Take the following iron ore mine setup:

Diagram omits waste and low grade dumps for clarity.

Processing Paths

Processing paths describe the properties of every product, at every point, along every unique path to port.

Processes
- Dry Plant
- Wet Plant 1
- Wet Plant 2
Points
- Rail
- Ship
Sub Products
- Lump
- Fine

Crushed material may have different lump/fine properties, plants may apply different recoveries and upgrades, and rail may have different moisture from ship.

Note that even though there are two "dry plant" crusher outputs, both have the same recoveries and upgrades, making them a single dry plant stream for ATS purposes.

Crushers

Crushers in ATS may only have one processing stream and one set of product specs. Some duplication is required in order to feed multiple plants from the same crusher, and to target multiple grades.

Crusher 1 and Crusher 2 are represented by eight feed points in this project:

CR1_dry_prod1
CR1_dry_prod2
CR1_wet_prod1
CR1_wet_prod2
CR2_dry_prod1
CR2_dry_prod2
CR2_wet_prod1
CR2_wet_prod2

Where the aggregate feed across all CR1* crushers will be constrained to one (1) crusher capacity.

Destination Logic

Destination Logic describes the final resting place for material at the end of the period.

Ex-Pit1:
- Waste to Dumps
- HG* to ROM1, CR1, CR2
- LG to LTS, ROM1, CR1, CR2
Ex-Pit2:
- Waste to Dumps
- HG* to ROM2, CR1, CR2
- LG to LTS, ROM2, CR1, CR2
Rehandle:
- ROM1 to CR1, CR2
- ROM2 to CR1, CR2
- LTS to CR1, CR2

Where HG* represents all high grade materials, and CR1 represents all Crusher 1 variants.

Steps Logic

Steps Logic describes the in-period waypoints between original source and final destination, and what fleet (or conveyor) is used on each leg.

Ex-Pit1
- Ore => CR1
  1. Ore => CR1 @ 70%
  2. Ore => ROM1 => CR1 @ 30%
- Ore => ROM1 => ROM2 => CR2
- LG => LTS
- W => Dumps
Ex-Pit2
- Ore => CR2
  1. Ore => CR2 @ 70%
  2. Ore => ROM2 => CR2 @ 30%
- Ore => ROM2 => ROM1 => CR1
- LG => LTS
- W => Dumps
Rehandle
- ROM1 => CR1
- ROM2 => CR2
- ROM1 => ROM2 => CR2
- ROM2 => ROM1 => CR2

Constraints

Constraints may be applied to limit long haul quantities, total crusher throughput, plant capacity, and product output.

Constraint Type	Name	Configuration
Standard Constraint	CR1 long haul limit	(Pit2,ROM2) => (CR1_dry_prod1, CR1_dry_prod2, CR1_wet_prod1, CR1_wet_prod2)
Standard Constraint	CR2 long haul limit	(Pit1,ROM1) => (CR2_dry_prod1, CR2_dry_prod2, CR2_wet_prod1, CR2_wet_prod2)
Standard Constraint	CR1 feed limit	(All sources) => (CR1_dry_prod1, CR1_dry_prod2, CR1_wet_prod1, CR1_wet_prod2)
Standard Constraint	CR2 feed limit	(All sources) => (CR2_dry_prod1, CR2_dry_prod2, CR2_wet_prod1, CR2_wet_prod2)
Standard Constraint	Plant1 capacity	(All sources) => (CR1_wet_prod1, CR1_wet_prod2)
Standard Constraint	Plant2 capacity	(All sources) => (CR2_wet_prod1, CR2_wet_prod2)
Standard Constraint	Prod1 product tonnes	(All sources) => (CR1_dry_prod1, CR1_wet_prod1, CR2_dry_prod1, CR2_wet_prod1)
Standard Constraint	Prod2 product tonnes	(All sources) => (CR1_dry_prod2, CR1_wet_prod2, CR2_dry_prod2, CR2_wet_prod2)

Product Specifications

Suppose we want to apply the following rules to the optimisaiton:

Product1 rail fines output:
- 60.0 < Fe < 61.0
- 2.0 < Al < 4.0
- 5.0 < Si < 7.0
Product2 rail fines output:
- 61.0 < Fe < 62.0
- 1.0 < Al < 3.0
- 3.0 < Si < 5.0
Crusher feed should not exceed 25% Low Grade

We can achieve this with the right cash flows and grade targets.

