A method for preferential flotation separation of fine-grained refractory lead-zinc sulfide ore

Abstract

The present application relates to a kind of fine-grained refractory sulfide lead-zinc ore preferential flotation separation method, belong to mineral processing engineering, mineral processing engineering and mineral resources comprehensive technical field.The fine-grained refractory sulfide lead-zinc ore is ground and classified operation, grinding to fineness is-0.074mm content is 80%-90%, slurry is obtained by adjusting pulp;The ore pulp is added lime, sodium hexametaphosphate, sphalerite combined inhibitor, ethyl xanthate, 2# oil preferential flotation galena, and obtain lead concentrate and preferential flotation tailings;Among them, the sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate and sodium sulfite;The obtained preferential flotation tailings are added with copper sulfate, ethyl xanthate and 2# oil to float sphalerite, and zinc concentrate and tailings are obtained.The present application uses sodium trithiocarbonate+L-cysteine combined with traditional inhibitors zinc sulfate+sodium carbonate, to achieve the inhibition of sphalerite, and to effectively separate the fine-grained refractory sulfide lead-zinc ore.

Description

Technical Field

[0001] This invention relates to a preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores, belonging to the fields of mineral processing engineering, mineral processing engineering, and comprehensive mineral resource technology. Background Technology

[0002] With the continuous mining and processing of lead-zinc ore resources, high-quality lead-zinc resources are decreasing year by year, and the resources are characterized by being "poor, fine-grained, and mixed". Due to the close and complex intergrowth relationship and fine particle size among sulfide lead-zinc ore minerals, the presence of lattice defects in some sphalerite minerals, the influence of unavoidable ions in the slurry, and their mechanical activation, some sphalerite is difficult to suppress during lead-zinc beneficiation, resulting in excessive zinc content in lead concentrate. Some lead concentrate products have zinc content as high as 10% to 15%, which is difficult to meet the quality standards of lead concentrate. At the same time, because some zinc is lost in the lead concentrate, the zinc recovery rate of zinc concentrate is low, and the separation of fine-grained sulfide lead-zinc ore is extremely difficult, resulting in resource waste.

[0003] Addressing the issue that some sphalerite is difficult to suppress under conventional depressant conditions during the preferential flotation of fine-grained, difficult-to-select sulfide lead-zinc ore, resulting in poor lead-zinc separation performance, this invention introduces sodium trithiocarbonate and L-cysteine, combined with traditional sphalerite depressants zinc sulfate and sodium sulfite, to leverage the synergistic effect between the reagents and enhance the suppression performance of sphalerite. This achieves highly efficient and selective suppression of sphalerite, enabling effective separation of lead and zinc ore and efficient resource recovery, which is of great significance. Summary of the Invention

[0004] To effectively suppress sphalerite in fine-grained, refractory sulfide lead-zinc ore, achieve efficient lead-zinc separation, and improve lead-zinc beneficiation and separation indicators, this invention provides a preferential flotation separation method for fine-grained, refractory sulfide lead-zinc ore. This invention is achieved through the following technical solution.

[0005] A method for preferential flotation separation of fine-grained, difficult-to-process lead-zinc sulfide ores includes the following steps:

[0006] S1. Grinding and classifying the fine-grained, difficult-to-process lead-zinc sulfide ore to a fineness of -0.074 mm and a content of 80%-90%, and then preparing the slurry.

[0007] S2. Add lime, sodium hexametaphosphate, sphalerite combination inhibitor, ethyl xanthate, and No. 2 oil to the slurry in S1 for preferential flotation of galena to obtain lead concentrate and preferential flotation tailings; wherein the sphalerite combination inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate and sodium sulfite.

[0008] S3. Add copper sulfate, ethyl xanthate, and No. 2 oil to the preferential flotation tailings obtained in S2 to flotation sphalerite to obtain zinc concentrate and tailings.

[0009] In S2, the preferential flotation of galena uses a one-roughing, four-cleaning, two-scavenging operation. After roughing and flotation, the lead concentrate is regrinded to a fineness of 0.045mm-0.074mm and a lead concentrate content of 95%.

[0010] The zinc sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate and sodium sulfite in a mass ratio of (0.5-1):(3-6):(40-60):(20-30), and the zinc sphalerite combined inhibitor is prepared into a 5% zinc sphalerite combined inhibitor solution and added to the flotation.

