Combined method for extracting iron and dephosphorizing by reducing, smelting and dressing low-grade high-phosphorus hard-dressing iron (manganese) ore

Abstract

The invention belongs to the technical field of metallurgy and in particular relates to a combined method for extracting iron and dephosphorizing by reducing, smelting and dressing low-grade high-phosphorus hard-dressing iron (manganese) ore. Raw ore is firstly subjected to fine grinding, dressing, iron extracting and dephosphorizing to obtain relatively low-phosphorous rich ore powder, then separation of iron from slag and reduction are carried out on the low-phosphorous rich ore powder, and after reduced metallized pellets are cooled, fine grinding and wet magnetic separation are carried out, so that metal iron powder / manganese-containing metal iron powder with TFe content more than or equal to 90%, etaFe content more than or equal to 92% and P content less than or equal to 0.07% is obtained. The combined method for extracting iron and dephosphorizing by reducing, smelting and dressing the low-grade high-phosphorus hard-dressing iron (manganese) ore has the advantages that low reduction temperature and short reduction time are controlled, increase of P content in the final product is avoided as high temperature above 1250 DEG C and long reaction time are adopted in the traditional method and P element and Fe in phosphorite react to generate phosphide, especially stable Fe3P; and if the raw ore is ferrous manganese ore, a manganese-rich powder byproduct with Mn content more than or equal to 45% can be obtained, additional value of the product is high, and energy conservation, environmental protection and low carbon content are realized.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for reducing, smelting, and combining iron extraction and dephosphorization of low-lean, high-phosphorus, refractory iron (manganese) ores. Background technique [0002] China is the largest steel country in the world. In 2013, the annual output has exceeded 800 million tons, but the dependence on imported rich ore is 55%, and the proportion of high-quality electric furnace steel is less than 20%. Although my country's iron ore resources are widely distributed and have large reserves, the distribution of low-poor, fine and refractory iron ore resources accounts for more than 96%. Due to technical reasons, they cannot be well developed and utilized at all, resulting in idle and waste of resources. [0003] As my country's coking coal reserves are increasingly scarce and environmental protection problems are becoming more and more serious, the state has intr...

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Problems solved by technology

[0017] Using rich ore powder for iron and phosphorus reduction, followed by chemical leaching, the method can achieve iron dephosphorization, but the operation cost is high and the environmental pollution is serious; the microbial method is environmentally friendly and feasible, but the production efficiency is low and cannot meet the needs of industrialized large-scale production

[0018] 3. Metallurgy and smelting reduction Due to the high reduction temperature, the temperature is generally 1300-1600 °C, and the phosphorus in apatite can be easily reduced to relatively stable Fe. 3 P, therefore, it is necessary to add dephosphorization flux, slag dephosphorization, resulting in complex process, high production and operation costs, and it is difficult to completely achieve dephosphorization, so it can only be processed by adding other low-phosphorus furnace materials to dilute the P element.

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