CN1605824A - Drying and pulverizing process for preparing powder material with high dispersibility - Google Patents
Drying and pulverizing process for preparing powder material with high dispersibility Download PDFInfo
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Abstract
The present invention relates to one kind of new drying and crushing technique, in which high temperature air flow is used to impact material to disperse the material highly and to evaporate its water instantaneously, or, to make the material hydrolyze and condensate instantaneously to form highly dispersed dry fine particles. The technique may be used in dispersing inorganic pigment, inorganic stuffing and nanometer material.
Description
Technical field
This invention relates to a kind of employing elevated temperature heat air-flow high speed impact material to be processed, processed material moment is smashed, moisture content flash evapn in the material to be processed, dehydration, the heat treatment in moment of particle in the material, obtain the powder body material of high degree of dispersion, perhaps moment hydrolysis, condensation, trickle particle, dehydration, the heat treatment of formation take place in the material in the material, form the novel dried disintegrating process of the powder body material of high degree of dispersion.This technology is with the dispersion problem of inorganic pigment, inorganic filler and the nano material of the solution classics of success.The quality that improves homemade titanium dioxide, iron oxide red and the preparation of nano titanium oxide there is important economic value.This technological invention is accumulate and is being deposited huge business opportunity.
Background technology
Inorganic pigment, filler, nano-ceramic powder are the preparation method that chemistry is generally adopted in the preparation of nano oxide powder, chemical reaction takes place in liquid phase, generate product, reaction system is filtered washing, removed accessory substance and other impurity in the system, and obtaining product is the filter cake semi-finished product of water content.With filtration cakes torrefaction or heat treatment, pulverizing, obtain finished product.The interaction force of the surface molecular of trickle pigment that chemical combination forms in the preparation process or filler, nano particle chemical bonding, formation strong, that surface molecular between particle takes place in the process of drying are easily combined closely, aggregation phenomenon, seriously influenced the dispersiveness of product, bring bad shadow noon in the application process of product, the performance of product in application system can not fully play out.Prevent that the particle in the filter cake from the dispersiveness of product taking place to reunite closely, improve in dry run, in the use of product, allow its performance fully play out and have great significance.It is not ideal to adopt classical drying and breaking method to improve in the preparation process dispersion of nano-particles, the powder of easily combining closely when especially handling for dry heat, as: iron oxide red, iron oxide yellow, titanium dioxide, chrome yellow, white carbon black, superfine alumina silicate, nano-calcium carbonate, nano zircite, nano titanium oxide, nano-stannic oxide, nano zine oxide, trickle aerosil, nanometer iron oxide red, nanometer iron oxide yellow etc.
Classical drying and crushing method is general to adopt more popular spray drying process, and the agglomerated particles after spray-dried is generally greater than 20 microns, and the single particle that generates during than reaction is much bigger, the dispersiveness leeway that also improves a lot.For the dispersiveness that improves product, to filter cake pulp again, add surface conditioning agent and carry out surface treatment, allow inorganic agent be coated on the surface of particle, prevent particle generation tight agglomeration in the dry run, this seems incompatible to the product that needs high-temperature heat treatment, as products such as iron oxide red, titanium dioxide, zirconium dioxide, chrome yellow.For nano-powder, specific surface surface conditioning agent consumption big, that requirement adds is big, can produce bad shadow noon to the nanometer finished product.Adopt the method that adds surface conditioning agent to seem not effectively with feasible.
The supercriticality of researching and developing is synthetic, drying and crushing method, the powder dispersity height that obtains, but the temperature height under the supercriticality, pressure height, as the above-critical state of water, to spend 400, the pressure of 220atm, this requirement to equipment is very high, operation easier is big, energy consumption is higher, is not suitable for the processing of extensive amount.
Found a kind of new drying-breaking method, the dispersiveness (the especially dispersiveness of nano material) that further improves powder product should have significant values and meaning.
The present invention is intended to solve the dispersion problem of above-mentioned powder body material.
