Flotation method for niobium-containing minerals

Abstract

The invention relates to a flotation method for niobium-containing minerals, and belongs to the technical field of mineral separation. The method comprises the steps that niobium-containing ore is subjected to crushing, ore grinding and size mixing, obtained ore pulp is subjected to weak magnetic treatment to remove strong magnetic minerals, after the pH of magnetic separation tailings is adjusted, a flotation reagent containing an iron mineral inhibitor and an amine collecting agent is added for silicon-niobium bulk flotation, and after the pH of obtained silicon-niobium bulk concentrate is adjusted, the obtained silicon-niobium bulk concentrate is subjected to flotation separation. And a flotation reagent containing a hydroximic acid metal organic complex collecting agent and a siliceous mineral inhibitor is added for silicon-niobium separation flotation, and niobium concentrate is obtained. According to the method, iron gangue mineral removal is achieved through step-by-step flotation by means of the amine collecting agent, silicon separation is achieved by means of the hydroximic acid metal organic complex collecting agent, efficient enrichment of the niobium mineral is achieved, the step of strong magnetic iron removal is avoided, the process is simplified, and the loss rate of the niobium mineral is reduced.

Description

Technical Field

[0001] The invention relates to a flotation method for niobium-containing minerals, in particular to a step-by-step flotation enrichment method for niobium-containing minerals, and belongs to the technical field of mineral processing. Background Art

[0002] Niobium is an emerging mineral resource. In the steel industry, adding only 0.03% to 0.05% niobium can increase the yield strength of steel by more than 30%, greatly reducing the cost of steel manufacturing. Due to the high temperature resistance, corrosion resistance, wear resistance, and good thermal conductivity of niobium metal, it is widely used in aerospace, superconducting materials, medicine and other national technical fields.

[0003] Niobium deposits are mainly divided into carbonate niobium deposits, alkaline rock niobium-tantalum deposits, rare metal granite niobium-tantalum deposits and pegmatite niobium-tantalum deposits. The main mineral types are pyrochlore, columbite and columbite-tantalum ore. Most of its gangue minerals are ferrous gangue minerals (magnetite, hematite, ilmenite, limonite, etc.) and siliceous gangue minerals (quartz, mica, chlorite, feldspar, kaolin, etc.).

[0004] The grade of niobium ore resources that can be developed in China is low, the composition of niobium ore is complex, the particle size is fine, and the separation is difficult. Most of the foreign niobium ores are carbonate-type pyrochlore ores, which are high-grade and easy to separate. The common separation process is to first add fatty acid collectors, suppress pyrochlore by adding regulators, remove carbonate minerals by reverse flotation, and then add cationic collectors to float pyrochlore. However, there are still disadvantages such as complex process and large amount of reagents.

[0005] At present, there are reports on the use of hydroxamic acid collectors for niobium ore flotation. Hydroxamic acid collectors show excellent collection and selectivity for niobium ore, but hydroxamic acid collectors are sensitive to iron components. The use of hydroxamic acid collectors alone will cause the niobium concentrate to contain a large amount of uncontrollable iron impurities, affecting the flotation index of niobium ore. At present, niobium iron concentrate is mainly recovered in the form of iron-niobium co-floatation. For example, a Chinese patent application (publication number: CN118268138A) discloses a method for co-enrichment of iron-niobium resources in rare earth tailings. The method is to adjust the pH of the ore pulp to alkaline after flotation desulfurization of rare earth tailings, use metal organic complexes (formed by coordination of divalent or higher metal ions and hydroxamic acid organic ligands) as co-floatation collectors for iron and niobium minerals, and use gangue mineral inhibitors for flotation separation to obtain a concentrate that is a mixed iron-niobium concentrate. As for the recovery of niobium resources in iron-niobium mixed concentrate, the alkali decomposition method, acid decomposition method and chlorination roasting method are currently mainly used. These technologies have technical problems such as low niobium yield, large acid and alkali consumption, high energy consumption and complex process. Summary of the invention

[0006] In view of the difficulties in the current niobium-containing mineral beneficiation process, such as lengthy process, complex process, high cost and low niobium ore recovery rate, the purpose of the present invention is to provide a flotation method for niobium-containing minerals. The method firstly utilizes the weak capture of amine collectors for iron minerals and the strong capture of siliceous minerals and niobium minerals to achieve pre-co-enrichment of siliceous and niobium minerals, and then utilizes the weak capture of hydroxamic acid metal organic complex collectors for siliceous gangue minerals and the strong capture of niobium minerals to achieve efficient separation of siliceous minerals and niobium minerals. The method has high niobium recovery rate, small reagent consumption, low energy consumption, simple process, and is conducive to large-scale promotion and application.

