A combined depressant for the flotation separation of fluorite and calcite and its usage method

Abstract

The present invention discloses a combined depressant for the flotation separation of fluorite and calcite and a method for using the same. The combined depressant is composed of sulfonated lignite, 3,4,5-trihydroxybenzoic acid and a dispersant. By weight percentage, the sulfonated lignite is 75% - 85%, the 3,4,5-trihydroxybenzoic acid is 5% - 15%, and the dispersant is 5% - 15%. The combined depressant is applied to the flotation separation of fluorite and calcite minerals through the synergistic effect among the agents, can effectively inhibit the flotation of calcite, has no inhibitory effect on the flotation of fluorite, and has the advantages of high separation efficiency, economic environmental protection, convenient operation, easy treatment of ore dressing wastewater, etc.

Description

Technical Field

[0001] The present invention belongs to the technical field of ore dressing, and particularly relates to a combined inhibitor for flotation separation of fluorite and calcite and a using method thereof. Background Art

[0002] Fluorite is also known as fluorspar. With the rapid development of the fluorine chemical industry in recent years, the demand for fluorite resources has been increasing day by day, and many countries have restricted the export of fluorite resources as strategic reserve resources. Flotation is the most commonly used method for fluorite enrichment. Fluorite often coexists with other minerals, such as calcite, quartz, etc. For calcite-fluorite type ores, since both fluorite and calcite contain active sites of calcium ions, their floatabilities are similar, and it is difficult to carry out flotation separation. Finding an inhibitor with good selectivity is the key to recovering high-grade fluorite.

[0003] At present, the commonly used inhibitors in the flotation separation process of fluorite and calcite include silicic acid and silicate inhibitors and phosphoric acid and its salt inorganic inhibitors. The silicate inhibitors are mainly water glass inhibitors. These agents have the disadvantages of poor selectivity and stability during use, and also affect the backwater treatment. The phosphate inhibitors are mainly sodium hexametaphosphate. These agents have weak inhibitory ability, usually need to be used in combination with other agents, and have an adverse effect on the backwater. The reported organic inhibitors of calcite mainly include organic inhibitors such as tannic acid, tannin extract, and lignosulfonate. The macromolecular organic inhibitors have the drawback of poor selectivity, and it is difficult to regulate the pulp environment. Therefore, developing green and environmentally friendly calcite inhibitors with high selectivity is of great significance for improving the utilization rate of fluorite resources. Summary of the Invention

[0004] The purpose of the present invention is to provide a combined inhibitor for flotation separation of fluorite and calcite and a using method thereof. The combined inhibitor is a new type of environmentally friendly combined inhibitor, which is used for flotation separation of fluorite and calcite minerals, and can solve the problems of poor selectivity of agents and low grade of fluorite concentrate during the separation process of fluorite and calcite minerals.

[0005] The combined inhibitor for flotation separation of fluorite and calcite provided by the present invention is composed of sulfonated lignite, 3,4,5-trihydroxybenzoic acid and a dispersant; by weight percentage, the contents of each component are: 75% - 85% of sulfonated lignite, 5% - 15% of 3,4,5-trihydroxybenzoic acid, and 5% - 15% of the dispersant.

[0006] Preferably, the dispersant is at least one of sodium hexametaphosphate, sodium carbonate, and water glass.

[0007] The using method of the combined inhibitor for flotation separation of fluorite and calcite provided by the present invention includes the following steps:

[0008] 1) Grind the raw ore by ball milling to obtain a grinding product;

[0009] 2) Adjust the grinding product into pulp, add a pH adjuster to adjust the pH of the pulp to an appropriate range, and then sequentially add the combined inhibitor and collector for rough selection operation. After the rough selection is completed, separate to obtain a rough concentrate of fluorite and rough tailings;

[0010] 3) Add the combined inhibitor to the rough concentrate of fluorite obtained in step 2) for 6 - 7 times of cleaning operations to obtain a fluorite concentrate; add a collector to the rough tailings obtained in step 2) for 2 - 3 times of scavenging operations.

