Method for separating and purifying high-purity quartz sand from series of rocks of twinkling, quartz twinkling, granite twinkling and granite

Abstract

The invention belongs to the field of quartz sand separation and purification, and particularly discloses a method for separating and purifying high-purity quartz sand from series rocks such as twinkle, quartz twinkle, granite twinkle and granite, and the method comprises the following steps: S1, crushing, grinding and screening magmatic rock ore samples; s2, performing multi-stage magnetic separation on the sand sample; s3, the coarse sand is subjected to multi-channel continuous reverse flotation; s4, the quartz coarse sand concentrate is scrubbed; s5, the scrubbed quartz coarse sand concentrate is subjected to re-grinding, screening and multi-stage magnetic separation; s6, the quartz fine sand is subjected to multi-channel continuous reverse flotation; according to the method, through multi-channel continuous flotation, the energy consumption is reduced, meanwhile, the quartz monomer dissociation rate is greatly increased, through acid pickling, high-temperature chlorination and magnetic separation, the purity of the quartz raw material is greatly increased, high-purity quartz sand is separated and purified from high-storage magmatic rock, the raw material resource cost is greatly reduced, and the high-purity quartz sand raw material resource range is widened.

Description

Technical Field

[0001] The present invention belongs to the field of separation and purification of quartz sand, and specifically relates to a method for separating and purifying high-purity quartz sand from rocks of the diorite, quartz diorite, granodiorite, and granite series. Background Art

[0002] High-purity quartz sand is the core raw material for strategic industries such as photovoltaic glass, semiconductor crucibles, and optical fibers;

[0003] Traditional technological process for separating and purifying quartz sand: raw ore crushing → calcination and water quenching → grinding → magnetic separation → flotation → acid leaching → high-temperature chlorination → finished product; this method is highly dependent on ore resources: it is only applicable to high-quality vein quartz or granitic pegmatite. Due to mineralogical limitations and insufficient flotation separation technology, it cannot be adapted to magmatic rocks such as diorite, quartz diorite, granodiorite, and granite;

[0004] Magmatic rocks such as diorite, quartz diorite, granodiorite, and granite have huge global reserves, while the output ratio of high-quality vein quartz or granitic pegmatite is limited, making the existing production technology and mode of high-purity quartz a supply bottleneck for a long time.

[0005] Mineralogical limitations: In diorite, quartz diorite, granodiorite, and granite, quartz - feldspar - mica shows an interlaced structure. Quartz usually crystallizes last and fills the gaps between early-crystallized minerals, and the crystal grains are relatively fine, making it difficult to achieve monomer dissociation by mechanical crushing and color sorting separation;

[0006] Insufficient flotation separation technology: It is relatively simple to separate and remove impurity minerals in vein quartz and granitic pegmatite with flotation reagents; however, it is difficult to selectively separate complex mineral combinations in diorite, quartz diorite, granodiorite, and granite. There are many associated impurity minerals such as feldspar, mica, and accessory minerals, and the technological process is complex, making it difficult to economically separate and purify. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for separating and purifying high-purity quartz sand from rocks of the diorite, quartz diorite, granodiorite, and granite series, so as to solve the problem that the traditional technological process for separating and purifying quartz sand is difficult to fully separate and purify impurities in high-reserve magmatic rocks and economically separate and purify quartz sand, resulting in insufficient supply of raw materials for high-purity quartz glass at home and abroad as mentioned in the above background art.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A method for separating and purifying high-purity quartz sand from rocks of the diorite, quartz diorite, granodiorite, and granite series, comprising the following steps:

[0010] S1. Crush, grind and screen the magmatic rock ore sample, with the screening particle size being 20 - 80 mesh, to obtain a sand sample;

[0011] S2. Conduct multi - stage magnetic separation on the said sand sample to remove magnetic impurities and obtain coarse sand;

[0012] S3. Conduct multi - pass continuous reverse flotation on the said coarse sand to enrich quartz particles and obtain a quartz coarse sand concentrate;

[0013] S4. Scrub the said quartz coarse sand concentrate and adjust the pH of the pulp to 6.5 - 7.5;

