Collecting agent composition for flotation of rutile, process for preparing high-purity quartz sand from titanium-containing pegmatite and high-purity quartz sand

Abstract

The invention provides a collecting agent composition for flotation of rutile, a process for preparing high-purity quartz sand from titanium-containing pegmatite and the high-purity quartz sand, and particularly relates to the technical field of quartz sand preparation. The collecting agent composition for flotation of rutile is composed of a main collecting agent, an auxiliary collecting agent and a surfactant according to the mass ratio of (1-3): (1-3): 2. The main collecting agent is a phosphoric acid collecting agent, and the auxiliary collecting agent is fatty alcohol. The phosphoric acid collecting agent serves as a main collecting agent, the fatty alcohol serves as an auxiliary collecting agent, and meanwhile the flotation efficiency is improved through the surface active agent. The composition shows excellent selectivity and collection effect on rutile. By introducing the auxiliary collecting agent, the use amount of the phosphoric acid collecting agent is effectively reduced, and therefore the production cost of the whole flotation process is remarkably reduced. According to the collecting agent composition, the flotation efficiency of rutile is improved, the use cost is reduced, and the development of downstream industries is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of quartz sand preparation, in particular to a collector composition for flotation of rutile, a process for preparing high-purity quartz sand from titanium-containing pegmatite, and the high-purity quartz sand. Background Art

[0002] High-purity quartz sand, as an important industrial raw material, is widely used in fields such as semiconductors, photovoltaics, fiber optic communications, and precision casting. With the development of science and technology and industrial upgrading, the purity requirements for high-purity quartz sand are becoming increasingly stringent. The presence of titanium impurities in quartz sand seriously affects its quality and application range. Titanium impurities mainly come from minerals such as rutile, anatase, and ilmenite in the ore. These minerals coexist with quartz and are difficult to separate.

[0003] Traditional methods for producing high-purity quartz sand rely primarily on physical and chemical purification techniques. Physical purification techniques include crushing, screening, magnetic separation, gravity separation, and flotation, while chemical purification techniques include acid washing, alkaline washing, and chlorination roasting. Flotation is widely used due to its ease of operation and relatively low cost. Flotation uses collectors to separate target minerals from gangue minerals by exploiting differences in mineral surface properties. However, existing flotation collectors have significant limitations in removing titanium impurities.

[0004] Existing flotation processes can only remove most rutile, with recovery rates ranging from approximately 60% to 80%. They are unable to completely remove titanium impurities, resulting in a high titanium content in the final product that cannot meet the requirements of high-end applications. Furthermore, when capturing titanium impurities, quartz is often also captured, resulting in quartz loss, affecting product yield and purity. Some collectors are also toxic, posing a threat to the environment and human health, limiting their use in areas with strict environmental protection requirements. High-performance collectors are often expensive, increasing the production cost of high-purity quartz sand and affecting the economic benefits of the company.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The present invention aims to provide a collector composition for flotation of rutile, a process for preparing high-purity quartz sand from titanium-containing pegmatite, and high-purity quartz sand, aiming to solve at least one of the above-mentioned technical problems in the prior art.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted: A first aspect of the present invention provides a collector composition for flotation of rutile, comprising a primary collector, an auxiliary collector, and a surfactant in a mass ratio of (1-3):(1-3):2; The main collector is a phosphoric acid collector, and the auxiliary collector is a fatty alcohol.

[0008] Furthermore, the phosphoric acid collector includes at least one of dodecyl phosphate monoester, dodecyl phosphoric acid, octyl phosphate, decyl phosphoric acid and decyl phosphate.

[0009] Preferably, the fatty alcohol comprises at least one of isobutanol, n-pentanol, n-hexanol, n-heptanol, dodecanol and tetradecanol.

[0010] Preferably, the surfactant comprises stearate.

[0011] Preferably, the stearate comprises sodium octadecanoate.

