A downhole explosive detonation comprises a high voltage electro-explosive initiator comprising an input high voltage power supply with a low impedance shunting fuse, a flexible electrical link and a capacitor discharge unit. Explosive is initiated in a direction approximately parallel, or in another version perpendicular to the capacitor discharge unit. A unique configuration and construction of the assembly allows installation through a small service port in the gun housing structure for more efficient gun arming. A real time downhole voltage monitoring is described that transmits voltage readings to the surface during a firing sequence.

Systems for automatedly delivering explosives with variable densities are disclosed herein. Methods of automatedly delivering explosives with variable densities are disclosed herein. Methods of determining an emulsion explosive density profile are disclosed herein.

Systems for automatedly delivering explosives with variable densities are disclosed herein. Methods of automatedly delivering explosives with variable densities are disclosed herein. Methods of determining an emulsion explosive density profile are disclosed herein.

The invention provides an apparatus and method for preventing surrounding loose rock fragments from falling or collapsing into a blast hole. The apparatus includes a flexible sheet including a pair of spaced apart longitudinally extending side edges and a pair of spaced apart laterally extending end edges. The sheet has a curved form defining a longitudinal passage extending between openings at longitudinally opposite ends, one end of the curved sheet being insertable into the open end of a blast hole whereby the curved sheet closely faces an internal surface of the blast hole and forms a barrier preventing surrounding loose rock fragments from falling or collapsing into the open end of the blast hole. The invention also provides a bench blasting method and a deployment device for deploying the apparatus into a blast hole.

The invention provides an apparatus and method for preventing surrounding loose rock fragments from falling or collapsing into a blast hole. The apparatus includes a flexible sheet including a pair of spaced apart longitudinally extending side edges and a pair of spaced apart laterally extending end edges. The sheet has a curved form defining a longitudinal passage extending between openings at longitudinally opposite ends, one end of the curved sheet being insertable into the open end of a blast hole whereby the curved sheet closely faces an internal surface of the blast hole and forms a barrier preventing surrounding loose rock fragments from falling or collapsing into the open end of the blast hole. The invention also provides a bench blasting method and a deployment device for deploying the apparatus into a blast hole.

An explosive tube having an air gap and a method of blasting bedrock using the same, comprising: a filling tube having a filling space which is to be filled with explosives; and an air tube, the upper part of which is connected with another tube to form an air gap space therein, and which has an insertion hole formed on the bottom of the air tube to introduce the explosives into the filling space, the air tube being integrally formed on the filling tube. A plurality of tubes filled with explosives are connected with each other and inserted into blasting holes formed through bedrock to break the bedrock by blasting the explosives. By forming an air gap in the upper part of the tube.

An explosive tube having an air gap and a method of blasting bedrock using the same, comprising: a filling tube having a filling space which is to be filled with explosives; and an air tube, the upper part of which is connected with another tube to form an air gap space therein, and which has an insertion hole formed on the bottom of the air tube to introduce the explosives into the filling space, the air tube being integrally formed on the filling tube. A plurality of tubes filled with explosives are connected with each other and inserted into blasting holes formed through bedrock to break the bedrock by blasting the explosives. By forming an air gap in the upper part of the tube.

The present invention provides a rock movement sensor including an inertial measurement assembly, a control assembly responsive to said inertial measurement assembly and a communication assembly coupled to the control assembly. The control assembly is arranged to determine a displacement associated with a blast or drop based on signals from the inertial measurement assembly. The communication assembly is preferably a wireless communication assembly. A surface unit corresponding to the rock movement sensor is provided which includes a processor programmed to operate a communications assembly to receive displacement data from the rock movement sensor. Consequently, the movement of an ore body due to a blast may be determined by locating a number of the rock movement sensors at known locations about the ore body prior to the blast and subsequently retrieving data values indicating a displacement relative to the known locations from the rock movement sensor post blast.

The present invention provides a rock movement sensor including an inertial measurement assembly, a control assembly responsive to said inertial measurement assembly and a communication assembly coupled to the control assembly. The control assembly is arranged to determine a displacement associated with a blast or drop based on signals from the inertial measurement assembly. The communication assembly is preferably a wireless communication assembly. A surface unit corresponding to the rock movement sensor is provided which includes a processor programmed to operate a communications assembly to receive displacement data from the rock movement sensor. Consequently, the movement of an ore body due to a blast may be determined by locating a number of the rock movement sensors at known locations about the ore body prior to the blast and subsequently retrieving data values indicating a displacement relative to the known locations from the rock movement sensor post blast.

A cartridge (1) is provided which includes an elongate tube (3) having a central body (5) that is closed at each end (11, 13) and containing a gas producing substance (30) therein. The tube (3) is made from a plastics material that is capable of outward deformation and a band (15) of an elastically deformable material is provided about the tube (3) adjacent each closed end. The tube (3) is configured such that internal pressure in the tube (3) caused by initiation of the gas producing substance (30) results in outward deformation of the body (5) and each band (15) and subsequent rupture of the body (5) prior to the closed ends being ruptured or opened.