CN105948110B - Method for improving sulfate process titanium dioxide cleanliness - Google Patents

Abstract

The invention belongs to a production process of sulfate process titanium dioxide, and particularly relates to a method for improving sulfate process titanium dioxide cleanliness. The method includes the following steps of screening a material obtained after roasting ends through a 150-200-mesh screen, making the on-screen material directly enter a plain flour process to be post-processed to obtain a titanium dioxide finished product, conducting strengthened smashing process, 325-mesh screen passing and under-screen material post-processing on the under-screen material to obtain the titanium dioxide finished product. A better separation method is put forward for TiO2 fine hard particles which influence the sulfate process titanium dioxide cleanliness, and the cleanliness of the titanium dioxide finished product can be improved through subsequent grinding and smashing.

Description

A kind of method for improving sulfuric acid method titanium pigment cleannes

Technical field

The invention belongs to sulfuric acid method titanium pigment production technology, and in particular to a kind of side of raising sulfuric acid method titanium pigment cleannes Method.

Background technology

Cleannes-and according to dispersed method configuration slurry is surveyed, a small amount of slurry for mixing then is taken with toolsetting, it is placed on and scrapes The deeper one end of plate fineness gauge groove, with the quick scraping blade of scraper plate after, the rapid dispersiveness that reads is the granule number between 0~6.5, each Sample is read twice, and grain number is the arithmetic mean of instantaneous value of two times result, and reading is smaller, and cleannes are better.

In sulfuric acid method titanium pigment production industry, metatitanic acid obtains titanium white first product by rotary kiln calcining, is limited to domestic water Solution technical merit, the broad particle distribution of metatitanic acid, at the same time at present country's rotary kiln calcination process controlled level it is limited and Not good etc. enough reason of crystal formation conversion agent dispersing uniformity, by inevitably producing some tiny compared with hard aggregation in calcination process Particle, these titanium white first product particles can not effectively be broken and disperse in normal in powder operation, into operation below, finally Reduce the cleannes of product.

Wang Bin et al. researchs show：Coarse grained presence is the main cause for influenceing cleannes, and by Experimental comparison point Analysis is obtained, and the coarse granule in domestic titanium dioxide is mainly made up of Ca, Al, Si etc., and maximum particle diameter is up to 210 μm, and external quality Preferable titanium dioxide coarse granule main component is TiO₂, 30 μm are less than particle diameter more.Wang Bin et al. has found can be by inorganic surfaces Slurry after treatment intercepts screening (500 mesh sieve), can be effectively improved the cleannes of product, and then improve dividing for final titanium white product Dissipate property.

But the above method mainly improves the coarse granule being made up of Ca, Al, Si etc. causes the cleannes of titanium white product poor The reason for.If thick and stiff particle main component is TiO₂, the particle is mainly shown as 2 μm or so in finished product, if by inorganic table Slurry after the treatment of face is intercepted and carries out 500 mesh sieves point, because the screen size of 500 mesh sieves is 25 μm, can not screen out 2 μm of left sides Right coarse granule.

The content of the invention

Inevitably produce some tiny compared with grit, some of them particle during existing method for producing gtitanium dioxide with sulphuric acid Main component is TiO₂, at 2 μm or so, these particles can not effectively be broken and disperse particle diameter in middle powder operation, if by Slurry after inorganic surface treatment is intercepted and sieved, and sieve aperture is larger can not to be obtained granularity and meet desired titanium dioxide, sieve aperture compared with Small slurry cannot be sieved again, so as to influence the cleannes of final titanium dioxide.For the coarse granule of this influence titanium dioxide cleannes Predominantly TiO₂Situation, the invention provides it is a kind of improve sulfuric acid method titanium pigment cleannes method.

The method is comprised the following steps：The material being calcined after terminating is sieved with 150~200 eye mesh screens, oversize is direct Powder operation, post processing obtain finished product titanium dioxide in.

Further, in the above method, screenings is ground into sand milling discharging-material size by strengthening pulverizing process, then Cross 325 eye mesh screens, screenings post processing and obtain finished product titanium dioxide.

Preferably, in the above method, described reinforcing pulverizing process is sanded using Raymond mill+two-stage, roll mill+wet ball mill + repeatedly be sanded in any one mode.

Preferably, in the above method, described screen area is sufficiently large.

Preferably, in the above method, the setting angle of the screen cloth is 4~10 degree.

Further, in the above method, the setting angle of described screen cloth is 5 degree.

The inventive method controls rational screening aperture, sulfate process titanium dioxide is fallen into kiln product coarse granule and thin grit is carried out Separate, thick soft particle is sent to middle powder operation, and thin grit is sent to reinforcing pulverizing process, is so sent to the titanium white of postprocessing working procedures Slurry will be in the range of suitable particle size, so as to finally improve the cleannes of titanium white product.

Specific embodiment

Inevitably produce some tiny compared with grit, some of them particle during existing method for producing gtitanium dioxide with sulphuric acid Main component is TiO₂, at 2 μm or so, these particles can not effectively be broken and disperse particle diameter in middle powder operation, if by Slurry after inorganic surface treatment is intercepted and sieved, and sieve aperture is larger can not to be obtained granularity and meet desired titanium dioxide, sieve aperture compared with Small slurry cannot be sieved again, so as to influence the cleannes of final titanium dioxide.

Coarse granule for this influence titanium dioxide cleannes is mainly TiO₂Situation, inventor by research find, The vibratory sieve of 150~200 eye mesh screens is installed after roasting terminates, by screening, during larger softer particle is directly entered on sieve Powder operation, post processing obtain finished product titanium dioxide；Relatively thin harder particle carries out reinforcing pulverizing process and grinds sand milling under sieve After stock discharge granularity, finished product is obtained after 325 mesh sieves, screenings post processing.

