Screening method of alaite type high-purity quartz raw material

Abstract

The invention provides a method for screening alaite type high-purity quartz raw materials. The method comprises the following steps: judging whether an alaite raw material sample is a linear inclusion alaite raw material or not, and if yes, carrying out a separation and purification test on the alaite raw material sample to obtain high-purity quartz sand; under the condition that the high-purity quartz sand meets the first standard and does not meet the second standard, the process system of the separation and purification test is optimized for multiple times, the separation and purification test is carried out on the alaite raw material sample according to the process system optimized each time, and as long as the high-purity quartz sand obtained through one-time optimization meets the second standard, the separation and purification test is carried out on the alaite raw material sample. If yes, taking the alaite raw material sample as the screened raw material; under the condition that the high-purity quartz sand meets a second standard, taking the alaite raw material sample as a screened raw material; according to the screening method, accurate screening of the high-purity quartz raw materials can be achieved, and the efficiency and accuracy of the screening method for the alaite type high-purity quartz raw materials are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of high-purity quartz, and more specifically, to a method for screening raw materials of alaskite-type high-purity quartz. Background Art

[0002] High-purity quartz has the dual attributes of resources and materials. As a material attribute, it refers to quartz sand and its products with a purity of more than 99.99%. As a resource attribute, it refers to raw material minerals that can be used for processing (separation and purification) high-purity quartz sand. Ordinary high-purity quartz sand has a wide range of uses, and its raw materials are also diverse in type and widespread in distribution. However, high-purity quartz sand above 4N8 (purity of 99.998%) required for strategic emerging industries such as semiconductor chips and solar photovoltaics is an indispensable and irreplaceable key basic material, and its raw material minerals are scarce resources formed under extremely harsh geological conditions and with extremely limited distribution.

[0003] Currently, relying on the unique alaskite-type high-purity quartz mine in Spruce Pine, North Carolina, USA, and the corresponding processing technology, Sibelco company occupies the global supply of high-purity quartz sand above 4N8 for semiconductors. Although China has abundant ordinary high-purity quartz raw materials, high-purity quartz sand above 4N8 and its raw materials rely on imports. Therefore, discovering high-quality high-purity quartz raw materials, especially finding alaskite raw materials of the same type as those in the US mines, is the key and urgent need to solve the high-purity quartz problem in China. The applicant, the Institute of New Materials Industry Technology for Ultra-Pure Minerals, has discovered alaskite-type high-purity quartz raw materials in the East Qinling area, which is the second alaskite-type high-purity quartz raw material production area in the world outside the United States. Currently, there is little information reported globally on processing high-purity quartz using alaskite as a raw material, and the method for screening and discriminating alaskite-type high-purity quartz raw materials is still a technical blank. To accelerate the technological development of high-purity quartz, it is urgent to develop a method for screening alaskite-type high-purity quartz raw materials. Summary of the Invention

[0004] The purpose of the present invention is to solve at least one of the above-mentioned deficiencies existing in the prior art. For example, one of the purposes of the present invention is to provide a method for screening alaskite-type high-purity quartz raw materials, which improves the efficiency and accuracy of the method for screening alaskite-type high-purity quartz raw materials and realizes the precise screening of high-purity quartz raw materials.

[0005] To achieve the above object, the present invention provides a method for screening high-purity quartz raw materials of granite type, including: determining whether the granite raw material sample is a granite raw material with linear inclusions, and if so, conducting separation and purification tests on the granite raw material sample to obtain high-purity quartz sand; when the high-purity quartz sand meets the first standard but does not meet the second standard, optimizing the process system of the separation and purification test several times, and conducting separation and purification tests on the granite raw material sample according to the process system optimized each time. As long as the high-purity quartz sand obtained from one optimization meets the second standard, the granite raw material sample is used as the selected raw material; when the high-purity quartz sand meets the second standard, the granite raw material sample is used as the selected raw material; wherein, the first standard includes: Ti is less than 2 ppm, Li is less than 1 ppm, Al is less than 20 ppm, Ca is less than 1.2 ppm, P is less than 0.5 ppm; the second standard includes that all impurities meet the quality standard of high-purity quartz sand; the separation and purification test includes: sand making, magnetic separation, then obtaining flotation concentrate through the flotation process, and then conducting calcination, water quenching, pickling and chlorination operations; the optimization includes the adjustment of at least one link in the separation and purification test.

[0006] Optionally, the granite raw material sample includes one or more granite ore samples from the same mining area, and one or more thin sections are cut from each granite ore sample.

[0007] Optionally, the step of determining whether the granite raw material sample is a granite raw material with linear inclusions includes: cutting the granite ore sample into thin sections, placing them under a polarized light microscope for observation, and determining whether it is a granite with linear inclusions. If so, the granite raw material is a granite raw material with linear inclusions.

[0008] Optionally, the sand making includes crushing and grinding for sand making.

[0009] Optionally, the sand obtained from the sand making is 80 - 200 mesh.

[0010] Optionally, the intensity of the magnetic separation is 1.2 - 1.8 T, and the number of magnetic separation times is 3 - 6 times.

[0011] Optionally, the flotation process includes a mica-feldspar mixed flotation process or a flotation process of mica first and then feldspar.

