BE372524A

BE372524A -

Info

Publication number: BE372524A
Authority: BE

Description

       

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  Engrais à base de nitrate   ammonique   et son procédé de fabrication., 
De multiples produits , tels que le gypse , les phosphorites , le calcaire ou telsque dessels donnant par la suite lieu à des réactions   chimiques ,   ont été proposés pour être mélangés au nitrate ammonique et rendre l'emploi agricole de ce dernier aussi pratique que celui des engrais 
 EMI1.1 
 facilement emmagasina,bles et épendables 
L'emploi de corps inertes a cependant pour inconvénient de ne permettre qu'un certain taux d'azote , maximum (au plus 20%), sous peine de voir la mélange montrer una   hygroscopicité   très nuisible pour son   emploi .   



   La présente invention permet de réaliser avec du nitrate ammonique et un produit inerte , un mélange dans lequel la teneur en azote peut être très élevée et aller jusqu'à   32% .   



   Ce produit inerte est obtenu à partir des silicates simples ou complexes   que   l'on obtient comme sous-produit dans l'industrie métallurgique ou dans la fabrication du phosphore 
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 au four ordinaire ou au four blectrique . 



   Ces sous-produits na sont pas utilisables tels quels car ils renferment des corps , comme la chaux libre , le 

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 sulfure de calcium ou autres , qui réagissant avec le nitrate ammonique causent des pertes d'azote par   volati-   lisation de l'ammoniaque . 



   Il est donc indispensable d'empêcher cette action nuisible de ces divers composés 
On a déjà. dans ce but proposé de traiter les scories Thomas par l'acide nitrique puis par du KCl , soit par du sulfate d'ammoniaque et des écumes de défécation de sucre- rie , soit encore par du sulfate ammonique seul , l'ammo- niaque dégagé étant récupéré . 



   Dans la présente invention , la chaux , le sulfure de calcium , et les autres composés qui   libèrent   niaque sont transformés par traitement à l'aide d'acide sulfurique   60 Bé ,   additionné éventuellement de la quantité d'eau nécessaire pour réaliser de bonnes conditions   d'attaque .    



   La quantité d'acide sulfurique à employer est calculée par la détermination de la quantité d'ammoniaque libérée par traitement du produit envisagé à l'aide d'une solution de nitrate   ammonique .   Il est évidemment possible d'envi- sager une quantité nettement supérieure , pouvant aller jusqu'à celle nécessaire pour transformer tous les sili- cates en silice libre et en sulfate   correspondant .   



   L'acide   suif hydrique   dégagé peut être récupéré par les moyens connus . En travaillant de cette fagon , on      obtient un produit très facilement   broyable ,     devenant   d'une finesse remarquable , se mélangeant aisément au nitrate ammonique et empêchant la déliquescence de celui- ci même aux faibles doses de l'ordre de 10% . Le mélange peut se faire soit avec du nitrate ammonique sec , soit 

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 de Préférence dans les cuves de cristallisation ,dans les- quelles le nitrate ammonique est encore liquide   à   une richesse de 96% de pureté environ ,ou à l'état d'une solution concentrée et chaude   EXEMPLE   I . 



   100 kg de laitier de haut fourneau , renfermant notamment 1,5% de soufre sous forme de   CaS  sont attaqués par 29 kg d'acide sulfurique 60 Bé , dilués par 15 kg d'eau o 
On récupère l'H2S dégagé 
Le produit refroidi est broyé , une finesse correspon- dant au tamis 100 est suffisante puis mélangé à des quantités de nitrate ammonique à l'état fondu , vers 125  pouvant aller jusqu'à 1300 kg de nitrate ammonique ,ce qui , dans ce cas , donne un engrais à 32% d'azote , se conservant encore suffisamment bien et pouvant être épandu sans difficultés . 



    EXEMPLE II .   

**ATTENTION** fin du champ DESC peut contenir debut de CLMS **.



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  Fertilizers based on ammonium nitrate and its manufacturing process.,
Many products, such as gypsum, phosphorites, limestone or such as salts which subsequently give rise to chemical reactions, have been proposed to be mixed with ammonium nitrate and to make the latter's agricultural use as practical as that of fertilizer
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 easily stored, damaged and releasable
The use of inert bodies, however, has the drawback of allowing only a certain maximum nitrogen content (at most 20%), under penalty of seeing the mixture show a hygroscopicity which is very harmful for its use.



   The present invention makes it possible to produce, with ammonium nitrate and an inert product, a mixture in which the nitrogen content can be very high and range up to 32%.



   This inert product is obtained from simple or complex silicates which are obtained as a by-product in the metallurgical industry or in the manufacture of phosphorus
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 in the ordinary oven or in the electric oven.



