Silicate mineral and method for producing same

Abstract

[Problem] To make available a silicate mineral having an average particle size larger than several hundred nm without containing impurities such as crystalline silica. [Solution] The content of crystalline silica and asbestos is 0.1 wt% or less in the silicate mineral of the present invention. The mineral preferably contains a carbonate and preferably has an average particle size of 100 nm or more. In addition, the mineral is suitably used in cosmetics, sanitary goods, pharmaceuticals, and foods. The silicate mineral is obtained by subjecting a natural silicate mineral to warm water or hot water treatment or hydrothermal reaction treatment at a pH of 9.4 or less.

Description

Silicate minerals and their manufacturing method

[0001] The present invention relates to a silicate mineral and a method for producing the same.

[0002] Silicate compounds are one of the most diverse minerals, and are widely used in cosmetics, food, medicines, and industrial products. Deep underground, groundwater is heated by volcanic activity, becoming hot water with high temperature and pressure (subcritical or supercritical water), which dissolves rocks and turns into a supercritical aqueous solution. When the pressure is reduced and cooled near the surface, the solubility decreases and the mineral precipitates. This is the principle behind the formation of mineral veins. As can be seen by looking at the composition of soil and sand on the surface, silica compounds are the main constituents. Examples of silica compounds include silica SiO ２ In addition, many minerals containing metals such as Al, Ca, Fe, K, Na, Mg, etc., such as calcium silicate, magnesium silicate, iron silicate, sodium silicate, etc., or minerals containing multiple metals, and their hydrates, are also formed.

[0003] Due to the precipitation principle, it is natural that impurities are often included. Among them, the constituent SiO ２ It often contains as an impurity.

[0004] The present invention aims to remove these impurities that are generated during the precipitation process of silicate minerals, and targets aluminum silicate, calcium silicate, magnesium silicate, iron silicate, etc., and their hydrates. This technology will be explained below using hydrous magnesium silicate (also known as talc, talc, etc.) as an example, but in principle, this technology can also be applied to other silicate minerals.

[0005] Hydrous magnesium silicate is widely used in cosmetics, food, pharmaceuticals, and industrial products, but as it is a natural mineral, it often contains impurities. For commercial use, toxic substances and heavy metals are separated and removed. However, in many cases, these materials, including talc, which is a natural mineral, contain impurities such as SiO ２These materials are prone to being contaminated with components that tend to precipitate simultaneously during mineral formation, such as crystalline SiO. These components often end up in products. For example, they often contain small amounts of tremolite and chrysotile, which are caused by asbestos. The inclusion of asbestos is not permitted in industrial products, let alone cosmetics, food, and pharmaceuticals. ２ The contamination of silica (also called crystalline silica or quartz) has also recently become a problem.

[0006] However, the formation of minerals underground is a precipitation process due to temperature and pressure, and the composition of the precipitates varies depending on the location where the minerals are mined. The only solution has been to carefully examine and select the parts that contain almost no impurities, but even so, there are many cases where trace amounts of impurities are still present, which is a major problem, especially in fields where minerals are applied to medicine, food, cosmetics, etc.

[0007] In addition, crystalline SiO ２ Focusing on the above, hydrated magnesium silicate and SiO ２ Since the physical properties required for existing compositional separation, such as specific gravity, are almost the same, it has been thought that separation of these substances is impossible not only by centrifugation, sedimentation, and specific gravity separation, but also by adsorption procedures such as chromatography.

[0008] It has been proposed to artificially synthesize fine particle talc using hydrothermal synthesis including supercritical fields (see Patent Document 1).

[0009] Special Publication No. 2014-520743

[0010] However, the synthetic talc obtained by the method described in Patent Document 1 has a small particle size of 20 nm to 100 nm. In practical application fields where hydrated silicate compounds such as talc are used, natural minerals are crushed and sieved before use, so the particle size is several tens of μm or more, and at the smallest, sub-μm or more. From the perspective of user safety (nano risk), it is desirable to provide talc with a larger particle size. In principle, it is possible to increase the particle size using a hydrothermal method, etc., but artificial synthesis has issues with production costs, productivity, and property optimization, and in reality, it is not a method for industrially producing particles of several hundred nm or more.

[0011] Therefore, even if we try to remove impurities from natural minerals, when we look at crystalline silica, it is difficult to remove impurities from the natural mineral. ２ From the mixed system, SiO ２ In terms of dissolving and removing impurities, impurities can be dissolved by applying alkaline conditions, but at the same time, hydrous magnesium silicate also dissolves. ２ No investigation has been conducted into the separation and removal of impurities while leaving hydrous magnesium silicate. In principle, an industrial method is to separate SiO2 without dissolving hydrous magnesium silicate. ２ However, considering that minerals are formed simultaneously in nature, they are mixed in because their solubilities are almost the same, and it is extremely difficult to find the conditions that will dissolve them.

[0012] As for asbestos, it is serpentine and amphibolite, and is generally stable to both acid and alkali, as well as heat resistant. In other words, under conditions that would allow its dissolution and removal, other components, such as hydrated magnesium silicate, would also be dissolved, making it generally very difficult to remove.

[0013] The present invention has been made in view of such problems, and aims to provide a silicate mineral having an average particle size of more than several hundred nanometers without containing impurities such as crystalline silica.

[0014] As a result of extensive research, the present inventors discovered that by treating silicate minerals derived from natural minerals with warm or hot water or a hydrothermal reaction at a pH of 9.4 or less, toxic impurities such as crystalline silica and asbestos can be dissolved in water or reactively modified and removed, leading to the completion of the present invention. Specifically, the present invention provides the following.

[0015] The present invention provides a method for producing silicate mineral powder, which includes a step of subjecting a silicate mineral derived from a natural mineral to a hot water or hot water treatment or hydrothermal reaction treatment at a pH of 9.4 or less. Carbonate or the like can also be present in the reaction field, which allows the pH to be controlled low and also enables the reactive modification and removal of impurities.

[0016] Hydrothermal reactions are widely used as a method for growing single crystals of metal oxides, including quartz. Under hydrothermal conditions, metal oxides repeatedly dissolve and precipitate, resulting in crystal growth. This crystal growth is called Ostwald ripening. Unstable microparticles and sharp edges with high surface energy are more likely to dissolve, and single crystal growth progresses in such a way that more stable surfaces are exposed. In fact, the mechanism and principles of Ostwald ripening are utilized to promote faster crystal growth and are used industrially as a method for producing large single crystals.

[0017] Because the solubility of metal oxides varies with temperature, generally, to promote single crystal growth, a temperature distribution is created within the crystal growth vessel to achieve faster crystal growth. Under subcritical hydrothermal conditions or high-pressure supercritical conditions (high water density), the raw material is dissolved at a high temperature and seed crystals are grown at a low temperature. When using a supercritical water state with relatively low pressure and low density, on the other hand, precipitation is carried out at a high temperature (low water density), and natural retention, which tends to occur, is actively utilized. This usually takes at least several hours, and more commonly several days to several weeks.

[0018] Considering the principle of Ostwald ripening, when hydrothermal ripening is performed on hydrated magnesium silicate such as talc, which has different particle sizes and shapes, both components will dissolve, starting with the fine particles and pointed particles. Unlike crystal growth, the present invention does not focus on the growth of tremolite, chrysotile, or crystalline silica (quartz), which may be contained as impurities, but on the dissolution or reactive modification removal of impurities. By suppressing the dissolution of silicate minerals and more selectively causing the dissolution or reactive modification of impurities such as crystalline silica, it is possible to prepare a main component silicate mineral that does not contain impurities such as crystalline silica.

[0019] Furthermore, compared to the artificial synthesis of talc using hydrothermal synthesis, which in principle also allows for the preparation of silicate minerals that do not contain crystalline silica or chrysotile as impurities, this method is superior in terms of production cost. Furthermore, because the raw material is a pulverized product of a natural mineral, it is possible to recover particles with diameters of several hundred nanometers or more, which are in demand in the market.

[0020] Because this is the reaction site where Ostwald ripening occurs, the shape of the recovered silicate mineral particles is rounder and contains fewer fine particles than common crushed natural products. In addition, the surface hydroxyl groups of the products are more abundant.

[0021] The pH is 9.4 or less. At a high pH, ​​crystalline silica can be dissolved, but silicate minerals also dissolve. In fact, a low pH is desirable for the subcritical and supercritical hydrothermal synthesis (artificial synthesis) of silicate minerals. Since silicate minerals precipitate under these conditions, this is considered to be a desirable condition in principle for dissolving only crystalline silica without dissolving silicate minerals.

[0022] This concept also applies to the removal of impurities from asbestos such as chrysotile. Because asbestos such as chrysotile is a basic mineral, it is theoretically possible to set conditions under which asbestos is dissolved and silicate minerals are precipitated by not setting the pH high under hydrothermal conditions.

[0023] These impurities are particularly problematic when they are needle-shaped products, but under hydrothermal conditions, the needle-shaped material dissolves from its tip. Considering the dissolution rate and amount of a large amount of silicate minerals, even if the same amount is dissolved, ultimately only the silicate minerals present in large quantities will remain.

[0024] Acid can be added to lower the pH, and carbonic acid can be used as the acid. In this case, depending on the conditions, carbonate formation may occur. The following reaction is known to be the mechanism by which talc is formed in the reaction field of mineral formation deep underground.

[0025] This is because serpentine (chrysotile) is heated under hydrothermal conditions with CO ２ This shows that talc is produced by reacting with chrysotile. The magnesium in chrysotile precipitates as magnesium carbonate. However, because the solubility of magnesium carbonate under hydrothermal conditions is higher than that of other products, it can also be dissolved and removed by semi-batch extraction.

