A method of obtaining a pigment of titanium dioxide

 

(57) Abstract:

Usage: for paper, fibers, ceramics, paint and coatings industry. The inventive when implementing the method provides for the reaction in solution precursor tetrachloride titanium with sulfuric acid to obtain an intermediate titanylsulphate product. After crystallization and isolate this intermediate product is crystallized from a solution of the intermediate product is again dissolved in the aqueous solvent medium and hydrolyzing at elevated temperature to obtain amorphous titanium dioxide intermediate product in the form of particles. After separation from the aqueous solvent medium, the intermediate product is subjected to calcination at an elevated temperature to obtain the desired titanium dioxide end product in the form of particles. 24 C.p. f-crystals, 1 Il.

The invention relates to methods for producing titanium oxide in the form of particles of cytotechnologists predecessors, in particular to methods of producing pigmentary titanium dioxide from titanium tetrachloride.

Developed many ways of obtaining titanium dioxide in the form of particles generally dioxide pigment and the Itno for use in the production of pigmentary titanium dioxide. Of these ways chloride method gained popularity due to various advantages over sulfate. One of the advantages of this method is that the installation, which is designed for its implementation, are more economical in operation. In addition, when implementing chloride method in the production of pigmentary titanium dioxide such pigments cleaner, whiter and have greater resistance than pigmentary titanium dioxide produced as a product of the implementation of the earlier sulfate way. A particularly important advantage chloride method lies in the fact that in a practical implementation it is more acceptable in environmental terms, than the sulphate process.

However, the chloride method is not acceptable to obtain pigmentary titanium dioxide with anatase crystal structure, the most desirable in the manufacture of titanium dioxide pigments used in the manufacturing processes for products such as paper, fiber, ceramics, etc., Although the chloride method, which allows to produce titanium dioxide pigments having rutile crystal structure, can be used in these areas of technology, such use often St. thetic fibers, can be used titanium dioxide pigment that has only the anatase crystal structure. This is mainly due to reduced abrasiveness, which is characteristic of titanium dioxide pigments with a special crystalline structure.

Due to the need of pigmentary titanium dioxide with anatase crystal structure application sulfate method continues despite the associated problems of environmental pollution. To get rid of these environmental problems, which are fundamental for selecting large quantities of sulphuric acid gases and the formation of large quantities of waste with diluted sulfuric acid, are the result of the implementation of this method were proposed numerous technical solutions. Two of them have been proposed and are widely used in industry to fight with such significant quantities discharged into the waste diluted sulfuric acid. They are in the neutralization of calcium carbonate (which as waste forms calcium sulfate) and the concentration of the diluted acid to 95-98% sulfuric acid, sent for reuse in processes, for example, the use of the first technical solution, i.e., neutralization, usually leads to the fact that for each weight part directed to the waste diluted acid (or an equivalent amount of sulfate ions) are formed from one to three parts by weight of calcium sulphate as a waste that poses a problem associated with their placement. Similarly, concentration is directed to the waste diluted sulfuric acid is quite expensive in terms of energy consumption, because each weight part of the resulting concentrated acid should evaporate approximately nine parts by weight of water. In addition, the quality of such concentrated acid is usually unacceptable for reuse in the process. This is mainly due to the presence of impurities, in particular chromium and manganese (due to exposure to sulfuric acid or source containing titanium mineral, which is used in the implementation of the sulphate method), present in the concentrated acid and have undesirable effects on the quality of the final pigment product.

The objective of the invention is to develop a method of producing pigment ti the th crystal structure, which allows to eliminate or to avoid the disadvantages inherent in conventional sulfate method.

The proposed method is characterized by versatility, as its implementation allows not only to obtain pigmentary titanium dioxide with anatase crystalline structural, but also titanium dioxide with rutile crystal structure.

The task is solved in that in the method of producing a pigment of titanium dioxide preparing a first aqueous solution, which contains tetravalent titanium and sulfuric acid as main compounds. This first aqueous solution is heated to a high temperature sufficient for reaction between tetrachloride titanium and sulfuric acid as reagents, and get dissolved intermediate product comprising titanylsulphate. Then extract the first solution containing the dissolved intermediate product at elevated temperatures continue in the presence of a certain number of titanylsulphate in the form of particles, resulting in crystallization of the specified dissolved intermediate product in the first aqueous solution.

The obtained crystallized elapsed the underwater solvent, resulting in a second aqueous solution. At this stage of the proposed method the number of used aqueous solvent medium should be sufficient to ensure dissolution of the specified crystallized titanylsulphate, but insufficient to cause hydrolysis of the latter.

After dissolving crystallized titanylsulphate the second aqueous solution is mixed with an additional quantity of aqueous solvent medium, and the second aqueous solution and additional water solvent medium is heated to high temperature, allowing re-dissolved titanylsulphate hydrolyzed to titanium dioxide. Due to continued heating the mixed solution and hydrolysis in it titanylsulphate so produced titanium dioxide is precipitated from the mixed solution. After separation of precipitated precipitated titanium dioxide from the mixed solution is subjected to calcination and get almost as product, calcined titanium dioxide in the form of particles.

The drawing shows a diagram illustrating the direction of movement of material flows at various stages presegmental titanium dioxide in the form of particles, with either anatase or rutile crystal structure, using any of the known tetrachloride titanium as source material. He illustrated a specific example of obtaining titanium dioxide in the form of particles using as a source tetrachloride reagent of titanium tetrachloride.

