CN104310454A - Process method of rare earth oxysulfide by using alkali chloride - Google Patents

Abstract

The invention discloses a process for preparing rare earth sulfur oxides from alkali metal chlorides. The preparation steps are as follows: ① Weigh the required material RE ₂ O ₂ S according to the stoichiometric ratio (wherein RE is the rare earth elements Y, La, one of Gd or Sm), Na ₂ CO ₃ , sublimed sulfur and alkali metal chloride AMCl (wherein AM is one of alkali metal Li, Na or K), mix the weighed materials evenly; ② put The uniformly mixed material is put into a crucible with a cover both inside and outside, and high-temperature resistant powder is filled in the gap between the two crucibles and compacted; ③ Gradiently raise the temperature of the crucible with the mixed material to 1100-1250°C, sinter for 3h-5h, and then Cool down to room temperature with the furnace; ④ Wash the sintered product with hot water, stir it, and filter it with suction; ⑤ Dry the washed product in a constant temperature blast drying oven to obtain rare earth sulfur oxides. The invention uses RE ₂ O ₃ , Na ₂ CO ₃ , sublimed sulfur and alkali metal chloride AMCl as raw materials, is prepared by a sulfur melting method, has a simple preparation method and is easy to operate, and can be used in the fields of luminescent materials and light-absorbing materials.

Description

A kind of process method of preparing rare earth sulfur oxide with alkali metal chloride

technical field

The invention relates to a process for preparing rare earth sulfur oxides from alkali metal chlorides, in particular to the preparation and modification of rare earth sulfur oxides by sulfur melting, and the preparation and optimization of rare earth sulfur oxides with narrow particle distribution.

Background technique

Rare earth sulfur oxides have high chemical stability and thermal stability, are insoluble in water, and have a melting point as high as 2000-2200°C; the band gap is 4.6-4.8eV, suitable for doping ions; its maximum phonon energy is 520cm ^{- 1.} It is suitable as a host material for luminescent materials, and has very high light absorption and energy transfer efficiency. The biggest feature of the hexagonal Ln ₂ O ₂ S crystal structure is that it has a relatively spacious space structure, allowing a certain amount of cation and anion vacancies to form and a certain amount of interstitial ions to enter, while the crystal structure remains basically unchanged. Among them, La ₂ O ₂ S, Y ₂ O ₂ S, and Gd ₂ O ₂ S are used as the host material of the luminescent material. By doping Eu ³⁺ , Tb ³⁺ , Ce ³⁺ and other luminescent ions, they have Good luminescence performance, and Sm ₂ O ₂ S as an optical absorption material has good light absorption characteristics for 1.06μm and 1.54μm lasers. Therefore, rare earth oxysulfides have been widely used as optical materials. The main preparation method of rare earth sulfur oxides is the sulfur melting method, which is suitable for large-scale industrial production, with complete crystals and better luminescent properties than products prepared by other methods. However, the amount and type of flux used in the sulfur melting method are not fixed, and there is no clear range. At present, the rare earth sulfur oxides prepared by the sulfur melting method have large particles and require ball milling, which greatly reduces the luminescent performance, and the size distribution of the particles needs to be further improved. Therefore, it is very necessary to optimize the process of preparing rare earth sulfur oxides by sulfur melting method and improve the particle properties of rare earth sulfur oxides.

Contents of the invention

The technical problem to be solved in the present invention is to overcome the above-mentioned defects, and prepare rare earth sulfur oxides with the chemical formula RE ₂ O ₂ S through the sulfur melting method assisted by alkali metal chloride AMCl.

