A combination of depressants for flotation separation of scheelite and its application

Abstract

This invention discloses a combined depressant for the flotation separation of scheelite and its application. The combined depressant comprises a 2% ferric chloride (FeCl3) solution and YZJ reagent; the YZJ reagent comprises 70%–80% citric acid, 10%–20% xanthan gum, and 5%–10% water glass. This invention also provides the application of the combined depressant for calcium-bearing gangue minerals, specifically including the following steps: first, grinding the ore sample; adjusting the slurry to the required slurry concentration and pH value, adding the combined depressant, and performing one roughing stage to obtain scheelite rough concentrate and calcium-bearing gangue tailings; two to three cleaning stages to obtain the final scheelite rough concentrate product; and one to two scavenging stages to obtain the calcium-bearing gangue tailings. The combined depressant of this invention has strong selectivity, is green, economical, and environmentally friendly, and achieves high efficiency with low dosage, effectively separating calcium-bearing gangue minerals, with broad application prospects.

Description

Technical Field

[0001] This invention relates to a flotation separation inhibitor for scheelite and its application, belonging to the field of mineral processing flotation technology. Background Technology

[0002] my country has the world's largest tungsten reserves, accounting for approximately 60% to 70% of the world's total reserves. Tungsten exists in two forms: scheelite and wolframite. With the ever-expanding demand for tungsten resources, wolframite, which has lower recycling costs, is becoming increasingly depleted. How to economically and efficiently separate and utilize low-grade scheelite resources with complex composition and distribution has become a challenge for the industry. The flotation separation of scheelite from calcium-bearing gangue has not yet been well resolved, which directly affects the utilization rate of tungsten resources and increases the smelting cost of subsequent scheelite concentrate.

[0003] The main reasons for the difficulty in separating scheelite from calcium-bearing gangue by flotation are: calcium-bearing minerals have complex and similar crystal structures; calcium-bearing minerals and flotation reagents have strong chemical reactivity; calcium-bearing minerals have complex dissolution behavior, and the chemical reactions and interconversions of dissolved ions on the mineral surface lead to the complexity of the flotation behavior of each mineral; in the process of scheelite flotation, achieving selective inhibition of calcium-bearing gangue minerals is the key to flotation separation.

[0004] Therefore, the development of depressants for calcium-bearing gangue has become a research hotspot. Currently, although some novel depressants have been successfully developed, they have not been widely used industrially. Traditional depressants, such as water glass, still dominate. In the flotation process, large quantities of water glass are used, and its selective inhibition effect is poor. Adding large amounts of water glass also leads to highly dispersed tailings, making settling difficult. Therefore, developing green, low-cost, and efficient depressants for calcium-bearing gangue minerals is a future trend in mineral processing and is of great significance for improving the utilization rate of tungsten resources in my country. Summary of the Invention

[0005] To address the existing problems in scheelite flotation, one objective of this invention is to provide a combined inhibitor for scheelite flotation separation, wherein the combined inhibitor comprises a 2% ferric chloride solution and YZJ.

[0006] YZJ contains 70%–80% citric acid, 10%–20% xanthan gum, and 5%–10% water glass, with the total mass percentage of citric acid, xanthan gum, and water glass being 100%. The specific preparation method is as follows: First, dissolve the xanthan gum in deionized water (here, deionized water only serves to dissolve the xanthan gum; the amount required is specific, just enough to fully dissolve the xanthan gum), then add water glass, and finally add citric acid, with each reagent stirred at 3–5 minutes intervals.

[0007] Another objective of this invention is to provide the application of combined inhibitors in the flotation separation of scheelite, obtaining scheelite rough concentrate and calcium-bearing gangue tailings through a flotation process of one roughing, two scavenging, and three cleaning steps or one roughing, two scavenging, and two cleaning steps; wherein, in the roughing process, the amount of FeCl3 added is 60-80 g / t, and the amount of YZJ added is 360-560 g / t; in the first cleaning step, the amount of FeCl3 added is 20-30 g / t, and the amount of YZJ added is 120-210 g / t; in the second cleaning step, the amount of FeCl3 added is 10-15 g / t, and the amount of YZJ added is 60-120 g / t. The specific steps are as follows:

[0008] (1) Grind the ore sample and adjust the slurry to the required slurry concentration and pH value.

