Method of stabilising a blasthole

1. A method of stabilizing a blasthole which comprises the step of spraying the inner wall of the blasthole with a stabilizing composition after the blast hole has been drilled and prior to detonation wherein spraying provides a coating of the stabilizing composition on the inner wall of the blasthole.

2. A method as defined in claim 1 wherein the stabilizing composition comprises a silicate containing resin; a thermoset resin system comprising polyurethanes, polyesters, epoxides, or phenolics; a cement based mortar or material.

3. A method as defined in claim 1 wherein the stabilizing composition comprises a resin containing foam material.

4. A method as defined in claim 1 wherein the spraying step further comprises a coating step, wherein the coating step comprises a moveable spraying application of the stabilizing composition from a first position at a base of the blasthole to a second position at an opening of the blasthole.

5. A method as defined in claim 4 wherein the movement is variable and controllable.

6. A method as defined in claim 5 wherein the retraction rate is between 1 and 50 meters/minute.

7. A method as defined in claim 1 which comprises the steps of:

(a) moving a source of stabilizing composition from a proximal end of the blast hole to a distal end; and

(b) moving the source from the distal end to the proximal whilst operating the source to coat an inner wall of the blasthole with the stabilizing composition.

8. A method as defined in claim 1 wherein the rate of spraying is variable and controllable.

9. A method as defined in claim 8 wherein the spraying rate is between 1 and 20 liters/minute.

10. A method as defined in claim 1 wherein the spraying step provides the inner wall of the blasthole with a coating of the stabilizing composition between 1 mm and 5 mm in thickness.

11. A method as defined in claim 1 wherein at least 60% of the total internal surface area of the blasthole is coated with the stabilizing composition.

12. A method as defined in claim 1 wherein the stabilizing composition comprises a polymeric composition.

13. A blasthole stabilization kit which comprises a stabilizing composition as defined in claim 2 and instructions to use said kit in accordance with the method of stabilizing a blasthole which comprises the step of spraying the inner wall of the blasthole with a stabilizing composition after the blast hole has been drilled and prior to detonation and wherein the kit additionally comprises a spraying apparatus which sprays the blasthole prior to detonation.

14. A kit as defined in claim 13 wherein the spraying apparatus comprises separate chambers containing a resin base composition and a hardener composition.

15. A kit as defined in claim 14 wherein the spraying apparatus comprises mixing means.

16. A kit as defined in claim 13 wherein the spraying apparatus comprises a spray head or nozzle.

17. A kit as defined in claim 13 wherein the spraying apparatus comprises a pump for spraying the stabilizing composition under high pressure.

18. A kit as defined in claim 13 which additionally comprises retraction means for moving and/retracting the spraying apparatus within the blasthole.

19. A kit as defined in claim 13 which additionally comprises means to control the spraying and/or retraction rates.

20. A blasthole stabilization kit which comprises a stabilizing composition as defined in claim 3 and instructions to use said kit in accordance with the method of stabilizing a blasthole prior to detonation which comprises the step of spraying the inner wall of the blasthole with a stabilizing composition after the blast hole has been drilled and prior to detonation and wherein the kit additionally comprises a spraying apparatus which sprays the blasthole prior to detonation.