A pyrite mineral-type combined inhibitor and its application, and a mineral processing method

Abstract

This invention provides a pyrite mineral-type combined inhibitor and its application, as well as a mineral processing method. The active components of the pyrite mineral-type combined inhibitor include nano-sized serpentine and EDTA, with a mass ratio of (0.5~1):(0.1~1.5). The nano-sized serpentine has a particle size of 500nm~1000nm. The EDTA is prepared as an aqueous solution with a mass concentration of 1.0%~5.0%. The mass ratio of nano-sized serpentine to the EDTA aqueous solution is (0.5~1):(10~30). The mineral processing method obtains molybdenum concentrate through mixed flotation-pre-cleaning-roughing-separation roughing-separation cleaning-separation cleaning to separation cleaning. During the operation, other gangue minerals are first suppressed with water glass to reduce the gangue content. Then, the pyrite mineral-type inhibitor is added during the separation roughing and separation cleaning operations to further achieve molybdenum-sulfur separation. The pyrite mineral-type combined inhibitor used in this invention has low dosage, high selectivity, is environmentally friendly, readily available, and easy to process. It has high adaptability to different types of molybdenum-sulfur ores and has great application prospects.

Description

Technical Field

[0001] This invention belongs to the field of mineral flotation, specifically relating to a pyrite mineral-type combination inhibitor and its application, as well as a mineral processing method. Background Art

[0002] Molybdenum is an important strategic metal resource in my country. Due to its unique atomic structure, molybdenum metal has good high-temperature resistance, and its addition to steel can effectively improve the strength of steel. Therefore, it is widely used in aerospace, military, and automobile manufacturing. Molybdenum is also used in battery materials and conductor materials due to its good electrical and thermal conductivity, wear resistance, and corrosion resistance. my country is the world's largest producer of molybdenum, but it still faces the problem of significant depletion of its molybdenum resources. Molybdenite is the main mineral form in which molybdenum is found in nature, while pyrite is a common semi-biological mineral in sulfide ores. Because pyrite has a certain degree of natural floatability, it is often mixed in with molybdenum concentrate, causing a decrease in the grade of the molybdenum concentrate and making it difficult to meet national standards. At the same time, the doping of pyrite will worsen the subsequent molybdenum smelting process, causing environmental pollution and deteriorating product purity. Since pyrite is often closely associated with molybdenite, and the two have fine particle sizes, the beneficiation of high-sulfur molybdenum ores suffers from incomplete pyrite removal, substandard molybdenum grade, and reduced recovery rate.

[0003] In conventional processes, various inorganic depressants are used to suppress pyrite. These inorganic depressants include sulfites, cyanides, lime, sodium hypochlorite, and sodium sulfide. However, these inorganic depressants also have certain drawbacks. For example, lime adds OH- ions to the slurry, making the pyrite surface hydrophilic. However, the use of lime can also lead to sticky foam and scaling in pipes and equipment. Furthermore, these inorganic depressants have problems such as high dosage requirements, high toxicity, significant environmental hazards, limited adaptability, and difficulties in wastewater treatment.

[0004] In addition, many organic inhibitors are used to inhibit pyrite, such as lactic acid, sodium humate, xanthan gum, and galactose. Chinese patent application CN114471958A discloses a combined inhibitor for separating pyrite from complex molybdenite. This combined inhibitor includes polyaspartic acid, calcium hypochlorite, and sodium humate, which can achieve efficient separation of molybdenite and pyrite. However, these inhibitors have a narrow pH range, are mostly difficult to dissolve in slurry, and have poor selectivity, inhibiting molybdenite while inhibiting pyrite. Furthermore, the inhibition effect is not ideal at low dosages.

[0005] Chinese invention patent CN107824341B discloses a method for improving the beneficiation index of refractory copper sulfide ore. The copper sulfide ore includes gangue such as quartz, pyrite, and pyrrhotite. By adjusting the pH of the slurry to 5-7, fine-grained serpentine minerals are added and stirred to adjust the slurry. This allows the hydrophilic fine-grained serpentine to be adsorbed onto the surface of the gangue minerals, inhibiting the floating of the gangue minerals. Then, calcium lignin sulfonate inhibitor, butyl xanthate collector, and No. 2 frother are added for flotation, achieving the separation of copper sulfide minerals from gangue minerals such as quartz and pyrrhotite. This patent uses fine-grained serpentine to adsorb and aggregate pyrite, increasing its hydrophilicity and inhibiting its flotation. However, serpentine is also a gangue mineral that is difficult to suppress in the flotation of sulfide ores. Even though its natural floatability is poor, it will still float during the flotation process due to factors such as "heterogeneous aggregation", mechanical entrainment by foam water, and changes in mineral phase, which will worsen the flotation environment. Moreover, the amount of serpentine added in this patent is 1000-8000g / t, which is a large amount. If some of the serpentine floats, it will affect the mineral recovery rate and reduce the concentrate grade.

