阅读说明：本技术 一种高温高压下合成含水斜长石固溶体的方法 (Method for synthesizing water-containing plagioclase under high temperature and high pressure ) 是由 胡海英 代立东 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种高温高压下合成含水斜长石固溶体的方法,它包括：根据斜长石固溶体中钠长石和钙长石的摩尔比为4：1,分别称出钠长石和钙长石化学计量比对应重量的初始原料,并用玛瑙研钵在酒精中研磨混合均匀后在烘箱中干燥；高温下斜长石玻璃合成；将装有斜长石玻璃的铂金坩埚在压片机上把斜长石玻璃粉碎后,放入高频振动球磨机,研磨成颗粒均匀的粉末,之后放入烘箱中烘干；子母紫铜管制备；含水样品组装；高温高压合成组装；把组装块放置在六面顶大压机上在高温高压条件下进行含水样品合成得到成品；解决了现有技术合成含水斜长石固溶体时合成技术样品尺寸受限,样品水含量控制不精,实验成本较高等技术问题。(The invention discloses a method for synthesizing a water-containing plagioclase solid solution at high temperature and high pressure, which comprises the following steps: according to the molar ratio of albite to anorthite in the anorthite solid solution of 4: 1, weighing initial raw materials of albite and anorthite in stoichiometric ratio and corresponding weight respectively, grinding and uniformly mixing the raw materials in alcohol by using an agate mortar, and drying the mixture in an oven; synthesizing plagioclase feldspar glass at high temperature; crushing plagioclase glass in a platinum crucible filled with plagioclase glass on a tablet press, putting the plagioclase glass into a high-frequency vibration ball mill, grinding the plagioclase glass into powder with uniform particles, and then putting the powder into an oven for drying; preparing a primary and secondary copper tube; assembling an aqueous sample; high-temperature high-pressure synthesis and assembly; placing the assembly block on a cubic apparatus press, and synthesizing a water-containing sample under the conditions of high temperature and high pressure to obtain a finished product; the method solves the technical problems that the size of a synthetic technology sample is limited, the water content of the sample is not accurately controlled, the experiment cost is high and the like when the water-containing plagioclase feldspar solid solution is synthesized in the prior art.)

1. A method for synthesizing a water-containing plagioclase solid solution at high temperature and high pressure comprises the following steps:

step 1, according to albite (NaAlSi) in the anorthite solid solution₃O₈) And anorthite (CaAl)₂Si₂O₈) Respectively weighing Al as the initial raw materials in the stoichiometrical ratio of albite and anorthite₂O₃、SiO₂、Na₂CO₃、CaCO₃The oxide powder is ground and mixed evenly in alcohol by an agate mortar, and then dried in an oven at 200 ℃;

step 2, synthesizing plagioclase glass at high temperature: pressing the mixture powder obtained in the step 1 into a cylinder with the diameter of 13 multiplied by 2mm, placing a sample in a platinum crucible, and placing the platinum crucible in a high-temperature furnace for decarbonization reaction to obtain the anorthite glass at high temperature;

step 3, crushing plagioclase glass in a platinum crucible filled with plagioclase glass on a tablet press, putting the plagioclase glass into a high-frequency vibration ball mill, grinding the plagioclase glass into powder with uniform particles, and then putting the powder into an oven for drying; the particle size is 5-10 μm;

step 4, preparing the primary and secondary copper tubes: preparing a first red copper inner tube with the inner diameter of 6mm, the wall thickness of 0.5mm, the height of 12mm and the bottom thickness of one end of 0.5; preparing a red copper outer tube II with the inner diameter of 7.05mm, the wall thickness of 0.5mm, the height of 12.5mm and the bottom thickness of one end of 0.5 mm;

step 5, assembling a water-containing sample: rolling a gold foil with the thickness of 0.05mm into a tube, placing the tube into the first red copper inner tube, placing a gold foil wafer with the same thickness at the bottom of the tube, placing the plagioclase feldspar glass powder prepared in the step 3 into the red copper inner tube prepared in the step 4, adding distilled water or deionized water into the solution transfer gun, compacting sample powder, and sealing the sample powder by using the gold foil wafer; the red copper outer pipe II with the inner diameter of 7.05mm prepared in the step 4 and the red copper inner pipe I filled with the sample are reversely buckled, and the interface of the two copper pipes is sealed by a laser welding machine;

step 6, high-temperature high-pressure synthesis and assembly: placing the sealed copper tube in the step 5 in a high-temperature high-pressure assembly block with the periphery composed of an h-BN tube and an h-BN plug pressure transmission medium;

step 7, placing the assembly block on a cubic apparatus large press, and synthesizing a water-containing sample under the conditions of high temperature and high pressure;

and 8, after the step 7 is finished, turning off the heating current, quenching and cooling, and then slowly reducing the pressure to the normal temperature to obtain a finished product.

