Method for sorting high-phosphorus iron ore by combining microwave reduction roasting and low intensity magnetic separation

Abstract

The invention relates to a method for refining iron and removing phosphorus from complex refractory high-phosphorus iron ore, in particular to a method for sorting high-phosphorus iron ore by combining microwave reduction roasting and low intensity magnetic separation, and belongs to the technical field of mineral processing, particularly iron ore beneficiation. The method comprises the following steps: crushing refractory high-phosphorus iron ore used as raw material into granules with granularity of less than 2mm; mixing the crushed raw ore with a fluxing agent and a reducing agent in a certain proportion; transferring the obtained mixed material into a microwave reaction furnace for reduction roasting; and carrying out water-quenching, cooling, ball-milling and wet-magnetic-separating on the obtained roasted ore to finally obtain iron ore concentrate. In the method, the ore is reduced by utilizing a microwave roasting technology, wherein microwave reduction roasting time is short, and the temperature of the ore is raised quickly; and meanwhile the fluxing agent is added so as to promote gangue softening and improve refractory ore structure together with microwave roasting reaction. By utilizing the method for sorting the high-phosphorus iron ore, the iron ore concentrate with grade of more than 58.39% can be obtained, and phosphorus removal rate reaches over 70.44%, thus a new technique is provided for sorting the high-phosphorus iron ore.

Description

Technical field [0001] The invention relates to a beneficiation method for increasing iron and reducing phosphorus of complex and difficult-to-select high-phosphorus iron ore, in particular to a method for separating high-phosphorus iron ore by microwave roasting combined with weak magnetic separation, and belongs to mineral processing-iron ore beneficiation technology field. Background technique [0002] There are large amounts of high-phosphorus iron ore worldwide. A large amount of phosphorus-containing weakly magnetic iron ore exists in North America's Superior region, Minnesota region, Northern Europe, Australia, Saudi Arabia and my country's Yangtze River Basin. China's reserves of high-phosphorus iron ore are 7.445 billion tons, accounting for 14.86% of the country's total iron ore reserves. In the world, China is both a major steel producer and a major consumer. China's steel production and consumption account for about half of the global total, ranking first in the wo...

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Problems solved by technology

But this method has the following disadvantages: 1. It is mainly suitable for the separation of iron ores with better selectivity in water-deficient areas, and has a relatively large effect on the separation of iron ores such as high-phosphorus iron ores with poor selectivity. 2. The raw ore needs to be roasted after being ball milled by a ball mill, which consumes a lot of energy; 3. Using simple microwave roasting, the ore structure changes little during the roasting process, which is not conducive to subsequent magnetic separation; 4. Using dry Type wind magnetic separation, the minerals can not achieve the best dispersion state, the separation index for fine-grained iron ore is not high, and the cleanliness of the magnetic separation operation environment is also limited

Since the final product of iron ore smelting is metallic iron, this method uses metallic iron powder as a reducing agent to reduce the ore to magnetite, which not only causes duplication of processes, but also consumes a large amount of iron powder, and is not economical and environmentally friendly. requirements

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