Shock Tube: Avoiding unplanned energy release on the stope face

30 September 2014

WealthUnearthed

Agenda

What is unplanned energy release?

Unintentional detonation: Blast incidents

Non detonation

Incorrect timing

Product compatibility

Where does the Uni-delay come from?

Finally

Finally

Questions, Myths and Comments.

At what impact will shock tube detonate?

What is snap and shoot?

Can I detonate an In hole detonator by detonating the Out hole detonator?

It is difficult to detect misfired Shock Tube

Shock Tube is too fast and damages my hanging wall

Questions, Myths and Comments.

At what impact will shock tube detonate?

40 Joules for a typical shock tube detonator under the perfect impact conditions

Fall Hammer Test

Impact Tests

Questions, Myths and Comments.

At what impact will shock tube detonate?

What is snap and shoot?

Myth:

Snap and shoot does NOT exist

What really happens………

AEL`s experience:

• In the field – Not ever experienced

• In the factory – coiling during extrusion

Questions, Myths and Comments.

At what impact will shock tube detonate?

What is snap and shoot?

Can I detonate an In hole detonator by detonating the Out hole detonator?

Reverse propagation Test

Questions, Myths and Comments.

At what impact will shock tube detonate?

What is snap and shoot?

Can I detonate an In hole detonator by detonating the Out hole detonator?

It is difficult to detect misfired Shock Tube

Significant difference

Vivid

Questions, Myths and Comments.

At what impact will shock tube detonate?

What is snap and shoot?

Can I detonate an In hole detonator by detonating the Out hole detonator?

It is difficult to detect misfired Shock Tube

Shock Tube is too fast and damages my hanging wall

Shock Tube is too fast and damages my hanging wall.

200ms out-hole delay (Time between shots)

Timing?

Reverse Timing

Blast model to be put in here

FOG`s in South African Mines

Falls of Ground vs Shock Tube growth

1092

950

779

833

720

655621

526

86 7656 64 48 39 25 32

0

200

400

600

800

1000

1200

0

20000000

40000000

60000000

80000000

100000000

120000000

140000000

160000000

180000000

2006 2007 2008 2009 2010 2011 2012 2013

Shock tube units Injuries Fataities

Explosives related fires in the mining industry

Questions posed up front

References and acknowledgements

Derek Nel – Product Manager AEL Shock Tube Products

DMR – Annual Reports

Christo de Klerk – RTS

Simon Tose – AEL

Sandy Etchells - AEL

Mauritz Kotze - AEL

Andries Botha – AEL

My Team in the Free State

Shock Tube: Avoiding unplanned Energy Release in the Stope Face30 September 2014

Thank You