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A bit of self promotion.  There is still time to sign up and join us next Tuesday, Wednesday, and Thursday mornings (PST) for the EduMine course on Mine Waste Management and Treatment.  See this link for details.

This is an entirely new course–none of the materials we will present have been presented before.  The reason this is new and important are the presenters:

Jack Caldwell will focus on the engineering side of water management, discussing available state-of-the-art technologies and appropriate management systems for advanced mine water management from design through closure, including a renewed focus on risk assessment and decision making. David Kratochvil and Patrick Littlejohn of BioteQ will address recent advances in processing and treating water for mine uses, mine reuse, and discharge.

In particular this is the first time that David and Patrick are presenting an EduMine webcast.   I have known them both for many years and have become more and more impressed by their knowledge, skills, and ability.  I just had to get them with me onto an EduMine course.  I know that what they present will be state-of-the art, practical, and relevant.

We will deal with the new ICMM guidelines on mine water management, on limiting water use on mines, on treating water to recycle water, and preparing water for discharge in accordance with more stringent regulations.  We will discuss the best papers of the past year in InfoMine and other conference on mine water management & treatment.  In short we aim to bring you up-to-date with the best, newest, and most practical approaches to making your mine use less water, use water wisely, and reduce the increasing cost of water and it use.

All three of us stand ready to talk with you about the course before the course if you like.  Contact me at jcaldwell@infomine.com and I will direct you as appropriate to David or Patrick.  In fact if you have special issues, join us, let us know of your specific interest, and we will address them in the course.

See you there.

 

I am working on a new EduMine course on Cover.  It will probably be a year or so before it is available.  SO here is some interesting information I compiled yesterday.

Undoubtedly the best way to control erosion on sideslope covers is to place a layer of durable rock. We perfected the design procedures on the UMTRA Project, and full details of the design and analytical approaches can be found in the Technical Approach Document. The methods described in the Technical Approach Document for selection of the size of the rock are based on methods described in Methodologies for Evaluating Long-term Stabilization Design of Uranium Mill Tailings Impoundments NUREG/CR-4620 and Development of Riprap Design Criteria by Riprap Testing in Flumes NUREG/CR-4651. It is worth downloading these three documents and reading them even if you never need to calculate the size of rock for cover erosion control. At the very least see a magnificent summary of the methods in a paper Erosion Cover Design for Disposal Sites by Berg Keshian and Mike Bone, who in truth deserve the credit for the methods and their practical implementation.

The guidance documents referenced above were written in the 1980s. Since then many more rip rap design guidance documents have been published. One that is easy to read is Riprap Design and Construction Guide from the British Columbia Ministry of Environment. Many other jurisdictions have published similar guidance document that focus on local conditions and requirements. A good example is the National Cooperative Highway Research Program’s Report 568 Riprap Design Criteria, Recommended Specifications, and Quality Control. Seek them out if you need to size the rock for a cover. Finally see Steven Abt’s 2013 assessment of the many methods for designing riprap in the paper Evaluation of overtopping riprap design relationships. A good example calculation of the rock size is at this link which is an appendix to the Sequoyah Facility Reclamation Plan.

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On Saturday I succumbed and bought an electric bicycle.  It is marked Evo-Race and Easy Motion.  I got it from a small store in North Vancouver on Forrester Avenue for about half of what I paid for my five-year old Honda Civic when the lease ran out.  A bargain—the Honda, not the bike.

Yesterday I rode the new bike up the Lower Seymour Conservation Reserve road. Some fourteen kilometer uphill and the same downhill.  Those hitherto steep hills faded to nothing.  Put the bike in level five electric assist and up you go at far greater speed than is polite.  Then coming back downhill, I put it to level one assist and hit a high of 55 km/hr.  This speed, amazing to me, was not the electric assist.  For the assist cuts out at 39 km.hr.  Rather the speed is the result of long, steep downhill stretches and a bit of pedalling.

Today I rode into and back from town along the usual routes I take with my ordinary bicycles: the Cannondale Quick, the Trek roadbike, or the Trek cross country bike.  I prefer the Cannondale as it light and easy to maneuver.  You sit more or less upright and can see and weave in and out of traffic in the city streets and bike lanes.

But it is a whole different ride on the Evo.  I took me but 45 minutes to get home across the second narrows bridge; it normally take an hour and a quarter—half an hour more to drink!   The ride down to the SeaBus was not much different as it is all downhill.  But those steep hills, that get steeper each year, melted in the face of level five assist and a bit of pedalling–for you have to pedal otherwise the assist cuts out.