[0006] Therefore, finding an efficient and economical reagent for separating molybdenite and pyrite is of great significance for improving the comprehensive utilization rate of molybdenum resources. Summary of the Invention

[0007] To address the problems of high toxicity of inorganic inhibitors and poor selectivity and large dosage of organic inhibitors in current pyrite inhibitors, this invention aims to provide a mineral-based combined inhibitor for pyrite, its application, and a beneficiation method. Its active ingredients include nano-sized serpentine (Mg,Fe)3Si2O5(OH)4 and ethylenediaminetetraacetic acid (EDTA). This combined inhibitor is used to efficiently and selectively inhibit pyrite, achieving flotation separation of molybdenum concentrate and pyrite. It requires a small dosage and is environmentally friendly.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A pyrite mineral-type composite inhibitor, the active components of which include nano-sized serpentine and EDTA in a mass ratio of (0.5-1):(0.1-1.5); the nano-sized serpentine has a particle size of 500 nm to 1000 nm; the EDTA is prepared as an aqueous solution with a mass concentration of 1.0% to 5.0%; the mass ratio of the nano-sized serpentine to the aqueous EDTA solution is (0.5-1):(10-30).

[0010] In preparing the above-mentioned pyrite mineral-type composite inhibitor, serpentine is first ground to 500nm-1000nm, and EDTA is added in an aqueous solution with a mass concentration of 1.0%-5.0%. The nano-sized serpentine and the EDTA aqueous solution are mixed at a mass ratio of (0.5-1):(10-30). Serpentine is a layered silicate mineral mainly containing magnesium, which is often replaced by iron. Serpentine itself has a strong hydrophilic ability and often forms a fine gangue coating on the surface of other minerals. This invention grinds serpentine to the nanoscale, which firstly improves its dispersion ability in the slurry, reduces the amount needed as an inhibitor, and secondly, enhances the hydrophilicity of the nano-sized serpentine surface. Ethylenediaminetetraacetic acid (EDTA) is an organic compound with a strong ability to chelate metal ions, mainly Fe. 2+ Mg 2+ Strong chelation occurs between metal ions. The pyrite mineral-type combined inhibitor comprises nano-sized serpentine and EDTA, effectively inhibiting pyrite in the slurry with high selectivity. Its inhibition mechanism involves dispersing nano-sized serpentine in the slurry through stirring; serpentine, through electrostatic adsorption, coats the active sites on the pyrite surface, enhancing the hydrophilicity of the pyrite surface while hindering the action of collectors and frothers. Furthermore, serpentine acts as a bridge, and the addition of EDTA effectively allows Fe2+ ions to pass through the serpentine surface. 2+ Mg 2+ The active sites undergo metal chelation with serpentine. Due to the strong hydrophilicity of the four carboxylic acid structures of EDTA, it can further promote the hydrophilicity of the pyrite surface. However, the surface of molybdenite exhibits an almost saturated layered structure with few surface active sites and extremely high natural hydrophobicity. Serpentine is unlikely to form a cap on the surface of molybdenite, and EDTA is also difficult to bind to molybdenite through its active sites. Therefore, the pyrite mineral-type composite inhibitor has almost no effect on molybdenite, but can selectively inhibit pyrite, achieving a highly efficient separation of molybdenum and sulfur.

[0011] Furthermore, the particle size of the nano-sized serpentine is 700nm to 900nm; the mass concentration of the EDTA aqueous solution is 1.5% to 3.0%; and the mass ratio of the nano-sized serpentine to the EDTA aqueous solution is (0.5 to 1):(15 to 25).

[0012] Preferably, the nano-sized serpentine has a particle size of 800 nm.

[0013] Preferably, the mass concentration of the EDTA aqueous solution is 2.0%.

[0014] Preferably, the mass ratio of the nano-sized serpentine to the EDTA aqueous solution is 0.5:20.

