초록 ▼

A method of pyroprocessing mineral ores, such as iron ore. The method includes receiving a preheated product stream of iron-containing pellets at an infeed end of a rotary kiln and introducing an oxidizing gas into the tumbling bed toward the infeed end of the rotary kiln. Additionally, a combustibl

A method of pyroprocessing mineral ores, such as iron ore. The method includes receiving a preheated product stream of iron-containing pellets at an infeed end of a rotary kiln and introducing an oxidizing gas into the tumbling bed toward the infeed end of the rotary kiln. Additionally, a combustible fuel is introduced through ports above the tumbling bed such that combustion of the introduced fuel increases the temperature of the product stream toward the infeed end. The increase in the temperature of the product stream allows the intensity of the flame from the centerline burner to be decreased, resulting in a reduction in the production of NO.sub.x. The apparatus for introducing both the oxidizing gas and fuel into the rotary kiln are common with each other.

대표청구항 ▼

[ I claim:] [1.]1. A method of oxidizing a mineral ore passing through an inclined rotary kiln comprising the steps of:receiving the mineral ore at an infeed end of the rotary kiln so that the mineral ore forms a continuous tumbling product stream proceeding from the infeed end to a discharge end of

[ I claim:] [1.]1. A method of oxidizing a mineral ore passing through an inclined rotary kiln comprising the steps of:receiving the mineral ore at an infeed end of the rotary kiln so that the mineral ore forms a continuous tumbling product stream proceeding from the infeed end to a discharge end of the rotary kiln;positioning a burner near the discharge end of the rotary kiln;operating the burner to maintain the temperature in the rotary kiln at a level sufficient to achieve oxidation and induration of the mineral ore;positioning a plurality of ports along the rotary kiln;injecting an oxidizing gas through the plurality of ports when the ports are beneath the product stream to increase the gas-ore interaction; andinjecting a fuel through the plurality of ports only when the ports are above the product stream such that the fuel burns above the product stream to elevate the temperature in the rotary kiln, wherein the oxidizing gas and the fuel are injected alternately through the same ports as the rotary kiln rotates.