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    • 专利摘要:
    This invention relates to a process for the production of phosphoric acid by the method of the sulfuric acid decomposition of various natural phosphates. The aim of the invention is to increase the yield of P 2 O 5 and the quality of the calcium sulphate produced. Phosphoric acid is obtained by decomposition of crushed phosphate raw material into circulating phosphoric and sulfuric acids in two stages in several reaction zones, vacuum cooling of the formed reaction pulp and its circulation through the reaction zones in the amount of 300-400% of the main stream, through vacuum cooling in the amount of 2000 - 4000% of the main stream, within each reaction zone in the amount of 500-2000% of the main stream, with the amount of circulation through the reaction zones and within each reaction zone being more than or equal to 2500% of the bases flow. The first stage is carried out in two stages with the formation of either calcium sulfate α-hemihydrate or α-hemihydrate, containing 2-12% by weight of calcium sulfate anhydride, while maintaining the following regime: the concentration in the liquid phase of the pulp P 2 O 5 and sulfuric acid, respectively 44-52 and 0.25-2.5 wt.%, the solids content in the pulp is 20-38 wt.%, the temperature is 65-85 ° C, the time is 1.5-7.0 hours, the product is separated from the calcium sulphate precipitate, the precipitate is washed solutions formed by filtering the precipitate in the second stage, with the return of washing solutions for decomposition. In the second stage, the precipitate of calcium sulfate is either washed by repulation in a solution of phosphoric and sulfuric acids, or recrystallized into other hydrated forms while maintaining the following mode: the concentration in the liquid phase of the P 2 O 5 pulp and sulfuric acid, respectively, 15-38 and 4-25 wt. %, the solids content in the pulp is 20-70% by weight, the temperature is 30-105 ° C, the time is 0.5-18 h, the precipitate of calcium sulfate containing 2-95% by weight of calcium sulfate anhydrite is separated from the solution by filtration, washed , the solution and the washings are returned to the process. These differences allow increasing the yield of P 2 O 5 to 96.5-98.8% and reducing the content of P 2 O 5 in calcium sulfate to 0.20-0.95%. 8 hp f-ly.
    公开号:SU1614756A3
    申请号:SU3972921
    申请日:1985-11-04
    公开日:1990-12-15
    发明作者:Лоран Давистер Арман；Артур Тирсон Фраксис
    申请人:Прейон Девлоппман С.А. (Фирма)；
    IPC主号:
    专利说明:

    The invention relates to a process for the production of phosphoric acid by the method of the sulfuric acid decomposition of various natural phosphates.
    The purpose of the invention is to increase the output of the quality of the calcium sulphate obtained.
    Example 1. Crushed Moroccan phosphates of mark 70-72 BPL (residue on a 100 mesh sieve - 25.8%) and sulfuric acid with a concentrate of 98% were introduced into the first reactors of the plant for a one- or two-stage process. The solids content in said reactors is controlled by recycling the phosphoric acid produced, while the content is. in the liquid phase, they are supported by recirculating the filters coming from the filters: “The number of reintroduced and recycled; the circulating reagents are selected so as to maintain the initial flow rate of 12 m / t produced during the reaction volume for 3 hours circulation and circulation through the evaporator 4000%. The following reaction conditions in the first reactors are used: temperature: 72 ° C., Solids content in the pulp is 24%, content in the liquid phase is 43%, sulfuric acid content in the liquid phase is 1.2%. Calcium sulfate is precipitated in the form of pJ hemihydrate and anhydrite II; CaSO4 content is 5% of total calcium sulphate
    Obtained in the form of a glassy mass, the crystals have a good filterability. The yield is 96.5%. The resulting solid products, which are more juicy than the ob-hemihydrate and anhydrite II, contain about 6% of water of crystallization and 1.6% of the total amount in the solid phase based on the product which is dried at 250 ° C.
    During the first experiment carried out in a single-stage installation, the entire amount of pulp removed from the cycle and corresponding to the initial amount is filtered and after washing with water is removed from the filter "The residue thus obtained on the filter contains 1.8% of the total content and has consistency 31% (based on the product dried at 250 ° С). The yield in the product is 92.5%.
    In the second experiment, 80% of the initial quantity of pulp was retracted to the filter. The precipitate obtained after filtration is
    TO)
    0
    five
    0
    five
    0
    p (.- hemihydrate and anhydrite II. It is again transferred to the pulp in the second-stage reactor using the filtrate from the second filtration and the remaining 20% pulp.
    In the second stage reactors, the conditions (temperature, concentration of sulfuric acid and concentration of P205. Are adjusted in such a way as to obtain with ai.-hemihydrate and anhydrite II (20% of the total amount of calcium sulfate) „
    Thus, the temperature is maintained at 68 ° C by cooling. The solids content is again adjusted to 26% by recycling the filtrate from the second filtration, the content is maintained at 32% by using phosphoric acid, and the content of free sulfuric acid is 15%,
    The initial pulp consumption in the second stage is 11 m while keeping the pulp for 3 hours in the reaction volume. The multiplicity of the general circulation is 2500%, the multiplicity of circulation through the evaporator is 4000%. The precipitate after filtration, consisting of the oC hemihydrate and anhydrite II, is removed from the filter. The sediment contains 0.65% 6 of water based on the product dried at 2500 s; humidity of the sediment is equal to 28% „P-P yield to the product is 97%„
    When carrying out the third experiment, the entire amount of pulp obtained in the first stage is fed to the filter, and the precipitate of the hemihydrate and anhydrite
    The second stage is converted to dihydrate and anhydrite II (10% of the total amount of calcium sulfate) as a result of a decrease in temperature to 45 s. The following reaction conditions are used: the solids content of the pulp is 48%, the content is 17% and the content. 13%. The pulp consumption is 5.5 m with a retention time in the reaction zones of 12 hours; the multiplicity of the total circulation corresponds to 2500%, the multiplicity of circulation through the evaporator is 3500%
    - The residue obtained after filtration on the filter consists mainly of dihydrate and anhydrite II, contains 0.35% and 17.6% (based on the product dried at 250 ° C) and has a moisture content of 32%. 2.j product 98.5%.

