Method of producing cation-substituted tricalcium phosphate

FIELD: chemistry.

SUBSTANCE: invention relates to chemical and medical industries and can be used in production of initial biocompatible material, suitable for making dense and porous ceramics, applicable as scaffolds in engineering of bone tissue, targets for creation of coatings on metallic implants in surgery and dentistry and in other fields of medicine. Method of producing cation-substituted tricalcium phosphate is described by deposition of average calcium phosphates, formed during pouring off and constant mixing of aqueous solutions of calcium nitrate and disubstituted ammonium phosphate, taken in molar ratio of 3:2, at pH 7.0 with subsequent filtering of formed precipitate and its thermal treatment at temperatures of 700–1,300 °C. Wherein calculated amount of solutions of salts of nitrates or acetates, or chlorides of following elements is added to reaction mixture: iron, zinc, copper, sodium, potassium, strontium, barium bismuth, silicon at following ratio of reagents, mol%: calcium nitrate – 40–59.9, disubstituted ammonium phosphate – 40; salt – 0.1–20.

EFFECT: powders formed after thermal treatment are characterized by homogeneous phase composition, corresponding to whitlokite structure, finely dispersed state with particle size of 20 nm to 2 mcm and antimicrobial activity.

1 cl, 1 tbl, 4 ex

 



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention can be used in producing magnetic powders, permanent magnets, resin-bonded magnets, magnetic liquids and high-density magnetic recording devices. The method of producing barium hexaferrite includes preparing a barium hexaferrite suspension, depositing said suspension in a neutral or weakly alkaline medium and drying. The barium hexaferrite suspension is obtained using an electrochemical method by dissolving electrodes made of steel St3, the distance between which is 5-15 mm, in an electroconductive solution of barium hydroxide and sodium chloride. The process is carried out with concentration of Ba(OH)2 7-10 mg/dm3, NaCl 3-5 mg/dm3, voltage 8-10 V, temperature 85-90°C, current density 0.11 A/cm2.

EFFECT: invention simplifies production of fine barium hexaferrite powder.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in producing pigments for white paints and coatings, including thermal control coatings. Producing solid solution powders Ba(1-x)SrxTiO3 is ensured by mixing barium carbonate BaCO3, strontium carbonate SrCO3 and titanium dioxide TiO2 powders in the required weight parts. The prepared mixture is heated. The mixed powders are heated sequentially: 2 hours at 800°C, then after cooling down, 2 hours at 1,200°C.

EFFECT: invention enables avoiding the high-temperature heating, compaction and disintegration in producing the solid solution powders Ba(1-x)SrxTiO3, increasing the yield.

1 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: installation for obtaining calcium carbide includes reactor with case in form of hermetic cylindrical vertical reservoir, upper end of which is equipped with loading channel, coaxial with it (3). Bottom part (2) of case is made conical and is equipped with outlet jet (12). Upper end of loading channel (3) is equipped with hermetic lid, on which placed is plasmatron (18), which forms plasma cord (21), directed downwards into the space between edges (22) of pouring platforms (7). Cavity of loading channel (3) is connected with sources of carbon dioxide (6) and sources of raw material mixture (4), which is connected with coal source (15) and limestone (16). Coal source (15) is connected with loading channel (3) by additional channel of coal supply (29). Upper (10) and lower (11) electromagnetic coils are installed below the lower edge of feed channel (3) coaxially to reactor case and along it on different height. Upper (10) electromagnetic coil is fastened on the surface of rotary platform (13) and is equipped with drive (14) of its rotation relative to base (27), and lower (11) electromagnetic coil is placed near the bottom part (2) of reactor. Space of upper part (1) of reactor case is connected with gas-separating unit (25), outlets of which are connected respectively with source of carbon dioxide (6) and reactor of carbonic acid synthesis (26) by means of gas-discharging channels (23, 24).

EFFECT: increase of target product output and reduction of power consumption of calcium carbide production.

