Originally Posted by blakeyg

Hello all,

I am more of a dry materials handling man getting into slurry pipelines.

I am looking at a 6km tailing pipeline that needs to be able to hand quite a variable slurry.

What is the best way to approach this. Is this complex slurry or can I just do some of the calculation I find books by BEA Jacobs or Abulnaga +10% power.

What are the pitfalls?

Should I get a slurry expert to design such a pipeline or could it be done using calculations found in textbook?

Slurry details below. Basically a gold tailings.

Slurry density is 1.3-1.5,

13-21% solids by volume

Particle size

1mm 0.32%

0.85mm 0.62%

0.5mm 1.58%

0.35mm 2.88%

0.25mm 6.43%

0.15mm 10.17%

0.11mm 9.64%

0.075mm 10.41%

0.045mm 15.18%

0.038mm 5.19%

0.025mm 5.13%

-0.025mm 32.91%

Best regards,

G

The biggest worry is silting/siltation and the reducion of the pipelines efficiency due

to the restriction which will act as a simple barrier slowing down the enire stream

and as result seeing more material drop out.

I would contact a Gould Pump representative on your side of the world and chat about

dredging pumps to allow you understand how this mess works. This will be the quickest

way for you to do this. ■

The easiest way is also the most accurate. Do your calcs using all the methods at your disposal and then present them to the pump applications engineer for fine tuning. If you get 2 results which are not very far from yours then you've cracked it. Warman have a CD to help and I supect some of the others will have similar.

I used to have a copy of Abulnaga but for what use it was I left it in my flat in Perth because it wasn't worth paying the excess baggage. Others will say they wouldn't be without it. ■

Blakeyg,

A 6km slurry pipeline is no small matter even with a well defined stable slurry. You mention that yours is 'quite a variable slurry'. I would be very cautious about entering a design of this pipeline as a novice. Long slurry pipelines not designed properly can be disastrous. The best approach for this pipeline is to have a test done in a lab if a pipeline of similar size and material transported is not available. If a similar pipeline is available, you will want to install pressure gauges on a test length of the pipeline to determine head loss. You will also want to get access to the inside to see if a bed has developed or not.

From the threads posted by D.R. Kaushal, it appears he has a test facility that could help you if a lab is required.

Softedge ■

It is good to use a slurry expert - Some rheology tests are recommended. A good pipeline profile is also needed. You can get some help by contacting sales@mazdakpumps.com they can do some of the test work for you. ■

If you ask the question then you are admitting you need the expert help.

It would be unwise to use the McGraw Hill textbook on slurry flow. It is useless unless you need a doorstop or similar. I bought mine from that expensive bookshop in Hayes Street and within a couple of weeks I was looking for a door to prop open. I left it behind in your Promet office because it wasn't worth the excess baggage and also I thought that while it cost so much some other poor soul might find it; study it and become equally confused. ■

Hello Gareth,

As mentioned above, a 6km line will not be forgiving at all. You are targeting a range of up to 40% solids by mass and you have significant fines in you tailings. Unfortunately this means that it will not fall into any of the "Text book" classifications of slurry - not purely settling and not homogenous. Assuming only one or the other will result in a very expensive over powered system or a simple plugged pipeline.

The main reason for failed slurry systems design is incorrect material characterization. You definitely need to get a bucket of sample to a rheology lab so that you have accurate data about your tailings with its specific mineral make up, grind and concentration. I am not sure what process you are using, but any additives, flocculants or pH levels of your tailings will be incorporated in those results - somethings that can only be identified through loop or viscometer tests.

I have extensive experience in tailings system design and as we do the actual rheology testing we are able to use both the physical experience of handling the sample as well as the theoretical model in completing a reliable, but practical design.

To answer your question: "your tailings pipeline DOES need an expert"

If you require any assistance or guidance contact me. ■