A method for stepwise deep copper recovery from copper furnace slag containing natural copper

Abstract

The application discloses a kind of copper furnace slag containing natural copper, and the copper furnace slag containing natural copper is gradually deep copper selection method, and the copper furnace slag containing natural copper gradually deep copper selection method includes one-stage classification flotation, two-stage classification flotation and three-stage flotation steps.The application adopts step-by-step grinding, step-by-step selection, conventional grinding equipment+vertical stirring mill combined grinding equipment, flotation machine+flotation column combined flotation equipment, magnetic separation+screening+flotation combined process step-by-step deep selection of copper element in copper furnace slag.Copper element in copper furnace slag is selected by step-by-step deep selection.Copper element in copper furnace slag is selected by step-by-step deep selection.Adopting reverse magnetic separation process, coarse-grained and coarse-grained natural copper is recovered from one-stage grinding classification sand, and adopting screening process, relatively coarse-grained natural copper is recovered from one-stage grinding classification overflow, and adopting flotation process, fine-grained natural copper is recovered, which avoids natural copper from being deposited in grinding circuit or flotation tank by conventional flotation process.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical technology, specifically relating to a method for stepwise deep copper selection from copper slag containing native copper. Background Technology

[0002] Copper slag, a major byproduct of copper pyrometallurgical processes, generates approximately 2.2 tons of slag for every ton of copper produced. Copper slag has a high copper content, typically exceeding 0.5%, and is characterized by its dense, hard, and brittle structure, as well as its high density. Its chemical composition varies depending on the raw materials fed into the furnace and the smelting process. Generally, copper slag mainly consists of copper minerals (copper sulfide, small amounts of metallic copper and copper oxide), magnetite, fir olivine, and a glassy phase, and also contains precious metals such as gold and silver. Methods for recovering copper from copper slag can be categorized into three types: pyrometallurgical depletion, hydrometallurgy, and mineral processing. Compared to pyrometallurgical depletion and hydrometallurgical methods, mineral processing offers advantages such as lower cost, less pollution, and more stable processes, and has been widely adopted. Flotation is the most commonly used mineral processing method. The copper minerals in copper slag exhibit uneven distribution, and concentrated grinding can easily lead to the mudification of coarse copper minerals, while fine and micro-fine copper minerals fail to dissociate, affecting the separation effect. Native copper, due to its high density, coarse particle size, and good ductility, tends to deposit in grinding circuits or flotation cells, affecting the grinding and beneficiation efficiency of copper slag. Therefore, it is essential to develop a method that can solve the above-mentioned technical problems. Summary of the Invention

[0003] The purpose of this invention is to provide a method for stepwise deep copper selection from copper slag containing native copper.

[0004] The objective of this invention is achieved as follows: the method for graded deep copper beneficiation of copper slag containing native copper includes three stages of flotation: a first-stage flotation, a second-stage flotation, and a third-stage flotation. Specifically, it includes: A. First-stage flotation: 1) After the raw ore is ground in one stage, it is classified in one stage to obtain classified overflow slurry a and classified sand b; 2) The graded overflow slurry a is screened through a 120-mesh vibrating screen to obtain the oversize product c of natural copper and the undersize product d. 3) The graded sand b is subjected to reverse magnetic separation using a magnetic separator to obtain magnetic concentrate e and magnetic tailings f. The magnetic tailings f are native copper. The magnetic concentrate e is returned to a grinding step. B. Two-stage fractional flotation: 1) Add an adjuster to the screened product d to adjust the pH value to 9~10, then add a collector to carry out flotation to obtain flotation concentrate g and flotation tailings h. Flotation concentrate g is copper concentrate. 2) The flotation tailings h are classified in two stages to obtain the classification overflow slurry i and the classification sand j. The classification sand j is returned to the previous step after two stages of grinding. 3) The graded overflow slurry i is processed through a roughing, scavenging, and finishing process to obtain copper concentrate k and scavenging tailings l; C. Three-stage flotation: 1) After the scavenging tailings l are subjected to magnetic separation, magnetic concentrate m and magnetic tailings n are obtained; 2) The magnetic concentrate m is classified in three stages to obtain the graded overflow slurry o and the graded underflow p. The graded underflow p is ground in three stages and then returned to the previous step. 3) The graded overflow slurry is processed through a roughing and finishing process to obtain copper concentrate and tailings.

