SU1537995A1 - Method of starting a coke-fired cupola - Google Patents

Abstract

The invention relates to metallurgy and can be used in the smelting of metal in a cupola. The purpose of the invention is to eliminate the release of off-grade cast iron at the start of the cupola. The essence of the invention is to load coke with an undissolved fine fraction, flux and large starting iron scrap in the intake charge and preheat the mixture with gas burners before starting the cupola coke furnace. Elimination of the release of off-specular cast iron is achieved by creating conditions for overheating of the first portions of cast iron flowing on the hearth: a developed surface of coke, decomposition of limestone before the work earthing of workers, and overheating of large-sized scrap before smelting.

Description

The invention relates to metallurgy and can be used in the smelting of metal in a cupola.

The purpose of the invention is to eliminate the release of off-grade cast iron at the start of the cupola.

The blank ear is collected from unassorted coke, the flux is poured into the single ear before it is heated up, and the first metal heads of the charge column are collected from large-piece cast iron scrap. In addition, on top of the flux layer, prior to warming up, the idle colosha is poured in the first working coke ear and the first metal ear is formed from large thick-walled cast iron scrap.

Large pieces of scrap melt relatively slowly, and a moderate amount of melt flows into the idle ear. The blank has a highly developed surface that provides overheating of the metal to the required temperature, which provides the possibility of pouring into the forms of its first portions. The process of smelting is especially effective in cupolas with two rows of molds, where, thanks to the supply, the blowing in the second row of single dummy tufts warms up even more intensively.

Example. At the bottom of the cupola, they form a collar of idleness, filling the coke CL-1 without screening small items, containing from 1 to 90 mm in the delivery of the fraction. The coke layer is 1100 mm. On top of a layer of coke load limestone, creating a layer of 130 mm. On top of a layer of limestone, a lumpy mixture of thick-walled scrap is loaded (pieces

SP

W

WITH

coke

weighing 140-50 kg, with a wall thickness of 12-20 mm) in an amount of 1800 kg and a working coke stack weight of 205 kg. Then, using gas burners inserted into the tuyeres, the coke is heated to red heat, and after warming up the coke, the idle fuel of the coal is ignited by blowing air through it for 17 minutes to a white heat.

The subsequent workers of the charge of the charge and coke are similar. Their number is six to set the primary charge column in the cupola. After the charge is set, they start smelting, feeding 18,000-21,000 mm3 per hour into the cupola. In 13 minutes after the start of blowing, the openings open, they begin to release metal. Measuring its temperature indicates that it meets the technology requirements for the steady state process and allows it to be poured into molds.

The use of the proposed method eliminates the receipt of low-grade pig iron of the first release after blowing.

Claims (1)

The invention of the method of ignition of the coke cupola, which includes loading on its bottom the idle coke shell, its heating, loading of the flux on it and the charge column set alternating with working metal and coke heads, characterized in that, in order to prevent the release of substandard iron, the idle ear is collected from the unassorted coke, while the flux is loaded on the idle ear, over the flux layer the first coke is loaded prior to the start of heating, the idle coke colosha, and the first metal coloscans are collected from large-size cast iron scrap.