US1701286A - Briquetted charge and process for producing phosphorus and potash therefrom - Google Patents

Description

Patented Feb. 5, 1929.

} UNITED STATES WILLIAM H. WAGGAMAN AND HENRY W. EASTERWOOD, OI CHICAGO HEIWTS, ILLI- PATENT OFFICE.

N 018, ASSIGNOBS TO VICTOR CHEMICAL WORKS, OF OHIGAGO,,ILLINOIS, A CORPORA- TION or rumors.

BRIQUETTED CHARGE AND PROCESS FOR PRODUCING PHOSPHORUS POTASH THEREFROM.

'No Drawing.

This invention relates to a new and improved type of briquetted charge and to processes of usin said charge for the production of phos ioric acid and potash in 5 various types of electric and fuel fired furnaces. It relates particularly to the use of briquetted mixtures of natural phosphates; potash bearing silicates with or without additions of free silica, and a solid reducing agent such as coal, coke, charcoal or the like, in the roduction of phosphoric acid and potash by the volatilization or pyrolytic process. It has for its object the accomplishment of this purpose more expeditiously -and economically than has heretofore been possible.

This naces o the electrlc are or resistance type or fuel fired furnaces, of the blast furnace open hearth or reverberatory type, or in kilns of the shaft or rotary type ordinarily employed in the production of lime and cement.

In order that the invention may be clearly understood and distinguished from the prior art, it may be said that it is a well known fact that phosphoric acid and potash can both be volatilized as a whole or in part from properly proportioned intimate mixtures of natural phosphates, a potash bearing silicate, and a SOI'IdHfGdHCiIIg agent such as coal. or'coke, by heating said, mixtures to temperatures ranging from 1200 to 1600 degrees C. The phosphoric acid and potash '35 thus volatilized can be subsequently recovered either by absorption in water, "in a solution of phosphoric acid, or by means of the Cottrell electrical precipitator, in a manner well known in the art.

The reactions which take place under these conditions may be represented by the following equations:

It has not yet been proposed however, to employ the mixtures above described in briquetted form. Neither has it been suggested" process may be carried out in furheating source we have found that the inpresent in amounts more nearly equal to Application filed January 18, 1924. Serial No. 687,124.

'to employ mixtures of natural phosphates,

potash silicate, and. coke or other solid reducing agents in types of furnaces other than the electric arc furnace. We have found that the use of a charge containing the above mentioned ingredients finely ground, thoroughly mixed, and moulded or pressed into briquettes, with or without the addition of a binding material, has distinct advantages over' the use of a loose incoherent charge of the same or similar composition.

These advantages are: first, the Very close contact which can thus be obtained between the various ingredients in the charge, which permits of a more prompt and rapid reac tion; and second, the ease with which reducing conditions may be maintained where the carbonaceous material is within the body of the briquette and thus protected from external oxidizing influences.

It is now generall agreed that ,in order to bring about comp etc or nearly complete elimination of phosphoric acid from mixtures of natural hosphate, silica and carbonaceous materials, reducing conditions must be maintained throughout the operation. In furnaces where fuel is used as a corporation of coal, coke or other carbonaceous material in the body of the briquette is the most efiicient and economical method of maintaining said reducing conditions.

We do not'wish to confine our process, 55 however, to the use of a briquetted charge of anyone definite composition, but we propose to so vary the proportions of the several'ingredients that we can obtain any ratio of acid to basic constituents, which may best be adapted to the process andto the type of furnace in which the heating of the charge is conducted. As an example, if we wish to obtain a fluid slag which can be readily tapped from furnaces of the electric arc and blast furnace types, we so proportion the quantities of natural phosphate and potash silicate that the lime, silicaand alumina are those in ordinary blast furnace It is recognized that the raw materials which we propose to use in the briquetted charge contain various impurities such as compounds of iron, manganese, magnesium,

titanium, sodium, etc., such impurities do not, however, affect our briquetted charge or our method of using such charge.

We claim:

1. The process for the production of phosphoric acid and potash by the volatilization or pyrolytic method, consisting in heating in a chamber to a smelting temperature of from 1200 degrees to 1600 degrees C., an intimate briquetted mixture of a finely ground natural phosphate, a potash bearing silicate and a carbonaceous material until substantially all of the potash, phosphorus and phosphoric acid are driven off, and collecting these volatile products.

2. The process for the production of phosphoric acid and potash by the volatilization or pyrolytic method, consisting in heating in a chamber to a smelting temperature of from 1400 degrees to 1600 degrees 0., an intimate briquetted mixture of a finely ground natural phosphate, a potash bearing silicate, free silica, a carbonaceous material and a binder until substantially all of the potash, phosphorus and phosphoric acid are driven 0E, and collecting these volatile products.

3. The process for the production of phosphoric acid and potash by the volatilization or pyrolytic method, consisting in heating in a vertical shaft furnace of the blast furnace type to a smelting temperature of from 1400 degrees to 1600 degrees C. an intimate briquetted mixture of a finely ground natural phosphate, a potash bearing silicate, and carbonaceous material until substantially all of the phosphoric acid, phosphorus and potash are driven off, and'collecting these volatile products.

4. The process for the production of phosphoric acid and potash by the volatilization or pyrolytic method, consisting in heating in a vertical shaft furnace of the blast furnace type to a smelting temperature of from 1400 degrees to 1600 degrees C. an intimate briquetted mixture of a finely ground natural phosphate, a potash bearing silicate, free silica, carbonaceous material and a binder, until substantially all of the phosphoric acid, phosphorus and potash are driven ofi' and collecting these volatile products.

Signed at Chicago Heights, Cook 00., Ill.,

this 15th day of January, 1924.

WILLIAM H. WAGGAMAN. HENRY W.,EAS1ERWOOD.