Method for comprehensively utilizing red mud and bauxite

Abstract

The invention provides a method for comprehensive utilization of red mud and bauxite, and relates to the technical field of bauxite, and the method comprises the following steps: mixing red mud and bauxite, adding water and a conditioning agent, and fully stirring in a tank with a stirring function to disperse red mud and bauxite particles to obtain slurry; performing electrochemical treatment on the slurry to enable valuable elements in the slurry to be subjected to oxidation-reduction reaction, and then performing thermochemical treatment to form a compound; according to the method, the red mud and the bauxite are mixed, particle dispersion is conducted, electrochemical treatment is conducted, an oxidation-reduction reaction is conducted, then thermochemical treatment is conducted, a compound is formed, separation is conducted through a cyclone separation technology, and multi-grade iron powder products are obtained by conducting multi-stage high-gradient magnetic separation on the undersize materials, the whole process is convenient to achieve, various expensive reagents are not needed, and the method is suitable for industrial production. Therefore, iron in the red mud can be greatly recycled, iron powder products of different grades can be screened out, the requirements of different downstream customers are met, and the utilization rate of the red mud is increased.

Description

Technical Field

[0001] The invention relates to the technical field of bauxite, and in particular to a method for comprehensive utilization of red mud and bauxite. Background Art

[0002] Bauxite refers to the general term for industrially usable ores with gibbsite, boehmite or diaspore as the main minerals. It is widely used in the production of refractory materials, abrasive materials, chemicals and high-alumina cement. Bauxite is mainly used in the production of alumina. In the production process, red mud is the main solid waste. Its large-scale storage not only occupies a lot of land resources, but also may cause environmental pollution. Red mud, as the main waste in the production process of alumina, contains multiple elements such as iron, aluminum, silicon, etc., but due to its complex composition and high water content, it is difficult to utilize it as a resource. At the same time, bauxite, as the main raw material for alumina production, also produces a large amount of waste during its mining and utilization. In the prior art, there is a lack of effective treatment methods for red mud and bauxite. Generally, they are simply stored and treated. Some methods use screening and other means to extract iron from red mud. The iron grade obtained is insufficient, and other elements in the waste are directly wasted and cannot be comprehensively utilized. Therefore, the present invention proposes a method for comprehensive utilization of red mud and bauxite to solve the problems existing in the prior art. Summary of the invention

[0003] In view of the above problems, the present invention proposes a method for comprehensive utilization of red mud and bauxite. The method for comprehensive utilization of red mud and bauxite is convenient to implement throughout the entire process, does not require various expensive reagents, can achieve a large-scale recovery of iron in red mud, and screen out iron powder products of different grades to meet the needs of different downstream customers, thereby improving the utilization rate of red mud.

[0004] To achieve the purpose of the present invention, the present invention is implemented by the following technical scheme: a method for comprehensive utilization of red mud and bauxite, comprising the following steps: S1: Mix red mud and bauxite, add water and a regulator, and stir them fully in a tank with a stirring function to disperse the red mud and bauxite particles to obtain a slurry; S2: electrochemically treating the slurry to cause redox reaction of the valuable elements in the slurry, followed by thermochemical treatment to form compounds; S3: using cyclone separation technology, the compounds are separated through a cyclone to obtain a cyclone underflow and a cyclone overflow; S4: Screening the cyclone bottom flow to obtain oversize and undersize, and subjecting the undersize to multi-stage high-gradient magnetic separation to obtain multi-grade iron powder products; S5: high gradient magnetic separation is performed on the cyclone overflow to obtain a low-grade fine iron powder product; S6: crushing and grinding the material on the sieve, and then using bauxite extraction technology to extract aluminum elements therein to obtain aluminum products; S7: The remaining and generated liquid in the above process is evaporated, crystallized and precipitated to obtain a silicate product, and the clear liquid after evaporation is simultaneously collected.

[0005] A further improvement is that in the S1, the components of the red mud are Fe2O3≥35%, Al2O3≤20%, and Na2O≤5%, the red mud is the slurry washed by the sedimentation process, L / S>1, and the alkali concentration is>5g / L.