[0012] Further optionally, the flotation process of mica first and then feldspar includes: mica flotation is carried out 2 to 5 times, and then feldspar flotation is carried out 3 to 5 times; among them, the pH value of mica flotation is 3 to 4, and the collector is one or more of dodecylamine, octadecylamine, and propylenediamine, with a dosage of 100 to 200 g / t; the pH value of feldspar flotation is 2 to 3, the dosage of activator hydrofluoric acid is 1000 to 1500 g / t, and the collector includes a cationic collector and / or an anionic collector. The cationic collector is one or more of dodecylamine, octadecylamine, and propylenediamine, with a dosage of 100 to 200 g / t, and the anionic collector is one or more of oxidized paraffin soap, oleic acid, and sodium oleate, with a dosage of 50 to 100 g / t.

[0013] Still further optionally, the number of mica flotation times is 2 times, and the feldspar flotation is 3 times; among them, the parameters of each mica flotation are pH value 3 and dodecylamine 150 g / t; the parameters of each feldspar flotation are pH value 2.5, hydrofluoric acid 1000 g / t, dodecylamine 150 g / t, and oxidized paraffin soap 50 g / t.

[0014] Optionally, the temperature of the calcination is 800 to 1200 degrees, and the time is 30 to 120 min.

[0015] Optionally, the water quenching includes: quickly pouring the calcined quartz sand into pure water. The temperature of the pure water is 5 to 20 degrees higher than the spontaneous combustion temperature, and the liquid-solid ratio is 10:1 to 30:1, so as to ensure that the high-temperature quartz sand can be fully immersed and cooled.

[0016] Optionally, the pickling includes multiple picklings, and the conditions of each pickling are the same. The pickling conditions include: the acids used are multiple of hydrochloric acid, hydrofluoric acid, sulfuric acid, nitric acid, and oxalic acid, with a concentration of 10% to 30%, the liquid-solid ratio is 8:1 to 2:1, the temperature is 80 to 100 degrees, and the time is 10 to 40 h.

[0017] Further optionally, the number of pickling times can be 2 times.

[0018] Optionally, the chlorinating gas is chlorine or hydrogen chloride gas, the temperature is 1000 to 1300 degrees, and the time is 0.5 to 3 hours.

[0019] Optionally, the optimization includes the optimization of at least one link of the separation and purification test. The optimization of one link includes: the selection of at least one type of parameters and substances within the determined range, and / or the optimization and adjustment of the link process.

[0020] Optionally, when the optimization includes sand making, the proportion of the undersize product passing through a 200-mesh sieve after optimization is 20% to 50%.

[0021] Optionally, when the flotation process is a mica-feldspar mixed flotation process, if the optimization includes the optimization of the flotation process, the optimization includes the optimization of the number of flotation times, or the flotation process is adjusted to a flotation process of mica first and then feldspar.

[0022] Optionally, the judgment of whether the high-purity quartz sand meets the first standard may include: judging whether the Ti and Li contents meet the requirements, judging whether the Al content meets the requirements when the above is met, and judging whether the Ca and P contents meet the requirements when the Al content meets the requirements.

[0023] Optionally, the quality standard of the high-purity quartz sand may include: the IOTA-CG standard.

[0024] Optionally, all impurities in the second standard may include: Al, B, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Ti, and Zn.

[0025] Compared with the prior art, the beneficial effects of the present invention include: the method of the present invention is convenient and fast, can realize the precise screening of high-purity quartz raw materials, improves the efficiency and accuracy of the screening method for alaskite-type high-purity quartz raw materials, and helps to promote the development of high-purity quartz technology. Brief Description of the Drawings

[0026] Through the following description with reference to the accompanying drawings, the above and other objects and / or features of the present invention will become more clear, wherein:

[0027] Figure 1 Shows a schematic diagram of a screening step of the screening method for alaskite-type high-purity quartz raw materials of the present invention.

[0028] Figure 2 Shows an image of the observation of linear inclusions in a thin section under a polarized light microscope;

[0029] Figure 3A Shows a micrograph of a high-purity quartz sand product;

[0030] Figure 3B Shows another micrograph of a high-purity quartz sand product. Detailed Description of the Embodiments

[0031] In the following, a screening method for alaskite-type high-purity quartz raw materials of the present invention will be described in detail with reference to exemplary embodiments.

[0032] Exemplary Embodiment 1

[0033] The screening method for alaskite-type high-purity quartz raw materials in this exemplary embodiment includes:

[0034] S10: Determine whether the granite raw material sample is a granite raw material with linear inclusions. If so, conduct a separation and purification test on the granite raw material sample once to obtain high-purity quartz sand.

[0035] S20: Determine whether the granite raw material sample can be used as the selected raw material based on the high-purity quartz sand. Specifically:

[0036] S21: When the high-purity quartz sand meets the first standard and does not meet the second standard, optimize the process system of the separation and purification test several times, and conduct the separation and purification test on the granite raw material sample according to the process system optimized each time. As long as the high-purity quartz sand obtained from one optimization meets the second standard, the granite raw material sample is used as the selected raw material.

[0037] S22: When the high-purity quartz sand meets the second standard, use the granite raw material sample as the selected raw material.

[0038] Among them, the first standard includes: Ti is less than 2 ppm, Li is less than 1 ppm, Al is less than 20 ppm, Ca is less than 1.2 ppm, and P is less than 0.5 ppm.

[0039] The second standard includes the quality standard of high-purity quartz sand.

[0040] The separation and purification test includes: crushing and grinding to make sand, magnetic separation, then obtaining flotation concentrate through the flotation process, and then conducting calcination, water quenching, pickling, and chlorination operations.

[0041] The optimization includes the adjustment of at least one link in the separation and purification test.