[0007] In order to achieve the above technical objectives, the present invention provides a flotation method for niobium-containing minerals, which comprises the following steps:

[0008] 1) crushing, grinding and slurrying the niobium-containing ore to obtain slurry;

[0009] 2) subjecting the slurry to weak magnetic treatment to remove strongly magnetic minerals to obtain magnetically separated tailings;

[0010] 3) After adjusting the pH value of the magnetic separation tailings, flotation reagents including iron mineral inhibitors and amine collectors are added to carry out silicon-niobium mixed flotation to obtain a silicon-niobium mixed concentrate;

[0011] 4) After adjusting the pH value of the silicon-niobium mixed concentrate, flotation reagents including a hydroxamic acid metal organic complex collector and a siliceous mineral inhibitor are added to carry out silicon-niobium separation flotation to obtain a niobium concentrate.

[0012] The flotation method of niobium-containing minerals provided by the present invention is mainly for siliceous minerals, ferrous minerals and niobium minerals among niobium-containing minerals. At present, it is difficult to separate siliceous minerals, ferrous minerals and niobium minerals. A large number of studies have shown that amine collectors and hydroxamic acid collectors can be used as niobium ore flotation collectors. Although a single hydroxamic acid collector has excellent capture and selectivity for niobium minerals, it is relatively sensitive to ferrous minerals. Usually, ferrous minerals and niobium minerals are enriched in the form of mixed concentrates, and subsequent separation of ferrous minerals and niobium minerals is difficult. A single amine collector has good capture for niobium minerals and weak capture capacity for ferrous minerals, but it is relatively sensitive to ore mud and siliceous minerals, and it is difficult to separate siliceous minerals from niobium minerals. The present invention aims at the characteristics of current niobium-containing minerals and the defects in the existing flotation separation process between siliceous minerals, iron minerals and niobium minerals. The present invention designs a reasonable step-by-step flotation enrichment method for niobium ore. The method first performs weak magnetic separation on niobium minerals to remove strongly magnetic gangue minerals including magnetite, and non-magnetic minerals are preferentially pre-enriched using amine collectors. By utilizing the characteristics of amine collectors that have strong capture properties for niobium minerals and siliceous minerals but are insensitive to iron minerals, iron minerals can be preferentially removed, while siliceous minerals and niobium minerals are co-enriched. The silicon-niobium mixed concentrate is then pre-enriched using hydroxamic acid metal organic solvents. The niobium ore is further enriched by using the organic complex of hydroxamic acid metal to separate the siliceous minerals and the strong capture property of hydroxamic acid metal organic complex to remove the siliceous minerals. In summary, the process of the present invention combines the capture property advantages of hydroxamic acid metal organic complex collector and amine collector for silicon-containing minerals, iron-containing minerals and niobium-containing minerals, solves the technical problem that it is difficult to separate niobium, iron and silicon by using a single amine collector or a hydroxamic acid metal organic complex collector, simplifies the process flow, reduces the loss rate of niobium ore, and effectively realizes the resource utilization of such niobium ore.

[0013] As a preferred solution, the main minerals of the niobium ore are siliceous minerals, iron minerals and niobium minerals; the siliceous minerals include at least one of quartz, mica, feldspar, kaolin and chlorite.

[0014] As a preferred solution, the iron mineral includes at least one of magnetite, hematite, titanomagnetite, ilmenite, hematite, limonite, siderite and ankerite.

[0015] As a preferred solution, the niobium mineral includes at least one of pyrochlore, niobite, calcite and niobium ferrochlore.

[0016] As a preferred solution, the grinding is performed to meet the requirement that the mass proportion of the -200 mesh particle size is more than 80%. The ore is ground to an appropriate particle size to achieve sufficient monomer dissociation of the niobium minerals, which is beneficial to subsequent flotation separation.

