Beneficiation method for magnesium-containing carbonate type low-grade fluorite mine

Abstract

The invention provides a beneficiation method for low-grade fluorite ore containing magnesium carbonate, and belongs to the technical field of fluorite beneficiation. According to the method, the fluorite raw ore is subjected to classification and waste pre-discarding treatment, and pre-enriched minerals are obtained; the pre-enriched minerals are subjected to ore grinding treatment, and first ore pulp is prepared after water is added; carrying out flotation operation on the first ore pulp by adopting a flotation reagent; the flotation reagent comprises a compound inhibitor and a compound regulator, the compound inhibitor comprises aluminum sulfate, sodium hexametaphosphate, tannic acid, citric acid and sodium alginate, and the compound regulator comprises calcium lignosulphonate, hydroxyethyl cellulose and potassium dichromate. Through the mode, the beneficiation method for the magnesium-containing carbonate type low-grade fluorite ore can utilize the synergistic effect between the specific beneficiation technological process and the improved reagent system, acid leaching operation is omitted, meanwhile, the recovery rate and grade of fluorite are improved through the simpler process and the lower reagent cost, and the beneficiation efficiency is improved. And the method has an extremely high industrial application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of fluorite beneficiation, and in particular to a beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore. Background Art

[0002] Fluorite is an indispensable source of raw materials for fluorine chemical industry and a non-metallic mineral resource with strategic significance. While the economic market has an increasing demand for fluorine chemical products, it is also facing the current situation of increasingly scarce high-grade, easy-to-select single-type fluorite resources. Therefore, it is urgent to efficiently develop and utilize low-grade and difficult-to-select fluorite ores. At present, in the process of utilizing low-grade fluorite mineral resources, the beneficiation research of magnesium-containing carbonate-type low-grade fluorite ores is relatively difficult. Many beneficiation researchers have conducted a lot of research on the beneficiation technology of carbonate-type fluorite dominated by calcite, but there are few studies on magnesium-containing carbonate-type low-grade fluorite ores dominated by (iron) dolomite. Among the numerous fluorite deposits in northern my country, the reserves of magnesium-containing carbonate-type low-grade fluorite mineral resources dominated by (iron) dolomite are very rich. Therefore, the research on magnesium-containing carbonate-type low-grade fluorite ores is of great significance.

[0003] Since (ferro) dolomite and fluorite are both calcium-containing non-metallic minerals, their hardness and density are not much different, their floatability is similar, and they are both easy-to-grind minerals, which makes the separation process of magnesium carbonate-type low-grade fluorite ore more complicated. At present, the "de-sludge-flotation-acid leaching (washing)" method is mainly used to recover magnesium carbonate-type low-grade fluorite ore. The magnesium carbonate-type low-grade fluorite ore is first crushed and screened, and then the minerals on the screen are physically de-sludged by ordinary cyclones and sedimentation. The gangue minerals with smaller specific gravity are pre-discarded, and the discarded concentrate products and the under-screen minerals are successively subjected to grinding, flotation, and acid leaching operations, and finally qualified fluorite concentrate products are produced. However, through laboratory comparison and verification of the current separation methods, combined with production data analysis, it is found that the current method has a low recovery rate for raw ore resources. While ordinary cyclones are separating muddy gangue, a large amount of fine-grained fluorite is lost, and the separation effect of (iron) dolomite and fluorite in the process is poor. The fluorite concentrate obtained by flotation operation must be reprocessed (a large amount of hydrochloric acid acid leaching) to form a more marketable fluorite concentrate product. However, since the acid leaching operation requires the use of a large amount of hydrochloric acid for acid leaching, the service life of the equipment will be severely shortened, and the return water from the acid leaching is difficult to handle, resulting in a sharp increase in the operation and management costs of the ore dressing plant.

[0004] In view of this, it is still necessary to design an improved beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore to solve the above problems. Summary of the invention

[0005] In view of the technical problems existing in the background technology, the present application provides a beneficiation method for low-grade fluorite ore containing magnesium carbonate, aiming to solve the technical problems of low recovery rate, poor separation effect of fluorite and other minerals, and the need for acid leaching in the existing beneficiation methods.

[0006] The present application provides a method for beneficiating magnesium-containing carbonate-type low-grade fluorite ore, comprising the following steps:

[0007] S1. Classify and pre-discard the fluorite ore to obtain pre-enriched minerals;

[0008] S2. Grinding the pre-enriched mineral and adding water to prepare a first slurry;

[0009] S3. The first pulp is subjected to flotation operation using a flotation agent; the flotation agent comprises a compound inhibitor and a compound regulator, the compound inhibitor comprises aluminum sulfate, sodium hexametaphosphate, tannic acid, citric acid and sodium alginate, and the compound regulator comprises calcium lignin sulfonate, hydroxyethyl cellulose and potassium dichromate.

