A method for the flotation separation of a refractory mixed lead-zinc ore

Abstract

This application relates to a flotation separation method for refractory mixed lead-zinc ores. The method includes: lead-preferential flotation, lead-zinc mixed flotation, lead-zinc separate flotation, and zinc flotation. During the lead-zinc separate flotation, a novel sphalerite depressant composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride, and sodium carbonate is added. Using the scheme provided in this application, lead and zinc concentrates can be produced separately, achieving efficient recovery of dense disseminated and fine-veined, complex, and refractory mixed lead-zinc ores, and has broad prospects for industrial application.

Description

Technical Field

[0001] This application relates to the field of mineral processing technology, and in particular to a flotation separation method for refractory mixed lead-zinc ores. Background Technology

[0002] Lead-zinc ores can be classified into sulfide lead-zinc ores, mixed lead-zinc ores, and oxide lead-zinc ores according to the degree of oxidation, with their beneficiation decreasing accordingly. Mixed lead-zinc ores generally have the characteristics of a wide variety of minerals, variable ore properties, and complex co-existence and intergrowth relationships between lead and zinc minerals and gangue minerals, which increases the difficulty of lead-zinc flotation and separation.

[0003] Especially for some difficult-to-process mixed lead-zinc ores, due to their dense disseminated and / or veinlet disseminated ore structures, or severe oxidation and weathering, traditional preferential flotation is ineffective, resulting in significant intermingling of lead and zinc concentrates and large grade fluctuations. Furthermore, fine grinding is necessary during flotation to achieve complete liberation of lead and zinc minerals, leading to high beneficiation costs. Therefore, it is essential to strengthen research on new beneficiation processes and reagents for mixed lead-zinc ores. Developing a process flow suitable for the ore characteristics and correctly selecting the reagent regime are fundamental to achieving lead-zinc separation and recovery.

[0004] Regarding the beneficiation method for refractory mixed lead-zinc ore, the prior art publication number CN 117772405 B discloses "A beneficiation method for refractory mixed lead-zinc ore". The beneficiation method for refractory mixed lead-zinc ore provided in this application processes sulfide ore and oxide ore separately. First, the sulfide ore is classified according to the difference in the natural floatability of the ore. Then, the oxide ore is treated by gravity separation. This overcomes the adverse effects of using oxide ore beneficiation reagents on the recycling of recycled water and solves the problem of poor flotation index of oxide ore.

[0005] The problems with this method are twofold: First, in addition to conventional flotation processes, spiral sluice classification and shaking table gravity separation are used to recover oxide lead-zinc ore during the flotation process. This places relatively high demands on the equipment and site requirements of the concentrator, and it cannot be implemented directly using existing equipment. Second, in the beneficiation indicators of this method, apart from the lead concentrate, zinc concentrate, and lead-zinc mixed concentrate that can be directly utilized, the gravity concentrate obtained has a main grade that does not meet the minimum grade requirements for lead concentrate, zinc concentrate, or even the minimum grade of mixed lead-zinc concentrate. Therefore, how to effectively handle these products is a significant problem for enterprises. Furthermore, if the lead and zinc indicators of the gravity concentrate, which are not convenient to be directly recycled, are excluded, and only the lead and zinc indicators in the lead concentrate, zinc concentrate, and lead-zinc mixed concentrate are calculated, the lead recovery rate is only 63.09%, and the zinc recovery rate is only 82.27%. Summary of the Invention

[0006] To address the problems existing in the background technology, this application provides a flotation separation method for refractory mixed lead-zinc ores. This flotation separation method, utilizing specific reagents and conventional flotation processes and equipment, can achieve efficient separation and recovery of refractory mixed lead-zinc ores. In the end, apart from the lead concentrate and zinc concentrate obtained from the flotation, all other products can be discarded. Furthermore, based on the directly usable lead concentrate and zinc concentrate obtained from the recovery, the overall lead recovery rate is 89.92%, and the zinc recovery rate is 75.34%.

[0007] For typical lead-zinc ores, the conventional lead-zinc separation process prioritizes lead flotation, using zinc suppression to float lead, followed by activation of the zinc flotation to obtain lead and zinc concentrates respectively. For difficult-to-separate lead-zinc ores, a mixed flotation process is often used to obtain a mixed concentrate and flotation tailings. The process described in this application combines both methods. First, a zinc suppression and lead flotation process is used to float easily floated lead metal. Then, through reagent action, mixed flotation is performed to float difficult-to-separate lead metal and a large amount of zinc metal together. The resulting mixed coarse concentrate is regrinded to fully liberate the fine and micro-finely embedded lead and zinc metals. Then, a novel reagent is used again to suppress zinc and float lead, concentrating the lead metal into lead concentrate. The suppressed zinc minerals (separation flotation tailings) are then activated to float zinc, yielding zinc concentrate.

