A method for improving the beneficiation index of low-grade high-oxidation rate molybdenum ore

Abstract

The present invention introduces a method for improving the beneficiation index of low-grade, high-oxidation-rate molybdenum ore. S1: The raw ore is crushed in a crusher, ground in a ball mill, and water is added to adjust the pulp concentration. S2: The pulp from step S1 is subjected to molybdenum roughing I, II, and III in a flotation device. S3: The selected tailings obtained in S2 are combined with molybdenum roughing II concentrate and molybdenum roughing III concentrate, stirred and slurried, and the resulting flotation product is re-ground in a ball mill and beneficiated to obtain molybdenum concentrate 2. S4: The selected molybdenum tailings in S2 are first concentrated, and then tungsten is flotated at room temperature in a flotation machine using a roughing-scavenging-cleaning process. The present invention overcomes the shortcomings of the existing technology by flotating molybdenum in steps, separating copper-containing molybdenum rough concentrate, and selecting tungsten at room temperature. The process of flotation can achieve efficient recovery of molybdenum, tungsten, and other valuable elements from the raw ore. The process of flotation can achieve efficient recovery of unevenly distributed molybdenite, improve separation indexes, and simplify the flotation process.

Description

Technical Field

[0001] The present invention relates to the technical field of ore dressing methods, in particular to a method for improving the ore dressing index of low-grade and high-oxidation-rate molybdenum ore. Background Art

[0002] Approximately 30 molybdenum minerals and molybdenum-containing minerals are known in nature. Molybdenite (MoS2) is the most widely distributed and industrially valuable of these minerals. Other common molybdenum-containing minerals include molybdenite (Fe2(MoO4)3·8H2O), molybdenite (MoO3), calcium molybdenite (CaMoO4), and lead molybdenite (PbMoO4). These are molybdenum oxides and molybdates, which are difficult to smelt and utilize.

[0003] Molybdenum ore can be classified based on its oxidation rate—the ratio of the molybdenum content in molybdenum oxide to the total molybdenum content—as sulfide ores (with an oxidation rate of less than 10%) and oxidized ores (with an oxidation rate of at least 10%). The recovery of molybdenum sulfide from oxidized ores is complex and costly, necessitating enhanced smelting and research to identify effective recovery pathways.

[0004] Molybdenum ores with high oxidation rates usually have strong overall rock alteration. The ore will contain a certain amount of easily muddied minerals such as diopside, hornblende, and chlorite. The fine mud produced will have a certain impact on mineral processing. The Mo grade in this type of molybdenum ore is low, generally 0.06-0.08%, the tungsten grade is generally 0.1-0.15%, and the molybdenum oxidation rate is 20-30%. The ore has a high content of molybdenum oxide. Some molybdenites have good floatability, while some have poor floatability and slow floating speed. In addition, the particle size of the molybdenite is uneven. The use of traditional process selection procedures results in low molybdenum concentrate grade and recovery rate.

[0005] In view of this, for this kind of low-grade, high-oxidation-rate molybdenum ore, first, the influence of ore slime should be eliminated; second, the two types of molybdenite with large differences in floatability should be recovered in steps; third, molybdenite with different embedded particle sizes should also be recovered in steps to reduce grinding energy consumption. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a method for improving the beneficiation index of low-grade, high-oxidation rate molybdenum ore, so as to achieve efficient separation between minerals and effectively reduce the mutual inclusion of minerals, thereby achieving the purpose of effectively improving the molybdenum grade and recovery rate and significantly reducing production energy consumption.

[0007] The technical solution adopted in the present invention is:

[0008] A method for improving the beneficiation index of low-grade, high-oxidation-rate molybdenum ore, comprising the following steps:

[0009] S1: The raw ore is crushed by a crusher and ground by a ball mill, and water is added to adjust the pulp concentration; the grinding fineness is -0.074mm, and the particle size content is 55-75%, that is, the mass percentage of the -0.074mm particle size material is 55-75%; the pulp concentration after grinding and classification is 30-40%;

[0010] S2: The slurry from step S1 is subjected to a molybdenum roughing I operation in a flotation device to obtain a molybdenum roughing I concentrate and a molybdenum roughing I tailings. The molybdenum roughing I concentrate is flotated to recover coarsely embedded molybdenum minerals, which are then subjected to 2 to 3 blank concentration operations to obtain a molybdenum concentrate 1 and a concentrated tailings. Most of the undissociated fine molybdenum minerals in the molybdenum roughing I tailings enter a molybdenum roughing II operation to obtain a molybdenum roughing II concentrate and a molybdenum roughing II tailings. The molybdenum roughing II tailings enter a molybdenum roughing III operation to obtain a molybdenum roughing III concentrate and a molybdenum roughing III tailings. The molybdenum roughing III tailings are then subjected to 2 to 4 scavenging operations to obtain a selected molybdenum tailings.

