Preparation method of quartz processing micro-nano material

Abstract

The application provides a preparation method of quartz processing micro-nano material, which comprises the following steps: obtaining quartz powder material of a required grade by performing preliminary cleaning, rough crushing, fine crushing, rough grinding, magnetic separation and screening on quartz ore raw materials; mixing the obtained quartz powder material with a grinding aid agent, wherein the grinding aid agent is PVA grafted silica microspheres; performing classification on the obtained powder by a high-performance gravity-free negative pressure grinder, and performing separation on the fine powder obtained after the classification by a high-efficiency powder separator to obtain micro-nano material with a particle size less than 150 nm; and removing PVA from the micro-nano material after treatment. After obtaining the quartz powder material with uniform size, performing secondary fine grinding, and adding the grinding aid agent PVA grafted silica microspheres, on one hand, the nano microspheres have a small particle size, and on the other hand, after the quartz powder material is filled with the microspheres, the microspheres assist in impacting and rubbing the quartz particles when grinding, so that the quartz powder material is more easily formed into smaller substances to obtain the micro-nano material with a required particle size.

Description

TECHNICAL FIELD

[0001] The present application relates to a micro-nano processing technology, in particular to a technology for industrial processing of quartz ore to form micro-nano materials. BACKGROUND

[0002] Quartz is a mineral widely present in the earth's crust, with a chemical composition of silicon dioxide (SiO2). It is one of the most common minerals on Earth and is a major component of many rocks.

[0003] Quartz has high hardness, chemical stability and corrosion resistance, and is not easily affected by chemical environment, so it has a wide range of applications in the industry. Quartz can be divided into various varieties according to its crystal structure, the most common of which are alpha-quartz (normal quartz), beta-quartz (high-temperature quartz) and amorphous quartz with irregular crystal structure.

[0004] The main source of quartz is quartz ore, and the processing of quartz ore usually includes the following main steps: mining and beneficiation: first, the ore containing quartz ore is mined, and then the quartz ore is separated from other minerals or impurities by beneficiation. Crushing and grinding: the quartz ore is crushed and ground to a suitable particle size for processing. Washing: using washing method to remove surface impurities and soil of quartz ore. Classification and efficient powder selection: according to the use and specification requirements of quartz ore, classification and efficient powder selection are carried out to divide it into products of different particle sizes. Magnetic separation: using magnetic separation technology to remove magnetic impurities in quartz ore. Finally, after crushing and grinding, the required product form such as sand, powder, particle, micro-nano powder, etc. is obtained for different industrial application fields.

[0005] However, in the prior art, when quartz ore needs to be processed into micro-nano materials, it is relatively difficult, usually only small-scale operation, which is mainly because it is difficult to obtain micro-nano materials by later grinding; and the quality of the obtained micro-nano materials cannot be guaranteed; among them, the more important index is to control the amount of metal elements such as aluminum and calcium elements in the final product, the amount of aluminum and calcium elements needs to be controlled below a certain amount, but this index often exceeds the standard, because the performance of magnetic separation process to remove trace metal elements is not complete. SUMMARY

[0006] In order to solve the problems existing in the above-mentioned technology, the present application provides a technology capable of reducing the content of metal elements in quartz ore.

[0007] The present application provides a preparation method of quartz processing micro-nano material, which comprises the following steps:

[0008] Step 1: A preliminary cleaning, coarse crushing, fine crushing, coarse grinding, magnetic separation and screening of the quartz ore raw material are performed to obtain a quartz powder material of a desired grade, and the particle size of the quartz powder material is below 600 nm;

[0009] Step 2: The quartz powder material obtained in Step 1 is mixed with a grinding aid, and the grinding aid is PVA grafted silica microspheres.

[0010] Step 3: The powder obtained by regrinding through a high-performance gravity-free negative pressure grinder is classified and separated by a high-efficiency powder separator, and the fine powder obtained is separated by a high-efficiency separation powder separator to obtain a micro-nano material with a particle size of less than 150 nm.