[0006] A further improvement is that in S1, in the process of mixing red mud and bauxite to form a uniform slurry, sulfuric acid is used as a regulator, and a mixture of polyacrylamide and polyaluminum chloride is used as a dispersant to promote the dispersion and sedimentation of red mud and bauxite particles, and the slurry is controlled to be neutral and the viscosity is controlled to be fluid, between viscous and thin.

[0007] A further improvement is that: S2 comprises the following steps: The slurry is sent to an electrochemical treatment device, and an electric field is applied using the electrolysis principle to cause redox reactions of the valuable elements in the slurry; During this process, the current density is controlled to 150-300A / m², the voltage is controlled to 9-29V, and the processing time is controlled to 20-40min; After the electrochemical treatment, the slurry is sent to a thermochemical treatment device, the temperature is controlled to be 800-1400° C., the pressure is controlled to be 5-15 atmospheres, and the time is controlled to be 60-100 minutes to obtain the compound.

[0008] A further improvement is that in S3, during the cyclone separation process, the feed pressure is controlled to be 49-157 kPa.

[0009] A further improvement is that in S4, the multi-stage high gradient magnetic separation of the undersize material comprises the following steps: Prepare a high gradient magnetic separator and set different magnetic field strengths according to the magnetic separation requirements of iron powders with different qualities; The undersize material is subjected to high gradient magnetic separation to obtain medium-grade iron powder products; The medium-grade iron powder is subjected to high-gradient magnetic separation with increasing magnetic field strength to obtain high-grade iron powder products; The tailings after magnetic separation are subjected to high gradient magnetic separation with the highest magnetic field intensity to obtain low-grade iron powder products.

[0010] A further improvement is that in S4, after high gradient magnetic separation, a medium-grade iron powder product with a grade of 45-50% is obtained, a high-grade iron powder product with a grade of 50-55% is obtained, and a low-grade iron powder product with a grade of 40-45% is obtained.

[0011] A further improvement is that in S5, the cyclone overflow is subjected to high-gradient magnetic separation with the highest magnetic field intensity to obtain a low-grade iron powder product with a grade of 40-45%.

[0012] A further improvement is that: S6 comprises the following steps: The material on the screen is crushed and ground to obtain crushed material; The crushed material is reacted with a weak base in water to convert aluminate into soluble metaaluminate; The resulting solution is clarified and filtered to separate insoluble matter to obtain a pure sodium aluminate solution; Adding carbon dioxide into the sodium aluminate solution causes sodium hydrogen aluminate to precipitate; The precipitate is dehydrated at high temperature to obtain alumina, which is then electrolyzed to obtain aluminum.

[0013] A further improvement is that: said S7 comprises the following steps: Pre-treating the liquid product, including filtering and removing impurities; Use an evaporator for evaporation crystallization, send the pretreated liquid product into the evaporator, evaporate the water by heating, the heating temperature is controlled at 80-120°C, the evaporation pressure is controlled at 0.1-1MPa, concentrate the silicate and stir to control the crystallization; After crystallization is complete, the crystals are separated from the mother liquor by centrifugation, filtration, and sedimentation; The separated crystals are dried to remove residual water and volatile substances to obtain a silicate product, and the clear liquid after evaporation is simultaneously collected.

[0014] The beneficial effects of the present invention are: 1. The present invention mixes red mud and bauxite, disperses the particles, performs an oxidation-reduction reaction through electrochemical treatment, and then performs a thermochemical treatment to form a compound, which is separated by a cyclone separation technology, and the screened material is subjected to multi-stage high-gradient magnetic separation to obtain iron powder products of various grades. The whole process is convenient to implement, and a large amount of iron in red mud can be recovered without various expensive reagents, and iron powder products of different grades can be screened out to meet the needs of different downstream customers and improve the utilization rate of red mud.

