从钼尾矿中回收云母的选矿方法

Abstract

本发明提供一种从钼尾矿中回收云母的选矿方法，属于选矿技术领域，依次通过磁选、重选、筛分将钼尾矿中的多种有用矿物进行分离，同时对筛分后得到的矿石进行浮选，浮选后得到品位为80‑85％的云母精矿，且云母精矿中锂的含量为0.1‑0.2％；在浮选时，采用碳酸钠和硫化钠作为调整剂，烷基磺酸钠、过氧羟基油酸和聚葡萄糖作为第一浮选剂，氮杂环庚烷‑2‑硫酮、胺类捕收剂和混合烃作为第二浮选剂。本发明采用磁选‑重选‑筛分‑浮选联合工艺，对钼尾矿中多种有价矿石进行回收利用，同时在进行浮选时，由多种类型的浮选剂共同作用，大大提高了云母浮选时的效率，提高了云母的回收率和云母精矿的品位，实现了高回收率和高品位的云母的回收。

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a mineral processing method for recovering mica from molybdenum tailings. Background Technology

[0002] Molybdenum is a transition metal element with high electrical conductivity, high strength, high melting point, and corrosion resistance, making it widely used in alloys, chemicals, and electronics. In recent years, with the rapid development of the national economy, the demand for molybdenum has gradually increased, and the mining and processing volume of molybdenum ore in my country has also increased rapidly. However, due to the low molybdenum grade of molybdenum ore, more than 95% of the mined molybdenum ore is discharged as tailings during the extraction process using flotation technology. If these molybdenum tailings are piled up as solid waste, it not only occupies a large amount of land resources and increases the cost of tailings dam construction and maintenance, but also causes water and soil pollution and poses safety hazards to the surrounding residential environment. Therefore, promoting the recycling and utilization of molybdenum tailings has received considerable attention.

[0003] Most molybdenum mines in my country are complex polymetallic minerals or associated minerals with intricate compositions. During mining, other metals besides molybdenum are typically not purified or recovered and are instead stored as gangue minerals in tailings ponds. If appropriate production processes are used to reuse molybdenum tailings, valuable minerals can be effectively recovered, the safety hazards caused by large-scale tailings accumulation can be mitigated, and the secondary resource utilization of molybdenum tailings can be achieved.

[0004] The main minerals in Jindi Mining's molybdenum tailings are mica, quartz, and feldspar, along with iron-bearing minerals such as pyrite, pyrite, and magnetite, and some chlorite. According to the process mineralogical report of the molybdenum tailings, the mica in Jindi Mining's molybdenum tailings contains approximately 0.01% lithium, with a lithium distribution rate of 99.06%. However, conventionally recyclable molybdenum tailings typically contain 0.1-0.2% lithium, while tailings with a lithium content less than 0.1% are treated as waste, resulting in resource waste. With the rapid development of new energy vehicles in China, the domestic market demand for lithium resources has exploded. In response, Jindi Mining has enriched and recovered the mica in its molybdenum tailings, then extracted the lithium using hydrometallurgical methods or roasting, recovering previously unusable lithium resources and improving production efficiency.

[0005] In existing technologies, common methods for recovering and enriching mica from molybdenum tailings include flotation, magnetic separation, heavy media separation, and combined beneficiation. Flotation is the primary separation method for mica recovery and enrichment; however, due to the complex composition and numerous harmful impurities in molybdenum tailings, flotation often consumes large amounts of flotation reagents. Furthermore, the collecting performance and selectivity of the flotation reagents cannot be well balanced, resulting in low mica recovery rates and resource waste. Heavy media separation and magnetic separation are both physical separation processes; although simple, they yield mica concentrates of lower grades. Conventional combined mineral processing methods employ magnetic flotation, gravity flotation, or a combination of gravity and magnetic flotation. Before mineral processing, the molybdenum tailings need to be ground. Other valuable minerals in the molybdenum tailings, such as quartz, feldspar, iron-bearing minerals, and chlorite, are not recycled but are instead discharged and piled up as secondary tailings, resulting in a waste of resources. Furthermore, during flotation, mica may contain fine mud that was not cleaned up during the magnetic flotation and gravity flotation processes, which increases the difficulty of flotation. Summary of the Invention

[0006] This invention provides a mineral processing method for recovering mica from molybdenum tailings, which solves the problems of difficulty in recovering low-lithium molybdenum tailings, high consumption of flotation reagents, inability to balance the collection performance and selectivity of flotation reagents, and low mica recovery rate and mica concentrate grade in the current process of recovering mica from molybdenum tailings. At the same time, it also solves the problems in conventional combined mineral processing methods where other useful resources in molybdenum tailings are not recovered and utilized, and the flotation difficulty caused by fine mud entrained in mica during flotation.

[0007] This invention can be achieved through the following technical solutions:

[0008] A mineral processing method for recovering mica from molybdenum tailings includes the following steps:

[0009] S1: Molybdenum tailings are separated into magnetic and non-magnetic materials by magnetic separation under a magnetic field strength of 0.8-1.4T.

[0010] S2: The magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 15-20 mm to remove iron ores and obtain light mineral 1; the non-magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 25-30 mm to remove quartz and feldspar and obtain light mineral 2.

[0011] S3: Combine the light mineral 1 and light mineral 2 obtained in S2, and then sieve them to remove the fine mud.

[0012] S4: Add modifier, first flotation agent and second flotation agent to the mica rough obtained after screening in S3 for flotation to finally obtain mica concentrate;

[0013] The modifier is a mixture of sodium carbonate and sodium sulfide; the first flotation agent is a mixture of sodium alkyl sulfonate, peroxyhydroxyoleic acid and polydextrose; the second flotation agent is a mixture of aziridine-2-thionone, amine collector and mixed hydrocarbons, wherein the mixed hydrocarbons are a mixture of hydrocarbons with 10-15 carbon atoms.

