CN109762995A - A method of molybdenum element in recycling nickel base superalloy waste cut materials - Google Patents

Abstract

A method for recovering molybdenum element in nickel-based superalloy cutting waste, the specific steps are as follows: (1) melting the nickel-based superalloy cutting waste; (2) atomizing the alloy liquid into powder; (3) pulverizing the powder The alloy is oxidized; (4) alkali leaching is performed, and solid-liquid separation is performed; (5) pH is adjusted to remove some impurities; (6) pH adjustment is performed to remove residual impurities in the solution; (7) the obtained solution is concentrated, Cool, filter and dry to obtain sodium molybdate crystals. The advantages of the invention are: the recovery and utilization of metal molybdenum in the superalloy is realized, and high-purity sodium molybdate is prepared, the molybdenum leaching rate and the recovery rate are high, and the nickel-based superalloy with high or low molybdenum content can be The treatment and recovery process is simple, and the method is an efficient, low-cost and environment-friendly method for recovering and preparing sodium molybdate from nickel-based superalloy cutting waste.

Description

A method for recovering molybdenum element in nickel-based superalloy cutting waste

technical field

The invention belongs to the technical field of hydrometallurgy, and relates to a method for recovering molybdenum element in nickel-based superalloy cutting waste.

Background technique

Molybdenum is a rare transition element with high melting point, which is located in the fifth period VIB group in the chemical periodic table, and its stable valence is +6. Molybdenum is a silver-white metal, hard and tough, with a high melting point and relatively high thermal conductivity, and is not easily oxidized by air at room temperature. As a transition element, molybdenum can easily change its oxidation state, and the color of molybdenum ions will also change with the change of oxidation state.

With the continuous development of the molybdenum industry in the world, the consumption of molybdenum mineral raw materials is increasing, and the recoverable resources are becoming less and less. In order to protect the environment and make full use of molybdenum resources, developed countries have begun to pay attention to molybdenum regeneration since the mid-1980s. In terms of resource utilization value, the United States recovered 3,800 tons of molybdenum from spent catalysts in 1995, accounting for about 30% of the total molybdenum supply. In addition, the molybdenum content of molybdenum-containing waste is usually higher than that of molybdenum ore, the cost of extracting molybdenum and other metals from molybdenum is usually lower than that of ore, energy consumption is also relatively low, and exhaust emissions are also small. Superalloys usually contain a certain amount of metallic molybdenum, so it is of great significance to recycle molybdenum resources in nickel-based superalloys.

Molybdate has low toxicity and low degree of environmental pollution, and is currently used as a new type of water treatment agent. Molybdate has high thermal stability and can be used in circulating water systems with high heat flux density and local overheating. And sodium molybdate can be used in the manufacture of alkaloids, inks, fertilizers, molybdenum red pigments and lightfast pigments as precipitants, catalysts, molybdenum salts, as well as in the manufacture of flame retardants and metal inhibitors for pollution-free cold water systems. For galvanizing, polishing agent and chemical reagent.

At present, most of the research on the recovery of molybdenum renewable resources focuses on the recovery of waste catalysts and molybdenum from low-grade ores, while the relevant research on the recovery of metal molybdenum in superalloys is not sufficient. The invention can recover the molybdenum element in the superalloy to obtain sodium molybdate with higher purity, which can satisfy the industrial application, the recovery rate of metal molybdenum is high, and the separated leaching slag and precipitation can be used to recover other valuable materials in the superalloy. element.

SUMMARY OF THE INVENTION

Aiming at the shortcomings of the current technology for recovering molybdenum from nickel-based superalloy scraps, the present invention provides a method for recycling molybdenum elements in nickel-based superalloy cutting scraps.

The implementation of the present invention can be carried out according to the following steps:

A method for recovering molybdenum element in nickel-based superalloy cutting waste, comprising the steps of:

(1) melting nickel-based superalloy cutting waste to obtain liquid alloy;

(2) carry out atomization pulverizing treatment to the liquid alloy obtained in step (1);

(3) carrying out oxidation treatment on the alloy powder obtained in step (2) in an air atmosphere, the oxidation treatment temperature is 600～650 ℃, and the oxidation time is 4～6 hours;

(4) carry out alkali leaching treatment to the alloy powder after the oxidation treatment obtained in step (3) with alkali solution to obtain leaching solution and leaching slag; the alkali solution used in alkali leaching is one or both of sodium hydroxide and sodium carbonate; The mass fraction of the alkaline solution is between 5% and 35%; the mass ratio of the alkaline solution to the alloy powder is 5-8:1; the leaching temperature is 70-90° C.; the leaching time is 1-3h;

(5) carry out precipitation and impurity removal to the leaching solution in step (4) with acid solution, the pH range is 8.5～9.5, and the precipitation impurity removal temperature is 60～80 ℃; The impurities removed by the described precipitation are impurities such as cobalt and nickel; Separation to obtain liquid phase and solid phase;

(6) Precipitate and remove impurities from the liquid phase obtained in the step (5) with an acid solution, the pH range is 7.0-8.0, and the temperature for precipitation and removal of impurities is 60-80°C; the impurities removed by the precipitation are aluminum; obtain molybdenum Sodium solution;

(7) Concentrating, cooling, filtering and drying the sodium molybdate solution obtained in step (6) to obtain sodium molybdate crystals.