In spite of what I imagined, you still get a good workout on the electric bike.  It is heavy and needs human (arm and upper body) power to control.  You still have to pedal furiously to keep it moving in the lower gears and lower assist settings.  You still need to move those legs and breath fast to keep moving.  Faster than a normal bike, perhaps, but an equal physical workout over an hour and a half there and back.

So I am glad I stopped hesitating and at 68 gave into to a modern contraption–an electric bike.  If you are hesitating, getting old, and the hills are getting intolerably steep, go get an electric bike.  It is great and I will still ride the other bikes to keep in peak fitness.  Promise.

And in closing let us stop to sympathize with the Iranian blogger Farshid Fathi and the Saudi Arabian blogger Raif Badawi both of whom are sentenced to and have been flogged and imprisoned for blogging.  I have done in a secular sense what they did otherwise.  So now I blog poetry and electric bikes.  Makes you wonder?

 

The city was built on Cambrian rifts,
boot-sucking mud, a rush to stake alliances.
Now it’s birch, white pine, and alder creaking,
a low, flat tailings pond where nothing thrives.
Cat’s cradle of a radio tower the only hint

that the human hive once buzzed,
air-drilling its way from darkness to darkness.
Like trees in Kyiv that have been dead for twenty years,
still fully in leaf, you imagine breaking a branch
and hearing the hiss and crack of a voice.

Doesn’t an engine revving somewhere seem to lend the flies
that gather round us like a prayer? There’s no one here.
Mushrooms tilt their  mitres like a brotherhood,
break the locked box in the wood.  A sticking point:
that the day has never been more beautiful and clear:

this is the place you’re more likely to be struck by lightening
than attacked by a bear. Into spore-charged air
the blow-by-blow seems to take—that, in the beginning,
houses bloomed like campanulas on the highest point;
that, in the end, it wasn’t the mine but the mall that collapsed.

 

This copied with thanks and admiration from the April 2015 issue of The Walrus.

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Here is a challenge written up in a recent comment on a previous blog posting:

I would love to see someone write a paper on the merits of a wet tailings pond. Today’s lovechild seems to be the filtered tailing concept but let’s hear some kudos for a properly designed wet tailings pond. It gives the ability to deal with seasonal or short term storm water surges, the ability to store water for use in low flow periods, avoids needing to continually withdraw process water from rivers or lakes, keeps ARD materials submerged, lower capex & opex, lower power consumption via natural clarification instead of mechanical clarification, and less greenhouse gas emissions related to lower power consumption. Where are the friends of the conventional tailings pond or have they gone into hiding from the filtered tailings mob?

Today I had lunch with John Gadsby who is 82 and still active in tailings.  Way back in 1983, he and Syd Hillis were the peer reviewers of my work on the design and construction of the Cannon Mine tailings facility besides Wenatchee, Washington.  I asked him the questions implicit in the comment above.

He quickly reminded me that the Cannon tailings facility was a very successful wet tailings deposition facility that was also designed to contain lots of water from heavy rains in the catchment area of the Cascades.  He reminded me that that facility was built to be secure as it is upgradient of a significant part of Wenatchee.  He said he thought the facility must surely represent the best tailings technology for wet tailings deposition ever.  And now it is closed and part of the Dry Gulch Riding Stables–an asset to the local community.

Without being too bold & boastful, I know this dam was good, is good, and will remain stable for a very long time hence.  It proves, in my mind, that you can mine close to communities, can safely manage wet tailings in sensitive environments, and can close mine sites for sustainable use.  Here are links to some papers I wrote on its design & construction:

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You can get all these papers by going to the InfoMine Library and doing a search for Cannon Caldwell.  You can also get a lot more information at the official Cannon Mine website.

So now let us have a debate about whether this tailings facility built in 1983 and 1984 represent current best practice or best available technology for wet tailings management.  I think it does, but then I am hopelessly prejudiced.  And I recognize parochial sentiments sometime inhibit cross-boarder admiration of engineering works.  Still you can get there in a four-hour drive from Vancouver.  Go see it sometime.

 

 

 

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It has been a tumultuous week of many events.   No blogging however. No topic caught my attention enough to spur the muse and misogynist.  So here a few stories of mining to entertain us and prompt the responsible journalist to attention. Continue Reading »

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The Fraser Institute survey came out in February. I missed it—so here is a brief summary. Continue Reading »

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