[0010] In the technical solution of the embodiment of the present application, the fluorite ore is first classified and pre-discarded, so as to improve the grade of the ore entering the flotation, reduce the amount of grinding, and reduce the cost of mineral processing; on this basis, the present application optimizes the flotation reagents and adopts the method of compound reagents to combine inorganic inhibitors and organic regulators, so that it can specifically inhibit dolomite and calcite in magnesium-containing carbonate-type low-grade fluorite ore, and give full play to the compound synergistic effect between the reagents, reduce the heterogeneous coagulation between fluorite and carbonate particles, strengthen the dispersion degree of slurry, reduce the adsorption amount of collector on the surface of fine carbonate minerals, and enhance the inhibition effect on silicate minerals while inhibiting carbonate minerals, so as to accelerate the floating rate of fluorite and thereby improve the selectivity of fluorite collector.

[0011] In some embodiments, the composite inhibitor includes, by mass percentage, 20% to 50% aluminum sulfate, 10% to 30% sodium hexametaphosphate, 5% to 20% tannic acid, 5% to 20% citric acid, and 5% to 20% sodium alginate.

[0012] In this embodiment, the flotation reagent also includes an inhibitor, acidified water glass, and a collector, saponified oleic acid. In the flotation system with saponified oleic acid as the collector, the surfaces of (ferro)dolomite and calcite in the slurry are strongly negatively charged, and electrostatic adsorption or micellar adsorption may occur, while saponified oleic acid exists in the form of ions and ion-molecule associations. The adsorption of saponified oleic acid on the surface of calcite is greatly affected by pH, but saponified oleic acid has strong adsorption on fluorite in the entire pH range. Therefore, in a weakly acidic environment, the separation of fluorite and gangue minerals such as (ferro)dolomite and calcite can be better achieved. In the flotation reagent system provided in this embodiment, the acidified water glass and the aluminum sulfate, citric acid, etc. in the composite inhibitor provide an acidic environment for the slurry system, and the (RCOO)2 in the collector 2- and RCOO - The anions react chemically with carbonate gangue minerals such as dolomite to form precipitates, making it difficult for dolomite and calcite to be captured by the collector.

[0013] More specifically, in weak acidic conditions, aluminum sulfate hydrolysis produces Al 3+ Alm(OH) n 3m-n It exists in the form of, it can clean the mineral surface, accelerate the dissolution of some carbonate minerals in fluorite, and does not affect the surface electrical properties of fluorite, Alm (OH) n 3m-n It is mainly adsorbed on the surface of dolomite, calcite and barite by hydrogen bond electrostatic force, thereby changing its surface electrical properties and inhibiting the floatability of these gangue minerals. Sodium hexametaphosphate in the composite inhibitor component can make various phosphate ions compete for adsorption on the surface of carbonate minerals in the slurry, generating calcium phosphate to inhibit carbonate minerals, and the dispersion effect of sodium hexametaphosphate can effectively reduce the heterogeneous flocculation of fine-grained fluorite minerals and gangue minerals during the flotation process, so that the collector can better act on the active sites on the surface of fluorite minerals. The phenolic hydroxyl group of the hydrolyzate of tannic acid in the composite inhibitor component and the carboxyl group produced by hydrolysis can react with the Ca2+ on the surface of the mineral. 2+ Forms hydroxy complex Ca(OH) in solution + The reaction product is precipitated on the surface of the mineral. Usually, calcite has stronger solubility than fluorite, and the hydroxyl complex CaOH is produced. + More, CaOH +The adsorption amount of compound agents is greater, thereby achieving selective inhibition of gangue minerals. A large number of polar groups contained in tannic acid, citric acid, and sodium alginate in the compound inhibitor are adsorbed on the mineral surfaces of carbonate gangue minerals such as (ferro) dolomite and calcite in the slurry, but less adsorbed on the surface of fluorite minerals, resulting in differences in the wettability of the surfaces of fluorite and gangue minerals. These polar groups have hydrogen bonds with water molecules, thereby enhancing the hydrophilicity of the surface of gangue minerals and achieving the purpose of selective inhibition. Because sulfide minerals co-exist in fluorite deposits, they are harmful components for the flotation of fluorite and usually have an adverse effect on the grade of continuously produced fluorite concentrates. Therefore, sodium alginate components are added to the compound inhibitor. Chelating groups such as hydroxyl and carboxyl groups exist in the sodium alginate molecule, which can undergo chelation reactions on the surface of metal minerals and enhance their surface hydrophilicity. They also have a certain inhibitory effect on fine-grained silicates, which can achieve the purpose of synergistic cooperation with other compound inhibitor components.

[0014] Through the above-mentioned method, the synergistic effect between the raw materials in the composite inhibitor can be fully utilized, the inhibition effect on carbonate minerals and silicates can be improved, and the selectivity of the fluorite collector can be improved, thereby improving the recovery rate and grade of fluorite.

[0015] In some embodiments, the compound regulator comprises, by mass percentage, 20% to 60% of calcium lignin sulfonate, 5% to 40% of hydroxyethyl cellulose, and 5% to 40% of potassium dichromate.