[0012] Furthermore, the collector composition is composed of monolauryl phosphate, isobutanol and sodium octadecanoate in a mass ratio of (1-3):(1-3):2.

[0013] A second aspect of the present invention provides a process for preparing high-purity quartz sand from titanium-containing pegmatite, comprising the following steps: A. grinding titanium-containing pegmatite and then slurrying to obtain a first slurry, and performing gravity separation on the slurry to obtain a gravity separation concentrate; B. performing magnetic separation on the gravity concentrate to obtain non-magnetic minerals, performing primary flotation and secondary flotation on the non-magnetic minerals to obtain flotation concentrate; then performing hot-pressing acid leaching and chlorination roasting on the flotation concentrate to obtain high-purity quartz sand; Wherein, the collector used in the second-stage flotation is the collector composition described in the first aspect.

[0014] Furthermore, the two-stage flotation includes a primary flotation and a secondary flotation performed in sequence.

[0015] Preferably, the pH of the second stage flotation is 4.5-6.

[0016] Preferably, the amount of collector used in the primary flotation is 400-600 g / t.

[0017] Preferably, the amount of collector used in the secondary flotation is half of the amount of collector used in the primary flotation.

[0018] Furthermore, the magnetic separation includes a first stage magnetic separation and a second stage magnetic separation performed in sequence.

[0019] Preferably, the magnetic field strength of the first stage magnetic separation is 1500-2000 GS.

[0020] Preferably, the magnetic field strength of the second-stage magnetic separation is 15000~22000GS.

[0021] Furthermore, the hot-pressing acid leaching process is as follows: placing the flotation concentrate into a polytetrafluoroethylene tank, adding mixed acid, and then transferring it to a hydrothermal kettle for hot-pressing acid leaching.

[0022] Preferably, the mixed acid is hydrofluoric acid and hydrochloric acid in a volume ratio of 3:1.

[0023] Preferably, the volume ratio of the mixed acid to the flotation concentrate is (0.8-1.2):1.

[0024] Preferably, the pressure of the hot-pressing acid leaching is ≥2 MPa.

[0025] Preferably, the temperature of the hot-pressing acid leaching is 200-250° C., and the time is 10-15 hours.

[0026] Furthermore, the chlorination roasting process is as follows: washing the concentrated sand after hot-pressing acid leaching to neutrality, drying it, heating it to 1000-1200° C. under vacuum conditions, and introducing HCl gas for roasting.

[0027] Preferably, the purity of the HCl gas is ≥99.9%, and the flow rate is 1-5 L / min.

[0028] Preferably, the calcination time is 0.5 to 2 hours.

[0029] Furthermore, the collector used in the first stage flotation is composite collector HR-1.

[0030] Preferably, the usage of the composite collector HR-1 is 100-400 g / t.

[0031] Preferably, the pH of the first stage flotation is 1.5-2.5 and the temperature is 40-50°C.

[0032] The third aspect of the present invention provides high-purity quartz sand, which is prepared using the process described in the second aspect.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects: The collector composition for rutile flotation provided by the present invention utilizes a phosphoric acid collector as the primary collector, supplemented with a fatty alcohol as an auxiliary collector, and a surfactant to enhance flotation efficiency. This composition exhibits excellent selectivity and capture efficiency for rutile. By introducing the auxiliary collector, the present invention effectively reduces the amount of phosphoric acid collector used, thereby significantly lowering the production cost of the entire flotation process. This collector composition not only improves rutile flotation efficiency but also reduces operational costs, promoting the development of downstream industries.

[0034] The process for preparing high-purity quartz sand from titanium-containing pegmatite provided by the present invention comprises the following steps: first, dissociated heavy media such as ilmenite and anatase in the titanium-containing pegmatite are removed by gravity separation, followed by magnetic separation to remove magnetic minerals, then aluminosilicate minerals are removed by a first-stage flotation, rutile is removed by a second-stage flotation, and finally, titanium-containing impurities are removed by hot-pressing acid leaching, followed by chlorination roasting to remove isomorphous titanium in the quartz lattice, thereby finally obtaining high-purity quartz sand.