3 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention can be used in production of construction materials. Photocatalytic composite material practically free from titanium dioxide contains limestone in amount at least 0.05% by the weight of sodium and calcium titanate in crystalline phases CT2 and/or CT5, characterised by the following diffraction maximums: CT2: (002) d=4.959; (210-202) d=2.890; (013) d=2.762 and (310-122) d-2.138; CT5: (002) d=8.845; (023) d-4.217; (110) d=3.611 and (006) d=2.948. The empirical formula of calcium titanate in phase CT2 is CaTi2O5, and the empirical formula of calcium titanate in phase CT5 is CaTi5O11.

EFFECT: invention makes it possible to increase photocatalytic activity of composite materials without application of titanium dioxide.

18 cl, 8 dwg, 7 ex

FIELD: chemistry.

SUBSTANCE: hydroxyapatite is obtained by mixing 1-1.5% water suspension of calcium carbonate, saturated with carbon dioxide in concentration 1-1.5 g/l, and 1-1.5 water solution of sodium hydroorthophosphate at temperature 20-37°C, with constant mixing and molar ratio CaCO3/Na2HPO4=5-7. The result lies in providing possibility of obtaining hydroxyapatite under harmless for people conditions, under which obtained hydroxyapatite can be used immediately after its obtaining.

EFFECT: method makes it possible to considerably reduce duration of production process.

2 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention can be applied in microelectronics. To obtaining complex yttrium, barium and copper oxide YBa2Cu3O7-δ, from water solution, which contains yttrium, barium and copper nitrates, combined sorption of yttrium, barium, copper in given molar ratio Y:Ba:Cu = 1:2:3 is carried out at the stage of sorption from the said solution on carboxyl cationite KB-4p-2. After that, obtained material is dried and subjected to successive heating at temperature 110 - for 2 h, at 250°C - for 2 h, at 450°C - for 5 h, at 600°C - for 3 h, at 850°C - for 6 h and after that for 1 hour in oxygen atmosphere.

EFFECT: invention makes it possible to simplify obtaining complex yttrium, barium and copper oxide.

1 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in paint-and-varnish industry, in making plastic, ceramics and construction materials. The molybdate-based pigment, which contains cerium and an alkali-earth metal, is a complex molybdate with a scheelite structure of the composition Ca1-3/2XCexMoO4, where 0.10≥x≥0.02.

EFFECT: invention enables to obtain environmentally safe pigments based on calcium molybdate doped with cerium, with colour ranging from orange-yellow to yellow, with high heat and chemical resistance.

1 dwg, 1 tbl, 5 ex

FIELD: metallurgy.

SUBSTANCE: method involves separate dilution of metallic barium and strontium mixed with organic solvent and carboxylising agent for synthesis of carboxyl-containing derivatives of barium and strontium, which are then mixed and combined with titanium alkoxide in stoichiometric ratio of Ba:Sr:Ti=[0.1÷0.9]:[0.9÷0.1]:1 to perform complexing reactions, and after that, the obtained homogeneous solution is diluted with organic solvent. Dilution of metallic barium and strontium and complexing reactions are performed at the temperature of 15÷40°C, and all the operations of the method are performed in dried inert atmosphere.

EFFECT: rather high electrophysical characteristics of ferroelectric films of barium-strontium titanate; excluding occurrence of non-controlled amount of water in the system and increasing stability and service life of film-forming solutions.

6 cl, 1 dwg, 1 ex

FIELD: process engineering.

SUBSTANCE: invention relates to production of beta-tribasic calcium phosphate ceramic articles fur use as bone implants. Proposed method comprises the following steps: preliminary heat treatment of gypsum preforms for 2.0-2.5 hours, conversion of said gypsum preform in hydroxyapatite in 1-molecular solution of ammonium phosphate for, at least, 24 hours and further heat treatment at 970-1030°C.

EFFECT: hardness of, at least, 2,2 MPa.

1 tbl, 2 ex

FIELD: physics.