[0016] In this embodiment, since the gangue components of magnesium-containing carbonate-type low-grade fluorite ore are relatively complex, the flotation operation needs to add a composite adjusting agent to further regulate the floatability difference between fluorite and carbonate gangue minerals such as (iron) dolomite and calcite in the flotation reagent system, and other gangue minerals, so as to enhance the capture effect of the target mineral. Among them, the addition of calcium lignin sulfonate can not only improve the hydrophilicity of the surface of gangue minerals such as calcite, but also reduce the viscosity of the flotation pulp, increase the surface tension of the flotation foam, and accelerate the drainage speed of the interlayer fluid between the foam and the foam, thereby reducing the non-selective entrainment phenomenon in the froth flotation process. The inward polar group of hydroxyethyl cellulose can have a strong affinity with the surface of the gangue mineral, and produce competitive adsorption with saponified oleic acid. In addition, the outward part of the polar group can form a hydrophilic film on the gangue surface, thereby strengthening the hydrophilicity of the mineral surface, thereby strengthening the inhibition effect. Since aluminum sulfate will weaken the capture ability of fatty acid collectors, the recovery rate of fluorite will be negatively affected to a certain extent, while potassium dichromate (K2Cr2O7) can activate fluorite. The two complement each other to achieve effective flotation of fluorite and reduce the recovery effect of target minerals due to the inhibition of gangue minerals.

[0017] In some embodiments, in step S1, the classification and pre-disposal process includes the following steps:

[0018] The fluorite ore is crushed and then sieved to obtain the oversize mineral and undersize mineral;

[0019] The above-screen minerals are pre-discarded by using a heavy medium cyclone to obtain pre-discarded concentrate and tailings I;

[0020] The pre-enriched mineral is obtained by combining the undersize mineral and the pre-disposal waste concentrate.

[0021] In this embodiment, the ore is pre-enriched by first screening and then using a heavy medium cyclone to discard the minerals on the screen, thereby giving full play to the complementary advantages of equipment and technology, effectively reducing the loss of fine-grained fluorite while improving the grade of the ore entering flotation, and improving the recovery rate of fluorite.

[0022] In some embodiments, the screening process uses a vibrating screen having an aperture of 0.2 to 2 mm.

[0023] In this embodiment, by using a vibrating screen with a specific aperture to classify the raw ore, the under-screen minerals with a suitable particle size can be screened out, and it is convenient to subsequently use a heavy medium cyclone to discard the over-screen minerals.

[0024] In some embodiments, in step S2, after the grinding treatment, the proportion of particles with a diameter of -0.074 mm in the ore sample is 60% to 90%; and the concentration of the first slurry is 30% to 35%.

[0025] In this embodiment, the grinding method is preferably wet grinding, which is to grind the ore sample to a specific fineness and add water to prepare a first ore pulp of a specific concentration, so as to facilitate the efficient implementation of the subsequent flotation process.

[0026] In some embodiments, in step S3, the flotation operation includes 1 roughing operation, 6 to 9 cleaning operations and 1 to 3 scavenging operations; in the cleaning operation, the middlings obtained from the 1st cleaning and the 2nd cleaning are combined and concentrated into a second slurry with a concentration of 30% to 35%, and then the second slurry is subjected to a middling re-selection operation, and the obtained middling re-selection concentrate is returned to the roughing operation.

[0027] In this embodiment, when the first slurry formed by the pre-enriched mineral is subjected to flotation, the recovery rate and grade of fluorite can be further improved by concentrating the middling ore and then returning it to the roughing operation, so as to obtain a fluorite concentrate grade that is easier to sell.

[0028] In some embodiments, the reagents added during the roughing operation include 500-1500 g / t of sodium carbonate, 800-2000 g / t of acidified water glass, 200-600 g / t of the compound inhibitor, 100-600 g / t of the compound regulator and 100-600 g / t of saponified oleic acid.

[0029] In some embodiments, during the selection operation, the reagents added during the first four selections include 100-1000 g / t of acidified water glass, 10-400 g / t of the compound inhibitor and 10-200 g / t of the compound adjuster; the reagents added during the 5th to 9th selections include 0-300 g / t of acidified water glass and 0-80 g / t of the compound inhibitor.

[0030] In some embodiments, the reagents added during the scanning operation include 100-400 g / t of acidified water glass, 20-200 g / t of the compound inhibitor, 10-200 g / t of the compound regulator and 10-150 g / t of saponified oleic acid.

[0031] In the above embodiment, by regulating the dosage of the reagent, the reagent effect can be fully exerted with a smaller dosage, and the fluorite in the magnesium carbonate-type low-grade fluorite ore can be efficiently floated.

[0032] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 This is a schematic diagram of the process for the beneficiation method of magnesium carbonate-type low-grade fluorite ore provided in Example 1 of the present application. DETAILED DESCRIPTION

[0035] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0037] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0038] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0039] Since the traditional beneficiation method of magnesium-containing carbonate-type low-grade fluorite ore usually adopts the "de-sludging-flotation-acid leaching (washing)" process, not only the recovery rate is low, but also acid leaching is required to improve the fluorite grade, resulting in a sharp increase in the operation and management costs of the beneficiation plant. In order to solve the above problems, the present application provides a beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore, comprising the following steps:

[0040] S1. Classify and pre-discard the fluorite ore to obtain pre-enriched minerals;

[0041] S2. Grinding the pre-enriched mineral and adding water to prepare a first slurry;

[0042] S3. The first pulp is subjected to flotation operation using a flotation agent; the flotation agent comprises a compound inhibitor and a compound regulator, the compound inhibitor comprises aluminum sulfate, sodium hexametaphosphate, tannic acid, citric acid and sodium alginate, and the compound regulator comprises calcium lignin sulfonate, hydroxyethyl cellulose and potassium dichromate.