[0014] Optionally, the specific steps of flotation in S4 are as follows:

[0015] (1) Roughing: First, add a modifier to adjust the pH of the mica rough to 8-10, then add 100-250 g / t of the first flotation agent and 100-200 g / t of the second flotation agent. After stirring for 2-4 minutes, add the remaining second flotation agent in stages to obtain the roughing concentrate and roughing tailings. The total amount of the second flotation agent added is 250-500 g / t.

[0016] The specific conditions for segmented dosing are: the interval is 2-4 minutes, the amount added each time is 30-60 g / t, and the number of additions is 5 times.

[0017] (2) Fine treatment I: Add 100-130g / t of the first flotation agent to the roughing concentrate for fine treatment to obtain fine concentrate and fine tailings 1;

[0018] (3) Scavenging: The rough tailings and the clean tailings 1 are combined into flotation fines and returned to step (1) for roughing;

[0019] (4) Refinement II: Add 50-70g / t of the first flotation agent to the refined concentrate for secondary refinement to obtain mica concentrate and refined tailings 2. The refined tailings 2 are returned to step (2) for further refinement.

[0020] Optionally, the mass ratio of sodium carbonate to sodium sulfide in the modifier is (3-4):1.

[0021] Optionally, the mass ratio of sodium alkyl sulfonate, peroxyhydroxy oleic acid and polydextrose in the first flotation agent is 1:(1.5-2):(1.5-2).

[0022] Optionally, the mass ratio of aziridine-2-thionone, amine collector and mixed hydrocarbons in the second flotation agent is (0.2-0.3):(2-3):1.

[0023] Optionally, the amine collectors include dodecylamine, hexadecylamine, and octadecylamine, with a mass ratio of dodecylamine:hexadecylamine:octadecylamine = 1:(1-1.5):(3-4).

[0024] Optionally, the mixed hydrocarbon is a mixture of saturated hydrocarbons and aromatic hydrocarbons with 10-15 carbon atoms, wherein the mass ratio of saturated hydrocarbons to aromatic hydrocarbons is (7-8):1.

[0025] Optionally, the sieve used in S3 has a mesh size of 325, and the sieve is sieved 5-10 times.

[0026] Optionally, the number of magnetic separation stages in S1 is 1-3 stages, and the equipment used for magnetic separation is either a flat ring high gradient magnetic separator or a vertical ring high gradient magnetic separator.

[0027] Optionally, the mica concentrate contains 80-85% mica and 0.1-0.2% lithium.

[0028] The mineral processing method for recovering mica from molybdenum tailings provided by this invention achieves high recovery rate and high grade mica while separating and recovering other valuable minerals (such as chlorite, iron-bearing minerals, quartz, and feldspar) in the molybdenum tailings through a combined mineral processing method of magnetic separation, gravity separation, screening, and flotation. Screening removes fine mud from the mica, which has the beneficial effect of reducing the difficulty of subsequent flotation.

[0029] This invention employs sodium carbonate and sodium sulfide as modifiers. While adjusting the slurry to alkalinity, a sulfide film forms on the mineral surface. Under alkaline conditions, this sulfide film enhances the adsorption of amine collectors, thereby improving the selectivity of the second flotation agent for mica. Sodium alkyl sulfonate, peroxyhydroxyoleic acid, and polydextrose, as the first flotation agent, adsorb onto the calcite surface to form a hydrophilic film, increasing the hydration of the calcite mineral surface and weakening the adsorption activity of the second flotation agent on calcite, further increasing the selectivity of the second flotation agent for mica. Azacycloheptan-2-thione, amine collectors, and mixed hydrocarbons are used as the second flotation agent. The thiocarbonyl S atom of azacycloheptan-2-thione is the chemical reaction center of the azacycloheptan-2-thione collector, which can form bonds with various metal ions. Simultaneously, azacycloheptan-2-thione has a conjugated structure, exhibiting characteristics of a planar collector, which can improve the stability of the mineral-metal interface-collector complex and enhance the hydrophobic separation and enrichment of mineral particles. The mixed hydrocarbons can increase the hydrophobicity of the mineral surface, thereby improving the working effect of the amine collector. During the flotation process, the modifier, the first flotation agent, and the second flotation agent work synergistically to improve the collecting performance and selectivity of the flotation agents, thereby increasing the flotation efficiency and yield. This, in turn, increases the yield and grade of the mica concentrate obtained from flotation, while also reducing the consumption of flotation agents and lowering production costs.

[0030] Through the synergistic effect of various technical means provided by this invention, the goal of enriching and recovering lepidolite with a higher lithium content from molybdenum tailings with a lithium content of less than 0.1% is achieved, thereby improving the utilization rate of mineral resources. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic flowchart of a mineral processing method for recovering mica from molybdenum tailings according to an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of the present invention.

[0034] like Figure 1 As shown, a mineral processing method for recovering mica from molybdenum tailings includes the following steps:

[0035] S1: Molybdenum tailings are separated into magnetic and non-magnetic materials by magnetic separation under a magnetic field strength of 0.8-1.4T.

[0036] Preferably, the number of magnetic separation stages in S1 is 1-3 stages, and the equipment used for magnetic separation is one of a flat ring high gradient magnetic separator or a vertical ring high gradient magnetic separator.

