US1814215A - Grinding graphite - Google Patents

Description

v v Patented July 14, 1931 UNITED STATES PATENT orrlcn G-EORG' HANEK OP, F HANOVER, GERMANY GRINDING onarnrrn Ho Drawing. Application filed Harch'fl, 1928, Serial No.266,444, and in Germany Harold, 1925.

This'invention refers broadly to a method of grinding graphite, and in particular the purer grades thereof to a flour-like condition and to thereby obtain a purer and more I voluminous and more finely disintegrated owder than generally obtainable heretofore.

it has been ascertained by tests made with difierent grades of commercial graphites that the poorer grades are almost as a rule more 19 finely ground than the superior grades ofshould be understood that only such kinds of material are suitable for the purpose, as will admit of being removed'after the fine grinding, and of these water-soluble salts have been found to be very suitable. Thus or-.

dinary salt or rock-salt have produced very satisfactory results. In case it should be desired to also remove substances from the graphite which are only soluble in acids; salt solutions and the like, such substances may also be added which are not entirely soluble in water, but only in acids, such as low grade potash salts, residues from-the extraction of potash and soda-salts and the like. The grinding up of the graphite with the salts may be efi'ected in the dry condition, as well as in the presence of a small amount of water. It should however be noted that only so much 4 water may be added, as will still leave large quantities of the salts undissolved. After the desired degree of fineness has been obtained, the salts are removed by water or by the addition of acids and lixiviation.

By treating according. to this method for instance the species of graphites known in the trade by the name of powder-graphite, it has been found that, when treated accord ing to this method, a considerably finer dis- .5 tribution of the particles of graphite may still be obtained. 'The graphite thus pro- 'duced has been found to be particularly By the grinding up with salts'the graphites become considerably more voluminous, so that larger quantities of pyrolusite or. of particles of artificial pyrolusite than heretofore may be enveloped by such treated graphites, as compared with graphites of less fine subdivisio It should be understood that the scope of the invention is not restricted to the specific details herein recited, but modifications are possible without deviating from the spirit of the invention as defined in the appended claims, and that the highly disintegrated graphite which is the product. of this invention is applicable to all the various uses in the arts to which graphite is usually applied.

I claim v 1. The process of highly disintegrating graphite, which comprises grinding up and treating graphite with salts possessing substantially the physical and chemical properties'of rock-salts.

2. The process of highly disintegrating graphite, which comprises intimately grinding graphite with mineral salts possessing substantially the physical and chemical character of ordinary salt and of rock-salt.

3. The process of disintegrating graphite,

which consists in intimately grinding graphite with mineral salts of the physical and chemical character of ordinary salt and of rock-salt andin the presence of an insulticiency of solvent, and then removing said salt by treatment with a solvent.

4. The process of disintegrating graphite, which consists in grinding graphite and intimately treating it with ordinary neutral salt and thoroughly agitating it therewith,

and after a sufficient degree of fineness has been obtained, dissolving the salt and removing it from the graphite.

5. The process of highly disintegrating graphite, which comprises most intimately grinding the graphite with sand-like fragments of mineral salts of the class of ordinary salt and of rock-salt and with an insufiiciency of solvent, and after the desired fineness is obtained lixiviating the product and 15 removing the salt.

6, As a new product most highly disintegrated, fluffy, uncolloidal graphiteoccupying a relatively very large volume as compared with its weight, and suitable for use for batteries and the like.

- GEORG HANEKOP.