[0026] In addition, recent research has shown that calcium silicate and CO ２Carbonation due to the reaction with Calcium silicate compounds has been reported. In addition to research into the mechanism of mineral formation, carbonation of calcium silicate compounds has also been reported (Goto et al., Inorganic Materials, Vol. 5, Jan. 22-27 (1998)). ２ Absorption (CO ２ -SUICOM (registered trademark) process) and CO2 synthesis with calcium silicate by Professor Richard Riman of Rutgers University in the United States. ２ Synthesizing artificial marble through coexisting hydrothermal reactions, etc. ２ It is being put into practical use as a research and development for solving problems and technological development. ２ Carbonation proceeds under coexisting hydrothermal conditions.

[0027] Meanwhile, in the field of geophysics, the following is known as another mechanism for underground talc formation.

[0028] This reaction mechanism is a reaction in which talc is produced in the presence of silica under hydrothermal conditions. As mentioned above, this suggests that it is possible to modify carbonate to talc through the reaction between carbonate and silica.

[0029] That is, tremolite, which is mixed in as a trace component, is Ca ２ (Mg, Fe) ５ Si ８ O ２２ (OH) ２ (Here, Mg / (Mg+Fe)=1.0-0.9) However, when a small amount of tremolite is mixed in, it is not only dissolved and removed under hydrothermal conditions, but also CO ２ In the presence of these compounds, carbonation occurs, and at the same time, silica components present as impurities also dissolve and react, resulting in modification to talc.

[0030] In the present invention, the hot water or hot water treatment or the hydrothermal reaction treatment is preferably carried out in the presence of Mg ions. When crystalline silica or the like is contained in the mineral, the coexistence of Mg may promote the formation of magnesium silicate in terms of equilibrium. Simply put, SiO ２However, in reality, Mg ions and Si ions coexist due to the dissolution of silica and magnesium silicate, but if magnesium ions are supplied, the dissolution equilibrium between silica and magnesium silicate can be made to favor the dissolution of silica.

[0031] The silicate mineral derived from natural minerals used as raw materials is obtained by crushing the natural minerals, and therefore it is difficult to reduce the average particle size to less than 200 nm, and the average particle size of the product after hydrothermal reaction treatment is 200 nm or more.

[0032] Therefore, according to the present invention, talc having an average particle size of more than 100 nm can be provided without containing impurities such as crystalline silica and asbestos components.

[0033] In the present invention, the temperature in the warm water or hot water treatment or the hydrothermal reaction treatment is preferably 70° C. or higher and 370° C. or lower, and the pressure is preferably equal to or higher than the saturated vapor pressure of water.

[0034] According to the present invention, impurities such as crystalline silica or asbestos can be dissolved and reacted to remove them by using low-temperature heat of 370°C or less (preferably 300°C or less, more preferably 250°C or less, even more preferably 200°C or less, and particularly preferably 150°C or less), which is even more advantageous in terms of production costs. As low-temperature heat, not only heat from a heat source device but also reuse of waste heat within a factory can be considered.

[0035] The present invention can be applied to any of a batch apparatus, a semi-batch apparatus, and a flow-through apparatus. However, it is preferable to carry out the hot water or hot water treatment or the hydrothermal reaction treatment using a semi-batch apparatus or a flow-through apparatus, and it is more preferable to carry out the hot water or hot water treatment or the hydrothermal reaction treatment using a semi-batch apparatus.

[0036] The solubility of silica in pure water has been reported. However, in the case of hydrothermal treatment of minerals containing other ions, as in this system, the dissolution of those minerals naturally occurs, resulting in a different solubility from that of silica in high-temperature, high-pressure water. In general, the solubility of a specific component in the presence of other minerals and the concentration of dissolved chemical species can be solved by simultaneously solving the solubility equilibrium equation for any substance, as well as the water dissociation equilibrium and charge balance. The necessary chemical equilibrium can be accurately predicted, including in the supercritical region, using the HKF (Helgeson, Kirkham, Flouer) model or the improved HKF model by Sue et al. (Sue, K., Hakuta, Y., Smith, RL, Adschiri, T., & Arai, K. (1999). Solubility of lead(II) oxide and copper(II) oxide in subcritical and supercritical water. Journal of Chemical & Engineering Data, 44(6), 1422-1426. https: / / doi.org / 10.1021 / je9901029)

[0037] For example, the addition of alkali or the influence of coexisting ions increases the saturated solubility. Furthermore, during the process of mineral precipitation underground, when silica precipitates as an impurity, the solubility of the precipitated mineral is low and the precipitation rate is also high. It is inferred that the conditions are favorable for silica dissolution not only from the equilibrium theory mentioned above but also from a kinetic perspective. This has been verified experimentally, and it can be fully explained why dissolution is achieved more than 10 times faster, not only from the equilibrium theory but also from a kinetic perspective.

[0038] The optimum amount of water to be passed through when operating a reaction system is determined based on the equilibrium theory and kinetic theory.

[0039] The use of a semi-batch system allows for heat recovery and preheating during hot water / hot water treatment or hydrothermal reaction treatment, resulting in a further advantage in terms of production costs. Furthermore, impurities such as crystalline silica and asbestos that have been extracted can be removed from the system, preventing contamination due to their reprecipitation.

[0040] When the reaction apparatus is a semi-batch apparatus, the amount of aqueous solvent supplied to the semi-batch apparatus is preferably 0.1 times or more the theoretical amount at which the crystalline silica contained in the silicate mineral as the raw material is saturated and dissolved in the reaction solution containing the coexisting ions of the reaction field. Alternatively, the amount of crystalline silica contained in the silicate mineral as the raw material charged to the semi-batch apparatus is preferably 10 times or less the theoretical amount at which the crystalline silica is saturated and dissolved in the reaction solution containing the coexisting ions of the reaction field.

[0041] When using a flow-through system, silicate minerals are supplied in a suspended state in water and subjected to hot water, hot water treatment, or hydrothermal reaction treatment. Heat can be recovered at the outlet and used to preheat the raw material. Unlike semi-batch systems, the extraction tank temperature is increased. Heat loss during cooling is eliminated, improving heat recovery. In this case, silica dissolved in the cooling section may be reprecipitated in the subsequent cooling section. To avoid this, sufficient crystalline silica dissolution and rapid cooling are required to suppress Ostwald ripening and recrystallization of the remaining silica. The conditions can be examined in small-scale batch tests.

[0042] In addition, the concentration of the silicate mineral water slurry supplied to the flow-through device is preferably 0.1 times or more the theoretical amount at which the crystalline silica contained in the silicate mineral as the raw material is saturated and dissolved in the reaction solution containing the coexisting ions in the reaction field.

[0043] According to the present invention, it is possible to provide a silicate mineral having an average particle size of more than several hundred nanometers without containing impurities such as crystalline silica.

[0044] Fig. 1 is a schematic diagram of a manufacturing apparatus 1 according to this embodiment. Fig. 2 shows the results of an X-ray diffraction test on natural talc before and after hydrothermal reaction treatment. Fig. 3 shows the results of an X-ray diffraction test on natural talc after hydrothermal reaction treatment.

[0045] Specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0046] <Apparatus for Producing Hydrous Magnesium Silicate Powder> FIG. 1 is a schematic diagram of an apparatus 1 for producing hydrous magnesium silicate powder.

[0047] The manufacturing apparatus 1 includes an extraction means 10 and, if necessary, a cooling means 20 .

[0048] [Extraction means 10] The extraction means 10 is an apparatus that brings the raw material liquid into contact with an aqueous material and subjects the raw material to hot water or hot water treatment or hydrothermal reaction treatment. The extraction means 10 may be in the form of a batch apparatus, a semi-batch apparatus, or a continuous apparatus, but the extraction means 10 is preferably a batch apparatus or semi-batch apparatus, since it can lower the temperature in the hydrothermal reaction treatment, etc., and is advantageous in terms of production costs because it can utilize not only heat from a heat source apparatus but also waste heat within the factory, and it is more preferable to perform the hot water or hot water treatment or hydrothermal reaction treatment using a semi-batch apparatus.

[0049] The use of a semi-batch system allows for heat recovery and preheating during hot water / hot water treatment or hydrothermal reaction treatment, resulting in a further advantage in terms of production costs. Furthermore, impurities such as crystalline silica and asbestos that have been extracted can be removed from the system, preventing contamination due to their reprecipitation.

[0050] The extraction means 10 may also be a continuous device (flow-type device). When a flow-type device is used, silicate mineral is supplied in a suspended state in water and subjected to hot water or hot water treatment or hydrothermal reaction treatment. Heat can be recovered at the outlet and used to preheat the raw material. Unlike semi-batch devices, the extraction tank temperature is increased. Heat loss during cooling is eliminated, improving the heat recovery rate. In this case, silica dissolved in the cooling section may be reprecipitated in the subsequent cooling section. To avoid this, sufficient dissolution of crystalline silica and rapid cooling are required to suppress Ostwald ripening and recrystallization of the remaining silica. The conditions can be examined using small-scale batch tests.

[0051] Unless otherwise specified, the following description will be given assuming that the extraction means 10 is a semi-batch device, but this is not intended to be limiting.

[0052] [Raw Material] The raw material charged into the extraction means 10 is a silicate mineral, which may be derived from a natural mineral or a synthetic mineral, but is preferably a silicate mineral derived from a natural mineral.