[0015] Furthermore, the main component of the nano-sized serpentine is (Mg,Fe)3Si2O5(OH)4, with a purity of 90% to 95%.

[0016] The present invention also provides the application of the above-mentioned pyrite mineral-type composite inhibitor in the beneficiation of high-sulfur molybdenum ore.

[0017] Based on the same inventive concept, the present invention also provides a method for beneficiation of high-sulfur molybdenum ore using the above-mentioned pyrite mineral-type composite inhibitor, comprising the following steps:

[0018] (1) Grinding: Grind the raw ore to obtain slurry I with a fineness of -74μm accounting for 60% to 70%;

[0019] (2) Water glass, collector I and frother are added to the slurry I, and mixed flotation, pre-cleaning and one to three roughing are carried out in sequence to obtain molybdenum-sulfur mixed concentrate and roughing tailings; wherein, the middlings from the pre-cleaning and roughing are returned to the previous stage of operation in sequence;

[0020] (3) The molybdenum-sulfur mixed concentrate is regrinded to obtain slurry II with a fineness of -38μm accounting for 85% to 95%;

[0021] (4) Add the pyrite mineral type combination inhibitor, collector II and frother to the slurry II, and perform separation roughing, one to two separation cleaning and one to two separation scavenging in sequence to obtain molybdenum concentrate and molybdenum-sulfur separation tailings; wherein, the middlings from separation cleaning and separation scavenging are returned to the previous operation in sequence.

[0022] Furthermore, in step (1), the molybdenum grade of the raw ore is 0.1% to 0.3%, and wet ball milling is used for grinding.

[0023] Further, in step (2), the dosage of reagents added relative to the raw ore in the mixed flotation is 1000-2000 g / t of water glass, 50-200 g / t of collector I, and 10-30 g / t of pine oil. Each is stirred for 2-3 minutes and floated for 4-6 minutes to obtain a molybdenum-sulfur mixed flotation concentrate and a molybdenum-sulfur mixed flotation underflow. The molybdenum-sulfur mixed flotation concentrate is then pre-selected. The dosage of reagents added relative to the raw ore in the pre-selection is 500-1000 g / t of water glass, 10-50 g / t of collector I, and 10-20 g / t of pine oil. Each is stirred for 2-3 minutes and floated for 3-4 minutes to obtain a molybdenum-sulfur mixed concentrate. The molybdenum-sulfur mixed flotation concentrate is then pre-selected. The bottom stream is subjected to one to three roughing operations: the first roughing operation involves adding 800-1500 g / t of water glass, 50-150 g / t of collector I, and 10-20 g / t of pine oil relative to the raw ore, stirring for 2-3 minutes and then flotating for 2-4 minutes; the second roughing operation involves adding 20-80 g / t of collector I and 5-15 g / t of pine oil relative to the raw ore, stirring for 2-3 minutes and then flotating for 1-3 minutes; the third roughing operation involves adding 10-50 g / t of collector I and 5-10 g / t of pine oil relative to the raw ore, stirring for 2-3 minutes and then flotating for 1-3 minutes, to obtain the roughing tailings.

[0024] Furthermore, in step (3), the regrinding is performed using a wet ball mill.

[0025] Further, in step (4), the relative dosage of reagents added to the roughing process relative to the raw ore is 10-80 g / t of pyrite mineral-type combination inhibitor, 10-40 g / t of collector II, and 10-30 g / t of pine oil. After adding the pyrite mineral-type combination inhibitor and collector II, the mixture is stirred for 2-3 minutes. After adding the pine oil, the mixture is stirred for 1-3 minutes and then floated for 3-4 minutes to obtain the molybdenum-sulfur separation roughing froth and the molybdenum-sulfur separation roughing underflow. The molybdenum-sulfur separation roughing froth is then subjected to one to two separation and refining operations: the relative dosage of reagents added to the raw ore for the first separation and refining operation is 10-20 g / t of pyrite mineral-type combination inhibitor, stirred for 1-3 minutes, and then floated for 3 minutes. ~4min; the secondary separation and beneficiation operation involves adding 5-10g / t of pyrite mineral-type combined inhibitor relative to the raw ore, stirring for 1-3min, and flotation for 1-2min to obtain molybdenum concentrate; the bottom stream of the molybdenum-sulfur separation roughing process is subjected to one to two separation and scavenging operations: the primary separation and scavenging operation involves adding 10-20g / t of collector II and 10-20g / t of pine oil relative to the raw ore; the secondary separation and scavenging operation involves adding 5-10g / t of collector II and 5-15g / t of pine oil relative to the raw ore; after adding collector II, stirring for 2-3min, and after adding pine oil, stirring for 1-3min, and flotation for 1-2min to obtain molybdenum-sulfur separation tailings.

