Improved method of mass production of phosphoric acid with application of rotation furnaces

FIELD: chemistry.

SUBSTANCE: method involves the following steps: (1) primary processing of raw materials, (2) preparing internal areas of the granules, (3) forming composite pellets, (4) restoring composite pellets on heating method, and (5) hydrating and absorbing phosphorus.

EFFECT: energy-saving, environmentally safe and highly efficient process, which allows to produce high-quality phosphoric acid.

13 cl, 20 dwg

 



 

Same patents:

FIELD: construction.

SUBSTANCE: method for burning the expanded clay in the rotary kiln comprises assignment of the required values of the expanded clay temperature at point corresponding to the end of the heating zone, and temperature at point corresponding to the middle zone of swelling, determination of temperature at point corresponding to the end of the heating zone, and temperature at point corresponding to the middle zone of swelling, determination of difference between the required and actual value of temperature of expanded clay at point corresponding to the end of the heating zone, formation in function of difference magnitude of these temperatures of control influence on drive of belt feeder, definition of difference between the required and actual value of the expanded clay temperature at point corresponding to the middle zone of swelling, formation in function of difference magnitude of these temperatures of control influence on the furnace burner, the required value of the expanded clay temperature at point corresponding to the end of the drying zone is specified additionally, temperature at point corresponding to the end of the drying zone is determined, difference between the required and actual value of the expanded clay temperature at point corresponding to the end of the drying zone is determined, control influence on drive of the furnace rotation is formed in function of difference magnitude of these temperatures. Invention also relates to the device for the expanded clay burning.

EFFECT: improving the quality of expanded clay, including its strength, reducing the number of process wastes during the production of expanded clay, stabilization of burning process.

2 cl, 2 dwg

FIELD: metallurgy.

SUBSTANCE: furnace includes a cylindrical housing, a burner device, a loading opening, a tap hole for pouring out molten metal, a heat insulating layer consisting of three sheets of flexible heat-insulating glass-fibre mullite silica cardboard and a layer of chamotte lightweight, on which a refractory layer of mullite shrink-proof ramming mixture is put; the burner device is made in the form of a four-mixing injection rectangular gas burner, in which two mixers with a perforated hemisphere are arranged in the lower row, and in the upper row there are two mixers with twelve ribs at the end of the mixer on the inner side. The furnace has a turning mechanism of a burner screen, with a possibility of charge loading to the furnace through the opening for the burner at the retracted burner, a drive mechanism for rotation of the furnace relative to the horizontal axis to both sides through an angle of 105, a dust-gas cleaning system containing a mixing chamber, an ID fan, a dust-gas cleaning unit and a cartridge filter.

EFFECT: simplifying the design; increasing operating life; reducing emissions of harmful gases to atmosphere.

4 cl, 7 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to field of industrial heat-and-power engineering and can be applied in obtaining activated coal. Method of activating fractionated by size coal particles is realised by their continuous re-pouring and interaction with countercurrent torch in inclined relative to horizontal plane reactor with heating, separation and burning of volatile substances, formation and output from reactor of mixture of volatile substances and products of burning, further re-pouring and cooling by countercurrent flow of products of burning in inclined relative to horizontal plane cooler and after-burning volatile substances and release of products of burning into atmosphere. Processes of activation and cooling are realised in reactor and cooler of drum type and/or chamber type with mechanised grate. Torch is formed by separately introduced jets of gas, air, steam and products of burning, with steam, being obtained in boiler-utiliser in the process of after-burning of mixture of volatile substances, products of burning are output from cooler, and products of burning from boiler-utiliser are supplied into cooler.

EFFECT: invention ensures reduction of heat loss and gas consumption.

4 cl, 4 dwg

FIELD: power engineering.

SUBSTANCE: reactor comprises a cylindrical vessel installed on a fixed support as capable of rotation, in the lower part of which there are at least two holes for unloading of material with gates made as capable of opening in its lower position and closing in its upper position relative to the vertical line under gravity as the reactor rotates. Gates are equipped with rollers. The cylindrical vessel of the reactor along the outer perimeter of its cylindrical surface is installed coaxially on the support of the fixed support arc, which covers at least a half of the reactor circumference and is made as capable of roller rocking along the support arc with the closed position of gates.

EFFECT: invention provides for dosed unloading of loose materials.

5 cl, 2 dwg

FIELD: metallurgy.

