Originally Posted by
Trapper-Jack
I have read many of the articles and a few things that stand out to me is the moisture during the mixing. The swiss booklet says they will use up to 10% moisture during the wheel milling. (Page 15) Most of what I've read here is about dry milling in a ball mill but that is about the only option without a large investment. It may be comparing apples to oranges but I'm continually thinking about the moisture during the pressing. Normally I use 4.8% on newly balled powder, 4.5% when reprocessing the fines from previously balled powder. If I go higher than that I'll get excess bleeding of water (and I'm sure a portion of the potassium nitrate) out the bottom of my die using a 20 ton jack. Page 19 describes their roller press where the powder is compressed into a cake that is about .5 to 1 cm thick. Page 20 states that the powder from the wheel mill, being low density, is compressed 35 to 40% reduction in volume. The densification and consolidation of the powder doesn't require a great deal of pressure for a period of time as with a plate press but depends on the loss of moisture through evaporation to complete the mechanical strength in the grains. I'm sure I'm compressing my green powder way more than the 35 to 40%. What I've been doing seems to have been working, but would more moisture and less compression work better? I'm trying to wrap my mind around this new information and comprehend how it would improve what I'm already doing.