[0026] Furthermore, the collector I is an ethyl thiocyanate or xanthate collector; the foaming agent is pine oil or MIBC; and the collector II is kerosene or diesel oil.

[0027] In one embodiment of the present invention, the collector I is ethyl thiocyanate; the foaming agent is pine oil; and the collector II is kerosene. Ethiocyanate, which has a strong collecting ability, is used for mixed collection of pyrite and molybdenite. However, kerosene has a stronger collecting ability for molybdenite than pyrite. Therefore, kerosene is used to specifically collect molybdenite in step (4).

[0028] The active components of the pyrite mineral-type combined inhibitor provided by this invention include nano-sized serpentine and EDTA. Nano-sized serpentine, due to its small particle size and strong dispersibility, can selectively cap pyrite at low dosages, enhancing the hydrophilicity of the pyrite surface. Meanwhile, EDTA has strong Fe chelation properties. 2+ Mg 2+ The ability of nano-sized serpentine to bridge and further promote the hydrophilicity of pyrite surface, while molybdenite, due to the stability of its surface charge, is unaffected by nano-sized serpentine and EDTA, thus achieving effective separation of molybdenum concentrate and pyrite. The beneficiation method provided by this invention first uses mixed flotation to mix molybdenite and pyrite, then further improves the purity of the molybdenum-sulfur mixed concentrate through a pre-cleaning operation. During this operation, water glass is used to suppress other gangue minerals and reduce gangue content. The resulting molybdenum-sulfur mixed concentrate is then regrinded to promote complete liberation of molybdenite and pyrite. The pyrite mineral-type inhibitor is added during the roughing and cleaning operations to further achieve molybdenum-sulfur separation.

[0029] The beneficial effects of this invention are as follows:

[0030] 1. Compared with traditional inorganic pyrite inhibitors, the pyrite mineral-based combined inhibitor used in this invention has the advantages of being non-toxic, harmless, environmentally friendly and easily degradable, and is a green inhibitor.

[0031] 2. Compared with existing organic pyrite inhibitors, the pyrite mineral-type combined inhibitor used in this invention has a stronger inhibitory effect and requires less dosage, resulting in high economic efficiency. Compared with existing inhibitors such as xanthan gum, lactic acid, and galactose, it has a more efficient selectivity and hardly interacts with molybdenite.

[0032] 3. The pyrite mineral-type combined inhibitor used in this invention has one of its active components, serpentine, which is easy to obtain, brittle, and easy to grind. It can be ground to the nanoscale using a ball mill. The other active component, EDTA, is also a highly efficient water treatment agent that can prevent secondary pollution of water bodies.

[0033] 4. The pyrite mineral-type combined inhibitor used in this invention has high adaptability to beneficiation of different types of high-sulfur molybdenum ores, and the resulting molybdenum concentrate grade and molybdenum concentrate recovery rate are good, which has great industrial application prospects.

[0034] Instruction manual illustrations

[0035] Figure 1 This is a schematic diagram of the process flow of one embodiment of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0037] Example 1

[0038] Sample No. 1 from a high-sulfur molybdenum mine in Inner Mongolia contains 0.12% molybdenum, 8.26% sulfur, 0.012% copper, 0.01% lead, 60.02% SiO2, and 15.02% Al2O3. Molybdenum is the main recoverable metal resource, with 97% existing in the form of molybdenite. It contains a small amount of molybdenum oxide. The copper and lead are of low grade and have no recovery value. The sulfur content is high, mainly in the form of pyrite, except for a small amount of sulfur contained in molybdenite. Therefore, this ore is a typical high-sulfur molybdenum ore, and also contains some gangue minerals such as feldspar and quartz.

[0039] Mineral processing tests were conducted using the pyrite mineral-type composite inhibitor and its application provided by this invention. The mineral processing flow and reagent system are as follows: Figure 1 As shown.

