Method for improving grade of sulfur concentrate by utilizing centrifugal cyclone separation principle

Abstract

The invention belongs to the technical field of mineral processing, and particularly relates to a method for improving the grade of sulfur concentrate by utilizing a centrifugal cyclone separation principle. The method for improving the grade of the sulfur concentrate by utilizing the centrifugal cyclone separation principle comprises the following steps: crushing, screening, grinding and grading the iron-copper-sulfur polymetallic ore, then carrying out bulk flotation, and finally obtaining copper concentrate and sulfur tailings through separation flotation. Sulfur tailings are conveyed to an ore feeding pool, water is added for size mixing, then the sulfur tailings are conveyed into a cyclone for centrifugal rotational flow, sand is discharged from a bottom flowing opening to form settled sand, filtering and dewatering are conducted, and sulfur concentrate is obtained. According to the method for improving the grade of the sulfur concentrate by using the centrifugal cyclone separation principle, the sulfur grade can be improved without introducing redundant chemicals by using the centrifugal cyclone separation principle and adopting a desliming, product extraction and concentration integrated treatment method, the process is simple, and the influence of the chemicals and the like on the environment is reduced.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, specifically relating to a method for improving the grade of sulfur concentrate by utilizing the principle of centrifugal cyclone separation. Background Technology

[0002] Sulfur concentrate is typically recovered from flotation tailings of pyrite, pyrrhotite, and non-ferrous metal sulfide ores (such as copper, lead, and zinc sulfide ores), or obtained as a main product from pyrite. Common beneficiation methods include flotation, gravity separation, magnetic separation, and combined processes. Flotation is suitable for fine-grained, low-grade pyrite ores ores with associated valuable metals, but it has disadvantages such as high reagent costs, significant environmental pressure, and complex processes. Gravity separation is suitable for coarse-grained, high-density pyrite, but it has disadvantages such as low fine-grain recovery and unstable grades. Magnetic separation is suitable for ores dominated by pyrrhotite, but it has disadvantages such as narrow application range and high impurities in the concentrate. In addition, although combined processes can handle ores with polymetallic symbiosis or uneven dissemination, they involve high investment and complex management.

[0003] CN103433120A discloses a gravity-flotation combined separation method for producing high-grade sulfur concentrate. Using lead-zinc flotation tailings as raw material, the concentrate is concentrated in a thickener, pH is adjusted with concentrated sulfuric acid, and two roughing and two scavenging processes are performed to obtain a rough concentrate. This rough concentrate is then subjected to gravity separation in a hydrocyclone to obtain underflow and overflow. Finally, the underflow and the refined concentrate are mixed and filtered to obtain a sulfur concentrate with a sulfur content of over 47%. This separation method preferentially separates coarse-grained sulfur concentrate, providing qualified feed for subsequent flotation; it simplifies the process, reduces costs, and improves the utilization rate of pyrite resources. The ore grade is high; CN110064519A discloses a production process for high-grade sulfur concentrate. Zinc tailings are processed through preliminary roughing, fine enrichment, and tailings scavenging and recovery, which improves the sulfur content of the sulfur concentrate and the recovery rate of the sulfur concentrate. The process is simple and the production cost is low. However, the above processes all adopt flotation processes, which require the use of various flotation reagents and multiple separations to obtain sulfur concentrate. The process is long and the production cost is high, which is not suitable for enterprises that need to commercialize sulfur tailings with simple modifications. Summary of the Invention

[0004] To overcome the aforementioned problems in the existing technology, this invention provides a method for improving the grade of sulfur concentrate using the principle of centrifugal cyclone separation. By using the principle of centrifugal cyclone separation and adopting an integrated treatment method of desliming, upgrading and concentration, the sulfur grade can be improved without the introduction of excess reagents. The process is simple and reduces the environmental impact of reagents.

[0005] The method for improving the grade of sulfur concentrate using the principle of centrifugal cyclone separation, as described in this invention, includes the following steps: (1) The iron, copper, sulfur and polymetallic ore is crushed, screened, ground and classified, and the slurry after grinding and classification is put into the beneficiation operation. (2) First, mixed flotation is carried out. Collectors and frothers are added to the slurry to initially separate the target minerals from the gangue minerals. Then, through separation flotation, the pH of the slurry is adjusted to 12-14 with lime to further separate copper and sulfur, and finally copper concentrate and sulfur tailings are obtained. The collectors are ethyl xanthate and butyl xanthate. The dosage of ethyl xanthate is 16 g / t of raw ore fed into the mill, and the dosage of butyl xanthate is 8 g / t of raw ore fed into the mill. The frother is No. 2 oil, and the dosage is 8 g / t of raw ore fed into the mill. The raw ore fed into the mill refers to the ore that has been crushed and screened and has entered the milling and classification. (3) The sulfur tailings obtained in step (2) are transported to the feed pool, water is added to adjust the slurry, and the slurry in the feed pool is transported to the hydrocyclone for centrifugal swirling through the hydrocyclone feed pump. The low-density components are discharged through the upper overflow port to obtain tailings, and the high-density components are discharged through the bottom outlet to form sediment. The sediment is filtered and dewatered to finally obtain sulfur concentrate.