In accordance with the submitted drawing the image of the titanium tetrachloride and an aqueous solution of sulfuric acid in lines 4 and 6 respectively injected into the reaction zone 10, where these materials are thoroughly mixed with the formation of the first aqueous solution. In the reaction zone 10, the temperature of the first aqueous solution is supported in the interval from approximately 25aboutWith up to a temperature approximately equal to the boiling temperature of the first aqueous solution, under autogenous pressure, which prevails in the zone 10, resulting in a reaction takes place between the titanium tetrachloride and sulphuric acid materials contained in the solution, and the formed soluble intermediate technicality product and gaseous hydrochloric byproduct. In a preferred variant, the temperature of the first aqueous solution contained in the reactions is t to be achieved optimal speed of reaction.

Usually sulfuric acid concentration in the first aqueous solution is the concentration, which is chosen to reduce to the minimum solubility of the reaction products, i.e. titanylsulphate intermediate product and hydrochloric gaseous by-product in the first aqueous solution. In a broad sense the concentration of sulfuric acid in aqueous sulfuric acid solution used in accordance with the invention, may be in the range from about 60 to 80 wt. the preferred concentration of the solution is in the range of about from 65 to 75 wt. The amount of aqueous solution of sulfuric acid depends on the concentration of sulfuric acid used in specific aqueous solution. However, this number should always be set sufficient to achieve at the required stoichiometric amount of sulfuric kislota required to ensure complete reaction tiontechnologies reagent with the formation of the target titanylsulphate intermediate product. However, usually the amount of aqueous acid solution should be sufficient to achieve the quantity of sulphuric acid, which exceeds stagionale approximately from 1 to 4 stoichiometric amounts.

The reaction between the titanium tetrachloride and sulfuric acid contained in the first aqueous solution in the reaction zone 10, flows quickly, especially at temperatures in excess of approximately 65aboutWith, emitting gaseous hydrochloric byproduct and education target intermediate titanylsulphate product. Side hydrochloric gaseous product is removed from the reaction zone 10 through the pipe 12, and it can pass through the scrubber unit (not shown), where it is dried, and then send in the unit for regeneration of chlorine (not shown) for conversion to chlorine and allocation of gaseous chlorine.

After completion of the reaction and removal during the course side of gaseous hydrogen chloride from the reaction zone 10, the remainder of the first aqueous solution contained in the reaction zone 10. consists mostly of sulfuric acid, water and dissolved intermediate product, i.e. the titanylsulphate. This remaining the first aqueous solution is removed from the reaction zone 10 through the pipe 14 and is directed into the zone 18 of crystallization. Parallel to the flow of the remainder of the specified first aqueous solution in the nozzle 16 in the crystallization zone 18 in the soba. The amount of diluted sulfuric acid solution (a solution that contains from about 15 to 35 wt. sulfuric acid) introduced into the crystallization zone 18 should be equal to that amount which is sufficient to reduce the concentration of sulfuric acid contained in the residue of the first aqueous solution to a level in the range from about 36 to 50 wt. The decrease in the concentration of sulfuric acid in the first aqueous solution to such levels is crucial in the case, if you want to get the filtered solution described below crystallized titanylsulphate intermediate product.

Within the specified crystallization zone 18 the temperature of the dilute aqueous solution is maintained at a level exceeding the level at which maintain the temperature in the reaction zone 10. In accordance with a preferred temperature of this diluted aqueous solution should be maintained approximately equal to its boiling point, which is when the concentration of sulfuric acid in the range from about 35 to 50 wt. is normally in the range from about 108 to 125aboutC.

To facilitate crystallization rastvorennogo in the presence of so many titanylsulphate in the form of particles, which is the preferred option previously obtained by the proposed method. Usually the number of titanylsulphate in the form of particles, which is present in the crystallization zone 18, is in the range from about 0.1 to 20 wt. in terms of the total weight of the dilute aqueous solution contained in the crystallization zone 18.

When the operation is complete crystallization of the dissolved titanylsulphate intermediate product diluted aqueous solution containing the crystallization of the intermediate product, the nozzle 20 is transferred from the crystallization zone 18 in the separation zone 22, where the crystallized intermediate product is separated and recovered from dilute aqueous solution (or mother liquor). Usually this operation is division and separation with the greatest efficiency can be performed by filtering a dilute aqueous solution containing crystallized intermediate product, suspended in it, under pressure greater than atmospheric. Pressure filtration and the pressure inside the installation for carrying out such operations is known. For example, for a practical embodiment of the present invention use is stoway pressure filter, etc. Descriptions such pressure filter presses can be found in the Handbook Perry's Chemical Engineer''s Hand book section 19,62-73, edition 4th, 1963. However, in the case when the proposed method is carried out during the semi-continuous or continuous process, especially acceptable pressure filter-presses are vertical filter presses Hose, which combine the valuable properties of conventional filter presses with the advantages of drum and belt filters. These filter pressy can be fully automated.

Regardless of the particular type or design of the filter press used in zone 22 division, this unit operates at a pressure greater than atmospheric pressure. Usually, this pressure should be sufficient to obtain a wet filter cake containing residual mother liquor and crystallized intermediate product in the weight ratios of approximately 2.0 to 1.0 or less, preferably about 0.2: 1.0 to 1.0:1.0 in. Usually excessive pressure, it is acceptable to obtain a wet filter cake containing components in the above weight ratio can be in the range from about 100 to 300 pounds per square inch (i.e., CA is 7 kg/cm2).

