CN114477189B - Purification method of ultra-high purity quartz sand - Google Patents
Purification method of ultra-high purity quartz sand Download PDFInfo
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- CN114477189B CN114477189B CN202210199336.XA CN202210199336A CN114477189B CN 114477189 B CN114477189 B CN 114477189B CN 202210199336 A CN202210199336 A CN 202210199336A CN 114477189 B CN114477189 B CN 114477189B
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- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
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Abstract
In order to solve the problems of impurity residues and influence on the purity of quartz sand in the existing quartz sand purification process, the invention provides a purification method of ultra-high purity quartz sand, which comprises the following operations: acquiring quartz sand; carrying out dynamic impact compression on quartz sand to enable the quartz sand to be in a disordered metastable state; and (3) treating the quartz sand by using a chemical solution to remove impurities, and cleaning to obtain the high-purity quartz sand. According to the purification method of the ultra-high purity quartz sand, the quartz sand is in a disordered metastable state with loose structure by dynamic impact compression, so that chemical solution can be fully infiltrated, deep impurities are removed, and the purification effect is better. The method can be combined with other quartz crystal lattice impurity purification steps such as chloridizing roasting and the like to realize the preparation of 4N8 and 5N-level ultra-high purity quartz sand required by the semiconductor manufacturing industry.
Description
Technical Field
The invention belongs to the technical field of quartz sand treatment, and particularly relates to a purification method of ultra-high purity quartz sand.
Background
The high-purity quartz sand is SiO obtained by treating quartz ore physically (crushing, heating, etc.) and chemically (acid leaching, alkali leaching, etc.) 2 The granular quartz product with the content of more than 99.9 percent has wide application in a plurality of fields such as semiconductors, aerospace, optical communication, photovoltaics and the like. Acid leaching, alkaline leaching and the like are key steps for purifying quartz sand in the prior art, and the main principle is that impurities in the quartz sand are dissolved through chemical reaction, and then the high-purity quartz sand with the impurities removed is obtained through steps of filtering, cleaning and the like. However, the direct purification effect of acid leaching, alkaline leaching and other technologies is limited, deep impurities in quartz sand are difficult to remove, and the quality requirement of the high-end application field on ultra-high purity quartz sand cannot be met. Particularly for applications in the semiconductor field, ultra-high purity quartz sand is often required to achieve ultra-high purity on the order of 4N8, 5N. Accordingly, the impurity removal capacity of the purification process also needs to meet higher requirements.
Disclosure of Invention
Aiming at the problems that impurities remain and the purity of quartz sand is affected in the existing quartz sand purification process, the invention provides a purification method of ultra-high purity quartz sand.
According to the purification method of the ultra-high purity quartz sand, provided by the invention, the quartz sand is in a disordered metastable state by dynamic impact compression, when the quartz sand is in the disordered metastable state, silicon-oxygen bonds in the original crystal structure of the quartz sand are broken, the structure is loose, microcracks are generated in the crystal structure, and the internal impurities are exposed, so that the chemical solution is convenient to permeate more thoroughly, and the purification effect is better.
The technical scheme adopted by the invention for solving the technical problems is as follows:
the invention provides a purification method of ultra-high purity quartz sand, which comprises the following operations:
acquiring quartz sand;
carrying out dynamic impact compression on quartz sand to enable the quartz sand to be in a disordered metastable state;
treating quartz sand with chemical solution to remove impurities, and separating and removing the chemical solution after soaking;
and cleaning the quartz sand by using a cleaning solution to obtain purified quartz sand.
Optionally, in the case of dynamic impact compression of quartz sand, pulse microwave treatment is further included.
Optionally, after "treating the quartz sand with a chemical solution to remove impurities, immersing and separating to remove the chemical solution", the quartz sand is mixed with a chlorinating agent and heated in a roasting furnace at a temperature of 800-1500 ℃ for 1-10 hours.