[0008] Specifically, the novel inhibitor in this application is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride, and sodium carbonate, wherein the polyferric chloride can effectively inhibit Fe in gangue. 2+ Fe 3+ Iron ions often exist in minerals in the form of sphalerite, so adding polyferric chloride can enhance the inhibition effect of sphalerite. Sodium cyanurate, with the chemical formula C3H4N3NaO3, is a reducing agent with reducing properties, causing a chemical reaction on the surface of zinc minerals and promoting the interaction between the zinc mineral surface and zinc sulfate, thereby improving the inhibition effect. Thiourea, an organic sulfur-containing compound with the chemical formula CH4N2S, is a sulfidation accelerator. Sodium carbonate plays a role in adjusting the pH reaction environment of the agents, promoting the synergistic effect between different drugs such as zinc sulfate, sodium cyanurate, thiourea, and polyferric chloride, so as to effectively inhibit the ion-symbiotic zinc in gangue.

[0009] When this novel sphalerite combined inhibitor is used, the surface sphalerite components are partially covered by inhibitor and collector components. There are five types of surface inhibitor components. By measuring the adsorption amount of various inhibitors and collectors on the surface using infrared spectroscopy, it was found that after inhibition by the novel sphalerite combined inhibitor, the surface of the sphalerite mineral is preferentially adsorbed by the inhibitor components, with only a very small amount of collector components adsorbed. This is beneficial for the flotation separation of lead and zinc and can significantly improve the inhibition effect of sphalerite mineral.

[0010] This application presents a novel sphalerite combined inhibitor that inhibits the desorption of collectors on the surface of sphalerite minerals during the flotation separation of lead-zinc mixed concentrates. The inhibitor adsorption exhibits a high reactivity tendency, significantly reducing the floatability of sphalerite and increasing the difference in hydrophobicity between galena and sphalerite. Therefore, compared with conventional sphalerite inhibitors, this novel sphalerite combined inhibitor can significantly reduce the intermingling of lead and zinc concentrates, improve lead and zinc metal recovery rates, and increase production efficiency.

[0011] The technical solution provided in this application may include the following beneficial effects:

[0012] (1) The novel sphalerite combined inhibitor used in this application is composed of zinc sulfate, sodium cyanate, thiourea, polyferric chloride and sodium carbonate. The cyanide-like groups, iron ions and carbonate ions in the combined inhibitor have a synergistic effect, which plays a role in inhibiting the Fe content in gangue. 2+ Fe 3+ Cu 2+ The strong cyanidation effect of these ions effectively inhibits zinc in the ore that coexists with these ions, and has the advantages of small dosage, good inhibition effect and strong inhibition effect.

[0013] (2) This application incorporates a novel sphalerite depressant during the separation and flotation process. Since it is primarily inorganic, it avoids the predicament of zinc minerals being difficult to reactivate after separation. Furthermore, the zinc minerals reactivated after depressant treatment often exhibit better floatability, which is beneficial for improving the quality of the zinc concentrate. Moreover, due to the relatively stable complexing effect of this novel sphalerite depressant, sodium cyanurate, which has high water solubility and stability and is not easily decomposed, although it may decompose and produce toxic gases under strong acid or high temperature conditions, the experiments in this application were conducted in an alkaline environment at room temperature. Therefore, no free CN will be generated in the slurry. - ion.

[0014] (3) This application employs preferential flotation of easily beneficiated lead sulfide minerals, followed by mixed flotation to maximize the mixing and recovery of both difficult-to-benefit lead and suppressed zinc minerals. Re-grinding after reagent removal restores the mineral properties of the mixed concentrate to their original state before reagent addition. At this point, a novel inhibitor is added to strongly suppress zinc minerals in the mixed concentrate, resulting in better lead-zinc separation. This method achieves efficient recovery of densely disseminated and finely disseminated, symbiotically complex, and difficult-to-benefit mixed lead-zinc ores. Furthermore, compared to traditional single-benefit processes, the separation method of this invention avoids fine grinding during the raw ore grinding stage, only regrinding the mixed concentrate, significantly reducing grinding energy consumption and substantially lowering beneficiation costs for tightly symbiotic and difficult-to-benefit lead-zinc ores.