[0011] S3: The tailings obtained from 2-3 blank concentrations in S2 are combined with the molybdenum rougher II concentrate and the molybdenum rougher III concentrate to stir and slurry, and blank concentration is carried out in a flotation device. The obtained flotation product is re-grinded in a ball mill to improve the dissociation degree of molybdenite. The grinding product is subjected to 2-3 rounds of concentration to obtain the product molybdenum concentrate 2;

[0012] S4: The molybdenum tailings from S2 are first sent to a thickener for thickening, and the pulp concentration after concentration is adjusted to 35-45%. Then, tungsten is flotated at room temperature in a flotation machine using a roughing-scavenging-cleaning process. The tungsten roughing operation produces tungsten rougher concentrate and tungsten rougher tailings. The tungsten rougher concentrate undergoes 3-5 closed-circuit cleaning processes to obtain the product tungsten concentrate. The tungsten rougher tailings undergo 3-5 closed-circuit scavenging processes to obtain the final tailings.

[0013] Specifically, in the molybdenum roughing I operation in S2, 800-1200 g / t of adjusting agent, 80-100 g / t of collector and 20-40 g / t of foaming agent, 80-120 g / t of copper mineral inhibitor and 80-120 g / t of auxiliary collector are added; 10-30 g / t of collector and 4-15 g / t of foaming agent are added in the molybdenum roughing II operation and the molybdenum roughing III operation respectively; 5-15 g / t of collector and 3-10 g / t of foaming agent are added in the 2nd to 4th sweeping of the molybdenum roughing III tailings respectively.

[0014] More specifically, in the molybdenum roughing I operation, the adjusting agent is sodium carbonate, the collecting agent is kerosene, the foaming agent is 2# oil, the copper mineral inhibitor is sodium thioglycolate, and the auxiliary collecting agent is sodium sulfide.

[0015] More specifically, the collectors added in the molybdenum roughing II operation, the molybdenum roughing III operation and the scavenging of the molybdenum roughing III tailings are all kerosene, and the foaming agent is all 2# oil.

[0016] Specifically, the flotation of the molybdenum roughing concentrate I in S2 is a closed-circuit process, and the obtained molybdenum concentrate I has a grade of Mo≥50.00%.

[0017] Specifically, the grinding fineness of the flotation product regrinding operation in S3 is -0.037mm, accounting for 50-70%, and sodium thioglycolate is used as a copper mineral inhibitor for the beneficiation of the grinding product. The grade Mo of the molybdenum concentrate 2 is ≥54.00%.

[0018] Specifically, the roughing operation of tungsten in S4 adopts sodium carbonate as dispersant, water glass as inhibitor, sodium saponify as collector, blank selection is adopted for tungsten concentration, and sodium saponify as collector for tungsten scavenging; the grade of tungsten concentrate WO3≥30%.

[0019] Due to the adoption of the above-mentioned technical solution, the present invention has the following advantages:

[0020] The method of the present invention processes low-grade, high-oxidation-rate molybdenum ore, performs step-by-step molybdenum flotation, separates copper-containing molybdenum coarse concentrate, and selects tungsten at room temperature, thereby overcoming the drawbacks of the prior art and achieving efficient recovery of valuable elements such as molybdenum and tungsten from the raw ore. The step-by-step molybdenum flotation process achieves efficient recovery of unevenly distributed molybdenite while avoiding overgrinding. Sodium sulfide is used as an auxiliary collector to improve the floatability of some fine-grained molybdenite, thereby improving separation indicators and simplifying the flotation process, thereby achieving efficient recovery with a molybdenum recovery rate of over 69%. Non-toxic organic acid inhibitors are used to solve the problem of excessive copper content in the molybdenum concentrate due to the good floatability of copper minerals in the ore, resulting in a copper content of less than 0.025%, thereby alleviating the pressure on tailings wastewater treatment and standard discharge. Sodium carbonate is used as a dispersant to eliminate the influence of easily argillizing minerals such as diopside, hornblende, and chlorite on flotation indicators. The technology improves the comprehensive utilization rate of molybdenum and copper resources and achieves efficient recovery of low-grade molybdenum and copper ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic flow diagram of the present invention. DETAILED DESCRIPTION

