Beneficiation method of coal-series cryptocrystalline graphite

Abstract

The invention relates to the technical field of beneficiation and purification of cryptocrystalline graphite, in particular to a beneficiation method of coal-series cryptocrystalline graphite. The beneficiation method specifically comprises the following steps that raw ore is crushed to be smaller than 15 mm, products with the particle size smaller than 0.5 mm are screened out, and tailings of the products with the particle size of 0.5-15 mm are discarded in advance in a heavy liquid floating and sinking mode; the obtained gravity concentrate is combined with a product with the particle size smaller than 0.5 mm and crushed to be smaller than 0.5 mm for ore grinding and flotation; and stage grinding and stage grading are adopted, namely two times of grinding, one time of roughing, one time of scavenging and six times of concentration. According to the beneficiation method, tailings are discarded in advance, the content of gangue entering flotation is reduced, the influence of gangue argillization mixed in foam on flotation indexes is relieved, the beneficiation cost and reagent consumption are reduced, the graphite concentrate with the fixed carbon grade being 90% or above is obtained, and efficient utilization of coal-series cryptocrystalline graphite is achieved.

Description

Technical Field

[0001] This application relates to the technical field of beneficiation and purification of cryptocrystalline graphite, and particularly relates to a beneficiation method for coal-series cryptocrystalline graphite. Background Art

[0002] At present, the beneficiation of cryptocrystalline graphite mainly adopts the flotation process.

[0003] In the prior art, the invention patent with the publication number CN103072975A discloses a beneficiation and purification method for low-grade cryptocrystalline graphite. This method uses polyethylene oxide and acidified water glass as flocculants, water glass as an inhibitor, kerosene as a collector, and MIBC as a foaming agent. After multiple grinding and multiple re-selection, the flotation concentrate is magnetically separated to remove impurities, and two products meeting grade WT88 and grade W80 can be obtained, with a total recovery rate of 80%.

[0004] The invention patent with the publication number CN102773152A discloses a beneficiation process for fine flake-cryptocrystalline mixed graphite. This method adopts a process of one-time rough grinding and rough selection, five times of re-grinding, six times of fine selection, and centralized treatment of middlings. In the multiple fine selection processes, a gradually decreasing low fine selection concentration is adopted to ensure the dispersion of the pulp, thus solving the problem of serious impurity entrainment in the flotation foam, and obtaining beneficiation indexes with a fixed carbon content of 91.35% and a recovery rate of 91.30% for the final concentrate.

[0005] The invention patent with the publication number CN118022972A discloses a preparation method for high-carbon cryptocrystalline graphite. When grinding the graphite raw ore, a grinding aid accounting for 1 wt% of the cryptocrystalline graphite is added and ground in a stirred mill until the proportion of -mesh is more than 97%. Diesel oil, No. 2 oil, and fatty alcohol are used as an ultrasonic composite flotation agent. After the graphite pulp and the composite agent are fully adjusted and mixed, multiple flotation operations are carried out using a flotation machine, and the flotation foam is dried to obtain a high-carbon cryptocrystalline graphite product.

[0006] The invention patent with the publication number CN118080172A discloses a flotation method for cryptocrystalline graphite combining surface scrubbing and reagent emulsification. In this method, the graphite raw ore is fed into a grinding mill for closed-circuit grinding. The product after grinding is mixed with water to form a pulp, and then the pulp is fed into a scrubbing machine for scrubbing. After scrubbing, the pulp is adjusted and diluted, and a pH adjuster, a dispersant, an emulsified collector, and a foaming agent are added in sequence for flotation. The rough concentrate is subjected to multiple fine selections to obtain the final concentrate, and the rough tailings are subjected to multiple scavenging to obtain the final tailings.

[0007] The invention patent with the publication number CN105381867A discloses a flotation method for cryptocrystalline graphite. The method includes grinding operation, two-stage pulp conditioning operations and flotation operation. After two-stage pulp conditioning, roughing is carried out. The roughing concentrate is subjected to multi-stage cleaning to obtain the final concentrate, and the roughing tailings are subjected to multi-stage scavenging to obtain the final tailings.

[0008] For the flotation of cryptocrystalline graphite, multiple grinding and multiple separation are usually adopted, and the reagent system and beneficiation process are relatively complex. The main reason for this is that the disseminated particle size of coal-series cryptocrystalline graphite is relatively fine, closely symbiotic with gangue minerals, and the gangue is interspersed or wrapped in graphite particles. Very fine grinding fineness is required to achieve the monomer dissociation of graphite and gangue minerals. However, too fine grinding fineness will increase the energy consumption of beneficiation, and it is easy to over-grind, resulting in pulp slimeification. The gangue minerals are entrained in the foam and float up, which is difficult to inhibit, deteriorating the flotation index.

