A high-efficiency comprehensive recovery method of copper-sulfur ore

Abstract

The application discloses a high-efficiency copper-sulfur ore comprehensive recovery method and belongs to the technical field of mineral separation. First, the ore is crushed and ground to achieve the monomer dissociation among minerals, and a small amount of lime is added into the mill to adjust the pH to 8-9; diethyl thiourea and ethyl xanthate are used as a selective combined collector of chalcopyrite, and a copper concentrate is obtained after one roughing, two scavenging and two cleaning operations; the tailings after copper selection are subjected to desliming and sulfuric acid activation, and a sulfur concentrate and tailings are obtained through one roughing, three scavenging and three cleaning operations. The method uses the high-efficiency copper combined collector diethyl thiourea and ethyl xanthate, can greatly reduce the dosage of pyrite inhibitor, simultaneously reduces the use of a subsequent pyrite activator, and has the advantages of high feasibility, wide application range and high product index.

Description

Technical Field

[0001] This invention relates to a highly efficient method for the comprehensive recovery of copper-sulfur ores, specifically relating to the field of mineral sorting technology. Background Technology

[0002] Chalcopyrite is a major source of copper metal and is often associated with pyrite. Flotation is a key technology for separating and recovering both. Because the natural floatability of chalcopyrite and pyrite are similar, and because the collectors used in the flotation process lack selectivity (such as xanthates), separating them presents many difficulties.

[0003] Currently, the industrial application of suppressing pyrite under high-alkalinity conditions (pH around 12) by adjusting the slurry with lime and then using high-grade xanthates (such as isobutyl and isoamyl xanthates) for chalcopyrite flotation is mature. However, this method has drawbacks such as low copper recovery, poor concentrate quality, and difficulty in recovering associated precious metals. In addition, subsequent sulfur beneficiation operations under these conditions require the addition of large amounts of activators, resulting in high production costs. Summary of the Invention

[0004] To address the shortcomings in the copper-sulfur separation process, the present invention aims to provide a highly efficient method for the comprehensive recovery of copper-sulfur ores, achieving copper-sulfur separation under low-alkali conditions while also activating and recovering pyrite at low cost.

[0005] The technical solution of the present invention is: a comprehensive recovery method for copper-sulfur ore, using diethylthiourea and ethyl xanthate as selective combined collectors I for chalcopyrite, wherein the mass ratio of diethylthiourea and ethyl xanthate is 2-2.5:1.

[0006] Preferably, the amount of the combined collector of the present invention added is 60-80 g / t.

[0007] Preferably, the recycling method of the present invention specifically includes the following steps:

[0008] (1) Add 500-800g / t of lime during the grinding of copper-sulfur ore to adjust the pH of the slurry to between 8 and 9;

[0009] (2) Add combined collector I and frother No. 2 oil to the slurry obtained in step (1), and then carry out a roughing, scavenging and finishing process to obtain copper concentrate and copper tailings.

[0010] (3) After the copper tailings obtained in step (2) are deslimed and concentrated, an activator composed of ferrous sulfate and sodium carbonate is added, wherein the amount of ferrous sulfate is 800-1000 g / t and the amount of sodium carbonate is 400-500 g / t; then a collector II composed of ethyl xanthate, isopropyl xanthate and isobutyl xanthate is added, and frother No. 2 oil is added. Under the conditions of one roughing, three scavenging and three cleaning, sulfur concentrate and tailings are obtained.

[0011] The desliming and thickening operation described in step (3) of this invention is as follows: after the copper tailings undergo a first-stage thickening operation, the overflow from the first-stage thickener enters a hydrocyclone to remove the -15μm particle size of the ore slime. The bottom flow from the first-stage thickener and the sediment from the hydrocyclone enter the second-stage thickener. The overflow from the second-stage thickener returns to the first-stage thickener, and the bottom flow from the second-stage thickener enters the pyrite activation flotation operation.

[0012] Preferably, the fineness of the slurry of the present invention is 74-76% -200 mesh; or it achieves relative dissociation between useful minerals and between useful minerals and gangue minerals.

[0013] Preferably, in step (2) of the present invention, the coarse selection operation time is 5-6 minutes, the sweeping operation time is 3-4 minutes, and the fine selection operation time is 5-6 minutes.

[0014] Preferably, the mass ratio of ferrous sulfate to sodium carbonate in the activator in step (3) of the present invention is 2:1.

[0015] Preferably, in step (3) of the present invention, the mass ratio of ethyl xanthate, isopropyl xanthate and isobutyl xanthate is 3:3:4.

[0016] Preferably, the total amount of ethyl xanthate, isopropyl xanthate and isobutyl xanthate added in step (3) of the present invention is 150-200 g / t.

