Method for smelting high-purity nickel-molybdenum alloy by using complex nickel-molybdenum 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 complex low-grade nickel-molybdenum ore proposed in this project, there are currently two exploration schemes: one is the smelting process of nickel-molybdenum ore combined with pyro-wet method; The main feature of the combination of method and wet method is that the molybdenite smelting process is applied mechanically, and the roasting and desulfurization of the fire method is followed by the wet leaching process, which consumes a lot of reagents, produces a lot of industrial waste, and is difficult to handle. After discharge, the pollution to the environment is serious. What's more critical is that when using this combination of fire method and wet method, it is difficult to effectively recover the nickel in the nickel-molybdenum ore, and the leaching rate of molybdenum is also difficult to reach more than 90%. It is also proposed to use The process of extracting molybdenum by wet method and then extracting nickel by fire method is difficult because of the complex composition of molybdenum ore, especially when nickel sulfide exists, the leaching rate of molybdenum is low, and the remaining molybdenum will interfere with nickel extraction by fire method , the main difficulty of the full wet smelting process of nickel-molybdenum ore is the process of leaching to extract nickel or molybdenum. Alkaline gangue will form insoluble molybdate with molybdenum, which will affect the leaching rate of molybdenum; When nickel is extracted, calcium carbonate (Ca 2 CO 3 ) and other impurities will consume a large amount of acid and directly affect the recovery rate of metals. In addition, for complex ores that are difficult to separate low-grade nickel and molybdenum, the biggest disadvantages of hydrometallurgical processes are the large consumption of reagents and the production of industrial waste liquid. And the treatment is difficult, and the pollution to the environment after discharge is serious. Therefore, from the existing technical research, it is found that there is currently no industrialized method for the efficient utilization of low-grade nickel-molybdenum difficult-to-separate complex ores. Undoubtedly, with the further mining of rich ore , and the strong global demand for nickel and molybdenum, nickel-molybdenum ore will 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