12 Quarry Operations12 Quarry Operations

©2010 Dr. B. C. Paul©2010 Dr. B. C. Paul

Note – The slides contain many ideas about quarry design that are considered Note – The slides contain many ideas about quarry design that are considered by the author to be common knowledge to those familiar with the subject. This by the author to be common knowledge to those familiar with the subject. This

material was not drawn from any one source in particular. The slides do material was not drawn from any one source in particular. The slides do contain many screen shots from the program MineSight which was developed contain many screen shots from the program MineSight which was developed

by Mintec Inc.by Mintec Inc.

The Impact of Deposit ShapeThe Impact of Deposit Shape Consider Crushed Stone FirstConsider Crushed Stone First Some Deposits have a single thick layer of rock with significant Some Deposits have a single thick layer of rock with significant

overburden and fairly level.overburden and fairly level.– These operations advance like strip minesThese operations advance like strip mines– Backfill of pit depends on relative amount of overburdenBackfill of pit depends on relative amount of overburden

Often may not fill back to original level like some coal strip minesOften may not fill back to original level like some coal strip mines– Truck and Front End Loader dominatesTruck and Front End Loader dominates– Quarries usually collapse the highwall in blasting so that equipment digs Quarries usually collapse the highwall in blasting so that equipment digs

from broken rock pile rather than a facefrom broken rock pile rather than a face

The Dip SeamThe Dip Seam

Can have open pits similar to Phosphate or steep dipping Can have open pits similar to Phosphate or steep dipping seam coalseam coal

These kinds of deposits can also have lots of faults and These kinds of deposits can also have lots of faults and complex geologycomplex geology– Local costs can be highLocal costs can be high– But $12-20/ton transportation cost is pretty significant for a $6 to But $12-20/ton transportation cost is pretty significant for a $6 to

$12/ton product.$12/ton product.

Break Even Limit To steep to backfill while

Working – overburden is usedTo fill separate pits (or they mineDown the strike)

Midwestern Thick SeamMidwestern Thick Seam

May get areas with very thin soil layers and May get areas with very thin soil layers and then layer of layer of limestone and dolomitethen layer of layer of limestone and dolomite– Mines look somewhat like a true open pitMines look somewhat like a true open pit

Soil Layer

How Do You Decide Bench Height?How Do You Decide Bench Height? SafetySafety

– May be prescribed by a local ordinanceMay be prescribed by a local ordinance– May come from a safe distance for no catch bermMay come from a safe distance for no catch berm

Product PurityProduct Purity– Different layers may have different markets that require them to be Different layers may have different markets that require them to be

separateseparate Less consideration on digging height because face is usually collapsed Less consideration on digging height because face is usually collapsed

in blastingin blasting

How Do You Decide Bench Width?How Do You Decide Bench Width?

Bench widths are usually very generousBench widths are usually very generous– Often have limited number of work areasOften have limited number of work areas

Most benches may be nothing more than catchMost benches may be nothing more than catch

– Grade uniformity issue for mill may not come up hereGrade uniformity issue for mill may not come up here

Slope issues are less criticalSlope issues are less critical– Toe to Crest slopes usually near vertical (high quality Toe to Crest slopes usually near vertical (high quality

rock)rock)– The amount of overburden compared to rock is often The amount of overburden compared to rock is often

very small (doubling a 0.001 to 1 stripping ratio is not very small (doubling a 0.001 to 1 stripping ratio is not much of an issue)much of an issue)

Pit SequencePit Sequence

Grade control is usually mostly product Grade control is usually mostly product controlcontrol– You open up the rock layers you need for You open up the rock layers you need for

productproduct Because most rock is about the same grade Because most rock is about the same grade

the most profitable rock is the lowest costthe most profitable rock is the lowest cost– Lowest cost normally does work top downLowest cost normally does work top down– May see very little of whole pit sides pushing May see very little of whole pit sides pushing

backback

Example of A Quarry DesignExample of A Quarry Design

Soil 10 ft

AAggregate GradeLimestone 30 ft.Waste Rock 5 ft.