[0035] The high-purity quartz sand provided by the present invention can have a titanium content as low as 7.84 μg / g, thereby improving the purity of the quartz sand, allowing the raw material to be better applied in high-tech fields such as semiconductors, photovoltaics, and optical fiber communications, providing better optical and electrical properties and reliability, thereby enhancing the overall performance of downstream products. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 This is the process route diagram of Example 6. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0039] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present invention, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0040] A first aspect of the present invention provides a collector composition for flotation of rutile, comprising a primary collector, an auxiliary collector, and a surfactant in a mass ratio of (1-3):(1-3):2; The main collector is a phosphoric acid collector, and the auxiliary collector is a fatty alcohol.

[0041] The collector composition for rutile flotation provided by the present invention utilizes a phosphoric acid collector as the primary collector, supplemented with a fatty alcohol as an auxiliary collector, and a surfactant to enhance flotation efficiency. This composition exhibits excellent selectivity and capture efficiency for rutile. By introducing the auxiliary collector, the present invention effectively reduces the amount of phosphoric acid collector used, thereby significantly lowering the production cost of the entire flotation process. This collector composition not only improves rutile flotation efficiency but also reduces operational costs, promoting the development of downstream industries.

[0042] Typically, but not limiting, the mass ratio of the primary collector to the auxiliary collector can be 1:1, 1:2, 1:3, 2:1, 2:2, 2:3, 3:1, 3:2, 3:3, or any ratio within the range of (1-3):(1-3). At the same time, the amount of surfactant is fixed at 2 parts to ensure the performance of the collector.

[0043] Furthermore, the phosphoric acid collector includes at least one of dodecyl phosphate monoester, dodecyl phosphoric acid, octyl phosphate, decyl phosphoric acid and decyl phosphate.

[0044] Preferably, the fatty alcohol comprises at least one of isobutanol, n-pentanol, n-hexanol, n-heptanol, dodecanol and tetradecanol.

[0045] Preferably, the surfactant comprises stearate.

[0046] Preferably, the stearate comprises sodium octadecanoate.

[0047] Furthermore, the collector composition is composed of monolauryl phosphate, isobutanol and sodium octadecanoate in a mass ratio of (1-3):(1-3):2.

[0048] A second aspect of the present invention provides a process for preparing high-purity quartz sand from titanium-containing pegmatite, comprising the following steps: A. grinding titanium-containing pegmatite and then slurrying to obtain a first slurry, and performing gravity separation on the slurry to obtain a gravity separation concentrate; B. performing magnetic separation on the gravity concentrate to obtain non-magnetic minerals, performing primary flotation and secondary flotation on the non-magnetic minerals to obtain flotation concentrate; then performing hot-pressing acid leaching and chlorination roasting on the flotation concentrate to obtain high-purity quartz sand; Wherein, the collector used in the second-stage flotation is the collector composition described in the first aspect.

[0049] The process for preparing high-purity quartz sand from titanium-containing pegmatite provided by the present invention comprises the following steps: firstly, dissociated heavy media such as ilmenite and anatase in the titanium-containing pegmatite are removed by gravity separation, followed by magnetic separation to remove magnetic minerals, then aluminosilicate minerals are removed by a first-stage flotation, rutile is removed by a second-stage flotation, and finally, titanium-containing impurities are removed by hot pressing and acid leaching, followed by chlorination and roasting to remove isomorphous titanium in the quartz lattice, thereby finally obtaining high-purity quartz sand.

[0050] Specifically, the titanium-containing pegmatite is first crushed into 3-8mm coarse sand by a crusher, and then the 3-8mm coarse sand is crushed into 60-200 mesh fine sand by a vertical shaft crusher; after screening, the 60-200 mesh fine sand is used to prepare a 35-40% concentration of slurry for the subsequent mineral processing process.

