Determine and report insoluble matter, aluminium oxide (Al_{2}O_{3}),
ferric oxide (Fe_{2}O_{3}), ferrous oxide (FeO), basicity ratio, and, if
present, free acid as H_{2}SO_{4}. If the material is what is known as
“granular” sulfate mix it well before sampling. If it is in lump form
crush it to ⅛ to ¼ inch size, mix, and sample it. It is unnecessary to
grind the sample to a fine powder, but it is preferable to have the
particles fairly uniform in size.