[0053] The type of metal constituting the silicate mineral is not particularly limited, and examples thereof include alkali metals, alkaline earth metals, aluminum, iron, etc. Specific examples of silicate minerals include aluminum silicate, magnesium silicate, calcium silicate, iron silicate, and silicate minerals containing a plurality of these metals. Furthermore, the silicate mineral may be a hydrous silicate mineral in the form of a hydrate thereof.

[0054] For example, when the silicate mineral is a natural mineral such as talc (hydrated magnesium silicate), the asbestos content (tremolite, chrysotile, etc.) contained in the natural mineral is set at 0.1% or less according to the Enforcement Order of the Industrial Safety and Health Act (Cabinet Order No. 318 of 1972) and the Asbestos Hazard Prevention Regulations (Ministry of Health, Labour and Welfare Order No. 21 of 2005). Therefore, it is preferable to use a silicate mineral with such a content of 0.1% or less as the raw material.

[0055] The method for determining the asbestos content in talc using X-ray diffraction is the "Method for Analyzing Asbestos Content in Natural Minerals," an appendix to the Ministry of Health, Labor, and Welfare's (MHLW) Notification No. 0828001. This method requires the use of a standard X-ray diffractometer (XRD) under the following measurement conditions ("Method for Analyzing Asbestos Content in Talc," Asbestos Analysis Manual for Preliminary Surveys Based on the Asbestos Regulations, March 2018, Ministry of Health, Labor, and Welfare). Tube voltage: 40 kV or higher; Tube current: 30 mA or higher; Anticathode: Cu; Monochromator: Graphite monochromator or Ni filter; Detector: Scintillation counter, proportional counter, Geiger counter, semiconductor detector, etc.; Slit system: Receiving slit 0.3 mm or 0.2 mm; Divergence slit: 1°; Scattering slit: 1°; Goniometer scanning speed: 1 / 8° per minute or less; Time constant: Use an appropriate time constant. Chart full scale: The intensity of the diffraction line is measured by subtracting the background to obtain the net peak area. Select an appropriate full scale for the recording chart so that the diffraction line can be confirmed as a peak.

[0056] Generally, when measuring trace components, the measurement peak may be hidden by baseline noise, so a long integration time is required to increase the signal-to-noise ratio, which in principle makes it possible to detect trace components without using a powerful radiation source.

[0057] However, if the evaluation is performed within the measurement time used for general crystal structure analysis, the integration time may be insufficient to detect the peaks sufficiently, and the asbestos content may be determined to be below the safety standard of 0.1% by weight.

[0058] In the invention described in this embodiment, long-term measurements are carried out with due consideration of this point, and analysis is carried out based on the results of creating a calibration curve based on a precise baseline evaluation. Asbestos is reactively modified and removed, and the asbestos content is truly reduced to 0.1 wt% or less, that is, as specified in the appendix to Kianka Notification No. 0828001, it is confirmed with sufficient accuracy that the safety standards in the appendix are met by utilizing precise analytical methods in addition to the judgment results using a popular X-ray diffraction device.

[0059] [Dispersion medium] The dispersion medium for dispersing the raw materials is an aqueous material. The aqueous material refers to water, a polar organic solvent, or a mixed solvent of water and a polar organic solvent. Examples of aqueous materials include water, alcohols, carboxylic acids, ketones, ethers, esters, amides, amines, sulfur compounds, and mixtures thereof.

[0060] Examples of alcohols include methanol, ethanol, isopropyl alcohol, t-butyl alcohol, propylene glycol, and phenol.

[0061] Examples of the carboxylic acids include lower carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, and caproic acid.

[0062] Examples of the ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0063] Examples of the ethers include ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, tetrahydrofuran, dioxane, and methyl cellosolve.

[0064] Examples of the esters include ethyl acetate and butyl acetate.

[0065] Examples of amides include formamide, dimethylformamide, acetamide, dimethylacetamide, nitromethane, and acetonitrile.

[0066] Examples of amines include methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, and hexamethylenediamine.

[0067] Examples of sulfur compounds include dimethyl sulfoxide.

[0068] Among these, the aqueous material preferably contains one or more selected from water, alcohols, and carboxylic acids, and more preferably water, because it is easy to handle.

[0069] In addition, a pH adjuster, an oxidizing agent, or a reducing agent can be added to the aqueous material to control the reaction field.

[0070] Examples of pH adjusters include acids such as hydrochloric acid, nitric acid, acetic acid, sulfuric acid, carbonic acid, and ammonium salts thereof, and alkalis such as potassium hydroxide, sodium hydroxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and ammonia.

[0071] Examples of the oxidizing agent and reducing agent include hydrogen peroxide, oxygen, nitric acid, formic acid, hydrazine, hydrogen, ammonia, ethanol, and formaldehyde.

[0072] These materials not only contribute to the solubility of the target impurity but also function as reactive materials.

[0073] For example, carbon dioxide or CO ２ The coexistence of these minerals can result in the formation of carbonates, and through reactions with silica, can also result in the transformation of toxic impurity minerals into non-toxic carbonate minerals or talc.

[0074] Furthermore, it is preferable that Mg ions are added to the aqueous material, so that the subsequent hot water or hot water treatment or hydrothermal reaction treatment is carried out in the presence of Mg ions.

[0075] When crystalline silica or the like is contained in the mineral, the coexistence of Mg in equilibrium may promote the formation of magnesium silicate. ２ However, in reality, Mg ions and Si ions coexist due to the dissolution of silica and magnesium silicate. However, if magnesium ions are supplied, the dissolution equilibrium between silica and magnesium silicate can be shifted to favor the dissolution of silica. Therefore, it is preferable that Mg ions are added to the aqueous material.

[0076] [Raw material liquid] In this embodiment, a raw material liquid in which raw materials are dispersed using a dispersion medium is charged into the extraction means 10. The form of the raw material liquid may be charged as a powder or as a fluid. There are no particular limitations on the form of the raw material liquid as long as it has fluidity, and examples thereof include an aqueous solution, slurry, paste, or suspension containing raw material components.

[0077] If it is difficult to prepare a water slurry, the raw material may be dispersed in an aqueous material such as ethanol to form a slurry.

[0078] When the reaction apparatus is a semi-batch apparatus, the amount of aqueous solvent supplied to the semi-batch apparatus is preferably 0.1 times or more, more preferably 0.3 times or more, even more preferably 0.5 times or more, and even more preferably 0.8 times or more of the theoretical amount at which the crystalline silica contained in the silicate mineral as the raw material is saturated and dissolved in the reaction solution containing the coexisting ions of the reaction field. Alternatively, the amount of crystalline silica contained in the silicate mineral as the raw material charged into the semi-batch apparatus is preferably 10 times or less, more preferably 3.5 times or less, even more preferably 2 times or less, and even more preferably 1.3 times or less of the theoretical amount at which the crystalline silica is saturated and dissolved in the reaction solution containing the coexisting ions of the reaction field.

[0079] In this specification, it is preferable that the amount of crystalline silica is 0.1 times or more the theoretical amount that will dissolve to saturation in the reaction solution containing coexisting ions in the reaction field. If we simply consider chemical equilibrium, the preferred amount of crystalline silica would be greater than the theoretical amount of water that will dissolve to saturation, leaving little room for flexibility. However, in the present invention, reaction kinetics dominates over chemical equilibrium, and the property that silica dissolves more easily than talc is utilized. For example, the addition of alkali or Mg ions changes the chemical equilibrium. At the same time, the dissolution rate of crystalline silica is higher than that of other minerals such as talc, and therefore, in semi-batch processing, processing in a flow device, or short-term batch processing, it is kinetically advantageous, so the amount of crystalline silica can be less than the theoretical amount of water that will dissolve to saturation. Therefore, the amount of crystalline silica has a high degree of freedom, and it is sufficient if it is 0.1 times or more the theoretical amount.

[0080] The same applies when the extraction means 10 is a flow-type device, and the concentration of the silicate mineral water slurry supplied to the flow-type device is preferably 0.1 times or more, more preferably 0.3 times or more, even more preferably 0.5 times or more, and even more preferably 0.8 times or more of the theoretical amount at which the crystalline silica contained in the silicate mineral as raw material is saturated and dissolved in the reaction solution containing the coexisting ions in the reaction field.

[0081] In the present invention, the theoretical amount of saturation solubility in a reaction solution containing coexisting ions in the reaction field can be determined using the HKF (Helgeson Kirkham Flour) model. The solubility evaluation method is as described above.

[0082] The pH of the raw material solution fed to the extraction means is 9.4 or less. If the pH exceeds 9.4, even if hydrothermal reaction treatment is performed using hydrated magnesium silicate derived from natural minerals as the raw material, the crystalline silica that may be contained in the raw material may not be sufficiently dissolved, which is undesirable.

[0083] In order to more suitably dissolve impurities in the solvent, the upper limit of the pH is preferably 7 or less. ２ In view of the fact that the coexistence of the above causes the impurity minerals to be degenerated into talc, the pH is more preferably 6 or less, and even more preferably 5 or less.

[0084] The lower limit of the pH is not particularly limited, but from the viewpoint of suppressing corrosion of the apparatus including the extraction means 10, the lower limit of the pH is preferably 1 or more, more preferably 2 or more. ２ In view of the fact that the coexistence of the above causes the impurity minerals to denature into talc, the pH is more preferably 3 or higher, and even more preferably 4 or higher.

[0085] The timing for bringing the raw material liquid into the presence of an acid or a base is not particularly limited, and it is sufficient that the raw material liquid is brought into the presence of an acid or a base before the raw material liquid and the aqueous material come into contact with each other in the extraction means 10. However, in order to simplify the configuration of the production apparatus 1, it is preferable to supply an acid or a base at the stage of preparing the raw material to bring the raw material liquid into an acidic or basic state.