The mother liquor is separated from the crystallized intermediate product within the separation zone 22, away from this zone through line 24 and is directed into a zone of concentration of sulfuric acid (not shown).

Then the wet filter cake obtained in separation zone 22 and includes residual mother liquor and crystallized intermediate product in the weight ratio shown above, is removed from the separation zone 22 through the pipe 26.

From the separation zone 22 wet filter cake on the nozzle 26 is directed into the zone 28 of dissolution, which is a simple vessel with a stirrer or the tank. Within the zone 28 of the dissolution of the wet filter cake is mixed with a certain quantity of aqueous solvent environment, the accuracy of the water supplied to the area 28 of the dissolution of the pipe 30, is sufficient to dissolve the crystallized intermediate product containing wet filter cake, and insufficient to cause premature hydrolysis of crystalline intermediate product. Typically, such an operation of mixing and dissolution was performed at room temperature using a water solvent environments is Litvinova intermediate product, contained in the wet filter cake subjected to hydrolysis.

Then the prepared solution (or the second aqueous solution) containing aqueous solvent medium, the residual mother liquor and re-dissolved technicality intermediate product away from the zone 28 of the dissolution of the pipe 32 and directed to the area 34 of hydrolysis. In accordance with a preferred variant of the method of the second aqueous solution is first subjected to a final filtering before its introduction into the zone 34 of hydrolysis. The purpose of this final stage of filtration is to remove all the solid impurities that may be present in the second aqueous solution and can have side effects on the final properties of the final titanium dioxide product in the form of particles. This filtering can be done at any typically the filtering device, which can be used for filtering of liquid materials, including gravity, vacuum and pressure filters.

Within the zone 34 hydrolysis adding a second aqueous solution, which was preheated to a high temperature of approximately 85 to 105aboutC, and mixed with an additional quantity is heated to elevated temperature, approximately 85 to 105aboutWith, enter into a zone 34 of hydrolysis on line 36. In a broad sense the amount of additional water solvent environment, which is added to the second aqueous solution is in the range of approximately from 1.0 to 50.0 vol. in terms of the total amount of additional water solvent medium and the second aqueous solution (preferably about 10.0 to 25.0.).

Within the zone 34, the hydrolysis is carried out in the presence of a certain amount of seed or particles of titanium dioxide, which provides the acceleration of the process of hydrolysis titanylsulphate intermediate product with the formation of amorphous dioxide based intermediate product in the form of particles and the adjustment with the optimal particle size, and (depending on whether the seed particles of the anatase or rutelinae) target crystal structure of the final titanium dioxide product. For the implementation of the proposed method such seed or particles can be prepared outside the zone 34 of hydrolysis, in particular by thermal hydrolysis of an aqueous titanium tetrachloride, and then enter into the zone of the nozzle (not shown) or received at the place of use within the zone 34 is C crystals of titanium dioxide, which enter into joint second aqueous solution and additional water solvent environment in the area 34 of hydrolysis, generally is in the range from about 0.1 to 10.0 wt. of the total weight of the combined water and materials. In a preferred variant the amount of seed crystals or particles that are obtained outside of the zone 34 of hydrolysis, and then entered into it or at the place of use must be in the range of approximately from 0.1 to 5.0 wt.

In accordance with one variant of implementation of the proposed method for obtaining titanium dioxide in the form of particles having the anatase crystal structure, the above hydrolysis is carried out in the presence of titanium dioxide seed crystals or particles obtained at the place of use within the zone 34 of hydrolysis. Typical conditions that are necessary for on-site use of such seed crystals or particles and hydrolysis of the remaining dissolved intermediate product described in the U.S. patent N 18854. Typically heated second aqueous solution is carefully added to the heated additional amount of aqueous solvent medium at a given speed. After seasonality solution contained in the zone 34 of hydrolysis, is maintained at an elevated temperature in the range from about 90aboutWith (preferably from 100about(C) to a temperature corresponding to the boiling point of the solution. This heated solution is maintained at an elevated temperature for a period of time sufficient for complete hydrolysis. In this regard, typically, the duration of hydrolysis can be in the range from 1 to 4 h, which allows to achieve a complete or almost complete hydrolysis of the dissolved intermediate product (i.e., titanylsulphate) before formation of the amorphous titanium dioxide intermediate product in the form of particles.

In accordance with another alternative implementation of the present invention to obtain a titanium dioxide product in the form of particles or anatase, or rutile crystal structure above the stage hydrolysis can also be carried out using the seed crystals or particles of titanium dioxide obtained outside the zone 34 of hydrolysis. These are obtained from outside the seed crystals or particles of either anatase or retiling induction depending on the method, according to which they are obtained, you can enter the zone 34 hydrolysis is Stacy can be designed to produce titanium dioxide pigment products in the subsequent calcination of amorphous titanium dioxide intermediate product, obtained at the stage of hydrolysis with either the anatase or rutile crystal structure.