[0009] (2) Chevron roughing: Add FeCl3 to the slurry obtained in step (1), stir, add YZJ, stir, add collector, stir, float to obtain chevron rough concentrate and calcium gangue tailings.

[0010] (3) Scheelite scavenging: The rough tailings obtained in step (2) are subjected to scavenging with scheelite. Scavenging I: Add collector, stir, and float; Scavenging II: Add collector, stir, add YZJ, stir, and float to obtain the final calcium-bearing gangue tailings.

[0011] (4) Scheelite Refinement: The rough concentrate obtained in step (2) is subjected to scheelite refinement. For refinement I, FeCl3 is added, stirred, YZJ is added, and stirred flotation is performed. For refinement II, FeCl3 is added, stirred, YZJ is added, and stirred flotation is performed to obtain the final tungsten rough concentrate.

[0012] Preferably, in step (1), the grinding fineness satisfies that 70% to 85% is -74μm.

[0013] Preferably, in step (1), the slurry concentration is 20%-30%, the slurry pH is 8-11, and the adjuster is one or two of sodium hydroxide and sodium carbonate in any proportion.

[0014] Preferably, in step (2), the amount of FeCl3 added is 60-80 g / t, the amount of YZJ added is 360-560 g / t, the collector is 733 aqueous solution or 731 aqueous solution, and the amount added is 300-350 g / t; the stirring time is 2 min, and the flotation time is 5-6 min.

[0015] Preferably, in step (3), the collector in scavenging I is an aqueous solution of 733 or 731, and the amount added is 80-100 g / t; the collector in scavenging II is an aqueous solution of 733 or 731, and the amount added is 40-50 g / t; the stirring time for scavenging I is 2 min, and the flotation time is 3-4 min; the stirring time for scavenging II is 2 min, and the flotation time is 2-3 min.

[0016] Preferably, in step (4), the amount of FeCl3 added in Selected I is 20-30 g / t, the amount of YZJ added is 120-210 g / t, the amount of FeCl3 added in Selected II is 10-15 g / t, and the amount of YZJ added is 60-120 g / t; the stirring time for Selected I is 2 min, the flotation time is 2-3 min, the stirring time for Selected II is 2 min, and the flotation time is 2 min.

[0017] Preferably, the collector used in the flotation process includes, but is not limited to, an aqueous solution of 733 or an aqueous solution of 731; other collectors that can achieve the desired effect may also be used.

[0018] Preferred calcium-containing gangue minerals include, but are not limited to: fluorite, calcite, apatite, dolomite, etc.

[0019] Preferably, the selection in step (4) can be performed 3 times, and selection III does not involve the addition of any reagents.

[0020] The principle of this invention: Fe 3+ Fe undergoes chemical complexation with citric acid (CA) and is thus co-adsorbed on the surface of fluorite / calcite. 3+ The addition of Fe also increases the adsorption of xanthan gum (XG) on the fluorite / calcite surface, causing strong inhibition of both minerals. 3+ The promoting effect of CA and XG is that the hydrophilic films of CA and XG overlap and cover the surface of fluorite / calcite, preventing the collector from adsorbing on the surface of both, and thus strongly inhibiting the collector due to the strong hydrophilicity of the surface. The addition of water glass can further enhance the inhibition of calcium-containing gangue such as fluorite / calcite. Water glass also has a strong dispersing effect, effectively reducing the viscosity of the slurry and increasing the probability of the inhibitor interacting with calcium-containing gangue, which is beneficial to the inhibition of calcium-containing gangue.

[0021] Beneficial effects of the present invention

[0022] 1. This invention is the first to propose the use of metal ions Fe 3+ Its application in the flotation of scheelite, when combined with citric acid, xanthic acid and water glass as a calcium gangue inhibitor, has not yet been reported.

