CN107584137B

CN107584137B - Method for preparing metal cobalt by solution method

Info

Publication number: CN107584137B
Application number: CN201710827432.3A
Authority: CN
Inventors: 程继鹏; 马克远; 刘芙
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2017-09-14
Filing date: 2017-09-14
Publication date: 2020-04-03
Anticipated expiration: 2037-09-14
Also published as: CN107584137A

Abstract

The invention discloses a method for preparing metal cobalt by a solution method, which comprises the steps of dissolving cobalt acetate tetrahydrate in a mixed solution consisting of ethylene glycol and deionized water, transferring the solution to a high-pressure reaction kettle, placing the sealed reaction kettle into a pre-preheated oven, gradually heating the temperature of the oven to 200-210 ℃ at the heating rate of 2-5 ℃/min, preserving the temperature for 20-24 hours at the temperature, cooling the reaction kettle to room temperature after the reaction is finished, and filtering, washing and drying the mixed solution to obtain the metal cobalt. The method has the advantages of simple process, low cost and high purity of the finally obtained product.

Description

Method for preparing metal cobalt by solution method

Technical Field

The invention relates to the field of preparation of material powder, in particular to a method for preparing metal cobalt by a solution method.

Background

The metal cobalt is an important functional material, has excellent physical and chemical properties and has important application in many fields. Cobalt metal has excellent magnetic properties, and thus it has wide applications in the fields of high-density storage media and magnetic memory devices. In addition, metallic cobalt is widely applied to various fields such as high-strength high-temperature-resistant alloy, industrial catalysis, functional ceramics, batteries and the like.

At present, there are many methods for preparing metallic cobalt, such as oxide reduction method, electrolytic method, liquid phase reduction method, etc. The oxide reduction method is to reduce cobalt oxide with a reducing substance such as hydrogen and carbon monoxide to obtain metallic cobalt. The electrolytic method is to obtain the metallic cobalt by an electrochemical reduction method, and the microscopic morphology of the metallic cobalt prepared by the electrolytic method is mostly dendritic or acicular. The liquid phase reduction method is to disperse solid compounds of cobalt in a liquid, usually a mixed liquid of a polyol (e.g., ethylene glycol) and a liquid phase reducing agent, and then to heat the liquid to a certain temperature, thereby causing the compounds to undergo a reduction reaction to obtain metallic cobalt. Compared with other methods, the liquid phase reduction method has the advantages of simple production process, easy operation, various production raw material forms and effectively adjustable and controllable product granularity. However, the reaction solution system of the conventional liquid phase reduction method is often completed by adding a plurality of chemical reagents, so that the cost is high, the product purity is not high, and the operation is complex.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for preparing metal cobalt by a solution method, which has low cost and high product purity, and the specific technical scheme is as follows:

a method for preparing metal cobalt by a solution method comprises the following specific steps:

(1) dissolving cobalt acetate tetrahydrate in a mixed solution consisting of ethylene glycol and deionized water, and stirring to fully dissolve the cobalt acetate tetrahydrate in the mixed solution;

(2) and (2) transferring the solution in the step (1) into a high-pressure reaction kettle, wherein the filling rate is 60-75 vol%, placing the sealed reaction kettle into an oven preheated to 140-150 ℃, gradually raising the temperature of the oven to 200-210 ℃ at a temperature raising speed of 2-5 ℃/min, preserving the heat at the temperature for 20-24 hours, cooling the reaction kettle to room temperature after the reaction is finished, and filtering, washing and drying the mixed solution to obtain the metallic cobalt.

Further, the volume ratio of the ethylene glycol to the deionized water is 10: 0.9-10: 1.1.

furthermore, 1-2 g of cobalt acetate tetrahydrate is dissolved in each 100mL of mixed solution consisting of ethylene glycol and deionized water.

Compared with the prior art, the invention has the following beneficial effects:

compared with the conventional liquid phase reduction method (polyalcohol), the method can prepare the metal cobalt in the mixed solution of water and glycol by direct chemical reaction only by using one chemical reagent, namely cobalt acetate, and the raw material reagent is simpler and is easy to master and implement; and the preparation temperature is low, the energy consumption is low, the preparation period is short, and the product purity is high.

Drawings

Fig. 1 is an XRD chart, a digital chart and an SEM photograph of metallic cobalt prepared according to the method of example 1;

FIG. 2 is an XRD pattern of metallic cobalt prepared according to the method of example 2;

fig. 3 is an SEM morphology of metallic cobalt prepared according to the method of example 2.

Detailed Description

Example 1

Weighing 0.6g of cobalt acetate tetrahydrate, dissolving the cobalt acetate tetrahydrate in a mixed solution consisting of 55mL of ethylene glycol and 5mL of deionized water, stirring to fully mix and dissolve the cobalt acetate tetrahydrate, transferring the solution to a reaction kettle with the volume of 100mL, putting the sealed reaction kettle into an oven preheated to 140 ℃, heating the oven to 200 ℃ at the speed of 2 ℃/min, and then preserving heat for 20 hours at the temperature of 200 ℃; and after the reaction is finished, cooling the reaction kettle to room temperature, and filtering, washing and drying the mixed solution to obtain the metal cobalt. The XRD pattern of the obtained metallic cobalt is shown as (a) in figure 1, and the product is metallic cobalt of face-centered cubic and hexagonal crystal systems, and has no diffraction peak of other impurities; the digital photograph is shown in FIG. 1 (b) and the SEM micrographs are shown in FIGS. 1 (c) - (d).

Example 2

Weighing 1.3g of cobalt acetate tetrahydrate, dissolving the cobalt acetate tetrahydrate in a mixed solution consisting of 60mL of ethylene glycol and 6.6mL of deionized water, stirring to fully mix and dissolve the cobalt acetate tetrahydrate, transferring the solution to a reaction kettle with the volume of 90mL, putting the sealed reaction kettle into an oven preheated to 150 ℃ in advance, heating the oven to 210 ℃ at the speed of 5 ℃/min, and then preserving heat for 24 hours at the temperature of 210 ℃; and after the reaction is finished, cooling the reaction kettle to room temperature, and filtering, washing and drying the mixed solution to obtain the metal cobalt. The XRD pattern of the obtained metal cobalt is shown in figure 2, and the figure shows that the product is mainly face-centered cubic and a little amount of hexagonal metal cobalt without diffraction peaks of other impurities; the SEM morphology of the obtained metallic cobalt is shown in FIG. 3.

Claims

1. A method for preparing metal cobalt by a solution method is characterized by comprising the following specific steps:

(2) transferring the solution in the step (1) into a high-pressure reaction kettle, wherein the filling rate is 60-75 vol%, putting the sealed reaction kettle into an oven preheated to 140-150 ℃ in advance, gradually raising the temperature of the oven to 200-210 ℃ at a temperature raising speed of 2-5 ℃/min, preserving the heat at the temperature for 20-24 hours, cooling the reaction kettle to room temperature after the reaction is finished, and filtering, washing and drying the mixed solution to obtain metal cobalt;

the volume ratio of the ethylene glycol to the deionized water is 10: 0.9-10: 1.1;

1-2 g of cobalt acetate tetrahydrate is dissolved in each 100mL of mixed solution consisting of ethylene glycol and deionized water.