Neil Ringdahl Profile picture
May 4, 2021 9 tweets 4 min read Read on X
1/8 Dimension Stone (DS): Now if there ever was a cut-throat business, it would be this one. Worse than the diamond industry in terms of competitiveness, it seems the Taiwanese & the Italians have pretty much cornered the market. This particular granite mine is in Zimbabwe🇿🇼
2/8 Dimension stone is a really messy mining business with quite a serious environmental footprint. Hard to rehab the holes and tonnes of oversize rubble. Blame the banks & other rich Co's that want beautiful skyscrapers & floors, for example the Scotiabank building in Toronto.
3/8 Only 10-25% of what is mined goes out as sellable product. This is because its only possible to sell big, clean blocks with no faults or joints; natural weaknesses which cause a block to split when it is cut by a diamond saw. Breaks easily. Blocks are huge & generally
4/8 difficult to move. Earthmoving equipment does not last long at all➡️High maintenance cost per tonne. The blocks are mined by a combination of diamond wire cutting &drilling lots of parallel holes, then splitting it off. Just imagine breaking out the four 4 sides of each block
5/8 perfectly every time: Hard to impossible without first mining a slot behind / beneath the block you are targeting. In this pic they are drilling the bottom holes. Holes have to be slowly, surveyed exactly parallel to create a clean split. Diamond wire cutting is done by
6/8 threading a continuous steel rope impregnated with diamonds around the block, and then tensioning it and running it through a machine. its a similar mechanism to a ski lift, but the abrasion of the rope cuts a smooth slot in the rock instead of returning over a pulley.
7/8 It is not hard to imagine that with all the mining losses & labour-intensive & time consuming setup and recovery results in the highest cost per tonne in the industry. The price of the blocks is determined by size, colour, weight and quality & market demand which is
8/8 variable & susceptible to global economic conditions. Red and black granites are only found in a few parts of the world like 🇨🇦🇿🇦and 🇿🇼 while 🇪🇸& 🇮🇹are famous for their white marbles. Certainly its a specialist, often marginal field, one I have no plans to venture into.😑

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More from @NeilRingdahl

Nov 29, 2022
Good tactical & strategic planning along with execution is more important than grade. A 🧵

Our case study today is Pure Gold $PGM
& how it turned into Pure ..💩

1st, some theory you'll know if you have been following me 4 a while:
/1
These concepts are important because the decision was to use large trackless machines in the mining of the new access ramp & therefore say to say all ore development will be of a similar size as well. We should therefore expect dilution issues in narrower orebodies of Marsden /2
SRK (Vancouver) did quite a nice MRE for the Co. I know Wayne Barnett, he is quite a smart fellow & a good geo with solid experience. The report reads well, and tellingly, there are NO RESERVES & NO MINE PLAN. Alarm🔔's beginning to ring. /3
Read 13 tweets
Nov 23, 2022
#Mining with Electric machines: A modern miracle to save the environment or a pipe dream? 🧵
I'll discuss both open pit & underground apps.
For 60yrs, engineers have been innovating electric mining machines b/c they're cheaper. An electric dragline moves 60t each swing.😳1/
These monsters are so huge, a ship's diesel engines don't cut it. Way before I was even born, the clever guys worked out its cheaper -on a per-tonne basis- to use electric motors connected to the grid. They work well and are excellent in soft-rock stripping operations. 2/
Mining is about LOGISTICS of moving large masses of material to expose what is valuable & then move the valuable material to extract the metal. All this movement requires a LOT of energy.👇If you have ever dug your own swimming pool, you understand.😏 3/
Read 20 tweets
Oct 23, 2022
The DANGERS of spreadsheet mining. A🧵

Some of you may have been following the $AUN debacle, a good e.g. when the Lassonde curve goes south. 😬

I will discuss a few important technical flaws in the Aurcana investment thesis. /1
A couple of things in the 2022 Feasibility study Mineral Reserve Estimate immediately jump out.
1- The reserve is small
2- The min. mining width is crazy
3- The dilution No.'s seem too precise

One thing mining is not is precise. It can be accurate, but that's a different thing/2
Let's learn all about this mining method from $AUN. Below are excerpts from the FS tech report with my comments in red.
A (nice) investor video of the mine explains the resue method quite well by the then COO during minutes 16:41-23:33.

/3
Read 11 tweets
Aug 25, 2022
1/ Lets review this Q:
@Darken_Man got it right, well done.
Look at the pit floor: Very uneven, by far the biggest negative impact on this operation. Why? Slower reversing in, slower truck tramming, more difficult loading & damage to tyres. "How so?", you may ask.
Thread:
2/ Have you ever driven a car on a really bad road? Its slow and hurts the car. With trucks its way, way worse b/c trucks are the most expensive part of the open pit mining biz. & they're also the production conveyor that moves your product in diluted form to the plant.
3/ Consider a typical medium-sized OP operation with 180t dump trucks running an avg. cycle of 45 minutes, for 19 effective hrs/day. That works out to 1.64 million tonnes per truck per yr (with 5days off). Now, if the floor was level it would likely save 20-40 seconds reversing; Image
Read 15 tweets
May 17, 2022
1) Thread: From Drilling to Open Pit Optimization For Dummies.
Imagine you have project and hire a truly great geologist who has drilled some fantastic looking sections based on a small surface anomaly he found from a surface geochem sampling program. Image
2) Your geologist (lets call him George) tells you its a pipe-like copper skarn, vertical in nature about 50m wide and open at depth that he interprets (a key word here) in section in this pic below. (We will keep things simple by staying in only two dimensions X & Y). Image
3) Your drill results come back and your copper values are amazing. The consultants concur with George's interp, and then create a 3D grid over of blocks over it, each block being approximately equal to a the minimum mining unit size, which for open pit would be about 10x10x10m. Image
Read 19 tweets
Mar 28, 2022
1/11 $REG REVIEW Thread: - I'm a hopeful shareholder, underwater🙄for 3yrs now. Bought it at 1.65 - yeah crazy I know. Here's a review & why I'm still in. The pic below says it in 1000 words.
2/11 Probably the most important point is the property is and in particular the resource is part and the same of an adjacent operating mine, Tantahuatay, which is 40.1% owned by Buenaventura (the operators), 44.2% by Southern Copper & 15.7% by Regal Ware Inc. out of the USA.
3/11 Tantahuatay is a sweet oxide OP mine hitting the oxide cap above a huge porphyry & produced 110koz Au & 2.1Moz Ag last year. However this year production is F/casted to be 77koz Au as they start to get into the sulphides which cannot yet be processed.
Read 11 tweets

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