Hydrolysis titanylsulphate intermediate product to the amorphous titanium dioxide intermediate product in the form of particles in the presence or received inside or outside of the seed crystals or particles leads to the formation of an aqueous slurry containing a solid component of the intermediate product, the amount of which is in the range from about 10 to 30 wt. This sludge away from the zone 34 of hydrolysis of the pipe 38 and send it to the zone 40 of the filter, which represents, for example, vacuum filter drum. Within the zone 40 of the filter a substantial portion of the aqueous solvent environment, and residual sulfuric acid coming from the mother liquor, which is contained in the above filter cake, sludge divert the pipe 42, receiving the filter cake, which contains amorphous titanium dioxide intermediate product in the form of particles. At this stage filtration of the obtained filter cake is subjected to washing to remove all the remaining sulfuric acid, which is captured by the filter cake. Prom environment, i.e., water, in an area of 40 filter by pipe 41.

The washed filter cake is removed from the zone 40 of the filter by pipe 44 and send it to the zone 46 calcination. Before the introduction of the filter cake in zone 46 calcination preferably in the filter cake mix in some extension agents. These may include known materials, which are used to impart various characteristics and properties of the finished pigment, for example a special crystalline structure of titanium dioxide product, the desired size of the particles and prevent agglomeration of the individual particles of amorphous titanium dioxide intermediate product in the process of calcination. Typical examples of such extension agents include, for example, rutelinae titanium dioxide seed crystallization nuclei or particles, alkali metal salts, in particular potassium chloride, potassium sulfate, etc., and phosphorus-containing compounds, in particular phosphoric acid, etc.

However, the number of such used extension agents are small. They can vary in a wide range within from about 0 to 10.0 wt. in terms of weight amorphous titanium dioxide intermediate is and the number of such extension agents are in the range from about 2.0 to 6.0 wt. for retiling titanium dioxide seed of crystallization nuclei or particles and from about 0.1 to 0.75 wt. for salts of alkali metals and phosphorus in terms of their oxides, as potassium oxide and phosphorus pentoxide.

In the burning zone, which may include, for example, rotary kiln, the filter cake is heated to a temperature in the range from about 800 to 1000aboutWith (preferably from 850 to 950aboutC). Typically, the residence time in the burning zone, required for the formation of this crystal structure and other properties required for the crushed calcined product based on titanium dioxide, will vary from 6 to 12 hours During firing precipitate filtered exhaust gases such as water vapor, vaporized sulfuric acid and any other volatile substances present in the filtered sludge is injected into the burning zone through line 48. Completely crushed calcined product on the basis of titanium dioxide discharged from the burning zone through line 50. This extracted crushed calcined product may subsequently be further processed, for example, through processing, including grinding surface, etc. to obtain the final solicitorami reactor with glass paneling, equipped with stirrer, download 149,27 h solution H2SO4containing 98 h H2SO4, 50 h H2Oh and of 1.27 h TiO2. The concentration of H2SO4approximately 66.2 per cent TiO2present due to the acid, which is taken from the stage of regeneration of the acid. The temperature of the solution supports equal or approximately 65aboutC.

1.2. In this solution (stage 1.1) add 54,3 h anhydrous TiCl4. The addition is accompanied by vigorous selection 41,73 h Hcl gas. After the selection HCl is completed, the solution is passed to the next stage for crystallization.

2.1. TiOSO4(titanylsulphate) in excess of a solution of N2SO4from 1.2 loaded into the mold, equipped with heating coils and an agitator. This composite solution consists of 98 h H2SO4, 39,71 h H2Oh and 24,13 h TiO2. The concentration of H2SO4approximately 71,16% In the mould contains a small amount of TiOSO4.2H2O related from the previous substrate. This TiOSO4.2H2O represents the seed crystals for the next substrate. It is only necessary that the number of TiOSO4.2H2O with bring to a boil, while TiOSO4solution cause yet to crystallize in the form of TiOSO4.2H2O. during the crystallization process gradually add 198,69 h transparent diluted sulphuric acid by-product from the stage filtration 6.1. Diluted acid (stage 6.1) consists of 41,03 h H2SO4, 156,47 h H2Oh and 1.2 h TiO2. The concentration of H2SO4in this diluted acid is about 20.8% of

Using a dilution of the original solution crystallization from 71% to 37-38% increases significantly (up to 95%) extract TiOSO4.2H2O. in Addition, the Department of TiOSO4.2H2O from the initial solution H2SO4facilitated by education less structured mass of crystals. When this diluted acid phase 6.1 spent in a useful way.

The wet mass of crystals is then transferred to filtration under pressure in order to remove the excess of the initial solution.

3.1. Department of TiOSO4.23H2O from the exhaust source solution reached by the use of acid-resistant filter, pressure disk or prison type, which can operate up to 250 psig. COI

Thus was filtered 360,65 h TiOSO4.2H2O and spent the initial solution in the form of a suspension, receiving 103,29 h essentially dry mass TiSOSO4.2H2O, mixed with a small amount of exhaust source solution and 257,36 h exhaust source solution.

Composite dry product consisted of 24,07 h TiO2, 43,32 h H2SO4and 35,9 h H2O. the ratio of the H2SO4:TiO2in dry weight was 1.80.

The composition of spent source solution: 95,7 h H2SO4, 160,39 h H2Oh and of 1.27 h TiO2. This exhaust source solution send then at the stage of concentration of the acid 8,1 before using on stage 1.1.

