阅读说明：本技术 一种高纯锂长石的制备方法 (Preparation method of high-purity lithium feldspar ) 是由 崔月华 张向华 刘潇 兰晓松 钟育其 刘明 于 2020-05-20 设计创作，主要内容包括：本发明属于矿物原料合成技术领域,具体公开了一种高纯锂长石的制备方法,包括如下步骤：将锂盐、铝盐、四乙氧基硅烷分别溶于溶剂中,形成溶液1、溶液2、溶液3；然后将溶液1、溶液2、溶液3混合,搅拌均匀,形成溶液4；将(NH<Sub>4</Sub>)<Sub>2</Sub>CO<Sub>3</Sub>盐溶于水中,加入氨水,形成溶液5；将溶液4和溶液5混合反应得到呈凝胶状态的沉淀,将沉淀干燥后得到锂长石前驱体,最后将前驱体焙烧得到锂长石。本方法在特定条件下形成胶体,无需过滤洗涤等繁杂的纯化步骤,即可在较低温度下焙烧生成基本没有杂离子的高纯度锂长石,步骤简单,反应条件容易控制,生产效率高,适用于工业化生产。(The invention belongs to the technical field of mineral raw material synthesis, and particularly discloses a preparation method of high-purity lithium feldspar, which comprises the following steps: respectively dissolving lithium salt, aluminum salt and tetraethoxysilane in a solvent to form a solution 1, a solution 2 and a solution 3; then mixing the solution 1, the solution 2 and the solution 3, and uniformly stirring to form a solution 4; will be (NH) 4 ) 2 CO 3 Dissolving salt in water, and adding ammonia water to form a solution 5; and mixing the solution 4 and the solution 5 for reaction to obtain a precipitate in a gel state, drying the precipitate to obtain a lithium feldspar precursor, and finally roasting the precursor to obtain the lithium feldspar. The method forms colloid under specific conditions, complex purification steps such as filtering and washing are not needed, the high-purity lithium feldspar basically free of the impurity ions can be generated by roasting at a lower temperature, the steps are simple, the reaction conditions are easy to control, the production efficiency is high, and the method is suitable for industrial production.)

1. The preparation method of the high-purity lithium feldspar is characterized by comprising the following steps of:

(1) respectively dissolving lithium salt, aluminum salt and tetraethoxysilane in a solvent to form a solution 1, a solution 2 and a solution 3;

(2) mixing the solution 1, the solution 2 and the solution 3, and uniformly stirring to form a solution 4;

(3) will (NH4)₂CO₃Dissolving salt in water, and adding ammonia water to form a solution 5;

(4) and mixing the solution 4 and the solution 5 for reaction to obtain a precipitate in a gel state, drying the precipitate to obtain a lithium feldspar precursor, and finally roasting the precursor to obtain the lithium feldspar.

2. The method of claim 1, wherein: in the step (1), the molar ratio of the lithium salt to the aluminum salt to the tetraethoxysilane is (0.1-1) to (0.2-1) to (4-5).

3. The method of claim 1, wherein: in the step (1), the lithium salt is selected from LiNO₃At least one of LiCl and lithium oxalate;

and/or, in the step (1), the aluminum salt is selected from AlCl₃·6H₂O、Al(NO₃)₃·9H₂At least one of O.

4. The method of claim 1, wherein: in the step (1), the solvent for dissolving the lithium salt is at least one selected from water, ethanol and acetone;

and/or, in the step (1), the solvent for dissolving the lithium salt is at least one selected from water and ethanol;

and/or in the step (1), the solvent for dissolving the tetraethoxysilane is a mixed solution consisting of water, ethanol and a nitric acid aqueous solution.

5. The method of claim 4, wherein: in the nitric acid aqueous solution, the mass ratio of nitric acid to water is (0.01-0.1) to 2.

6. The method of claim 1, wherein: in the solution 1 in the step (1), the concentration of lithium salt is not higher than the saturated concentration of lithium salt in the solvent;

and/or, in the solution 2 in the step (1), the concentration of the aluminum salt is not higher than the saturation concentration of the aluminum salt in the solvent;

and/or, in the solution 3 in the step (1), the volume ratio of the tetraethoxysilane to the solvent is (1-2) to (1.5-5).

7. The method of claim 1, wherein: in the step (3), the dosage of ammonia water is 9-20 ml;

and/or, in the solution 5 in the step (3), (NH)₄)₂CO₃The concentration of the salt is not higher than its saturation concentration in the solvent.

8. The method of claim 1, wherein: in the step (4), the drying temperature is 50-80 ℃, and the drying time is 6-24 h;

and/or, in the step (4), the roasting temperature is 550-800 ℃.

9. The lithium feldspar prepared by the preparation method according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of mineral raw material synthesis, in particular to a preparation method of high-purity lithium feldspar.