[0051] Typically, but not limited to, the concentration of the slurry can be 35%, 36%, 37%, 38%, 39%, or 40%, or any concentration value within the range of 35% to 40%. Unless otherwise specified, percentage concentrations in the present invention are by mass concentrations.

[0052] In the sand making process, the crusher used can be an impact crusher.

[0053] In other embodiments of the present invention, the raw ore is crushed into coarse sand using a jaw crusher.

[0054] After the slurry adjustment is completed, the slurry is subjected to gravity separation. In one embodiment of the present invention, a diaphragm jig is used for gravity separation. The slurry is evenly fed into the diaphragm jig to separate the heavy minerals that have been dissociated during the sand making process. The heavy minerals include anatase and / or ilmenite.

[0055] The re-selected concentrate is fed to the electromagnetic wet magnetic separator through a feeder for two-pass magnetic separation. The magnetic separation includes the first stage magnetic separation and the second stage magnetic separation carried out in sequence.

[0056] Preferably, the magnetic field strength of the first stage magnetic separation is 1500-2000 GS, so as to separate out the strongly magnetic minerals.

[0057] Typically but not limiting, the magnetic field strength of one stage magnetic separation may be, for example, 1500 GS, 1600 GS, 1700 GS, 1800 GS, 1900 GS or 2000 GS, or any value within the range of 1500 GS to 2000 GS.

[0058] Preferably, the magnetic field strength of the second-stage magnetic separation is 15,000-22,000 GS, and the weakly magnetic minerals are separated to obtain non-magnetic minerals.

[0059] Typically but not limitatively, the magnetic field strength of the second-stage magnetic separation can be, for example, 15000 GS, 16000 GS, 17000 GS, 18000 GS, 19000 GS, 20000 GS, 21000 GS or 22000 GS, or any value within the range of 15000-22000 GS.

[0060] Then, the non-magnetic mineral is introduced into the flotation tank for slurry preparation, heating, and pH adjustment to carry out the first stage flotation. The collector for the first stage flotation is the composite collector HR-1, and the first stage flotation is carried out by aeration and scraping.

[0061] It should be noted that the composite collector HR-1 is a mixed solution of dodecylamine and sodium dodecylsulfonate. The preparation method for composite collector HR-1 is to mix the cationic collector dodecylamine and the anionic collector sodium dodecylsulfonate in a ratio of 1:2.5, add a certain amount of ethanol, heat and stir in a water bath, and when the solid agent is completely dissolved, add deionized water to dilute to 10%. Continue heating and stirring until the solution is completely free of suspended solids.

[0062] Preferably, the usage of the composite collector HR-1 is 100-400 g / t.

[0063] Typically, but not limited to, the usage amount of the composite collector HR-1 can be, for example, 100 g / t, 150 g / t, 200 g / t, 250 g / t, 300 g / t, 350 g / t or 400 g / t, or any value within the range of 100 g / t to 400 g / t.

[0064] Preferably, the pH of the first stage of flotation is 1.5-2.5 and the temperature is 40-50°C.

[0065] Typically, but not limiting, the pH of one stage of flotation can be 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5, and the temperature can be 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C or 50°C, or any value within the range of pH 1.5 to 2.5 and temperature 40 to 50°C.

[0066] In some embodiments of the present invention, one stage of flotation is repeated three times, and in each subsequent flotation process, the amount of the composite collector HR-1 used is half of that of the previous one.

[0067] Furthermore, the two-stage flotation includes a primary flotation and a secondary flotation performed in sequence.

[0068] Preferably, the pH of the second stage flotation is 4.5-6.

[0069] Typically, but not limiting, the pH of the secondary flotation can be, for example, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5 or 6, or any value within the range of 4.5 to 6.

[0070] Preferably, the amount of collector used in the primary flotation is 400-600 g / t.