[0042] For example, relative to the separation and purification test, the content of the optimization test includes process flow, magnetic field intensity, number of magnetic separation times, flotation process, screening of flotation reagents, ratio of flotation reagents, dosage of flotation reagents, adjustment of pickling formula, pickling time and temperature, calcination time and temperature, etc.

[0043] Specifically, the optimization of the process flow, etc. can include: the selection of preferential flotation of mica feldspar and mixed flotation of mica feldspar, the adjustment of the number of flotation times, the adjustment of the number and sequence of calcination and water quenching, etc.

[0044] The optimization of magnetic separation includes the optimization of magnetic field intensity and number of times. For example, the magnetic field intensity is adjusted between 1.2 and 1.8 T, and the number of magnetic separation times is adjusted between 3 and 6 times.

[0045] Flotation reagent screening and flotation reagent ratio, mainly for the screening of collectors. Collectors with strong collecting ability have poor selectivity and are difficult to remove impurities targeted. Selective collectors have poor collecting ability and are difficult to effectively "grip" impurities, so it is also difficult to select cleanly, affecting the discrimination. Therefore, different collectors need to be screened, including cationic and anionic collectors, such as dodecylamine, octadecylamine, oxidized paraffin soap, oleic acid, sodium oleate. Through screening and ratio tests, suitable collectors are selected.

[0046] The dosage, type and number of flotation reagents are adjusted and optimized within the following ranges: the number of flotation times for mica flotation operation is 2 - 5 times, the pH value is 3 - 4, the collector is one or more of dodecylamine, octadecylamine, and propylenediamine, and the dosage is 100 - 200 g / t; the number of flotation times for feldspar flotation operation is 3 - 5 times, the pH value is 2 - 3, the dosage of the activator hydrofluoric acid is 1000 - 1500 g / t, the cationic collector is one or more of dodecylamine, octadecylamine, and propylenediamine, and the dosage is 100 - 200 g / t; the anionic collector is one or more of oxidized paraffin soap, oleic acid, and sodium oleate, and the dosage is 50 - 100 g / t.

[0047] The pickling formula is adjusted, and the pickling time and temperature are adjusted and optimized within the following ranges: the pickling acids are multiple of hydrochloric acid, hydrofluoric acid, sulfuric acid, nitric acid, and oxalic acid, the ratio is determined according to the test results, the concentration is 10% - 30%, the liquid - solid ratio is 8:1 - 2:1, the temperature is 80 - 100 degrees, and the time is 10 - 40 h.

[0048] The calcination time and temperature are adjusted and optimized within the following ranges: the calcination temperature is 800 - 1200 degrees, and the calcination time is 30 - 120 min.

[0049] In this embodiment, the step S20 may further include:

[0050] S23: If the high - purity quartz sand does not meet the first standard, the albite raw material sample cannot be used as the selected raw material.

[0051] S24: If the high - purity quartz sand meets the first standard but does not meet the second standard, the process system of the separation and purification test is optimized several times, and the albite raw material sample is subjected to the separation and purification test according to the optimized process system each time. If the optimized high - purity quartz sand still does not meet the second standard, the albite raw material sample cannot be used as the selected raw material.

[0052] In this embodiment, in step S10, the albite raw material sample includes one or more albite ore samples from the same mining area. Further, to ensure the accuracy of the results, multiple albite ore samples can be selected.

[0053] The steps for determining whether the alaskite raw material is a linear inclusion include: cutting a thin slice of the alaskite ore sample, placing it under a polarized light microscope for observation, and determining whether it is alaskite with linear inclusions. If so, the alaskite raw material is the alaskite raw material with linear inclusions. When the number of alaskite ore samples is multiple, the observation results of all thin slices must have linear inclusions to consider the determination result as yes.

[0054] In this embodiment, in the separation and purification test (i.e., the separation and purification test before optimization):

[0055] The sand making includes crushing and sand making, and sand with a mesh size of 80 - 200 can be obtained.

[0056] The intensity of the magnetic separation is 1.2 - 1.8T, and the number of magnetic separation times is 3 - 6 times.

[0057] When the flotation process is the preferential flotation process of mica and feldspar, the process flow includes: mica flotation 2 - 5 times, and then feldspar flotation 3 - 5 times; among them, the pH value of mica flotation is 3 - 4, the collector is one or more of dodecylamine, octadecylamine, and propylenediamine, and the dosage is 100 - 200g / t; the pH value of feldspar flotation is 2 - 3, the dosage of the activator hydrofluoric acid is 1000 - 1500g / t, the capturing agent includes at least one of a cationic capturing agent and an anionic capturing agent, the cationic collector is one or more of dodecylamine, octadecylamine, and propylenediamine, and the dosage is 100 - 200g / t, and the anionic collector is one or more of oxidized paraffin soap, oleic acid, and sodium oleate, and the dosage is 50 - 00g / t.

[0058] The temperature of the calcination is 800 - 1200 degrees, and the time is 30 - 120min.

[0059] The water quenching includes: quickly pouring the calcined quartz sand into pure water, the temperature of the pure water is 5 - 20 degrees of the spontaneous combustion temperature, and the liquid-solid ratio is 10:1 - 30:1 to ensure that the high-temperature quartz sand can be fully immersed and cooled.

