Ultrafine particle ilmenite flotation inhibitor and application thereof

Abstract

The invention discloses an ultra-fine particle ilmenite flotation inhibitor and application thereof, and relates to the technical field of mineral separation. The ultra-fine particle grade ilmenite flotation inhibitor comprises the following components in percentage by mass: 52%-85% of silicate, 4%-14% of a pH buffering agent, 2%-5% of a cellulose derivative, 5%-25% of a dispersing agent and 2%-10% of a flocculating agent. The ultra-fine particle ilmenite flotation inhibitor is good in gangue mineral selectivity in the flotation separation process, and floating of gangue minerals can be effectively inhibited; the effect of inhibiting selective flocculation of gangue is achieved, and the influence of fine silt on flotation can be reduced; the applicability is wide, and the efficient inhibition performance can be kept in the flotation environment with the strongly acidic pH value; and more than 80% of titanium resources can be effectively recovered while the grade of the flotation concentrate reaches the standard, so that the waste of the titanium resources is avoided. In addition, a raw material for producing titanium dioxide by a chlorination process can be stably provided.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, in particular to an ultra-fine ilmenite flotation inhibitor and application thereof. Background Art

[0002] The Panzhihua region, a key mineral resource base in my country, boasts the world's largest ilmenite reserves, primarily distributed across the four major mining areas of Panzhihua, Baima, Hongge, and Taihe. Since the 1990s, the region has gradually established a comprehensive ilmenite sorting system, forming a mature combined magnetic separation and flotation process. Existing flotation processes are capable of consistently producing titanium concentrates that meet commercial standards, but research on the flotation of ultrafine-grained ilmenite is relatively limited. As primary ilmenite resources become increasingly depleted, impure, and fine, mineral flotation becomes increasingly difficult. Existing flotation depressants are poorly adapted to complex gangue systems, making the development of new flotation depressants for ultrafine-grained ilmenite a key research area.

[0003] At present, the research on ultrafine-grained ilmenite flotation inhibitors mainly faces the following problems: (1) Insufficient selectivity: It is difficult to accurately distinguish ilmenite from gangue minerals in complex ore systems, especially the poor inhibitory effect on olivine in olivine pyroxenite-type ores; (2) Limited adaptability: The performance of the agent is greatly affected by the pH value, temperature, ion composition and other conditions of the slurry, and the stability is poor; (3) Weak synergistic effect: There is a lack of effective intermolecular interaction between different inhibitor components, making it difficult to achieve the effect of "1+1>2"; (4) Mineral Fine particle size: Ultrafine ilmenite has a particle size of less than 18 μm, and its specific surface area is large, resulting in fine mud agglomeration, resulting in high flotation reagent consumption and poor separation effect; (5) High reagent consumption: Ultrafine minerals contain ultrafine particles of ore, which will absorb a large amount of reagents, causing the flotation inhibitor to lose its inhibitory effect and the quality of the concentrate to decline; (6) High calcium and magnesium content in the concentrate: Ultrafine ilmenite flotation is prone to inclusion of calcium and magnesium-containing gangue minerals into the concentrate, resulting in an inability to provide a stable raw material for the chloride process to produce titanium dioxide. These technical bottlenecks have seriously restricted the efficient utilization of my country's titanium resources.

[0004] To address these issues, mineral processing researchers have conducted a series of research and practical applications. Chinese patent CN116371610A discloses a calcium-reducing inhibitor for the flotation of high-calcium-magnesium titanium concentrate, as well as its preparation and use methods. The inhibitor, formulated with sulfuric acid, water glass, and sodium polyacrylate, is used to flotate high-calcium titanium concentrate containing 0.9% to 1.2% calcium to a low-calcium, high-quality titanium concentrate containing 0.15% to 0.35% calcium via a closed-circuit flotation process involving a coarse and fine process. While this method effectively reduces impurity levels in titanium concentrate, it is less effective for the flotation of ultrafine-grained ilmenite.