[0071] Typically, but not limiting, the amount of collector used in a primary flotation can be any value within the range of 400 g / t, 450 g / t, 500 g / t, 550 g / t, and 600 g / t.

[0072] Preferably, the amount of collector used in the secondary flotation is half of the amount of collector used in the primary flotation.

[0073] After flotation, the flotation concentrate is obtained, which is dehydrated and dried before undergoing a hot-pressing acid leaching process. The hot-pressing acid leaching process comprises placing the flotation concentrate in a polytetrafluoroethylene tank, adding mixed acid, and then transferring the polytetrafluoroethylene tank to a hydrothermal kettle for hot-pressing acid leaching.

[0074] Preferably, the mixed acid is hydrofluoric acid and hydrochloric acid in a volume ratio of 3:1.

[0075] Preferably, the volume concentration of the mixed acid is 20%.

[0076] Preferably, the volume ratio of the mixed acid to the flotation concentrate is (0.8-1.2):1.

[0077] Typically, but not limited to, the volume ratio of mixed acid to flotation concentrate may be, for example, 0.8:1, 0.9:1, 1.0:1, 1.1:1 or 1.2:1, or any ratio within the range of 0.8 to 1.2.

[0078] Preferably, the pressure of the hot-pressing acid leaching is ≥2 MPa.

[0079] Preferably, the temperature of the hot-pressing acid leaching is 200-250° C., and the time is 10-15 hours.

[0080] Typically, but not limited to, the hot press pickling temperature may be 200° C., 210° C., 220° C., 230° C., 240° C., or 250° C., or any value within the range of 200° C. to 250° C. The hot press pickling time may be 10 h, 11 h, 12 h, 13 h, 14 h, or 15 h, or any value within the range of 10 h to 15 h.

[0081] Furthermore, the chlorination roasting process is as follows: washing the concentrated sand after hot-pressing acid leaching to neutrality, drying it, heating it to 1000-1200° C. under vacuum conditions, and introducing HCl gas for roasting.

[0082] Typically, but not limiting, the temperature of the chlorination roasting may be 1000°C, 1050°C, 1100°C, 1150°C or 1200°C, or any value within the range of 1000°C to 1200°C.

[0083] Preferably, the purity of the HCl gas is ≥99.9%, and the flow rate is 1-5 L / min.

[0084] Typically, but not limiting, the HCl gas flow rate is 1 L / min, 1.5 L / min, 2 L / min, 2.5 L / min, 3 L / min, 3.5 L / min, 4 L / min, 4.5 L / min or 5 L / min, or any value within the range of 1 L / min to 5 L / min.

[0085] Preferably, the calcination time is 0.5 to 2 hours.

[0086] The third aspect of the present invention provides high-purity quartz sand, which is prepared using the process described in the second aspect.

[0087] The high-purity quartz sand provided by the present invention can have a titanium content as low as 7.84 μg / g, thereby improving the purity of the quartz sand, allowing the raw material to be better applied in high-tech fields such as semiconductors, photovoltaics, and optical fiber communications, providing better optical and electrical properties and reliability, thereby enhancing the overall performance of downstream products.

[0088] The following examples describe some embodiments of the present invention in detail. The following examples and features may be combined unless otherwise specified. The raw materials used in Example 5 and the comparative examples of the present invention, unless otherwise specified, were prepared under conventional conditions or manufacturer-recommended conditions. Reagents and instruments used without manufacturer identification are commercially available conventional products.

[0089] Example 1 This embodiment provides a collector composition for flotation of rutile, which is composed of monolauryl phosphate, isobutanol, and sodium octadecanoate in a mass ratio of 1:1:2.

[0090] Example 2 This embodiment provides a collector composition for flotation of rutile, which is composed of monolauryl phosphate, isobutanol and sodium octadecanoate in a mass ratio of 3:1:2.

[0091] Example 3 This embodiment provides a collector composition for flotation of rutile, which is composed of monolauryl phosphate, isobutanol, and sodium octadecanoate in a mass ratio of 1:3:2.