2. The method for synthesizing the aqueous plagioclase solid solution at high temperature and high pressure as claimed in claim 1, wherein: the method for decarbonization reaction in the high-temperature furnace comprises the following steps: decarbonizing at 1000-1200 deg.c for 10-12 hr, raising the temperature to 1600 deg.c to melt the mixture into glass state and lowering the temperature to room temperature; the high-temperature furnace is a closed high-temperature furnace.

3. The method for synthesizing the aqueous plagioclase solid solution at high temperature and high pressure as claimed in claim 1, wherein: the drying method in the oven in the step 3 comprises the following steps: drying in a drying oven at 100 ℃ for two hours; after drying, the sample is dried in an oven until the sample is assembled and taken out.

4. The method for synthesizing the aqueous plagioclase solid solution at high temperature and high pressure as claimed in claim 1, wherein: the method for synthesizing the water-containing sample under the conditions of high temperature and high pressure in the step 7 comprises the following steps: carrying out water-containing sample synthesis at the temperature of 1100-1200 ℃ and under the pressure of 1-2 GPa; the reaction time is 6-10 h.

5. The method for synthesizing the aqueous plagioclase solid solution at high temperature and high pressure as claimed in claim 1, wherein: the high-temperature high-pressure synthesis and assembly method comprises the following steps:

step 6.1, manufacturing an h-BN pipe: processing an h-BN rod with the diameter of 11mm into an h-BN pipe with the inner diameter of phi 8mm and the outer diameter of phi 11mm on a lathe, then polishing the inner diameter by using abrasive paper, putting sealed red copper filled with a sample into the h-BN pipe, and plugging two ends by using h-BN wafers with the diameters of phi 11mm and the thicknesses of 2 mm;

step 6.2, manufacturing a heater: processing a graphite heating furnace with the inner diameter of phi 11mm, the outer diameter of 13mm and the height of 32.5mm on a lathe;

step 6.3, processing pyrophyllite: selecting a cubic pyrophyllite block with the side length of 32.5mm, and punching a circular through hole with the diameter of phi 13mm in the center;

step 6.4, assembling: placing a graphite heating furnace in a pyrophyllite block, then placing a red copper sealing tube filled with a sample into a boron carbide tube, placing the red copper sealing tube and the boron carbide tube together in the graphite heating furnace, and respectively sealing two ends of the red copper sealing tube and the boron nitride plug and the pyrophyllite plug in sequence;

and 6.5, drilling a small hole in the middle of the edge of the pyrophyllite block, and placing a thermocouple capable of directly contacting a sample copper pipe for accurately controlling the experiment temperature.

6. The method for synthesizing the aqueous plagioclase solid solution at high temperature and high pressure as claimed in claim 1, wherein: it still includes:

step 9, taking out the sample in the step 8, cutting the copper tube by using a diamond wire cutting machine, taking out the sample, polishing the surface of the sample to form a cylinder, and measuring the related physical properties;

step 10, performing powder XRD measurement on the sample obtained in the step 9, analyzing and comparing obtained results, and determining that the sample is anorthite crystal, is a triclinic system and has a space group of C- ī;

and step 10, cutting the obtained sample into a slice, polishing the two sides of the slice to obtain a sample with the thickness of 300 mu m, and then measuring the water content and the distribution of the sample by using a Fourier infrared spectrometer, wherein the result shows that the sample has a characteristic peak of the structural water and is uniformly distributed.

7. The method for synthesizing the aqueous plagioclase solid solution at high temperature and high pressure as claimed in claim 1, wherein: and 5, when distilled water or deionized water is added by using a pipette, the amount of water is as follows: 0.1-0.5. mu.l.

Technical Field

The invention belongs to the field of geochemical research of high-temperature and high-pressure experiments, and particularly relates to a method for synthesizing a water-containing plagioclase feldspar solid solution at high temperature and high pressure.

