On Sep 13, 5:58*pm, "Lew Hodgett" wrote:
"Robatoy" wrote:

Well, Lew... now you're into my area of expertise. The bulk of
pulverized coal turns into 'fly-ash' and is caught by electrostatic
precipitators. The clinkers are a minimal product of most coals burned
for power generation.
That doesn't mean I disagree with the possibilities of using fly-ash
as fillers for road contructuon, etc, but the mineral remnant is
notoriously weak in structure and is hard to bind with anything cheap.
...


I used to work for Stock Equipment company, though sadly, not until
after Arthur Stock had sold the company. The bread and butter of
our business was gravimetric feeders.

As I am sure you know, like coal itself fly ashes have enormous
variation in their properties. Something like 10 - 15% are
pozzolanic,
meaning they set like cement.

A few years ago utilities were experimenting with adding materials
to their scrubbers to produce, on the fly, useful materials like
(IIRC)
gypsum.

A major impediment to this sort of innovation is that Electric
power companies are in the business of producing electricity,
not 'stuff'.

A worse impediment to cost savings and especially fuel savings
measures in general is the economic regulatory structure.
Utilities typically have two sources of funding. Investors,
and ratepayers. The Public Utility Commissions (affectionately
referred to as pukes) typically restrict expenditures for capital
improvements to invested dollars, while allowing ratepayer
dollars to be spent on operational costs. Rates (with some
limitations) are allowed to go up and down with fuel usage
and costs. Investors expect a relatively short term return
on their investment. Consequently, when I was in the business
a utility would not make any improvements not required by law
unless they expected a return on the investment within nine
months.

That problem is by no means unique to the power industry and
is a major reason for why our economy has largely become
a house of cards. No long term investment.

So, while conversion from volumetric to gravimetric feeders
would typically reduce coal usage by 15% a number of utilities
would not do it.

Sometimes a utility would receive permission from their puke
to invest ratepayer money in a capital improvement. This
was typically reported in the Press as "charging customers
for electricity they had not yet generated", though that particular
phrase was more often used in the context of investing rate-
payer money in nuclear plant construction.

--

FF