High precision rare earth polishing powder and preparation thereof

A rare earth polishing powder, high-precision technology, applied in chemical instruments and methods, polishing compositions containing abrasives, other chemical processes, etc. Fluctuation and other problems, to achieve the effect of easy control of polishing accuracy stability, easy control of wear resistance, and small fluctuation of product quality

Active Publication Date: 2009-07-08
上海华明高纳稀土新材料有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The wear resistance and polishing precision stability of this kind of polishing powder products composed of aggregate particles are difficult to control, and due to the complex production process, the cost increases and impurity ions have been introduced, causing quality fluctuations and is not conducive to particle size distribution control
[0007] Chinese patent application CN1939990A discloses a production method of cerium-rich rare earth polishing powder, which utilizes the addition of specific grain size seeds to increase the grain size of carbonate precipitates and avoid the formation of agglomerates. Although this method can improve carbon However, in this document, dimethyl oxalate or diethyl oxalate is used to heat and decompose oxalic acid to react with cerium particles to form single-phase oxalate precipitation. This method of preparing seed crystals is expensive and not conducive to industry Large-scale efficient production
The inventor found that the defect of this method is that there are too many small-sized particles, and there is a serious defect in the polishing speed

Method used

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  • High precision rare earth polishing powder and preparation thereof
  • High precision rare earth polishing powder and preparation thereof
  • High precision rare earth polishing powder and preparation thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] (1) Preparation of seed crystals: Heat 1 L of 20 g / L oxalic acid solution to a temperature of 70° C., add ammonia water with a weight concentration of 12.5% ​​until the pH is 5.5, add 50 g / L lanthanum cerium chloride solution, and heat at 70° C. React for 0.5h and age for 2h to obtain lanthanum cerium oxalate crystal seeds with a particle size distribution between 0.50 and 0.70 μm, see figure 1 ;

[0034] (2) Precipitation: Add 2.5 g Lanthanum cerium oxalate seed crystals, at 50°C, add an aqueous solution of sodium bicarbonate with a mass fraction of 25% while stirring until the pH value is 6, to obtain precipitated lanthanum cerium carbonate;

[0035] (3) Fluorination: add 9.9 g of hydrofluoric acid aqueous solution with a weight concentration of 15% to lanthanum cerium carbonate, react at room temperature for 0.5 h, and perform fluorination;

[0036] (4) Roasting: The partially fluorinated lanthanum cerium carbonate is filtered and washed with a centrifuge, dried in...

Embodiment 2

[0038] (1) Preparation of seed crystals: 1L concentration of 50g / L oxalic acid solution is heated to a temperature of 70°C, and the mass concentration of 12.5% ​​ammonia is added until the pH is 4.5, slowly adding 100g / L lanthanum cerium chloride solution, React at 70°C for 1.5 hours, crystallize for 4 hours, and the particle size distribution of the obtained lanthanum cerium praseodymium oxalate crystal seeds is between 0.60 and 0.90 μm;

[0039](2) Precipitation: Add 22.5g of lanthanum cerium praseodymium oxalate seed crystals to 1L of lanthanum cerium chloride aqueous solution with a concentration of 150g / L, and add 25% sodium bicarbonate aqueous solution while stirring until the pH Value is 7, obtains the lanthanum cerium carbonate of precipitation;

[0040] (3) Fluorination: 28.8 g of hydrofluoric acid aqueous solution with a weight concentration of 15% was added to lanthanum cerium carbonate, and reacted for 1 hour at room temperature to carry out fluorination;

[0041]...

Embodiment 3

[0043] (1) Preparation of seed crystals: Heat 1L of 50g / L oxalic acid solution to a temperature of 70°C, add ammonia water with a mass concentration of 12.5% ​​until the pH is 5, slowly add 100g / L lanthanum cerium nitrate solution at 80°C Reaction for 1.0h, aging for 3h, the particle size distribution of lanthanum cerium oxalate seeds is between 0.80-1.00μm;

[0044] (2) Precipitation: Add 10 g of lanthanum cerium oxalate seed crystals to 1 L of lanthanum cerium nitrate aqueous solution with a concentration of 100 g / liter, and add 25% ammonium bicarbonate aqueous solution while stirring until the pH value is 6.5, obtaining precipitated lanthanum cerium carbonate;

[0045] (3) Fluorination: adding 28.8 g of hydrofluoric acid aqueous solution with a weight concentration of 15% to lanthanum cerium carbonate and reacting for 1 hour at room temperature for fluorination;

[0046] (4) Roasting: filter and wash the partially fluorinated lanthanum cerium carbonate with a centrifuge, d...

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Abstract

The invention discloses a high-precision rare-earth polishing powder and a method for preparing the same. The high-precision rare-earth polishing powder is characterized in that D50 particle diameter is between 0.5 and 1.80 mu m; the powder also meets the conditions that D10 is more than or equal to 0.5D50, D90 is less than or equal to 2D50, and D100 is less than or equal to 3D50; a cerium lanthanum nitrate or cerium lanthanum chloride solution is added to an ammonium oxalate solution with PH value of between 4.5 and 5.5 to generate monodisperse lanthanum cerium oxalate or lanthanum cerium praseodymium oxalate deposit; and the deposit is used as a crystal seed to prepare the high-precision rare-earth polishing powder. The high-precision rare-earth polishing powder prepared by the method does not need airflow pulverization and precise classification and has the characteristics of small median particle diameter and narrow granularity distribution range; the stability of the wearing resistance and polishing precision is easy to control; and the quality of a product has small fluctuation.

Description

technical field [0001] The invention relates to a rare earth polishing powder and a preparation method thereof, more precisely, to a rare earth polishing powder with small median particle size, narrow particle size distribution and high precision and a preparation method thereof. Background technique [0002] Rare earth polishing powder is used for polishing lenses, flat glass, glass bulbs, glasses, watch cases, etc. It has the characteristics of fast polishing speed and high precision. Since the invention of rare earth polishing powder in the 1940s, the production volume and application volume have gradually increased. The production process of rare earth polishing powder has changed with the progress of rare earth separation process. In recent years, with the rapid development of the information industry, liquid crystal displays, flat-panel displays, optical components, etc. have more and more demands for polishing powder, and the requirements for polishing precision are ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09G1/02C09K3/14
Inventor 高玮陈曦赵月昌吴秋芳杨筱琼
Owner 上海华明高纳稀土新材料有限公司
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