Ron Roy on mon 21 dec 98
I have calculated a substitution for cornwall stone and come up with
different results. I am basing my calculations on the analysis I have for
Cornish Stone which I received from Hamill & Gillespie but we have to
understand - there are at least 4 varieties of this stuff and they all melt
differently. The is another factor involved - Cornish Stone is a "cooked"
material like other products such as the feldspars - so they are easier to
melt than "uncooked."
When you start adding other material to a spar - because they are
"uncombined" more heatwork will be needed to melt it than the original
natural material.
There are other oxides in Cornwall Stone which will have an effect on the
melt - sometimes Fluorine and always P2O3.
Anyway - if anyone cares to do a line blend between these three
substitutions and what ever kind of Cornwall Stone they have we would all
be interested to hear the results.
Ron's Seger molecular unity formula for Cornwall Stone based on H&G's analysis
-----------------
CORN STN............ 100.00
----------
100.00
FORMULA & ANALYSIS
------------------
*CaO........ .26 2.02%
*MgO........
*K2O........ .29 3.74%
*Na2O....... .44 3.74%
Fe2O3...... .01 .14%
TIO2....... .01 .07%
AL2O3...... 1.16 16.14%
SiO2....... 9.03 73.65%
P2O5....... .03 .51%
RATIO 7.76
EXPAN 399.42
WEIGHT 735.81
Ron's calculated sub (untested) for his Cornwall Stone (untested) based on
the unity formula - note higher expansion than the original.
-----------------
G 200 SPAR.......... 59.00
EPK................. 12.50
SILICA.............. 26.00
WHITING............. 2.50
----------
100.00
FORMULA & ANALYSIS
------------------
*CaO........ .26 1.93%
*MgO........ .00 .02%
*K2O........ .52 6.54%
*Na2O....... .22 1.84%
Fe2O3...... .01 .16%
TIO2....... .00 .04%
AL2O3...... 1.17 16.07%
SiO2........... 9.12 73.39
P2O5....... .00 .02%
RATIO 7.77
EXPAN 424.57
WEIGHT 746.03
Rons duplication based on the calculated percent of oxides in the fired
material. Note the calculated expansion in this last one compares better
with the H&G analysis but there is a greater difference in the oxides
present when you look at the unity formula - can someone explain the
difference to me?
I do know there are some people in industry that use the fired % analysis
instead of the molecular formula for problem solving - anyone have a clue
as to why?
-----------------
G 200 SPAR.......... 53.00
EPK................. 15.50
SILICA.............. 28.50
WHITING............. 3.00
----------
100.00
FORMULA & ANALYSIS
------------------
*CaO........ .30 2.18%
*MgO........ .01 .03%
*K2O........ .49 5.94%
*Na2O....... .21 1.66%
Fe2O3...... .01 .18%
TIO2....... .00 .05%
AL2O3...... 1.23 16.20%
SiO2....... 9.50 73.74%
P2O5....... .00 .02%
RATIO 7.74
EXPAN 398.48
WEIGHT 772.69
Happy holidays everyone - hope I didn't spoil any ones with all this - R
>----------------------------Original message----------------------------
>Date: Thu, 17 Dec 1998 16:39:08 -0500 (EST)
>From: David Orser
>To: tmartens@jhb-proxy.mweb.co.za
>Subject: cornwall stone
> came across this substitution for cornish stone a while back.
>
> potash spar 67
> silica 22
> kaolin 11
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
| |
|
