Using Economic compositing in Leapfrog Geo

Economic compositing classifies assay data into “ore” and “waste” categories, taking into account grade thresholds, mining dimensions and allowable internal dilution

Video Transcript

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<v Narrator>Welcome to our bite-sized video</v>

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on the economic compositing.

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The short demonstration is designed to give you

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an introduction to using the economic compositing tool.

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For a detail review and guide,

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we have a longer video available on our YouTube channel.

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In Leapfrog, you have the option to composite drill holes.

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Compositing is a process to reduce the variability

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of sample sizes, that may exist in a database.

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There are several reasons

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why you may want to composite drill hole data,

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and leapfrog provides different methods

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to achieve the desired output.

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For today’s video,

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we are focusing on the economic composite tool.

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The economic composite tool takes the raw assay data

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and sets always rules based on run length grade

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and internal dilution.

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The output includes all waste categorical intervals,

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as well as numeric composite intervals

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based on a cutoff grade,

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which can then be used to generate geological model volumes,

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and used for statistical analysis and numeric modeling.

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The aim is to create a reasonable mineralized envelope

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from all intervals that have been generated

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based on mine ability parameters,

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in addition to a cutoff grade.

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This is useful when geology is maybe poorly understood,

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geology doesn’t control mineralization,

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or when assay is the only information that is available.

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So we’ll jump into leapfrog,

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and we’ll start by having a look our assay data.

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So here you can see one of our datasets,

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where we’ve had a number of drill holes

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intersecting mineralization.

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In more advanced deposits,

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you may know,

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or want to evaluate

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a number of mining in an economic parameters,

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such as the impact of applying gray cutoffs

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and minimum mining widths.

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All compositing tools in leapfrog

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can be found under the drill holes object,

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in the composites folder.

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Right click and will bring up the menu.

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And then we can select the economic composite tool.

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When you initially open the economic compositing tool,

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there are a number of options available.

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Firstly, you set the numeric value of interest.

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In this case, we’re going to be looking today at zinc.

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You can set rules for missing values.

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You can either use a fixed value.

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Sometimes things like half the detection limit,

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or you can use an average of the enclosed intervals,

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if your mineralization is more continuous.

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In particularly nuggety deposits,

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or ones with extreme outliers,

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you can cap high grades as well.

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Next, we have the compositing tab.

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There are three composting types to choose from,

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basic, advanced and advanced plus.

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Basic uses a simple length weighted average,

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and will tend to produce longer waste or composites.

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The advanced and advanced plus

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are generally more conservative,

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in that they provide greater control

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over waste dilution of ore.

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For today’s exercise we’ll pick advanced.

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For the cut off grade, the histogram can be used as a guide.

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There’s an option to set a standard view or lock scale,

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and you can also adjust the number of bins.

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Depending on what you set your cut-off grade at

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values greater than or equal to the cutoff grade

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is considered ore and less than is considered waste.

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For today’s analysis we will set the cutoff at five.

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And for the minimum ore composite length,

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we will set the value at five meters.

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The minimum ore interval can be designed to meet

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a predetermined mineable ore size

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or other factors that you may need to consider.

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Use true thickness setting can be applied when drilling

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is a bleak to the major trend of mineralization,

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which can result in some…

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sample intervals becoming much longer than the true width

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selecting this option requires composting algorithm.

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To composite using true thickness,

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measured perpendicular to a specified reference plane,

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essentially weighting the value,

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so as not to over-represent mineralized samples.

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Max included waste is an optional threshold.

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The constraints is the total length of waste

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that can be accumulated within an ore composite.

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Increasing this value will permit

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greater dilution of ore with waste

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before the candidate ore section will be rejected.

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Max consecutive waste is an optional threshold for basic,

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and advanced dilution rules,

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but it is required for the advanced plus.

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It constraints the length of the consecutive end force

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classified as waste that can be considered

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for addition to an old composite.

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keep short high grade or composites is an option that allows

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all composites less than the minimum length to be included.

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This is provided at the minimum linear grade is exceeded.

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Compositing direction,

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just determines which way the algorithm runs

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up or down the hole.

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And when you use an advanced,

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advanced plus, both is selected as default.

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compositing twice,

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will run the compositing process a second time

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after the first pass,

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which can sometimes help to smooth out and the results.

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Once we’ve set a cut-off grade of 5%

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and a minimum length of five,

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I’m going to leave the other ones as default,

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and we’ll just pick an appropriate name

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for our composite table.

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click okay and let this run.

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Once this is processed,

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we now have the new table in our composite folder.

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If we double click to look at the table,

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we can see it brings up an overview of the data available.

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To quickly run through these,

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status is the category, is defined as ore or waste

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based on our parameters.

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Using the same column gives you the weighted average grade

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of that interval.

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The true length is the linear length of that interval.

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Linear grade is the average grade times by the true length.

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The dilution true length,

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is the total length of any diluting intervals.

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i.e, intervals that fall below the cutoff we’ve specified.

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Your dilution linear grade, is the weighted linear grade

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below the cutoff material times by the length

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and the percentage missing,

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is the percentage of missing samples within the composite.

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If we load, our composite table onto the scene,

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we can turn off the assays, and have a look at the results.

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So you can see we had the legend.

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That the composting tool has gone through

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and classified our drill holes

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into waste in blue, and ore intervals in red.

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If we turn off the waste,

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we can start to get an idea of the trend,

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and the direction of the mineralization.

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To have a look at this in a bit more detail

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what we’ll do is,

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we’ll focus in on one particular drill hole.

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If I click on my ore interval,

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I get the same statistics that we looked at on the table.

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So in this case,

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I can see that my ore interval is 55.1 meters long

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and average grade of 12.72%.

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Within this ore interval, I have 2.5 meters of dilution,

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and we can see that 2.5 meters is probably this

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sample sits in here.

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I can color this by the same discreet color map

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to see what falls above and below.

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We can then start to understand the impacts

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of these decisions through numerical models

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or use the category data to model domains.

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For a reasonably complex topic.

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This is a very brief overview.

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As mentioned at the start of the video,

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we have a more detailed discussion around the settings

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and processes on our YouTube channel,

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which I’d recommend you watch.

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If this is something that may be of value to you.

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Thanks very much for joining.