SLURRY DENSITY

[dainebryce]

I would like to know if it is possible for a tailings slurry's density to change from the plant, to the deposition at the tailings dam.
The pipes come from the plant which is almost 30km away and goes through a series of diameter changes, also it splits into several directions (T-pieces)several times. Would it be possible for these splits and long distances to effect or change the final density of the slurry??

What could be some factors that effect a change in density for the slurry?

 

[BUGGAR]

Concrete loses slump when pumped long distances in "slicklines". Maybe unrelated but it proves things can happen in mixtures pumped over distances.
Does the density increase or decrease?

 

[dainebryce]

Thank you, Im not too sure yet, I need to investigate and test that...I have a feeling it will have a finer consistancy? so a decrease in density...is that what happens to the concrete?

 

[Ron]

Particle abrasion will change the gradation with long pumping distances. Is the material one that might also go through a chemical change during transport? (such as hydration)

 

[dainebryce]

Not really, it is slurry that comes from a mine that is sent to a tailings dam

 

[oldestguy]

Describe the problem. Is the deposited material more or less fluid? Is there sign of lack of affinity of water to the product?

 

[dainebryce]

I am doing an investigation on tailings dam cyclones, they are not performing properly. I thought maybe it could be that the density is changing from when the slurry leaves the plant to when it gets to the tailings dam site, as the density will affect the split ratio from the cyclone. But before I go and do actual tests I wanted to know if its possible for a mine tailings slurry to change density over long distances in a pipe. Yes it is more or less a fluid. Its almost like a mud! Is this enough detail?

 

[Ron]

I would anticipate changes in density along the transport line. Assuming you have booster pumps along the way, the density will likely be higher just after the booster pump discharge.

For concrete, there is a lot going on during pumping, so I doubt there is a reasonable comparison. Concrete viscosity changes with time, without regard to changes in density.

 

[miningman]

If you post a description of the details of how the cyclones aren't behaving , in the mining engineering forum , you might get better and more usefull responses. Nearly all mining engineers have some experience with pumping tailings.

 

[dainebryce]

Thanks for that...I didn't know you could do that...

 

[itdepends]

I would expect little impact in the particle size density over the pipeline distance given this is mines tailings stream (unless it's a very soft ore). I'd expect no change in slurry density either.

The exception to the above is the tee pieces- they may result in preferential splitting of solid/liquid fractions resulting in lower density at one location and higher at another.

Also please be aware that getting a representative sample of slurry lines is notoriously difficult. The finer the slurry, the better mixed (e.g. directly after a pump) and the thicker it is- the easier it is to get a representative sample.

As a chem eng/metallurgist the first part of any answer I give starts with "It Depends"

 

[zelgar]

You also mention that the pipes go through a series of diameter changes which could affect the flow of the slurry. A bigger pipe might allow more liquid, but it can also reduce the flow-rate of the slurry which could result in acting like a settling basin (just a long, thin one).