[0017] The copper-sulfur ore described in this invention is preferably a high-sulfur, low-copper type copper-sulfur ore, with chalcopyrite as the main copper mineral and pyrite as the main sulfur mineral.

[0018] This invention reveals that diethylthiourea exhibits good selective collecting ability for chalcopyrite under low-alkali conditions, but almost no collecting ability for pyrite under weakly alkaline conditions. Using a small amount of lime under low-alkali conditions can inhibit pyrite formation to some extent while preserving the high floatability of chalcopyrite. Low-grade xanthates such as ethyl xanthate can be used to ensure the overall copper recovery rate. In subsequent sulfur beneficiation operations, due to the relatively small degree of inhibition, efficient recovery of pyrite can be achieved with a small amount of activator and the use of relatively low-grade xanthates such as ethyl, isopropyl, and isobutyl xanthates as collectors.

[0019] Beneficial effects of the present invention

[0020] (1) The highly efficient copper collector diethylthiourea used in this invention has strong selectivity, and when combined with ethyl xanthate, it can achieve efficient separation of copper-sulfur minerals under low alkalinity conditions.

[0021] (2) Compared with the high-alkali inhibition of using a large amount of lime, the copper-sulfur separation method under low alkalinity adopted in this invention can improve the copper recovery rate by about two percentage points while ensuring the quality of copper concentrate.

[0022] (3) Compared with the high-alkali inhibition of using a large amount of lime, the copper-sulfur separation method under low alkalinity adopted in this invention can reduce the amount of activator by nearly half in the activated flotation of pyrite, thus saving a lot of reagent costs.

[0023] (4) The copper-sulfur ore comprehensive recovery method used in this invention has good copper-sulfur mineral separation effect, more complete overall recovery of copper-sulfur resources, strong adaptability, and can bring higher economic benefits to enterprises. Attached Figure Description

[0024] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0026] The minerals used in the embodiments of this invention are derived from raw ore from a copper-sulfur mine in Yunnan Province, with a total copper grade of 0.5-0.6% and a total sulfur grade of 8-10%. The copper minerals are mainly chalcopyrite, and the pyrites are mainly pyrite.

[0027] Example 1

[0028] A comprehensive recovery method for copper-sulfur ore, the flotation flow chart is as follows: Figure 1 As shown, the specific steps include:

[0029] (1) Example 1 corresponds to a raw ore with low copper and sulfur content, with a total copper content of 0.51% and a total sulfur content of 8.62%. 500g / t of lime was added during grinding to adjust the pH of the slurry to between 8 and 8, and the slurry was obtained by grinding.

[0030] (2) Add selective combined collector I for chalcopyrite to the slurry obtained in step (1), add frother No. 2 oil, and return the middlings products step by step to obtain copper concentrate and copper tailings under the process of one roughing, three scavenging and two cleaning; the roughing operation time is 6 minutes, the scavenging operation time is 3 minutes, and the cleaning operation time is 6 minutes.

[0031] (3) After a thickening process, the copper tailings overflow from the thickener enter the hydrocyclone to remove the -15μm sludge. The thickener underflow and hydrocyclone sediment enter the second thickening process. The thickener overflow from the second thickening process returns to the first thickening process. The thickener underflow from the second thickening process enters the pyrite activation flotation process.

[0032] (4) Before the activation flotation of pyrite, add the combined activator, collector II, frother No. 2 oil, and return the middlings in sequence to obtain pyrite concentrate and tailings under the process of one roughing, three scavenging and three cleaning; the roughing operation time is 6 minutes, the scavenging operation time is 4 minutes, and the cleaning operation time is 5 minutes.

[0033] In this embodiment, the total dosage of selective combined collector I for chalcopyrite is 60 g / t, and the frother is 30 g / t. The copper beneficiation reagents are distributed as follows: roughing operation accounts for 45%, scavenging I operation accounts for 20%, scavenging II operation accounts for 15%, and scavenging III operation accounts for 10%.

[0034] In this embodiment, the total dosage of collector II for sulfur selection is 180 g / t, and the frother is 40 g / t. The sulfur selection reagents are distributed as follows: 45% for roughing, 20% for scavenging I, 15% for scavenging II, and 10% for scavenging III. The sulfur selection activator is added only before roughing, with 800 g / t of ferrous sulfate and 400 g / t of sodium carbonate.

[0035] The flotation product parameters of Example 1 are shown in Table 1.

[0036] Table 1 Flotation parameters for Example 1

[0037]

[0038] When using the method of this invention to process relatively low-grade ore, Example 1 yielded a copper concentrate with a copper grade of 19.03% and a copper recovery rate of 91.25%; after desliming, a sulfur concentrate with a sulfur grade of 47.83% and a sulfur recovery rate of 78.83% was obtained. The results show that Example 1 has a significant copper-sulfur separation effect, producing high-quality copper and sulfur concentrates.

