be employed as by pressurization with an inert gas although no advantages for this are apparent the product is recovered by conventional techniques of solids separation such as sedimentation and decantation filtration or centrifuging it is readily freed of any retained liquid phase by washing with a dilute alkaline solution and or with water and drying by conventional reduction procedures hematite particles of the present invention have been converted to magnetites having the following property ranges upon reoxidation gamma iron oxides have been obtained having the following property ranges in the following examples the concentrations of iron in the reaction mixtures are gram ions per liter but the symbol m for molar is used for convenience a mixture of 33 93 mls of 4 42m lioh and 39 71 ml of deionized water was added with stirring to 76 37 ml of 0 983m fe 2 so 4 3 reagent grade chemicals were used final concentrations of both iron and lithium were 1 0m aliquots were sealed as follows in glass ampoules ampoules 23 cm long and 0 1 cm o d 0 8 cm i d were charged with 7 ml of reactant mixture ampoules 22 cm long and 2 55 cm o d 1 76 cm i d 25 ml reactants and ampoules 30 cm long and 2 25 cm o d 1 62 cm i d 38 45 ml reactants the ampoules were sealed in steel bombs and heated to 200 u00b0 c with rocking or horizontal agitation after 3 hours at 200 u00b0 c the bombs were allowed to cool slowly overnight.