Method and Apparatus for Efficient Metal Distillation and Related Primary Production Process

Patent metadata

Field	Value
Publication number	US-2024141528-A1
Application number	US-202318376216-A
Country	US
Kind code	A1
Filing date	Oct 3, 2023
Priority date	Jul 30, 2019
Publication date	May 2, 2024
Grant date	—

Abstract

Method and apparatus are provided for efficient metal distillation, and for related primary product process. Vertically stacked and gravity-driven evaporators and condensers are employed to distill metals, such metals having different volatilities. A multiple-effect thermal system of magnesium and other volatile metals is used to efficiently distill and separate metals from multiple metal alloys.

First claim

1 . A process for producing a first metal by electrolysis of an oxide of the first metal in an electrolysis cell, comprising:
melting an alloy including at least the first metal and a second metal; in a liquid mixture of halide salts and oxides, applying a direct current potential between at least one anode and at least one cathode; and adding the oxide of the first metal to the liquid mixture of halide salts, with a dense liquid including the second metal at least one cathode such that an alloy forms at the cathode comprising the first and second metals at the cathode; and removing the alloy including the first and second metals from the electrolysis cell.

2 . The process of claim 1 further comprising:
using distillation to remove a portion of the first metal from the alloy including the first and second metals, where the distillation evaporates a portion of the first metal and uses a heat released in condensation of the first metal to provide at least 30% of the heat required for evaporation of the first metal.

3 . The process of claim 1 wherein the first metal is Mg.

4 . The process of claim 3 wherein the second metal is Sn.

5 . The process of claim 1 wherein melting includes at least 50-80% of the first metal and at least 10-30% of an oxide of the first metal.

6 . The process of claim 1 wherein melting includes a mixture of at least 30% of the first metal and at least 5% of an oxide of the first metal, by weight.

7 . The process of claim 1 wherein melting occurs at a temperature that is:
above a melting points of the first metal;
and
below a melting point of the oxide.

8 . The process of claim 1 further comprising recovering the first metal from the oxide of the first metal.

9 . The process of claim 1 in which a plurality of the alloy including the first and second metals is returned to the electrolysis cell cathode.

10 . The process of claim 1 in which a plurality of impurity metals are removed from the alloy including the first and second metals, by:
introducing the alloy into a separation vessel, reducing a temperature of the alloy by at least 50° C.; and
maintaining the alloy in the vessel for a period of time in which a plurality of the impurity metals separate from the alloy as a plurality of impurity metal solids, then removing the alloy, from which the plurality of the impurity metal solids separated, from the separation vessel.

11 . The process of claim 10 in which the separation vessel is rotated in order to enhance a rate of solid impurity metal separation.

12 . The process of claim 1 in which some impurity metals are removed from the alloy including the first and second metals by reducing its temperature by at least 50° C. and using a filter or sieve to remove a plurality of impurity metal solids.

13 . The process of claim 1 in which the second metal is selected from a list comprising copper, gallium, germanium, silver, indium, tin, antimony, thallium, lead, or bismuth.

14 . A method of distilling a metal using a plurality of vessels, comprising:
introducing a metal alloy into a top alloy-containing vessel; causing the metal alloy to flow down a first liquid flow tube into an uppermost evaporator of at least two evaporators, with at least:
an uppermost evaporator; and
at least a lowest evaporator, then caused to flow down a second liquid flow tube into a second evaporator, and wherein from the uppermost evaporator one or more metals evaporates into a metal vapor and flows into a first condenser where the metal vapor condenses and is stored as a liquid metal distillate having a temperature; and harvesting the distilled metal.

15 . The method of claim 14 wherein from the second evaporator one or more metals evaporates into a metal vapor and flows into a second condenser where the metal vapor condenses and is stored as a liquid metal distillate having a temperature,
and where as each metal vapor condenses in a condenser,
the metal vapor transfers heat into the evaporator adjacent to the condenser, with heat primarily being transferred to the uppermost of the evaporators and cascading upward from each condenser to evaporator to provide heat for vaporization for all of the evaporators.

16 . The method of claim 14 , in which the liquid metal distillate has a temperature of at least 400° C.

17 . The method of claim 14 , in which the metal alloy introduced is at least 50 mol % magnesium.

18 . The method of claim 14 , in which the metal alloy introduced is at least 50 mol % a metal selected from a list comprising zinc, cadmium, tellurium, thallium, bismuth, lithium, sodium, potassium, calcium, strontium, barium samarium, europium, or ytterbium.

19 . The process of claim 3 wherein the second metal is Pb.

Assignees

• Worcester Polytech Inst

Inventors

• Powell Adam C
• Dussault David
• Earlam Matthew
• Tajima Aaron
• Raymes Connor

Classifications

• C25C3/04 Primary

  of magnesium · CPC title

• C22B7/004

  separating two or more metals by melting out (liquation), i.e. heating above the temperature of the lower melting metal component(s); by fractional crystallisation (controlled freezing) · CPC title

• C22B9/02

  Refining by liquating, filtering, centrifuging, distilling, or supersonic wave action {including acoustic waves; (C22B9/003, C22B9/006, C22B9/05, C22B9/22 take precedence)} · CPC title

• C22B26/22 Primary

  Obtaining magnesium · CPC title

• C25C3/34

  of metals not provided for in groups C25C3/02 - C25C3/32 · CPC title