[0009] Through the conventional flotation process, the fixed carbon grade of coal-series cryptocrystalline graphite can generally be increased from 60 - 70% to 80 - 87%. It is very difficult to further increase the concentrate grade. At the same time, a relatively high recovery rate will be lost, and the beneficiation cost is relatively high. This restricts the development and efficient utilization of coal-series cryptocrystalline graphite. Many mining enterprises simply hand-pick to increase the ore grade to about 85%, which is used as a low-end recarburizer or directly as high-quality anthracite, resulting in serious waste of graphite resources. Summary of the Invention

[0010] This application provides a beneficiation method for coal-series cryptocrystalline graphite.

[0011] The beneficiation method provided by this application discards the tailings in advance, reduces the gangue content entering the flotation, reduces the influence of gangue slime entrained in the foam on the flotation index, reduces the beneficiation cost and reagent consumption, obtains a graphite concentrate with a fixed carbon grade of more than 90%, and realizes the efficient utilization of coal-series cryptocrystalline graphite.

[0012] In the first aspect, this application provides a beneficiation method for coal-series cryptocrystalline graphite, adopting the following technical solution:

[0013] A beneficiation method for coal-series cryptocrystalline graphite, the beneficiation method specifically includes the following steps:

[0014] Crush the raw ore to less than 15 mm, screen out the products with a particle size less than 0.5 mm, and pre-discard the tailings of the products with a particle size of 0.5 - 15 mm by means of heavy liquid flotation and sinking; combine the obtained gravity separation concentrate with the products with a particle size less than 0.5 mm, and crush them to less than 0.5 mm for grinding and flotation; adopt stage grinding and stage separation, that is, two-stage grinding, one-stage roughing, one-stage scavenging, and six-stage cleaning.

[0015] In this application, after primary grinding, rough flotation is carried out. After the rough concentrate of rough flotation is subjected to secondary grinding, cleaning is carried out. Among them, the scavenger concentrate and the tailings of the first cleaning are returned to the rough flotation, and the remaining cleaning tailings are returned to the first cleaning.

[0016] Optionally, the pH adjuster used in flotation is quicklime.

[0017] Optionally, the inhibitor used in flotation is water glass.

[0018] Optionally, the collector used in flotation is diesel oil.

[0019] Optionally, the foaming agent used in flotation is 2 # oil.

[0020] Optionally, the separation specific gravity of heavy liquid flotation is 2.3 g / cm 3 .

[0021] In summary, this application includes at least one of the following beneficial technical effects:

[0022] The reagent system of the beneficiation method of coal-series cryptocrystalline graphite provided by this application is simple. By pre-discarding tailings, the ore grade of the flotation operation can be improved, the power consumption and reagent dosage in the grinding and flotation sections can be reduced, the economic benefits can be improved, and at the same time, the gangue mineral content in the flotation operation can be reduced, and the inclusion of gangue minerals in the flotation foam can be reduced.

[0023] For the ore sample with an original ore grade of 67.90%, the comparative example adopts the direct flotation method, that is, a closed-circuit process flow of three-stage grinding, one-stage roughing, one-stage scavenging, and seven-stage cleaning, with the middlings concentrated and returned to the roughing, and a flotation concentrate with a fixed carbon grade of 89.01% and a concentrate recovery rate of 84.99% can be obtained. While this application adopts a combined process of heavy liquid flotation - flotation, discards tailings in advance, and the grade of the ore sample entering the flotation is 80.18%.

[0024] From the test results, it can be seen that compared with the direct flotation method, the beneficiation method adopted in this application has an increase of 18.09% in the grade of the ore sample entering the flotation, can pre-discard 20.70% of the tailings of heavy liquid flotation, can reduce one-stage grinding and one-stage cleaning, streamline the grinding and flotation process, reduce the quicklime dosage by 20.70%, reduce the water glass dosage by 27.21%, reduce the collector dosage by 34.82%, and reduce the 2 # oil dosage by 36.74%, effectively reducing the reagent consumption. The concentrate grade is increased from 89.01% to 90.03%, and the concentrate recovery rate is increased from 84.99% to 87.36%. Brief Description of the Drawings

[0025] Figure 1 It is the technical route map of the beneficiation method of coal-series cryptocrystalline graphite provided by this application.

[0026] Figure 2 This is the process flow diagram of the beneficiation method for cryptocrystalline graphite in coal series provided in Embodiment 1 of the present application.

[0027] Figure 3 This is the process flow diagram of the beneficiation method for cryptocrystalline graphite in coal series provided in Comparative Example 1 of the present application. Detailed implementation manners

[0028] Before describing the embodiments of the present application in detail, it should be understood that the terms used herein are for the purpose of describing specific embodiments only. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this term belongs.

