Electrolytic preparation of tin, other metals, alloys and compounds

Claim 1

A process for electrolytically producing elemental free-standing single crystals and free-standing dendritic crystalline materials chosen from the group consisting of: beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, actinium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, boron, aluminum, indium, thallium, carbon, tin, lead, arsenic, antimony, bismuth, selenium and tellurium, by performing the steps of: forming a solvent molten salt bath such as a single alkali halide salt or a eutectic metal halide mixture capable of supporting high solubilities for cations of the to-be-deposited material with molten salt bath melting point less than the melting point of the material to be produced as a single crystal; purifying the solvent eutectic metal halide molten salt bath with appropriate oxygen removal and purification treatments such as: electropurification, addition of free metal, and bubbling of gases such as HF, HCl, HBr, HI, and H2 under vacuum; dissolving a metal halide salt composed of the to-be-deposited metal and appropriate halide ion(s) as the solute in the molten salt bath in order to provide sufficient bulk-replenishing concentration (activity) of the cations of the material to be deposited as a crystal upon passage of electrical current; purifying the electrolytic bath containing the to-be-deposited cations through electropurification where current is passed from a high purity sacrificial anode of the material to be deposited to a cathode operated at potentials slightly more negative than the cathodic surface potential used in production of the to-be-produced material; immersing a cathode and an anode into said bath, said cathode being shaped in a manner to be capable of providing for nucleation of the cations on the tip of the pointed cathode, and said anode shaped to substantially replicate the crystallographic morphology desired; application of an electrical voltage between the anode and the cathode, with applied cathodic potentials more negative than the reduction potential of the cations of the to-be-produced material, yet above the critical overpotential (cathode driving negative) for the composition of the bath; and reduction of the cations of the material to be deposited at the cathode by the passage of said electrical current to thereby form a crystalline metal deposit at the cathode.