CN111410203B

CN111410203B - Method for synthesizing pyrophyllite by utilizing leucite

Info

Publication number: CN111410203B
Application number: CN202010233863.9A
Authority: CN
Inventors: 刘梅堂; 马鸿文; 姚文贵; 王启凯
Original assignee: Zhongshan Qingrong Jiachuang Energy Technology Co ltd
Current assignee: Zhongshan Qingrong Jiachuang Energy Technology Co ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2023-07-21
Anticipated expiration: 2040-03-27
Also published as: CN111410203A

Abstract

A method for synthesizing pyrophyllite by using leucite. Mixing leucite powder with sulfuric acid solution, performing hydrothermal reaction for 12-72 hours at the temperature of 180-250 ℃, filtering, washing, and drying the obtained solid phase product at the temperature of 100+/-5 ℃ to obtain pyrophyllite powder. The invention takes leucite and sulfuric acid as raw materials to synthesize the pyrophyllite, fully utilizes aluminum and silicon components in the leucite, has simple process in the whole process, can meet the modern industrial requirements of high-efficiency energy-saving and clean production of '100% of resource utilization rate' and 'zero emission of three wastes', and is easy to realize industrial production.

Description

Method for synthesizing pyrophyllite by utilizing leucite

Technical Field

The invention belongs to the technical field of mineral resource processing and utilization, and particularly relates to a method for preparing pyrophyllite powder by using leucite.

Background

The theoretical composition of leucite is K [ AlSi ] ₂ O ₆ ]Tetragonal, often pseudo-equiaxed. The space group is C ⁶ _4h -I4/a；a ₀ ＝1.304nm，c ₀ =1.385 nm, z=16. Its theoretical composition (w) _B ％)：Al ₂ O ₃ 23.4％，SiO ₂ 55.02％，K ₂ O21.58%. The main rock-making minerals in the rocks such as leucite, leucite basalt, leucite coarse rock and the like are usually in the form of banners. Often intergrowth with spodumene and nepheline.

The pyrophyllite theory composition is Al ₂ [Si ₂ O ₁₀ ](OH) ₂ There are two types of polytypes. Monoclinic (2M) is more common. The space group is C ⁶ _2h -C2/c；a ₀ ＝0.515nm，b ₀ ＝0.892nm，c ₀ =1.895 nm, β=99.55 °; z=2. Triclinic system(1Tc)，C ¹ _i -P1；a ₀ ＝0.5173nm，b ₀ ＝0.8960nm，c ₀ =0.9360 nm, α=91.2°, β=100.4°, γ=90°, z=2. Theoretical chemical composition (w) _B ％)：Al ₂ O ₃ 28.3％，SiO ₂ 66.7％，H ₂ O5.0%. The structural unit layer is formed by sandwiching a layer of an octahedral layer of aluminum hydroxide between two layers of silicon oxygen tetrahedral layers to form a 2:1 layered structure. 2/3 of the octahedra are coated with Al ³⁺ Occupancy (M) ₁ ) The other 1/3 of the octahedral sites are vacancies (M ₂ ). Pyrophyllite has good chemical stability and thermal insulation, and can be used for ceramic materials and refractory materials. Meanwhile, the pyrophyllite has low hardness, slidability, good covering power and adsorptivity, and is used for filling materials and carriers in the industries of papermaking, rubber, paint, chemical industry, pesticide coating and the like.

Pyrophyllite is the main raw material in the glass fiber industry, and the cost of the pyrophyllite is about 50% of the raw material in the glass fiber industry. The demand of the domestic glass fiber enterprises for pyrophyllite raw materials is increased to more than 200 ten thousand tons in 2018, but the high-quality medium-quality aluminum pyrophyllite is tense in resources, and the method becomes a main reason for restricting the cost control of the glass fiber industry.

Disclosure of Invention

The invention aims to provide a method for synthesizing pyrophyllite by utilizing leucite. The method takes leucite powder and sulfuric acid solution as raw materials, and synthesizes pyrophyllite by a hydrothermal method. The method has the advantages of simple and easy process, high resource utilization rate, no three-waste emission, higher added value and good economic benefit.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a method for synthesizing pyrophyllite by using leucite, comprising the following steps:

I. uniformly mixing leucite powder, sulfuric acid and water according to the mass ratio of 1: (0.2-1.5) to (10-50) to form slurry;

II, placing the slurry uniformly mixed in the step I into a stainless steel reaction kettle with a polytetrafluoroethylene lining, and performing hydrothermal reaction at 180-250 ℃ for 12-72 hours;

III, placing the reaction kettle in the step II in cold water for rapid cooling, and performing solid-liquid separation on the obtained slurry to obtain filtrate and a filter cake;

and IV, washing the filter cake obtained in the step III until the pH value of the washing liquid is 9-10, and drying the filter cake to obtain pyrophyllite powder.

Preferably, the purity of the leucite in the leucite powder is > 90wt% and the granularity-200 mesh is > 95%.

Preferably, the hydrothermal reaction temperature of the step II is 180-220 ℃ and the reaction time is 12-24 hours.

