Louis Katz on sat 18 oct 97
Find the relative numbers of molecules of each of the oxides in a glaze.
Teaching Glaze Calculation to someone who really understands the basic
chemistry that they were taught in junior high (hopefully) and proportions,
is no great challenge.
The challenge comes in trying to make this make sense to someone who does
not know molecular weight from atomic number, or a proton from a futon. For
these people it is best to not start with Avagadro's number, but to talk
about numbers of atoms in a bucket, or bag, and then get to understanding
that Avagadro counted molecules and atoms in Mols, just as I count bagels
or pots in dozens.
I don't think that starting on a computer is the best way to go about this.
I like starting with very simple problems.Some examples:
Problem One.
How much red iron oxide do you need to get the same number of molecules as
you would get from 1 gram of black iron oxide
Problem Two.
You want to substitue a mixture of Magnesium Carbonate and Calcium
Carbonate for 100 grams of Calcium Carbonate and are going to use dolomite.
How much dolomite should you use?
Problem Three.
a. What is the unity formula for the following recipe? Use theoretical
values for the ingredients.
Katz 111 Cone 10 reduction
1 whting
1 silica
1 kaolin
b. Diversify the fluxes using these numbers
..1 ZnO
..8 CaO
..1 BaO
and calculate a recipe using the following ingredients:
Zinc Oxide, Barium Carbonate, Kaolin(theoretical),Calcium Carbonate, Silica
Problem Four
Repeat problem Three using Edgar's Plastic Kaolin instead of Theoretical
Kaolin.
How will you deal with the small amounts of oxides not included in your
Unity formula, such as potassia, soda and titania?
Louis
David Hewitt on wed 22 oct 97
In message , Louis Katz writes
>----------------------------Original message----------------------------
snip
>I don't think that starting on a computer is the best way to go about this.
>I like starting with very simple problems.Some examples:
>
snip
I very much agree with this. It is all too easy to become bemused by the
figures that you see on a screen and forget to actually think what they
might mean and how they have been arrived at.
This is not to say that computer glaze programs aren't very useful. I
think they are extremely valuable, but I more often than not use one
based on a spreadsheet. One of the advantages of this type of program
is that the user can quite readily see how each calculation has been
made and hence check his understanding of what the figures mean as one
can see the formula used in each cell of the spreadsheet.
Such programs, however, may not have all the sophisticated features of
the stand alone programs, but with stand alone programs one cannot look
into the 'black box' and see how the programmer has done the
mathematics.
--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP6 1DQ, UK. Tel:- +44 (0) 1633 420647
URL http://digitalfire.com/education/people/hewitt.htm
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