Patent EP-2664681-A1 (EP)
Inventor: MILLNER ROBERT
IPC: C21B7/00
Filed: 2012-05-16
Abstract: The method comprises directly introducing fine particle-shaped material (4) into a fluidized bed (24) and/or in a free space (25) above the fluidized bed of a reduction unit (1) using a burner (2), and agglomerating the fine particle-shaped material to form agglomerates during the introduction so that agglomerates are held in the fluidized bed of the reduction unit until the agglomerates are discharged out of the fluidized bed reduction unit. A temperature in the fluidized bed is less than 800[deg] C. A portion of the fine particle-shaped material is originated by a dust removal device. The method comprises directly introducing fine particle-shaped material (4) into a fluidized bed (24) and/or in a free space (25) above the fluidized bed of a reduction unit (1) using a burner (2), and agglomerating the fine particle-shaped material to form agglomerates during the introduction so that agglomerates are held in the fluidized bed of the reduction unit until the agglomerates are discharged out of the fluidized bed reduction unit. A temperature in the fluidized bed is less than 800[deg] C. A portion of the fine particle-shaped material is originated by a dust removal device such as a dry dust collection device, a smelting reduction unit and/or a direct reduction plant. The introducing step includes oxidation of iron-containing particles, reduction of iron-containing particles, increasing a porosity of the iron-containing particles, and drying the fine particle-shaped material. The fine particle-shaped material is conveyed pneumatically to the burner at a temperature of more than 150[deg] C by a conveying gas. The iron-containing particles include magnetite, dust from the dry dust collection device, off-gas dust from the dry dust collection device, a dust from a compacting device such as a hot compacting device, a briquette machine or a hot briquette machine, a smelter dust from a casting-hall dedusting device, fine iron ores of less than 200 mu m. The fine particle-shaped material comprises carbon-containing substances. The burner is operated by a gaseous fuel, a liquid fuel, a solid fuel and/or an oxygen-containing gas. The fuel includes a product gas from a carbon dioxide removal device, tail gas from the carbon dioxide removal device, cooling gas, export gas, top gas, off-gas, coke oven gas, natural gas, by pressure liquefied gas, gas from biomass gasification, carbon and/or hydrogen-containing gas, and/or solid carbon carriers and/or solid hydrocarbon carriers. The gaseous fuel and/or the solid fuel after exit from the burner is partially oxidized with the oxygen-containing gas. The oxygen-containing gas includes air, oxygen, nitrogen, and steam. The conveying gas includes a product gas from the carbon dioxide removal device, tail gas from the carbon dioxide removal device, cooling gas, export gas, top gas, off-gas, coke oven gas, natural gas, gas from biomass gasification, carbon and/or hydrogen-containing gas, air, oxygen, nitrogen, and steam. A portion of the gaseous fuel and/or a portion of the oxygen-containing gas is used as the conveying gas for the pneumatic transport of the fine particle-shaped material into the burner. The oxygen-containing gas is reacted with a hydrogen, carbon monoxide, methane and/or hydrocarbon-comprising gas atmosphere in the reduction unit during operation of the burner. Solid carbon and/or hydrocarbon carriers such as coke breeze and/or coal fines is supplied to the burner. The fine particle-shaped material is located in a memory device before the introduction step. The method further comprises adding additives to the fine particle-shaped material in the fluidized-bed reduction unit, partially reducing iron precursors using a reducing gas, supplying the oxygen-containing gas to iron precursors in a melt-reduction unit, and melting liquid pig iron or liquid steel pre-products. An independent claim is included for a device for introducing fine particle-shaped material into the fluidized bed of a fluidized bed reduction unit.