Method for synchronously extracting iron and niobium from Bayan Obo low-grade ores

Abstract

The invention provides a method for synchronously extracting iron and niobium from Bayan Obo low-grade ores. The method comprises the following process steps: 1) pretreating low-grade niobate to obtain high-temperature aggregates; 2) carrying out smelting reduction on the high-temperature aggregates to obtain niobium-containing molten iron and niobium-containing iron removed slag; 3) carrying out oxidative slagging on the niobium-containing molten iron to obtain niobium removed crude iron and niobium-rich slag; 4) carrying out mixed hardening and tempering on the iron removed slag in the step 2) and the niobium-rich slag in the step 3) to obtain low-viscosity niobium-containing slag; 5) carrying out chlorination on the low-viscosity niobium-containing slag to obtain niobium removed slag and a gaseous multi-metal chloride; and 6) carrying out condensation separation on the gaseous multi-metal chloride to obtain a chloride of niobium. Rare earth elements in the ores, such as niobium, are separated while iron is extracted from the low-grade ores by adopting the method, thus achieving short-process stepped extraction separation of multiple metal resources in a same thermal process.

Description

technical field [0001] The invention relates to a chlorination metallurgical method for extracting iron and separating trace rare earth elements from low-grade Baiyunebo mine, and belongs to the field of pyrometallurgy. Background technique [0002] The Baiyun Obo Mine in Baotou is mainly composed of iron, niobium, rare earth and other polymetallic co-associated deposits. The proven rare earth reserves are 43.5 million tons, ranking first in the world, and the niobium reserves are more than 6.6 million tons, ranking second in the world. The most important niobium resource base. Niobium and iron co-exist in Baiyan Obo Mine, closely inlaid, low-grade, and difficult to smelt. During the iron ore separation process, part of the niobium is extracted with the iron, and the rest of the niobium remains in the iron separation tailings, which makes the extraction of niobium more difficult. The extraction of niobium from iron ore concentrates used the method of blast furnace reductio...

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Problems solved by technology

Studies have shown that during the reduction process of the blast furnace, niobium minerals will be reduced to niobium carbide (NbC), forming a NbC stagnation zone at the slag-iron interface, which limits the dissolution of niobium in molten iron, so that the recovery rate of niobium in the blast furnace is only 40%. -70%, which limits the application of this niobium extraction technology

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