Background

Plagioclase is the main nominally anhydrous mineral of the crust, usually containing small amounts of OH and H₂Structural water in the form of O, the content of which is from tens to thousands of ppm. The presence of water not only affects the physical and chemical properties of plagioclase, such as mechanical, elastic, electrical, thermal, elementsDiffusion of elements, order/disorder of Al/Si and the like, and the water-containing plagioclase has important significance for researching the circulation of underground crust water, the formation and evolution of the crust, the stability of a rock ring and rheological results.

The water content range of the natural plagioclase is limited, and the water content changes often depending on factors such as temperature, pressure and oxygen fugacity. If the natural sample is adopted to research the correlation between the water content and the physical properties and chemical behaviors of plagioclase, the research may be limited by the limited water content change in the natural sample, and the accuracy and credibility for carrying out the research work are difficult to ensure. The experimental synthesis of plagioclase with different water contents is an effective method for solving the problem. At present, the water-containing synthesis experiment of nominal anhydrous mineral mainly adopts the following two modes: (1) talc and brucite as water sources; the two kinds of water-containing minerals are added to both ends of the sample, and the water fluid released by their dehydration reaction at high temperature and high pressure is diffused into the sample, thereby synthesizing the water-containing sample. The water content of the synthesized sample is changed by adjusting the weight ratio of the talc to the brucite to control the content of water fluid released after dehydration of the talc and the brucite. (2) Distilled water or deionized water is used as a water source; adding a certain amount of distilled water into a metal tube filled with a sample, welding the metal tube, and allowing free water to diffuse into crystal lattices of the sample under high temperature and high pressure. Method (1) since the entry of water into the sample is by dehydration diffusion at high temperature of talc and brucite, the water content at both ends of the sample directly contacting the talc and brucite may be higher than in the middle of the sample, resulting in non-uniformity of water content in the longitudinal section of the sample. Thus, the method is limited to the synthesis of smaller aqueous samples, meaning that the size of the aqueous sample can be limited. The method (2) uses water fluid as a water source, the amount of water added in the sample assembling process is easy to calculate accurately, the added water can be uniformly distributed around the sample particles, the water content in the synthesized sample can be uniformly distributed, and the size of the synthesized sample is not limited. The method adopts a single-bag or double-bag metal tube (a gold tube or a platinum tube) to package a sample, the wall of the metal tube is usually thin, the sample tube is easy to be sealed untight in the welding process, and water in the sample leaks in the high-temperature high-pressure synthesis process. Meanwhile, the metal pipe may be welded through during the laser welding and sealing process, so that the water in the sample is evaporated and lost at high temperature, and the water content in the synthesized sample is difficult to ensure to be a target value. In addition, the cost of the gold tube or the platinum tube is high, the size needs to be customized, the processing period is long, and the like.

In summary, the existing methods for artificially synthesizing water-containing samples have certain disadvantages, such as too small synthesis size, inaccurate control of water content in the synthesized samples, high experiment cost, and the like.

The invention content is as follows:

the technical problem to be solved by the invention is as follows: the method for synthesizing the water-containing plagioclase under high temperature and high pressure is provided, and the technical problems that the size of a synthetic technology sample is limited, the water content of the sample is not accurately controlled, the experiment cost is high and the like in the synthesis of the water-containing plagioclase in the prior art are solved. The technical scheme of the invention is as follows:

a method for synthesizing a water-containing plagioclase solid solution at high temperature and high pressure comprises the following steps:

step 1, according to albite (NaAlSi) in the anorthite solid solution₃O₈) And anorthite (CaAl)₂Si₂O₈) Respectively weighing Al as the initial raw materials in the stoichiometrical ratio of albite and anorthite₂O₃、SiO₂、Na₂CO₃、CaCO₃The oxide powder is ground and mixed evenly in alcohol by an agate mortar, and then dried in an oven at 200 ℃;

step 2, synthesizing plagioclase glass at high temperature: pressing the mixture powder obtained in the step 1 into a cylinder with the diameter of 13 multiplied by 2mm, placing a sample in a platinum crucible, and placing the platinum crucible in a high-temperature furnace for decarbonization reaction to obtain the anorthite glass at high temperature;