Summary of the invention
Know-why of the present invention is:
The fine particle that adopts the chemical method liquid phase to generate is present in the moisture content environment, and particle surface generally has hydroxyl and exists, and the hydroxyl condensation on surface has formed chemical bond combination closely dispersiveness is caused shadow noon between particle.Before condensation takes place mutually in the surface hydroxyl between the particle, allow same particle surface the mutual condensation of hydroxyl, heat treatment, dewater, no longer include the existence of surface hydroxyl, will help the raising of particle system dispersiveness.There is the thicker moisture film of one deck in fine particle surface in the moisture content environment, and the particle and the particle aggregation that have moisture film have formed the slurry fluid together or be distributed in formation colloidal sol body in the system uniformly.Tight agglomeration does not take place between particle and particle, form before chemical bond combine, the pressure of generation can smash the particle that has moisture film, form single fine particle when allowing moisture film instant vaporization between the particle, moisture film vaporization.The particle of removing moisture film should be in the high temperature system, the hydroxyl on surface obtains condensation in moment, and the chemical combination power between particle and the particle when colliding once more reduces, and no longer forms chemical bond combination closely, and the dispersiveness of the powder that forms is improved.Reduce the time that formed particle stops as much as possible in liquid phase environment, avoid particle that the tendency of mutual bonding is arranged in liquid phase environment, will be of value to the raising of particle system dispersiveness.For the slaine with easy generation hydrolysis is that raw material prepare powder particle, can accomplish to reduce to greatest extent the generation time of staying of fine particle in liquid phase environment.The aqueous solution or these slaines that the slaine (comprising alkoxide) of hydrolysis easily takes place add the midbody solution system (both are called for short molten fluid) that alkali partly neutralizes, hydrolysis forms, and when contacting with high-temperature medium, the intensification of being heated of system moment, moisture content is in instant vaporization.At moisture content fast in the process of vaporization, slaine generation complete hydrolysis, form trickle intermediate particle, the intermediate particle forms trickle finished product particle in moment internal condensation, heat treatment.The probability that is in contact with one another of the particle that forms is very little in the process, can not form chemical bond combination more closely in particle high speed heat treated moment, obtains the super-fine metal oxide powder of high dispersive.Moisture content in moisture film between the particle or the molten fluid will be vaporized in moment, should be possessed following condition:
1 particle system or the molten fluid that has moisture film should place hot environment, contact with high-temperature medium, improves heat transfer temperature difference.
2 have the particle system of moisture film or the dispersion that molten fluid should obtain height, improve the contact area of the particle system or molten fluid and the high-temperature medium that have moisture film as much as possible, improve heat transfer area.
3 have the particle system of moisture film or molten fluid and high-temperature medium is in turbulence state, improves heat transfer coefficient.
Adopt Venturi tube, allow high temperature gas flow (generally adopting air) from Venturi tube, flow through.With filter cake pulp once more, breaing up becomes the suitable slurry fluid of viscosity or intermediate preparation is become the colloidal sol body.Allow slurry fluid or colloidal sol body or molten fluid around the throat of Venturi tube, inject.The slurry fluid that injects is (as the hydrate metatitanic acid slurry fluid of the titanium dioxide of producing the titanium dioxide process, the titanium deoxide slurry fluid, the slurry fluid of iron oxide hydrate, the slurry fluid of Silicon dioxide, hydrate, titanic wintercherry fluid, produce the intermediate zinc hydroxide of nano zine oxide or the slurry fluid of basic carbonate acid zinc, the slurry fluid of zirconium dioxide hydrate, the alumina hydrate slurry fluid, the slurry fluid of tin dioxide hydrate) or colloidal sol body (as: titanic acid-sol body, metatitanic acid colloidal sol body, the TiO 2 sol body, the silicon dioxide gel body, hydrate colloidal sol body of iron oxide or the like), or molten fluid is (as: as butter of tin, titanium tetrachloride, chlorination oxygen titanium, Titanium Nitrate, the aqueous solution such as ferric nitrate), or it adds the molten fluid of product after alkali partly neutralizes, perhaps be above-mentioned NM other arbitrary processed materials, comprise through mixing or Combined Processing prepares and mixes or the material to be processed of composite powder material, at throat and high temperature, the high speed hot fluid is the effect of air-flow body.Hot fluid at a high speed will be starched fluid or colloidal sol body or molten fluid in throat moment and break up, becomes trickle slurry fluid or colloidal sol body particle or droplet particles, be distributed in the high temperature fluid of turbulent flow, form contact area widely, high heat transfer temperature difference, big heat transfer coefficient.The moment decline of hot fluid pressure, vacuum in throat improve greatly, and the boiling point of moisture content greatly descends in the system, and the moisture content in trickle slurry fluid or the colloidal sol body particle generates single anhydrous powder particle in instant vaporization.When being the liquid fluid particles, in the process of moisture content instant vaporization, metallic compound be heated moment complete hydrolysis, condensation, the trickle powder particle of formation.The moment intensification in high temperature fluid of these dry powder particles is heat-treated.The time of contact of the mutual collision in heat treatment between the powder particle is extremely short, and the probability of combining closely descends, and the dispersiveness of product is not produced tangible influence.High temperature fluid is carrying