Flotation purification method for fluorite mine with high calcite content

Abstract

The invention discloses a high-calcite-content fluorite ore flotation purification method which comprises the following steps: metal ion pretreatment: metal ions such as iron and copper are added for pretreatment, and the metal ions are selectively attached to the surface of calcite through chemical reaction, so that the surface property of the calcite is changed; flotation separation: organic inhibitors such as tartaric acid and tannic acid interact with metal ions attached to the surface of the calcite, so that efficient inhibition of the calcite is achieved. A high-quality fluorite concentrate product with the CaF2 content larger than 97.5% and the CaCO3 content smaller than 1.0% can be obtained through the flotation purification method for the high-calcite-content fluorite ore with the fluorite content ranging from 25% to 35% and the calcite content ranging from 30% to 50%, and the flotation purification method has the advantages of being simple and efficient in technological process, excellent in grading index and the like and has good application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of fluorite flotation purification, and in particular to a method for flotation purification of fluorite ore with high calcite content. Background Art

[0002] Fluorite (CaF2) is the main raw material for industrial fluorine products. It is widely used in metallurgy, chemical industry, optics and semiconductor manufacturing and other industrial fields. It also has great application potential in strategic emerging fields such as new energy, atomic energy industry, aerospace, etc. It is listed as a strategic / critical mineral by major economies such as China, the United States, the European Union and Japan. Fluorite is mainly formed by the interaction of fluorine ions in volcanic magma and calcium ions in rocks. Therefore, calcium-containing minerals such as calcite (CaCO3) often appear as co-existing minerals in fluorite deposits. With the continuous consumption of high-grade and easy-to-smelt fluorite resources in my country, and the growing demand for fluorite products, the development of fluorite resources with high calcite content has been put on the agenda, bringing new and greater challenges to fluorite beneficiation. Since calcium-containing minerals such as fluorite and calcite have extremely similar surface properties, their flotation separation has always been a major problem in the field of mineral processing. Therefore, in order to efficiently develop fluorite resources with high calcite content, it is necessary to innovate flotation technology and improve the separation index of this type of fluorite ore.

[0003] In order to achieve efficient flotation separation of fluorite and calcite, existing literature has done a lot of research work on the screening and development of selective collectors and inhibitors. For example, the invention patent with an application date of August 1, 2023 and an application number of CN202310522104.8 discloses a combined inhibitor for flotation separation of fluorite and calcite and its use method. The combined inhibitor consists of sulfonated lignite, 3,4,5-trihydroxybenzoic acid and a dispersant. The combined inhibitor is used to treat fluorite ore with a CaF2 content of 32.8%-37.1% and a CaCO3 content of 9.89%-17.2%. A concentrate product with a CaF2 content of 87.01%-91.71% and a CaCO3 content of 3.26%-4.7% can be obtained. The CaF2 content of the fluorite concentrate is low, and the impurity CaCO3 content is still high.

[0004] For another example, the invention patent with application date of August 23, 2023 and application number of CN202311066124.5 discloses a method for applying a fluorite flotation inhibitor in calcite-fluorite separation, wherein sawdust is ground and pyrolyzed under a protective atmosphere, and the gas in the pyrolysis product is condensed and collected to obtain the fluorite flotation inhibitor, and then the flotation inhibitor is used for fluorite flotation. The inhibitor is used to treat fluorite ore with a raw ore CaF2 content of 29.81% and a CaCO3 content of 38.71%, and a concentrate product with a CaF2 content of 93.74%-94.84% can be obtained, and the quality of the fluorite concentrate is relatively low.