[0086] Although not essential, it is preferable that the raw material liquid is degassed. Examples of degassing devices for raw materials include degassing devices based on existing technologies such as degassing devices that use ultrasonic waves, degassing devices that reduce pressure, degassing devices that inject rare gases into the raw material liquid, and degassing devices that use permeable membranes, as well as degassing devices that combine these existing technologies. Degassing the raw material liquid can prevent corrosion of the extraction means 10 and the cooling means 20 due to dissolved oxygen.

[0087] [Supply of Aqueous Material] Next, the aqueous material to be continuously supplied to the extraction means 10 will be described.

[0088] As the type of water-based material, the materials previously described as the dispersion medium can be mentioned.

[0089] Although not essential, it is preferable that the aqueous material is degassed. Examples of degassing devices for aqueous materials include the device previously described as a raw material degassing device. By degassing the aqueous material, fluctuations in the supply amount of the aqueous material caused by bubbles generated by dissolved gases can be suppressed. Furthermore, corrosion of the extraction means 10 and the cooling means 20 due to dissolved oxygen can be suppressed. Furthermore, dissolved oxygen affects the redox state of the hydrothermal treatment reaction field, and CO ２ The presence of gases such as HCl, which have a strong effect on the reforming reaction under hydrothermal conditions, is also an important factor for controllable processing.

[0090] The aqueous material is in a pressurized state by a pressure pump, etc. By pressurizing and further heating the aqueous material, the aqueous material is brought into a subcritical state, and the aqueous material can be continuously supplied to the extraction means 10.

[0091] The aqueous material after pressurization is preferably hot water or a subcritical aqueous material. When the aqueous material is water, subcritical water has high solubility for silica. Therefore, it is preferable that the aqueous material is liquid water (liquid phase) after pressurization, or that the liquid phase is included as the main phase. However, even water in a gaseous phase or a state called water vapor (or steam) may form a condensed phase between particles due to capillary forces and exhibit the same properties as liquid water, so water in these states is also included. Furthermore, when the aqueous material is in a supercritical state, high density is required to achieve high solubility, and the pressure required to achieve this must be higher than the critical pressure, which is undesirable for industrial mass production. Furthermore, the amount of hydroxyl groups generated on the surface of the raw material is lower than in a precritical state, which may affect the dissolution of crystalline silica, asbestos, etc. that may be contained in the raw material.

[0092] The "hot water conditions, hot water conditions, or hydrothermal conditions" according to the present invention are defined as conditions in which liquid water coexists at a reaction temperature of 70° C. or higher and 370° C. or lower. However, when fine particles are the target, since reaction and dissolution in a condensed state due to capillary forces between the fine particles also occur, in such special cases, the supply system may be under conditions in which water in a gas phase known as water vapor (or steam) coexists.

[0093] The pressure of the aqueous material after pressurization is equal to or greater than the saturated vapor pressure. If the pressure is less than the saturated vapor pressure, impurities such as crystalline silica and asbestos that may be contained in the raw material may not be sufficiently dissolved or reactively modified and removed, even when the raw material liquid is brought into contact with the pressurized aqueous material, which is not preferable.

[0094] However, in special cases, the particle size is small and capillary forces act between the particles, so that the same dissolving effect can be achieved even with water that is below saturated vapor pressure, i.e., in a state called water vapor (or steam).

[0095] In order to more efficiently remove impurities such as crystalline silica and asbestos that may be contained in the raw material, it is desirable that the pressure of the aqueous material after pressurization be equal to or greater than the saturated vapor pressure at the treatment temperature. For example, when the treatment temperature is 120°C, the pressure is 0.2 MPa or greater, and when the treatment temperature is 170°C, the pressure is 0.8 MPa or greater. The pressure is lower at low temperatures and higher at high temperatures, and when the critical point is 374°C, the pressure is 22.1 MPa or greater. The pressure of the aqueous material after pressurization is preferably 0.2 MPa or greater, more preferably 0.5 MPa or greater, and even more preferably 1 MPa or greater. Even at lower temperatures, such as 70°C, the solubility decreases, so the treatment efficiency and treatment speed decrease, but in principle, a similar removal effect is expected. In this case, the pressure is 0.03 MPa, which is below atmospheric pressure, so hot water treatment can be performed even when operation is performed at normal pressure.

[0096] Furthermore, in the supercritical region, the pressure of the aqueous material after pressurization is 40 MPa or less, more preferably 20 MPa or less, and even more preferably 10 MPa or less. However, a liquid phase is basically formed if the pressure is above the saturated vapor pressure, and even if the pressure is increased above that, the water density hardly changes, and therefore an increase in solubility cannot be expected. Therefore, a sufficient dissolution effect can be expected if the pressure is only a few atmospheres higher than the saturated vapor pressure. Conversely, if the pressure of the aqueous material is too high, the cost of increasing the pressure resistance of the manufacturing apparatus 1 significantly increases and the extraction means 10 is more likely to deteriorate, which is not desirable.

[0097] The type of heating device for heating the water-based material is not particularly limited. Examples of heating devices include a heating device that irradiates the water-based material with microwaves, a heating device that heats the water-based material by heat conduction from a heating element such as a heater, etc. By heating the pressurized water-based material, the water-based material can be brought into a subcritical state.

[0098] High-temperature steam may also be available. This steam can be used in a heat exchanger or in combination with the heating device described above to produce pressurized water. If clean, impurity-free heated steam at a temperature higher than the processing temperature is available, it can be introduced directly. By controlling the pressure with a pressure control valve, the steam can be converted into a liquid phase and used as heated water for extraction.

[0099] Crystalline silica contained in the raw material can be extracted at temperatures above 70° C. The saturated vapor pressure of water at 70° C. is approximately 0.03 MPa, the saturated vapor pressure of water at 100° C. is approximately 0.1 MPa, the saturated vapor pressure of water at 120° C. is approximately 0.2 MPa, and the saturated vapor pressure of water at 170° C. is approximately 0.8 MPa.

[0100] The temperature of the aqueous material after heating is 70° C. or higher. If the temperature is lower than 70° C., impurities such as crystalline silica and asbestos that may be contained in the raw material may not be sufficiently dissolved or reactively modified and removed even when the raw material liquid is brought into contact with the pressurized aqueous material, which is not preferable.

[0101] The temperature of the aqueous material after heating is preferably 100°C or higher, more preferably 120°C or higher, and even more preferably 150°C or higher, in order to more efficiently dissolve or react, modify, and remove impurities such as crystalline silica and asbestos that may be contained in the raw materials.

[0102] The temperature of the aqueous material after heating is 370° C. or less, preferably 300° C. or less, more preferably 250° C. or less, and even more preferably 200° C. or less. If the temperature of the aqueous material is too high, the amount of hydroxy groups on the surface of the raw material will decrease, which is not preferable.

[0103] According to this embodiment, impurities such as crystalline silica or asbestos can be dissolved and reacted to remove them by using low-temperature heat of 370°C or less (preferably 300°C or less, more preferably 250°C or less, even more preferably 200°C or less, and particularly preferably 150°C or less), which is even more advantageous in terms of manufacturing costs. As low-temperature heat, not only heat from a heat source device but also reuse of waste heat within a factory can be considered.

[0104] [Contact Between Raw Material Liquid and Aqueous Material] The raw material liquid is charged into the extraction means 10, and then the aqueous material is continuously supplied to the extraction means 10, thereby bringing the raw material liquid into contact with the aqueous material. The raw material liquid is instantly heated to a subcritical temperature by the heat contained in the aqueous material, and a reaction between the raw material liquid and the aqueous material begins. This reaction initiates an extraction reaction or a modification reaction of the aqueous material, such as crystalline silica or asbestos, which may be contained in the raw material.

[0105] The shape of the extraction means 10 is not particularly limited as long as it can maintain the subcritical state, which is the extraction condition for crystalline silica into an aqueous material, for a predetermined period of time. Examples of the shape of the extraction means 10 include a spiral tube wound multiple times inside a heating barrel, a molten salt bath jacket, a reactor covered with a thermostatic layer such as a fluidized sand bath, and the like.

[0106] By configuring the extraction means 10 in the form of a spiral tube wound multiple times inside a heating cylinder or a reactor covered with a constant temperature layer, it is possible to prevent temperature changes and temperature unevenness in the mixture of the raw material liquid and aqueous material due to heat conduction through the device wall, and to achieve the precise temperature control required for impurity extraction in a subcritical state.

[0107] A high-temperature, high-pressure fluid containing dissolved impurities such as crystalline silica and asbestos flows out of the outlet of the extraction means 10. Because the solubility (i.e., solution concentration) is low and the temperature and pressure are relatively low, it is possible to remove the impurities directly. After extraction, a high-temperature, high-pressure fluid containing hydrous magnesium silicate derived from natural minerals with the impurities removed is discharged to the extraction means 10.

[0108] From the viewpoint of properly removing impurities such as crystalline silica and asbestos, the time for the hydrothermal reaction treatment in the extraction means 10 is preferably 1 minute or more, more preferably 5 minutes or more, and even more preferably 10 minutes or more.

[0109] On the other hand, from the viewpoint of production efficiency, from the viewpoint of suppressing deterioration of the extraction means 10, and from the viewpoint of reducing the effect of impurity crystal growth due to Ostwald ripening, the reaction time for the hydrothermal reaction treatment is preferably 10 hours or less, more preferably 5 hours or less, and even more preferably 2 hours or less.