[0023] 2. The combined suppression method in this invention is applied to scheelite flotation to achieve efficient flotation separation of scheelite from calcium-bearing gangue minerals such as fluorite / calcite, obtain high-grade scheelite rough concentrate, control the rough concentrate yield, reduce the load on the beneficiation system, provide higher-grade scheelite rough concentrate for the scheelite heating and beneficiation section, and reduce production costs. It has the characteristics of small dosage, strong selective suppression effect and good separation index.

[0024] 3. The active ingredients of the combined inhibitors in this invention are all conventional drugs, which are widely available, non-toxic, water-soluble, easily degradable, and inexpensive.

[0025] 4. The combination inhibitor in this invention has a simple formulation and is easy to implement industrially, successfully avoiding the problems of difficult wastewater settling and reuse when using a single water glass as an inhibitor. Attached Figure Description

[0026] Figure 1 The flotation process flow for scheelite in Example 1 and Comparative Example 1 is shown below.

[0027] Figure 2 The flotation process flow for scheelite in Example 2 and Comparative Examples 2-4 is shown below. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0029] Example 1

[0030] In this embodiment, YZJ is composed of citric acid, xanthic acid, and water glass, with a mass percentage of 70%, 20%, and 10%, respectively, and the collector is an aqueous solution of 731.

[0031] In a copper-zinc polymetallic mine in Yunnan Province, the tailings from the sulfide ore flotation were used as feed for scheelite flotation. The sulfide ore tailings contained 0.14% WO3. The main gangue minerals in the raw ore were quartz and calcite (with a small amount of dolomite), with relative contents of 25.20% and 22.30%, respectively. This was followed by andradite, mica, and fluorite, with relative contents of 11.60%, 9.00%, and 7.10%, respectively, and small amounts of clay minerals such as kaolinite. Tungsten mainly existed in the form of scheelite, accounting for 93.57%. The flotation separation process is as follows: Figure 1 As shown, the specific steps are as follows:

[0032] (1) Grind the raw ore to a fineness of -74μm accounting for 84.6% and a slurry concentration of 20%; add a pH adjuster composed of sodium hydroxide and sodium carbonate to adjust the pH of the slurry to 10, wherein the amounts of sodium oxide and sodium carbonate are 800g / t and 1000g / t, respectively.

[0033] (2) Perform scheelite roughing on the qualified raw ore slurry from step (1): First, add FeCl3 at a dosage of 60 g / t and stir for 2 minutes, then add YZJ at a dosage of 360 g / t and stir for 2 minutes; add collector at a dosage of 300 g / t and stir for 2 minutes, then float for 5 minutes; finally, obtain roughing concentrate and roughing tailings.

[0034] (3) Scavenging of scheelite into the rough tailings obtained in step (2): Scavenging I: Add collector at a dosage of 80 g / t, stir for 2 minutes, and float for 4 minutes; Scavenging II: Add collector at a dosage of 40 g / t, stir for 2 minutes, and float for 3 minutes; to obtain the final calcium-bearing gangue tailings.

[0035] (4) Perform scheelite refining on the rough concentrate obtained in step (2): Refining I: Add 20 g / t FeCl3 reagent to the raw ore, stir for 2 minutes, add 120 g / t YZJ reagent to the raw ore, stir for 2 minutes, and float for 2 minutes; Refining II: Add 10 g / t FeCl3 reagent to the raw ore, stir for 2 minutes, add 60 g / t YZJ reagent to the raw ore, stir for 2 minutes, and float for 2 minutes; Refining III: No inhibitor is added, blank refining, float for 1.5 minutes to obtain the final tungsten rough concentrate.

[0036] Table 1. Results of the full-process closed-loop test for Example 1 and Comparative Example 1

[0037]

[0038] Example 2

[0039] In this embodiment, YZJ is composed of citric acid, xanthic acid, and water glass, with a mass percentage of 85%, 10%, and 5% respectively. The collector is an aqueous solution of 733.

