Synthesis and flotation activity of reagent-collectors based on dithiocarbonyl and phosphoryl derivatives of amino alcohols

Research has been carried out to study the flotation activity of new surface active substances among dithiocarbonyl and phosphoryl derivatives of monoethanolamine and diethanolamine on the gold-bearing sulphide ore of the Bestobinskoye deposit of Kazakhstan. Among the first synthesized compounds, effective collectors for selective enrichment of sulfide polymetallic gold ores were found. Sodium N-octyl-N-2-hydroxyethyldithiocarbamate (AA-41) and sodium O-2-(dimethoxyphosphoryl-2-hydroxyethylamino)ethylxanthate (GF-2) were proposed as new flotation reagents. They were tested in the flotation of gold-bearing polymetallic ore as additional collectors and showed good results, contributing to an increase in the percentage of gold extraction in the collective concentrate in comparison with the factory basic regime in which a mixture of butyl xanthate (BX) and ditiophosphate butyl ether or butyl airoflot (BAF) was used. The results of flotation tests indicate that the collective ability of AA-41 flotation agent as an additional collector is at the level of BX. While the GF-2 flotation agent as a collector in combination with BAF provides a higher gold recovery to the concentrate of 90.8%, which is higher than gold recovery when combined with BX and BAF collectors (87.7%). It should be specially emphasized that the consumption of collectors AA-41 and GF-2 in comparison with the BX consumption in the base mode is much lower, so the AA-41 consumption is 11% lower and the consumption of GF-2 is lower by 33%. Methods for synthesizing the AA-41 flotation reagents and GF-2 flotation agents were developed, and the evidence of their structure was given with the help of physicochemical methods (IRS and NMR 1Н, 13С). The principal technological scheme of the process of obtaining the flotation agent-collector GF-2, which showed the best results in the flotation of gold-bearing polymetallic ore, was developed. In the synthesis of the flotation reagent AA-41, one of the principles of "green" chemistry was used, namely, the principle 9, stating that "catalytic systems and processes (as selective as possible) are in all cases better than stoichiometric ones." The use of tetrabutylammonium iodide as catalyst in the syntheses allows shortening the reaction time, reducing the reaction temperature to room temperature, and increasing the selectivity