In the above-described method, preferably, the washing liquid obtained by washing in the step IV is used in the step I instead of water for recycling.

The sulfuric acid in step I may preferably be replaced by other strong mineral acids, in the process described above.

Preferably, the filter cake in the step IV is dried for 6 to 12 hours at the temperature of 95 to 105 ℃ to prepare pyrophyllite powder.

The main reactions of the invention are:

the method has the beneficial effects that the method adopts a hydrothermal method, solid-liquid separation is carried out after the reaction is finished, a filter cake is obtained, and a pyrophyllite product can be obtained after drying, wherein the pyrophyllite content exceeds 90%, and the method has good quality and is a superior raw material in the glass fiber industry. The filtrate can be concentrated to be used for processing potassium salt products. The invention fully utilizes the silicon, aluminum and potassium components in the leucite, has high resource utilization rate, no three-waste discharge, simple process, mild reaction condition and low cost, and has good economic benefit. On the one hand, the method can effectively expand the industrial application of the leucite minerals, and more importantly, can effectively relieve the current situation of high-quality pyrophyllite resource shortage caused by the rapid development of the glass fiber industry in China.

Drawings

FIG. 1 is an X-ray powder diffraction pattern of the leucite starting material and synthetic pyrophyllite powder in example 1.

Detailed Description

Example 1

The X-ray powder diffraction pattern analysis of the garnet powder produced in a certain place in Fujian used in example 1 is shown in FIG. 1, and the chemical composition analysis results are shown in Table 1. As can be seen from FIG. 1, all diffraction peaks of the raw material correspond to a leucite PDF standard card (JCPDS: 81-2222), and the consistency is good. And the component analysis result is matched with the theoretical composition of the leucite, and the purity of the leucite is more than 90 percent.

TABLE 1 chemical composition analysis results (w _B ％)

Accurately weighing 6g of leucite powder (the chemical component analysis result is shown in Table 1), firstly diluting 98wt% sulfuric acid with distilled water to 1.5mol/kg, mixing and stirring uniformly, then placing the mixture into a stainless steel reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal reaction for 18h at 220 ℃, immediately taking out the reaction kettle, placing the reaction kettle into cold water for rapid cooling, carrying out solid-liquid separation after opening the kettle, washing a filter cake with distilled water until the pH value of the filtrate is 9-10, and finally drying at 95-105 ℃ for 6h to obtain the leucite. The X-ray powder diffraction pattern of the obtained pyrophyllite is shown in figure 1. The results of the component analysis are shown in Table 2.

TABLE 2 analysis of chemical Components of synthetic pyrophyllite powder (w _B ％)

According to XRD results, all diffraction peaks of the obtained powder are well matched with a PDF standard card (JCPDS: 75-0856) of pyrophyllite, and the impurity peaks are few. The pyrophyllite product with good crystallization degree can be successfully synthesized through acidic hydrothermal conditions in the embodiment. And the analysis result of chemical components shows that the obtained pyrophyllite is a medium-high alumina pyrophyllite product, and meets the index requirement of glass fiber enterprises on the pyrophyllite.

Example 2

The analysis results of chemical components of garnet powder produced in a certain place of Zhejiang used in the example are shown in table 3, and the components are relatively consistent with the theoretical composition of garnet, and the purity of garnet is above 95%.

TABLE 3 analysis results of chemical composition of leucite powder (w _B ％)

Accurately weighing 8g of leucite powder, firstly diluting 98wt% sulfuric acid with distilled water to a concentration of 1.5mol/kg, mixing and stirring the leucite powder and the sulfuric acid solution uniformly, then placing the mixture into a stainless steel reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal reaction for 24 hours at 200 ℃, immediately taking out the reaction kettle, placing the reaction kettle into cold water for rapid cooling, carrying out solid-liquid separation after opening the kettle, washing a filter cake with distilled water until the pH value of the filtrate is 9-10, and finally drying the filter cake at 95-105 ℃ for 8 hours to obtain the leucite. The results of the component analysis are shown in Table 4.

TABLE 4 chemical composition analysis results (w) _B ％)

From table 4, it can be seen that the pyrophyllite product successfully synthesized by acidic hydrothermal conditions belongs to a medium-high alumina pyrophyllite product, and meets the index requirements of glass fiber enterprises on pyrophyllite.

Claims

1. A method for synthesizing pyrophyllite by using leucite, which is characterized by comprising the following steps:

2. The method according to claim 1, characterized in that the purity of the leucite in the leucite powder is > 90wt%, the particle size-200 mesh > 95%.

3. The process according to claim 1, wherein the hydrothermal reaction temperature of step II is 180 to 220 ℃ and the reaction time is 12 to 24 hours.

4. The process according to claim 1, wherein the washing liquid obtained in step IV is used in step I instead of water for recycling.

5. The method according to claim 1, wherein the sulfuric acid in step I is replaced by other strong mineral acids.

6. The method according to any one of claims 1 to 5, wherein the filter cake in step IV is dried at 95 to 105 ℃ for 6 to 12 hours to produce pyrophyllite powder.