Step #1 Matching ©Dr. B. C. Paul 2000 revised 2008 Note many of the ideas expressed in these slides...
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Transcript of Step #1 Matching ©Dr. B. C. Paul 2000 revised 2008 Note many of the ideas expressed in these slides...
Step #1 Matching
©Dr. B. C. Paul 2000 revised 2008Note many of the ideas expressed in these slides can be found in Surface Mining Manuals, the Book Surface Mining Equipment or
publications by Caterpillar Equipment Company. The Slides contain equipment specifications from the Caterpillar Performance Handbook
and screenshots from the FPC program by Caterpillar Equipment Company.
More Step #1
Make a First Pass with Conceptual - Feel Adjustments to decide where to start
Material Characteristics often favor one type of loader or truck
Mine grades and distances often restrict best truck choice
Sensitivity of organization to capital and operating costs will push toward one machine or another
Example of Conceptual First Pass Match
Quarry Mining Dolomite Heavy lumpy rock
• not a good match for any bottom dump configurations
• Suggests a rear dump truck Quarries usually have steep haul
roads but limited distance• favors a high power to payload• points to Rear Dump Model
Can Usually Match Capital Preference During Conceptual
Phase This is a Quarry Most Quarries Require great equipment
mobility and shifting They maintain bench networks in active
areas They don’t handle fixed infrastructure in
pit well They tend to limit capital investments Suggests a Truck - FEL fleet
Step #1 Gets Quantitative
After Visualization comes three critical Quantitative Checks
#1 Match the Truck to the Material #2 Match the Truck to the Mine
Layout #3 Match the Truck to the Loader
(of visa-versa)
Need to Match Material to Truck
Trucks have both a volume and a weight limit
Consider Komatsu HD785-3• weight limit is 86 tons• volume limit is 69 cubic yards heaped
Dolomite breaks into odd shape chunks that give a lot of air space
Truck Specifications From Manufactures Handbooks
The Meaning of Swell (No it doesn’t always mean things
are great) Tendency of material to break and
pick up air space is called swell• Most materials will have an in place density• Will also have a swelled density• If volume increases 40% say we have 40%
swell• Density Swelled = In Place Density/ 1.4
Don’t get # mixed up
Example of Materials Table from Cat
Matching Material Check the Dolomite against the
Komatsu HD785-3• 2600 lb/Yd3 * 69 yd3 / 2000 lb/ton =
89.7 tons But the Weight Limit is 86 tons
• Truck is weight limited because full volume is hard to use
Can generally overload 5% would allow 90 tons but pushing it
Another Example
Try a Cat 789 for Coal Haulage• Truck is rated for 195 tons• 137 yd3 heaped
Loose Coal is about 1600 lbs/yd3
1600 * 137 / 2000 = 109.6 tons Volume is filled before weight limit
is reached - Volume Limited
Multi-bed Option
Cat 789 can be ordered with a larger bed• 157 yd3 optional bed
1600 * 157 /2000 = 126 tons Still Very Volume Limited Manufactures Often Have special
models optimized to try to balance both - Cat Quarry Trucks are example
Match the Truck to Pit Geometry
Length - Steepness and profile are important• Lot has been done in visualization
In life there is matching of road to vehicles• Spacing - rise and fall• banking or turns and sharpness• Road base
Only Briefly in this Class - too Civil
Checking Turn Sharpness
Terex 3311E 94 ton truck• Wheels have turning radius of 35 feet• Frame has radius of 40 feet• Watch cause manufactures list spec
differently
Tells about switch backs May also be significant in loading
area• May need to pick a loading arrangement and
check the room
Matching Truck and Loader
Three Major Checks• # passes check• loading height check• loader and material Check
Also review compatibility of loading layout and equipment to pit and objectives
# of Passes
# of passes guidelines based on experience with where optimum often lies
Cable Shovels (3 to 4 passes) Hydraulic Shovels (4 or 5 passes) FEL (4 to 6 passes) Backhoes (often 5 to 7 passes)
Go to The Fleet Selection Tab of FPC
I can start out byNaming my firstTrial fleetAnd inputting aDescription
I will then select theAdd Hauler Button
The Select Hauler Screen Comes Up
Program Allows youTo input any machineOr modified machine-Easiest thing is to useCat machines alreadyIn the program
Need to choose whatKind of machine –Hmm – maybe aTruck?
A Wish List of Machines Comes Up
Lets say I’m thinkingA 5 million ton perYear quarry
Guessing Out of the Blue
I want a reasonable number of trucks
I want my production Begin with a cycle time guess
• You know about how far things are and have probably seen a truck drive before
• My silly guess will be 20 minutes
Guestamation Circle
I have 1800 hours per year• At 50 minutes per hour that’s about
1500 hour working time• At 20 minutes per trip that’s about
4500 trips per year If I guess about 85% availability
and 90% utilized of available• About 3450 trips/truck year
Continuing my Guestamation
If I have a 20 minute cycle time and a truck load time around 3 minutes• About six trucks per loader• I’ll guess 6 trucks
6 trucks making 3450 trips each is 20,700 trips
5 million tons over 20,700 trips is• 241 tons• That’s a bit big for a quarry• Maybe 120 ton trucks will be more
reasonable
Things to Notice
Most calculations involve a circle of guessing checking and refining
I want to make a guess at a truck size• I used a rough estimate (which happens to
indicate I knew what calculations would come next)
• Some people compare to existing operations they know
Lets Go Shopping for a Truck
Hows about a Cat785 for about150 tons(click on to highlight)
Then click OK
It Immediately Fills Out the Screen for Me
Filling Out a Couple of Items
I’ll give a startingGuess on the # ofTrucks - 10
I assumed 85%availability
There are other thingsTo fill out but IWill defer them forNow.