Chemical Grade Rock25 ft

Aglime and AggregateRock 80 ft.

A Plan – Contract for soil removalAbove pit

Set up a 30 ft benchUse Dozers and Rippers on WasteRock

Set up a 25 ft bench chemical rock

Try 2 40 ft benches on Aglime andAggregate

(Say the legal constraint is 80 ftMax bench height)

I chose 40 ft to try to avoid different types of drills being neededFor blasting operations.

Market ConstraintsMarket Constraints

Aggregate 4 million tons/yearAggregate 4 million tons/year Chemical Stock 800,000 ton per yearChemical Stock 800,000 ton per year Aglime 1,200,000 tons per yearAglime 1,200,000 tons per year Scrubbers 1,300,000 tons per yearScrubbers 1,300,000 tons per year

Match My Layers and MarketsMatch My Layers and Markets

Top is only good for aggregate – 4 Million tons 5 years20 million tons (about 235,300,000 cubic feet or about 7,850,000Square foot area)

My Chemical and scrubber limestone here 2.1 million tons/year5 years need 10.5 million tons (about 123,500,000 cubic feet orAbout 4,950,000 square foot area)

Aglime 1.2 million tons5 years need 6 million tons (about 70,600,000 cubic feet or about 1,770,000 square foot area if I only take top 40 ft bench)

Logic I Was UsingLogic I Was Using

The Cheapest Material is at the topThe Cheapest Material is at the top Sell my best layer for my highest price productsSell my best layer for my highest price products I only mined aglime from the top of the 2 benches I only mined aglime from the top of the 2 benches

– I’ll go down further when I need to but the – I’ll go down further when I need to but the cheapest stuff is near the topcheapest stuff is near the top

I got volumes knowing my rock was about 170 I got volumes knowing my rock was about 170 lbs/cubic foot and knowing thickness of the rock lbs/cubic foot and knowing thickness of the rock layerlayer– Example – My 20,000,000 tons of aggregateExample – My 20,000,000 tons of aggregate

Multiply by 2,000 lbs per ton is 40,000,000,000 lbsMultiply by 2,000 lbs per ton is 40,000,000,000 lbs Divided by 170 lbs per cubic foot is 235,294,000 cubic feetDivided by 170 lbs per cubic foot is 235,294,000 cubic feet But the layer is 30 feet thick so 235,294,000 / 30 = 7,843,000 But the layer is 30 feet thick so 235,294,000 / 30 = 7,843,000

square ft.square ft.

My PropertyMy Property

5,280 ft

5,280 ft

2,640 ft

1,320 ft

2,640 ft

6,600 ft.

AccessRoad

Consider Pit Area Here

Processing and StockpileHere

Pit Advance StrategyPit Advance Strategy

5,280 ft

5,280 ft

2,640 ft

1,320 ft

2,640 ft

6,600 ft.

AccessRoad

Processing and StockpileHere

Expand Pit This Way

Then this

A 10% ramp goingUp 40 feet is 400Feet long.(Make my pit 600Feet wide)

Coordinateorigin

Geometry TrialsGeometry Trials

13,000 ft long

600 ft wideAbout 7,850,000 ft square

My first guess is way to long for the property

A fit about 4,700 feet long will have nice buffer space and fit betterIt would be about 1,680 ft which also fits

Lets Try Setting It Up in MineSight®Lets Try Setting It Up in MineSight®

I’m going to start a brand new file I call Quarry Demo – it has nothing in itAt all

It Asks Me For Permission to Add It Asks Me For Permission to Add the MineSight Starter Filesthe MineSight Starter Files

Of course I say yes.

Now It Wants to Know About My Now It Wants to Know About My Coordinate AreaCoordinate Area

I Set Up Coordinates That Match My I Set Up Coordinates That Match My ProjectProject

When You DoYour HomeworkYou will have aGreater thicknessTo deal with.

