出典:Wiktionary
leonardite (複数形 leonardites)
出典:Wikipedia
出典:『Wikipedia』 (2011/05/02 09:54 UTC 版)
Leonardite is a soft waxy, black or brown, shiny, vitreous mineraloid that is easily soluble in alkaline solutions. It is an oxidation product of lignite, associated with near-surface mining. It is a rich source of humic acid (up to 90%) and is used as a soil conditioner, as a stabilizer for ion-exchange resins in water treatment, in the remediation of polluted environments and as a drilling additive. It was named for Dr. A.G. Leonard, first director of the North Dakota Geological Survey, in recognition of his work on these deposits.