View Single Post
  #13  
Old 05-02-2018, 12:55 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 21,924
Pete VanderLaan is on a distinguished road
It's called "Whiting" and that's yet another name for Calcium Carbonate, also called Marble Dust, Lime, and a few others but it's all CaCO3. Hydrate is CaOH. Big differences on that Borax as well. Most formulas call for 5 mole, not ten. There is also anhydrous borax.

In some spreadsheets, it may not let you try both so the thing to do is to zero everything in the spreadsheet and then just add the single item, like feldspar. Then look at how your spreadsheet( that you likely didn't write) assigns the components for feldspar. Some will now be silica, some alumina but then it gets interesting where it puts sodium and potassium and in some cases (spodumene) lithium. The same sort of thing will happen with Borax, or alumina, so pay attention. The differences between Hydrated alumina and calcined are large.
After that, you may develop interest in how much moisture you are carrying around in a bag on chemicals that is additive and not chemically bound. If you had 1% moisture in a 100 lb bag, it's got 1 pound of water in it. Continue pondering that math when you look at expansion factors. Fritz used a simple trick to determine moisture. He put 100 grams of the questionable material in an annealer and turned it up to 250F for four hours. Then he measured the weight a second time. If it now weighed 97 grams, it was 3% water.

Doing this successfully requires a lot of careful deliberation and some occasional navel gazing.
__________________
Where are we going and why am I in this basket?
Reply With Quote