| Popis: |
The necessity of an integrated approach in assessing and choosing a technology for secondary desulfurization of cast iron has been substantiated. It is shown that one of the main parameters and indicators is the consumption of the reagent, which determines all the main indicators of the process. A comparative analysis of the indicators in Table 1 also indicates that in the KR process, an increase in the mass of pig iron in the ladle reduces the desulfurization efficiency, since the transition from a ladle with a mass of 80 and 100 tons of pig iron to large ladles (260 tons) is accompanied by a decrease in the specific degree of desulfurization, removal increases the consumption of the reagent per unit of sulfur removed. Significant specific consumption of reagents (up to 8-17 kg / t of cast iron) and the duration of mixing (up to 8-20 minutes), as well as the cycle - up to 25-68 minutes, which causes tangible losses in the temperature of the cast iron - on average 40-42 ° С, and in a number of desulfurization modes - up to 92-128 °С. This is due to the fact that with an increase in the mass of cast iron, the mass transfer processes between the slag and the molten iron of the ladle deteriorate. The highest specific consumption of reagents in the KR-process ultimately determined the highest costs in the implementation of this process. The lowest specific costs for monoinjection of magnesium predetermine the lowest costs for the industrial development of this process. Actual indicators of industrial blowdowns indicate ohm. that monoinjection of granular magnesium is characterized by the lowest consumption of reagents - on average 0.42-0.55 kg / t of cast iron, the shortest duration of the desulfurization operation - on average 5.5-7.7 minutes and at the same time providing up to super deep desulfurization of cast iron - up to 0.0003–0.001%, desulfurization degree - up to 99%, high sulfur removal rate - on average 12–14.4% / min, high reagent assimilation rate - on average 75–92%. The actual data on the technology applied KR-processes (CaO + CaF2), co-injection of lime with magnesium (CaO + Mg) and monoinjection of granular magnesium according to the Ukrainian injection technology are presented. The costs of desulfurization by KR processes - koninjection - monoinjection are in the ratio 3: 2: 1. The advantage of injection processes of cast iron desulfurization has been substantiated. |