[0017] As a preferred solution, the slurry adjustment is to meet the slurry mass concentration of 30% to 40%.

[0018] As a preferred solution, the magnetic field strength used in the weak magnetic treatment is 1000-2000 Gs. After the weak magnetic treatment, magnetite, ilmenite, hematite and the like with a high proportion and strong magnetism can be preferably removed, reducing the difficulty of subsequent flotation separation.

[0019] As a preferred solution, in step 3), the pH is adjusted to 2.5-4. The pH is adjusted using an acid, such as hydrochloric acid. Adjusting the pH to a weakly acidic state provides a favorable pH environment for silicon-niobium mixed flotation.

[0020] As a preferred solution, the silicon-niobium mixed flotation includes 1 roughing, 1 to 3 fines and 1 to 2 scavenging. As a more preferred solution, the reagent system of the roughing is: 300 to 800 g / t of iron mineral depressant, 1000 to 2000 g / t of amine collector. As a more preferred solution, the reagent system of the fine is: only iron mineral depressant is used, and the principle of reducing the reagent by half is followed. As a more preferred solution, the reagent system of the scavenging is: only amine collector is used, and the principle of reducing the reagent by half is followed. Under the preferred flotation conditions, the iron minerals in the niobium-containing minerals can be efficiently removed, and the silicon minerals and niobium minerals are efficiently enriched to obtain a silicon-niobium mixed concentrate.

[0021] As a preferred solution, the amine collector includes at least one of tallow diamine, dodecyl acetic acid amine, and a fatty diamine with a carbon number of 10 to 20. The preferred amine collector has a strong ability to act on niobium minerals, is sensitive to silicon, and has a weak ability to act on iron minerals. The use of amine collectors can achieve efficient enrichment of silicon minerals and niobium minerals. A further preferred amine collector is tallow diamine.

[0022] As a preferred solution, the iron mineral inhibitor includes at least one of fluorosilicic acid, sodium fluorosilicate, oxalic acid, and sodium humate. The preferred iron mineral inhibitor can selectively act on the iron ions and ferrous ions on the surface of the iron mineral, thereby achieving hydrophilic modification of the surface, thereby inhibiting the flotation of the iron mineral. The use of the iron mineral inhibitor can improve the removal efficiency of the iron mineral.

[0023] As a preferred solution, in step 4), the pH is adjusted to 6-8. Alkaline compounds such as Na2CO3 and NaOH are used to adjust the pH. Under different pH conditions, the chemical structures of the hydroxamic acid metal organic complexes formed by the assembly of divalent or higher metal ions and hydroxamic acid ligands are different, thus showing different capture capabilities. Within the preferred pH range, it is beneficial for the hydroxamic acid metal organic complexes to act on the surface of niobium minerals, thereby enhancing the flotation separation of niobium minerals.

[0024] As a preferred solution, the silicon-niobium separation flotation includes 1 roughing, 3 to 6 fine selections and 1 to 2 scavenging. As a more preferred solution, the reagent system of the roughing is: 30 to 100 g / t of siliceous mineral inhibitor, 300 to 800 g / t of hydroxamic acid metal organic complex collector; 5 to 30 g / t of frother; as a more preferred solution, the reagent system of the fine selection is: only siliceous mineral inhibitors are used, and the principle of reducing the reagent by half is followed. As a more preferred solution, the reagent system of the scavenging is: only hydroxamic acid metal organic complex collector is used, and the principle of reducing the reagent by half is followed. Under the preferred flotation conditions, the efficient removal of siliceous minerals in niobium minerals can be achieved, and niobium minerals are efficiently enriched to obtain niobium concentrate.

[0025] As a more preferred solution, the hydroxamic acid metal organic complex collector is composed of at least one of benzohydroxamic acid, salicylic hydroxamic acid, and an alkyl hydroxamic acid having 5 to 9 carbon atoms and Pb 2+ 、Zn 2+ 、Al 3+ , Cu 2+ , Fe 2+ , Fe 3+ At least one of them is assembled by coordination at a mass ratio of 0.5:1 to 1:3. The template effect of high-valent metal ions is used to regulate and assemble hydroxamic acid ligands, and the hydroxamic acid metal organic complex with a deionized hydration layer structure is pre-assembled, which has special crystal chemical properties and surface physicochemical properties, and exhibits more excellent properties in terms of capture ability and selectivity. In particular, micelles with specific structures and specific capture abilities are formed by assembling high-valent metal ions such as lead ions, zinc ions, aluminum ions, copper ions, and iron ions with hydroxamic acid ligands, which have high selective action on niobium minerals and are beneficial to the enrichment of niobium minerals. In addition, the hydroxamic acid metal organic complexes generated under different molar ratios of high-valent metal ions to hydroxamic acid ligands have different capture abilities for minerals. Under the preferred ratio relationship, the hydroxamic acid metal organic complex has a stronger capture ability for niobium-containing minerals and better selectivity.

