1) Soil improver 
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 remediati...