[0040] A scheelite-fluorite mine in Inner Mongolia has tungsten and fluorite as the main recoverable components in its ore. The raw ore contains 0.70% WO3, 55.58% CaF2, and 1.63% CaO. Tungsten is mainly found in scheelite (90.54%), with smaller amounts in wolframite and tungsten spores (8.11% and 1.35%, respectively). The ore has a simple mineral composition; the target minerals are scheelite and fluorite, with limonite as the main metallic mineral, and minor amounts of hematite and pyrite. The gangue minerals are mainly quartz, followed by calcite. The ore contains high levels of calcium-bearing gangue minerals, such as fluorite and calcite, which is detrimental to the flotation of scheelite. The flotation separation process is as follows: Figure 2 As shown, the specific steps are as follows:

[0041] (1) Grind the raw ore to a fineness of -74μm, accounting for 78.8%. Add a pH adjuster composed of sodium hydroxide and sodium carbonate to adjust the pH of the slurry to 10. The amounts of sodium hydroxide and sodium carbonate are 1200g / t and 800g / t, respectively.

[0042] (2) Perform scheelite roughing on the qualified raw ore slurry from step (1): Add FeCl3 aqueous solution, 80 g / t of raw ore, stir for 2 minutes, add YZJ aqueous solution, 560 g / t of raw ore, stir for 2 minutes, add collector, 350 g / t of raw ore, stir for 2 minutes, and float for 6 minutes; finally obtain roughing concentrate and roughing tailings.

[0043] (3) Scavenging of scheelite into the rough tailings obtained in step (2): Scavenging I: Add 100g / t of collector, stir for 2 minutes, and float for 3 minutes; Scavenging II: Add 50g / t of collector to the raw ore, stir for 2 minutes, and float for 2 minutes; to obtain the final calcium-bearing gangue tailings.

[0044] (4) Perform scheelite refining on the rough concentrate obtained in step (2): Refining I: Add 30 g / t FeCl3 reagent, stir for 2 minutes, add 210 g / t YZJ reagent, stir for 2 minutes, and float for 3 minutes; Refining II: Add 15 g / t FeCl3 reagent to the raw ore, stir for 2 minutes, add 120 g / t YZJ reagent to the raw ore, stir for 2 minutes, and float for 2 minutes to obtain the final tungsten rough concentrate.

[0045] The flotation results are shown in Table 2.

[0046] Table 2. Results of the full-process closed-loop test of Example 2 and Comparative Examples 2-4

[0047]

[0048]

[0049] Comparative Example 1

[0050] The difference between this embodiment and Embodiment 1 is that the inhibitor uses a single water glass, and the specific operating steps are as follows:

[0051] (1) Grind the raw ore to a fineness of -74μm, accounting for 84.6%; add a pH adjuster composed of sodium hydroxide and sodium carbonate to adjust the pH of the slurry to 10, wherein the amounts of sodium oxide and sodium carbonate are 800g / t and 1000g / t, respectively.

[0052] (2) The qualified raw ore slurry from step (1) is subjected to scheelite roughing: water glass is added at a dosage of 1200 g / t and stirred for 2 minutes; collector is added at a dosage of 300 g / t and stirred for 2 minutes, and flotation is carried out for 5 minutes; finally, roughing concentrate and roughing tailings are obtained.

[0053] (3) Scavenging of scheelite into the rough tailings obtained in step (2): Scavenging I: Add collector at a dosage of 80 g / t, stir for 2 minutes, and float for 4 minutes; Scavenging II: Add collector at a dosage of 40 g / t, stir for 2 minutes, and float for 3 minutes; to obtain the final calcium-bearing gangue tailings.

[0054] (4) Perform scheelite refining on the rough concentrate obtained in step (2): Refining I: Add water glass at a dosage of 600 g / t, stir for 2 minutes, and float for 2 minutes; Refining II: Add water glass at a dosage of 300 g / t, stir for 2 minutes, and float for 2 minutes; Refining III: No inhibitor is added, perform blank refining, and float for 1.5 minutes to obtain the final tungsten rough concentrate.

[0055] Comparative Example 2

[0056] The difference between this embodiment and Embodiment 2 is that the inhibitor uses a single water glass, and the specific operating steps are as follows:

[0057] (1) Grind the raw ore to a fineness of -74μm, accounting for 78.8%. Add a pH adjuster composed of sodium hydroxide and sodium carbonate to adjust the pH of the slurry to 10. The amounts of sodium hydroxide and sodium carbonate are 1200g / t and 800g / t, respectively.

