Method of residual products containing phosphoric acid processing to calcium phosphates

FIELD: chemistry.

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

 

The invention relates to the processing of waste containing phosphate solutions, calcium phosphate, and specifically to the waste generated in the process of peredishki phosphoric acid.

This phosphate solution contains from 10% to 20% P2O5.

Difficulties processing waste containing mainly phosphorus compounds, related to the fact that the concentration of P2About them is small and mixing them with calcium-containing products, such as carbonate compounds (limestone, chalk), there is a strong enough effect providentia associated with intense evolution of carbon dioxide, which may be the release of partially neutralized phosphate pulp from the apparatus. Application in the production of carbonate calcium compounds due to the availability and cheapness of the latter.

There are many ways to get calcium phosphates using carbonate calcium compounds when using concentrated phosphoric acid, for example, AS the USSR №1463733, CL. SW 25/32, the concentration of phosphoric acid is 45% R2O5and in the method of producing dicalcium phosphate, described in the book "Technology of phosphate and compound fertilizers" M, "Chemistry", 1987, p. 166, the concentration of P2O5ranges from 48 to 52%.

However, in the connection with the foregoing to use these methods for processing on calcium phosphate solutions, a reduced-R2O5impossible. Therefore, in the processing of waste containing a small amount of P2O5apply other calcium-containing compounds (but not limestone or chalk).

So, for example, known is a method of processing waste gelatin containing up to 3.5% P2O5containing mainly phosphate (ICF), free phosphoric acid, a small quantity of phosphate of magnesium, calcium fluoride, etc. By this method the solution is mixed with milk of lime at a temperature of 20-30°and bring the pH up to 4.5-5.0. Then the resulting slurry is thickened and filtered on a vacuum filter. ("Trends in the development of fodder production of dicalcium phosphate and complex mineral supplements based on it". Review., M., 1987, p.7-9).

There is also known a method of producing dicalcium phosphate in the processing of phosphate solution containing 10-20% R2O5where as calcium-containing raw materials used Apatite concentrate. (A.S. No. 197531, CL. SW 25/32, 1967).

Due to the fact that the proposed method for processing wastes containing phosphoric acid with a concentration of P2O510-20%, involves the use of limestone (chalk), the closest solution is chosen, the method of producing dicalcium phosphate (precipitate), in which use phosphoric acid with a concentration of P2O522% is closest to the content of P2O5in the proposed method.

The method includes mixing the phosphate solution with a calcium-containing component, separating the resulting slurry by filtering and drying the separated product. According to this method, the slurry of the precipitate produced by the interaction of phosphoric acid (concentration of 22% P2O5with the suspension of limestone, introducing into the mixture rature (dry product) to obtain moisture in the product 30-32% and then drying it at a temperature of not more than 90°C. (Posin ON "Technology of mineral salts., L., Chemistry, 1970, s).

However, this method in the processing of waste containing P2O5in smaller quantities, and the use of natural limestone is not applicable, because it is not possible to obtain a product in granular form because of the large returnest process and poor performance; in addition, it is not possible to avoid the formation of a sufficiently large amount of foam.

We were set a task to process the waste containing phosphoric acid at a concentration of R2O5in them, equal to 10-20%, using the cheapest raw materials - natural limestone or chalk, granular calcium phosphate, to achieve the high performance of the finished granular product, to reduce flaking of production.

The problem is solved in the method of processing waste containing phosphoric acid, calcium phosphate, comprising mixing them with calcium-containing compounds, separating the resulting slurry by filtering and drying the product. Under the proposed method first as calcium compounds take limestone and submit it to the mixture with a source solution containing phosphoric acid, in an amount necessary to obtain the phosphate, the resulting slurry is separated into two streams in a ratio of 1:1.5 to 4, more flow is mixed with lime, taken in the quantity necessary to form a pulp, dicalcium phosphate, divide the resulting slurry by filtration, and the separated dicalcium phosphate before drying and granulating impose a lesser flow of pulp phosphate. Receiving phosphate lead in two stages: in the first phase to pH 2,9-3,1, and the second stage - to a pH of 3.5-3.7, and when the mixture of the pulp of phosphate of lime pH support equal to 5.4 and 5.6. Drying are simultaneously granulating drum granulator-dryer.

The essence of the method lies in the fact that first by using limestone receive the pulp international film festival. IFF is a water-soluble product, a subsequent stage of the granulation plays a role of a binder, which then allows not only to obtain the product in granular form, but to optimize the process of granulation, using a drum granulator-dryer (BGS).

In addition, the process of obtaining pulp international film festival is carried out in two stages, which allows, on the one hand, to avoid allocating a large amount of carbon dioxide (CO2and, consequently, a significant providentia, and on the other hand - saturation for calcium ion under these conditions is minimal, which further leads to the formation of well-filterable crystals of dicalcium phosphate (DCP).

The resulting slurry international film festival is divided into two streams in a certain ratio, which is selected based on a quality product and conditions of granulation. When the flow ratio less than 1:1.5 to reduced consumer properties of the final product due to the loss of prolongirovannomu (contents DFC decreases)with the increase of this ratio greater than 1:4 worse conditions for the formation of granules, i.e. performance is decreased granulation and output commodity fraction.

In our proposed process a greater flow of pulp international film festival is mixed with lime, as use at this stage of the limestone will not completely precipitated from the original solutions of phosphorus (limestone besieging his only 20-25%). Full deposition of phosphorus is necessary from the point of view of obtaining almost pure filtrate at the stage of deposition of D is f, that will allow it to be used as technical water.