[0037] First, the molybdenum tailings undergo magnetic separation. A high magnetic field strength of 0.8-1.4T is used to ensure thorough separation of magnetic and non-magnetic components. The magnetic components consist of pyrite, magnetite, pyrite, mica, and some chlorite inclusions. The non-magnetic components consist of feldspar, quartz, mica, and some chlorite inclusions. Magnetic separation primarily separates the iron-bearing minerals from the quartz and feldspar in the molybdenum tailings for subsequent recovery.

[0038] S2: The magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 15-20 mm to remove iron ores and obtain light mineral 1; the non-magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 25-30 mm to remove quartz and feldspar and obtain light mineral 2.

[0039] Magnetic materials are subjected to shaking table gravity separation to separate mica from iron-containing minerals. Since the density of mica is 2.7-3.5 g / cm³... 3The density of iron ore ranges from 4.8 to 5.2 g / cm³. 3 The density difference between iron ore and mica is significant, therefore, a stroke of 15-20 mm is sufficient for thorough separation during gravity separation. Quartz and feldspar have densities between 2.5-2.7 g / cm³. 3 Since the density difference between quartz and mica is relatively small, a stroke of 25-30mm is sufficient to completely separate quartz and feldspar from mica. The separated iron-bearing ore can be further purified to extract the iron, while the quartz and feldspar can be recycled as building materials.

[0040] S3: Combine the light minerals 1 and 2 obtained in S2, and then sieve them to remove the fine mud.

[0041] After gravity separation of magnetic and non-magnetic materials, the remaining light minerals 1 and 2 are mainly composed of mica, with some chlorite as well. If the chlorite adhering to the mica is not screened and flotation is performed directly, the efficiency and effectiveness of flotation will be reduced, resulting in a lower grade of the mica concentrate. Therefore, the mica must be screened before flotation. During screening, the chlorite will pass through the screen, while the mica will remain on the screen, thus achieving the separation of mica and chlorite.

[0042] S4: Add modifier, first flotation agent and second flotation agent to the mica rough obtained after screening in S3 for flotation, and finally obtain mica concentrate.

[0043] After magnetic separation, gravity separation and screening, the main product obtained is crude mica, i.e., mica crude ore. Therefore, flotation is carried out on the mica crude ore to obtain high-grade mica concentrate. The grade of the mica concentrate after flotation can reach 80-85%.

[0044] Furthermore, the modifier is a mixture of sodium carbonate and sodium sulfide; the first flotation agent is a mixture of sodium alkyl sulfonate, peroxyhydroxy oleic acid and polydextrose; the second flotation agent is a mixture of aziridine-2-thionone, amine collector and mixed hydrocarbons, wherein the mixed hydrocarbons are a mixture of hydrocarbons with 10-15 carbon atoms.

[0045] Single-component modifiers and flotation agents are often affected by the working environment, such as pH and temperature, during flotation, which reduces flotation efficiency and leads to a decrease in the grade of mica concentrate. To avoid this, multi-component mixtures should be used when selecting modifiers and flotation agents to improve the selectivity and flotation efficiency, thereby obtaining high-grade mica concentrate.

[0046] Optionally, the mass ratio of sodium carbonate to sodium sulfide in the modifier is (3-4):1.

[0047] Sodium carbonate and sodium sulfide are used as modifiers. While adjusting the pulp to alkalinity, a sulfide film is formed on the mineral surface. Under alkaline conditions, the sulfide film enhances the adsorption of amine collectors, thereby improving the selectivity of the flotation agent for mica.

[0048] Optionally, the mass ratio of sodium alkyl sulfonate, peroxyhydroxy oleic acid and polydextrose in the first flotation agent is 1:(1.5-2):(1.5-2).

[0049] Sodium alkyl sulfonate, peroxyhydroxy oleic acid, and polydextrose, as the first flotation agent, can be adsorbed on the surface of calcite to form a hydrophilic film, which improves the hydration of the calcite mineral surface and weakens the adsorption activity of the collector on calcite, thereby further increasing the selectivity of the flotation agent for lepidolite.

[0050] Optionally, the mass ratio of aziridine-2-thionone, amine collector and mixed hydrocarbons in the second flotation agent is (0.2-0.3):(2-3):1.

[0051] Azaheptan-2-thione, amine collectors, and mixed hydrocarbons are used as secondary flotation agents. The thiocarbonyl S atom of azaheptan-2-thione is the chemical reaction center of azaheptan-2-thione collectors, which can form bonds with various metal ions. At the same time, azaheptan-2-thione has a conjugated structure, which has the characteristics of a planar collector, and can improve the stability of the mineral-metal interface-collector complex, and enhance the hydrophobic separation and enrichment of mineral particles. Mixed hydrocarbons can enhance the hydrophobic surface, thereby improving the working effect of amine collectors.

[0052] Optionally, the amine collectors include dodecylamine, hexadecylamine, and octadecylamine, with a mass ratio of dodecylamine:hexadecylamine:octadecylamine = 1:(1-1.5):(3-4).

[0053] Amine collectors have a good collecting effect on lepidolite, especially when used in combination with other collectors, they can effectively improve the Li2O content in mica.

[0054] Optionally, the mixed hydrocarbon is a mixture of saturated hydrocarbons and aromatic hydrocarbons with 10-15 carbon atoms, wherein the mass ratio of saturated hydrocarbons to aromatic hydrocarbons is (7-8):1.

[0055] The foam stability of mixed hydrocarbons is high and they are not easy to break, which can ensure the stability of flotation and improve the beneficiation efficiency. The types and proportions of saturated hydrocarbons and aromatic hydrocarbons in the mixed hydrocarbons can be arbitrarily selected, and their flotation effects are not significantly different.

