CN114657420A - Light rare earth-zinc alloy, preparation method and application thereof, and application of smelting container - Google Patents

Abstract

The invention discloses a light rare earth-zinc alloy, a preparation method and application thereof and application of a smelting container. The light rare earth-zinc alloy and the preparation method thereof comprise the following steps: smelting raw materials consisting of light rare earth metal and zinc in a smelting container, and then refining and casting to obtain light rare earth-zinc alloy; wherein the light rare earth metal is selected from one or more of lanthanum, praseodymium or neodymium; the light rare earth metal accounts for 0-10.0 wt% of the total weight of the raw materials, but does not contain 0, and the balance is zinc; the part of the smelting vessel, which is in contact with the raw material, is formed by tungsten. The preparation method can reduce the content deviation of the light rare earth element in the light rare earth-zinc alloy.

Description

Light rare earth-zinc alloy, preparation method and application thereof, and application of smelting container

Technical Field

The invention relates to a light rare earth-zinc alloy, a preparation method and application thereof, and also relates to application of a smelting container.

Background

The steel is easy to corrode in the using process, and serious economic loss can be caused. The galvanization on the surface of the steel is a more effective measure for preventing the corrosion of the steel. The addition of proper rare earth elements in the zinc can improve the performance of the coating, reduce the thickness of the coating and increase the corrosion resistance of the coating. However, the melting point of zinc (about 419.5 ℃) is low, the melting point of rare earth metal (about 798-1663 ℃) is high, the solubility of the rare earth metal in zinc is extremely low, and the two are difficult to be smelted together; and the rare earth metal has strong activity and is easy to be oxidized in the smelting process. The traditional smelting method has the problems that the alloy components are difficult to control accurately, the impurity elements are difficult to control and the like.

CN101100732A discloses a preparation method of a binary alloy plating material, wherein the binary alloy is composed of Zn and RE, the material further comprises trace additive elements, and the total content of the trace additive elements is below 0.5%; proportionally adding the elements into a smelting furnace according to the alloy composition, smelting, stirring, refining, removing slag, and casting into alloy ingots.

CN111334688A discloses a preparation method of Zn-RE series zinc alloy, which comprises the steps of mixing pure zinc and non-radioactive rare earth element RE to obtain a mixture; in CO₂And SF₆Under the protection of atmosphere, the mixture is placed in a jade crucible or a graphite crucible for smelting, and the Zn-RE series zinc alloy is obtained after casting and cooling.

However, the method disclosed in the prior art has the disadvantages that the deviation of the content of the rare earth in the obtained alloy and the content of the rare earth in the original feeding materials is large, and the content of impurities in the obtained alloy is large.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a method for preparing a light rare earth-zinc alloy, which has a small deviation of the content of light rare earth elements in the light rare earth-zinc alloy prepared by the method. Further, the light rare earth-zinc alloy has low impurity content.

Another object of the invention is to provide a light rare earth-zinc alloy.

It is a further object of the present invention to provide the use of a light rare earth-zinc alloy.

It is a further object of the present invention to provide the use of a smelting vessel that is capable of reducing the variation in light rare earth element content in light rare earth-zinc alloys.

In one aspect, the invention provides a preparation method of a light rare earth-zinc alloy, which comprises the following steps:

smelting raw materials consisting of light rare earth metal and zinc in a smelting container, and then refining and casting to obtain light rare earth-zinc alloy;

wherein the light rare earth metal is selected from one or more of lanthanum, praseodymium or neodymium; the light rare earth metal accounts for 0-10.0 wt% of the total weight of the raw materials, but does not contain 0, and the balance is zinc; the part of the smelting vessel, which is in contact with the raw material, is formed by tungsten.

According to the preparation method of the invention, preferably, the oxygen content in the light rare earth is less than or equal to 0.02 wt%, the phosphorus content is less than or equal to 0.03 wt%, and the sulfur content is less than or equal to 0.02 wt%.

According to the production method of the present invention, preferably, the melting is performed in an inert atmosphere; the smelting temperature is 460-800 ℃, and the smelting pressure is 0.01-0.06 MPa.

According to the preparation method of the invention, preferably, the refined raw materials are cast into a water-cooled ingot mold or an ingot mold with an electromagnetic stirring function, so as to obtain the light rare earth-zinc alloy.