[0040] Preparation of pyrite mineral-type composite inhibitor: Serpentine with a purity of 90% to 95% was ground to 800 nm, and EDTA was added to water to prepare an EDTA aqueous solution with a mass concentration of 2.0%; the nano-sized serpentine and the EDTA aqueous solution were mixed at a mass ratio of 0.5:20 to obtain the pyrite mineral-type composite inhibitor, which was stored for later use.

[0041] The mineral processing technology adopts a closed-circuit test throughout the entire process: after mixed roughing, pre-cleaning, and three roughing and scavenging processes, a molybdenum-sulfur mixed concentrate is obtained. The molybdenum-sulfur mixed concentrate is then subjected to separation roughing, two separation cleaning processes, and two separation scavenging processes, specifically including the following steps:

[0042] (1) The raw ore was ground by wet ball milling to obtain slurry I with a fineness of -74μm accounting for about 65%.

[0043] (2) Molybdenum-sulfur mixed flotation: Add 1500g / t of water glass, 100g / t of ethyl nitrogen, and 20g / t of pine oil (2# oil) to slurry I, stir each for 2min, and float for 6min to obtain molybdenum-sulfur mixed flotation concentrate and molybdenum-sulfur mixed flotation underflow.

[0044] (3) Pre-selection operation: Add 500g / t of water glass, 20g / t of ethyl nitrogen and 20g / t of pine oil to the molybdenum-sulfur mixed flotation concentrate, stir each for 2min, float for 4min, and return the middlings of the pre-selection operation to the previous operation; to obtain the molybdenum-sulfur mixed concentrate.

[0045] (4) Rough scavenging operation: The molybdenum-sulfur mixed flotation underflow is subjected to three rough scavenging operations. In the first scavenging operation, 1000 g / t of water glass, 60 g / t of ethyl thiocyanate, and 20 g / t of pine oil are added, and each is stirred for 2 min and floated for 4 min. In the second scavenging operation, 40 g / t of ethyl thiocyanate and 10 g / t of pine oil are added, and each is stirred for 2 min and floated for 3 min. In the third scavenging operation, 20 g / t of ethyl thiocyanate and 5 g / t of pine oil are added, and each is stirred for 2 min and floated for 3 min. The ore from the rough scavenging is returned to the previous operation in sequence to obtain the rough tailings.

[0046] (5) The molybdenum-sulfur pre-concentrate was regrinded using a wet ball mill to ensure that 90% of the pulp II had a fineness of -38μm. Molybdenum-sulfur separation roughing was performed on pulp II by adding 50g / t of pyrite mineral-type combination inhibitor, 20g / t of kerosene, and 20g / t of pine oil. Each was stirred for 2 minutes and then floated for 3 minutes to obtain molybdenum-sulfur separation roughing froth and molybdenum-sulfur separation roughing underflow.

[0047] (6) Molybdenum-sulfur separation and beneficiation operation: The roughing froth of molybdenum-sulfur separation is subjected to a second separation and beneficiation operation. In the first separation and beneficiation operation, 10 g / t of pyrite mineral type combination inhibitor is added, stirred for 2 min, and floated for 3 min. In the second separation and beneficiation operation, 5 g / t of pyrite mineral type combination inhibitor is added, stirred for 2 min, and floated for 2 min. The middlings from the separation and beneficiation operation are returned to the previous operation in sequence to obtain molybdenum concentrate.

[0048] (7) Molybdenum-sulfur separation scavenging operation: The underflow of the roughing separation of molybdenum-sulfur is subjected to a second separation scavenging operation. In the first separation scavenging operation, 10g / t of kerosene and 10g / t of pine oil are added, and each is stirred for 2min and floated for 2min. In the second separation scavenging operation, 5g / t of kerosene and 5g / t of pine oil are added, and each is stirred for 2min and floated for 2min. The ore from the separation scavenging is returned to the previous operation in sequence; the molybdenum-sulfur separation tailings are obtained.

[0049] The results of the mineral processing test are shown in Table 1, 1-1#.

[0050] Comparative Example 1

[0051] The mineral processing flow of Example 1 is repeated, except that in the molybdenum-sulfur separation roughing and cleaning operations, the pyrite mineral-type composite inhibitor is replaced with the existing pyrite organic inhibitor galactose, wherein:

[0052] Molybdenum-sulfur separation roughing operation: galactose 50 g / t; molybdenum-sulfur separation cleaning operation: primary separation and cleaning: galactose 10 g / t; secondary separation and cleaning: galactose 5 g / t. The results of the mineral processing test are shown in Table 1, section 2-1#.