    According to a known method, phosphoric acid is obtained by the phosphate raw material coagulation in the presence of circulating pulp with a mixture of circulating phosphoric and sulfuric acids when circulating the reaction pulp through the reaction zones (300-4000%), through vacuum cooling (2000-4000%) inside the reaction zone ( local, 500-2200%) with total circulation through the reaction zones and vacuum cooling not more than 2500%. Raw materials are decomposed at a concentration of sulfuric acid of 15-30 g / l (1.1-2.2%). I get phosphoric acid with a 29-30% quality of by-product, well filtering 51hosphogypsum containing
    0.62-1.0% (total). Р205 96%
    I
    Example 2. Grinded phosphates of Florida grade 70-72 BPL (residue on a 200 mesh screen — 61.5%) are fed to reactors of the first stage together with concentrated sulfuric acid (98%). The content of the hp # 1 products and the content in the liquid phase are maintained at the same level as in Example 1. The initial consumption is 12.5 m / t of the obtained residence time in the reaction zones of 4 hours. The total circulation corresponds to 2500%, the circulation through the evaporator is 4000%.
    The conditions of the reaction in various reactors of the first stage are as follows: temperature 78 ° C, solids content in the pulp 23%, content in the liquid phase 45%, content of sulfuric acid in the liquid phase 1.5%. Calcium sulfate is precipitated in the form of oi-hemihydrate and anhydrite II (7% of the total amount of calcium sulfate). The precipitate is obtained in the form of glassy crystals with good filterability. Yield 95.5%. The precipitate after filtration contains about 6% H, and 1.5% of the total composition of the solid phase per product dried at 250 ° C.
    In the first experiment, all the initial amount of pulp is filtered off and after washing, the precipitate containing 1.9% is removed from the filter, at a humidity of 27.4%. The yield in the product is 92.5%.
    In the second experiment, 80% of the initial amount of pulp is one filter, and the residue is after filtration, consisting of ob-hemihydrate and anhydrite II
    6
    re-pulped using the filtrate from the second filtration as well as the remaining 20% of the base pulp.
    The reaction conditions for the second stage are selected in such a way as to obtain (α-hemihydrate with anhydrite II in the amount of 25% of the total mass of calcium sulfate.
    The temperature is maintained at 72 G by cooling. The solids content in the pulp is again adjusted to 26% by recycling the filtrate from the second filtration. The content of 5 is 34%, and the content of free sulfuric acid is 15%. The initial consumption of pulp in the second stage is 12 m, with a continuation of residence in the reaction zones 2.5 times the total circulation of 2500%, circulation through the evaporator is 4000%. The precipitate hemihydrate and anhydrite II, obtained on the filter contains 0.80%
    at 4.2% (based on the product dried at 250 s), the moisture content of the sediment corresponds to 28%. The yield in the product is 96%.
    In the third experiment, the amount of pulp obtained in the first stage is increasingly filtered, and the precipitate obtained as a result of filtering is converted into dihydrate and anhydrite, and anhydrite II accounts for 10% of the total amount of calcium sulfate as a result of a decrease in temperature to 45 C. use the following reaction conditions: the solids content in the pulp is 45%, the content
    Re. the liquid phase is 15%, the content in the same phase of sulfuric acid is 17%. The initial flow rate is 6 m with a residence time in the reaction zones of 10 hours. The total circulation is 2500%,
    Circulation through an evaporator of 3500%. The precipitate after filtration, which is almost completely a mixture of dihydrate and anhydrite II, contains 0.33% PgOj. and 17.8% (based on the product dried at 250 ° C), the moisture content of the sediment corresponds to 33.4%. The product yield is 98.5%.
    Example 3. A mixture of crushed phosphates of Cola and Morocco at a ratio of 70:30 is introduced into the first reactors of the first stage of the installation.
    Reaction conditions: initial flow rate of 10 NtVT with semi-free TjO with time in the reaction zones 3 hours; the total circulation, the circulation through the evaporator is 4000%, the temperature is 72 ° C, the content in the liquid phase is 43.5%, the content of sulfuric acid in the liquid phase is 1.5%. Calcium sulfate is precipitated in the form of rb hemihydrate and anhydrite II (approximately 8% of the total amount of calcium sulfate). Calcium sulphate is obtained in the form of glassy crystals with good filterability. The yield is 97%. The solid product (oi-semi-hydrate and anhydrite II) contains about 5.9% and 1.5% of the total amount of the solid phase based on product. In the first experiment, all the base amount of pulp was filtered, and after washing, a precipitate of OC-hemihydrate and anhydrite II was obtained, with a content of 1.6% P 0
     about .J.
    sulfuric acid 9%. The initial consumption is 5 m with a duration of stay in the reaction zones of 12 hours. The total circulation is 2500%, circulation through the evaporator is 4000%.,
    The filter cake consisting of dihydrate and anhydrite II contains fO. 0.30% 17% -H2.0 (based on the product dried at 250 s) the moisture content of the sediment corresponds to 35%. The yield in the product is 98.5%.
    15 Example 4. Ground 70-72 BPL crushed Moroccan phosphates and concentrated sulfuric acid (98%) were added. howl stage
    20 The solids content in said reactors is controlled by recycling the phosphoric acid produced, while the content in the liquid phase is maintained by recycling the filters obtained by filtration.
    The amount of reagents injected and recycled is controlled in such a way as to maintain the initial flow rate of 10 MVT produced by the RE-EP-PR, the dwelling of reagents in the reaction volume for 3 hours with total circulation and circulating through the evaporator as a whole 4000%. At the first stage of 20% humidity Output P oJ
    in the product is 94%.
    In the second experience, all initial
    the amount of pulp produced in re- 25
    due to the implementation of the first stage
    filtered and at the second stage
    d t filter cake back to the bullet; poo under conditions that are confined; bake getting-hemihydrate and
    anhydrite II, which forms 15% of: total calcium sulfate.
    In this case the temperature is 65 ° С.
