Multi-stage fluid magnetization roasting method for powdery refractory low-grade iron ore

Abstract

The invention provides a powdery difficult-separation low-grade iron ore multistage fluidized magnetic roasting furnace, and a difficult-separation low-grade iron ore multistage fluidized magnetic roasting method using the roasting furnace. The roasting furnace comprises a cylindrical furnace body, a plurality of partition boards are arranged in the furnace body, a rotating shaft is arranged in the center of the furnace body in penetration, a material outlet is arranged at the bottom of the furnace body, and a first smoke inlet, a second smoke inlet and a third smoke inlet are sequentially arranged at an upper portion, a middle portion and a lower portion of the furnace body; a water pool is arranged below the material outlet; the partition board is provided with a push arm, and the push arm is connected with the roasting shaft; and the partition board is provided with a blanking hole. The magnetic roasting furnace has the advantages of large adjustment range of the temperature in the furnace, flexible atmosphere control, large gas-solid contact area, high unit volume production capability, fast reduction reaction speed, high magnetic iron conversion efficiency and the like, and is a good magnetic roasting apparatus for processing powdery difficult-separation low-grade specularitem, hematite, limonite and siderite.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and relates to a multi-stage fluidized coal-based magnetization roasting furnace for powdery refractory low-grade iron ore and a magnetization roasting method for powdery refractory low-grade iron ore using the roaster. Background technique [0002] Most of my country's iron ore resources are lean iron ores with an average iron content of less than 35%. The iron minerals in these iron ores mainly exist in the form of specularite, siderite, limonite and hematite. The embedded particle size is fine and accompanied by a large amount of iron-containing silicates with similar physical and chemical properties. Using gravity separation, magnetic separation, flotation and other conventional beneficiation processes to process these low-grade refractory iron ore resources not only makes it difficult to obtain high-quality iron ore concentrates, but also produces a considerable amount of refracto...

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Problems solved by technology

[0003] Among them, the shaft furnace is generally used to process lump ore with a particle size of more than 15 mm, and there is a phenomenon that small-size lump ore is over-reduced, while large-size lump ore is under-reduced, and because the specific surface area per unit of large-size iron ore is small, Thus iron ore and reducing agents (CO and H 2 etc.) have less contact opportunities, and the reduction process is relatively slow, resulting in a lower output of hard furnace roasting; the rotary kiln is used to process powder ore with a particle size below 15mm, and there are uneven ore reduction, and the rotary kiln is easy to form rings, etc. Problem: Fluidized fluidized furnace (and flash roaster are mainly furnace types for processing ores with a particle size below 3mm. The quality of magnetized roasting of ores is better than that of shaft furnaces and rotary kilns, but there are also problems of uneven iron ore reduction and Problems such as high roasting cost

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