GREY:ABGPF - Post by User
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DoctorFouadon Jan 10, 2015 2:29pm
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Post# 23305741
Importance of low stripping ratios for Graphite projects
Importance of low stripping ratios for Graphite projectsA comparison of stripping ratios of different graphite projects (first part, I will complete with some analysis when i have time)
While the ore head grade of carbon content (in % cg) of graphite deposits is important in determining the potential profitability of a graphite mining project, the head grade doesn't tell the whole story. Another important factor to consider, often neglected by investors, is the stripping ratio, or how much waste should be moved to get a certain amount of ore.
The lowest waste to ore (stripping ratio) is, the lower the cost of mining will be. A graphite deposit with lower head grade could offset this shortcoming if the stripping ratio is low as a result for example of the deposit being at surface, oxidized with low rock hardness, resulting in a potentially lower operating and capital costs than other supposedly higher head grade deposits. (this may be the case of alabama graphite deposit, but we should wait for the PEA/DFA to confirm this).
Definition of strip ratio in mining projects :
"A strip ratio is a measurement related to the open-pit mining process that shows the amount of waste material, also known as overburden, that has to be moved to get a certain amount of ore.
However, strip ratios are not only about the volume of unwanted material present at a site. They also take into account what kind of material must be removed to reach ore. That’s because moving lightweight material like sand or dirt is relatively simple, while moving material like hard rock to get to ore is difficult."
Source :
https://resourceinvestingnews.com/72422-strip-ratio-western-copper-gold-nemaska-lithium.html
Focus Graphite : (1.8:1)
"Life of Mine Plan resulted in an overall average strip ratio of 1.8 to 1 for 25 years."
Source : (feasibility study highlights, published june 2014)
https://www.focusgraphite.com/focus-graphites-lac-knife-projects-benchmark-feasibility-study-reports/
Mason Graphite : (0.76:1)
Overall M&I grade of 15.6% Cg; the main parameters of the preliminary economic assessment for the Lac Guéret project (the "PEA") are still valid: 22 years of production at 27.4% with a low stripping ratio at 0.76:1 and low operating costs at $390/tonne
Source : (Preliminary Economic Assessment Highlights, published December 2013)
https://www.masongraphite.com/news/news-details/2013/Mason-Graphite-reports-658-increase-in-measured-and-indicated-mineral-resources-to-50-million-tonnes-including-67-million-tonnes-grading-324-Cg/default.aspx
Northern Graphite : (0.5:1)
"Northern Graphite tabled a bankable feasibility study in July. It is based on a 23-year mine life, an open-pit probable reserve of 18.9 million tonnes of 1.89% graphitic carbon at a cutoff of 1.2%, strip ratio of 0.5:1"
Source : an article by Mickey Fulp, published in november 2012, based on the results of the july 2012 Feasibility study of Northern graphite project
https://m.resourceinvestor.com/2012/11/27/three-sharp-pencils-in-the-graphite-game