[0011] In the aforementioned roughing, cleaning, and scavenging operations, the sphalerite combination inhibitor solution described in step S2 is added to the roughing, cleaning I, and cleaning II operations, respectively. Ethyl xanthate is added as a lead mineral collector to the roughing, cleaning I, scavenging I, and scavenging II operations, and No. 2 oil is added as a frother to the roughing, cleaning I, cleaning II, scavenging I, and scavenging II operations.

[0012] In the roughing process of preferential flotation of galena in S2, lime of 1000g / t to 5000g / t and sodium hexametaphosphate of 100g / t to 500g / t are added.

[0013] The dosage of the combined inhibitor for sphalerite in the roughing, cleaning I, and cleaning II operations is 3000g / t~4500g / t, 300g / t~600g / t, and 100g / t~300g / t, respectively.

[0014] The amount of ethyl xanthate added in the roughing, cleaning I, scavenging I and scavenging II operations is 40g / t~100g / t, 10g / t~20g / t, 10g / t~20g / t, and 10g / t~20g / t, respectively; the amount of No. 2 oil added in the roughing, cleaning I, cleaning II, scavenging I and scavenging II operations is 40g / t~70g / t, 10g / t~20g / t, 10g / t~20g / t, 10g / t~20g / t, and 10g / t~20g / t, respectively.

[0015] The S3 flotation process for sphalerite employs a roughing, cleaning, and scavenging operation. Copper sulfate is added to activate the sphalerite during the roughing operation. Ethyl xanthate is added as a sphalerite collector and No. 2 oil as a frother during the roughing, cleaning (I), cleaning (II), scavenging (I), and scavenging (II) operations, respectively.

[0016] The amount of copper sulfate added is 200g / t to 500g / t.

[0017] The amounts of ethyl xanthate added in the roughing, cleaning I, cleaning II, scavenging I, and scavenging II processes are 50g / t~100g / t, 10g / t~30g / t, 10g / t~30g / t, 10g / t~30g / t, and 10g / t~20g / t, respectively; and the amounts of No. 2 oil added in the roughing, cleaning I, cleaning II, scavenging I, and scavenging II processes are 30g / t~50g / t, 10g / t~20g / t, 10g / t~20g / t, 10g / t~20g / t, and 10g / t~20g / t, respectively.

[0018] The beneficial effects of this invention are:

[0019] (1) The present invention uses sodium trithiocarbonate + L-cysteine ​​and traditional inhibitor zinc sulfate + sodium carbonate to suppress difficult-to-inhibit sphalerite and achieve effective separation of fine-grained difficult-to-select lead-zinc sulfide ores.

[0020] (2) The dosage of the combined inhibitor used in this invention is controlled within a suitable range. The inhibited sphalerite can be recovered normally after activation with copper sulfate, and the zinc recovery rate is not affected. Attached Figure Description

[0021] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] Example 1

[0024] A lead-zinc sulfide ore in Xishuangbanna, Yunnan Province, has a raw ore grade of 2.15% Pb and 1.98% Zn, with a lead oxidation rate of 5.69% and a zinc oxidation rate of 9.07%. This ore belongs to the category of fine-grained, difficult-to-process lead-zinc sulfide ore.

[0025] like Figure 1 As shown, the specific process of this preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores is as follows:

[0026] S1. Grinding and classifying the fine-grained, difficult-to-process lead-zinc sulfide ore to a fineness of -0.074 mm and a content of 80%, and then preparing the slurry to obtain a concentration of 30%.

[0027] S2. The slurry from S1 is subjected to flotation using a process of one roughing step, four cleaning steps, and two scavenging steps:

[0028] S2.1 Roughing: Add 2000g / t lime, 400g / t sodium hexametaphosphate, sphalerite combined inhibitor solution, 50g / t ethyl xanthate, and 45g / t No. 2 oil to the slurry in S1. The sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate, and sodium sulfite in a mass ratio of 1:5:60:20. The amount of sphalerite combined inhibitor added is 4300g / t (the specific dosage of each component is 50g / t of trithiocarbonate, 250g / t of L-cysteine, 3000g / t of zinc sulfate, and 1000g / t of sodium sulfite). Prepare a 5% sphalerite combined inhibitor solution. Roughing yields lead rough concentrate and roughing tailings.