step 3, crushing plagioclase glass in a platinum crucible filled with plagioclase glass on a tablet press, putting the plagioclase glass into a high-frequency vibration ball mill, grinding the plagioclase glass into powder with uniform particles, and then putting the powder into an oven for drying; the particle size is 5-10 μm;

step 4, preparing the primary and secondary copper tubes: preparing a first red copper inner tube with the inner diameter of 6mm, the wall thickness of 0.5mm, the height of 12mm and the bottom thickness of one end of 0.5; preparing a red copper outer tube II with the inner diameter of 7.05mm, the wall thickness of 0.5mm, the height of 12.5mm and the bottom thickness of one end of 0.5 mm;

step 5, assembling a water-containing sample: rolling a gold foil with the thickness of 0.05mm into a tube, placing the tube into the first red copper inner tube, placing a gold foil wafer with the same thickness at the bottom of the tube, placing the plagioclase feldspar glass powder prepared in the step 3 into the red copper inner tube prepared in the step 4, adding distilled water or deionized water into the solution transfer gun, compacting sample powder, and sealing the sample powder by using the gold foil wafer; the red copper outer pipe II with the inner diameter of 7.05mm prepared in the step 4 and the red copper inner pipe I filled with the sample are reversely buckled, and the interface of the two copper pipes is sealed by a laser welding machine;

step 6, high-temperature high-pressure synthesis and assembly: placing the sealed copper tube in the step 5 in a high-temperature high-pressure assembly block with the periphery composed of an h-BN tube and an h-BN plug pressure transmission medium;

step 7, placing the assembly block on a cubic apparatus large press, and synthesizing a water-containing sample under the conditions of high temperature and high pressure;

and 8, after the step 7 is finished, turning off the heating current, quenching and cooling, and then slowly reducing the pressure to the normal temperature to obtain a finished product.

The method for decarbonization reaction in the high-temperature furnace comprises the following steps: decarbonizing at 1000-1200 deg.c for 10-12 hr, raising the temperature to 1600 deg.c to melt the mixture into glass state and lowering the temperature to room temperature; the high-temperature furnace is a closed high-temperature furnace.

The drying method in the oven in the step 3 comprises the following steps: drying in a drying oven at 100 ℃ for two hours; after drying, the sample is dried in an oven until the sample is assembled and taken out.

The method for synthesizing the water-containing sample under the conditions of high temperature and high pressure in the step 7 comprises the following steps: carrying out water-containing sample synthesis at the temperature of 1100-1200 ℃ and under the pressure of 1-2 GPa; the reaction time is 6-10 h.

The high-temperature high-pressure synthesis and assembly method comprises the following steps:

step 6.1, manufacturing an h-BN pipe: processing an h-BN rod with the diameter of 11mm into an h-BN pipe with the inner diameter of phi 8mm and the outer diameter of phi 11mm on a lathe, then polishing the inner diameter by using abrasive paper, putting sealed red copper filled with a sample into the h-BN pipe, and plugging two ends by using h-BN wafers with the diameters of phi 11mm and the thicknesses of 2 mm;

step 6.2, manufacturing a heater: processing a graphite heating furnace with the inner diameter of phi 11mm, the outer diameter of 13mm and the height of 32.5mm on a lathe;

step 6.3, processing pyrophyllite: selecting a cubic pyrophyllite block with the side length of 32.5mm, and punching a circular through hole with the diameter of phi 13mm in the center;

step 6.4, assembling: placing a graphite heating furnace in a pyrophyllite block, then placing a red copper sealing tube filled with a sample into a boron carbide tube, placing the red copper sealing tube and the boron carbide tube together in the graphite heating furnace, and respectively sealing two ends of the red copper sealing tube and the boron nitride plug and the pyrophyllite plug in sequence;

and 6.5, drilling a small hole in the middle of the edge of the pyrophyllite block, and placing a thermocouple capable of directly contacting a sample copper pipe for accurately controlling the experiment temperature.

It still includes:

step 9, taking out the sample in the step 8, cutting the copper tube by using a diamond wire cutting machine, taking out the sample, polishing the surface of the sample to form a cylinder, and measuring the related physical properties;

step 10, performing powder XRD measurement on the sample obtained in the step 9, analyzing and comparing obtained results, and determining that the sample is anorthite crystal, is a triclinic system and has a space group of C- ī;

and step 10, cutting the obtained sample into a slice, polishing the two sides of the slice to obtain a sample with the thickness of 300 mu m, and then measuring the water content and the distribution of the sample by using a Fourier infrared spectrometer, wherein the result shows that the sample has a characteristic peak of the structural water and is uniformly distributed.