    The content of solid products is 24%, the content of RoOS is 30%. saltine i nn--
    bodysuit H, so / if%. n; p ::;: sLr / - s-35; c :: oLr :: aT: and; r the turn in the second stage is 11 mz f ...:. "2 C in with a duration of stay in the reaction zones of 2.5 hours; the total circulation is 1500%, the circulation through the evaporator is 4000%. The filter cake, consisting of cvi hemihydrate and anhydrite II, contains 0.75% and 5.2% HgO (calculated on the dried product), and the moisture content of the precipitate is 36%. The yield to the product is 96.5%.
    In the third experiment, the entire amount of pulp obtained in the first stage is filtered. The resulting precipitate Ob-hemihydrate and hemihydrite II pe
    .. V A - ... a. 1 in iJO. Oi, V
    the first part and 72 s in the second part, the solids content in the reaction pulp is 34%, the content is 7 "0
    40 in the liquid phase is 36%, the content of sulfuric acid in the liquid phase is 0.3% in the first part and 1.25% in the second part „
    Calcium sulfate precipitated in dihydrate form. Glassy crystals
    45 have good filterability at a reaction yield of 96.5%, and the solid product consisting of the dihydrate contains about 20% of a crystal of water and 1.6% of the total amount of - - .vj 4. fi . i ci J, JL Jlcptr
    WATER into dihydrate and anhydrite II (15% of the total amount of calcium sulphate) by reducing the temperature to. With this, the following conditions are met; the solids content in the pulp is 50%, the PgO content, in the liquid phase, 19%, the content in the same phase
    50
    jf, y v
    solid phase is calculated on dry at 250 ° C product
    In the first experiment, the initial ko-. the amount of pulp is filtered.
    The resulting precipitate on. The filter, consisting of the dihydrate, is transferred back to the slurry in the second stage reactor using for this purpose the filtrate from the second filtration. In reactors of the second stasic acid, 9%. Initial - consumption is 5 m with a residence time in the reaction zones of 12 hours. The total circulation is 2500%, the circulation through the evaporator is 4000%.,
    The filter cake consisting of dihydrate and anhydrite II contains fO. 0.30% 17% -H2.0 (based on the product dried at 250 s) the moisture content of the sediment corresponds to 35%. The yield in the product is 98.5%.
    5 Example 4. The crushed Moroccan phosphates of mark 70-72 BPL and concentrated sulfuric acid (98%) were introduced. The first reactors per -. howl stage
    0 The content of solids in these reactors is controlled by recycling the phosphoric acid produced, while the content in the liquid phase is maintained by recycling the filters obtained by filtration.
    The amount of reagents injected and recycled is controlled in such a way as to maintain the initial flow rate of 10 MVT produced by the RE-EE-PR reagents in the reaction volume for 3 hours with a total circulation and circulating through the evaporator as a whole 4000%. On the first stage5
    -
    5; c :: oLr :: aT: and; r; c :: oLr :: aT: and; r ...:. "2 C in
    .. V A - ... a. 1 in iJO. Oi, V
    the first part and 72 s in the second part, the solids content in the reaction pulp is 34%, the content is 7 "0
    in the liquid phase 36%, the content of sulfuric acid in the liquid phase is 0.3% in the first part and 1.25% in the second part „
    Calcium sulfate precipitated in dihydrate form. Glassy crystals
    have a good filterability at a reaction yield of 96.5%, and the solid product consisting of the dihydrate contains about 20% of the crystal of standing water and 1.6% of the total
    jf, y v
    solid phase is calculated on dry at 250 ° C product
    In the first experiment, the initial amount of pulp is filtered.
    The resulting precipitate on iltre, consisting of the dihydrate, is transferred back into the slurry into the second-stage reactor using the second filtrate for this purpose. In the second hundred I reactors
    Din PPDD, rzhirbyut g, yc; i (4; iH (rcMii ratuu) a, concentra tion center cennoii cgg lots and horse and j - phosphorus) to ensure y-hemihydrate and anhydrite II (in the amount of 5% of the amount of sulfate calcium)
    The temperature is maintained at 90 ° C by steam injection and the solids content is again brought to 30% by recycling the filtrates from the second filtration, the content is maintained at 24%, feeding phosphoric acid, and the free sulfuric acid content is maintained at 15%.
    The initial volume in the second stage is 9 m with a residence time in the reaction volume of 1 hour, and the circulation corresponds to 2500%. The precipitate after filtration containing 6-hemihydrate and anhydrite II is removed from the filter. The precipitate contains 0.30% and 5.6% based on the product produced at 250 ° C. Sediment moisture 18%. The product yield is 98.8%.
    The entire initial volume of pulp coming from the first stage is filtered, and the resulting dihydrate precipitate is subjected to a second stage of secondary treatment to produce the dihydrate when the temperature is changed to in the presence of liquid sulfuric and phosphoric acids.
    The processing conditions are as follows: the content of solid products in the pulp is 38%, the content of P is 17% and the content ;;; a - 10%. The initial volume is 6.5 m with a residence time in the reaction zones t, 5 hours; The total circulation is 2500% and the circulation through the evaporator is 3500%. The precipitate after filtration consists almost entirely of dihydrate and contains 0.95% of P oc-and 19.6% (based on the product dried at), the moisture content of the precipitate is 34%. The yield in the product is 96%,
    I
    Example 5. Crushed phosphates of Florida grade 70-72 BPL serves. in reactors of the first stage of installation together with concentrated sulfuric acid (98%). The solids content in the indicated reactors and the concentration of .P-2.5- correspond to an initial volume of 11 obtained with a residence time in the reaction zones of 3.5 hours; about 756
    on circulation of 2500%, circulation through the evaporator of 4000%.
    When implementing the proposed method, the conditions for carrying out the reaction in various reactors of the first stage are as follows: temperature 78 ° C in the first part and 70 ° C in the second part, the solids content in the pulp is 33%,
    l content in the liquid phase 38%, the content of H S0, in the liquid phagzo 0.5% in the first part and 1.5% in the second part. Calcium sulfate is precipitated in the form of a digrite, which is a glassy crystal with good
    0
    0
    filterability. The yield of the reaction is 95.5% o The precipitate obtained during filtration contains approximately 20% BUT and 1.5% RLOC, of the total amount of the solid phase, based on the product dried at 250 ° C. I
    In the first experiment, all the initial amount of pulp is filtered.