[0058] (2) The qualified raw ore slurry from step (1) is subjected to scheelite roughing: water glass is added at a dosage of 2500 g / t and stirred for 2 minutes; collector is added at a dosage of 300 g / t and stirred for 2 minutes, and flotation is carried out for 5 minutes; finally, roughing concentrate and roughing tailings are obtained.

[0059] (3) Scavenging of scheelite into the rough tailings obtained in step (2): Scavenging I: Add collector at a dosage of 80 g / t, stir for 2 minutes, and float for 3 minutes; Scavenging II: Add collector at a dosage of 40 g / t, stir for 2 minutes, and float for 2 minutes; to obtain the final calcium-bearing gangue tailings.

[0060] (4) The rough concentrate obtained in step (2) is subjected to scheelite refining: Refining I: Add water glass at a dosage of 1000 g / t, stir for 2 minutes, and float for 3 minutes; Refining II: Add water glass at a dosage of 500 g / t, stir for 2 minutes, and float for 2 minutes to obtain the final tungsten rough concentrate. The flotation results are shown in Table 2.

[0061] Comparative Example 3:

[0062] The difference between this embodiment and Embodiment 2 is that the inhibitor uses a single water glass, and the specific operating steps are as follows:

[0063] (1) Grind the raw ore to a fineness of -74μm, accounting for 78.8%. Add a pH adjuster composed of sodium hydroxide and sodium carbonate to adjust the pH of the slurry to 11.5. The amounts of sodium hydroxide and sodium carbonate are 2500g / t and 1000g / t, respectively.

[0064] (2) The qualified raw ore slurry from step (1) is subjected to scheelite roughing: water glass is added at a dosage of 2500 g / t and stirred for 2 minutes; collector is added at a dosage of 300 g / t and stirred for 2 minutes, and flotation is carried out for 5 minutes; finally, roughing concentrate and roughing tailings are obtained.

[0065] (3) Scavenging of scheelite into the rough tailings obtained in step (2): Scavenging I: Add collector at a dosage of 80 g / t, stir for 2 minutes, and float for 3 minutes; Scavenging II: Add collector at a dosage of 40 g / t, stir for 2 minutes, and float for 2 minutes; to obtain the final calcium-bearing gangue tailings.

[0066] (4) The rough concentrate obtained in step (2) is subjected to scheelite refining: Refining I: Add water glass at a dosage of 1000 g / t, stir for 2 minutes, and float for 3 minutes; Refining II: Add water glass at a dosage of 500 g / t, stir for 2 minutes, and float for 2 minutes to obtain the final tungsten rough concentrate. The flotation results are shown in Table 2.

[0067] Comparative Example 4:

[0068] The difference between this embodiment and Embodiment 2 is that the inhibitor uses a single water glass, and the specific operating steps are as follows:

[0069] (1) Grind the raw ore to a fineness of -74μm, accounting for 78.8%. Add a pH adjuster composed of sodium hydroxide and sodium carbonate to adjust the pH of the slurry to 12.5. The amounts of sodium hydroxide and sodium carbonate are 3000g / t and 1000g / t, respectively.

[0070] (2) The qualified raw ore slurry from step (1) is subjected to scheelite roughing: water glass is added at a dosage of 2500 g / t and stirred for 2 minutes; collector is added at a dosage of 300 g / t and stirred for 2 minutes, and flotation is carried out for 5 minutes; finally, roughing concentrate and roughing tailings are obtained.

[0071] (3) Scavenging of scheelite into the rough tailings obtained in step (2): Scavenging I: Add collector at a dosage of 80 g / t, stir for 2 minutes, and float for 3 minutes; Scavenging II: Add collector at a dosage of 40 g / t, stir for 2 minutes, and float for 2 minutes; to obtain the final calcium-bearing gangue tailings.

