Coal-based fluidization reducing roasting system and roasting method thereof

Abstract

The invention discloses a coal-based fluidization reducing roasting system which comprises a coal-fired vaporization unit, a mineral powder preheating unit, a roasting unit, a waste heat utilizing unit and a dust removal unit. The coal-fired vaporization unit comprises a coal-fired vaporization furnace and a cyclone dust extractor. The roasting unit comprises a roasting furnace, a solid-gas separator and a reducing reactor. The waste heat utilizing unit comprises a heat exchanger. High-temperature flue gas produced by the coal-fired vaporization unit does not need to be cooled and is divided into two paths, one path is connected with a gas inlet of the roasting furnace, and the other path is purified and pressurized through the cyclone dust extractor and then is connected with a gas inletof the reducing reactor. A feed inlet of the roasting unit is connected with a discharge outlet of the mineral powder preheating unit. A discharge outlet of the roasting unit is connected with a feedinlet of the waste heat utilizing unit. A gas outlet of the mineral powder preheating unit is connected with a gas inlet of the dust removal unit. The invention further discloses a using method of thecoal-based fluidization reducing roasting system. The coal-based fluidization reducing roasting system has the advantages of being high in efficiency, high in yield, low in energy consumption, low incost, wide in application range, good in product quality and the like.

Description

technical field [0001] The invention relates to an ore roasting system and a roasting process method thereof, in particular to a coal-based fluidized reduction roasting system and a use method thereof. Background technique [0002] my country's iron ore resources are relatively rich. As of the end of 2015, the ascertained resource reserves reached 85.08 billion tons, but most of them are "poor", "fine" and "miscellaneous" ores with poor quality; among them, siderite, limonite, oolitic The resource reserves of hematite, fine-grained hematite and their symbiotic (associated) complex refractory iron ore resources are as high as millions of tons. The current commonly used physical beneficiation technology cannot make full use of this kind of ore. ) magnetic, flotation, iron concentrate grade and recovery rate are still difficult to improve, currently such ore except for a few mining areas are mined and utilized, most of them have not been developed and utilized. A large number of...

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Problems solved by technology

Microwave roasting is used to process 0-3mm ore. This roasting method has low energy consumption and clean production environment. However, due to the need to use secondary energy and the difficulty of large-scale equipment, it is currently not available in iron ore with large output and added value. used in low production

[0004] CN201510647362, CN200610032484 and CN200720064996 have all proposed the fluidized reduction roasting method that adopts coal as heat source and reducing medium, the roasting reaction process of this kind of magnetized roasting method can be finished within tens of seconds, but the adjustable range of reduction reaction time is small, for Ores with a dense structure may have the defect of insufficient reduction; CN102127635 A discloses a method for oxidizing and roasting coal and sulfide gold ore in an external circulating fluidized bed reactor after dry grinding, in which coal and raw materials are mixed and sent to roast Furnace, coal combustion only provides the temperature required for oxidation roasting, and the reactor used cannot separate the coal ash, the material that has completed the oxidation reaction, and the material that has not completed the oxidation reaction, resulting in a large cycle load of materials in the reactor , and because the reaction time is difficult to accurately control, the overoxidation or underoxidation of sulfide gold ore may occur, and the content of useful elements in the roasted ore is also reduced; CN 103031432 A, CN201510139825 and CN201010621731 proposed the use of gas as a heat source and reducing medium The fluidized oxidation (reduction) roasting method, but this kind of roasting method is only suitable for areas with gas or natural gas, and the cleanliness of the gas is required, which greatly limits its application area

[0005] Relying on technological progress to develop an ore fluidized roasting device and method that is more energy-saving, environmentally friendly, more adaptable, and better in quality of beneficiation products, to maximize the use of my country's limited iron ore resources, especially the efficient development and utilization of the above complex Iron ore resources that are difficult to select and can be used but with low product quality and utilization rate, so as to increase the market share of my country's self-produced iron ore resources, has always been the goal pursued by technicians in the field

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