DE3000987A1 - NATURAL DEFLUORED CALCIUM PHOSPHATE FOR ANIMAL FOOD - Google Patents

Description

PATENT ADVOCATE DR. HANS-GUNTHER EGGERT ₁ DIPLOMA CHEMIST

S COLOGNE 51, OBERLÄNDER UFER 90 - 4 -

description

The present invention relates to a defluorinated calcium phosphate with new properties for animal nutrition and a process for its production.

Defluorinated calcium phosphates are important industrial products that are used to supplement the diet or animal feed as important components of such supplements in addition to nitrogen-containing derivatives, sugars, oligoelements and vitamins be used.

An earlier method of making defluorinated Calcium phosphate, which has been used by the applicant for a long time, consists in the neutralization of a defluorinated one Phosphoric acid, i.e. a phosphoric acid obtained thermally or wet and with a calcium compound, such as lime, calcium carbonate or calcium chloride has been cleaned in finely ground form. The received Product that is a mixture of dicalcium phosphate and monocalcium phosphate represents and is practically not colored, is well suited for animal nutrition, but it has the serious disadvantage that the cost price is too high.

Another method of making defluorinated Calcium phosphates consists in the thermal treatment of a natural phosphate, generally in the presence of additives required to facilitate the defluorination to obtain a product which is assimilable by animals.

The phosphates obtained by this process have for the disadvantage that they are strongly colored.

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For this reason, the manufacturers of animal feed or additives for animal nutrition reject them in favor of phosphates that are produced by wet means.

On the other hand, the thermally defluorinated phosphates currently on the market do not have the total same properties as phosphates produced by wet means.

There is therefore a need for natural defluorinated Calcium phosphate, which is just as suitable for animal nutrition as the calcium phosphate produced by wet means e.

In the course of its investigations into calcium phosphate a quality of a thermally produced calcium phosphate created that is particularly good Animal nutrition requirements are sufficient. This quality of calcium phosphate is characterized by the following properties characterizes:

Total P _{15 to 21 wt} i _ch tsprozent

F.
Approx

^Na 6 to 10

^As = dO ppm

Crystalline phase Na ^ Ca, - (PO,) ^ ^ = 70 "Crystalline apatite phase ^^ 1" Crystalline Ca ₃ (PO ₄ ) ₂ ß-phase <= c5 "Solubility in citric acid:>90"

For the production of these phosphates, the applicant has a demonstration enf-.aktivfsl t, dnr; compared to the known method Λ <: ΐι dopp <: lt cn Vott.oil has that as the starting material

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all currently available natural calcium phosphates can be used, including those with a lower content of Ρ ^ Ο ^, such as the Algerian phosphates with 28.5% P ₉ O ₁ -, and that it leads to an excellent thermal balance that allows consumption heavy fuel oil No. 2 in the order of magnitude of 80 to 100 kg per ton of the defluorinated phosphate obtained, while in the processes known to the applicant usually two to four times as much fuel is consumed.

One of the particular advantages of this process is that phosphates can be used in the same way that are poor or rich in silicate, whereas in the processes proposed so far it has been described as essential that either a crude ore with an SiO ^ content above 2 , 5 percent by weight (GB-PS 9o2 361) or a raw ore with an SiO ₂ content below 2 percent by weight (FR-PS 2 026 878) is used.

The claimed process is a thermal process which in practice can only be carried out continuously and which has the following stages: pre-sealing, conditioning, calcination and quenching.

1. The pre-closing of the mineral is carried out by first adding phosphoric acid and then, after a reaction time of more than 5 minutes, the sodium-containing additive and the recycled fines. These reagents are added in such an amount that the molar ratio of CaO: Na ₂ O: P ₂ ° ₅ in the end product is between 7.6: 1: 2.9 and 3.6: 1: 1.5.

The mineral used should have such a particle size distribution that the phosphoric acid reacts to the mineral

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done quickly enough. In general, one starts from a raw ore with an average particle diameter of 15ο μπι. The attack can be carried out in any suitable mixer, such as in the pans which are customary for the digestion of phosphoric acid, or in the mixers with a horizontal mixing arm. The phosphoric acid is preferably a wet-sourced acid with a content of 22 to 55% ^ ₂ ⁰ S * ^This acid can be used in the cold or at 5o "to 6o C if it was made in a nearby factory, which is a Reduction of the digestion time allowed.

