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Tavares UFRJ Breakage model - dummy particle size

Hello,

I would like to ask about the size of dummy class particles, what value should be used? How does it influence the simulation/results? From what I understand the dummy particles are responsible for representing fines created during breakage and they are unbreakable. How does it relates to the smallest particle size defined in physics card? In my model I have dummy particles of size (~100 mm where smalles particle size is taken as 5 mm).

Best regards,

Radek

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v2022.1

Accepted answers

Renan

Hi Radek,

Regarding your first question: we recommend using the same size as the original particle. The easiest way to do this is just copy the original bulk material then changing the particle's name to YourParticleName_dummy

For the next question: you're right, the dummy particles are there just so we can keep track of the total amount of fines generated and are unbreakable, so they won't have a major influence on your simulation result. What will affect your results is the breakage parameters used and the D minimum

Best regards,

Renan

All comments

Renan

Hi Radek,

Best regards,

Renan

Radosław Kasztelan

Hi Radek,

Regarding your first question: we recommend using the same size as the original particle. The easiest way to do this is just copy the original bulk material then changing the particle's name to YourParticleName_dummy

For the next question: you're right, the dummy particles are there just so we can keep track of the total amount of fines generated and are unbreakable, so they won't have a major influence on your simulation result. What will affect your results is the breakage parameters used and the D minimum

Best regards,

Renan

Thank you Renan for your response.

Regarding the influence of the diameter of dummy_particle, I've tested it and found out, that increasing or decreasing the diameter violation of mass conservation e.g. total mass generated by factory was ~850 kg and while using 5 mm dummy diameter at the end of simulation I got only 750 kg, for 60 mm diameter at the end was ~ 1100kg. While using same size as original material, the mass was conserved (with an error less than 1%).

My question was inspired by an information that I've found in the Tavares model overview post [LINK], where in setup guideline file it was stated: "The dummy particle prototype needs to be the same size as the ore particle or the largest size from the size distribution". Since in my model I have some normal distribution with mean of 3 and cap size of (1.5 and 4.5 radius), then what value should I take - 4.5 times bigger than my initial?

Best regards,

Radek

Renan

Thank you Renan for your response.

Regarding the influence of the diameter of dummy_particle, I've tested it and found out, that increasing or decreasing the diameter violation of mass conservation e.g. total mass generated by factory was ~850 kg and while using 5 mm dummy diameter at the end of simulation I got only 750 kg, for 60 mm diameter at the end was ~ 1100kg. While using same size as original material, the mass was conserved (with an error less than 1%).

My question was inspired by an information that I've found in the Tavares model overview post [LINK], where in setup guideline file it was stated: "The dummy particle prototype needs to be the same size as the ore particle or the largest size from the size distribution". Since in my model I have some normal distribution with mean of 3 and cap size of (1.5 and 4.5 radius), then what value should I take - 4.5 times bigger than my initial?

Best regards,

Radek

Hi Radek,

Just to clarify: when you set the dummy particle size to 5 mm the factory is only able to generate 750 kg and when you set it to 60 mm the factory generates 1100 kg. Is that it?

Best regards,

Renan

Radosław Kasztelan

Hi Radek,

Just to clarify: when you set the dummy particle size to 5 mm the factory is only able to generate 750 kg and when you set it to 60 mm the factory generates 1100 kg. Is that it?

Best regards,

Renan

Hi Renan,

The factory output is the same ~850kg, but total mass of all particles - proper and dummy, at the end of the simulation.

Best regards,

Radek