4.1. Dry solids from the stage 3.1 was then sent in an acid-resistant vessel equipped with a mixer, to serve as a dissolved substance. Thus, 103,29 h TiOSO4.2H2O from the stage 3,1 mixed with 48,07 h H2About room temperature and left to slowly dissolve in a small mixing. During the dissolution of the heating is not used, as in this case, existing in a solution of TiO2will prematurely be either hydrolyzed.

4.2. As t the formation to remove any traces of insoluble substances, mainly TiO2that could cause premature hydrolysis.

5.1. 151,36 h transparent solution with stage 4.2 then transferred to the tank in which the temperature was raised to 90-95aboutC. In a separate vessel equipped with a stirrer and means for supplying heat to the contents and used for the specific purpose of carrying out the hydrolysis, downloaded 23,17 h H2O. the temperature of the H2Then it increased to 90-95aboutC. At the time when both of the solution reached the desired temperature, the solution TiOSO4added to H2About speeds of 6%/min up until the addition was not completed. The temperature is then brought to the boiling point, at which it was maintained for a period of time equal to 3 h to ensure that at least 95% of TiO2hydrolytically was deposited in the form of TiO2.H2O.

6.1. Department of TiO2.H2O from the initial solution hydrolysis was achieved by filtration. Exhaust source, the solution was removed from the TiO2.xH2O using multiple displacement washes N2Oh, amounting in total to 81,29 including the Release of TiO2xH2O was 57,16 h with the composition: 22,86 h TiO2, 2,29 B>SO4, 157,47 h H2Oh and 1.2 h TiO2. The concentration of H2SO4in this diluted acid is about 20.8% of

7.1. Before firing TiO2.xH2O added a small amount TO2In form TO a2SO4and R2ABOUT5as H3RHO4in order to control the particle size and their growth. Control of the firing temperature and the aging time in the furnace is thus, in order to maximize the opportunity of staying in a furnace without sintering product. A detailed description of this process is not presented as experts in the field of production of dyes on the basis of TiO2familiar with this method.

8.1. Acid raw material stage of concentration is obtained from the acid stage crystallization 3.1.

The concentration of this acid increases from 37% to 66% by evaporation and addition of fresh acid to replace the acid lost during roasting TiO2.xH2O. Thus, 257,36 hours spent acid having the structure: 95,7 h H2SO4; 160,39 h H2Oh and of 1.27 h TiO2was filed in the hub together with 2.3 h fresh H2SO4.During the concentration was removed 111,46 h water education 149,27 is B>2SO4approximately 66.2 per cent This acid then becomes the raw material stage 1.1.

1. A method of OBTAINING a PIGMENT of TITANIUM DIOXIDE from tetrachloride titanium, characterized in that the first aqueous solution containing tetravalent titanium and sulfuric acid, is heated to a temperature enabling communication tetrachloride titanium with sulfuric acid, maintained at this temperature in the presence of crystalline titanylsulphate, separating the resulting crystals titanylsulphate filtration, the obtained wet draught add water solvent environment in a quantity sufficient to dissolve the crystal titanylsulphate, but not sufficient to hydrolysis, heat received by the second solution and add to it the additional amount of heated water solvent environment, separate the formed amorphous titanium dioxide and calicivirus his obtaining crystalline titanium dioxide.

2. The method according to p. 1, characterized in that as tetrachloride titanium using titanium tetrachloride.

3. The method according to p. 1, wherein the first aqueous solution contains sulfuric acid in the amount of 60 to 80 wt.

4. --- The temperature of boiling.

5. The method according to p. 4, characterized in that the first aqueous solution is heated to boiling point.

6. The method according to p. 1, characterized in that the crystalline titanylsulphate is present in the first aqueous solution in a quantity sufficient to initiate crystallization.

7. The method according to p. 6, characterized in that the number titanylsulphate is 0.1 to 20.0 wt.

8. The method according to p. 1, characterized in that during the heating of the first aqueous solution the concentration of sulfuric acid is reduced.

9. The method according to p. 8, characterized in that the sulfuric acid concentration is reduced by the addition of dilute sulfuric acid solution.

10. The method according to p. 9, characterized in that use a dilute solution of sulfuric acid with a concentration of 15 to 35 wt.

11. The method according to p. 9, characterized in that the sulfuric acid solution is added in a quantity sufficient to reduce the concentration of sulfuric acid in the first aqueous solution to 35 to 50 wt.

12. The method according to p. 1, wherein filtering the first aqueous solution is performed under a pressure in excess of atmospheric, with getting wet sludge containing the original solution and the titanylsulphate.

13. Pocomania.

14. The method according to p. 1, characterized in that as the aqueous solvent environment use water.

15. The method according to p. 1, characterized in that the number of initial solution in the filtered precipitate is 3 to 50% by weight titanylsulphate.

16. The method according to p. 1, characterized in that the second solution and an additional amount of aqueous solvent medium is heated separately to a temperature of 85

105oC.

17. The method according to p. 1, characterized in that after adding the second solution additional quantity of solvent environment, the temperature is set from the 90oC to the boiling point.

18. The method according to p. 1, characterized in that the hydrolysis titanylsulphate carried out in the presence of the seed crystallization nuclei or particles of titanium dioxide.

19. The method according to p. 18, characterized in that the seed crystallization nuclei or particles of titanium dioxide are used in a quantity sufficient to initiate hydrolysis titanylsulphate.