[0092] Example 4 This embodiment provides a collector composition for flotation of rutile, which is composed of dodecylphosphoric acid, n-pentanol, and sodium octadecanoate in a mass ratio of 1:1:2.

[0093] Example 5 This embodiment provides a collector composition for flotation of rutile, which is composed of octyl phosphate, n-heptyl alcohol and sodium octadecanoate in a mass ratio of 1:1:2.

[0094] Comparative Example 1 This comparative example provides a collector composition for flotation of rutile, which is composed of monolauryl phosphate and isobutanol in a mass ratio of 1:1.

[0095] Comparative Example 2 This comparative example provides a collector composition for flotation of rutile, which is composed of monolauryl phosphate and sodium octadecanoate in a mass ratio of 1:2.

[0096] Comparative Example 3 This comparative example provides a collector composition for flotation of rutile, which is composed of isobutanol and sodium octadecanoate in a mass ratio of 1:2.

[0097] Example 6 The sample in this embodiment is a pegmatite from Hunan Province, and the Ti grade is 1.22% as determined by phase analysis.

[0098] The above Ti-containing pegmatite is used as raw material to prepare high-purity quartz sand, combined with Figure 1 The specific process is as follows: (1) The Ti-bearing pegmatite ore was crushed into 3-8 mm coarse sand by a PE250*150 jaw crusher, and then crushed into fine sand by a 600 type vertical shaft crusher. The fine sand was screened by a percussion screen to obtain 60-200 mesh fine sand.

[0099] (2) Put 60-200 mesh fine sand into a bucket, add water and stir evenly to make a 40% concentration slurry. Feed the slurry evenly to the diaphragm jig for gravity separation to separate the dissociated ilmenite, anatase and other heavy minerals. The concentrate after gravity separation is gravity separation concentrate.

[0100] (3) Power the electromagnetic wet magnetic separator, adjust the magnetic field strength to 2000GS for the first pass, and then feed the gravity separation concentrate to the magnetic separator to separate the strong magnetic minerals; in the second pass, adjust the magnetic field strength to 18000GS, feed the concentrate after the first magnetic separation, and separate the weak magnetic minerals to obtain non-magnetic minerals.

[0101] (4) Dehydrate and dry the non-magnetic mineral pulp, take 300g and put it into a 1.5L single-tank flotation machine, add pure water to adjust the pulp to 30% concentration, heat the pulp to 45℃ with a heating rod, then adjust the pulp pH to about 2 with HF acid and stir for 5min, add composite collector HR-1, 300g / t, stir for 3min, aerate and scrape until no bubbles float up, then follow the same operation steps to reduce the reagent dosage to 200g / t and 100g / t and perform two flotation.

[0102] (5) After completing three rounds of primary flotation, the pH of the pulp was adjusted to 5, and the collector composition of Example 1 was added at a concentration of 400 g / t. After stirring for 3 minutes, the mixture was aerated and scraped until no bubbles floated up, and then the secondary flotation was performed. The same operating steps were then repeated, but the amount of reagent was reduced by half, and the secondary flotation was performed. The flotation concentrate was obtained by aerating and scraping until no bubbles floated up.

[0103] (6) Dehydrate and dry the flotation concentrate, take 30g of the sample and put it into a polytetrafluoroethylene tank, add electronic grade HF acid and analytical grade hydrochloric acid into the polytetrafluoroethylene tank at a ratio of 3:1, add pure water to dilute the mixed acid concentration to 20%, and the liquid-solid ratio is 1:1. Then put the polytetrafluoroethylene tank containing the sample into a hydrothermal reactor, heat the homogeneous reactor to 220℃, and the pressure to 2.3MPa, and perform hot press acid leaching for 12h.

