MODERN TECHNICAL SOLUTIONS FOR NEW AND RECONSTRUCTED SINTER PLANTSReport 1AVERAGING OF IRON ORE RAW MATERIALS AND PREPARATION OF MIX COMPONENTSFOR SINTERING

Abstract

The analysis of the level of technology and equipment of the complex for receiving and averaging iron ore raw materials of sinter plant No. 5 (SP-5) of Magnitogorsk Iron and Steel Works PJSC, commissioned in 2019, was performed. The complex is equipped with modern averaging equipment. Autonomous dosing of iron ore raw material components with lime before averaging, used for the first time at sinter plants in Russia, ensured high quality of mixture averaging with a chemical composition homogeneity of 90%. Due to the absence of a mixing drum in front of the closed warehouse, the specific productivity of SP-5 sinter machines was lower by 8.2% in the cold season than in the warm season. After installing the mixing drum, the homogeneity of iron ore raw materials with lime in chemical composition at the input to it was 82.5%, and at the output – 92.4%. The duration of lime aging in a stockpile for complete lime quenching in wet raw materials was determined to be 7 days. As a result, the productivity of the sinter machines does not depend now on the season. The design averaging of several types of coke breeze has not been implemented, which leads to increased variability of its moisture and ash content. In general, provided that the fuel is averaged, the modernized averaging complex meets modern requirements. The design solutions for SP-5 did not provide for additional crushing of lime of fraction 0–10 mm to 0–3 mm with its feed to the dosing department of the sinter plant. A hammer crusher is installed, the lime is crushed to a fraction of 0–3 mm and fed to the dosing department by pneumatic transport. A rational ratio has been established between the consumption of lime of fraction 0–10 mm entering to the averaging warehouse – 1.5% of the total 5% attributed to the lime content in the iron ore mixture, and the remaining 3.5% of lime of fraction 0–3 mm entering to the dosing department. The specific productivity of the sinter machines has increased by 5.2% compared to the design solution. The SP-5 solid fuel preparation complex, including screening of 0–3 mm fraction on a vibrating screen before crushing, preliminary crushing of the oversize product to 10 mm in a two-roll crusher and final crushing in a four-roll crusher, meets modern requirements. The same applies to typical limestone preparation equipment. The characteristics of the ore yard of the sinter plant of the Yenakiyevo Steel Plant are given for perspective construction of averaging warehouse with the use of modern technical solutions is given.