A method for smelting high-purity nickel-molybdenum alloy by using nickel-molybdenum complex ore

Abstract

The invention provides a method for smelting high-purity nickel-molybdenum alloy by using complex nickel-molybdenum ore. The alloy comprises the following components in percentage by mass: 8 to 30 percent of Ni, 10 to 30 percent of Mo, less than or equal to 0.5 percent of Si, less than or equal to 0.5 percent of C, less than or equal to 0.1 percent of Cu, less than or equal to 0.03 percent of P, less than or equal to 0.03 percent of S, and the balance of iron. According to the characteristic that the complex nickel-molybdenum ore is difficult to separate, the high-purity nickel-molybdenum alloy is smelted by adopting the routes of oxidizing and roasting nickel-molybdenum sulfide type mineral to remove sulfur, reducing and smelting high-alkalinity slag to obtain crude alloy, refining high-alkalinity weak oxidative slag to remove silicon and phosphorus and treating and refining Ba-Ca in vacuum to deeply remove phosphorus, sulfur and oxygen; the alloy can be used for nickel-molybdenum alloying and alloying of high nickel-molybdenum alloy steel in high-purity steel production, and has the advantages of high purity, no pollution, good alloying effect and the like; and the method has the characteristics of pure fire method, greenness, no pollution, simplicity in process and the like, realizes efficient utilization of the difficultly separated complex nickel-molybdenum ore, and is worthy of popularization.

Description

technical field [0001] The invention relates to a high-purity nickel-molybdenum alloy, in particular to a method for smelting a high-purity nickel-molybdenum alloy by utilizing nickel-molybdenum complex ore. Background technique [0002] Nickel and molybdenum are important strategic metals. Due to their unique physical and chemical properties, they become the matrix, main component or additive of advanced structural materials and functional materials, such as nickel-based superalloys, nickel-molybdenum alloy steel, etc., are widely used in In the fields of national economy, national defense and military industry, the current market is in great need of high-purity nickel-molybdenum alloys, especially in the fields of aerospace, nuclear power and military industry in recent years, the demand for high-purity nickel-molybdenum-based alloys is increasing. High-purity nickel And molybdenum is expensive. [0003] Nickel-molybdenum ore is a kind of multi-metal complex mineral resou...

AI Technical Summary

Problems solved by technology

[0004]For the low-grade nickel-molybdenum difficult-to-separate complex ore proposed in this project, there are currently two exploration schemes: one is the combined pyro-wet smelting of nickel-molybdenum ore The second is: nickel-molybdenum ore all-wet smelting process, the main feature of the combined pyro-wet process is the application of the molybdenite smelting process, the roasting and desulfurization of the fire method is followed by the wet leaching process, and the reagents The consumption is large, the industrial waste liquid generated is large and the treatment is difficult, and the pollution to the environment after discharge is serious. What is more critical is that when this combined fire-wet process is used, the nickel in the nickel-molybdenum ore is difficult to effectively recover. The leaching rate of molybdenum is also difficult to reach more than 90%. It is also proposed to use wet extraction of molybdenum and then fire method to extract nickel. The difficulty of this route is due to the complex composition of molybdenum ore, especially when nickel sulfide exists. The residual molybdenum interferes with the pyrometallurgical nickel extraction. The main difficulty in the full wet smelting process of nickel-molybdenum ore is the process of leaching nickel or molybdenum. Alkaline gangue will form insoluble molybdenum acid with molybdenum. Salt, which affects the leaching rate of molybdenum; while alkaline leaching slag is used to extract nickel with acid, impurities such as calcium carbonate (Ca2CO3 ) in the slag will consume a large amount of molybdenum. The acid directly affects the recovery rate of metals. In addition, for complex ores that are difficult to separate low-grade nickel and molybdenum, the biggest disadvantages of the hydrometallurgical process are the large consumption of reagents, the large amount of industrial waste produced and the difficulty in treatment. The pollution to the environment is serious. Therefore, from the investigation of the existing technology, it is found that there is currently no industrialized method for the efficient utilization of low-grade nickel-molybdenum difficult-to-separate complex ores. There is no doubt that with the further mining of rich ore and the global demand for nickel and molybdenum The strong demand of nickel-molybdenum ore will definitely become a valuable resource to be utilized, and the recovery of nickel-molybdenum from low-grade nickel-molybdenum ore has become an urgent problem to be solved

[0005] In the prior art, the Chinese invention patent (application number 200310106190.7, invention name: nickel-molybdenum alloy and its preparation method) proposes a method of using nickel-molybdenum ore through roasting— Reduction, and then the nickel-molybdenum alloy is prepared by medium-frequency smelting and synthesis. The reducing agent used in this invention is ferrosilicon powder and aluminum powder. The cost of the reducing agent is high, and the silicon content in the alloy is difficult to control to a level lower than 3%. , especially after roasting and reduction of ferrosilicon powder and aluminum powder, it is difficult to reduce the phosphorus and sulfur in the alloy to the level required by the pure alloy at the same time

[0006]At present, in the production fields of pure alloy steel and superalloy, high-purity nickel and molybdenum elements are needed for alloying, but the price of pure nickel and pure molybdenum is too expensive The content of impurity elements such as silicon, phosphorus, and sulfur in the nickel-molybdenum alloy produced by the existing technology is relatively high, and at the same time, the complex and difficult-to-separate minerals of nickel and molybdenum in our country cannot be comprehensively utilized without pollution and high recovery rate. Therefore, in order to solve the current For the above-mentioned problems in the production of nickel-molybdenum alloys, the present invention proposes a method for smelting high-purity nickel-molybdenum alloys through pure pyrotechnic pollution-free smelting of nickel-molybdenum difficult-to-separate complex ores