[0110] [Cooling Means 20] The provision of the cooling means 20 is not essential. The cooling means 20 is an optional configuration that may be provided as needed. In the case of relatively high temperature and pressure, or when the elution concentration is high, cooling before the pressure control valve may cause the dissolved impurities to re-precipitate, potentially damaging the pressure control valve. In such cases, providing the cooling unit 20 can reduce the load on the downstream pressure control valve by re-precipitating and removing the dissolved and extracted impurity components.

[0111] Cooling is performed by mixing a high-temperature, high-pressure fluid supplied from the extraction means 10 with a low-temperature, high-pressure aqueous material pressurized by a pressure pump or the like. By mixing the high-temperature, high-pressure fluid with the low-temperature, high-pressure fluid, the heat associated with the change in state of the fluid, i.e., the heat equivalent to the latent heat of vaporization, can be quickly removed, enabling safe and stable operation. Furthermore, if the high-temperature, high-pressure fluid is cooled to below its critical temperature by this mixing, the high-temperature, high-pressure fluid is rapidly cooled, and the reaction that produces particles can be stopped almost instantaneously. Therefore, the product particles can be made to have a nearly uniform particle size.

[0112] Such a cooling method is sufficient when operating at low temperatures, but when operating at relatively high temperatures, heat recovery may be required from the perspective of energy utilization. In such cases, a cooling pipe is installed to perform indirect cooling, i.e., heat exchange, and the recovered heat is used to preheat the raw materials or circulating water.

[0113] Regarding the recovery of particles from the extraction tank 10, if the powder is charged into the container, the particles are recovered as is. If the particles are recovered as a slurry, the fluid containing the product particles is passed through a filter to separate the product particles from the fluid. The type of filter is not particularly limited, but an in-line filter is an example. The filter can collect hydrous magnesium silicate derived from natural minerals with impurities removed.

[0114] In semi-batch operation, the impurities are dissolved and removed, so the cooling operation of the extractor 10 is not important. However, when the present system is operated in batch mode, the dissolved impurities precipitate on the silicate mineral product upon cooling. In this case, if the cooling rate is slow, reprecipitation of crystalline components may occur, so the cooling operation of the entire apparatus becomes important.

[0115] <Silicate mineral> The average particle size of the silicate mineral obtained as a product is preferably 100 nm or more. When the raw material is a natural mineral, the silicate mineral is obtained by pulverizing the natural mineral. Therefore, it is difficult to make the average particle size less than 100 nm, and the average particle size of the product after the hydrothermal reaction treatment will also be 100 nm or more.

[0116] From the viewpoint of safety for users of talc, the average particle size is more preferably 200 nm or more, more preferably 500 nm or more, even more preferably 1 μm or more, and particularly preferably 5 μm or more.

[0117] Generally, when natural talc minerals are used, they are crushed and then classified using a sieve. In this case, the particle size becomes even larger, exceeding several tens of micrometers. For finer particles, gas-phase classification is used, but even in this case, particles of several micrometers in size are generally recovered, and in special cases, sub-micrometer particles can be recovered.

[0118] In the present invention, the average particle size refers to the median diameter D50 measured by the centrifugal sedimentation method in accordance with JIS R1619.

[0119] From the viewpoint of industrial production efficiency, the lower limit of the silicate mineral treatment concentration is preferably 1 wt % or more, more preferably 3 wt % or more. The upper limit of the silicate mineral treatment concentration is preferably 30 wt % or less, more preferably 20 wt % or less. In particular, the upper limit of the silicate mineral treatment concentration is more preferably 10 wt % or less, and particularly preferably 5 wt % or less, in order to be able to appropriately treat impurities (crystalline silica and asbestos) even when the concentration of impurities in the silicate mineral is relatively high.

[0120] Furthermore, the content of crystalline silica in the silicate mineral obtained as a product is 0.1% by weight or less, more preferably 0.08% by weight or less, even more preferably 0.05% by weight or less, and even more preferably below the detection limit.

[0121] Furthermore, the asbestos content in the silicate mineral powder obtained as a product is 0.1% by weight or less, preferably 0.08% by weight or less, more preferably 0.05% by weight or less, and even more preferably below the detection limit.

[0122] In this embodiment, the contents of crystalline silica and asbestos are determined using an X-ray diffractometer. The conditions for the X-ray diffractometer are as follows: tube voltage: 45 kV, tube current: 200 mA, anticathode: Cu, monochromator: graphite monochromator, detector: scintillation counter SC-70S, slit system: receiving slit box 1 1.000 mm, receiving slit box 2 1.125 mm, entrance slit box 1.000 mm, length limiting slit 15 mm, goniometer scanning speed: 0.10° per minute, chart full scale: the intensity of the diffraction line is measured by subtracting the background to determine the net peak area. An appropriate full scale is selected for the recording chart so that the diffraction line can be confirmed as a peak.

[0123] The X-ray diffraction device can be set to these conditions if it is, for example, a SmartLab 9MTP (manufactured by Rigaku Corporation).

[0124] The quartz content of crystalline silica is determined from the peak intensity at a diffraction angle (2θ) of 26.6° in powder X-ray diffraction using a calibration curve obtained using a standard quartz sample. The cristobalite content is determined from the peak intensity at a diffraction angle (2θ) of 22.0° in powder X-ray diffraction using a calibration curve obtained using a standard cristobalite sample. The tridymite content is determined from the peak intensity at diffraction angles (2θ) of 20.5° and 21.6° in powder X-ray diffraction using a calibration curve obtained using a standard tridymite sample.

[0125] The content of tremolite among asbestos is determined from the peak intensity at a diffraction angle (2θ) of 10.4° in powder X-ray diffraction using a calibration curve obtained using a standard tremolite sample, and the content of chrysotile is determined from the peak intensity at diffraction angles (2θ) of 12.1° and 24.3° in powder X-ray diffraction using a calibration curve obtained using a standard chrysotile sample.

[0126] Other matters shall be in accordance with "8.4.3.1. Analysis method for asbestos content in talc" in the Asbestos Analysis Manual for Preliminary Surveys Based on the Asbestos Regulations [Version 1.20], March 2018, Ministry of Health, Labour and Welfare.

[0127] Generally, when measuring trace components, the measurement peaks may be hidden by baseline noise, requiring a long integration time to increase the signal-to-noise ratio. This makes it possible, in principle, to detect trace components using a conventional XRD analyzer without using a powerful radiation source. In the present embodiment, this issue is fully addressed by performing long-term measurements and creating a calibration curve based on a precise baseline evaluation. This allows crystalline silica or asbestos to be dissolved and removed in an aqueous material, truly reducing the asbestos content to 0.1 wt.% or less. In other words, as specified in the appendix to the Basic Chemical Regulations No. 0828001, the safety standards set forth in the appendix are met with sufficient accuracy by utilizing precise analytical techniques in addition to the results determined using a standard X-ray diffraction analyzer.

[0128] Whether a product is a silicate mineral powder or not is determined based on the diffraction peaks in powder X-ray diffraction. For example, whether a product is a hydrous magnesium silicate powder (talc powder) or not is determined based on whether the product has diffraction peaks at diffraction angles (2θ) of 9.45°, 18.97°, and 28.62° in powder X-ray diffraction using the precision analytical method described above.

[0129] Furthermore, the amount of NaOH aqueous solution (0.01 M) required in the following method (Sears method) is preferably 180 μl or more, and more preferably 200 μl or more. (1) Disperse 0.1 g of silicate mineral powder in 10 ml of water. (2) Add 2 g of NaCl, and then adjust the pH to 4 or less with dilute hydrochloric acid (0.12 M). (3) Add NaOH aqueous solution (0.01 M) gradually until the pH reaches 4, and then measure the amount of NaOH aqueous solution (0.01 M) required to reach a pH of 9.

[0130] Hydrothermal treatment of natural talc increases the amount of OH groups on the surface. Furthermore, the amount of OH groups increases with increasing hydrothermal temperature. Whether or not hydrothermal treatment is performed also affects wettability. Hydrothermal treatment of natural talc reduces the contact angle. This means that wettability, or in other words, hydrophilicity, has improved. Therefore, it can be said that hydrothermal treatment of silicate minerals improves their affinity with polar solvents for cosmetics, improving their blendability.

[0131] When the silicate mineral obtained by the present invention is a hydrous magnesium silicate powder, the hydrous magnesium silicate powder can be applied to, for example, the plastics field (filler (improvement of rigidity, heat resistance, and dimensional stability), crystal nucleating agent), the papermaking field (filler, pitch control agent, coating agent), the paint field (extender pigment (adjustment of viscosity and gloss), powder paint), the electronic parts field (laminates, molded products, resist ink, adhesives), the ceramics field (ceramic glaze, honeycomb ceramic raw material), the rubber field (filler (improvement of heat resistance, reinforcement, etc.), mold release agent), the cosmetics field (foundation, body powder, baby powder, eye shadow, lipstick), the hygiene product field (baby powder; prevention of heat rash and other skin rashes in babies), the pharmaceutical field (tablet excipient, lubricant, lubricant for medical rubber gloves), the food field (gum base, manufacturing aid (anti-sticking)), the agricultural field (fertilizer anti-caking agent, pesticide carrier), etc. In particular, since the hydrous magnesium silicate powder obtained by the present invention has a high level of safety equivalent to that of synthetic talc, it is preferable that the powder be applied to the fields of cosmetics, hygiene products, pharmaceuticals and / or food.

[0132] For example, when applied to the cosmetic field, the cosmetic composition may contain, in addition to the silicate mineral of the present invention, various components such as colorants, extender pigments, lustrous agents, oily components, moisturizers, surfactants, thickeners, preservatives, UV scattering agents, antioxidants, and chelating agents, as needed.