The particle size of the alloy particles of the atomized powdering described in the above step (2) is between 20 and 200 μm;

The acid solution in the above steps (5) and (6) is one or more of hydrochloric acid solution, nitric acid solution and sulfuric acid solution.

The mass fraction of the acid solution described in the above steps (5) and (6) is between 3% and 15%.

The concentration process described in the above step (7) has a volume mass of 1.1-1.6g/cm ³ ; the concentration temperature is 80-100°C; the final temperature of the cooling process is 20-30°C; the The drying temperature is 70 ~ 80 ℃.

Compared with the existing recycling technology, the advantages of the present invention are:

The recovery of molybdenum in nickel-based superalloy is realized by a simple process, and sodium molybdate with high purity is prepared. The leaching rate of molybdenum in the leaching process is high, and the recovery rate is also high. High or low amount of nickel-based superalloys can be processed, the operation process is simple, and it is an efficient and environmentally friendly recycling method.

Description of drawings

Fig. 1 is the process flow diagram of the present invention.

Detailed ways

Example 1:

The mass fraction of molybdenum in the nickel-based superalloy cutting scrap used in this example is 2%.

(1) melting nickel-based superalloy cutting waste to obtain liquid alloy;

(2) Atomizing and powdering the liquid alloy described in step (1), and the particle size is between 20 and 200 μm;

(3) carrying out oxidation treatment of the alloy powder described in step (2) in an air atmosphere, the oxidation time is 4 hours, and the oxidation treatment temperature is 640 ° C;

(4) using 20% sodium carbonate solution to carry out alkali leaching treatment to the alloy powder after the oxidation treatment described in step (3) to obtain leaching solution and leaching slag; the leaching solution-solid ratio is 5:1, and the leaching temperature is 85 ° C , the leaching time is 1h;

(5) using 3% hydrochloric acid solution to adjust pH to 9.0 for the leaching solution described in step (4), and separate to obtain liquid phase and solid phase; described precipitation impurity removal temperature is 60 ℃;

(6) utilize 3% hydrochloric acid solution to adjust pH to 7.0 to the liquid phase obtained in step (5), obtain sodium molybdate solution, and described precipitation impurity removal temperature is 60 ℃;

(7) Concentrating the sodium molybdate solution described in step (6) at a temperature of 100° C., cooling to 25° C., filtering, and drying at 70° C. to obtain sodium molybdate crystals.

Example 2:

The mass fraction of molybdenum in the nickel-based superalloy cutting scrap used in this example is 3%.

(1) melting nickel-based superalloy cutting waste to obtain liquid alloy;

(2) Atomizing and powdering the liquid alloy described in step (1), and the particle size is between 20 and 200 μm;

(3) carrying out oxidation treatment of the alloy powder described in step (2) in an air atmosphere, the oxidation time is 4 hours, and the oxidation treatment temperature is 630 ° C;

(4) using 5% sodium hydroxide solution to carry out alkali leaching treatment to the alloy powder after the oxidation treatment described in step (3) to obtain leaching solution and leaching slag; the leaching solution-solid ratio is 6:1, and the leaching temperature is 70 ℃ ℃, the leaching time is 2h;

(5) using 5% hydrochloric acid solution to adjust pH to 9.2 for the leaching solution described in step (4), and separate to obtain liquid phase and solid phase; described precipitation impurity removal temperature is 60 ℃;

(6) utilize 5% hydrochloric acid solution to adjust pH to 7.5 to the liquid phase obtained in step (5), obtain sodium molybdate solution, and described precipitation impurity removal temperature is 60 ℃;

(7) Concentrating the sodium molybdate solution described in step (6) at a temperature of 100° C., cooling to 25° C., filtering, and drying at 70° C. to obtain sodium molybdate crystals.

Example 3:

The mass fraction of molybdenum in the nickel-based superalloy cutting scrap used in this example is 5%.