[0014] S5. Conduct re - grinding, screening and multi - stage magnetic separation on the scrubbed quartz coarse sand concentrate to obtain quartz fine sand with a particle size of 50 - 200 mesh;

[0015] S6. Conduct multi - pass continuous reverse flotation on the said quartz fine sand to obtain a quartz concentrate;

[0016] S7. Scrub the said quartz concentrate, rinse the pulp until the pH is 6.5 - 7.5 and then dehydrate it;

[0017] S8. Conduct mixed acid leaching on the dehydrated quartz concentrate to obtain quartz sand;

[0018] S9. Wash the said quartz sand, adjust the pH of the pulp to 6.5 - 7.5 and then dehydrate and roast the sand;

[0019] S10. Conduct high - temperature chlorination treatment on the roasted and dehydrated quartz sand;

[0020] S11. Collect and package the quartz sand after high - temperature chlorination treatment to obtain the finished high - purity quartz sand.

[0021] Preferably, the magmatic rock is one of diorite, quartz diorite, granodiorite, and granite.

[0022] Preferably, the flotation reagents used in the multi - pass continuous reverse flotation include a pulp conditioner and a collector for non - quartz impurity minerals. The pulp conditioner includes sulfuric acid, hydrofluoric acid, and sodium hydroxide, and the collector includes dodecylamine hydrochloride and sodium oleate.

[0023] Preferably, the process of conducting multi - pass continuous reverse flotation on the coarse sand in step S3 is as follows:

[0024] Mix the coarse sand with plasma water at a solid - liquid ratio of 1:2 to form a uniform slurry;

[0025] Add sulfuric acid and hydrofluoric acid to the slurry, with the ratio of sulfuric acid to hydrofluoric acid being 1:1. Adjust the pH of the pulp to 2 - 3 and then add dodecylamine hydrochloride to float out the impurities;

[0026] Hydrofluoric acid is added to the mortar, and after adjusting the pH of the pulp to 3-4, dodecylamine hydrochloride is added to float out the impurities.

[0027] Preferably, the process of multi-stage continuous reverse flotation of the fine quartz sand in step S6 is as follows:

[0028] Mix the fine quartz sand with plasma water at a solid-liquid ratio of 1:2 to form a uniform pulp;

[0029] Sulfuric acid and hydrofluoric acid are added to the pulp, and the ratio of sulfuric acid to hydrofluoric acid is 1:1. After adjusting the pH of the pulp to 2-4, dodecylamine hydrochloride is added to float out the impurities;

[0030] Hydrofluoric acid is added to the pulp, and after adjusting the pH of the pulp to 4-5, dodecylamine hydrochloride is added to float out the impurities;

[0031] Sodium hydroxide is added to the pulp, and after adjusting the pH of the pulp to 9-11, sodium oleate is added to float out the impurities;

[0032] Sodium hydroxide is added to the pulp, and after adjusting the pH of the pulp to 12-14, sodium oleate is added to float out the impurities.

[0033] Preferably, the multi-stage magnetic separation adopts three-stage gradient magnetic separation. The first stage is 0.5-1.0T to remove strongly magnetic impurities; the second stage is 1.0-1.5T to remove medium magnetic impurities; the third stage is 1.5-2.0T to remove weakly magnetic impurities.

[0034] Preferably, the parameters of the mixed acid leaching in step S7 include: time 10-20 hours, temperature 50-100 °C;

[0035] The mixed acid is composed of 10%-15% concentration hydrochloric acid and 5%-8% concentration hydrofluoric acid in a volume ratio of 3:1, and the liquid-solid ratio is controlled to be 1:2-3:1.