[0011] Preferably, in step 1), the grinding fineness is that -74μm accounts for 65% - 85%.

[0012] Preferably, in step 2), the pH adjuster is sodium carbonate or sodium hydroxide, and the pH of the pulp is adjusted to 8 - 10.

[0013] Preferably, in step 2), for the combined inhibitor, before adding, first prepare aqueous solutions with a mass concentration of 0.2% - 2% of sulfonated lignite, 3,4,5 - trihydroxybenzoic acid and a dispersant respectively, and then add the three aqueous solutions to the pulp together according to the composition ratio of the combined inhibitor.

[0014] Preferably, the collector is sodium oleate.

[0015] Preferably, in step 2), relative to the feed ore, the dosage of the combined inhibitor is 200 - 700 g / t, and the dosage of the collector is 100 - 300 g / t.

[0016] Preferably, in step 3), relative to the feed ore, the dosage of the combined inhibitor is 50 - 500 g / t, and the dosage of the collector is 30 - 150 g / t.

[0017] Preferably, in step 3), the intermediate ores obtained from scavenging and cleaning are sequentially returned to the previous - stage flotation operation.

[0018] In the present invention, sulfonated lignite, 3,4,5 - trihydroxybenzoic acid and a dispersant are used in combination as a calcite inhibitor according to a ratio. The combined inhibitor has a strong inhibitory effect on calcite through the synergistic effect among the agents, and has no influence on the flotation of fluorite. Sulfonated lignite and 3,4,5 - trihydroxybenzoic acid are organic inhibitors, which can complex calcium ions, have strong inhibitory effects and selectivity, and can prevent the collector from adsorbing on the surface of calcite; at the same time, the combined inhibitor contains a dispersant, which can improve the dispersion effect of the pulp, thereby improving the separation effect between fluorite and calcite.

[0019] The advantages of the technical solution of the present invention are as follows: During the flotation separation process of fluorite and calcite, compared with traditional inhibitors, the dosage of the reagent is greatly reduced, while the wastewater treatment cost and treatment difficulty are reduced. Moreover, the reagent has a wide source and is easy to prepare, and it will not pose a threat to the physical health of on-site production personnel. At the same time, it can adsorb some heavy metal ions in the flotation solution, the process is environmentally friendly, and the quality of the concentrate product can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the flotation flow chart of the embodiment in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Example 1

[0022] The ore used in this example is selected from a fluorite mine in Hunan. The fluorite content in the raw ore is 35.4%, the calcite content is 13.5%, and the main gangue minerals are calcite, kaolinite and quartz. For this ore, under the condition that the grinding fineness is 70% passing through -0.074mm, a separation process of one roughing, six cleaning and two scavenging is adopted (the specific process is shown in Figure 1 ), and the middlings are sequentially returned to the closed-circuit process. The combined inhibitor used in this example is composed of sulfonated lignite, 3,4,5-trihydroxybenzoic acid and sodium hexametaphosphate. The specific composition ratio and reagent conditions are as follows:

[0023] Rough separation of fluorite and calcite: Adjust the pulp pH to 8.5 with sodium carbonate. The combined inhibitor is sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium hexametaphosphate, 300 + 50 + 50 g / t, stir for 2 min; sodium oleate 200 g / t, stir for 2 min. First cleaning separation of fluorite and calcite: The combined inhibitor is sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium hexametaphosphate, 120 + 15 + 15 g / t, stir for 2 min. Second cleaning separation of fluorite and calcite: The combined inhibitor is sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium hexametaphosphate, 80 + 10 + 10 g / t, stir for 2 min. Third cleaning separation of fluorite and calcite: The combined inhibitor is sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium hexametaphosphate, 80 + 10 + 10 g / t, stir for 2 min. Fourth cleaning separation of fluorite and calcite: The combined inhibitor is sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium hexametaphosphate, 40 + 5 + 5 g / t, stir for 2 min. Fifth cleaning separation of fluorite and calcite: The combined inhibitor is sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium hexametaphosphate, 40 + 5 + 5 g / t, stir for 2 min. Sixth cleaning separation of fluorite and calcite: The combined inhibitor is sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium hexametaphosphate, 40 + 5 + 5 g / t, stir for 2 min. First scavenging separation of fluorite and calcite: Sodium oleate 100 g / t, stir for 2 min. Second scavenging separation of fluorite and calcite: Sodium oleate 50 g / t, stir for 2 min. The results of the flotation test are shown in Table 1.