In order to solve the above problems, the present invention adopts the following technical solutions:

A process for preparing rare earth sulfur oxides with alkali metal chlorides, characterized in that AM is one of the alkali metal elements Li, Na or K in the alkali metal chlorides AMCl; the chemical formula of the rare earth sulfur oxides In RE ₂ O ₂ S, RE is one of the rare earth elements Y, La, Gd or Sm; the rare earth sulfur oxide whose chemical formula is RE ₂ O ₂ S is prepared by sulfur melting method, and the preparation steps are as follows:

① Weigh the required materials RE ₂ O ₂ S (where RE is one of the rare earth elements Y, La, Gd or Sm), Na ₂ CO ₃ , sublimed sulfur and alkali metal chloride AMCl (where AM It is one of the alkali metal elements Li, Na or K), and the weighed materials are mixed uniformly;

②Put the uniformly mixed material into a crucible with a cover inside and outside, fill the gap between the two crucibles with high-temperature resistant powder and compact it;

③Gradiently raise the temperature of the crucible containing the mixture to 1100-1250°C, sinter for 3h-5h, and then cool down to room temperature with the furnace;

④ The sintered product is washed with hot water and stirred, and suction filtered;

⑤Put the washed product into a constant temperature blast drying oven to dry to obtain the rare earth sulfur oxide.

In the step ①, mol(Na ₂ CO ₃ ): mol(RE ₂ O ₃ )=1.5～2, mol(sublimed sulfur): mol(RE ₂ O ₃ )=3.5～4.5, mol(AMCl):mol( RE ₂ O ₃ )=0.25~1.

The gradient heating system in the step ③ is to raise the temperature to 300-400°C at a heating rate of 2-3°C/min, and keep it warm for 1h-2h, then raise the temperature to 1100-1250°C at a heating rate of 3-5°C/min, and keep it warm 3h～5h.

The rare earth sulfur oxide of the present invention is based on RE ₂ O ₃ (where RE is one of the rare earth elements Y, La, Gd or Sm), Na ₂ CO ₃ , sublimed sulfur and alkali metal chloride AMCl (wherein AM is alkali metal One of the elements Li, Na or K) is used as a raw material, and is prepared by a sulfur melting method, and the preparation and synthesis method is simple and easy to operate.

The rare earth sulfur oxides La ₂ O ₂ S, Y ₂ O ₂ S and Gd ₂ O ₂ S synthesized by the present invention are used as the host material of the luminescent material, and the luminescent ions such as Eu ³⁺ , Tb ³⁺ or Ce ³⁺ are doped in the It has good luminescent performance under ultraviolet and vacuum ultraviolet excitation, and Sm ₂ O ₂ S, as an optical absorption material, has good light absorption characteristics for 1.06 μm and 1.54 μm lasers. Through the selection of the type and amount of alkali metal chloride, The rare earth sulfur oxide with narrow particle distribution is prepared by adopting the sulfur melting method, so that it can be used in the fields of light-emitting materials and light-absorbing materials. In addition, the invention develops a new use of alkali metal chloride, which reduces the particle distribution range of rare earth sulfur oxides, makes the product unnecessary for ball milling, and reduces production costs.

Detailed ways

The present invention will be further described below in conjunction with specific examples.

The present invention uses alkali metal chloride-assisted sulfur melting method to synthesize chemical formula RE ₂ O ₂ S (wherein RE is a kind of in rare earth element Y, La, Gd or Sm) 4 specific examples of rare earth sulfur oxides are shown in the table 1 shows:

Table 1

Embodiment 1 ^# :

Raw material composition is as shown in 1 ^# in table 1, and concrete preparation method comprises the following steps:

①Weigh 18.672g Y ₂ O ₃ , 13.146g Na ₂ CO ₃ (mol(Na ₂ CO ₃ ):mol(Y ₂ O ₃ )=1.5), 9.280g sublimated sulfur (mol(sublimed sulfur):mol (Y ₂ O ₃ )=3.5) and 0.876gLiCl (mol(LiCl):mol(Y ₂ O ₃ )=0.25), mix the weighed materials evenly;

②Put the uniformly mixed material into a crucible with a cover inside and outside, fill the gap between the two crucibles with high-temperature resistant powder and compact it;

③Raise the temperature of the crucible containing the mixture to 300°C at a heating rate of 2°C/min, and keep it warm for 1h, then raise the temperature to 1100°C at a heating rate of 3°C/min, sinter for 3h, and then cool down to room temperature with the furnace;

④ The sintered product is washed with hot water and stirred, and suction filtered;

⑤Put the washed product into a constant temperature blast drying oven to dry to obtain rare earth sulfur oxides.