Optionally, the chemical solution comprises one or more of sulfuric acid, hydrochloric acid and hydrofluoric acid, wherein the mass concentration of the acid in the chemical solution is 10% -30%, the acid soaking temperature is 50-150 ℃, and the acid soaking time is 2-6 h.
Optionally, in the "dynamic impact compression of quartz sand", after the quartz sand is subjected to impact compression, detecting the birefringence value of the quartz sand, and when the birefringence value of the quartz sand is greater than 0.003, performing dynamic impact compression on the quartz sand again; and when the double refractive index value of the quartz sand is smaller than 0.003, soaking the quartz sand by using a chemical solution.
Optionally, the quartz sand is obtained by pre-treating a quartz raw material, wherein the pre-treatment comprises one or more of crushing, screening, calcining, water quenching, crushing, magnetic separation and floatation.
Optionally, in the "pretreatment of the quartz raw material", the quartz raw material is crushed to 1 to 40mm particles, and then the quartz raw material is rinsed to remove obvious impurities.
Optionally, after crushing the quartz raw material, calcining the quartz raw material at 800-1200 ℃ for 2-4 hours, and then carrying out water quenching on the calcined quartz raw material; and drying the quartz raw material after water quenching.
Optionally, after the water quenched quartz raw material is dried, crushing and grinding the quartz raw material to obtain quartz sand with different particle sizes, classifying and screening the quartz sand, and then carrying out magnetic separation and impurity removal on the quartz sand by using a magnetic separator under the magnetic field intensity of 0.8-1.5T.
Optionally, after "classifying and screening the quartz sand", adding a cation collector and the quartz sand into water, adjusting the pH value of the solution to be 2-4, and performing multiple flotation on the quartz sand.
Optionally, after "cleaning the quartz sand with the cleaning liquid", the method further comprises heating and drying the quartz sand with a drying oven.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects solved by the invention more clear, the invention is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
An embodiment of the invention provides a method for purifying ultra-high purity quartz sand, which comprises the following operations:
and obtaining quartz sand.
And carrying out dynamic impact compression on the quartz sand, wherein the impact pressure is specifically 40 GPa-60 GPa, so that the quartz sand is in a disordered metastable state.
The quartz sand is treated with a chemical solution to remove impurities, and the chemical solution is separated and removed after soaking.
And cleaning the quartz sand by using a cleaning solution to obtain purified quartz sand. Specifically, the quartz sand is firstly washed by dilute hydrochloric acid, and then repeatedly washed by ultra-pure water.
By carrying out dynamic impact compression on quartz sand, the quartz sand is in a disordered metastable state, when the quartz sand is in the disordered metastable state, silicon-oxygen bonds in the original crystal structure of the quartz sand are broken, the structure is loose, microcracks are generated in the crystal structure, and impurities in the crystal structure are exposed, so that chemical solution permeation is more thorough, and the purifying effect is better.
In some embodiments, the dynamic impact compaction of the quartz sand is also included in the pulsed microwave treatment of the quartz sand. Specifically, the pulse microwave frequency is 600-1500 MHz, and the power is 10 kW-400 kW. When quartz sand is in a disordered metastable state, inclusion impurities in the quartz sand can be destroyed by adopting pulse microwaves, and meanwhile, under the simultaneous effects of impact compression and pulse microwaves, the quartz sand is easy to crack, the impurities in the quartz sand are exposed, the coverage of chemical solution on the quartz sand is increased, and the dissolving and adsorbing effects on the impurities are improved.
In some embodiments, after "treating quartz sand with chemical solution to remove impurities, separating to remove chemical solution after soaking", the quartz sand is mixed with chlorinating agent and heated in a roasting furnace at 800-1500 ℃ for 1-10 hours to remove the like impurities in the crystal lattice. In particular, the chlorinating agent may be one or more of sodium chloride, ammonium chloride, hydrogen chloride, chlorine.
In some embodiments, the chemical solution comprises one or more of sulfuric acid, hydrochloric acid and hydrofluoric acid, wherein the mass concentration of the acid in the chemical solution is 10% -30%, the acid soaking temperature is 50-150 ℃, and the acid soaking time is 2-6 h.