    5 and wash the filter cake using filters for this purpose after the second filter. After that, the filter residue is removed. The moisture content in the sediment is 40%.
    JQ The resulting precipitate is processed in the second stage to give the dihydrate at 80 s; the solids content in the pulp is 34%, the content is 20% and the content of sulfuric acid is 8%. Initial number
     8 m with a duration of stay in the reaction zones - 1.5 hours. The total circulation corresponds to 2500%, the circulation through the evaporator is 3000%.
    The precipitate after filtration is the dihydrate; its content is 1.1 liters, the humidity is 35%. Output R2.G) 5 product 96%.
    .c In the second experiment, which was aggravated in the same installation, 100% of the initial quantity of pulp was filtered. The precipitate on the dihydrate filter is again transferred to the slurry using filtrates from the second filtration.
    The conditions for the reaction were selected in such a way that, in the second stage, the OC-hemihydrate with a small amount of anhydrite II was obtained; it was 5% of the total amount of calcium sulfate.
    GE temperature is kept (secret 92 C by injecting 1) aii of water -
    five
    eleven
    steam pair. The solids content in the pulp is adjusted to 28% by recycling the filtrates after repeated filtration. The P-0 content is 22%, and the free sulfuric acid content is 10%. The initial volume in the second stage is 10 m with a residence time of 1.0 h in the reaction zones and a total circulation of 2500%. The hemihydrate and anhydrite precipitate 11, after the second filtration, contains 0.35% 5.8% HjO based on the product dried at 250 ° C; the moisture content in the sediment is 20%.
    Woo y b% o
    in the third experiment, the entire amount of pulp coming from the first stage is filtered and the precipitate obtained during filtration is converted to anhydrite II by lowering the temperature to 55 anhydrite II, which accounts for 95% of the total amount of sulphate and kalysh dihydrate Reaction conditions: solids content in pulp 40%, content P, in the liquid phase 15%, content 25%. An initial volume of 6 m with a residence time in the reaction zones of 1 hour. The total circulation corresponds to 2500% circulation through the evaporator. 3500% The precipitate on the filter, consisting entirely of anhydrite II, is removed from the filter. The precipitate contains 0.38% P, 05- and 0.7% based on the product dried at 250 ° C; moisture content in the sediment is 40%. Exit R2.05 in product 98%,
    Example 6. A mixture of crushed phosphates of Cola and Morocco in the ratio of 70:30 is fed to the first reactor. The conditions of the process are as follows: the initial volume of 10 produced with a residence time of 3.5 hours in the reaction zones, a total circulation of 500%, circulation through the evaporator 4000%, a temperature of 80 ° C in the first part and 72 ° C in the second part, containing sulfuric acid in the liquid phase is 0.4% in the first part and 1.5% in the second part. Calcium sulfate is precipitated in dihydrate form. Said sulphate is itself a glassy crystal with good filterability. The reaction yield is 97%. The solid product (dihydrate) contains
    one
    CTD a1614756
    ten
    approximately 19% HgO and 1.0%, calculated on a product at 250 ° C.
    In the first test, the entire amount of pulp coming from the first stage is filtered and, in the second stage, the precipitate is again transferred to the pulp under conditions such that the hemihydrate and anhydrite II is obtained, which is 5% of the total calcium sulfate. .
    The temperature in this case is equal, the content of solids is 30%, the content of free sulfuric acid is 15%. The initial volume in this second stage is 9 m with a residence time of 1.0 h in the reaction zones. The total circulation is 1500%. The precipitate of p6-hemihydrate 20 and anhydrite II, obtained on the filter, contains 0.28% and 5.8% calculated on the dried product at 250 ° C, the moisture content in the precipitate is 18.5%. The yield of P, 2.s-per product is 98.5%.
    15
    25 When the second experiment was carried out, the entire amount of pulp obtained in the first stage was filtered. The resulting dihydrate precipitate is reacted with solutions at 30 6 ° C. The following reaction conditions are met: the solids content in the pulp is 38%, the content in the liquid phase is 19%, and the sulfuric acid content is 9%. The initial volume is 9 m with a duration of stay in the reaction zones of 1.2 hours; 2500% total circulation, 4000% evaporator circulation.
    0 The resulting precipitate contains dihydrate and anhydrite II (3% of the total calcium sulphate obtained on the filter), the precipitate contains 0.85% PiOg-H 18.5% in the calculation
    5 for dried with product. The moisture content in the sediment is 35%. The yield of PjOj– to the product is 96.5%.
    PRI me R 7 about Crushed Moroccan phosphates brand 70-72 BPL and
    Q concentrated sulfuric acid (98%) is fed into the first reactors of the first stage.,
    The content of solids in the reactors is controlled by recirculating the phosphoric acid produced, while the content of P, 0, .. in the liquid phase is maintained by recirculating fstrats obtained after the first and second filtration.
    The amount of reagents injected and recycled is selected so that the initial volume is 12 m / t produced with a residence time of 3 hours. Total circulating and circulating through the evaporator correspond to 4000%. In the first stage reactors, the following reaction conditions are maintained: 82 ° C in the first part and 72 ° C in the second part, the solids content in the pulp is 24%, the content in the liquid phase is 43%, the content in the liquid phase in the first part and 1.2 % in the second part.
    Calcium sulfate precipitates in the form of Ob-hemihydrate and anhydrite II; the CaSO content is 5% of the total amount.
    The resulting glassy crystals have good filterability. The yield is 96.5%. The formed solid product in the form of 0-hemihydrate and anhydrite II contains approximately .6% water of crystallization and 1.6% PyOf of the total amount of solid phase based on the product dried at 250 ° C.
    In the first experiment, 80% of the initial amount of pulp was filtered.