[0005] Chinese patent CN112871460A discloses a dispersion inhibitor suitable for ultrafine ilmenite, its preparation method, and application. The inhibitor uses a combination of hydroxyethylidene diphosphonate, sodium carboxymethyl cellulose, and water glass to form a titanium concentration inhibitor. This inhibitor, combined with an MOH collector, can produce a concentrate with a TiO2 grade greater than 33% from a float ore containing greater than 20% TiO2. However, the TiO2 content in the tailings exceeds 8%. While the inhibitor maintains a certain degree of selectivity, the lack of synergistic effect between hydroxyethylidene diphosphonate, sodium carboxymethyl cellulose, and water glass results in a high TiO2 loss rate in the tailings.

[0006] Liu Jiayan studied the mechanism of action of small-molecule alcoholamine depressants in the flotation of ilmenite. She compared the effects of small-molecule alcoholamine depressants on fine-grained (-23μm) and conventional-grained (38μm-74μm) ilmenite. The results showed that the TiO2 grade and recovery rate of the concentrate of conventional-grained artificial mixed ore flotated with the depressant NHS2 and the collector NaOL were 40.45% and 39.41%, respectively, while the TiO2 grade and recovery rate of the concentrate of fine-grained artificial mixed ore were 36.24% and 44.05%, respectively. Furthermore, the TiO2 grade and recovery rate of the concentrate of conventional-grained artificial mixed ore flotated with the depressant NH213 and the collector NaOL were 39.72% and 33.37%, respectively, while the TiO2 grade and recovery rate of the concentrate of fine-grained artificial mixed ore were 36.73% and 40.07%, respectively. The flotation effect of fine particles using small molecule alcoholamine inhibitors in the flotation process of ilmenite is worse than that of conventional particles, and the flotation concentrate grade and recovery rate are both low.

[0007] Therefore, the development of new and efficient inhibitors has become a key breakthrough in improving the recovery rate of ultrafine ilmenite.

[0008] In view of this, the present invention is proposed. Summary of the Invention

[0009] The object of the present invention is to provide an ultra-fine ilmenite flotation depressant and its application to solve the above technical problems.

[0010] The present invention is achieved in that: In a first aspect, an embodiment of the present invention provides an ultrafine ilmenite flotation depressant comprising the following components by mass percentage: Silicate 52% to 85%, pH buffer 4% to 14%, cellulose derivative 2% to 5%, dispersant 5% to 25% and flocculant 2% to 10%.

[0011] In a second aspect, an embodiment of the present invention provides a use of the aforementioned ultrafine-grained ilmenite flotation depressant in the flotation separation of ultrafine-grained ilmenite and gangue minerals.

[0012] The present invention has the following beneficial effects: The ultrafine-grained ilmenite flotation depressant provided by the present invention has excellent selectivity for gangue minerals in the flotation separation process, effectively inhibiting the flotation of gangue minerals. Its selective flocculation inhibition of gangue can reduce the impact of fine mud on flotation. It has wide applicability and can maintain high inhibition performance in flotation environments with a strongly acidic pH. It maintains a stable zeta potential of the ore pulp, effectively reducing the impact of inevitable ions on flotation and inhibiting hydrophobic agglomeration of gangue. The flotation concentrate can effectively recover more than 80% of titanium resources while meeting the grade standard, avoiding waste of titanium resources. Furthermore, it can provide a stable raw material for the production of titanium dioxide by the chloride process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 This is a schematic diagram of the flotation process of ultra-fine ilmenite. DETAILED DESCRIPTION

[0015] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0016] Taking a mineral processing plant in the Panxi region as an example, the traditional "strong magnetic-flotation" process for treating ultrafine-grained ilmenite only achieved a TiO2 grade of 46.62% and a full-process recovery rate of 43.78%, with a large amount of useful minerals lost in the tailings. The present invention, starting with ultrafine-grained ilmenite flotation inhibitors and combining them with the actual flotation process, ultimately produces titanium concentrate with high grade and high recovery, as follows: In a first aspect, an embodiment of the present invention provides an ultrafine ilmenite flotation depressant comprising the following components by mass percentage: Silicate 52% to 85%, pH buffer 4% to 14%, cellulose derivative 2% to 5%, dispersant 5% to 25% and flocculant 2% to 10%.

