A beneficiation method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings

Abstract

The present invention discloses a beneficiation method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings. After the polymetallic tungsten ore tailings are slurried, mixed flotation is carried out using a metal ion-hydroxamic acid complex as a collector and a composition of aluminum sulfate, water glass and sodium fluorosilicate as a depressant to obtain a tungsten, tin and sulfur mixed concentrate; the tungsten, tin and sulfur mixed concentrate is subjected to reverse flotation desulfurization using oxalic acid as an activator, xanthate as a collector and single water glass as a depressant, the reverse flotation concentrate being a sulfur concentrate and the tailings being a tungsten-tin mixed concentrate. This method achieves preliminary co-enrichment of sulfide ore, tungsten ore and cassiterite in the polymetallic tungsten ore tailings based on mixed flotation, and then efficiently separates the sulfide ore as a sulfide ore concentrate by a reverse flotation desulfurization method, while the tungsten ore and cassiterite are efficiently recovered as a tungsten-tin mixed concentrate, truly realizing the resource recovery of the polymetallic tungsten ore tailings.

Description

Technical Field

[0001] The present invention relates to a method for recovering polymetallic tungsten ore tailings, in particular to a beneficiation method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings, belonging to the technical field of beneficiation. Background Art

[0002] As mineral resources are gradually depleted, it is of great significance to re-select the stockpiled tailings from existing concentrators and further obtain valuable metal resources from them. At present, polymetallic tungsten tailings still contain a large amount of metal resources, including tungsten, tin, sulfur, etc., as follows:

[0003] Scheelite: Currently, the most widely used flotation process for tungsten mines, whether single scheelite or mixed scheelite ores, is the fatty acid method. Examples include the Luoyang Molybdenum Group Scheelite Mine in Henan, the Xiaoliugou Scheelite Mine in Gansu, and the Xianglushan Tungsten Mine in Jiangxi. Fatty acids have a strong capture capacity for scheelite, but their selectivity is poor. Therefore, the fatty acid flotation process often requires the addition of large amounts of water glass as a gangue mineral depressant. When the mineral composition is complex, water glass often has poor selectivity, suppressing gangue minerals like calcite and fluorite while also affecting the flotation of tungsten. Consequently, the tungsten tailings contain tungsten that was not floated in the main process.

[0004] Tin Resources: Furthermore, due to the similar differentiation behavior and affinity of W and Sn during geochemical mineralization (Mineralization Geochemistry, Geological Publishing House, 2015, 134-135), cassiterite is found in numerous polymetallic tungsten ores, such as those at Huangshaping and Shizhuyuan. However, cassiterite is not effectively recovered in existing tungsten beneficiation processes and remains primarily in the beneficiation tailings. Traditional tungsten smelting methods primarily rely on "hydrochloric acid decomposition followed by alkaline dissolution." Tin in tungsten concentrates enters the leachate along with the tungsten, making subsequent separation difficult. Therefore, the previous tungsten concentrate standard, YS / T 231-2015, requires a tin grade of 0.15 to 0.50 in tungsten concentrate. In recent years, the development of new tungsten smelting technologies, such as the "Sulfur-Phosphorus Mixed Acid Co-Leaching Technology" (Patent CN104878223A) and the "Key Technology for Green Scheelite Smelting Using an Ammonium Salt System" (Patent CN109439929A), has enabled the tin in tungsten concentrate to be incorporated into the slag phase during the tungsten leaching process, achieving high-value utilization. Therefore, achieving the co-enrichment and recovery of cassiterite and tungsten from polymetallic tungsten ore tailings is of great significance.

[0005] Sulfide Ores: The common beneficiation process for polymetallic tungsten ores in existing technology includes magnetic separation for iron removal, flotation desulfurization, and tungsten flotation. In this process, the majority of the easily floatable sulfide ores are recovered in the full-sulfur flotation stage. However, some pyrrhotite and pyrite have poor floatability, making them difficult to fully recover in the conventional full-sulfur flotation stage. This is especially true when the ore is highly oxidized, further reducing its floatability. Consequently, these unremoved sulfide ores enter the tailings with the slurry, resulting in the loss of sulfur resources.