[0005] Therefore, for fluorite ores with high calcite content, innovating flotation separation technology to obtain high-quality fluorite concentrate is of great significance to the efficient development of my country's high calcite content fluorite resources. Summary of the invention

[0006] The present invention aims to overcome the defects of the prior art and proposes a flotation purification method for fluorite ore with a high calcite content, which includes two stages: metal ion pretreatment and flotation separation. The technical method can achieve efficient flotation purification of fluorite ore with a high calcite content and obtain high-quality fluorite concentrate (CaF2 content>97.5wt.%, CaCO3 content<1.0wt.%). The technical method has the advantages of simple and efficient process flow, excellent separation index, etc., and has good application prospects.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a flotation purification method for fluorite ore with high calcite content, comprising the following steps:

[0008] (1) Metal ion pretreatment: After grinding and slurrying of fluorite ore with a calcite content of 30wt.%-50wt.%, a slurry product is obtained, and metal ions are added to the slurry product for stirring pretreatment;

[0009] (2) Flotation separation: The pretreated pulp is subjected to flotation purification to obtain fluorite concentrate, in which the CaF2 content is greater than 97.5wt.%, and the CaCO3 content is less than 1.0wt.%.

[0010] Furthermore, in step (1), the particle size of the fluorite ore is -2 mm, the grinding fineness is -0.074 mm, accounting for 55%-75wt.%, and the pulp concentration is 25%-40wt.%.

[0011] Furthermore, in step (1), the metal ion is any one of iron, copper, aluminum, and lead, the dosage is 3000g / t-15000g / t, the stirring intensity is 1500r / min-2500r / min, and the pretreatment time is 15min-60min.

[0012] Furthermore, in step (2), an inhibitor and a collector are added to the pretreated slurry for flotation purification, and the inhibitor is any one of tartaric acid and tannic acid.

[0013] Furthermore, the collector is any one of sodium oleate, oleic acid, and sodium dodecyl sulfate.

[0014] Furthermore, in step (2), flotation purification includes a roughing process to obtain a roughing concentrate and a roughing tailings, the roughing concentrate is subjected to 6-8 rounds of concentrating to obtain a fluorite concentrate and a concentrated middling, the roughing tailings are subjected to a scavenging process to obtain tailings 1 and a scavenging concentrate, the scavenging concentrate and the concentrated middling are subjected to middling re-selection to obtain a middling re-selection concentrate and tailings 2, the middling re-selection concentrate is returned to the roughing concentrate, and tailings 1 and tailings 2 are combined into the final tailings.

[0015] Furthermore, the amount of inhibitor in the roughing operation is 200g / t-1200g / t (relative to the dry weight of the original ore, the same below), and the amount of collector is 150g / t-500g / t; the amount of inhibitor in the scavenging operation is 50g / t-300g / t, and the amount of collector is 50g / t-100g / t; the total amount of inhibitor in the concentrating operation is 300g / t-1200g / t, and the total amount of collector is 50g / t-150g / t.

[0016] Furthermore, the dosage of the inhibitor in the middling ore reselection operation is 100-300 g / t, and the dosage of the collector is 25-75 g / t.

[0017] Furthermore, in step (1), the fluorite content of the fluorite ore is 25wt.%-35wt.%.

[0018] The beneficial effects of the present invention are:

[0019] The present invention utilizes metal ions such as iron, copper, aluminum, and lead to selectively attach to the surface of calcite through chemical reactions, thereby changing the surface properties of calcite. In the flotation separation process, organic inhibitors such as tartaric acid and tannic acid are used to interact with metal ions attached to the surface of calcite to achieve efficient inhibition of calcite. The above technical method is used to treat high-calcite fluorite ore with a raw fluorite content of 25wt.%-35wt.%, and a calcite content of 30wt.%-50wt.%, and a high-quality fluorite concentrate product with a CaF2 content of more than 97.5wt.%, and a CaCO3 content of less than 1.0wt.% can be obtained. Compared with the prior art, the technical method of the present invention has the advantages of simple and efficient process flow, better concentrate quality, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a principle process flow chart in a specific implementation manner of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] The fluorite sample processed in this embodiment was collected from a place in Xinjiang. The original fluorite content was 32.60% (expressed as CaF2 content in the concentrate index) and the calcite content was 48.52% (expressed as CaCO3 content in the concentrate index). Figure 1 The process shown in the figure includes the following steps:

[0025] 1) The rod mill is used to grind the -2mm raw ore, the grinding concentration is 60%, and the grinding fineness is -0.074mm, accounting for about 68wt.%;

[0026] 2) The grinding product is transferred to an XFD flotation cell, and the pulp concentration is adjusted to about 35wt.% to obtain a pulp product;