The chemical solution may be treated one or more times independently selected from an acid solution. The acid liquor treatment can effectively dissolve impurities such as metal oxides or metal salts on the surface of the quartz sand, and remove partial impurities in the quartz sand.
In some embodiments, in the "dynamic impact compression of quartz sand", after the quartz sand is impact compressed, detecting the birefringence value of the quartz sand, and when the birefringence value of the quartz sand is greater than 0.003, dynamically impact compressing the quartz sand again; and when the double refractive index value of the quartz sand is smaller than 0.003, soaking the quartz sand by using a chemical solution. Specifically, the birefringence of quartz sand is determined by optical coherence tomography.
The quartz sand is in a crystal structure before being impacted and compressed, has an optical double refraction effect, becomes disordered metastable state after being stamped, and weakens the double refraction capability of the quartz sand.
In some embodiments, the silica sand is obtained by pre-treating a silica feedstock, the pre-treatment including one or more of crushing, screening, calcining, water quenching, crushing, magnetic separation, and flotation.
In some embodiments, in "pretreatment of the quartz feedstock," the quartz feedstock is crushed, the quartz feedstock is crushed to 1-40 mm particles, and then rinsed by high pressure water jets to remove significant impurities.
In some embodiments, after "crushing the quartz raw material", the quartz raw material is put into a high temperature furnace at 800-1200 ℃ to be calcined for 2-4 hours, and then the calcined quartz raw material is water quenched. And drying the water quenched quartz raw material at 105 ℃ for 2 hours.
In some embodiments, after the water quenched quartz raw material is dried, the quartz raw material is crushed and ground to obtain quartz sand with different particle sizes, the quartz sand is classified and screened, and then the magnetic separator is used for carrying out magnetic separation and impurity removal on the quartz sand at the magnetic field intensity of 0.8-1.5T, and the magnetic separation and impurity removal are carried out for one or more times. Specifically, quartz raw materials are put into a jaw crusher to obtain a discharge with the diameter of less than 1.25mm, then the discharge is milled by a planetary ball mill, quartz sand with the diameter of more than 100 meshes is screened out, the quartz sand with the diameter not meeting the requirement is recovered, and the quartz sand is crushed and milled again.
In some embodiments, after "classifying the silica sand", cationic collector and silica sand are added to the water, the pH of the solution is adjusted to = 2-4, and the silica sand is subjected to multiple flotation. Specifically, in the flotation treatment, the mass fraction of quartz sand in the solution is 20%. The solution pH was adjusted by dilute sulfuric acid. The cationic collector is dodecylamine, and the dosage of dodecylamine is 240g/t.
The invention is further illustrated by the following examples.
Example 1
The embodiment is used for explaining the purification method of the ultra-high purity quartz sand disclosed by the invention, and comprises the following operation steps:
(1) Coarse crushing-cleaning: crushing the quartz raw material to below 40mm, flushing the quartz raw material by using high-pressure water jet, and screening out obvious impurities.
(2) Calcination-water quenching: the quartz raw material is put into a box-type high-temperature furnace, calcined for 2 hours at the high temperature of 850 ℃, taken out, put into normal-temperature ultra-pure water for water quenching, and then put into a drying oven for drying at the drying temperature of 105 ℃ for 2 hours.
(3) Crushing and screening: and (3) putting the calcined and water quenched quartz raw material into a jaw crusher to obtain a discharge material with the diameter of less than 1.25mm, grinding by a planetary ball mill, screening quartz sand with the diameter of more than 100 meshes, and crushing and grinding again for quartz sand return materials with diameter not meeting the requirement.
(4) Magnetic separation: selecting quartz sand for 2 times by using a dry magnetic separator to obtain magnetic separation refined sand, wherein the magnetic field strength is 1.2T;
(5) And (3) flotation: and (3) carrying out flotation treatment on the quartz sand after magnetic separation, adding a cationic collector and the quartz sand into water, wherein the mass fraction of the quartz sand is 20%, regulating the pH value of the solution to 2.5 by using dilute sulfuric acid, pulping for 3min, adopting dodecyl amine as the cationic collector, and carrying out flotation operation for 3 times in a hanging tank flotation machine with the dosage of 240g/t, thereby obtaining the flotation concentrate after cleaning.