[0026] As a preferred solution, the siliceous mineral inhibitor includes at least one of fluorosilicic acid, sodium hexametaphosphate, carboxymethyl cellulose, oxalic acid, water glass, salinized water glass, and sodium fluorosilicate. The hydroxamic acid metal organic complex with high selectivity for niobium minerals and strong capture ability can be used in combination with a suitable siliceous mineral inhibitor to improve the removal efficiency of siliceous minerals.

[0027] As a preferred solution, the foaming agent includes BK205.

[0028] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0029] (1) The present invention makes full use of the collection characteristics of amine collectors for iron minerals, siliceous minerals and niobium minerals, eliminates the early strong magnetic and desiliconization processes, realizes the separation of iron minerals, and solves the technical problem that iron and niobium minerals are difficult to separate in the hydroxamic acid metal ion complex niobium ore collection system.

[0030] (2) The present invention makes full use of the selectivity and capture property of hydroxamic acid metal organic complex collector for siliceous minerals and niobium minerals, realizes the separation of gangue minerals mainly composed of siliceous minerals and niobium minerals, and solves the problem that amine collectors are difficult to separate silicon and niobium minerals.

[0031] (3) In view of the composition characteristics of niobium-containing minerals, the present invention first uses amine collectors to achieve flotation de-ironization and achieve co-enrichment of silicon and niobium, and then uses hydroxamic acid metal ion complex collectors to flotation de-siliconization to enhance the recovery of niobium concentrate. This process replaces the complex strong magnetic separation and desiliconization operations at the front end of the traditional niobium flotation process, eliminates the large amount of niobium loss generated in the multi-stage strong magnetic separation-desiliconization operations, simplifies the niobium ore selection process, and improves the comprehensive recovery rate of niobium ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention provides a flotation process flow chart of niobium-containing minerals. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the following specific embodiments are intended to further illustrate the content of the present invention rather than to limit the protection scope of the claims.

[0034] Example 1

[0035] The niobium-containing phosphorus tailings of a Brazilian concentrator were taken as the research object, and a step-by-step flotation enrichment experiment was carried out. The main components of the phosphorus tailings are magnetite-maghemite, hematite, limonite, ilmenite, quartz, apatite, barite, magnesium serpentine, mica, barium strontium pyrochlore, and columbite. Among them, the iron-containing minerals mainly include magnetite-maghemite, accounting for about 6%, limonite, hematite, and ilmenite accounting for about 35%; the silicon-containing minerals mainly include quartz, mica, etc., accounting for about 41%; the niobium-containing minerals are mainly barium strontium pyrochlore, accounting for about 0.74%; the Nb2O5 content in the tailings is about 0.76%.

[0036] (1) The tailings had a -200 mesh ratio of about 52%, and the tailings were ground in a ball mill for 3 minutes until the -200 mesh ratio reached 86%, and then water was added to adjust the pulp to a pulp mass concentration of 30%;

[0037] (2) Use a weak magnet of 2000 Gs to remove strongly magnetic minerals;

[0038] (3) The product after strong magnetic stripping is subjected to silicon-niobium pre-enrichment flotation: The silicon-niobium pre-enrichment process is as follows: hydrochloric acid is added as a pH adjuster to adjust the pH of the pulp to 4.5, stirring and slurrying for 3 minutes, then 500 g / t of fluorosilicic acid is added as an inhibitor, stirring and slurrying for 3 minutes, and finally 1500 g / t of tallow diamine is added as a collector, slurrying for 3 minutes, and roughing operation is carried out; the rough concentrate is subjected to three concentration operations to gradually lower the pH to 2.5, and inhibitors are added and the dosage is gradually reduced by half; the rough tailings are subjected to one scavenging operation and only the collector is added and the dosage is reduced by half; the silicon-niobium pre-enrichment concentrate has an Nb2O5 grade of 4.39% and a recovery rate of 70.21%, an Fe2O3 grade of 3.2%, and a silicon grade of 35.65%.

