Michael G Pojar

US Patent:

54965268, Mar 5, 1996

Filed:

Aug 30, 1993

Appl. No.:

8/130080

Inventors:

Michael G. Pojar - Lino Lakes MN
John C. Nigro - Bloomington MN

Assignee:

The United States of America as represented by the Secretary of the
Interior - Washington DC

International Classification:

C22B 4700
C22B 100
C01G 4900
B03C 130

US Classification:

423 49

Abstract:

A process for producing intermediate grade manganese concentrate from low grade manganiferous ores is disclosed. A low grade manganiferous ore containing silicon, iron, between 1 and 20 per cent manganese and oxides of silicon, iron and manganese is first crushed to reduce the size of the manganiferous ore to a fraction of its original size. The crushed manganiferous ore is then heated to a temperature sufficient to chemically transform the manganese and iron in the manganiferous ore to an artificial magnetic, manganese-iron spinel. The heat treated manganiferous ore is cooled, preferably by air, and then beneficiated by further crushing and grinding to liberate the artificial manganese iron spinel from the silicon and other oxides within the ore. Finally, the artificial manganese-iron spinel is magnetically separated from the silicon and other oxides within the ore to increase the concentration of the manganese and thereby provide an intermediate grade manganese concentrate.