Inventor has found, sieve number is too big when then mesh opening size is too small, and the relatively thin harder particle of granularity has part On sieve, powder operation, post processing necessarily affect the cleannes of product during such as directly oversize is entered；When sieve number too it is small then When mesh opening size is too big, the larger softer particle of granularity has part under sieve, such as enters reinforcing pulverizing process, will necessarily increase The burden that reinforcementization is crushed.So, need to be by the Task-size Controlling of vibratory sieve in 150~200 mesh.

Sieved by the vibratory sieve of this mesh number, general 99.9% is sized on sieve, and this partial material particle is larger Softer, carrying out conventional middle powder operation, post processing can just prepare the preferable titanium dioxide of cleannes；General 0.1% is sized sieve Under, this partial material particle relatively it is thin it is harder (herein be carefully compared with oversize, but for relative finished product, its granularity compared with Slightly), if do not carried out specially treated, directly carrying out conventional middle powder operation, post processing will influence the cleannes of titanium dioxide, institute So that inventor has found that the partial material should be made to be crushed to sand milling stock discharge granularity by the way of crushing is strengthened, after 325 mesh Screen cloth, screenings post processing can also prepare the preferable titanium dioxide of cleannes.

Technique and equipment that reinforcing pulverizing process described in the inventive method does not determine, as long as can be thin grit under sieve Grind sand milling stock discharge granularity requirements, such as can recommend using " Raymond mill+two-stage sand milling " or " roll mill+ Wet ball mill+be sanded repeatedly " technique meets sand milling slurry granularity requirements until slurry granularity.

The mesh oversize of the inventive method 150~200, the post processing of screenings can respectively be post-processed and remixed, or mixing Post-processed again afterwards.

Further, in order to efficiently separate, the sieving area of vibratory sieve should be sufficiently large.

Further, in order to prevent titanium white first product from buildup and being kept for certain residence time in vibratory sieve, vibratory sieve is installed Angle be set to 4~10 degree.Preferably 10 degree.

In actual production technique, screenings can use titanium white storage tank, and titanium dioxide storage tank and corresponding pipeline answer wear-resisting and corrosion resistant Erosion, tank capacity 20m³, the nominal diameter of titanium white first product feed pipe and discharge nozzle is selected as 20cm in case line clogging, feed pipe peace Mounted in the top of tank body, discharge nozzle is arranged on bottom, and the bottom of tank body should be designed as cone, so that blowing is not accumulated Material phenomenon.

Embodiment 1

Taking the oversize 100g of 200 mesh shaking screens carries out middle powder operation, post-processes to obtain finished product titanium dioxide；Screenings 100g titaniums In vain fall kiln first product, at a high speed crush 30s after, according to 300g/L be beaten, 0.6mm zirconiums pearl be sanded 40min (2000rpm, zirconium oxide bead with For 1/1), after 325 mesh sieves, then inorganic coating is surface-treated titanium white first product mass ratio, adds 5 ‰ organosilicons to be had Vapour powder after machine treatment, then measures its cleannes.

Comparative example 1

Directly take sulfate process titanium dioxide to fall kiln first product 100g, after crushing 30s at a high speed, be beaten according to 300g/L, 0.6mm zirconium pearl sand (2000rpm, for 1/1), after 325 mesh sieves, then inorganic coating carries out table to mill 40min for zirconium oxide bead and titanium white first product mass ratio Face is processed, and adds 5 ‰ organosilicons to carry out vapour powder after organic process, then measures its cleannes.

Comparative example 2

Taking the oversize 100g of 100 mesh shaking screens carries out middle powder operation, post-processes to obtain finished product titanium dioxide；Screenings 100g titaniums In vain fall kiln first product, at a high speed crush 30s after, according to 300g/L be beaten, 0.6mm zirconiums pearl be sanded 40min (2000rpm, zirconium oxide bead with For 1/1), after 325 mesh sieves, then inorganic coating is surface-treated titanium white first product mass ratio, adds 5 ‰ organosilicons to be had Vapour powder after machine treatment, then measures its cleannes.

Table 1

From above-described embodiment 1, comparative example 1,2, in addition to screen number difference, other specification all same；By so Treatment after titanium dioxide cleannes be shown in Table 1, from table 1, be calcined in separating sulfuric acid legal system titanium dioxide using the inventive method After material, the cleannes of titanium white product are significantly improved, and 200 mesh sieves with respect to product after 100 mesh sieves cleannes Improve.

Claims (5)

1. it is a kind of improve sulfuric acid method titanium pigment cleannes method, it is characterised in that：Comprise the following steps：After roasting is terminated Material is sieved with 150~200 eye mesh screens, and oversize is directly entered middle powder operation, post processing and obtains finished product titanium dioxide；By screenings Sand milling discharging-material size is ground by strengthening pulverizing process, finished product titanium white is obtained after 325 eye mesh screens, screenings post processing Powder.

2. method according to claim 1, it is characterised in that：Described reinforcing pulverizing process uses Raymond mill+two-stage sand Mill, roll mill+wet ball mill+repeatedly be sanded in any one mode.

3. method according to claim 1, it is characterised in that：150~200 described mesh sieve web areas are sufficiently large.

4. method according to claim 1, it is characterised in that：The setting angle of 150~200 eye mesh screen is 4~10 Degree.

5. method according to claim 4, it is characterised in that：The setting angle of 150~200 described eye mesh screens is 5 degree.