Method for improving vanadium yield in vanadium extraction process via sodium salt roasting of vanadium slag

• Main Authors: LI LANJIE, CHEN DONGHUI, GAO MINGLEI, BAI RUIGUO
• Format: Patent
• Language: English
• Published: 08.04.2015
• Subjects: CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; FERROUS OR NON-FERROUS ALLOYS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The invention discloses a method for improving vanadium yield in a vanadium extraction process via sodium salt roasting of vanadium slag. The method comprises the following process steps: (1) ball milling-leaching: mixing vanadium slag with sodium salt, carrying out sodium salt roasting to obtain roasting clinker, adding liquid caustic soda or high-alkalinity vanadium liquid into the roasting clinker, and ball milling and crushing the materials in a ball mill to obtain crushed slag slurry; (2) thickening-leaching: conveying the crushed slag slurry into a thickening pond, adding liquid caustic soda, and thickening and leaching to obtain thick leachate; (3) washing tailings: pumping the thick leachate into a horizontal filter for filtering to obtain leaching residues and eluate, and the eluate can be used as the high alkalinity vanadium liquid. Since the method of increasing the alkali concentration in the vanadium liquid to leach for extracting vanadium is adopted in the invention, the pH value of the eluate is increased, the solubility of silicon in the vanadium liquid is improved, the formation of silica gel is reduced, the vanadium content in the vanadium mud without silicon is lowered, the loss of the vanadium liquid is reduced, and compared with the existing process, the vanadium recovery is improved by 5-10% and is higher than 90%.