[TheForge] Re: Chip forge

[Mike Spencer]

> Good grief Mike! Who in their right mind would want to dispose of
> perfectly good sludge?

Good point. Frosty.  Read on...

> So, how do you fluidize a bed? You force something through it at the
> media's terminal velocity right? In the case of a fluidized heating
> furnace it's the terminal velocity of the "chips" in burning
> gas/air. In the case of certain gold extraction devices it's the
> velocity of water/chemical mix through crushed gold bearing ore.

Happens I spent an afternoon dicking around with that.  A geologist
friend was working at a gold mine that used a vibration table to
extract the gold "dust" from pulverized ore.  But due to a factor I
forget -- something like the gold was so pure or the grains so fine --
the ore mill was delivering "gold to airy thinness beat", i.e. very
tiny, thin, gold-leaf-like flakes to the table instead of nice, dense
round granules. So they were just flushing them off into the sludge in
quantities sufficient to make the difference between profit and loss.

So we built a water column, diddled with samples from the line and
from the sludge for a few hours.  Our conclusion was that they would
have to budget some real money to experiment with a bunch of variables
and build a pilot plant, evaluate, rinse and repeat a few times.  I
believe they didn't do that.  Wasn't long before the mine closed up.
But I know where there's a biiiig puddle of sludge that has a lot of
very airy, thin gold flakes in it.


- Mike

-- 
Michael Spencer                  Nova Scotia, Canada       .~. 
                                                           /V\ 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^