(6) Microwave-stamping: the flotation concentrate was subjected to pulsed microwave treatment, wherein the pulsed microwave frequency was 915MHz and the power was 80kW. Meanwhile, the flotation concentrate is subjected to dynamic impact compression, and the impact pressure is 50GPa, so that the quartz sand becomes a disordered metastable state.
(7) Acid leaching: and (3) carrying out acid leaching treatment on quartz sand, wherein the acid liquor is mixed acid of hydrochloric acid with the concentration of 20%, sulfuric acid with the concentration of 20% and hydrofluoric acid with the concentration of 10%, and the acid leaching temperature is 80 ℃ for 4 hours. Washing the quartz sand subjected to acid leaching by dilute hydrochloric acid, repeatedly washing by ultra-pure water, and then putting into a drying oven for drying.
(8) Chloridizing roasting: mixing the dried quartz sand with NH 4 Cl is mixed and heated in a roasting furnace for 1.5h at 900 DEG C. And (3) cleaning the roasted quartz sand with dilute hydrochloric acid, repeatedly washing with ultra-pure water, and then putting into a drying oven for drying.
Example 2
This example is for illustrating the purification method of ultra-high purity silica sand disclosed in the present invention, and includes most of the operation steps in example 1, which are different in that:
in the step (6), the quartz sand is not subjected to the pulse microwave treatment when the quartz sand is subjected to dynamic impact compaction.
Comparative example 1
This comparative example is a comparative illustration of the disclosed method for purifying ultra-high purity silica sand, comprising most of the operating steps of example 2, with the difference that:
the dynamic impact compression treatment of the quartz sand in step (6) is not performed.
Performance testing
The quartz sand prepared by the method is subjected to the following performance test:
analysis of silica sand SiO with inductively coupled plasma atomic emission Spectrometry ICP-OES with reference Standard JC/T2027-2010 2 Content, the test results obtained are filled in Table 1.
TABLE 1
| Sample of | Example 1 | Example 2 | Comparative example 1 |
| SiO 2 (％) | 99.99904 | 99.99847 | 99.99633 |
As can be seen from the test results in Table 1, the method for purifying the ultra-high purity quartz sand provided by the invention can effectively reduce the impurity content in the quartz sand and improve the purity of the quartz sand.
From the test results of example 2 and comparative example 1, it is evident that the punching operation performed before pickling can promote sufficient contact between the acid liquor and the quartz sand, the impurity content is relatively reduced, and the quartz sand purification result is effectively improved.
As is apparent from the test results of examples 1 and 2, the pulse microwave treatment can effectively expose impurities in the quartz sand during punching, and improve the dissolution and adsorption effects of the impurities.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.
Claims (10)
1. The purifying method of the ultra-high purity quartz sand is characterized by comprising the following operations:
acquiring quartz sand;
carrying out dynamic impact compression on quartz sand to enable the quartz sand to be in a disordered metastable state;
treating quartz sand with chemical solution to remove impurities, and separating and removing the chemical solution after soaking;
and cleaning the quartz sand by using a cleaning solution to obtain purified quartz sand.
2. The method for purifying ultra-high purity silica sand according to claim 1, further comprising subjecting the silica sand to pulsed microwave treatment at the time of "dynamic impact compaction of the silica sand".
3. The method for purifying ultra-high purity silica sand according to claim 1, wherein after "treating silica sand with chemical solution to remove impurities, separating out the chemical solution after soaking", the silica sand is mixed with a chlorinating agent and heated in a roasting furnace at a temperature of 800 ℃ to 1500 ℃ for 1 to 10 hours.