The proposed process of obtaining calcium phosphates allows not only to obtain the product in granular form, but to use the most effective equipment, in particular BGS.

Thus, the developed process is economical because it provides not only the recycling of waste products, but also the use of most of cheap raw materials. You get a prolonged fertilizer in granular form. Significantly increase the environmental friendliness of the process by reducing harmful emissions.

The method is illustrated by the following examples.

Example 1. Solution - waste production of phosphoric acid and products on its basis - the number of 5600 kg/h containing (in %): P2O510; SO44; of 1.6 Mg; Fe 0,23; F 0,07 mixed with 392 kg/h of a suspension of limestone (224 kg/h 95% caso3) to a pH of 2.9, when the process temperature is 35°C, for 60 minutes as a result of receiving the pulp phosphate (ICF) in the amount of 5924,8 kg/hour. To the pulp add 168 kg/h) suspension of caso3to a pH of 3.6, at a temperature of 35-40°C for 60 min In the result 6064,8 kg/h pulp international film festival. The resulting slurry is divided in the ratio 1:2,875. However 4500 kg/HR slurry mixed with 1008 kg/h of a suspension of lime milk (178 kg/h 90% Cao) for the of 60 min and stirred for 60 min to pH 5.5. Next 5508 kg/HR slurry of dicalcium phosphate (DCP) is filtered on a belt filter under vacuum (filtration performance is 15 t/m2· the day when the height of the sediment layer 26 mm), 1645 kg/hour wet DCP (humidity - 30%) is mixed with the remaining 1564,8 kg/h pulp international film festival and 3209,8 kg/hour, the resulting slurry mixture UF and DCP dried and granularit apparatus BGS at a temperature of coolant 576°With inlet and 105°With output. You get a 1555 kg/h commercial product - monocalciumphosphate (MDCF)containing (%): P2O5total- 36,0; P2O5SPM(Trilon B) - 35,9; [P2O5SPM(of 0.4% HCL) - 35,7]; P2O5water- 7,0; SO4- 14,4; Ca - 12,1; Mg - 5,8; Ftotal- 0,1%; Fe - 0,83; the moisture content (W) is 3.0, which can be used both as a fertilizer and as feed.

3863 kg/h of Filtrate after precipitation DCP containing (%): P2O5- 0,1; Sa - 0,8; SO4- 1,0, directed partially (336 kg/h) to receive suspensions international film festival and the lime milk suspension (830 kg/hour)and the rest (697 kg/h) use technology as technical water.

The results of other experiments are shown in table 1

Table 1
The results of the experiments on the proposed the method of solution Flow - waste production - 5600 kg/hour
The weight ratio of flow UF and DCPpH 1 stage receiving UFpH 2 stage receiving UFpH after mixing of the pulp international film festival and DCPOutput MDCF, kg/hThe composition MDCF, %
The content of P-flsCAMgSO4FFe
totalSPM Tr BSPM of 0.4% HCLwaters
1:1,52,93,75,61505,437,237,237,016,410,86,014,90,200,83
1:4,03,13,5of 5.41582,035,435,335,2of 5.4a 12.7the 5.714,20,180,81

1. Method for processing waste containing phosphoric acid, calcium phosphate, comprising mixing them with calcium-containing compounds, separating the resulting slurry by filtration and drying, characterized in that the first as to Leicestershire connections take limestone and submit it to the mixture in the amount required to obtain phosphate, the resulting slurry is separated into two streams in a ratio of 1:1.5 to 4, more flow is mixed with lime, taken in the quantity necessary for the formation of dicalcium phosphate, divide the resulting slurry by filtration, and the separated dicalcium phosphate before drying and granulating impose a lesser flow of pulp phosphate.

2. The method according to claim 1, characterized in that the receiving pulp phosphate lead in two stages, the first stage phosphoric acid is mixed with limestone to a pH of a mixture of 2,9-3,1, at the second stage to a pH of 3.5-3.7, and mixing the pulp of phosphate of lime pH support equal to 5.4 and 5.6.

3. The method according to any one of claims 1 and 2, characterized in that the drying are simultaneously granulating drum granulator-dryer.



 

Same patents:

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.

1 tbl

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: 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: 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

The invention relates to the technology of production of fine high-purity calcium hydroxyapatite (microgranules), which can be used in the manufacture of composite materials, bioceramics, materials, stimulating regeneration of the bone tissue, the pharmaceutical carrier

The invention relates to a method of obtaining high temperature protonotaria double phosphates of calcium with iron and copper, which can be used as fuel cells, materials for the two-stage oxidation of fuel, gas sensors and catalysts
The invention relates to the production of phosphate salts of magnesium, particularly to a method of obtaining high-water translesanas phosphate magnesium [Mg3(PO4)2nH2O] suitable for use as hydrated on the units for production of desalinated water, and it may also find application as catalysts, adsorbents and light fillers
The invention relates to the processing of natural phosphate Apatite, and in particular to methods of decomposition of the complex fluoride raw material - fluorapatite, and can be used to obtain metaphosphoric acid and hydrogen fluoride used in the chemical industry, and calcium sulphate (anhydrite), used in the manufacture of building materials

The invention relates to the production of calcium phosphates, in particular calcium orthophosphate one-deputizing used in the food industry
The invention relates to the production of pure salts of calcium phosphate and can be used in the manufacture of composite materials, bioceramics, sorbents and catalysts

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.

1 tbl

FIELD: chemistry.

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

FIELD: chemistry.

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

FIELD: chemistry.

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

FIELD: chemistry.

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

FIELD: nanotechnology.

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

Up!