[0006] In step (1), the sulfur grade in the iron-copper-sulfur polymetallic ore is 1.0 wt.%-1.2 wt.%.

[0007] In step (1), the particle size of the ore after crushing and screening is ≤12mm.

[0008] In step (1), the slurry after grinding and classification has a particle size of less than 200 mesh, accounting for 55wt.%-60wt.%.

[0009] In step (2), the particle size of the sulfur tailings is such that the proportion of particles smaller than 200 mesh in the sulfur tailings is 70wt.%-75wt.%.

[0010] In step (2), the sulfur grade in the sulfur tailings is 20wt.%-25wt.%, preferably 20wt.%-22wt.%.

[0011] In step (3), after adding water to adjust the slurry, the concentration of the slurry is 10wt.%-15wt.%.

[0012] The hydrocyclone in step (3) has the following structural parameters: diameter 150mm, cone angle 6°-10°.

[0013] In step (3), the feed pressure of the hydrocyclone feed pump is 0.09-0.11 MPa.

[0014] In step (3), after centrifugal swirling by a hydrocyclone, the concentration of the sediment is 23-25 ​​wt.%.

[0015] Compared with traditional flotation, gravity separation or combined processes, the present invention uses hydrocyclones alone to avoid complex reagent systems, numerous equipment configurations and high investment and operating costs. By making full use of the centrifugal classification characteristics of hydrocyclones, it achieves efficient recovery of sulfur resources, early reduction of filtration load and optimization of the overall process with the lowest investment and operating costs and the simplest operation and management.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention utilizes the principle of centrifugal cyclone separation to improve the grade of sulfur concentrate. By designing the hydrocyclone and coordinating the feed pressure and slurry concentration, the sulfur grade is increased to more than 30 wt.%, which meets the market's quality requirements for sulfur concentrate and forms product sulfur concentrate, effectively solving the problem of sulfur tailings being unable to be commercialized.

[0017] (2) The present invention utilizes the centrifugal cyclone separation principle to improve the grade of sulfur concentrate. The process is simple. After the sulfur tailings are classified by the hydrocyclone, the concentration of the produced sand meets the feed requirements of the filter and is directly fed into the filter dewatering operation, eliminating the thickener concentration process and thus reducing the load of subsequent dewatering operations.

[0018] (3) The present invention utilizes the centrifugal cyclone separation principle to improve the grade of sulfur concentrate. It can achieve the integrated "desliming-upgrading-concentration" of sulfur tailings by relying solely on the hydrocyclone, without the need for roughing with flotation reagents, thus avoiding environmental pollution and reducing production costs. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of the method for improving the grade of sulfur concentrate using the centrifugal cyclone separation principle of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the embodiments.

[0021] like Figure 1 As shown, the method for improving the grade of sulfur concentrate using the principle of centrifugal cyclone separation includes the following steps: (1) The iron-copper-sulfur polymetallic ore is crushed and screened to obtain ore with a particle size <12mm. Then it is ground and classified. In the slurry after grinding and classification, the proportion of particles with a particle size less than 200 mesh is 57.5±2.5wt.%, which enters the beneficiation operation. (2) First, mixed flotation is carried out. Ethyl xanthate, butyl xanthate and No. 2 oil are added to the slurry to initially separate the target mineral from the gangue mineral. Then, through separation flotation, the pH value of the slurry is adjusted to 12-14 with lime to further separate copper and sulfur, and finally copper concentrate and sulfur tailings are obtained. The proportion of particles smaller than 200 mesh in the sulfur tailings is 72.5±2.5wt.%, and the sulfur grade in the sulfur tailings is 20-22%. The dosage of ethyl xanthate is 16g / t of raw ore fed into the mill, the dosage of butyl xanthate is 8g / t of raw ore fed into the mill, and the dosage of No. 2 oil is 8g / t of raw ore fed into the mill. (3) The sulfur tailings obtained in step (2) are transported to the feed pool, and water is added to adjust the slurry concentration to 10-15 wt.%. Then, the slurry in the feed pool is tangentially fed into the hydrocyclone (structural parameters: diameter 150 mm, cone angle 6°-10°) at a feed pressure of 0.09-0.11 MPa through the hydrocyclone feed pump. The low-density components are discharged through the upper overflow port to obtain tailings, and the high-density components are discharged through the bottom outlet to form sediment. The sediment concentration is 23-25 ​​wt.%. The sediment is filtered and dewatered to finally obtain sulfur concentrate.