[0011] Step 4: The micro-nano material is treated to remove PVA.

[0012] Preferably,

[0013] Step 1 includes the following steps:

[0014] Raw material preparation: First, the collected quartz ore is preliminarily screened and cleaned to remove impurities and soil;

[0015] Coarse crushing: The cleaned quartz ore is sent to a crusher for preliminary crushing to break the quartz blocks into smaller particles;

[0016] Fine crushing: The quartz particles after coarse crushing are sent to a jaw crusher or a grinding machine for fine crushing to make them into finer particles;

[0017] Grinding: The fine crushed quartz particles are sent to a grinding machine for further crushing to grind the quartz particles into fine powder;

[0018] Magnetic separation: The powder is sent to a magnetic separator for magnetic separation to reduce the content of metal elements;

[0019] Classification and high-efficiency powder separation: The crushed quartz powder is screened by a vibrating screen device, and classified and high-efficiency powder separated according to different particle size requirements.

[0020] Preferably, the preparation process of the PVA grafted silica microspheres is as follows:

[0021] First, the acidic silica microspheres are connected with PVA to form PVA grafted silica nanomicrospheres.

[0022] Preferably, the molecular weight of PVA in the PVA grafted silica microspheres is 10,000 to 30,000, and the ratio of the amount of silica nanoparticles to PVA is 5:1 to 10:1.

[0023] Preferably, the micro-nano material is added into concentrated hydrochloric acid in water and heated to 50 to 70 DEG C, and after stirring for 1 to 2 hours, the layering is separated after standing, the process makes PVA separate from the silica microspheres, the solid material at the bottom is the desired micro-nano material, and the product is obtained after drying.

[0024] Preferably, the acidic silica nanoparticles are reacted with PVA under the catalysis of DMAP and DCC, the mass usage ratio of DMAP and DCC is 1:3 to 1:5, the mass usage of DMAP and DCC is 1% to 5% of the total reactants; the reaction temperature is 25 to 30 DEG C, and the reaction is carried out in dichloromethane solvent for 12 to 24 hours.

[0025] The beneficial effects of the present application are: after obtaining the quartz powder material with uniform size, secondary fine grinding is carried out, and the microspheres of PVA grafted silica are added, on the one hand, the nano microspheres have small particle size, and after filling in the quartz powder material, the small balls assist the impact and friction on the quartz particles when grinding, so that the quartz powder material is more easily formed into smaller substances to obtain the micro-nano material with the desired particle size; and in the subsequent cleaning process, PVA can well adsorb trace amounts of aluminum ions and calcium ions in the aqueous solution, and play a chelating adsorption role; and after acid treatment, PVA is completely dissolved in the aqueous phase, so that it is separated from the quartz powder by layering, thereby improving the purity; the final data obtained by detection show that the contents of aluminum ions and calcium ions are lower than those of the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is the PVA grafted silica microspheres and the adsorption of metal ions and the subsequent separation process reaction process schematic diagram of the present application. DETAILED DESCRIPTION

[0027] The present application provides a kind of quartz processing micro-nano material preparation method, it includes the following steps:

[0028] Step 1: the quartz ore raw material is preliminarily washed, coarsely broken, finely broken, coarsely ground, magnetically selected and screened to obtain a quartz powder material of a required grade, the particle size of the quartz powder material being below 600 nm; Step 1 includes the following steps: raw material preparation: the collected quartz ore is first preliminarily screened and washed to remove impurities and soil; coarse breaking: the washed quartz ore is sent into a breaker to be preliminarily broken into smaller particles; fine breaking: the quartz particles after the coarse breaking are sent into a jaw crusher or a grinding machine for fine breaking to become finer particles. Grinding: the finely broken quartz particles are sent into a grinding machine for further grinding to grind the quartz particles into fine powder. Magnetic selection: the powder is sent into a magnetic separator to reduce the content of metal elements; grading and high-efficiency powder selection: the ground quartz powder is screened by a vibrating screen device to be graded and high-efficiency selected according to different particle size requirements.