powder particle through throat, the temperature moment decline of self, flow through the expanding reach of Venturi tube, flow velocity slows down, and the powder in the system and the active force of fluid are strengthened because of deceleration, particle is played broken effect, further prevent to take place between particle tight agglomeration.High temperature fluid is carrying powder and flowing into conveyance conduit behind the Venturi tube expanding reach, and this moment, the particle performance of powder was definite.Perhaps adopt the less common tube of internal diameter, allow thermal current from pipe, flow through at a high speed, starch fluid or colloidal sol body or molten fluid and, finish said process from pipe injection on every side.Perhaps adopt other effective working equipments to finish said process.Other effective equipment and device were meant to provide and allow the processed material of elevated temperature heat air-flow high speed impact, processed material can be smashed process equipment that the moisture content of material evaporates and device in moment in moment.Here preferred Venturi tube.The temperature of high temperature fluid is higher, contains more heat energy, and this portion of energy is recycled.The high temperature system that will contain powder imports in the waste-heat recoverer, heats the initial cryogen that enters system, and the temperature of hot fluid further descends, (lower as the hot fluid temperature of coming out from Venturi tube, do not need through waste heat recovery.) system is imported the gas solid separation system: as equipment such as cyclone separator, electrostatic precipitator, gas-solid is effectively separated, and separates back gas and goes emptying, as atmosphere is polluted, must carry out emptying again after the purified treatment.Powder is collected the back packing and is handled, and obtains the finished product of high degree of dispersion.The initial fluid (air) that enters system becomes hot-air through waste-heat recoverer, temperature rising.Before entering Venturi tube,, adopt the direct and oil liquefied gas burning of hot-air, generate high temperature fluid, by the controlled temperature that heats fluid of the addition of combustion gas in order to obtain high-temperature hot fluid.Preparation material to Venturi tube does not add concrete definite.The length of the import contraction section of Venturi tube and outlet expanding reach do not added specifically determine, can determine the general design of Venturi tube according to country.Can inject energy carrier simultaneously at the position behind throat or the throat or add energy, the system temperature that further raises is of value to the heat treatment of product.When energy carrier can mix with slurry fluid or solution, both can be mixed injection.Before carrying out gas solid separation, thermal current should be cooled to the operating temperature of cleaner.The turnover implication speed of Venturi tube does not add concrete determining.
In order to obtain the slurry fluid of good fluidity, help it is smashed and be thinner particle, a little dispersant of adding that can be suitable when pulp improves mobile.The existence that allows acid or neutralized reaction product salt in colloidal sol body or the molten fluid is as ammonium chloride, ammonium sulfate or the like.
Carrying out before drying and crushing handles, in processed material, can add other material, mixing or compound, mixed after the processing or compound powder body material.
Processed material is present in sour environment as product after processing, as: the existence of hydrochloric acid gas is arranged, and product has suction-operated to sour gas, can have the sour gas of a little in the product, should adopt air in blowing off tower, and sour gas is blown out.
Determining of technological parameter of the present invention and technological process:
Determining of the high-temperature hot fluid inlet temperature of 1 Venturi tube.
The inlet temperature of high temperature fluid is high more good more theoretically, but too high temperature has relatively high expectations to the material of Venturi tube inducer, and the oxygen content in the hot fluid requires high, can not have the charing phenomenon to exist fuel completing combustion, and product is polluted.Here selecting temperature is more than 200 degree, is preferably 900 degree-1600 degree.
2 hot fluids are selected in the gas speed of throat.
The design of Venturi tube can be carried out Venturi tube design related standards according to country.Slurry fluid that the hot fluid flow velocity of throat injects from throat refinement or colloidal sol body or molten fluid have important shadow noon.Flow velocity is high more, and thinning effect is good more.The air velocity that is under the condition of pressure loss permission, should improves throat is as much as possible fallen at throat pressure.The thermal current flow velocity of determining throat here is greater than 20m/s, is preferably 200-300m/s.
3 Venturi tubes are imported and exported determining of hot fluid flow velocity.
This import and export flow velocity can be determined according to the flow velocity range of choice of relevant on " chemical process design manual " general gas under normal pressure.Generally at 10-20m/s.Perhaps on the low side or higher flow velocity.
Determining of the slurry fluid of 4 injection throat or the water content of colloidal sol body or molten fluid.
Filter cake is added water break up, prepare slurry once more during fluid, flowability permission at the slurry fluid, inject, be difficult under the condition of blockage phenomenon from the hole that throat is opened on every side, should reduce the content of moisture content as much as possible, reach the firing rate of minimizing processing procedure and the loss of merit, reduce the purpose of the processing cost of processing procedure.The slurry fluid of preparation different material, the amount difference of its water content; With the finer particles that a kind of material generates, the moisture content in the slurry fluid is just high more.The slurry fluid moisture content height of nano particle, the slurry fluid moisture content of general pigment, filler is few.The active ingredient solid content generally should be more than 1% when (both are called for short solution) for colloidal sol body or molten fluid.
Determining of 5 venturi outlet temperature.
