Preparation method for high purity magnesium oxide powder

A magnesium oxide powder, high-purity technology, applied in magnesium oxide and other directions, can solve the problems of poor light transmission of MgO film, affecting the deposition and growth of MgO film, low secondary electron emission coefficient, etc., and achieves easy mass production. , low cost, simple and easy to implement effect

Active Publication Date: 2012-04-04
有研资源环境技术研究院(北京)有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The existence of metal ions leads to poor light transmission and low secondary electron emission coefficient of MgO film, which seriously affects the deposition and growth of MgO film. Therefore, it is necessary to separate these impurity ions

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] Weigh a certain amount of commercially available MgCl 2 ·6H 2 O raw material, the magnesium chloride solution 5L of preparation 2mol / L, through measuring its main impurity ion content by atomic emission spectrometry is: [Ca 2+ ]=0.006mol / l, [Fe 2+ ]=0.002mol / l, [Al 3+ ]=0.1mol / l, [Si 4+ ] = 0.1 mol / l.

[0039] According to the dissolution equilibrium principle, the initial precipitation pH value of the main impurity ions and Mg ions was calculated by using the solubility product data of different ion hydroxides. After calculation, the initial precipitation pH value of each ion is shown in Table 3.

[0040] Table 3. The initial precipitation pH value of each ion

[0041] ion

[0042] To MgCl 2 Add NH to the solution 3 ·H 2 0, adjust the pH value of the solution to 7.8~8.3, as can be seen from Table 2, Fe, Al, Si impurity ions precipitate; fully stir, after the pH value of the solution is stable, filter, and the filtrate is for use; the filter cake is d...

Embodiment 2

[0050] Weigh a certain amount of commercially available MgCl 2 ·6H 2 O raw material, its main impurity ion content after determination is: [Ca 2+ ]=0.01mol / l, [Fe 2+ ]=0.0026mol / l, [Al 3+ ]=0.15mol / l, [Si 4+ ] = 0.1 mol / l. Prepare 10L of 3mol / L magnesium chloride solution with deionized water, and divide the solution into 2 parts;

[0051] According to the dissolution equilibrium principle, the initial precipitation pH value of the main impurity ions and Mg ions was calculated by using the solubility product data of different ion hydroxides. After calculation, the initial precipitation pH value of each ion is shown in Table 5.

[0052] Table 5. The initial precipitation pH value of each ion

[0053] ion

[0054]Add ammonia water to the first part, adjust the pH between 8 and 8.5, stir, Fe, Al, and Si impurity ions precipitate, let stand for 24 hours, filter, and the filtrate is ready for use; dissolve 200g of ammonium oxalate in 1.4L of deionized water , to g...

Embodiment 3

[0060] Using the raw materials used in Example 2, 10 L of 3 mol / L magnesium chloride solution was prepared with deionized water, and the solution was equally divided into 2 parts.

[0061] Add ammonia water to the first part, adjust the pH between 8 and 8.5, stir, let stand for 24 hours and then filter to remove Fe, Al, Si ions, and the filtrate is set aside; dissolve 40g of ammonium oxalate in 300ml of deionized water to prepare 1mol / l ammonium oxalate solution, add the ammonium oxalate solution into the filtrate (the molar ratio of ammonium oxalate to magnesium chloride is 1:100), stir well, and filter after standing for 24 hours; adjust it into ammonium carbonate with ammonia water and ammonium bicarbonate solution, according to CO 3 2- Excessive 5% to 30%, add to the filtrate, neutralize the precipitate, and control the pH value between 10 and 11.5; wash and filter, put the filter cake in an oven to keep a constant temperature of 120°C for drying, and dry to obtain magnes...

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PUM

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Abstract

The present invention relates to a preparation method for high purity magnesium oxide powder, and belongs to the field of hydrometallurgy. The preparation method comprises the following steps: dissolving magnesium chloride by deionized water to prepare a magnesium chloride solution; according to the dissolution equilibrium principle, calculating precipitation starting pH values of various impurity ions, and determining the precipitation pH value ranges of the impurity ions of Fe, Al, and Si; adding an alkaline reagent, adjusting the pH value, neutralizing the precipitation, and filtering to remove the impurities such as Fe, Al, Si, and the like, wherein the filtrate is provided for a spare use; adding an alkaline reagent to the filtrate, neutralizing the precipitation of Mg, filtering andseparating to obtain the filter cake; placing the filter cake in an oven, holding a constant temperature of 120 DEG C, and carrying out drying to obtain Mg (OH) 2; carrying out calcination for 3 hours at the constant temperature of 920 DEG C, and carrying out crushing and screening to obtain the MgO powder. According to the present invention, the method of the present invention has characteristics of simpleness, easy batch production and low cost; the metal impurity ions in the prepared MgO powder meet the requirements of the PDP medium layer to the purity of the MgO material, and the high purity magnesium oxide powder of the present invention can be used for preparation of the MgO optical coating material.

Description

technical field [0001] The invention relates to a preparation method of high-purity magnesium oxide powder. The method of the invention has low cost and belongs to the field of hydrometallurgy. The powder prepared by the invention can be used to prepare the MgO optical coating material used for the medium layer thin film of PDP (plasma display screen). Background technique [0002] At present, there are many preparation methods for MgO, and there are related preparation studies on high-purity MgO, but there is no report on the separation of specific impurity ions for PDP. At present, high-purity MgO is rarely obtained in China, and mass production has not been realized. For the preparation of MgO coating material for PDP abroad, relevant studies on purity control have been carried out, but MgCl 2 There is no public report for the relevant purification technology of the raw material. The sensitive impurities in the MgO material for PDP are mainly metal impurity ions Ca, Si...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F5/08
Inventor 王星明何芬段华英张碧田储茂友石志霞孙静韩沧
Owner 有研资源环境技术研究院(北京)有限公司
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