RU2072324C1 - Method for production of calcium fluoride - Google Patents

Abstract

FIELD: chemical industry. SUBSTANCE: method involves hydrolysis of silicium hydrogen fluoride acid by ammonium-containing reagent and filtration thus obtained pulp of silicium dioxide to prepare solution of ammonium fluoride. The process is followed by interaction of said solution with calcium carbonate and by separation of calcium fluoride. Mentioned above hydrolysis takes place at 35-50 C; before filtration said pulp of silicium dioxide is concentrated. Said solution of ammonium fluoride is divided in two streams at their ratio 1:(0.5-5) respectively, the former is fed for production of mentioned above ammonium-containing reagent, the latter is fed for interaction with calcium carbonate. EFFECT: improves efficiency of the method. 12 cl

Description

 The invention relates to chemical technology, in particular to the production of calcium fluoride used in the production of hydrogen fluoride or as a flux in steelmaking.

A known method of producing calcium fluoride, including the processing of hydrofluoric acid with a solution of ammonia, separation of silicon dioxide and the subsequent interaction of ammonium fluoride with calcium carbonate at elevated temperatures, the reactants being supplied in atomized form and the process is carried out at a temperature of 300 500 ^o C (SU, Auth. N 1 142 446, CL C 01 F 11/22, 1985).

 The disadvantage of this method is the high reaction temperature, and as a result, high energy consumption, which dramatically increases the cost of the product. In addition, the hydrolysis of hydrofluoric acid with an ammonia solution requires a large amount of circulating water, therefore, it worsens the environmental situation in the workplace.

 The objective of the invention is to reduce energy consumption and, accordingly, the cost of production, as well as improving the environmental situation at the factory.

The problem is solved due to the fact that in the method for producing calcium fluoride, which includes hydrolysis of hydrofluoric acid with an ammonium-containing reagent of an alkaline nature, filtering the resulting silica pulp to obtain a solution of ammonium fluoride and reacting the latter with calcium carbonate, followed by separation of calcium fluoride, the hydrolysis is carried out at a temperature of 35-50 ^o C, before filtration of the silica slurry carried thickening and ammonium fluoride solution is divided into two streams in a ratio of 1: (0.5 5.0), wherein the first homo is directed to the preparation of ammonium-alkali reagent character, and the second stream is directed to interact with the calcium carbonate.

 In this case, hydrofluoric acid obtained as a waste from the production of phosphoric mineral fertilizers or hydrofluoric acid obtained as a waste from the production of phosphoric acid can be used.

 As an ammonium-containing reagent of an alkaline nature, ammonia water can be used, and ammonia water is used as a waste product of ammonia production.

 As an ammonium-containing reagent of an alkaline nature, ammonium carbonate can be used, and ammonium carbonate obtained as a waste product of the production of mineral fertilizers can be used.

 Hydrofluoric acid can be fed into at least one storage tank.

 At least part of the housing of at least one storage tank can be made in the form of a cylinder of circular or elliptical, or oval, or ovoidal shape in transverse and / or longitudinal sections and / or in the form of a combination or combinations of these configurations.

 At least one storage tank can be partitioned at least in the direction of the longitudinal axis. At least one storage tank can be made in the form of volumetric bodies of a combined configuration, including a combination of at least one cylindrical section of a circular and / or elliptical section of a circular and / or elliptical and / or oval and / or ovoid configuration with a conical and / or hypovarious , and / or combined sections, including at least one flat face, or at least one insert of the second or third, or fourth order of curvature.

 The bottom of the storage tank may contain at least one mono- and polyconic section.

 The bottom of the storage tank can be made in the form of a tapering shell downward, representing at least part of the body of revolution forming in the form of an unduloid or branch of a hyperbola, or a combined configuration, including including a combination of straight or broken sections, or their combination with at least one curvilinear an element.

 The bottom of the storage tank may be provided with at least one means for draining hydrofluoric acid, located in the lowest portion of the bottom.

 Means for draining hydrofluoric acid can be used multiplicatively and placed symmetrically relative to the longitudinal axis of the storage tank.

 Means for draining hydrofluoric acid can be placed asymmetrically relative to the longitudinal axis of the storage tank, mainly in the area adjacent to the side wall of the tank and / or at least partially insert into the bottom zone of the side wall.

 At least part of the housing of the storage tank can be made semi-cylindrical or from a combination of shells successively covering each other of the same height or at least partially different in height of the upper edges of the shells.

 At least part of the walls of the housing of the storage tank can be made in the form of diaphragms of chemically resistant material.

 At least one diaphragm in the upper and / or lower part thereof may be provided with means for communicating the partitioned zones of the storage tank.

 The longitudinal axis of at least one storage tank may be oriented vertically.

 The longitudinal axis of at least one storage tank or at least one section of the storage tank may be inclined.

 The storage tank can be configured to absorb hydrostatic and / or dynamic pressure of hydrofluoric acid supplied to it.

 At least one storage tank can be configured to operate under excess pressure, which is created by additional injection of an inert gas or an inert gas mixture.

 At least part of hydrofluoric acid can be transported in tanks, including rail.

 At least one storage tank can be made in the form of a closed or temporarily sealed tank with the ability to work under excessive pressure and supply hydrofluoric acid from it, including at levels exceeding the maximum fill levels of hydrofluoric acid in this tank.

 An ammonium-containing alkaline reagent can be fed into at least one storage tank.

 At least part of the housing of the storage tank for the ammonium-containing reagent can be made in cross section in the form of a cylinder of round or elliptical, or oval, or ovoid shape, or in the form of a combination of these configurations.

 At least one storage tank can be partitioned at least in the direction of the longitudinal axis.

 At least one storage tank for the ammonium-containing reagent can be made in the form of volumetric bodies of a combined configuration, including a combination of at least one cylindrical section of a round or elliptical, or oval, or ovoid configuration with a conical or hypovar, or combined sections, including including at least one flat face or at least one insert of the second or third, or fourth order of curvature.

 The bottom of the storage tank for the ammonium-containing reagent may contain at least a conical section.

 The bottom of the storage tank can be made in the form of a tapering shell downward, representing at least part of the body of revolution forming in the form of an unduloid or branch of a hyperbola, or a combined configuration that includes a combination of straight or broken sections, or a combination of them with at least one curvilinear element.

 The bottom of the storage tank for the ammonium-containing reagent may be provided with at least one means for draining the alkaline ammonium-containing reagent.

 If there are at least two means for draining the alkaline ammonium reagent, the latter can be placed symmetrically with respect to the longitudinal axis of the storage tank. 2 Means for draining the alkaline ammonium reagent can be placed asymmetrically with respect to the longitudinal axis of the storage tank, mainly in the area adjacent to the side wall of the tank and / or at least partially inset into the bottom zone of the side wall.

 At least part of the walls of the housing of the storage tank can be made in the form of diaphragms of chemically resistant material.

 At least one diaphragm in the upper and / or lower part thereof may be provided with means for communicating sections of the storage tank formed by the diaphragm.

 The longitudinal axis of at least one storage tank can be oriented vertically.

 The longitudinal axis of at least one storage tank or at least one section of the storage tank may be inclined.

 The storage tank for the ammonium-containing reagent can be configured to sense hydrostatic perception of the hydrostatic and / or dynamic pressure of an alkaline ammonium-containing reagent supplied thereto.

 At least one storage tank can be configured to operate under excess pressure, which is created by additional injection of an inert gas or an inert gas mixture.

 At least part of the ammonium-containing alkaline reagent can be transported in tanks.

 At least part of the ammonium-containing alkaline reagent can be transported in railway tanks or in tanks installed on automobile and / or tracked vehicles.

 Hydrochloric acid can be obtained by dissolving silicon tetrafluoride in water.

 A solution of hydrofluoric acid as a waste product of the production of mineral phosphorus fertilizers with a concentration of 8-12 wt. can be added with concentrated hydrofluoric acid to a concentration of 20 to 25 wt.

Hydrofluoric acid can be fed for hydrolysis by a centrifugal pump with a capacity of 11 kW and a capacity of 45 m ³ / h.

 Hydrolysis can be carried out in a reactor system with increasing concentration of silicon oxide in the form of pulp.

 The reactor system can be performed in the form of a cascade of reactors.

 At least part of the surface of the reactors in contact with the reaction mixture may be made of a neutral, chemically resistant material or protected by a coating of a neutral, chemically resistant material.

 At least one of the reactors can be implemented in the form of a sectioned reactor, divided into at least three sections partially aligned in volume and / or on the contact surface.

 The sectioned reactor can be made in the form of an extended tray or pipe, or a combination of these forms and can provide at least a portion of the length with an inclined bottom.