[0029] S2.2 regrinding: The rough concentrate obtained in S1 is regrinded to a fineness of 0.045mm-0.074mm and a lead content of 95%, to obtain regrinded rough concentrate;

[0030] S2.3 Refinement I: The regrinded rough concentrate obtained in S2.2 is added to a sphalerite combined inhibitor solution, 50 g / t of ethyl xanthate, and 20 g / t of No. 2 oil. The sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate, and sodium sulfite in a mass ratio of 1:5:60:20. The amount of sphalerite combined inhibitor added is 600 g / t. After refinement I, refinement I lead concentrate and refinement I tailings are obtained. Refinement I tailings are returned to the roughing stage for flotation.

[0031] S2.4 Refined II: The refined I lead concentrate obtained in S2.3 is added to a sphalerite combined inhibitor solution and 15 g / t of No. 2 oil. The sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate and sodium sulfite in a mass ratio of 1:5:60:20. The amount of sphalerite combined inhibitor added is 300 g / t. After refined II, refined II lead concentrate and refined II tailings are obtained. The refined II tailings are returned to the S2.2 regrinding process.

[0032] S2.5 Refinement III and Refinement IV: The lead concentrate obtained from Refinement II in S2.4 is processed through Refinement III and Refinement IV to finally obtain lead concentrate. The tailings obtained in this process are returned to the previous processing step for flotation.

[0033] S2.6 Scavenging I: Add 20g / t ethyl xanthate and 15g / t No. 2 oil to the roughing tailings obtained in S2.1. Scavenging I yields Scavenging I lead ore and Scavenging I zinc ore. The Scavenging I lead ore is returned to the roughing process in S2.1.

[0034] S2.7 Scavenging II: Add 10g / t of ethyl xanthate and 15g / t of No. 2 oil to the zinc ore obtained from S2.6 Scavenging II yields Scavenging II lead ore and Scavenging II zinc ore. The lead ore from Scavenging II is returned to the S2.6 Scavenging I process.

[0035] S3. The zinc ore slurry from S2.7 (Scavenging II) is prepared using a flotation process consisting of one roughing step, three cleaning steps, and two scavenging steps:

[0036] S3.1 Roughing: Add 300g / t copper sulfate, 80g / t ethyl xanthate and 45g / t No. 2 oil to zinc ore with a pulp concentration of 28-32% to roughing to obtain rough zinc ore and rough zinc tailings;

[0037] S3.2, Fine Concentration I: Add 20g / t of ethyl xanthate and 15g / t of No. 2 oil to the rough zinc ore obtained from S3.1. Fine Concentration I yields Fine Concentration I zinc ore and Fine Concentration I zinc tailings. Fine Concentration I zinc tailings are returned to the roughing process in S3.1.

[0038] S3.3, Selected II: Add 20g / t of ethyl xanthate and 15g / t of No. 2 oil to the zinc ore selected in S3.2, and select II to obtain zinc ore selected in S3.2 and tailings selected in S3.2. The tailings selected in S3.2 are returned to the process of selecting I.

[0039] S3.4, Refinement III: The zinc ore obtained from Refinement II in S3.3 is refined into zinc concentrate and tailings from Refinement III. The tailings from Refinement III are returned to the Refinement II process in S3.3.

[0040] S3.5, Scavenging I: Add 30g / t ethyl xanthate and 15g / t No. 2 oil to the rough zinc tailings obtained in S3.1, and scavenging I will obtain scavenging I zinc ore and scavenging I tailings. Return the scavenging I zinc ore obtained in S3.5 to the roughing process in S3.1.

[0041] S3.6, Scavenging II: Add 20g / t of ethyl xanthate and 15g / t of No. 2 oil to the tailings obtained from Scavenging I in S3.5. Scavenging II will produce Scavenging II zinc ore and tailings. The Scavenging II zinc ore will be returned to the S3.5 Scavenging I process.

[0042] The test results of this embodiment are shown in Table 1.

[0043] Comparative Example 1

[0044] The ore used in the experiment was the same as that in Example 1. The process flow and parameters were basically the same as in Example 1, except that the sphalerite depressant was the traditional depressant zinc sulfate + sodium sulfite. Lead roughing process: 3000 g / t zinc sulfate + 1000 g / t sodium sulfite; Lead beneficiation I: 450 g / t zinc sulfate + 150 g / t sodium sulfite; Lead beneficiation II: 225 g / t zinc sulfate + 75 g / t sodium sulfite. The experimental results are shown in Table 1.

