A method for extracting vanadium by carbonization of vanadium-containing steel slag

Abstract

The invention relates to a carbonization vanadium extraction method of vanadium contained steel slag. The method includes the steps that the vanadium contained steel slag and a sodium containing compound solution are mixed, and carbon dioxide is led in under the heating and pressurization condition for carbonization decomposition reaction; and slurry obtained after reacting is subject to solid-liquid separation, and vanadium contained lixivium is obtained. According to the carbonization vanadium extraction method, efficient vanadium extraction from the vanadium contained steel slag is achieved, the conversion rate of vanadium is 85% or above, and a vanadium pentoxide product with extremely-low Na content can be obtained. In the vanadium extraction process, a direct pressure leaching method is adopted for extracting the vanadium in a vanadium raw material, a large amount of energy consumption in the roasting process is avoided, and roasting harmful kiln gas is prevented from being generated; meanwhile, the sodium salt using amount is greatly reduced, consumption of the raw material is reduced, and the follow-up acid process vanadium deposition difficulty is reduced; and the obtained lixivium can be repeatedly used many times, the emission amount of waste water is reduced, the carbonization vanadium extraction method is an efficient, low-cost and clean vanadium extraction method, and the carbonization vanadium extraction method is suitable for industrial production and has the good application prospect.

Description

technical field [0001] The invention relates to the technical field of vanadium chemical metallurgy, in particular to a method for extracting vanadium by carbonization of vanadium-containing steel slag. Background technique [0002] Vanadium-containing steel slag is a by-product of smelting vanadium-titanium magnetite, and is formed by vanadium-containing molten iron steelmaking. 2 o 5 In 2-10% steel slag (compared with vanadium slag, its calcium content is larger), there are two ways to produce it, one is that the residual vanadium in the semi-steel is oxidized into the slag after steelmaking, and the other is that it is not The vanadium-containing steel slag is obtained by direct steelmaking by blowing the molten iron of the vanadium slag. Vanadium-containing steel slag has the following characteristics: (1) high content of CaO and iron, perfect crystallization, dense texture, and poor dissociation degree; (2) complex composition and large fluctuation; (3) low vanadium c...

AI Technical Summary

Problems solved by technology

However, this method only stays in the stage of laboratory research, and the proportion of phosphate is large, the cost is high, and there is no industrial promotion at present.

Direct acid leaching refers to the complete wet extraction of vanadium without roasting process, but due to the high content of CaO in steel slag, the acid consumption is large and the cost is high; Difficult for subsequent separation

[0004] CN 102071321 A proposes a method for extracting vanadium and chromium from vanadium-containing steel slag using a high-basic potassium hydroxide medium. This method does not require high-temperature roasting, and the reaction temperature is reduced to 160-240 ° C. The wet method extracts vanadium and chromium. effectively eliminates C1 2 , HCl, SO 2 , dust and other air pollutants, and reduce the amount of wastewater produced and discharged; the disadvantage is that the KOH medium is expensive, and the mass ratio of KOH to steel slag is 3:1 to 5:1, and the reaction alkali concentration is 60%-90%. The loss of KOH medium is more, resulting in higher production costs and lower product benefits

[0005] CN 102094123 A proposes a method for extracting vanadium from vanadium-containing steel slag using a high-concentration sodium hydroxide medium. The reaction temperature of this method is 180-240°C. Vanadium is extracted by wet method, and there is no waste gas and dust pollution in the process; the disadvantage is The alkali concentration is too high, and the alkalinity is 65%-90%, which will lead to higher heat required for evaporation and concentration during medium recycling, resulting in higher production costs, and the residual V in the final slag is higher, and the leaching rate is not high. , the V content in the final slag is 0.3%-0.5%

Images