(under subclass 177) Processes wherein mineral oil is treated with an alkali or alkaline earth metal compound.
(1) Note. For the purpose of this classification, the alkali metals are sodium, potassium, lithium, rubidium, cesium and francium and the alkaline earth metals are calcium, barium and strontium and also including magnesium.
(2) Note. Natural clays which generally contain some alkali metal component are not included in this or indented subclasses but are classified instead with the aluminum or silicon containing compounds.
SEE OR SEARCH THIS CLASS, SUBCLASS:
203+, for processes of sweetening using alkali metal hydroxides and carbonates.
226+, for processes of desulfurizing mineral oils with alkali or alkaline earth metal compounds. 259, for processes of removing gums or gum formers with alkali or alkaline earth metal compounds.
