US923864A - Process for the electric dissociation of metals by the wet method. - Google Patents

Description

. The first of which-t alkaline salt use UNITED STATES PA ENT OFFICE.

ALFRED. LEVY, OF PARIS; FRANCE.

PROCESS FOR THE ELECTRIC DISSOOIATION OF METALS IBY THE WET METHOD.

Specification of Letters Patent.

Patented June 8, 1909.

\ Application filed February 3, 1908. Serial No. 414,005.

-Method, of which the following is a specification.

Itis a well known fact that metal articles intended to receive metallic de osit in an electrolytic bath must revious y be freed from greases and impurlties which may ad- 'here to them in consequence of the preceding stages of manufacture.

Therefore two successive but different operations are required.

e cleaning-demands a reat deal of time and care.

y invention relates to a process by which it is possible to carry out both 0 erations at the same time, no matter what t e metal or alloy of which a deposit is desired, whether lsilliver, tin, copper, zinc, nickel, brass or the The following is a description .of the rocess: The metal articles are used as a cat ode in a bath made of aconcentrated solution of an alkaline substance, soda, potash and the like with a sli ht addition of an alkaline cyanid, and at tlie same time an anode is employed, made of the metal or alloy intended to be deposited. The latter ingredient added to the bath may vary accordin to the nature of the'material to form the deposit. For instance, for coppering excellent results have been found from the use of a qluantity of cyanid corresponding to one ten of the In place of cyanids other alkaline salts may be used as additions to the alkaline solution, such as chlorids or iodids and the like. In these cases however asuitable solvent, such as alkaline sulfites or hyposulfites, must also. be added to the electrolytes. These latter ingredients may'also be added jointly with cyanids as addition to the The passage of the current through such an electrolyte effects, in the first place, the complete removal of grease from the metal articles serving as the cathode and at the same time, owing to the attack of the anode, results in the formation of the necessary electrolyte for the subsequent metallic deposit on these articles. Therefore this bath must be under current for some time before it sulpplies satisfactory deposits; nevertheless t e result may be obtained immediately if instead of the whole or part of the alkaline cya'nid a like quantity of the corres ondin metallic cyanid, metallic chlorid, io id, an the like, metallic phosphates and pyrophosphates are used. The same substitution of the corresponding metallic salt can be made when using a'chlorid, iodid, and the like, a phosphate or a pyrophosphate, as already mentioned. t

The process described has the advanta e that the cleanin of the articles and the ga vanic deposit ta res place successively in one and the same bath, and besides that the formation of the metallic salts required for the deposit takes place in the bath itself when t e metal anode is used, and thus does away with the necessit of using the very expensive pure metal sa ts for producing the electrolytes. I

What I claim and desire to secure by Letters Patent of the United States is 1. An electrolytic process of cleaning metal articles and subsequently coating them with metal which includes placing the article to be coated in a bath consisting of a 10% to 20% alkaline solution containing a metallic salt, placin in the solution a quantity of the metal wit which the article is to be coated, and connecting both the article and the coating metal to a suitable source of electricity; the former as the cathode and the latter as the anode.

2. An electrolytic process for cleaning metal articles and subsequentl coating them with metal which'consists of p acing the article to'be coated in a bath consisting of a concentrated alkaline solutionand an alkaline salt, lacing in the solution a quantity of the meta of the kind of. which the coating is to be formed, and connecting both the article and the coating metal to a suitable source of electricity, the former as the cathode and the latter as the anode. g

3. electrolytic process for cleaning 1 metal articles and subsequently coating them article to be coated in a bath consisting of a concentrated alkaline solution and an alkaline cyanid, placing in the solution a quan tity of the metal of the kind of which the coating is to be formed, and connecting both the article and the coating metal to a suitable source ofelectricity, the former as the cathode and the latter as the anode.

i i i i i l i ALFRED LEVY.

Witnesses ALEXANDER WAERBER, EMILE BACHING.