[0015] 2. The present invention performs high-gradient magnetic separation on the cyclone overflow to obtain a low-grade fine iron powder product, and the iron recovery efficiency is higher. At the same time, the cyclone screen material is crushed and ground, and the aluminum element is extracted using bauxite extraction technology. Then, the remaining and generated liquids in all processes are evaporated, crystallized and precipitated to obtain silicate products, which is conducive to diversified recovery of various elements, diversified utilization, and environmental friendliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0017] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0018] Embodiment 1 according to Figure 1 As shown, this embodiment proposes a method for comprehensive utilization of red mud and bauxite, comprising the following steps: S1: Mix red mud and bauxite, add water and a regulator, and stir them fully in a tank with a stirring function to disperse the red mud and bauxite particles to obtain a slurry; S2: electrochemically treating the slurry to cause redox reaction of the valuable elements in the slurry, followed by thermochemical treatment to form compounds; S3: using cyclone separation technology, the compounds are separated through a cyclone to obtain a cyclone underflow and a cyclone overflow; S4: Screening the cyclone bottom flow to obtain oversize and undersize, and subjecting the undersize to multi-stage high-gradient magnetic separation to obtain multi-grade iron powder products; S5: high gradient magnetic separation is performed on the cyclone overflow to obtain a low-grade fine iron powder product; S6: crushing and grinding the material on the sieve, and then using bauxite extraction technology to extract aluminum elements therein to obtain aluminum products; S7: The remaining and generated liquid in the above process is evaporated, crystallized and precipitated to obtain a silicate product, and the clear liquid after evaporation is simultaneously collected.

[0019] The components and contents of red mud are Fe2O3-50%, Al2O3-18%, and Na2O-2.5%. Water is added to the tank to disperse the red mud particles to the maximum extent under stirring. During separation, the bottom flow is magnetically separated by a high-gradient magnetic separation device to obtain a medium-grade iron powder product with a grade of 45-50%. The medium-grade iron powder is separated by high-gradient magnetic separation to obtain a high-grade iron powder product with a grade of 50-55%; the tailings of the magnetic separator are separated by high-gradient magnetic separation to obtain a low-grade iron powder product with a grade of 40-45%; the overflow of the cyclone is separated by high-gradient magnetic separation to obtain a low-grade iron powder product with a grade of 40-45% and a finer particle size, which realizes a large-scale recovery of iron oxide in red mud. For iron powder products of different grades, the needs of different downstream customers are met, which not only improves the utilization rate of red mud, but also makes the product diversified, and has the advantage of being environmentally friendly.