[0005] This invention employs a multi-stage grinding and beneficiation process, combining conventional grinding equipment with a vertical stirred mill, a flotation machine with a flotation column, and a magnetic separation, screening, and flotation combination to achieve deep separation of copper from copper slag. Reverse magnetic separation is used to recover lumpy and coarse-grained native copper from the first-stage grinding and classification sediment; screening is used to recover relatively coarse-grained native copper from the first-stage grinding and classification overflow; and flotation is used to recover fine-grained native copper, avoiding the deposition of native copper in the grinding loop or flotation cell using conventional flotation processes. Simultaneously, utilizing the characteristics of the flotation machine and flotation column, a multi-stage process is employed to efficiently recover coarse, fine, and micro-fine-grained copper minerals, thereby achieving deep separation and high-value utilization of copper from copper slag. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the existing technology process. Figure 2 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0007] The present invention will be further described below with reference to embodiments, but this is not intended to limit the present invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0008] The method for graded deep copper selection from copper slag containing native copper described in this invention includes three stages: a first-stage flotation, a second-stage flotation, and a third-stage flotation. Specifically, it includes: A. First-stage flotation: 1) After the raw ore is ground in one stage, it is classified in one stage to obtain classified overflow slurry a and classified sand b; 2) The graded overflow slurry a is screened through a 120-mesh vibrating screen to obtain the oversize product c of natural copper and the undersize product d. 3) The graded sand b is subjected to reverse magnetic separation using a magnetic separator to obtain magnetic concentrate e and magnetic tailings f. The magnetic tailings f are native copper. The magnetic concentrate e is returned to a grinding step. B. Two-stage fractional flotation: 1) Add an adjuster to the screened product d to adjust the pH value to 9~10, then add a collector to carry out flotation to obtain flotation concentrate g and flotation tailings h. Flotation concentrate g is copper concentrate. 2) The flotation tailings h are classified in two stages to obtain the classification overflow slurry i and the classification sand j. The classification sand j is returned to the previous step after two stages of grinding. 3) The graded overflow slurry i is processed through a roughing, scavenging, and finishing process to obtain copper concentrate k and scavenging tailings l; C. Three-stage flotation: 1) After the scavenging tailings l are subjected to magnetic separation, magnetic concentrate m and magnetic tailings n are obtained; 2) The magnetic concentrate m is classified in three stages to obtain the graded overflow slurry o and the graded underflow p. The graded underflow p is ground in three stages and then returned to the previous step. 3) The graded overflow slurry is processed through a roughing and finishing process to obtain copper concentrate and tailings.

[0009] In step 3), the magnetic field strength of the reverse magnetic separation is 3000~5000Gs.

[0010] The modifier mentioned in step 1) is sodium carbonate.

[0011] The collectors mentioned in step 1) are butyl xanthate and isopentyl xanthate.

[0012] The mass ratio of butyl xanthate to isopentyl xanthate is (0.5~1):(0.5~1).

[0013] In step 3 of section B, the roughing, scavenging, and finishing processes use Na2CO3 + Na2S as modifiers, control the pulp pH value in the range of 9-10, and use butyl xanthate + isopentyl xanthate as collectors.

[0014] The mass ratio of butyl xanthate to isopentyl xanthate is (0.5~1):(0.5~1).

[0015] In step C, the magnetic field strength for magnetic separation is 2000~4000 Gs.

[0016] In step 3) of C, the roughing and cleaning process uses Na2CO3 + Na2S as an adjuster, the pH value of the pulp is controlled in the range of 9 to 10, and butyl xanthate + isopentyl xanthate are used as collectors.

[0017] The mass ratio of butyl xanthate to isopentyl xanthate is (0.5~1):(0.5~1).

[0018] The present invention will be further described below with reference to specific embodiments: All embodiments of the present invention are based on Figure 2 The process flow and its specific operation are as follows: 1. The crushed copper slag containing native copper is first subjected to a first-stage grinding and classification. The fineness of the classification overflow (-0.045mm) is controlled at 60%-70%. The classification sand is subjected to reverse magnetic separation using a magnetic separator with a magnetic field strength of 4000Gs. The magnetic concentrate is returned to the first-stage grinding, and the magnetic tailings are native copper. The classification overflow is screened using a vibrating screen with a screen size of 120 mesh. The product on the screen is native copper, and the product under the screen is subjected to rapid flotation.

[0019] 2. Using Na2CO3 as a modifier, the pH value of the pulp is controlled in the range of 9-10. Butyl xanthate + isoamyl xanthate are used as collectors to rapidly float the undersize product using a flotation machine. The fast flotation concentrate is the copper concentrate, and the fast flotation tailings enter the second-stage grinding and classification.

[0020] 3. The content of -0.045mm in the two-stage overflow fineness is controlled at 75%-85%. The overflow product is subjected to flotation using a flotation machine with a process of one roughing, two scavenging, and three cleaning. Na2CO3+Na2S is used as a modifier, the pulp pH is controlled in the range of 9-10, and butyl xanthate+isoamyl xanthate is used as a collector. The scavenging concentrate is returned centrally, and the cleaned tailings are returned sequentially to obtain copper concentrate and tailings.