[0056] Optionally, the sieve used in S3 has a mesh size of 325, and the sieve is sieved 5-10 times.

[0057] Mica is in the form of flakes with a relatively large diameter, while chlorite particles are smaller. Chlorite and mica can be separated using a 325-mesh sieve.

[0058] Optionally, the specific steps of flotation in S4 are as follows:

[0059] (1) Roughing: First, add a modifier to adjust the pH of the mica rough to 8-10, then add 100-250 g / t of the first flotation agent and 100-200 g / t of the second flotation agent. After stirring for 2-4 minutes, add the remaining second flotation agent in stages to obtain the roughing concentrate and roughing tailings. The total amount of the second flotation agent added is 250-500 g / t.

[0060] The specific conditions for segmented dosing are: the interval is 2-4 minutes, the amount added each time is 30-60 g / t, and the number of additions is 5 times.

[0061] (2) Fine treatment I: Add 100-130g / t of the first flotation agent to the roughing concentrate for fine treatment to obtain fine concentrate and fine tailings 1;

[0062] (3) Scavenging: The rough tailings and the clean tailings 1 are combined into flotation fines and returned to step (1) for roughing;

[0063] (4) Refinement II: Add 50-70g / t of the first flotation agent to the refined concentrate for secondary refinement to obtain mica concentrate and refined tailings 2. The refined tailings 2 are returned to step (2) for further refinement.

[0064] The flotation process employs a "roughing, cleaning, and scavenging" method. During roughing, a conditioning agent is added to adjust the pH of the mica rough to 8-10, allowing flotation to proceed in an alkaline environment. This avoids corrosion of the equipment caused by acidic pulp, while the alkaline environment also improves the flotation efficiency of the flotation agent. When adding the second flotation agent, a staged addition method is adopted instead of adding the full amount at once: 50-60% of the total amount of the second flotation agent is added first, with the remaining 40-50% added in batches. This staged addition method improves the quality of the roughing concentrate. After roughing, cleaning processes I and II further enhance the grade of the mica concentrate. Scavenging recovers mica from the roughing tailings and cleaning tailings I to increase the mica recovery rate.

[0065] Optionally, the mica concentrate contains 80-85% mica and 0.1-0.2% lithium.

[0066] The present invention will be further described in detail below with reference to specific embodiments.

[0067] Example 1

[0068] A mineral processing method for recovering mica from molybdenum tailings includes the following steps:

[0069] S1: Molybdenum tailings are subjected to magnetic separation under a magnetic field strength of 0.8T, with one magnetic separation stage, to separate the molybdenum tailings into magnetic and non-magnetic materials;

[0070] S2: The magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 15 mm to remove iron ores and obtain light mineral 1; the non-magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 25 mm to remove quartz and feldspar and obtain light mineral 2.

[0071] S3: Combine the light minerals 1 and 2 obtained in S2, and then screen them 5 times using a 325-mesh sieve to remove the fine mud.

[0072] The composition results of the mica crude obtained by sieving are shown in Table 1:

[0073] Table 1

[0074] name Lithium mica calcite content(%) 19.31 80.69

[0075] S4: The mica rough ore after screening in S3 is subjected to flotation. During flotation, the modifier is a mixture of sodium carbonate and sodium sulfide in a mass ratio of 3:1; the first flotation agent is a mixture of sodium dodecyl sulfonate, sodium peroxyoleate, and polydextrose in a mass ratio of 1:1.5:1.5; the second flotation agent is a mixture of aziridine-2-thione, amine collectors, and mixed hydrocarbons in a mass ratio of 0.2:2:1, wherein the mass ratio of dodecylamine:hexadecylamine:octadecylamine in the amine collector is 1:1:3, and the mass ratio of saturated hydrocarbons to aromatics in the mixed hydrocarbons is 7:1. The specific steps of the flotation are as follows:

[0076] (1) Roughing: Add a modifier to adjust the pH of the mica crude to 8, then add 150 g / t of the first flotation agent and 100 g / t of the second flotation agent. Stir for 2 min, then continue to add 30 g / t of the second flotation agent in multiple stages, repeating the addition 5 times with a time interval of 2 min between each addition, to obtain the roughing concentrate and roughing tailings; the total amount of the second flotation agent added is 250 g / t.

[0077] (2) Fine treatment I: Add 100g / t of the first flotation agent to the roughing concentrate for fine treatment to obtain fine concentrate and fine tailings 1;

[0078] (3) Scavenging: The rough tailings and the clean tailings 1 are combined into flotation fines and returned to step (1) for roughing;

[0079] (4) Refinement II: Add 50g / t of the first flotation agent to the refined concentrate for secondary refinement to obtain mica concentrate and refined tailings 2. The refined tailings 2 are returned to step (2) for further refinement.

[0080] The final composition of the mica concentrate obtained from flotation is shown in Table 2:

[0081] Table 2

[0082] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 95.23％ 80.41％ 0.11％

[0083] Example 2

[0084] A mineral processing method for recovering mica from molybdenum tailings includes the following steps:

[0085] S1: Molybdenum tailings are subjected to magnetic separation under a magnetic field strength of 1.4T, with 3 magnetic separation stages, to separate the molybdenum tailings into magnetic and non-magnetic materials;

[0086] S2: The magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 20 mm to remove iron ores and obtain light mineral 1; the non-magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 30 mm to remove quartz and feldspar and obtain light mineral 2.

[0087] S3: Combine the light minerals 1 and 2 obtained in S2, and then screen them 10 times using a 325-mesh sieve to remove the fine mud.

