... alum 2.free sample 3.good quality 4.low price food grade potash alum1.Specifications 2012 Potash alum for water treatment 1 ... puckery, astringent, easily soluble in water, its water solution appears acid,is would lose crystal water and become white powder on ... used to prepare aluminum, paints, tanning, mordant, paper, waterproof agent. food grade potash alum