The sodium-containing reagents are added after the phosphoric acid digestion has taken at least 5 minutes, which depends on the mineral used and the equipment. Sodium carbonate or hydroxide are preferred used, but it is also possible to use any other sodium salt, such as the sulfate, nitrate, chloride or phosphate to use. Mixing is continued until the treated mass has been sufficiently homogenized.

The conditioning is carried out at a drying temperature higher than 100 ⁰ C by means of the flue gases of the calcination and resulting in granules of sizes between 0.5 and 5 mm. The conditioning device differs depending on whether a solid sodium-containing reagent, such as sodium carbonate, or a liquid, such as sodium hydroxide solution, is used.

When using a solid sodium-containing reactant, the mixture homogenized according to 1 is placed in a vibrator (Emdfcteur), which is followed by a sieve by the larger particles are separated, which are returned to the feed of the oscillator, while the others be fed to a drying device. All means

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a drying which do not cause destruction of the granules, are useful, in particular, one may use a rotary furnace or a heated with the gases of the calcination tunnel furnace where the temperature of the product is brought to 100 ⁰ C. The dried product is ground in order to separate the fractions below 0.5 mm, which are returned to the supply of the sodium-containing compound in the pre-digestion of the mineral, while the particles above 5 mm are returned to the vibratory crusher, while the products between 0.5 and 5 mm are fed to the calcination preheater.

When a liquid, sodium-containing reagent is supplied, the pulp leaving the pre-digestion is fed directly to a granulation dryer. The granules formed and brought to a temperature of at least 100 ^° C. are sieved. The fine fractions are added again at the entrance of the granulating device and the coarse fractions are fed back into the pre-digestion, while the particles between 0.5 and 5 mm are fed directly into the preheater of the calcination.

3. The calcination is preferably carried out from 1100 to 1300 ⁰ C, 1180-1250 ⁰ C, a preheating ^ upstream of the introduced particles are pre-heated with the exhaust gases of the calciner to approximately 700 ⁰ C. The calcination can take place in a fluidized bed or in a rotary kiln.

When using a fluidized bed, the preheating and calcination at 1150 to 1250 ⁰ C in two different apparatuses are performed, while when using a rotary kiln only one apparatus is needed and carried out the preheating in the coldest part of the rotary kiln. The gases leaving the preheating are used for the conditioning of the second phase and the combustion air is used during the subsequent quenching by cooling the

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calcined product preheated.

It is generally preferable to carry out the calcination in the presence of steam as is known. if the calcination is done using an oil burner, then 10 to 10 are added to the gas mixture obtained 20 percent by volume of water vapor. If the calcination is carried out with a gas burner, the one by the Using the gas obtained water vapor sufficient.

4. The quenching must enable the calcined product to cool as quickly as possible, but in any case in less than 2 minutes. Preferably, the quenching with cold air is vorzugenommen under conditions such that the temperature of the calciner abandoned product is cooled in less than 2 minutes from 1150 to 1250 ⁰ C to at least 800 ⁰ C. Fluidized bed techniques are particularly suitable for performing such a quench. A belt cooler for cold air, for example, or a fluidized bed brings the defluorinated phosphate obtained to ambient temperature and the heat gained in this stage can be used to operate a heater or for drying in the second stage.

The defluorinated phosphates obtained by the process with the properties given above meet the various requirements of consumers. The respective Contents of the various crystalline phases are particularly important for the products for animal nutrition fully satisfy.

The production of the defluorinated phosphate according to the claimed process is possible with numerous apparatuses. The attached figure illustrates an embodiment, which is practiced with success by the applicant.

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The mineral and phosphoric acid are fed through lines 1 and 2, respectively, into the first part I of a horizontal mixer introduced with twin screw I-II. In the second part II of this mixer, the is supplied at 3 necessary sodium-containing reagent and at 4 the fines of sieves VI or XIII are returned. When using a solid sodium-containing reagent, the mixture obtained is the grinder III and then the Sieve IV via lines 5 and 6 and then fed to dryer V and sieve VI via 8 and 9. The fines from VI over 4 to II and the coarse parts over

22 and 7 returned to III. When using a liquid sodium-containing reagent, the resulting mixture is over

23 of the granulating and drying device XII then passed through the sieve XIII, its coarse and fine fractions via 26 and 4 can be returned to II.

The preheating of the calcination via 10 and 25 is charged with the granules obtained in VI or XIII. The calcining device VIII connects to the preheater VII, the 11 with hot air and 13 with it Fuel and optionally via 14 is fed with steam. The calcined product passes through 11 in the quenching device IX, where it is cooled with cold air supplied at 15. Then it comes over 16 in the cooler X, which is operated with air that is supplied cold at and exits at 27. The obtained defluorinated Phosphate is obtained cold at 17.