[0088] The composition results of the mica crude obtained by sieving are shown in Table 3:

[0089] Table 3

[0090] name Lithium mica calcite content(%) 22.09 77.91

[0091] S4: The mica rough ore after screening in S3 is subjected to flotation. During flotation, the modifier is a mixture of sodium carbonate and sodium sulfide in a mass ratio of 4:1; the first flotation agent is a mixture of sodium dodecyl sulfonate, sodium peroxyoleate, and polydextrose in a mass ratio of 1:2:2; the second flotation agent is a mixture of aziridine-2-thione, amine collectors, and mixed hydrocarbons in a mass ratio of 0.3:3:1, wherein the mass ratio of dodecylamine:hexadecylamine:octadecylamine in the amine collector is 1:1.5:4, and the mass ratio of saturated hydrocarbons to aromatics in the mixed hydrocarbons is 8:1. The specific steps of the flotation are as follows:

[0092] (1) Roughing: Add a modifier to adjust the pH of the mica crude to 10, then add 250 g / t of the first flotation agent and 200 g / t of the second flotation agent. Stir for 4 min, then continue to add 60 g / t of the second flotation agent in multiple stages, repeating the addition 5 times with an interval of 4 min between each addition, to obtain the roughing concentrate and roughing tailings; the total amount of the second flotation agent added is 500 g / t.

[0093] (2) Fine treatment I: Add 130g / t of the first flotation agent to the roughing concentrate for fine treatment to obtain fine concentrate and fine tailings 1;

[0094] (3) Scavenging: The rough tailings and the clean tailings 1 are combined into flotation fines and returned to step (1) for roughing;

[0095] (4) Refinement II: Add 60g / t of the first flotation agent to the refined concentrate for secondary refinement to obtain mica concentrate and refined tailings 2. The refined tailings 2 are returned to step (2) for further refinement.

[0096] The final composition of the mica concentrate obtained from flotation is shown in Table 4:

[0097] Table 4

[0098] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 97.75％ 84.22％ 0.19％

[0099] Example 3

[0100] A mineral processing method for recovering mica from molybdenum tailings includes the following steps:

[0101] S1: Molybdenum tailings are subjected to magnetic separation under a magnetic field strength of 1.1T, with two magnetic separation stages, to separate the molybdenum tailings into magnetic and non-magnetic materials;

[0102] S2: The magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 17 mm to remove iron ores and obtain light mineral 1; the non-magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 27 mm to remove quartz and feldspar and obtain light mineral 2.

[0103] S3: Combine the light minerals 1 and 2 obtained in S2, and then sieve them 7 times using a 325-mesh sieve to remove the fine mud.

[0104] The composition results of the mica crude obtained by sieving are shown in Table 5:

[0105] Table 5

[0106] name Lithium mica calcite content(%) 19.62 80.38

[0107] S4: The mica rough ore after screening in S3 is subjected to flotation. During flotation, the modifier is a mixture of sodium carbonate and sodium sulfide in a mass ratio of 3.5:1; the first flotation agent is a mixture of sodium dodecyl sulfonate, sodium peroxyoleate, and polydextrose in a mass ratio of 1:1.7:1.7; the second flotation agent is a mixture of aziridine-2-thione, amine collectors, and mixed hydrocarbons in a mass ratio of 0.2:2.5:1, wherein the mass ratio of dodecylamine:hexadecylamine:octadecylamine in the amine collector is 1:1:3.5, and the mass ratio of saturated hydrocarbons to aromatics in the mixed hydrocarbons is 7.5:1. The specific steps of the flotation are as follows:

[0108] (1) Roughing: Add a modifier to adjust the pH of the mica crude to 9, then add 200 g / t of the first flotation agent and 150 g / t of the second flotation agent. Stir for 3 min, then continue to add 45 g / t of the second flotation agent in multiple stages, repeating the addition 5 times with a time interval of 3 min between each addition, to obtain the roughing concentrate and roughing tailings; the total amount of the second flotation agent added is 375 g / t.

[0109] (2) Fine treatment I: Add 115g / t of the first flotation agent to the roughing concentrate for fine treatment to obtain fine concentrate and fine tailings 1;

[0110] (3) Scavenging: The rough tailings and the clean tailings 1 are combined into flotation fines and returned to step (1) for roughing;

[0111] (4) Refinement II: Add 60g / t of the first flotation agent to the refined concentrate for secondary refinement to obtain mica concentrate and refined tailings 2. The refined tailings 2 are returned to step (2) for further refinement.

[0112] The final composition of the mica concentrate obtained from flotation is shown in Table 6:

[0113] Table 6

[0114] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 96.31％ 82.06％ 0.16％

[0115] Example 4

[0116] A mineral processing method for recovering mica from molybdenum tailings includes the following steps:

[0117] S1: Molybdenum tailings are subjected to magnetic separation under a magnetic field strength of 0.8T, with 3 magnetic separation stages, to separate the molybdenum tailings into magnetic and non-magnetic materials;

[0118] S2: The magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 20 mm to remove iron ores and obtain light mineral 1; the non-magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 25 mm to remove quartz and feldspar and obtain light mineral 2.

[0119] S3: Combine the light minerals 1 and 2 obtained in S2, and then sieve them 9 times using a 325-mesh sieve to remove the fine mud.

