Abstract
Production of 1 ton of manganese ferroalloy generates 8-30 kg of aspiration dust that often contains non-ferrous metals such as lead and zinc from Kazakhstani raw materials. At Taraz Metallurgical Plant LLP, the dust can contain up to 2% zinc and 4.5% lead. The article presents experimental studies on processing dust produced during the manufacture of ferrosilicomanganese at the plant. Results from electric smelting reveal that raising the amount of ferrosilicomanganese from 34% to 40%—while keeping a constant basicity modulus—improves manganese extraction and increases silicon content in the alloy, yet it reduces the overall manganese concentration. Notably, the highest manganese extraction (80%) was achieved with a basicity modulus of 1.1–1.3 and 40% MnC17, while the maximum manganese concentration (86.2%) was attained at 34% MnC17. Moreover, a minimal silicon concentration (2.6%) occurred at a basicity modulus of 1.1 and 34% MnC17. The optimal conditions for producing medium-carbon FeMn88 grade ferromanganese—with 86% manganese, less than 3.0% silicon, and 1.3–1.4% carbon (translating to 78–79% manganese extraction)—are a basicity modulus of 1.0–1.19 and 37.7–38% ferrosilicomanganese.