Gas-based shaft furnace direct reduction-electric furnace smelting separation process of vanadium titano-magnetite

Abstract

The invention discloses a gas-based shaft furnace direct reduction-electric furnace smelting separation process of vanadium titano-magnetite. The process comprises the following steps of: a, forming finished product pellets; b, putting the finished product schreyerite pellets as raw materials into a direct-reduction shaft furnace and introducing a reducing gas to the shaft furnace to reduce the pellet ore, thus obtaining thermal-state direct reduced iron; c, feeding the thermal-state direct reduced iron to a smelting-separation electric furnace for reduction and smelting separation, thus separating out titanium slag and obtaining vanadium-containing iron liquid; and d, transferring the vanadium-containing iron liquid to a converter for blowing so as to separate out vanadium slag and semisteel. According to the gas-based shaft furnace direct reduction-electric furnace smelting separation process of vanadium titano-magnetite, the shortcomings of the existing process are improved, effective and clean separation of titanium, vanadium and iron is realized, the recovery and utilization rate of vanadium and titanium metal elements is improved and energy consumption and equipment one-time investment are reduced; and therefore, the process is suitable for large-scale production.

Description

technical field [0001] The invention belongs to the field of direct reduction engineering in the metallurgical industry, and relates to a process of gas-based shaft furnace direct reduction-electric furnace melting vanadium-titanium magnetite. Background technique [0002] Vanadium-titanium magnetite is a compound ore in which iron, vanadium, titanium and other valuable elements are symbiotic. The key to the comprehensive utilization of its products lies in the recycling of iron, vanadium, titanium and other precious metals in the smelting process. my country has always attached great importance to it. Development of comprehensive utilization of vanadium-titanium magnetite. [0003] At present, the relatively mature vanadium-titanium magnetite smelting process is divided into two categories: one is to use the blast furnace-converter process, and the other is to use the direct reduction-electric furnace melting process; the blast furnace-converter process is limited by the flu...

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Problems solved by technology

[0005] At present, there are two types of related processes for gas-based shaft furnace direct reduction-electric furnace melting in my country: one is the direct reduction of vanadium-titanium magnetite by gas-based shaft furnace proposed by Chongqing Iron and Steel Mining Co., Ltd., which requires the temperature of the reducing gas to be controlled at 900 ° C ~ 1100 ° C , the pressure is 0.35MPa~0.65MPa, H 2 The volume ratio to CO is 5.4 to 3.1 (molar ratio), and the volume percentage is ≥85%; due to the high pressure of the shaft furnace in this process route, in order to prevent carbon formation during heating, the H 2 The / CO ratio is extremely high, and the effective gas CO+H 2 The content requirements are relatively high, and the overall process route conditions are harsh, so energy consumption and equipment investment are relatively high

[0006] The other is the comprehensive utilization of vanadium-titanium magnetite by using the shaft furnace reduction-electric furnace melting process proposed by Beijing Shenwu. Mix with binder to make oxidized pellets of 8mm to 20mm, and reduce in a shaft furnace fed with reducing gas for 4 to 6 hours to obtain a reduced product, then send it to an electric furnace for melting to obtain molten iron and slag containing vanadium and titanium, and then Extraction of vanadium and titanium from molten slag; the temperature of the shaft furnace is 900℃~1200℃, the pressure is 0.2MPa~0.3MPa, H 2 The volume ratio to CO is 1 to 3 (molar ratio), the volume percentage is ≥90%, and the melting temperature is 1500 ° C to 1700 ° C; this process not only affects the H of the shaft furnace 2 / CO ratio, CO+H 2 The content requirements are high, and the pelletizing process also requires high energy consumption and high investment, so the investment and consumption of the entire process are high; in addition, the melting temperature of the electric furnace of this process is 1500 ° C ~ 1700 ° C, and it must be used at this temperature To ensure that vanadium enters the slag phase, it is necessary to strictly control the amount of carbon in the melting electric furnace, which is extremely difficult, and in order to allow vanadium to enter the slag, it must be ensured that there is a high amount of ferrous oxide in the slag, which will reduce the recovery rate of metallic iron At the same time, due to the high ferrous oxide in the slag, it will aggravate the erosion of the lining of the submerged arc furnace and affect the life and productivity of the electric furnace

[0007] To sum up, at present, there is no reasonable and economical process for the comprehensive recovery of vanadium-titanium magnetite in China.

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