[0045] Example 2

[0046] A lead-zinc sulfide ore in Shangri-La, Yunnan Province, has a raw ore grade of 2.94% Pb and 3.02% Zn, with a lead oxidation rate of 5.22% and a zinc oxidation rate of 6.56%. The ore is classified as a fine-grained, difficult-to-process lead-zinc sulfide ore.

[0047] like Figure 1 As shown, the specific process of this preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores is as follows:

[0048] S1. Grinding and classifying the fine-grained, difficult-to-process lead-zinc sulfide ore to a fineness of -0.074 mm and a content of 90%, and then preparing the slurry to a concentration of 35%.

[0049] S2. The slurry from S1 is subjected to flotation using a process of one roughing step, four cleaning steps, and two scavenging steps:

[0050] S2.1 Roughing: Add 5000g / t lime, 100g / t sodium hexametaphosphate, sphalerite combined inhibitor solution, 60g / t ethyl xanthate, and 45g / t No. 2 oil to the slurry from S1. The sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate, and sodium sulfite in a mass ratio of 0.5:4:60:20. The amount of sphalerite combined inhibitor added is 3380g / t (the specific dosage of each component is 20g / t of trithiocarbonate, 160g / t of L-cysteine, 2400g / t of zinc sulfate, and 800g / t of sodium sulfite). Prepare a 5% sphalerite combined inhibitor solution. Roughing yields lead rough concentrate and roughing tailings.

[0051] S2.2 regrinding: The rough concentrate obtained in S1 is regrinded to a fineness of 0.045mm-0.074mm and a lead content of 95%, to obtain regrinded rough concentrate;

[0052] S2.3 Refinement I: The regrinded rough concentrate obtained in S2.2 is added to a sphalerite combined inhibitor solution, 20 g / t of ethyl xanthate, and 20 g / t of No. 2 oil. The sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate, and sodium sulfite in a mass ratio of 0.5:4:60:20. The amount of sphalerite combined inhibitor added is 600 g / t. After refinement I, refinement I lead concentrate and refinement I tailings are obtained. The refinement I tailings are returned to the roughing stage for flotation.

[0053] S2.4 Refined II: The refined I lead concentrate obtained in S2.3 is added to a sphalerite combined inhibitor solution and 15 g / t of No. 2 oil. The sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate and sodium sulfite in a mass ratio of 0.5:4:60:20. The amount of sphalerite combined inhibitor added is 200 g / t. After refined II, refined II lead concentrate and refined II tailings are obtained. The refined II tailings are returned to the S2.2 regrinding process.

[0054] S2.5 Refinement III and Refinement IV: The lead concentrate obtained from Refinement II in S2.4 is processed through Refinement III and Refinement IV to finally obtain lead concentrate. The tailings obtained in this process are returned to the previous processing step for flotation.

[0055] S2.6 Scavenging I: Add 20g / t ethyl xanthate and 15g / t No. 2 oil to the roughing tailings obtained in S2.1. Scavenging I yields Scavenging I lead ore and Scavenging I zinc ore. The Scavenging I lead ore is returned to the roughing process in S2.1.

[0056] S2.7 Scavenging II: Add 10g / t of ethyl xanthate and 15g / t of No. 2 oil to the zinc ore obtained from S2.6 Scavenging II yields Scavenging II lead ore and Scavenging II zinc ore. The lead ore from Scavenging II is returned to the S2.6 Scavenging I process.

[0057] S3. The zinc ore slurry from S2.7 (Scavenging II) is prepared using a flotation process consisting of one roughing step, three cleaning steps, and two scavenging steps:

[0058] S3.1 Roughing: Add 200g / t copper sulfate, 60g / t ethyl xanthate, and 30g / t No. 2 oil to zinc ore with a pulp concentration of 28-32% to roughing to obtain rough zinc ore and rough zinc tailings;

[0059] S3.2, Fine Concentration I: Add 20g / t of ethyl xanthate and 15g / t of No. 2 oil to the rough zinc ore obtained from S3.1. Fine Concentration I yields Fine Concentration I zinc ore and Fine Concentration I zinc tailings. Fine Concentration I zinc tailings are returned to the roughing process in S3.1.