[0043] In the technical scheme of the embodiment of the present application, by first grading and pre-discarding the fluorite ore, the grade of the ore entering the flotation is improved, the amount of grinding is reduced, and the cost of mineral processing is reduced; on this basis, the present application optimizes the flotation reagent, and adopts the method of compound reagent to combine the inorganic inhibitor and the organic regulator, so that it can suppress the dolomite and calcite in the magnesium carbonate type low-grade fluorite ore in a targeted manner, and give full play to the compound synergistic effect between the reagents, reduce the heterogeneous coagulation between fluorite and carbonate particles, strengthen the dispersion degree of the slurry, reduce the adsorption amount of the collector on the surface of the fine carbonate mineral, and improve the inhibitory effect on silicate minerals while suppressing carbonate minerals, so as to accelerate the floating rate of fluorite, thereby improving the selectivity of the fluorite collector. And the above-mentioned compound reagent has the advantages of non-toxic and environmentally friendly, easy to obtain raw materials, and low reagent consumption, and has a very high industrial application prospect.

[0044] Further, in some embodiments, the compound inhibitor includes 20% to 50% aluminum sulfate, 10% to 30% sodium hexametaphosphate, 5% to 20% tannic acid, 5% to 20% citric acid, and 5% to 20% sodium alginate by mass percentage. More preferably, the mass ratio of aluminum sulfate, sodium hexametaphosphate, tannic acid, citric acid, and sodium alginate in the compound inhibitor is 4:2:2:1:1. At the same time, the compound adjuster includes 20% to 60% calcium lignin sulfonate, 5% to 40% hydroxyethyl cellulose, and 5% to 40% potassium dichromate by mass percentage. More preferably, the mass ratio of sodium lignin sulfonate, hydroxyethyl cellulose, and potassium dichromate in the compound adjuster is 5:3:2.

[0045] In the technical solution of the embodiment of the present application, by regulating the ratio of each raw material in the compound inhibitor and the compound adjuster, the synergistic effect between the raw materials can be fully exerted, the inhibition effect on carbonate minerals and silicates can be improved, and the selectivity of the fluorite collector can be improved, thereby improving the recovery rate and grade of fluorite.

[0046] Furthermore, in some embodiments, in step S1, the classification and pre-disposal process comprises the following steps:

[0047] The fluorite ore is crushed and then sieved to obtain the oversize mineral and undersize mineral;

[0048] The above-screen minerals are pre-discarded by using a heavy medium cyclone to obtain pre-discarded concentrate and tailings I;

[0049] The pre-enriched mineral is obtained by combining the undersize mineral and the pre-disposal waste concentrate.

[0050] In the technical solution of the embodiment of the present application, the ore is pre-enriched by first screening and then using a heavy medium cyclone to discard the minerals on the screen, thereby giving full play to the complementary advantages of equipment and technology, effectively reducing the loss of fine-grained fluorite while improving the grade of the ore entering flotation, and improving the recovery rate of fluorite.

[0051] Furthermore, in some embodiments, the screening process uses a vibrating screen with an aperture of 0.2 to 2 mm, so as to screen out under-screen minerals with suitable particle sizes and facilitate the subsequent use of a heavy medium cyclone to discard the over-screen minerals.

[0052] Furthermore, in some embodiments, in step S2, after the grinding treatment, the proportion of particles with a diameter of -0.074 mm in the ore sample is 60% to 90%; and the concentration of the first slurry is 30% to 35%.

[0053] In the technical solution of the embodiment of the present application, the grinding method is preferably wet grinding, which is beneficial to the efficient implementation of the subsequent flotation process by grinding the ore sample to a specific fineness and adding water to prepare a first slurry of a specific concentration.

[0054] Further, in some embodiments, in step S3, the flotation operation includes 1 roughing operation, 6 to 9 cleaning operations and 1 to 3 scavenging operations, and specifically includes the following steps:

[0055] S31. Adding roughing agents to the first slurry to obtain roughing concentrate and roughing tailings; wherein the roughing agents include: sodium carbonate added in an amount of 500-1500 g / t, acidified water glass added in an amount of 800-2000 g / t, the compound inhibitor added in an amount of 200-600 g / t, the compound regulator added in an amount of 100-600 g / t and saponified oleic acid added in an amount of 100-600 g / t.

[0056] In the above-mentioned agent, acidified water glass is prepared by mixing water glass and sulfuric acid in a mass ratio of 2:1, and its dosage is calculated based on water glass; saponified oleic acid is formed by mixing vegetable oleic acid and sodium carbonate in a mass percentage of 25% to 60%: 40% to 75% and then undergoing a saponification reaction. When preparing saponified oleic acid, sodium carbonate is first prepared into a sodium carbonate solution with a mass fraction of 20% to 40%, and then the sodium carbonate is fused with oleic acid in a water bath at 90 to 100°C for saponification. The preferred compositions and preparation methods of acidified water glass and saponification in the following text are the same and will not be described in detail.

