Process for extracting vanadium by acid leaching of stone coal

[0022] Example 1

[0023] Vanadium (V 2 O 5 1.06%) of stone coal was added with 6% of CaO to be broken, and then calcined at 800 °C for 2 hours. The calcine was added to sulfuric acid solution at a solid-to-liquid ratio of 1:1.2 g/ml, leached at room temperature for 6 hours and filtered to obtain vanadium (V 2 O 5 6.42g/L) of the leaching solution was added with ammonia water to adjust the pH value to 0.5, and the ammonium aluminum sulfate NH was crystallized out. 4 Al(SO 4 ) 2 ·12H 2 O crystal, add NaHCO to the liquid after crystallization 3 Adjust the pH value to 2.0 to remove iron, to contain 0.21% V 2 O 5 The iron removal slag is then oxidized to 2.0 times of the chemical reaction stoichiometric number of V(V) in the liquid after iron removal, add hydrogen peroxide to oxidize at room temperature for 2h, use strong alkali resin 201×7 to absorb vanadium, contact time 40min, negative vanadium resin 4.0mol/L NH 3 The ammonia water was absorbed, the contact time was 60min, and 2.0mol/L H 2 SO 4Dilute sulfuric acid solution regenerates the resin, desorbs the solution obtained by precipitation of vanadium at room temperature for 24 hours to obtain ammonium metavanadate, and pyrolyzes ammonium metavanadate at 550 °C for 1.0 hours to obtain V with a purity of 99.7%. 2 O 5 product. The recovery rate of vanadium was 98.3% from stone coal acid leaching solution to ion exchange desorption solution.

[0024] Example 2

[0025] Vanadium (V 2 O 5 1.17%) of the stone coal was crushed and then added concentrated sulfuric acid and mixed well, and then calcined at 250 ° C for 2 hours, and the calcined sand was added at a solid-to-liquid ratio of 1: 1.2 g/ml to the ion-exchange solution obtained in Example 1, leached at 85 ° C for 1.0 hours, and filtered to obtain Vanadium (V 2 O 5 7.23g/L) of the leaching solution, the leaching solution is NH 4 Al(SO 4 ) 2 ·12H 2 O crystals are precipitated by adding 2.0 times the stoichiometric number of the chemical reaction (NH 4 )SO 4 In addition to aluminum, add CaCO to the liquid after aluminum removal 3 Adjust the pH value to 1.9, according to Fe in the solution 2+ oxidized to Fe 3+ Add V(V) 1.0 times the number of chemical reactions, remove iron at 40°C for 1.5h and filter, the filter residue contains 0.05% V 2 O 5 , the filtrate is oxidized to 1.2 times the number of chemical reactions of V(V) according to the low-valent vanadium, and sodium chlorate is oxidized at 70 ℃ for 1.5h, and the feed liquid is adsorbed with weak base anion resin (D314), the contact time is 60min, and the negative vanadium resin is 2.0 mol/L NaOH solution was desorbed, the contact time was 40min, and then the resin was regenerated with 2.0mol/L HCl dilute hydrochloric acid solution. The desorbed solution was 1.6 times of the chemical reaction count and ammonium chloride was added to precipitate ammonium metavanadate, and the ammonium metavanadate was heated at 500 °C. Solution for 1.5 hours yields V with a purity of 99.5% 2 O 5 product. Crystallized NH 4 Al(SO 4 ) 2 ·12H 2 After the O crystals are dissolved in water, stir and add lime to adjust the pH to 7.0 and filter. The recovery rate of vanadium was 99.1% from stone coal acid leaching solution to ion exchange desorption solution.

[0026] Example 3

[0027] Vanadium (V 2 O 5 0.83%) of the stone coal is crushed and then added to the exchanged liquid obtained in Example 2 at a solid-to-liquid ratio of 1: 1.2 g/ml, and then added concentrated sulfuric acid and oxygen pressure leaching and filtration to obtain vanadium-containing (V 2 O 5 6.62g/L) of the leaching solution, the leaching solution is NH 4 Al(SO 4 ) 2 ·12H 2 1.5 times of the stoichiometric number of O crystals were added to the ammonium-containing transformation solution obtained in Example 2, and N was added. 4 HCO 3 Adjust pH to 2.5 to crystallize out NH 4 Al(SO 4 ) 2 ·12H 2 O crystal, according to Fe in the liquid after crystallization 2+ oxidized to Fe 3+ Add hydrogen peroxide to 1.1 times the number of chemical reactions, stir at room temperature for 1.0h to remove iron, and obtain a solution containing 0.13% V 2 O 5 After iron removal, the liquid is oxidized to ammonium persulfate 1.5 times the number of V(V) chemical reaction stoichiometric quantities after iron removal, and oxidized at 85 °C for 0.5h, and adsorbed vanadium with strong alkali anion resin (D231), and the contact time was 80min. The negative vanadium resin is desorbed and regenerated with a mixed solution of 1 mol/L NaOH and 3.0 mol/L NaCl. The contact time is 50 minutes. The desorbed liquid is 2.5 times the number of chemical reactions and ammonium chloride is added to precipitate and precipitate ammonium metavanadate. The ammonium metavanadate is pyrolyzed at 500 °C. 1.5 hours to obtain V with 99.6% purity 2 O 5 product. Crystallized NH 4 Al(SO 4 ) 2 ·12H 2 After the O crystals are dissolved in water, stir and add lime to adjust the pH to 7.5 and filter. The recovery rate of vanadium was 98.6% from stone coal acid leaching solution to ion exchange desorption solution.