Mining Demo models

Here are some mining demo models!

There are two models:
1. Open Pit Mine: This model has three loadzones and two dumpzones. There are two Front Shovel loadzones and one Excavator loadzone.
2. Block Cave Mine: This model is of a fictional block cave mine that has 6 LHD's that have to use 1 of 2 dump positions. When the blocks go red that means that they are blocked and the LHD can not go past that area because a drill rig is there.

Unload the attached zip file into your "userprojects" directory to get the 3D shapes to appear correctly. These are Flexsim Version 4.3 models.

Good Luck,
Brandon

All,

I have gotten a question about these models that I would like to address on the forum as I think that it might be usefull to everyone.

Question: What went into building the models?

The Underground Demo model was built using traditional task executers, traffic controllers, and Sources. The sources are the objects that determine when a draw point breaks down (goes red) and how much material is left at the draw point. Generally the sources just produce items that represent a defined amount of material and the dispatcher calls the LHD (transporter) that services that draw point. When a draw point goes down the source will call stopobject on all of the sources that are further into the entry way than it is. Stop object is used so that if multiple draw points go down it will requre multiple resumeobject commands before a source can call the LHD back to it.

The Open Pit model was built over a considerable amount of time. This model uses custom objects that had to be built individually and specifically for the task they perform. This model runs primarily off of task sequences that call sub tasks. This means that the original task sequence given to a truck is to travel to a load zone, call subtasks, travel to a dump, call subtasks, and finally send a message to the dispatcher to do it all over again. When the truck reaches a loadzone or dump the sub task will allocate a load or dump spot and then call subtasks on that spot that will inform the truck how to travel to the spot. After the truck has traveled to the load or dump spot it is loaded by a shovel or it dumps on its own. This is a very interesting model to study if someone is interesed in task sequences.

If anyone has any more questions about these models please post them here and I will answer them as quickly as possible.

Thanks,
Brandon

Brandon - how did you model the coal? Is it modelled as a fluid or item?

I have a scenario where i need to model the movement of coal (source being a stockpile at a mine) by truck, train then ship, with stockpiles between each transit.

As with any truck-load, there will be slight differences in the loads each run.

I suspect using fluid modelling would be the most accurate but not sure how to transport fluid. Options I'm considering

• use fluid model all the way, transporting as fluid
• chunk up and use multiple items of coal
• use fluid for the stockpiles and convert fluidtoitem and back for each transit.

Any suggestions?

Thanks

Kenny

Kenny,

The coal is modeled as an item that has a label on it to store the amount being moved. The pile can also have the same label. this would be the easiest way to model what you want if you are using trucks. If you are primarily using conveyors then you may want to use the fluid objects.

Good Luck,
Brandon

Thanks Brandon,

This is sort of what I had tried for a one-stage transportation but hadn't thought about using it for multi-stage scenario. I agree that this would be the easiest way IF i can increment the stockpiles at each stage with the values transported and then decrement the stockpile as coal is removed for the next stage of its journey.

The key purpose of the model is to determine the number of vehicles required at each stage and the capacity of the stockpiles (buffers) required between each section. (there’s a stockpile before each transit stage)
Mine (stockpile) -> Road-train (100T capacity) –> stockpile –> train (4,000T) – > stockpile –> Conveyor to ship (50,000T)

How would you manage the flow/management of items downstream? At each stage ther e are less items being transported so I guess it's feasible to leave "empty" items at each stockpile (queue). Or would you suggest a hidden sink and source at each stockpile, with the contents being carried by a variable.

Any suggestions on tracking the amount of coal through the process and managing the items through the process?

Kenny

Kenny,

On entry of the stock pile I would increment the label and probaly destroy the item or send it to a sink. The open pit model is driven by a task sequence loop that tells the trucks what to do. The only reason for the flowitems is so that the shovel has something to load and unload in the truck. If you wanted you could easily remove the items from the model entirely.

The main driver of that model is a task sequence that is as follows:

Travel to a load zone
Call subtasks on the load zone
Travel to the dump zone
Call subtasks on the dump zone
Send a message to redo the loop

So you could create a stock pile area and then change the main dispatch logic and it would behave how you wanted it.

Brandon

Thanks Brandon, I appreciate your advice.

Kenny

Hi Brandon,

There is a node "Front Shovel>special/reportvariables" which I think is not standard in Flexsim. What's that for and how? Is it used for generating report? I have a customized object which has some unstandard states like cutting, supporting, etc which I add into the end of states profile list; and I want them to be reported. Do you have any suggestion? Thanks.