** Red Mountain Mining RMX.AX soars as much as 20% to A$0.036, highest since October 2
** Mineral explorer acquires Silver Dollar Antimony project in Idaho, U.S.
** Nearly 28.6 mln shares traded, in line with 30-day avg
** YTD, RMX surges 294.4%
(Reporting by Roshan Thomas in Bengaluru)
((Roshan.Thomas@thomsonreuters.com;))