[0027] 3) The ore pulp product was pretreated with iron ions at a dosage of 12000 g / t, a stirring intensity of 2000 r / min, and a pretreatment time of 30 min;

[0028] 4) After the pretreatment is completed, 300 g / t of tartaric acid inhibitor and 250 g / t of sodium oleate collector are added in sequence, and after stirring for 3 minutes, flotation and roughing are started to obtain roughing concentrate and roughing tailings, and the roughing time is 2 minutes; for the roughing tailings, 100 g / t of tartaric acid inhibitor and 80 g / t of sodium oleate collector are added in sequence, and after stirring for 3 minutes, flotation and scavenging are started to obtain scavenging concentrate and tailings 1, and the scavenging time is 1 minute;

[0029] 5) The rough concentrate is subjected to 7 cleaning operations, wherein 200 g / t of tartaric acid as an inhibitor is added in cleaning 1, and the cleaning time is 2 min; 100 g / t of tartaric acid as an inhibitor is added in cleaning 2, and the cleaning time is 2 min; 50 g / t of tartaric acid as an inhibitor and 50 g / t of sodium oleate as a collector are added in cleaning 3, and the cleaning time is 2 min; 50 g / t of tartaric acid as an inhibitor is added in cleaning 4, and the cleaning time is 1.5 min; 50 g / t of tartaric acid as an inhibitor is added in cleaning 5, and the cleaning time is 1.5 min; 50 g / t of tartaric acid as an inhibitor is added in cleaning 6, and 50 g / t of sodium oleate as a collector are added, and the cleaning time is 1.5 min; 50 g / t of tartaric acid as an inhibitor is added in cleaning 7, and the cleaning time is 1 min, to obtain fluorite concentrate;

[0030] 6) The scavenged concentrate obtained by scavenging and the middlings 1 to 7 obtained by concentrating 1 to concentrating 7 are combined, and 200 g / t of tartaric acid, an inhibitor, and 50 g / t of sodium oleate, a collector, are added in sequence, and after stirring for 3 minutes, the middling reselection is started to obtain the middling reselected concentrate and tailings 2;

[0031] 7) The middling concentrate is returned to the main process 1; and tailings 1 and tailings 2 are combined as the final tailings.

[0032] Comparative Example 1:

[0033] Except that step 3) is omitted and metal ions are not added to pretreat the slurry product, other experimental conditions and dosages of reagents are the same as those in Example 1.

[0034] Comparative Example 2:

[0035] Step 3) is omitted. In step 4), the metal ions and the inhibitor are added to the slurry product at the same time. Other experimental conditions and dosages of the reagents are the same as those in Example 1.

[0036] Table 1 Comparison of flotation effects of Example 1 / %

[0037]

[0038] Analysis of Table 1 shows that, compared with pretreatment without metal ions, the use of iron ions for pretreatment increases the CaF2 grade of the concentrate by 2.18% and decreases the CaCO3 by 1.21%. This indicates that calcite is better inhibited by pretreatment with iron ions. In addition, the inhibitory effect of calcite is greatly reduced when metal ions and inhibitors are added simultaneously. The CaF2 grade of the concentrate is only 94.38%, and the CaCO3 content is as high as 3.06%. This is related to the fact that when metal ions and inhibitors are added simultaneously, the two will consume each other and become ineffective, thereby reducing the inhibitory effect on calcite.

[0039] Example 2

[0040] This embodiment is basically the same as embodiment 1, except that the metal ion is copper ion and the inhibitor is tannic acid.

[0041] Comparative Example 3

[0042] Step 3) was omitted, and no metal ions were added to pretreat the slurry. Other test conditions and dosages of reagents were the same as those in Example 2.

[0043] Table 2 Comparison of flotation effects of Example 2 / %

[0044]

[0045] From the analysis of Table 2, it can be seen that, compared with the case where no metal ions were used for pretreatment, the concentrate CaF2 grade increased by 1.40% and CaCO3 decreased by 0.83% after copper ion pretreatment, indicating that calcite was better suppressed by copper ion pretreatment.