[0133] Examples of colorants include, but are not limited to, inorganic pigments, organic pigments, dyes, and natural colors.

[0134] Examples of extender pigments include, but are not limited to, inorganic powders such as silica, mica, synthetic fluorphlogopite, glass powder, barium sulfate, kaolin, bentonite, hectorite, zeolite, bismuth oxychloride, zirconium oxide, magnesium oxide, aluminum oxide, calcium sulfate, barium sulfate, magnesium sulfate, calcium carbonate, magnesium carbonate, and talc. Further examples include, but are not limited to, silicone elastomers such as nylon, polyethylene, and (vinyl dimethicone / methicone silsesquioxane) crosspolymer, dispersants such as polymethyl methacrylate, lauroyl lysine, silk powder, cellulose powder, and polyvalent metal salts of long-chain fatty acids, and organic powders such as various wax powders.

[0135] Examples of shining pigments include, but are not limited to, those obtained by coating the surface of plate-like powders such as mica, synthetic fluorophlogopite, glass, silica, alumina, etc. with colorants such as titanium oxide, iron oxide, silicon oxide, Prussian blue, chromium oxide, tin oxide, chromium hydroxide, gold, silver, carmine, and organic pigments such as Red No. 202 and Yellow No. 4, and those obtained by cutting raw film rolls such as polyethylene terephthalate-polymethyl methacrylate laminated powder, polyethylene terephthalate-aluminum vapor-deposited powder, polyethylene terephthalate-gold vapor-deposited laminated powder, etc. into any shape.

[0136] Examples of oily components that can be used include hydrocarbon oils, ester oils, waxes, higher alcohols, and animal and vegetable oils. Examples of hydrocarbon oils include squalane, dodecane, tetradecane, and hexadecane. Examples of ester oils include phytosteryl macadamiate, octyldodecyl myristate, tri(caprylic / capric acid)glyceryl, stearyl stearate, methylheptyl isostearate, hexyl laurate, isoacyl laurate, coconut (caprate / caprate), isocetyl myristate, and isostearyl isostearate. Examples of waxes include beeswax, Japan wax, carnauba wax, rice bran wax, sunflower seed wax, candelilla wax, gay wax, and montan wax. Examples of higher alcohols (monohydric alcohols with 6 or more carbon atoms) include methylheptyl isostearate, ... Examples of suitable oils include cetyl alcohol, stearyl alcohol, isostearyl alcohol, lauryl alcohol, and behenyl alcohol; and examples of suitable animal and vegetable oils include avocado oil, linseed oil, almond oil, olive oil, cacao oil, sesame oil, wheat germ oil, safflower oil, jojoba oil, phytosteryl macadamiate, shea butter, turtle oil, camellia oil, persic oil, castor oil, grape oil, macadamia nut oil, palm oil, rosehip oil, soybean oil, egg yolk oil, hydrogenated castor oil, hydrogenated palm oil, hydrogenated cocoa oil, hydrogenated turtle oil, hydrogenated mink oil, beef tallow, mink oil, lanolin (wool fat), and oily components extracted from these ingredients, but are not limited to these.

[0137] Examples of moisturizing agents include, but are not limited to, polyhydric alcohols such as glycerin, 1,3-butylene glycol, propylene glycol, polyethylene glycol, and diglycerin trehalose; polymeric compounds such as sodium hyaluronate, heparinoids, sodium chondroitin sulfate, collagen, elastin, keratin, chitin, and chitosan; amino acids such as glycine, aspartic acid, and arginine; natural moisturizing factors such as sodium lactate, urea, and sodium pyrrolidone carboxylate; lipids such as ceramide, cholesterol, and phospholipids; and plant extracts such as chamomile extract, witch hazel extract, tea extract, and perilla extract.

[0138] The surfactant may be an anionic surfactant, a cationic surfactant, a nonionic surfactant, or an amphoteric surfactant. Examples of the glycerin fatty acid ester include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, monocetyl glyceryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene derivatives such as polyoxyalkyl allyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene hydrogenated castor oil, and polyoxyethylene lanolin; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monooleate, sorbitan sesquioleate, and sorbitan monostearate; polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan monooleate; polyoxyethylene sorbitol fatty acid esters such as polyoxyethylene sorbitan tetraoleate; polyethylene glycol fatty acid esters such as polyethylene glycol monolaurate and polyethylene glycol monooleate; alkyl glyceryl ethers such as isostearyl glyceryl ether; and glycerin fatty acid esters such as glyceryl monobehenate. Examples of surfactants include, but are not limited to, one or more selected from anionic surfactants such as fatty acid monocarboxylates, polyoxyethylene alkyl ether acetates, alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphate esters, stearoyl methyl taurine and salts thereof; and amphoteric surfactants such as fatty acid amidopropyl betaine, alkyl imidazolium betaine, alkyl dimethyl aminoacetic acid betaine, alkyl dimethyl sulfobetaine, alkyl dimethyl amine oxide, and alkyl hydroxy sulfobetaine.

[0139] Examples of thickeners include, but are not limited to, guar gum, locust bean gum, carrageenan, xanthan gum, carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydrophobized hydroxypropyl methyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, carboxyvinyl polymer, acrylate / alkyl methacrylate copolymer, polyethylene glycol, bentonite, (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer, (ammonium acryloyldimethyltaurate / vinylpyrrolidone) copolymer, and the like.

[0140] Examples of preservatives include, but are not limited to, benzoic acid, sodium benzoate, dehydroacetic acid, sodium dehydroacetate, isobutyl parahydroxybenzoate, isopropyl parahydroxybenzoate, butyl parahydroxybenzoate, ethyl parahydroxybenzoate, propyl parahydroxybenzoate, benzyl parahydroxybenzoate, methyl parahydroxybenzoate, phenoxyethanol, chlorobutanol, chlorhexidine, salicylic acid, benzalkonium chloride, cetyltrimethylammonium bromide, acrinol, benzethonium chloride, cresol, gluconic acid and its derivatives, povidone-iodine, potassium iodide, iodine, isopropylmethylphenol, triclocarban, triclosan, Photosensitizer No. 101, Photosensitizer No. 201, paraben, phenoxyethanol, 1,2-pentanediol, alkyldiaminoglycine hydrochloride, piroctone olamine, and miconazole.

[0141] Examples of ultraviolet absorbers include para-aminobenzoic acid, glyceryl para-aminobenzoate, ethyl dihydroxypropyl para-aminobenzoate, octyl dimethyl para-aminobenzoate, amyl para-dimethylaminobenzoate, diethylaminohydroxybenzoyl hexyl benzoate, methyl anthranilate, homomenthyl salicylate, 2-ethylhexyl salicylate, triethanolamine salicylate, 2-ethylhexyl para-methoxycinnamate, and glyceryl di-para-methoxycinnamate mono-2-ethylhexanoate. , methyl 2,5-diisopropylcinnamate, methyl bis(trimethylsiloxy)silylisopentyl trimethoxycinnamate, isopropyl paramethoxycinnamate, isopropyl paramethoxycinnamate-diisopropyl cinnamate mixture, 2-ethoxyethyl paramethoxycinnamate, diethanolamine paramethoxycinnamate, 4-isopropyldibenzoylmethane, 4-tert-butyl-4'-methoxydibenzoylmethane, 2,4,6-tris[4-(2-ethylhexyloxycarbonyl) anilino]-1,3,5-triazine, 2,4-bis-[{4-(2-ethylhexyloxy)-2-hydroxy}-phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'4,4'-tetrahydroxybenzophenone, 4-(2-β-glucopyranosyloxy)propanol Examples of the benzotriazolidine dibenzoate include, but are not limited to, 2-hydroxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-ethylhexyl dimethoxybenzylidene dioxoimidazolidinepropionate, octocrylene, cinoxate, phenylbenzimidazole sulfonic acid, 1-(3,4-dimethoxyphenyl)-4,4-dimethyl-1,3-pentanedione, 3-(4-methylbenzylidene)camphor, methylenebisbenzotriazolyltetramethylbutylphenol, and the like.

[0142] Examples of ultraviolet scattering agents include, but are not limited to, titanium oxide, zinc oxide, and cerium oxide.

[0143] Examples of antioxidants include, but are not limited to, natural vitamin E, tocopherol, dibutylhydroxytoluene, butylhydroxyanisole, sorbic acid, sodium sulfite, ascorbic acid, erythorbic acid, L-cysteine ​​hydrochloride, etc. Examples of pH adjusters include, but are not limited to, inorganic acids (hydrochloric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, boric acid, etc.), organic acids (lactic acid, acetic acid, citric acid, sodium citrate, tartaric acid, malic acid, succinic acid, sodium succinate, oxalic acid, gluconic acid, fumaric acid, propionic acid, acetic acid, aspartic acid, ε-aminocaproic acid, glutamic acid, aminoethylsulfonic acid, etc.), gluconolactone, ammonium acetate, inorganic bases (sodium bicarbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, calcium hydroxide, magnesium hydroxide, etc.), and organic bases (monoethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, lysine, etc.).

[0144] Examples of chelating agents include, but are not limited to, ethylenediaminetetraacetic acid (edetic acid), ethylenediaminetetraacetic acid salts (sodium salts (sodium edetate: Japanese Pharmacopoeia, EDTA-2Na, etc.), potassium salts, etc.), phytic acid, gluconic acid, polyphosphoric acid, metaphosphoric acid, and the like.