[0029] It should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Further, in the description of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0030] In the present application, the endpoints and any values within the disclosed ranges are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0031] In the present application, the term "comprising" or "including" is an open expression, that is, it includes the content specified in the present application, but does not exclude other aspects.

[0032] The present application provides a beneficiation method for cryptocrystalline graphite in coal series. The beneficiation method specifically includes the following steps:

[0033] Combined with Figure 1 , the raw ore is crushed to less than 15 mm, the product with a particle size less than 0.5 mm is screened out, and the product with a particle size of 0.5 - 15 mm is pre - tail - discarded by means of heavy - liquid flotation and sinking; the obtained gravity - separation concentrate is combined with the product with a particle size less than 0.5 mm and crushed to less than 0.5 mm for grinding and flotation; stage grinding and stage separation are adopted, that is, two - stage grinding, one - stage roughing, one - stage scavenging, and six - stage cleaning.

[0034] To make the objectives, technical solutions and advantages of this application more clear, the technical solutions in the embodiments of this application will be described clearly and completely below. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of this application. The embodiments described below are exemplary and are only used to explain this application and should not be construed as a limitation of this application.

[0035] For those technologies or conditions not specified in the embodiments, they shall be carried out according to the technologies or conditions described in the literature in this field or according to the product specifications. For the reagents or instruments whose manufacturers are not specified, they are all conventional products that can be obtained through commercial purchases.

[0036] The following further elaborates on this application in conjunction with the embodiments and test results.

[0037] Embodiment

[0038] Embodiment 1

[0039] This embodiment provides a beneficiation method for cryptocrystalline graphite in coal measures. Beneficiation is carried out on cryptocrystalline graphite in coal measures with a grade of 67.90%.

[0040] Combined with Figure 2 , the beneficiation method specifically includes the following steps:

[0041] (1) Crushing: Crush the raw ore to less than 15 mm.

[0042] (2) Screening: Screen the product after crushing, screen out the product with a particle size less than 0.5 mm, and retain the product with a particle size of 0.5 - 15 mm.

[0043] (3) Heavy liquid flotation: Use the method of heavy liquid flotation to pre-reject the tailings of the product with a particle size of 0.5 - 15 mm. The separation specific gravity is 2.3 g / cm 3 . The floating product is the concentrate of heavy liquid flotation (gravity separation concentrate), and the sinking product is the tailings of heavy liquid flotation (gravity separation tailings). A gravity separation concentrate with a grade of 82.66% is obtained, and the yield of the gravity separation tailings is 20.70%.

[0044] (4) Crushing: Combine the product with a particle size less than 0.5 mm obtained in step (2) with the gravity separation concentrate obtained in step (3) to obtain a flotation ore sample with a grade of 80.18%; and crush it to less than 0.5 mm.

[0045] (5) Grinding and flotation: Adopt staged grinding and staged separation, that is, two-stage grinding.

[0046] First-stage grinding: Add 793 g / (t of raw ore) of quicklime, and the grinding fineness with a particle size less than -0.0308 mm is 63.70%.

[0047] Add 6582 g of water glass per ton of raw ore, 1429 g of collector (diesel) per ton of raw ore, and 476 g of oil per ton of raw ore. After pulp conditioning, conduct one rough selection and one scavenging; grind the rough concentrate twice; # For the second stage of grinding: the fineness of grinding is 94.61% with a particle size of -0.0308 mm, and conduct six times of cleaning;

[0048] Return the scavenging concentrate and the tailings of the first cleaning to the rough selection, and return the remaining cleaning tailings to the first cleaning.

[0049] (6) Closed-circuit process flow, and cryptocrystalline graphite concentrate of coal series with a fixed carbon grade of 90.03% can be obtained, with a concentrate recovery rate of 87.36%.

[0050] (6) Closed-circuit process flow, and cryptocrystalline graphite concentrate of coal series with a fixed carbon grade of 90.03% can be obtained, with a concentrate recovery rate of 87.36%.

[0051] Example 2 - 4

[0052] Examples 2 - 4 respectively provide a beneficiation method for cryptocrystalline graphite of coal series.

[0053] The difference between the above examples and Example 1 is that the separation specific gravity in the heavy liquid flotation and sinking in step (3) is as shown in Table 1 specifically, and the remaining steps are the same as those in Example 1.

[0054] Table 1 Partial parameters in Examples 1 - 4

[0055]

[0056] From the comparison of the results of Examples 1 - 5, it can be seen that when the separation specific gravity is set to 2.3 g / cm 3 it can not only ensure the tailing rejection effect of the heavy liquid but also ensure the recovery rate. When the separation specific gravity is lower than 2.3 g / cm 3 the tailing grade will be too high, resulting in a loss of recovery rate. Therefore, it is preferred that the separation specific gravity is set to 2.3 g / cm 3 .