[0053] Comparative Example 2

[0054] The mineral processing flow of Example 1 is repeated, except that in the molybdenum-sulfur separation roughing and cleaning operations, the pyrite mineral-type composite inhibitor is replaced with the existing pyrite organic inhibitor sodium humate, wherein:

[0055] Molybdenum-sulfur separation roughing operation: sodium humate 50 g / t; molybdenum-sulfur separation cleaning operation: primary separation and cleaning: sodium humate 10 g / t; secondary separation and cleaning: sodium humate 5 g / t. The results of the mineral processing test are shown in Table 1, 3-1#.

[0056] Comparative Example 3

[0057] The mineral processing flow of Example 1 was repeated, except that in the molybdenum-sulfur separation roughing and cleaning operations, the pyrite mineral-type composite inhibitor was replaced with individual nano-sized serpentine (serpentine with a purity of 90%–95% ground to 800 nm), wherein:

[0058] Molybdenum-sulfur separation roughing operation: 50 g / t of nano-sized serpentine; Molybdenum-sulfur separation cleaning operation: primary separation cleaning: 10 g / t of nano-sized serpentine; secondary separation cleaning: 5 g / t of nano-sized serpentine. The results of the mineral processing test are shown in Table 1, section 4-1#.

[0059] Comparative Example 4

[0060] The mineral processing flow of Example 1 was repeated, except that in the molybdenum-sulfur separation roughing and cleaning operations, the pyrite mineral-type combination inhibitor was replaced with EDTA alone, wherein:

[0061] Molybdenum-sulfur separation roughing operation: EDTA 50g / t; Molybdenum-sulfur separation cleaning operation: primary separation and cleaning: EDTA 10g / t; secondary separation and cleaning: EDTA 5g / t. The results of the mineral processing test are shown in Table 1, 5-1#.

[0062] Table 1. Results of closed-loop comparison tests of Example 1 and Comparative Examples 1-4 (%)

[0063]

[0064]

[0065] As shown in Table 1, when different pyrite inhibitors were used for beneficiation of a high-sulfur molybdenum mine sample 1# in Inner Mongolia, the pyrite mineral-type combined inhibitor provided by this invention (1-1#) yielded better closed-loop indicators for molybdenum concentrate grade (48.59%) and molybdenum concentrate recovery rate (76.93%). Experiments 2-1# and 3-1# represent the closed-loop indices for Comparative Examples 1 and 2, respectively, when galactose and sodium humate were used as inhibitors. When galactose was used as the pyrite inhibitor, the closed-loop indices were a molybdenum concentrate grade of 40.13% and a molybdenum concentrate recovery of 72.23%. It can be observed that, at the same reagent dosage, galactose's inhibitory ability is inferior to that of the pyrite mineral-type combined inhibitor, resulting in a significantly higher concentrate yield but a lower molybdenum grade. When sodium humate was used as the pyrite inhibitor, the closed-loop indices were a molybdenum concentrate grade of 48.13% and a molybdenum concentrate recovery of 64.17%. It was found that, at the same reagent dosage, the use of sodium humate resulted in more tailings being discarded and a lower concentrate yield, indicating... Sodium humate also inhibits molybdenite, but its selectivity is not as good as that of the pyrite mineral-type combined inhibitor. When nano-sized serpentine (4-1#) is used alone, its inhibitory ability is poor, with both molybdenite and pyrite floating to the surface. Although the molybdenite recovery rate is 80.84%, the molybdenum concentrate grade is extremely low at only 33.45%, resulting in low tailings yield and almost all pyrite floating to the surface. EDTA (5-1#) alone shows some selective inhibitory ability, with a molybdenum concentrate grade of 38.45%, but this is still low. This indicates that EDTA alone is not very effective at inhibiting pyrite; only the combined use of nano-sized serpentine and EDTA can demonstrate good selective inhibitory ability. In contrast, the pyrite mineral-type combined inhibitor provided by this invention combines strong pyrite inhibitory ability at low dosages with greater selectivity in the molybdenum-sulfur separation process, demonstrating better results in practical mining applications.