[0120] The composition results of the mica crude obtained by sieving are shown in Table 7:

[0121] Table 7

[0122] name Lithium mica calcite content(%) 20.16 79.84

[0123] S4: The mica rough ore after screening in S3 is subjected to flotation. During flotation, the modifier is a mixture of sodium carbonate and sodium sulfide in a mass ratio of 3:1; the first flotation agent is a mixture of sodium dodecyl sulfonate, sodium peroxyoleate, and polydextrose in a mass ratio of 1:1.5:2; the second flotation agent is a mixture of aziridine-2-thione, amine collectors, and mixed hydrocarbons in a mass ratio of 0.3:2:1. The amine collectors contain dodecylamine:hexadecylamine:octadecylamine in a mass ratio of 1:1.5:3, and the mixed hydrocarbons contain saturated hydrocarbons and aromatic hydrocarbons in a mass ratio of 7:1. The specific steps of the flotation are as follows:

[0124] (1) Roughing: Add a modifier to adjust the pH of the mica crude to 9, then add 150 g / t of the first flotation agent and 100 g / t of the second flotation agent. Stir for 2 min, then continue to add 30 g / t of the second flotation agent in multiple stages, repeating the addition 5 times with a time interval of 2 min between each addition, to obtain the roughing concentrate and roughing tailings; the total amount of the second flotation agent added is 250 g / t.

[0125] (2) Fine treatment I: Add 130g / t of the first flotation agent to the roughing concentrate for fine treatment to obtain fine concentrate and fine tailings 1;

[0126] (3) Scavenging: The rough tailings and the clean tailings 1 are combined into flotation fines and returned to step (1) for roughing;

[0127] (4) Refinement II: Add 70g / t of the first flotation agent to the refined concentrate for secondary refinement to obtain mica concentrate and refined tailings 2. The refined tailings 2 are returned to step (2) for further refinement.

[0128] The final composition of the mica concentrate obtained from flotation is shown in Table 8:

[0129] Table 8

[0130] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 97.92％ 82.06％ 0.17％

[0131] Example 5

[0132] A mineral processing method for recovering mica from molybdenum tailings includes the following steps:

[0133] S1: Molybdenum tailings are subjected to magnetic separation under a magnetic field strength of 0.9T, with two magnetic separation stages, to separate the molybdenum tailings into magnetic and non-magnetic materials;

[0134] S2: The magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 15 mm to remove iron ores and obtain light mineral 1; the non-magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 30 mm to remove quartz and feldspar and obtain light mineral 2.

[0135] S3: Combine the light minerals 1 and 2 obtained in S2, and then screen them 10 times using a 325-mesh sieve to remove the fine mud.

[0136] The composition results of the mica crude obtained by sieving are shown in Table 9:

[0137] Table 9

[0138] name Lithium mica calcite content(%) 21.03 78.97

[0139] S4: The mica rough ore after screening in S3 is subjected to flotation. During flotation, the modifier is a mixture of sodium carbonate and sodium sulfide in a mass ratio of 3:1; the first flotation agent is a mixture of sodium dodecyl sulfonate, sodium peroxyoleate, and polydextrose in a mass ratio of 1:2:1.5; the second flotation agent is a mixture of aziridine-2-thione, amine collectors, and mixed hydrocarbons in a mass ratio of 0.3:2.5:1, wherein the mass ratio of dodecylamine:hexadecylamine:octadecylamine in the amine collector is 1:1:3, and the mass ratio of saturated hydrocarbons to aromatics in the mixed hydrocarbons is 7.5:1. The specific steps of the flotation are as follows:

[0140] (1) Roughing: Add a modifier to adjust the pH of the mica crude to 8, then add 150 g / t of the first flotation agent and 200 g / t of the second flotation agent. Stir for 2 min, then continue to add 30 g / t of the second flotation agent in multiple stages, repeating the addition 5 times with a time interval of 2 min between each addition, to obtain the roughing concentrate and roughing tailings; the total amount of the second flotation agent added is 350 g / t.

[0141] (2) Fine treatment I: Add 100g / t of the first flotation agent to the roughing concentrate for fine treatment to obtain fine concentrate and fine tailings 1;

[0142] (3) Scavenging: The rough tailings and the clean tailings 1 are combined into flotation fines and returned to step (1) for roughing;

[0143] (4) Refinement II: Add 70g / t of the first flotation agent to the refined concentrate for secondary refinement to obtain mica concentrate and refined tailings 2. The refined tailings 2 are returned to step (2) for further refinement.

[0144] The final composition of the mica concentrate obtained from flotation is shown in Table 10:

[0145] Table 10

[0146] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 97.22％ 83.85％ 0.16％

[0147] Comparative Example 1

[0148] The only difference between Comparative Example 1 and Example 1 is that the S3 screening process was omitted, and the light minerals 1 and 2 after reselection were combined and then directly subjected to flotation. The other steps and operating conditions were the same as in Example 1.

[0149] The composition of the mixed mineral of light mineral 1 and light mineral 2 obtained by gravity separation is shown in Table 11:

[0150] Table 11

[0151] name Lithium mica calcite chlorite numerical values 16.51％ 64.47％ 19.02％

[0152] The composition of the final mica concentrate obtained from flotation is shown in Table 12:

[0153] Table 12

[0154] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 85.31％ 75.01％ 0.05％

[0155] Comparative Example 2

[0156] The only difference between Comparative Example 2 and Example 1 is that the order of S1 magnetic separation and S2 re-separation is reversed, that is, re-separation is performed first, followed by magnetic separation.

[0157] The composition of the sieved mica crude is shown in Table 13:

[0158] Table 13

[0159] name Lithium mica calcite chlorite numerical values 9.13％ 75.54％ 15.33％

[0160] The final composition of the mica concentrate obtained from flotation is shown in Table 14:

[0161] Table 14

[0162] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 86.12％ 76.53％ 0.09％

[0163] Comparative Example 3

[0164] The only difference between Comparative Example 3 and Example 2 is that only sodium carbonate was used as the modifier in the flotation process, while the other methods and conditions were the same as in Example 1.

