Wet vanadium production process starting from vanadium slag. According to the current state of vanadium resources in the world, vanadium slag mainly has three sources.

1. Vanadium-titanium magnetite

Vanadium-titanium magnetic iron ore is the main vanadium resources. Take the Mapoch mine in South Africa as an example. The ore contains 1.51% to 1.70% vanadium pentoxide.

(1) Electric furnace shake method

1000 ℃ with the first pre-reduction in a rotary kiln coal; and then further reduced to obtain pig iron in an electric arc furnace containing vanadium _{(V 2 O 5 1.4%,} TiO 2 30%), and finally blowing in oxygen by shaking the package, vanadium Enter the slag. The vanadium in the vanadium slag is present as FeO·V ₂ O _{3 and} is water-insoluble (about 25% of V ₂ O ₅ ). About half of the world's vanadium is produced by this method (South Africa), and about 1/4 is produced in Russia (vanadium slag contains about 12% to 18% of V ₂ O ₅ ).

(2) Atomization and vanadium extraction

In this method, the vanadium-containing pig iron produced by the blast furnace is atomized into fine droplets by compressed air in an atomizing furnace (see FIG. 1), so that vanadium in the molten iron is fully oxidized, and only a small amount of carbon is oxidized. It is called vanadium removal and carbon preservation. The pig iron after blowing vanadium is called semi-steel and is further blown into carbon steel in the converter. The vanadium slag obtained is V ₂ O ₅ with vanadium up to 20% (but the iron content is high, which not only affects the quality, but also increases the cost. ). In 1979, China's Panzhihua Iron and Steel Co., Ltd. from molten iron to vanadium slag, the recovery rate of vanadium reached 76.55%, but it has not yet reached the highest level in the world (82.4% in the former Soviet Union, and 91.6% in South Africa). The composition of the atomized vanadium slag in 1979 is shown in Table 1.

Table 1 Composition of vanadium slag in Panzhihua Iron and Steel Co., Ltd. in 1979 (%)

Figure 1 Panzhihua No. 2 atomizing furnace after reconstruction

1-iron water tank; 2-intermediate tank; 3- atomizer; 4-flue

5-spray chamber; 6-sub-flue; 7-outlet

8-half steel can; 9-hood

(3) Vanadium extraction by converter

In order to solve the problem of high atomization and vanadium iron loss and low recovery rate, Panzhihua changed to use vanadium in the converter instead of atomization to extract vanadium in 1995. The first two years have already begun to bear fruit, but it is not ideal. After further optimization and improvement, breakthrough progress was made in 1998, technical indicators were comprehensively improved, and the results in 2000 were more stable.

From the vanadium extraction by atomization to the vanadium extraction from the converter, the core goal is to “de-vanadium and carbon preservation”. In order to achieve excellent results while conquering this difficulty, a number of technical measures have been added, including: hot metal slag, slag retention operation, SiO ₂ slag, special oxygen lance, "iron block + composite ball + iron ore "To make vanadium coolant, slag out of semi-steel, optimize the temperature and cooling system for vanadium extraction, and use magnesia carbon to build furnaces." By 2000, the technical index of vanadium extraction from Panzhihua Iron and Steel Co., Ltd. has been significantly improved compared with the vanadium extraction by atomization, and is close to the international advanced level. Specific indicators are shown in Table 2.

Table 2 Comparison of technical indicators for vanadium extraction in China with international advanced level

It can be seen from the data in Table 2 that the main technical indicators for vanadium extraction from Panzhihua Iron and Steel Co., Ltd. are: vanadium in semi-steel, vanadium oxidation rate, vanadium recovery rate and semi-steel yield have reached the world advanced level, while the furnace age is higher than that of Russia. The Lower Tajik is doubled.

From the perspective of future development, the addition of sodium carbonate to the flux and the use of top and bottom composite blowing technology will further increase the level of vanadium extraction from the Pangang converter.

(4) Vanadium-containing steel slag method

In this method, when vanadium-containing molten iron is used for steelmaking in a converter, vanadium is transferred into the slag as an impurity, and high calcium vanadium slag is obtained. The calcium oxide in the slag is as high as 45% to 60%. One of the current successful methods is to add alkali to the sodium oxide roasting, then extract the vanadium by water leaching, and then hydrolyze vanadium. The conditions for roasting are:

(5) Sodium halide vanadium slag method

The soda ash is directly added to the blast furnace molten iron for blowing, so that vanadium enters the slag phase, and is also beneficial for removing sulfur, phosphorus and silicon in the molten iron. The semi-steel after sodium-sulphide blowing is very low in sulfur and phosphorus, and can be further made into high-quality steel without slag or less slag steel. The resulting sodium vanadium slag can be subjected to one-step water immersion, carbonation leaching, and recovery of NaHCO ₃ and V ₂ O ₅ . The denitrification rate of the molten iron sodiumation test device can reach 80% to 90%, the dephosphorization rate is greater than 75%, the desulfurization rate is greater than 70%, and the vanadium conversion rate in the sodium slag is 95% to 99%.

Second, vanadium, lead, zinc ore

Produced in Namibia vanadium, lead, zinc ore, first by flotation, to obtain vanadium, lead, zinc concentrate. Since the vanadium, lead and zinc minerals contained are non-water soluble, acid leaching is required. Another method is to add soda ash while processing vanadium, lead and zinc ore, add carbon to reduce, so that zinc evaporates, lead is melted into lead water, and vanadium is transferred into the slag phase to become water-soluble vanadium.

3. Extraction of vanadium from refinery residues and boiler soot

Although the content of vanadium in petroleum is low, its total amount is very large and it has become one of the important sources of vanadium. Representativeally for Venezuela and Russia's oil, its fuel boiler soot and refinery residue, as a by-product, containing vanadium up to 40% V ₂ O ₅ . The asphaltic oil produced by Orinoco in Venezuela is currently burned by the method of atomizing magnesium nitrate with water. The vanadium contained in the produced soot has reached the vanadium slag produced by vanadium-titanium magnetite. The level of vanadium.

Fourth, other sources

Other sources of vanadium are vanadium-bearing uranium , vanadium in the aluminum- vanadium diagram, vanadium-bearing shale, and vanadium recovered from the catalyst. Except for vanadium-bearing uranium ore, vanadium production does not occupy an important position.

DIN69871 DAT SK40 Tool Holders