[0029] Step 2: the quartz powder material obtained in Step 1 is mixed with a grinding aid, the grinding aid being PVA grafted silica microspheres; the preparation process of the PVA grafted silica microspheres is as follows: first, acid silica microspheres are connected with PVA to form PVA grafted silica nanomicrospheres. The molecular weight of the PVA in the PVA grafted silica microspheres is 10,000 to 30,000, and the use amount ratio of the silica nanoparticles to the PVA is 5:1 to 10:1. The combination process of the silica and the PVA is as follows: the acid silica nanoparticles and PVA (polyvinyl alcohol) are reacted under the catalysis of DMAP (4-dimethylaminopyridine) and DCC (dicyclohexyl carbodiimide), the mass use amount ratio of DMAP to DCC being 1:3, the mass use amount of DMAP and DCC being 1% of the total reactants; the reaction temperature is 25°C, and the reaction is carried out in dichloromethane solvent for 12 hours.

[0030] The acid silica microspheres are obtained by using the acid silica microspheres produced by Xi'an Qiyue Reagent, or by using the method mentioned in Chinese Patent CN201110022611.2, a carboxylated mesoporous silica nanoparticle carrier material and a preparation method.

[0031] Step 3: the powder obtained by regrinding by a high-performance gravity-free negative pressure grinder is graded and high-efficiency selected to obtain fine powder, and the fine powder is separated by a high-efficiency separation powder separator to obtain micro-nano material with a particle size of less than 150 nm; the high-performance gravity-free negative pressure grinder can be a Zhejiang nano negative pressure grinder or a Mi negative pressure grinder.

[0032] Step 4: The micro-nano material is treated to remove PVA. The process is as follows: the micro-nano material is added to concentrated hydrochloric acid in water and heated to 70°C, stirred for 2 hours and then allowed to separate into layers. This process separates PVA from the silica microspheres. After standing, the solid at the bottom is the desired micro-nano material, which is dried to obtain the product. The separated water phase contains the separated PVA, which carries impurity metal ions.

[0033] Example 1 uses PVA with a molecular weight of 20,000, and the ratio of the amount of silica nanoparticles to PVA is 5:1.

[0034] Example 2 uses PVA with a molecular weight of 20,000, and the ratio of the amount of silica nanoparticles to PVA is 8:1.

[0035] Example 3 uses PVA with a molecular weight of 20,000, and the ratio of the amount of silica nanoparticles to PVA is 10:1.

[0036] Control Example 1 uses ordinary silica nanoparticles as a grinding aid.

[0037] Control Example 2 does not add a grinding aid for grinding.

[0038] Table 1 shows the particle size data and metal content data obtained by different grinding times and the effect of the grinding aid for Examples 1 to 3 and Control Examples 1 / 2.

[0039]

[0040] From the above table, on the one hand, by adding a grinding aid, the micro-nano material with a particle size below 150 nm is obtained after 6 hours of grinding. In comparison, in Control Example 1, this requirement can also be met, while in Control Example 2, since no grinding aid is added, the grinding time is prolonged during the grinding process, and the grinding effect is not good.

[0041] From the Al content, by introducing PVA, it can adsorb and chelate the metal ions, so that the metal ions can enter the water layer and separate from the micro-nano material, and through acidolysis, PVA and silica microspheres are separated, so that PVA and silica are separated, thereby taking away the Al element. This way makes the metal element content in the final product lower and easier to control, without the need to use other more complex or high-cost metal impurity removal technologies, reducing enterprise production costs.

[0042] In addition, the Ca content is also controlled and reduced.