 The axis of the tray, at least on the part of the tray, can be broken and / or curved and / or combined.

 The reactor vessel may be helical.

 The axis of the reactor can be performed with a variable angle of inclination, increasing to the lower boundary of the reactor. 2 The sectional reactor, at least for part of the length, can be equipped with a screw for moving the reaction mixture.

 The hydrolysis of hydrofluoric acid and an alkaline ammonium-containing reagent can be carried out in two stages, the hydrolysis being carried out in the first stage until a pH of 7.3 7.8 is reached, and the hydrolysis with a pH of at least 9.0 is completed in the second stage.

Hydrochloric acid can be fed for hydrolysis with a concentration of 20 25% and ammonium-containing alkaline reagents are fed with a concentration of at least 15%
Hydrofluoric acid can be fed for hydrolysis with a flow rate of not more than 10 m ³ / hour.

 Hydrolysis can be carried out in a cascade of reactors made of carbon steel, gummed with ebonite and rubber and lined with graphite tiles, equipped with a stirrer installed with the possibility of rotation of the blades 30 50 rpm

 The mixer can carry out the anchor type.

The hydrolysis reaction mixture can be pumped from the reactor to the reactor by a centrifugal pump with a capacity of 315 m ³ / h.

 Hydrolysis of the reaction mixture from hydrofluoric acid and an alkaline ammonium-containing reagent can be carried out with additional heat removal, for which the reaction mixture is recycled through a heat exchanger and at least one of the cascade reactors.

Heat can be removed in a horizontal shell-and-tube heat exchanger, while maintaining the working pressure in the annular and tube space of 16 kg / cm ² .

 Hydrolysis products can be thickened in a thickener.

The thickener can be performed in the form of a reactor with a shell mounted vertically or at an angle to the vertical axis of not more than 35 ^o , while the reaction mixture after hydrolysis is fed into the Central part of the reactor under a layer of liquid.

 After hydrolysis, the reaction mixture can be fed into a zone comprising 1/3 2/3 of the thickener height.

 The thickener may be provided with a groove installed along its perimeter.

 The gutter can be mounted on the inside of the shell or on the outside of the shell.

 The gutter can be installed with passage through the thickener body or partially placed in the thickness of the thickener body.

 Silica gel precipitated from the reaction mixture on the walls of the thickener can be removed with a scraper mixer.

 A scraper mixer can be performed with scrapers in an amount of at least four.

 The blades of the scraper mixer can be performed with at least a working edge facing the wall and / or to the bottom area with precipitated silica gel having a configuration in the form of a fragment of a cylindrical spiral or helix.

 The angle of inclination of the spiral or helix, at least in the area of the working edge, can be made variable.

 The angle of inclination to the horizon of the spiral part of the blade can perform growing from the upper end to the lower end of the blade.

 The angle of inclination to the horizon of the spiral part of the blade can be performed decreasing from the upper end to the lower end of the blade. 2 After filtering, additional control filtering can be carried out.

 Control filtering can be carried out on bag filters.

 Control filtering can be carried out on bag filters mounted in a vertical apparatus with a conical bottom and a spherical cover, inside of which are installed cartridges, fitted with filtering sleeves.

 The bag filter cartridges can be equipped in 19 sections.

Sediment in bag filters can be removed by supplying air inside the cartridge with a pressure of 0.5 kgf / cm ² .

 Chalk, including synthetic chalk, can be used as calcium carbonate.

 As calcium carbonate, synthetic chalk obtained by treating calcium nitrate tetrahydrate with ammonium carbonate can be used.

 Can use synthetic chalk with a crystal size of 5 to 40 microns, containing not more than 1% phosphates in terms of phosphorus pentoxide and not more than 0.5 fluorides in terms of fluorine.

 Before the interaction of chalk and ammonium fluoride can prepare chalk pulp, which is subjected to thickening, filtering, washing.

 Cretaceous pulp can be prepared in a solution of ammonium nitrate and fed to a thickener, which is performed in the form of a reactor with a turbine mixer, to obtain a thickened pulp.

 The thickened chalk pulp can be fed for filtering to a belt vacuum filter, which is made in the form of a horizontal welded frame, with drive and tension drums installed on it, on which an endless perforated rubber tape is mounted, on which filter cloth is placed.

 Filtration on a tape vacuum filter can be carried out with at least three countercurrent washing of the chalk sediment, and a solution of ammonium nitrate is used as the washing liquid.

 The interaction of calcium carbonate with ammonium fluoride can be carried out in two stages, with calcium carbonate fed to the first stage, and ammonium fluoride to the second, the filtrate after the second stage fed to the first, and the precipitate obtained in the first stage, fed to the second.

 The first stage of the interaction of chalk with ammonium fluoride can be carried out in a reactor with the supply of a precipitate of chalk, which is pre-pulp with a solution of ammonium fluoride.

The chalk can be pulp until a pulp with a density of 1.4-1.5 g / cm ^{3 is} obtained.

The temperature in the first stage of interaction can maintain 90 - 95 ^o C.

 The reaction temperature can be maintained by the introduction of hot steam into the reactor.

 The pulp of the reaction products after the first stage can be fed to a plate thickener and then to a drum vacuum filter.

 The pulp can be fed into the middle part of the thickener with the formation of a clarified solution and thickened pulp.

 The thickened pulp can be fed to a drum vacuum with a filter with a knife, made in the form of a box with a horizontally located filter drum partially immersed in it, on the cylindrical surface of which the filter cloth is strengthened.

 The precipitate layer formed on the surface can be washed, dried by vacuum, purged with compressed air, cut with a knife and fed to the second stage of interaction.

 The filtrate can be fed through the distribution head of the filter to the receiver, in which the liquid and gaseous phases are separated by inertial forces.

 After filtering, the precipitate can be pulped with a solution of ammonium fluoride and fed to the second stage of interaction.

 The second stage of the interaction of calcium carbonate with ammonium fluoride can be carried out in a cascade of reactors.

 The interaction can be carried out in a cascade of reactors containing at least three reactors.

 The reaction products may be cooled in a heat exchanger.

 The reaction products can be cooled in a coil heat exchanger.

 The configuration of the walls of the coil, at least for part of the length, can perform a variable cross-section.

The reaction products of the second stage can be fed to the belt vacuum filter in an amount of 10 11 m ³ / h.

 The precipitate of calcium fluoride on a belt vacuum filter can be washed at least three times, the obtained filtrate is fed to the first stage of the interaction of calcium carbonate with ammonium fluoride.

 Calcium fluoride precipitate can be dried.

 Drying can be carried out in a fluidized bed reactor with flue gases.

 As granules for a fluidized bed can be used granules of inert material, for example alundum granules.

 Flue gases for drying can be obtained by burning in a calorifer of natural gas, previously purified from mechanical impurities.

Natural gas can be fed into the air heater in an amount of 50 to 100 m ³ / h.

 Natural gas can be burned in a heater made in the form of a cylindrical horizontally arranged apparatus, inside which a gas manifold is installed in the form of two coaxially located chambers with an autonomous supply of natural gas, injection burners and an ignition burner.

 The drying reactor can be made in the form of a vertical casing, with a horizontal gas distribution grid located in it, with the formation of an upper drying chamber and a lower sublattice chamber made of a cylindrical shape, lined from the inside and connected to a heater.

 Dried calcium fluoride particles can be fed sequentially to dry and wet cleaning.

 Dry cleaning of calcium fluoride can be carried out in at least two series-connected cyclones connected to storage bins.

 Calcium fluoride can be unloaded from storage bins through airlock feeders.

 The gas-air stream from cyclones can be fed for wet cleaning to the upper part of the coagulator pipe, inside which a coil with cooling water is placed, the outgoing gas stream is fed to the second stage of interaction of calcium carbonate with ammonium fluoride.

 The technical result provided by the specified set of features is that due to the absence of the need for high temperature, it is possible to reduce energy consumption, and the environmental situation at the plant is improved due to the exclusion of large costs of circulating water during hydrolysis.