[0017] It should be noted that the ultrafine-grained ilmenite flotation depressant used in the present invention is a novel flotation depressant. The functional groups of each component of the ultrafine-grained ilmenite flotation depressant effectively chemically adsorb to active sites on the surface of gangue minerals, thereby forming a hydrophilic film on the gangue and effectively inhibiting its flotation. Furthermore, the macromolecular depressant component can cause the gangue minerals to flocculate in the slurry, thereby reducing the non-selective adsorption of the gangue minerals onto the collector and into the concentrate.

[0018] Specifically, the carboxyl groups in the cellulose derivatives react with the silicate molecules H2SiO3 and silicate ions HSiO3 in the silicate solution. — Forming a claw-type adsorption structure, Ca 2+ Mg 2+ 、Si 4+ Chemical adsorption occurs at active sites such as the quartz and other active sites, thereby forming a hydrophilic layer on the surface of the gangue, effectively inhibiting the floating of gangue minerals.

[0019] In an optional embodiment, the pH buffer is selected from at least one of citric acid-sodium dihydrogen phosphate, acetic acid-sodium acetate, disodium hydrogen phosphate-potassium dihydrogen phosphate and tartaric acid-citric acid.

[0020] In the most preferred embodiment, the pH buffer is citric acid-sodium dihydrogen phosphate; in other embodiments of the present invention, other types of buffers can be selected according to actual needs.

[0021] It should be noted that pH buffer helps to maintain the pH of the pulp in a specific range and optimize the interaction between the collector and the mineral surface; it also has the function of chelating metal ions (such as Ca 2+ ), inhibiting fine particle agglomeration, improving flotation selectivity, and dispersing ore slime. The citric acid-phosphate buffer system used in the present invention stabilizes the zeta potential of the ore pulp at -15 mV to -20 mV, effectively reducing the impact of inevitable ions on flotation and inhibiting hydrophobic agglomeration of gangue.

[0022] In an optional embodiment, the cellulose derivative is selected from at least one of sodium carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose ether and xanthan gum.

[0023] In the most preferred embodiment, the cellulose derivative is sodium carboxymethyl cellulose; in other embodiments of the present invention, other types of cellulose derivatives can be selected according to actual needs.

[0024] It should be noted that cellulose derivatives form a hydration film by adsorbing on the surface of the ore, preventing the adsorption of the collector; the high-molecular-weight cellulose derivatives are entangled on the surface of the sludge particles, which is beneficial to reduce heterogeneous coagulation, reduce excessive foam mineralization, and improve the quality of the concentrate.

[0025] In an optional embodiment, the dispersant is selected from at least one of polyepoxysuccinic acid, polyaspartic acid, lignin sulfonate and sodium humate.

[0026] In the most preferred embodiment, the dispersant is polyepoxysuccinic acid; in other embodiments of the present invention, other types of dispersants can be selected according to actual needs.

[0027] The dispersant used in this invention is biodegradable, phosphorus-free, and suitable for green flotation. It has dispersing and scale-inhibiting properties, adsorbing on the surface of metal hydroxides (such as ferric hydroxide and aluminum hydroxide) through carboxylic acid groups, preventing collector adsorption and reducing the floatability of gangue. It also readily competes with silicate for adsorption, reducing quartz activation. It and the flocculant form electrostatically bridged flocs, and by adjusting the pH and reagent ratio, it achieves efficient separation of gangue from useful minerals.

[0028] In an optional embodiment, the flocculant is selected from at least one of cationic starch, carboxymethyl starch, corn starch and potato starch.

[0029] In the most preferred embodiment, cationic starch is used as the flocculant; in other embodiments of the present invention, other types of flocculants can be selected according to actual needs.