[0104] (7) After hot pressing and acid leaching, the concentrated sand is taken out and washed with pure water to neutrality, then dehydrated and dried. 20g of the dried concentrated sand is placed in a quartz tube of a tubular furnace. The quartz tube is then evacuated and heated. When the temperature of the tubular furnace reaches 1100℃, hydrogen chloride gas is introduced at a gas flow rate of 2L / min. The high-temperature roasting time is 2h. After the quartz tube cools down, the sample is taken out to obtain high-purity quartz sand.

[0105] Example 7 The sample in this embodiment is an artificial mixed ore, which is made by uniformly mixing rutile: ilmenite: anatase: quartz sand at a ratio of 2:1:1:96. Phase analysis shows that the Ti grade is 2.42%.

[0106] (1) The artificial mixed ore is screened by a beating screen, and the fine sand after vertical shaft crushing is screened out into fine sand of 60-200 mesh.

[0107] (2) Same as the step in Example 6.

[0108] (3) Power the electromagnetic wet magnetic separator, adjust the magnetic field strength to 2000GS in the first pass, and then feed the re-selected concentrate to the magnetic separator to separate the strongly magnetic minerals; in the second pass, adjust the magnetic field strength to 20000GS, feed the concentrate after the first magnetic separation, and separate the weakly magnetic minerals to obtain non-magnetic minerals.

[0109] (4) Dehydrate and dry the non-magnetic mineral pulp, take 300 g, and place it in a 1.5 L single-tank flotation machine. Add pure water to adjust the pulp to 30% concentration, heat the pulp to 45°C with a heating rod, and then adjust the pH of the pulp to 5 with HF acid. Add the collector composition provided in Example 1 at a rate of 400 g / t, stir for 3 minutes, and then aerate and scrape until no bubbles float to the surface for secondary flotation. Then, repeat the same procedure with half the reagent amount for secondary flotation, aerate and scrape until no bubbles float to the surface to obtain flotation concentrate.

[0110] (5) Same as step (6) of Example 6.

[0111] (6) Same as step (7) of Example 6.

[0112] Examples 8-12 These embodiments provide high-purity quartz sand. Unlike Example 6, the collector composition is provided by Examples 2-5 respectively. The remaining steps are the same as those in Example 6 and will not be repeated here.

[0113] Comparative Example 4 The samples used in this comparative example are the same as those in Example 6. The difference from Example 6 is that step (3) is omitted and dodecyl phosphate monoester is replaced by dodecylamine dimethyl phosphate. The remaining steps are the same as those in Example 6 and are not repeated here.

[0114] Comparative Example 5 The samples used in this comparative example are the same as those in Example 6. The difference from Example 6 is that the gravity separation process in step (2) is omitted and the slurry is directly subjected to magnetic separation. The remaining steps are the same as those in Example 6 and are not repeated here.

[0115] Comparative Example 6 The sample used in this comparative example is the same as that in Example 6. The difference from Example 6 is that steps (2) and (3) are omitted, and the chlorination roasting in step (7) is cancelled. The remaining steps are the same as those in Example 6 and are not repeated here.

[0116] Comparative Example 7 The samples used in this comparative example are the same as those in comparative example 6. The difference from comparative example 6 is that in step (7), the concentrated sand after hot pressing and acid leaching is directly subjected to chlorination roasting without washing. The remaining steps are the same as those in comparative example 6 and are not repeated here.

[0117] Comparative Examples 8-10 These comparative examples provide high-purity quartz sand. Unlike Example 6, the collector compositions are provided by Comparative Examples 1-3 respectively. The remaining steps are the same as those in Example 6 and will not be repeated here.

[0118] Test Case The high-purity quartz sand obtained in the embodiment and the comparative example was tested for titanium content using an inductively coupled plasma atomic emission spectrometer (ICP). The obtained data are shown in Table 1 below.