In another aspect, the present invention provides a light rare earth-zinc alloy prepared by the above method.

According to the light rare earth-zinc alloy of the invention, preferably, the content deviation of the light rare earth element in the light rare earth-zinc alloy is less than or equal to 0.004;

wherein, the deviation of the content of the light rare earth element in the light rare earth-zinc alloy is calculated by adopting the following formula:

|X-I|/X；

wherein X represents the content of light rare earth metal in the raw material, and the unit is wt%;

i represents the content of light rare earth elements in the light rare earth-zinc alloy, and the unit is wt%.

In a further aspect, the invention provides the use of the light rare earth-zinc alloy described above in the preparation of a rare earth zinc coating.

According to the use of the invention, the light rare earth-zinc alloy is preferably added to a zinc bath and a rare earth zinc coating is formed on the surface of the article to be coated by hot dip coating.

In a further aspect, the present invention provides the use of a smelting vessel in reducing the variation in the content of light rare earth elements in a light rare earth-zinc alloy, the site of the smelting vessel in contact with feedstock for forming the light rare earth-zinc alloy being formed from tungsten;

the light rare earth element in the light rare earth-zinc alloy is selected from one or more of lanthanum, praseodymium or neodymium; the light rare earth-zinc alloy contains 0-10.0 wt% of light rare earth elements, but does not contain 0, and the balance is zinc;

the deviation of the content of the light rare earth element in the light rare earth-zinc alloy is calculated by adopting the following formula:

|X-I|/X；

wherein X represents the content of light rare earth metal in the raw material, and the unit is wt%;

i represents the content of light rare earth elements in the light rare earth-zinc alloy, and the unit is wt%.

The use according to the invention preferably comprises the following steps: smelting raw materials consisting of light rare earth metal and zinc in a smelting container, and then refining and casting to obtain light rare earth-zinc alloy;

wherein the light rare earth metal is selected from one or more of lanthanum, praseodymium or neodymium; the light rare earth metal accounts for 0-10.0 wt% of the total weight of the raw materials, but does not contain 0, and the balance is zinc.

The invention reduces the content deviation of light rare earth elements in the light rare earth-zinc alloy by selecting the specific material of the smelting container which is in contact with the raw materials, and solves the long-term problem that the components of the light rare earth-zinc alloy are difficult to accurately control. The light rare earth-zinc alloy obtained by the preparation method has low impurity content.

Detailed Description

The present invention will be further described with reference to the following specific examples, but the scope of the present invention is not limited thereto.

The deviation of the content of the light rare earth element in the light rare earth-zinc alloy is calculated by adopting the following formula: i X-I/X; wherein X represents the content of light rare earth metal in the raw material, and the unit is wt%; i represents the content of light rare earth elements in the light rare earth-zinc alloy, and the unit is wt%.

< preparation of light rare earth-zinc alloy >

The preparation method of the light rare earth-zinc alloy comprises the following steps: smelting raw materials consisting of light rare earth metal and zinc in a smelting container, and then refining and casting to obtain the light rare earth-zinc alloy.

The raw material of the invention consists of light rare earth metal and zinc. Of course, some unavoidable impurities, such as oxygen, phosphorus, sulfur, etc., may be included in the feedstock.

The light rare earth metal is selected from one of lanthanum, praseodymium and neodymium. In certain embodiments, the light rare earth metal is lanthanum or praseodymium. In other embodiments, the light rare earth metal is neodymium. The oxygen content in the light rare earth metal is less than or equal to 0.02 wt%; preferably, the oxygen content in the light rare earth metal is less than or equal to 0.008 wt%. The phosphorus content in the light rare earth metal is less than or equal to 0.03 wt%; preferably, the phosphorus content of the light rare earth metal is < 0.01 wt%. The sulfur content in the light rare earth metal is less than or equal to 0.02 wt%; preferably, the sulfur content in the light rare earth metal is < 0.0050 wt%. The light rare earth metal material may be pretreated to obtain light rare earth metals having the above-mentioned oxygen, phosphorus and sulfur contents. The light rare earth metal material may be light rare earth metal obtained by electrolysis. The pre-treatment step may include grinding, melting, refining, etc.