[0057] Comparative example

[0058] Comparative example 1

[0059] This comparative example provides a beneficiation method for cryptocrystalline graphite of coal series. The difference between this comparative example and Example 1 is that no pre-tailing rejection is carried out.

[0060] Combined with Figure 3 , the above beneficiation method specifically includes the following steps:

[0061] (1) Crushing: Crush the raw ore to less than 0.5 mm.

[0062] (2) Grinding and flotation: Adopt stage grinding and stage separation, that is, three-stage grinding,

[0063] The first stage of grinding: Add 1000 g of quicklime per ton of raw ore, and the grinding fineness is 59.23% with a particle size of -0.0308 mm;

[0064] Add 8300 g of water glass per ton of raw ore, 2000 g of collector per ton of raw ore, and 700 g of No. 2 oil per ton of raw ore. After pulp adjustment, conduct one rough selection and one scavenging; the rough concentrate is subjected to secondary grinding; # The second stage of grinding: The grinding fineness is 80.30% with a particle size of -0.0308 mm, and three cleaning operations are carried out; the concentrate is subjected to the third stage of grinding;

[0065] The third stage of grinding: The grinding fineness is 92.91% with a particle size of -0.0308 mm, and four cleaning operations are carried out;

[0066] The scavenging concentrate and the cleaning tailings are collectively returned to the rough selection.

[0067] (3) Closed-circuit process flow, and cryptocrystalline graphite concentrate of coal series with a fixed carbon grade of 89.01% can be obtained, with a concentrate recovery rate of 84.99%.

[0068] In Comparative Example 1, a closed-circuit process flow of three-stage grinding, one rough selection, one scavenging, and seven cleaning operations, with the middlings collectively returned to the rough selection, can obtain a flotation concentrate with a fixed carbon grade of 89.01% and a concentrate recovery rate of 84.99%. In the solution of this application,

[0069] By comparing the beneficiation methods of the above examples and comparative examples, the ore samples of the examples are compared with direct flotation using this beneficiation method. A combined process of heavy liquid flotation and flotation is adopted to discard the tailings in advance. The grade of the ore sample entering the flotation is 80.18%, and the grade of the ore sample entering the flotation is increased by 18.09% ((80.18% - 67.90%) / (67.90%) = 18.09%). 20.70% of the heavy liquid flotation tailings can be discarded in advance, which can reduce one grinding and one cleaning operation, streamline the grinding and flotation process, reduce the quicklime consumption by 20.70%, and reduce the water glass consumption by 27.21% (combining

[0070] and Figure 2 and Figure 3 , the total water glass consumption in Example 1 is 14194 g / (t of raw ore), and the total water glass consumption in Comparative Example 1 is 19500 g / (t of raw ore)), the collector consumption is reduced by 34.82% (combining Figure 2 and Figure 3 , the total collector consumption in Example 1 is 1786 g / (t of raw ore), and the total collector consumption in Comparative Example 1 is 2740 g / (t of raw ore)), the frother consumption is reduced by 36.74% (combining Figure 2 and Figure 3 , the total consumption of No. 2 oil in Example 1 is 601 g / (t of raw ore), and in Comparative Example 1, No. 2 # oil total consumption is# The total amount of oil used is 950 g / (t of raw ore), effectively reducing the consumption of reagents. The concentrate grade is increased from 89.01% to 90.03%, and the concentrate recovery rate is increased from 84.99% to 87.36%.

[0071] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, not to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of this application.

Claims

1. A method for beneficiating coal-based cryptocrystalline graphite, characterized in that: The ore dressing method specifically comprises the following steps: The raw ore is crushed to less than 15mm, the products with a particle size of less than 0.5mm are screened out, and the products with a particle size of 0.5-15mm are pre-discarded by heavy liquid flotation; the obtained gravity separation concentrate is combined with the products with a particle size of less than 0.5mm, and crushed to less than 0.5mm for grinding and flotation; stage grinding and stage separation are adopted, that is, two grindings, one roughing, one scavenging and six cleaning.

2. The ore dressing method according to claim 1, characterized in that: The pH adjuster used in flotation is quicklime.

3. The ore dressing method according to claim 1, characterized in that: The depressant used in flotation is water glass.

4. The ore dressing method according to claim 1, characterized in that: The capture agent used for flotation is diesel.

5. The ore dressing method according to claim 1, characterized in that: The frother used in flotation is 2 # Oil.

6. The ore dressing method according to claim 1, characterized in that: The separation specific gravity of heavy liquid is 2.3g / cm 3 .

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