Beneficiation method for improving copper metal recovery rate of quenched slag by slow-cooled slag

Abstract

This invention relates to a mineral processing method for improving the copper metal recovery rate of quench slag using slow-cooling slag. The method includes the following steps: (1) after crushing the slow-cooling slag, wet-milling it to a fineness of 60%~65%-325 mesh, and then performing copper flotation to obtain slow-cooling slag flotation copper concentrate; (2) after crushing and wet-milling the quench slag, adjusting the slurry, and sequentially adding sodium sulfide, butyl xanthate, and 2 # (2) The oil is subjected to coarser-grained copper mineral flotation to obtain copper rough concentrate I and primary rougher tailings; (3) The primary rougher tailings are concentrated and slurry-adjusted, then ground, and sodium sulfide is added first, followed by slow-cooling slag to float the copper concentrate for a second rougher, to obtain fine-grained copper rough concentrate II and secondary rougher tailings; (4) Copper rough concentrate I and copper rough concentrate II are combined and subjected to two cleaning processes to obtain copper concentrate and middlings from each cleaning process; (5) The secondary rougher tailings are slurry-adjusted and then added to slow-cooling slag to float the copper concentrate for copper mineral scavenging, to obtain scavenged middlings and scavenged tailings. This invention has a high copper recovery rate, simple operation, and strong process applicability.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a mineral processing method for improving the copper metal recovery rate of rapidly cooled slag using slow-cooled slag. Background Technology

[0002] The slag produced in the copper smelting process is of high grade and is a valuable secondary resource. With the rapid growth of industrial demand for copper and the increasingly tight supply of copper resources, the slag is now mostly cooled by a slag bag after discharge. This is because slow cooling can promote the growth of copper grains in the slag, which is beneficial for the subsequent beneficiation and recovery of copper metal.

[0003] However, due to limitations in early technological development, most copper smelting plants did not employ slow cooling processes when discharging slag. Instead, they typically used water quenching to cool it down and then directly stockpiled it in slag yards for natural cooling, a process known as "quench slag." Although these quench slags contain similar types of valuable minerals as slow-cooled slags, the rapid cooling process hinders the growth and precipitation of mineral particles, resulting in uneven copper mineral distribution and extremely fine grains in some valuable minerals with low liberation. This necessitates extremely high grinding fineness in the beneficiation process, but excessive grinding fineness leads to over-grinding of some metallic minerals. Furthermore, the high degree of oxidation on the surface of minerals stored for extended periods results in copper recovery rates in conventional beneficiation processes often below 45%, far lower than the beneficiation targets for slow-cooled slags (where copper recovery rates are mostly above 80%). Consequently, large amounts of quench slag stockpiles still exist both domestically and internationally. These stockpiles of quench slag occupy land, pollute the environment, and represent a significant waste of resources. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a mineral processing method that utilizes slow-cooling slag to improve the copper metal recovery rate of rapid-cooling slag, which has high economic benefits, good process stability, strong operability, and wide applicability.

[0005] To address the aforementioned problems, the present invention provides a mineral processing method for improving copper metal recovery from rapidly cooled slag using slow-cooling slag, comprising the following steps:

[0006] (1) After crushing the slow-cooling slag, wet-grind it to a fineness of 60%~65%-325 mesh, and then carry out copper flotation to obtain slow-cooling slag flotation copper concentrate;

[0007] (2) After crushing the quenched slag, wet grind it to a fineness of 75%~80%-325 mesh, then adjust the slurry to a concentration of 32%~35%, and add sodium sulfide, butyl xanthate, and 2% sodium sulfide in sequence. # The oil was subjected to coarser copper mineral flotation to obtain copper rough concentrate I and primary roughing tailings, respectively.

[0008] (3) After concentrating and adjusting the primary roughing tailings to a concentration of 65%~70%, the ore is ground, with the grinding fineness controlled at 80%~85%-400 mesh, and the slurry concentration adjusted to 32%~35%. Then, 600~800 g / t of sodium sulfide is added to the slurry and stirred for 5 minutes, followed by 5~10 kg / t of the slow-cooling slag flotation copper concentrate, and stirred for 8 minutes. After that, butyl xanthate and 2... # The oil undergoes a second roughing process to obtain fine-grained copper concentrate II and tailings from the second roughing process.