The light rare earth metal is 0-10.0 wt% (not including 0) of the total weight of the raw materials; preferably 0.2 to 5.0 wt%; more preferably 0.5 to 4.0 wt%; most preferably 1.0 to 3.0 wt%.

The zinc can be obtained by pretreating zinc metal. The pre-treatment step may include grinding or the like. The zinc accounts for 90-100 wt% (not including 100%) of the total weight of the raw materials; preferably 95-99.8 wt%; more preferably 96-99.5%; most preferably 97 to 99 wt%.

The smelting vessel is a vessel for carrying raw materials in the processes of smelting, refining and the like of the raw materials. Such as a crucible, etc. The portion of the smelting vessel that contacts the raw material is formed of tungsten. Tungsten is a simple metal. Preferably, the inner surface of the smelting vessel is formed of tungsten. The inner surface of the smelting vessel refers to the surface forming the raw material receiving cavity. It is of course also possible that the entire smelting vessel is formed from tungsten. The application surprisingly finds that the deviation of the content of light rare earth elements in the formed light rare earth-zinc alloy can be reduced by adopting the smelting container to smelt and refine the raw materials.

The melting may be performed in an inert atmosphere. Inert atmospheres include, but are not limited to, helium, neon, argon, and the like. According to one embodiment of the invention, the inert atmosphere is argon. The smelting pressure can be 0.01-0.06 MPa; preferably 0.02-0.05 MPa; more preferably 0.03 to 0.04 MPa. The smelting temperature can be 460-800 ℃; preferably 550-750 ℃; more preferably 670 to 700 ℃. The smelting time is based on the complete melting of zinc. Melting may be carried out in a vacuum melting furnace.

Refining time is more than 10 min; preferably, the refining time is 20-120 min; more preferably, the refining time is 30-60 min. Thus, the light rare earth and zinc can be fully alloyed. The refining may be carried out in a vacuum melting furnace.

Casting the refined raw materials to obtain the light rare earth-zinc alloy. The mould used for casting can be a water-cooled ingot mould or an ingot mould with stirring function. The mold may be formed of copper. In certain embodiments, a step of cooling the cast alloy ingot may also be included.

< light rare earth-zinc alloy and use thereof >

The light rare earth-zinc alloy is prepared by the method. The deviation of the content of the light rare earth element in the light rare earth-zinc alloy is less than or equal to 0.004; preferably, the content deviation of the light rare earth element in the light rare earth-zinc alloy is less than or equal to 0.0035; more preferably, the deviation of the content of the light rare earth element in the light rare earth-zinc alloy is less than or equal to 0.0000001. In certain embodiments, the deviation in light rare earth element content in the light rare earth-zinc alloy may be zero.

The light rare earth-zinc alloy can be applied to preparing rare earth zinc coatings. Therefore, the invention also provides the application of the light rare earth-zinc alloy in preparing the rare earth zinc coating. Specifically, the method comprises the following steps:

and adding the light rare earth-zinc alloy into a zinc bath, and forming a rare earth zinc coating on the surface of the object to be plated by adopting a hot dipping method.

The light rare earth-zinc alloy can be added to the zinc bath through multiple addition points. The number of the adding points can be 5, 10 or 15, etc. The light rare earth-zinc alloy may be used in the form of a light rare earth-zinc alloy block. The weight of each light rare earth-zinc alloy is less than 100 kg; preferably 5-30 kg; more preferably 9 to 11 kg. The temperature of the zinc bath can be 350-600 ℃; preferably 400-550 ℃; more preferably 450 to 500 ℃.

The article to be plated may be formed of steel. For example, a steel plate.

< use of melting vessel >

The present application has found that the deviation of the content of light rare earth elements in a light rare earth-zinc alloy can be reduced by placing raw materials in a melting vessel formed of a specific material for melting, refining, and the like. Thus, the present invention provides the use of a smelting vessel to reduce the variation in light rare earth element content in a light rare earth-zinc alloy.

The portion of the melting vessel of the present invention that contacts the raw material is formed of tungsten. The smelting vessel is a vessel for carrying raw materials in the processes of smelting, refining and the like of the raw materials. Such as a crucible, etc. Preferably, the inner surface of the smelting vessel is formed of tungsten. The inner surface of the smelting vessel refers to the surface forming the raw material receiving cavity. It is of course also possible that the entire smelting vessel is formed from tungsten.