 In FIG. 1 shows a diagram of a processing line for implementing the method; in FIG. 2 storage capacity, side view; in FIG. 3 is a cross-section or longitudinal section of a portion of the housing of the storage tank, an elliptical embodiment; in FIG. 4 the same, an oval-shaped variant; in FIG. 5 the same, a variant of the ovoid shape; in FIG. 6 embodiment of a sectioned container, longitudinal section; in FIG. 7 embodiment of the bottom of the storage tank in the form of a tapering-down shell with drainage means, a longitudinal section; in FIG. 8 the same, with an asymmetric arrangement of means for draining relative to the longitudinal axis; in FIG. 9 embodiment of a part of the housing from a combination of shells successively covering each other partially different in height, a longitudinal section; in FIG. 10 embodiment of the walls of the housing of the storage tank in the form of a diaphragm, one of which has in the upper part of the means for communicating the partitioned zones of the storage tank; in FIG. 11 cascade of reactors, side view; in FIG. 12 is a partitioned reactor, an embodiment with an inclined bottom; in FIG. 13 is an embodiment of an axis of a pubis forming a reactor of combined shape, a longitudinal section; in FIG. 14 embodiment of the reactor vessel spiral, side view; in FIG. 15 embodiment of a reactor axis with a variable angle of inclination increasing to the lower boundary of the reactor, a longitudinal section; in FIG. 16 horizontal shell-and-tube heat exchanger, side view; in FIG. 17 thickener in the form of a reactor with a shell and a groove around the perimeter, a schematic side view; in FIG. 18 the same, with a gutter installed with a passage through the housing; in FIG. 19 blade scraper mixer, an embodiment of the working edge in the form of a helix, top view; in FIG. 20 the same, with a variable angle of inclination of the helix, growing from the upper end to the lower end of the blade, top view; in FIG. 21 bag filters in a vertical apparatus with a conical bottom and a spherical cap, longitudinal section; in FIG. 22 belt vacuum filter in the form of a horizontal frame, with drums and endless tape, side view; in FIG. 23 a knife of a drum vacuum filter in the form of a box with a horizontally located filter drum partially immersed in it; in FIG. 24 coil heat exchanger with walls of variable cross-section for part length, longitudinal section; in FIG. 25 reactor for drying in the form of a vertical body with a horizontal grate placed in it, forming the upper and lower chambers, a schematic longitudinal section; in FIG. 26 pipe coagulator with a coil, a longitudinal section.

 The method is as follows.

A method of producing calcium fluoride includes hydrolysis of hydrofluoric acid (CPVC) with an alkaline ammonium-containing reagent, filtering the resulting silica pulp to produce a solution of ammonium fluoride and reacting the latter with calcium carbonate, followed by separation of calcium fluoride. The hydrolysis is carried out at a temperature of 35 - 50 ^o C, before filtering the silica pulp, thickening is carried out and the ammonium fluoride solution is divided into two streams in the ratio 1 (0.5 5), the first stream being sent to the preparation of an alkaline ammonium-containing reagent, and the second stream being directed on interaction with calcium carbonate.

 Can be used hydrofluoric acid obtained as a waste of the production of phosphoric mineral fertilizers or as a waste of the production of phosphoric acid.

 The hydrolysis of hydrofluoric acid and an ammonium-containing alkaline reagent are carried out in two stages, the hydrolysis being carried out in the first stage until a pH of 7.3 to 7.8 is reached, and the hydrolysis with a pH of at least 9.0 is completed in the second stage.

 Hydrolysis of hydrofluoric acid can be carried out in two ways.

 In the first embodiment, the hydrolysis is carried out with ammonia water with the removal of the chemical heat of the reaction by circulating the reaction mass through external heat exchangers.

The temperature of the reaction mass supplied to the filtration 35 50 ^o C, the concentration of the solution for ammonium fluoride 130 200 g / l, the concentration of excess ammonium 10 20 g / l.

 In the second embodiment, hydrolysis is carried out in two stages. At the first stage, using a solution of ammonium carbonate, hydrofluoric acid is neutralized to ammonium silicofluoride and its hydrolysis by 50; in the second stage, using the ammonia water, the hydrolysis of the remaining part of ammonium silicofluoride is completed.

 Hydrolysis according to the second option allows you to drastically reduce the total thermal effect of the process and eliminates the need for heat removal through the heat exchange surface.

 They can use ammonium carbonate obtained as a waste of the production of mineral fertilizers.

 Hydrochloric acid is fed into at least one storage tank 1.

 At least part of the housing of at least one storage tank is circular (not shown) or elliptical 2, or oval 3, or ovoid 4 in a transverse and / or longitudinal section, or in the form of a section, or a combination of these configurations.

 At least one storage tank 5 is partitioned at least in the direction of the longitudinal axis.

 At least one storage tank can be made in the form of volumetric bodies of a combined configuration, including a combination of at least one cylindrical section of a round and / or elliptical, and / or oval and / or ovoid configuration with conical and / or hypovaroid and / or combined sections including at least one flat face or at least one insert of the second, third, or fourth order of curvature (not shown).

 The bottom 6 of the storage tank 1 contains at least one section of a mono- or polyconic shape.

 The bottom of the storage tank 1 can be made in the form of a shell 7 tapering downward, representing at least a part of the body of revolution forming in the form of an unduloid or branch of a hyperbola, or a combined configuration, including including a combination of straight or broken sections or their combination with at least one curved element (not shown).

 The bottom 6 of the storage tank 1 is provided with at least one means 8 for draining hydrofluoric acid, located in the lowest portion of the bottom.

 Means 8 for draining hydrofluoric acid are used multiplicatively and placed symmetrically with respect to the longitudinal axis of storage tank 1 or means 8 for draining hydrofluoric acid are placed asymmetrically with respect to the longitudinal axis of storage tank 1, mainly in an area adjacent to the side wall of the tank and / or at least partially insert into the bottom zone of the side wall (not shown).

 At least part of the housing of the storage tank 1 is made semi-cylindrical or from a combination of shells successively covering each other of the same height (not shown) or at least partially different in height of the upper edges of the shells 9.

 At least part of the walls of the housing of the storage tank 1 is made in the form of a diaphragm 10 of chemically resistant material.

 In at least one diaphragm 10 in the upper and / or lower part thereof, means 11 are provided for communicating the partitioned zones 12 of the storage tank 1.

 The longitudinal axis of at least one storage tank 1 is oriented vertically or the longitudinal axis of at least one storage tank or at least one section of the storage tank can be inclined (not shown).

 The storage tank is configured to absorb hydrostatic and / or dynamic pressure supplied to it by hydrofluoric acid.

 At least one storage tank is configured to operate under excess pressure, which is created by additional injection of an inert gas or an inert gas mixture.

 At least a portion of the hydrofluoric acid is transported in tanks (not shown), or at least a portion of the hydrofluoric acid is transported in railway tanks (not shown).

 At least a portion of hydrofluoric acid is transported in tanks mounted on motor vehicles or caterpillar tractors (not shown).

 At least one storage tank is made in the form of a closed or temporarily sealed tank with the ability to work under excess pressure and supply hydrofluoric acid from it, including at levels exceeding the maximum filling levels of hydrofluoric acid in this tank.

 An ammonium-containing alkaline reagent is supplied to at least one storage tank 13.

 At least part of the housing of the storage tank 13 for the ammonium-containing reagent is made in cross section in the form of a cylinder of round (not shown) or elliptical 14, or oval 15, or ovoid 16 shape, or as a combination of these configurations (not shown).

 At least one storage tank is partitioned 17 at least in the direction of the longitudinal axis.

 At least one storage tank is made in the form of volumetric bodies with a combined configuration, including a section of at least one cylindrical section of a round or elliptical, or oval, or ovoid configuration with conical or hypovaroid, combined sections, including including at least one flat face or at least one insert of the second or third, or fourth order of curvature (not shown).

 The bottom 18 of the storage tank 13 contains at least a section of a conical shape.

 The bottom 18 of the storage tank 13 is made in the form of a tapering shell 19, which represents at least a part of the body of revolution forming in the form of an unduloid or branch of a hyperbola, or a combined configuration, including a combination of straight or broken sections, or their combination with at least one curved element (not shown).

 The bottom 18 of the storage tank 13 is provided with at least one means 19 for draining the alkaline ammonium-containing reagent.

 If there are at least two means 19 for discharging an alkali-containing ammonium reagent, the latter are placed symmetrically with respect to the longitudinal axis of the storage tank or means 19 for discharging an alkali-containing ammonium-containing reagent are disposed asymmetrically with respect to the longitudinal axis of the storage tank 13, mainly in the area adjacent to the side wall of the tank and / or at least partially inset into the bottom zone of the side wall (not shown).

 At least part of the walls of the housing of the storage tank is made in the form of a diaphragm 20 made of chemically resistant material.

 At least one diaphragm 20 in the upper and / or lower part thereof comprises means 21 for communicating sections 22 of the storage tank 13 formed by the diaphragm.

 The longitudinal axis 23 of at least one storage tank is oriented vertically.

 The longitudinal axis of at least one storage tank or at least one section of the storage tank is inclined (not shown).

 The storage tank 13 is configured to absorb hydrostatic and / or dynamic pressure supplied to it by an alkaline ammonium-containing reagent.