[0009] (4) After merging the copper crude concentrate I and the copper crude concentrate II, copper concentrate and middlings from each of the two refining processes are obtained.

[0010] (5) After adjusting the secondary roughing tailings slurry to a concentration of 30%~33%, add 0.5~1 kg / t of the slow-cooling slag flotation copper concentrate, stir for 8 minutes, and then add butyl xanthate and 2% xanthate in sequence. # The oil is subjected to copper mineral scavenging to obtain scavenged ore and scavenged tailings.

[0011] In step (1), the slow-cooling slag refers to copper-containing slag formed by using a slag bag slow-cooling process after the slag from copper smelting is discharged.

[0012] In step (1), copper flotation involves adjusting the pulp of the slowly cooled slag grinding product to a concentration of 30%–35%, and then adding 50–60 g / t of butyl xanthate as a collector based on the mass of the slowly cooled slag. # Using 20-30g / t of oil as a frother, the slow-cooled copper concentrate and flotation tailings are obtained after one roughing process.

[0013] In step (2), based on the mass of the quenched slag, the dosage of sodium sulfide is 500-600 g / t, and the dosage of butyl xanthate is 40-50 g / t. # The amount of oil used is 20~30g / t.

[0014] In step (3), the dosage of butyl xanthate is 100-120 g / t based on the mass of the quenched residue. # The amount of oil used is 60~80g / t.

[0015] In step (5), the dosage of butyl xanthate is 20-30 g / t based on the mass of the quenched residue. # The amount of oil used is 10~20g / t.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. This invention utilizes the similarity of copper mineral types and the differences in the embedding characteristics of copper minerals in slow-cooling slag and rapid-cooling slag obtained by different cooling processes in copper smelting slag. First, the slow-cooling slag is treated with conventional flotation process to obtain slow-cooling slag flotation copper concentrate. Then, the rapid-cooling slag is ground to a certain fineness, and a portion of the coarse-grained copper minerals is recovered by sulfidation flotation. Subsequently, the coarse-grained copper mineral flotation tailings are finely ground to an even finer fineness, and the minerals are sulfidated with sodium sulfide. Finally, the copper concentrate obtained by flotation of the slow-cooling slag is used as a carrier for the fine-grained copper minerals in the rapid-cooling slag, and the fine-grained copper is carried out by carrier flotation.

[0018] 2. On the one hand, this invention addresses the issue of uneven particle size distribution in quenched slag, with some exhibiting extremely fine distribution characteristics. It first preferentially floats a portion of the copper concentrate with coarser particle size distribution under relatively coarse fineness conditions, reducing the over-grinding loss rate. On the other hand, for the extremely fine copper-containing minerals, a carrier is prepared using the slow-cooled slag as raw material after staged fine grinding. This not only improves the recovery efficiency of fine-grained minerals through carrier flotation but also offers the advantages of readily available raw materials and a simple preparation process.

[0019] 3. In this invention, the slow-cooling slag flotation copper concentrate, as the carrier mineral, has similar properties to the supported mineral except for the particle size distribution. Therefore, there is no need to separate the carrier and the target mineral in the subsequent process.

[0020] 4. This invention fully utilizes the differences and similarities in properties between slow-cooling slag and rapid-cooling slag, and combines the advantages of carrier flotation to improve the copper metal beneficiation recovery rate in rapid-cooling slag using slow-cooling slag. It has the advantages of high copper recovery rate, simple operation, strong process applicability, and good economic benefits.

[0021] 5. This invention is applicable to the recovery of copper metal from slag (hereinafter referred to as quench slag) generated during copper pyrometallurgical processes that is directly discharged without undergoing a slow or rapid slag cooling process and is stored in outdoor slag yards for a long period of time. Detailed Implementation

[0022] A mineral processing method for improving copper metal recovery rate from quenched slag using slow-cooling slag includes the following steps:

[0023] (1) After crushing the slow-cooling slag, wet-grind it to a fineness of 60%~65%-325 mesh, and then carry out copper flotation to obtain slow-cooling slag flotation copper concentrate.