    The precipitate obtained in this way after filtration consists of Ob-semi hydrate and anhydrite II; it is again transferred to the slurry in a second-stage reactor using the filtrate from the second filtration, as well as the remaining 20% pulp.
    In the second stage reactors, such conditions (temperature, sulfuric acid concentration and concentration) are maintained to ensure the mixture is obtained (X.-hemihydrate and anhydrite II (20% based on the total amount of calcium sulfate),
    The temperature is maintained at B8 ° C by cooling. The content of solids is supported on the Fovne by 26% recirculation of the filtrate from the second filtration, the content in phosphoric acid is maintained at 32%, the content of free true acid is equal to 15%.
    The base quantity in the second stage is 11 m with a residence time of 3 hours. The total circulation corresponds to 2500%, the circulation through the evaporator
    1475614
    4000%. The precipitate obtained on the fgpter and consisting of od-hemihydrate and anhydrite II contains 0.65% and 4.6% H (based on the product dried at 250 ° C), the moisture content of the precipitate is 28%. Exit U2. per product 97%.
    In the second experiment, the entire amount of pulg obtained in the first stage, 10 is filtered, and the resulting
    the precipitate (X-hemihydrate and anguilrite II is transferred in the second stage to dihydrate and anhydrite II (10% of the total amount of sulfate capt)) by lowering 15 temperatures to 45 ° C.
    Conditions under which the - There are operations that follow: the solids content in the pulp is 48%, the content is 17%, the content is 20–13%. The initial volume is 5.5 m with a residence time in the reaction zones of 12 °. The total circulation is 2500%, the circulation through the evaporator is 3500%. The residue obtained 25 after filtration is
    is predominantly dihydrate and anhydrite II and contains 0.35% and 17.6% H20 based on the product dried at 250 ° C; the moisture content of 30 in the sediment 32%. The yield in the product is 96.8%.
    Various experiments in accordance with the examples described are carried out in a plant with a capacity of 20 kg 35 VV 3 24 hours.
    In examples 1-3, in the first experiment, a plant containing two reactors was used, in the second experiment - having two reactors in the first and second dd stages, and in the third experiment - having two reactors in the first stage and four reactors in the second stage, in examples 4-7, in the first test, an installation containing three 45 reactors is used, in the second experiment it contains two reactors in the first and second stages, and in the third experiment it contains two reactors in the first stage and one reactor in the second stage. 0 Example 8. Phalaborna phosphate is loaded into the first reactor of the first stage of the installation.
    The operating conditions are as follows: the main flow rate is 7 m / t obtained by 5 with a residence time in the reaction zones of the first and second stages, respectively 6 hours and 1 hour, total circulation 500%, circulation to the evaporator 4000%, temperature 85 ° C
     one
    Isa TieppoM and 75 C or the second stage content. in the liquid phase of 0.25% in the First and 1% in the second stages.
    Calcium sulfate is precipitated in the form of dig 1drata. This sulphate is in the form of double crystals with good filability. The yield from chemical exposure is 95.8%, the solid dihydrated substances contain about 20% and 2.2%. in C | hlom in the solid phase based on the product dried at 250 C
     The first variant of 80% of the main pulp debit is filtered. The precipitate after filtration is repulped into the reactor, the second stage with filtrates from the second filtration and the remaining 20% pulp. In the conditional stage set for | obtaining 0-hemihydrate and anhydrite II, forming 2% of total calcium sulfate,
    Thus, at 105 ° C, the BeuitecTB solid matter content is 28%. For the liquid, the content is 22%, the free content. - 10%. The main flow in this stage is 9 m / h with a residence time of 0.5 h in the reaction zones and a total circulation of 1500%. The precipitate of α-hemigra and anhydrite II discharged from the filter contains 0.25% and 5.8% of the product, npi, extruded. The moisture content in the precipitate i on the filter is 19%.
    I The output in the calculation of the content in the waste calcium sulphate above 99%,
    In the second trial, also carried out in an installation of this type, 80% of the bulk of the pulp of the first stage is filtered and the precipitate obtained after filtration, repulpable together with the remaining 20% of the pulp, is converted to anhydrite II, maintaining a temperature of 75 ° C. 60% of the total sulphate is felted, and the remaining 40% is LugidraTo. Other reaction wells are as follows: the content of solid matter in the pulp is 30%, in the liquid phase the content of RF is 20%, the content is 12%. The main flow rate of 8 m with a residence time in the recovery zones of 1.5 hours, a total circulation of 2500%, installs a furnace on the evaporator of 3500% from the Sediment after filtration, formed mainly by
    61b.
    once anhydrite- 1 and udl. Ü1 of the filter, contains 0.30% and 327 per product, pulverized at 250 ° C, the moisture content in the sediment is 30%, and the yield is 98.5%.
    Example 9: Florida Phosphate (Hookers Prairie) is loaded into reactors 1; the first stage of the plant, together with concentrated 98% sulfuric acid. The solids content in the reactors is 20% for a concentration of 33%, the nominal flow rate 12 obtained by 2. at a residence time in the reaction zones of the first and second stages is 5 and 1 h, the total circulation is 2500% and the circulation is set to the evaporator 3000
    The reaction conditions in the various reactors of this first stage are as follows: the temperature at the first and 70 ° C at the second stage, the solids content in the pulp is 20%, the content of P205-B in the liquid phase is 33%, the content. in the liquid phase, 0.6% at the first stage and 2.0% at the second stage. The calcium sulfate remaining in the dihydrate form is in the form of double crystals with good filterability. The yield is 95.5% and the precipitate after filtration contains about 19% and 1.2% of the total Pj. solid phase based on dry weight when dried at 250 ° C
    I
    In the first test, the bulk of the pulp is filtered off and the resulting precipitate is filtered with the filtrates from the second filtration and cured. It has a moisture content of 38%,
    The precipitate obtained (after filtration) is recrystallized in the second stage to dihydrate and anhydrite II, the latter forming 15% of the total calcium sulphate while maintaining the temperature 80 ° С, the solids content in the pulp is 20%, the content of P, jOg is 25%, the content of 4% The main flow rate is 12 m with a duration of stay in the reaction zones of 2.0 hours; 2500% total circulation and 2000% circulation set on the evaporator,
    The precipitate after filtration is formed mainly by dihydrate and anhydrite II, containing 0.7% PgO, 18.2 NyO based on the product dried in, moisture content 34%, You 17
    P, 0 stroke in waste calcium sulphate is above 97.5%.
