The Barren Solution Recovery Plant completed in 2007 was designed to recover vanadium solids and ammonia from the barren solution using proprietary Kemplant technology. The turnkey project was designed to process up to 70 m3/hr of combined barren solution fed from the APV and AMV processing plants. All plant operations are automatically controlled via the dedicated PLC/SCADA system also provided by Kemplant.
The plant comprises a large capacity (10000m3) buffer storage facility for each of the two streams, with each stream being fed through respective filtration units to recover vanadium solids. The filtered streams were then combined and pumped to a neutralisation station where the pH is adjusted. The liquor is treated to precipitate dissolved silica followed by a filtration step to recover the precipitate.
The treated barren solution is preheated to a specific temperature and the pH adjusted before entering the stripping column. The ammonia is stripped from the liquor with the stripped barren liquor returned to the client for further processing. The ammonia is recovered in an absorption column. The ammonium salt solution produced is bled off at a controlled rate to the clients’ storage and make-up tank, in order to maintain the desired concentration in the absorption column.