SU12A1 - The method of galvanic removal of gilding from silver products without a noticeable change in their shape - Google Patents

Description

The proposed method of electroplating gilding from silver products without a noticeable change in their shape is the ultimate goal, unlike the methods used for refining, to extract them in a cheap way, without damaging the originals containing gilded gold products and at the same time makes it possible to easily restore objects of the former brilliant metallic appearance, almost did not change their weight, as well as their samples.

This method allows cheap and mass processing of gold-plated products, which require insignificant costs for equipment that can be applied with equal success, both in the handicraft workshop and in the national scale when processing church and other valuables.

According to the author, to obtain these results, an electric direct current is applied, the voltage and power of which can vary within fairly wide limits, although the limits of 2 - 3V and 100A per square meter are more desirable. meter. Items that are broken up are exposed to the anode blades on silver or copper wire; as the cathode serves as a lead sheet coated with a mixture of graphite and fat; the electrolyte is an aqueous solution of sodium chloride or its mixture with an acid, or a solution of hydrochloric acid; Concentration does not play a special role, but it is recommended to use a solution of about 15% for sodium chloride and 10% for hydrochloric acid. To reduce the risk of short-circuiting, the cathodes are separated from the anodes by wooden arrays with oblique steps A (Figs. 1 and 2). For the convenience of extracting gold deposited on the bottom of a bath, wooden frames B with a canvas stretched on them are used (Fig. 3 and 4, the drawing of the canvas is shown partially removed). Ceramics or wooden baths upholstered with lead, which are usually used in galvanoplastic technology, serve as electrolysers. Bath temperature - room. Under these conditions, only one gold is removed from the products, which precipitates as a sponge powder on lead cathodes and on a frame placed on the bottom of the bath; the very same products are coated with thin

a bloom of silver chloride, which prevents further dissolution of the silver original, as a result of which the inventor believes that the weight and the sample of the products remain almost unchanged.

To give metallic gloss to objects, silver chloride deposits are washed away with sodium sulfate salt or liquid ammonia, after which the articles are carcinated. Since the precipitated gold sludge is highly polluted by other metals contained in the products and in the wires on which the products are suspended, in order to obtain pure gold, chemical cleaning of the powder is carried out by the usual method: by fusion with carbonates of alkali metals.

granulating the alloy in water, dissolving it in acids and then fusing the precipitate.

SUBJECT OF INVENTION.

1. Electroplating method for removing gold from silver products without a noticeable change in their shape, characterized in that the anode is a cracked object and the electrolyte is sodium chloride solution (about 15%) or its mixture with acid or hydrochloric acid solution (approx. 10%).

2. With the method specified in paragraph 1 of the method, use vertical frames with braided steps to separate the cathodes from the anodes and horizontal frames with the sheet to deposit recoverable gold on them.

To a ische 1 I. Bershsha

№12

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