SUBSTANCE: method of obtaining textured coatings with anisotropic coercitive force based on magnetic compounds involves synthesis of magnetic composite powders. To this end, strontium hexaferrite magnetic powder is uniformly placed in a channel on the surface of deformed metals and alloys and premoulding is performed. Milling is then carried out with a protective interlayer of titanium foil between the powder and mill rolls in a temperature interval from 20°C to 600°C, with subsequent annealing at temperature of 800-850°C or not less than 2.5 hours.

EFFECT: invention increases coercitive force and degree of anistropy thereof in magnetic coatings based on strontium hexaferrite.

2 tbl

FIELD: metallurgy.

SUBSTANCE: invention relates to methods for obtaining colloids of a metal oxide (versions), namely silicon dioxide, as well as to colloids themselves. The method involves addition of a chemically active metal oxide to a reaction tank at optimum mass velocity of addition of the metal oxide, which is based on a mathematical model that considers (i) particle nucleation rate, (ii) rate of metal oxide deposition on existing particles of metal oxide and (iii) growth of metal oxide particles in the reaction tank. Mass velocity of addition of metal oxide increases as a reaction time function. Introduction of inoculating particles of metal oxide to the reaction tank is performed prior to a stage of addition of the chemically active metal oxide. An optimum mass velocity of addition of metal oxide q is presented by the following formula: q=(3moGr/Dpo3)(Dpo+Grt)2, where: mo represents mass of metal oxide particles in the reaction tank in grams; Gr represents growth rate of metal oxide particles for metal oxide particles in the reaction tank as is determined as per increase of particle diameter, in nanometres per hour; Dpo represents average diameter of metal oxide particles in nanometres; t represents time in hours. Gr is within approximately 10 to approximately 50 nm/hours and q is within approximately 10.6 to approximately 52.8 g/1000 m2-hour during at least some part of the reaction period.

EFFECT: methods according to the invention are more effective due to reduction of reaction periods necessary to obtain colloids of metal oxide.

25 cl, 5 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention can be applied in chemical industry. Method of complex processing of natural brines of magnesium-calcium chloride type includes obtaining calcium chloride crystallohydrate with admixture of magnesium chloride and enriching brine by lithium with further processing of lithium concentrate into lithium compounds. After operation of enrichment by lithium, bromine, magnesium oxide and chlorine are obtained by electrolysis of mother brine, enriched with sodium chloride. After separation of lithium and bromine brine is subjected to purification from magnesium, is evaporated until sodium chlorides salt out and separated from NaCl crystals. Said brine or water is used for dissolution of calcium chloride crystallohydrate with obtaining solution, containing 400-450 kg/m3 of calcium chloride. Calcium chloride solution is used in exchange reaction with sodium hypochlorite with obtaining calcium hypochlorite. Calcium chloride solution is used to obtain calcium bromide by transfer of cationite KU-2-8chs from H+- form into Ca+- form. After that, calcium is desorbed from cationite with hydrobromic acid, which is obtained by interaction of bromine with water solution of reducing agent, represented by ammonia derivative. Calcium chloride solution is also used to obtain calcium carbonate.

EFFECT: invention makes it possible to obtain calcium hypochlorite, calcium bromide and calcium carbonate in addition to lithium compounds, bromine and magnesium oxide from brines of magnesium-calcium chloride type with application of reagents, obtained from the same brine.

3 cl, 3 dwg, 10 ex

FIELD: chemistry.

SUBSTANCE: layered double hydroxide is described by general formula Mg(1-x)Al3+(x-y)Ni3+y(OH)2(Ann-)x/n·mH2O, wherein triply charged metal cations are simultaneously used as aluminium and nickel cations; y possesses the value of 0.0025 to 0.0625, and x=0.25. A method for preparing the above layered double hydroxide with a hydrotalcite-compound structure consists in the fact that a solution containing magnesium, aluminium and nickel nitrates with the total metal ion concentration is 1M; a precipitator solution containing sodium hydroxide and sodium hypochlorite is added at ~3 ml/min at constant stirring. The precipitate is subject to age hardening under a mother solution for 48 hours at room temperature and for 72 hours at 80°C. The mother solution is cooled to room temperature and rinsed. The precipitate is first subject to anionic exchange, washed in distilled water and dried at room temperature.