 At least one storage tank is configured to operate under excess pressure, which is created by additional injection of an inert gas or an inert gas mixture.

 At least a portion of the alkaline ammonium-containing reagent is transported in tanks (not shown), or at least a portion of the alkaline ammonium-containing reagent is transported in railway tanks or in tanks mounted on automobiles and / or tracked vehicles (not shown).

 Hydrochloric acid is obtained by dissolving silicon tetrafluoride in water.

 A solution of hydrofluoric acid as a waste product of the production of mineral phosphorus fertilizers with a concentration of 8 to 12 wt. can be added with concentrated hydrofluoric acid to a concentration of 20 to 25 wt.

 Hydrofluoric acid is fed to the hydrolysis by a 11 kW centrifugal pump (not shown).

 Hydrolysis is carried out in the reactor system with increasing concentration of silicon oxide in the form of pulp.

 The reactor system is made in the form of a cascade of reactors 24.

 At least a portion of the surface of the reactors 24 in contact with the reaction mixture is made of a neutral chemically resistant material or protected by a coating of a neutral chemically resistant material.

 At least one of the reactors is performed in the form of a partitioned reactor, divided into at least three sections 25, partially combined in volume and / or along the contact surface.

 Sectionalized reactor 25 is performed in the form of an extended tray 26 or pipe, or a combination of these forms and provide at least part of the length with an inclined bottom 27.

 The axis 28 of the tray 26, at least on a portion of the length of the tray, is broken and / or curved and / or combined.

 The reactor vessel may be helical 29.

 The axis 30 of the reactor 24 is performed with a variable angle, increasing to the lower boundary of the reactor 24.

 The sectional reactor 25 is provided with at least a portion of the length of the screw for moving the reaction mixture (not shown).

Hydrofluoric acid is fed for hydrolysis with a concentration of 20 25 and ammonium-containing alkaline reagents are fed with a concentration of at least 15
Hydrofluoric acid is fed for hydrolysis with a flow rate of not more than 10 m ³ / h.

 Hydrolysis is carried out in a cascade of reactors 24, 25 made of carbon steel, gummed with ebonite and rubber and lined with graphite tiles, equipped with a stirrer installed with the possibility of rotation of the cavities 30 250 rpm (not shown).

 The mixer can carry out the anchor type (not shown).

The hydrolysis reaction mixture is pumped from the reactor to the reactor by a centrifugal pump with a capacity of 315 m ³ / h.

 Hydrolysis of the reaction mixture from hydrofluoric acid and an alkaline ammonium-containing reagent can be carried out with additional heat removal, for which the reaction mixture is recycled through a heat exchanger 31 and at least one of the cascade reactors 24.

Heat is removed in a horizontal shell-and-tube heat exchanger 31 while maintaining a working pressure of 16 kg / cm ² in the annulus and in the tube space.

Ammonium carbonate solution supplied by the pump from the reactor in an amount of not more than 15 m ³ / h enters the first reactor of the cascade of neutralization reactors and KFVK hydroxide. KFVK is supplied to the same reactor from the pump with a flow rate of not more than 10 m ³ / h, the value of which is maintained by the control loop. In the second reactor of the same cascade, the residual amount of ammonia water needed to complete the hydrolysis is dosed by the control loop. The process is carried out to a pH of the reaction mass, which should be at least 9 pH.

 Due to the fact that using 2 different hydrolyzing agents (ammonium carbonate solution and ammonia water) is achieved by the thermal neutrality of the whole process, there is no need to remove excess heat and the cooling circuit is not involved in operation.

The temperature of the reaction mass after hydrolysis is not more than 50 ^o C, the concentration of the solution for ammonium fluoride is 140,200 g / l.

 The industrial unit provides that in order to exclude additional watering, a solution of ammonium carbonate is prepared on a reverse solution of ammonium fluoride. The silica gel pulp obtained by hydrolysis is diluted in the solid phase; therefore, the technological scheme provides for its preliminary thickening in a thickener 32 with subsequent filtration of the thickened part on a drum vacuum filter 33. The resulting filtrate is divided into two parts: one part is used as a working solution for preparing a solution of ammonium carbonate , the second for processing synthetic chalk.

 The processing of synthetic chalk with a solution of ammonium fluoride is carried out in two stages, implementing the principle of countercurrent.

In the first stage, all of the original synthetic chalk is treated with the mother liquor from the second stage. In this case, a so-called intermediate product (a mixture of CaCO ₃ + CaF ₂ ) and a mother liquor containing not more than 1 g / l of fluoride and about 30 g / l of ammonium carbonate are obtained.

 The intermediate product is separated from the mother liquor by thickening in a plate thickener (not shown), followed by filtration and fed to the second stage, where they are treated with the entire stream of ammonium fluoride solution. In this case, calcium fluoride is obtained, practically free of carbonate, and a mother liquor depleted in ammonium fluoride, which is sent to the first stage.

The processing at both stages is carried out at a temperature of 80 95 ^o C, the heat is supplied with hot steam, ammonia released into the gas phase is captured by nitric acid.

Thickener 32 is made in the form of a reactor with a shell mounted vertically or at an angle to the vertical axis of not more than 35 ^o , while the reaction mixture after hydrolysis is fed into the Central part of the reactor under a layer of liquid.

 After hydrolysis, the reaction mixture is fed into the zone comprising 1/3 2/3 of the height of the thickener 32.

 Thickener 32 is provided with a groove 34 mounted around its perimeter.

 The gutter is mounted on the inside of the shell (not shown).

 The gutter can be mounted on the outside of the shell.

 The groove 34 may be installed with a passage 35 through the thickener body 32 or partially placed in the thickness of the thickener body 32.

 Silica gel deposited from the reaction mixture on thickener 32 machines is removed with a scraper mixer (shown).

 A scraper mixer is performed with scrapers in an amount of at least four (not shown).

 The blades 36 of the scraper mixer are performed at least with the working edge 37 facing the wall and / or to the bottom area with the precipitated silica gel, having a configuration in the form of a fragment of a cylindrical spiral or helix.

 The angle of inclination of the spiral or helix at least in the area of the working edge can perform variable (Fig. 20).

 The angle of inclination to the horizon of the spiral part of the blade can perform growing from the upper end to the lower end of the blade.

 The angle of inclination to the horizon of the spiral part of the blade is performed decreasing from the upper end to the lower end of the blade 36.

 The neutralization and hydrolysis products of KFVK (solid phase silica gel, liquid solution of ammonium fluoride) from the reactor are pumped to the filter in the trough of the drum vacuum filter 33, the excess pulp is discharged back to the reactor via an overflow line.

 In order to avoid overfilling, a sensor is installed in the filter trough, the alarm from which is displayed on a mimic diagram (not shown). On the filter, under the influence of vacuum, the solid phase (silica gel) is separated from the filter and forms a precipitate layer on the surface of the drum. The precipitate is washed, dried by vacuum, purged with compressed air and cut into heat with a knife. In estrus, the sediment is pulped with promine solution and enters the reactor, from where it is discharged via an overflow line into a silica gel pulp collector. As the collection tank is filled, silica gel pulp is transferred via pumps to the evaporation site or to the tailing dump.

The filtrate (ammonium fluoride solution) through the distribution head of the filtrate enters the receiver (not shown), where under the action of inertial forces, the liquid and gaseous phases are separated, and gravity merges into the reactor at a temperature of more than 40 ^o C.

From the reactor, a solution of ammonium fluoride with a temperature of not more than 40 ^o C pump is transferred to the control filtration in a cartridge filter.

When the temperature of the reaction mixture in the reactor is above 40 ^o C, the filtrate after the receiver is sent to the reactor.

 The reactor is connected by a lower overflow to the tank on which the submersible pump is mounted. A contaminated solution of ammonium fluoride from the tank is pumped through a heat exchanger, where it is cooled by circulating water, to the reactor.

The temperature of ammonium fluoride at the outlet of the heat exchangers is not more than 40 ^o C is automatically supported by the control circuit, the valve of which is installed on the supply line of recycled water into the annular space of the heat exchanger.

 Cooled ammonium fluoride from the reactor is pumped to a control filtration in cartridge filters.

 During the operation of heat exchangers, silica gel may deposit in the tube space. To remove silica gel deposits, periodic washing of heat exchangers with a 25% sodium hydroxide solution is provided.

 Rinsing is carried out by circulating the solution from the reactor with a pump through heat exchangers and returning to the reactor. The spent alkali solution is discharged from the reactor to the reactor. To empty the heat exchangers from the remnants of the washing solution, purging of lines from the pump (not shown) is provided.

