The method of obtaining calcium orthophosphate one-deputizing
(57) Abstract:The invention relates to the production of calcium phosphates, in particular calcium orthophosphate one-deputizing used in the food industry. The invention consists in the method of producing calcium orthophosphate one-deputizing, which includes evaporation of phosphoric acid to the content of P2O565-67,5%, followed by neutralization with calcium carbonate when the initial molar ratio of CaO/P2O5equal (0,95-1,0):1 and grinding the mass to obtain a particle size of not more than 0.10 mm, the Technical result of the developed method consists in reducing the duration of the process and excluding energy-intensive technological operations by ensuring conditions that reduce the viscosity and humidity the mass of calcium orthophosphate one-deputizing, as well as in increasing output and improving the quality of end product. table 1. The invention relates to the production of calcium phosphates, in particular calcium orthophosphate one-deputizing used in the food industry as a leavening agent, acidity regulator, flour improver, bread, stabilizer texturebrush substances, otveta of one-deputizing calcium (phosphate), including the neutralization of phosphoric acid with calcium carbonate to free acidity equal 144-264 g/l followed by parcoy and crystallization upon cooling to 25oC and separation of products by centrifugation (ed. St. USSR N 1169941, IPC C 01 B 25/32, publ. 30.07.85, bull. N 28).The disadvantage of this method is its low efficiency, due to the presence of energy-intensive crystallization and centrifugation, also on the efficiency of the process has a negative impact in that it provides chemically pure raw materials. In addition, obtained in a known manner brand monocalcium phosphate has a limited scope due to the presence of free phosphoric acid. A close analogue of the claimed invention is a method of obtaining calcium orthophosphate one-deputizing (phosphate), including the process of evaporation of phosphoric acid, followed by neutralization with calcium carbonate (ed. St. USSR N 193917, IPC C 01 B 25/32, publ. 13.03.67, bull. N 3).The known method provides for concentrating wet-process phosphoric acid to the content of P2O545-55% in the presence of silica is added in an amount up to is about 57%2O5and up to 0.2% of fluoride.The disadvantage of this method is its low efficiency, due to the duration and intensity of the process, as well as low quality commodity calcium orthophosphate one-deputizing.As shown by experiments carried out under conditions known way, the deficiencies noted primarily due to the fact that the thus obtained semi-product is a viscous wet mass containing unreacted products (for example, the free acid), a drying process which is extremely difficult and prolonged (up to 1-2 days). The yield of the finished product is not more than 85%.The claimed invention is directed to the development of a simple and economical method of obtaining calcium orthophosphate one-deputizing, allowing to obtain high-quality marketable product.The technical result of the developed method consists in reducing the duration of the process by ensuring conditions that reduce the viscosity and moisture content of the intermediate product, as well as increasing output and improving the quality of commercial calcium orthophosphate one-deputizing.This technical result costigliola neutralizing calcium carbonate, in which phosphoric acid is evaporated to contents P2O565-67,5%, neutralization is carried out at the initial molar ratio of CaO/P2O5equal (0,95-1,0):1, and the resulting mass is crushed to obtain particles with a size of not more than 0.10 mmThe essence of the proposed method consists in the following.Research has established that carrying out neutralization previously one stripped off before the content of P2O565-67,5% phosphoric acid calcium carbonate in the claimed ratio of the components, with subsequent grinding of the mass to the particle size of no more than 0.10 mm provides obtaining dietary calcium orthophosphate one-deputizing high quality while significantly reducing the duration and intensity of the process.Thus, it was determined that the preliminary evaporation of phosphoric acid to the claimed content of P2O5equal 65,0 is 67.5%, can significantly reduce the amount of water produced during the neutralization reaction mass of calcium orthophosphate one-deputizing, as