** Shares of St George Mining SGQ.AX rise as much as 14.3% to A$0.024, their biggest intraday pct gain since Oct 21
** Co signs co-venture with Brazilian scientific agencies EMBRAPII and SENAI for development of downstream processing and production of niobium, rare earths at Araxa project in Brazil
** 6.8 mln shares traded so far vs 30-day avg of 6.4 mln
** Stock fell 26.5% in 2024
(Reporting by Manasi Dasa Sundeep in Bengaluru)
((Manasi.DasaSundeep@ThomsonReuters.com))