Step-by-step enrichment flotation method for niobium ore

Abstract

The invention discloses a step-by-step enrichment flotation method for niobium ore, and belongs to the technical field of mineral processing. The method comprises the steps that niobium ore is subjected to crushing, ore grinding and size mixing, then weak magnetic treatment is carried out to remove strong magnetic minerals, after pH adjustment is carried out on magnetic separation tailings, a siliceous mineral inhibitor, a foaming agent and a hydroximic acid metal organic complex collecting agent are added for iron-niobium bulk flotation, and obtained iron-niobium pre-enriched concentrate is subjected to reagent removal treatment; and then an amine collecting agent and an iron mineral inhibitor are adopted for iron-niobium separation flotation, and niobium concentrate is obtained. According to the method, the collecting characteristic advantages of a hydroximic acid metal organic complex collecting agent and an amine collecting agent on siliceous minerals, iron minerals and niobium minerals are combined, efficient separation of silicon, iron and niobium is achieved by conducting flotation desiliconization firstly and then conducting flotation deferrization, the conventional desiliconization and deferrization technological process is simplified, the loss rate of the niobium minerals is reduced, and the yield of the niobium minerals is increased. The resource utilization of the niobium ore is effectively realized.

Description

Technical Field

[0001] The invention relates to a niobium ore beneficiation method, in particular to a step-by-step enrichment and flotation method of niobium ore, belonging to the technical field of ore beneficiation. Background Art

[0002] Niobium is a grayish white metal with extremely high melting and boiling points. Niobium has the characteristics of corrosion resistance, friction resistance, and good ductility. Adding an appropriate amount of niobium to metal materials can significantly improve their ductility, conductivity, and heat resistance. The above characteristics make niobium one of the core materials for high-end advanced technologies such as aerospace, nuclear energy, medical treatment, and superconductivity.

[0003] At present, the main types of niobium deposits developed are those related to granite and those related to alkaline and basic-ultramafic complexes. The main types of gangue minerals in the two types of deposits are siliceous gangue minerals (quartz, mica, chlorite, feldspar, kaolin, etc.) and iron gangue minerals (magnetite, hematite, ilmenite, limonite, etc.). At present, flotation is one of the main methods for industrial recovery of niobium resources. Hydroxamic acid collectors are the main reagents for niobium ore flotation. Hydroxamic acid collectors show excellent capture and selectivity for niobium ore. However, hydroxamic acid collectors are sensitive to iron components. The single use of hydroxamic acid collectors will cause a large amount of uncontrollable iron impurities in the niobium concentrate, affecting the flotation index of the niobium ore. At present, the niobium concentrate is mainly recovered in the form of iron-niobium co-floatation. Chinese patent CN118268138A discloses a method for co-enrichment of iron and niobium resources in rare earth tailings. The method is to flotation desulfurize the rare earth tailings, adjust the pH of the slurry to alkaline, use a metal organic complex (formed by coordination between divalent or higher metal ions and hydroxamic acid organic ligands) as a co-floatation collector for iron and niobium minerals, and use a gangue mineral inhibitor to perform flotation separation to obtain a concentrate that is an iron-niobium mixed concentrate.

[0004] As for the recovery of niobium resources in iron-niobium mixed concentrate, alkali decomposition, acid decomposition and chlorination roasting are currently mainly used. These technologies have certain advantages and disadvantages: alkali decomposition mainly refers to alkali melting decomposition and alkaline hydrothermal decomposition. Alkali melting decomposition is the earliest method used in the hydrometallurgical industry of niobium resources. Its main disadvantages are low niobium yield (<80%), large alkali consumption and complex process. When treating niobium ore with alkaline hydrothermal method, the reaction temperature is much lower than that of alkali melting decomposition, and the alkali consumption is greatly reduced, which is about 1 / 6 of that of alkali melting method. However, the process is operated under pressure and is difficult to operate, which has led to its failure to achieve industrialization. Acid decomposition mainly refers to sulfuric acid low-temperature roasting and hydrofluoric acid decomposition. Sulfuric acid low-temperature roasting has a high metal decomposition rate and can recover most of the valuable metal components in niobium ore, but it can only be used for easily decomposable niobium minerals, with a narrow raw material application range, low product purity, long operation process, and large sulfuric acid consumption in the process. It is rarely used in actual production. The main advantages of the hydrofluoric acid decomposition method are low energy consumption, simple process, and a decomposition rate of 98% to 99% for concentrates with high niobium content. Its main disadvantages are low decomposition rate for low-grade niobium concentrates, large amount of waste slag, large consumption of hydrofluoric acid in the process, and high toxicity and strong corrosiveness of hydrofluoric acid. This method has high requirements on equipment materials, good ventilation and recovery systems, and high production costs. Chlorination roasting is a relatively common and industrially valuable method for extracting niobium. It can be used to process complex niobium concentrates, but the existing technology still has certain defects, such as the poor chlorine supply performance of traditional solid chlorinating agents, resulting in low metal resource recovery rate; the enhanced chlorine supply measures taken are prone to secondary pollution during implementation. Summary of the invention