[0024] Comparative Example 1

[0025] This comparative example is basically the same as Example 1, except that the combined inhibitor is changed to traditional water glass. The specific reagent regime is as follows:

[0026] Rough separation of fluorite and calcite: Adjust the pulp pH to 8.5 with sodium carbonate. Water glass 1000 g / t, stir for 2 min; sodium oleate 200 g / t, stir for 2 min. First cleaning separation of fluorite and calcite: Water glass 300 g / t, stir for 2 min. Second cleaning separation of fluorite and calcite: Water glass 200 g / t, stir for 2 min. Third cleaning separation of fluorite and calcite: Water glass 200 g / t, stir for 2 min. Fourth cleaning separation of fluorite and calcite: Water glass 100 g / t, stir for 2 min. Fifth cleaning separation of fluorite and calcite: Water glass 100 g / t, stir for 2 min. Sixth cleaning separation of fluorite and calcite: Water glass 50 g / t, stir for 2 min. First scavenging separation of fluorite and calcite: Sodium oleate 100 g / t, stir for 2 min. Second scavenging separation of fluorite and calcite: Sodium oleate 50 g / t, stir for 2 min. The results of the flotation test are shown in Table 1.

[0027] Table 1 Results of the flotation test

[0028]

[0029] The experimental results show that, compared with the traditional inhibitor sodium silicate, the combined inhibitor of the present invention can improve the fluorite grade and recovery rate in the concentrate, effectively improve the quality of the concentrate, have less impact on the environment, and use less reagent dosage.

[0030] Example 2

[0031] The ore used in this example is selected from a fluorite mine in Zhejiang. The fluorite content in the fluorite ore is 32.8%, the calcite content is 17.2%, the ore dissemination size is relatively fine, and the symbiotic relationship is complex. For this ore, the ore is first ground to -0.074mm accounting for 75%, and a separation process of one roughing, six cleanings and two scavengings is adopted (the specific process is shown in Figure 1 as shown). The combined inhibitor used in this example is composed of sulfonated lignite, 3,4,5-trihydroxybenzoic acid, and sodium silicate. The specific composition ratio and reagent conditions are as follows:

[0032] Rough separation of fluorite and calcite: Sodium carbonate 1000g / t, stirring for 3min; Combined inhibitor sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium silicate 400 + 50 + 50g / t, stirring for 2min; Sodium oleate 200g / t, stirring for 2min;

[0033] First cleaning of fluorite and calcite: Combined inhibitor sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium silicate 150 + 25 + 25g / t, stirring for 2min;

[0034] Second cleaning of fluorite and calcite: Combined inhibitor sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium silicate 120 + 15 + 15g / t, stirring for 2min;

[0035] Third cleaning of fluorite and calcite: Combined inhibitor sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium silicate 120 + 15 + 15g / t, stirring for 2min;

[0036] Fourth cleaning of fluorite and calcite: Combined inhibitor sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium silicate 80 + 10 + 10g / t, stirring for 2min;

[0037] Fifth cleaning of fluorite and calcite: Combined inhibitor sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium silicate 80 + 10 + 10g / t, stirring for 2min;

[0038] Sixth cleaning of fluorite and calcite: Combined inhibitor sulfonated lignite + 3,4,5-trihydroxybenzoic acid + sodium silicate 40 + 5 + 5g / t, stirring for 2min;

[0039] First scavenging of fluorite and calcite: Sodium oleate 100g / t, stirring for 2min;

[0040] Separation scavenging of fluorite and calcite II: Sodium oleate 50 g / t, stirring for 2 min.