[0030] It's important to note that the positively charged amino / quaternary ammonium groups in cationic starch adsorb onto the surfaces of negatively charged minerals (such as kaolin and mica), hindering collector adsorption. The cationic groups interact with the surface charge of bubbles to stabilize the foam layer, and they preferentially flocculate impure minerals, achieving selective hydrophobicity. The branch chain length of cationic starch (DP = 500-800) synergistically works with polyepoxysuccinic acid to meet the bridging flocculation requirements of -20μm gangue particles. This effectively and selectively suppresses gangue minerals containing Ca, Mg, and Si, while also selectively flocculating slimes, thereby reducing the impact of fine slime on flotation.

[0031] In an optional embodiment, the ultrafine-grained ilmenite flotation depressant is prepared by the following method: Mixing, dissolving, and heating the cellulose derivative and the dispersant to prepare a first mixed system; wherein the heating temperature is 20° C. to 60° C.; uniformly mixing the first mixed system and the flocculant to prepare a second mixed system; The second mixed system, silicate and pH buffer are uniformly mixed to prepare an ultrafine ilmenite flotation inhibitor.

[0032] Specifically, the temperature setting during the preparation of the first mixed system can be adjusted appropriately based on the actual amount of material being processed. Appropriate heating helps the cellulose derivative and dispersant dissolve more thoroughly and mix more evenly. The second mixed system is prepared by adding the flocculant cationic starch. To ensure its complete dissolution and reaction, the second mixed system is prepared in a transparent, colloid-like state.

[0033] It should be noted that, during the preparation of the first mixing system, the second mixing system and the ultrafine ilmenite flotation inhibitor, stirring or ultrasonic treatment may be appropriately performed to ensure more uniform mixing.

[0034] In a second aspect, an embodiment of the present invention provides a use of the aforementioned ultrafine-grained ilmenite flotation depressant in the flotation separation of ultrafine-grained ilmenite and gangue minerals.

[0035] In an optional embodiment, during the flotation separation process, the ultrafine ilmenite flotation depressant is added in the form of an aqueous solution with a mass concentration of 3% to 6%.

[0036] It's important to note that inhibitors in aqueous solution disperse quickly and evenly throughout the slurry, ensuring uniform coverage of the mineral surface by the inhibitor molecules or colloidal particles, thus avoiding uneven inhibition caused by localized concentrations being too high or too low. Ultrafine minerals (<10 μm) have large surface areas and high surface energies, easily agglomerating to form a "sludge cap." Inhibitors in aqueous solution can effectively penetrate and stably adsorb onto the mineral surface, blocking the interaction between the collector and the gangue minerals. Direct use of dry powders can lead to uneven dispersion due to slurry turbulence. Using an emulsion can be unstable and require the addition of additional emulsifiers, increasing investment costs.

[0037] The mass concentration of the ultrafine ilmenite flotation inhibitor may be selected from any one of 3%, 4%, 5%, 5.5% and 6%, or other values ​​within the range of 3% to 6%.

[0038] In an optional embodiment, the flotation collector includes MPF. In other embodiments of the present invention, other types of collectors can be selected according to actual needs.

[0039] In an optional embodiment, the particle size of the ultrafine ilmenite ore includes -0.038mm+0.018mm particle size and -0.018mm particle size; wherein, the TiO2 proportion of the -0.038mm particle size is greater than 75%, and the TiO2 proportion of the -0.018mm particle size is greater than 55%.

[0040] It should be noted that ultrafine-grained ilmenite ore is difficult to beneficiate, and it is difficult to simultaneously ensure the total titanium content of the flotation tailings. However, by using the ultrafine-grained ilmenite flotation depressant of the present invention for flotation, the flotation concentrate can meet the grade requirements while effectively recovering more than 80% of the titanium resource, thus avoiding the waste of titanium resources.

[0041] In an optional embodiment, the flotation separation of ultrafine ilmenite and gangue minerals adopts a "one roughing, two sweeping and five cleaning" operation process, that is, one roughing, two sweeping and five cleaning. The specific operation process diagram is shown in Figure 1 .

