APPARATUS AND METHOD FOR USE IN CALCINATION

1 . A calcining system, comprising:

a calcining chamber of a length to effect a desired level of calcination of solid particles;

a hot gas source to communicate hot gases into said calcining chamber; and

an entrainment gas source operable to communicate an entrainment gas to transport the solid particles into said calcining chamber to calcine the solid particles to form calcined solid particles.

2 . The system as recited in claim 1 , wherein said hot gas source is a burner that combusts a fuel and an oxidizer.

3 . The system as recited claim 1 , wherein said calcining chamber is a tube such with an exit at a higher elevation than an inlet.

4 . The system as recited claim 3 , further comprising a separator in communication with said exit, said separator operable to separate the calcined solid particles from said hot gases and said entrainment gas.

5 . The system as recited claim 4 , further comprising a cooling system downstream of said separator.

6 . The system as recited claim 5 , wherein said cooling system includes a cooling bath at a temperature lower than a temperature of the calcined solid particles.

7 . The system as recited claim 6 , wherein said solid particles are less that 500 microns in diameter.

8 . The system as recited claim 6 , wherein said solid particles are less that 100 microns in diameter.

9 . The system as recited claim 6 , wherein said solid particles are less that 50 microns in diameter.

10 . A method for calcining, comprising:

delivering solid particles to a hot gas source;

heating the solid particles to at least a threshold temperature; and

maintaining a temperature of the solid particles at least at the threshold temperature for a time duration to calcine the solid particles to form calcined solid particles.

11 . The method as recited in claim 10 , wherein the delivering solid particles further comprises entraining the solid particles in a gas flow containing a fuel.

12 . The method as recited in claim 11 , wherein the heating of the solid particles further comprises combusting the fuel with an oxidizer.

13 . The method as recited in claim 10 , further comprising cooling the calcined solid particles.

14 . The method as recited in claim 10 , further comprising separating the calcined solid particles from byproduct gases which entrain the calcined solid particles.

15 . The method as recited in claim 10 , wherein the solid particles are exposed to the heating for less than 1 minute.

16 . The method as recited in claim 10 , wherein the time duration is less than 5 minutes.

17 . The method as recited in claim 10 , wherein the threshold temperature is between 1400-1900 degrees F.