[0036] Preferably, the parameters of the high-temperature chlorination treatment in step S10 include: using dry HCL gas with a purity ≥99%, introducing it under a nitrogen protection atmosphere, the ventilation flow rate is 0.5L-5L / min, the heating temperature of the sand sample is 1100-1200 °C, and the time is 60-120 min.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] The present invention reduces energy consumption and greatly improves the monomer dissociation rate of quartz through multi-stage continuous flotation. Through pickling, high-temperature chlorination, and magnetic separation, the purity of quartz raw materials is greatly improved, and the purity of the separated and purified quartz sand and the content of micro gas-liquid inclusions meet the requirements for melting into quartz glass in industries such as optical fibers, semiconductors, photovoltaics, and special industries. It realizes the separation and purification of high-purity quartz sand from high-reserve magmatic rocks, greatly reduces the raw material resource cost, and expands the range of raw material resources for high-purity quartz sand. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0040] Figure 1 It is a block diagram of the method steps of the present invention;

[0041] Figure 2 It is a block diagram of the process flow of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following will make a detailed description of the specific embodiments of the present invention in conjunction with the drawings of the specification.

[0043] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0044] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an individual or alternative embodiment that mutually excludes other embodiments.

[0045] As shown in Figure 1 to Figure 2 shown:

[0046] Embodiment 1: This embodiment provides a method for separating and purifying high-purity quartz sand from diorite, quartz diorite, granodiorite, and granite series rocks, including the following steps:

[0047] S1. Crush, grind, and screen the granodiorite ore sample, and the screening particle size is 20 - 80 mesh to obtain a sand sample;

[0048] Through mechanical crushing and grinding, the original structure of the ore is destroyed, enabling the preliminary dissociation of quartz from other minerals (such as feldspar and mica); screening controls the particle size range to ensure the efficiency of subsequent flotation and magnetic separation.

[0049] S2. Conduct multi-stage magnetic separation on the sand sample to remove magnetic impurities and obtain coarse sand;

[0050] Avoid interference from strongly magnetic impurities in subsequent flotation.

[0051] S3. Conduct multi-pass continuous reverse flotation on the coarse sand to enrich quartz particles and obtain a quartz coarse sand concentrate;

[0052] Use flotation reagents to selectively separate non-quartz impurities, including feldspar, mica, and iron-containing minerals.

[0053] S4. Scrub the quartz coarse sand concentrate and adjust the pH of the pulp to 7;

[0054] Mechanically scrub to strip off the fine-grained impurities and residual flotation reagents attached to the surface of quartz. A pH of 7 is used to avoid secondary dissolution of quartz or re-adsorption of impurities caused by acidic or alkaline environments. A mechanical scrubber can be selected as the scrubbing equipment. The high-speed rotation of the impeller at 400 - 500 rpm generates shear force to strengthen the stripping of impurities and improve the cleanliness of the quartz surface, creating conditions for deep purification.

[0055] S5. Conduct re-grinding, screening, and multi-stage magnetic separation on the scrubbed quartz coarse sand concentrate to obtain quartz fine sand with a particle size of 50 - 200 mesh;

[0056] Further refine the quartz particles, improve the monomer dissociation degree of quartz, promote the exposure of inclusion impurities, and release impurities in micro-cracks; screening controls the target particle size, and magnetic separation removes magnetic particles introduced by mechanical iron contamination during grinding. Re-grinding at 20 - 80 mesh can greatly improve the efficiency.

[0057] S6. Conduct multi-pass continuous reverse flotation on the quartz fine sand to obtain quartz concentrate;

[0058] Regulate the pH in gradients to target and remove trace impurities, including residual feldspar, iron film, and surface-adsorbed ions, greatly improving the purity of quartz.

[0059] S7. Scrub the quartz concentrate, rinse the pulp to a pH of 7 and then dehydrate;

[0060] Remove residual flotation reagents, rinse the pulp to a pH of 7 to neutralize the residual acid and alkali, prevent violent reactions during acid leaching, and then dehydrate to reduce the consumption of acid leaching reagents in subsequent acid washing and improve the reaction efficiency.

[0061] S8. Conduct mixed acid leaching on the dehydrated quartz concentrate to obtain quartz sand;

[0062] Trace impurities (such as Al, Li, B, etc.) at the edges of the dissolved quartz lattice and surface inclusions.

[0063] S9. Wash the quartz sand with water, adjust the pH of the pulp to 7, and then dehydrate and roast the sand.