The light rare earth element in the light rare earth-zinc alloy is selected from one or more of lanthanum, praseodymium or neodymium. In certain embodiments, the light rare earth element is selected from one of lanthanum, praseodymium. In other embodiments, the light rare earth element is neodymium. The content of light rare earth elements in the light rare earth-zinc alloy is 0-10.0 wt% (not including 0); preferably 0.2 to 5.0 wt%; more preferably 0.5 to 4.0 wt%; most preferably 1.0 to 3.0 wt%.

The content of zinc element in the light rare earth-zinc alloy is 90-100 wt% (not including 100%); preferably 95-99.8 wt%; more preferably 96-99.5%; most preferably 97 to 99 wt%.

The deviation of the content of the light rare earth elements in the light rare earth-zinc alloy is calculated by adopting the following formula:

|X-I|/X；

wherein X represents the content of light rare earth metal in the raw material, and the unit is wt%;

i represents the content of light rare earth elements in the light rare earth-zinc alloy, and the unit is wt%.

The deviation of the content of the light rare earth element in the light rare earth-zinc alloy is less than or equal to 0.004; preferably, the content deviation of the light rare earth element in the light rare earth-zinc alloy is less than or equal to 0.0035; more preferably, the deviation of the content of the light rare earth element in the light rare earth-zinc alloy is less than or equal to 0.0000001. In certain embodiments, the deviation in light rare earth element content in the light rare earth-zinc alloy may be zero.

Specifically, the method comprises the following steps: smelting the raw material consisting of light rare earth metal and zinc in a smelting container until the zinc is molten, and then refining and casting to obtain the light rare earth-zinc alloy. The selection of the raw materials and the specific operations of the steps are as described above, and are not described herein again. The test method is described below:

measuring the content of rare earth in the light rare earth-zinc alloy by adopting an inductively coupled plasma emission spectrometer (ICP-OES);

the carbon content and the sulfur content in the light rare earth-zinc alloy are measured by an infrared carbon-sulfur analyzer (model LECO-400, purchased from Like, USA);

the phosphorus content in the light rare earth-zinc alloy is measured by a spectrophotometer (model number 722, purchased from Shanghai precision instruments and factories);

the oxygen content in the light rare earth-zinc alloy is measured by adopting an oxygen nitrogen hydrogen analyzer (type is ONH-2000).

Preparation example 1

And (3) polishing the metal zinc to remove impurities on the surface of the metal zinc to obtain the zinc.

Preparation example 2

And polishing the metal lanthanum obtained by electrolysis, and then melting and refining the polished metal lanthanum in a vacuum melting furnace to obtain the lanthanum. The oxygen content in the obtained lanthanum is less than or equal to 0.008 wt%, the phosphorus content is less than 0.01 wt%, and the sulfur content is less than 0.0050 wt%.

Preparation example 3

Praseodymium metal obtained by electrolysis was treated by the method of preparation example 2 to obtain praseodymium. The oxygen content in the obtained praseodymium is less than or equal to 0.008 wt%, the phosphorus content is less than 0.01 wt%, and the sulfur content is less than 0.0050 wt%.

Preparation example 4

The metallic neodymium obtained by electrolysis was treated in accordance with the method of preparation example 2 to obtain neodymium. The obtained neodymium contains oxygen less than or equal to 0.008 wt%, phosphorus less than 0.01 wt% and sulfur less than 0.0050 wt%.

Examples 1 to 3 and comparative examples 1 to 5

(1) Placing the raw material consisting of the zinc and the light rare earth metal obtained in the preparation example 1 in a crucible; placing the crucible in a smelting furnace; vacuumizing the pressure in the smelting furnace to below 10Pa, and then filling argon into the smelting furnace to ensure that the pressure in the smelting furnace is 0.03 MPa; heating the temperature in the smelting furnace to a smelting temperature for smelting until the zinc is completely molten;

(2) refining the smelted raw materials for 30 min;

(3) and casting the refined raw materials into a water-cooled copper ingot mold, and cooling to room temperature to obtain the light rare earth-zinc alloy.