[0024] In copper flotation, the grinding product of the slowly cooled slag is adjusted to a concentration of 30%~35%, and 50~60 g / t of butyl xanthate is added as a collector based on the mass of the slowly cooled slag. # Using 20-30g / t of oil as a frother, the slow-cooled copper concentrate and flotation tailings are obtained after one roughing process.

[0025] Slow-cooling slag refers to copper-containing slag formed by using a slow-cooling slag bag process after the slag from copper smelting is discharged.

[0026] (2) After crushing the quenched slag, wet grind it to a fineness of 75%~80%-325 mesh, then adjust the slurry to a concentration of 32%~35%; based on the mass of the quenched slag, add 500~600g / t of sodium sulfide as a modifier, 40~50g / t of butyl xanthate as a collector, and 2 # Using 20-30 g / t of oil as a frother, coarser copper minerals were floated to obtain copper rough concentrate I and primary roughing tailings.

[0027] (3) After concentrating and adjusting the primary roughing tailings to a concentration of 65%~70%, grind the ore, controlling the grinding fineness to 80%~85%-400 mesh, and adjust the slurry concentration to 32%~35%. Then, based on the mass of the rapid cooling residue, add 600~800 g / t of sodium sulfide to the slurry and stir for 5 minutes. Next, add 5~10 kg / t of slow cooling residue for copper concentrate flotation and stir for 8 minutes. After that, add 100~120 g / t of butyl xanthate as a collector, 2... # Oil (60-80 g / t) was used as a frother for the second roughing process, yielding fine-grained copper concentrate II and tailings from the second roughing process.

[0028] (4) After merging copper crude concentrate I and copper crude concentrate II, copper concentrate and middlings from each of the two fine-tuning processes are obtained.

[0029] (5) After adjusting the secondary roughing tailings slurry to a concentration of 30%~33%, add 0.5~1 kg / t of slow-cooling slag for copper flotation based on the mass of the rapid cooling slag. After stirring for 8 minutes, add 20~30 g / t of butyl xanthate as a collector, 2... # Oil of 10-20 g / t was used as a frother for copper mineral scavenging to obtain scavenged ore and scavenged tailings.

[0030] Example 1

[0031] A smelting slag beneficiation plant in Gansu Province processes slow-cooling slag produced by a nearby copper smelter year-round. There is a slag dump around the plant containing a large amount of quenched slag produced by an early copper smelter, with a copper grade of about 0.51%. By using the plant's slow-cooling slag beneficiation process and conditions to process the quenched slag, the copper recovery rate of the resulting copper concentrate is about 41%.

[0032] The experimental study used the quenched slag as the research object and employed the method of this invention for mineral processing and recovery. The specific process is as follows:

[0033] (1) Take 1 kg of slow-cooling slag that has been processed annually in the beneficiation plant, crush it, wet grind it to a fineness of 60 mesh, adjust the slurry to a concentration of 34%, and add 50 g / t of butyl xanthate as a collector. #30 g / t of oil was used as a frother in copper flotation. After one roughing stage, slow-cooling slag copper concentrate and flotation tailings were obtained. The copper grade of the obtained slow-cooling slag copper concentrate was analyzed and tested for later use.

[0034] (2) After crushing the quenched slag, wet grind it to a fineness of 80%-325 mesh, then adjust the slurry to a concentration of 34%; add sodium sulfide 500g / t as a modifier, butyl xanthate 40g / t as a collector, and 2 # Using 20g / t of oil as a frother, coarser copper minerals were floated to obtain copper rough concentrate I and primary roughing tailings.

[0035] (3) After concentrating and adjusting the primary roughing tailings to a concentration of 67%, the ore is ground, with the grinding fineness controlled at 85%-400 mesh. The slurry is then adjusted to a concentration of 33%. 600 g / t sodium sulfide is added to the slurry and stirred for 5 minutes. Then, 5 kg / t of slow-cooling slag is added for copper concentrate flotation, and the mixture is stirred for 8 minutes. Afterward, 100 g / t of butyl xanthate is added sequentially as a collector, followed by 2... # 70g / t of oil was used as a frother for the second roughing process, yielding fine-grained copper concentrate II and tailings from the second roughing process.