[0060] The pickling includes multiple picklings, and the conditions for each pickling are the same. The pickling conditions include: the acids used are multiple of hydrochloric acid, hydrofluoric acid, sulfuric acid, nitric acid, and oxalic acid, the ratio is determined according to the test results, the concentration is 10% - 30%, the liquid-solid ratio is 8:1 - 2:1, the temperature is 80 - 100 degrees, and the time is 10 - 40h;

[0061] The gas for chlorination is chlorine or hydrogen chloride gas, and the time is 0.5 - 3 hours.

[0062] Further, the number of mica flotation times is 2, and the feldspar is flotated 3 times; among them, the parameters for each mica flotation are pH value 3 and dodecylamine 150 g / t; the parameters for each feldspar flotation are pH value 2.5, hydrofluoric acid 1000 g / t, dodecylamine 150 g / t, and oxidized paraffin soap 50 g / t.

[0063] In this embodiment, the standards for Ti, Li, Al, Ca, and P in the high-purity quartz sand A to meet the requirements include: Ti is less than 2 ppm, Li is less than 1 ppm, Al is less than 20 ppm, Ca is less than 1.2 ppm, and P is less than 0.5 ppm.

[0064] In this embodiment, as a preference of the present invention, according to the potential magnitude, the steps of judging whether Ti, Li, Al, Ca, and P in the high-purity quartz sand A all meet the requirements may include: judging whether the contents of Ti and Li both meet the requirements, and if they do, judging whether the Al content meets the requirements, and if the Al content meets the requirements, judging whether the contents of Ca and P both meet the requirements.

[0065] In this embodiment, the quality standard of the high-purity quartz sand includes: IOTA-CG standard.

[0066] Exemplary Embodiment 2

[0067] As Figure 1 shown, the method for screening the leucogranite-type high-purity quartz raw material may include the following steps:

[0068] S1: First-round screening: Select a representative leucogranite specimen group, cut thin slices, observe under a polarized light microscope, and screen out the leucogranite with linear inclusions.

[0069] Among them, the specimen group may include multiple representative ore samples, such as 3 to 5 pieces, and the colors and appearances of the ores should be kept as consistent as possible to ensure the representativeness of the samples. Each ore sample can be cut into several thin slices; the number of the specimen group and the thin slices can be the same, for example, each ore is cut into one thin slice; or, the amount of thin slices can be slightly more, for example, one ore is cut into two slices in different directions.

[0070] S2: Separation and purification test: Select a representative leucogranite specimen for separation and purification test, obtain a high-purity quartz sand product, and conduct chemical analysis. Among them, the parameters of a single test can be relatively fixed at a certain value, and when abnormalities occur, adjustments are made according to the situation.

[0071] S3: Second-round screening: Mainly taking the lattice impurities of Ti and Li that are difficult to remove, screen out the leucogranite with the contents of Ti and Li meeting the requirements.

[0072] S4: Third-round screening; Mainly taking the impurity element Al that has the greatest impact on purity, screen out the leucogranite with the Al content meeting the requirements.

[0073] S5: The fourth round of screening; mainly using Ca and P impurity elements that reflect the characteristics of inclusions, select albite with Ca and P contents meeting the requirements.

[0074] S6: The fifth round of screening: Conduct separation and purification optimization tests on the albite with linear inclusions screened in step (1), optimize the separation and purification process flow and reagent formula, and then conduct comparative analysis with the quality standard of high-purity quartz sand to select albite with all 15 impurity elements meeting the requirements.

[0075] Furthermore, in step S1, the number of thin sections is 3 - 5 to ensure the representativeness of the samples, avoid contingency, and select albite raw materials with linear inclusions. The linear inclusions are mostly distributed in a bead-like shape and are easy to burst during the heat treatment process, while the distribution of other morphological inclusions, especially planar inclusions, can be directly excluded.

[0076] Furthermore, the process flow of the separation and purification test in step S2 is as follows: Use jaw crushers and roll crushers for crushing, use rod mills or ball mills for grinding and sand making, screen with standard sieves to obtain sand with a mesh size of 80 - 200, use the process flow of preferential flotation of mica and feldspar to obtain flotation concentrate, and then conduct calcination, water quenching, pickling, and chlorination operations to obtain high-purity quartz sand products. This step mainly makes a preliminary judgment on the products, rather than obtaining high-purity quartz products under optimal parameters.

[0077] Furthermore, in the second round of screening in step S3, for the high-purity quartz sand products, Ti is less than 2 ppm and Li is less than 1 ppm. Since the two impurity elements Ti and Li are relatively fixed and generally exist in the form of lattice substitution, they are difficult to remove, and their limit values are slightly higher than the IOTA-CG standard, which can avoid potential raw materials meeting the requirements of high-purity quartz from being missed during the screening process.

[0078] Furthermore, in the third round of screening in step S4, for the high-purity quartz sand products, Al is less than 20 ppm. The Al element has the greatest impact on the purity of high-purity quartz products. When the Al content reaches 20 ppm, the purity of high-purity quartz is already lower than 99.998%, and it is basically difficult to be used as high-purity quartz sand for crucibles.

[0079] Furthermore, in the fourth round of screening in step S5, for the high-purity quartz sand products, Ca is less than 1.2 ppm and P is less than 0.5 ppm. The Ca element mostly exists in the form of mineral inclusions such as calcite, anorthite, and apatite, and the P element mostly exists in the form of apatite mineral inclusions. Mineral inclusions can be further reduced to a certain extent through process optimization.