[0064] Remove the residual acid leaching solution to prevent the residual acid from corroding the equipment or affecting the chlorination reaction. Dry the quartz sand to remove the adsorbed water to avoid the reaction of water vapor with HCl to generate corrosive gases during high-temperature chlorination.

[0065] S10. Perform high-temperature chlorination treatment on the dehydrated and roasted quartz sand.

[0066] Remove the gas-liquid inclusions and trace metal impurities in the quartz lattice through a gas-solid reaction.

[0067] S11. Collect and package the quartz sand after high-temperature chlorination treatment to obtain the finished high-purity quartz sand.

[0068] Specifically, the flotation reagents used in multi-stage continuous reverse flotation include pulp regulators and collectors for non-quartz impurity minerals. The pulp regulators include sulfuric acid, hydrofluoric acid, and sodium hydroxide, and the collectors include dodecylamine hydrochloride and sodium oleate.

[0069] Specifically, the process of multi-stage continuous reverse flotation of the coarse sand in step S3 is as follows:

[0070] Mix the coarse sand with plasma water at a solid-liquid ratio of 1:2 to form a uniform slurry.

[0071] Add sulfuric acid and hydrofluoric acid to the slurry. The ratio of sulfuric acid to hydrofluoric acid is 1:1. Adjust the pH of the pulp to 2-3, then add dodecylamine hydrochloride to float out the impurities.

[0072] The strong acidic environment dissolves Al on the surface of feldspar 3+ , activates feldspar so that it is adsorbed by dodecylamine hydrochloride, corrodes the edges of mica, exposes the internal structure for the action of the collector. Dodecylamine hydrochloride is a cationic collector, which preferentially adsorbs on the negatively charged surfaces of feldspar and mica, causing them to float.

[0073] Add hydrofluoric acid to the slurry. Adjust the pH of the pulp to 3-4, then add dodecylamine hydrochloride to float out the impurities.

[0074] Fine-tune the acidity to strengthen the flotation selectivity for residual iron-containing minerals, remove the main silicate impurities in stages, and improve the quartz recovery rate.

[0075] Specifically, the process of multi-stage continuous reverse flotation of the fine quartz sand in step S6 is as follows:

[0076] Mix the fine quartz sand with plasma water at a solid-liquid ratio of 1:2 to form a uniform slurry.

[0077] Sulfuric acid and hydrofluoric acid are added to the pulp, and the ratio of sulfuric acid to hydrofluoric acid is 1:1. After adjusting the pH of the pulp to 2-4, dodecylamine hydrochloride is added to float out the impurities.

[0078] The residual feldspar and iron-containing minerals are flotation-selected for the second time.

[0079] Hydrofluoric acid is added to the pulp. After adjusting the pH of the pulp to 4-5, dodecylamine hydrochloride is added to float out the impurities.

[0080] Fine-tune the acidity to remove the surface Fe 3+ Complex.

[0081] Sodium hydroxide is added to the pulp. After adjusting the pH of the pulp to 9-11, sodium oleate is added to float out the impurities.

[0082] The sodium oleate is activated in an alkaline environment, and the calcium and magnesium minerals adsorbed on the surface of quartz are flotation-selected. Dodecylamine hydrochloride is replaced with sodium oleate to adapt to the change of the surface electric property of impurities at different pH values.

[0083] Sodium hydroxide is added to the pulp. After adjusting the pH of the pulp to 12-14, sodium oleate is added to float out the impurities.

[0084] The strong alkaline hydroxylation reaction strips the iron oxide film on the surface of quartz.

[0085] Specifically, the multi-stage magnetic separation adopts three-stage gradient magnetic separation. The first stage is 0.5-1.0T to remove strongly magnetic impurities; the second stage is 1.0-1.5T to remove medium magnetic impurities; the third stage is 1.5-2.0T to remove weakly magnetic impurities.

[0086] Specifically, the parameters of the mixed acid leaching in step S7 include: time 10-20 hours, temperature 50-100 °C;

[0087] The mixed acid is composed of 10%-15% concentration hydrochloric acid and 5%-8% concentration hydrofluoric acid according to the volume ratio of 3:1, and the liquid-solid ratio is controlled to be 1:2-3:1.