[0043] The beneficial effects of the present application are: after obtaining the quartz powder material with uniform size, secondary fine grinding is carried out, and the microspheres of PVA grafted silica are added, on the one hand, the nano microspheres are small in size, and after filling the quartz powder material, the small balls assist the negative pressure airflow to impact and rub the quartz particles when grinding, so that the quartz powder material is more easily formed into smaller substances to obtain the micro-nano material with the required particle size; and in the subsequent cleaning process, PVA can well adsorb trace amounts of aluminum ions and calcium ions in the aqueous solution, play a chelating adsorption role, and after acid treatment, PVA is completely dissolved in the aqueous phase, so that it is separated from the quartz powder by layering, thereby improving the purity; the final data obtained by detection show that the contents of aluminum ions and calcium ions are lower than those of the prior art.

[0044] In the treatment process of the present application, when hydrochloric acid is added, the effect of pickling is achieved. In addition, the existing pickling process can also be carried out in the crushing process such as fine crushing and coarse grinding to further remove impurities. In addition, if the material below 600 nm below the requirement is not obtained in the first screening process, the grinding and crushing can be carried out again until the required material is obtained.

Claims

1. A method for preparing quartz micro / nanomaterials, characterized in that, include: Step 1: The quartz ore raw material is initially cleaned, coarsely crushed, finely crushed, coarsely ground, magnetically separated and screened to obtain quartz powder material of the required grade. The particle size of the quartz powder material is less than 600nm. Step 2: Mix the quartz powder material obtained in Step 1 with a grinding aid, which is PVA-grafted silica microspheres; Step 3: The powder obtained by grinding again with a high-performance zero-gravity negative pressure mill is classified and separated by a high-efficiency air classifier. The fine powder obtained is then separated by a high-efficiency air classifier to obtain micro-nano materials with a particle size of less than 150nm. Step 4: Remove PVA from the micro / nano materials through processing.

2. The method for preparing quartz micro / nanomaterials according to claim 1, characterized in that, Step 1 includes the following steps: Raw material preparation: First, the collected quartz ore is preliminarily screened and cleaned to remove impurities and dirt. Coarse crushing: The washed quartz ore is fed into a crusher for preliminary crushing, breaking the quartz blocks into smaller particles; Fine crushing: The quartz particles after coarse crushing are then fed into a jaw crusher or grinding mill for fine crushing to make them into even finer particles. Grinding: The finely crushed quartz particles are fed into a grinding mill for further crushing, and the quartz particles are ground into fine powder; Magnetic separation involves feeding powder into a magnetic separator to reduce the content of metal elements. Grading and efficient powder selection: The crushed quartz powder is sieved using a vibrating screen and graded and efficiently selected according to different particle size requirements.

3. The method for preparing quartz micro / nanomaterials according to claim 1, characterized in that, The preparation process of the PVA-grafted silica microspheres is as follows: First, acidic silica microspheres are linked with PVA to form PVA-grafted silica nanospheres.

4. The method for preparing quartz micro / nanomaterials according to claim 3, characterized in that, The PVA in the PVA-grafted silica microspheres has a molecular weight of 10,000 to 30,000, and the ratio of silica nanoparticles to PVA is 5:1 to 10:

1.

5. The method for preparing quartz micro / nanomaterials according to claim 1, characterized in that, The micro-nano materials are added to water with concentrated hydrochloric acid and heated to 50 to 70°C. After stirring for 1 to 2 hours, the mixture is allowed to stand and separate into layers. This process separates the PVA from the silica microspheres, and the solid at the bottom is the desired micro-nano materials. After drying, the product is obtained.

6. The method for preparing quartz micro / nanomaterials according to claim 3, characterized in that, Acidic silica nanoparticles react with PVA under the catalysis of DMAP and DCC, with a mass ratio of DMAP to DCC of 1:3 to 1:5 and the mass amounts of DMAP and DCC being 1% to 5% of the total reactants; the reaction temperature is 25°C to 30°C, and the reaction is carried out in dichloromethane solvent for 12 to 24 hours.

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