US713278A - Electrodeposited lead. - Google Patents

Description

No. 713,278. Patented Nov. ll, |902;

' A. G. BETTs.

L ECTBODEPOSITED LEAD.

(Application filed Oct. 9, 1902.)

.(Nn Moden) tlNiTED STATES PAJLRNLOFFICE.

ANsoN GARDER isnr'rs, oF LANSINGBURG, NEW YORK.

ELECTRODEPOSITED LEAD.

SPECIFICATION forming part of Letters'Patent No. 713,278, dated November 11, 1902. Application filed 0otober9, 1902. Serial No. 1261576. (N0 Specimens.)

To all whom it may concern:

Be it known that I, ANsoN GARDNER BE'rTs,

The present invention relates to a lead prod-I uct obtained by electrolysis.

The lead resulting from electrolysis by methods heretofore commonly employed is characterized by lack of density,incoherency, and by a crystalline spongy'formation, rendering the electrodeposit unsuitable for fusion.

The object of my invention is to produce by electrolytic treatment substantially pure lead having substantially the density and homogeneity of cast lead. Such object is attained by the employment in connection with a suitable electrolyte of an agent capable of restraining the crystallization of the deposit.

To carry ont my invention, I employ a suitable electrolyte-such as, for example, a solution of a lead salt of Iiuorin acid-as described in United States Letters Patent No. 679,824, granted to me August 6, 1901. To the electrolyte is added a quantity of a reducing agent, which I have found gives adeposit characterized as herein described. Among the substances which I have found available for such purposes are: gelatin, pyrogallol, resorcinol, saligenin, orthoamidophenol, hydroquinone, and sulfurous acid. Phenols of the aromatic series are well adapted for use in the present process by reason of their being easily oxidizable. The characteristics of the electrodeposit are believed to be due to the reducing action of the agent employed.

The agent contained in the electrolyte, as above stated, serves to restrain the crystallization of the electrodeposited lead and causes the same to form at or upon the cathode in a solid coherent body of substantially uniform structure throughout having substantially the density and homogeneity of cast lead,con stituting a product which by reason of its physical properties facilitates the practical electrolytic refining operations and which may be fused without the formation of an un due amount of dross. By the present process l I am able to produce without mechanical treatmenta deposit that can be made of considerable thickness and which is non-porous, as shown by the specilic gravity of a mass of it. A product is easily made with a specic gravity of'1l.36, the same metal remelted and cast having the same density. I have observed with some of the more active of these agents,as gelatin and pyrogallol,the projections that always occur on thick electrodeposits are nodular, while with some of the weaker agents, as orthoamidophenol and saligenin,the projections are apt to be crystals. When the projections are nodular,they swell into lumps on the surface during electrolysis,reducing the liability of short-circuiting during practical working of the process. With the crystalline form of projection shortcircuiting occurs, rendering such deposits less desirable or suitable for electrolytic refining or electroplating, although the deposit is superior to that obtained by prior electrolytic processes. There appears to be a very slight increasein the weight of the lead deposit in connection with the use of the above agents. These agents also affect to sonne extent the solution of lead at the anode by preserving the mass of solid lead underneath the anode slime with a somewhat smoother surface.

In practicing my present invention I prefer a current strength of ten to twenty amperes per square foot of cathode surface and a corresponding tension of .15 to .35 volts for each element. With higher currents the lead becomes harder and more brittle and takes on a whitishcolor and silvery luster. A sample deposited with a current of forty amperes per square foot showed a specific gravity of 11.276. In general the deposited lead is apt to be slightly stiffer than ordinary lead; but this stiffness may be regulated at will by varying the current density and the quantity of agent in the solution.

Of the above-named agents I have found gelatin the cheapest and to give the best results and prefer its use in the proportion of one part of gelatin, by weight, to five thousand parts of solution. The current efficiency does not appear to be affected bythe presence of gelatin or of any of the othe'rnamed agents in the electrolyte. The agent may be applied to the electrolyte in such quantities as desired from time to time. If gelatin is used, it is dissolved in hot Water and a suiiicientquantity of this solution added to the electrolyte so as to make the desired proportion.

The product of the method described is superior to VLead products of prior processes for remelting and for maintaining without attention the proper conditions of work in the electrolytic retining-tanks-that is,without shortcircuiting. As the electrodeposit is not mechanically treated while being formed by the present process, it retains undisturbed the normal structural characteristics due to electrolysis. The appearance of the surface of the deposit changes as the electrolysis proceeds, beginning with a frosty7 appearance and becoming coarser until it has a pebbly or botryoidal appearance.

Any suitable electrolylic apparatus may be employed to carry out the present process. I have shown one form of apparatus in the accompanying drawings, in which- Figure 1 is a vertical cross-section of the apparatus employed in treating lead by my improved process. Fig. 2 is a plan view of a metallic plate electroplated with lead by my improved process, the plate being partly broken away. Fig. 3 is a vertical cross-section of the same.

1 is the electrolytic vat containing the electrolyte 2, with a restraining agent, as above described.

3 is the anode, and 4 the cathode, suspended in the electrolyte and connected with the respective poles of an electric energizer. (Not shown.) The anode consists of lead or lead alloy to be refined. The cathode is shown of a metallic plate suspended in position to receive the deposited lead.

represents the electrodeposited lead, having the characteristics above described.

I claim and desire to obtain by Letters Patent the following:

1. As a new product, electrodeposited lead characterized by substantial purity, cohereucy, uniformity of structure throughout, and having substantially the density and homogeneity of cast lead.

2. As a new product, electrodeposited lead characterized by substantial purity, coherency and uniformity of structure throughout, practically free from crystallization, and having substantially the homogeneity, with a density of about 11.3, and retaining the normal structural characteristics due to electrolysis.

3. As a new product electrodeposited lead formed by subjecting to electrolysis an electrolyte containing in solution a lead salt ofa fluorin acid and a reducing agent.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

ANSON GARDNER BETTS.

Witnesses:

EDGAR H. BETTS, S. D. NICHOLS.

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