[0006] The main useful components in most polymetallic tungsten ore tailings are WO3, S, and Fe. The main metallic minerals are scheelite, cassiterite, pyrrhotite, and pyrite, while the gangue minerals are primarily feldspar, fluorite, quartz, pyroxene, calcite, and garnet. The WO3 content is 0.07-0.25%, the S content is 2-3%, and the TFe content is 8-12%. The vast majority of existing polymetallic tungsten ore tailings are stored in tailings ponds, resulting in a low rate of comprehensive utilization. To address this situation, mineral processing researchers are primarily focused on addressing the pressure on tailings ponds and researching the large-scale utilization and disposal of tailings, including the recovery of non-metallic minerals such as fluorite, feldspar, and quartz. Fluorite is primarily used as a raw material for the production of hydrofluoric acid, while quartz and feldspar are used as inorganic materials in the building materials industry. Currently, efforts to recover metallic minerals from tungsten polymetallic mine tailings primarily focus on re-processing using the same processes as the main process. However, due to challenges with economic efficiency and production costs, most efforts remain at the laboratory level, with few large-scale applications. Summary of the Invention

[0007] In view of the defects of the existing methods for treating polymetallic tungsten ore tailings, the purpose of the present invention is to provide a beneficiation method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings. The method is based on mixed flotation to achieve preliminary co-enrichment of sulfide ore, tungsten minerals and cassiterite in polymetallic tungsten ore tailings, and then uses a reverse flotation desulfurization method to efficiently separate the sulfide ore as a sulfide ore concentrate, while the tungsten ore and cassiterite are efficiently recovered as a tungsten-tin mixed concentrate, truly realizing the resource recovery of polymetallic tungsten ore tailings.

[0008] In order to achieve the above technical objectives, the present invention provides a beneficiation method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings. The method comprises the following steps: slurrying the polymetallic tungsten ore tailings, performing mixed flotation using a metal ion-hydroxamic acid complex as a collector I, and a composition of aluminum sulfate, water glass and sodium fluorosilicate as an inhibitor I to obtain a tungsten-tin-sulfur mixed concentrate; the tungsten-tin-sulfur mixed concentrate is subjected to reverse flotation desulfurization using oxalic acid as an activator, xanthate as a collector II, and single water glass as an inhibitor II, the concentrate being a sulfur concentrate and the tailings being a tungsten-tin mixed concentrate.

[0009] The technical solution of the present invention is based on the characteristics of the mineral composition and occurrence state of polymetallic tungsten ore tailings (the main metal minerals are scheelite, cassiterite, pyrrhotite and pyrite, and the gangue minerals are mainly feldspar, fluorite, quartz, pyroxene, calcite and garnet). Under the action of a combined inhibitor of special aluminum sulfate, water glass and sodium fluorosilicate, it can simultaneously and efficiently inhibit calcium-containing gangue such as fluorite and calcite and silicate gangue such as garnet, quartz and feldspar. Moreover, by using a metal ion-hydroxamic acid complex as a collector, tungsten minerals, cassiterite and sulfide ores can be simultaneously and efficiently enriched and recovered in the form of mixed concentrates. Then, oxalic acid is used for activation, xanthate is used as a collector, and single water glass is used as an inhibitor to inhibit scheelite and cassiterite, and reverse flotation desulfurization is carried out, while the tungsten ore and cassiterite are retained in the tailings, thereby ultimately achieving comprehensive recovery of tungsten, tin and sulfur in polymetallic tungsten ore tailings.

[0010] As a preferred solution, the slurry adjustment is to adjust the slurry mass concentration to 38% to 45% and the pH to 9.5 to 10.5. Under the preferred pH conditions, the capture capacity of the metal ion-hydroxamic acid complex is improved.