[0020] Embodiment 2 according to Figure 1 As shown, this embodiment proposes a method for comprehensive utilization of red mud and bauxite, comprising the following steps: Mix red mud and bauxite, add water and a regulator, and stir them fully in a tank with a stirring function to disperse the red mud and bauxite particles, which is helpful for separation and extraction of red mud particles in subsequent steps to obtain slurry; among the components of red mud, Fe2O3≥35%, Al2O3≤20%, and Na2O≤5%, the red mud is a slurry after washing using a sedimentation process, L / S>1, and the alkali concentration is>5g / L. In the process of mixing red mud and bauxite to form a uniform slurry, sulfuric acid is used as a regulator, and a mixture of polyacrylamide and polyaluminum chloride is used as a dispersant to promote the dispersion and sedimentation of red mud and bauxite particles, and the slurry is controlled to be neutral, and the viscosity is controlled to be fluid, between viscous and thin; The slurry is electrochemically treated to make the valuable elements in the slurry undergo redox reactions, and then thermochemical treatment is performed to form compounds; specifically, the following steps are included: the slurry is sent to an electrochemical treatment device, and an electric field is applied using the electrolysis principle to make the valuable elements in the slurry undergo redox reactions; in this process, the current density is controlled to 150-300A / m², the voltage is controlled to 9-29V, and the treatment time is controlled to 20-40min; after the electrochemical treatment, the slurry is sent to a thermochemical treatment device, the temperature is controlled to 800-1400℃, the pressure is controlled to 5-15 atmospheres, and the time is controlled to 60-100min to obtain compounds; after the combined electrochemical and thermochemical treatment, the valuable elements in the slurry are effectively extracted and separated. This method not only improves the utilization efficiency of resources, but also reduces environmental pollution and energy consumption. At the same time, since the process can optimize the extraction efficiency and product quality by precisely controlling various parameters, it has high flexibility and adaptability; in the electrochemical treatment process, current density and voltage are two critical parameters. The magnitude of current density directly affects the reaction rate and extraction efficiency, while voltage determines the direction and depth of the reaction. By precisely controlling these two parameters, the extraction efficiency of valuable elements can be optimized to ensure that as many valuable elements as possible are extracted, while reducing unnecessary energy consumption and the generation of by-products; under high temperature and high pressure conditions, the valuable elements in the slurry will further undergo chemical reactions to form easily separated compounds. In the thermochemical treatment process, temperature, pressure and reaction time are three key parameters. The temperature determines the reaction rate and depth, the pressure affects the direction of the reaction and the stability of the product, and the reaction time determines the thoroughness of the reaction and the purity of the product. By precisely controlling these three parameters, the separation effect of valuable elements and product quality can be optimized to ensure that the final product has high purity and added value; Using cyclone separation technology, the compounds are separated through the cyclone to obtain the cyclone bottom flow and cyclone overflow; during the cyclone separation process, the feed pressure is controlled to be 49-157kPa; in liquid-solid separation, the cyclone bottom flow refers to the material discharged from the discharge port of the solid particles. When the suspension enters the cyclone, due to the action of centrifugal force, the solid particles with higher density will be thrown to the wall of the device and move downward with the external vortex, and finally discharged from the bottom flow port. The cyclone bottom flow is mainly solid particles; the cyclone overflow refers to the material discharged from the top or side of the cyclone (through the overflow pipe). Inside the cyclone, most of the fluid will turn upward to form an internal vortex after reaching the vicinity of the bottom flow port, and flow out from the overflow pipe. Since the sedimentation speed of particles with lower density is lower, they do not have time to settle to the wall of the device, and will be discharged from the overflow along with the internal vortex formed by most of the liquid. The cyclone overflow is mainly liquid; In the process of separation, control the diameter of the feed port: the diameter of the feed port is 0.13-0.25 times the diameter of the cyclone. Increasing the diameter of the feed port can increase the processing capacity, but the classification efficiency will be reduced. The shape and configuration of the feed pipe: the feed pipe is mostly circular or rectangular in cross-section, and the configuration is mostly in the form of the long side parallel to the axis of the cyclone and the short side perpendicular to the axis of the cyclone. The involute feed pipe has the functions of reducing energy consumption, increasing production capacity and improving separation efficiency. Control the diameter of the overflow pipe: usually 0.2-0.3 times the diameter of the cyclone. Its main function is to steadily, constantly and continuously lead the separated overflow product out of the body. Control the diameter of the sand settling port: confirm To ensure that the sand is discharged in an umbrella shape, an angle of 20°-30° is ideal. The diameter of the sand outlet is 0.07-0.1 times the diameter of the overflow pipe. Control the insertion depth of the overflow pipe: the insertion depth has a significant impact on the separation effect. It is generally 0.5-0.8 times the height of the cylindrical barrel. Too shallow insertion will increase the short-circuit flow, shorten the separation time, and increase the content of coarse particles in the overflow product; too deep insertion will cause the coarse particles at the bottom to enter the overflow, reducing the classification efficiency. Control the feed pressure. The feed pressure has a direct impact on the cyclone processing capacity and separation particle size. Keep it in the range of 49-157kPa. Increasing the feed pressure can reduce the classification particle size and increase the processing capacity; The cyclone bottom flow is screened to obtain the oversize and undersize materials, and the undersize materials are subjected to multi-stage high-gradient magnetic separation to obtain multi-grade iron powder products; the multi-stage high-gradient magnetic separation of the undersize materials includes the following steps: preparing a high-gradient magnetic separator, and setting different magnetic field strengths according to the magnetic separation requirements of iron powders of different grades; performing high-gradient magnetic separation on the undersize materials to obtain medium-grade iron powder products; performing high-gradient magnetic separation on the medium-grade iron powder with increasing magnetic field strength to obtain high-grade iron powder products; performing high-gradient magnetic separation on the tailings after magnetic separation with the highest magnetic field strength to obtain low-grade iron powder products; after high-gradient magnetic separation, a medium-grade iron powder product with a grade of 45-50% is obtained, a high-grade iron powder product with a grade of 50-55% is obtained, and a low-grade iron powder product with a grade of 40-45% is obtained; The overflow of the cyclone is subjected to high gradient magnetic separation to obtain a low-grade fine iron powder product; specifically: high gradient magnetic separation with the highest magnetic field intensity is performed to obtain a low-grade and fine iron powder product with a grade of 40-45%; the iron recovery efficiency is higher; The material on the sieve is crushed and ground, and then the aluminum element is extracted using bauxite extraction technology to obtain aluminum products; the specific steps include: The material on the screen is crushed and ground to obtain crushed material; The crushed material is reacted with a weak base in water to convert aluminate into soluble metaaluminate, A1203+ 2NaOH+3H20→2NaAI(OH)4; The resulting solution is clarified and filtered to separate insoluble matter to obtain a pure sodium aluminate solution; Adding carbon dioxide to the sodium aluminate solution causes sodium hydroaluminate to precipitate, 2NaAI(0H)4+C02-Na2C03+2A1(0H)3↓+ H20; The precipitate is dehydrated at high temperature to obtain aluminum oxide, 2AI(OH)3→A1203+ 3H20; Then aluminum is obtained by electrolysis, Hall-Heroult electrolysis, 2A12O3+3C→4A1 + 3C02; The remaining and generated liquid in the above process is evaporated, crystallized and precipitated to obtain a silicate product, and the clear liquid after evaporation is collected simultaneously. Specifically, the following steps are included: pre-treating the liquid product, including filtering and removing impurities; using an evaporator for evaporation and crystallization, sending the pre-treated liquid product into the evaporator, evaporating the water by heating, the heating temperature is controlled to 80-120°C, the evaporation pressure is controlled to 0.1-1MPa, concentrating the silicate and stirring to control the crystallization; after the crystallization is completed, the crystals are separated from the mother liquor by centrifugation, filtration and sedimentation; the separated crystals are dried to remove residual water and volatile substances to obtain a silicate product, and the clear liquid after evaporation is collected simultaneously. The evaporation rate depends on the heating temperature, evaporation pressure and properties of the liquid product, and is controlled to be 9-15t per hour, the crystallization temperature is controlled to be near the saturation temperature of the silicate, the crystallization time depends on factors such as the concentration of the silicate, the crystallization temperature and the stirring intensity, and is controlled to be 5-12h, and the stirring intensity has an important influence on the growth and morphology of the crystals, and is controlled to be 2500-3800r / min.