[0060] S3.3, Selected II: Add 10g / t of ethyl xanthate and 15g / t of No. 2 oil to the zinc ore selected in S3.2, and select II to obtain zinc ore selected in S3.2 and tailings selected in S3.2. The tailings selected in S3.2 are returned to the process of selecting I.

[0061] S3.4, Refinement III: The zinc ore obtained from Refinement II in S3.3 is refined into zinc concentrate and tailings from Refinement III. The tailings from Refinement III are returned to the Refinement II process in S3.3.

[0062] S3.5, Scavenging I: Add 30g / t ethyl xanthate and 15g / t No. 2 oil to the rough zinc tailings obtained in S3.1, and scavenging I will obtain scavenging I zinc ore and scavenging I tailings. Return the scavenging I zinc ore obtained in S3.5 to the roughing process in S3.1.

[0063] S3.6, Scavenging II: Add 20g / t of ethyl xanthate and 15g / t of No. 2 oil to the tailings obtained from Scavenging I in S3.5. Scavenging II will produce Scavenging II zinc ore and tailings. The Scavenging II zinc ore will be returned to the S3.5 Scavenging I process.

[0064] The test results of this embodiment are shown in Table 1.

[0065] Comparative Example 2

[0066] The ore used in the experiment was the same as that in Example 2. The process flow and parameters were basically the same as in Example 2, except that the sphalerite depressant was the traditional depressant zinc sulfate + sodium sulfite. Lead roughing process: 2400 g / t zinc sulfate + 800 g / t sodium sulfite; Lead beneficiation I: 450 g / t zinc sulfate + 150 g / t sodium sulfite; Lead beneficiation II: 225 g / t zinc sulfate + 75 g / t sodium sulfite. The experimental results are shown in Table 1.

[0067] Example 3

[0068] A lead-zinc sulfide ore in Baoshan, Yunnan Province, has a raw ore grade of 1.51% Pb and 3.40% Zn, with a lead oxidation rate of 9.55% and a zinc oxidation rate of 7.21%. The ore is classified as a fine-grained, difficult-to-process lead-zinc sulfide ore.

[0069] like Figure 1 As shown, the specific process of this preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores is as follows:

[0070] S1. Grinding and classifying the fine-grained, difficult-to-process lead-zinc sulfide ore to a fineness of -0.074 mm and a content of 80%, and then preparing the slurry to a concentration of 32%.

[0071] S2. The slurry from S1 is subjected to flotation using a process of one roughing step, four cleaning steps, and two scavenging steps:

[0072] S2.1 Roughing: Add 3000g / t lime, 300g / t sodium hexametaphosphate, sphalerite combined inhibitor solution, 60g / t ethyl xanthate, and 45g / t No. 2 oil to the slurry from S1. The sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate, and sodium sulfite in a mass ratio of 0.7:4:60:20. The amount of sphalerite combined inhibitor added is 4235g / t (the specific amounts of each component are 35g / t of trithiocarbonate, 200g / t of L-cysteine, 3000g / t of zinc sulfate, and 1000g / t of sodium sulfite). Prepare a 5% sphalerite combined inhibitor solution. Roughing yields lead rough concentrate and roughing tailings.

[0073] S2.2 regrinding: The rough concentrate obtained in S1 is regrinded to a fineness of 0.045mm-0.074mm and a lead content of 95%, to obtain regrinded rough concentrate;

[0074] S2.3 Refinement I: The regrinded rough concentrate obtained in S2.2 is added to a sphalerite combined inhibitor solution, 20 g / t ethyl xanthate, and 20 g / t No. 2 oil. The sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate, and sodium sulfite in a mass ratio of 0.7:4:60:20. The amount of sphalerite combined inhibitor added is 400 g / t. After refinement I, refinement I lead concentrate and refinement I tailings are obtained. Refinement I tailings are returned to the roughing stage for flotation.

[0075] S2.4 Refined II: The refined I lead concentrate obtained in S2.3 is added to a sphalerite combined inhibitor solution and 15 g / t of No. 2 oil. The sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate and sodium sulfite in a mass ratio of 0.7:4:60:20. The amount of sphalerite combined inhibitor added is 200 g / t. After refined II, refined II lead concentrate and refined II tailings are obtained. The refined II tailings are returned to the S2.2 regrinding process.

