Separation process for refractory iron ores

Abstract

The invention provides a separation process for refractory iron ores. The separation process comprises the following steps of: magnetizing and baking dry powdered raw ores with the particle size being less than 1mm at flash speed under a high-temperature reduction atmosphere condition at the temperature of 520 to 560 DEG C to obtain baked materials with available ores being Fe3O4, separating the baked materials to obtain concentrate. By the process, a baking process is executed under a stable and controllable condition by controlling the particle size of the raw ores, reducing the baking temperature and selecting proper baking time; the raw ores (such as ferrous carbonate) are fully decomposed, and reducing reaction is stable; furthermore, overburning is avoided, and a phenomenon that a part of magnetite is reduced into Fourier bodies is avoided; the quality of a baked product is uniform; loss of available ores is low; the reaction energy consumption is low; the reaction condition is mild; a process is stable and easy to control and the separation process can be used for separation of the refractory iron ores, such as poor (magnetic) iron cores, siderite, limonite and oolitic hematite; gamma-Fe2O3 fine ores with high grade which is generally not lower than 60 percent) can be obtained; and the full iron recycling rate is not lower than 75 percent.

Description

technical field [0001] The invention relates to a beneficiation method of iron ore, in particular to a separation process of refractory iron ore. Background technique [0002] There are many kinds of iron minerals. At present, more than 300 kinds of iron minerals and iron-containing minerals have been discovered, of which more than 170 kinds are common. However, under the current technical conditions, the main ones with industrial utilization value are magnetite, hematite, maghemite, ilmenite, limonite and siderite. [0003] The complex and refractory iron ores in my country mainly include Anshan-type lean red (magnetic) iron ore, siderite, limonite, oolitic hematite, etc., which are disseminated by fine particles. Iron ore, Panzhihua vanadium-titanium magnetite, Jilin Lingyang iron ore, etc. [0004] Among them, the Anshan-style magnetic-depleted (red) iron ore impregnated with fine particles has extremely fine particle size, and the dissociation and separation of mineral ...

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Problems solved by technology

[0014] Based on the above reasons, the iron ore reduction roasting-oxidation-magnetic separation process in the prior art has always had high roasting temperature, insufficient magnetism of roasted products, and Fe 3 o 4 Oxidation to prepare γ-Fe 2 o 3 The process is not stable enough, γ-Fe 2 o 3 Insufficient crystal transformation, difficult magnetic separation of products, high iron loss, low concentrate grade and many other defects lead to a low level of utilization of refractory iron ore

Those skilled in the art have so far been unable to find a refractory iron ore separation process based on the principle of reduction roasting-oxidation-magnetic separation that can be truly industrially applied with milder roasting conditions and better roasting effects

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