[0039] (4) The silicon-niobium pre-enriched concentrate was subjected to silicon-niobium separation flotation: the silicon-niobium separation process was as follows: sodium hydroxide was added as a pH adjuster to adjust the pH of the pulp to 8, the pulp was stirred for 3 minutes, 50 g / t of fluorosilicic acid was added as an inhibitor, the pulp was stirred for 3 minutes, 500 g / t of benzohydroxamic acid-lead metal ion complex collector (the mass ratio of benzohydroxamic acid to lead was 1:1) was added, 10 g / t of BK205 was added as a frother, and roughing operation was carried out; only inhibitors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; only collectors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; on this basis, one roughing, four concentrations and one scavenging were carried out, and finally a niobium concentrate with a Nb2O5 grade of 28.75% and a recovery rate of 50.42% was obtained.

[0040] Example 2

[0041] The same niobium-containing phosphorus tailings from a Brazilian concentrator as in Example 1 were used as the research object, and a step-by-step flotation enrichment experiment was carried out on it.

[0042] (1) The tailings had a -200 mesh ratio of about 52%. The ball mill was used to grind the tailings for 3 minutes until the -200 mesh ratio reached 86%. Water was then added to adjust the pulp to a pulp mass concentration of 30%;

[0043] (2) Use a weak magnet of 2000 Gs to remove strongly magnetic minerals;

[0044] (3) The product after strong magnetic stripping is subjected to silicon-niobium pre-enrichment flotation: The silicon-niobium pre-enrichment process is as follows: hydrochloric acid is added as a pH adjuster to adjust the pH of the pulp to 4.5, stirring and slurrying for 3 minutes, then 600 g / t of fluorosilicic acid is added as an inhibitor, stirring and slurrying for 3 minutes, and finally 1300 g / t of dodecyl acetate amine is added as a collector, slurrying for 3 minutes, and roughing operation is carried out; the rough concentrate is subjected to three concentration operations to gradually lower the pH to 2.5, and inhibitors are added and the dosage is gradually reduced by half; the rough tailings are subjected to one scavenging operation and only the collector is added and the dosage is reduced by half; the Nb2O5 grade of the silicon-niobium pre-enrichment concentrate obtained is 4.05%, the recovery rate is 66.85%, the Fe2O3 grade is 3.6%, and the silicon grade is 37.21%.

[0045] (4) The silicon-niobium pre-enriched concentrate was subjected to silicon-niobium separation flotation: the silicon-niobium separation process was as follows: sodium hydroxide was added as a pH adjuster to adjust the pH of the pulp to 8, the pulp was stirred for 3 minutes, 60 g / t of fluorosilicic acid was added as an inhibitor, the pulp was stirred for 3 minutes, 550 g / t of benzohydroxamic acid-lead metal ion complex collector (the mass ratio of benzohydroxamic acid to lead was 1:1) was added, 12 g / t of BK205 was added as a frother, and roughing operation was carried out; only inhibitors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; only collectors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; on this basis, one roughing, four concentrations and one scavenging were carried out, and finally a niobium concentrate with a Nb2O5 grade of 26.53% and a recovery rate of 47.28% was obtained.

[0046] Example 3

[0047] The same niobium-containing phosphorus tailings from a Brazilian concentrator as in Example 1 were used as the research object, and a step-by-step flotation enrichment experiment was carried out on it.