[0005] In view of the technical difficulties of the long process flow, complex process and high loss rate of niobium ore in the prior art for the recovery of niobium ore, the purpose of the present invention is to provide a step-by-step enrichment and flotation method of niobium ore. The method firstly utilizes the weak capture of gangue minerals mainly composed of siliceous minerals and the strong capture of ferro-niobium minerals by a hydroxamic acid metal organic complex collector to achieve pre-enrichment of ferro-niobium minerals, and then utilizes the weak capture of gangue minerals mainly composed of ferrous minerals and the strong capture of niobium minerals by an amine collector to achieve flotation separation of ferrous minerals and niobium minerals, so as to obtain high-grade niobium minerals. The method fully combines the capture advantages of hydroxamic acid metal organic complex collectors and amine collectors for silicon-containing minerals, iron-containing minerals and niobium-containing minerals, simplifies the separation process of niobium, iron and silicon, reduces the loss of a large amount of niobium, effectively improves the flotation recovery rate of niobium ore, and has the advantages of reducing energy consumption, reducing acid and alkali consumption, saving costs and the like compared with the existing wet and pyrometallurgical processes for realizing niobium-iron separation.

[0006] In order to achieve the above technical purpose, the present invention provides a step-by-step enrichment and flotation method for niobium ore, which comprises the following steps: 1) Crushing, grinding and slurrying the niobium ore to obtain slurry; 2) subjecting the slurry to weak magnetic treatment to remove strongly magnetic minerals to obtain magnetically separated tailings; 3) After the pH value of the magnetic separation tailings is adjusted, a siliceous mineral inhibitor, a frother and a hydroxamic acid metal organic complex collector are added to carry out iron-niobium mixed flotation to obtain an iron-niobium pre-enriched concentrate; 4) removing the drug from the iron-niobium pre-enriched concentrate to obtain an iron-niobium concentrate; 5) The iron-niobium concentrate is subjected to iron-niobium separation and flotation by using an amine collector and an iron mineral inhibitor to obtain a niobium concentrate and iron tailings.

[0007] The step-by-step enrichment flotation method of niobium ore provided by the present invention is mainly for siliceous minerals, ferrous minerals and niobium minerals in niobium ore. 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. When a single hydroxamic acid collector is used, although it shows excellent capture and selectivity for niobium minerals, it is more 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. When a single amine collector is used, although it shows good capture for niobium minerals and the capture capacity of ferrous minerals is not strong, it is more sensitive to ore mud and siliceous minerals, and it is difficult to separate siliceous minerals from niobium minerals. The present invention designs a reasonable niobium ore step-by-step flotation and enrichment flotation method in view of the characteristics of current niobium ores and the defects of amine collectors and hydroxamic acid collectors in the flotation separation process between siliceous minerals, iron minerals and niobium minerals. The method firstly performs weak magnetic separation on niobium minerals to remove strongly magnetic gangue minerals including magnetite, and pre-enriches non-magnetic minerals by preferentially using hydroxamic acid metal organic complex collectors. By utilizing the characteristics of hydroxamic acid metal organic complex collectors that have strong capture properties for niobium minerals and iron minerals but are insensitive to siliceous minerals, siliceous minerals can be preferentially removed, while iron minerals and niobium minerals can be obtained. After pre-enrichment, the niobium-iron mixed concentrate is separated by an amine collector. The amine collector has the characteristics of weak capture of iron minerals and strong capture of niobium minerals to remove iron minerals and achieve further enrichment of niobium ore. In summary, the process of the present invention combines the advantages of the capture characteristics of hydroxamic acid metal organic complex collectors and amine collectors 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.

[0008] 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; 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.

[0009] 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%. Grinding to an appropriate particle size can achieve sufficient monomer dissociation of niobium minerals, which is beneficial to subsequent flotation separation.

[0010] As a preferred solution, the slurry adjustment is to meet the slurry mass concentration of 30% to 40%.

