High calcium phosphorus vanadium slag are different v process contrast resolution
a, sodium roasting - Water extraction method of vanadium
the main principle: vanadium slag with sodium mixed in certain proportion, under oxidizing atmosphere will contain trivalent vanadium and vanadium slag tetravalent vanadium into water-soluble pentavalent vanadium ( Mainly exists in the form of sodium vanadate) 。
the main technological process: sodium salt vanadium slag - Roasting - Water - Purifying - Heavy vanadium - Filter washing - Drying calcination
the advantages and disadvantages, mature technology, the leaching process is simple, but produce HCl roasting, CL2, SO2, SO3 gas, such as erosion can introduce sodium, sodium salt additives that residue is difficult to continue to use.
2, calcifying roasting - Acid leaching vanadium
the main principle: vanadium slag mixed with calcium salt according to certain proportion, under oxidizing atmosphere V3 + and V4 + oxidation into insoluble in water, but soluble in acid V5 + ( Mainly in the form of calcium vanadate)
the main process: calcium salt vanadium slag - Roasting - Acid leaching - Purifying - Heavy vanadium - Filter washing - Drying calcination
the advantages and disadvantages, avoids the production of harmful gases, eased restrictions on the calcium content in vanadium slag, not to introduce sodium ions, influence the further use of vanadium slag, but for in and out of the devices require high corrosion resistance.
3, calcifying roasting - Sodium carbonate leaching v
the main principle: the clinker calcification after roasting vanadium slag with sodium carbonate leaching, in and out of the process are mainly carbonate ions and vanadium acid radical ion exchange, calcium carbonate precipitation, vanadium with vanadate form soluble in water.
the main process: calcium salt vanadium slag - Roasting - Sodium carbonate leaching - Purifying - Filter washing - Drying calcination
the advantages and disadvantages, avoids the production of harmful gas, reduce the corrosion of equipment requirements, reduce the impurity content in the leach liquor, but adding sodium ions influence during the process of leaching residue recycling.
4, the method of solvent extraction v containing vanadium solution
the main principle: with extraction solvent extraction vanadium containing vanadium solution into the organic phase, with back extraction make vanadium extraction agent into water phase.
the main process: containing vanadium solution - Extraction - The extraction - Heavy vanadium - Washing filter - Drying calcination
the advantages and disadvantages: balance speed, good separation effect and processing capacity, the vanadium recovery rate is high, the extraction solvent can be recycled, the production cost is low, the product purity is up to 99. 9%, large upfront investment, easy to operate, stable, high degree of automation.
5, solution containing vanadium ion exchange method v
the main principle: with ion exchange column containing vanadium in vanadium solution adsorbed on the ion exchange resin, reoccupy desorption agent for stripping.
the main process: containing vanadium solution - Ion exchange -- Stripping - Filter washing - Drying calcination
the advantages and disadvantages, short process, raw material consumption, low pollution, heavy vanadium mother liquid can be recycled, a high degree of product, but the resin is easy to poisoning or contaminated, harsh operating conditions, can't automatic continuous production.