[0011] As a preferred embodiment, the collector I is a metal ion-hydroxamic acid complex formed by the coordination of a hydroxamic acid ligand and a metal ion. The metal ion is Fe 3+ 、Fe 2+ , Pb 2+ 、Cu 2+ 、Zn 2+ 、Al 3+ 、Mn 2+ 、Ni 2+ or Ca 2+ ; A further preferred metal ion is Fe 3+ 、Fe 2+ or Pb 2+ The hydroxamic acid ligand is salicylic acid, benzoic acid, naphthyl hydroxamic acid or C6~C 12 The molar ratio of the metal ion to the hydroxamic acid ligand is 1:1 to 16, and more preferably 1:1 to 8.

[0012] As a preferred solution, the inhibitor I is composed of aluminum sulfate, water glass, and sodium fluorosilicate in a mass ratio of 1:2-4:2-4. Under the synergistic effect of aluminum sulfate, water glass, and sodium fluorosilicate, aluminum sulfate and water glass mainly form Al-SiO3 colloids, which have a strong selective inhibitory ability for calcium-containing gangue minerals such as calcite and fluorite, and have little effect on the recovery rate of tungsten ore, cassiterite, and sulfide ores. Sodium fluorosilicate is mainly used to selectively inhibit silicate minerals and disperse ore mud to prevent entrainment. In addition, aluminum sulfate and sodium fluorosilicate can both provide an acidic environment in aqueous solution and also facilitate the formation of highly selective silicate colloids. The proportion of aluminum sulfate must be moderate. Too high a proportion will lead to insufficient inhibitory ability, while too low a proportion will reduce selectivity and easily lead to a reduced recovery rate of tungsten and tin minerals.

[0013] As a preferred solution, the flotation includes one roughing selection, 2 to 4 cleaning selections and 1 to 3 scavenging selections.

[0014] As a preferred solution, the roughing reagent system of the mixed flotation is: collector I 300-800g / t; depressant I 200-600g / t, frother 10-50g / t; the frother is 2# oil.

[0015] As a preferred solution, the concentration reagent system of the mixed flotation is: inhibitor I 100-200g / t.

[0016] As a preferred solution, the scavenging of the mixed flotation is a blank scavenging, and no reagent needs to be added.

[0017] As a preferred solution, the reverse flotation includes one roughing selection, 1 to 3 cleaning selections and 1 to 3 scavenging selections.

[0018] As a preferred solution, the roughing reagent system for reverse flotation is as follows: activator 100-500g / t; collector II 300-600g / t; inhibitor II 500-3000g / t, preferably inhibitor II 1500-3000g / t; frother 10-50g / t; the frother is 2# oil.

[0019] As a more preferred solution, the reverse flotation is blank flotation without adding flotation reagents.

[0020] As a more preferred solution, the scavenging agent system of the reverse flotation is: 10-20 g / t of frother. No collector is added during the scavenging process.

[0021] Compared with the existing technology, the technical solution of the present invention brings the following beneficial technical effects:

[0022] The technical solution of the present invention achieves preliminary enrichment of sulfide ores, tungsten ores and cassiterite in polymetallic tungsten ore tailings, and then efficiently recovers the sulfide ores (mainly pyrite and pyrrhotite) separately as sulfur concentrate through a reverse flotation desulfurization method, with a sulfur recovery rate of about 67%. Tungsten ore and cassiterite are efficiently recovered as tungsten-tin mixed concentrates, with a WO3 recovery rate of about 70% and a Sn recovery rate of about 45%, truly realizing the resource recovery of polymetallic tungsten ore tailings.

[0023] The technical solution of the present invention is simple to operate for the beneficiation method of polymetallic tungsten ore tailings, has low reagent cost, is suitable for various polymetallic tungsten ore tailings, and is conducive to large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a flow chart of the mineral processing process for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings.

[0025] Figure 2 This is the closed-circuit experimental process of Example 1 and Control Example 1.

[0026] Figure 3 This is the closed-circuit experimental process of Example 2.

[0027] Figure 4 This is a simplified diagram of the industrial equipment layout of Example 2. DETAILED DESCRIPTION

[0028] The following specific examples are intended to further illustrate the present invention, rather than to limit the scope of protection of the claims.

