Flotation separation method for recovering pyrite from barite associated ore

Abstract

The invention relates to a flotation separation method for recovering pyrite from barite associated ore. The invention relates to a flotation separation method for recovering pyrite from barite associated ore. The flotation separation method comprises the following steps that raw ore is taken and put into a flotation tank to be subjected to size mixing treatment; a regulator is added into the ore pulp, the pH value is regulated, and then a barite inhibitor, a collecting agent and a foaming agent are sequentially added; and at least two times of roughing and one time of scavenging are conducted on the ore pulp, and finally a pyrite product and a barite product are obtained respectively. According to the flotation separation method for recycling the pyrite from the barite associated ore, the aluminum salt modified water glass with the selective inhibition capacity is used for effectively inhibiting barite, and the pyrite can be better separated out; meanwhile, carbon dioxide gas is used for replacing sulfuric acid to regulate and control the pH of the system, the floatability of the pyrite can be remarkably improved, and meanwhile potential safety hazards and environmental pollution are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ore dressing, and in particular to a flotation separation method for recovering pyrite from barite associated ore. Background Art

[0002] Barite is an important non-metallic mineral, the main component of which is barium sulfate. The quality of barite resources in my country is relatively good, with an average grade of 75.2%. Among them, high-grade rich ores are mainly concentrated in Guizhou, Guangxi Zhuang Autonomous Region and other places. In order to improve the purity and output of barite, a variety of mineral processing technologies are often used, including hand selection, flotation and gravity separation. The hand selection method is simple and convenient, with low cost, but it has high requirements for ore and low production efficiency, while flotation and gravity separation can effectively improve the quality and purity of the concentrate.

[0003] Pyrite is one of the most widely distributed sulfides in the earth's crust and is widely present in various ores. When dealing with complex ores containing pyrite, flotation is usually used for separation and enrichment. However, for barite-associated ores containing pyrite, due to their similar floatability, complex mineral composition and fine embedded particle size, traditional flotation processes and flotation agents are difficult to achieve the expected results. Therefore, the development of a new flotation separation method for barite and pyrite is of great significance for the recovery and utilization of pyrite from barite-associated ores. Summary of the invention

[0004] Based on this, the object of the present invention is to provide a flotation separation method for recovering pyrite from barite associated ore, by using aluminum salt modified water glass with selective inhibition ability as a barite inhibitor, the barite is effectively inhibited, and the pyrite can be better separated; at the same time, by using carbon dioxide gas instead of sulfuric acid to control the pH of the slurry system, the floatability of pyrite can be significantly improved, while reducing safety hazards and environmental pollution problems.

[0005] The present invention is achieved through the following technical solutions:

[0006] A flotation separation method for recovering pyrite from barite associated ore comprises the following steps:

[0007] S1, slurry preparation: take the raw ore into the flotation tank and add appropriate amount of water for slurry preparation;

[0008] S2, pretreatment: adding a regulator to the slurry to adjust the pH value, and then adding a barite inhibitor, a collector and a frother in sequence;

[0009] S3, flotation: the pulp is subjected to at least two roughing selections and one scavenging selection, and finally flotation foam and in-tank pulp are obtained respectively. The flotation foam is the pyrite product, and the in-tank pulp is the barite product.

[0010] Furthermore, in step S1, the raw ore is preliminarily crushed and screened before being added to the flotation cell, particles with a particle size of less than 1 mm are finely ground, the product is screened, and samples with a particle size of less than 0.08 mm are taken for flotation.

[0011] Furthermore, in step S1, the feed concentration is controlled to be 40% to 50%.

[0012] Furthermore, in step S2, the adjusting agent is carbon dioxide, and the pH is adjusted to 6.0-6.5.

[0013] Compared with the traditional sulfuric acid as an adjuster to adjust the pH of the slurry system, carbon dioxide, as a common gas, has low cost and low chemical activity. When adjusting the pH of the slurry, carbon dioxide can make pyrite more easily attached to bubbles, significantly improving the floatability of pyrite, thereby improving flotation efficiency. At the same time, carbon dioxide is added to the slurry system in a gaseous state, which can improve its mixing efficiency with the slurry. In addition, carbon dioxide has low chemical activity and will not produce toxic and harmful by-products during mixing with the slurry, which can reduce safety hazards and environmental pollution in the flotation separation process. In addition, carbon dioxide is easier to store and transport than sulfuric acid.