[0039] Example 2

[0040] The variables between Example 2 and Example 1 are described in the specific implementation, and the conditions not described are the same as in Example 1.

[0041] The specific implementation method is as follows:

[0042] (1) Example 2 corresponds to a raw ore with high copper and sulfur grades, with a total copper grade of 0.58% and a total sulfur grade of 9.88%. 800g / t of lime was added during grinding to adjust the pH of the slurry to between 8 and 9.

[0043] (2) In Example 2, the total dosage of selective combined collector I for chalcopyrite was 80 g / t, the total dosage of sulfur beneficiation collector II was 180 g / t, the sulfur activator was 1000 g / t of ferrous sulfate, and the dosage of sodium carbonate was 500 g / t.

[0044] The flotation results of Example 2 are shown in Table 2.

[0045] Table 2. Flotation results of Example 2

[0046]

[0047] Compared to Example 1, when using the method of this invention to process relatively high-grade raw ore, the required amounts of lime, combined collector I, collector II, and activator need to be appropriately increased. Example 2 produced a copper concentrate with a copper grade of 19.25% and a copper recovery rate of 91.37%; and a sulfur concentrate with a sulfur grade of 47.66% and a sulfur recovery rate of 77.65%. The flotation indicators of Example 2 are similar to those of Example 1, indicating that this method has strong adaptability to processing this type of copper-sulfur ore and can achieve good copper-sulfur separation.

[0048] Comparative Example 1

[0049] Comparative Example 1 treats the same type of ore as Example 1. Process variables are described in the specific implementation method. Undescribed conditions are the same as in Example 1.

[0050] The specific implementation method is as follows:

[0051] (1) In Comparative Example 1, 2000g / t of lime was added during grinding to adjust the pH of the slurry to around 12.

[0052] (2) The copper selection collector is prepared by mixing ethyl xanthate and isopentyl xanthate in a 1:1 ratio to form collector III. The dosage and addition method are the same as in Example 1.

[0053] (2) In the comparative example 1, the amount of ferrous sulfate activator used in the sulfur selection operation was 2000 g / t, and the amount of sodium carbonate used was 1000 g / t.

[0054] The flotation parameters of Comparative Example 1 are shown in Table 3.

[0055] Table 3. Flotation Indicators of Comparative Example 1

[0056]

[0057] Compared to Example 1, when using a large amount of lime to suppress pyrite, copper minerals such as chalcopyrite are also suppressed to some extent, requiring the use of high-grade xanthates such as isoamyl xanthate for collection. Furthermore, the subsequent pyrite activation operation requires more than twice the amount of activator. Regarding product indicators, compared to Example 1, Example 1 yielded a copper concentrate with a copper grade of 19.18% and a copper recovery rate of 89.83%; and a sulfur concentrate with a sulfur grade of 46.96% and a sulfur recovery rate of 76.53%. Although the copper concentrate produced by this method has a slightly higher grade, the copper recovery rate is reduced by approximately 1.4 percentage points compared to Example 1. In addition, the copper recovery rate in the sulfur concentrate indicators increased by approximately 1.5 percentage points, while the sulfur concentrate grade and recovery rate were slightly lower.

[0058] Comparative Example 2

[0059] Comparative Example 2 treats the same type of ore as Example 2. Process variables are described in the specific implementation method. Conditions not described are the same as in Example 2.

[0060] The specific implementation method is as follows:

[0061] (1) In Comparative Example 1, 3000g / t of lime was added during grinding to adjust the pH of the slurry to about 12.

[0062] (2) The copper selection collector is prepared by mixing ethyl xanthate and isopentyl xanthate in a 1:1 ratio to form collector III. The dosage and addition method are the same as in Example 2.

[0063] (3) In Comparative Example 2, the amount of ferrous sulfate activator used in the sulfur operation was 3000 g / t, and the amount of sodium carbonate used was 1500 g / t.

[0064] The flotation parameters of Comparative Example 2 are shown in Table 4.

[0065] Table 3. Flotation Indicators of Comparative Example 2

[0066]

[0067] Compared to Example 2, the process parameters require more high-grade xanthate and a greater amount of pyrite activator when using more lime to suppress pyrite. Product indicators compared to Example 2: Example 2 yielded a copper concentrate with a copper grade of 19.20% and a copper recovery rate of 89.25%; and a sulfur concentrate with a sulfur grade of 47.17% and a sulfur recovery rate of 76.38%. While the copper and sulfur concentrate grades in Example 2 are similar, the copper recovery rate is reduced by approximately 2 percentage points in the sulfur concentrate, and the sulfur recovery rate is reduced by approximately 2 percentage points in the tailings.