[0066] Example 2

[0067] Sample 2# from a high-sulfur molybdenum mine in Inner Mongolia contains 0.14% molybdenum, 12.26% sulfur, 0.001% copper, 0.009% lead, 0.56% zinc, 60.02% SiO2, 10.02% CaO, and 4.5% Al2O3. Compared with sample 1# in Example 1, sample 2# also mainly contains molybdenite, the main carrier for molybdenum metal recovery. The grades of copper and lead are also relatively low. Some zinc was found in this sample, occurring in the form of zinc sphalerite sulfide, which is not worth recovering. The sulfur content in sample 2# is relatively higher, still mainly existing in the form of pyrite. This mineral also contains a small amount of tremolite and talc.

[0068] The pyrite mineral type assemblage inhibitor and its application provided by this invention were used to conduct beneficiation tests on ore sample #2. The preparation of the pyrite mineral type assemblage inhibitor was the same as in Example 1, and the beneficiation process was similar to that in Example 1. The main difference was the change in the dosage of the reagent to address the changes in the ore sample. Specifically:

[0069] Step (2) Molybdenum-sulfur mixed flotation: Add 2000g / t of water glass, 120g / t of ethyl nitrogen, and 25g / t of pine oil to slurry I.

[0070] Step (3) Pre-selection operation: Add 500g / t of water glass, 25g / t of ethyl nitrogen and 20g / t of pine oil to the molybdenum-sulfur mixed flotation concentrate.

[0071] Step (4) Coarse scavenging operation: For the first coarse scavenging operation, add 1500g / t of water glass, 80g / t of ethyl thiocyanate, and 20g / t of pine oil; for the second coarse scavenging operation, add 50g / t of ethyl thiocyanate and 15g / t of pine oil; for the third coarse scavenging operation, add 20g / t of ethyl thiocyanate and 5g / t of pine oil.

[0072] Step (5) Molybdenum-sulfur separation roughing operation: Add 70g / t of pyrite mineral-type combined inhibitor, 25g / t of kerosene, and 30g / t of pine oil.

[0073] Step (6) Molybdenum-sulfur separation and beneficiation: 20 g / t of pyrite mineral-type combination inhibitor is added for the first separation and beneficiation operation; 10 g / t of pyrite mineral-type combination inhibitor is added for the second separation and beneficiation operation.

[0074] Step (7) Molybdenum-sulfur separation and scavenging operation: 15g / t of kerosene and 15g / t of pine oil are added for the first separation and scavenging operation; 10g / t of kerosene and 10g / t of pine oil are added for the second separation and scavenging operation.

[0075] The results of the mineral processing test are shown in Table 2, 1-2#.

[0076] Comparative Example 5

[0077] The mineral processing flow of Example 2 is repeated, except that in the molybdenum-sulfur separation roughing and cleaning operations, the pyrite mineral-type composite inhibitor is replaced with the existing pyrite organic inhibitor galactose, wherein:

[0078] Molybdenum-sulfur separation roughing operation: galactose 70 g / t; molybdenum-sulfur separation cleaning operation: primary separation and cleaning: galactose 20 g / t; secondary separation and cleaning: galactose 15 g / t. The results of the mineral processing test are shown in Table 1, section 2-2#.

[0079] Comparative Example 6

[0080] The mineral processing flow of Example 2 is repeated, except that in the molybdenum-sulfur separation roughing and cleaning operations, the pyrite mineral-type composite inhibitor is replaced with the existing pyrite organic inhibitor sodium humate, wherein:

[0081] Molybdenum-sulfur separation roughing operation: sodium humate 70 g / t; molybdenum-sulfur separation cleaning operation: primary separation cleaning: sodium humate 20 g / t; secondary separation cleaning: sodium humate 15 g / t. The mineral processing test results are shown in Table 1, section 3-2#.

[0082] Table 2. Results of closed-loop comparison tests of Example 2 and Comparative Examples 5-6 (%)

[0083]

[0084]

[0085] As shown in Table 2, when different pyrite inhibitors were used for beneficiation of sample 2# from a high-sulfur molybdenum mine in Inner Mongolia, the pyrite mineral-type combined inhibitor provided by this invention (samples 1-2#) yielded better results in molybdenum concentrate grade (49.88%) and molybdenum concentrate recovery rate (74.82%). Compared with sample 1# in Example 1, the pyrite content in sample 2# was increased, thus requiring a larger amount of inhibitor. Similarly, when using galactose and sodium humate, the former exhibited weak inhibitory ability, while the latter showed poor selectivity. This further demonstrates that the pyrite mineral-type combined inhibitor provided by this invention exhibits both high inhibitory efficiency and selectivity compared to other existing organic inhibitors for different molybdenum-sulfur ores.