The test results of this rare earth sulfur oxide are as follows:

Analyze the phase composition of the dried powder in process ⑤ with an X-ray diffractometer (XRD, D/Max2500). The results show that the positions of the main diffraction peaks correspond to hexagonal Y ₂ O ₂ S, and there is no other substance phase. The peak exists; the scanning electron microscope (SEM, JEOL-6310) is used to analyze the particle morphology, and the software is used for particle size statistics. The results show that the particle distribution is uniform, and the average particle size is 3 μm.

Embodiment 2 ^# :

①Weigh 19.060g La ₂ O ₃ , 10.541g Na ₂ CO ₃ (mol(Na ₂ CO ₃ ):mol(La ₂ O ₃ )=1.7), 7.034g sublimated sulfur (mol(sublimed sulfur):mol (La ₂ O ₃ )=3.75) and 1.709gNaCl (mol(NaCl):mol(La ₂ O ₃ )=0.5), mix the weighed materials evenly;

②Put the uniformly mixed material into a crucible with a cover inside and outside, fill the gap between the two crucibles with high-temperature resistant powder and compact it;

③Raise the temperature of the crucible containing the mixture to 330°C at a heating rate of 2.5°C/min, and keep it warm for 1.5h, then raise the temperature to 1150°C at a heating rate of 3.5°C/min, sinter for 4h, and then cool down to room temperature with the furnace;

④ The sintered product is washed with hot water and stirred, and suction filtered;

⑤Put the washed product into a constant temperature blast drying oven to dry to obtain rare earth sulfur oxides.

The test results of this rare earth sulfur oxide are as follows:

Analyze the phase composition of the dried powder in process ⑤ with an X-ray diffractometer (XRD, D/Max2500). The results show that the positions of the main diffraction peaks correspond to hexagonal La ₂ O ₂ S, and there is no other substance phase. The peak exists; the scanning electron microscope (SEM, JEOL-6310) is used to analyze the particle morphology, and the software is used for particle size statistics. The results show that the particle distribution is uniform, and the average particle size is 2.3 μm.

Embodiment 3 ^# :

Composition is as shown in 3 ^# in table 1, and concrete preparation method comprises the following steps:

①Weigh 19.151g Gd ₂ O ₃ , 10.639g Na ₂ CO ₃ (mol(Na ₂ CO ₃ ):mol(Gd ₂ O ₃ )=1.9), 7.200g sublimated sulfur (mol(sublimed sulfur):mol( Gd ₂ O ₃ )=4.25) and 2.954g KCl (mol(KCl):mol(Gd ₂ O ₃ )=0.75), mix the weighed materials evenly;

②Put the uniformly mixed material into a crucible with a cover inside and outside, fill the gap between the two crucibles with high-temperature resistant powder and compact it;

③Raise the temperature of the crucible containing the mixture to 360°C at a heating rate of 3°C/min, and keep it warm for 2h, then raise the temperature to 1200°C at a heating rate of 4°C/min, sinter for 5h, and then cool down to room temperature with the furnace;

④ The sintered product is washed with hot water and stirred, and suction filtered;

⑤Put the washed product into a constant temperature blast drying oven to dry to obtain rare earth sulfur oxides.

The test results of this rare earth sulfur oxide are as follows:

Analyze the phase composition of the dried powder in process ⑤ with an X-ray diffractometer (XRD, D/Max2500). The results show that the positions of the main diffraction peaks correspond to hexagonal Gd ₂ O ₂ S, and there is no other substance phase The peak exists; the scanning electron microscope (SEM, JEOL-6310) is used to analyze the particle morphology, and the software is used for particle size statistics. The results show that the particle distribution is uniform, and the average particle size is 1.8 μm.

