The phrase "are circulated back" is correct and usable in written English.
It can be used when referring to information or materials that are returned or sent back to a previous point in a process or system.
Example: "Once the feedback is collected, the results are circulated back to the team for further discussion."
Alternatives: "are returned" or "are sent back".
The catalyst is circulated back into the regenerator where coke is burned and the catalyst regenerated.
This loss was due to carbon formation on the catalyst which was circulated back to the oxygen-containing zone of the bed where the carbon was combusted.
This water, flowing from the Indian Ocean into the Atlantic, became known as the "Agulhas leakage" and helped us understand how the ocean's salt is circulated back into the North Atlantic Ocean.
Modeling of the RO process demonstrates that SSP RO had the highest energy efficiency when the permeate from the 7th element (i.e., the last one in the single pass RO configuration) was circulated back and mixed with the feed.
Drill crew members referred to it as the "well from hell". The BP engineers were concerned most with "lost returns" — the fear that drilling mud and cement that would push into porous rock rather than be circulated back up the rig.
However, very often not all the drilling fluid is circulated back to the surface.
Under the optimized conditions obtained from the preliminary experiments, the concentrate stream was circulated back to the feed tank, whereas the permeate was collected individually.
Then the fluid with cuttings is circulated back up to the surface through the annular space between the drill pipe and the hole.
Once the train leaves, the empty containers are removed from the cradle, which then returns to the original position and is circulated back to the LD3 loading bay to await more bags for the next train.
Results were circulated back to participants for verification.