Venturi outlet temperature height is of value to the raising of process heat transfer rate, and powder dispersity is produced wholesome effect.At high temperature can cause qualitative change to some product, require the temperature of venturi outlet fluid should not be too high.As when handling iron oxide yellow, high temperature can make product become iron oxide red.Here determine to improve outlet temperature as much as possible under the condition of permission, outlet temperature should be more than 100 degree.Be preferably as much as possible near the 400-600 degree.
Determining of 6 waste-heat recoverers outlet hot fluid temperature.
Waste-heat recoverer outlet hot fluid temperature is low more, and recuperation of heat is complete more.Cross low outlet temperature and can cause the thermal driving force of diabatic process to reduce, requiring has bigger heat transfer area just can finish diabatic process, and this requirement has very big heat exchanger.General definite hot fluid outlet temperature is more than 30 degree, is preferably the 200-250 degree.
Selecting of 7 powder separation process devices.
This separation process device can be determined according to the relevant cleaner of " chemical process design manual ".Here preferably adopt the two-stage cleaner: cyclone separator and electrostatic precipitation or pulse bag type dust collector.
The number of the throat perforate of 8 Venturi tubes is determined.
Slurry fluid or solution inject around the throat of Venturi tube, must be in throat evenly perforate on every side, and the number of perforate is The more the better in principle, but number is many more, and the influx minimizing from each hole causes the obstruction in hole easily, slurry fluid or solution amount that big Venturi tube is handled are big, and the number of perforate should be many.Here determine that general minimum hole count is 1-3.The flow velocity that fluid injects does not add definite, is preferably 5-10m/s.
Determining of 9 Venturi tube quantity and connected mode.
For handle large-minded the time, the oversize meeting of Venturi tube causes harmful effect to process, a plurality of Venturi tubes can be together in parallel.Narrow-minded for hot fluid, require to handle under the big situation of slurry fluid or solution amount, a plurality of Venturi tubes can be together in series, after high temperature fluid descends through the Venturi tube temperature, reinject fuel or energy carrier rising fluid temperature (F.T.), enter second level Venturi tube and handle, behind the Venturi tube of afterbody, advance the waste-heat recoverer recovery waste heat again.This method is adapted to handle resistant to elevated temperatures inorganic pigment and nano particle.As titanium dioxide, nano titanium oxide etc.
The slurry fluid of 10 injection Venturi tubes or the temperature of solution are determined.
Slurry fluid or the solution temperature of injecting Venturi tube are generally normal temperature, can hyperthermic treatment, the particle of the minimizing that is of value to high temperature gas flow and course of injection smashes.
11 can inject energy or energy carrier simultaneously at the position or the position behind the throat of throat, and the hot stream temperature that further raises is convenient to the heat treatment of product.
12 thermal currents can be the hot fluids that produces behind air and the fuel chemical combination, can also be the hot fluid of other media.Generally adopt the former.
If 13 to enter the hot fluid temperature of dust pelletizing system too high, the hot fluid processing of should lowering the temperature, the hot fluid temperature drops to the operating temperature of dust pelletizing system equipment.
14 powders after gas solid separation should blow out sour gas in blowing off tower as having sour gas.
The superiority of technology of the present invention is:
This technology adopts the heat treated limit processing method of wink-dry, material is carried out drying and crushing handle, and obtains the powder body material of polymolecularity.
1 adopt this technology success solution the dispersion problem of traditional classical pigment, the trickle powder of filler, adopt classical preparation technology to obtain the intermediate filter cake of powder, filter cake is carried out just can adopting this technology to come the pigment of processing polymolecularity, the end product of filler after good pulp is handled.This technology makes the quality of classical pigment, filler product that huge variation take place, and is a milestone on the drying and crushing history of technique.
2 adopt this technology, precursor sol, solution or presoma slurry with nano material are the processing object, can directly prepare the ultra-fine nano material of high dispersive, during the course the fine particle of nano material formed, drying, be that nano particle generates, dry, the integral process process pulverized.Process is a process of finishing fast, and the defective of the nano particle of generation is more, specific surface is big, and the best that helps the nano particle function embodies.Adopt this technology to come the production and processing nano material, make the preparation of nano material and the solution that dispersion problem is all succeeded thereof, for the suitability for industrialized production of nano material provides technical guarantee with using widely.
Significance of the present invention is:
1 adopt this technology success solution the dispersion problem of traditional product, make the quality of traditional product be greatly improved.With the titanium dioxide is example: it is 40 to come ten thousand tons, nearly 200,000 tons of import that China produces the titanium dioxide amount per year.The dispersiveness of homemade titanium dioxide is very different than the product of import, makes the price of homemade titanium dioxide than the low 5000-9000 unit/ton of import.Adopt titanium dioxide pigment quality homemade after this technology will with the quality that is equal to or is higher than import of import, this will significantly reduce the import of China to titanium dioxide, improve the outlet of titanium dioxide.China is the big producing country of an iron oxide inorganic pigment, homemade iron oxide pigment is not resolved on dispersed this technical barrier, the product of producing is some low-grade iron oxide products mostly, and the product of outlet also is some low-grade products mostly, and value-added content of product is lower.After adopting this technology, the dispersiveness of homemade iron oxide pigment can be improved on a large scale.After being improved, the quality of product has great significance to exporting high-grade iron oxide pigment.Adopt this technology to come the traditional product of processing that huge economic implications is arranged!