[0042] It should be noted that in the embodiments of the present invention, the flotation separation process is a closed-loop production process, and the ultrafine-grade ilmenite flotation depressant has high on-site stability. This process, combined with the ultrafine-grade ilmenite flotation depressant, effectively enables the separation of high-quality titanium concentrate from ultrafine-grade ilmenite.

[0043] Specifically, the flotation separation process of ultrafine ilmenite and gangue minerals includes the following steps: The flotation process of ultra-fine ilmenite adopts "one roughing, two scavenging and five concentrating" process, and the selected tailings and scavenging concentrate are returned to the previous flotation stage in sequence.

[0044] In an optional embodiment, the ultrafine-grained ilmenite ore has a TiO2 grade of 12% to 16%, and the titanium concentrate obtained after flotation separation has a TiO2 grade greater than 46.0%, with a recovery rate greater than 80%.

[0045] In addition, in the embodiment of the present invention, the calcium and magnesium contents in the titanium concentrate can be effectively reduced to meet the titanium concentrate requirements of the chloride process. The sum of the CaO and MgO contents is less than 1.14%, which can stably provide raw materials for the production of titanium dioxide by the chloride process.

[0046] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0047] Example 1 This embodiment provides an ultrafine-grained ilmenite flotation depressant, the preparation method of which comprises the following steps: (1) Dissolve 5 kg of sodium carboxymethyl cellulose and 15 kg of polyepoxysuccinic acid in deionized water at 60° C. to prepare a first mixed system; (2) Add 2 kg of cationic starch to the first mixed system and stir in the 1# mixing tank to form a transparent colloid to prepare the second mixed system; (3) The second mixed system, 70 kg of sodium silicate and 8 kg of citric acid-sodium dihydrogen phosphate buffer system were mixed and ultrasonicated for 30 minutes to prepare an ultrafine ilmenite flotation inhibitor.

[0048] (4) The obtained ultrafine ilmenite flotation inhibitor was diluted with water to a mass concentration of 3%.

[0049] Wherein, based on the total amount of ultrafine ilmenite flotation inhibitor being 100 kg, the usage ratio of silicate, pH buffer, cellulose derivative, dispersant and flocculant is 7:0.8:0.5:1.5:0.2.

[0050] This example also provides an application of an ultrafine ilmenite flotation inhibitor in the flotation separation of ultrafine ilmenite and gangue minerals. Specifically, the product of this example was used as an inhibitor (ultrafine ilmenite flotation inhibitor with a mass concentration of 5%), and MPF was used as a flotation collector to conduct a flotation test on the Hongge ilmenite mine in the Panxi region. The test process and relevant data are shown in Table 1: Table 1 Particle size composition and distribution of floating materials

[0051] The particle sizes in the ore vary greatly, mainly concentrated in the two particle sizes of -0.018mm and -0.038+0.018mm, with yields of 63.29% and 21.37% respectively; from the perspective of TiO2 distribution rate, the +0.038mm particle size is only 5.95%, the -0.038mm particle size reaches 94.05%, and the -0.018mm particle size reaches 76.97%.

[0052] When the TiO2 grade of the original ore is 15.75%, through the pre-desulfurization-"one coarse, two scavenging and five fine" flotation operation process, using ultra-fine particle size ilmenite flotation inhibitor and MPF flotation collector, the final titanium concentrate can be obtained with a TiO2 grade of 46.78%, a yield of 27.95%, and a flotation recovery rate of 83.02%.

[0053] Example 2 This embodiment provides an ultrafine ilmenite flotation depressant, the preparation method of which differs from that of Example 1 only in that: Based on the total amount of ultrafine ilmenite flotation inhibitor being 100 kg, the usage ratio of silicate, pH buffer, cellulose derivative, dispersant and flocculant is 6:1:0.5:2:0.5.

[0054] The mass concentration of the prepared ultrafine ilmenite flotation inhibitor is 3%.

