RELIABILITY OF “WORKABILITY INDEX” OF FIRE-CLAY PLASTIC REFRACTORIES*

A measure of the facility with which plastic refractory material can be rammed into place as determined with a specified sand rammer has been designated “workability index” by the American Society for Testing Materials. In the method for determining the index, cognizance apparently has not been taken of numerous variables which may give a misleading value. Several of these variables have been investigated by the authors. As a result it is concluded that a determination of the work required with the sand rammer to produce maximum bulk density is a more reliable indicator of the suitability of a plastic for ramming purposes.     

REACTION OF DIFFERENT CLAY MINERALS WITH SOME ORGANIC CATIONS*

Selected pure samples of kaolinite, illite, and montmorillonite were washed with 0.05 N HCl until free from replaceable bases, washed with water or methanol, and then reacted with sufficient KOH to saturate the exchange complex with K⁺ at pH 7. These K clays were given variable dosages of n-butylamine acetate, dodecylamine acetate, and ethyldimethyloctadecenylammonium bromide. The conclusions are as follows: (1) additions of amines or other organic cations in amounts less than equivalent to the base-exchange capacity of the clay are rather. completely adsorbed in base-exchange reactions; amounts of large organic cations added in excess of the base-exchange capacity of the clay tend to be adsorbed by a different reaction, probably dependent on the action of the van der Waals' forces; and (2) the ability of clays to absorb water is greatly reduced by treating the‘clays with certain compounds that furnish a large organic cation.     

A qualitative method for detecting surface active agents

A NEW METHOD is presented for the qualitative detection of small amounts of surface active agents which is generally applicable to all types, i.e. anionic, cationic, and non-ionic. This method is based on the solubilization in aqueous solution of certain oil soluble dyes, particularly Brilliant Oil Blue BMA. Presented at 20th annual fall meeting, American Oil Chemists' Society, Oct. 30 to Nov. 1, 1946, in Chicago, Ill.