In order to improve the recovery of the heat, the air leaving the preheater at 19 is e.g. Dryer V supplied as shown (or the granulating dryer XII). The cooled flue gases are fed through 20 of a cleaning wash XI and then discharged through 21 into the atmosphere.

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The following examples describe in a non-limiting manner what is claimed by the applicant defluorinated calcium phosphate and the process described above, which is shown schematically in the drawing is.

example 1

The mixer 1 is charged per hour at 1 with 100 parts by weight of a phosphate from Togo with a mean diameter of 150 μm and a content of 36.5 % ^ o ^ S ', 4.15 % F and 51% CaO 52 parts of H ₃ PO ₄ per hour with a P ₃ O ₅ gel of 35% are added and then 25 parts of sodium carbonate per hour are added over 3 per hour. dried in V at 120 ^° C. and sieved again at VI in order to remove the fine and coarse fractions that have formed during drying. The granules obtained are preheated and then calcined for 2 hours in the rotary kiln VII-VIII, the temperature being increases from 120 ⁰ C to 124O ⁰ C. the flue gases exit at 55O ⁰ C. the exiting product is quenched in a fluidized bed IX to 600 ⁰ C, and then cooled at X to room temperature, taking into account the as indicated recirculated quantities are obtained hourly. 127 parts of an en fluorinated phosphate with the following characteristics:

Total P 18.45%

F. 0.02%

Approx. 29.5%

Na 7.8%

As 8 ppm

crystalline phase Na Ca ₆ (PO ₄ ) ₅ 95% crystalline apatite phase not detectable crystalline B-Ca ₃ (PO ₄ J ₃ - phase "" citric acid solubility 96%

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Example 2

The mixer 1 is charged with 100 parts of the same phosphate from Togo as in Example 1, 45.5 parts of H ₃ PO ₄ with 35% P ₂ O ₅ and 20 parts of Na ₃ CO ₃ . The treatment is carried out as in Example 1 and 122 parts of a defluorinated phosphate are obtained, which is suitable for animal nutrition and has the following characteristics:

Total P 18.0% F. 0.18% Approx 29.8% N / A 6.2% As 8 ppm

crystalline Na ₃ Ca ₆ (PO ₄ J ₅ phase 90%

crystalline apatite phase not detectable crystalline G-Ca ₃ (PO ₄ ) ₂ ~ phase 2%

Citric acid solubility 92%

Example 3

This example is carried out with the same togo phosphate under the same conditions as in example 1 with the exception of the preheating of the calcination. This preheating of 120 was carried out at 700 ⁰ C in a cyclone, directly joined to the calcination in the fluidized bed at 122o C ^0. The defluorinated phosphate obtained has the same properties as the product prepared according to Example 1.

Example 4

Under the conditions of Example 1, 100 parts per hour of a Moroccan phosphate mineral with 32.3% P ₂ ° 5 ' ^{4% F and 51} ' ^{9% Ca0 rait 63} ' ⁵ parts by weight H ₃ PO ₄ ( ^p 2 ° 5 = 35% ) and 25 parts of Na ₃ CO ₃ . 129 parts by weight of a phosphate with the following properties are obtained per hour:

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30Q09S

Total P 18.3 % F. 0.06 % Approx 29.5% N / A 6.9% Ace " 6 ppm

crystalline Na ₀ Ca ,. (PO-) _c - phase 94%

crystalline apatite phase not detectable crystalline B-Ca ₃ (PO ₄ ) ₂ phase 3%

Citric Acid Soluble 94%

Example 5

This example is carried out with the same Moroccan phosphate under the same conditions as Example 4, with the exception of preheating and calcination, in which, instead of a rotary kiln, preheating from 120 to 700 ^° C. in a cyclone followed immediately by calcination at 12 20 ^° C is made. The defluorinated phosphate obtained has the following properties:

Total P 18.5% F. 0.12% Approx 29.5% N / A 6.9% As 6 ppm

crystalline Na ₃ Ca ₆ (PO ₄ ) ₅ ~ phase 90%

crystalline apatite phase not detectable crystalline B-Ca ₃ (PO ₄ ) - - phase 4%

Citric Acid Soluble 90%

Example 6

This example is carried out with the same Moroccan phosphate under the same conditions as Example 4, _{except that 82.3 parts of H 3} PO ₄ with a P ₃ O ₅ content of 27% and 38 parts of a 50% 9gen aqueous sodium hydroxide solution are used per hour will.