[0046] Example 3

[0047] The fluorite sample processed in this embodiment was collected from a place in Yunnan. The original fluorite content was 28.53% (expressed as CaF2 content in the concentrate index) and the calcite content was 32.10% (expressed as CaCO3 content in the concentrate index). Figure 1 The process shown in the figure includes the following steps:

[0048] 1) The rod mill is used to grind the -2mm ore, the grinding concentration is 60%, and the grinding fineness is -0.074mm, accounting for about 72.5%;

[0049] 2) The grinding product is transferred to the XFD flotation cell, and the pulp concentration is adjusted to about 35% to obtain a pulp product;

[0050] 3) The ore pulp product was pretreated with iron ions at a dosage of 15000 g / t, a stirring intensity of 2000 r / min, and a pretreatment time of 35 min;

[0051] 4) After the pretreatment is completed, 500 g / t of inhibitor tannic acid and 300 g / t of collector sodium oleate are added in sequence, and after stirring for 3 minutes, flotation roughing is started to obtain roughing concentrate and roughing tailings, and the roughing time is 2 minutes; for the roughing tailings, 150 g / t of inhibitor tannic acid and 100 g / t of collector sodium oleate are added in sequence, and after stirring for 3 minutes, flotation scavenging is started to obtain scavenging concentrate and tailings 1, and the scavenging time is 1 minute;

[0052] 5) The coarse concentrate is subjected to 8 concentrations, wherein 250 g / t of tannic acid is added as an inhibitor in concentration 1, and the concentration time is 2 min; 150 g / t of tannic acid is added as an inhibitor in concentration 2, and the concentration time is 2 min; 100 g / t of tannic acid is added as an inhibitor and 50 g / t of sodium oleate is added as a collector in concentration 3, and the concentration time is 2 min; 50 g / t of tannic acid is added as an inhibitor in concentration 4, and the concentration time is 1.5 min; 50 g / t of tannic acid is added as an inhibitor in concentration 5, and the concentration time is 1.5 min; 50 g / t of tannic acid is added as an inhibitor in concentration 6, and 50 g / t of sodium oleate is added as a collector, and the concentration time is 1.5 min; 50 g / t of tannic acid is added as an inhibitor in concentration 7, and the concentration time is 1 min; 50 g / t of tannic acid is added as an inhibitor in concentration 8, and the concentration time is 1 min, to obtain fluorite concentrate;

[0053] 6) The scavenged concentrate obtained by scavenging and the middlings 1 to 8 obtained by concentrating 1 to concentrating 8 are combined, and 200 g / t of tannic acid, an inhibitor, and 50 g / t of sodium oleate, a collector, are added in sequence, and after stirring for 3 minutes, the middling reselection is started to obtain the middling reselected concentrate and tailings 2;

[0054] 7) The middling concentrate is returned to the main process 1; and tailings 1 and tailings 2 are combined as the final tailings.

[0055] Comparative Example 4

[0056] Except that step 3) is omitted and metal ions are not used to pretreat the slurry product, other experimental conditions and dosages of reagents are the same as those in Example 3.

[0057] Comparative Example 5

[0058] In steps 4) to 6) of flotation purification, the inhibitor is water glass, and other experimental conditions and dosage of reagents are the same as those in Example 3.

[0059] Table 3 Comparison of flotation effects of Example 3 / %

[0060]

[0061] Analysis of Table 3 shows that, compared with the pretreatment without metal ions, the concentrate CaF2 grade increased by 1.75% and CaCO3 decreased by 1.14% after the pretreatment with iron ions. This shows that calcite is better inhibited by the pretreatment with iron ions. In addition, the inhibitory effect of water glass on calcite after the pretreatment with iron ions was greatly reduced, and the concentrate CaF2 grade was 96.54%, and the CaCO3 content was as high as 1.63%, which proves that the selective inhibitory effect of water glass on calcite is much lower than that of tannic acid.

[0062] Example 4

[0063] This embodiment is basically the same as embodiment 3, except that the metal ion is aluminum ion and the collector is sodium dodecyl sulfate.

[0064] Comparative Example 6

[0065] Except that step 3) is omitted and metal ions are not used to pretreat the slurry product, other test conditions and reagent dosages are the same as those in Example 4.

