Direct reduction process of iron ore powder with carbon porous block

Abstract

The invention belongs to the field of metallurgy and in particular relates to a direct reduction process of a carbon-burdened porous block of iron ore powder, which can improve the heat transfer efficiency so as to solve the technical problems. According to the technical scheme, the direct reduction process comprises the following steps: uniformly mixing iron ore concentrate, a carbonaceous reducing agent, a bonder and water in proportion, pressing into a block, forming holes with the diameters of 10mm to 30mm in the obtained block, drying, and reducing in a direct reduction furnace, wherein the total hole volume is 10%-20% that of the block. According to the process, the carbon-burdened porous block can be arranged on the bottom of a kiln such as a rotary hearth furnace, a car bottom furnace, a tunnel kiln or the like for reduction, the thickness of a material layer can reach 80mm to 300mm, equivalently carbon-burdened pellets with the heights of 20mm to 30mm are stacked for 5-10 layers, and the reduction production efficiency can be greatly improved; moreover, the process is simple and easy to popularize, and a small quantity of equipment is required.

Description

technical field [0001] The invention belongs to the field of metallurgy, and in particular relates to a direct reduction process of iron ore powder with carbon porous block. Background technique [0002] Iron ore powder with carbon pellets is the main iron-containing raw material for non-blast furnace ironmaking. Its preparation is to transform the powdery mixture into physical properties, chemical composition and mechanical properties that can meet the next step of direct reduction smelting, that is, to prepare metals. The process required for pelletizing ore. [0003] As the main iron-containing raw material for non-blast furnace ironmaking, there are many studies on iron ore powder with carbon pellets in the prior art. The shapes of pellets mainly include spherical, flat spherical, oval, short pillow and long. There are many kinds such as pillow shape, and its three-dimensional size is basically 15mm to 45mm. During the direct reduction process of the pellets (such as d...

AI Technical Summary

Problems solved by technology

During the direct reduction process of the pellets (such as direct reduction in fixed bed furnaces such as rotary hearth furnaces, car bottom furnaces, and drawer kilns), the thickness of the material layer arranged on the hearth bed is not allowed to be too thick, generally 2 to 3 layer, the thickness is 20mm ~ 30mm, because the material layer is too thick, the heat transfer effect in the material layer is too poor, and the internal temperature gradient is too large, resulting in poor direct reduction effect

The thermal conductivity of iron ore powder with carbon pellets detected by experiments is 0.5-0.8W / (m·K), which is relatively small compared with carbon-free pellets, which results in a , the metallization rate of the direct reduction process is low, and the overall reduction efficiency is relatively low