[0088] 10%-15% concentration hydrochloric acid dissolves metal oxides, including Fe2O3 and Al2O3, and 5%-8% concentration hydrofluoric acid corrodes silicate impurities to open the micropores on the surface of quartz. The temperature of 50-100 °C accelerates the acid reaction kinetics and shortens the treatment time. The liquid-solid ratio ensures that the acid solution fully wets the quartz particles.

[0089] Specifically, the parameters of the high-temperature chlorination treatment in step S10 include: using dry HCL gas with a purity of ≥99%, introducing it under a nitrogen protection atmosphere, the gas flow rate is 0.5L-5L / min, the heating temperature of the sand sample is 1100-1200 °C, and the time is 60-120 min.

[0090] The temperature reaches the quartz α-β phase transition temperature at 1100 - 1200 °C, the lattice expands to release inclusions, and the dry HCl gas reacts with impurity metals (such as Fe, Al) to form volatile chlorides (FeCl3↑, AlCl3↑). The ventilation flow rate of 0.5 - 5 L / min is used to balance the reaction rate and gas utilization rate.

[0091] The purity data of granodiorite after being treated by the above method is shown in the following table:

[0092]

[0093] The particle size distribution data of granodiorite after being treated by the above method is shown in the following table:

[0094]

[0095] This application realizes the separation and purification of high-purity quartz sand from diorite, quartz diorite, granodiorite, and granite (initial quartz content 5 - 60%), greatly reducing the raw material resource cost and expanding the range of raw material resources for high-purity quartz sand;

[0096] Through multi-stage continuous flotation, while reducing energy consumption, the dissociation rate of quartz monomers is increased to over 99.95%;

[0097] Through pickling, high-temperature chlorination, and magnetic separation, the purity of the final quartz raw material reaches a purity of over 99.995;

[0098] The purity of the finished quartz sand and the content of micro gas-liquid inclusions meet the requirements for melting into quartz glass in industries such as optical fibers, semiconductors, photovoltaics, and special industries.

[0099] Importantly, it should be noted that the construction and arrangement of the present application shown in multiple different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who refer to this disclosure should easily understand that many modifications are possible without materially departing from the novel teachings and advantages of the subject matter described in this application (e.g., changes in the dimensions, scales, structures, shapes and proportions of various elements, as well as parameter values (such as temperature, pressure, etc.), installation arrangements, use of materials, colors, orientations, etc.). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature, number or position of discrete elements may be altered or changed. Accordingly, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be altered or re-ordered according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover the structures that perform the recited function as described herein, and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present invention. Accordingly, the present invention is not limited to a particular embodiment, but extends to various modifications that still fall within the scope of the appended claims.

[0100] In addition, in order to provide a concise description of the exemplary embodiments, all features of the actual embodiments may not be described (i.e., those features that are not relevant to the currently contemplated best mode of carrying out the present invention or those features that are not relevant to the implementation of the present invention).

[0101] It should be understood that in the development of any actual implementation, as in any engineering or design project, numerous specific implementation decisions may be made. Such development efforts may be complex and time-consuming, but for those of ordinary skill in the art who benefit from this disclosure, without undue experimentation, such development efforts will be a routine task of design, manufacturing and production.

[0102] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A method for separating and purifying high-purity quartz sand from diorite, quartz diorite, granodiorite and granite series rocks, characterized in that: The following steps are involved: S1. crushing, grinding and screening the igneous rock sample, with the screening particle size being 20-80 meshes, to obtain a sand sample; S2, subjecting the sand sample to multi-stage magnetic separation to remove magnetic impurities and obtain coarse sand; S3, subjecting the coarse sand to multiple continuous reverse flotation to enrich quartz particles and obtain quartz coarse sand concentrate; S4, scrubbing the quartz coarse sand concentrate, and adjusting the pH of the slurry to 6.5-7.5; S5, re-grinding, screening and multi-stage magnetic separation of the scrubbed quartz coarse sand concentrate to obtain quartz fine sand of 50 to 200 mesh; S6, subjecting the quartz fine sand to multiple continuous reverse flotation to obtain quartz concentrate; S7, scrubbing the quartz concentrate, and dehydrating the slurry after the pH value is 6.5 to 7.5; S8, subjecting the dehydrated quartz concentrate to mixed acid leaching to obtain quartz sand; S9, washing the quartz sand with water, adjusting the pH of the slurry to 6.5-7.5, and then dehydrating and roasting the sand; S10, subjecting the dehydrated and baked quartz sand to high temperature chlorination treatment; S11, collecting and packaging the quartz sand after high-temperature chlorination treatment to obtain finished high-purity quartz sand.