[0021] 4. Scavenging tailings are separated using a magnetic separator with a magnetic field strength of 3000 Gs. The magnetic tailings are discarded. The magnetic concentrate is then subjected to three-stage grinding and classification. The three-stage grinding mill is a vertical stirred mill. The overflow fineness of the classification overflow (-0.037mm) is controlled at 85%-90%. The overflow product is then subjected to flotation using a flotation column with a one-roughing and two-cleaning process. Na2CO3 + Na2S is used as a modifier, and the pulp pH is controlled in the range of 9-10. Butyl xanthate + isopentyl xanthate is used as a collector to obtain copper concentrate and tailings.

[0022] 5. The natural copper obtained from steps 1-4 is combined with copper concentrate and then proceeded to the subsequent dehydration process.

[0023] Comparative proportion Figure 1 The process flow, the indicators obtained from the examples and comparative examples are shown in Tables 1 and 2: Table 1. Techno-economic indicators of mineral processing obtained from existing processes.

[0024] Table 2. Techno-economic indicators of mineral processing obtained from the process flow of this invention.

[0025] As can be seen from the comparison between Table 1 and Table 2, the copper concentrate grade and recovery rate obtained by the process of the present invention are higher than those of the existing technology process, especially the copper recovery rate.

Claims

1. A method for stepwise deep copper selection from copper slag containing native copper, characterized in that, The method for graded deep copper selection from copper slag containing native copper includes three stages: primary stage flotation, secondary stage flotation, and tertiary stage flotation. Specifically, it includes: A. First-stage flotation: 1) After the raw ore is ground in one stage, it is classified in one stage to obtain classified overflow slurry a and classified sand b; 2) The graded overflow slurry a is screened through a 120-mesh vibrating screen to obtain the oversize product c of natural copper and the undersize product d. 3) The graded sand b is subjected to reverse magnetic separation using a magnetic separator to obtain magnetic concentrate e and magnetic tailings f. The magnetic tailings f are native copper. The magnetic concentrate e is returned to a grinding step. B. Two-stage fractional flotation: 1) Add an adjuster to the screened product d to adjust the pH value to 9~10, then add a collector to carry out flotation to obtain flotation concentrate g and flotation tailings h. Flotation concentrate g is copper concentrate. 2) The flotation tailings h are classified in two stages to obtain the classification overflow slurry i and the classification sand j. The classification sand j is returned to the previous step after two stages of grinding. 3) The graded overflow slurry i is processed through a roughing, scavenging, and finishing process to obtain copper concentrate k and scavenging tailings l; C. Three-stage flotation: 1) After the scavenging tailings l are subjected to magnetic separation, magnetic concentrate m and magnetic tailings n are obtained; 2) The magnetic concentrate m is classified in three stages to obtain the graded overflow slurry o and the graded underflow p. The graded underflow p is then ground in three stages and returned to the previous step. 3) The graded overflow slurry is processed through a roughing and finishing process to obtain copper concentrate and tailings.

2. The method for stepwise deep copper selection from copper slag containing native copper according to claim 1, characterized in that, In step 3), the magnetic field strength of the reverse magnetic separation is 3000~5000 Gs.

3. The method for stepwise deep copper selection from copper slag containing native copper according to claim 1, characterized in that, The modifier mentioned in step 1) is sodium carbonate.

4. The method for stepwise deep copper selection from copper slag containing native copper according to claim 1, characterized in that, The collectors mentioned in step 1) are butyl xanthate and isopentyl xanthate.

5. The method for stepwise deep copper selection from copper slag containing native copper according to claim 4, characterized in that, The mass ratio of butyl xanthate to isopentyl xanthate is (0.5~1):(0.5~1).

6. The method for stepwise deep copper selection from copper slag containing native copper according to claim 1, characterized in that, In step 3 of section B, the roughing, scavenging, and finishing processes use Na2CO3 + Na2S as modifiers, control the pulp pH value in the range of 9-10, and use butyl xanthate + isopentyl xanthate as collectors.

7. The method for stepwise deep copper selection from copper slag containing native copper according to claim 6, characterized in that, The mass ratio of butyl xanthate to isopentyl xanthate is (0.5~1):(0.5~1).

8. The method for stepwise deep copper selection from copper slag containing native copper according to claim 1, characterized in that, In step C, the magnetic field strength for magnetic separation is 2000~4000 Gs.

9. The method for stepwise deep copper selection from copper slag containing native copper according to claim 1, characterized in that, In step 3) of C, the roughing and cleaning process uses Na2CO3 + Na2S as an adjuster, the pH value of the pulp is controlled in the range of 9 to 10, and butyl xanthate + isopentyl xanthate are used as collectors.

10. The method for stepwise deep copper selection from copper slag containing native copper according to claim 9, characterized in that, The mass ratio of butyl xanthate to isopentyl xanthate is (0.5~1):(0.5~1).

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