[0072] (4) The rough concentrate obtained in step (2) is subjected to scheelite refining: Refining I: Add water glass at a dosage of 1000 g / t, stir for 2 minutes, and float for 3 minutes; Refining II: Add water glass at a dosage of 500 g / t, stir for 2 minutes, and float for 2 minutes to obtain the final tungsten rough concentrate. The flotation results are shown in Table 2.

[0073] Comparing the flotation results of Example 1 and Comparative Example 1, in Comparative Example 1, using conventional water glass as a depressant, the closed-circuit test yielded a WO3 grade of 2.34% in the scheelite rough concentrate, with a WO3 recovery rate of 82.90%. In Example 1, using FeCl3 and YZJ as a combined depressant, the closed-circuit test yielded a WO3 recovery rate in the scheelite rough concentrate that was comparable to that obtained using water glass as a depressant, at approximately 82.90%. Clearly, the WO3 grade was 4.81%, an increase of 2.47% compared to using water glass alone, indicating that the combined depressant of this invention can effectively improve the grade of the tungsten rough concentrate. Regarding reagent usage, the amount of combined depressant added in the roughing stage of Example 1 was approximately one-third of the amount of water glass added in the roughing stage of Comparative Example 1.

[0074] When conventional water glass was used as a depressant, the flotation results of Comparative Examples 2, 3, and 4 were compared. In Comparative Example 2, the closed-circuit test yielded a WO3 grade of 4.53% for the scheelite concentrate and a WO3 recovery rate of 85.94%; in Comparative Example 3, the closed-circuit test yielded a WO3 grade of 10.09% for the scheelite concentrate and a WO3 recovery rate of 86.34%; and in Comparative Example 4, the closed-circuit test yielded a WO3 grade of 11.84% for the scheelite concentrate and a WO3 recovery rate of 66.70%. This indicates that when water glass is used as a depressant, the suitable pH value is around 11.5. Further increasing the pH value inhibits the flotation of scheelite. When the combined depressant FeCl3+YZJ was used, the pulp pH was around 10, and the closed-circuit test yielded a WO3 grade of 11.60% for the scheelite concentrate and a WO3 recovery rate of 86.43%. Compared to Comparative Example 3, under the weakly alkaline conditions of Example 2, the WO3 grade of the scheelite concentrate was increased by 1.51% while maintaining a similar WO3 grade. In terms of reagent usage, the amount of combined inhibitors added in the rough selection of Example 2 was nearly 1 / 4 of the amount of water glass added in the rough selection of Comparative Example 1.

Claims

1. A combined flotation separation depressant for scheelite, characterized by: The combination inhibitor comprises a 2% iron chloride solution and YZJ; the YZJ comprises 70-80% citric acid, 10-20% xanthan gum and 5-10% water glass, wherein the total mass percentage of the citric acid, the xanthan gum and the water glass is 100%.

2. The combined depressant for the flotation separation of scheelite according to claim 1, characterized in that: The YZJ is prepared as follows: firstly, the xanthan gum is dissolved in deionized water; secondly, the water glass is added and stirred; and finally, the citric acid is added and stirred uniformly, with an interval of 3-5 minutes between each stirring.

3. Use of the combination inhibitor of claim 1 in the flotation separation of scheelite, characterized in that: The white tungsten rough concentrate and the calcium-containing gangue tailings are obtained from the calcium-containing gangue through a roughing-two-scavenging-three-cleaning or roughing-two-scavenging-two-cleaning flotation process.

4. Use of the combination inhibitor of claim 3 in the flotation separation of scheelite, characterized in that: FeCl3 and YZJ are added in the roughing, the first cleaning and the second cleaning processes.

5. Use of the combination inhibitor of claim 4 in the flotation separation of scheelite, characterized in that: In the roughing process, the addition amount of FeCl3 is 60-80 g / t, and the addition amount of YZJ is 360-560 g / t; in the first cleaning process, the addition amount of FeCl3 is 20-30 g / t, and the addition amount of YZJ is 120-210 g / t; in the second cleaning process, the addition amount of FeCl3 is 10-15 g / t, and the addition amount of YZJ is 60-120 g / t.

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