The method of producing peraluminous alkali metal

 

(57) Abstract:

The invention relates to the field of chemical technology and metallurgy, and in particular to methods of obtaining peraluminous. Periluminal use in chemical current sources, catalysts, optical coatings, such as modifying additives in electrolytic production of metals, special alloys and materials on their basis, flux for soldering and welding of aluminium and its alloys. The method includes the interaction in aqueous solution containing aluminum and fluorine-containing reagents, and as aluminium-containing agent use aluminum alum, and as the fluorine-containing agent is a fluoride of an alkali metal. As the fluoride of the alkali metal can be used fluoride potassium or rubidium fluoride. For maximum transfer of aluminum and fluorine in periluminal alum and alkali metal fluorides take for interaction calculated as the ratio of atomic masses in solution F:A1=(3-6):1. Moreover, potassium alum and potassium fluoride to interact optimally to take calculated as the ratio of atomic masses in solution F:A1=(4-5):1, almoravides alum and rubidium fluoride is calculated as the ratio of atomic masses in the solution is s production at the expense of the most complete selection of ingredients in the form of useful products. 6 C.p. f-crystals, 2 ill., 3 table.

The invention relates to the field of chemical technology and metallurgy, and in particular to methods of obtaining peraluminous.

Complex fluorides of alkali elements periluminal - formed as intermediate compounds in the processing of various mineral raw materials, and is retrieved and used as standalone products for a variety of purposes in chemistry and metallurgy. Comprehensive periluminal have practical value in the technology concentration and separation of alkali metals by extraction and crystallization from aqueous media in the processing of alumina and mica materials. Periluminal can be used in chemical current sources, catalysts, optical coatings, such as modifying additives in electrolytic production of metals, special alloys and materials on their basis, fluxes for brazing and welding of aluminium and its alloys. These fluxes have a lower melting temperature than the weldable aluminum alloys have corrosion-resistant properties, as well as allow you to clean the welded surface oxide films.

A known method of producing periluminal, including , reaction products of aluminum hydroxide in aqueous solution [J. Schoonman, Huggins R. A. J. Solid State Chem. 1976. V. 16. # 4. pp. 413-422; U.S. Pat. USA 4579605, 1985].

The disadvantage of this method is the high cost of the starting materials for the production of periluminal. In addition, in the reaction between the source components in addition to periluminal formed of fluorine-containing solutions. These solutions must be returned to the process or disposed of, because the content of fluorine in the liquid waste production is regulated by existing regulations.

Also known is a method of obtaining periluminal, including contact solution containing potassium ions and fluorine, with metallic aluminum or its alloy [U.S. Pat. USA 4643241, 1985].

The method has the same disadvantages and even more raw material cost, because to get periluminal used metal aluminum or its alloy.

A known method of producing periluminal, including hydrothermal synthesis at 350oFrom a stoichiometric mixture of KF and AlF55-normal solution of hydrofluoric acid [J. L. Fourquet, Boulard Century, Plet F. J. Solid State Chem. 1989. V. 81. N 1. Pp. 35-39].

The disadvantages of the method are the complexity of instrumentation associated with the use of autoclaves from resistant to aggressive Sestan way to get periluminal, comprising preparing a solution of fluoride of aluminum from aluminum hydroxide and hydrofluoric acid, mixing it with potassium hydroxide solution, filtering and drying [U.S. Pat. USA 6010578, 1997].

The disadvantages of this method are the high cost of initial substances, as well as the complexity of instrumentation associated with the use of hydrofluoric acid and disposal of liquid waste.

The prototype of the claimed invention is a method of obtaining periluminal, including interaction in the aquatic environment of the fluoride of the alkali metal and aluminum in a molar ratio of KF:lF3=2-10:1 [Tanaev, I. C., Nechamkin M. A. Izv. section physico-chemical analysis of the USSR Academy of Sciences. 1950. So 20. C. 227-237].

The disadvantages of the prototype method are the high cost of aluminum fluoride and the need for disposal of generated liquid waste.

The technical objective of the proposed method is a simplification of obtaining peraluminous alkali metal, as well as reducing waste production at the expense of the most complete selection of ingredients in the form of useful products.

The technical result is achieved by the interaction in aqueous solution containing aluminum and fluorine-containing reagents, the corresponding connection - the alkali metal fluorides.

As the fluoride of the alkali metal can be used fluoride potassium or rubidium fluoride.