And 5, when distilled water or deionized water is added by using a pipette, the amount of water is as follows: 0.1-0.5. mu.l.

The invention has the beneficial effects that:

the invention adopts the gold foil to be rolled into a straight cylinder as the inner tube which is directly contacted with the sample, replaces the commonly used gold tube or platinum tube, reduces the cost, has simple manufacture, is not limited by the size of the established noble metal tube, and can be randomly rolled into sample tubes with different sizes; meanwhile, the copper tube outside the gold foil tube is convenient to process and very low in cost, and the primary and secondary copper tubes with certain thickness and bottoms are sleeved together and welded, so that water in a sample can be completely sealed, and the water content of the sample is prevented from being accurately controlled due to the loss of water in the welding process and the high-temperature and high-pressure synthesis process; the synthesized sample has larger size, can be ground into various sizes according to the measurement requirement, and is used for various analysis tests. The synthesized water-containing plagioclase sample has the characteristics of large sample size, uniform particle size, high purity, uniform water distribution and the like, and provides important sample support for experimental research on physical properties, geochemical behaviors and circulation of water in middle and lower shells.

The method solves the technical problems that the size of a synthetic technology sample is limited, the water content of the sample is not accurately controlled, the experiment cost is high and the like when the water-containing plagioclase feldspar solid solution is synthesized in the prior art.

Description of the drawings:

FIG. 1 is a scanning electron microscope image of the prepared anorthite containing water.

The specific implementation mode is as follows:

example (b): synthesis of water-containing plagioclase solid solution (An) at high temperature and high pressure₂₀，Na_0.8Ca_0.2Al_1.2Si_2.8O₈) The method comprises the following steps:

step 1, according to albite (NaAlSi) in the anorthite solid solution₃O₈) And anorthite (CaAl)₂Si₂O₈) In a molar ratio of 4: respectively weighing Al as initial raw materials of albite and anorthite in stoichiometric ratio₂O₃,SiO₂,Na₂CO₃And CaCO₃High-purity oxide powder is ground and mixed evenly in alcohol by an agate mortar, and then dried for 4 hours in an oven at 200 ℃;

the selection of the oxide raw materials is based on that the components of the raw materials are simple, some impurity elements cannot be added, and the price is low; meanwhile, the corrosion resistance is ensured, and the safety is ensured; unlike some acid-base reagents, corrosivity can occur during the manufacturing process.

Step 2, synthesizing plagioclase glass at high temperature: in order to obtain a pure glass sample and avoid the residue of initial raw materials, the mixture powder obtained in the step 1 is pressed into a cylinder with the diameter of phi 13 multiplied by 2mm by a tablet press, so that the raw materials are contacted more closely and react more fully at high temperature to generate a pure glass phase; the method is beneficial to ensuring that the high-temperature reaction is more sufficient after the initial raw materials are closely contacted, then placing a sample into a platinum crucible, placing the platinum crucible into a high-temperature furnace, performing decarburization reaction at the temperature of 1000-; because the decarbonization reaction is carried out in the closed high-temperature furnace, impurities and moisture can not be introduced in the cooling process; the preparation of a transparent, bubble-free and residual reactant-free homogeneous glass is ensured.

Step 3, preparing plagioclase glass powder: step 2, obtaining transparent uniform glass without bubbles and residual reactants, crushing the glass on a platinum crucible filled with transparent plagioclase glass on a tablet press, putting the crushed glass into a high-frequency vibration ball mill, and grinding the crushed glass into powder with uniform particles, wherein the particle size is 5-10 mu m; and then putting the sample into a 100 ℃ oven for drying, wherein the sample can be dried after being dried for about two hours generally.

Step 4, preparing the primary and secondary copper tubes: preparing a first red copper inner tube with the inner diameter of 6mm, the wall thickness of 0.5mm, the height of 12mm and the bottom thickness of one end of 0.5; preparing a red copper outer tube II with the inner diameter of 7.05mm, the wall thickness of 0.5mm, the height of 12.5mm and the bottom thickness of one end of 0.5 mm; and (3) setting primary and secondary copper tubes with different sizes according to the size of the sample to match the size of the sample.