[0011] 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, etc., which have a high proportion and strong magnetism, can be preferably removed, reducing the difficulty of subsequent iron-niobium flotation separation.

[0012] As a preferred solution, the pH is adjusted to 8.5-10. Alkaline compounds such as Na2CO3 and NaOH are used to adjust the pH. The optimal flotation pH range of the hydroxamic acid metal organic complex collector is 8.5-10. Within the preferred pH range, divalent or higher metal ions and their hydroxide complexed metal ions are assembled with hydroxamic acid ligands to form hydroxamic acid metal organic complexes, which not only have colloidal properties, but also have a colloidal structure that carries positive charge, and can be adsorbed on the mineral surface through electrostatic action. The surface potential of the mineral changes from negative to positive, thereby enhancing the adsorption and binding ability of the collector on the mineral surface.

[0013] As a preferred solution, the iron-niobium mixed flotation includes 1 roughing, 1-2 fines and 1-2 scavenging. As a more preferred solution, the reagent system of the roughing is: 300-800 g / t of siliceous mineral inhibitor, 1000-2000 g / t of hydroxamic acid metal organic complex collector, and 20-100 g / t of frother. As a more preferred solution, the reagent system of the roughing is: only siliceous mineral inhibitor is used, and the reagent is halved in turn. As a more preferred solution, the reagent system of the scavenging is: only hydroxamic acid metal organic complex collector is used, and the reagent is halved in turn. Under the preferred flotation conditions, the efficient removal of silicon in niobium minerals can be achieved, and the iron minerals and niobium minerals are efficiently enriched to obtain niobium iron concentrate.

[0014] 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 coordinated and assembled in a mass ratio of 0.5:1 to 1:3. The divalent or higher metal ions are derived from metal salt chemical reagents that are easily soluble in water, such as lead nitrate, lead chloride, aluminum chloride, and copper chloride. The template effect of high-valent metal ions is used to regulate and assemble the hydroxamic acid ligands, and the hydroxamic acid metal organic complexes with deionized hydration layer structure are pre-assembled, which have special crystal chemical properties and surface physicochemical properties, and show better properties in terms of capture ability and selectivity. In particular, high-valent metal ions such as lead ions, zinc ions, aluminum ions, copper ions, and iron ions are assembled with hydroxamic acid ligands to form micelles with specific structures and specific capture abilities, which have high selectivity for niobium minerals and iron minerals, and are beneficial to the co-floatation of iron and niobium. In addition, the capture ability of hydroxamic acid metal organic complexes for minerals is different under different molar ratios of high-valent metal ions to hydroxamic acid ligands. Under the optimal ratio, the capture ability of hydroxamic acid metal organic complexes for niobium-containing minerals and iron minerals is stronger and the selectivity is better.

[0015] As a more preferred solution, the siliceous mineral inhibitor includes at least one of sodium hexametaphosphate, carboxymethyl cellulose, tannin, water glass, salinized water glass, sodium fluorosilicate, fluorosilicic acid, and starch. The hydroxamic acid metal organic complex, which has high selectivity for niobium minerals and iron minerals and strong capture ability, can be used in combination with a suitable siliceous mineral inhibitor to improve the removal efficiency of siliceous minerals.

[0016] As a more preferred solution, the foaming agent includes BK205.

[0017] As a preferred solution, the conditions for the drug removal treatment are: pH is adjusted to 11-12, stirring speed is 1000-3000 r / min, and time is 10-30 min. Under strong alkaline conditions and high-speed stirring conditions, the hydroxamic acid metal organic complex can be removed from the mineral surface, which is beneficial to the subsequent amine collector and iron mineral inhibitor on the surface of niobium minerals and iron minerals. A strong base such as sodium hydroxide is used to adjust the pH.

[0018] As a preferred solution, the iron-niobium separation flotation includes 1 roughing, 3 to 6 cleaning 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 roughing 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 flotation separation of niobium minerals and iron minerals can be achieved.

[0019] 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 effect on niobium minerals, but a weak effect on iron minerals. Under the premise of flotation desiliconization, the use of amine collectors can achieve efficient separation of iron minerals and niobium minerals. A further preferred amine collector is tallow diamine.

[0020] As a preferred solution, the iron mineral inhibitor includes at least one of fluorosilicic acid, sodium fluorosilicate, oxalic acid, sodium humate, dextrin, starch, and carboxymethyl cellulose. The preferred iron mineral inhibitor can selectively act on the ferric ions and ferrous ions on the surface of the iron mineral, thereby achieving hydrophilic modification of the surface, thereby achieving the purpose of inhibiting the flotation of iron minerals.

