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Archive for the ‘Mining history’ Category

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I was always healthy until I visited the doctor for a checkup.  Then they found all sorts of things wrong with me:  internal components not working; high levels of this and that and consequential concerns; indications of too much drink and smoking; blood pressure where it should not be;  weight too high; and so on.  Although I did loose some fifteen lbs on my recent trip to Peru and Chile. Maybe not enough alcohol,  lots of walking, and all that terrible Peruvian food.  How can you like raw fish in vinegar; black potatoes in squid ink; or slimy muscles in red pepper?  I cannot and probably ate too little.

No matter.  We get old and things go wrong.   I suppose it is all a matter of what will get me first.  As long as it is not an angry reader of this blog.  But the doctor laughed and told me to keep going for there are many years yet to write this stuff, she said.  When did the doctor become a lady younger than my daughters?  It is just not fare.

So instead I spent the day writing reports on tailings dam I have recently observed.  I am amazed at the low standard of stability analyses I have seen.  Fourteen analyses and not one of them is correct!  Here is a list of the most common mistakes.  At least I have set those so-called reputable consultants working again.

  • Failure to include foundation soils in the stability analyses.  Apparently they did no foundation drilling, so did not include foundation layers.  Subsequent drilling has shown there are liquefiable layers in the foundation.
  • Failure to include the phreatic line in the cross section.  Apparently they had not yet installed piezometers so had no water table.  Subsequent work has shown that there is a high phreatic line in the cross section.
  • Use of circular arc failure surfaces in cohesionless materials.  We all know that planar failure surface develop in such materials.
  • Failure to use planar failure surface to calculate stability analyses involving sliding along a weak foundation layer.  They used circular arcs which simply cut through strong and weak foundation layers.
  • Use of the pseudostatic coefficient for seismic stability analyses in high earthquake regions.  They should be doing deformation analyses in order to estimate deformation.
  • Failure to account for buildup of excess pore pressures as the tailings rises.  Too complex to do I suppose.
  • Incorrect use of strengths of materials:  UU for slow failure and CU for fast failure.

No wonder these things fail.  Not only are the stability analyses done by amateurs, the phreatic surfaces they calculate using standard programs are just simply wrong.  But that is another blog topic.

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Many, many years ago I was in Sitka for a conference on Marine Tailings Disposal.  The proceedings were published in a book edited by D.V. Ellis.  You can get a copy from amazon.com for $4.00.  My copy is in the attic of the house in Huntington Beach.  Bet none of the kids will ever read the paper therein that I wrote with John Welsh. Recently one of the many who communicate with me via private email sent me a remarkable document.  It is the DSTP Initiative: 2014 Knowledge Workshop Report dated May 2014.   Keep in mind DSTP stands for Deep Sea Tailings Placement. (more…)

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In February next year I shall go to the Society of Mining Engineers (SME) conference in Denver.  One evening I shall dine with Andy Robertson and his party.  We will celebrate his induction into the Mining Hall of Fame. This is a signal honor for him and due recognition of his many contributions to the mining industry.  He well deserves it.  Not that he needs more recognition–most people I speak to know and respect him.  He is well-known for his superior intellect, his accomplishments, and his human gentleness.  For he is first and foremost a gentleman in all meanings of the word. (more…)

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This year I have visited at least sixteen tailings facilities from the far north of Canada to the far south of Chile.  Mainly I was there to see about the state, safety, and ongoing operation of the facilities.  But along the way I had an incredible opportunity to observe and photograph mine water management facilities and systems. In next week’s EduMine webcast on Mine Water Management, I will have a chance to distill these many observations into a coherent whole.  So come join us in the webcast next Tuesday, Wednesday, and Thursday.  But three hours a day each morning and I will update you on the many systems, practices, components, and ideas I have gleaned from these trips and observations.  Many new case histories courtesy of the mines I visited. (more…)

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Woke up late this morning after twelve hours sleep—seems the older I get the more I want to sleep.  Maybe it is old age or maybe riding my bicycle to work tires out the old body.  Or maybe there is something breaking down inside that the doctors cannot discern. (more…)

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The Tyee, a local Vancouver newspaper at this link, with some amazement recognizes with regard to the Morgenstern, Vick, and Van Zyl panel: (more…)

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ohnesans.tumblf.com_Lorenzo posing for charity calendar_by Erwoud Broeksma[1]

At this link is a great Master thesis recently completed by Genki Taguchi, a student of the University of British Columbia.  He is now back in Japan working in the coal mining industry.  Dirk Van Zyl supervised the thesis.  And if that link does not work, here is a second link.  A great job by both.  And a document which should become required reading by all in tailings. (more…)

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