US2082362A - Method of producing finely divided metallic products - Google Patents

Description

Patented June 1, 1937 PATE METHOD METALLIC 0F PRODUCING FINELY DIVIDED PRODUCTS James L. Stevens, Hayden, Ariz.

No Drawing.

Application June 1'7,

Serial No. 27,047

19 Claims.

This invention relates to a method of obtaining metals in a pulverized or finely divided condition, and more specifically to a method of obtaining metals in a, finely divided condition such as is suitable for use as a paint pigment or other purpose for which a fine state of division is required or advantageous. particularly in finely dias a paint useful for the production of copper vided or pulverized condition for use pigment.

The invention may also be utilized for the production of alloys of copper and other metals such as zinc, and. it will be understood that references to the use or treatment of copper, in the following general the appended claims, are intended to include either copper alone or copper in conjunction with another metal, and that references to the formation of a metallic product comprising copper are intended to include either copper alone or an alloy containing copper.

The principal object of the invention is to provide a novel and advantageous method for producing finely divided metallic products comprising copper, and particularly for the production of such finely divided metallic products adapted for use as paint pigments.

A particular object of the invention is to proprocess for the above purpose, in which a relatively small expenditure of power is required for reducing the metal to the desired state of division for use.

A further object of the invention is topro-- vide a method for obtaining such finely divided metallic products of a high state of purity and freedom from oxidation.

A further object of the invention is to provide for the production of a finely divided metallic pigment material in pure condition, either alone or in suspension in a liquid paint vehicle.

A further object of the invention is to provide for the production of copper alloys in pulverized or finely divided condition.

Other objects of this invention will be either pointed out hereinafter or will be apparent from the following description of the invention and of certain specific embodiments thereof.

In carrying out the invention, I form an amalgam of copper (or copper and another metal) with mercury, by any suitable amalgamating method; then heat the amalgam to distil off the mercury, leaving a metallic residue containing the copper (either alone or alloyed with said other metal) in a spongy or more or less loosely coherent and easily disintegrated form; and then mechanically break up said metallic residue to reduce it to the desired finely divided condition, as by grinding or pulverizing in any suitable manner.

The physical structure of the metallic residue remaining after distillation of the mercury is quite porous or spongy, comprising, a thin-walled metallic skeleton penetrated throughout by fine voids or pores, and has relatively little mechanical strength, so that only a relatively light grind ing or pulverizing action is required to reduce this residue to the form of finely divided metallic particles.

The formation of a copper amalgam may be carried out in any suitable or well-known manner, such as by electrolytic deposition from solution containing a copper salt, using metallic mercury as a cathode, or by chemical reduction and precipitation of the copper from such a solution in the presence of mercury, or by bringing the copper, preferably in divided condition, into contact with mercury in any desired manner.

The proportion of copper introduced into the amalgam may be varied between wide limits. As the concentration of amalgamated metal in the mercury amalgam increases, the fluidity of the amalgam decreases, and I have carried out the process using amalgams of various concentrations, ranging from fiuid to substantially solid amalgams. In general, however, I have found that the best results are obtained by using an amalgam of a plastic, pasty, or semi-fluid consistency, and I therefore prefer to use an amalgem of such a consistency, particularly where the amalgam is apt to be contaminated by impurities, since an amalgam of this concentration is susceptible to purification by washing, puddling, or working the same, as hereinafter described. It will be appreciated, however, that the amount of metal recovered in an actual embodiment of the process is dependent upon the concentration of the metal in the amalgam, and I therefore prefer to use as high a concentration as is consistent with other requirements of the process. In the case of copper alone, I have found that the optimum proportions are about eleven parts of copper to eighty-nine parts of mercury by weight, at which concentration the amalgam may be puddled or worked for removal of impurities, although it is to be understood that the invention is by no means limited to these proportions.

The amalgam formed as above described if desired, be purified, as by washing with water or other solvent, or by puddling, working, or agitating the same, either alone or in the presence of water or other liquid or fluent medium.

the puddling operation, is in some cases advantageous, to assist in the elimination of impurities otherwise worked to break prevent oxidation of the amalgam. After preparation of the amalgam, and after desirable treatment thereof to remove impurities o to produce an amalgam of uniform consistency, the amalgam is introduced into a retort or other vessel and heated to distil ofi the mercury, the varporized mercury being preferably recovered by condensation.

The temperature during the distillation operation should be held below the point at which the residual copper might fuse sufiiciently to impair subsequent reduction of the metallic mass to a pulverized condition. The distillation may be carried out under atmospheric pressure, or under any desired higher or lower pressure. In order to provide complete vaporization of the mercury,

5 the mass may be heated to a temperature considerably above the boiling point of mercury at the pressure employed, during the later stages of the operation.

or damaging The grinding may be in the presence of a product. carried out either dry or The amalgam may, if deor copper and any other amalgamable metal or metals adapted to form an alloy with copper, the procedure is similar to that above described, ex-

precipitation, or by other known means. Alternatively, I may form separate amalgams of the showed a homogeneous combination of the two metals cury but insulated from the electrolyte by means of a glass tube.

the retort and ground in a pebble mill in the The pulverized metal was removed from the mill and separated from the .The product from this particular operation appeared to be in the form of crystalline or fiaky masses averaging about .02 mm. in size.