Aluminum alum and alkali metal fluorides take for interaction calculated as the ratio of atomic masses in solution F:Al=(3-6):1. Moreover, potassium alum and potassium fluoride to interact optimally to take calculated as the ratio of atomic masses in solution F:Al=(4-5):1, almoravides alum and rubidium fluoride is calculated as the ratio of atomic masses in solution F:Al=(5-6):1.

Double sulfate salt-alum obtained when sulfuric acid refining and aluminium-containing micaceous rare metal raw materials (nepheline, lepidolite, zinnwaldite, alunite). After separating them from technological solutions and subsequent recrystallization transition to simple salts and clean the impurities products technically difficult.

According to the claimed method is simple sulfates and peraluminous alkali metals can be obtained from aqueous solutions of aluminum alum in the interaction with alkali metal fluorides:

MeAl(SO4)2+(3+x)MeF-->MexAlF3+x+Me2SO4< / BR>
where x=03

Me = alkali raw materials alum is achieved by simplifying the process and reducing waste production, because of the resulting stock solutions by evaporation can be selected alkali metal sulfate in the form of a simple salt, which is a commercial product. The simplification process in the present method in comparison with the prototype is achieved through the use of for cooking periluminal aluminum alum, which, in contrast to aluminum fluoride are the intermediate product of the processing of aluminium-containing minerals. In the method prototype to obtain aluminum fluoride necessary aluminum hydroxide and hydrofluoric acid, the final products are technically complex and environmentally unsound technologies.

During the interaction, a sufficiently wide range of peraluminous, and the predominance of one or another of periluminal in the solid product of the reaction depends on the ratio of the reacting substances.

The method is as follows. Aluminum alum and a fluoride of an alkali metal mixed in aqueous solution, separating the precipitate, if necessary, washed it and dried to obtain the final product. Alum and alkaline fluoride is a high excretion of fluoride from the liquid phase in peraluminous. From the mother liquor by evaporation and subsequent cooling of produce sulfate of an alkali metal in the form of a commercial product.

The rationale of the proposed parameters is illustrated by examples.

Example 1

An aqueous solution of potassium alum (mark "h") was mixed with potassium fluoride (mark "H. D. A.") when various atomic ratio F:AI in range (1-9):1. The resulting mixture was kept under stirring at the temperature of 90oC for 2 h the Resulting solid phase was separated from the mother liquor by filtration, washed with acetone and analyzed the leachate and precipitation on the content of the main components of weight, volume and photometric methods. The phase composition of the sediments was determined by x-ray method and using ICS. Shooting diffraction was carried out on automatic powder diffractometer Philips using Cotoradiation and graphite monochromator. IR spectra were taken on the spectrometer Perkin-Elmer in the range of wave numbers 400-3800 cm-1. Samples for imaging were prepared by pressing tablets with KBR. The pH value of the solutions was determined by ionometry type EV-74. In table.1, 3 and Fig.1 presents the composition of the resulting solid and liquid phases depending on the sediment provided mainly solfataras periluminal. When the ratio (4-5):1 allocated mainly dnovotny pentacarinat, while ratios above 6:1 hexafluoroaluminate together with potassium sulfate. When the ratio of atomic masses (4-5):1 fluorine fully transferred from the solution to precipitate periluminal. The IR spectra of peraluminous potassium, obtained for different ratios of F:Al(1-2:1; 2-3:1; 3-4:1; 4-5:1; 5-6:1; 6-7:1), presented on Fig.1.

The filtrate obtained after separation of periluminal, was evaporated and cooled emitting in the precipitate of potassium sulfate.

To obtain periluminal without admixture of potassium sulfate precipitation was washed with water at a ratio of W:t=3:1, and dried at 90oC. the Filtrates evaporated to dryness and progulivali. After calcination received potassium sulfate content of the basic substance 97-98%.

Example 2

An aqueous solution almoravides alum ("h") was mixed with fluoride, rubidium ("h D. A.") when various atomic ratio F:AI in range (1-11): 1. The resulting mixture was kept under stirring at the temperature of 90oC for 2 h With a ratio F:Al less than 3:1 precipitation almost did not stand out. Formed when the ratio F:Al more than 3:1 solid phase was separated from the mother liquor by filtration, Promavtomatika solid and liquid phases depending on the ratio F:Al in the original solution. As can be seen from the presented data, the ratio of atomic masses (3-4):1 in the sediment is allocated a mixture of the two-water tetravelent and solfataras periluminal. With a ratio more than 5:1 are allocated mainly dnovotny pentacarinat. When the ratio of atomic masses (5-6):1 fluorine fully transferred from the solution to precipitate periluminal. The IR spectra of peraluminous rubidium obtained for different ratios of F: Al(1-3:1; 2-4:1; 3-7:1; 4-9:1), presented on Fig.2.

