POE can be used as a flocculant in some applications. The term "thickening" in the mining industry is equivalent to "dewatering" in equipment called thickeners. Which is a tank with a mechanism inside? The thickener you mentioned is not the same. If you want a substance that change the flow properties; most "flocculants" will do. Clay could also change the flow properties as in "drilling mud’s".

PEO can be used as a flocculant in thickeners and clarifiers. It’s used in some applications because it can be food grade. Its use in mineral tailings is pretty rare.

Yes it can - as the saying goes, "horses for courses" one has to find the application best suited for this. As it is typically non-toxic that would help. Years ago wax was used in helping particles coagulate, however, that was years ago.

Work at the University of South Australia looked at PEO in clay flocculation and claimed some benefits in dewatering relative to conventional flocculants (McFarlane, A.J., Addai-Mensah, J., Bremmell, K., 2005. Rheology of flocculated kaolinite dispersions. Korea-Australia Rheology Journal, 17, 181-190). Feedback I've had from on industry contact is that PEO is not as friendly to work with as other products.

We started using it at Port Pirie in the copper matte leach circuit in about 1986 as a colloidal silica coagulant to aid thickening and to reduce crud formation in the subsequent solvent extraction circuit. It had a positive effect on the circuit.

Thanks to you all for your responses and information. I may have some follow-up questions as my knowledge is limited regarding many of these applications.