System for oxidizing roasting-reducing roasting of titaniferous iron concentrate and roasting process

Abstract

The invention discloses a system for oxidizing roasting-reducing roasting of titaniferous iron concentrate and a roasting process. A fluidized bed oxidation reactor is adopted for the oxidizing roasting of the titaniferous iron concentrate; the oxidized titaniferous iron concentrate enters a fluidized bed reduction reactor for reducing roasting; the reduced titaniferous iron concentrate is sequentially and spirally cooled by a cyclone cooler and water cooling and then enters a downstream section; and reduced coal gas is firstly subjected to heat exchange by the cyclone cooler, then preheated by a coal gas preheater, and enters a reducing furnace, latent heat of unreacted reducing gas in tail gas exhausted from the fluidized bed reduction reactor is firstly released through combustion in a combustion chamber, and hot flue gas generated by the combustion is mixed with the tail gas exhausted by the fluidized bed oxidation reactor and then enters a multi-stage cyclone preheater to exchange heat with the titaniferous iron concentrate for heat recovery. The system disclosed by the invention has the advantages of high reaction efficiency, full heat utilization, good economical efficiency in the roasting process and the like, and is suitable for large-scale continuous industrial production.

Description

Technical field [0001] The invention relates to chemical and metallurgical technologies, in particular to an ilmenite concentrate oxidation roasting-reduction roasting system and roasting process. Background technique [0002] High-quality titanium-rich materials are raw materials for the production of chloride titanium dioxide and sponge titanium. Since there are few natural high-quality titanium ore (rutile ore) in nature, high-quality titanium-rich materials are currently mainly obtained from the production of ilmenite concentrates. my country has rich reserves of ilmenite resources. Only the Panzhihua-Xichang area (Panxi area) has nearly 10 billion tons of vanadium-titanium magnetite resources, of which titanium reserves are about 870 million tons (with TiO 2 Calculated), but the ilmenite resource endowment is relatively poor, mainly manifested in the low grade of ilmenite concentrate, TiO 2 The content is only 44-47%, but non-ferrous impurities are as high as 10-15%, especial...

AI Technical Summary

Problems solved by technology

From the perspective of practical application, this kind of principled process is not operable, because how to realize oxidation roasting and reduction roasting, including what equipment is used for ilmenite concentrate? How to provide heat for oxidation roasting and reduction roasting? What equipment is used for roasting ore, and how is it cooled in the absence of air? How to use the heat of roasting tail gas? How to recover the unreacted reducing gas in the tail gas of reduction roasting is not covered, but these are the key issues that must be solved in the specific implementation process of oxidation roasting and reduction roasting

The second category proposes a specific process for roasting, but there are fewer relevant literature reports, such as U.S. Patent 4,097,574, which proposes a process for oxidative roasting and reduction roasting of ilmenite concentrate

[0006] (1) The hot tail gas at the outlet of the oxidation furnace is directly discharged, resulting in low heat utilization efficiency;

[0007] (2) The tail gas circulation of this process is only applicable to pure H 2 As a reducing agent, if the gas contains an inert gas (such as N 2 ), the cycle will accumulate; if it contains CO, the reaction process will generate CO 2 , CO 2 Cannot be effectively removed by washing with water alone

However, pure hydrogen can only be used as a reducing agent, which will greatly limit the application of the process;

[0008] (3) The reducing fluidized bed adopts intermittent operation. In order to realize continuous operation, two intermediate silos are required, which not only complicates the system, but also limits the system capacity due to intermittent operation.

[0009] (4) The process does not specify what equipment the reduced ore uses to achieve isolated air cooling

[0010] The above-mentioned deficiencies of the existing ilmenite concentrate oxidative roasting-reduction roasting process have seriously limited the development of utilizing ilmenite concentrate to prepare high-quality rich state material technology. System and process for making full use of energy in roasting process

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