[0048] (1) The tailings had a -200 mesh ratio of about 52%. The ball mill was used to grind the tailings for 3 minutes until the -200 mesh ratio reached 86%. Water was then added to adjust the pulp to a pulp mass concentration of 30%;

[0049] (2) Use a weak magnet of 2000 Gs to remove strongly magnetic minerals;

[0050] (3) The product after strong magnetic stripping is subjected to silicon-niobium pre-enrichment flotation: The silicon-niobium pre-enrichment process is as follows: hydrochloric acid is added as a pH adjuster to adjust the pH of the pulp to 4.5, stirring and slurrying for 3 minutes, then 550g / t of fluorosilicic acid is added as an inhibitor, stirring and slurrying for 3 minutes, and finally 1400g / t of dodecyl diamine is added as a collector, slurrying for 3 minutes, and roughing operation is carried out; the rough concentrate is subjected to three concentration operations to gradually lower the pH to 2.5, and inhibitors are added and the dosage is gradually reduced by half; the rough tailings are subjected to one scavenging operation and only the collector is added and the dosage is reduced by half; the Nb2O5 grade of the silicon-niobium pre-enrichment concentrate obtained is 4.20%, the recovery rate is 68.92%, the Fe2O3 grade is 3.4%, and the silicon grade is 36.53%.

[0051] (4) The silicon-niobium pre-enriched concentrate was subjected to silicon-niobium separation flotation: the silicon-niobium separation process was as follows: sodium hydroxide was added as a pH adjuster to adjust the pH of the pulp to 8, the pulp was stirred for 3 minutes, 55 g / t of fluorosilicic acid was added as an inhibitor, the pulp was stirred for 3 minutes, 520 g / t of benzohydroxamic acid-lead metal ion complex collector (the mass ratio of benzohydroxamic acid to lead was 1:1) was added, 12 g / t of BK205 was added as a frother, and roughing operation was carried out; only inhibitors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; only collectors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; on this basis, one roughing, four concentrations and one scavenging were carried out, and finally a niobium concentrate with a Nb2O5 grade of 27.86% and a recovery rate of 49.06% was obtained.

[0052] Example 4

[0053] Taking a niobium mine in Australia as the research object, a step-by-step flotation enrichment experiment of niobium-containing minerals was carried out. The main gangue minerals in the niobium mine are quartz, chlorite, magnetite, hematite, etc., and the niobium-containing minerals are mainly niobite, pyrochlore, etc. The ore composition is relatively simple. The Fe2O3 content is about 35%, the SiO2 content is about 55%, and the Nb2O5 content is about 3.60%.

[0054] (1) Grind the raw ore in a ball mill for 4 min until the -200 mesh size reaches 85%, and then add water to adjust the slurry to a slurry mass concentration of 30%;

[0055] (2) Use a weak magnet of 2000 Gs to remove strongly magnetic minerals;

[0056] (3) The product after strong magnetic stripping is subjected to silicon-niobium pre-enrichment flotation: The silicon-niobium pre-enrichment process is as follows: hydrochloric acid is added as a pH adjuster to adjust the pH of the pulp to 4.5, stirring and slurrying for 3 minutes, then 500 g / t of fluorosilicic acid is added as an inhibitor, stirring and slurrying for 3 minutes, and finally 1500 g / t of tallow diamine is added as a collector, slurrying for 3 minutes, and roughing operation is carried out; the rough concentrate is subjected to three concentration operations to gradually lower the pH to 2.5, and inhibitors are added and the dosage is gradually reduced by half; the rough tailings are subjected to one scavenging operation and only collectors are added and the dosage is reduced by half; the silicon-niobium pre-enrichment concentrate has an N2O5 grade of 8.22% and a recovery rate of 76.21%, an Fe2O3 grade of 4.1%, and a silicon grade of 65.65%.

[0057] (4) Silicon-niobium separation flotation was carried out on the silicon-niobium pre-enriched concentrate: the silicon-niobium separation process was as follows: sodium hydroxide was added as a pH adjuster to adjust the pH of the pulp to 8, the pulp was stirred for 3 minutes, 50 g / t of fluorosilicic acid was added as an inhibitor, the pulp was stirred for 3 minutes, 500 g / t of benzohydroxamic acid-lead metal ion complex collector (the mass ratio of benzohydroxamic acid to lead was 1:1) was added, 10 g / t of BK205 was added as a frother, and roughing operation was carried out; only inhibitors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; only collectors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; on this basis, one roughing, four concentrations and one scavenging were carried out, and finally a niobium concentrate with a Nb2O5 grade of 45.75% and a recovery rate of 61.32% was obtained.

[0058] Example 5

[0059] Taking a certain Australian niobium ore which is the same as that in Example 4 as the research object, a step-by-step flotation enrichment experiment of niobium-containing minerals was carried out.