[0165] The final composition of the mica concentrate obtained from flotation is shown in Table 15:

[0166] Table 15

[0167] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 90.01％ 80.75％ 0.14％

[0168] Comparative Example 4

[0169] The only difference between Comparative Example 4 and Example 3 is that the first flotation agent used in the flotation process is a mixture of sodium dodecyl sulfonate and sodium peroxyoleate in a ratio of 1:1, while the other methods and conditions are the same as in Example 1.

[0170] The final composition of the mica concentrate obtained from flotation is shown in Table 16:

[0171] Table 16

[0172] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 91.05％ 80.53％ 0.12％

[0173] Comparative Example 5

[0174] The only difference between Comparative Example 5 and Example 4 is that the second flotation agent used in the flotation process is a mixture of amine collector and kerosene in a ratio of 1:1. The other methods and conditions are the same as in Example 1.

[0175] The final composition of the mica concentrate obtained from flotation is shown in Table 17:

[0176] Table 17

[0177] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade <!-- 10 -->]]> numerical values 91.32％ 79.02％ 0.13％

[0178] Comparative Example 6

[0179] The only difference between Comparative Example 6 and Example 5 is that the second flotation agent in the flotation process is added all at once, while the other methods and conditions are the same as in Example 1.

[0180] The final composition of the mica concentrate obtained from flotation is shown in Table 18:

[0181] Table 18

[0182] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 93.12％ 80.31％ 0.12％

[0183] Comparative Example 7

[0184] The only difference between Comparative Example 7 and Example 2 is that: only sodium carbonate was used as the modifier in the flotation process; the first flotation agent was a mixture of sodium dodecyl sulfonate and sodium peroxyoleate in a ratio of 1:1; and the second flotation agent was a mixture of amine collector and kerosene in a ratio of 1:1. Other methods and conditions were the same as in Example 2.

[0185] The final composition of the mica concentrate obtained from flotation is shown in Table 19:

[0186] Table 19

[0187] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 75.30％ 75.76％ 0.06％

[0188] Comparative Example 8

[0189] Comparative Example 8 is based on Comparative Example 7, but the amount of the first flotation agent and the second flotation agent is increased by three times, while other methods and conditions are the same as in Example 2.

[0190] The final composition of the mica concentrate obtained from flotation is shown in Table 20:

[0191] Table 20

[0192] name Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> numerical values 86.31％ 79.62％ 0.11％

[0193] The molybdenum tailings used in Examples 1-5 and Comparative Examples 1-8 above were all tailings obtained from the molybdenum flotation of Jindi Mining, and their composition is shown in Table 21:

[0194] Table 21

[0195] name Pyrite magnetite Pyrite chlorite mica quartz Feldspar numerical values 10-20％ 15-20％ 10-25％ 10-20％ 5-10％ 10-15％ 15-30％

[0196] The results of Examples 1-5 and Comparative Examples 1-8 are summarized in Table 22:

[0197] Table 22

[0198] name Lithium mica calcite chlorite Lithium mica yield Lithium mica grade <![CDATA[Li2O grade]]> Example 1 19.31％ 80.69％ 0 95.23％ 80.41％ 0.11％ Example 2 22.09％ 77.91％ 0 97.75％ 84.22％ 0.19％ Example 3 19.62％ 80.38％ 0 96.31％ 82.06％ 0.16％ Example 4 20.16％ 79.84％ 0 97.92％ 82.06％ 0.17％ Example 5 21.03％ 78.97％ 0 97.22％ 83.85％ 0.16％ Comparative Example 1 16.51％ 64.47％ 19.02％ 85.31％ 75.01％ 0.05％ Comparative Example 2 9.13％ 75.54％ 15.33％ 86.12％ 76.53％ 0.09％ Comparative Example 3 22.09％ 77.91％ 0 90.01％ 80.75％ 0.14％ Comparative Example 4 19.62％ 80.38％ 0 91.05％ 80.53％ 0.12％ Comparative Example 5 20.16％ 79.84％ 0 91.32％ 79.02％ 0.13％ Comparative Example 6 21.03％ 78.97％ 0 93.12％ 80.31％ 0.12％ Comparative Example 7 22.09％ 77.91％ 0 75.30％ 75.76％ 0.06％ Comparative Example 8 22.09％ 77.91％ 0 86.31％ 79.62％ 0.11％

[0199] As can be seen from Example 1 and Comparative Example 1, screening and desliming before flotation can filter out the chlorite mixed in with mica, thus avoiding the influence of chlorite on the flotation reagents during flotation, and effectively improving the yield of lepidolite and the grade of Li2O in lepidolite.

[0200] As can be seen from Example 1 and Comparative Example 2, the magnetic separation-gravity separation-screening-flotation process is more effective in recovering mica than the gravity separation-magnetic separation-screening-flotation process. The main reason is that the primary purpose of magnetic separation is to separate iron-containing minerals from non-iron-containing minerals. After magnetic separation, mica exists in both magnetic and non-magnetic materials. Gravity separation with different strokes can then separate the mica from the magnetic and non-magnetic materials, resulting in better separation. However, if gravity separation is performed first and then magnetic separation, the gravity separation will focus on separating iron-containing ore, and quartz and feldspar will be mixed in with the mica obtained from gravity separation. During magnetic separation, mica will be carried away in the non-magnetic materials and separated, resulting in a decrease in mica yield. Furthermore, during the subsequent flotation separation, some quartz and feldspar will be mixed in with the mica, leading to a decrease in mica grade.