[0022] The following is combined with Figure 1 The present invention is further explained with reference to the following examples, which are not intended to limit the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0023] Example 1

[0024] Feed 1 is a high-oxidation-rate molybdenum ore in Henan Province, with a Mo grade of 0.06%, a WO3 grade of 0.10%, and a copper content of 0.016%. The raw ore contains 72.13% molybdenum sulfide and 27.87% molybdenum oxide. The main useful minerals in the raw ore are molybdenite and scheelite. The useful minerals are mainly fine-grained, accounting for 60.0% of -0.045. The metallic minerals in the ore are mainly pyrite, magnetite, molybdenite, scheelite and chalcopyrite, and contain trace amounts of chalcocite and bornite. The non-metallic minerals are mainly garnet, quartz, diopside and amphibole formed by alteration, and contain a small amount of carbonate minerals, plagioclase, apatite, fluorite and epidote formed by alteration.

[0025] A method for improving the beneficiation index of low-grade, high-oxidation-rate molybdenum ore according to the present invention comprises the following steps:

[0026] S1: Use a crusher to crush and screen the raw ore until the particle size of all raw ore reaches -2mm level. The crushed -2mm raw ore is ground in a closed circuit by a ball mill to a fineness of -0.074mm with a content of 65%. Water is added to adjust the slurry concentration to 35%;

[0027] S2: The raw ore with a pulp concentration of 35% in S1 is subjected to molybdenum roughing I in the flotation equipment. 1000 g / t of sodium carbonate as an adjusting agent, 100 g / t of sodium thioglycolate as a copper mineral inhibitor, 100 g / t of sodium sulfide as an auxiliary collector, 90 g / t of kerosene as a collector, and 25 g / t of 2# oil are added successively. The molybdenum roughing I operation produces molybdenum roughing I concentrate and molybdenum roughing I tailings. The molybdenum roughing I concentrate undergoes two blank cleanings to produce molybdenum concentrate 1 and selected tailings. The molybdenum roughing I tailings enter the molybdenum roughing II operation. The molybdenum roughing II operation is stirred and slurried. 20 g / t of kerosene as a collector and 6 g / t of 2# oil as a foaming agent were added in sequence, and the molybdenum rougher II operation produced molybdenum rougher II concentrate and molybdenum rougher II tailings. The molybdenum rougher II tailings were fed into the molybdenum rougher III operation, which was stirred and slurried, and 20 g / t of kerosene and 4 g / t of 2# oil were added in sequence, producing molybdenum rougher III concentrate and molybdenum rougher III tailings. The molybdenum rougher III tailings were then scavenged twice to produce molybdenum tailings, and 10 g / t of kerosene as a collector and 4 g / t of 2# oil as a foaming agent were added in each of the two scavenging operations.

[0028] S3: The selected tailings, molybdenum rougher II concentrate, and molybdenum rougher III concentrate obtained from the two blank concentrations in S2 are combined, stirred, and slurried. A blank concentration operation is performed in a flotation device. The flotation product obtained from this operation is re-ground in a ball mill to a fineness of -0.037 mm, accounting for 50%. Water is added to adjust the slurry concentration to 20%. The ground product is subjected to a second concentration, and 25 g / t and 13 g / t of sodium thioglycolate, a copper mineral inhibitor, are added to the second concentration, respectively, to obtain molybdenum concentrate 2.

[0029] S4: The molybdenum tailings from S2 are fed into a thickener for thickening, reaching a slurry concentration of 35%. Tungsten roughing is then carried out in a flotation plant, with 1000g / t of sodium carbonate as a dispersant, 500g / t of water glass as an inhibitor, and 300g / t of sodium saponify as a collector added. The roughing process produces tungsten rougher concentrate and rougher tailings. The rougher concentrate undergoes three blank cleaning rounds to produce the final tungsten concentrate. The rougher tailings undergo three scavenging rounds to produce the final tailings. The sodium saponify collector dosages for the three scavenging rounds are 100g / t, 70g / t, and 40g / t, respectively.

