Why does dialkyl thiocarbamate have frothing property?

O-N-dialkyl thiocarbamate (Z-200/O-isopropyl ethylthiocarbamate) is the most common collector for chalcopyrite flotation in China. However, due to its strong frothing property and weak selectivity, its application performance is poor in mines of polymetallic ore and high content of slime.

So why does dialkylthiocarbamate have such strong frothing ability? I visited some famous mines in China and communicated with many beneficiation engineers about this problem. Some engineers thought that in order to reduce the cost of reagents, frother (mainly terpineol oil) was added to the finished formate products. In order to investigate the real cause of the problem, our company's technical personnel contacted with the manufacturers of dialkylthiocarbamate, after meticulous discussion and communication with the production technical personnel, finally we understood the real reason.

The main raw material to produce dialkyl thiocarbamate is xanthate, this process will produce the by-product named methanethiol in the first stage. If the purity of raw xanthate is not enough or the by-product methanethiol is not removed thoroughly in the production process, the frothing property will be enhanced. This is also the reason why the performances of dialkylthiocarbamate from different manufacturers are quite different.