[0076] S2.5 Refinement III and Refinement IV: The lead concentrate obtained from Refinement II in S2.4 is processed through Refinement III and Refinement IV to finally obtain lead concentrate. The tailings obtained in this process are returned to the previous processing step for flotation.

[0077] S2.6 Scavenging I: Add 20g / t ethyl xanthate and 15g / t No. 2 oil to the roughing tailings obtained in S2.1. Scavenging I yields Scavenging I lead ore and Scavenging I zinc ore. The Scavenging I lead ore is returned to the roughing process in S2.1.

[0078] S2.7 Scavenging II: Add 10g / t of ethyl xanthate and 15g / t of No. 2 oil to the zinc ore obtained from S2.6 Scavenging II yields Scavenging II lead ore and Scavenging II zinc ore. The lead ore from Scavenging II is returned to the S2.6 Scavenging I process.

[0079] S3. The zinc ore slurry from S2.7 (Scavenging II) is prepared using a flotation process consisting of one roughing step, three cleaning steps, and two scavenging steps:

[0080] S3.1 Roughing: Add 200g / t copper sulfate, 80g / t ethyl xanthate, and 30g / t No. 2 oil to zinc ore with a pulp concentration of 28-32% to roughing to obtain rough zinc ore and rough zinc tailings;

[0081] S3.2, Fine Concentration I: Add 20g / t of ethyl xanthate and 15g / t of No. 2 oil to the rough zinc ore obtained from S3.1. Fine Concentration I yields Fine Concentration I zinc ore and Fine Concentration I zinc tailings. Fine Concentration I zinc tailings are returned to the roughing process in S3.1.

[0082] S3.3, Selected II: Add 10g / t of ethyl xanthate and 15g / t of No. 2 oil to the zinc ore selected in S3.2, and select II to obtain zinc ore selected in S3.2 and tailings selected in S3.2. The tailings selected in S3.2 are returned to the process of selecting I.

[0083] S3.4, Refinement III: The zinc ore obtained from Refinement II in S3.3 is refined into zinc concentrate and tailings from Refinement III. The tailings from Refinement III are returned to the Refinement II process in S3.3.

[0084] S3.5, Scavenging I: Add 20g / t ethyl xanthate and 15g / t No. 2 oil to the rough zinc tailings obtained in S3.1, and scavenging I will obtain scavenging I zinc ore and scavenging I tailings. Return the scavenging I zinc ore obtained in S3.5 to the roughing process in S3.1.

[0085] S3.6, Scavenging II: Add 100g / t of ethyl xanthate and 15g / t of No. 2 oil to the tailings obtained from Scavenging I in S3.5. Scavenging II will produce Scavenging II zinc ore and tailings. The Scavenging II zinc ore will be returned to the S3.5 Scavenging I process.

[0086] The test results of this embodiment are shown in Table 1.

[0087] Comparative Example 3

[0088] The ore used in the experiment was the same as that in Example 3. The process flow and parameters were basically the same as in Example 3, except that the sphalerite depressant was the traditional depressant zinc sulfate + sodium sulfite. Lead roughing process: 3000 g / t zinc sulfate + 1000 g / t sulfite; Lead beneficiation I: 300 g / t zinc sulfate + 100 g / t sodium sulfite; Lead beneficiation II: 150 g / t zinc sulfate + 50 g / t sodium sulfite. The experimental results are shown in Table 1.

[0089] Table 1. Results of the Examples and Comparative Examples

[0090]

[0091]

[0092] Table 1 shows that the combined inhibitor of sodium trithiocarbonate + L-cysteine ​​+ zinc sulfate + sodium sulfite has a significantly better inhibitory effect on sphalerite than the traditional zinc sulfate + sodium sulfite inhibitor. The addition of sodium trithiocarbonate and L-cysteine ​​significantly reduces the zinc content in lead concentrate and greatly improves the zinc recovery rate. Within a suitable dosage range, the combined inhibitor does not inhibit galvanite. Sphalerite inhibited by the combined inhibitor can be normally recovered after activation with copper sulfate, and the zinc recovery rate is unaffected. The use of the combined inhibitor for sphalerite enables efficient separation of fine-grained, difficult-to-process sulfide lead-zinc ore, yielding qualified lead and zinc concentrate products with excellent beneficiation indicators.