[0080] Further, in the fifth-round screening of step S6, the process flow includes one or more of flotation sequence and times, pickling sequence and times, heat treatment temperature, times and duration, and the reagent formula includes types and proportions of flotation reagents and types and proportions of pickling reagents, and all 15 impurity elements meet the IOTA-CG standard.

[0081] Further, in step (2), the process flow for preferential flotation of mica and feldspar is that the number of mica flotation times is 2, followed by 3 times of feldspar flotation. Each time the mica flotation parameters are pH value of 3 and dodecylamine of 150 g / t. Each time the feldspar flotation parameters are pH value of 2.5, hydrofluoric acid of 1000 g / t, dodecylamine of 150 g / t, and oxidized paraffin soap of 50 g / t. The calcination temperature is 950 degrees Celsius. The pickling reagent is hydrochloric acid:hydrofluoric acid with a mass ratio of 5:1 and a solid-liquid ratio of 1:3. The chlorination gas is hydrogen chloride and the time is 1 hour.

[0082] To better understand the above exemplary embodiments, further descriptions will be given below with specific examples.

[0083] Example 1

[0084] Select a representative group of leucogranite specimens, cut 5 thin sections, and observe them under a polarized light microscope. They are all linear inclusions, and it is determined that further screening can be carried out. Among them, Figure 2 shows an image of the observation of linear inclusions in a thin section under a polarized light microscope. Multiple linear inclusions are shown in the figure, such as the linear bodies next to the red line.

[0085] Carry out separation and purification tests on the samples to obtain high-purity quartz sand product A. Among them, the separation and purification tests specifically include: the process flow is crushing and sand making - strong magnetic separation - mixed flotation of feldspar and mica - calcination and water quenching - pickling - chlorination. The crushing and sand making is controlled to have -74 microns accounting for 20 - 50%, and sand with a mesh size of 80 - 200 is obtained through screening; the intensity of strong magnetic separation is 1.2 T and the number of magnetic separation times is 3; the number of mixed flotation times of feldspar and mica is 4, the pH value is 2 - 3, and the collector for each time is dodecylamine with a dosage of 100 g / t; the calcination temperature is 800 degrees and the time is 30 min; water quenching ensures a liquid-solid ratio of 10:1; the number of pickling times is 1, the acid used is hydrochloric acid + hydrofluoric acid with a ratio of 3:1, a concentration of 10%, a liquid-solid ratio of 2:1, a temperature of 80 degrees, and a time of 10 h; the chlorination gas is hydrogen chloride gas, the time is 0.5 hour, and the temperature is 1200 degrees.

[0086] Use ICP-MS to conduct chemical analysis on high-purity quartz sand A; according to the test results, the Ti content is 1.8 ppm, the Li content is 0.9 ppm, and it is determined that further screening can be carried out; the Al content is 16 ppm, and it is determined that further screening can be carried out; the Ca content is 1.0 ppm, the P content is 0.4 ppm, and it is determined that further screening can be carried out.

[0087] Optimize the technological process and reagent regime to obtain high-purity quartz sand product B. Among them, the optimization of the technological process and reagent regime includes: the technological process is crushing and sand making - high-intensity magnetic separation - combined flotation of feldspar and mica - calcination and water quenching - acid washing - chlorination. The crushing and sand making is controlled to have 20 - 50% passing through -74 μm, and the sand of 80 - 200 mesh is obtained through screening; the intensity of high-intensity magnetic separation is 1.8 T, and the number of magnetic separation times is 5; the number of combined flotation times of feldspar and mica is 5, the pH value is 2 - 3, the collector for each time is dodecylamine, and the dosage is 200 g / t; the calcination temperature is 1100 °C, and the time is 120 min; the water quenching ensures a liquid-solid ratio of 10:1; the number of acid washing times is 2, the acids used are hydrochloric acid + hydrofluoric acid, the ratio is 3:1, the concentration is 10%, the liquid-solid ratio is 5:1, the temperature is 80 °C, and the time is 10 h; the gas for chlorination is hydrogen chloride gas, the time is 1 hour, and the temperature is 1200 °C.

[0088] The ICP-OES test results of high-purity quartz sand product B are shown in Table 1. The 15 impurity elements all meet the IOTA-CG standard, and it is determined that it has the potential to be used as high-purity quartz sand for crucibles. At the same time, samples of high-purity quartz sand product B are taken and tested and analyzed by a polarized light microscope. The results are as Figure 3A and 3B shown. It can be seen from the figure that the high-purity quartz sand particles are basically completely transparent, and gas-liquid inclusion particles are rarely or not seen, indicating that the appearance quality of the high-purity quartz sand is good.

[0089] Table 1 Test results of high-purity quartz sand product in Example 1

[0090] Al B Ca Cr Cu Fe K Li Mg 13.35 0.1 0.5 Not detected 0.002 Not detected 0.5 0.21 Not detected Mn Na Ni P Ti Zn Total amount Purity / % 0.002 0.73 Not detected 0.1 1.03 Not detected 16.524 99.9983

[0091] Among them, the unit of each impurity element in Table 1 is ppm, and the total amount refers to the sum of the masses of 15 impurity elements.

[0092] Example 2

[0093] Select a representative group of leucogranite specimens, cut 5 thin sections, and observe them under a polarized light microscope. They are all linear inclusions, and it is determined that further screening can be carried out.