[0086] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

Claims

1. A pyrite mineral-type assemblage inhibitor for high-sulfur molybdenum ore beneficiation, characterized in that, The active components include nano-sized serpentine and EDTA in a mass ratio of (0.5~1):(0.1~1.5); the nano-sized serpentine has a particle size of 500nm~1000nm; the EDTA is prepared as an aqueous solution with a mass concentration of 1.0%~5.0%; the mass ratio of the nano-sized serpentine to the aqueous EDTA solution is (0.5~1):(10~30). The main component of the nano-sized serpentine is (Mg,Fe)3Si2O5(OH)4.

2. The pyrite mineral-type assemblage inhibitor according to claim 1, characterized in that, The nano-sized serpentine has a particle size of 700nm~900nm; the mass concentration of the EDTA aqueous solution is 1.5%~3.0%; and the mass ratio of the nano-sized serpentine to the EDTA aqueous solution is (0.5~1):(15~25).

3. The pyrite mineral-type assemblage inhibitor according to claim 1 or 2, characterized in that, The purity of the nano-sized serpentine is 90%~95%.

4. A method for beneficiating high-sulfur molybdenum ore using the pyrite mineral-type assemblage inhibitor as described in any one of claims 1 to 3, characterized in that, Includes the following steps: (1) Grinding: Grind the raw ore to obtain a slurry I with a fineness of -74μm accounting for 60%~70%; (2) Water glass, collector I and frother are added to the slurry I, and mixed flotation, pre-cleaning and one to three roughing are carried out in sequence to obtain molybdenum-sulfur mixed concentrate and roughing tailings; wherein, the middlings from the pre-cleaning and roughing are returned to the previous operation in sequence. (3) The molybdenum-sulfur mixed concentrate is regrinded to obtain a slurry II with a fineness of -38μm accounting for 85%~95%; (4) The pyrite mineral type combination inhibitor, collector II and frother are added to the slurry II, and the separation roughing, one to two separation cleaning and one to two separation scavenging are carried out in sequence to obtain molybdenum concentrate and molybdenum-sulfur separation tailings; wherein, the middlings from the separation cleaning and separation scavenging are returned to the previous level operation in sequence.

5. The method according to claim 4, characterized in that, In step (1), the molybdenum grade of the raw ore is 0.1%~0.3%, and wet ball milling is used for grinding.

6. The method according to claim 4, characterized in that, In step (2), the dosage of reagents added relative to the raw ore in the mixed flotation is 1000~2000 g / t of water glass, 50~200 g / t of collector I, and 10~30 g / t of frother; the dosage of reagents added relative to the raw ore in the pre-selection is 500~1000 g / t of water glass, 10~50 g / t of collector I, and 10~20 g / t of frother; in the first to third rough scavenging operations: the dosage of reagents added relative to the raw ore in the first rough scavenging is 800~1500 g / t of water glass, 50~150 g / t of collector I, and 10~20 g / t of frother; the dosage of reagents added relative to the raw ore in the second rough scavenging is 20~80 g / t of collector I and 5~15 g / t of frother; the dosage of reagents added relative to the raw ore in the third rough scavenging is 10~50 g / t of collector I and 5~10 g / t of frother.

7. The method according to claim 4, characterized in that, In step (3), the regrinding is performed using a wet ball mill.

8. The method according to claim 4, characterized in that, In step (4), the dosage of reagents added relative to the raw ore in the roughing separation is 10-80 g / t of pyrite mineral type combination inhibitor, 10-40 g / t of collector II, and 10-30 g / t of frother. In the first and second separation and beneficiation operations: the dosage of reagents added relative to the raw ore in the first separation and beneficiation operation is 10-20 g / t of pyrite mineral type combination inhibitor; the dosage of reagents added relative to the raw ore in the second separation and beneficiation operation is 5-10 g / t of pyrite mineral type combination inhibitor. In the first and second separation and scavenging operations: the dosage of reagents added relative to the raw ore in the first separation and scavenging operation is 10-20 g / t of collector II and 10-20 g / t of frother; the dosage of reagents added relative to the raw ore in the second separation and scavenging operation is 5-10 g / t of collector II and 5-15 g / t of frother.

9. The method according to any one of claims 4-8, characterized in that, Collector I is an ethyl thiocyanate or xanthate collector; the foaming agent is pine oil or MIBC; collector II is kerosene or diesel oil.

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