[0021] The method for comprehensive utilization of red mud and bauxite is to mix red mud and bauxite, disperse the particles, perform redox reaction through electrochemical treatment, then perform thermochemical treatment to form compounds, separate them by cyclone separation technology, perform multi-stage high-gradient magnetic separation on the undersize material, and obtain multi-grade iron powder products. The whole process is convenient to implement, and no various expensive reagents are required. It can achieve a large-scale recovery of iron in red mud, and screen out iron powder products of different grades to meet the needs of different downstream customers, thereby improving the utilization rate of red mud. At the same time, the present invention performs high-gradient magnetic separation on the overflow of the cyclone to obtain a low-grade fine iron powder product, and the iron recovery efficiency is higher. At the same time, the oversize material of the cyclone is crushed and ground, and the aluminum element therein is extracted by using bauxite extraction technology, and then the remaining and generated liquids in all processes are evaporated, crystallized, and precipitated to obtain silicate products, which is conducive to diversified recovery of various elements, diversified utilization, and environmental friendliness.

[0022] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for comprehensive utilization of red mud and bauxite, characterized in that: The following steps are involved: S1: Mix red mud and bauxite, add water and a regulator, and stir them fully in a tank with a stirring function to disperse the red mud and bauxite particles to obtain a slurry; S2: electrochemically treating the slurry to cause redox reaction of the valuable elements in the slurry, followed by thermochemical treatment to form compounds; S3: using cyclone separation technology, the compounds are separated through a cyclone to obtain a cyclone underflow and a cyclone overflow; S4: Screening the cyclone bottom flow to obtain oversize and undersize, and subjecting the undersize to multi-stage high-gradient magnetic separation to obtain multi-grade iron powder products; S5: high gradient magnetic separation is performed on the cyclone overflow to obtain a low-grade fine iron powder product; S6: crushing and grinding the material on the sieve, and then using bauxite extraction technology to extract aluminum elements therein to obtain aluminum products; S7: The remaining and generated liquid in the above process is evaporated, crystallized and precipitated to obtain a silicate product, and the clear liquid after evaporation is simultaneously collected.

