in solution
4 2-] concentration reaches 0.05mol/L to suppress crystal growth, after pass into NH
3adjust slip pH to 7.0, chuck is warming up to 78 ℃, at this temperature agitator treating after 1 hour solid-liquid separation obtain filter cake and filtrate, filtrate is processed discharge, filter cake flash evaporation drying obtains spherical nano barium sulfate product 7
#, it is carried out to barium sulfate content, Mn content, Fe content, whiteness, fineness (325 screen residue), the mensuration of particle diameter and particle morphology is in Table 1.
Embodiment 8
The hydrated barta of technical grade is joined in deionized water and prepares baryta water, and wherein in barium hydroxide solution, barium ion concentration is 0.25mol/L, by this Ba (OH)
2solution temperature is adjusted into 33 ℃, with 0.5 μ m aperture accurate filter, filters stand-by.With technical grade ammonium sulfate preparation ammonium sulfate solution (please supplement the requirement of the aspects such as source, purity of ammonium sulfate), wherein (NH
4)
2sO
4strength of solution is 0.25mol/L, under normal temperature, with 0.5 μ m aperture accurate filter, filters stand-by.Controlling and flowing continuous synthesizer stirring velocity is 1100rpm, and with constant flow pump, controlling barium hydroxide solution flow is 4500L/h, with constant flow pump, controls (NH
4)
2sO
4solution flow is 5000L/h, controls building-up reactions [Ba
2+]/[SO
4 2-] mol ratio is 1.00/1.08, by the Ba after above-mentioned processing (OH)
2solution and (NH
4)
2sO
4solution is ejected into and flows in flow reactor and react, and carries out solid-liquid separation and obtains filter cake and mother liquor, stripping recovery NH after the supplementary the addition of C aO of mother liquor in reaction process after continuous collection slurry
3, filter cake enters next-step operation;
Filter cake obtained in the previous step is placed in acid-resistant container, by material-water ratio, add deionized water to make slip at 1: 6, dispersed with stirring, add a small amount of sulfuric acid to adjust pH value of solution to 2.7, after in every cubic metre of slip, add the ratio of 2.5 liters of technical grade hydrogen peroxide to add hydrogen peroxide, chuck heat temperature raising, hierarchy of control temperature is 70 ℃, at this temperature, stir oxidation rinsing solid-liquid separation after 2 hours, filtrate is processed discharge, and filter cake enters next-step operation.
The filter cake that upper step is obtained is placed in washing pot, by material-water ratio, adds deionized water at 1: 6, and dispersed with stirring adds appropriate (NH simultaneously
4)
2sO
4make [SO in solution
4 2-] concentration reaches 0.05mol/L to suppress crystal growth, after pass into NH
3adjust slip pH to 7.0, chuck is warming up to 73 ℃, at this temperature agitator treating after 1 hour solid-liquid separation obtain filter cake and filtrate, filtrate is processed discharge, filter cake flash evaporation drying obtains spherical nano barium sulfate product 8
#, it is carried out to barium sulfate content, Mn content, Fe content, whiteness, fineness (325 screen residue), the mensuration of particle diameter and particle morphology is in Table 1.
The barium sulfate product property testing result that table 1 embodiment of the present invention prepares
By the result in upper table, show, the content of the barium sulfate that the embodiment of the present invention prepares is all greater than 99.0%, and wherein the content of the barium sulfate in embodiment 2,5 and 8 is greater than 99.3%; Embodiment 1-8 prepares Mn content in barium sulfate and Fe content all lower than 1.0ppm, and whiteness is all greater than 98.5%, and fineness is in 325 screen residues, all lower than 0.10%; The median size of the barium sulfate preparing all reaches 20-40nm, and the median size of the barium sulfate of embodiment 2-5,7 and 8 preparations all reaches 20-30nm, and particle morphology is spherical.Barium sulfate prepared by above-mentioned digital proof the present invention has high whiteness, high purity, and particle diameter has reached nano level feature.
The present invention has carried out above-mentioned description to some preferred implementation and embodiment, to help the public to use suitable experimental technique in implementing process of the present invention, obtain good experiment effect, this does not get rid of the experimental technique being equal to of not enumerating in the present invention also can implement the present invention.It will be appreciated by those skilled in the art that the present invention is except specifically described mode, can also be applicable to distortion and revise.Should be understood that, the present invention includes all these distortion and modification.Further, denomination of invention, title or similar part are in order to strengthen the public to understanding herein, should not regarded as limiting the scope of the present invention.
Make a general survey of whole specification sheets and claims, unless context needs, otherwise word " comprises ", " comprising " and similar word, and the implication that is interpreted as comprising but not the implication got rid of that is to say, look like for " including, but are not limited to ".