20. The method according to p. 19, characterized in that the seed crystallization nuclei or particles of titanium dioxide are used in an amount of 0.1 to 10.0 wt.

21. The method according to p. 18, characterized in that the seed centre is icesta aqueous solvent environment.

22. The method according to p. 1, characterized in that at least one additional substance is added to the amorphous titanium dioxide.

23. The method according to p. 22, characterized in that as an additional substance use substance from the group of alkali metal salts, phosphorus-containing substance, the seed crystallization nuclei and particles of rutile titanium dioxide.

24. The method according to p. 22, wherein the additional substance is added in an amount of 0.1 to 10.0% by weight of amorphous titanium dioxide.

25. The method according to p. 1, characterized in that the calcining is carried out at 800 - 1000oC.

 

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7 cl, 68 ex

FIELD: sulfate method of production of titanium dioxide from titanium-containing material.

SUBSTANCE: proposed method includes leaching-out of titanium-containing materials with sulfuric acid solution for obtaining lye, deposition of ferrous sulfate from lye, extraction of titanyl sulfate from lye by means of solvent, hydrolysis of extracted titanyl sulfate followed by roasting of solid phase obtained at hydrolysis stage. At least part of raffinate from extraction stage is used as part of leaching solution at initial leaching-out stage.

EFFECT: high degree of purity of titanium dioxide; reduced amount of acid; reduced power requirements.

20 cl, 2 dwg, 9 tbl, 13 ex

FIELD: industrial inorganic synthesis.

SUBSTANCE: invention relates to a sulfate process for titanium dioxide production from titanium-containing material. Process comprises leaching starting material to produce leaching lye containing acidic solution of titanyl sulfate, which is separated from the lye and then hydrolyzed to form hydrated titanium oxides further fired to produce desired titanium dioxide. Hydrolysis step is properly controlled to form hydrated titanium oxides with desired particle size distribution.

EFFECT: enhanced commercial process efficiency.

29 cl, 2 dwg, 9 tbl, 13 ex

FIELD: sulfate method of production of titanium dioxide from titanium-containing material.

SUBSTANCE: proposed method includes leaching-out of titanium-containing material by sulfuric acid solution, thus obtaining lye containing titanyl sulfate, separation of titanyl sulfate from lye, hydrolysis of titanyl sulfate for forming solid phase containing hydrated titanium oxides followed by roasting the solid phase obtained at the hydrolysis stage. Proposed method includes additional leaching-out stage for leaching-out of solid phase remaining after leaching-out of initial titanium-containing material by means of solution containing sulfuric acid.

EFFECT: enhanced efficiency of process.

24 cl, 2 dwg, 9 tbl, 13 ex

FIELD: light-sensitive catalysts.

SUBSTANCE: invention is directed to preparation of titanium dioxide-based catalysts for photocatalytic treatment of water and air polluted with organics and pathogenic floras. Invention provides a method comprising preparation of reaction solution containing mineral titanium salt, fluoride ion, and activation additive; hydrolysis of mineral titanium salt to form precipitate; washing and calcination of the precipitate. Activation additive utilized is ammonium hydroxide in 5-10% stoichiometric excess. Hydrolysis is conducted for 0.25-0.5 h at pH 10-13, while concentration of fluoride ion in reaction solution is maintained at least 5 wt % based on TiO2. Mineral titanium salt is selected from titanium tetrachloride, titanyl sulfate, and titanium-ammonium chloride.

EFFECT: increased degree of recovering titanium dioxide into target product, increased heat resistance and specific surface of photocatalytic anatase-modification titanium, and reduced process duration.

6 cl, 1 tbl, 14 ex

FIELD: chemistry.

SUBSTANCE: invention can be applied in production of rutile-structured pigment based on titanium dioxide. The method of obtaining the base for pigment rutile titanium dioxide involves obtaining of source solution containing a titanium compound, addition of effective quantity of a salt catalyst to that solution, preferable addition of a chemical control agent to the solution, solution evaporation for obtaining dry amorphous intermediary product containing a mixture of titanium compounds, and baking of the intermediary product at the temperature under 500°C. Another variant of the method of obtaining the base for pigment rutile titanium dioxide uses eutectic mix of two or more NaCl, KCl and LiCl salts as the salt catalyst, melting temperature of the salt catalyst being lower than baking temperature.

EFFECT: reduction of rutile crystallisation temperature.

42 cl, 12 ex, 19 dwg

FIELD: nanotechnologies.

SUBSTANCE: invention is related to methods for production of nanosize particles of titanium dioxide, which may be used as photocatalysts, light sensitive materials of sun batteries, photo luminophors, as cathode materials of chemical current sources. Method for production of such particles of titanium dioxide includes hydrolysis of water solution that contains titanium ions, in presence of acid during heating. Water solution containing titanium ions is produced by dissolution of titanium hydride or metal titanium in 37% hydrochloric or 96% sulfuric acid dissolved with water, accordingly, as 1:2 or 1:3.4, to obtain ratio of Ti+3 : Cl-, equal to 1:6, or Ti+3 : SO42-, equal to 1:3. Hydrolysis may be performed in presence of nickel chloride or cobalt chloride.

EFFECT: invention makes it possible to simplify production of nanosize particles of titanium dioxide of different shape - in the form of nanobars, nanorods, nanoneedles, without negative effect at environment.