[0015] (4) The process cost and equipment configuration proposed in this application are far lower than those of the preferential flotation separation process, and the quality of the concentrate obtained is better than that of preferential flotation alone; it is an efficient method for processing dense disseminated, fine vein disseminated and complex symbiotic ores, and has broad application and promotion prospects. Attached Figure Description

[0016] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0017] Figure 1 This application shows a schematic diagram of the flotation separation process for refractory mixed lead-zinc ores.

[0018] Figure 2 This is a schematic diagram of the conventional preferential floatation method for separating lead and zinc, as shown in this application. Detailed Implementation

[0019] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0020] Example 1: Flotation Separation of Difficult-to-Process Mixed Lead-Zinc Ores

[0021] Mineralogical studies of ore from a difficult-to-process mixed lead-zinc mine in Yunnan Province show that the main recoverable elements are Pb and Zn, with grades of 7.38% and 5.37%, respectively. Lead is mainly in the form of lead sulfide, accounting for 85.44%, while zinc is mainly in the form of zinc sulfide, accounting for 82.11%. Galena and sphalerite are medium- to fine-grained disseminated, while pyrite is medium- to coarse-grained. The cumulative distribution rates of galena, sphalerite, and pyrite with a particle size of +0.074 mm are 49.7%, 59.4%, and 65.9%, respectively. The main factor affecting lead and zinc recovery is the fine-grained nature of galena and sphalerite (microparticles -0.01 mm account for 10.5%, and fine particles +0.01-0.074 mm account for 30.8%).

[0022] The flotation separation method for refractory mixed lead-zinc ores provided in this application includes the following steps:

[0023] (1) Add difficult-to-select mixed lead-zinc ore and modifier to the mill, and after grinding and classification, obtain slurry 1 with 0.074mm content of 70-80% and pH of 8-10;

[0024] The adjuster is lime, and the dosage is adjusted according to the pH value, with a dosage of 500-800g / t;

[0025] (2) The slurry 1 to be processed is fed into the flotation machine, and conventional sphalerite inhibitor, lead flotation collector and frother are added in sequence. Then, aeration flotation is carried out to obtain lead roughing concentrate 1 and lead roughing tailings.

[0026] The conventional sphalerite depressant is zinc sulfate, with a dosage of 500-1000 g / t; the lead flotation collector is ethyl thiocyanate and No. 25 black powder, with a ratio of ethyl thiocyanate and No. 25 black powder of 2:1, and a dosage of 60-150 g / t; the frother is pine oil, with the dosage adjusted according to the foaming situation, ranging from 10-40 g / t.

[0027] (3) Lead concentrate 1 was obtained by adding conventional sphalerite inhibitor to lead crude concentrate 1 and repeatedly fine-tuning it.

[0028] The conventional zincblende depressant is zinc sulfate, with a dosage of 300-1000 g / t;

[0029] (4) After adding sphalerite activator, pentyl sodium xanthate and frother to lead roughing tailings, flotation is carried out to float out difficult-to-disperse lead and zinc minerals together, and lead-zinc mixed rough concentrate and mixed flotation tailings 1 are obtained.

[0030] The activator for sphalerite is copper sulfate, with a dosage of 100-500 g / t; the dosage of sodium pentyl xanthate is 40-100 g / t; and the foaming agent is pine oil, with a dosage of 10-40 g / t.

[0031] After adding sphalerite activator, sodium pentyl xanthate and frother to mixed flotation tailings 1 in sequence, the tailings were scavenged to obtain the final mixed flotation tailings. The mixed flotation tailings were discarded after repeated scavenging.

[0032] The activator for sphalerite is copper sulfate, with a dosage of 50-250 g / t; the dosage of sodium pentyl xanthate is 40-100 g / t; and the foaming agent is pine oil, with a dosage of 5-20 g / t.

[0033] (5) The lead-zinc mixed rough concentrate is added with activated carbon and then regrinded and classified in a mill to obtain a slurry 2 with a -0.074mm content of 92-95%. The slurry 2 is then transported to a flotation machine, and a modifier is added to adjust the pH of the slurry to 9-12. Then, a new type of sphalerite combined inhibitor, lead flotation collector and frother are added in sequence to obtain a lead rough concentrate 2 with a high lead content and a separate flotation tailings.

[0034] The novel sphalerite depressant consists of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride, and sodium carbonate in a mass ratio of 3:3:1:2:1, with a dosage of 30-200 g / t; the lead flotation collector is ethyl thiocyanate, with a dosage of 40-80 g / t; the modifier is lime, with a dosage of 300-2000 g / t; and the frother is pine oil, with a dosage of 5-20 g / t.

