Method and apparatus for efficient metal distillation and related primary production process

Patent metadata

Field	Value
Publication number	US-11773500-B2
Application number	US-202016944147-A
Country	US
Kind code	B2
Filing date	Jul 31, 2020
Priority date	Jul 30, 2019
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

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

Accordingly, what is claimed is:

1. An apparatus for distilling a liquid metal, the apparatus comprising:
a plurality of two or more evaporators, for containing a liquid metal and a metal vapor in each of the evaporators; and
a plurality of two or more condensers, for containing a distillate metal liquid and metal vapor in each of the condensers, arranged in succession vertically, comprising:
a lowest evaporator and an uppermost evaporator; and at least one liquid flow tube connecting each evaporator to the evaporator that is next below it,
where the evaporators are referred to as an upper evaporator and a lower evaporator with regard to each liquid flow tube; and
where each such liquid flow tube has:
an upper opening in the upper evaporator with regard to that liquid flow tube; and
and a lower opening in the lower evaporator with regard to that liquid flow tube; and

where a first evaporator is both below a second evaporator, if present, and connected to the second evaporator with a first liquid flow tube, and where the first evaporator is above a third evaporator, if present, and connected to the third evaporator with a second liquid flow tube,
the lower opening of that first liquid flow tube in the first evaporator is below the upper opening of the second liquid flow tube in the first evaporator;
and wherein at least one vapor flow tube connects each condenser to one of the plurality of evaporators below that condenser; and
with each condenser in thermal communication with one of the plurality of evaporators above the evaporator in vapor flow connection to that condenser; and
wherein a heater is configured to provide heat to the lowest evaporator of the plurality of evaporators.

2. The apparatus of claim 1 , in which the lowest evaporator further comprises a temperature-measuring-device.

3. The apparatus of claim 1 , in which the uppermost evaporator further comprises a temperature-measuring-device.

4. The apparatus of claim 1 , in which a liquid concentrate vessel is below and connected to the lowest evaporator, which lowest evaporator is connected to a condenser.

5. The apparatus of claim 1 , further comprising an outer chamber having an inside and an outside, in which the plurality of evaporators and the plurality of condensers are enclosed in the outer chamber.

6. The apparatus of claim 5 , in which the outer chamber comprises a means of reducing pressure below 0.5 atm.

7. The apparatus of claim 5 , in which the outer chamber comprises a means of restricting heat flow.

8. The apparatus of claim 5 , further comprising a plurality of distillate tubes connecting a plurality of condensers inside the outer chamber to a plurality of points outside the outer chamber.

9. The apparatus of claim 8 , further comprising a heater outside of the outer chamber, in which at least one of the distillate tubes connecting from a condenser to at least one point outside the outer chamber is configured with the heater, which heater is configured to provide heat to the distillate tube.

10. The apparatus of claim 5 , further comprising a plurality of valves connecting the uppermost evaporator to the outside of the outer chamber, wherein the plurality of valves are configured to control flow of the liquid metal into the uppermost evaporator.

11. The apparatus of claim 5 , further comprising a multi-gated assembly comprising at least one conduit and at least two reversibly openable gates for blocking the conduit, which multi-gated assembly enables periodic flow of liquid or solid metal from outside the outer chamber to the uppermost evaporator, and wherein at least one of the gates is closed at all times.

12. The apparatus of claim 1 , further comprising a means of controlling a rate of flow down the liquid flow tube between the uppermost evaporator and the next evaporator below the uppermost condenser.

13. The apparatus of claim 1 , in which one or more of the vapor flow tubes further comprises at least one flow device which increases a curvature of the flow of the metal vapor.

14. The apparatus of claim 1 , in which a plurality of the evaporators include a plurality of path complicators for guiding a flow of the liquid metal and the metal vapor in a manner which increases an effective length of atho liquid metal flow path and a metal vapor flow path.

15. The apparatus of claim 1 , in which a plurality of the condensers include a plurality of plates for guiding flow of the distillate metal liquid and the metal vapor in a manner which increases an effective length of a flow path of the liquid metal and the metal vapor, and the apparatus further comprises an exit vent tube.

16. The apparatus of claim 1 , in which a heat sink is in thermal contact with the uppermost evaporator.

17. The apparatus of claim 16 , in which the heat sink contains a plurality of a liquid metal.

18. the apparatus of claim 16 , in which the heat sink further comprises a melter.

19. 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
wherein from the second evaporator one or more metals preferentially 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.

20. The method of claim 19 , in which the liquid metal distillate has a temperature of at least 400° C.

21. The method of claim 19 , in which the metal alloy introduced is at least 50 mol % magnesium.

22. The method of claim 19 , in which the metal alloy introduced is at least 50 mol % a metal selected from a list comprising zinc, cadmium, tellurium, thallium, or bismuth.

23. The method of claim 19 , in which the metal alloy introduced is at least 50 mol % a metal selected from a list comprising lithium, sodium, potassium, calcium, strontium, or barium.

24. The method of claim 19 , in which the metal alloy introduced is at least 50 mol % a metal selected from a list comprising samarium, europium, or ytterbium.

25. The method of claim 19 , in which a heater is configured to provide heat to the lowest evaporator, and the heat supplied by the heater is controlled to maintain a temperature within ±20° C. of a temperature setpoint in the lowest evaporator.

26. The method of claim 19 , in which the lowest evaporator is connected to an alloy concentrate storage vessel by a concentrate liquid flow tube.

27. The method of claim 19 , in which a rate of flow of liquid metal alloy from the top alloy-containing vessel through one or more top liquid flow tubes to the first eva

Assignees

• Worcester Polytech Inst

Inventors

• Powell Iv Adam Clayton
• Dussault David
• Earlam Matthew
• Tajima Aaron
• Raymes Connor

Classifications

• C25C3/04 Primary

  of magnesium · CPC title

• B01D1/0082

  Regulation; Control · CPC title

• B01D1/26

  Multiple-effect evaporating · CPC title

• B01D5/006

  with evaporation or distillation · CPC title

• C22B26/22

  Obtaining magnesium · CPC title