[0060] (1) Grind the raw ore in a ball mill for 4 min until the -200 mesh size reaches 85%, and then add water to adjust the slurry to a slurry mass concentration of 30%;

[0061] (2) Use a weak magnet of 2000 Gs to remove strongly magnetic minerals;

[0062] (3) The product after strong magnetic removal is subjected to silicon niobium pre-enrichment flotation: The silicon niobium pre-enrichment process is to add hydrochloric acid as a pH adjuster to adjust the pH of the pulp to 4.5, stir and mix the pulp for 3 minutes, then add 500g / t of fluorosilicic acid as an inhibitor, stir and mix the pulp for 3 minutes, and considering the difference in properties between dodecyl acetic acid amine and tallow diamine, after preliminary test optimization, add 1300g / t of dodecyl acetic acid amine as a collector, mix the pulp for 3 minutes, and carry out roughing operation; the rough concentrate is subjected to three concentration operations to gradually lower the pH to 2.5, and inhibitors are added and the dosage is gradually reduced by half; the rough tailings are subjected to one scavenging operation to add only collectors and the dosage is reduced by half; the silicon niobium pre-enrichment concentrate has an Nb2O5 grade of 7.56% and a recovery rate of 70.35%, an Fe2O3 grade of 4.5%, and a silicon grade of 68.21%.

[0063] (4) Silicon-niobium separation flotation was carried out on the silicon-niobium pre-enriched concentrate: the silicon-niobium separation process was as follows: sodium hydroxide was added as a pH adjuster to adjust the pH of the pulp to 8, the pulp was stirred for 3 minutes, 50 g / t of fluorosilicic acid was added as an inhibitor, the pulp was stirred for 3 minutes, 550 g / t of benzohydroxamic acid-lead metal ion complex collector (the mass ratio of benzohydroxamic acid to lead was 1:1) was added, and 12 g / t of BK205 was added as a frother to carry out roughing operation; only inhibitors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; only collectors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; on this basis, one roughing, four concentrations and one scavenging were carried out to finally obtain a niobium concentrate with a Nb2O5 grade of 43.35% and a recovery rate of 57.28%.

[0064] Example 6

[0065] Taking a certain Australian niobium ore which is the same as that in Example 4 as the research object, a step-by-step flotation enrichment experiment of niobium-containing minerals was carried out.

[0066] (1) Grind the raw ore in a ball mill for 4 min until the -200 mesh size reaches 85%, and then add water to adjust the slurry to a slurry mass concentration of 30%;

[0067] (2) Use a weak magnet of 2000 Gs to remove strongly magnetic minerals;

[0068] (3) The product after strong magnetic stripping is subjected to silicon-niobium pre-enrichment flotation: The silicon-niobium pre-enrichment process is as follows: hydrochloric acid is added as a pH adjuster to adjust the pH of the pulp to 4.5, stirring and slurrying for 3 minutes, then 500g / t of fluorosilicic acid is added as an inhibitor, stirring and slurrying for 3 minutes, 1400g / t of carbon atom number dodecyl diamine is added as a collector, slurrying for 3 minutes, and roughing operation is carried out; the rough concentrate is subjected to three concentration operations to gradually lower the pH to 2.5, and inhibitors are added and the dosage is gradually reduced by half; the rough tailings are subjected to one scavenging operation and only collectors are added and the dosage is reduced by half; the silicon-niobium pre-enrichment concentrate has an Nb2O5 grade of 7.98% and a recovery rate of 73.66%, an Fe2O3 grade of 4.3%, and a silicon grade of 66.85%.

[0069] (4) Silicon-niobium separation flotation was carried out on the silicon-niobium pre-enriched concentrate: the silicon-niobium separation process was as follows: sodium hydroxide was added as a pH adjuster to adjust the pH of the pulp to 8, the pulp was stirred for 3 minutes, 50 g / t of fluorosilicic acid was added as an inhibitor, the pulp was stirred for 3 minutes, 520 g / t of benzohydroxamic acid-lead metal ion complex collector (the mass ratio of benzohydroxamic acid to lead was 1:1) was added, 12 g / t of BK205 was added as a frother, and roughing operation was carried out; only inhibitors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; only collectors were added in the concentration operation of silicon-niobium separation, and the amount was gradually reduced by half; on this basis, one roughing, four concentrations and one scavenging were carried out, and finally a niobium concentrate with a Nb2O5 grade of 44.68% and a recovery rate of 59.15% was obtained.

