Presentation on theme: "How to Set Up a Processing Plan in MSOPIT’s Economics Panel."— Presentation transcript:
How to Set Up a Processing Plan in MSOPIT’s Economics Panel
Understanding the Panel You have 5 grade Items. We have your Metal targets but You may add one For value per ton Once that is Computed into The block model You could also have Things like a free Milling gold grade And an encapsulated Gold grade (your project is simplified to have constant percentages By ore type).
Ore Types Ore types go Across the Top. The Material Code identifies The block model Item containing The data. You have a type 8 carbonate Ore but no type 7.
Processes Processes run down Columns. You may have a host Of processes that May apply to one Or more ore types You may have high Cost high recovery Low cost low recovery Processes. Usually best recovery Is at the top. A zero recovery waste process must be last on the list.
Each Cost and Economics Subpanel Applies only to one ore type and process How do I deal With ore and Overburden Mining costs? When you are in A process/ ore type Box the mining Cost is an ore Mining cost When you are in A waste cell the Mining cost is for Waste. (Important note 1- You do not build a stripping ratio into a mining cost) (Important note 2 – Haulage distance and handle costs may differ by location)
What’s this business about haulage and handling costs may vary by location? You may blast ore more carefully than waste – This could make ore mining higher cost Your waste dump could be further than the mill – This could make haulage costs more for waste – There may also be a placement cost for waste You could put this in waste mining cost Or have a non-zero process cost for waste placement You may have a leach with its unique haulage distance You may have more than 1 mill each with a unique haulage distance
Now Lets Get a Processing Cost It is important to understand that a block of ore will only be assigned to one process. – If you have 5 mills, 2 leaches, and 1 dump, a block of ore will go only to one of those processes. Significance will become apparent in the example
Now Let Me Take Ore Type 3 This is 50% mix of oxide and 2ndary sulfide ore – it is assumed I can partition the block by Truckloads to one process or the other (oxide or sulfide). Lets look at the oxide track - I reclaim from stockpiles and crush for $1.10/tonne Next I gravity concentrate – my gold concentrate I get 95% recovery on my gold I get 0.95 * 0.12 recovery on silver in the gold cons 11.4% I get 90% of 76% recovery of silver on my silver cons 68.4% I add $1.25/tonne to my processing – total to this point $2.35/tonne I go to the VAT leach and recover 96% of my copper (the silver is not recovered) I add $4.00/tonne to the process cost – total to this point $6.35/tonne
Oxide Ore Products and Values SX/EW produces finished copper from solutions for 40 cents/lb – My copper to the end of the concentrator process is worth $3.25 - $0.40 = $2.85/lb I get 0.96*0.995 = 95.52% My gravity gave me – 95% recovery with gold cons valued at $1,134.3/oz – 11.4 % silver recovery valued at $25/oz * 0.93 = $23.25/oz – 68.4% silver recovery valued at $22.09/oz
So What Do I Get for a Oxide Tonne Processing Cost $6.35/tonne Copper 95.52% recovery valued at $2.85/lb Gold 95% recovery valued at $1,134.3/oz Silver – Add up the recoveries 11.4 + 68.4 = 79.8% – Take a weighted average of the values (11.4*$23.25+68.4*$22.09)/(79.8) = $22.25/oz
Oh But that is Half the Story What happened to the sulfide? – It was pulled out of a stockpile and crushed $1.10/ton – It went to gravity concentration for $1.25/tonne – $2.35/tonne to this point – It still made gold and silver cons but recovery is different
Gold and Silver Recovery in Gravity on the Sulfides Gold is 50% free milling so recovery of gold is – 0.95 * 0.5 = 47.5% valued at $1134.3/oz Silver – only 12.5 is going with the gold and only half the gold was free milling – 6.25% * 0.95 = 5.94% valued at $23.25/oz – The silver in sulfides will go on to flotation There will be no gravity silver concentrate
Our Story Moves to Flotation We Have 3 Flotation Stages for $5.25/tonne – Cost to this point $7.60/tonne Copper 94% recovery valued at $2.86/lb – (Price per lb for this example is coming from earlier presentation on obtaining the value of metals in concentrate) Gold – gold encapsulated in pyrite is recovered by floating the pyrite – 90% of 50% - 0.9*0.5 = 45% recovery – Now we need the value of the gold in that pyrite concentrate Silver Sulfides are recovered as a floatation product – 87% recovery of 75% of the contained total – 0.87 * 0.75 = 65.25% – Suppose that the value of silver in sulfide concentrate back calculates to $19/oz.
Lets Look at the Pyrite Concentrate Looking at the ore support 1.36% pyrite has about 0.046 oz per tonne of gold – One tonne of ore would contain 2205*0.0136 = 29.98 lbs pyrite (about 30 lbs) Thus a tonne of pyrite concentrate would have 3.38 oz of gold in it The process roasts the pyrite for $4.5/tonne – 4.5/3.38 = $1.33/oz We then recover 92% of the gold as relectrowon metal for $1.25/oz – $2.58/0.92 = $2.8/oz off – Thus we have 0.45 * 0.92 = 41.4% gold recover valued at $1,200/oz - $2.8 = $1,197.3/oz
Of Course we Have Silver in the Pyrite Concentrate 6.25% of the silver is in pyrite concentrate The silver will be electrowon with about 87% recovery and costs covered by gold – 0.0625*0.87 = 5.44% valued at $25/oz Let us assume that the silver in the copper concentrates goes as a credit to cancel some penalty
So Putting it Together for Sulfide Process Cost $7.6/tonne Copper 94% recovery valued at $2.86/lb Gold – summing up – 47.5% valued at $1,134.3/oz from gravity – 41.4% valued at $1,197.3/oz float and roast – Total Recovery 88.9% – Weighted average value (47.5*$1,134.3+41.4*$1197.3)/88.9 = $1,163.64/oz
Continuing On With Silver 5.94% silver recovery with gold value $23.25/oz 65.24% silver sulfide float valued at $19/oz 5.44% from electrowin valued at $25/oz Total 76.62% Weighted average value – (5.94*23.25+65.24*19+5.44*25)/76.62 = $19.76/oz
Now Where Are We? We know the cost and recovery for oxide ore We know the cost and recovery for sulfide ore But our type 3 ore can only go through one mill process – We are assuming we can separate it by the truck load – Thus half of each block will go through each process For an over-all we can just take the average
Our Average Oxide $6.35/tonne Copper 95.52 rec at $2.85/lb Gold 95% at $1134.3 Silver 79.8% at $22.25/oz Sulfide $7.60/tonne – (average $6.98/tonne) Copper 94% at $2.86/lb – (average 94.76% rec at $2.855) Gold 88.9% at $1,163.64 – (average 91.95% rec at $1148.48) Silver 76.62% at $19.76/oz – (average 78.21% at $21.03/oz)
Thus for the Mill Cell for Ore Type 3 The processing cost is $6.98/tonne Copper recovery is 94.76% and copper value is $2.855/lb in various concentrates Gold recovery is 91.95% valued at $1,148.48/oz Silver recovery is 78.21% valued at $22.03/oz
Disclaimer The layout of your process may differ. Your recoveries, costs, and product values may vary – This illustration is intended to show how a result compatible with MSOPIT can be obtained – It is not intended to suggest that the exact values shown here can be used in your project.