Open Pit Planning and DesignThe Standard Approach for Open Pit2007 revised 2010 Dr. B. C. PaulNote This presentation includes screenshots from the MineSight computer program developed by Mintec. The views and procedures identified in this presentation are considered by the author to be common knowledge to those in the trade and many of the ideas expressed here can be found in numerous books and journals.

The Ajo Open Pit in ArizonaThey mined around the barren core

Lacks Clear Steps and Has A Lot of Interaction Computers Almost a NecessityIn general need to know you have a large ore reserve close enough to the surface to be open pit minedGenerally comes from geologic dataOpen pit designs normally represent ore reserves and geology as a block modelSlice and dice the ore reserve up into small blocks that sit end to end and on top of each other10s of Millions of blocks common

The Program We Will UseMineSight is a suite of mining tuned computer programsHeart is a 3D CAD graphics program called MineSightHas a wide array of mining calculations programs that link production planning to the graphics functions in the 3D CAD programMineSight development started with first computer routines in the 1970s and list has grown sinceCollection includes everything from old fortran routines to modern python program language routines

MineSights Visually Linked Calculation Routines MineSight CompassA windows like user interface built over a bunch of old Dos, Fortran and Unix ProgramsCollection of over 400 routinesHave the feel of old mainframe batch programsThats because they are old mainframe routines and subroutines with a modern windows like graphical interface to feed themLooks new but has you do some things to set up runs that are like old mainframe batch routines

New Kids on the BlockBuilt a Suite of New Programs that run in Python visual languageEconomic PlannerState of the Art Open Pit Metal Mining Optimization and integrated togetherActivities PlannerMicrosoft Projects Gant Charts set up for MiningData AnalystOre Reserves Statistics and GeostatisticsInteractive PlannerLink between databases and 3D graphics for planningStrategic PlannerOther procedures constantly being prepared

Editorial CommentaryLack of ConsistencyA 40 year collection and operating systems have run in fundamentally different ways over the yearsMade to look windows like but cant always hide the architecture underneathHas bugs in itMost bugs are triggered by assuming people will input in a certain way and you dontMining has lots of local terms in it so wording can encourage you to do unexpected thingsMost bugs are operator error triggered but it is rather unforgivingVery computer and graphically intensivePushes hardware and designs to the limit and a lot of hardware and system components misbehave when they are at their limitIts wonderful to have so much integrated power and routines all in one semi-coherent package

Lets Start this Puppy Up!If Used Often MineSight has an icon that saysMS3D (ie MineSight 3 D)

Can Also Do A Menu Fishing Start#1 -Click Start#2- Pick All Programs#3- Find MineSightAnd Highlight it untilA side menu pops out#4- Click on theMS3D icon(note you do haveIcons for some ofThe other routinesI mentioned).

Look for the Desktop Icon for MS3D and Click on ItOk I Dont Have One Cause I Dont StartThat way but some people do.

Programs Splash ScreenMines or designsAre kept asProjects It can defaultStart where theProgram lives

Or be sent toWhere you storeA projectIf you have aProject or designAlready you canHave it loadedAnd ready to go.

Operating the Starting PromptIf you pull down theMenu it will showYou were up to theLast 10 projectsWorked on wereStored.You can alsoTrigger a WindowsExplorer stylePick using aBrowse function.It has typical Windows Options for Oking or CancelingThe strange lookingX symbol isMineSights Delete command.

MineSight Opens (sometimes it will prompt you to do something first)Looks a little likeAn Autocad forWindowsIt has a 3D displayArea similar toAutocad.Data Manager isA two tieredWindowsExploringDown below itHas a messageAnd info window

Two Tiered Windows ExploringHas two LevelsTop Level Shows YouThe FoldersBottom Level ShowsYou the Files in a folder

(as a 3D geometry programHas a variety of differentFile types that supportThe program logic noYou probably wont understand them on sight).

The X BoxThe little redX box closesThings.

You can closeThe WindowsExplorer likeData Manager

You can close a 3DVisualizationwindowYou can close theWhole program

Driving OptionsUses the familiarDrop down menusOf a windowsProgram(some options doAppear on more thanOne drop down)Also has a hugeCollection of icons(They are short-cutsTo the mostPopular functions.You also will onlyLearn what theseFunny symbols standFor by experience)

General Quirks and ObservationsMineSight does not have an escape key functionYou right click to finish a function which gets you out of it (but might also finish a goof)MineSight has a more enforced save structureSome drawing functions will not let you move on until you save you last group of editsIt is not consistent in when this happens but if the program stops taking orders a right click to finish what ever it thinks your doing and then a save is a good guess.MineSight has limited Undo functionalityYou can save the last set of edits and then go back and undo it.It does not keep a step by step undo list that lets you go back and undo the last 20 things one at a timeUndo function often requires you to save before it becomes availableIf you really goof it keeps back-up copies of everything and you can go in and fetch a back up copy of what you screwed up.