well as to reduce its viscosity. The process with enough concentrated acid (65.0% and above) leads to a significant hydrolytic R is th product. Excessive (more 67,5%) concentration of phosphoric acid leads to the formation of impurities nakilat and lack crystallohydrates water in the finished product.The claimed range of molar ratios of CaO/P2O5average (0,95-1,0): 1, was determined experimentally on the basis of optimum moisture content in the intermediate (obtained mass of calcium orthophosphate one-deputizing) and the lack of any traces of unreacted reagents.It turned out that neutralised when the value of the ratio CaO/P2O5exceeding 1.0: 1, observed the formation of impurities of dicalcium phosphate, which leads to decrease in the content of the basic substance in the finished product, while not achieving the claimed ratio also leads to a decrease in the content of the basic substance due to the presence of excess unreacted acid.Essential as to increase the yield of marketable product and to improve its quality, as it turned out, renders the subsequent grinding of the mass of calcium orthophosphate one-deputizing.During the experiments it was found that in the case of grinding the aqueous product and its quality improved.It can be assumed that the above contributes to a more complete passage of the neutralization, namely the grinding of the mass of calcium orthophosphate to the claimed particle size leads to a significant increase of the contact surface phases, resulting enters the reaction of unreacted phosphoric acid, which ultimately provides higher yield and improved quality.Below is an example of confirming the possibility of implementing the claimed invention to obtain the above-mentioned technical result.Example
In the reactor with a working mixer serves phosphoric acid with a density of 1.57 g/cm3in the amount of 500 liters, then it is evaporated to a concentration of 66.0% of the P2O5In the reactor add the calcium carbonate in the amount of 283 kg (ratio of CaO/P2O5is to 0.96:1).The resulting suspension is cooled to a temperature of 20oC. the Resulting orthophosphate calcium crushed to particle size of not more than 0.1 mm, the Yield was 97% from stoichiometry, the content of the basic substance - 98,0%, the content of impurities meets the requirements of the calcium orthophosphate odnosima is.In this table compares the performance of the proposed method (NN experiments 2, 3, 6, 7, 9 and 10), and experiments, the conditions which go beyond regulated by the formula of the invention (experiments 1, 4, 5, 8 and 11).As can be seen from the presented data, only the totality of the claimed features enables optimal performance of the process of obtaining calcium orthophosphate one-deputizing. In violation of the proposed ratios of components a decrease in the quality and yield of the finished product (experiments 1, 4, 5, 8 and 11).Thus, the invention successfully solves the problem of creating a simple and economical method of obtaining calcium orthophosphate one-deputizing in order to reduce energy consumption by eliminating energy-intensive operations of drying and centrifugation, to ensure optimal performance of the process and high quality product. The method of obtaining calcium orthophosphate one-deputizing, including evaporation of phosphoric acid, followed by neutralization with calcium carbonate, characterized in that the phosphoric acid is evaporated to contents P2O565 is 67.5%, neutralization is carried out at ischaemic size of not more than 0.10 mm
FIELD: industrial inorganic synthesis.
SUBSTANCE: monocalcium phosphate, widely applied in agriculture, is prepared by mixing extraction phosphoric acid with calcium-containing component followed by granulation and drying of product. During mixing of components, appropriate temperature and moisture are maintained to ensure viscosity of mixture 3-7 mPa*s, and granulation and drying are carried out simultaneously in drum-type granulator drier. Calcium-containing component is either calcium carbonate or mixture thereof with limestone, whose does not exceed 15% of total weight of calcium-containing raw material. Moisture content in worked out drying agent leaving drum-type granulator drier equals 70-80 g per 1 kg dry air.
EFFECT: simplified process flowsheet, enabled granule size control, and increased strength of granules.
3 cl, 3 ex
FIELD: inorganic chemistry, chemical technology.