4 dwg, 7 ex

FIELD: mining industry.

SUBSTANCE: perovskite concentrate, which can be used for manufacture of pigment titanium dioxide for paints, paper, enamels, and plastics, is processed as follows. 1 kg of concentrate is treated under atmosphere conditions with concentrated HCl at 90-100оС for 10 to 20 h to solubilize 75-85% of titanium, radioactive, and other acid-soluble components. Concentration of HCl is then lowered by diluting it with 1-5% HCl solution until TiO2 concentration 50-100 g/L. Thermohydrolysis of solution at 100-105оС accompanied by distilling away HCl leads to residual HCl concentration 20-100 g/L. Distilled HCl is sent to processing of perovskite concentrate. Titanium-containing precipitate is separated from mother liquor, washed first with 15-37% HCl solution and then with water to pH 3. Washed precipitate is treated with aluminum acid phosphate with pH 2-4. Aluminum acid phosphate uptake (on conversion to Al2O3) constitutes 0.5 to 5.0% content of TiO2. Treated precipitate is separated and calcined at 850-870оС to give pigment titanium dioxide. From mother liquor (after separation of Ti-containing precipitate), radioactive components are isolated by 4-6-step extraction with tributyl phosphate. Organic phase-to-water phase ratio is (1.5-2.0):1. Degree of titanium recovery is at least 98%, whiteness at least 96.5 conv. units, brightening power 1650-1800 conv. units, spreading capacity 38.0-40.0 g/m2, oil capacity 25-27 g/100 g pigment. Yield of pigment TiO2 is 95.7-98.0%. Amount of radioactive precipitate does not exceed 0.06 kg.

EFFECT: optimized perovskite concentrate processing parameters.

12 cl, 4 ex

FIELD: paint and varnish industry.

SUBSTANCE: invention proposes a flowing pigment mixture comprising titanium dioxide of universal sort or sort used in internal works with the concentration 40-100 vol.%, a thickening agent, dispersing agent and, optionally, water. The volume content of dry TiO2 is 15%, not less. As a thickening agent the mixture can comprise at least one hydrophobically modified ethyleneoxide-urethane polymer or at least one hydrophobically modified alkali-soluble emulsion, or at least one hydrophobically modified hydroxyalkylcellulose. As a dispersing agent the indicated mixture can comprise, for example, copolymers of maleic acid and diisobutylene, or butyl methacrylate and methacrylic acid, or acrylic acid and hydroxypropyl acrylate. Mixture can comprise additionally one or more additive taken among the following series: froth breaker, surface-active substance, coalescent agent, base, biocide, mildewcide agent, combined disperser, polymeric binding agent, a polymer with cellular latex particles. Proposed mixtures are stable and don't require a stirring. Invention can be used in preparing universal dyes and dyes for internal finishing.

EFFECT: improved preparing method, improved and valuable properties of mixtures.

20 cl, 13 tbl, 8 ex

FIELD: composite materials.

SUBSTANCE: invention concerns powderlike composite filler suitable for elastomer materials intended for manufacturing articles operated under elevated wear or dry friction conditions. Filler particles contain at least one core made from ceramic material (metal carbide) and exterior layer made from polytetrafluoroethylene, volume fraction of cores in filler particles ranging from 1 to 10%. Powderlike composite is prepared by activating metal carbide particles in mechanochemical activator at mechanical power supply intensity between 1 and 5 kW/kg and dose 30 to 1000 kJ/kg in a medium selected from: air, nitrogen, argon, vacuum between 10-2 and 1 atm until particles with average size not larger than 15 μm are obtained, after which polytetrafluoroethylene is added to mechanochemical activator and metal carbide particles are modified at mechanical power supply intensity between 0.05 and 0.5 kW/kg and dose 3 to 100 kJ/kg in a medium selected from: air, nitrogen, argon, vacuum between 10-2 and 1 atm.

EFFECT: addition of powderlike composite filler to rubber compound results in reduction in friction coefficient under dry friction conditions and significant reduction in summary friction pair wear under hydroabrasive wear conditions.

4 cl, 2 dwg, 3 tbl

FIELD: composite materials.

SUBSTANCE: invention relates to a process of manufacturing composite powder filler for elastomer compositions designed for fabrication of articles operated under increased wear and dry friction conditions. Process resides in that titanium carbide particles are activated in a mechanochemical activator with mechanical energy supply intensity 1 to 5 kW/kg and dose 100 to 1000 kJ/kg in a medium selected from a series: air, nitrogen, argon, and vacuum at pressure from 10-2 to 1 atm until particles with average size not larger than 15 μm are obtained, after which high-pressure polyethylene is added to activator and titanium carbide particles are modified at mechanical energy supply intensity 0,05 to 0.5 kW/kg and dose 3 to 100 kJ/kg in a medium selected from a series: air, nitrogen, argon, and vacuum at pressure from 10-2 to 1 atm.

EFFECT: lowered coefficient of friction under dry friction conditions and reduced summary rate of wear of friction pair under hydroabrasive wear conditions.

1 tbl

FIELD: chemical industry; public health; medicine; production of the titanium dioxide composition.