[0029] Example 1

[0030] The method of the present invention is used to treat the tailings of the polymetallic tungsten mine in Huangshaping, Chenzhou, Hunan. The tungsten ore species of the mine is single scheelite, and the feed concentration is 40%. Figure 2 The process shown in the figure was closed-circuit experiment. The pH of tailings was adjusted to 9.5 by sodium carbonate, and metal ion complex collector (Pb 2+ The crude concentrate was obtained by roughing with 400 g / t of tantalum and salicylic acid (mass ratio of 1:1), 20 g / t of 2# oil as a foaming agent, and 200 g / t of a combined inhibitor (40 g / t of aluminum sulfate, 80 g / t of water glass and 80 g / t of sodium fluorosilicate); two blank sweeps were performed without adding any reagents; and a combined inhibitor was used for fine selection (the total amount of reagents used for the two selections was 200 g / t, 100 g / t each time, and the mass ratio of aluminum sulfate, water glass and sodium fluorosilicate was 1:2:2). After two selections, a tungsten-tin-sulfur mixed concentrate was obtained.

[0031] The tungsten-tin-sulfur mixed concentrate was subjected to reverse flotation desulfurization to obtain a tungsten-tin mixed concentrate. The reverse flotation desulfurization process consisted of a roughing run, two cleaning runs, and two scavenging runs. The roughing run used 500g / t oxalic acid as an activator, 3000g / t water glass as a depressant, 300g / t butyl xanthate as a collector, and 20g / t No. 2 oil as a frother. Only 10g / t No. 2 oil was added as a frother in the second scavenging run. No reagents were added to the second cleaning run. The final indicators, as shown in Table 1, achieved an overall WO3 recovery of 72.58%, an overall Sn recovery of 50.46%, and a S recovery of 68.3%.

[0032] Table 1 Experimental indicators of Example 1

[0033]

[0034] Comparative Example 1

[0035] This comparative example is used as a control with Example 1 to compare the effect of aluminum sulfate in the mixed roughing depressant on the flotation process:

[0036] The only difference from Example 1 is that the combined depressant is water glass and sodium fluorosilicate in a mass ratio of 1:1 (a total of 200 g / t). The flotation process and other conditions are the same as in Example 1.

[0037] The final indicators are shown in Table 2. The overall recovery of WO3 is only 35.92%, the overall recovery of Sn is 19.62%, and the recovery of S is 81.68%. These results show that when aluminum sulfate is not added, the selectivity of inhibitor I is poor, which seriously affects the recovery of tungsten and tin.

[0038] Table 2 Experimental indicators of control example 1

[0039]

[0040]

[0041] Example 2

[0042] The process is used to treat the polymetallic tungsten tailings of Shizhuyuan, Chenzhou, Hunan. The mine is a tungsten mine with black and white tungsten coexisting (the ratio of black and white tungsten is about 4:6). The feed concentration is adjusted to 42%. Figure 3 The reagents and processes shown in the figure were used for industrial experiments with a daily processing capacity of 1500t / d (the schematic diagram of the industrial equipment layout is shown in the figure). Figure 4 shown).

[0043] The pH of the tailings was adjusted to 9.6 by sodium carbonate, and a metal ion complex collector (Pb 2+The crude concentrate was obtained by roughing with 450 g / t of tungsten, tin and naphthyl hydroxamic acid (mass ratio of 1:1), 25 g / t of 2# oil as a foaming agent, and 300 g / t of a combined inhibitor (60 g / t of aluminum sulfate, 120 g / t of water glass and 120 g / t of sodium fluorosilicate). A blank was selected without adding any reagents for one sweep selection. A combined inhibitor was used for fine selection (the total amount of reagents used for two selections was 300 g / t, 150 g / t each time, and the mass ratio of aluminum sulfate, water glass and sodium fluorosilicate was 1:2:2). After two selections, a tungsten, tin and sulfur mixed concentrate was obtained.

