Barytes Currie Test Tile Reduction May 2015

Local barytes testing. Currie test tile format. Fired in mid-size LPG gas fibre kiln, cone 10, heavy reduction from 900 to 1280, then a very clean 30 min soak in oxidation. This cell is night and day to its twin fired in oxidation. There is evidence of good melting in most cells, probably much of this due to the high iron content of the barytes. I am left wondering if there is some other flux here besides just the iron which works well in reduction (in addition to the barium sulphate of course)

While the well melted zone is about where expected, there is a real difference in surface quality between, for instance, column 2 and column 3, and then again between column 3 and column 4. This suggests (to me at least) that there is a fairly specific quantity of silica which this barytes can absorb into the melt, as the surfaces are all matte-ish in column 2, well melted in most of column 3 (including right at the bottom with no clay!), and clear evidence of silica overload in most of column 4.