[0066] Comparative Example 7

[0067] As comparative condition 7: except that the aluminum ion pretreatment time was 2 minutes, other experimental conditions and dosage of reagents were the same as those in Example 4.

[0068] Table 4 Comparison of flotation effects of Example 4 / %

[0069]

[0070] Analysis of Table 4 shows that, compared with the case of no metal ion pretreatment, the CaF2 grade of the concentrate increased by 1.44% and the CaCO3 decreased by 1.07% after aluminum ion pretreatment. This indicates that calcite is better inhibited by aluminum ion pretreatment. In addition, the inhibitory effect on calcite decreased significantly when the aluminum ion pretreatment time was 2 minutes, and the CaF2 grade of the concentrate was 97.12%, and the CaCO3 content was as high as 1.37%, proving that when the metal ion pretreatment time is too short, it is difficult to form stable active sites for inhibitor adsorption on the calcite surface, resulting in a decrease in the inhibitor's selective inhibitory effect on calcite.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flotation purification method for fluorite ore with high calcite content, characterized in that: The following steps are involved: (1) Metal ion pretreatment: After grinding and slurrying of fluorite ore with a calcite content of 30wt.%-50wt.%, a slurry product is obtained, and metal ions are added to the slurry product for stirring pretreatment; (2) Flotation separation: The pretreated pulp is subjected to flotation purification to obtain fluorite concentrate, in which the CaF2 content is greater than 97.5wt.%, and the CaCO3 content is less than 1.0wt.%.

2. The method for flotation purification of fluorite ore with high calcite content according to claim 1, characterized in that: In step (1), the particle size of the fluorite ore is -2 mm, the grinding fineness is -0.074 mm, accounting for 55wt.%-75wt.%, and the slurry concentration is 25wt.%-40wt.%.

3. A flotation purification method for fluorite ore with high calcite content according to claim 1, characterized in that: In step (1), the metal ion is any one of iron, copper, aluminum and lead, the dosage is 3000g / t-15000g / t, the stirring intensity is 1500r / min-2500r / min, and the pretreatment time is 15min-60min.

4. The method for flotation purification of fluorite ore with high calcite content according to claim 1, characterized in that: In step (2), an inhibitor and a collector are added to the pretreated slurry for flotation purification, and the inhibitor is any one of tartaric acid and tannic acid.

5. The method for flotation purification of fluorite ore with high calcite content according to claim 1, characterized in that: The collector is any one of sodium oleate, oleic acid, and sodium dodecyl sulfate.

6. A flotation purification method for fluorite ore with high calcite content according to any one of claims 1 to 5, characterized in that: In step (2), flotation purification includes a roughing process to obtain a roughing concentrate and a roughing tailings, the roughing concentrate is subjected to 6-8 rounds of concentrating to obtain a fluorite concentrate and a concentrated middling, the roughing tailings are subjected to a scavenging process to obtain tailings 1 and a scavenging concentrate, the scavenging concentrate and the concentrated middling are subjected to middling re-selection to obtain a middling re-selection concentrate and tailings 2, the middling re-selection concentrate is returned to the roughing concentrate, and tailings 1 and tailings 2 are combined into the final tailings.

7. The method for flotation purification of fluorite ore with high calcite content according to claim 6, characterized in that: The dosage of inhibitor in roughing operation is 200g / t-1200g / t, and the dosage of collector is 150g / t-500g / t; The dosage of inhibitor in the sweeping operation is 50g / t-300g / t, and the dosage of collector is 50g / t-100g / t; the total dosage of inhibitor in the concentrating operation is 300g / t-1200g / t, and the total dosage of collector is 50g / t-150g / t.

8. The method for flotation purification of fluorite ore with high calcite content according to claim 6, characterized in that: The dosage of inhibitor in the middling ore re-selection operation is 100-300g / t, and the dosage of collector is 25-75g / t.

9. The method for flotation purification of fluorite ore with high calcite content according to claim 1, characterized in that: In step (1), the fluorite content of the fluorite ore is 25wt.%-35wt.%.

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