[0055] When the TiO2 grade of the original ore is 15.75%, the final titanium concentrate can have a TiO2 grade of 46.56%, a yield of 28.19%, and a flotation recovery rate of 83.34%.

[0056] Example 3 This embodiment provides an ultrafine ilmenite flotation depressant, the preparation method of which differs from that of Example 1 only in that: The mass concentration of the prepared ultrafine ilmenite flotation inhibitor is 5%.

[0057] When the original ore contains 15.75% TiO2, the final titanium concentrate can contain 46.71% TiO2, with a yield of 27.19% and a flotation recovery rate of 80.63%.

[0058] Example 4 This embodiment provides an ultrafine ilmenite flotation depressant, the preparation method of which differs from that of Example 1 only in that: When the original ore contains 13.56% TiO2, the final titanium concentrate can contain 46.51% TiO2, with a yield of 23.37% and a flotation recovery rate of 81.29%.

[0059] Comparative Example 1 This comparative example provides an ultrafine-grained ilmenite flotation depressant, the preparation method of which differs from that of Example 1 only in that: Based on the total amount of ultrafine ilmenite flotation inhibitor being 100 kg, the usage ratio of silicate, pH buffer, cellulose derivative and dispersant is 6:1:1:2.

[0060] The mass concentration of the prepared ultrafine ilmenite flotation inhibitor is 3%.

[0061] When the TiO2 grade of the original ore is 15.75%, the final titanium concentrate can have a TiO2 grade of 42.37% and a flotation recovery rate of 69.34%.

[0062] The main reason is that cationic starch is not added, resulting in the fine-grained gangue not being effectively suppressed by the inhibitor, and non-selective adsorption with the collector occurs, resulting in low concentrate grade.

[0063] Comparative Example 2 This comparative example provides an ultrafine-grained ilmenite flotation depressant, the preparation method of which differs from that of Example 1 only in that: Based on the total amount of ultrafine ilmenite flotation inhibitor being 100 kg, the usage ratio of water glass to sodium carboxymethyl cellulose is 8:2.

[0064] The mass concentration of the prepared ultrafine ilmenite flotation inhibitor is 3%.

[0065] When the TiO2 grade of the original ore is 15.75%, the final titanium concentrate can have a TiO2 grade of 41.79% and a flotation recovery rate of 67.25%.

[0066] Comparative Example 3 This comparative example provides an application of a conventional ilmenite flotation depressant in the flotation separation of ultrafine ilmenite and gangue minerals. The difference between this comparative example and Example 1 is that: Sodium fluorosilicate was used as an inhibitor in a solution with a mass concentration of 3%.

[0067] When the TiO2 grade of the original ore is 15.75%, the final TiO2 grade of the titanium concentrate is 40.63% and the flotation recovery rate is 47.38%.

[0068] The main reason is that the ultrafine-grained ilmenite ore samples contain a large amount of fine mud, which results in a poor flotation environment. The inhibitors are difficult to suppress the fine mud, resulting in a large amount of fine mud being entrained into the concentrate, and ultimately it is difficult to obtain qualified products and the recovery rate is low.

[0069] Comparative Example 4 This comparative example provides an application of a conventional ilmenite flotation depressant in the flotation separation of ultrafine ilmenite and gangue minerals. The only difference between this comparative example and Example 1 is that: A solution with a mass concentration of 3% water glass was used as an inhibitor.

[0070] When the TiO2 grade of the original ore is 15.75%, the final TiO2 grade of the titanium concentrate is 41.37% and the flotation recovery rate is 51.37%.

[0071] The main reason is that ultrafine-grained ilmenite contains a large amount of fine mud, which undergoes non-selective adsorption with the collector, resulting in low grade of titanium concentrate.

[0072] Comparative Example 5 This comparative example provides an application of a conventional ilmenite flotation depressant in the flotation separation of ultrafine ilmenite and gangue minerals. The only difference between this comparative example and Example 1 is that: Cationic starch was used as an inhibitor in a solution with a mass concentration of 3%.

