Abstract: A method is provided for inhibiting an increase in viscosity of coal/water slurries when such slurries are caused to contact petroleum oil during fuel changeover in power generation systems, the method comprising maintaining in the coal/water slurry during transitional contact with petroleum oil an effective amount of an agglomeration-inhibiting agent selected from the group consisting of nonionic and anionic dispersing agents sufficient to inhibit the formation of coal/oil agglomerates and provide a flowable mixture during transitional contact having a Brookfield viscosity of below about 50,000 cP.

Abstract: Directed to a flotation process for recovering molybdenite from a ground ore pulp containing the same which includes a rougher flotation step in which no collector is used by relatively high recovery of molybdenite in a rougher concentrate uncontaminated with collectors, which rougher concentrate can be cleaned to yield a high grade product while the rougher tailing can be treated by flotation to obtain high overall recovery of molybdenite along with a high recovery of other co-present metal values.