It Now Gives Me the Initial MineSight It Now Gives Me the Initial MineSight ViewView

I’m Going to Put In My Property I’m Going to Put In My Property BoundaryBoundary

You can see IHave created anActive editObject namedProperty

I’ll Also Create Gridset That Shows I’ll Also Create Gridset That Shows Land SectionsLand Sections

My gridset hasSquares every1320 feet(which happensTo match theDimensions forA quarter sectionOf land)

Gridsets and Edit GridsGridsets and Edit Grids

Gridsets are usually multiple planes used for Gridsets are usually multiple planes used for visual controlvisual control– I used them to rapidly move through cross-sections and I used them to rapidly move through cross-sections and

levels on by mine when I was doing pit expansion and levels on by mine when I was doing pit expansion and sequencingsequencing

An Edit Grid is a single plane that is used to aide An Edit Grid is a single plane that is used to aide drawing thingsdrawing things– When you are entering things in 3D stuff may really not When you are entering things in 3D stuff may really not

go where it looks like it is from one view pointgo where it looks like it is from one view point– Edit grids let you fix the plane you work on and snap to Edit grids let you fix the plane you work on and snap to

intesections and corners of the grid (which is what I intesections and corners of the grid (which is what I want to do now)want to do now)

Create An Edit GridCreate An Edit Grid

I attach myGridset to theViewer and setThe display toThe zero plane(property linesAre done on theZero datumPlane in surveying)

I’m Going to Make an Edit Grid from I’m Going to Make an Edit Grid from the 0 Datum Plane of My Gridsetthe 0 Datum Plane of My Gridset

I pick the SelectEdit Grid Icon

Then I left clickOn my prettyGreen gridset

Then I click theGray box toAttach just myEdit grid to theViewer.

I Do A Little ReArrangingI Do A Little ReArrangingEdit Grids areGray (by default)And Gridsets areGreen.

I changed theBackground soYou could see theGray edit grid.

I also turned offMy gridset.

I’ll Set The Viewer to Snap to a Point I’ll Set The Viewer to Snap to a Point

(So if I get close to a quarter section it will snap there)(So if I get close to a quarter section it will snap there)

Next I’ll Tell My Computer I Want to Next I’ll Tell My Computer I Want to Draw a PolylineDraw a Polyline (for my boundary of course) (for my boundary of course)

I Click My Way Around the Property I Click My Way Around the Property BoundaryBoundary

When I’m done IRight click myMouse.

My Line Turns RedMy Line Turns Red(Indicating that MineSight® believes I’ve completed a Polyline)(Indicating that MineSight® believes I’ve completed a Polyline)

I now click onMineSights®Unusual saveIcon.

The Line Turns Blue and My The Line Turns Blue and My Property Boundary is SavedProperty Boundary is Saved

I click the yellowOpen box toClose my editObject.

Now I’m Going to Set-Up to Draw My Now I’m Going to Set-Up to Draw My QuarryQuarry

I set up a gridsetThat was every100 ft.

I attached it to theViewer and set itTo the 150 plane(my surfaceElevation for myProject – but notYours)

I created a QuarryContours objectAnd put it in editMode.

What I’m Going to DoWhat I’m Going to Do

I’m going to draw my quarry with the pit I’m going to draw my quarry with the pit expansion toolexpansion tool– I’m going to start from the top and work downI’m going to start from the top and work down

Why would I do thatWhy would I do that– Because I’m going to put in my roads this timeBecause I’m going to put in my roads this time– Often I really want my road to come out a Often I really want my road to come out a

particular pointparticular point– I can control where my road starts or end from I can control where my road starts or end from

where I start my pitwhere I start my pit

Fire Up the Pit Expansion ToolFire Up the Pit Expansion Tool

I’m Going to Set Up to Digitize My I’m Going to Set Up to Digitize My Base String on the 150 level and go Base String on the 150 level and go

for a single expansionfor a single expansion

I Digitize My Base StringI Digitize My Base String

Note that I am goingTo expand down forMy first bench only.

I Set to Expand Down and InwardI Set to Expand Down and Inward

Note that I amUsing a much moreNarrow berm(bench) area thanIs practical for aQuarry.

