Ultrafast flash joule heating synthesis methods and systems for performing same

1 . A method of recovering metal, wherein the method comprises:

(a) mixing a material with a conductive additive to form a mixture, wherein the material is prepared from ores, fly ash, and/or bauxite residue;

(b) applying a voltage across the mixture to recover metal from the material, wherein

(i) the voltage is applied in one or more voltage pulses, and

(ii) duration of each of the one or more voltage pulses is for a duration period; and

(c) collecting the recovered metal, wherein the recovering and collecting of the metal comprises performing a leaching process after applying the voltage across the mixture.

2 . The method of claim 1 , wherein the material is prepared from ore.

3 . The method of claim 1 , wherein the material is prepared from fly ash.

4 . The method of claim 1 , wherein the material is prepared from bauxite residue.

5 . The method of claim 1 , wherein the material is prepared by performing a mechanical process to transform the material into a fine powder.

6 . The method of claim 1 , wherein the material and the conductive additive are mixed at a weight ratio in a range of 1:2 and 25:1.

7 . The method of claim 1 , wherein the voltage applied is in a range of 15 V and 300 V.

8 . The method of claim 1 , wherein

(a) mass of the mixture to which the voltage is applied is more than 1 kg; and

(b) the voltage applied is between 100 V and 100,000 V.

9 . The method of claim 1 , wherein

(a) mass of the mixture to which the voltage is applied is more than 1 kg; and

(b) the voltage is applied to produce a current between 1,000 amps and 30,000 amps.

10 . The method of claim 1 , wherein the mixture has a resistance in the range of 0.1 ohms and 25 ohms when the voltage is applied.

11 . The method of claim 1 , wherein the voltage pulse is performed using direct current (DC).

12 . The method of claim 1 , wherein the method is performed utilizing a pulsed direct current (PDC) Joule heating process.

13 . The method of claim 1 , wherein the voltage pulse is performed using alternating current (AC).

14 . The method of claim 1 , wherein the voltage pulse is performed by using both direct current (DC) and alternating current.

15 . The method of claim 14 , wherein the method switches back and forth between the use of direct current (DC) and alternating current (AC).

16 . The method of claim 1 , wherein the metal comprises a rare earth element.

17 . The method of claim 1 , wherein the metal comprises precious metal.

18 . The method of claim 1 , wherein

(a) the materials comprises a metal oxide; and

(b) the step of applying a voltage across the mixture results in a carbothermic reaction of the metal oxide to recover the metal.

19 . The method of claim 1 , wherein the applying of the voltage across the mixture to recover the metal from the material is performed at a pressure between 0.001 and 25 atmospheres.

20 . The method of claim 19 , wherein the method is performed using a pressurized cell.

21 . The method of claim 20 , wherein

(a) the applying of the voltage across the mixture to recover the metal from the material creates graphene from the mixture; and

(b) the applying of the voltage across the mixture to recover the metal from the material results in a majority of the metal remaining with the graphene created.

22 . The method of claim 21 , wherein the collecting of the recovered metal comprises separating the metal from the graphene.

23 . The method of claim 1 , wherein the step of collecting comprises collecting a gas stream comprising volatized products produced by the application of the voltage across the mixture.

24 . The method of claim 1 , wherein the leachability of metals in the mixture after applying a voltage across the mixture is more than two times the leachability content of the metals in the mixture before applying the voltage across the mixture, when conducted using the same pH and same volume of aqueous treatment.