[0014] Furthermore, in step S2, the collector is a mixed solution including butyl xanthate, DTC (dithiocarbamate), and thiocarbamate.

[0015] Furthermore, the collector is a solution in which butyl xanthate, DTC, and thiocarbamate are mixed with deionized water in a mass ratio of 5:3:2 to form a solute content of 7%.

[0016] Furthermore, the foaming agent is a combined foaming agent formed by mixing MIBC (methyl isobutyl carbinol) and pine oil in a ratio of 4:6.

[0017] Furthermore, the barite inhibitor is aluminum salt modified water glass, and its inhibitory effect on barite is mainly reflected in its selective inhibitory effect. Specifically, aluminum salt modified water glass can increase the negative charge on the surface of the mineral and reduce the hydrophilicity of the mineral surface during the flotation process, thereby inhibiting the flotation of the mineral. In addition, the silicate colloid particles formed during the acidification process have stronger hydrophilicity and selective adsorption capacity, which makes its inhibitory effect more obvious.

[0018] Furthermore, the aluminum salt modified water glass is prepared by stirring deionized water, sodium silicate and aluminum sulfate at a mass ratio of 10:3:2 at 80° C., and the amount added during flotation is 100 g / t.

[0019] Furthermore, in step S2, the addition interval of the various flotation reagents is 3 to 5 minutes, and after the addition of the flotation reagents is completed, stirring is continued for 2 minutes to perform scraping flotation.

[0020] In step S3, the specific flotation process is determined according to the pyrite grade in the original ore; when the pyrite grade in the original ore is greater than 18%, the flotation process is set to two roughing selections and one scavenging selection; when the pyrite grade in the original ore is ≤18%, the flotation process is set to two roughing selections, two concentrating selections and one scavenging selection, and the roughing concentrates obtained from the two roughing selections are combined for two concentrating selections to improve the grade of the recovered pyrite.

[0021] It is understandable that in actual production, the specific flotation process can be designed according to the pyrite grade and barite grade in the actual raw ore, but it is not limited to this.

[0022] It should be noted that the pH of the flotation system is always kept at 6.0-6.5 during the flotation process, and the collector and frother are added in sequence in each specific process of the flotation. In each process of the flotation process, the amount of the collector added is 10-120 g / t, and the amount of the frother is 5-45 g / t.

[0023] Specifically, in some flotation processes, two roughing steps and one scavenging step are included. For example, in the first roughing step, the amount of collector and frother added is 120g / t and 45g / t respectively; in the second roughing step, the amount of collector and frother added is 50g / t and 25g / t respectively; in the scavenging step, the amount of collector and frother added is 40g / t and 30g / t respectively.

[0024] In some other flotation processes, two concentration steps are also performed on the rougher concentrate obtained from the two roughing steps. For example, the amount of collector and frother added in the first concentration step is 10 g / t and 6 g / t respectively; the amount of collector and frother added in the second concentration step is 10 g / t and 6 g / t respectively.

[0025] Combination Figure 1 and Figure 2 As an example of a flotation separation method for recovering pyrite from barite associated ore, it includes two roughing selections, two cleaning selections and one scavenging selection, and its specific implementation steps are:

[0026] Take the raw ore into the flotation tank, add appropriate amount of water for slurry adjustment, and control the feed concentration to 50%;

[0027] Slowly introduce carbon dioxide gas into the slurry until the pH drops to 6.0-6.5, then add the prepared aluminum salt modified water glass, the addition amount is 100g / t, add the compounded collector after 3 minutes, stir for 3 minutes, add the combined frother, and stir for another 2 minutes before starting to scrape the foam;

[0028] The first roughing is performed to obtain a first roughing concentrate and a first roughing ore, a certain amount of collector and frother are added to the first roughing ore, and the second roughing is performed to obtain a second roughing concentrate and a second roughing ore.

