Method for extracting vanadium by using vanadium slag mixed alkali roasting

Abstract

The invention discloses a method for extracting vanadium by using vanadium slag mixed alkali roasting. The method comprises the following process steps: (1) uniformly mixing vanadium slag, Na2CO3 and NaOH mixed alkali, performing oxidizing roasting in a calcining kiln, thereby obtaining the roasted clinker; (2) leaching the roasted clinker by using water, controlling the pH value of the leaching solution to be 9-14, performing solid-liquid separation, thereby obtaining the leaching slag and the vanadium liquid. According to the method for extracting vanadium by virtue of mixed alkali roasting and water leaching, due to the absence of addition of sodium chloride and sodium sulfate salts, toxic and harmful gases are not produced; the mixed alkali roasting is adopted, and the immersion ratio of vanadium is higher than 95 percent; and moreover, the mixed alkali roasting temperature is reduced by 50-150 DEG C compared with pure alkali roasting, a sintering phenomenon is avoided in the roasting process, the energy consumption increased by ball-milling and roasting of the clinker at the later stage is eliminated, and the method is a clean and high-efficiency vanadium extraction method.

Description

technical field [0001] The invention belongs to the technical field of vanadium chemical industry and metallurgy, and in particular relates to a method for extracting vanadium by roasting vanadium slag mixed with alkali. Background technique [0002] Vanadium slag is a vanadium-enriched material produced by blowing vanadium-containing molten iron in the presence of oxygen-containing gas. In the iron and steel industry, vanadium slag produced from vanadium-titanium magnetite is the main raw material for vanadium extraction. Enterprises that use vanadium-titanium magnetite as raw materials to produce iron and vanadium products currently use the traditional vanadium slag sodium roasting process to extract vanadium from vanadium slag, such as my country's Panzhihua Iron and Steel Corporation, Chenggang Iron and Steel Co., Ltd. in South Africa, and New Zealand Iron and Steel Co., Ltd. Companies and so on are using the above process. The basic principle of sodium roasting process ...

AI Technical Summary

Problems solved by technology

The recovery rate of vanadium in the sodium roasting process is low, the recovery rate of vanadium in a single roasting is about 70%, and the recovery rate of vanadium after multiple roasting is only 85%; the roasting temperature is high (750-850 ° C), and multiple roasting is required , high energy consumption; in the roasting process will produce harmful HCl, Cl 2 and other corrosive gases, polluting the environment

[0003] Chinese patent CN101215005A proposes a method for roasting vanadium slag and sodium salt (sodium carbonate, sodium chloride) or potassium salt (potassium carbonate, potassium chloride). This patent is suitable for high-silicon and low-vanadium vanadium slag, and the roasting temperature is 700 ~820°C, multi-temperature stage roasting, by controlling the temperature system and salt ratio, it can prevent the furnace material from sintering, make the process go smoothly, and also reduce the roasting holding time, and the V in the tailings 2 o 5 The content can reach 0.5~1%; Chinese patents CN1884597A, CN86108218A, etc. have made different improvements to the additives and temperature systems of the sodium roasting process, and the basic principle is to use different ratios of additives (Na 2 CO 3 , NaCl, Na 2 SO 4 、Na 2 SO 3 etc.) and different temperature systems to improve and increase the extraction rate of vanadium, roasting time, furnace charge sintering and other indicators, but the above process is basically the same as the traditional sodium roasting principle, operation process, and operating temperature, and it is inevitable to produce toxic and harmful Gas, low recovery rate of vanadium, etc.

[0004] To sum up, in the prior art, the process of vanadium extraction from vanadium slag generally has high roasting temperature, low vanadium conversion rate and recovery rate, and there are problems such as toxic gas and a large amount of acidic ammonia nitrogen wastewater discharge in the process of vanadium recovery.

Images