(There isCurrently a bugIn the expansionTool that is onlyLikely to beTriggered in aQuarry setting)

This Time I Will Include My Haul This Time I Will Include My Haul Road so I go to the Road TabRoad so I go to the Road Tab

When I click AddIt will add by firstRoad.

The default nameIs road one butI can change theName according toMy choosing

Note that the statusIs Unset.

I click on Edit toProvide info on myRoad.

The Edit Road Box OpensThe Edit Road Box Opens

Check that it isGoing to beginThe road on theRight level

Identify the Road Start PointIdentify the Road Start Point

Click on the pointIcon

And then click onThe spot youWant the road toBegin

The pretty greenDot appears.

Specify Road Width, Grade and Specify Road Width, Grade and Direction.Direction.

The road grade isGiven inDecimal form.Thus a 10% gradeIs entered as 0.1

1 is clockwise0 is counter-clockwise

When You Exit the Edit Box Your When You Exit the Edit Box Your Road Now is Listed as SetRoad Now is Listed as Set

Click Preview to Have a Look at Click Preview to Have a Look at ThingsThings

You of courseClick apply onceYou are happy.

I Exited the Pit Expansion Tool I Exited the Pit Expansion Tool Without Triangulating Because I Had Without Triangulating Because I Had

Some Issues to Deal WithSome Issues to Deal With

Current Pit Expansion ProblemsCurrent Pit Expansion Problems

Quarries often have very wide benches or bermsQuarries often have very wide benches or berms– Quarries usually have fewer working benches and often collapse Quarries usually have fewer working benches and often collapse

the face in blasting so more work room is needed on the benchthe face in blasting so more work room is needed on the bench When the bench gets wide enough to block the road with When the bench gets wide enough to block the road with

just one level down the software won’t draw in the roadjust one level down the software won’t draw in the road– (The problem is being fixed)(The problem is being fixed)– This issue will not appear in most open pit mines but can appear in This issue will not appear in most open pit mines but can appear in

quarries with very wide benchesquarries with very wide benches The road start point needs to be near a point on the base-The road start point needs to be near a point on the base-

stringstring– Almost all pits have enough base string points that this is not an Almost all pits have enough base string points that this is not an

issueissue– A quarry with a very simple shape and corner points defining the A quarry with a very simple shape and corner points defining the

base string might not have a point on the base string to start the base string might not have a point on the base string to start the road if you start in the middleroad if you start in the middle There is a fix that I will show you.There is a fix that I will show you.

Pondering What I Will Do NextPondering What I Will Do Next

I have a 8,000,000 squareFoot top bench pit.

I need 5,000,000 squareFeet for my chemicalGrade limestone.

I also need to strip offAbout 5 feet of reject stone.

I’ll get my chemical gradeStone close to myProcess point first andProbably strip off most ofThe reject rock.

I’m Going to Widen My Bench to 300 I’m Going to Widen My Bench to 300 feet feet

I will do this withA Polyline Offset.

I must first selectThe polyline toOffset

I pick selection

Make newSelection.

I Click on the Crest of My Next I Click on the Crest of My Next Bench and Right Click to Complete Bench and Right Click to Complete

SelectionSelection

Note that mySelection has turnedRed.

I Then Select Polyline OffsetI Then Select Polyline Offset

The Offset Polyline Box Comes Up The Offset Polyline Box Comes Up But Most Everything is GrayBut Most Everything is Gray

MineSight Sometimes requiresYou to select twice(this allows you toSelect a bunch ofThings for anOperation but thenAllows to apply thatOperation differentlyTo different parts –Not handy to usNow but it can beWork saving)

Click on reselectAnd then reselectThe samePolyline.

Click on the Line and Then Right Click on the Line and Then Right ClickClick

Note the yellowOvercolor thatAllows you toIdentify theSpecific part ofYour selection youWill work with thisSecond.

The Menu Is Now AliveThe Menu Is Now Alive

I will specify a 270 foot offset(30+270= 300 foot wide workingBench)

I’ll also preview my art work.