[0057] S32. The roughing concentrate is subjected to 6 to 9 concentration operations, and the flotation concentration in the concentration operation stage is 10% to 28%; wherein, the middlings obtained from the first and second concentrations are combined and concentrated into a second slurry with a concentration of 30% to 35%, and then the second slurry is subjected to a middling re-selection operation, and the reagent used in the middling re-selection operation is saponified oleic acid with an addition amount of 10 to 100 g / t, to obtain a middling re-selection concentrate and a middling re-selection tailings, the middling re-selection concentrate is returned to the roughing operation, and the middling re-selection tailings is used as the final tailings II; the middlings produced in the subsequent concentration operations are returned to the previous operation step by step, and the concentrate obtained in the last concentration operation is used as the final fluorite concentrate product.

[0058] In the above-mentioned selection operation, the reagents for the first selection include 100-1000g / t of acidified water glass, 50-400g / t of compound inhibitor and 50-200g / t of compound adjuster; the reagents for the second selection include 100-800g / t of acidified water glass, 50-200g / t of compound inhibitor and 20-100g / t of compound adjuster; the reagents for the third selection include 100-600g / t of acidified water glass, 20-100g / t of compound inhibitor and 10-80g / t of compound adjuster; the reagents for the fourth selection include 100-400g / t of acidified water glass, 10-100g / t of compound inhibitor and 10-100g / t of compound adjuster. The reagent for the 5th selection includes acidified water glass with an addition amount of 100-300g / t and a compound adjusting agent with an addition amount of 5-80g / t; the reagent for the 6th selection includes acidified water glass with an addition amount of 100-400g / t and a compound inhibitor with an addition amount of 5-60g / t; the reagent for the 7th selection includes acidified water glass with an addition amount of 100-300g / t and a compound inhibitor with an addition amount of 5-40g / t; the reagent for the 8th selection includes acidified water glass with an addition amount of 100-300g / t and a compound inhibitor with an addition amount of 0-20g / t; the reagent for the 9th selection includes acidified water glass with an addition amount of 0-300g / t and a compound inhibitor with an addition amount of 0-60g / t.

[0059] S32. Perform 1 to 3 scavenging operations on the roughing tailings to obtain final tailings III, and return the scavenging concentrate obtained from the scavenging operations to the roughing operation.

[0060] The reagents used in the sweeping operation include 100-400 g / t of acidified water glass, 20-200 g / t of the compound inhibitor, 10-200 g / t of the compound regulator and 10-150 g / t of saponified oleic acid.

[0061] Through the above-mentioned method, the beneficiation method for magnesium-containing carbonate low-grade fluorite ore provided in the embodiment of the present application can utilize the synergistic effect between a specific beneficiation process and an improved reagent system, while eliminating the acid leaching operation and improving the recovery rate and grade of fluorite with a simpler process and lower reagent cost. The overall process is stable and reliable, and the beneficiation reagent cost is reduced by more than 40% compared with the existing process, with high economic benefits, and the use of hydrochloric acid is omitted, which is more environmentally friendly and has extremely high industrial application prospects.

[0062] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0063] Example 1

[0064] The present embodiment provides a beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore. A magnesium-containing carbonate-type low-grade fluorite ore in Inner Mongolia is used as a test object. The original ore has a CaF2 content of 20.70%, a CaCO3 content of 19.07%, and a MgO content of 3.94%. It also contains a small amount of altered feldspar, quartz and other gangue minerals. The carbonate gangue mainly exists in the form of dolomite, calcite, and ankerite minerals.

[0065] The schematic flow diagram of the beneficiation method for magnesium carbonate-type low-grade fluorite ore provided in this embodiment is as follows: Figure 1 As shown, the method specifically comprises the following steps:

[0066] S1. After the raw ore is crushed to -2mm, it is graded using a vibrating screen with a mesh size of 0.5mm to obtain oversize minerals and undersize minerals; the oversize minerals are sent to a heavy medium cyclone for pre-disposal treatment to obtain pre-disposal concentrate and tailings I; the undersize minerals and pre-disposal concentrate are combined to obtain pre-enriched minerals.

[0067] S2. The pre-enriched mineral is subjected to wet grinding, and the mineral powder particles with a grinding fineness of -0.074 mm account for 70.18% of the total amount of mineral powder entering the grinding, and water is added to prepare a first slurry with a mass concentration of 33%.

[0068] S3. The first pulp is subjected to flotation operation using a flotation agent; the flotation operation includes 1 roughing operation, 9 cleaning operations and 1 scavenging operation, and the specific steps are as follows:

[0069] S31. Add a roughing agent to the first slurry to obtain a roughing concentrate and a roughing tailing; wherein the roughing agent includes: sodium carbonate added in an amount of 800 g / t, acidified water glass added in an amount of 1500 g / t, a composite inhibitor added in an amount of 400 g / t (i.e. Figure 1 CD-WN in the mixture), a compounding agent with an addition amount of 200g / t (i.e. Figure 1 CN-WH) and saponified oleic acid added in an amount of 500g / t.

[0070] S32. The roughing concentrate is subjected to 9 concentration operations; wherein, the middlings obtained from the first and second concentrations are combined and concentrated into a second slurry with a concentration of 31%, and then 50 g / t of saponified oleic acid is added to the second slurry for middling re-selection to obtain middling re-selection concentrate and middling re-selection tailings, the middling re-selection concentrate is returned to the roughing operation, and the middling re-selection tailings is used as the final tailings II; the middlings generated in the subsequent concentration operations are returned to the previous operation step by step, and the concentrate obtained from the last concentration operation is used as the final fluorite concentrate product.