SUBSTANCE: furnace includes a lined bottle with two support rings, each of which is supported on two rollers, a burner screen with a gas injection burner fixed in it and provided with fourteen mixers, a receiving chute, a furnace rotation drive and a burner screen supply-discharge drive. The lined bottle has a heat insulating layer of two layers of flexible heat insulating fibre glass mullite silica cardboard and a layer of chamotte lightweight material, onto which a lining layer from mullite nonshrinking ramming compound is put. The burner includes an air flow rate control device, installed with an inclination of 15° to the bottle axis with possibility of gas supply to the burner along upper part of a turning column and a branch pipe. The furnace has an add-on receiving lined chute with handles, which is mounted on a trolley, a turning frame that is supported on front and rear pedestals when in operating position, on which the lined bottle is installed with possibility of being turned about the axis from the drive. The furnace can operate at natural and artificial thrust.

EFFECT: increasing furnace service life, reducing heat losses and hazardous emissions to atmosphere.

2 cl, 8 dwg

FIELD: metallurgy.

SUBSTANCE: furnace consists in cylindrical housing, burner device, charging loading, tap hole for melted metal drainage and tap hole for liquid slag. Furnace also has heat-insulating layer that consists of four layers of asbestos-sheet millboard and layer of lightweight chamotte that is covered by refractory layer from mullite-corundum mass. Burner device is presented by gas induction burner fixed in the cover that closes charging hole located in the front end wall of the furnace. Burner has thirteen agitators, five of which are equipped with nozzles and located in the centre with provision of flame 2.6 m long, and eight agitators are located along the periphery with provision of flame 1.5 m long in case of gas-air mixture combustion. Note that the furnace is done with the possibility of operation on natural and artificial draft with the system of gas treatment for obtaining ecologically pure process that consists of mixing chamber, smoke exhauster, gas treatment machine, cyclone and framed bag-type filter.

EFFECT: invention allows decreasing emission of hazardous substances into the atmosphere, decreasing heat loss and extension of furnace service life.

3 cl, 8 dwg

Melting furnace // 2439456

FIELD: metallurgy.

SUBSTANCE: in melting furnace containing the base installed on the foundation, housing with cover and door, which is installed on the base, detachable melting drum arranged in the housing and having the possibility of being installed on the projecting drive shaft, and heater installed on the housing by means of hinges; the base is installed on foundation by means of a hinge with horizontal rotation axis perpendicular to drum rotation axis, and heater can be equipped with the device providing its vibratory motion.

EFFECT: providing the possibility of action on mirror area of molten metal in melting drum and thus increasing the grasping of metallic beads from the charge; reducing the melting time; increasing service life of melting drum and increasing metallic yield; simplifying the removal of meting drum from drive shaft; besides, providing the possibility of applying metal coatings by means of thermodiffusion method in cases when the length of processed part is close to the drum depth.

2 cl, 4 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to production of nickel carbonyl by medium-pressure synthesis by means of metalloorganic compound synthesis reactor, slightly inclined and rotating. Initial loose material is fed into reaction chamber. Reactor housing is arranged at preset inclination and rotated about its lengthwise axis. Reactor inner space is flushed by nitrogen. Carbon oxide is forced into reactor to 50-70 atm. Circulation compressor is cut in to force carbon oxide through reactor. Heat carrier is fed into heat exchanger arranged inside reaction chamber to heat initial loose material to preset temperature. Synthesis is carried out at carbon oxide pressure of 50-70 atm while loose material is mixed in presence of carbon oxide. Mixing is performed by mixer integrated with heat exchanger. Along with mixing, loose material is transferred from one end of reaction chamber to another one to circulate loose material in closed loop into reactor inner space. After heating initial loose material to preset temperature coolant is fed into heat exchanger instead of heat carrier. Further, reaction chamber temperature is maintained equal to 170-220°C. In case temperature is this chamber decreases heat carrier is again fed into reaction chamber. In synthesis, reaction product is discharged from said chamber along with filtration of dust and retaining loose material that did not react in reaction chamber. After synthesis, reaction chamber pressure is decreased to atmospheric pressure, filtration elements are blown by nitrogen and solid residues of loose materials are decontaminated in reaction chamber, now, loose material solid residues are withdrawn from reaction chamber.

EFFECT: higher efficiency of nickel carbonyl synthesis.

10 cl, 8 dwg

FIELD: heating.