[0029] Then the first rougher concentrate and the second rougher concentrate are combined, and a certain amount of collector and frother are added to carry out the first concentration, and the first concentration obtains the first concentrated concentrate and the first concentrated middlings; wherein a certain amount of collector and frother are added to the first concentrated concentrate, and the second concentration is carried out to obtain the second concentrated concentrate and the second concentrated middlings, and the second concentrated concentrate is the pyrite enriched sample.

[0030] At the same time, a certain amount of collector and frother is added to the second roughing ore for scavenging to obtain tailings and scavenged concentrate; the first roughing ore, the second roughing ore, and the scavenged concentrate are returned to the original ore.

[0031] It should be noted that Figure 2 This is only one example of a flotation separation method for recovering pyrite from barite associated ore involved in the present invention, and is not limited thereto.

[0032] The beneficial effects of the present invention are:

[0033] (1) By using carbon dioxide gas instead of sulfuric acid to control the pH of the system, the safety hazards and environmental pollution problems existing when traditional sulfuric acid is used as a regulator can be effectively solved; and carbon dioxide can significantly improve the floatability of pyrite, thereby improving the flotation efficiency;

[0034] (2) Adding carbon dioxide to the slurry system in a gaseous state can improve its mixing efficiency with the slurry;

[0035] (3) Aluminum salt-modified water glass with selective inhibition ability is used as a barite inhibitor. It can produce a specific effect on the surface of barite through specific chemical groups and structural characteristics, thereby achieving effective inhibition and better separation of pyrite.

[0036] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The present invention provides a flotation separation method for recovering pyrite from barite associated ore;

[0038] Figure 2 A flow chart of a flotation separation method for recovering pyrite from a barite associated ore provided in Example 1;

[0039] Figure 3 A flow chart of a flotation separation method for recovering pyrite from barite associated ore provided in Example 2. DETAILED DESCRIPTION

[0040] 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.

[0041] Example 1

[0042] See also Figure 2 , take the lead-zinc tailings containing barite as the original ore, the barite grade in the original ore is 15% to 20%, and the pyrite grade is 5% to 7%.

[0043] The ore powder is screened and the ore powder with suitable particle size is selected to enter the flotation tank. Water is added to adjust the slurry to control the feed concentration to 50%. The flotation machine used is an XFD-type single-tank flotation machine. Stir for 10 minutes to mix the ore sample and water evenly.

[0044] Slowly introduce carbon dioxide into the slurry until the pH drops to 6.5, then add the prepared aluminum salt modified water glass in an amount of 100g / t, add the compounded collector after 3 minutes, stir for 3 minutes, add the combined frother, and stir for another 2 minutes before starting to scrape the foam.

[0045] The pretreated slurry system is subjected to the first roughing and the second roughing, and then the roughing concentrate obtained twice is subjected to the first concentrating and the second concentrating to obtain the second concentrating concentrate; at the same time, the roughing middling obtained in the second roughing is subjected to scavenging to obtain scavenging concentrate and tailings, and the first concentrating middling, the second concentrating middling and the scavenging concentrate obtained in the first concentrating and the second concentrating respectively are returned to the original ore.

[0046] The tailings are barite-enriched samples, and the second concentrated concentrate is pyrite-enriched samples. The samples from each process were dried at 40°C and sent for testing. The test data is shown in Table 1.

[0047] In the above flotation steps, the amounts of collector and frother added in the first roughing process are 120 g / t and 45 g / t respectively; the amounts of collector and frother added in the second roughing process are 50 g / t and 25 g / t respectively; the amounts of collector and frother added in the scavenging process are 40 g / t and 30 g / t respectively; the amounts of collector and frother added in the first concentrating process are 10 g / t and 6 g / t respectively; the amounts of collector and frother added in the second concentrating process are 10 g / t and 6 g / t respectively.