[0094] Separation and purification tests were carried out on the samples to obtain high-purity quartz sand products. Among them, the separation and purification tests specifically included: the process flow was crushing and sand making - strong magnetic separation - preferential flotation of mica and feldspar - calcination and water quenching - acid washing - chlorination. The crushing and sand making was controlled to have 20 - 50% of -74 microns, and the sand of 80 - 200 mesh was obtained through screening; the intensity of strong magnetic separation was 1.8T, and the number of magnetic separation times was 5; mica was flotated 2 times, and then feldspar was flotated 3 times; among them, the pH value of mica flotation was 3 - 4, the collector was dodecylamine, and the dosage was 100g / t; the pH value of feldspar flotation was 2 - 3, the dosage of the activator hydrofluoric acid was 1000g / t, and the capturer was octadecylamine + oleic acid, and the dosage was 150 + 50g / t; the calcination temperature was 1000 degrees, and the time was 100min; water quenching ensured a liquid-solid ratio of 10:1; the number of acid washing times was 2, the acids used were hydrochloric acid + hydrofluoric acid, the ratio was 3:1, the concentration was 10%, the liquid-solid ratio was 5:1, the temperature was 80 degrees, and the time was 10h; the gas for chlorination was hydrogen chloride gas, the time was 1 hour, and the temperature was 1200 degrees.

[0095] ICP-MS was used to analyze high-purity quartz sand A; according to the test results, the Ti content was 1.4ppm, the Li content was 0.5ppm, and it was determined that further screening could be carried out; the Al content was 14ppm, and it was determined that further screening could be carried out; the Ca content was 0.8ppm, and the P content was 0.2ppm, and it was determined that further screening could be carried out.

[0096] Optimization tests of the process flow and reagent system were carried out to obtain high-purity quartz sand product B. Among them, the optimization of the process flow and reagent system included: the process flow was crushing and sand making - strong magnetic separation - preferential flotation of mica and feldspar - calcination and water quenching - acid washing - chlorination. The crushing and sand making was controlled to have 20 - 50% of -74 microns, and the sand of 80 - 200 mesh was obtained through screening; the intensity of strong magnetic separation was 1.8T, and the number of magnetic separation times was 5; mica was flotated 3 times, and then feldspar was flotated 5 times; among them, the pH value of mica flotation was 3 - 4, the collector was dodecylamine, and the dosage was 150g / t; the pH value of feldspar flotation was 2 - 3, the dosage of the activator hydrofluoric acid was 1500g / t, and the capturer was octadecylamine + oleic acid, and the dosage was 200 + 75g / t; the calcination temperature was 1000 degrees, and the time was 100min; water quenching ensured a liquid-solid ratio of 10:1; the number of acid washing times was 2, the acids used were hydrochloric acid + hydrofluoric acid, the ratio was 3:1, the concentration was 10%, the liquid-solid ratio was 8:1, the temperature was 90 degrees, and the time was 48h; the gas for chlorination was hydrogen chloride gas, the time was 1 hour, and the temperature was 1200 degrees.

[0097] The ICP-OES test results of high-purity quartz sand product B are shown in Table 2. The 15 impurity elements all meet the IOTA-CG standard, and it is determined that it has the potential to be used as high-purity quartz sand for crucibles.

[0098] Table 2 Chemical analysis results of high-purity quartz sand products in Example 2

[0099] Al B Ca Cr Cu Fe K Li Mg 12.1 Not detected 0.6 Not detected Not detected 0.23 0.73 0.15 Not detected Mn Na Ni P Ti Zn Total amount Purity / % 0.002 0.61 Not detected 0.08 1.15 Not detected 15.652 99.9984

[0100] Among them, the unit of each impurity element in Table 2 is ppm, and the total amount refers to the sum of the masses of 15 impurity elements.

[0101] Example 3

[0102] Select a representative group of albite specimens, cut 5 thin sections, and observe them under a polarized light microscope. They are all linear inclusions, and it is determined that further screening can be carried out.

[0103] Carry out separation and purification tests on the samples to obtain high-purity quartz sand products. Among them, the separation and purification tests specifically include: the process flow is crushing and sand making - high-intensity magnetic separation - preferential flotation of mica and feldspar - calcination and water quenching - pickling - chlorination. The crushing and sand making is controlled to have 20 - 50% of -74 microns, and the sand of 80 - 200 mesh is obtained through screening; the intensity of high-intensity magnetic separation is 1.4 T, and the number of magnetic separation times is 2; mica is flotated 3 times, and then feldspar is flotated 3 times; among them, the pH value of mica flotation is 3 - 4, the collector is dodecylamine, and the dosage is 100 g / t; the pH value of feldspar flotation is 2 - 3, the dosage of the activator hydrofluoric acid is 1000 g / t, and the collector is dodecylamine + oxidized paraffin soap, and the dosage is 100 + 50 g / t; the calcination temperature is 800 °C, and the time is 30 min; water quenching ensures a liquid-solid ratio of 10:1; the number of pickling times is 2, the acids used are hydrochloric acid + hydrofluoric acid, the ratio is 3:1, the concentration is 10%, the liquid-solid ratio is 8:1, the temperature is 80 °C, and the time is 20 h; the gas for chlorination is hydrogen chloride gas, the time is 1 hour, and the temperature is 1200 °C.

[0104] Use ICP-MS to analyze and test high-purity quartz sand A; according to the test results, the Ti content is 1.3 ppm, the Li content is 0.4 ppm, and it is determined that further screening can be carried out; the Al content is 13 ppm, and it is determined that further screening can be carried out; the Ca content is 0.7 ppm, and the P content is 0.3 ppm, and it is determined that further screening can be carried out.