 The filtration of silica gel pulp in a solution of ammonium fluoride can be carried out by separation of the reaction mass using a radial thickener (not shown).

 With this method of separation of the reaction mass, it is clarified in a radial thickener and filtered.

 The products of neutralization and hydrolysis of KFVK, a solid phase silica gel, a liquid solution of ammonium fluoride, are pumped from the reactor to a radial thickener. The supply of the reaction mass to the radial thickener is organized in its central part under the liquid layer. The medium level in the thickener is formed by filling the thickener to an overflow chute mounted on the inside of the shell around the entire perimeter. During the movement of the medium from the center of the thickener to the outer wall, silica gel crystals are deposited, which form a sediment layer at the bottom. Inside the thickener, for example, a 4-blade scraper mixer is mounted, during rotation of which with the help of scrapers slanted on its blades, the precipitated sediment moves from the entire surface of the thickener bottom to the discharge opening in the center of the bowl.

The condensed silica gel thus formed with a solution of ammonium fluoride is picked up by a pump and fed to the filtration in the trough of a drum vacuum filter. The consumption of the condensed part in an amount of not more than 8 m ³ / h is regulated by a valve installed on the pump discharge line. The density of the thickened part is controlled by the readings of the densitometer.

 The process of filtering the condensed silica gel on a drum vacuum filter completely repeats the known process.

The part of the reaction mixture clarified in a radial thickener, which is a pure solution of ammonium fluoride, is collected in an overflow trough 34 and is fed to the pump suction, which transfers it either to the reactor at a temperature of the working solution of more than 40 ^o C, or to the reactor at a temperature of less than 40 ^o C .

 After filtering, additional control filtering is carried out.

 The control filtering is carried out on bag filters 38 mounted in a vertical apparatus with a conical bottom 39 and a spherical cover 40, inside of which are installed cartridges 41, fitted with filtering sleeves.

 Cartridges of sleeves of the filter are completed in 19 sections.

The sediment from the bag filters is removed by supplying air inside the cartridge with a pressure of 0.5 kgf / cm ² .

 Chalk is used as calcium carbonate.

 Synthetic chalk may be used as calcium carbonate.

 Synthetic chalk obtained by treating calcium nitride tetrahydrate with ammonium carbonate can be used as calcium carbonate.

Can use synthetic chalk with a crystal size of 5 to 40 microns and a content of not more than 1% phosphate in terms of P ₂ O ₅ and not more than 0.5 percent fluorides in terms of fluorine.

 The further process of control filtration of a solution of ammonium fluoride on cartridge filters is a known method.

The flow rate of the reaction mass in an amount of up to 25 m ³ / h is regulated by a valve installed on the pump discharge line, flow rate control by the flow meter.

 In winter, steam heating of the radial thickener body is provided through an external coil heat exchanger and a steam satellite of external pipelines.

 To enable partial circulation of the thickened silica gel pulp through a radial thickener, a bypass is provided from the pump discharge to the apparatus inlet.

 This is followed by a two-step conversion of chalk with a solution of ammonium fluoride and filtration of conversion products.

For a more complete use of the reagents, the conversion process is carried out in two stages with countercurrent phase motion: solid chalk (calcium carbonate) and liquid (ammonium fluoride solution). Chalk pulp in a solution of ammonium nitrate is supplied in an amount of 15 m ³ / h, controlled by a flow meter. The reception of chalk pulp is carried out in the reactor, shut-off valves on the receiving pipelines are closed by a signal. The pulp density in the reactor is monitored using a density meter (not shown).

 The reactor is equipped with a turbine stirrer. The pulp of chalk from the reactor is pumped to a vacuum belt filter 42 for filtration. Shut-off valves are interlocked with pump operation (not shown). In the event of a drop in the pulp flow to the filter, the ABP pumps are triggered by a signal from the device.

The flow rate of the supplied chalk pulp to the filter is maintained by the control loop within 8-15 m ³ / h.

 The belt vacuum filter 42 is made in the form of a horizontal welded frame 43, with a drive 44 and a tension 45 reels installed on it, on which an endless perforated rubber tape 46 is mounted, on which filter cloth 47 is placed.

 The main filtrate, 20 30% solution of ammonium nitrate, after a vacuum receiver is collected in a reactor buffer (not shown). The level in the reactor is maintained by a control loop, the valve of which is installed on the pipeline for the output of a solution of ammonium nitrate.

 Precipitate chalk (calcium carbonate) is subjected to countercurrent washing from nitrates on the filter with a sharp condenser of juice vapor.

 Filtration on a tape vacuum filter is carried out with at least three countercurrent washing of the chalk sediment, and a solution of ammonium nitrate is used as the washing liquid.

 The interaction of calcium carbonate with ammonium fluoride is carried out in two stages, with calcium carbonate fed to the first stage and ammonium fluoride to the second, the filtrate after the second stage fed to the first, and the precipitate obtained in the first stage is fed to the second.

 After washing, the precipitate enters the first stage of conversion. The washing solution is supplied to the 3 and 4 sections of the filter. After 3 and 4 steps, the wash solution is separated from the gas phase in the vacuum receiver and the reactor wash water collector comes in, from where it is pumped to the evaporation section. The level in the reactor is controlled by the operator.

The chalk filtration unit stops when the vacuum in the system drops to a value less than (-0.3) kgf / cm ³ (-0.03) MPa according to the signal from the vacuum gauge. This stops the drive of the filter drum and closes the shut-off valves on the pulp supply line to the filter and on the vacuum lines of the filter.

 The gas phase after the vacuum receivers is sent along the vacuum line to remove ammonia vapor and to condense the moisture vapor into a barometric condenser.

 The condenser is a hollow type apparatus equipped with a droplet eliminator (not shown). The gas-air mixture, passing the apparatus from the bottom up, is subjected to washing with a circulating solution supplied by a submersible pump. As a circulating solution, a purified juice vapor condenser (OKSP) is used, which fills the collection. Water is fed automatically by the control circuit, the valve of which is installed on the OKSP pipeline (not shown in the drawings). The level in the collection is maintained by the level controller, the excess solution is transferred to the reactor.

To improve the absorption of gases, the circulation solution is cooled down to a temperature of 35 ^o in the heat exchanger 48. The refrigerant is recycled water from the tower. Temperature control is carried out using a control loop, the valve of which is installed on the return water pipe (not shown).

 In a barometric condenser (not shown) as a result of the contact of the gas-air mixture with the irrigated solution, partial absorption of ammonia vapors and condensation of moisture occur. After the condenser, the gas-air mixture is sent to the suction of the vacuum pumps.

 The washed chalk from the belt filter enters the reactor of the cascade of the first conversion stage. The solution of ammonium fluoride enters the reactor from the site of the II-stage conversion.

If chalk filtration occurs on the filter, the precipitate is discharged into the reactor, where it is pulped with a solution of ammonium fluoride to a density of 1.4
1.5 g / cm ³ and is pumped into the reactor. The operating level in the reactor-repulpator is supported by a level regulator, the valve of which is installed on the pipeline for supplying pulp to the reactor.

The temperature of the reaction mass is maintained by means of a control loop in the range of 90 95 ^o C and is controlled by changing the flow of sharp steam into the reactor.

 The degree of conversion of chalk is controlled by instruments.

Overflow conversion products are supplied for cooling. The cooling agent is recycled water, which is fed into the coil of the reactor. The temperature of the conversion products in the reactor decreases to 80 ^o C, and the subsequent reactor to 70 ^o C. The flow rate of recycled water in the coil of the reactor is maintained using a control loop (not shown).

 Cooled products of the conversion of the 1st stage by gravity enter the reactor and are pumped to a belt vacuum filter 42, a plate thickener (not shown) or a drum vacuum filter 33.

 The scheme provides for independent operation of filters and plate thickener, while the thickener is paired with a filter. Depending on the selected technological scheme, the separation of the solid and liquid phases of the pulp of the products of the 1st stage of conversion is carried out either on a belt vacuum filter, or on a plate thickener and a drum vacuum filter, or on a drum vacuum filter.

 The difference between these three options from each other is that on the belt vacuum filter, washing of the precipitated precipitating precipitates is washed out; from the thickener and filter, the sediment enters the 1st line of conversion, while the pulp is pre-concentrated before filtration; on the filter, products of the I stage of conversion stand out, coming to the 2nd thread of the II stage of conversion.

 In the second variant of filtration, the pulp of the products of the first stage of conversion is fed into the middle part of the thickener, where it is separated into a clarified solution, which from the upper part of the thickener is gravity drained into the reactor, and the thickened pulp, which is drained from the bottom of the thickener into a drum vacuum trough. filter.