[0201] As can be seen from Example 2 and Comparative Example 3, when a modifier is added, the effect of the mixture of sodium carbonate and sodium sulfide is better than that of using sodium carbonate alone as a modifier. Sodium sulfide has a synergistic effect on the collector, and the lepidolite grade and Li2O grade are both good.

[0202] As can be seen from Example 3 and Comparative Example 4, when using the first flotation agent, the mixed formulation of sodium dodecyl sulfonate, sodium peroxyoleate and polydextrose is more effective than the first flotation agent without polydextrose.

[0203] As can be seen from Example 4 and Comparative Example 5, when using the second flotation agent, the flotation effect of the mixture of azircycloheptane-2-thionone, amine collector and mixed hydrocarbon is better than that of the second flotation agent mixed with amine collector and kerosene.

[0204] As can be seen from Example 5 and Comparative Example 6, when adding the second flotation agent, the effect of adding the second flotation agent in stages is better than the effect of adding it all at once.

[0205] As can be seen from Example 2 and Comparative Example 7, the synergistic effect of adding sodium sulfide to the modifier, polydextrose to the first flotation agent, and azircycloheptane-2-thione to the second flotation agent is better than the effect of adding only one or two of them.

[0206] As can be seen from Examples 2, 7, and 8, in the absence of sodium sulfide, polydextrose, and azircycloheptan-2-thione in the flotation agent, the amount of flotation agent required to achieve good flotation results is much higher than that with the addition of the aforementioned three substances, and the flotation results are also worse than those with the addition of these substances.

[0207] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A mineral processing method for recovering mica from molybdenum tailings, characterized in that, Includes the following steps: S1: Molybdenum tailings are separated into magnetic and non-magnetic materials by magnetic separation under a magnetic field strength of 0.8-1.4T. S2: The magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 15-20 mm to remove iron ores and obtain light mineral 1; the non-magnetic material obtained in S1 is subjected to shaking table gravity separation with a stroke of 25-30 mm to remove quartz and feldspar and obtain light mineral 2. S3: Combine the light mineral 1 and light mineral 2 obtained in S2, and then sieve them to remove the fine mud. S4: Add modifier, first flotation agent and second flotation agent to the mica rough obtained after screening in S3 for flotation to finally obtain mica concentrate; The modifier is a mixture of sodium carbonate and sodium sulfide; the first flotation agent is a mixture of sodium alkyl sulfonate, peroxyhydroxy oleic acid and polydextrose; the second flotation agent is a mixture of azircycloheptane-2-thionone, amine collector and mixed hydrocarbons, wherein the mixed hydrocarbons are a mixture of hydrocarbons with 10-15 carbon atoms.

2. The beneficiation method for recovering mica from molybdenum tailings according to claim 1, characterized in that, The specific steps of flotation in S4 are as follows: (1) Roughing: First, add a modifier to adjust the pH of the mica rough to 8-10, then add 100-250 g / t of the first flotation agent and 100-200 g / t of the second flotation agent. After stirring for 2-4 minutes, add the remaining second flotation agent in stages to obtain roughing concentrate and roughing tailings. The total amount of the second flotation agent added is 250-500 g / t. The specific conditions for the segmented dosing are as follows: the interval is 2-4 minutes, the amount added each time is 30-60 g / t, and the number of additions is 5 times. (2) Fine treatment I: Add 100-130g / t of the first flotation agent to the roughing concentrate for fine treatment to obtain fine concentrate and fine tailings 1; (3) Scavenging: The rough tailings and the clean tailings 1 are combined into flotation fines and returned to step (1) for roughing; (4) Refinement II: Add 50-70g / t of the first flotation agent to the refined concentrate for secondary refinement to obtain mica concentrate and refined tailings 2. The refined tailings 2 are returned to step (2) for further refinement.

3. The beneficiation method for recovering mica from molybdenum tailings according to claim 1, characterized in that, The mass ratio of sodium carbonate to sodium sulfide in the modifier is (3-4):

1.

4. The beneficiation method for recovering mica from molybdenum tailings according to claim 1, characterized in that, The mass ratio of sodium alkyl sulfonate, peroxyhydroxy oleic acid and polydextrose in the first flotation agent is 1:(1.5-2):(1.5-2).

5. The beneficiation method for recovering mica from molybdenum tailings according to claim 1, characterized in that, The mass ratio of aziridine-2-thionone, amine collector and mixed hydrocarbon in the second flotation agent is (0.2-0.3):(2-3):

1.

6. The beneficiation method for recovering mica from molybdenum tailings according to claim 1, characterized in that, The amine collectors include dodecylamine, hexadecylamine, and octadecylamine, with a mass ratio of dodecylamine:hexadecylamine:octadecylamine = 1:(1-1.5):(3-4).

7. The beneficiation method for recovering mica from molybdenum tailings according to claim 1, characterized in that, The mixed hydrocarbon is a mixture of saturated hydrocarbons and aromatic hydrocarbons with 10-15 carbon atoms, wherein the mass ratio of saturated hydrocarbons to aromatic hydrocarbons is (7-8):

1.

8. The beneficiation method for recovering mica from molybdenum tailings according to claim 1, characterized in that, The sieve used in S3 has a mesh size of 325, and the sieve is sieved 5-10 times.

9. The beneficiation method for recovering mica from molybdenum tailings according to claim 1, characterized in that, The number of magnetic separation stages in S1 is 1-3 stages, and the equipment used for magnetic separation is either a flat ring high gradient magnetic separator or a vertical ring high gradient magnetic separator.

10. The mineral processing method for recovering mica from molybdenum tailings according to any one of claims 1-9, characterized in that, The mica concentrate contains 80-85% mica and 0.1-0.2% lithium.

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