Carbon reducing, sulfur reducing, iron removing and iron ore concentrate recovering method for coal ash

Abstract

The invention discloses a carbon reducing, sulfur reducing, iron removing and iron ore concentrate recovering method for coal ash with unburned carbons and higher SO3 and Fe (hematite) contents. With the unburned carbons in the coal ash as reducing agent, dry coal ash raw materials (9%+ / -1% of loss on ignition and 9.5%+ / -1% of SO3 content) mixed beforehand are reduced and roasted for 15-30 minutes at 900 DEG C, then are quickly separated from oxygen for water quenching and cooling; the iron ore concentrate is magnetically separated by a wet low-intensity magnetic separator. Gypsum (CaSO4) in the coal ash is converted to CaS after reducing and roasting, so that the SO3 content is reduced; the hematite with weak magnetism is converted to a magnetite with strong magnetism; weak magnetic separator is adopted to separate. The carbon, Fe and SO3 contents of the treated coal ash are respectively reduced below 5.3%, 5% and 1.32%; the coal ash can be directly used in the fields such as production of cement and concrete; at the same time, the iron ore concentrate with 48-53% of TFe level is obtained, and can be used as iron smelting raw materials or dense medium powder in industries such as coal dressing. The method has the advantages of prominent overall economic efficiency, no need of adding reducing agent, fewer auxiliary facilities, short process flow and easy realization of industrialization.

Description

technical field [0001] The invention relates to a comprehensive utilization method of fly ash, in particular to unburned carbon, SO 3 , Recover iron concentrate from fly ash with high Fe content and reduce C, SO in fly ash 3 , Fe content method, belonging to the field of solid waste resource utilization. Background technique [0002] Fly ash is a bulk solid waste discharged from coal-fired power plants. The annual output of fly ash in my country is huge, and the utilization rate is relatively low. The storage of fly ash occupies a large amount of land, increasing the operating cost of coal power enterprises; polluting water and air, seriously endangering the surrounding environment and the health of residents. Utilizing fly ash as a resource and turning waste into treasure can not only alleviate environmental pollution problems but also create considerable economic benefits, which can be said to kill two birds with one stone. In my country's "Twelfth Five-Year Plan" spec...

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The basic chemical reaction formula is as follows

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