2. The method for comprehensive utilization of red mud and bauxite according to claim 1, characterized in that: In the S1, the components of the red mud are Fe2O3≥35%, Al2O3≤20%, and Na2O≤5%. ​​The red mud is the slurry washed by the sedimentation process, L / S>1, and the alkali concentration is>5g / L.

3. The method for comprehensive utilization of red mud and bauxite according to claim 2, characterized in that: In S1, in the process of mixing red mud and bauxite to form a uniform slurry, sulfuric acid is used as a regulator, and a mixture of polyacrylamide and polyaluminum chloride is used as a dispersant to promote the dispersion and sedimentation of red mud and bauxite particles, and the slurry is controlled to be neutral and the viscosity is controlled to be fluid, between viscous and thin.

4. The method for comprehensive utilization of red mud and bauxite according to claim 1, characterized in that: The S2 comprises the following steps: The slurry is sent to an electrochemical treatment device, and an electric field is applied using the electrolysis principle to cause redox reactions of the valuable elements in the slurry; During this process, the current density is controlled to 150-300A / m², the voltage is controlled to 9-29V, and the processing time is controlled to 20-40min; After the electrochemical treatment, the slurry is sent to a thermochemical treatment device, the temperature is controlled to be 800-1400° C., the pressure is controlled to be 5-15 atmospheres, and the time is controlled to be 60-100 minutes to obtain the compound.

5. The method for comprehensive utilization of red mud and bauxite according to claim 1, characterized in that: In S3, during the cyclone separation process, the feed pressure is controlled to be 49-157 kPa.

6. The method for comprehensive utilization of red mud and bauxite according to claim 1, characterized in that: In S4, the multi-stage high gradient magnetic separation of the undersize material comprises the following steps: Prepare a high gradient magnetic separator and set different magnetic field strengths according to the magnetic separation requirements of iron powders with different qualities; The undersize material is subjected to high gradient magnetic separation to obtain medium-grade iron powder products; The medium-grade iron powder is subjected to high-gradient magnetic separation with increasing magnetic field strength to obtain high-grade iron powder products; The tailings after magnetic separation are subjected to high gradient magnetic separation with the highest magnetic field intensity to obtain low-grade iron powder products.

7. The method for comprehensive utilization of red mud and bauxite according to claim 6, characterized in that: In S4, after high gradient magnetic separation, a medium-grade iron powder product with a grade of 45-50% is obtained, a high-grade iron powder product with a grade of 50-55% is obtained, and a low-grade iron powder product with a grade of 40-45% is obtained.

8. The method for comprehensive utilization of red mud and bauxite according to claim 1, characterized in that: In S5, the cyclone overflow is subjected to high gradient magnetic separation with the highest magnetic field intensity to obtain a low-grade iron powder product with a grade of 40-45%.

9. The method for comprehensive utilization of red mud and bauxite according to claim 1, characterized in that: The S6 comprises the following steps: The material on the screen is crushed and ground to obtain crushed material; The crushed material is reacted with a weak base in water to convert aluminate into soluble metaaluminate; The resulting solution is clarified and filtered to separate insoluble matter to obtain a pure sodium aluminate solution; Adding carbon dioxide into the sodium aluminate solution causes sodium hydrogen aluminate to precipitate; The precipitate is dehydrated at high temperature to obtain alumina, which is then electrolyzed to obtain aluminum.

10. The method for comprehensive utilization of red mud and bauxite according to claim 1, characterized in that: The S7 comprises the following steps: Pre-treating the liquid product, including filtering and removing impurities; Use an evaporator for evaporation crystallization, send the pretreated liquid product into the evaporator, evaporate the water by heating, the heating temperature is controlled at 80-120°C, the evaporation pressure is controlled at 0.1-1MPa, concentrate the silicate and stir to control the crystallization; After crystallization is complete, the crystals are separated from the mother liquor by centrifugation, filtration, and sedimentation; The separated crystals are dried to remove residual water and volatile substances to obtain a silicate product, and the clear liquid after evaporation is simultaneously collected.

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