[0022] Example 1 The method for improving the grade of sulfur concentrate using the principle of centrifugal cyclone separation includes the following steps: (1) The iron-copper-sulfur polymetallic ore with a sulfur grade of 1.03 wt.% was crushed and screened to obtain ore with a particle size of <12 mm. Then it was ground and classified. In the slurry after grinding and classification, the proportion of particles with a particle size of less than 200 mesh was 57.5 ± 2.5 wt.%, which was then put into beneficiation. (2) Ethyl xanthate, butyl xanthate and No. 2 oil are added to the slurry to initially separate the target mineral from the gangue mineral; then, through separation flotation, the pH of the slurry is adjusted to 12 with lime to further separate copper and sulfur, and finally copper concentrate and sulfur tailings are obtained. The proportion of particles smaller than 200 mesh in the sulfur tailings is 72.5±2.5wt.%, and the sulfur grade in the sulfur tailings is 20.1wt.; the dosage of ethyl xanthate is 16g / t of raw ore fed into the mill, the dosage of butyl xanthate is 8g / t of raw ore fed into the mill, and the dosage of No. 2 oil is 8g / t of raw ore fed into the mill. (3) The sulfur tailings obtained in step (2) are transported to the feed pool, and water is added to adjust the slurry concentration to 10 wt.%. Then, the slurry in the feed pool is tangentially fed into the hydrocyclone (structural parameters: diameter 150 mm, cone angle 6°) at a feed pressure of 0.10 MPa through the hydrocyclone feed pump. The low-density components are discharged through the upper overflow port to obtain tailings, and the high-density components are discharged through the bottom outlet to form sediment. The sediment concentration is 25 wt.%. The sediment is filtered and dewatered to finally obtain sulfur concentrate. The sulfur grade in the sulfur concentrate is 30.3 wt.%.

[0023] Example 2 The method for improving the grade of sulfur concentrate using the principle of centrifugal cyclone separation includes the following steps: (1) The iron-copper-sulfur polymetallic ore with a sulfur grade of 1.09 wt.% was crushed and screened to obtain ore with a particle size of <12 mm. Then it was ground and classified. In the slurry after grinding and classification, the proportion of particles with a particle size of less than 200 mesh was 57.5 ± 2.5 wt.%, which was then put into beneficiation. (2) Ethyl xanthate, butyl xanthate and No. 2 oil are added to the slurry to initially separate the target mineral from the gangue mineral; then, through separation flotation, the pH of the slurry is adjusted to 13 with lime to further separate copper and sulfur, and finally copper concentrate and sulfur tailings are obtained. The proportion of particles smaller than 200 mesh in the sulfur tailings is 72.5±2.5wt.%, and the sulfur grade in the sulfur tailings is 20.7wt.%; the dosage of ethyl xanthate is 16g / t of raw ore fed into the mill, the dosage of butyl xanthate is 8g / t of raw ore fed into the mill, and the dosage of No. 2 oil is 8g / t of raw ore fed into the mill. (3) The sulfur tailings obtained in step (2) are transported to the feed pool, and water is added to adjust the slurry concentration to 13 wt.%. Then, the slurry in the feed pool is tangentially fed into the hydrocyclone (structural parameters: diameter 150 mm, cone angle 8°) at a feed pressure of 0.11 MPa through the hydrocyclone feed pump. The low-density components are discharged through the upper overflow port to obtain tailings, and the high-density components are discharged through the bottom outlet to form sediment. The sediment concentration is 23 wt.%. The sediment is filtered and dewatered to finally obtain sulfur concentrate with a sulfur grade of 30.9 wt.%.