[0119] Table 1

[0120] The data in Table 1 show that the association between phosphate, higher fatty alcohol and surfactant can improve the capture effect of rutile. The combined process of hot pressing acid leaching and high-temperature atmosphere roasting can significantly remove titanium impurities. The titanium content of high-purity quartz is reduced to 7.84 ug / g, equivalent to only 7.84 ppm, resulting in higher purity high-purity quartz, providing downstream industries with higher purity and more reliable quartz sand raw materials.

[0121] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A collector composition for flotation of rutile, characterized in that: It is composed of a main collector, an auxiliary collector and a surfactant in a mass ratio of (1-3): (1-3): 2; The main collector is a phosphoric acid collector, and the auxiliary collector is a fatty alcohol.

2. The collector composition according to claim 1, wherein The phosphoric acid collector includes at least one of dodecyl phosphate monoester, dodecyl phosphoric acid, octyl phosphate, decyl phosphoric acid and decyl phosphate; Preferably, the fatty alcohol comprises at least one of isobutanol, n-pentanol, n-hexanol, n-heptanol, dodecanol and tetradecanol; Preferably, the surfactant comprises stearate; Preferably, the stearate comprises sodium octadecanoate.

3. The collector composition according to claim 1 or 2, characterized in that It is composed of monolauryl phosphate, isobutanol and sodium octadecanoate in a mass ratio of (1~3):(1~3):

2.

4. A process for preparing high-purity quartz sand from titanium-containing pegmatite, characterized in that: The following steps are involved: A. grinding titanium-containing pegmatite and then slurrying to obtain a first slurry, and performing gravity separation on the slurry to obtain a gravity separation concentrate; B. performing magnetic separation on the gravity concentrate to obtain non-magnetic minerals, performing primary flotation and secondary flotation on the non-magnetic minerals to obtain flotation concentrate; then performing hot-pressing acid leaching and chlorination roasting on the flotation concentrate to obtain high-purity quartz sand; Wherein, the collector used in the second-stage flotation is the collector composition according to any one of claims 1 to 3.

5. The process according to claim 4, characterized in that The two-stage flotation includes a primary flotation and a secondary flotation carried out in sequence; Preferably, the pH of the second stage flotation is 4.5-6; Preferably, the amount of collector used in the primary flotation is 400-600 g / t; Preferably, the amount of collector used in the secondary flotation is half of the amount of collector used in the primary flotation.

6. The process according to claim 4, characterized in that The magnetic separation includes a first stage magnetic separation and a second stage magnetic separation carried out in sequence; Preferably, the magnetic field strength of the first stage magnetic separation is 1500-2000 GS; Preferably, the magnetic field strength of the second-stage magnetic separation is 15000~22000GS.

7. The process according to claim 4, characterized in that The process of hot pressing acid leaching is: The flotation concentrate is placed in a polytetrafluoroethylene tank, mixed acid is added, and then transferred to a hydrothermal kettle for hot-pressing acid leaching; Preferably, the mixed acid is hydrofluoric acid and hydrochloric acid in a volume ratio of 3:1; Preferably, the volume ratio of the mixed acid to the flotation concentrate is (0.8-1.2):1; Preferably, the pressure of the hot press acid leaching is ≥2MPa; Preferably, the temperature of the hot-pressing acid leaching is 200-250° C., and the time is 10-15 hours.

8. The process according to claim 4, characterized in that The process of described chlorination roasting is: The concentrated sand after hot pressing and acid leaching is washed to neutral, dried, heated to 1000-1200°C under vacuum conditions, and calcined by introducing HCl gas; Preferably, the purity of the HCl gas is ≥99.9% and the flow rate is 1-5 L / min; Preferably, the calcination time is 0.5 to 2 hours.

9. The process according to claim 4, characterized in that The collector used in the first stage flotation is composite collector HR-1; Preferably, the usage of the composite collector HR-1 is 100-400 g / t; Preferably, the pH of the first stage of flotation is 1.5-2.5 and the temperature is 40-50°C.

10. A high-purity quartz sand, characterized in that: The product is prepared by the process according to any one of claims 4 to 9.

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