[0073] When the TiO2 grade of the raw ore is 15.75%, the final TiO2 grade of the titanium concentrate is 39.78% and the flotation recovery rate is 59.29%.

[0074] Comparative Example 6 This comparative example provides an application of a conventional ilmenite flotation depressant in the flotation separation of ultrafine ilmenite and gangue minerals. The difference between this comparative example and Example 1 is that: DL-1-amino-2-propanol was used as an inhibitor in a solution with a mass concentration of 3%. When the TiO2 grade of the original ore is 15.75%, the final TiO2 grade of the titanium concentrate is 40.32% and the flotation recovery rate is 67.39%.

[0075] Comparative Example 7 This comparative example provides an application of a conventional ilmenite flotation depressant in the flotation separation of ultrafine ilmenite and gangue minerals. The difference between this comparative example and Example 1 is that: Sodium hexametaphosphate was used as an inhibitor in a solution with a mass concentration of 3%.

[0076] When the TiO2 grade of the original ore is 15.75%, the final TiO2 grade of the titanium concentrate is 41.29% and the flotation recovery rate is 69.29%.

[0077] Comparative Example 8 This comparative example provides an application of a conventional ilmenite flotation depressant in the flotation separation of ultrafine ilmenite and gangue minerals. The difference between this comparative example and Example 1 is that: Sodium polystyrene sulfonate was used as the inhibitor in a solution with a mass concentration of 3%.

[0078] When the TiO2 grade of the original ore is 15.75%, the final TiO2 grade of the titanium concentrate is 43.18% and the flotation recovery rate is 71.21%.

[0079] Comparative Example 9 This comparative example provides an application of a conventional ilmenite flotation depressant in the flotation separation of ultrafine ilmenite and gangue minerals. The difference between this comparative example and Example 1 is that: A solution with a mass concentration of 3% carboxymethyl cellulose was used as an inhibitor.

[0080] When the TiO2 grade of the original ore is 15.75%, the final TiO2 grade of the titanium concentrate is 40.39% and the flotation recovery rate is 65.24%.

[0081] In summary, the ultrafine ilmenite flotation depressant provided by the present invention has the following characteristics: (1) Ultrafine-grained ilmenite flotation inhibitors have good selectivity for gangue minerals. The functional groups of each component can effectively chemically adsorb to the active sites on the surface of the gangue minerals, thereby forming a hydrophilic film on the gangue and effectively inhibiting the floating of the gangue minerals. At the same time, the macromolecular inhibitor components can cause the gangue minerals to flocculate in the slurry, thereby reducing the non-selective adsorption of the gangue minerals and the collector into the concentrate.

[0082] (2) The ultrafine-grained ilmenite flotation inhibitor has a wide range of applicability and can maintain high inhibitory performance in a flotation environment with a strongly acidic pH. At the same time, the citric acid-phosphate buffer system stabilizes the zeta potential of the ore pulp at -15mV to -20mV, effectively reducing the influence of inevitable ions on flotation and inhibiting the hydrophobic agglomeration of gangue.

[0083] (3) The components of ultrafine ilmenite flotation inhibitors cooperate with each other to inhibit the Ca2+ 2+ Mg 2 + 、Si 4+ Plasma chemical adsorption occurs, and sodium carboxymethyl cellulose reacts with the surface Ca of the gangue through -COO- 2+ / Mg 2+ Chelation, while sodium silicate forms Si-O-Si hydrophobic film on the mineral surface. At the same time, polyepoxysuccinic acid and cationic starch act synergistically on -20μm gangue particles, producing selective flocculation inhibition on them and reducing the influence of fine mud on flotation.

[0084] (4) The flotation ore used in the embodiments of the present invention has a very fine particle size: the TiO2 content in the -0.038mm particle size of the original ore is greater than 75%, and the TiO2 content in the -0.018mm particle size is greater than 55%. TiO2 is mainly concentrated in the fine particle size of -0.018mm, which makes flotation difficult and it is difficult to ensure the total titanium content of the flotation tailings at the same time. However, through the reagent of the present invention, the flotation concentrate can effectively recover more than 80% of the titanium resources while meeting the grade standard, thus avoiding the waste of titanium resources.