 The drum vacuum filter 33 is an assembly consisting of a trough 49 with a horizontally positioned filter drum 50. The filter fabric is mounted on the cylindrical wall of the drum 50. The selection of a vacuum, a filter, the supply of purified condensate of juice vapor (OKPS) for washing the sludge and compressed air for its blowing is carried out through the distribution head 51 of the filter on the end wall of the drum on its axis. A pendulum mixer 52 is installed inside the filter trough. Electric drives for rotating the drum and mixer are mounted on the trough frame.

 To avoid overfilling, a sensor is installed in the filter trough. On the filter under vacuum, the solid phase of the thickened pulp is separated from the filtrate and forms a sediment layer on the surface of the drum. As the drum 50 rotates, the sediment is washed with an OKSP, dried with vacuum, blown with compressed air, cut with a knife 53, and falls into estrus. In estrus, the sediment, which is a mixture of calcium fluoride and unreacted chalk, enters the 1st reactor of the 2nd stage of conversion of the 1st technological string.

 The filtrate, the spent secondary solution of ammonium fluoride, through the distribution head 51 of the filter enters a receiver (not shown), where under the influence of inertial forces, the liquid and gaseous phases are separated. The filtrate is gravity drained into the reactor and then through the reactor for evaporation, and the gas-air mixture from the filter is fed through a vacuum manifold to a barometric condenser for condensation and partial purification of ammonia vapor.

 When pulp of products of the first stage of conversion is fed to the filter, it is filtered without preliminary thickening. The process technology is completely similar to the filter operation described above.

 Wet sediment, consisting of 70% calcium fluoride and 30% of unreacted chalk, enters the second stage of conversion to the reactor.

 The filtration unit of the I-stage conversion products stops when the vacuum in the system decreases by a signal from a vacuum gauge (not shown).

To improve the process of gas absorption and condensation of moisture vapor, the circulating solution is cooled in a heat exchanger to a temperature of 30 ^o C. The temperature of the circulating solution is maintained using a control loop, a valve of which is installed on the pipe for supplying circulating water (not shown) to the heat exchanger.

 The precipitate from the drum vacuum filter 33 enters the reactor of the cascade of the second stage of conversion and is pulped by a solution of ammonium fluoride. The precipitate from the filter tape is pulped by a solution of ammonium fluoride and pumped to the 1st reactor of the cascade.

 In the cascade of the second stage of conversion, the conversion of chalk to calcium fluoride is completed. The conditions for the conversion at the second stage are similar to the conditions of the first stage.

The temperature of the reaction mixture is maintained using control loops (not shown), respectively, in the reactors. Further, the conversion products are fed by gravity to the cascade of reactors for cooling to a temperature of up to 70 ^o C. The cooling agent is recycled water entering the reactor coils in the amount supported by the control loops, respectively.

 Conversion products by gravity enter the reactor and are pumped for filtration on a belt-type vacuum filter.

The pulp of II-stage conversion products enters the belt vacuum filter in an amount of 10 11 m ³ / h.

 On the belt filter, separation of the precipitate of calcium fluoride and the filtrate of a 12% solution of ammonium fluoride and countercurrent three-stage washing of the precipitate.

 The filtrate after the receiver is discharged into the reactor and through the upper overflow enters the reactor buffer. From the reactor, a solution of ammonium fluoride is pumped to the reactors of the first stage conversion unit. The level in the reactor is monitored using a level gauge (not shown).

 The washed calcium fluoride is transferred from the filtrate to drying.

 The calcium fluoride filtration unit stops when the vacuum in the system decreases by the signal from the vacuum gauge. At the same time, the filter drive stops and shut-off valves on the pulp supply line to the filter and on the vacuum line pipeline (not shown) are closed.

 The gas phase after the vacuum receivers (not shown) is sent through a vacuum line to a barometric condenser for cleaning (not shown in the drawings). As a working solution, purified KPS is used, with which the tank is filled.

 The working level in the tank is maintained by the level controller, the excess solution is transferred to the reactor. The supply of a circulating solution for irrigation of a barometric condenser is carried out according to the scheme: tank pump - heat exchanger condenser tank.

 The precipitate of calcium fluoride is served for drying.

 Drying is carried out by flue gases in a fluidized bed reactor 54.

 As granules for a fluidized bed using granules of inert material, for example, alundum granules.

 Flue gases for drying are obtained by burning natural gas, previously purified from mechanical impurities, in a heater (not shown).

Natural gas is fed into the air heater in an amount of 50-100 m ³ / h.

 Natural gas is burned in a heater made in the form of a cylindrical, horizontally located apparatus, inside which a gas manifold is installed in the form of two coaxially arranged chambers with an autonomous supply of natural gas, injection burners and an ignition burner (not shown).

 The drying reactor 54 is in the form of a vertical housing 55 with a horizontal gas distribution grill 56 located therein, with the formation of the upper drying chamber 57 and the lower sublattice chamber 58 of a cylindrical shape lined from the inside and connected to a heater (not shown).

 To release the dryer from the material (emergency, partial or complete unloading) at the grate level there is a fitting 59 with flanges. Material is discharged into a trough, from which it is recycled back to the dryer through a manhole (not shown).

 In order to create a "fluidized bed" of alundum granules in the dryer, the pressure difference of the flue gases under the distribution grid and in the upper part of the drying chamber is used. Flue gases, passing through the gas distribution grid, liquefy a layer of alundum granules, intensively give them their heat. The wet sediment entering the dryer envelops the alundum granules and dries on their surface. The drying process in a "fluidized bed" proceeds with high intensity, due to the high coefficients of heat conductivity and heat transfer, as well as the developed heat transfer surface. Intensive "boiling" of particles and granules leads to almost complete temperature equalization in the drying chamber, which eliminates the possibility of local overheating of the dried calcium fluoride.

 Particles of dried calcium fluoride are carried away from the drying chamber of the dryer by a gas stream to a gas treatment unit (not shown).

 The dried particles of calcium fluoride are fed sequentially for dry and wet cleaning.

 Dry cleaning of calcium fluoride is carried out in at least two series-connected cyclones connected to storage bins (not shown).

 Steam-gas-gas mixture enters the cyclone body. Particles of calcium fluoride under the action of inertial forces settle on the inner surface of the cyclone and are collected in a cyclone storage hopper. The vapor-gas flow, under the influence of the vacuum created by the tail fans, is drawn through a discharge pipe and enters the cyclone. To prevent air leakage, which affects the degree of capture of the cyclone, the discharge of the product of the cyclone hoppers is carried out through the gate feeders.

 The operation of the gateway feeder is interlocked with the upper and lower levels in the storage bins.

 Calcium fluoride is unloaded from storage hoppers via airlock feeders (not shown).

 The gas-air stream from the cyclones is fed for wet cleaning to the upper part of the coagulator pipe 60, inside which a coil 61 with cooling water is placed, the outgoing gas stream is fed to the second stage of the interaction of calcium carbonate with ammonium fluoride.

Claims (119)