[0035] (6) Lead concentrate 2 was obtained by adding a novel sphalerite combination inhibitor to lead crude concentrate 2 and repeatedly selecting it.

[0036] The novel sphalerite inhibitor is composed of zinc sulfate, sodium cyanate, thiourea, polyferric chloride and sodium carbonate in a mass ratio of 3:3:1:2:1, and the dosage is 30-200 g / t.

[0037] (7) Add lead collector to separate flotation tailings, and use the scavenged tailings as slurry 3 to be treated; the lead collector is ethyl thiocyanate, and the dosage is 20-40 g / t.

[0038] The slurry to be treated, slurry 3, is sequentially supplemented with a modifier, sphalerite activator, zinc collector, and frother. After flotation, zinc rougher concentrate and zinc rougher tailings are obtained. The modifier is lime, with a dosage of 100-500 g / t; the sphalerite activator is copper sulfate, with a dosage of 150-400 g / t; and the zinc collector is butyl sodium xanthate, with a dosage of 30-60 g / t.

[0039] (8) Zinc concentrate is obtained by adding a modifier to the zinc roughing concentrate and then finely selecting it. The modifier is lime, with a dosage of 50-300 g / t, and the pH of the pulp is adjusted to 9-11. Zinc tailings are added sequentially with sphalerite activator, zinc collector and frother, and then scavenged to obtain zinc tailings. The sphalerite activator is copper sulfate, with a dosage of 150-400 g / t, the zinc collector is butyl sodium xanthate, with a dosage of 30-60 g / t, and the frother is pine oil, with a dosage of 5-20 g / t.

[0040] Using the method of this application, lead concentrate 1 was obtained with a lead grade of 67.28% and a zinc grade of 4.21%; lead concentrate 2 was obtained with a lead grade of 64.48% and a zinc grade of 5.62%, with a combined lead recovery rate of 89.28%; zinc concentrate was obtained with a zinc grade of 52.85% and a lead grade of 2.80%, with a zinc recovery rate of 66.82%.

[0041] Comparative Example 1

[0042] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 adopts a conventional preferential flotation process, preferentially floats lead and suppresses zinc. The inhibitor is zinc sulfate and sodium carbonate added in a 1:1 ratio. After one roughing, three cleaning and three scavenging process, lead concentrate is obtained. The lead flotation tailings enter the zinc flotation process, with copper sulfate as the activator at a dosage of 400-600 g / t. Butyl xanthate and pentyl xanthate are combined in a 1:1 ratio as the collector at a dosage of 80-100 g / t. The zinc concentrate is obtained by adopting a flotation process of one roughing, three cleaning and four scavenging.

[0043] Zinc flotation tailings are the final tailings. Lead concentrate contains only 56.07% lead and 7.02% zinc, with a lead recovery rate of 76.93%. Zinc concentrate contains 40.65% zinc and 4.67% lead, with a zinc recovery rate of 59.47%. The low grades of the main elements in the lead and zinc concentrates, coupled with their high mutual inclusion and low recovery rates, severely impact the company's profitability.

[0044] The experimental results of Example 1 and Comparative Example 1 are shown in Table 1.

[0045] Table 1 Comparison of indicators before and after application in difficult-to-process mixed lead-zinc ore (%)

[0046]

[0047] As the yield decreases, the concentrate grade increases, and the concentrate quantity decreases using the flotation separation method of this application, the concentrate transportation cost also decreases significantly.

[0048] Example 2: Flotation Separation of Low-Grade Mixed Lead-Zinc Ores

[0049] A beneficiation plant in Yunnan Province, after process mineralogical studies, found that the main recoverable elements from the ore to be processed were Pb and Zn, with grades of 2.94% and 3.22%, respectively. Lead was primarily in lead sulfide form, accounting for 93.2%, while zinc was primarily in zinc sulfide form, accounting for 91.93%. The main factor affecting the recovery of useful metals was the excessively fine particle size of the minerals: lead ore had a particle size of micro-fine (parts -0.01mm accounted for 8.5%, fine particles +0.01-0.074mm accounted for 37.8%), and sphalerite also had a particle size of micro-fine (parts -0.01mm accounted for 9.3%, fine particles +0.01-0.074mm accounted for 29.3%).