[0021] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects: (1) The present invention makes full use of the selectivity and capture property of the hydroxamic acid metal organic complex collector for iron minerals and niobium minerals, and uses a siliceous mineral inhibitor in combination to achieve the inhibition of gangue minerals mainly composed of siliceous minerals, thereby achieving efficient desiliconization and eliminating the influence of siliceous minerals on the subsequent flotation separation process of iron minerals and niobium minerals using an amine collector.

[0022] (2) The present invention makes full use of the collection characteristics of amine collectors for niobium minerals, and uses iron mineral inhibitors and a pre-drug removal process in combination to solve the technical problem that it is difficult to further separate iron minerals from niobium minerals in iron-niobium mixed concentrates, thereby achieving effective flotation enrichment of niobium ore.

[0023] (3) The present invention adopts a flotation method to replace the complex desludging and desiliconization operations at the front end of the traditional niobium flotation process, eliminating the large amount of niobium loss generated in the multi-stage grinding-desludging-desiliconization operations, while simplifying the niobium ore selection process and improving the recovery rate of niobium ore.

[0024] (4) The present invention adopts the flotation method to achieve efficient separation of iron and niobium, which greatly reduces the technical problems of high energy consumption, large reagent consumption and high cost in achieving niobium and iron separation by wet or pyrolysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention provides a flow chart of the step-by-step enrichment and flotation process of niobium ore. DETAILED DESCRIPTION

[0026] The following specific examples are intended to further illustrate the present invention, rather than to limit the scope of protection of the claims of the present invention.

[0027] Example 1

[0028] The niobium-containing phosphorus tailings of a Brazilian mine were used as the research object, and a step-by-step flotation enrichment experiment of niobium ore was carried out. The main components of the phosphorus tailings are quartz, magnesium serpentine, mica, magnetite-maghemite, hematite, limonite, ilmenite, pyrochlore, and barium strontium pyrochlore. Among them, the siliceous minerals are mainly quartz, magnesium serpentine, and mica, accounting for about 50%; the iron minerals include magnetite-maghemite, accounting for about 14%, limonite, hematite, and ilmenite, accounting for about 21%; the niobium minerals mainly include pyrochlore and barium strontium pyrochlore, accounting for about 0.58%; the N2O5 content in the niobium-containing phosphorus tailings is about 0.59%.

[0029] (1) The proportion of -200 mesh of niobium-containing phosphate tailings is about 55%. The ball mill is used to grind the ore for 2 minutes until the proportion of -200 mesh of the original ore reaches 80%. Most of the niobium minerals are fully dissociated into monomers. Then water is added to adjust the slurry to a slurry mass concentration of 33%.

[0030] (2) A weak magnet of 2000 Gs is used to remove strongly magnetic minerals to obtain magnetic products and non-magnetic products.

[0031] (3) The non-magnetic products continued to undergo the iron-niobium pre-enrichment experiment: in the iron-niobium pre-enrichment roughing operation, sodium hydroxide was used as the pH adjuster to adjust the pH of the ore pulp to 9.5, 500 g / (t·original ore) of sodium fluorosilicate was used as the inhibitor, 1500 g / (t·original ore) of benzohydroxamic acid-lead metal ion complex collector (the mass ratio of benzohydroxamic acid to lead was 1:1), and 50 g / (t·original ore) of BK205 was used as the frother; in the iron-niobium pre-enrichment and concentration operation, only inhibitors were added and the dosage was halved; in the iron-niobium pre-enrichment and scavenging operation, only collectors and frothers were added and the dosage was halved; on this basis, one roughing, two concentrations and one scavenging were carried out to obtain the iron-niobium pre-enrichment concentrate.

[0032] (4) Drug removal experiment of iron-niobium pre-enriched concentrate: The pH of the iron-niobium pre-enriched concentrate was adjusted to 11.5 using sodium hydroxide as a pH adjuster, and the slurry adjustment speed was set to 2000 r / min and the slurry adjustment time was set to 20 min. A roughing flotation operation of drug removal was carried out to obtain a foam product and an iron-niobium pre-enriched concentrate after drug removal.