Some Rigidity in Menu and Icon StructureMicrosoft Office allows you to pick groups of icons, call them toolbars and dock your favorites in a certain positionVulcan has created some tool bar dockabilityMineSight has notMineSight does allow you to right click and pull up an on the spot menu of recently used and custom chosen functions

So Why Should I Learn MineSightCAD like mine design packages are rapidly becoming an industry standard knowing one increases your marketabilityThere is enough similarity in packages that knowing one will allow you to learn any other with greater ease (in case your employer didnt make the same choice for basic package as we did or if your employer changes his/her mind later).We are using it in this class and you dont want to even think about life without it.

Using the Data ManagerUpper LevelDetermines whichFiles are openLower LevelControls individualobjects

To Open An ObjectHighlight the objectAnd then right clickWith your mouseTo bring up amenu

Check the Menu for the Open (or Close) option

Most Likely You Will Start With Some Surface Information(In Our Case It Will Already be Pre-Entered)Our MineSight operator read in or digitized surface topography and then had theComputer create a surface that fit the data

You Can Play with the Surface ViewPush and hold the left and right keysOn your mouse as you move it toRotate your object in 3D (so you canLook at it from different directions).

You Can Move Your Surface Up and Down (Pan Around)Hold the right click button and theCenter button down (often the centerButton is a roller) and move the mouseAround.

You Can Zoom In and Zoom OutHold the left click button and theCenter button down (often the centerButton is a roller) and move the mouse around.

Now We Have A Tool Lets Consider that Block ModelStart by specifying block dimensionsLook at drill and sampling data for how continuous the mineralization isUse computer routines to estimate the ore grade of the blocks using samplesOne of the most popular is Kriging (also polygonal and IDS)Not going to study how interpolation is done in this class. (Youll be given a block model to work with)In the field your geologists may way give you your Block Model

Your Assignment #5Copy a Prepared Starter FileStart MineSightBring up the Surface and Rotate and ManeuverBring up your block model and examine it.Are other do this tasks

Determine the Minable Ore ReserveAssume economics for material removalLook at geology for how steep the pit slopes can stand without sliding inHave the computer analyze the largest set of blocks that can be removed without taking stuff that looses moneyThis set measures the size of the pit that can ultimately be mined (called the Ultimate Pit)Too complex to visualizeDone with either a Floating Cone Miner or Learch-Grossman computer routine (Easily Available in MineSight)

Computer Views of Pits

SequencingStart with an Unmined Surface and end up with an ultimate pitNeed to figure out how to get thereOne easy approach is to just mine from the top down in layersBut that is often not the way it is done

The Time Value of MoneyA Review for those with Engineering EconSome new thoughts for othersWould you rather get $100 now or $100 five years from nowMost would pick nowOne reason if you put money in CD at 3% interest in 5 years you would have $116Youd only need $86 now to earn to $100 in five years so how can $100 not delivered for five years be worth more than $86?

Handling the Time Value of MoneyMoney can be multiplied by a discount factor to adjust to how much right now money it is equal to.Mining commonly looks for investments to earn 15%If you get $100 now its $100If you get $100 in 1 year its like $87If you get $100 in 5 years its like $50If you get $100 in 10 years its like $25You see the pattern the longer the money takes to get here the less it is worth

What Does the Time Value of Money Do to Mine Plans?0 1 2 34 5 6 7 8 9 10 11 12 13$100,000,000$100,000,000Just adding up money gives $600,000,000 TotalBut not all the money got here at the same time if we apply discount factors andThen add we get $1,670,000 almost even money (at 15% interest)(A Total After Multiplying by Discount Factors is called a Net Present Value The more a project is worth the hotter the item!)

Same Money But Some is Moved Forward in Time0 1 2 34 5 6 7 8 9 10 11 12 13$100,000,000$150,000,000$50,000,000Same money but I collect more money sooner and less later

NPV is now $57,100,000 instead of $1,670,000

Get more of your money faster = Better NPV!

Put-Off Expenses0 1 2 34 5 6 7 8 9 10 11 12 13$150,000,000$0$50,000,000$100,000,000Same Money Again but now the NPV is $197,374,000

Getting money early and putting off expenses makes project values improveA WHOLE LOT!

How Can I Make That Happen in the FieldSuppose I mine my best and most valuable ore first?Suppose I delay spending money stripping waste materialIf I mine from the top down I will usually mine mostly waste at firstAnd wait a long time to get down to the best oreWhat I would like to do for a sequence is to ask the computer to find me the best ore with the least stripping firstI will get the computer to identify a series of nested pits that have the most value and use that as my draft sequence

Developing a Practical LayoutWith a series of nested pit shells as a guide design a set of pits that follows the guides but has benches, and roads required for practical mining.MineSight is a 3D Cad program so I can draw in my roads and benchesLook at Further boosting earnings by running artificially high Cut-Off grades at first and sizing mine productionCan be done with VALP in MineSightSize up your equipment fleets and haulage timesMineSights haulage program is still weak (we will use FPC)Develop detailed long term schedules of what will be mined from whereMineSight Strategic Planner can do thisIn for major refinement in March or AprilCollectively these steps are called long term mine planning