Abstract:
As one of the valuable metallurgical secondary resources, vanadium-bearing steel slag produced in steelmaking process of vanadium-titanium magnetite, could be used as the important raw materials for vanadium extraction. However, the content of negative component calcium in vanadium bearing steel slag is very high, which could greatly reduce the extracting vanadium index and increase the cost of vanadium extraction. Therefore, purification and recovery of negative component calcium is a necessary pretreatment measure before vanadium extraction. According to the properties of negative component calcium in vanadium-bearing steel slag, the research progress in purification and recovery of calcium from vanadium-bearing steel slag was analyzed, the existing problems and corresponding suggestions were proposed, mainly as follows: As for gravity separation by shaking table, the purification rate is not high, a certain amount of positive component vanadium would be lost, and the purified calcium could not be recovered, and in future adopting the gravity separation equipment with large treatment capacity, strengthening the gravity separation process, and improving the precision and selectivity of gravity separation are the development direction of this method. High temperature roasting method has problems including high cost, serious pollution, so has little value of promotion and application. Some other technologies, with good reference, are not yet clear whether they could be transplanted and need to be further improved and developed. The leaching with ammonium chloride has many advantages such as good selectivity, high purification rate, and no loss of vanadium. And meanwhile, the purified calcium by this method can be enriched in the leaching solution by this method to realize recovery by precipitation of calcium. The leaching with ammonium chloride is a promising method and its recovery and recycling need to be further studied and improved.