DE1592512B2 - PROCESS FOR THE MANUFACTURE OF GRANULATED FERRICHLORIDE HEXAHYDRATE - Google Patents

Description

Instead of a horizontal rotating drum, other granulating devices, in particular an inclined rotating plate, can be used. ■■

Another way of doing this is to let droplets of a solution of ferric chloride at 60%, inoculated with particles of FeCl ₃ .6H ₂ O, fall into an organic solvent.

The following examples serve to illustrate and provide ways of carrying out the invention Method again and reveal the advantages that result from the invention.

example 1

_{700 g of FeCl 3} .6H ₂ O, comminuted to about 2 mm, are introduced into a glass cylinder 100 mm in diameter and 300 mm in length. The cylinder is closed at its ends and placed on drive rollers which rotate it at a speed of 54 revolutions / minute.

^{1 m 3} / hour of air at normal pressure and temperature of 21 ° C and 11% relative humidity is introduced through an axial opening and the entire surface of the layer is sprayed with liquid ferric chloride at 60% and 37 ° C in an amount of 500 g / hour.

The temperature of the layer adjusts to 31 ° C and one gains continuously through exit over an overflow completely dry granules with a smooth surface, the diameter of which is approximately Is 2 mm.

Example 2

_{300 kg granules of FeCl 3} .6H ₂ O are fed into a horizontal drum with a diameter of 0.8 mm and a length of 3 m with a metal jacket, which is coated on the outside and inside with a protective layer of epoxy resin, at a speed of 9 revolutions of the drum / Minute one.

The entire surface of the layer is poured over an inclined slide with adjustment options with liquid ferric chloride at 60% and 28 ° C at a rate of 100 kg / hour. The HCl content of the ferric chloride is 0 to 0.4%. An approximate amount of 5 m ³ / hour of dry air at normal pressure and temperature is introduced through an axial opening in order to remove the HCl and to prevent any re-entry of moisture into the apparatus. The temperature of the bed settles at 30 ° C and one continuously collects completely dry granules with a rough surface, the diameter of which is approximately 8 mm, through an overflow at one end. The granules are free from HCl and have advantageous properties in terms of the absence of fines, mobility and the rate of dissolution in water. They are particularly suitable for modern methods of handling and use, for example for feeding a solution tank with a constant amount. The speed at which the granules dissolve in water is significantly better than that of cast ferric chloride which has been comminuted to the same size.

Example 3

A solution of ferric chloride of 60% is cooled to 10 to 15 ° C and inoculated by adding about 0.5 g of powdered FeCl ₃ .6H ₂ O per kg. The inoculated solution is treated in a vibrating mixer for 5 to 10 minutes, then it is introduced dropwise with vigorous stirring into a column 180 cm high and 5 cm in diameter, which contains trichlorethylene and is cooled externally in such a way that the temperature it is -16 ° C at the top of the column and about -5 ° C at the bottom of the column. During the free fall of the drops of the inoculated solution through the solvent (approximately 15 seconds), crystallization occurs in spheres approximately 4 mm in diameter. When they arrive at the base of the column, the spheres are not completely crystallized, but contain a liquid core which solidifies after about 5 minutes. It is advisable to avoid prolonged contact of the spheres with the cold solvent in order to prevent them from disintegrating into powder.
If the operation is carried out batchwise, the granules should be separated from the trichlorethylene immediately after the completion of the crystallization, it being possible, of course, to recycle the recovered solvent. The traces of solvent remaining on the granules can be driven off in vacuo. The trichlorethylene can be replaced by another organic liquid which remains inert under the working conditions.

In addition to the prior art, the following is also noted.

According to Gmelin, Handbook of Inorganic. Chemie 59, Eisen Teil B (1932), eighth edition, FeCl ₃ .6H ₂ O is obtained as crystalline aggregates in kidney form by slowly evaporating an aqueous concentrated solution of the product at room temperature. This is obviously a laboratory test and not a technically feasible extraction process. There is no mention of granules or a granulation process.

It is not disputed that granulation processes are known, e.g. B. from the Australian patent 210115 and French patent specification 1179 177.

French patent specification 1179 177 describes such a method for making pearls from chemical substances, such as B. sucrose or urea, being a concentrated solution or melt passes in the form of drops through a suitable liquid or gaseous cooling medium.

Australian patent 210115 relates to a Granulation process of aluminum sulphate by injecting the liquid sulphate in a finely divided state over a mass of solid sulphate globules that are constantly in motion in a rotating drum is held.

In contrast, the invention does not relate to a general granulation process, but rather to extraction of a particular product in granular form, creating an undeniable asset the technology was created. If this extraction had been as close as it was afterwards may appear, it is incomprehensible why it has not yet been carried out.

