| 摘要 |
<p>Column for stripping annonia from annonacal solns. or suspensions has a feed of the soln. in at the top and steam in at the base. It is divided into several zones by means of a series of trays mounted one above the other having normal liquid downcomers from tray to tray. IT is cooled in several stages down the column bypassing a coolant through the trays. The trays or pertitions can be double skinned with a passage for coolant through them. They can be conical shaped with run offs. Vapour lines can be provided to allow transfer of vapour from the vapour space of one stage to a subsequent stage. Method for stripping NH3 out of solns. and suspensions derived from the NH3 treatment of certain metal ores for metal recovery e.g. Ni, Zn, Cu, and Co. Soluble complexes are leached out of the ores and the metal is recovered as oxide or carbonate by stripping out the NH3 which is recovered. In conventional tray columns deposits of these oxides and carbonates level to form on the trays on the better surfaces. Cooling the trays avoids this.</p> |