SUBSTANCE: invention relates to technology for preparing fodder calcium phosphates, namely to producing monocalcium phosphate. Method involves mixing wet-process phosphoric acid with a calcium-containing component in the presence of recycle, granulation and drying the product. Mixing process is carried out for two stages. At the first stage wet-process phosphoric acid with the concentration 62-65% of P2O5 is fed and process is carried out at recycle index = 1:(0.3-0.5) up to decomposition degree of calcium-containing raw = 0.89-0.92 at this stage. The second stage is combined with granulation and carried out its in high-speed mixer in water addition to obtain moisture in mixture 9.5-13%. The rate and time for mixing are regulated to provide the decomposition degree of calcium-containing raw = 0.93-0.99, and temperature at the next drying stage is maintained in the level 105-115°C. Method provides simplifying the process, reducing energy consumption and preparing product with the high content of P2O5 in water-soluble form and low content of fluorine.
EFFECT: improved method for preparing.
2 cl, 3 ex
FIELD: production of pure phosphoric acid and calcium monohydrophosphate.
SUBSTANCE: proposed method includes decomposition of phosphate ore by first hydrochloric acid solution at concentration not exceeding 10 mass-%, separation of liquid decomposition product into insoluble solid phase containing admixtures and separate aqueous phase containing phosphate, chloride and calcium ions in form of solution, neutralization of aqueous phase separated from liquid decomposition product by adding calcium compound for obtaining insoluble settled-out calcium phosphate by means of phosphate ions, separation of neutralized aqueous phase into aqueous phase containing calcium and chloride ions in form of solution and settled solid phase on base of water-insoluble calcium phosphate and dissolving of at least part of separated settled solid phase in second aqueous hydrochloric acid solution containing hydrochloric acid in the amount exceeding its content in first hydrochloric acid solution, thus forming aqueous solution containing phosphate, chloride and calcium ions extracted by organic extracting agent at extraction in "liquid-liquid" system. Proposed method makes it possible to avoid fine grinding or roasting of ore.
EFFECT: enhanced efficiency of extraction for production of pure concentrated phosphoric acid solution with no contamination of surrounding medium.
24 cl, 2 dwg, 1 tbl, 4 ex
FIELD: paint and varnish industry.
SUBSTANCE: anticorrosive pigment comprises , in mass per cents, 3.0-4.7 of calcium chromate and waterless dicalciumphosphate as the balance.
EFFECT: improved anticorrosion capabilities.
SUBSTANCE: method of processing of residual products containing phosphoric acid to calcium phosphates comprises its mixing with calcium-containing compounds, separation of derived slurry with filtration and drying. The limestone is used as calcium-containing compound, initially it is fed for mixing in quantity necessary for monocalcium phosphate, then derived slurry is divided to two flows in ratio 1:(1.5-4), the major flow is mixed with lime taken in quantity necessary for dicalcium phosphate formation, derived slurry is separated with filtration and minor flow of monocalcium phosphate slurry is added to separated dicalcium phosphate before drying and granulating. Preparation of monocalcium phosphate slurry is carried out in two stages, at first stage the phosphoric acid is mixed with limestone up to mixture pH =2.9-3.1, at second stage - up to mixture pH =3.5-3.7, during mixing of monocalcium phosphate slurry with lime pH is maintained in the range 5.4-5.6. Drying and granulating are carried out at the same time in drum granulator-dryer.
EFFECT: method enables to process the residual products to granulated calcium phosphates with usage the lowest-cost raw materials.
3 cl, 1 tbl, 1 ex
SUBSTANCE: invention relates to technology of obtaining inorganic materials, namely to methods of obtaining nanosized highly pure hydroxylapatite (HAP) in form of colloid solution or gel, which can be used for production of medico-preventive preparations for stomatology, for application on bone implants. Method of obtaining nanosized colloid hydroxylapatite includes synthesis of hydroxylapatite in saturated solution of calcium hydroxide, decanted after 24-hour settling from sedimented aggregates Ca(OH)2, by adding at rate 1.5-2.2 ml/min per litre of alkali solution 10-20% solution of orthophosphoric acid with constant mixing until pH value of reaction mixture is not lower than 10.5±0.5. Mixture is mixed during 20-30 minutes, settled during 1-2 hours and decanted until liquid phase stops forming on the surface. Obtain product represents colloid solution of highly pure hydroxylapatite with concentration 1.5-2%. Increase of hydroxylapatite concentration within the range from 2 to 30% is carried out by evaporation at temperature not higher than 60°C, and for obtaining nanosized hydroxylapatite with concentration 40±2% initial colloid solution is subjected to complete freezing with further unfreezing at temperature not more than 60°C and liquid phase decanting.