[0033] (5) After the removal of the drug, the iron-niobium pre-enrichment concentrate was used for iron-niobium separation: 500 g / (t·original ore) of fluorosilicic acid and 250 g / (t·original ore) of corn dextrin were used as inhibitors, and 1000 g / (t·original ore) of tallow diamine was used as collector for roughing of iron-niobium separation; only inhibitors were added in the fine separation of iron-niobium and the dosage was halved; only collectors were added in the iron-niobium pre-enrichment scavenging operation and the dosage was halved; on this basis, one roughing, four fines and one scavenging were carried out to finally obtain a niobium concentrate with a N2O5 grade of 25.39% and a recovery rate of 53.49%.

[0034] Example 2

[0035] A niobium ore in Australia was used as the research object to conduct a step-by-step flotation enrichment experiment. The main gangue minerals in the niobium ore are quartz, chlorite, magnetite, hematite, and columbite. Quartz accounts for about 60%, and the N2O5 content is about 3.80%.

[0036] (1) The raw ore is crushed and ground to -200 mesh, accounting for 80%, so that most of the niobium minerals are fully dissociated into monomers, and then water is added to adjust the slurry to a slurry mass concentration of 33%.

[0037] (2) A weak magnet of 2000 Gs is used to remove strongly magnetic minerals to obtain magnetic products and non-magnetic products.

[0038] (3) The non-magnetic product continued to undergo the iron-niobium pre-enrichment experiment: in the iron-niobium pre-enrichment roughing operation, sodium hydroxide was used as the pH adjuster to adjust the pH of the ore pulp to 9.5, 200 g / (t·original ore) of fluorosilicic acid was used as the inhibitor, 2000 g / (t·original ore) of benzohydroxamic acid-lead metal ion complex collector (the mass ratio of benzohydroxamic acid to lead was 1:1), and 50 g / (t·original ore) of BK205 was used as the frother; in the iron-niobium pre-enrichment and concentration operation, only inhibitors were added and the dosage was halved; in the iron-niobium pre-enrichment and scavenging operation, only collectors and frothers were added and the dosage was halved; on this basis, one roughing, two concentrations and one scavenging were carried out to obtain the iron-niobium pre-enrichment concentrate; (4) Drug removal experiment of iron-niobium pre-enriched concentrate: The pH of the iron-niobium pre-enriched concentrate was adjusted to 11.5 using sodium hydroxide as a pH adjuster, and the slurry adjustment speed was set to 2000 r / min and the slurry adjustment time was set to 20 min. A roughing flotation operation of drug removal was carried out to obtain a foam product and an iron-niobium pre-enriched concentrate after drug removal.

[0039] (5) After the removal of the drug, the iron-niobium pre-enrichment concentrate was used for iron-niobium separation: 100 g / (t·original ore) of fluorosilicic acid was used as an inhibitor and 1000 g / (t·original ore) of tallow diamine was used as a collector for the roughing operation of iron-niobium separation; in the concentrating operation of iron-niobium separation, only inhibitors were added and the dosage was halved; in the iron-niobium pre-enrichment scavenging operation, only collectors were added and the dosage was halved; on this basis, one roughing operation, three concentrating operations and one scavenging operation were carried out to finally obtain a niobium concentrate with a N2O5 grade of 43.80% and a recovery rate of 67.63%.

[0040] Example 3

[0041] Taking the original ore in Example 1 as the research object, the effects of different amine collectors on the enrichment of niobium ore were compared.

[0042] (1) The proportion of -200 mesh of niobium-containing phosphate tailings is about 55%. The ball mill is used to grind the ore for 2 minutes until the proportion of -200 mesh of the original ore reaches 80%. Most of the niobium minerals are fully dissociated into monomers. Then water is added to adjust the slurry to a slurry mass concentration of 33%.

[0043] (2) A weak magnet of 2000 Gs is used to remove strongly magnetic minerals to obtain magnetic products and non-magnetic products.

[0044] (3) The non-magnetic products continued to undergo the iron-niobium pre-enrichment experiment: in the iron-niobium pre-enrichment roughing operation, sodium hydroxide was used as the pH adjuster to adjust the pH of the ore pulp to 9.5, 500 g / (t·original ore) of sodium fluorosilicate was used as the inhibitor, 1500 g / (t·original ore) of benzohydroxamic acid-lead metal ion complex collector (the mass ratio of benzohydroxamic acid to lead was 1:1), and 50 g / (t·original ore) of BK205 was used as the frother; in the iron-niobium pre-enrichment and concentration operation, only inhibitors were added and the dosage was halved; in the iron-niobium pre-enrichment and scavenging operation, only collectors and frothers were added and the dosage was halved; on this basis, one roughing, two concentrations and one scavenging were carried out to obtain the iron-niobium pre-enrichment concentrate.

