Method for Producing Iron Powder Respectively Microalloyed Steel Powder Mainly for Metallurgical Applications and Method for Producing Thereof
AssigneeDr. Michael J. Ruthner
InventorMichael J. RUTHNER
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Abstract
A method for manufacturing of iron- respectively micro-alloyed steel powders, starting from fluffy spray roasted iron oxides exhibiting a specific surface area in excess of 2.0 m2/g and residual chloride contents over 440 ppm Cl′, decrease the chloride content in two steps to less than 100 ppm, the specific surface area (BET) of to a pre-selected value of less than 10.0 m2/g, preferably between 0.1 and 2.0 m2/g and reduce the pre-sintered granules exhibiting a bulk density in excess of 1.200 g/dm3.
Claims20
A method for manufacturing of iron—respectively micro-alloyed steel powders, wherein spray roasted iron oxides, originating from untreated or purified waste hydrochloric acid pickle liquor, exhibit a specific area in excess of 2.0 m2/g and residual chlorides over 400 ppm Cl′ are transformed into green micro-granules having a bulk density in excess of 1200 g/dm3, heat treated for a short period of time at temperatures between 900° C. and 1350° C. yielding pre-sintered micro-granules exhibiting lower residual chloride levels and lower specific surface areas, the pre-sintered micro-granules become reduced by gaseous reduction media and the reduction product is cooled to room temperature employing a reducing or inert atmosphere.
Dependencies are inferred from the claim text.