EFFECT: obtaining stable product with set in advance concentration, possessing higher penetrating ability and biochemical activity.
3 cl, 4 ex
SUBSTANCE: nano-sized highly-pure hydroxylapatite (HAP) is obtained in form of alcohol colloid solution (gel), which can be used for production of medicinal preventive preparations in stomatology, for applying bioactive coating on bone implants. Method includes hydroxylapatite synthesis by adding solution of orthophosphoric acid to calcium hydroxide solution and exposure to ultrasound impact, and ethyl or isopropyl alcohol is added to colloid of highly-pure nano-sized hydroxylapatite with concentration from 5% to 40±2% in order to obtain concentration of hydrooxylapatite in alcohol from 0.2 to 20%. After that alcohol mixture is processed with ultrasound with frequency 10-50 kHz during 1-2 hours.
EFFECT: alcohol colloid of nano-sized hydroxylapatite with high stability.
2 cl, 3 ex
SUBSTANCE: method of phosphate ore processing includes one-step counterflow process of phosphate ore decomposition, characterised by P2O5 content exceeding 20% in weight, by processing it with water solution of hydrochloric acid, which has HCl concentration lower than 10% in weight, with formation of processing solution, consisting of water phase, in which calcium phosphate is in dissolved state, and of solid phase, which contains admixtures; preliminary neutralisation of processing solution, containing calcium phosphate in solution, to first pH value, which is lower than pH value, at which essential part of said dissolved calcium phosphate precipitates in form of calcium monohydrophosphate (DCP), with precipitation of admixtures; first separation of insoluble solid phase and water phase of processing solution; repeated neutralisation of water phase obtained during first separation to second pH value, exceeding said first pH value, with DCP precipitation; and second separation of repeatedly neutralised water medium, which represents water solution of calcium chloride and precipitated DCP.
EFFECT: method allows optimising ratio between dissolved P2O5 output and purity degree of final product and ensure economically profitable process, which can be realised on simple equipment.
14 cl, 3 dwg, 2 tbl, 1 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: it is described a nanopatterned calcium phosphate material on the basis of threecalciumphosphate-hydroxyapatite system for reconstruction of osteal defects. The invention concerns to the calcium phosphate ceramic materials intended for manufacturing of osteal implants and-or replacement of defects at various osteal pathologies. The material on the chemical compound is close to a natural osteal tissue (the structure corresponds to the threecalciumphosphate-hydroxyapatite system). The unique ultradisperse structure of a material is formed at the expense of use of initial calcium phosphate nanopatterned powders and the additive.
EFFECT: reception of a ceramic material with uniform structure with the average size of particles less than 100 nanometres.
1 tbl, 3 ex
SUBSTANCE: invention relates to method of receiving of nano-crystalline hydroxyapatite. According to the invention calcium nano-crystalline hydroxyapatite is received by interaction of compound of calcium and ammonium hydro-phosphate. In the capacity of calcium compound it is used sugar lime C12H22-2nO11Can, at n, which is situated in the range from 0.5 up to 2. Particles size of the received hydroxyapatite is 30-50 nm.
EFFECT: receiving of nano-crystalline powder of calcium hydroxyapatite, which contains unaggressive biocompatible accompaniment of the reaction and that provides its usage in medicine.
3 dwg, 1 tbl, 1 ex