It’s beginning in the US (see work by NETL). But it’s not profitable yet anywhere, to my knowledge. What end REEs product are you aiming for and who do you expect to sell to?
Profitability of RE extraction is commercial in confidence - that means, only the organisations doing the work will have accurate figures. Do you have all the chemical steps and stages for your extraction process? Do you have figures for their costs? This is going to be a major task, but best wishes for your work!
Tony you are right the task is surmounting , but can and should be specified.
The decisive technology is anyhow the CO2 extraction and transformation on a profitable way besides finding new ways for coal(waste) gasification bringing the gas conversion thersould lower, which is almost impossible with the low natural gas prices at present