EFFECT: preparing the new magnesium-aluminium-nickel synthetic hydrotalcite-like materials containing nickel cations as a part of brucite-like layers with oxidation rate +3 and characterised by a single-phase nature, high crystallinity and stability of nickel with unstable oxidation rate +3.

3 cl, 4 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: extraction of molybdenum and cerium is carried out in two steps, where molybdenum is extracted at the first step and a cerium compound is extracted at the second step. The first step involves crushing a catalyst, adding a solution of a leaching agent in weight ratio to the spent catalyst of (0.5-10):1, in concentration of not less than 0.1 mol/l, stirring the suspension for 4-10 hours at temperature of 90-95°C, filtering the mixture to separate the residue and washing the residue with water. A mixture is then prepared from the filtrate and water from washing the residue containing molybdenum. The mixture is the evaporated to obtain an end product. The second step of extracting the cerium compound is then carried out, where the residue of the crushed catalyst is completely dissolved in hydrochloric acid, water is added and then evaporated to the initial volume of the solution, the undissolved portion is separated by filtering, the remaining solution is neutralised to pH 3.5-4.5 with control thereof, the solution is heated to 90-100°C while stirring, followed by successively adding a calcium salt solution in ratio of calcium to the catalyst from 1:100 to 5:100 and a saturated oxalic acid solution in ratio to the catalyst from 5:1 to 10:1, stirring at temperature of 70-100°C for 2-6 hours, holding the solution to precipitate the cerium compound for 4-24 hours at room temperature, separating the precipitate from the mother solution by filtering, washing and drying to constant mass. The invention also discloses a method of extracting molybdenum only from said catalyst and a method of extracting cerium only from said catalyst.

EFFECT: extracting molybdenum and cerium with high percentage output and purity by preventing the effect of the extracted components on each other.

19 cl, 2 tbl, 18 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing process salt solutions for mining production, particularly to increasing stability of said solutions. The method involves adding to the solution one or more linear, branched, hyperbranched or dendrimeric polyols or mixtures thereof as stabilising process additives. The process salt solution is a mother solution from a Bayer method, which is used in producing aluminium oxide from bauxite.

EFFECT: high stability of the aluminate in the mother solution and in red mud pipeline of a Bayer method.

17 cl, 9 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: production of complex oxide compounds of rare-earth metals involves preparation of a mixture from rare-earth metal oxide powder, metal powder and an oxygen-containing additive, taken in hyperstoichiometric ratio, putting the mixture onto a substrate and carrying out a combustion reaction. The oxygen-containing additive is perchlorate of an alkali or alkali-earth metal selected from sodium, potassium, lithium, barium, calcium or magnesium, which is first mixed with rare-earth metal oxide powder, with the following ratio of components in wt %: rare-earth metal oxide 65.71-88.06; metal 11.94-34.29; perchlorate of alkali or alkali-earth metal 13.49-24.71.

EFFECT: simple and faster process of obtaining the end product.

1 tbl, 2 ex

FIELD: oil and gas industry.

SUBSTANCE: suggested invention refers to oil producing industry. The method of programmed regulated maintaining of reservoir pressure for intensification of oil withdrawal includes water supply from a pump via a collector and a row of automated shut-off and regulating facilities-regulators to high pressure of liquid with mechanical impurities; the said regulators consist of a separating connection chamber and an output collection chamber. The chambers are united between them with electromagnetic valves regulated from a controller by feedback with electromagnetic flow meter. The separating connecting chamber is formed with an input connecting flange and a connecting case with seats for ceramic bushings. The output collection chamber is formed with a flange pass-through case and an output connecting flange. The multi-channel multi-shut-off regulating facility installed before a pressure well creates a row of controlled dynamic conditions of liquid flow both interrupted from short to durational stops of flow with various amplitude values and continuous flow with preset nominal-core value of amplitude from constantly open part of gates and fluctuating in the mode add-diminish by means of opening, shutting-off or simultaneous operation of the other part of gates regulated by individual programs from the controller; in its turn this creates a row of controlled gradients of flow rate in non-uniform oil reservoirs and changes oil extraction from weakly permeable layers.