[0030] The results of the mineral processing test are shown in Table 1 below:

[0031] Table 1 Ore dressing indexes of Example 1

[0032]

[0033] Example 2

[0034] Feed 2 is a high-oxidation molybdenum ore from Shaanxi, with a Mo grade of 0.07%, a WO3 grade of 0.15%, and a copper content of 0.023%. The raw ore contains 69.87% molybdenum sulfide and 30.13% molybdenum oxide. The main useful minerals in the raw ore are molybdenite and scheelite. The particle size of the useful minerals is mainly fine, with -0.045 accounting for 65.0%. The metallic minerals in the ore are mainly pyrite, molybdenite, scheelite and chalcopyrite, and contain trace amounts of chalcocite and bornite. The non-metallic minerals are mainly garnet, quartz, diopside and amphibole formed by alteration, and contain a small amount of carbonate minerals, plagioclase, apatite, fluorite and epidote formed by alteration.

[0035] A method for improving the beneficiation index of low-grade, high-oxidation-rate molybdenum ore according to the present invention comprises the following steps:

[0036] S1: Use a crusher to crush and screen the raw ore until the particle size of all raw ore reaches -3mm level. The crushed -3mm raw ore is ground in a closed circuit by a ball mill to a fineness of -0.074mm with a content of 70%. Water is added to adjust the slurry concentration to 35%;

[0037] S2: The raw ore with 35% pulp concentration in S1 is subjected to molybdenum roughing I in the flotation equipment, and 1100g / t of sodium carbonate as an adjusting agent, 120g / t of sodium thioglycolate as a copper mineral inhibitor, 110g / t of sodium sulfide as an auxiliary collector, 100g / t of kerosene as a collector, and 30g / t of 2# oil as a foaming agent are added successively. The operation produces molybdenum rougher I concentrate and molybdenum rougher I tailings; the molybdenum rougher I concentrate undergoes three blank cleanings to produce molybdenum concentrate 1 and cleaned tailings. The molybdenum rougher I tailings enter the molybdenum rougher II operation, where they are stirred and slurried, and 20 g / t of kerosene as a collector and 8 g / t of 2# oil as a foaming agent are added in sequence. The molybdenum rougher II operation produces molybdenum rougher II concentrate and molybdenum rougher II tailings; the molybdenum rougher II tailings enter the molybdenum rougher III operation, where they are stirred and slurried, and 20 g / t of kerosene and 6 g / t of 2# oil are added in sequence. The molybdenum rougher III operation produces molybdenum rougher III concentrate and molybdenum rougher III tailings; the molybdenum rougher III tailings undergo two scavenging cleanings to produce molybdenum tailings; 10 g / t of kerosene as a collector and 4 g / t of 2# oil as a foaming agent are added in the two scavenging cleanings, respectively.

[0038] S3: The selected tailings, molybdenum rougher II concentrate, and molybdenum rougher III concentrate obtained from the three blank concentrations in S2 are combined, stirred, and slurried in a flotation device for blank concentration. The flotation product obtained from this operation is re-ground in a ball mill to a fineness of -0.037 mm, accounting for 55%, and water is added to adjust the pulp concentration to 20%. The ground product is subjected to three concentrations, and a copper mineral inhibitor, sodium thioglycolate, is added in 30 g / t, 15 g / t, and 10 g / t, respectively, for the three concentrations to obtain molybdenum concentrate 2.

[0039] S4: The molybdenum tailings from S2 are first concentrated in a thickener, and the pulp concentration after concentration is 35%. Then, tungsten roughing is carried out in a flotation machine, and 1000g / t of dispersant sodium carbonate, 500g / t of inhibitor water glass, and 300g / t of collector sodium saponify are added respectively. The tungsten roughing operation produces tungsten roughing concentrate and tungsten roughing tailings. The tungsten roughing concentrate undergoes four blank selections to obtain the product tungsten concentrate. The tungsten roughing tailings undergo four scavenging selections to obtain the final tailings. The dosage of collector sodium saponify in the four scavenging selections is 100g / t, 80g / t, 50g / t and 25g / t respectively.

[0040] Table 2 Ore dressing indexes of Example 2

[0041]

[0042] The parts not described in detail in this invention are prior art.