    In the second test, also carried out in an installation of this type, the entire bulk of the pulp of the first stage is filtered and the precipitate obtained after filtration is converted to. anhydrite II lowering the temperature to 30 ° C, the latter forming 95% of the total calcium sulphate — and the remaining 5% is the dihydrate. Other reaction conditions are as follows: the solids content in the pulp is 45%, the content in the liquid phase is 15% and the content is 25%. The main volume is 6 m with a residence time of 1.5 hours in the reaction zones, a total circulation of 2500%, a circulation of 3500% to the evaporator.
    The precipitate after filtration, mainly formed by anhydrite II, is discharged from the filter 1.10, containing 0.30% and 0.2% starting from the product, dried at 250 s, and the moisture content in the sediment is 32%. The yield is 98.5%.
    Example 10. The crushed phosphate of Morocco 70-72 BPL and concentrated 98% sulfuric acid are loaded into the first reactors of the first stage of the installation.
    The solid content in the reactors is controlled by recycling the phosphoric acid obtained, and the concentration in the liquid phase is maintained by recycling the filtrates after the first and second filtration. The number of reagents added and recycled is such that the main flow rate tO m / tons obtained when staying in the first and second stages, respectively, 4 and 1 h, the total circulation and circulation to the evaporator is 4000% each. The reaction conditions in the baths of the first stage are as follows: the temperature is 80 and 70 ° C in the first and second stages, the solids content in the reaction pulp is 32%, the content in the liquid phase is 43%, the content. in the liquid phase of 0.3 and 1.0% in the first and second stages.
    Calcareous sulphate is precipitated in the form of 6i-polyhydrate and anhydrite II, the latter content being 2% of the total amount of calcium sulfate.
    t475618
    The resulting double crystals have good filterability. Yield 95.0%. The solids formed by pd-hemihydrate and anhydrite II contain about 6.1% water of crystallization and 1.4% of the total in the solid phase, calculated on the product that was dried at 250 ° C.
    10 In this test, 70% of the main flow rate of the pulp is filtered.
    The precipitate thus obtained, after filtration, formed by the pC-hemihydrate and anhydrite II, repulses into the second-stage reactor together with the filtrates after the second filter. and the remaining 30% pulp.
    In the second stage reactors, temperature conditions, concentrations of 20 and sequentially regulate
    to obtain 0-hemihydrate and anhydrite II in the amount of 20% of the total calcium sulfate
    The temperature is maintained at 60 ° C due to cooling by 25. The solids content (34%) is controlled by recycling the filters after the second filtration, the content of P ,, P is maintained at 38% in phosphoric acid, and the content of free sulfuric acid is maintained at 15%.
    The main flow rate of the second stage is about 9 m when it is in the reaction volume of 3 hours, and the total circus is 1 2500 mm and the circulation to the evaporator is set at 4000%. The precipitate after filtration, containing the CXL-sex of hydrate and anhydrite II, sustained -. of less than 0.7% and 4.8% in the calculation of the product, dried with a moisture content in the sediment of 27%. Exit 97%.
    IT example. The crushed phosphate of Florida 70-72 BPL is loaded into the red5 actors of the first stage of the installation together with concentrated 98% sulfuric acid. The solids content in these reactors is 26% for a concentration of 52%, a nominal 0 flow rate of 11 m / t obtained at a residence time in the reaction zones of the first and second stages is 1.5 hours, the total circulation is 2500%, and the circulation to the evaporator is 4000% . The reaction conditions in the reactor reactors of this first stage are as follows: the temperature is 75 and 65 ° C in the first and second stages, the solids content in the pulp is 26%. content
    in the liquid phase 52%; content in the liquid phase of 0.85 and 2.5% in the first and second stages. Osadivishy in the form of (H.-hemihydrate and anhydrite II sulfate, and (forming 12% of the total calcium sulfate) and has the form of double crystals {galls and good filterability. The yield from chemical exposure is 94.5% and the precipitate after filtration, it contains about 58% and 1.5% of the total in the solid phase, calculated on the dried product at 250 ° C,
    In this test, the main flow of gills is filtered, the precipitate is washed with the filtrate from the second filtration and discharged. Its moisture content is 20%.
    pg
    The precipitate is recrystallized in the second stage to the I: anhydrite II dihydrate, the latter forming 30% of the total calcium sulfate: and g (when the temperature drops to 30 ° C, the solids content in the pulp is 62%, the P content is 15%, and containing 25%, the main flow rate is 4 m at 4 m with a duration of g | reboot in reaction zones 18 x 4 4 h; and a circulation of 2500%, circulating 4000% on an evaporator. I The precipitate after filtration formed x by dihydrate and anhydrous tite 1 II, containing 0.2% P2.5 per product. obsession moisture 30%. You are a Yod based on the content of the calcium sulfate .othodah 99%.
