Molten metaphosphate electrolysis for production of white phosphorus

Patent metadata

Field	Value
Publication number	US-11767597-B2
Application number	US-201917275331-A
Country	US
Kind code	B2
Filing date	Sep 22, 2019
Priority date	Sep 23, 2018
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

An electrolytic system and method of manufacturing white phosphorus.

First claim

What is claimed is:

1. A method of generating elemental phosphorus comprising:
providing a melt of a metaphosphate salt;
applying an electrolysis voltage across a cathode and an anode in the melt,
collecting an elemental phosphorus separate from an oxidized product; and
adding phosphoric acid to the melt to replenish phosphorus.

2. The method of claim 1 , wherein the elemental phosphorus includes P 4 .

3. The method of claim 1 , wherein the oxidized product includes oxygen gas.

4. The method of claim 1 , wherein the oxidized product includes carbon monoxide or carbon dioxide.

5. The method of claim 1 , further comprising carrying the elemental phosphorus away from the melt using a gas.

6. The method of claim 1 , wherein the metaphosphate salt includes sodium metaphosphate, lithium metaphosphate, potassium metaphosphate, or a mixture thereof.

7. The method of claim 1 , further comprising maintaining the melt at a temperature less than 1500° C., less than 1300° C., less than 1100° C., less than 1000° C., less than 900° C., between 500° C. and 900° C., between 600° C. and 875° C., between 650° C. and 850° C., or between 750° C. and 850° C.

8. The method of claim 1 , wherein the electrolysis voltage is between 0.1 and 5.0 V, between about 0.4V and 2.0V, between about 0.5V and 1.8V, or between about 0.6V and 1.7V.

9. The method of claim 1 , wherein the electrolysis voltage is 0.1, 0.2, 0.3, 0.4, 0.5 V, 0.6V, 0.7V, 0.8V, 0.9V, 1.0V, 1.1V, 1.2V, 1.3V, 1.4V, 1.6V, 1.7V, 1.8V or 1.9V, 2.0 V, 2.1 V, 2.2 V, 2.3 V, 2.4 V, 2.5 V, 2.6 V, 2.7 V, 2.8 V, 2.9 V, 3.0 V, 3.1 V, 3.2 V, 3.3 V, 3.4 V, 3.5 V, 3.6 V, 3.7 V, 3.8 V, 3.9 V, 4.0 V, 4.1 V, 4.2 V, 4.3 V, 4.4 V, 4.5 V, 4.6 V, 4.7 V, 4.8 V, 4.9 V, or 5.0 V.

10. The method of claim 1 , wherein the melt is free of transition metals.

11. The method of claim 1 , wherein the melt is free of halides.

12. The method of claim 1 , wherein the melt is contained in a crucible.

13. The method of claim 1 , wherein the anode is an electrode material that facilitates oxygen production.

14. The method of claim 1 , wherein the anode includes platinum or carbon.

15. The method of claim 1 , wherein the cathode includes carbon.

16. The method of claim 1 , wherein the cathode is carbon having a sharp end.

17. The method of claim 1 , further comprising adding an additive to the melt.

18. The method of claim 17 , wherein the additive includes a metal salt, a phosphate mineral, a promoter or other compound.

Assignees

• Massachusetts Inst Technology

Inventors

• Surendranath Yogesh
• Licini Andrew

Classifications

• C25B1/23

  Carbon monoxide or syngas · CPC title

• C25B9/17

  Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof · CPC title

• C25B1/00

  Electrolytic production of inorganic compounds or non-metals · CPC title

• C25B1/01 Primary

  Products · CPC title

• C25B1/50

  Processes · CPC title