SUBSTANCE: invention relates to calcination of stock, for example oil or pitch coke, or hard coal in rotary kilns. Proposed device comprises heat exchange elements to mix up material. Said elements represent tooth with triangular part extending beyond kiln lining, triangle larger side being oriented in direction opposite to kiln unloading face. Angle between triangle larger side and adjacent sides makes at least 45°. Said tooth are located in the kiln material heating zone and arranged staggered in parallel rows relative to each other and adjacent sections.

EFFECT: higher efficiency and expanded operating performances.

3 cl, 3 dwg

FIELD: production of anhydrite plaster.

SUBSTANCE: rotating furnace for preparation of semi-hydrate and anhydrate II contains the first internal rotating cylindrical tubular element, which is closed from the back end and coaxially joined to the second top cylindrical tubular element of larger radius and shorter length. At that specified second tubular element covers larger portion of central part of the first tubular element. The third cylindrical tubular element is installed outside the second tubular element and is coaxially joined to the second tubular element. At that the third tubular element has larger radius than the second tubular element and limits together with the second tubular element discharge chamber that communicates with the internal volume of the first tubular element via outlet openings and is equipped with at least one opening for outlet of final product. Device has burner, stationary sole, ribs, doors and blades.

EFFECT: increase of capacity and improvement of prepared product quality.

7 cl, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to production of phosphoric acid. The method of producing phosphoric acid involves decomposition of phosphate material of sulphuric and phosphoric acid, obtaining phosphoric-acid pulp and two-step purification of phosphoric acid from impurities by introduction of settling agents, filtration of the pulp, washing phosphogypsum. At the first step of purification, impurities are precipitated by introducing phosphorite and alkaline agent into the phosphoric-acid pulp until pH of 1.8 to 2.1, where said introduction takes place after completion of decomposition of phosphate material. At the second step of purification, impurities are precipitated by neutralisation of phosphoric-acid solution with alkaline agent to pH 2.8 to 4.0.

EFFECT: method allows for obtaining phosphoric acid, pure from impurities, for production of sodium and potassium polyphosphates.

2 cl, 1 tbl, 3 ex

FIELD: technological processes; chemistry.

SUBSTANCE: invention is related to method of preparation of extraction phosphoric acid (EPA) from apatite concentrate, and also of high quality phosphorites (P2O5 content - no less than 36%). Method includes treatment of phosphate raw materials with sulfuric and phosphoric acids with crystallisation of calcium sulfate dihydrate, separation of production dihydrate pulp into two parts, preparation of production acid from one part of pulp, counterflow water flushing of calcium sulfate dihydrate cake and return of flushing solutions to the stage of decomposition, treatment of second part of dihydrate pulp with sulfuric acid at mass ratios in liquid phase of pulp P2O5 : H2SO4 = (2.5 - 6.0) : 1 and H2SO4 : F = (2.0 - 9.4) : 1 in the presence of live steam with preparation of semi-hydrate of calcium sulfate, separation of semi-hydrate pulp with filtration, counterflow water flushing of calcium sulfate semi-hydrate with its usage for preparation of gypsum binder and return of filtrate and flushing waters to decomposition stage. Crystallization of calcium sulfate dihydrate is carried out at contents of P2O5 25.0 - 28.5% and H2SO4 0.5 - 2.4%, dihydrate pulp is treated with sulfuric acid of concentration 93.0 - 98.5%, and semi-hydrate of calcium sulfate at stage of filtration is exposed to additional flushing with water on the basis of 0.2 - 0.6 m3/t of α-semi-hydrate of calcium sulfate with disposal of prepared filtrate at the stage of calcium sulfate dihydrate flushing.

EFFECT: reduction of steam consumption in semi-hydrate stage.

1 tbl, 2 ex

FIELD: chemical engineering.

SUBSTANCE: reactor comprises branch pipes (15) and (16) for supplying natural phosphate, sulfur acid and recirculation solution of phosphorus acid to the reactor, mixing devices (3) for mixing pulp, and circulator (4) mounted within central well (5) for causing the pulp to flow through top outlet port (7) to grate (12) of the apparatus for air cooling and circulation of pulp in the zone of reactor defined by apparatus for air cooling and port (6) in the central well. Circulators (4) in wells (9) provide circulation of pulp throughout the space of the reactor and pulp flow near the baffle from both its sides. The pulp is discharged from the reactor through branch pipe (18).

EFFECT: enhanced efficiency.