[0068] The flotation results of Comparative Examples 1 and 2 show that the separation of copper and sulfide minerals can be achieved when a large amount of lime is used as a depressant. However, while pyrite is strongly suppressed, copper minerals are also suppressed to some extent. The lost copper is enriched in the sulfur concentrate during the activated flotation of pyrite, while some sulfur is lost in the tailings. Furthermore, the pyrite activation process requires a higher amount of activator. Therefore, the separation effect of the methods in Comparative Examples 1 and 2 for this type of ore is poor, the overall recovery efficiency of copper and sulfide resources is lower, and the production cost is higher.

[0069] Comparative Example 3

[0070] Comparative Example 3 treats the same type of ore as Example 1. Process variables are described in the specific implementation method. Undescribed conditions are the same as in Example 1.

[0071] The specific implementation method is as follows:

[0072] (1) The copper-selecting collector is either diethylthiourea or ethyl xanthate alone, at a dosage of 60 g / t, and is added in the same way as in Example 1.

[0073] The flotation parameters of Comparative Example 3 are shown in Table 5.

[0074] Table 5. Flotation Indicators of Comparative Example 3

[0075]

[0076] When diethylthiourea was used alone as the collector, under the same conditions as in the examples, the copper concentrate grade reached 25.80%, but the copper recovery was poor at only 75.23%, while the copper recovery in the sulfur concentrate increased to 22.28%. When ethyl xanthate was used alone as the collector, the copper concentrate recovery was 95.64%, but the copper grade was only 14.22%, the sulfur grade in the copper concentrate reached 38.68%, and the sulfur recovery was 14.61%.

[0077] The flotation results of Comparative Example 3 show that, under the conditions of Example 1, using diethylthiourea alone as a collector has the disadvantage of strong selectivity but weak collecting ability; using ethyl yellow alone as a collector has the disadvantage of poor selectivity and excessively strong collecting ability. Therefore, the present invention uses a mixture of diethylthiourea and ethyl yellow in a ratio of 2-2.5:1 as a copper collector under these conditions, which compensates for the former's lack of collecting ability and the latter's lack of selectivity, thus achieving highly efficient copper-sulfur separation.

Claims

1. A comprehensive method for recovering copper-sulfur ore, characterized in that: The recycling method specifically includes the following steps: (1) Add 500-800g / t of lime during the grinding of copper-sulfur ore to adjust the pH of the slurry to between 8 and 9, and then grind to obtain the slurry. (2) Add combined collector I and frother No. 2 oil to the slurry obtained in step (1), and then carry out a roughing, scavenging and finishing process to obtain copper concentrate and copper tailings. (3) After the copper tailings obtained in step (2) are deslimed and concentrated, an activator composed of ferrous sulfate and sodium carbonate is added, wherein the amount of ferrous sulfate is 800-1000 g / t and the amount of sodium carbonate is 400-500 g / t; then a collector II composed of ethyl xanthate, isopropyl xanthate and isobutyl xanthate is added, and frother No. 2 oil is added. Under the conditions of one roughing, three scavenging and three cleaning, sulfur concentrate and tailings are obtained. Diethylthiourea and ethyl xanthate are used as selective combined collectors I for chalcopyrite, wherein the mass ratio of diethylthiourea to ethyl xanthate is 2~2.5:1; The addition amount of the combined collector I is 60-80 g / t.

2. The comprehensive recovery method for copper-sulfur ore according to claim 1, characterized in that: The grinding conditions in step (1) are: 74-76% of the slurry has a fineness of -200 mesh; or the useful minerals are relatively liberated from each other and from gangue minerals.

3. The comprehensive recovery method for copper-sulfur ore according to claim 1, characterized in that: The grinding conditions in step (1) are: the roughing operation time in step (2) is 5-6 minutes, the scavenging operation time is 3-4 minutes, and the cleaning operation time is 5-6 minutes.

4. The comprehensive recovery method for copper-sulfur ore according to claim 1, characterized in that: The mass ratio of ferrous sulfate to sodium carbonate in the activator in step (3) is 2:

1.

5. The comprehensive recovery method for copper-sulfur ore according to claim 1, characterized in that: In step (3), the mass ratio of ethyl xanthate, isopropyl xanthate and isobutyl xanthate is 3:3:

4.

6. The comprehensive recovery method for copper-sulfur ore according to claim 1, characterized in that: In step (3), the total amount of ethyl xanthate, isopropyl xanthate and isobutyl xanthate added is 180-200 g / t.

7. The comprehensive recovery method for copper-sulfur ore according to claim 1, characterized in that: In step (3), the coarse selection operation takes 5-6 minutes, the sweeping operation takes 4-5 minutes, and the fine selection operation takes 4-5 minutes.

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