[0093] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for preferential flotation separation of fine-grained, difficult-to-process lead-zinc sulfide ores, characterized in that, Includes the following steps: S1. Grinding and classifying the fine-grained, difficult-to-process lead-zinc sulfide ore to a fineness of -0.074 mm and a content of 80%-90%, and then preparing the slurry. S2. Add lime, sodium hexametaphosphate, sphalerite combination inhibitor, ethyl xanthate, and No. 2 oil to the slurry in S1 for preferential flotation of galena to obtain lead concentrate and preferential flotation tailings; wherein the sphalerite combination inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate and sodium sulfite. S3. Add copper sulfate, ethyl xanthate, and No. 2 oil to the preferential flotation tailings obtained in S2 to flotation sphalerite to obtain zinc concentrate and tailings.

2. The method for preferential flotation separation of fine-grained, difficult-to-process lead-zinc sulfide ores according to claim 1, characterized in that: In S2, the preferential flotation of galena uses a one-roughing, four-cleaning, two-scavenging operation. After roughing and flotation, the lead concentrate is regrinded to a fineness of 0.045mm-0.074mm and the lead concentrate content is 95%.

3. The preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores according to claim 2, characterized in that: The zinc sphalerite combined inhibitor is composed of sodium trithiocarbonate, L-cysteine, zinc sulfate and sodium sulfite in a mass ratio of (0.5-1):(3-6):(40-60):(20-30), and the zinc sphalerite combined inhibitor is prepared into a 5% zinc sphalerite combined inhibitor solution and added to the flotation.

4. The preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores according to claim 3, characterized in that: In the aforementioned roughing, cleaning, and scavenging operations, the sphalerite combination inhibitor solution described in step S2 is added to the roughing, cleaning I, and cleaning II operations, respectively. Ethyl xanthate is added as a lead mineral collector to the roughing, cleaning I, scavenging I, and scavenging II operations, and No. 2 oil is added as a frother to the roughing, cleaning I, cleaning II, scavenging I, and scavenging II operations.

5. The preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores according to claim 2, characterized in that: In the roughing process of preferential flotation of galena in S2, lime of 1000g / t to 5000g / t and sodium hexametaphosphate of 100g / t to 500g / t are added.

6. The preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores according to claim 4, characterized in that: The dosage of the combined inhibitor for sphalerite in the roughing, cleaning I, and cleaning II operations is 3000g / t~4500g / t, 300g / t~600g / t, and 100g / t~300g / t, respectively.

7. The preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores according to claim 4, characterized in that: The amount of ethyl xanthate added in the roughing, cleaning I, scavenging I and scavenging II operations is 40g / t~100g / t, 10g / t~20g / t, 10g / t~20g / t, and 10g / t~20g / t, respectively; the amount of No. 2 oil added in the roughing, cleaning I, cleaning II, scavenging I and scavenging II operations is 40g / t~70g / t, 10g / t~20g / t, 10g / t~20g / t, 10g / t~20g / t, and 10g / t~20g / t, respectively.

8. The preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores according to claim 1, characterized in that: The S3 flotation process for sphalerite employs a roughing, cleaning, and scavenging operation. Copper sulfate is added to activate the sphalerite during the roughing operation. Ethyl xanthate is added as a sphalerite collector and No. 2 oil as a frother during the roughing, cleaning (I), cleaning (II), scavenging (I), and scavenging (II) operations, respectively.

9. The preferential flotation separation method for fine-grained, difficult-to-process lead-zinc sulfide ores according to claim 8, characterized in that: The amount of copper sulfate added is 200g / t to 500g / t.

10. The method for preferential flotation separation of fine-grained, difficult-to-process lead-zinc sulfide ores according to claim 8, characterized in that: The amounts of ethyl xanthate added in the roughing, cleaning I, cleaning II, scavenging I, and scavenging II processes are 50g / t~100g / t, 10g / t~30g / t, 10g / t~30g / t, 10g / t~30g / t, and 10g / t~20g / t, respectively; and the amounts of No. 2 oil added in the roughing, cleaning I, cleaning II, scavenging I, and scavenging II processes are 30g / t~50g / t, 10g / t~20g / t, 10g / t~20g / t, 10g / t~20g / t, and 10g / t~20g / t, respectively.

Images