Abstract: A process and flotation agents are provided for flotation of lead-, uranium-, and rare earth-type minerals and ores in which an aqueous pulp of the mineral or ore is subjected to a froth flotation, characterized in that the flotation is performed in the presence of a tertiary amine flotation agent having the general formula: ##STR1## wherein: R is a aliphatic hydrocarbon group having from about six to about twenty four carbon atoms;A is an oxyalkylene group having from about two to about four carbon atoms;X is selected from the group consisting of hydrogen and hydroxyl;m is a number within the range from 0 to about 10;n .sub.1 is a number within the range from 1 to about 4;n .sub.2 is 1, 2 or 3;x is a number within the range from 0 to about 4;y is 0 or 1;The sum of m + y being within the range from 1 to about 11; and salts thereof.The process is especially applicable in the flotation of sulphide and oxide ores and minerals.

Abstract: A method in the manufacture of high alumina refractory bricks containing more than 50% by weight alumina, in which moist refractory starting material is pressed into brick shapes, dried and hydrothermally bound. The principal binding agent used is finely divided activated alumina and is either added alone or together with any one of the substances slaked lime, slaked magnesia and finely divided silicon dioxide. The conditions chosen for the hydrothermal treament being such as to convert essentially all the activated alumina into boehmite.