    F
    formula of invention
    权利要求:
    Claims (9)
    [1]
    1. A method of producing phosphoric acid, which includes decomposition of crushed phosphate feedstock by treating circulating phosphoric and sulfuric acid-ILI in several zones with the formation of a reaction pulp consisting of phosphoric acid and calcium sulfate precipitate, vacuum cooling the pulp and its circulation through the reaction
    zones in the amount of 300-4000% of basic phosphorus pentoxide in the liquid phase
    flow through vacuum cooling: in the amount of 2000-4000% of the main flow, within each reaction zone in the amount of 500-2000% of the main flow, and the amount of circulation through the reaction zones and within each reaction zone is maintained greater than or equal to 2500 % of main flow, product separation from sediment
    Calcium sulphate, i.e., i.e., washing the precipitate and returning the flow of water to the process,
    in order to increase the yield
    product and quality of calcium sulfate, the process is carried out in two stages, the first stage is carried out in two stages with the formation of either dihydrate,
    or about calcium sulfate hemihydrate containing 2–12% by weight „% calcium sulfate anhydrite, while maintaining the following regime: concentration in the liquid phase of phosphorus pentoxide pulp and
    sulfuric acid, respectively 33-52 and 0.25-2.5 wt.%, the solids content in the pulp is 20-38 wt.%, temperature 65-85 ° C, time 1.5-7.0 h, the product is separated from the precipitate sulfate calcium,
    wash the precipitate with solutions formed during the filtration of the precipitate in the second stage, with the return of the washing solutions to decomposition, in the second stage precipitate sulphate calyxes or
    washed by repulpation in a solution of phosphoric and sulfuric acids, or recrystallized into other hydrated forms while maintaining the following regime: concentration in the liquid phase
    phosphorus pentoxide and sulfuric acid pulps, respectively, 15-38 and 4-25 wt.%, the solids content in the pulp is 20-70 May0%, the temperature is 30- 105 ° C, the time is 0.5-18.0 hours, the precipitate of calcium sulfate containing 2-95 wt.% Calcium sulfate anhydrite is separated from the solution by filtration, washed and the solution and the washings are returned to the process.
    [2]
    2. Method of pop, 1, characterized in that in the first stage, followed by crystallization of calcium sulfate dihydrate, the first stage is carried out at 75-85 ° C and the concentration of sulfuric acid in the liquid phase of the pulp is 0.25-0.60% by weight, the second stage is at 72-75 ° C and the concentration of sulfuric acid in the liquid phase of the pulp 1-2 wt,% and at the stage maintain the concentration
    pulp 33-38 wt.%, the content. solid in the pulp 20-38 wt.% and the process is 3-7 hours
    .
    [3]
    3. The method according to claim 1, characterized by the 55 nd U and with the fact that in the first stage, followed by crystallization of the calcium sulfate hemihydrate, the first stage is carried out at 75-82 s and the concentration of C 11 and sulfuric acid in the liquid phase
    2116
    pulp 0.30-0.85 wt.%. the second stage - at 65-72 ° C and the concentration of sulfuric acid in the liquid pulp Lase is 1.0-2.5 wt.% and at the stage maintains the concentration of phosphorus pentoxide and the liquid phase of the pulp 43-52 wt.%, the solids content in the pulp is 23 -26 wt.% The process is 1.5-7.0 hours.
    [4]
    4, The method according to claims. 1 and 2, that is, the fact that the first stage is carried out in one stage at 72-78 s and the concentration of sulfuric acid in the liquid phase of the pulp is 1.2-1.5 wt.%.
    one
    [5]
    5. The method according to claim 1, characterized in that the repulping of calcium sulfate dihydrate is carried out at 75-80 ° C for 1.5 hours in a solution containing 17-20 wt.% Phosphorus pentoxide, 8-10 wt.% Sulfuric acid when the content of the solid in the pulp 34-38 wt.% o
    I
    [6]
    6. The method according to claim 1, characterized in that the recrystallization of the dihydrate sullate calcium to calcium sulfate, containing 3-95 wt.%. calcium sulfate anhydrite, carried out at 30-80 ° C for 1-2 hours in a solution containing 15-25% by weight of phosphorus dentoxide, 4-25% by weight of sulfuric acid, with a solids content in the pulp of 20-45% .%.
    475622
    [7]
    7. The method according to claim 1, which is also distinguished by the fact that the recrystallization of the dihydrate in o /., Α-sulfate hemihydrate and calcium, containing 2-60% by weight of calcium sulfate anhydrite, is carried out at 75-105 s for 0 , 5-1.5 hours in a solution containing .20-26 wt.% Phosphorus pentoxide, 10-15 wt.% Sulfuric acid with a solids content in the pulp of 28-70 wt.%.
    [8]
    8. Method pop. 1 and 2, in that recrystallization of the calcium sulfate hemihydrate calcium hemihydrate, containing
    15-25 wt.% Calcium sulfate anhydrite,. carried out at 60-72 seconds for 2.5-3.0 hours — in a solution containing 30-38 wt.% P, and 15 wt.% sulfuric acid, at 0 the solids content in the pulp 34 wt.%,
    [9]
    9. The method according to paragraphs. 1 and 2, characterized in that the recrystallization of od calcium sulfate hemihydrate into a dihydrate containing 10-30 wt.% Calcium sulfate anhydrite is carried out at 30-45 ° C for 10-18 h in a solution containing 15- 19 wt.%., And 9-25 wt.% Sulfuric acid, with a solid content in the pulp 45-62 wt.% „Priority points:
    11/05/84 on PP.1,6-9 21.05. 85 on PP. 2-4
    类似技术:
    公开号 | 公开日 | 专利标题
    SU1614756A3|1990-12-15|Method of producing phosphoric acid
    US3418077A|1968-12-24|Phosphoric acid
    US3552918A|1971-01-05|Process for the production of phosphoric acid