[0071] In the above-mentioned concentration operation, the reagents for the first concentration include 800g / t of acidified water glass, 200g / t of compound inhibitor and 100g / t of compound adjuster; the reagents for the second concentration include 500g / t of acidified water glass, 100g / t of compound inhibitor and 50g / t of compound adjuster; the reagents for the third concentration include 400g / t of acidified water glass, 100g / t of compound inhibitor and 20g / t of compound adjuster; the reagents for the fourth concentration include 300g / t of acidified water glass, 100g / t of compound inhibitor and 20g / t of compound adjuster. The reagents for the 5th selection include 200g / t of acidified water glass and 20g / t of compound inhibitor; the reagents for the 6th selection include 200g / t of acidified water glass and 15g / t of compound inhibitor; the reagents for the 7th selection include 100g / t of acidified water glass and 10g / t of compound inhibitor; the reagents for the 8th selection include 100g / t of acidified water glass and 5g / t of compound inhibitor; the 9th selection is blank selection, that is, no reagent is added.

[0072] S32. The roughing tailings are subjected to a scavenging operation to obtain final tailings III, and the scavenged concentrate obtained by the scavenging operation is returned to the roughing operation. The reagents used in the scavenging operation include 200 g / t of acidified water glass, 100 g / t of the compound inhibitor, 50 g / t of the compound regulator, and 100 g / t of saponified oleic acid.

[0073] In the above-mentioned agents, the compound inhibitor is prepared by mixing aluminum sulfate, sodium hexametaphosphate, tannic acid, citric acid and sodium alginate in a mass ratio of 4:2:2:1:1, and the compound adjuster is prepared by mixing calcium lignin sulfonate, hydroxyethyl cellulose and potassium dichromate in a mass ratio of 5:3:2.

[0074] The test results obtained after mineral processing according to the mineral processing method provided in this embodiment are shown in Table 1.

[0075] Table 1 Full process closed circuit test results in Example 1 (%)

[0076]

[0077] As can be seen from Table 1, the mineral processing method provided in this embodiment is used to recover a low-grade fluorite ore containing magnesium carbonate in Inner Mongolia, and the recovery rate of CaF2 is 78.77%. The final CaF2 grade is 95.46%, of which CaCO3 contains 1.38% and MgO contains 0.13%, which is a high-quality fluorite concentrate. This shows that the method provided in this embodiment is of great significance for the development and utilization of low-grade fluorite ore containing magnesium carbonate.

[0078] Example 2

[0079] This embodiment provides a beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore, taking a magnesium-containing carbonate-type low-grade fluorite ore in Xinjiang as the test object, the CaF2 content in the raw ore is 22.53%, the CaCO3 content is 19.15%, and the MgO content is 4.31%. The gangue is mainly quartz, etc., and the carbonate gangue mainly exists in the form of dolomite and calcite minerals. Compared with Example 1, the main difference between the beneficiation method provided in this embodiment and Example 1 is that the proportion of -0.074mm ore powder particles in step S2 to the total amount of ore powder entering the mill, the amount of some reagents in step S3, and the concentration of the second slurry when the middling ore is reselected are adjusted.

[0080] Specifically, in this embodiment, the -0.074 mm ore powder particles in step S2 account for 78.95% of the total amount of ore powder entering the mill; the concentration of the second slurry is 32%; the amount of sodium carbonate added during roughing is 1000 g / t, and the amount of compound inhibitor added is 450 g / t; the amount of compound inhibitor added during the first concentration is 250 g / t, the amount of compound regulator added during the second concentration is 100 g / t, the amount of compound inhibitor added during the third concentration is 80 g / t, the amount of compound inhibitor added during the fourth concentration is 40 g / t, the amount of compound inhibitor added during the fifth concentration is 30 g / t, and the amount of compound inhibitor added during the sixth concentration is 20 g / t. The rest is basically the same as in Example 1 and will not be repeated here.

[0081] The test results obtained after mineral processing according to the mineral processing method provided in this embodiment are shown in Table 2.

[0082] Table 2 Full process closed circuit test results in Example 2 (%)

[0083]

[0084] It can be seen from Table 2 that the mineral processing method provided in this embodiment is used to recover a low-grade fluorite ore containing magnesium carbonate in Xinjiang, and the recovery rate of CaF2 is 79.02%. The final CaF2 grade obtained is 95.52%, including 1.20% CaCO3 and 0.20% MgO, which is a high-quality fluorite concentrate.

[0085] Example 3

[0086] This embodiment provides a beneficiation method for magnesium carbonate-type low-grade fluorite ore, taking a magnesium carbonate-type low-grade fluorite ore in Fujian as the test object, the CaF2 content in the raw ore is 18.23%, the CaCO3 content is 17.96%, and the MgO content is 4.34%. The gangue is mainly feldspar, quartz, etc., and the carbonate gangue mainly exists in the form of calcite and ankerite minerals. Compared with Example 1, the main difference of the beneficiation method provided in this embodiment is that the proportion of -0.074mm ore powder particles in the total amount of ore powder entering the mill in step S2 and the concentration of the first ore pulp, the dosage of some reagents in step S3, and the concentration of the second ore pulp when the middling ore is reselected are adjusted.

