** Shares of Magnum Mining and Exploration Ltd MGU.AX rise
as much as 14.8% to A$0.031, set to mark best day since Nov. 8,
if gains hold
** Mineral exploration co says it has found additional
magnetite concentrate at Buena Vista Iron Project in Nevada, US
** Says ore will support an average annual concentrate
production of 800,000 tonnes of iron
** Magnetite concentrate is a grey-black magnetic mineral
used to extract iron ore
** Stock up 28.6% this year, as of last close
(Reporting by Megha Rani in Bengaluru)
((Megha.Rani2@thomsonreuters.com;))