[0036] (4) After merging copper crude concentrate I and copper crude concentrate II, copper concentrate and middlings from each of the two fine-tuning processes are obtained.

[0037] (5) After adjusting the secondary roughing tailings slurry to a concentration of 30%, add 0.5 kg / t of slow-cooling slag for copper flotation. After stirring for 8 minutes, add 20 g / t of butyl xanthate as a collector, and 2... # 10g / t of oil was used as a frother for copper mineral scavenging, yielding scavenged ore and scavenged tailings.

[0038] The above-mentioned process flow and conditions were used to conduct a closed-circuit test of the quench slag. The ore return method in the closed-circuit test was the conventional return method, that is, the middlings from each of the beneficiation processes described in step (4) and the middlings from the scavenging process described in step (5) were returned to the previous flotation operation in sequence.

[0039] The copper concentrate carrier obtained from the slow-cooling slag flotation, the copper concentrate obtained from the closed-circuit test, and the tailings were analyzed and tested separately. The metal content of the copper concentrate obtained from the closed-circuit test was deducted from the metal content of the carrier to obtain the metal content of the copper concentrate obtained by this method. The calculation showed that the copper recovery rate of the copper concentrate obtained by the closed-circuit test using the above process flow and conditions was about 55%, which is 14% higher than that of the conventional process, as shown in Table 1.

[0040] Table 1 Comparison of test results between the present invention and general technologies

[0041]

[0042] Example 2

[0043] A foreign copper smelter initially used a quenching process to cool the slag, resulting in a large stockpile of quenched slag with a copper grade of about 1%, which has a high metal value. In order to develop and utilize this secondary resource, the company owning the smelter has built a concentrator near the slag yard to process the slow-cooling slag newly discharged after the smelter's technological improvement and the stockpiled quenched slag. The copper recovery rate of the copper concentrate obtained when processing the quenched slag is low, about 45%.

[0044] The experimental study used the stockpiled quenched slag as the research object, and employed the method of this invention for mineral processing and recovery of the quenched slag. The specific process is as follows:

[0045] (1) Using the improved slow-cooling slag from the smelter as the raw material for carrier mineral production, 1.2 kg of slow-cooling slag was crushed, wet-milled to a fineness of 65 mesh, and the slurry was adjusted to a concentration of 34%. Then, 60 g / t of butyl xanthate was added as a collector. # 30 g / t of oil was used as a frother in copper flotation. After one roughing stage, slow-cooling slag copper concentrate and flotation tailings were obtained. The copper grade of the obtained slow-cooling slag copper concentrate was analyzed and tested for later use.

[0046] (2) After crushing the quenched slag, wet grind it to a fineness of 75%-325 mesh, then adjust the slurry to a concentration of 34%; add sodium sulfide 600g / t as a modifier, butyl xanthate 50g / t as a collector, and 2 # Using 30g / t of oil as a frother, coarser copper minerals were floated to obtain copper rough concentrate I and primary roughing tailings.

[0047] (3) After concentrating and adjusting the primary roughing tailings to a concentration of 67%, the ore is ground, with the grinding fineness controlled at 80%-400 mesh. The slurry is then adjusted to a concentration of 33%. 800 g / t sodium sulfide is added to the slurry and stirred for 5 minutes. Then, 8 kg / t slow-cooling slag is added for copper concentrate flotation, and the mixture is stirred for 8 minutes. Afterward, 120 g / t butyl xanthate is added sequentially as a collector, followed by 2... # 80g / t of oil was used as a frother for the second roughing process, yielding fine-grained copper concentrate II and tailings from the second roughing process.

[0048] (4) After merging copper crude concentrate I and copper crude concentrate II, copper concentrate and middlings from each of the two fine-tuning processes are obtained.

[0049] (5) After adjusting the secondary roughing tailings slurry to a concentration of 30%, add 1 kg / t of slow-cooling slag for copper concentrate flotation. After stirring for 8 minutes, add 30 g / t of butyl xanthate as a collector, 2 kg / t of... # 20g / t of oil was used as a foaming agent for copper mineral scavenging, yielding scavenged ore and scavenged tailings.