Embodiment 4 ^# :

Composition is as shown in 4 ^# in table 1, and concrete preparation method comprises the following steps:

①Weigh 19.119g Sm ₂ O ₃ , 11.620g Na ₂ CO ₃ (mol(Na ₂ CO ₃ ):mol(Sm ₂ O ₃ )=2), 7.910g sublimated sulfur (mol(sublimed sulfur):mol( Sm ₂ O ₃ )=4.5) and 4.087g KCl (mol(KCl):mol(Sm ₂ O ₃ )=1), mix the weighed materials evenly;

②Put the uniformly mixed material into a crucible with a cover inside and outside, fill the gap between the two crucibles with high-temperature resistant powder and compact it;

③Raise the temperature of the crucible containing the mixture to 400°C at a heating rate of 2.5°C/min, and keep it warm for 2h, then raise the temperature to 1250°C at a heating rate of 5°C/min, sinter for 4h, and then cool down to room temperature with the furnace;

④ The sintered product is washed with hot water and stirred, and suction filtered;

⑤Put the washed product into a constant temperature blast drying oven to dry to obtain rare earth sulfur oxides.

The test results of this rare earth sulfur oxide are as follows:

Analyze the phase composition of the dried powder in process ⑤ with an X-ray diffractometer (XRD, D/Max2500). The results show that the positions of the main diffraction peaks correspond to hexagonal Sm ₂ O ₂ S, and there is no other substance phase The peak exists; the scanning electron microscope (SEM, JEOL-6310) is used for particle morphology analysis, and the software is used for particle size statistics. The results show that the particle distribution is uniform, and the average particle size is 2.0 μm.

The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention, and various modifications to these embodiments will be apparent to those skilled in the art. The general terms defined herein The principles may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (3)

1. A process for preparing rare earth sulfur oxides with alkali metal chlorides is characterized in that AM is one of the alkali metal elements Li, Na or K in the alkali metal chlorides AMCl; the rare earth sulfur oxides The chemical formula of the compound is RE ₂ O ₂ S, and RE is one of the rare earth elements Y, La, Gd or Sm; the rare earth sulfur oxide with the chemical formula RE ₂ O ₂ S is prepared by sulfur melting method, and the preparation steps are as follows : ① Weigh the required materials RE ₂ O ₂ S (where RE is one of the rare earth elements Y, La, Gd or Sm), Na ₂ CO ₃ , sublimed sulfur and alkali metal chloride AMCl (where AM It is one of the alkali metal elements Li, Na or K), and the weighed materials are mixed uniformly; ②Put the uniformly mixed material into a crucible with a cover inside and outside, fill the gap between the two crucibles with high-temperature resistant powder and compact it; ③Gradiently raise the temperature of the crucible containing the mixture to 1100-1250°C, sinter for 3h-5h, and then cool down to room temperature with the furnace; ④ The sintered product is washed with hot water and stirred, and suction filtered; ⑤Put the washed product into a constant temperature blast drying oven to dry to obtain the rare earth sulfur oxide. 2. A process for preparing rare earth sulfur oxides with alkali metal chlorides according to claim 1, characterized in that mol(Na ₂ CO ₃ ) in the step ①: mol(RE ₂ O ₃ )= 1.5-2, mol (sublimed sulfur): mol (RE ₂ O ₃ ) = 3.5-4.5, mol (AMCl): mol (RE ₂ O ₃ ) = 0.25-1. 3. A process for preparing rare earth sulfur oxides from alkali metal chlorides according to claim 1, characterized in that the step ③ in the gradient heating system is to heat up to 300 °C at a heating rate of 2 to 3 °C/min. ~400°C, keep it warm for 1h~2h, then raise the temperature to 1100~1250°C at a heating rate of 3~5°C/min, and keep it warm for 3h~5h.