2 nano materials have development prospect widely, adopt this technology to prepare to handle classical nano material as nano titanium oxide, transparent iron oxide red, nano zine oxide, nano-stannic oxide or the like, make the dispersion problem of these nano materials be resolved, performance obtains best embodiment.This preparation to nano material has immeasurable meaning.Nano titanium oxide is one of most important nano ceramic material, has great significance in the photocatalytic degradation field, adopts this technology significant to preparing H.D nano titanium oxide.
Description of drawings
Fig. 1 is the process chart of embodiment one
The specific embodiment
Embodiment one
With the production line of producing 10000 titanium dioxides per year is example, designs the import and export technological parameter of Venturi tube:
After the metatitanic acid ageing went out, the titanium dioxide equivalent solid content after Shui Xi the filter cake pulp was 20% after filtration.The slurry fluid flow that injects the Venturi tube throat is: 1.75kg/s.
The temperature value of venturi outlet is: 400 degree.This slurry fluid is warmed up to 400 degree from normal temperature 30 degree, moisture content vaporization wherein, and the heat that is absorbed is altogether: 4675kj/s.
Adopt roots blower that the air pressure of 1atm is provided, the inlet temperature value of Venturi tube is 1600 degree, and under 2atm (absolute pressure), the air mass flow that enters Venturi tube can be defined as: 3.50kg/s.Volume flow (30 degree calculate) is 1.51m
3/ s.
The hot-air that adds that comes from waste-heat recoverer is set at 250 degree, is warmed up to the heat that 1600 degree are absorbed from 250 degree to be: 5400kj/s.
The combustion heat value of the combustion gas that will add in the process is: 54000kj/kg.The gas quantity of adding is: 0.100kg/s.
The hot fluid temperature value that goes out waste-heat recoverer is about 180 degree.
The process of Venturi tube is determined:
1 imports and exports determining of internal diameter:
The gas that comes out from roots blower to the import department of Venturi tube is a low-pressure gas: gauge pressure is 1atm, and for low-pressure gas, the flow velocity of inlet gas is elected 10m/s as.Volume flow when 1600 degree mass flows are about 3.50kg/s is about: 9.314m
3/ s, the internal diameter of import are 1100mm.Caliber is excessive, can cause the larynx footpath of throat excessive, is unfavorable for the slurry fluid is smashed, and adopts the Venturi tube of two parallel connections to handle at this.The caliber of each Venturi tube is: 780mm.The outlet internal diameter of Venturi tube can be equal to import.
Determining of 2 throat internal diameters:
In throat, hot fluid impacts hot fluid to be mixed with slurry fluid moment, and temperature moment reduces to 400 and spends, and the flow velocity value that goes out throat is: 300m/s.Amount after the moisture content vaporization is 1.40kg/s.Flow always is 4.90kg/s.The current density that goes out throat is calculated as 0.385kg/m
3, the volume flow that goes out throat is: 12.76m
3/ s.Single throat internal diameter is: 160mm.
3 Venturi tube import contraction sections, throat, the definite of outlet expanding reach equal length can carry out according to the design standard of the relevant Venturi tube of country.The length of throat can be suitable lengthening.
Perforate is 5 around the throat of 4 Venturi tubes, and injecting the slurry flow rate of fluid is 7.6m/s.The internal diameter of perforate is 5mm.
Operational process of craft:
1 will filter the filter cake after the washing, and making beating preparation titanium dioxide equivalent content is 20% slurry fluid.
2 adopt roots blower in parallel that air-flow with enough pressure heads and air quantity is provided.Air-flow comes out to enter the tubulation of tubular heat exchanger of waste-heat recoverer from roots blower, and temperature raises, go out heat exchanger after, the temperature of air-flow is elevated to about 250 degree.
The combustion gas reaction of 3 preheated gas flow and injection generates the 1600 elevated temperature heat air-flows of spending, and high temperature hot gas flows to into Venturi tube.
4 high temperature hot gas flow to into Venturi tube, the pore that the slurry fluid adopts the pump pressurization to be opened around the Venturi tube injects, and in throat high temperature gas flow and the effect of slurry fluid, hot fluid will be starched fluid and smash and become trickle slurry fluid particles, and, become the powder particle of high degree of dispersion with its moisture content instant vaporization.Self temperature moment drops to 400 and spends.