[0085] (5) The ultra-fine-grained ilmenite flotation inhibitor concentrate has high quality and high stability in on-site use. By using a float ore with a TiO2 grade of 12% to 17%, the grade of the ilmenite collected by closed-loop production can reach more than 46.50%, with a yield of more than 20% and a TiO2 recovery rate of more than 80%. The present invention can effectively select high-quality titanium concentrate products from ultra-fine-grained ilmenite.

[0086] (6) The present invention can effectively reduce the calcium and magnesium contents in the concentrate, meet the requirements of the titanium concentrate produced by the chloride process, and the sum of the CaO and MgO contents is less than 1.14%, thereby stably providing raw materials for the production of titanium dioxide by the chloride process.

[0087] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An ultrafine ilmenite flotation depressant, characterized in that: By mass percentage, it includes the following components: Silicate 52% to 85%, pH buffer 4% to 14%, cellulose derivative 2% to 5%, dispersant 5% to 25% and flocculant 2% to 10%.

2. The ultrafine ilmenite flotation depressant according to claim 1, characterized in that: The pH buffer is selected from at least one of citric acid-sodium dihydrogen phosphate, acetic acid-sodium acetate, disodium hydrogen phosphate-potassium dihydrogen phosphate and tartaric acid-citric acid; Preferably, the pH buffer comprises citric acid-sodium dihydrogen phosphate.

3. The ultrafine ilmenite flotation depressant according to claim 1, characterized in that: The cellulose derivative is selected from at least one of sodium carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose ether and xanthan gum; Preferably, the cellulose derivative comprises sodium carboxymethylcellulose.

4. The ultrafine ilmenite flotation depressant according to claim 1, characterized in that: The dispersant is selected from at least one of polyepoxysuccinic acid, polyaspartic acid, lignin sulfonate and sodium humate; Preferably, the dispersant comprises polyepoxysuccinic acid.

5. The ultrafine ilmenite flotation depressant according to claim 1, characterized in that: The flocculant is selected from at least one of cationic starch, carboxymethyl starch, corn starch and potato starch; Preferably, the flocculant comprises cationic starch.

6. The ultrafine ilmenite flotation depressant according to any one of claims 1 to 5, characterized in that: The ultra-fine ilmenite flotation depressant is prepared by the following method: Mixing, dissolving, and heating the cellulose derivative and the dispersant to prepare a first mixed system; wherein the heating temperature is 20° C. to 60° C.; uniformly mixing the first mixed system and the flocculant to prepare a second mixed system; The second mixed system, silicate and pH buffer are uniformly mixed to prepare an ultrafine ilmenite flotation inhibitor.

7. Use of the ultrafine ilmenite flotation depressant according to any one of claims 1 to 6 in the flotation separation of ultrafine ilmenite and gangue minerals.

8. The use according to claim 7, characterized in that During the flotation separation process, ultrafine ilmenite flotation depressant is added in the form of aqueous solution with a mass concentration of 3% to 6%; And / or, the flotation collector includes MPF.

9. The use according to claim 7, characterized in that The particle sizes of ultrafine ilmenite ore include -0.038mm+0.018mm and -0.018mm; among them, the TiO2 content in the -0.038mm particle size is greater than 75%, and the TiO2 content in the -0.018mm particle size is greater than 55%.

10. The use according to claim 7, characterized in that The flotation separation of ultra-fine ilmenite and gangue minerals adopts the "one roughing, two sweeping, five refining" operation process; And / or, the TiO2 grade of the ultrafine-grained ilmenite ore is 12% to 16%, and the TiO2 grade of the titanium concentrate obtained after flotation separation is greater than 46.5%, the yield is greater than 20%, and the recovery rate is greater than 80%.

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