In another laboratory operation, an alloy of zinc and copper was obtained. In this operation,

the two metals were deposited electrolytically with the mercury separately; the copper being deposited from a copper sulphate solution and the zinc from a zinc sulphate solution. After depositing the desired amounts of the metals, the amalgam was separated from the aqueous solution, washed and puddled to remove certain impurities and then subjected to distillation in a retort for removal of the mercury. The metallic spongy residue from the retort, having a characteristic color of dull light yellow brass, was broken up by. grinding in a pebble mill in the presence of just sufiicient gasoline to form a metallic paste. After grinding, the pulverized metal was removed from the mill by flushing out with gasoline. The metal was removed from the gasoline by the procedure described in the foregoing example.

I claim:

1. A method of making a finely divided metallic product which comprises forming an amalgam containing copper and mercury, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising said copper, and grinding said spongy metallic residue to form a finely divided product.

2. A method of making a finely divided metallic product which comprises forming an amalgam containing copper and mercury by electrolytic deposition of said copper, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising said copper, and grinding said spongy metallic residue to form a finely divided product suitable for use as a paint pigment.

3. A method of making a finely divided metallic product which comprises forming an amalgam containing copper and mercury, subjecting the amalgam to a puddling operation to remove impurities, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising said copper, and grinding said spongy metallic residue to form a finely divided product.

4. A method of making a finely divided metallic product which comprises forming an amalgam containing copper and mercury, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising said copper, and grinding said spongy metallic residue in the presence of an organic liquid to form a finely divided product.

5. In a method of making a finely divided product, the steps which comprise: subjecting an amalgam containing copper and mercury to distillation to remove the mercury under such conditions as to form a spongy and easily disintegrated metallic residue; and grinding said spongy metallic residue in the presence of an organic liquid to form a finely divided product.

6. A method of making a finely divided copper alloy which comprises forming an amalgam of copper and another metal with mercury, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising an alloy containing said copper and said other metal, and. grinding said spongy metallic residue to form, a finely divided product.

7. A method of making a finely divided copper alloy which comprises: forming an amalgam of copper and another metal with mercury, distilling the mercury from said amalgam under suchconditions as to form a spongy and easily disintegrated metallic residue comprising an alloy containing said copper and said other metal, and grinding said spongy metallic residue in the presence of an organic liquid to form a finely, divided product.

8. A method of making a finely divided copper alloy which comprises successively contacting copper and another metal with mercury to form an amalgam containing copper and said other metal, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising an alloy containing said copper and said other metal, and grinding said spongy metallic residue to form a finely divided product.

9. A method of making a finely divided copper alloy which comprises forming an amalgam of copper with mercury, separately forming an amalgam of another metal with mercury, combining said amalgams to form an amalgam containing copper and said other metal, distilling the mercury from the combined amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising an alloy containing said copper and said other metal, and grinding said spongy metallic residue to form a finely divided product.

10. A method of making a finely divided copper alloy which comprises: forming an amalgam of copper and another or metal by electrolytic deposition of copper and said other metal in contact with mercury, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising an alloy containing said copper and said other meta and grinding said spongy metallic residue to form a finely divided product.

11. A method of making a finely divided copper alloy which comprises successively electrolytically depositing copper and another metal in contact with mercury to form an amalgam containing copper and said other metal, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising an alloy containing said copper and said other metal, and grinding said spongy metallic residue to form a finely divided product.

12. A method of making a finely divided metallic product which comprises forming separate amalgams of copper and another metal with mercury by separate electrolytic deposition of copper and said other metal in contact with mercury, combining saidamalgams to form an amalgam containing copper and said other metal, distilling the mercury from the combined amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising an alloy containing said copper and said other metal, and grinding said spongy metallic residue to form a finely divided product.

13. A method of making a finely divided product which comprises: forming an amalgam containing copper and mercury, distilling the mercury from said amalgam under such conditions oxidation of said metallic residue, to form a finely divided metallic product, and separating said organic liquid from said metallic product.

14. A method of making finely divided copper which comprises forming an amalgam of copper 'with mercury, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated residue of metallic copper, and grinding said spongy metallic copper residue to form a finely divided product.

15. A method of making finely divided copper which comprises electrolytically depositing copper in contact with mercury to form a copper amalgam, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated residue of metallic copper, and grinding said spongy metallic copper residue to form a finely divided product.

16. A method of making finely divided copper which comprises forming an amalgam of copper with mercury, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated residue of metallic copper, and grinding said spongy metallic copper residue in the presence of an organic liquid to form a finely divided product.

17. A method of making a material suitable for use as a metallic pigment paint base which comprises forming an amalgam containing copaosascz ,to form a product containing said metallic residue, in finely divided form, suspended in said liquid.

18. A method of making a material suitable for use as a metallic copper paint base which comprises forming an amalgam of copper with mercury, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated residue of metallic copper, and grinding said spongy metallic liquid suitable for use as a paint vehicle, to form a product containing said metallic copper, in finely divided form, suspended in said liquid.

19. A method of making a material suitable for use as a metallic pigment paint base which comprises forming an amalgam of copper and another metal with mercury, distilling the mercury from said amalgam under such conditions as to form a spongy and easily disintegrated metallic residue comprising an alloy containing copper and said other metal, and grinding said spongy metallic residue in the presence of an organic liquid suitable for use as a paint vehicle, to form a product containing said metallic residue, in finely divided form, suspended in said liquid.

JAMES L. STEVENS.