Post Break Week 2

Comments for Consideration of Coal Miners One issue you have created is extreme variability in your coal tonnage – This will impact the markets you can actually go after Obviously you loose a lot of long term coal contracts – A side effect – your #5 coal is high chlorine and variable in sulfur content You loose all low chlorine coal markets You loose the ability to blend or average your coal sulfur content which will go up and down without control (unless you have incredible large stockpiles for blending) You have drastic turns in the size of your work crews.

Suggestion You have proven that your longwalls draw only 140 ft ahead of where they are – If you make #5 your timing control you can mine from #6 by room and pillar what ever is needed to keep steady tonnage Since #6 also has high and low sulfur areas you can mine from high or low sulfur areas to balance out the sulfur so long as the areas you mine are at least 140 ft ahead of the #5 longwall #6 can also provide you a low chlorine product (Yes that will cause a very wonky inefficient layout and timing in #6) To keep your own work crews steady use contract miners to mine room and pillar – use company employees to mine longwall – When you hit the weird labor drop around year 36 when you are mining only advance on the west side of the fault send some of your own employees to work room and pillar some place

Preparation Item to Look at You have washability curves on #7, #6, and #5 How high can you make your recovery and still meet your market specs? – You don’t have to go for the same recovery on all size fractions How will the sulfur content (and thus your coal price and markets) change as you mine – What is the average insitu sulfur level each year Get resulting mass balances worked through your coal preparation plant

Metal Miners There were huge problems with drawings last week – Your pits constructed by the expansion tool did not contain variable slopes – Because you never merged your pit surface with the topo surface you did not realize that half of your pit road to the end point at the surface was in the middle of the air Your road may not even come out and meet your other roads

Draw Me Pretty Pictures Your can adjust your pit slope in the pit expansion tool using the “options” tab. You will want to use pit slopes by sectors – Activate MineSight – On the menu at the far right click help On the drop down menu pick the first item “ms3d and compass help” – In the window that opens select the search tab – Type in pit expansion tool – On the list that appears pick pit expansion and then click display Read all about how to do variable slopes in the pit expansion tool You will be doing pit slopes by sector (my guess on how to best do this)

Construct Me Pits First put the borrow pit for Idris’s roads so that you are pre-stripping ore (this does not mean mine ore for use in roads) – Merge the borrow pit with the topo surface – Show me the surface with the borrow pit and roads in place – Show me a report on the borrow pit that shows you did not mine ore Be prepared in later drawing to show that the material you removed in fact was pre-stripping ore you would mine.

Continued Use the pit expansion tool and construct the pit at 3, 6, 9, 12,15,20,25,30,35,and 40 years (assuming a rate for a 40 year mine life) – These pits should honor the variable slopes by direction Use a set of 2D cross sections to show that your expansion pits follow the phase pit outlines produced by MSOPIT – The conveyor slope road in the pit should have a slope of 20% (recommended maximum slope prescribed by CEMA for copper ore) – Use your pit contours from the pit expansion tool and triangulate and surface and then intersect and merge that surface with the topo surface (ie don’t just have a topo surface and the pit contour objects on at the same time) Show that your road into the pit actually exists below ground for its entire length Do the same for your conveyor route Show that your roads and conveyor routes come out to meet your existing roads. (If they do not you may have to rebuild all your roads on the surface and rebalance your cut and fill and redesign your borrow pit).

Check Your Roads with Time Do any of your push-backs destroy the haul roads? – If so do a view of your pit before the push back with a replacement haul road in place before destroying the old haul road – Show that your pit is never without a viable haul road

Check Your Tonnages You already have surfaces created by MSOPIT for different phases of the pit being mined – Use the reserves function in MSOPIT and show the reserves by type and grade that you have between each pit Example – I have a pit surface at year 3 and year 6 – I do not want a total reserves report on the year 3 and the year 6 pit – I want the reserves between the 3 year and 6 year pit Now use the merged surface created from triangulating your pit expansion pit and intersecting it with the topo surface – Create a gridded surface from the topography – Now use the resulting gridded surfaces and MSOPIT to check the reserves between each pit as you actually built them. Compare your reserves by year for theoretical and as built pits – Show that your as built pits are reasonably following the theoretical pits – What is “reasonable” – within about 15% (Rio Tinto does this exercise and requires 5%)

Comment This will require hours and hours of MineSight drawing work – Don’t dump this on one person (he’ll die and won’t finish) – Divide the work up and get everyone doing MineSight drawings – Build the views to demonstrate pit and performance and put them in slides as you go along rather than praying for a 24 hour wonder of putting everything into a slide show at the last minute.