Combined preparation method for carbon-containing pellet used for blast furnace

Abstract

The invention discloses a combined preparation method for a carbon-containing pellet used for a blast furnace, which belongs to the technical field of carbon-containing pellets. The combined preparation method comprises the following steps: (1) weighing, by mass, 11 to 13 parts of ash collected from the head of a sintering machine through electric precipitation, 17 to 19 parts of calcium-free chromium slag, 20 to 22 parts of fly ash collected from an ore groove at the front of a furnace, 3 to 5 parts of zirconia and 1 part of calcium hydroxide; (2) mixing the materials mentioned in step (1) and gradually adding an obtained mixture into a disc type pelletizer to prepare pellets with a diameter of 7 to 9 mm; (3) weighing, by mass, 38 to 42 parts of blast furnace sludge, 10 to 12 parts of vanadic titanomagnetite and 1 to 2 parts of bentonite; (4) transferring the pellets prepared in step (2) to another disc type pelletizer, mixing the materials mentioned in step (3) and gradually adding an obtained mixture into the disc type pelletizer for continued pelletizing; and (5) adding carbon-containing pellets prepared in step (4) into a rotary hearth furnace for reduction. According to the invention, production cost for the carbon-containing pellet is substantially reduced, and the carbon-containing pellet has good mechanical properties.

Description

technical field [0001] The invention relates to the technical field of carbon-containing pellets, in particular to a composite preparation method of carbon-containing pellets for blast furnaces. Background technique [0002] The increasing shortage of coal resources for coking is a bottleneck for the sustainable development of the traditional blast furnace ironmaking method that relies too much on high-quality coking coal. The pre-reduced metallized pellet produced by the coal-based direct reduction method is an effective measure to reduce this dependence. Those with a metallization rate of 80-90% or more are called metallized pellets. When the metallization rate reaches 30-80%, it is called semi-metallized pellets. [0003] According to the practice of using metallized pellets in blast furnaces in the United States and Japan, it is shown that for every 10% increase in the metallization rate of pellets, the coke ratio can be reduced by 4~6%, and the output can be increased...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to overcome the disadvantages of the prior art that carbon-containing pellets have a low degree of utilization of dust waste in iron and steel plants and high production costs, and provide a composite preparation method for carbon-containing pellets for blast furnaces , by adopting the carbon-containing pellets of the present invention, it is possible to recycle and recycle sintering machine head electric dust, blast furnace gas mud, furnace front mine tank dust and calcium-free chromium slag