[0024] Example 3 The method for improving the grade of sulfur concentrate using the principle of centrifugal cyclone separation includes the following steps: (1) The iron-copper-sulfur polymetallic ore with a sulfur grade of 1.2 wt.% was crushed and screened to obtain ore with a particle size of <12 mm. Then it was ground and classified. In the slurry after grinding and classification, the proportion of particles with a particle size of less than 200 mesh was 57.5 ± 2.5 wt.%, which was then put into beneficiation. (2) Ethyl xanthate, butyl xanthate and No. 2 oil are added to the slurry to initially separate the target mineral from the gangue mineral; then, through separation flotation, the pH of the slurry is adjusted to 14 with lime to further separate copper and sulfur, and finally copper concentrate and sulfur tailings are obtained. The proportion of particles smaller than 200 mesh in the sulfur tailings is 72.5±2.5wt.%, and the sulfur grade in the sulfur tailings is 21.8wt.%; the dosage of ethyl xanthate is 16g / t of raw ore fed into the mill, the dosage of butyl xanthate is 8g / t of raw ore fed into the mill, and the dosage of No. 2 oil is 8g / t of raw ore fed into the mill. (3) The sulfur tailings obtained in step (2) are transported to the feed pool, and water is added to adjust the slurry concentration to 15 wt.%. Then, the slurry in the feed pool is tangentially fed into the hydrocyclone (structural parameters: diameter 150 mm, cone angle 10°) at a feed pressure of 0.09 MPa through the hydrocyclone feed pump. The low-density components are discharged through the upper overflow port to obtain tailings, and the high-density components are discharged through the bottom outlet to form sediment. The sediment concentration is 23.9 wt.%. The sediment is filtered and dewatered to finally obtain sulfur concentrate. The sulfur grade in the sulfur concentrate is 31.9 wt.%.

Claims

1. A method for improving the grade of sulphur concentrates using the principle of centrifugal cyclone separation, characterized in that, The method comprises the following steps: (1) crushing and screening, grinding and grading the iron-copper-sulfur polymetallic ore, and feeding the ground and graded ore slurry into the separation operation; (2) first performing mixed flotation, adding a collector and a foaming agent into the ore slurry to preliminarily separate the target mineral from the gangue mineral; then performing separation flotation, adjusting the pH value of the ore slurry to 12-14 by using lime to further separate copper and sulfur, and finally obtaining copper concentrate and sulfur tailings; (3) feeding the sulfur tailings obtained in step (2) into a feed tank, adding water to adjust the slurry, feeding the ore slurry in the feed tank into a cyclone through a cyclone feed pump to perform centrifugal cyclone in the cyclone, discharging the low-density components through the upper overflow port to obtain tailings, discharging the high-density components through the bottom flow port to form sand, filtering and dewatering the sand, and finally obtaining sulfur concentrate.

2. The method for improving the grade of sulphur concentrate using the principle of centrifugal cyclone separation according to claim 1, characterized in that, In step (1), the sulfur grade in the iron-copper-sulfur polymetallic ore is 1.0wt.%-1.2wt.%.

3. The method for improving the grade of sulphur concentrate using the principle of centrifugal cyclone separation as claimed in claim 1, wherein, In step (1), the particle size of the ore after crushing and screening is ≤12mm.

4. The method for improving the grade of sulphur concentrate using the principle of centrifugal cyclone separation as claimed in claim 1, wherein, In step (1), the particle size of the ore slurry after grinding and grading is 55wt.%-60wt.% of particles with a size of less than 200 mesh.

5. The method for improving the grade of sulphur concentrate using the principle of centrifugal cyclone separation as claimed in claim 1, wherein, In step (2), the particle size of the sulfur tailings is 70wt.%-75wt.% of particles with a size of less than 200 mesh.

6. The method for improving the grade of sulphur concentrate using the principle of centrifugal cyclone separation as claimed in claim 1, wherein, In step (2), the sulfur grade in the sulfur tailings is 20wt.%-25wt.%.

7. The method for improving the grade of sulphur concentrate using the principle of centrifugal cyclone separation as claimed in claim 1, wherein, In step (3), after adding water to adjust the slurry, the concentration of the ore slurry is 10wt.%-15wt.%.

8. The method for improving the grade of sulphur concentrate using the principle of centrifugal cyclone separation as claimed in claim 1, wherein, In step (3), the structure parameters of the cyclone are: diameter 150mm, and cone angle 6°-10°.

9. The method for improving the grade of sulphur concentrate using the principle of centrifugal cyclone separation as claimed in claim 1, wherein, In step (3), the feed pressure of the cyclone feed pump is 0.09-0.11MPa.

10. The method for improving the grade of sulphur concentrate using the principle of centrifugal cyclone separation as claimed in claim 1 wherein, In step (3), after centrifugal cyclone in the cyclone, the concentration of the sand is 23wt.%-25wt.%. In step (3), the structure parameters of the cyclone are: diameter 150mm, and cone angle 6°-10°. In step (3), the feed pressure of the cyclone feed pump is 0.09-0.11MPa. In step (3), after centrifugal cyclone in the cyclone, the concentration of the sand is 23wt.%-25wt.%.

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