Direct reduction reactor with hot discharge

A process for producing hot sponge iron from a particulate iron ore in a vertically arranged, moving bed reactor having a reduction zone in the upper portion thereof forming part of a reducing gas loop through which a reducing gas is circulated and a modifying zone in the lower portion thereof for adjusting at least one of the properties of temperature and of carbon content of the sponge iron formed in said reduction zone, which process comprises supplying ore to be reduced to the upper portion of said reducing zone, circulating a first gas stream largely composed of carbon monoxide and hydrogen through said loop, heating said first gas stream before it enters said reducing zone and cooling and de-watering it after it leaves said reducing zone, feeding to said loop a second gas stream comprising make-up gas largely composed of carbon monoxide and hydrogen, removing from said loop a portion of the circulating gas as a third gas stream, heating and then mixing said third stream with a fourth stream of a carbon-containing gas having a temperature below that of said third stream to form a hot carburizing gas mixture causing said mixture to flow upwardly through the modifying zone of the reactor with said mixture having been blended so as to be effective to modify the carbon composition of the sponge iron passing therethrough to between 1% and 4% by weight and to adjust the temperature of the sponge iron to between 600.degree. C. and 900.degree. C., and removing modified hot sponge iron at the bottom of said reactor.