The 5 high temperature gas flow temperature back that descends forms gas-solid mixture with fluid with injecting, and goes out Venturi tube and enters waste-heat recoverer, and is peripheral by the air in, the heating tube at the tubulation of waste-heat recoverer, go out waste-heat recoverer after, the temperature of system drops to about 180 degree.The design of relevant heat exchanger can be selected according to the size of heat exchange amount, throughput according to " chemical process design manual ".
6 systems enter cyclone separator, and with gas and dust initial gross separation, the temperature of fluid further reduces.The design of relevant cyclone separator can be according to " chemical process design manual ", determine according to handled throughput.
7 go out cyclone separator after, system enters pulse bag type dust collector, further high-effective dust-removing separates solid and gas.The design of relevant pulse bag type dust collector can be determined according to the size of throughput according to " chemical process design manual ".
Dust after the separation is an anatase structures, and the crystal formation that obtain rutile need carry out high temperature (about 800 degree) heat treatment again.Separate powder dispersiveness more much higher than adopting classical drying and crushing method, do not have tangible particle aggregation phenomenon, powder is loose, bulk density significantly is lower than and adopts the prepared powder that comes out of classical drying and crushing method.
Dispersed check experiment shows: the filter cake that adopts same quality, particle diameter after the titanium dioxide making beating that the method for the drying and crushing that utilization is classical obtains disperses is greater than 5 microns (adopting the detection of fineness scraper plate meter), adopt the particle diameter after the prepared titanium white powder of this method, making beating disperse on fineness scraper plate meter, can not show, less than 1 micron.
Embodiment two
To produce 10000 tons of photocatalytic degradation nano titanic oxide sols per year is that example is determined each technological parameter.The amount that contains nano titanium oxide in the colloidal sol is 10%.The solid content of the nano titanic oxide sol that ageing is come out under non high temperature gets 20%.This colloidal sol is carried out Venturi tube elevated temperature heat air-flow jet drying pulverize heat treatment.The colloidal sol flow that injects Venturi tube is 0.175kg/s.
The outlet temperature of Venturi tube is got 400 degree, and colloidal sol is elevated to 400 degree in the throat temperature from normal temperature 30 degree, and the total amount of heat that absorbs in the process is about: 467.5kj/s.
The inlet temperature of Venturi tube is got 1600 degree, and inlet pressure is 2atm, and the MAF that enters Venturi tube can be defined as 0.350kg/s, and volume flow is that 30 degree are 0.151m down
3/ s.
The preheated air that comes from waste-heat recoverer is defined as 250 degree, and air is 540.04kj/s by the heat that 250 degree are warmed up to the required absorption of 1600 degree.
The fuel value of the required combustion gas of adding is 54000kj/kg in the process.The gas quantity that needs is about 0.01kg/s.
The hot fluid temperature value that goes out waste-heat recoverer is 180 degree.
1 Venturi tube is imported and exported determining of internal diameter.
For atmosphere gas, the flow velocity of inlet gas is elected 10m/s as.Volume flow when 1600 degree mass flows are about 0.350kg/s is about: 0.9314m
3/ s, the internal diameter of import are 350mm.350mm is got in outlet.
Determining of 2 throat internal diameters:
In throat, hot fluid mixed with colloidal sol fluid moment, and temperature moment is reduced to 400 degree, and the flow velocity value that goes out throat is: 300m/s.The current density that goes out throat is calculated as 0.385kg/m
3, the volume flow that goes out throat is: 1.276m
3/ s.The throat internal diameter is: 73mm.
3 Venturi tube import contraction sections, throat, the definite of outlet expanding reach equal length can carry out according to the design standard of the relevant Venturi tube of country.The length of throat can be suitable lengthening.
Perforate is 4 around the throat of 4 Venturi tubes, and the internal diameter that injects the perforate of slurry fluid is 4.0mm.The mass flow of injecting is 0.175kg/s.Orifice flow speed is 3.00m/s.
Operational process of craft:
1 will filter the nano titanium oxide filter cake that goes out of non high temperature heat treatment ageing after the washing adds acid to break up, prepare titanium dioxide equivalent content is 20% colloidal sol fluid.
The 2-7 step adopts the same steps as among the embodiment one.
Prepared product shows by the check experiment of dispersiveness: the filter cake that adopts same quality, the nano titanium oxide that the method for the drying and crushing that utilization is classical obtains is difficult to disperse with ultrasonic wave, adopt the prepared nano titanium oxide of this method to be easy to be separated into the single sol particles of high degree of dispersion, obtain the nano titanic oxide sol body product of high-temperature heat treatment with ultrasonic wave.
Embodiment three
The mixed liquor of employing titanium tetrachloride and water directly prepares the nano-titanium dioxide powder of polymolecularity after venturi action: output is for producing 1000 tons per year.