[0045] (4) Drug removal experiment of iron-niobium pre-enriched concentrate: The pH of the iron-niobium pre-enriched concentrate was adjusted to 11.5 using sodium hydroxide as a pH adjuster, and the slurry adjustment speed was set to 2000 r / min and the slurry adjustment time was set to 20 min. A roughing flotation operation of drug removal was carried out to obtain a foam product and an iron-niobium pre-enriched concentrate after drug removal.

[0046] (5) A comparative test of amine collector flotation was carried out on the iron-niobium pre-enrichment concentrate after de-doping: 500 g / (t·ore) of fluorosilicic acid and 250 g / (t·ore) of corn dextrin were used as inhibitors, and 1000 g / (t·ore) of tallow diamine, dodecyl acetic acid amine, lauryl diamine, dodecylamine, and dodecyl tertiary amine were used as collectors for roughing operation of iron-niobium separation; only inhibitors were added in the fine operation of iron-niobium separation and the principle of halving the dosage was followed; only collectors were added in the iron-niobium pre-enrichment scavenging operation and the principle of halving the dosage was followed; on this basis, one roughing operation and four fine operations were carried out to finally obtain the final niobium concentrate.

[0047] It can be seen from Table 1 that when tallow diamine is used as a collector for separating niobium and iron in niobium-iron mixed concentrate, its niobium recovery rate and the grade of the obtained niobium concentrate are much higher than those of other amine collectors.

[0048]

Claims

1. A step-by-step enrichment and flotation method for niobium ore, characterized in that: The following steps are involved: 1) Crushing, grinding and slurrying the niobium ore to obtain slurry; 2) subjecting the slurry to weak magnetic treatment to remove strongly magnetic minerals to obtain magnetically separated tailings; 3) After the pH value of the magnetic separation tailings is adjusted, a siliceous mineral inhibitor, a frother and a hydroxamic acid metal organic complex collector are added to carry out iron-niobium mixed flotation to obtain an iron-niobium pre-enriched concentrate; 4) subjecting the iron-niobium pre-enriched concentrate to drug removal to obtain an iron-niobium concentrate; 5) The iron-niobium concentrate is subjected to iron-niobium separation and flotation by using an amine collector and an iron mineral inhibitor to obtain a niobium concentrate and iron tailings.

2. The step-by-step enrichment and flotation method of niobium ore 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. The step-by-step enrichment and flotation method of niobium ore 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. The step-by-step enrichment and flotation method of niobium ore according to claim 1, characterized in that: The pH is adjusted to be between 8.5 and 10.

5. A step-by-step enrichment and flotation method for niobium ore according to any one of claims 1 to 4, characterized in that: Iron-niobium mixed flotation includes 1 roughing separation, 1~2 cleaning separations and 1~2 scavenging separations.

6. The step-by-step enrichment and flotation method of niobium ore according to claim 5, characterized in that: The reagent system of the roughing selection is: 300-800 g / t of siliceous mineral inhibitor, 1000-2000 g / t of hydroxamic acid metal organic complex collector, and 20-100 g / t of foaming agent; The reagent system for rough selection is: only siliceous mineral inhibitors are used, and the reagent is reduced by half in turn; The reagent system for the scanning is: only hydroxamic acid metal organic complex collector is used, and the principle of reducing the reagent by half is followed.

7. The step-by-step enrichment and flotation method of niobium ore according to claim 6, characterized in that: 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 sodium hexametaphosphate, carboxymethyl cellulose, tannin, water glass, salinized water glass, sodium fluorosilicate, fluorosilicic acid, and starch; The foaming agent includes BK205.

8. The step-by-step enrichment and flotation method of niobium ore according to claim 1, characterized in that: The conditions of the drug removal treatment are: pH is adjusted to 11-12, stirring speed is 1000-3000 r / min, and time is 10-30 min.

9. The step-by-step enrichment and flotation method of niobium ore according to claim 1, characterized in that: The iron-niobium separation flotation comprises 1 roughing selection, 3 to 6 cleaning selections and 1 to 2 scavenging selections.

10. The step-by-step enrichment and flotation method of niobium ore according to claim 1, 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 reagent system for rough selection is: only iron mineral inhibitors are used, and the reagent is reduced by half in sequence; The reagent system of the sweep selection is: only amine collectors are used, and the reagents are halved in turn; 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, sodium humate, dextrin, starch, and carboxymethyl cellulose.

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