[0050] The flotation separation method for refractory mixed lead-zinc ores provided in this application includes the following steps:

[0051] (1) Add difficult-to-process mixed lead-zinc ore and modifier to the mill, and after grinding and classification, obtain slurry 1 with 0.074mm content of 75-85% and pH of 8-10; the modifier is lime, and the dosage is 300-500g / t;

[0052] (2) The slurry 1 to be processed is fed into the flotation machine, and conventional sphalerite inhibitor, lead flotation collector and frother are added in sequence. Then, aeration flotation is carried out to obtain lead roughing concentrate 1 and lead roughing tailings.

[0053] The conventional sphalerite depressant is zinc sulfate, with a dosage of 400-700 g / t; the lead flotation collector is ethyl thiocyanate, No. 25 black reagent, and sodium butyl xanthate, with the ratio of ethyl thiocyanate, No. 25 black reagent, and sodium butyl xanthate being 1:1:1, and the dosage is approximately 60-150 g / t; the frother is pine oil, with a dosage of 10-30 g / t.

[0054] (3) Lead concentrate 1 was obtained by adding conventional sphalerite inhibitor to lead crude concentrate 1 and repeatedly fine-tuning it.

[0055] The conventional inhibitor for sphalerite is zinc sulfate, with a dosage of 300-450 g / t;

[0056] After adding sphalerite activator, sodium pentyl xanthate and frother to the lead roughing tailings, flotation is carried out to float out the difficult-to-disperse lead and zinc minerals together, and the lead-zinc mixed rough concentrate and mixed flotation tailings 1 are obtained. The ore in the scavenging operation is returned to the previous stage of flotation operation in sequence. After 2-3 lead mixed scavenging, the scavenging tailings are the final tailings.

[0057] The activator for sphalerite is copper sulfate, with a dosage of 100-500 g / t; the pentyl sodium xanthate is pentyl sodium xanthate, with a dosage of 40-100 g / t; and the frother is pine oil, with a dosage of 10-40 g / t.

[0058] After adding sphalerite activator, sodium pentyl xanthate and frother to mixed flotation tailings 1 in sequence, the tailings were scavenged to obtain the final mixed flotation tailings. The mixed flotation tailings were discarded after repeated scavenging.

[0059] The activator for sphalerite is copper sulfate, with a dosage of 50-250 g / t; the pentyl sodium xanthate is pentyl sodium xanthate, with a dosage of 40-100 g / t; and the frother is pine oil, with a dosage of 5-20 g / t.

[0060] (5) The lead-zinc mixed rough concentrate is added with activated carbon and then regrinded and classified in a mill to obtain a slurry 2 with a -0.074mm content of 92-95%. The slurry 2 is then transported to a flotation machine, and a modifier is added to adjust the pH of the slurry to 9-12. Then, a new type of sphalerite combined inhibitor, lead flotation collector and frother are added in sequence to obtain a lead rough concentrate 2 with a high lead content and a separate flotation tailings.

[0061] The modifier is lime, with a dosage of 250-400 g / t; the novel sphalerite combined depressant consists of zinc sulfate, sodium cyanate, thiourea, polyferric chloride, and sodium carbonate in a mass ratio of 3:3:1:2:1, with a dosage of 30-200 g / t; the lead flotation collector is a combination of ethyl thiocyanate and 25# black reagent in a 4:1 ratio, with a dosage of 60-80 g / t; the frother is pine oil, with a dosage of 5-20 g / t.

[0062] (6) Lead concentrate 2 was obtained by adding a novel sphalerite combination inhibitor to lead crude concentrate 2 and repeatedly selecting it.

[0063] The novel sphalerite inhibitor is composed of zinc sulfate, sodium cyanate, thiourea, polyferric chloride and sodium carbonate in a mass ratio of 3:3:1:2:1, and the dosage is 30-200 g / t.

[0064] (7) Add lead collector to separate flotation tailings, and use the scavenged tailings as slurry 3 to be treated; the lead collector is ethyl thiocyanate, and the dosage is 20-40 g / t.

[0065] The slurry to be treated, slurry 3, is sequentially supplemented with a modifier, sphalerite activator, zinc collector, and frother. After flotation, zinc rougher concentrate and zinc rougher tailings are obtained. The modifier is lime, with a dosage of 100-500 g / t; the sphalerite activator is copper sulfate, with a dosage of 350-500 g / t; and the zinc collector is butyl sodium xanthate, with a dosage of 40-70 g / t.