1. A method of producing calcium fluoride, including hydrolysis of hydrofluoric acid with an ammonium-containing reagent of an alkaline nature, filtering the resulting silica pulp to obtain a solution of ammonium fluoride and reacting the latter with calcium carbonate, followed by separation of calcium fluoride, characterized in that the hydrolysis is carried out at 35 ^° -50 ^{° C.} before filtering the silica pulp, thickening is carried out and the ammonium fluoride solution is divided into two streams in a ratio of 1: 0.5 - 5, and the first stream is sent to the preparation ammonium-alkaline nature of the reagent, and the second stream is directed to interact with the calcium carbonate.  2. The method according to claim 1, characterized in that they use hydrofluoric acid obtained as a waste product of the production of phosphoric mineral fertilizers.  3. The method according to claim 1, characterized in that the use of hydrofluoric acid obtained as a waste product of phosphoric acid.  4. The method according to claim 1, characterized in that ammonia water is used as an ammonium-containing alkaline reagent.  5. The method according to claim 4, characterized in that the use of ammonia water as a waste of ammonia production.  6. The method according to PP.1 to 3, characterized in that as the ammonium-containing reagent is alkaline in nature, ammonium carbonate is used.  7. The method according to claim 6, characterized in that they use ammonium carbonate obtained as a waste product of the production of mineral fertilizers.  8. The method according to claim 1, characterized in that hydrofluoric acid is fed into at least one storage tank.  9. The method according to claim 8, characterized in that at least part of the housing of at least one storage tank is circular, or elliptical, or oval or ovoid in transverse and / or longitudinal section, and / or in the form of a combination and / or combinations of these configurations.  10. The method according to claim 8, characterized in that at least one storage tank is partitioned at least in the direction of the longitudinal axis.  11. The method according to claim 8, characterized in that at least one storage tank is made in the form of volumetric bodies of a combined configuration, comprising a combination of at least one cylindrical section of a round, and / or elliptical, and / or oval, and / or ovoid configuration with conical and / or hypovaroid and / or combined sections, including at least one flat face or at least one insert of the second, third, or fourth order of curvature.  12. The method according to p. 8, characterized in that the bottom of the storage tank contains at least one section of a mono- or polyconic shape.  13. The method according to p. 12, characterized in that the bottom of the storage tank is made in the form of a tapering shell downward, representing at least part of the body of revolution forming in the form of an unduloid, or branch of a hyperbola, or a combined configuration, including including a combination of straight lines or broken sections or their combination with at least one curved element.  14. The method according to p. 12, characterized in that the bottom of the storage tank is provided with at least one means for draining hydrofluoric acid, located in the lowest portion of the bottom.  15. The method according to p. 12, characterized in that the means for draining hydrofluoric acid is used multiplicatively and placed symmetrically with respect to the longitudinal axis of the storage tank.  16. The method according to p. 12, characterized in that the means for draining hydrofluoric acid are placed asymmetrically relative to the longitudinal axis of the storage tank, mainly in the area adjacent to the side wall of the tank and / or at least partially insert into the bottom zone of the side wall.  17. The method according to claim 8, characterized in that at least a part of the housing of the storage tank is polycylindrical, or from a combination of shells successively covering each other of the same height, or at least partially different in height of the upper edges of the shells.  18. The method according to claim 8, characterized in that at least part of the walls of the housing of the storage tank is made in the form of diaphragms of chemically resistant material.  19. The method according to p. 12, characterized in that at least in one diaphragm in the upper and / or lower part thereof, means are made for communicating the partitioned zones of the storage tank.  20. The method according to claim 8, characterized in that the longitudinal axis of at least one storage tank is oriented vertically.  21. The method according to claim 8, characterized in that the longitudinal axis of at least one storage tank or at least one section of the storage tank is inclined.  22. The method according to claim 8, characterized in that the storage tank is configured to absorb hydrostatic and / or dynamic pressure of hydrofluoric acid supplied to it.  23. The method according to p. 8, characterized in that at least one storage tank is configured to operate under excess pressure, which is created by additional injection of an inert gas or inert gas mixture.  24. The method according to PP.1 to 3, characterized in that at least a portion of hydrofluoric acid is transported in tanks.  25. The method according to paragraph 24, wherein at least a portion of hydrofluoric acid is transported in railway tanks.  26. The method according to paragraph 24, wherein at least a portion of hydrofluoric acid is transported in tanks mounted on vehicles or caterpillar tractors.  27. The method according to claim 8, characterized in that at least one storage tank is made in the form of a closed or temporarily pressurized tank with the ability to work under excess pressure and supply hydrofluoric acid from it, including levels exceeding the maximum filling levels of hydrofluoric acid acid in a given container.  28. The method according to claim 1, characterized in that the alkaline ammonium-containing reagent is fed to at least one storage tank.  29. The method according to p. 28, characterized in that at least part of the housing of the storage tank for the ammonium-containing reagent is performed in cross section in the form of a cylinder of round, or elliptical, or oval, or ovoid shape, or as a combination of these configurations.  30. The method according to p. 28, characterized in that at least one storage tank is partitioned at least in the direction of the longitudinal axis.  31. The method according to p. 28, characterized in that at least one storage capacity is performed in the form of volumetric bodies of a combined configuration, comprising a combination of at least one cylindrical section of a round, or elliptical, or oval, or ovoid configuration with a conical, or hyparoid , or combined sections, including including at least one flat face or at least one insert of the second, or third, or fourth order of curvature.  32. The method according to p. 28, characterized in that the bottom of the storage tank contains at least a section of a conical shape.  33. The method according to p. 28, characterized in that the bottom of the storage tank is performed in the form of a tapering shell downward, representing at least part of the body of revolution with forming in the form of an unduloid, or a branch of a hyperbola, or a combined configuration, including a combination of straight or broken sections or their combination with at least one curved element.  34. The method according to p. 28, characterized in that the bottom of the storage tank is provided with at least one means for draining an alkaline ammonium-containing reagent.  35. The method according to p. 28, characterized in that in the presence of at least two means for draining the ammonium-containing alkaline reagent, the latter are placed symmetrically with respect to the longitudinal axis of the storage tank.  36. The method according to p. 28, characterized in that the means for discharging an alkali-containing ammonium-containing reagent are placed asymmetrically relative to the longitudinal axis of the storage tank, mainly in the area adjacent to the side wall of the tank and / or at least partially insert into the bottom zone of the side wall .  37. The method according to p. 28, characterized in that at least part of the walls of the housing of the storage tank is made in the form of diaphragms of chemically resistant material.  38. The method according to p. 28, characterized in that in at least one diaphragm in the upper and / or lower part thereof, means for communicating sections of the storage capacity formed by the diaphragm are performed.  39. The method according to p, characterized in that the longitudinal axis of at least one storage tank is oriented vertically.  40. The method according to p, characterized in that the longitudinal axis of at least one storage tank or at least one section of the storage tank is inclined.  41. The method according to p. 28, characterized in that the storage capacity is performed with the possibility of perceiving hydrostatic and / or dynamic pressure supplied to it an ammonium-containing reagent of an alkaline nature.  42. The method according to p, characterized in that at least one storage tank is configured to operate under excess pressure, which is created by additional injection of an inert gas or inert gas mixture.  43. The method according to p. 28, characterized in that at least part of the alkaline ammonium-containing reagent is transported in tanks.  44. The method according to item 43, wherein at least a portion of the alkaline ammonium-containing reagent is transported in railway tanks or in tanks mounted on automobile and / or tracked vehicles.  45. The method according to claim 1, characterized in that hydrofluoric acid is obtained by dissolving silicon tetrafluoride in water.  46. The method according to p. 1, characterized in that the solution of hydrofluoric acid as a waste product of the production of mineral phosphate fertilizers with a concentration of 8 to 12 wt. add strength with concentrated hydrofluoric acid to a concentration of 20 to 25 wt.  47. The method according to PP. 1 to 7, characterized in that hydrofluoric acid is fed to the hydrolysis by a centrifugal pump with a capacity of 11 kTV.  48. The method according to PP.1 to 47, characterized in that the hydrolysis is carried out in the reactor system with increasing concentration of silicon oxide in the form of pulp.  49. The method according to p, characterized in that the reactor system is performed in the form of a cascade of reactors.  50. The method according to claims 48 and 49, characterized in that at least a part of the surface of the reactors in contact with the reaction mixture is made of a neutral chemically resistant material or protected by a coating of a neutral chemically resistant material.  51. The method according to § 48 to 50, characterized in that at least one of the reactors is performed in the form of a partitioned reactor, divided into at least three sections partially aligned in volume and / or on the contact surface.  52. The method according to p. 51, characterized in that the sectioned reactor is made in the form of an extended tray, or pipe, or a combination of these forms and provide at least a portion of the length with an inclined bottom.  53. The method according to paragraph 52, wherein the axis of the tray at least on a portion of the length of the tray is broken, and / or curved, and / or combined shape.  54. The method according to item 53, wherein the reactor vessel is helical.  55. The method according to item 54, wherein the axis of the reactor is performed with a variable angle, increasing to the lower boundary of the reactor.  56. The method according to paragraph 52, wherein the sectional reactor is provided with a screw for moving the reaction mixture at least in part of the length.  57. The method according to claim 1, characterized in that the hydrolysis of hydrofluoric acid and an ammonium-containing alkaline reagent are carried out in two stages, and in the first stage, hydrolysis is carried out until pH 7.3 7.8 is reached, and in the second stage, hydrolysis with pH not complete less than 9. 58. The method according to p. 57, characterized in that hydrofluoric acid is fed to the hydrolysis with a concentration of 20 to 25% and ammonium-containing alkaline reagents are served with a concentration of at least 15%