It Shows Me The Offset in Each It Shows Me The Offset in Each DirectionDirection

It gives meCheck-offs toDetermine whichOffset to keep.

I will keep theSecond to theInside.

Fill In My Window and Click ApplyFill In My Window and Click Apply

My Work Finishes and My Box Goes My Work Finishes and My Box Goes GrayGray

Note that if I hadA bunch of linesTo offset I am nowReady to reselectWithout having toEvoke the offsetCommand a Separate time(not valuable to meRight now but couldBe in otherCircumstances).

I Close the Box and Query the Offset I Close the Box and Query the Offset LineLine

I note that I haveNot removedEnough shale toGet to 5,000,000Square feet to takeFor chemical stone.

This means I’mGoing to have toMove some pointsOn the offset line toUncover enoughChemical gradeStone.

I Right Click and Save to Get Ready I Right Click and Save to Get Ready for My Next Movefor My Next Move

I Select My Offset PolylineI Select My Offset Polyline

My game plan isTo move the lineBack and shrink theBench to just wideEnough for truckTraffic in areasWhere I will noLonger beExpanding theQuarry.

(Remember thisLine defines theArea where I willHave removed theReject shale toUncover theChemical gradeLimestone)

Go to Point MoveGo to Point Move(To move points on my polyline)(To move points on my polyline)

I Shift My PointsI Shift My Points

Note I am leavingGenerous roomFor haul trucks toMove – but not toBe collapsing facesDuring blasting.

Right Click and Save My WorkRight Click and Save My Work

I Query My Line AgainI Query My Line Again

This time I haveEnough chemicalGrade rockUncovered butHaving room forBe to rip andLoad the shaleInto trucks isPretty shaky.

I Make a Few More Adjustments and I Make a Few More Adjustments and Prepare for another Pit ExpansionPrepare for another Pit Expansion

Note I have nowLeft full width workingBenches only to theSouth in the directionOf future pitExpansion.

Fire Up the Pit Expansion ToolFire Up the Pit Expansion Tool

I Get A WarningI Get A Warning

It tells me I haveBeen fooling aroundOutside the pitExpansion tool andAsks me forPermission toDelete the work andGo back to thePit expansion

My answer is heckNo.

I Set Up My New Base StringI Set Up My New Base String

Level set on 120

Pick copy

Click Add

Click my newBase string.

I’ve Got the New Base StringI’ve Got the New Base String

Set to Bench Down 5 feet through Set to Bench Down 5 feet through the Reject Shalethe Reject Shale

Set Myself Another RoadSet Myself Another Road

Pick My Road Starting Point and Pick My Road Starting Point and ParametersParameters

Finish My Next Bench DownFinish My Next Bench Down

Use Point Moves to Set My Bench Use Point Moves to Set My Bench Width for Stripping ShaleWidth for Stripping Shale

Make A 25 Foot Pit Expansion Down Make A 25 Foot Pit Expansion Down into My Chemical Grade Limestoneinto My Chemical Grade Limestone

Note that I madeA roadSwitch back goingCounter-clockwise

Do A Few More Point Moves to Get Do A Few More Point Moves to Get Me a Good Working BenchMe a Good Working Bench

My ThinkingMy Thinking

I need 1,800,000 square feet of aggregate grade I need 1,800,000 square feet of aggregate grade limestone if I use just 1 40 foot benchlimestone if I use just 1 40 foot bench

I also have a bunch of shale waste and very little I also have a bunch of shale waste and very little space to put it.space to put it.– I’m thinking of dumping it in the bottom of my pitI’m thinking of dumping it in the bottom of my pit

In order to not cover reserves I will need to go In order to not cover reserves I will need to go down at least 2 forty foot benches to dig a hole for down at least 2 forty foot benches to dig a hole for my waste.my waste.

I’m going to check out some measurements for I’m going to check out some measurements for what I will try next.what I will try next.

I See I Have 3,400,000 square feet I See I Have 3,400,000 square feet uncovered and only need 1,800,000uncovered and only need 1,800,000

Yes I’m playingWith the QueryTool again.