The preparation of the mixed solution of titanium tetrachloride and water:
Titanium tetrachloride is added dropwise in the concentrated hydrochloric acid solution, and the solid content that obtains equivalent titanium dioxide is 20% solution.The hydrochloric acid that the dropping process volatilizes is through collecting, obtain concentrated hydrochloric acid solution.
Mixed system to this titanium tetrachloride and water carries out Venturi tube elevated temperature heat air-flow jet drying pulverization process.The liquid inventory that injects Venturi tube is 0.175kg/s.
Following steps are with the corresponding steps among the embodiment two.
Operational process of craft:
1 is added dropwise to concentrated hydrochloric acid solution with titanium tetrachloride, makes titanium dioxide equivalent content and be 20% solution fluid.The hydrochloric acid recycling that evaporates in the process obtains concentrated hydrochloric acid, part circulates and prepares the mixed solution body of titanium tetrachloride and water as the concentrated hydrochloric acid of next batch of material.
The 2-7 step is with the corresponding steps among the embodiment two.Contain chlorination of hydrochloric acid hydrogen in the tail gas, tail gas is fed cooling tower, directly the water cooled exhaust gas forms dilute hydrochloric acid solution, has acid mist to form in the tail gas, adopts electrostatic precipitator acid mist in the tail gas to be removed tail gas emptying.The diluted acid of collecting in the process is used for absorbing titanium tetrachloride solution and water effect, the hydrochloric acid that hydrolysis is emitted takes place, and generates concentrated hydrochloric acid.
Have sour gas hydrochloric acid in 8 the powders after gas solid separation, in blowing off tower, adopt air that the hydrochloric acid in the powder is blown out, obtain qualified product.
The nano particle that adopts this method to produce is lower than 5 nanometers, and anatase titanium dioxide has good catalytic, dispersiveness.
Annotate: the percentage composition of mentioning in the specification is the quality percentage composition.Degree refers to degree centigrade ℃
Annotate to be equipped with in the drying and crushing process flow diagram of example one: if 1, the temperature that enters sack cleaner is too high, must cooling processing gas to operating temperature; 2, Venturi tube adopts two parallel connections, and roots blower can adopt many parallel connections; 3, cyclone separator can adopt two parallel connections; 4, pulse bag type dust collector can adopt a plurality of parallel connections.
Claims (8)
1, a kind of drying and crushing technology for preparing the polymolecularity powder body material, it is characterized in that: adopt the high temperature fluid that is heated at a high speed by the throat of Venturi tube or general gas flow tube, the slurry fluid that will inject around Venturi tube throat or the gas flow tube or the aqueous solution of colloidal sol body or metal ion compound or its add solution that alkali partly neutralizes and smash and be trickle fluid particles, fluid particles is the moisture content instant vaporization in the high-temperature low-pressure environment, group further breaks up with fluid particles, forms the powder particle of high dispersive; System enters dust pelletizing system through waste heat recovery or without waste heat recovery, the powder of the polymolecularity that obtains separating; Tail gas emptying after the separation or purified treatment emptying; The preferred Venturi tube that adopts is preferably through waste heat recovery; Can inject energy carrier simultaneously at the position behind throat or the throat or add energy, the system temperature that further raises is of value to the heat treatment of product; When energy carrier can mix with slurry fluid or solution, both can be mixed injection; Before carrying out gas solid separation, thermal current should be cooled to the operating temperature of cleaner.
2, drying and crushing technology according to claim 1 is characterized in that: the temperature that hot fluid enters Venturi tube is 200-2500 ℃, is preferably 900-1600 ℃; Hot fluid is a kind of air-flow in air, steam, the carbon dioxide, the high temperature gas flow that generally adopts air and fuel directly to burn and produce; This air-flow can carry out purified treatment before intensification, remove dust wherein.
3, this drying and crushing technology according to claim 1, it is characterized in that: the throat speed of Venturi tube is 20-600m/s, is preferably 200-300m/s; Have the hole of injecting fluid around the Venturi tube throat.
4, drying and crushing technology according to claim 1, it is characterized in that: the outlet temperature of Venturi tube system is decided on different materials, generally at 100-800 ℃, is preferably 400-600 ℃.
5, drying and crushing technology according to claim 1 is characterized in that: the water content in the slurry fluid reduces as much as possible; Effective content is that equivalent finished product content should be at 1-50%, preferably at 10-30% in slurry fluid or colloidal sol body or the molten fluid
6, drying and crushing technology according to claim 1 is characterized in that: Venturi tube can carry out a plurality of in parallel uses or the series connection use according to specific circumstances; Can add the temperature that energy carrier or fuel improve system between the Venturi tube of series connection; The series connection Venturi tube between can have other cleaners intervention, carry out gas solid separation, preferably stay out of other cleaners.