[0105] Optimization tests on the technological process and reagent system were carried out to obtain high-purity quartz sand product B. Among them, the optimization of the technological process and reagent system includes: the technological process is crushing and sand making - strong magnetic separation - preferential flotation of mica and feldspar - calcination and water quenching - acid washing - chlorination. The crushing and sand making is controlled to have 20 - 50% passing through -74 μm, and the sand of 80 - 200 mesh is obtained by screening; the intensity of strong magnetic separation is 1.8 T, and the number of magnetic separation times is 5 times; mica is flotated 3 times, and then feldspar is flotated 4 times; among them, the pH value of mica flotation is 3 - 4, the collector is dodecylamine, and the dosage is 150 g / t; the pH value of feldspar flotation is 2 - 3, the dosage of activator hydrofluoric acid is 1200 g / t, and the capturer is dodecylamine + oxidized paraffin soap, and the dosage is 180 + 60 g / t; the calcination temperature is 1100 °C, and the time is 60 min; water quenching ensures that the liquid-solid ratio is 10:1; the number of acid washing times is 2 times, the acids used are hydrochloric acid + hydrofluoric acid, the ratio is 3:1, the concentration is 10%, the liquid-solid ratio is 8:1, the temperature is 90 °C, and the time is 48 h; the gas for chlorination is hydrogen chloride gas, the time is 3 hours, and the temperature is 1200 °C.

[0106] The ICP-OES test results of high-purity quartz sand product B are shown in Table 3. The 15 impurity elements all meet the IOTA-CG standard, and it is determined that it has the potential for high-purity quartz sand for crucibles.

[0107] Table 3 Test results of high-purity quartz sand product in Example 3

[0108] Al B Ca Cr Cu Fe K Li Mg 11.97 0.1 0.33 Not detected 0.001 0.27 0.53 0.1 0.03 Mn Na Ni P Ti Zn Total amount Purity / % 0.0025 0.64 Not detected 0.09 1.05 Not detected 15.1135 99.9985

[0109] Among them, the unit of each impurity element in Table 3 is ppm, and the total amount refers to the sum of the masses of 15 impurity elements.

[0110] Example 4

[0111] A representative group of leucogranite specimens was selected, 5 thin sections were cut, and observed under a polarized light microscope. They are all linear inclusions, and it is determined that further screening can be carried out.

[0112] Separation and purification tests were carried out on the samples to obtain high-purity quartz sand products. Among them, the separation and purification tests specifically included: the process flow was crushing and sand making - high-intensity magnetic separation - preferential flotation of mica and feldspar - calcination and water quenching - pickling - chlorination. The crushing and sand making was controlled to have 20 - 50% of -74 microns, and the sand of 80 - 200 mesh was obtained through screening; the intensity of high-intensity magnetic separation was 1.2T, and the number of magnetic separation times was 5 times; mica was flotated 3 times, and then feldspar was flotated 4 times; among them, the pH value of mica flotation was 3 - 4, the collector was dodecylamine, and the dosage was 150g / t; the pH value of feldspar flotation was 2 - 3, the dosage of the activator hydrofluoric acid was 1200g / t, and the capturer was dodecylamine + sodium oleate, and the dosage was 100 + 30g / t; the calcination temperature was 1000 degrees, and the time was 60min; water quenching ensured a liquid-solid ratio of 10:1; the number of pickling times was 2 times, the acids used were hydrochloric acid + hydrofluoric acid, the ratio was 3:1, the concentration was 10%, the liquid-solid ratio was 5:1, the temperature was 90 degrees, and the time was 24h; the gas for chlorination was hydrogen chloride gas, the time was 1 hour, and the temperature was 1200 degrees.

[0113] ICP-MS was used to analyze high-purity quartz sand A; according to the test results, the Ti content was 1.5ppm, the Li content was 0.3ppm, and it was determined that further screening could be carried out; the Al content was 12ppm, and it was determined that further screening could be carried out; the Ca content was 0.8ppm, and the P content was 0.2ppm, and it was determined that further screening could be carried out.

[0114] Optimization tests of the process flow and reagent system were carried out to obtain high-purity quartz sand product B. Among them, the optimization of the process flow and reagent system included: the process flow was crushing and sand making - high-intensity magnetic separation - preferential flotation of mica and feldspar - calcination and water quenching - pickling - chlorination. The crushing and sand making was controlled to have 20 - 50% of -74 microns, and the sand of 80 - 200 mesh was obtained through screening; the intensity of high-intensity magnetic separation was 1.6T, and the number of magnetic separation times was 5 times; mica was flotated 3 times, and then feldspar was flotated 4 times; among them, the pH value of mica flotation was 3 - 4, the collector was dodecylamine, and the dosage was 150g / t; the pH value of feldspar flotation was 2 - 3, the dosage of the activator hydrofluoric acid was 1500g / t, and the capturer was dodecylamine + sodium oleate, and the dosage was 150 + 50g / t; the calcination temperature was 1100 degrees, and the time was 60min; water quenching ensured a liquid-solid ratio of 10:1; the number of pickling times was 2 times, the acids used were hydrochloric acid + hydrofluoric acid, the ratio was 3:1, the concentration was 10%, the liquid-solid ratio was 8:1, the temperature was 90 degrees, and the time was 36h; the gas for chlorination was hydrogen chloride gas, the time was 2 hours, and the temperature was 1200 degrees.