59. The method according to p, characterized in that hydrofluoric acid is fed to the hydrolysis with a flow rate of not more than 10 m ³ / h. 60. The method according to p. 58 and 59, characterized in that the hydrolysis is carried out in a cascade of reactors made of carbon steel, gummed with hard rubber and rubber and lined with graphite tiles, equipped with a stirrer with a rotational speed of the blades 30 250 min ^-1 .  61. The method according to p. 60, characterized in that the mixer is an anchor type. 62. The method according to PP 58 61, characterized in that the hydrolysis reaction mixture is pumped from the reactor to the reactor by a centrifugal pump with a capacity of 315 m ³ / h.  63. The method according to claims 58 to 62, characterized in that the hydrolysis of the reaction mixture from hydrofluoric acid and an ammonium-containing alkaline reagent is carried out with additional heat removal, for which the reaction mixture is recycled through a heat exchanger and at least one of the cascade reactors. 64. The method according to p. 63, characterized in that the heat is removed in a horizontal shell-and-tube heat exchanger with maintaining the working pressure in the annular and tube space of 16 kg / cm ² .  65. The method according to 58 64, characterized in that the hydrolysis products are fed to the thickening in the thickener. 66. The method according to item 65, wherein the thickener is performed in the form of a reactor with a shell mounted vertically or at an angle to the vertical axis of not more than 35 ^o , while the reaction mixture after hydrolysis is fed into the Central part of the reactor under a layer of liquid.  67. The method according to p, characterized in that the reaction mixture after hydrolysis is fed into the zone of 1/2 2/3 of the height of the thickener.  68. The method according to p, characterized in that the thickener is equipped with a groove installed along its perimeter.  69. The method according to p, characterized in that the trough is mounted on the inner side of the shell.  70. The method according to p, characterized in that the gutter is mounted on the outside of the shell.  71. The method according to p, characterized in that the trough is installed with the passage through the thickener body or partially placed in the thickness of the thickener body.  72. The method according to p, characterized in that the silica gel deposited from the reaction mixture on the walls of the thickener is removed with a scraper mixer.  72. The method according to p, characterized in that the scraper mixer is performed with scrapers in an amount of at least four.  73. The method according to p. 72, characterized in that the blades of the scraper mixer perform at least with a working edge facing the wall and / or to the bottom area with precipitated silica gel, having a configuration in the form of a fragment of a cylindrical spiral or helix.  74. The method according to p, characterized in that the angle of inclination of the spiral or helix at least in the area of the working edge is variable.  75. The method according to p, characterized in that the angle of inclination to the horizon of the spiral part of the blade is performed growing from the upper end to the lower end of the blade.  76. The method according to p, characterized in that the angle of inclination to the horizon of the spiral part of the blade is performed decreasing from the upper end to the lower end of the blade.  77. The method according to p. 1, characterized in that after filtering carry out additional control filtering.  78. The method according to p, characterized in that the control filtering is carried out on bag filters.  79. The method according to p, characterized in that the control filtering is carried out on bag filters mounted in a vertical apparatus with a conical bottom and a spherical cover, inside of which are installed cartridges, fitted with filtering sleeves.  80. The method according to p. 79, characterized in that the filter cartridges are equipped with 19 sections. 81. The method according to PP 78, characterized in that the precipitate from the bag filters is removed by supplying air into the cartridge with a pressure of 0.5 kgf / cm ² .  82. The method according to claims 1 to 81, characterized in that chalk is used as calcium carbonate.  83. The method according to claims 1 to 81, characterized in that synthetic chalk is used as calcium carbonate.  84. The method according to p, characterized in that the synthetic chalk obtained by treating calcium nitrate tetrahydrate with ammonium carbonate is used as calcium carbonate. 85. The method according to p. 84, characterized in that they use synthetic chalk with a crystal size of 5 to 40 microns, containing not more than 1% phosphates in terms of P ₂ About ₅ and not more than 0.5% fluorides in terms of fluorine.  86. The method according to PP.1 84, characterized in that before the interaction of chalk and ammonium fluoride, chalk chalk is prepared, which is subjected to thickening, filtering, washing.  87. The method according to p, characterized in that the chalk pulp is prepared in a solution of ammonium nitrate and served in a thickener, which is performed in the form of a reactor with a turbine mixer to obtain a condensed pulp.  88. The method according to p, characterized in that the thickened chalk pulp is fed for filtering to a belt vacuum filter, which is performed in the form of a horizontal welded frame with drive and tension drums mounted on it, on which an endless perforated rubber tape is worn, on which placed filter cloth.  89. The method according to p, characterized in that the filtering on a belt vacuum filter is carried out by at least three countercurrent washing of the chalk sediment, wherein a solution of ammonium nitrate is used as a washing liquid.  90. The method according to PP.1 to 89, characterized in that the interaction of calcium carbonate with ammonium fluoride is carried out in two stages, and calcium carbonate is fed to the first stage, and ammonium fluoride to the second, the filtrate after the second stage is fed to the first, and the precipitate obtained in the first stage, served in the second.  91. The method according to PP. 86 90, characterized in that the first stage of the interaction of chalk with ammonium fluoride is carried out in a reactor with the supply of a precipitate of chalk, which is pre-pulp with a solution of ammonium fluoride. 92. The method according to p. 91, characterized in that the chalking of the chalk is carried out to obtain a pulp with a density of 1.4 to 1.5 g / cm ³ . 93. The method according to p. 91, characterized in that the temperature in the first stage of interaction support 90 95 ^o C.  94. The method according to p. 93, characterized in that the interaction temperature is supported by the introduction of sharp steam into the reactor.  95. The method according to PP.90 94, characterized in that the pulp of the reaction products after the first stage is fed to a plate thickener and then to a drum vacuum filter.  96. The method according to p. 95, characterized in that the pulp is served in the middle part of the thickener with the formation of a clarified solution and a thickened pulp.  97. The method according to p. 95, characterized in that the thickened pulp is fed to a drum vacuum filter with a knife, made in the form of a box with a horizontally located filter drum partially immersed in it, on the cylindrical surface of which the filter cloth is strengthened.  98. The method according to p. 97, characterized in that the precipitate layer formed on the surface is washed, dried by vacuum, purged with compressed air, cut with a knife and fed to the second stage of interaction.  99. The method according to p. 97, characterized in that the filtrate is fed through a distribution head of the filter into a solution in which the liquid and gaseous phases are separated by inertial forces.  100. The method according to PP.90 to 99, characterized in that the filter cake is pulped with a solution of ammonium fluoride and fed to the second stage of interaction.  101. The method according to p, characterized in that the second stage of the interaction of calcium carbonate with ammonium fluoride is carried out in a cascade of reactors.  102. The method according to p. 101, characterized in that the interaction is carried out in a cascade of reactors containing at least three reactors.  103. The method according to PP.90 102, characterized in that the reaction products are cooled in a heat exchanger.  104. The method according to p. 103, characterized in that the reaction products are cooled in a heat exchanger with a coil.  105. The method according to p. 104, characterized in that the configuration of the walls of the coil at least part of the length perform a variable cross-section.  106. The method according to claims 100 to 105, characterized in that the products of the interaction of the second stage are fed to a belt vacuum filter. 107. The method according to p. 106, characterized in that the reaction products of the second stage are fed to the belt vacuum filter in an amount of 10 11 m ³ / h.  108. The method according to p. 107, characterized in that the precipitate of calcium fluoride on a belt vacuum filter is subjected to washing, at least three times, the obtained filtrate is fed to the first stage of the interaction of calcium carbonate with ammonia fluoride.  109. The method according to p, characterized in that the precipitate of calcium fluoride is served for drying.  110. The method according to p. 109, characterized in that the drying is carried out by flue gases in a fluidized bed reactor.  111. The method according to p. 110, characterized in that the granules for the fluidized bed using granules of inert material, for example alundum granules.  112. The method according to p. 110, characterized in that the flue gases for drying are obtained by burning in a heater natural gas, previously purified from mechanical impurities. 113. The method according to p. 112, characterized in that natural gas is supplied to the air heater in an amount of 50 to 100 m ³ / h.  114. The method according to PP 112 and 113, characterized in that the natural gas is burned in a heater made in the form of a cylindrical horizontally arranged apparatus, inside which a gas manifold is installed in the form of two coaxially arranged chambers with autonomous supply of natural gas, injection burners and an ignition burner .  115. The method according to PP 109 114, characterized in that the drying reactor is performed in the form of a vertical body with a horizontal gas distribution grid located therein with the formation of an upper drying chamber and a lower sublattice chamber made of a cylindrical shape, lined from the inside and connected to the air heater.  116. The method according to PP 109 114, characterized in that the dried particles of calcium fluoride are fed sequentially for dry and wet cleaning.  117. The method according to p, characterized in that the dry cleaning of calcium fluoride is carried out in at least two series-connected cyclones connected to storage bins.  118. The method according to p. 117, characterized in that the unloading of calcium fluoride from storage hoppers is carried out through airlock feeders.  119. The method according to p. 116, characterized in that the gas-air stream from the cyclones is fed for wet cleaning to the upper part of the coagulator tube, inside which a coil with cooling water is placed, the outgoing gas stream is fed to the second stage of the interaction of calcium carbonate with ammonium fluoride.

Images