A study of the colloid obtained from weathered lignite

When Lignite is exposed to the action of weather it undergoes various changes, probably due to oxidation. Surface beds of lignite are often rejected by the miners as inferior coal, due to the weathered condition. But when this weathered lignite is treated with sodium hydroxide, and the resulting solution allowed to evaporate to dryness, there is left a hard, shiny substance very similar in appearance to hard coal. This dried product has been exploited under the name of Dakolite. When dispersed in water this product makes a very good wood stain. Tests made on Dakolite show that it has colloidal properties. When the Dakolite is dispersed in water a negative hydrosol is formed, which exhibits the Tyndall effect, precipitated by electrolytes, and can be dialyzed by membranes. The material used in this study was found in a ditch in western North Dakota. It was in a jelly-like condition when found, but on drying became a hard, shiny substance like Dakolite. It is a thought that this Jelly-like substance was formed by the action of alkaline waters on weathered lignite. As the alkaline waters flowed over the lignite beds a portion of the weathered lignite was dissolved, and as the water evaporated the jelly-like substance was left, which on drying became a hard coal-like material. This study was undertaken to ascertain the chemical composition and some of the colloidal properties of this substance