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129 parts of a defluorinated phosphate with the same properties as in the example are obtained

Example 7

This example is carried out with the same Moroccan phosphates under the same conditions as Example 4 but using 57 parts of H ₃ PO ₄ with a ^P 2 ° 5 ^{content of 35% and 22 parts of} NaCl. _R is obtained 123 parts of a defluorinated phosphate with the following characteristics:

Total P 18.3% F. 0.08% Approx 29.5% N / A 6.4% As 6 ppm

crystalline Na, Ca _c (PO.) _c phase 91%

JO 4 D

crystalline apatite phase not detectable

crystalline tricalcium phosphate phase 3% citric acid solubility 92 %

Example 8

This example is carried out with the same Moroccan phosphate under the same conditions as in Example 7 but using 25 parts of anhydrous Na ^ SO ₄ instead of NaCl. 123 parts of a defluorinated phosphate are obtained with the following characteristics:

Total P 18.3% F. 0.09% Approx 29.5% N / A 6.4% As 6 ppm

crystalline Na ₃ Ca ₅ (PO ₄ ) ₅ - phase 90%

crystalline apatite phase not detectable

crystalline tricalcium phosphate phase 4%

Citonic acid solubility 91.6%

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Claims (11)

PATENT ADVERTISER DR.HANS-GUNTHER EGGERT1 DIPLOMCHEMIKER 5 KÖLN Sl, OBERLÄNDER UFER 90 Cologne, January 11, 1980 No. 108 PCUK Produits Chimiques Ugine Kuhlmann, TOUR MANHATTAN - LA DEFENSE 2, 5 & 6, Place de l'Iris, 92400 COURBEVOIE, France Natural defluorinated calcium phosphate for animal nutrition. Patent claims 1. Calcium phosphate characterized by the following Characteristics: Total P _{15 to 21 weight} percent i _CHTS , 2 ^Na 6 to 10 ^As - <d0 ppm Crystalline phase Na ₃ Ca ₆ (PO ₄ ) ₅ - = - 70 Crystalline apatite phase ^ 1 Crystalline Ca ₃ (PO ₄ ) ₂ ß phase <= c5 Solubility in citric acid 2. Phosphate according to claim 1, characterized by a phosphorus content of 18 to 19 percent by weight. 3. Phosphate according to one of claims 1 and 2, characterized by a citric acid solubility of more than %. Ö30030 / 0773 BATH ORIGINAL 4. Process for the production of calcium phosphate according to one of claims 1 to 3 from natural phosphates by thermal treatment, in which one first on the raw ore allows phosphoric acid and a sodium derivative to act, the product thus obtained under recycling the dust particles granulate, defluorination by calcination with the addition of steam carries out and deterring, characterized in that: 1. The first treatment is carried out by first adding phosphoric acid to the crude ore and then, after a reaction time of more than 5 minutes, adding the sodium-containing additive and the recycled dust particles, the reagents being added in an amount that the molar ratio of CaO in the end product / Na ₂ O / P ₂ O _{5 is} from 7.6 / 1 / 2.9 to 3.6 / 1 / 1.5. 2. The granulation is carried out at a drying ^{temperature above 100 0} C with the calcination gases, with the formation of granules with dimensions of 0.5 to 5 mm, 3. defluorination wherein the pre-heated during the quenching air is used as oxygen carrier is performed by calcining at a temperature of 1100 ⁰ C to 1300 ⁰ C, 4. the quenching of the calcined product with air at a temperature below 800 ^° C. is carried out in less than 2 minutes. 5. The method according to claim 4, characterized in that for the first treatment as sodium-containing Sodium carbonate reagent used. 030030/0773 6. The method according to claim 4, characterized in that for the first treatment as sodium-containing Sodium hydroxide reagent used. 7. The method according to claim 4, characterized in that the calcination is carried out in a fluidized bed at a temperature of 1150 to 1250 ⁰ C and the preheating to 700 to 800 ⁰ C by the gases emerging from the calcining furnace. 8. The method according to claim 7, characterized in that the preheating by direct heat exchange between the gases exiting the calciner and the feed product. 9. The method according to claim 4, characterized in that the calcination is carried out in a rotary kiln at a maximum temperature of 1150 ⁰ C to 1250 ⁰ C. 10. Use of the phosphate according to one of claims 1 to 3 to supplement animal nutrition or as Component of additives for animal nutrition. 030030/0773