blasting smallish tunnels in hard rock

Richard Smith · 2023-12-17T18:56:06+00:00

Anyone here know about blasting person-height&width tunnels in hardrock?I have some contacts here (UK), but broadening the casting around forinformation. Maybe bringing in North American perspective.Especially noting how much I have gained here from previous ask aboutmine haulage-shafts and skips.New to me. If I'm pointed in the right direction and told the realdeal(s) to look out for, I can do a lot of my own reading.Some of the rock here is "killas" - a heated "metamorphosed"sedimentary rock which is quite brittle. Usually associated with"wet" mines.Then there is hard granite. Very hard. A 4-carbide-teeth drill bitcannot touch some when driven by a rock-drill which can go 1~1/2metresin minutes with a simple chisel-edged carbide-tipped drill bit. Minesin that can go a mile out under the sea and be dry.As best I can explain from what I have seen; being a metallurgist andwelder.There's something which would be very useful here making everythingpossible, so it seems.Something about electronically timed detonators which can seriallydetonate "go off at the same time" charges a few microseconds apart,which is apparently enough that at the surface only the effect of onecharge is felt.So pointers on that would be appreciated.Blasting mine tunnels is done radially here I gather from what I haveseen explained at mining museums - blast from the middle outwards,sending the fractured rock towards the middle (heard of the centralhole being "reamed" - no charge in it obviously - provides the firstvoid to collapse the first ring of rock into).Historically gelignite but noted that "ampho" is usually cheaper now.Another reason for asking for a North American viewpoint is that folkare much less restricted there - and therefore you get a lot of verypractically experienced folk. eg. when in Texas my host took me tothe range every morning with two holdalls full of hardware - learned alot quickly.Everyone has to be very stern and restricted here trying to appeasethe powers-that-be...

Dec 17, 2023 Last reply: 2 years ago 121 Replies

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Jim Wilkins 2 years ago

Nuclear fission power has to way improve. In the USA you can have inland water-cooled-reactors - PWR's (and BWR's)

- because you have continental-sized rivers to take away the abundant! waste heat.

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The antis will find some excuse to cripple any energy source with lawsuits.

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But who protests against this?

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Do you see a pattern?

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pyotr filipivich 2 years ago

Richard Smith snipped-for-privacy@void.com on Fri, 29 Mar 2024 09:16:16 +0000 typed in rec.crafts.metalworking the following:

Could switch from Uranium fueled to Thorium. There isn't any such animal as "enriched thorium", which minimizes that issue.

Or scale down. Nuclear power's biggest issue is that effectively, all the plants are Mega Plants, and each one is a one-off, hand crafted artisan production. No economies of scale, which applies to the learning curve for manufacturing as well.

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