Rule Type	Short haul feed	Value
CrusherCashFlow	(Pit1,ROM1) => CR1	Cash flow = revenue per tonne - haulage cost per km = +$25/t
CrusherCashFlow	(Pit2,ROM2) => CR2	Cash flow = revenue per tonne - haulage cost per km = +$25/t
Rule Type	Long haul feed	Value
CrusherCashFlow	(Pit1,ROM1,LTS) => CR2	Cash flow = revenue per tonne - haulage cost per km = +$20/t
CrusherCashFlow	(Pit2,ROM2,LTS) => CR1	Cash flow = revenue per tonne - haulage cost per km = +$20/t
Rule Type	Short haul ROM build	Value
StockpileCashFlow	Pit1 => ROM1	Cash flow = rehandle cost to crusher = -$1/t
StockpileCashFlow	Pit2 => ROM2	Cash flow = rehandle cost to crusher = -$1/t
Rule Type	Long haul ROM build	Value
StockpileCashFlow	Pit1 => ROM2	Cash flow = extra haulage cost + rehandle cost = -$2/t
StockpileCashFlow	Pit2 => ROM1	Cash flow = extra haulage cost + rehandle cost = -$2/t
Rule Type	Long Term Stockpile Build	Value
StockpileCashFlow	LG => LTS	Cash flow = zero (no penalty for long term stockpile)
Rule Type	Product 1 Spec	Min	Target	Max	Content Deviation Penalty
CrusherGradeTarget	Fe	60.0	60.5	61.0	0.01
CrusherGradeTarget	Al	2.0	3.0	4.0	0.01
CrusherGradeTarget	Si	5.0	5.5	6.0	0.01
Rule Type	Product 2 Spec	Min	Target	Max	Content Deviation Penalty
CrusherGradeTarget	Fe	61.0	61.5	62.0	0.01
CrusherGradeTarget	Al	1.0	2.0	3.0	0.01
CrusherGradeTarget	Si	3.0	4.0	5.0	0.01
Rule Type	Blending	Value
CrusherBlendTarget	LowGradeRatio	Maximum = 25%

Simple Example

During the period, the Agent mines blocks. If the Destination Logic rule is marked as "Crusher Feed", then the material is held in a virtual stockpile until the end of the period. At the end of the period, the Agent assesses the product specifications and assigns the material to its final destination.

Pit1 HG:	Pit2 HG:	Stockpiled LG:
End of Period 1:
DryTonnes = 750 kt Fe = 60.0 Al = 4.0 Si = 6.5	DryTonnes = 750 kt Fe = 61.5 Al = 2.0 Si = 4.0	DryTonnes = 100 Mt Fe = 58 Al = 6.0 Si = 14.0
Pit1 cash flows:	Pit2 cash flows:	LTS cash flows:
Ore => CR1 @ +$25/t Ore => CR2 @ +$20/t Ore => ROM1 @ -$1/t Ore => ROM2 @ -$2/t	Ore => CR2 @ +$25/t Ore => CR1 @ +$20/t Ore => ROM2 @ -$1/t Ore => ROM1 @ -$2/t	LTS => CR1 @ +$20/t LTS => CR2 @ +$20/t

Suppose the optimiser returns this result:

Product1	Dry Tonnes	Fe	Al	Si	Cash Flow
Pit1	680 kt	60.0	4.0	6.5	+$17,000,000
Pit2	290 kt	61.5	2.0	4.0	+$7,250,000
LG	30 kt	58.0	6.0	14.0	+$750,000

Net	1000 kt	60.38	3.48	6.00
Target		60.5	3.00	5.50
Deviation		0.125	0.48	0.50
Penalty		-$125,000	-$480,000	-$500,000	-$1,105,000
Product2	Dry Tonnes	Fe	Al	Si	Cash Flow
Pit1	70 kt	60.0	4.0	6.5	+$1,750,000
Pit2	460 kt	61.5	2.0	4.0	+$11,500,000
LG	39.5 kt	58.0	6.0	14.0	+$984,000

Net	569.36 kt	61.073	2.52	5.00
Target		61.500	2.00	4.00
Deviation		0.427	0.52	1.00
Penalty		-$243,250	-$298,000	-$570,000	-$1,111,250
Total Cash Flow:					+$37,021,250

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