[0041] The results of the flotation test are shown in Table 2.

[0042] Table 2 Results of the flotation test

[0043]

[0044] Example 3

[0045] The ore used in this example is selected from a certain fluorite mine in Inner Mongolia. The fluorite ore contains 37.1% fluorite and 9.89% calcite. The specific flotation process is shown in Figure 1 as follows. First, grind the ore to 65% passing -0.074 mm, add 1500 g / t sodium carbonate, combined inhibitor sulfonated lignite + 3,4,5 - trihydroxybenzoic acid + water glass 240 + 30 + 30 g / t, and 200 g / t collector sodium oleate for rough selection. After the rough selection, conduct 6 times of cleaning. For cleaning 1 - 3, the combined inhibitor is sulfonated lignite + 3,4,5 - trihydroxybenzoic acid + sodium hexametaphosphate 120 + 15 + 15 g / t, and for cleaning 4 - 6, the combined inhibitor is sulfonated lignite + 3,4,5 - trihydroxybenzoic acid + water glass 80 + 10 + 10 g / t. After one rough selection and six cleanings, fluorite concentrate with a grade of 91.23% and a recovery rate of 86.87% can be obtained.

Claims

1. A combined depressant for the flotation separation of fluorite and calcite, characterized in that, The combined inhibitor is composed of sulfonated lignite, 3,4,5-trihydroxybenzoic acid and a dispersant; by weight percentage, the contents of each component are: 75% - 85% of sulfonated lignite, 5% - 15% of 3,4,5-trihydroxybenzoic acid, and 5% - 15% of the dispersant.

2. The combined inhibitor according to claim 1, wherein The dispersant is at least one of sodium hexametaphosphate, sodium carbonate, and water glass.

3. A method for using the combined inhibitor according to claim 1 or 2, comprising the following steps: 1) Grinding the raw ore to obtain a grinding product; 2) Adjusting the grinding product into a pulp, adding a pH adjuster to adjust the pH of the pulp to an appropriate range, and then sequentially adding the combined inhibitor and a collector for rough selection operation. After the rough selection is completed, separation is carried out to obtain a rough fluorite concentrate and rough selection tailings; 3) Adding the combined inhibitor to the rough fluorite concentrate obtained in step 2) for 6 - 7 times of cleaning operations to obtain a fluorite concentrate; adding a collector to the rough selection tailings obtained in step 2) for 2 - 3 times of scavenging operations.

4. The usage method according to claim 3, characterized in that, In step 1), the grinding fineness is that -74μm accounts for 65% - 85%.

5. The usage method according to claim 3, characterized in that, In step 2), the pH adjuster is sodium carbonate or sodium hydroxide, and the pH of the pulp is adjusted to 8 - 10.

6. The usage method according to claim 3, characterized in that, In step 2), before adding the combined inhibitor, sulfonated lignite, 3,4,5-trihydroxybenzoic acid and the dispersant are respectively prepared into aqueous solutions with a mass concentration of 0.2% - 2%, and then the three aqueous solutions are added to the pulp together according to the composition ratio of the combined inhibitor.

7. The usage method according to claim 3, characterized in that, The collector is sodium oleate.

8. The usage method according to claim 3, wherein In step 2), relative to the feed ore, the dosage of the combined inhibitor is 200 - 700 g / t, and the dosage of the collector is 100 - 300 g / t.

9. The usage method according to claim 3, characterized in that, In step 3), relative to the feed ore, the dosage of the combined inhibitor is 50 - 500 g / t, and the dosage of the collector is 30 - 150 g / t.

10. The usage method according to claim 3, characterized in that, In step 3), the middlings obtained from scavenging and cleaning are sequentially returned to the previous stage of flotation operation.

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