2 dwg

FIELD: industry inorganic synthesis.

SUBSTANCE: purified phosphoric acid is obtained from ammonium phosphate solution involving ion-exchange procedure. Process comprises sorption of ammonium ions from ammonium phosphate solution by feeding the latter to sorption column under cationite bed and withdrawing purified phosphoric acid from column at the site where dehydrated and swelled cationite beds come into contact with each other on achievement of volume ratio 1:(5-10), respectively.

EFFECT: reduced loss of valuable components and over-consumption of reagents caused by nonuniformity in hydrodynamic distribution of processed solution stream.

1 tbl, 2 ex

FIELD: chemical industry; food-processing industry; other industries; production of the heat-resistant alloys on the basis of the nickel.

SUBSTANCE: the invention is pertaining to the method of purification of the extracting phosphoric acid (EPA) with production of the product having the low content of the impurities, which may be used in production of the phosphorus salts of technical and alimentary qualification. The method of purification of the extracting phosphoric acid provides for extraction of the phosphoric acid by the tributyl phosphate with the withdrawal of the raffinate, water flushing of the extract with withdrawal of the water flushing solution and the flushed extract, the water reextraction pf the phosphoric acid from the flushed extract with obtaining of the productional acid, which are exercised by commixing of the water and organic phases with formation of the emulsion in the mode of pulsation. The water flushing of the extract is conducted by means of dispergation of the water in the organic phase at the consumption of the dispergated water of 0.04-0.25 t per 1 t of Р2О5 in the original extract and intensity of the pulsation equal to 1200-3000 mm/minute. The flushing solution is routed for extraction, where it is either admixed with the extracting phosphoric acid before treatment with the extragent, or it is introduced directly into the mixture of the acid and the extragent containing in the aqueous phase , 35-42 % of Р2О5. The water flushing of the extract is conducted in 1-4 stages. The method ensures the substantial improvement of the water flushing column performance standards, reduction of the losses of the expensive extragent and the metal consumption of the production process, stabilization of the process of the water flushing of the extract, and also the increased outlet of the productional extracting phosphoric acid.

EFFECT: the invention ensures the substantial improvement of the water flushing column performance standards, reduction of the expensive extragent losses and the metal consumption, stabilization of the process of the water flushing of the extract, the increased outlet of the productional extracting phosphoric acid.

3 cl, 1 tbl, 5 ex

The invention relates to techniques for the production of natural phosphates phosphoric acid extraction
The invention relates to a method of purification of wet-process phosphoric acid

The invention relates to mineral fertilizer industry and building materials that can simplify the process, reduce energy and labor costs and emissions

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry, particularly to phosphogypsum processing. The method of processing phosphogypsum involves mixing phosphogypsum and 42% phosphoric acid in the presence of a reagent for maintaining pH in the range of 6.8-7.2 while stirring constantly and separating dicalcium phosphate residue from the liquid phase. The reagent used to maintain pH is aqueous ammonia solution. Components are fed for mixing in the following ratio, wt %: phosphogypsum - 65.0, phosphoric acid - 31.0, aqueous ammonia solution (with respect to ammonia) - 4.0. Mixing is carried out at temperature not higher than 80°C.

EFFECT: use of the invention increases processing depth of phosphogypsum, enables to obtain two commercial products - feed grade dicalcium phosphate and ammonium sulphate, reduces the cost and cuts duration of obtaining the products.

3 cl, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the industry of mineral fertilisers and can be used for chemical enrichment of poor phosphate material with high content of silicon dioxide, and specifically high-silica phosphorites from the Kimovsk deposit. The method for chemical enrichment involves mixing Kimovsk phosphorites containing 40.5 wt % SiO2 with ammonium fluoride with addition of 1-3 wt % magnesium sulphate. Ammonium fluoride is taken in stoichiometric amount of 100-135% for formation of ammonium hexafluorosilicate. Thermal treatment is carried out using microwaves at temperature 149 - 180°C, followed by sublimation of the obtained ammonium hexafluoride at temperature 301 - 400°C. Phosphorus pentoxide content after chemical enrichment is equal to 20.34 - 21.85 wt % P2O5. The degree of desiliconisation of the phosphorite is equal to 99.5%.

EFFECT: method enables to cut duration of the desiliconisation process of phosphorites from the Kimovsk deposit, and also reduces consumption of ammonium fluoride and energy resources.

4 ex

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