[0043] The embodiments selected herein for the purpose of disclosing the invention are presently considered suitable, but it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of the concept and invention.

Claims

1. A method for improving the beneficiation index of low-grade, high-oxidation-rate molybdenum ore, characterized in that: The specific steps include: S1: The raw ore is crushed by a crusher and ground by a ball mill, and water is added to adjust the pulp concentration. The grinding fineness is -0.074 mm, and the particle size content is 55-75%, that is, the mass percentage of the -0.074 mm particle size is 55-75%. After grinding and classification, the pulp concentration is 30-40%. S2: The slurry from step S1 is subjected to a molybdenum roughing I operation in a flotation device to obtain a molybdenum roughing I concentrate and a molybdenum roughing I tailings. The molybdenum roughing I concentrate is flotated to recover coarsely embedded molybdenum minerals, and then 2 to 3 blank concentration operations are performed to obtain a molybdenum concentrate 1 and a concentrated tailings. The flotation of the molybdenum roughing I concentrate is a closed-circuit process to obtain a molybdenum concentrate 1 with a Mo grade of ≥50.00%; most of the undissociated fine-grained molybdenum minerals in the molybdenum roughing I tailings enter the molybdenum roughing II operation to obtain a molybdenum roughing II concentrate and a molybdenum roughing II tailings; the molybdenum roughing II tailings enter the molybdenum roughing III operation to obtain a molybdenum roughing III concentrate and a molybdenum roughing III tailings; the molybdenum roughing III tailings are then subjected to 2 to 4 scavenging operations to obtain a selected molybdenum tailings; S3: The selected tailings obtained from 2~3 blank concentrations in S2 are combined with molybdenum rougher II concentrate and molybdenum rougher III concentrate to stir and slurry, and blank concentration is carried out in a flotation device. The obtained flotation product is regrinded in a ball mill to improve the dissociation degree of molybdenite. The grinding fineness of the flotation product regrinding operation is -0.037mm, accounting for 50~70%. The grinding product is concentrated 2~3 times using sodium thioglycolate as a copper mineral inhibitor to obtain the product molybdenum concentrate 2. The grade of molybdenum concentrate 2 is ≥54.00%; S4: The molybdenum tailings from S2 are first sent to a thickener for thickening, and the pulp concentration after concentration is adjusted to 35-45%; then, tungsten is flotated at room temperature in a flotation machine using a roughing-scavenging-cleaning process; the tungsten roughing operation produces tungsten roughing concentrate and tungsten roughing tailings; the tungsten roughing concentrate undergoes 3-5 closed-circuit cleaning processes to obtain a tungsten concentrate product with a WO3 ≥ 30% grade; the tungsten roughing tailings undergo 3-5 closed-circuit cleaning processes to obtain the final tailings; the tungsten roughing operation uses sodium carbonate as a dispersant, water glass as a depressant, and sodium saponify as a collector; blank cleaning is used for tungsten cleaning, and sodium saponify is used as a collector for tungsten scavenging.

2. The method for improving the beneficiation index of low-grade, high-oxidation-rate molybdenum ore according to claim 1, wherein: In the molybdenum roughing I operation in S2, 800-1200 g / t of adjusting agent, 80-100 g / t of collecting agent, 20-40 g / t of foaming agent, 80-120 g / t of copper mineral inhibitor, and 80-120 g / t of auxiliary collecting agent are added; 10-30 g / t of collecting agent and 4-15 g / t of foaming agent are added to the molybdenum roughing II operation and the molybdenum roughing III operation respectively; During the 2nd to 4th sweeping of molybdenum rougher III tailings, 5 to 15 g / t of collector and 3 to 10 g / t of frother are added respectively.

3. The method for improving the beneficiation index of low-grade, high-oxidation-rate molybdenum ore according to claim 2, wherein: In the molybdenum roughing I operation, the adjusting agent is sodium carbonate, the collecting agent is kerosene, the foaming agent is 2# oil, the copper mineral inhibitor is sodium thioglycolate, and the auxiliary collecting agent is sodium sulfide.

4. The method for improving the beneficiation index of low-grade, high-oxidation-rate molybdenum ore according to claim 2, wherein: The collectors added in the molybdenum roughing II operation, molybdenum roughing III operation and molybdenum roughing III tailings scavenging are all kerosene, and the foaming agent is all 2# oil.

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