[0044] A tungsten-tin-sulfur mixed concentrate was subjected to reverse flotation desulfurization to obtain a tungsten-tin mixed concentrate. The reverse flotation desulfurization process consisted of a roughing operation, two cleaning operations, and two scavenging operations. The roughing operation used 400 g / t oxalic acid as an activator, 2400 g / t water glass as a depressant, 350 g / t butyl xanthate as a collector, and 20 g / t No. 2 oil as a frother. Only 10 g / t No. 2 oil was added as a frother in the second scavenging operation. No reagents were added to the second cleaning operation. The final indicators, as shown in Table 2, achieved an overall WO3 recovery of 73.93%, an overall Sn recovery of 58.60%, and a S recovery of 76.96%.

[0045] Table 2 Experimental indicators of Example 2

[0046] product Yield / % <![CDATA[WO3 grade / %]]> <![CDATA[WO3 Recovery Rate / %]]> Sn grade / % Sn recovery rate / % S grade / % S recovery rate sulfide ore 1.20 0.11 1.12 0.14 1.15 28.23 76.96 Mixed concentrate 0.66 13.22 73.93 12.99 58.60 0.50 0.75 Final tailings 98.14 0.03 24.95 0.06 40.25 0.10 22.29 Feed 100.00 0.12 100.00 0.15 100.00 0.44 100.00

Claims

1. A beneficiation method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings, characterized by: After the polymetallic tungsten ore tailings are slurried, mixed flotation is carried out using a metal ion-hydroxamic acid complex as a collector I and a combination of aluminum sulfate, water glass and sodium fluorosilicate as an inhibitor I to obtain a tungsten-tin-sulfur mixed concentrate; the tungsten-tin-sulfur mixed concentrate is subjected to reverse flotation desulfurization using oxalic acid as an activator, xanthate as a collector II and single water glass as an inhibitor II. The reverse flotation concentrate is a sulfur concentrate and the tailings are a tungsten-tin mixed concentrate.

2. The method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings according to claim 1, characterized in that: The slurry adjustment is to adjust the slurry mass concentration to 38% to 45% and the pH value to 9.5 to 10.

5.

3. The method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings according to claim 1, characterized in that: The collector I is a metal ion-hydroxamic acid complex formed by the coordination of a hydroxamic acid ligand and a metal ion; The metal ion is Fe 3+ 、Fe 2+ , Pb 2+ 、Cu 2+ 、Zn 2+ 、Al 3+ 、Mn 2+ 、Ni 2+ or Ca 2+ ; The hydroxamic acid ligand is salicylic acid, benzoic acid, naphthyl hydroxamic acid or C6-C 12 Alkyl hydroxamic acid; The molar ratio of the metal ion to the hydroxamic acid ligand is 1:1-16.

4. The method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings according to claim 1, characterized in that: The inhibitor I is composed of aluminum sulfate, water glass and sodium fluorosilicate in a mass ratio of 1:2-4:2-4.

5. A beneficiation method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings according to any one of claims 1 to 4, characterized in that: The mixed flotation includes one roughing selection, 2 to 4 cleaning selections and 1 to 3 scavenging selections.

6. The method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings according to claim 5, characterized in that: The roughing reagent system of the mixed flotation is: collector I 300-800g / t; inhibitor I 200-600g / t, frother 10-50g / t; the frother is 2# oil; The concentration reagent system of the mixed flotation is: inhibitor I 100-200g / t; The scavenging of the mixed flotation is blank scavenging.

7. The method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings according to claim 1, characterized in that: The reverse flotation comprises one roughing selection, 1 to 3 cleaning selections and 1 to 3 scavenging selections.

8. A beneficiation method for recovering tungsten, tin and sulfur from polymetallic tungsten ore tailings according to claim 1 or 7, characterized in that: The roughing reagent system of the reverse flotation is: activator 100-500g / t; collector II 300-600g / t; inhibitor II 500-3000g / t, frother 10-50g / t; the frother is 2# oil; The reverse flotation selection is blank selection; The scavenging agent system of the reverse flotation is: 10-20g / t of foaming agent; the foaming agent is 2# oil.

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