[0050] The above-mentioned process flow and conditions were used to conduct a closed-circuit test of the quench slag. The ore return method in the closed-circuit test was the conventional return method, that is, the middlings from each of the beneficiation processes described in step (4) and the middlings from the scavenging process described in step (5) were returned to the previous flotation operation in sequence.

[0051] The copper concentrate carrier obtained from the slow-cooling slag flotation, the copper concentrate obtained from the closed-circuit test, and the tailings were analyzed and tested separately. The metal content of the copper concentrate obtained from the closed-circuit test was deducted from the metal content of the carrier to obtain the metal content of the copper concentrate obtained by this technical scheme. The calculation showed that the copper recovery rate of the copper concentrate obtained by the closed-circuit test using the above process flow and conditions was about 58%, which is 13% higher than that of the conventional process, as shown in Table 2.

[0052] Table 2 Comparison of test results between the present invention and general technologies

[0053]

Claims

1. A mineral processing method for improving copper metal recovery rate from rapidly cooled slag using slow-cooled slag, comprising the following steps: (1) After crushing the slow-cooling slag, wet-grind it to a fineness of 60%~65%-325 mesh, and then carry out copper flotation to obtain slow-cooling slag flotation copper concentrate; (2) After crushing the quenched slag, wet grind it to a fineness of 75%~80%-325 mesh, then adjust the slurry to a concentration of 32%~35%, and add sodium sulfide, butyl xanthate, and 2% sodium sulfide in sequence. # The oil was subjected to coarser copper mineral flotation to obtain copper rough concentrate I and primary roughing tailings, respectively. (3) After concentrating and adjusting the primary roughing tailings to a concentration of 65%~70%, the ore is ground, with the grinding fineness controlled at 80%~85%-400 mesh, and the slurry concentration adjusted to 32%~35%. Then, 600~800 g / t of sodium sulfide is added to the slurry and stirred for 5 minutes, followed by 5~10 kg / t of the slow-cooling slag flotation copper concentrate, and stirred for 8 minutes. After that, butyl xanthate and 2... # The oil undergoes a second roughing process to obtain fine-grained copper concentrate II and tailings from the second roughing process. (4) After merging the copper crude concentrate I and the copper crude concentrate II, copper concentrate and middlings from each of the two refining processes are obtained. (5) After adjusting the secondary roughing tailings slurry to a concentration of 30%~33%, add 0.5~1 kg / t of the slow-cooling slag flotation copper concentrate, stir for 8 minutes, and then add butyl xanthate and 2% xanthate in sequence. # The oil is subjected to copper mineral scavenging to obtain scavenged ore and scavenged tailings.

2. The mineral processing method for improving copper metal recovery rate of rapidly cooled slag using slow-cooling slag as described in claim 1, characterized in that: In step (1), the slow-cooling slag refers to copper-containing slag formed by using a slag bag slow-cooling process after the slag from copper smelting is discharged.

3. The mineral processing method for improving copper metal recovery rate of rapidly cooled slag using slow-cooling slag as described in claim 1, characterized in that: In step (1), copper flotation involves adjusting the pulp of the slowly cooled slag grinding product to a concentration of 30%–35%, and then adding 50–60 g / t of butyl xanthate as a collector based on the mass of the slowly cooled slag. # Using 20-30g / t of oil as a frother, the slow-cooled copper concentrate and flotation tailings were obtained after one roughing process.

4. The mineral processing method for improving copper metal recovery rate of rapidly cooled slag using slow-cooling slag as described in claim 1, characterized in that: In step (2), based on the mass of the quenched slag, the dosage of sodium sulfide is 500-600 g / t, and the dosage of butyl xanthate is 40-50 g / t. # The amount of oil used is 20~30g / t.

5. A mineral processing method for improving copper metal recovery rate from rapidly cooled slag using slow-cooling slag as described in claim 1, characterized in that: In step (3), the dosage of butyl xanthate is 100-120 g / t based on the mass of the quenched residue. # The amount of oil used is 60~80g / t.

6. The mineral processing method for improving copper metal recovery rate of rapidly cooled slag using slow-cooling slag as described in claim 1, characterized in that: In step (5), the dosage of butyl xanthate is 20-30 g / t based on the mass of the quenched residue. # The amount of oil used is 10~20g / t.

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