Step 5, assembling a water-containing sample: rolling a gold foil with the thickness of 0.05mm into a tube, placing the tube into the red copper inner tube I processed in the step 4, placing a gold foil wafer with the same thickness at the bottom of the tube, placing the plagioclase feldspar glass powder prepared in the step 3 into the red copper inner tube prepared in the step 4, and adding 0.1-0.5 mu l of distilled water or deionized water into the plagioclase feldspar by using a liquid transfer gun in order to synthesize plagioclase feldspar with different water contents; according to different amounts of added water, the plagioclase feldspar solid solutions with different water contents can be obtained.

During assembly, water is distributed on the surfaces of sample powder particles to form adsorbed water, then the sample powder is compacted, the water has fluidity, and the adsorbed water uniformly exists among the sample particles after the sample powder is compacted; and sealed by a gold foil wafer; the red copper outer pipe II with the inner diameter of 7.05mm prepared in the step 4 and the red copper inner pipe I filled with the sample are reversely buckled, and the interface of the two copper pipes is sealed by a laser welding machine;

step 6, high-temperature high-pressure synthesis and assembly: placing the sealed copper tube in the step 5 in a high-temperature high-pressure assembly block with the periphery composed of an h-BN tube and an h-BN plug pressure transmission medium, wherein the h-BN is hexagonal boron nitride; then the assembly block is placed on a cubic apparatus press, the synthesis of the water-containing sample is carried out under the conditions that the temperature is 1100-1200 ℃ and the pressure is 1-2GPa, and the reaction time is 6-10 h; the transformation of the water-absorbed plagioclase glass into water-containing plagioclase crystal can be synthesized only under the high-temperature and high-pressure conditions of the present invention. In the high-temperature high-pressure synthesis process, the adsorbed water can enter the crystal lattice of the sample to form structural water which occupies the crystal lattice position. The temperature, pressure and time listed in the invention are synthesis conditions which are key parameters for successful synthesis.

Step 6, the high-temperature high-pressure synthesis device relates to the processing of h-BN pipes, heaters, transmission medium pyrophyllite blocks and the assembly of the materials, and the specific operation comprises the following steps:

step 6.1, manufacturing an h-BN pipe: processing an h-BN rod with the diameter of 11mm into an h-BN pipe with the inner diameter of phi 8mm and the outer diameter of phi 11mm on a lathe, slightly polishing the inner diameter by using abrasive paper, putting sealed red copper filled with a sample into the h-BN pipe, and using h-BN wafers with the diameters of phi 11mm and the thicknesses of 2mm at two ends;

step 6.2, manufacturing a heater: processing a graphite heating furnace with the inner diameter of phi 11mm, the outer diameter of 13mm and the height of 32.5mm on a lathe;

step 6.3, processing pyrophyllite: selecting a cubic pyrophyllite block with the side length of 32.5mm, and punching a circular through hole with the diameter of phi 13mm in the center;

step 6.4, assembling: the graphite heater is arranged in the pyrophyllite block, then the red copper sealing tube filled with the sample is arranged in the boron carbide tube and is arranged in the graphite tube, and the two ends of the red copper sealing tube are sequentially sealed by the boron nitride plug and the pyrophyllite plug.

6.5, drilling a small hole in the middle of the edge of the pyrophyllite block, and placing a thermocouple capable of directly contacting a sample copper pipe for accurately controlling the experiment temperature;

step 7, after step 6, turning off the heating current, quenching and cooling, and then slowly reducing the pressure;

step 8, taking out the sample in the step 7, cutting the copper tube by using a diamond wire cutting machine, polishing the surface of the sample after being taken out to form a cylinder shape, and measuring related physical properties such as electrical property, elasticity and thermodynamic property;

performing powder XRD measurement on the sample obtained in the step 9 and the step 8, analyzing and comparing obtained results, and determining that the sample is anorthite crystal which is a triclinic system and has a space group of C- ī;

and 10, cutting a small slice of the sample obtained in the step 8, polishing the two sides of the sample to obtain a thickness of about 300 mu m, and measuring the water content and the distribution of the sample by using a Fourier infrared spectrometer, wherein the result shows that the sample has a characteristic peak of the structural water and is uniformly distributed.