Claims

1. A flotation method for niobium-containing minerals, characterized in that: The following steps are involved: 1) crushing, grinding and slurrying the niobium-containing ore to obtain slurry; 2) subjecting the slurry to weak magnetic treatment to remove strongly magnetic minerals to obtain magnetically separated tailings; 3) After adjusting the pH value of the magnetic separation tailings, flotation reagents including iron mineral inhibitors and amine collectors are added to carry out silicon-niobium mixed flotation to obtain a silicon-niobium mixed concentrate; 4) After adjusting the pH value of the silicon-niobium mixed concentrate, flotation reagents including a hydroxamic acid metal organic complex collector and a siliceous mineral inhibitor are added to carry out silicon-niobium separation flotation to obtain a niobium concentrate.

2. A flotation method for niobium-containing minerals according to claim 1, characterized in that: The main minerals of the niobium ore are siliceous minerals, iron minerals and niobium minerals; the siliceous minerals include at least one of quartz, mica, feldspar, kaolin and chlorite; the iron minerals include at least one of magnetite, hematite, titanomagnetite, ilmenite, hematite, limonite, siderite and ankerite; the niobium minerals include at least one of pyrochlore, columbite, calcite and ferrocobalt rutile.

3. A flotation method for niobium-containing minerals according to claim 1, characterized in that: The grinding is performed so that the mass proportion of the -200 mesh particle size reaches more than 80%; The slurry adjustment is to ensure that the slurry mass concentration reaches 30% to 40%; The magnetic field strength used in the weak magnetic treatment is 1000~2000 Gs.

4. A flotation method for niobium-containing minerals according to claim 1, characterized in that: In step 3), the pH is adjusted to 2.5-4.

5. A flotation method for niobium-containing minerals according to any one of claims 1 to 4, characterized in that: The silicon-niobium mixed flotation comprises 1 roughing separation, 1 to 3 cleaning separations and 1 to 2 scavenging separations.

6. A flotation method for niobium-containing minerals according to claim 5, characterized in that: The reagent system for roughing is: 300-800 g / t of iron mineral inhibitor and 1000-2000 g / t of amine collector; The selected reagent system is: only iron mineral inhibitors are used, and the reagent dosage is halved in turn; The reagent system for the sweep is: only amine collectors are used, and the principle of reducing the reagent amount by half is followed.

7. A flotation method for niobium-containing minerals according to claim 6, characterized in that: The amine collector includes at least one of tallow diamine, dodecyl acetic acid amine, and a fatty diamine having 10 to 20 carbon atoms; The iron mineral inhibitor includes at least one of fluorosilicic acid, sodium fluorosilicate, oxalic acid and sodium humate.

8. The flotation method of niobium-containing minerals according to claim 1, characterized in that: In step 4), the pH is adjusted to 6-8.

9. A flotation method for niobium-containing minerals according to claim 1, characterized in that: The silicon-niobium separation flotation comprises 1 roughing selection, 3 to 6 cleaning selections and 1 to 2 scavenging selections.

10. A flotation method for niobium-containing minerals according to claim 1, characterized in that: The reagent system of the roughing selection is: 30-100 g / t of siliceous mineral inhibitor, 300-800 g / t of hydroxamic acid metal organic complex collector; 5-30 g / t of foaming agent; The selected reagent system is: only siliceous mineral inhibitors are used, and the reagent is halved in turn; The reagent system of the scanning selection is: only hydroxamic acid metal organic complex collector is used, and the reagent is reduced by half in sequence; The hydroxamic acid metal organic complex collector is composed of at least one of benzohydroxamic acid, salicylic hydroxamic acid, and an alkyl hydroxamic acid having 5 to 9 carbon atoms and Pb 2+ 、Zn 2+ 、Al 3+ , Cu 2+ , Fe 2+ , Fe 3+ At least one of them is assembled by coordination in a mass ratio of 0.5:1 to 1:3; The siliceous mineral inhibitor includes at least one of fluorosilicic acid, sodium hexametaphosphate, carboxymethyl cellulose, oxalic acid, water glass, salinized water glass, and sodium fluorosilicate; The foaming agent includes BK205.

Images