4. The method for purifying ultra-high purity silica sand according to claim 1, wherein the chemical solution comprises one or more of sulfuric acid, hydrochloric acid and hydrofluoric acid, the mass concentration of the acid in the chemical solution is 10% -30%, the acid soaking temperature is 50-150 ℃, and the acid soaking time is 2-6 h.
5. The method for purifying ultra-high purity silica sand according to claim 1, wherein in "dynamic impact compression of silica sand", after the silica sand is impact compressed, the birefringence value of the silica sand is detected, and when the birefringence value of the silica sand is greater than 0.003, dynamic impact compression is performed again on the silica sand; and when the double refractive index value of the quartz sand is smaller than 0.003, soaking the quartz sand by using a chemical solution.
6. The method for purifying ultra-high purity silica sand according to claim 1, wherein the silica sand is obtained by subjecting a silica raw material to pretreatment including one or more of crushing, screening, calcining, water quenching, pulverizing, magnetic separation, and floatation.
7. The method for purifying ultra-high purity silica sand according to claim 6, wherein in the pretreatment of the silica raw material, the silica raw material is crushed to 1 to 40mm particles, and then the silica raw material is rinsed to remove the remarkable impurities.
8. The method for purifying ultra-high purity silica sand according to claim 7, wherein after "crushing the silica raw material", the silica raw material is calcined at 800 ℃ to 1200 ℃ for 2 to 4 hours, and then the calcined silica raw material is water-quenched; and drying the quartz raw material after water quenching.
9. The method for purifying ultra-high purity silica sand according to claim 8, wherein after the water quenched silica raw material is dried, the silica raw material is crushed and ground to obtain silica sand with different particle sizes, the silica sand is classified and screened, and then the silica sand is subjected to magnetic separation and impurity removal by using a magnetic separator under the magnetic field strength of 0.8-1.5T.
10. The method for purifying ultra-high purity silica sand according to claim 9, wherein after "classifying the silica sand", a cationic collector and silica sand are added to water, and the pH of the solution is adjusted to = 2 to 4, and the silica sand is subjected to flotation a plurality of times.
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| CN105000565A (en) * | 2015-07-16 | 2015-10-28 | 安徽东阳矿业科技有限公司 | Compounding-based quartz sand purification technology |
| CN109081352A (en) * | 2018-09-04 | 2018-12-25 | 安徽科技学院 | A kind of ultrapure quartz sand and its purifying technique |
| CN112010317A (en) * | 2020-09-14 | 2020-12-01 | 昆明理工大学 | Method for purifying quartz sand by microwave-vacuum combined roasting |
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| NL8600283A (en) * | 1986-02-06 | 1987-09-01 | Philips Nv | METHOD FOR PURIFYING QUARTZ SAND |
| US5030433A (en) * | 1988-07-18 | 1991-07-09 | International Minerals & Chemical Corp. | Process for producing pure and dense amorphous synthetic silica particles |
| FR2994963B1 (en) * | 2012-08-31 | 2014-10-03 | Rhodia Operations | NOVEL PROCESS FOR THE PREPARATION OF PRECIPITATED SILICES, NOVEL PRECIPITED SILICES AND THEIR USES, IN PARTICULAR FOR THE STRENGTHENING OF POLYMERS |
| CN113735128A (en) * | 2021-08-16 | 2021-12-03 | 武汉理工大学 | Preparation method of high-purity quartz sand |
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| CN105000565A (en) * | 2015-07-16 | 2015-10-28 | 安徽东阳矿业科技有限公司 | Compounding-based quartz sand purification technology |
| CN109081352A (en) * | 2018-09-04 | 2018-12-25 | 安徽科技学院 | A kind of ultrapure quartz sand and its purifying technique |
| CN112010317A (en) * | 2020-09-14 | 2020-12-01 | 昆明理工大学 | Method for purifying quartz sand by microwave-vacuum combined roasting |
Non-Patent Citations (1)
| Title |
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| 石英砂提纯方法研究;郑翠红;孙颜刚;杨文雁;朱伟长;闫勇;;中国非金属矿工业导刊(第05期);全文 * |
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