[0087] Specifically, in this embodiment, in step S2, the mineral powder particles of -0.074 mm account for 68% of the total mineral powder entering the mill, the concentration of the first slurry is 30%, and the concentration of the second slurry is 35%; the amount of sodium carbonate added during roughing is 1000 g / t, the amount of compound inhibitor added is 500 g / t, and the amount of saponified oleic acid added is 400 g / t; the amount of compound inhibitor added during the first selection is 300 g / t, the amount of compound inhibitor added during the second selection is 150 g / t, the amount of compound regulator added is 100 g / t, the amount of compound inhibitor added during the third selection is 70 g / t, and the amount of compound inhibitor added during the fourth selection is 35 g / t; the amount of saponified oleic acid added during scavenging is 80 g / t. The rest is basically the same as in Example 1 and will not be repeated here.

[0088] The test results obtained after mineral processing according to the mineral processing method provided in this embodiment are shown in Table 3.

[0089] Table 3 Full process closed circuit test results in Example 3 (%)

[0090]

[0091]

[0092] It can be seen from Table 3 that the ore dressing method provided in this embodiment is used to recover a low-grade fluorite ore containing magnesium carbonate in Fujian, and the recovery rate of CaF2 is 80.19%. The final CaF2 grade is 95.11%, including 1.36% CaCO3 and 0.30% MgO, which is a high-quality fluorite concentrate.

[0093] According to the test results of Examples 1 to 3, it can be seen that the mineral processing method provided in the present application can be applied to different types of magnesium-containing carbonate-type low-grade fluorite ores, and the corresponding mineral processing parameters can be appropriately adjusted within a certain range. When mineral processing is carried out according to the method provided in the present application, the recovery rate of CaF2 can reach more than 78%, and the grade of CaF2 can reach more than 95%, thereby achieving high-grade, high-quality fluorite concentrate with a higher recovery rate, which is of great practical value for the efficient recovery of magnesium-containing carbonate-type low-grade fluorite ores.

[0094] Examples 4 to 5 and Comparative Examples 1 to 3

[0095] Examples 4 to 5 and Comparative Examples 1 to 3 respectively provide a beneficiation method for magnesium carbonate-type low-grade fluorite ore. Compared with Example 1, the difference is that the composition of the composite inhibitor is changed. The proportions of the raw materials in the composite inhibitor in each embodiment and comparative example are shown in Table 4. The total amount of the composite inhibitor, the raw ore used and the remaining steps are consistent with Example 1 and are not repeated here.

[0096] Table 4 Composition of compound inhibitors in Examples 4 to 5 and Comparative Examples 1 to 3

[0097]

[0098] After performing beneficiation according to the beneficiation methods provided in Examples 4 to 5 and Comparative Examples 1 to 3, the yield, grade and recovery rate of the obtained fluorite flotation concentrate are shown in Table 5.

[0099] Table 5 Full process closed circuit test results in Examples 4 to 5 and Comparative Examples 1 to 3 (%)

[0100]

[0101] As can be seen from Table 5, within the recommended reagent ratio range, the CaF2 grade in the fluorite flotation concentrate of Example 4 and Example 5 reached 95% grade, and the grades of CaCO3 and MgO were both within the qualified product range. Adjusting the proportion of aluminum sulfate and sodium hexametaphosphate in the inhibitor has a greater impact on the yield of the concentrate product, thereby affecting the recovery rate of the concentrate. After the ratio of the compound inhibitor deviates from the recommended range, it has a greater impact on the grades of CaF2, CaCO3 and MgO in the fluorite concentrate, and the synergistic effect between the reagents cannot be brought into play. The flotation concentrates of Comparative Examples 1-3 did not reach the 95% grade fluorite concentrate standard, and could only be sold as 93% grade fluorite concentrate, which greatly reduced the value of the ore dressing products. Therefore, depending on the different properties of the ore, the proportion of various inhibitors in the compound inhibitor needs to be reasonably allocated so that the synergistic effect between the reagents can be fully exerted and the effective utilization value of resources can be improved.

[0102] Examples 6 to 7 and Comparative Examples 4 to 7

[0103] Examples 6 to 7 and Comparative Examples 4 to 7 respectively provide a beneficiation method for magnesium carbonate-type low-grade fluorite ore. Compared with Example 1, the difference is that the composition of the compound adjusting agent is changed. The proportion of each raw material in the compound adjusting agent in each embodiment and comparative example is shown in Table 6. The total amount of the compound adjusting agent, the raw ore used and the remaining steps are consistent with Example 1, which will not be repeated here.

[0104] Table 6 Composition of compound adjusting agent in Examples 6 to 7 and Comparative Examples 4 to 7

[0105]

[0106]

[0107] After performing beneficiation according to the beneficiation methods provided in Examples 6 to 7 and Comparative Examples 4 to 7, the yield, grade and recovery rate of the fluorite flotation concentrate obtained are shown in Table 7.