7, drying and crushing technology according to claim 1 is characterized in that: the state that is injected into the material of processing can be that the slurry fluid (as: is produced the hydrate metatitanic acid slurry fluid of the titanium dioxide in the titanium dioxide process, the titanium deoxide slurry fluid, the slurry fluid of iron oxide hydrate, the slurry fluid of Silicon dioxide, hydrate, titanic wintercherry fluid, produce the intermediate zinc hydroxide of nano zine oxide or the slurry fluid of basic carbonate acid zinc, the slurry fluid of zirconium dioxide hydrate, the alumina hydrate slurry fluid, the slurry fluid of tin dioxide hydrate) or colloidal sol body (as: titanic acid-sol body, metatitanic acid colloidal sol body, the TiO 2 sol body, the silicon dioxide gel body, the hydrate colloidal sol body of iron oxide) or the aqueous solution that the metallic compound of hydrolysis mixes with water or the metallic compound that hydrolysis easily takes place and water mixed liquid easily take place by adding the alkali neutralization, obtain the product solution of partial hydrolysis; The metal ion aqueous solution of solubility facile hydrolysis is as pink salt, titanium salt, molysite, alkoxide solution; Molten fluid that part adds alkali neutralization is as tin-salt solution body, titanium salt solution body, the iron salt solutions body of part neutralization; Permission has other salts or the existence of acid or the existence of other organism auxiliary agents in the processed material.
8, a kind of purposes for preparing the drying and crushing technology of polymolecularity powder body material is characterized in that: this technology is suitable for the powder of polymolecularity such as iron oxide, chrome yellow, titanium dioxide inorganic pigment; Alumina silicate, the white carbon black of the precipitation method, aerosil filler; The preparation of nano-sized iron oxide, nano titanium oxide, nano zine oxide, nano-stannic oxide, nano zircite nano material.
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| Application Number | Priority Date | Filing Date | Title |
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| CN 200310110403 CN1605824A (en) | 2003-10-08 | 2003-10-08 | Drying and pulverizing process for preparing powder material with high dispersibility |
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| Application Number | Priority Date | Filing Date | Title |
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| CN 200310110403 CN1605824A (en) | 2003-10-08 | 2003-10-08 | Drying and pulverizing process for preparing powder material with high dispersibility |
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| CN1605824A true CN1605824A (en) | 2005-04-13 |
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| CN 200310110403 Pending CN1605824A (en) | 2003-10-08 | 2003-10-08 | Drying and pulverizing process for preparing powder material with high dispersibility |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104849410A (en) * | 2015-05-28 | 2015-08-19 | 河南佰利联化学股份有限公司 | Rapid detection method for dispersion of titanium dioxide in oil paint |
| CN105152175A (en) * | 2015-09-10 | 2015-12-16 | 安徽龙泉硅材料有限公司 | Method for utilizing waste heat generated in SiO2 aerogel production |
| CN105174275A (en) * | 2015-09-10 | 2015-12-23 | 安徽龙泉硅材料有限公司 | Preparation method of silicon dioxide aerogel |
| CN106168450A (en) * | 2016-08-11 | 2016-11-30 | 爱森（中国）絮凝剂有限公司 | A kind of chemical production equipment reducing powder stock moisture content |
| CN113563012A (en) * | 2020-04-29 | 2021-10-29 | 台湾气凝胶科技材料开发股份有限公司 | Preparation method of cold-resisting and heat-insulating hydrophobic aerogel composite jelly and related product thereof |
| CN115406185A (en) * | 2022-08-26 | 2022-11-29 | 攀钢集团攀枝花钢铁研究院有限公司 | Titanium tetrachloride slurry drying system and method |
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2003
- 2003-10-08 CN CN 200310110403 patent/CN1605824A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104849410A (en) * | 2015-05-28 | 2015-08-19 | 河南佰利联化学股份有限公司 | Rapid detection method for dispersion of titanium dioxide in oil paint |
| CN105152175A (en) * | 2015-09-10 | 2015-12-16 | 安徽龙泉硅材料有限公司 | Method for utilizing waste heat generated in SiO2 aerogel production |
| CN105174275A (en) * | 2015-09-10 | 2015-12-23 | 安徽龙泉硅材料有限公司 | Preparation method of silicon dioxide aerogel |
| CN106168450A (en) * | 2016-08-11 | 2016-11-30 | 爱森（中国）絮凝剂有限公司 | A kind of chemical production equipment reducing powder stock moisture content |
| CN113563012A (en) * | 2020-04-29 | 2021-10-29 | 台湾气凝胶科技材料开发股份有限公司 | Preparation method of cold-resisting and heat-insulating hydrophobic aerogel composite jelly and related product thereof |
| CN115406185A (en) * | 2022-08-26 | 2022-11-29 | 攀钢集团攀枝花钢铁研究院有限公司 | Titanium tetrachloride slurry drying system and method |
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