    GB1205122A|1970-09-16|Process for the production of phosphoric acid
    CA2016048C|1997-02-25|Method for the production of potassium magnesium phosphate
    US3600154A|1971-08-17|Process for the continuous preparation of nitrophosphate fertilizers
    US4321077A|1982-03-23|Method of preparation of multicomponent fertilizers
    US3984525A|1976-10-05|Manufacture of phosphoric acid
    SU582198A1|1977-11-30|Method of preparing phosphoric acid
    AU616540B2|1991-10-31|Recovery of P2O5 values from hemihydrate crystals
    SU872454A1|1981-10-15|Method of producing phosphoric acid
    SU1224259A1|1986-04-15|Method of producing phosphoric acid
    US3726660A|1973-04-10|Nitrophosphate fertilizer production
    SU975698A1|1982-11-23|Process for producing complex fertilizers
    SU1031897A1|1983-07-30|Process for producing phosphoric acid
    FI58485C|1981-02-10|FRAMEWORK FOR FRAMSTAELLNING AV PHOSFORSYRA MED HOEG HALT AV GOEDSLINGSNAERINGSAEMNEN
    SU887555A1|1981-12-07|Method of producing complex fertilizer
    DE2336254C3|1979-05-03|Process for the production of a monopotassium phosphate solution or of PK or NPK polymerization products
    SU420556A1|1974-03-25|
    SU556109A1|1977-04-30|The method of producing phosphoric acid
    SU390017A1|1973-07-11|METHOD OF OBTAINING PHOSPHORIC ACID'GVT "" ™ "
    SU1678761A1|1991-09-23|Method for obtaining phosphoric acid
    SU711019A1|1980-01-25|Method of preparing complex nitrogen-phosphorus fertilizer
    SU1527147A1|1989-12-07|Method of producing phosphoric acid
    IL29380A|1972-02-29|Manufacture of phosphoric acid
    同族专利:
    公开号 | 公开日
    FI854256L|1986-05-06|
    CN1007237B|1990-03-21|
    FI83209C|1991-06-10|
    AU4915385A|1986-05-15|
    ES549112A0|1988-03-16|
    IL76914A|1988-07-31|
    ES8801889A1|1988-03-16|
    IN166398B|1990-04-28|
    PH23909A|1989-12-18|
    CN85109003A|1986-05-10|
    OA08544A|1988-09-30|
    GR852672B|1986-03-05|
    JPH0617215B2|1994-03-09|
    MA20561A1|1986-07-01|
    MX168102B|1993-05-04|
    BR8505501A|1986-08-05|
    AU579414B2|1988-11-24|
    CA1264408A|1990-01-16|
    EP0181029B1|1991-06-12|
    IL76914D0|1986-04-29|
    US4777027A|1988-10-11|
    DZ854A1|2004-09-13|
    JPS61168510A|1986-07-30|
    FI83209B|1991-02-28|
    DE3583209D1|1991-07-18|
    EP0181029A3|1987-06-16|
    EP0181029A2|1986-05-14|
    FI854256A0|1985-10-30|
    引用文献:
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    US3632307A|1969-04-09|1972-01-04|Albatros Super Fosfaatfabrieke|Process for the preparation of phosphoric acid and gypsum from phosphate rock|
    US4277448A|1977-12-29|1981-07-07|Occidental Petroleum Corporation|Phosphoric acid process with high circulation rates|
    LU78457A1|1977-11-04|1979-06-13|Prayon Soc|PHOSPHORIC ACID MANUFACTURING PROCESS|
    FR2409230B1|1977-11-16|1981-05-29|Rhone Poulenc Ind|
    US4276270A|1978-01-06|1981-06-30|Occidental Research Corporation|Start-up procedure in producing phosphoric acid by the hemihydrate process|
    US4452770A|1981-12-14|1984-06-05|United States Gypsum Company|Phosphoanhydrite process|
    LU84713A1|1983-03-25|1984-11-14|Prayon Soc|PROCESS AND PREPARATION OF PHOSPHORIC ACID AND CALCIUM HEMIHYDRATE ALPHA SULFATE|DE4011716A1|1990-04-11|1991-10-17|Hoechst Ag|METHOD FOR PRODUCING ALKALIPHOSPHATE SOLUTIONS|
    US6235257B1|1991-03-14|2001-05-22|Gordon F. Palm|Process waters in phosphate manufacturing|
    US5262963A|1991-06-28|1993-11-16|Imc Fertilizer, Inc.|Automatic control system for phosphoric acid plant|
    US5188812A|1991-11-13|1993-02-23|Imc Fertilizer, Inc.|Automatic control system for a phosacid attack tank and filter|
    US5395603A|1993-04-21|1995-03-07|Imc Fertilizer, Inc.|Automatic control system for a chemical process, especially a wet process phosphoric acid plant|
    CN1340457A|2000-09-01|2002-03-20|山东鲁北企业集团总公司|Process for preparing phosphoric acid|
    BRPI0400875A|2004-03-08|2004-11-30|Copebras Ltda|Process and apparatus for the production of phosphoric acid|
    BE1016065A3|2004-06-01|2006-02-07|Prayon Technologies|Process phosphoric acid production.|
    FR2873119B1|2004-07-13|2008-02-01|Vichem Soc Par Actions Simplif|IMPROVED PROCESS FOR THE PRODUCTION OF PHOSPHORIC ACID|
    BE1019055A3|2009-12-02|2012-02-07|Prayon Technologies|PROCESS FOR PRODUCING PHOSPHORIC ACID|
    CA2837495C|2011-06-01|2018-01-09|Prayon Technologies|A method for producing phosphoric acid of the dihydrate/hemihydrate type|
    BR112015021526A2|2013-03-08|2017-07-18|Mosaic Co|phosphoric acid production by a two stage crystallization process|
    CN105253867B|2015-09-18|2017-10-17|金正大生态工程集团股份有限公司|A kind of production method of phosphoric acid by wet process by-product αsemiwatergypsum|
    CN105217590B|2015-09-18|2017-05-10|金正大诺泰尔化学有限公司|Method for production of wet process phosphoric acid and byproducts alpha-hemihydrated gypsum and high purity and high whiteness alpha-hemihydrated gypsum|
    CN107840317B|2017-10-30|2019-12-03|安徽六国化工股份有限公司|A kind of-half water wet method phosphoric acid manufacture process of two water of one-step method|
    CN107840316B|2017-10-30|2019-07-19|安徽六国化工股份有限公司|A kind of two step method dihydrate wet phosphoric acid production technology|
    法律状态:
    2005-05-10| REG| Reference to a code of a succession state|Ref country code: RU Ref legal event code: MM4A Effective date: 20031105 |
    优先权:
    申请号 | 申请日 | 专利标题
    LU85628A|LU85628A1|1984-11-05|1984-11-05|Wet process phosphoric acid and calcium sulphate prodn. - with adjustment of flow rates, temp. and concn. to control crystal form of the by=product|
    LU85906A|LU85906A1|1985-05-21|1985-05-21|Wet process phosphoric acid and calcium sulphate prodn. - with adjustment of flow rates, temp. and concn. to control crystal form of the by=product|
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