[0115] The ICP-OES test results of high-purity quartz sand product B are shown in Table 4. The 15 impurity elements all meet the IOTA-CG standard, and it is determined that it has the potential for high-purity quartz sand for crucibles.

[0116] Table 4 Test Results of High-Purity Quartz Sand Products in Example 4

[0117] Al B Ca Cr Cu Fe K Li Mg 10.656 0.075 0.58 Not detected Not detected 0.17 0.679 Not detected 0.002 Mn Na Ni P Ti Zn Total amount Purity / % Not detected 0.56 Not detected 0.07 1.06 Not detected 13.852 99.9986

[0118] Although the present invention has been described above in conjunction with exemplary embodiments and the accompanying drawings, those of ordinary skill in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A method for screening white granite type high-purity quartz raw materials, characterized in that: The method comprises: Determine whether the granite raw material sample is a granite raw material with linear inclusions, and if so, perform separation and purification tests on the granite raw material sample to obtain high-purity quartz sand; When the high-purity quartz sand meets the first standard but does not meet the second standard, the process system of the separation and purification test is optimized several times, and the separation and purification test is carried out on the white granite raw material sample according to the process system optimized each time. As long as the high-purity quartz sand obtained by one optimization meets the second standard, the white granite raw material sample is used as the screened raw material; When the high-purity quartz sand meets the second standard, the white granite raw material sample is used as the selected raw material; The first standard includes: Ti less than 2ppm, Li less than 1ppm, Al less than 20ppm, Ca less than 1.2ppm, P less than 0.5ppm; The second standard includes that all impurities meet the quality standards of high-purity quartz sand; The separation and purification test includes: sand making, magnetic separation, and then flotation concentrate is obtained through flotation process, followed by calcination, water quenching, pickling and chlorination operations; The optimization includes adjusting at least one step in the separation and purification experiment.

2. The method for screening granite-type high-purity quartz raw materials according to claim 1, characterized in that: The granite raw material sample comprises one or more granite ore samples produced from the same mining area, and each granite ore sample is cut into one or more thin slices.

3. The method for screening white granite type high-purity quartz raw materials according to claim 2, characterized in that: The step of judging whether the granite raw material sample is a granite raw material with linear inclusions comprises: The granite ore sample is cut into thin slices and observed under a polarizing microscope to determine whether it is granite with linear inclusions. If so, the granite raw material is granite raw material with linear inclusions.

4. The method for screening white granite type high-purity quartz raw materials according to claim 1, characterized in that: The sand making method obtains sand with a mesh size of 80 to 200; The intensity of the magnetic separation is 1.2 to 1.8 T, and the number of magnetic separations is 3 to 6 times; The flotation process includes a mica-feldspar mixed flotation process or a mica-feldspar-first flotation process; The calcination temperature is 800-1200 degrees and the time is 30-120 minutes; The pickling includes multiple picklings, and the conditions of each pickling are the same. The pickling conditions include: using multiple acids selected from hydrochloric acid, hydrofluoric acid, sulfuric acid, nitric acid and oxalic acid, with a concentration of 10% to 30%, a liquid-to-solid ratio of 8:1 to 2:1, a temperature of 80 to 100 degrees, and a time of 10 to 40 hours; The chlorinated gas is chlorine gas or hydrogen chloride gas, the temperature is 1000-1300 degrees, and the time is 0.5-3 hours.

5. The method for screening white granite type high-purity quartz raw materials according to claim 4, characterized in that: The flotation process of mica first and feldspar second comprises: mica flotation 2 to 5 times, and then feldspar flotation 3 to 5 times; wherein the pH value of mica flotation is 3 to 4, and the collector is one or more of dodecylamine, octadecylamine, and propylene diamine, and the dosage is 100 to 200 g / t; the pH value of feldspar flotation is 2 to 3, the dosage of activator hydrofluoric acid is 1000 to 1500 g / t, the collector comprises a cation collector and / or anion collector, the cation collector is one or more of dodecylamine, octadecylamine, and propylene diamine, and the dosage is 100 to 200 g / t, and the anion collector is one or more of oxidized paraffin soap, oleic acid, and sodium oleate, and the dosage is 50 to 100 g / t.

6. The method for screening white granite type high-purity quartz raw materials according to claim 1, characterized in that: The optimization includes optimization of at least one link of the separation and purification test, and the optimization of one link includes: selection of at least one type of parameters and substances within a determined range, and / or optimization adjustment of the link process.

7. The method for screening white granite type high purity quartz raw materials according to claim 4, characterized in that: In the case where the optimization includes the sand making, the proportion of undersize products of the sand obtained after optimization that passes through a 200-mesh sieve is 20-50%; In the case where the flotation process is a mica-feldspar mixed flotation process, if the optimization includes the optimization of the flotation process, the optimization includes the optimization of the flotation times, or the flotation process is adjusted to a flotation process of mica first and feldspar later.

8. The method for screening white granite type high-purity quartz raw materials according to claim 1, characterized in that: The determination of whether the high-purity quartz sand meets the first standard at the same time includes: Determine whether the Ti and Li contents meet the requirements. If they do, determine whether the Al content meets the requirements. If the Al content meets the requirements, determine whether the Ca and P contents meet the requirements.

9. The method for screening white granite type high-purity quartz raw materials according to claim 1, characterized in that: The high-purity quartz sand quality standards include: IOTA-CG standard.

10. The method for screening granite-type high-purity quartz raw materials according to claim 1, characterized in that: All impurities of the second standard include: Al, B, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Ti and Zn.

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