(1) melting nickel-based superalloy cutting waste to obtain liquid alloy;

(2) Atomizing and powdering the liquid alloy described in step (1), and the particle size is between 20 and 200 μm;

(3) carrying out oxidation treatment of the alloy powder described in step (2) in an air atmosphere, the oxidation time is 5 hours, and the oxidation treatment temperature is 650 ° C;

(4) using 25% sodium carbonate solution to carry out alkali leaching treatment to the alloy powder after the oxidation treatment described in step (3) to obtain leaching solution and leaching slag; the leaching solution-solid ratio is 5:1, and the leaching temperature is 85 ℃ , the leaching time is 1h;

(5) using 3% hydrochloric acid solution to adjust the pH to 9.5 for the leaching solution described in step (4), and separate to obtain liquid phase and solid phase; the temperature of described precipitation and impurity removal is 70 ℃;

(6) utilize 3% hydrochloric acid solution to adjust pH to 7.3 to the liquid phase obtained in step (5), obtain sodium molybdate solution, and described precipitation impurity removal temperature is 70 ℃;

(7) Concentrating the sodium molybdate solution described in step (6) at a temperature of 90° C., cooling to 20° C., filtering, and drying at 75° C. to obtain sodium molybdate crystals.

Example 4:

The mass fraction of molybdenum in the nickel-based superalloy cutting scrap used in this example is 8%.

(1) melting nickel-based superalloy cutting waste to obtain liquid alloy;

(2) Atomizing and powdering the liquid alloy described in step (1), and the particle size is between 20 and 200 μm;

(3) carrying out oxidation treatment of the alloy powder described in step (2) in an air atmosphere, the oxidation time is 5 hours, and the oxidation treatment temperature is 650 ° C;

(4) using 10% sodium hydroxide solution to carry out alkali leaching treatment to the alloy powder after the oxidation treatment described in step (3) to obtain leaching solution and leaching slag; the leaching solution-solid ratio is 6:1, and the leaching temperature is 75 ℃, the leaching time is 1h;

(5) using 5% hydrochloric acid solution to adjust pH to 9.3 for the leaching solution described in step (4), and separate to obtain liquid phase and solid phase; described precipitation impurity removal temperature is 65 ℃;

(6) utilize 5% hydrochloric acid solution to adjust pH to 7.0 to the liquid phase obtained in step (5), obtain sodium molybdate solution, and described precipitation impurity removal temperature is 65 ℃;

(7) Concentrating the sodium molybdate solution described in step (6) at a temperature of 90° C., cooling to 20° C., filtering, and drying at 70° C. to obtain sodium molybdate crystals.

Claims (5)

1. a method for recycling molybdenum element in nickel-based superalloy cutting waste, is characterized in that, comprises the steps as follows: (1) melting nickel-based superalloy cutting waste to obtain liquid alloy; (2) carry out atomization pulverizing treatment to the liquid alloy obtained in step (1); (3) carrying out oxidation treatment on the alloy powder obtained in step (2) in an air atmosphere, the oxidation treatment temperature is 600～650 ℃, and the oxidation time is 4～6 hours; (4) carry out alkali leaching treatment to the alloy powder after the oxidation treatment obtained in step (3) with alkali solution to obtain leaching solution and leaching slag; the alkali solution used in alkali leaching is one or both of sodium hydroxide and sodium carbonate; The mass fraction of the alkaline solution is between 5% and 35%; the mass ratio of the alkaline solution to the alloy powder is 5-8:1; the leaching temperature is 70-90° C.; the leaching time is 1-3h; (5) carrying out precipitation and impurity removal on the leaching solution in step (4) with acid solution, the pH range is 8.5～9.5, and the precipitation impurity removal temperature is 60～80 ℃; separate liquid phase and solid phase; (6) carry out precipitation and impurity removal to the liquid phase obtained in step (5) with acid solution, the pH range is 7.0～8.0, and the precipitation impurity removal temperature is 60～80 ℃; Obtain sodium molybdate solution; (7) Concentrating, cooling, filtering and drying the sodium molybdate solution obtained in step (6) to obtain sodium molybdate crystals. 2 . The method for recovering molybdenum element in nickel-based superalloy cutting waste according to claim 1 , wherein the particle size of the alloy particles in the atomized powdering process in step (2) is between 20 and 200 μm. 3 . 3. the method for reclaiming molybdenum element in nickel-based superalloy cutting waste according to claim 1 and 2, is characterized in that, the acid solution in step (5) and step (6) is hydrochloric acid solution, nitric acid solution, sulfuric acid solution one or more of them. 4. The method for recovering molybdenum in nickel-based superalloy cutting waste according to claim 3, wherein the acid solution mass fraction described in step (5) and step (6) is between 3% and 15% between. 5. the method for reclaiming molybdenum element in nickel-based superalloy cutting waste according to claim 1 or 2 or 4, is characterized in that, the concentration process described in the step (7) is 1.1～1.6g/cm to volume mass ³ ; the concentration temperature is 80-100°C; the final temperature of the cooling process is 20-30°C; the drying temperature is 70-80°C.