[0145] The colorants and extender pigments described above can be surface-treated with a surface treatment agent as needed. Examples of surface treatment agents include, but are not limited to, fluorine compound treatment, silicone treatment, silicone resin treatment, pendant treatment, silane coupling agent treatment, titanium coupling agent treatment, oil treatment, metal soap treatment, N-acylated lysine treatment, polyethylene glycol treatment, PVA treatment, polyacrylic acid treatment, hyaluronic acid treatment, alginic acid treatment, inorganic compound treatment, urethane cross-linked polymer treatment, plasma treatment, and mechanochemical treatment. Among these, metal stone treatment and urethane cross-linked polymer treatment are preferred. Examples of metal soap treatments include aluminum dimyristate treatment, aluminum stearate treatment, and aluminum distearate treatment. Examples of urethane cross-linked polymer treatments include (HDI / trimethylolhexyllactone) cross-polymer treatment.

[0146] Furthermore, until now, underground mineral formation has been caused by precipitation due to temperature and pressure, and the composition of the precipitate varies depending on the location of the mineral. The only solution has been to carefully examine and select parts that contain almost no impurities. However, with this invention, even raw materials that contain impurities above the specified value may be able to have the impurity content reduced to below the specified value. In this respect, the invention is of great advantage to silicate mineral processing and sales companies.

[0147] In the present invention, the term "products containing silicate minerals" refers to both cases where silicate minerals are contained in a composition and cases where silicate minerals are attached to an article. For example, the term "pharmaceutical products containing silicate minerals" refers to both cases where silicate mineral powder is contained in a pharmaceutical composition as a tablet excipient or lubricant, and cases where silicate mineral powder is attached to medical rubber gloves.

[0148] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0149]

[0150]

[0151] Test Example 1: Hydrothermal Reaction Treatment of Natural Talc Containing Quartz [Hydrothermal Reaction Treatment of Natural Talc] The test was carried out using a batch tester (device name: shaking reactor heating and stirring device, manufactured by AKICO Corporation). 0.45 g (concentration: 10 wt%) of natural talc having an average particle size of 5 μm and containing quartz as an impurity and H ２ After adding 04 ml of ethanol and mixing well, the mixture was subjected to a hydrothermal reaction treatment for 10 minutes in a batch tester under the conditions shown in Table 2. After cooling, the mixture was thoroughly washed with water to obtain a processed talc.

[0152] [Evaluation] When the processed talc after the hydrothermal reaction treatment was touched with a finger, it was found to be as smooth as the natural talc before the hydrothermal reaction treatment. The average particle size of the processed talc after the hydrothermal reaction treatment was measured. As a result, the average particle size was 5 μm in all Examples.

[0153] In addition, powder X-ray diffraction was performed on both the natural talc before the hydrothermal reaction treatment and the processed talc after the hydrothermal reaction treatment. Figure 2 shows the results for the natural talc before the hydrothermal reaction treatment, and Figure 3 shows the results for the processed talc after the hydrothermal reaction treatment according to Example 1-1. Table 3 shows the change in impurity content before and after the hydrothermal reaction treatment in each example and comparative example. In both Figures 2 and 3, the powder X-ray diffraction shows diffraction peaks at diffraction angles (2θ) of 9.45°, 18.97°, and 28.62°. This indicates that the material after the hydrothermal reaction treatment is talc.

[0154] On the other hand, a peak derived from quartz (crystalline silica) appears near 2θ = 26.6° before the hydrothermal reaction treatment, and a calibration curve obtained using a standard quartz sample shows that the talc before the hydrothermal reaction treatment contains 0.11 wt% quartz, whereas there is no alteration after the hydrothermal reaction treatment, and the peak derived from quartz disappears. In other words, it was confirmed that quartz could be sufficiently removed in Example 1-1.

[0155] Similarly, it was confirmed that quartz could be sufficiently removed from natural talc in Examples 1-2 to 1-13. In particular, it was confirmed that quartz could be sufficiently removed from natural talc even when the natural talc had a relatively high impurity content in Examples 1-10 to 1-13. Furthermore, it was confirmed that quartz could be sufficiently removed from natural talc in Examples 1-6 and 1-7 even when the natural talc concentration in the hydrothermal reaction treatment was relatively high.

[0156] Test Example 2: Hydrothermal reaction treatment of natural talc containing quartz (pH dependency) Processed talc was obtained in the same manner as in Example 1-1, except that the pH during hydrothermal treatment was adjusted to 1.4 (Example 2-1), 2.5 (Example 2-2), 6.4 (Example 2-3), and 12.0 (Comparative Example 2) by using nitric acid and sodium hydroxide.

[0157] As a result of evaluation by XRD, it was confirmed that the peaks derived from quartz decreased or disappeared in the products obtained by hydrothermal treatment at pH 1.4, 2.5, and 6.4. On the other hand, it was confirmed that the peaks derived from quartz remained in the product obtained by hydrothermal treatment at pH 12.0. In Example 1-1, the pH was 9.4, so it was confirmed that quartz could be removed at a pH lower than that, but conversely, quartz could not be removed at a pH that was too high.

[0158] The average particle size of the primary particles of the products obtained at pH 1.4, 2.5 and 6.4 was measured and found to be 5 μm in all cases.

[0159] Test Example 3 Hydrothermal Reaction Treatment of Natural Talc Containing Quartz (Addition of Mg Ions) 0.06 g of natural talc (concentration: 1.5 wt %) and MgCl ２ : 3 mg (concentration 0.075 wt%) and H ２ A processed talc was obtained in the same manner as in Example 1-1, except that 4 ml of HCl was added and the hydrothermal reaction time was set to 240 minutes.

[0160] As a result of evaluation by XRD, a reduction in the peaks derived from quartz was confirmed. Even when natural talc with a relatively high impurity content was used as in Example 1-5, the same amount of quartz was reduced even at a hydrothermal reaction temperature of 150°C.

[0161] Test Example 4 Hydrothermal Reaction Treatment of Natural Talc Containing Impurities Other Than Quartz Example 4-1 Hydrothermal Reaction Treatment of Natural Talc Containing Cristobalite Processed talc was obtained in the same manner as in Example 1-1, except that natural talc containing 0.12 wt % of cristobalite, a type of crystalline silica, was used as the raw material.

[0162] As a result of evaluation by XRD, the peak at a diffraction angle (2θ) of 22.0° attributable to cristobalite disappeared, confirming that the content of cristobalite could be reduced to 0.1 wt % or less by the hydrothermal reaction treatment.

[0163] Example 4-2 Hydrothermal Reaction Treatment of Natural Talc Containing Tridymite Processed talc was obtained in the same manner as in Example 1-1, except that natural talc containing 0.12 wt % of tridymite, a type of crystalline silica, was used as the raw material.

[0164] As a result of evaluation by XRD, the peaks at diffraction angles (2θ) of 20.5° and 21.6° attributable to tridymite disappeared, confirming that the tridymite content could be reduced to 0.1 wt % or less by hydrothermal treatment.

[0165] Examples 4-3 to 4-5 Hydrothermal Reaction Treatment of Chrysotile-Containing Natural Talc Processed talc was obtained in the same manner as in Example 1-1, except that natural talc containing 0.15 wt % chrysotile was subjected to hydrothermal treatment at 250°C for 10 minutes, 40 minutes, and 120 minutes.

[0166] As a result of evaluation by XRD, the chrysotile content was 0.075 wt % (treatment time 10 minutes), 0.03 wt % (treatment time 40 minutes), and below the detection limit (treatment time 120 minutes), confirming that the chrysotile content can be reduced to 0.1 wt % or less by hydrothermal reaction treatment.

[0167] Generally, chrysotile is a stable substance, but under hydrothermal conditions, compared to ordinary minerals, dissolution proceeds more easily from the tips of its needle-like mineral. However, even if it dissolves, there is a possibility that talc will also dissolve, so what is important is the dissolution rate, the ratio of the dissolved amount to the dissolved amount of talc, and the amount that ultimately remains. Considering the dissolution rate and amount of a large amount of silicate mineral, even if the same amount were to dissolve, it is possible that only magnesium silicate will ultimately remain. These results demonstrate that chrysotile can be sufficiently dissolved and removed, indicating that asbestos components can be removed from talc.

[0168] Test Example 5 Hydrothermal Reaction Treatment of Silicate Minerals Different from Natural Talc Example 5-1 Hydrothermal Reaction Treatment of Aluminum Magnesium Silicate Containing Quartz A processed mineral was obtained in the same manner as in Example 1-1, except that aluminum magnesium silicate containing 0.12 wt % quartz was used as the raw material.

[0169] As a result of evaluation by XRD, the diffraction peaks derived from quartz were reduced, and it was confirmed that the quartz content could be reduced to 0.04 wt % by hydrothermal treatment.

[0170] Example 5-2 Hydrothermal Reaction Treatment of Calcium Silicate Containing Quartz A processed mineral was obtained in the same manner as in Example 1-1, except that calcium silicate containing 0.12 wt % of quartz was used as the raw material.

[0171] As a result of evaluation by XRD, the diffraction peaks derived from quartz were reduced, and it was confirmed that the quartz content could be reduced to 0.04 wt % by hydrothermal treatment.

[0172] [Examples 5-3 to 5-4] Hydrothermal reaction treatment of magnesium silicate containing quartz A processed mineral was obtained in the same manner as in Example 1-1, except that magnesium silicate containing 0.12 wt % of quartz was used as the raw material (treatment times were 10 minutes and 40 minutes).

[0173] As a result of evaluation by XRD, the diffraction peaks derived from quartz disappeared, confirming that the hydrothermal treatment could reduce the quartz content to 0.01 wt % (treatment time 10 minutes), below the detection limit (treatment time 120 minutes).