2. A method for separating and purifying high-purity quartz sand from diorite, quartz diorite, granodiorite and granite series rocks according to claim 1, characterized in that: The igneous rock is one of diorite, quartz diorite, granodiorite and granite ore samples.

3. A method for separating and purifying high-purity quartz sand from diorite, quartz diorite, granodiorite and granite series rocks according to claim 1, characterized in that: The flotation reagents used in the multi-channel continuous reverse flotation include a pulp regulator and a collector for non-quartz impurity minerals, the pulp regulator includes sulfuric acid, hydrofluoric acid and sodium hydroxide, and the collector includes dodecylamine hydrochloride and sodium oleate.

4. A method for separating and purifying high-purity quartz sand from diorite, quartz diorite, granodiorite and granite series rocks according to claim 3, characterized in that: The process of performing multiple continuous reverse flotation on the coarse sand in step S3 is as follows: The coarse sand and plasma water are mixed at a solid-liquid ratio of 1:2 to form a uniform mortar; Add sulfuric acid and hydrofluoric acid to the mortar in a ratio of 1:1, adjust the pH of the slurry to 2-3, then add dodecylamine hydrochloride to float out impurities; Hydrofluoric acid is added to the mortar, and the pH of the slurry is adjusted to 3-4, and then dodecylamine hydrochloride is added to float out impurities.

5. A method for separating and purifying high-purity quartz sand from diorite, quartz diorite, granodiorite and granite series rocks according to claim 3, characterized in that: The process of performing multi-pass continuous reverse flotation on the quartz fine sand in step S6 is as follows: The quartz fine sand and plasma water are mixed at a solid-liquid ratio of 1:2 to form a uniform slurry; Adding sulfuric acid and hydrofluoric acid to the slurry in a ratio of 1:1, adjusting the pH of the slurry to 2-4, and then adding dodecylamine hydrochloride to float out impurities; Adding hydrofluoric acid to the slurry, adjusting the pH of the slurry to 4-5, and then adding dodecylamine hydrochloride to float out impurities; Adding sodium hydroxide to the slurry, adjusting the pH of the slurry to 9-11, and then adding sodium oleate to float out impurities; Sodium hydroxide is added to the slurry to adjust the pH of the slurry to 12-14, and then sodium oleate is added to float out impurities.

6. A method for separating and purifying high-purity quartz sand from diorite, quartz diorite, granodiorite and granite series rocks according to claim 1, characterized in that: The multi-stage magnetic separation adopts three-stage gradient magnetic separation, wherein the first stage is 0.5-1.0T to remove strong magnetic impurities; the second stage is 1.0-1.5T to remove medium magnetic impurities; and the third stage is 1.5-2.0T to remove weak magnetic impurities.

7. A method for separating and purifying high-purity quartz sand from diorite, quartz diorite, granodiorite and granite series rocks according to claim 1, characterized in that: The mixed acid pickling parameters in step S7 include: time 10 to 20 hours, temperature 50 to 100° C.; The mixed acid is composed of 10%-15% hydrochloric acid and 5%-8% hydrofluoric acid in a volume ratio of 3:1, and the liquid-to-solid ratio is controlled to be 1:2-3:

1.

8. The method for separating and purifying high-purity quartz sand from diorite, quartz diorite, granodiorite and granite series rocks according to claim 1, characterized in that: The high temperature chlorination treatment parameters in step S10 include: using dry HCL gas with a purity of ≥99%, passing it under a nitrogen protective atmosphere, a ventilation flow rate of 0.5L~5L / min, a sand sample heating temperature of 1100~1200°C, and a time of 60~120min.

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