The filtrate obtained after separation of periluminal, was evaporated and cooled emitting in the precipitate of sulphate of rubidium.

From table.1 and 2 shows that when the ratio in the original mixture F:AI less than 3:1 in the solution after the interaction remains significant amount of unreacted fluorine and aluminum, and with a ratio of over 6:1 in the solution remains excessive fluoride of an alkali metal.

Radiographic characteristics of peraluminous obtained according to examples 1 (when the ratio F:Al=2:1; 4:1; 7:1) and 2 (when the ratio F:Al=4:1; 7:1), presented in table.3.

The resulting peraluminous alkali metals and their compounds in its composition is close to that required for practical use.

1. The way what about the connection with a fluoride of an alkali metal, characterized in that aluminium-containing compounds are used aluminum alum, and aluminum alum and a fluoride of an alkali metal take for interaction calculated as the ratio of atomic masses in solution F: Al= (3-6): 1.

2. The method according to p. 1, characterized in that as the fluoride of the alkali metal used fluoride potassium.

3. The method according to p. 1, characterized in that as the fluoride of the alkali metal used rubidium fluoride.

4. The method according to any of paragraphs. 1-3, characterized in that aluminum alum use potassium alum.

5. The method according to any of paragraphs. 1-4, characterized in that potassium alum and potassium fluoride take for interaction calculated as the ratio of atomic masses in solution F: Al= (4-5): 1.

6. The method according to any of paragraphs. 1-5, characterized in that aluminum alum use almoravides alum.

7. The method according to any of paragraphs. 1-6, characterized in that almoravides alum and fluoride, rubidium take for interaction calculated as the ratio of atomic masses in solution F: Al= (5-6): 1.

 

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SUBSTANCE: the invention is pertaining to the field of nonferrous metallurgy, in particular, to processing of sodium sulfate solutions, which are released into a slime storage after a gas cleaning treatment electrolysis of bodies by production of aluminum. The method of processing of sodium sulfate solutions produced after the gas purification of the electrolysis bodies at production of aluminum provides for the gases purification from sulfuric oxides and fluorides by their sprinkling with a sodium sulfate solution in the washers, extraction from the solution after the gas purification of the fundamental quantity of sodium fluoride in the form of cryolite. The sodium sulfate solution purified from cryolite is in addition purified from sodium fluoride by its treatment at the temperature of 95-105°С within 1.5-2.0 hours with a lime milk injected into the sodium sulfate solution at the rate of stoichiometric binding of fluorine contained in the solution in CaF2. The sodium sulfate solution purified from fluorine is further subjected to a concentrating evaporation till achieving the density of a product solution of 1.37±0.02 g/l and extract a sodium sulfate from it into the sediment a in the form of berkeyit salt by introduction in the product solution of a carbonate soda till achieving the concentration of the titratabic alkali in the mother liquor of 215-230 g/l Na2Ot and the density of the solution in the suspension up to 1.35±0.02 g/l at stirring of the suspension at temperature of 95-100°С within 30-40 minutes. The invention ensures a more complete extraction of sodium sulfate from the product sodium sulfate solution in the form of berkeyit salt purified from sodium fluoride.

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FIELD: mining industry.

SUBSTANCE: method comprises charging cryolite in rinsing water, washing it at stirring, and dehydration of washed product. Washing is continued until content of sodium sulfate achieves 45-65% that in initial cryolite, which requires time from 5 to 60 min at rinsing water temperature 25 to 70°C and water-to-cryolite weight ratio (3-10):1.

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4 tbl, 2 ex

FIELD: mining industry.

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EFFECT: optimized process flowsheet.

1 tbl

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EFFECT: invention allows for obtaining cryolite and ammonium chloride at the same time.

2 ex

FIELD: metallurgy.

SUBSTANCE: proposed method washing off of regeneration cryolite pulp in condensate formed in heating of cryolite in pulping reactor. Duration of washing-off makes 30-60 minutes, temperature of condensate used for purifying if regeneration cryolite of sulfur compounds makes 50-80°C, volume ratio of used condensate to purifying pump makes (5÷8):1.

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4 cl, 1 dwg

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1 tbl, 5 ex

FIELD: metallurgy.

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3 cl, 1 tbl, 2 ex

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