[0174] Test Example 6: Relationship between hydrothermal treatment temperature, amount of OH groups on talc surface, and wettability

[0175] A processed mineral was obtained in the same manner as in Example 1-1, except that the conditions shown in Table 4 were used.

[0176] [Amount of OH groups on the talc surface] The amount of OH groups on the talc surface was evaluated using the Sears method. Specifically, the following procedure was performed: (1) 0.1 g of processed mineral was dispersed in 10 ml of water. (2) 2 g of NaCl was added, and then the pH was adjusted to 4 or less with dilute hydrochloric acid (0.12 M). (3) An aqueous NaOH solution (0.01 M) was gradually added until the pH reached 4, and the amount required to bring the pH down to 9 was then determined.

[0177] The results are shown in Table 5. It was confirmed that the amount of OH groups on the surface of natural talc increases when the natural talc is subjected to hydrothermal treatment, and that the amount of OH groups increases with increasing hydrothermal temperature.

[0178] [Wettability] For each of Example 6-2 and Comparative Example 6, talc was uniformly supported on a sample holder for X-ray diffraction. Thereafter, one drop (10 μl) of water was dropped onto the sample, and the contact angle was observed.

[0179] The results are shown in Table 5. The contact angle of natural talc was slightly reduced by hydrothermal treatment. This indicates that the wettability improved, i.e., the hydrophilicity improved. This suggests that hydrothermal treatment of silicate minerals improves their affinity with polar solvents for cosmetics, improving their compoundability.

[0180] Test Example 7 Application to Makeup Cosmetics Test Example 7-1 Application to Powder Foundation A powder foundation was prepared according to the formulation shown in Table 6. In Example 7-1, the hydrothermally treated talc obtained in Example 1-1 was used as the talc. In Comparative Example 7-1, natural talc before the hydrothermal treatment in Example 1-1 was used as the talc. (*) Example 7-1: Talc = hydrothermally treated talc obtained in Example 1-1 Comparative Example 7-1: Talc = natural talc before the hydrothermal treatment in Example 1-1

[0181] The resulting powder foundation was evaluated for slurry state, hardness, drop strength, and removal amount. As a result, it was confirmed that the powder foundation using hydrothermally treated talc had the same quality as the powder foundation using non-hydrothermally treated natural talc.

[0182] Test Example 7-2: Application to loose powder A loose powder was prepared according to the formulation shown in Table 7. In Example 7-2, the hydrothermally treated talc obtained in Example 7-1 was used as the talc. In Comparative Example 7-2, natural talc before the hydrothermal treatment in Example 1-1 was used as the talc. (*) Example 7-2: Talc = hydrothermally treated talc obtained in Example 1-1 Comparative Example 7-2: Talc = natural talc before the hydrothermal treatment in Example 1-1

[0183] The obtained loose powder was evaluated for slurry state, hardness, drop strength, and removal amount. As a result, it was confirmed that the loose powder using hydrothermally treated talc had the same quality as the loose powder using non-hydrothermally treated natural talc.

[0184] Test Example 7-3: Application to eyebrows Two types of eyebrows were prepared according to the formulations shown in Table 8. In Examples 7-3-1 and 7-3-2, the hydrothermally treated talc obtained in Example 1-1 was used as the talc. In Comparative Examples 7-3-1 and 7-3-2, natural talc before the hydrothermal treatment in Example 1-1 was used as the talc. (*) Example 7-3-1: Talc = hydrothermally treated talc obtained in Example 1-1. Formulation = as described in Test Example 7-3-1. Example 7-3-2: Talc = hydrothermally treated talc obtained in Example 1-1. Formulation = as described in Test Example 7-3-2. Comparative Example 7-3-1: Talc = natural talc before the hydrothermal treatment in Example 1-1. Formulation = as described in Test Example 7-3-1. Comparative Example 7-3-2: Talc = natural talc before the hydrothermal treatment in Example 1-1. Formulation = as described in Test Example 7-3-2.

[0185] The obtained eyebrow brow products were evaluated for their slurry state and drop strength. As a result, it was confirmed that the eyebrow brow products made with hydrothermally treated talc had the same quality as eyebrow brow products made with non-hydrothermally treated natural talc.

[0186] Test Example 8: Application to skin care cosmetics Test Example 8-1: Application to summer body lotion A summer body lotion was prepared according to the formulation shown in Table 9. In Example 8-1, the hydrothermally treated talc obtained in Example 1-1 was used as the talc. In Comparative Example 8-1, natural talc before the hydrothermal treatment in Example 1-1 was used as the talc. (*) Example 8-1: Talc = hydrothermally treated talc obtained in Example 1-1 Comparative Example 8-1: Talc = natural talc before the hydrothermal treatment in Example 1-1

[0187] The resulting summer body lotions were evaluated for their slurry state. As a result, it was confirmed that summer body lotions using hydrothermally treated talc had the same quality as summer body lotions using non-hydrothermally treated natural talc.

[0188] Test Example 8-2 Application to Pore Concealing Lotion A pore concealing lotion was prepared according to the formulation shown in Table 10. In Example 8-2, the hydrothermally treated talc obtained in Example 1-1 was used as the talc. In Comparative Example 8-2, natural talc before the hydrothermal treatment in Example 1-1 was used as the talc. (*) Example 8-2: Talc = hydrothermally treated talc obtained in Example 1-1 Comparative Example 8-2: Talc = natural talc before the hydrothermal treatment in Example 1-1

[0189] The slurry state of the obtained pore-concealing lotion was evaluated. As a result, it was confirmed that the pore-concealing lotion using hydrothermally treated talc had the same quality as the pore-concealing lotion using natural talc that had not been hydrothermally treated.

[0190] Test Example 8-3 Application to Powder Facial Cleanser A powder facial cleanser was prepared according to the formulation shown in Table 11. In Example 8-3, the hydrothermally treated talc obtained in Example 1-1 was used as the talc. In Comparative Example 8-3, natural talc before the hydrothermal treatment in Example 1-1 was used as the talc. (*) Example 8-3: Talc = hydrothermally treated talc obtained in Example 1-1 Comparative Example 8-3: Talc = natural talc before the hydrothermal treatment in Example 1-1

[0191] The resulting powder facial cleanser was evaluated for its slurry state. As a result, it was confirmed that the powder facial cleanser using hydrothermally treated talc had the same quality as the powder facial cleanser using non-hydrothermally treated natural talc.

[0192] 1 Manufacturing device 10 Extraction means 20 Cooling means

Claims

1. A silicate mineral containing less than 0.1% by weight of either crystalline silica or asbestos.

2. The silicate mineral according to claim 1, which contains carbonate.

3. The silicate mineral powder according to claim 1, wherein the average particle size of the primary particles is 100 nm or more.

4. The silicate mineral powder according to claim 1, in which the amount of NaOH aqueous solution (0.01M) required in the following procedure is 180 μl or more: (1) Disperse 0.1 g of silicate mineral powder in 10 ml of water; (2) Add 2 g of NaCl, and then adjust the pH to 4 or less with dilute hydrochloric acid (0.12M); (3) Add NaOH aqueous solution (0.01M) until the pH reaches 4, and then measure the amount of NaOH aqueous solution (0.01M) required to reach pH 9.

5. A cosmetic comprising the silicate mineral according to any one of claims 1 to 4.

6. A sanitary product comprising the silicate mineral according to any one of claims 1 to 4.

7. A pharmaceutical comprising a silicate mineral according to any one of claims 1 to 4.

8. A food product comprising the silicate mineral according to any one of claims 1 to 4.

9. A method for producing silicate minerals, comprising a step of subjecting silicate minerals derived from natural minerals to hot water or hot water treatment or hydrothermal reaction treatment at a pH of 9.4 or less.

10. The hot water or hot water treatment or the hydrothermal reaction treatment is carried out using carbon dioxide or CO ２ The method according to claim 9, wherein the method is carried out in the presence of 11. The method according to claim 9, wherein the warm water or hot water treatment or the hydrothermal reaction treatment is carried out in the presence of Mg ions.

12. The method according to claim 9, wherein the temperature in the warm water or hot water treatment or the hydrothermal reaction treatment is 70° C. or higher and 370° C. or lower, and the pressure is equal to or higher than the saturated vapor pressure of water.

13. The method according to claim 9, wherein the warm water or hot water treatment or the hydrothermal reaction treatment is carried out for a period of 1 minute or more.

14. The method according to claim 9, wherein the hot water or hydrothermal treatment or the hydrothermal reaction treatment is carried out using a batch or semi-batch apparatus.

15. The method according to claim 14, wherein the reaction apparatus is a semi-batch apparatus, and the amount of the aqueous solvent supplied to the semi-batch apparatus is 0.1 times or more the theoretical amount for dissolving the crystalline silica contained in the silicate mineral as the raw material to saturation in the reaction solution containing the coexisting ions in the reaction field.

16. The method according to claim 14, wherein the reaction apparatus is a semi-batch apparatus, and the amount of crystalline silica contained in the silicate mineral as the raw material charged to the semi-batch apparatus is 10 times or less of the theoretical amount that is saturated and dissolved in the reaction solution containing the coexisting ions in the reaction field.

17. The method according to claim 9, wherein the silicate mineral is supplied in a suspended state in water using a flow-through device, and the hot water or hot water treatment or the hydrothermal reaction treatment is carried out.

18. The method according to claim 17, wherein the concentration of the silicate mineral water slurry supplied to the flow-through device is 0.1 times or more the theoretical amount at which the crystalline silica contained in the silicate mineral as raw material is saturated and dissolved in the reaction solution containing the coexisting ions in the reaction field.

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