Background

The lithionite is an added mineral substance which is widely applied to preparing ceramics, the lithionite has the main properties of low thermal expansibility and the like required by a heat-resistant ceramic pot, and spodumene is adopted as a main raw material to produce the heat-resistant ceramic pot at home at present. The development and production of the daily heat-resistant ceramic pot in China begin at the beginning of 90 years in the 20 th century. The product has excellent low thermal expansion, thermal shock resistance, heat resistance and high-temperature chemical stability, and is widely applied to families and heat-resistant tableware industries for catering as a fine ceramic cooker. The raw spodumene ore is imported mainly from Australia, and in recent years, the price of the spodumene rises rapidly due to rapid development of new energy lithium batteries (spodumene is the main raw material) and monopoly and stir-frying of foreign suppliers, so that the raw material cost of the heat-resistant ceramic pot is continuously increased. In addition, spodumene is a chain silicate mineral, and α -spodumene in a low temperature state is converted into β -spodumene stable at a high temperature during firing, and may cause deformation of products or the like with about 30% volume expansion. Therefore, spodumene must be calcined at about 1100 ℃ prior to use, which also increases energy consumption and cost of product production. Therefore, the method for producing the lithium heat-resistant ceramic by adopting petalite with more abundant mineral sources as a main raw material is an effective measure for solving the problems of raw material shortage and high production cost in the industry.

Therefore, the high-purity lithium feldspar is one of the materials with significance in theoretical research and practical production. However, the existing preparation method of the lithionite has the disadvantages of large equipment investment, high production cost, easy introduction of impurity ions in the production process and low production efficiency.

Disclosure of Invention

In view of the above disadvantages of the prior art, the present invention aims to provide a method for preparing high purity petalite, which is used for solving the problems of the prior art that the reaction conditions of the method for preparing the petalite are harsh, the industrial production is difficult to realize, the raw material loss is serious, the environment is polluted, etc.

In order to achieve the above objects and other related objects, the present invention provides a method for preparing high purity petalite, comprising the steps of:

(1) respectively dissolving lithium salt, aluminum salt and tetraethoxysilane in a solvent to form a solution 1, a solution 2 and a solution 3;

(2) mixing the solution 1, the solution 2 and the solution 3, and uniformly stirring to form a solution 4;

(3) will be (NH)₄)₂CO₃Dissolving salt in water, and adding ammonia water to form a solution 5;

(4) and mixing the solution 4 and the solution 5 for reaction to obtain a precipitate in a gel state, drying the precipitate to obtain a lithium feldspar precursor, and finally roasting the precursor to obtain the lithium feldspar.

Further, in the step (1), the molar ratio of the lithium salt to the aluminum salt to the tetraethoxysilane is (0.1-1): (0.2-1):

further, in the step (1), the lithium salt is selected from LiNO₃At least one of LiCl and lithium oxalate.

Further, in the step (1), the aluminum salt is selected from AlCl₃·6H₂O、Al(NO₃)₃·9H₂At least one of O.

Further, in the step (1), the solvent for dissolving the lithium salt is at least one selected from water, ethanol, and acetone.

Further, in the step (1), the solvent for dissolving the aluminum salt is at least one selected from water and ethanol.

Further, in the step (1), the solvent for dissolving tetraethoxysilane is a mixed solution composed of water, ethanol and a nitric acid aqueous solution.

Preferably, the mass ratio of the nitric acid to the water in the nitric acid aqueous solution is (0.01-0.1): 2.

Further, in the solution 1 in the step (1), the concentration of the lithium salt is not higher than the saturation concentration of the lithium salt in the solvent. If the concentration exceeds the saturation concentration, the solution cannot be completely dissolved, and thus a precipitate cannot be uniformly formed.

Further, in the solution 2 of the step (1), the concentration of the aluminum salt is not higher than the saturation concentration thereof in the solvent. If the concentration exceeds the saturation concentration, the solution cannot be completely dissolved, and thus a precipitate cannot be uniformly formed.

Further, in the solution 3 described in the step (1), the volume ratio of tetraethoxysilane to solvent is (1-2): (1.5-5).

Furthermore, in the step (3), the dosage of ammonia water is 9-20 ml.

Further, in the solution 5 described in the step (3), (NH)₄)₂CO₃The concentration of the salt is not higher than its saturation concentration in the solvent.

Further, in the step (4), the drying temperature is 50-80 ℃, and the drying time is 6-24 h.

Further, in the step (4), the calcination temperature is 550-800 ℃.

The invention also provides the lithium feldspar prepared by the preparation method.

As described above, the method for preparing high-purity lithium feldspar according to the present invention has the following beneficial effects:

the method adopts a liquid phase precipitation method, firstly forms colloid under specific conditions, then calcines the colloid at a lower temperature to generate the lithium feldspar basically without impurity ions, complex purification steps such as filtering and washing are not needed, the operation steps are simple, the reaction conditions are easy to control, and the problems that the existing lithium feldspar preparation method is large in equipment investment, high in production cost, low in production efficiency, low in pollution and the like, and impurity ions are easily introduced in the production process are solved. The invention can be applied to industrial scale production and has a higher application prospect.

Drawings

FIG. 1 is a schematic diagram showing a gel-state precipitate obtained by mixing solution 4 and solution 5 in the above example.

FIG. 2 is a schematic diagram of the lithium feldspar obtained after calcination in the above example.

Fig. 3 shows an X-ray diffraction (XRD) pattern of the lithium feldspar product obtained in the above example.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

In the following examples, TEOS refers to tetraethoxysilane.