[0066] (8) Add a modifier to the zinc roughing concentrate and then finely select the zinc concentrate. The modifier is lime, with a dosage of 60-200 g / t, and the pH of the pulp is adjusted to 10-12. Add sphalerite activator, zinc collector and frother to the zinc roughing tailings in sequence. After scavenging, zinc tailings are obtained. The sphalerite activator is copper sulfate, with a dosage of 350-500 g / t. The zinc collector is butyl sodium xanthate, with a dosage of 40-70 g / t. The frother is pine oil, with a dosage of 5-20 g / t.

[0067] After experimental research, using the process and reagents provided in this application, and after two months of trial production, lead concentrate 1 was obtained with a lead grade of 77.85% and a zinc grade of 2.39%; lead concentrate 2 was obtained with a lead grade of 75.43% and a zinc grade of 3.07%, with a total lead recovery rate of 86.92%; zinc concentrate was obtained with a zinc grade of 52.02% and a lead grade of 1.96%, with a zinc recovery rate of 86.17%.

[0068] Comparative Example 2

[0069] The difference between Comparative Example 2 and Example 2 is that Comparative Example 2 adopts a conventional preferential flotation process, preferentially floats lead and suppresses zinc. Lead is obtained after one roughing, three cleaning and three scavenging process. The lead flotation tailings enter the zinc flotation process. Copper sulfate is used as the activator at a dosage of 450 g / t and butyl xanthate is used as the collector at a dosage of 55 g / t. The zinc flotation process of one roughing, three cleaning and three scavenging process is adopted to obtain zinc concentrate. The zinc flotation tailings are the final tailings.

[0070] The lead concentrate obtained using the above process has a lead grade of 63.92%, a zinc grade of 6.83%, and a lead recovery rate of 71.24%; the zinc concentrate has a zinc grade of 43.35%, a lead grade of 4.67%, and a zinc recovery rate of 74.44%. The excessively high levels of both lead and zinc content negatively impact the beneficiation plant's profitability.

[0071] The experimental results of Example 2 and Comparative Example 2 are shown in Table 2.

[0072] Table 2 Comparison of indicators before and after application in low-grade mixed lead-zinc ore (%)

[0073]

[0074] Example 3

[0075] The difference between Example 3 and Example 1 is that the novel zincblende composite inhibitor is composed of zinc sulfate, sodium cyanate, thiourea, polyferric chloride and sodium carbonate in a mass ratio of 3:3:1:2:2.

[0076] The test results of Example 3 are shown in Table 3.

[0077] Table 3. Results of the mixed lead-zinc ore test in Example 3 (%)

[0078]

[0079]

[0080] Example 4

[0081] The difference between Example 4 and Example 1 is that the novel zincblende composite inhibitor is composed of zinc sulfate, sodium cyanate, thiourea, polyferric chloride and sodium carbonate in a mass ratio of 3:3:1:2:3.

[0082] The test results of Example 4 are shown in Table 4.

[0083] Table 4. Results of the mixed lead-zinc ore test in Example 4 (%)

[0084]

[0085] Comparative Example 3

[0086] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 does not use a preferential flotation process, but uses a mixed flotation process.

[0087] The experimental results of Comparative Example 3 are shown in Table 5.

[0088] Table 5. Results of the comparative example 3 mixed lead-zinc ore test (%)

[0089]

[0090]

[0091] Comparative Example 4

[0092] The difference between Comparative Example 4 and Example 1 is that the novel zincblende composite inhibitor is composed of sodium cyanurate, thiourea, polyferric chloride and sodium carbonate in a mass ratio of 3:1:2:1.

[0093] The experimental results of Comparative Example 4 are shown in Table 6.

[0094] Table 6. Results of the comparative example 4 mixed lead-zinc ore test (%)

[0095]

[0096] Comparative Example 5

[0097] The difference between Comparative Example 5 and Example 1 is that the novel zincblende composite inhibitor is composed of zinc sulfate, thiourea, polyferric chloride and sodium carbonate in a mass ratio of 3:1:2:1.

[0098] The experimental results of Comparative Example 5 are shown in Table 7.

[0099] Table 7. Results of the comparative example 5 mixed lead-zinc ore test (%)

[0100]

[0101]

[0102] Comparative Example 6

[0103] The difference between Comparative Example 6 and Example 1 is that the novel zincblende composite inhibitor is composed of zinc sulfate, sodium cyanurate, thiourea and sodium carbonate in a mass ratio of 3:3:1:1.

[0104] The experimental results of Comparative Example 6 are shown in Table 8.