[0048] Example 2

[0049] See also Figure 3 , take the lead-zinc tailings containing barite as the raw ore, the barite grade in the raw ore is 8%-10%, and the pyrite grade is 20%-23%. Screen the ore powder, select the ore powder with suitable particle size for slurry adjustment, add water to adjust the slurry to control the feed concentration to 40%, and the flotation machine used is the XFD-type single-slot flotation machine, and stir for 10 minutes to mix the ore sample and water evenly.

[0050] Slowly introduce carbon dioxide into the slurry until the pH drops to 6.0, then add the prepared aluminum salt modified water glass in an amount of 100g / t, add the compounded collector after 3 minutes, stir for 3 minutes, add the combined frother, and stir for another 2 minutes before starting to scrape the foam.

[0051] The pretreated slurry system is subjected to a first roughing selection to obtain a first roughing concentrate and a first roughing middling; the first roughing middling is subjected to a second roughing selection to obtain a second roughing concentrate and a second roughing middling, and the second roughing middling is subjected to scavenging selection to obtain a scavenged concentrate and tailings, and the scavenged concentrate is returned to the original ore.

[0052] The tailings are barite-enriched samples, and the first rougher concentrate and the second rougher concentrate are pyrite-enriched samples. The samples from each process are dried at 40°C and sent for inspection and testing. The test data are shown in Table 2.

[0053] In the above flotation steps, the amounts of collector and frother added in the first roughing process are 120 g / t and 45 g / t respectively; the amounts of collector and frother added in the second roughing process are 50 g / t and 25 g / t respectively; and the amounts of collector and frother added in the scavenging process are 40 g / t and 30 g / t respectively.

[0054] Comparative Example 1

[0055] The difference between Comparative Example 1 and Example 1 is that sulfuric acid is used as an adjusting agent to adjust the pH value of the slurry system, and aluminum salt-modified water glass is not added as a barite inhibitor. The remaining steps are the same as in Example 1.

[0056] Comparative Example 2

[0057] The difference between Comparative Example 2 and Example 2 is that sulfuric acid is used as an adjusting agent to adjust the pH value of the slurry system, and aluminum salt-modified water glass is not added as a barite inhibitor. The remaining steps are the same as in Example 2.

[0058] The samples obtained in Example 1 and Comparative Example 1 were tested, and the obtained data are shown in Table 1. The samples obtained in Example 2 and Comparative Example 2 were tested, and the obtained data are shown in Table 2.

[0059] Table 1 Open circuit mineral processing indicators of Example 1 and Comparative Example 1

[0060]

[0061]

[0062] Table 2 Open circuit mineral processing indicators of Example 2 and Comparative Example 2

[0063]

[0064] The recovery requirements in the embodiment of the present invention are: the pyrite grade of the concentrate after flotation can reach more than 40%, and the pyrite grade of the tailings is less than 1%.

[0065] Although the grade of the raw ore used in Example 1 and Comparative Example 1 is relatively low, the reserves are large and the recovery value alone is low, but the comprehensive recovery of barite and pyrite from the lead-zinc tailings has certain economic value. As can be seen from Table 1, in Comparative Example 1, sulfuric acid is used to adjust the pH of the system, and no barite inhibitor is added. The pyrite recovery rate in the second concentrated concentrate is 56.06%, and the pyrite grade in the tailings is 3.19%. The pyrite grade in the second concentrated concentrate is only 30.9%, which does not meet the recovery requirements. In comparison, the pyrite recovery rate in the second concentrated concentrate of Example 1 can reach 81.41%, the pyrite grade in the tailings is 0.65%, and the pyrite grade in the second concentrated concentrate is greatly improved, up to 41.41%. The recovery rate of barium sulfate in the tailings obtained in Example 1 is increased to 95.10%, compared with the recovery rate of barium sulfate in the tailings obtained in Comparative Example 1 of 68.88%. Example 1 uses aluminum salt-modified water glass as a barite inhibitor, which can effectively inhibit the flotation of barite and improve the flotation efficiency.