Specifically, the results are shown in Table 1. The contents of light rare earth elements and impurities in the obtained alloy are shown in table 2.

TABLE 1

Note: the inner wall of the crucible is referred to as the surface of the raw material holding chamber.

TABLE 2

Note: the deviation of the content of the light rare earth elements is calculated by adopting the following formula: i X-I/X;

wherein X represents the content of light rare earth metal in the raw material, and the unit is wt%; i represents the content of light rare earth elements in the light rare earth-zinc alloy, and the unit is wt%.

Example 4

The plurality of light rare earth-zinc alloy blocks (10 kg/block) obtained in example 1 were added to a zinc bath at 10 addition points, the temperature of the zinc bath was controlled at 460 ℃, and a rare earth zinc plating layer was formed on the surface of a steel product to be plated (steel sheet) by a hot dip plating method.

The present invention is not limited to the above-described embodiments, and any variations, modifications, and substitutions which may occur to those skilled in the art may be made without departing from the spirit of the invention.

Claims (10)

1. The preparation method of the light rare earth-zinc alloy is characterized by comprising the following steps:

smelting raw materials consisting of light rare earth metal and zinc in a smelting container, and then refining and casting to obtain light rare earth-zinc alloy;

wherein the light rare earth metal is selected from one or more of lanthanum, praseodymium or neodymium; the light rare earth metal accounts for 0-10.0 wt% of the total weight of the raw materials, but does not contain 0, and the balance is zinc; the part of the smelting vessel, which is in contact with the raw material, is formed by tungsten.

2. The method according to claim 1, wherein the light rare earth metal has an oxygen content of 0.02 wt% or less, a phosphorus content of 0.03 wt% or less, and a sulfur content of 0.02 wt% or less.

3. The method of claim 1, wherein the smelting is carried out in an inert atmosphere; the smelting temperature is 460-800 ℃, and the smelting pressure is 0.01-0.06 MPa.

4. The preparation method according to any one of claims 1 to 3, characterized in that the refined raw material is cast into a water-cooled ingot mold or an ingot mold with an electromagnetic stirring function to obtain the light rare earth-zinc alloy.

5. A light rare earth-zinc alloy, characterized by being prepared by the preparation method of any one of claims 1 to 4.

6. The light rare earth-zinc alloy of claim 5, wherein the light rare earth-zinc alloy has a deviation in light rare earth element content of 0.004 or less;

wherein, the deviation of the content of the light rare earth element in the light rare earth-zinc alloy is calculated by adopting the following formula:

|X-I|/X；

wherein X represents the content of light rare earth metal in the raw material, and the unit is wt%;

i represents the content of light rare earth elements in the light rare earth-zinc alloy, and the unit is wt%.

7. Use of a light rare earth-zinc alloy according to claim 5 or 6 in the preparation of a rare earth zinc coating.

8. Use according to claim 7, characterized in that the light rare earth-zinc alloy is added to a zinc bath and a rare earth zinc coating is formed on the surface of the article to be coated by hot dip coating.

9. Use of a smelting vessel for reducing the variation in light rare earth element content in a light rare earth-zinc alloy, characterized by:

the part of the smelting container, which is in contact with the raw materials for forming the light rare earth-zinc alloy, is formed by tungsten;

the light rare earth element in the light rare earth-zinc alloy is selected from one or more of lanthanum, praseodymium or neodymium; the content of light rare earth elements in the light rare earth-zinc alloy is 0-10.0 wt%, but the light rare earth-zinc alloy does not contain 0, and the balance is zinc;

the deviation of the content of the light rare earth element in the light rare earth-zinc alloy is calculated by adopting the following formula:

|X-I|/X；

wherein X represents the content of light rare earth metal in the raw material, and the unit is wt%;

i represents the content of light rare earth elements in the light rare earth-zinc alloy, and the unit is wt%.

10. Use according to claim 9, characterized in that it comprises the following steps:

smelting raw materials consisting of light rare earth metal and zinc in a smelting container, and then refining and casting to obtain light rare earth-zinc alloy;

wherein the light rare earth metal is selected from one or more of lanthanum, praseodymium or neodymium; the light rare earth metal accounts for 0-10.0 wt% of the total weight of the raw materials, but does not contain 0, and the balance is zinc.