[0108] Table 7 Full-process closed-circuit test results in Examples 6 to 7 and Comparative Examples 4 to 7 (%)

[0109]

[0110] It can be seen from Table 7 that when the proportion of calcium lignin sulfonate in the compound adjuster is reduced, the yield of fluorite concentrate and the recovery rate of CaF2 are slightly increased, but the grades of CaCO3 and MgO are increased, and the hydrophobicity of the adjuster on the carbonate surface is weakened; after reducing the proportion of hydroxyethyl cellulose, its competitive adsorption with oleic acid on the surface of carbonate minerals is weakened, so that the grade of fluorite concentrate will be reduced to a certain extent, but the grade of CaCO3 and MgO in the concentrate is less affected. Potassium dichromate is added to partially inhibit the inhibitory effect of aluminum sulfate and other inhibitors on fluorite minerals during the flotation of fluorite. Therefore, if its proportion is eliminated, it will have a more obvious negative impact on the recovery rate of CaF2 in fluorite concentrate.

[0111] In summary, the present application provides a beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore, which belongs to the technical field of fluorite beneficiation. The present application obtains pre-enriched minerals by grading and pre-discarding fluorite ore; grinding the pre-enriched minerals, and preparing them into a first slurry after adding water; flotation agents are used to perform flotation operations on the first slurry; the flotation agents include compound inhibitors and compound regulators, the compound inhibitors include aluminum sulfate, sodium hexametaphosphate, tannic acid, citric acid and sodium alginate, and the compound regulators include calcium lignin sulfonate, hydroxyethyl cellulose and potassium dichromate. In the above manner, the beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore provided in the present application can utilize the synergistic effect between a specific beneficiation process and an improved reagent system, while eliminating the acid leaching operation, improving the recovery rate and grade of fluorite with a simpler process and lower reagent cost, and has a very high industrial application prospect.

[0112] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore, characterized in that: The steps include: S1. Classify and pre-discard the fluorite ore to obtain pre-enriched minerals; S2. Grinding the pre-enriched mineral and adding water to prepare a first slurry; S3. The first pulp is subjected to flotation operation using a flotation agent; the flotation agent comprises a compound inhibitor and a compound regulator, the compound inhibitor comprises aluminum sulfate, sodium hexametaphosphate, tannic acid, citric acid and sodium alginate, and the compound regulator comprises calcium lignin sulfonate, hydroxyethyl cellulose and potassium dichromate.

2. The beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore according to claim 1, characterized in that: The composite inhibitor comprises, by mass percentage, 20% to 50% of aluminum sulfate, 10% to 30% of sodium hexametaphosphate, 5% to 20% of tannic acid, 5% to 20% of citric acid, and 5% to 20% of sodium alginate.

3. The beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore according to claim 1, characterized in that: The compound regulator comprises, by mass percentage, 20% to 60% of calcium lignin sulfonate, 5% to 40% of hydroxyethyl cellulose, and 5% to 40% of potassium dichromate.

4. The beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore according to claim 1, characterized in that: In step S1, the classification and pre-disposal treatment includes the following steps: The fluorite ore is crushed and then sieved to obtain the oversize mineral and undersize mineral; The above-screen minerals are pre-discarded by using a heavy medium cyclone to obtain pre-discarded concentrate and tailings I; The pre-enriched mineral is obtained by combining the undersize mineral and the pre-disposal waste concentrate.

5. The beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore according to claim 4, characterized in that: The screening process uses a vibrating screen with a pore size of 0.2 to 2 mm.

6. The beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore according to claim 1, characterized in that: In step S2, after the grinding treatment, the proportion of particles with a diameter of -0.074 mm in the ore sample is 60% to 90%; and the concentration of the first slurry is 30% to 35%.

7. The beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore according to claim 1, characterized in that: In step S3, the flotation operation includes 1 roughing operation, 6 to 9 cleaning operations and 1 to 3 scavenging operations; in the cleaning operation, the middlings obtained from the 1st cleaning and the 2nd cleaning are combined and concentrated into a second slurry with a concentration of 30% to 35%, and then the second slurry is subjected to a middling reselection operation, and the obtained middling reselection concentrate is returned to the roughing operation.

8. The beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore according to claim 7, characterized in that: The reagents added during the roughing operation include 500-1500 g / t of sodium carbonate, 800-2000 g / t of acidified water glass, 200-600 g / t of the compound inhibitor, 100-600 g / t of the compound regulator and 100-600 g / t of saponified oleic acid.

9. The beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore according to claim 7, characterized in that: During the above-mentioned selection operation, the reagents added during the first four selections include 100-1000 g / t of acidified water glass, 10-400 g / t of the above-mentioned compound inhibitor and 10-200 g / t of the above-mentioned compound adjuster; the reagents added during the 5th to 9th selections include 0-300 g / t of acidified water glass and 0-80 g / t of the above-mentioned compound inhibitor.

10. The beneficiation method for magnesium-containing carbonate-type low-grade fluorite ore according to claim 7, characterized in that: The reagents added during the sweeping operation include 100-400 g / t of acidified water glass, 20-200 g / t of the compound inhibitor, 10-200 g / t of the compound regulator and 10-150 g / t of saponified oleic acid.

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