   These by-products cannot be used as they are because they contain substances, such as free lime,

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 calcium sulphide or others, which reacts with ammonium nitrate causing nitrogen losses by volatilization of ammonia.



   It is therefore essential to prevent this harmful action of these various compounds
We already have. with this proposed aim to treat Thomas slag with nitric acid then with KCl, either with ammonia sulphate and sugar factory defecation scum, or again with ammonium sulphate alone, the ammonia given off being recovered.



   In the present invention, lime, calcium sulphide, and the other compounds which release niac are transformed by treatment with sulfuric acid 60 Bé, optionally added with the quantity of water necessary to achieve good conditions of d. 'attack.



   The quantity of sulfuric acid to be employed is calculated by determining the quantity of ammonia liberated by treatment of the product envisaged with the aid of an ammonium nitrate solution. It is obviously possible to envisage a much greater quantity, which may go as far as that necessary to transform all the silicates into free silica and into the corresponding sulphate.



   The hydrous tallow acid released can be recovered by known means. By working in this way, a product is obtained which is very easily crushable, becoming remarkably fine, easily mixing with ammonium nitrate and preventing the latter from deliquescence even at low doses of the order of 10%. Mixing can be done either with dry ammonium nitrate or

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 Preferably in crystallization tanks, in which the ammonium nitrate is still liquid at a richness of about 96% purity, or in the form of a concentrated and hot solution. EXAMPLE I.



   100 kg of blast furnace slag, containing in particular 1.5% sulfur in the form of CaS, are attacked by 29 kg of sulfuric acid 60 Bé, diluted with 15 kg of water o
We recover the released H2S
The cooled product is ground, a fineness corresponding to the 100 sieve is sufficient then mixed with quantities of ammonium nitrate in the molten state, around 125 which can range up to 1300 kg of ammonium nitrate, which, in this case, produces a 32% nitrogen fertilizer, which still keeps well enough and can be applied without difficulty.



    EXAMPLE II.

** ATTENTION ** end of DESC field can contain start of CLMS **.

Claims

100 kg of Thomas slag are treated with 34 kg of sulfuric acid 60 Bé, diluted with 18 kg of water and the product obtained, after grinding is mixed with dry ammonium nitrate o By using for example 354 kg of ammonium nitrate, one obtains a very easily spreadable fertilizer, easy to conserve,

dosing 25% nitrogen and 3% phosphoric acid completely soluble in the reagent of Wagner CLAIMS. lo Simple or compound fertilizer based on ammonium nitrate, characterized in that it consists of a mixture of ammonium nitrate and by-products of the metallurgical or chemical industry such as slag from an ordinary or high furnace Thomas or Martin phosphorus or dephosphoric slag furnace <Desc / Clms Page number 4> 2.

Process for the manufacture of a simple or compound fertilizer based on ammonium nitrate as specified in claim 1, characterized in that the by-products are, prior to their mixing, transformed by treatment with the aid of an acid in order to eliminate the bodies which would cause a loss of nitrogen by volatilization of ammonia.

3. Method according to claim 1 c a r a c t erized in that the acid used is sulfuric acid at 60 Bé optionally diluted, 4. Process according to claims 2 and 3, charac- terized in that the sulfuric acid employed contains only the quantity of water necessary to provide the bodies formed with the necessary molecules of water of crystallization, for example for forming CaS04. 2H2O, hydrogen sulphide formed by the action of sulfuric acid on the sulphides of the by-products which can be recovered.

5. Method according to claims 2 to 4 c a - r a c t é r i s é in that the products obtained by treatment with sulfuric acid is mixed with dry ammonium nitrate.

6. Process according to claims 2 to 4, in that the product obtained by treatment at 1; Sulfuric acid is mixed with molten ammonium nitrate or a hot concentrated ammonium nitrate solution.

7. Simple or compound fertilizer based on ammonium nitrate characterized in that it is constituted by a mixture of ammonium nitrate and silicates <Desc / Clms Page number 5> from the metallurgical or chemical industry, such as slag from an ordinary blast furnace or from a phosphorus blast furnace, the impurities of the by-product proving to produce nitrogen losses by evolution of ammonia being transformed into inert bodies by the addition of 'sulfuric acid 8. A method of determining the impurities of the silicates which can give rise to nitrogen gates according to claims 2 and 7, characterized in that the quantity of sulfuric acid to be employed is calculated by determining the quantity by means of an ammonium nitrate solution. ammonia released by treatment of silicate 9.

Simple or compound fertilizer based on ammonium nitrate, process for the manufacture of this fertilizer and process for determining the impurities of the silicates which may give rise to losses of nitrogen, produced and implemented in substance as described