In addition, the above publications make no mention of the presence of crystallization nuclei which consist of solid particles of the material to be treated Product. The Australian patent describes an analogous procedure,

5 6

but refers to aluminum sulphate and not to be applied, but received a new product Ferric chloride, and it was by no means certain whether it will. The technical advance achieved with the invention this method would work with ferric chloride. step should be repeated again: no fine, Basically, it should be emphasized again that the flowability of the product and its manufacture according to the invention known method 5 shortening the recovery time.

Claims (4)

1 2 Pockets, which one of FeCl ₃ and HCl Claims: Containing saturated solution. The invention seeks to avoid the disadvantages mentioned by creating a granular process for the industry for the production of ferric chloride-5 lated, fines-free product, which hexahydrate in the form of solid corpuscles, is mobile and has improved uses, characterized by the fact that possesses an aqueous shaft. The invention enables an equal-60 percent by weight solution of ferric chloride, if the necessary time for the production of the product below 37 ° C in the presence of crystalline product to be markedly shortened,
The process according to the invention for the production of chloride hexahydrate of granulation with the formation of ferric chloride hexahydrate in the form of solid bodies of granules with a diameter between surfaces is characterized in that an aqueous 1 and 10 mm is subjected. ÖO weight percent solution of ferric chloride with 2. The method according to claim 1, characterized by about 37 ° C in the presence of crystallization, that the granulation by germination from solid particles of ferric chloride hexaspray of 100 percent by weight ferric chloride hydrate of the granulation with the formation of granule solution over a layer on ferric chloride hexalene with a diameter between 1 and 10 mm hydrate grains is effected, whereby this layer is subjected. In a horizontal rotating drum with a granulation is preferably carried out Temperature below 37 ° C kept in motion 20 spraying of oO weight percent ferric chloride will. solution over a layer of ferric chloride hexa- 3. The method according to claim 1, characterized by hydrate grains, this layer indicating that the granulation is kept in motion by drop-horizontal rotating drum at a temperature wise reading of a 60 percent by weight below 37 ° C.
Ferric chloride solution, inoculated with germs from 25 The granulation can also be carried out by dropwise ferric chloride hexahydrate, by an organic passage of an oO weight percent ferric chloride mixture with water immiscible solution, inoculated with germs containing ferric chloride hexahydrate and kept at below 37 ° C hydrate, is effected by a, an organic with water not column. Miscible solvent containing and on under 4. The method according to claim 1 and 3, thereby causing a column maintained at 3 ° 37 ° C,
characterized in that the organic solvent used is preferably used as the organic solvent - The solvent is trichlorethylene. ■ trichlorethylene. The granules of ferric chloride hexahydrate can in particular by dispersion of an aqueous 35 solution of ferric chloride with 60% over one layer obtained from granules, which layer is in motion in a horizontal, rotating Drum located, being the temperature of the layer is below 37 ° C. The heat of solidification, which 40 44 kcal / kg FeCl ₃ .6H ₂ O can be obtained by spraying The invention relates to a method for producing the outer drum wall by means of cold water treatment of ferric chloride hexahydrate with improved or with a cooling brine and / or by rinsing Usage properties. removed from the drum by means of a stream of cold air It is well known that ferric chloride hexahydrate will be used in. The latter cooling method is particularly suitable different branches of industry, especially for the 45 more in the case of the solution of ferric chloride Purification of water by flocculation and for hydrochloric acid, for example when the liquid used rotary engraving. It is used in all pickling residues. The air purge common by pouring and cooling the liquid evaporates the HCl and water, causing cooling 60% ferric chloride either in cast form or also contributes. received immediately in cardboard container. If one has 50 To dissipate the amount of heat to be removed Working in this way, to show up very significant rinngern it is beneficial to keep the drum up Hypothermia, and the natural solidification to feed 28 ° C supercooled ferric chloride, may take several weeks, although the crystal can be granules of different shapes obtained the ionization temperature of the ferric chloride hexahydrate and the apparent specific gravity, 37 ° C. On the other hand, the solidified 55 which one has somewhat of the operating conditions of the drum Product varies in the shape of large blocks, for example from mel. When the temperature of the solution is from 25 kg weight, which generally grinds ferric chloride lower than the temperature of the layer If the demands have to be responded to, the solution is instantly solidified on the enough for consumers. This crushing creates a granule, which then has a very rough surface arduous work, because the ferric chloride hexa-60 and a lower apparent specific hydrate is extremely corrosive and hygro- weight, for example 0.7 kg / dm ³ . Surrounding scopic. The crushing causes formation of dust to reverse when the temperature of the solution is higher out what attracts moisture and from this as the temperature of the layer that impregnates Reason is difficult to recover. If the solution completely clears the granules before they solidify, Aqueous solution with 60% ferric chloride used 65 The granules are then completely smooth and have a is obtained from liquid pickling residues, the apparent specific weight of 0.9 kg / dm ³ they contain a certain proportion of hydrochloric acid, analogous to that of the cast and ground which is in the solidified ferric chloride in product.