Investigations of alkylmorpholines––collectors for a new halite flotation process

Some physicochemical aspects of water-soluble mineral flotation

“…There is a good relationship between surfactant adsorption effectiveness and the efficiency of the surfactant as a collector [74]. Investigations on the influence of hydrocarbon chain length on alkylmorpholine flotation has shown an improvement in halite floatability with an increase in hydrocarbon chain length, the highest halite recovery being obtained using hexadecyl-morpholine at 18-20 o C [75].…”

“…For KCl and NaCl, it seems that there is no direct hydrogen bonding between KCl or NaCl and the collectors, or else the direct hydrogen bonding is very weak because the ability of Cl to form hydrogen bonds is much weaker than that of O, N, and F. There may be direct ionic hydrogen bonds between primary, secondary and tertiary amines and SO 4 2-, CO 3 2-, or HCO 3 -groups of the minerals. For indirect hydrogen bonds, it was reported that alkylmorpholine fixation to halite can occur via hydrogen bonding between the oxygen atoms of morpholine and the hydrated sodium ions at the halite surfaces [75].…”

“…Frother addition was reported to enhance alkylmorpholine adsorption at halite surfaces and to decrease alkylmorpholine consumption considerably [75]. During potash ore flotation using an amine as the collector, if a frother is mixed with the amine when the amine is dispersed in a hot, acidified aqueous solution, the spreading of the amine is dramatically enhanced.…”

“…Comparison of the operation efficiency of a single alkylmorpholine and an alkylmorpholine mixture has shown that the mixture results in better flotation activity. The best halite floatability has been obtained when a mixture of hexadecylmorpholine and octadecylmorpholine were used [75]. More effort should be made to understand the behavior and related interaction of mixed surfactants in the flotation of water-soluble minerals.…”

Utilization of Ammonium Chloride as a Novel Selective Depressant in Reverse Flotation of Potassium Chloride

“…Thus, globally, most potash ores are concentrated by froth flotation [3]. In this process, direct flotation collectors comprise alkyl fatty amines [4] and alkyl sulfonates [5], while reverse flotation collectors contain carboxylic acids [6], amides [7], and morpholines [8].…”