[0105] Table 8. Results of the comparative example 6 mixed lead-zinc ore test (%)

[0106]

[0107] Comparative Example 7

[0108] The difference between Comparative Example 7 and Example 1 is that the novel zincblende composite inhibitor is composed of zinc sulfate, sodium cyanate, thiourea and polyferric chloride in a mass ratio of 3:3:1:2.

[0109] The experimental results of Comparative Example 7 are shown in Table 9.

[0110] Table 9. Results of the comparative example 7 mixed lead-zinc ore test (%)

[0111]

[0112]

[0113] Comparative Example 8

[0114] The difference between Comparative Example 8 and Example 1 is that the novel zincblende composite inhibitor is composed of zinc sulfate, sodium cyanurate and sodium carbonate in a mass ratio of 3:3:1.

[0115] The experimental results of Comparative Example 8 are shown in Table 10.

[0116] Table 10. Results of the comparative example 8 mixed lead-zinc ore test (%)

[0117]

[0118] Comparative Example 9

[0119] The difference between Comparative Example 9 and Example 1 is that Comparative Example 9 does not use the novel zinc sphalerite combination inhibitor, but uses conventional zinc sulfate inhibitors.

[0120] The experimental results of Comparative Example 9 are shown in Table 11.

[0121] Table 11 Results of the comparative example 9 mixed lead-zinc ore test (%)

[0122]

[0123] Both Comparative Examples 1 and 2 of this application employ conventional preferential flotation processes. In Example 1, the zinc grade of lead concentrate 1+2 was calculated to be 4.70% using a weighted average method, while the zinc grade in Comparative Example 1 was 7.02%. In Example 2, the zinc grade of lead concentrate 1+2 was calculated to be 2.63% using a weighted average method, while the zinc grade in Comparative Example 2 was 6.83%. It is evident that the zinc grade of the lead concentrate obtained using the conventional preferential flotation process is greater than the zinc grade of the lead concentrate 1+2 obtained using the process flow of this application.

[0124] Comparative Example 3, using a conventional mixed flotation process, yielded only a mixed concentrate. The lead content of this concentrate was only 33.94%, and the zinc content was only 22.06%, both failing to meet the requirements for qualified products. This demonstrates that the product obtained using a conventional mixed flotation process is substandard and cannot achieve the desired lead-zinc separation.

[0125] Using the method of Example 1 of this application, the novel sphalerite combined inhibitor in Example 1 is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride, and sodium carbonate in a mass ratio of 3:3:1:2:1. This yields lead concentrate 1 with a lead grade of 67.28% and a zinc grade of 4.21%, lead concentrate 2 with a lead grade of 64.48% and a zinc grade of 5.62%, and zinc concentrate with a lead grade of 2.80% and a zinc grade of 52.85%. In Comparative Example 4, the novel sphalerite combined inhibitor is composed of sodium cyanurate, thiourea, polyferric chloride, and sodium carbonate in a mass ratio of 3:1:2:1. This yields lead concentrate 1 with a lead grade of 62.77% and a zinc grade of... Lead concentrate 2 contained 4.22% lead and 9.83% zinc, while zinc concentrate contained 2.87% lead and 51.10% zinc. Comparative Example 5 used a novel sphalerite inhibitor composed of zinc sulfate, thiourea, polyferric chloride, and sodium carbonate in a mass ratio of 3:1:2:1, resulting in lead concentrate 1 containing 67.01% lead and 4.20% zinc, lead concentrate 2 containing 59.13% lead and 7.63% zinc, and zinc concentrate containing 2.85% lead and 48.09% zinc. Comparative Example 6 used a novel sphalerite inhibitor composed of zinc sulfate, sodium cyanurate, thiourea, and sodium carbonate. The following minerals were used in a mass ratio of 3:3:1:1 to obtain lead concentrate 1 with a lead grade of 67.55% and a zinc grade of 4.22%; lead concentrate 2 with a lead grade of 59.52% and a zinc grade of 7.40%; and zinc concentrate with a lead grade of 2.76% and a zinc grade of 49.57%. Comparative Example 7 used a novel sphalerite inhibitor composed of zinc sulfate, sodium cyanate, thiourea, and polyferric chloride in a mass ratio of 3:3:1:2 to obtain lead concentrate 1 with a lead grade of 67.01% and a zinc grade of 4.23%; lead concentrate 2 with a lead grade of 63.58% and a zinc grade of 5.87%; and zinc concentrate with a lead grade of 2.79% and a zinc grade of 52.00%. Comparative Example 8 used a novel sphalerite inhibitor composed of zinc sulfate, sodium cyanurate, and sodium carbonate in a mass ratio of 3:3:1, yielding lead concentrate 1 with a lead grade of 66.95% and a zinc grade of 4.26%, lead concentrate 2 with a lead grade of 62.68% and a zinc grade of 5.70%, and zinc concentrate with a lead grade of 2.82% and a zinc grade of 52.48%. Comparative Example 9 used a conventional zinc sulfate inhibitor, yielding lead concentrate 1 with a lead grade of 67.08% and a zinc grade of 4.22%, lead concentrate 2 with a lead grade of 24.82% and a zinc grade of 28.54%, and zinc concentrate with a lead grade of 16.23% and a zinc grade of 37.68%.