I’ll Check How Much Area I Have I’ll Check How Much Area I Have Stripped the Shale Off OfStripped the Shale Off Of

Then I’ll Check the Length of My PitThen I’ll Check the Length of My PitI put my curserOn one point andHolding the leftMouse buttonDown I drag itAcross myDistance

The reading belowShows me myDistance.

What I’m PlanningWhat I’m Planning

I’ll dump my shaleIn the pit along thisBackside.

Figuring the Room Needed for My Figuring the Room Needed for My Waste ShaleWaste Shale

5,300,000*5=26,500,000 cubic feet of reject 5,300,000*5=26,500,000 cubic feet of reject rockrock– 26,500,000 / 3600 = 736126,500,000 / 3600 = 7361

0.58X

X

7361 = 0.58X^2 X= 113 Height of pile 65 feet

Figuring My Rock Removal Area for Figuring My Rock Removal Area for AglimeAglime

I need about 1,800,000 square feet for one bench I need about 1,800,000 square feet for one bench and 900,000 for twoand 900,000 for two

The problem is my aglimeArea if I expand down now is3,400,000 – way too much

I’ll experiment with my stringI’ll expand down for the nextBench.

First Adjustment TryFirst Adjustment Try

I got it down to1,600,000 squareFeet

If I get 2/3 rds fromTop 40 feet and1/3 rd from bottom

Top would be1,200,000 squarefeet

Bottom would be600,000 square feet

Try TwoTry Two

I still have1,500,000 onThe top bench

I Think I Have the Take Out Area for I Think I Have the Take Out Area for the Top Aglime Benchthe Top Aglime Bench

1,200,000 squareFeet achieved

Now for a pitExpansion down.

Set My Level and Select My Base Set My Level and Select My Base StringString

Expand DownExpand Down

Now I Need about600,000 area forThe second benchDown.

Adjust the Area to 600,000 Square Adjust the Area to 600,000 Square Feet for the Expansion DownFeet for the Expansion Down

Expand Down for the Last BenchExpand Down for the Last Bench

Triangulate the SurfaceTriangulate the Surface

Our QuarryOur Quarry

Our 30 footAggregate Bench

The 5 foot shaleStripping area

The 25 footChemical gradeRock

Two 40 footAglime Benches

Our Aglime Benches Advance This Our Aglime Benches Advance This WayWay

Our Aggregate and Chemical Grade Our Aggregate and Chemical Grade Benches Advance South Benches Advance South

Our Haul RoadsOur Haul Roads

Route goes clockwise down 30 feet to the baseOf the Aggregate BenchThen down 5 feet for shale strippingThen turns Counterclockwise down the chemical bench

Rest of Our Haulage RouteRest of Our Haulage Route

The Role of Our Quarry in Future The Role of Our Quarry in Future WorkWork

Our Next Unit will be on Production Blast Our Next Unit will be on Production Blast DesignDesign– We will use our Quarry to provide the benches We will use our Quarry to provide the benches

we will be designing blasts forwe will be designing blasts for Our Last Unit will be on selection of trucks Our Last Unit will be on selection of trucks

and loadersand loaders– The haul roads and production targets from the The haul roads and production targets from the

quarry we designed will be the mine we will pick quarry we designed will be the mine we will pick our truck and loader fleet forour truck and loader fleet for

Oh But You Don’t Have A Quarry to Oh But You Don’t Have A Quarry to Work WithWork With

That’s why I’m going to give you Assignment That’s why I’m going to give you Assignment 10 which will provide you the opportunity to 10 which will provide you the opportunity to lay out your quarrylay out your quarry– Just as my quarry was a 5 year plan and Just as my quarry was a 5 year plan and

showed where I would get the rock for the first 5 showed where I would get the rock for the first 5 yearsyears

– Yours will be a 5 year plan also!!!Yours will be a 5 year plan also!!!

And As An Added Bonus!And As An Added Bonus!

We Get to Plan Out the Time for Our First We Get to Plan Out the Time for Our First Exam – Woopy!!!Exam – Woopy!!!