SUBSTANCE: the invention is pertaining to production of the titanium dioxide composition. The invention may be used in production of the sun-protective products providing the effective protection against UV-radiation and including titanium dioxide. The composition of the titanium dioxide contains at least one nonionic surface-active substance having the value of HLB(hydrophilic -lipophilic balance) within the interval from 7 up to 18, and the hydrophobic particles of the titanium dioxide, where the average length of the primary, particles is within the interval from 50 to 90 nanometers, the average width of the primary particles is within the range from 5 to 20 nanometers, and the average-volumetric diameter of the secondary particles makes less than 45 nanometers. The hydrophobic particles of the titanium dioxide have the absorption factor at 524 nanometers (Е524) - less than 2.0 l/g/cm, the absorption factor at 450 nanometers (Е450) - less than 3.0 l/g/cm, the absorption factor at 360 nanometers (Е360) - more than 3 l/g/cm, the absorption factor at 308 nanometers (Е308) - more than 30 l/g/cm, the maximum factor of the absorption (Еmax) - more than 45 l/g/cm and λ(max) - within the interval from 260 to 290 nanometers. The invention allows to improve the transparency of the sun-protective products containing the titanium dioxide.

EFFECT: the invention ensures the increased transparency of the sun-protective products containing the titanium dioxide.

24 cl, 4 ex

FIELD: varnish-and-paint industry.

SUBSTANCE: process of producing titanium dioxide pigment according to chloride technology comprises oxidation of titanium tetrachloride with oxygen or oxygen-containing gas in plasmachemical reactor followed by cooling of reaction products in tempering chamber and subsequent multistep fine grinding of intermediate product, titanium dioxide, by way of affection with supersonic gas flow at 100-500°C and ratio of gas mass intake to titanium dioxide mass intake = 0.2. In the first step of titanium dioxide fine grinding, treatment of titanium dioxide is performed with a dry gas supplemented by vapor of organic or organosilicon modifier having in its molecule at least one of the following functional groups: -OH, -NH2, NH, SH at mass intake of modifier representing 0.1-2.0% of the mass intake of titanium dioxide.

EFFECT: improved quality of titanium dioxide pigment and simplified process of production thereof.

1 dwg, 1 tbl

FIELD: methods and plants for increase of volume density of aerated powders.

SUBSTANCE: proposed method of compacting the powder containing oxide or phosphate of metal consists in placing the powder in container and increasing the pressure in its area above atmospheric pressure sufficient for compacting the powder before diffusion of considerable part of gas into powder. Powder containing oxide or phosphate of metal is placed in container and its volume density is increased. Then, concentrated suspension of pigment which is titanium dioxide is prepared. Specification gives description of plant proposed for increase of volume density of powder containing oxide or phosphate of metal and plant for increase of volume density of aerated loose pigment which is just titanium dioxide.

EFFECT: increased volume density of aerated powder; improved consistency; facilitated dispersion in latex paints.

22 cl, 6 dwg, 3 tbl, 8 ex

FIELD: chemistry.

SUBSTANCE: invention can be applied in production of rutile-structured pigment based on titanium dioxide. The method of obtaining the base for pigment rutile titanium dioxide involves obtaining of source solution containing a titanium compound, addition of effective quantity of a salt catalyst to that solution, preferable addition of a chemical control agent to the solution, solution evaporation for obtaining dry amorphous intermediary product containing a mixture of titanium compounds, and baking of the intermediary product at the temperature under 500°C. Another variant of the method of obtaining the base for pigment rutile titanium dioxide uses eutectic mix of two or more NaCl, KCl and LiCl salts as the salt catalyst, melting temperature of the salt catalyst being lower than baking temperature.

EFFECT: reduction of rutile crystallisation temperature.

42 cl, 12 ex, 19 dwg

FIELD: chemistry.

SUBSTANCE: invention can be used in lacquer-paint industry, in production of plastics, paper and other branches. Method of superficial procession of pigment titanium dioxide includes dechlorisation of titanium dioxide, wet milling and hydro-classification of titanium dioxide suspension, superficial procession of titanium dioxide, filtration, washing of titanium dioxide paste, its procession with organic compound, drying and microgrinding. Dechlorisation process is carried out at temperature of 50-60°C by combined dispersion of titanium dioxide in water and reduction of admixture chlorine in TiO2 with sodium hypophosphite in the amount twice exceeding content of chlorine in titanium dioxide, with further neutralisation of suspension with solution of sodium silicate to pH 6.5-7.0 and filtration. Suspension stabilisation before hydro-classification is carried out with solution of sodium silicate to pH of suspension 9.0-9.5 at temperature of 50-60°C. Superficial procession of fine fraction of suspension TiO2 is carried out at temperature of 60-70°C with compounds of titanium and aluminium using 1.0% weight TiO2 from solution of titanium tetrachloride, 2.5% weight Al2O3 from solution of sodium aluminate and 1.2-1.5% weight Al2O3 from solution of aluminium chloride. Processed suspension is filtered; paste is repulped in water to remove water-soluble substances; suspension is filtered. Prior to drying TiO2 paste is processed with organic compounds in The form of alkyl dioxyethylene in amount of 0.3-0.6% weight to TiO2, dried and microground.

EFFECT: increased indices of titanium dioxide, such as output of fine fraction of suspension TiO2 on hydro-classification, reduction of content of water-soluble substances in pigment, improvement of dispersibility in organic binders and gloss in akril paint and an increase in atmosphere-resistance.

2 cl, 5 ex, 3 tbl

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