[0066] As can be seen from Table 2, the ore grade used in Example 2 is relatively high, and a good separation effect can be achieved by only two roughing and one scavenging. Similarly, compared with Comparative Example 2, Example 2 uses carbon dioxide instead of sulfuric acid as an adjusting agent to adjust the pH value of the slurry system, and at the same time increases the barite inhibitor to inhibit the flotation of barium sulfate, and its various beneficiation indicators are better than Comparative Example 2. Specifically, the grade of pyrite in the first roughing concentrate of Example 2 can reach 47.85%, the grade of pyrite in the second roughing concentrate can reach 40.29%, and the grade of pyrite in the tailings is as low as 0.55%, meeting the recovery requirements. At the same time, the recovery rate of barium sulfate in the tailings of Example 2 is 95.27%, highlighting that the use of aluminum salt-modified water glass as a barite inhibitor has an excellent inhibitory effect on the flotation of barite in the ore.

[0067] Compared with the prior art, the beneficial effects of the present invention are:

[0068] (1) By using carbon dioxide gas instead of sulfuric acid to control the pH of the system, the safety hazards and environmental pollution problems existing when traditional sulfuric acid is used as a regulator can be effectively solved; and carbon dioxide can significantly improve the floatability of pyrite, thereby improving the flotation efficiency;

[0069] (2) Adding carbon dioxide to the slurry system in a gaseous state can improve its mixing efficiency with the slurry;

[0070] (3) Aluminum salt-modified water glass with selective inhibition ability is used as a barite inhibitor. It can produce a specific effect on the surface of barite through specific chemical groups and structural characteristics, thereby achieving effective inhibition and better separation of pyrite.

[0071] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A flotation separation method for recovering pyrite from barite associated ore, characterized in that: The steps include: S1, slurry preparation: take the raw ore into the flotation tank and add appropriate amount of water for slurry preparation; S2, pretreatment: adding a regulator to the slurry to adjust the pH value, and then adding a barite inhibitor, a collector and a frother in sequence; S3, flotation: the pulp is subjected to at least two roughing selections and one scavenging selection, and finally flotation foam and in-tank pulp are obtained respectively. The flotation foam is the pyrite product, and the in-tank pulp is the barite product.

2. A flotation separation method for recovering pyrite from a barite associated ore according to claim 1, characterized in that: In step S1, the feed ore concentration is controlled to be 40% to 50%.

3. A flotation separation method for recovering pyrite from a barite associated ore according to claim 1, characterized in that: In step S2, the adjusting agent is carbon dioxide, and the pH is adjusted to 6.0-6.

5.

4. A flotation separation method for recovering pyrite from a barite associated ore according to claim 1, characterized in that: In step S2, the collector is a mixed solution including butyl xanthate, DTC, and thiocarbamate.

5. A flotation separation method for recovering pyrite from a barite associated ore according to claim 4, characterized in that: The collector is a mixed solution of butyl xanthate, DTC, thiocarbamate and deionized water in a mass ratio of 5:3:2 with a solute content of 7%.

6. A flotation separation method for recovering pyrite from a barite associated ore according to claim 1, characterized in that: The foaming agent is a combined foaming agent formed by mixing MIBC and pine oil in a ratio of 4:

6.

7. A flotation separation method for recovering pyrite from a barite associated ore according to claim 1, characterized in that: The barite inhibitor is aluminum salt modified water glass.

8. A flotation separation method for recovering pyrite from barite associated ore according to claim 7, characterized in that: The aluminum salt modified water glass is prepared by stirring deionized water, sodium silicate and aluminum sulfate at a mass ratio of 10:3:2 at 80° C., and the amount added during flotation is 100 g / t.

9. A flotation separation method for recovering pyrite from barite associated ore according to claim 1, characterized in that: In step S3, the specific flotation process is determined according to the pyrite grade in the original ore; when the pyrite grade in the original ore is greater than 18%, the flotation process is set to two roughing selections and one scavenging selection; when the pyrite grade in the original ore is ≤18%, the flotation process is set to two roughing selections, the roughing concentrates obtained from the two roughing selections are combined for two concentrating selections, and the roughing concentrates obtained from the second roughing selection are scavenged.

10. A flotation separation method for recovering pyrite from barite associated ore according to claim 1, characterized in that: During the flotation process of step S3, the pH of the flotation system is always maintained at 6.0-6.5.

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