[0126] It is evident that the zinc content in lead concentrate 2 obtained using four of the following: zinc sulfate, sodium cyanate, thiourea, polyferric chloride, and sodium carbonate, is greater than the 5.62% zinc content in Example 1. In Comparative Example 9, the zinc content in lead concentrate 2 obtained using a conventional zinc sulfate inhibitor is even worse, with a zinc content as high as 28.54%. Therefore, the novel sphalerite combined inhibitor of this application, in which zinc sulfate, sodium cyanate, thiourea, polyferric chloride, and sodium carbonate work synergistically to reduce the zinc content in the ore.

[0127] Therefore, this application adopts a combination of preferential flotation and mixed flotation processes, and uses a novel sphalerite combined inhibitor composed of zinc sulfate, sodium cyanate, thiourea, polyferric chloride and sodium carbonate, which can effectively inhibit zinc in the ore that coexists with these ions, and has the advantages of small dosage, good inhibition effect and strong inhibition effect.

[0128] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A flotation separation method for refractory mixed lead-zinc ores, characterized in that, Includes the following steps: A. Lead preferentially floated (1) Lime is added to the difficult-to-process mixed lead-zinc ore, and after grinding and classification, a slurry 1 with a pH of 8-10 is obtained. Conventional sphalerite inhibitor, lead flotation collector and frother are added to the slurry 1 in sequence, and then flotation is carried out to obtain lead crude concentrate 1 and lead crude tailings. (2) Lead concentrate 1 was obtained by adding conventional sphalerite inhibitor to lead crude concentrate 1 and then finely selecting it. B. Mixed flotation of lead and zinc (1) Lead rough tailings were added with sphalerite activator, pentyl sodium xanthate and frother and then floated to obtain lead-zinc mixed rough concentrate and mixed flotation tailings 1; (2) After adding sphalerite activator, pentyl sodium xanthate and frother to the mixed flotation tailings 1 in sequence, the final mixed flotation tailings are obtained by scavenging. C. Lead-zinc separation flotation (1) The lead-zinc mixed rough concentrate was regrinded with activated carbon to obtain slurry 2 to be treated. Lime was added to adjust the pH to 9-12. Then, a new type of sphalerite combined inhibitor, lead flotation collector and frother were added in sequence. The lead rough concentrate 2 and the flotation tailings were obtained by lead-zinc separation flotation. (2) Lead concentrate 2 was obtained by adding a novel sphalerite combination inhibitor to lead crude concentrate 2 and then finely selecting it. (3) Add lead collector to separate flotation tailings, and the tailings after scavenging are used as slurry 3 to be treated; lime, sphalerite activator, zinc collector and frother are added to slurry 3 in sequence, and zinc roughing concentrate and zinc roughing tailings are obtained by flotation. (4) Zinc concentrate is obtained by fine selection of zinc roughing concentrate; (5) Zinc tailings are obtained by scavenging the zinc roughing tailings; The conventional zincblende inhibitor is zinc sulfate; The novel zincblende composite inhibitor is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, wherein the mass ratio of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate is 3:3:1:2:(1-3).

2. The method according to claim 1, characterized in that, The mass ratio of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride, and sodium carbonate is 3:3:1:2:

1.

3. The method according to claim 1, characterized in that, The grinding fineness of the slurry 1 to be processed is -0.074 mm, and its content is 70%-80%.

4. The method according to claim 1, characterized in that, The zincblende activator is copper sulfate.

5. The method according to claim 1, characterized in that, The lead flotation collector is one or more of ethyl thiocyanate, 25# black powder, and butyl sodium xanthate.

6. The method according to claim 1, characterized in that, The grinding fineness of the slurry 2 to be treated is -0.074 mm, and the content is 92%-95%.

7. The method according to claim 1, characterized in that, The foaming agent is pine oil.

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