EFFECT: increased oil withdrawal from reservoirs.

8 dwg

FIELD: chemistry, inorganic.

SUBSTANCE: invention is related to the field of chemical and hydrometallurgical technology and can be used for decomposition of silicate ores and utilisation of slags of metallurgical and coal industries. The method of separation of mineral oxide mixture into individual components includes the steps of hydrofluorination at a temperature of 150 - 200 °C by means of ammonium fluoride, sublimation separation of volatile fluorides at 350 - 400 °C, pyrohydrolysis, leaching of soluble fluorides from the fluorinated mass, ammonia precipitation of insoluble hydroxides, filtering separation, hydrochlorination at a temperature of 200 - 250 °C by means of ammonium chloride. The proposed invention allows separation of mineral raw stock into individual components, reuse of reagents being possible.

EFFECT: separation of mineral raw stock into individual components with a possibility of reuse of reagents.

1 dwg, 3 ex

FIELD: chemical industry; petrochemical industry; other industries; production of the filtering devices having the internal containers.

SUBSTANCE: the invention is pertaining to the filtering device containing the mixer, which mixing share at the change on the whole volumetric stream remains significantly constant. The filtering device contains the filtering tract "A" with the first filtration section and the mixing tract "B" with the second filtration section. The tracts are connected to the inlet channel for water and the outlet channel for the pure water. The hydrodynamic characteristic of the components of the mixing tract "B" is matched with the hydrodynamic characteristic of the components of the filtering tract "A". The internal container for the filtering device has the first filtering chamber, in which the second filtering chamber is disposed. Under the chambers there is the collection chamber. The technical result consists in saving of the constant share of commixing at the variations of the whole volumetric stream.

EFFECT: the invention ensures, that the filtering device with the internal container maintains the constant share of commixing at the variations of the whole volumetric stream.

20 cl, 10 dwg

FIELD: extraction of beryllium at processing the beryllium concentrates obtaining the beryllium sulfate solution.

SUBSTANCE: proposed method includes activation of concentrate, sulfating the activated concentrate by sulfuric acid, aqueous leaching-out of sulfated product, separation of leaching pulp into beryllium sulfate solution and cake, washing the cake with water for removal of beryllium sulfate, separation of pulp after washing into washing solution and waste cake. Beryllium concentrate is activated by grinding till obtaining roentgeno-amorphous product at size of particles lesser than 5 mcm; activated concentrate is sulfated by sulfuric acid for at least 0.5 h at temperature of 95-105°C at continuous mechanical removal of products of reaction from surfaces of concentrate particles, after which procedure is continued at temperature of 250-300°C for at least 1.5 h.

EFFECT: avoidance of use of fluxes; reduced number of operations at concentrate activation stage; reduced amount of waste cake.

1 tbl, 1 ex

FIELD: medicine.

SUBSTANCE: what is presented is a method for preparing submicron biphasic tricalcium phosphate and hydroxyapatite ceramics involving synthesis of single-phase powder of calcium salts and ammonium hydrophosphate, disaggregation, moulding and annealing. According to the invention, the calcium salt is presented by calcium acetate in the form of an aqueous solution of the concentration of 1M - 2M in Ca/P ratio applicable for initial salts and falling within the range of 1.5-1.6. The synthesis procedure involves single-step pouring of an aqueous solution of ammonium hydrophosphate to the aqueous solution of calcium acetate and mixing of the above solutions for 10-20 minutes, and separating the precipitate. The products are annealed at a temperature falling within the range of 1,050-1,150°C and kept at the above temperature for 0.5-1.5 hours. The produced ceramics contains β-tricalcium phosphate and hydroxyapatite with a grain size of 400-600 nm.

EFFECT: preparing the submicron biphasic ceramics having a uniform microsctructure.

2 dwg, 1 tbl, 1 ex

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