Archive for the ‘Reclamation’ Category
The numbers just do not add up. As I read the many sites on the web, I learn that British Columbia has about thirty operating mines. The BC government has about $172 million in closure bonds. Say about five or six million a mine. That seems grossly inadequate to me. I have just finished estimating closure of one mine and it came to nearly $60 million. Does this mean BC should have $1.7 billion in closure bonds? Here are some observations from various websites that may help you ponder this issue. (more…)
The most confident fellow in the meeting was the specialist in permitting from Toronto. He was old, like me, and in total command of his subject. He reminded us: “California is both the most difficult and yet the easiest state in the Union in which to permit a mine. It is easy because the process is simple: fill in the boxes, check off the items of the checklist, and it is done. It is the most difficult because you need to have done the work to ensure the right answer to fill in the boxes. If you do not have a comprehensive, well-thought-out, and defensive plan, you cannot fill in the boxes, complete the checklist, and get the regulators to say OK.” (more…)
I am told that yesterday’s posting was hard to read. So rather than write tonight, let me simply post some pictures I took from a public road of tailings facilities closed by the Peruvian regulators. Not sure how long the gabion baskets will last.
Posted in consulting, Geosynthetics, Geotechnical, Heap leach, Reclamation, Tailings, Waste Rock, tagged cover, erosion, geosynthetic, mine closure, Reclamation, rock cover, slope stability on July 2, 2014 | Leave a Comment »
The exterior surface of most tailings, waste rock, and heap leach facilities include:
- A top deck which is the flatter surface that forms the top surface of the facility. This is usually sloped at between one and five percent, primarily to promote runoff.
- The sideslopes which are easily covered if they are inclined at about five horizontal to one vertical (5H:1V) but which in practice may be as steep as 1.4H:1V.
Covers on the top deck are less subject to erosion, slope instability, and soil creep than covers on sideslopes. Thus different covers may be appropriate at the same facility on the top deck as compared to the sideslopes. Here are a few idle thoughts on sideslope covers for mine waste facilities. (more…)
Subaqueous disposal means placement of tailings into or beneath a water cover. Deposition of tailings into a lake is the most common subaqueous method. In many instances the embankment dam is constructed as a water retaining structure and the impoundment is filled with water into which the tailings are discharged. (more…)
Posted in consulting, Enviromental, environmental, Human relations and mining, Latin America, Reclamation, tagged Anglo American, Chile, guidance, mine closure, promises & lies, toolbox on May 16, 2014 | 2 Comments »
Today we completed a successful three-day EduMine webcast on mine closure. Folk from Germany, Finland, Mauritania, South Africa, Australia, Guatemala, the USA, and Canada “attended.” We are flattered and thankful to them and applaud their interest in a critical topic and facet of mining. If you missed the webcast, contact EduMine and ask them to repeat it. (more…)