Flotation separation method for refractory mixed lead-zinc ore

Abstract

The invention relates to a flotation separation method for refractory mixed lead-zinc ore. The method comprises the steps of lead preferential flotation, lead-zinc bulk flotation, lead-zinc separation flotation and zinc flotation, and a novel sphalerite combined inhibitor composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate is added during lead-zinc separation flotation. The method realizes efficient recovery of compact dip-dyed and fine vein dip-dyed symbiotic complex refractory mixed lead-zinc ores, and has wide industrial application and popularization prospects.

Description

Technical Field

[0001] The present application relates to the technical field of mineral processing, and in particular to a flotation separation method for difficult-to-separate mixed lead-zinc ore. Background Art

[0002] Lead-zinc ore can be divided into sulfide lead-zinc ore, mixed lead-zinc ore and oxidized lead-zinc ore according to the deepening of oxidation degree, and its selectivity is also decreasing. Mixed lead-zinc ore resources generally have the characteristics of a wide variety of minerals, variable ore properties, and complex co-existence and embedding relationship between lead, zinc minerals and gangue minerals, which increases the difficulty of lead-zinc flotation and separation.

[0003] Especially for some difficult mixed lead-zinc ores, due to their dense impregnation and / or fine vein impregnation ore structures, or due to severe oxidation and weathering, the traditional preferential flotation separation effect is poor, the obtained lead and zinc concentrates contain more serious inter-containment phenomenon, the grade fluctuation is also large, and in the flotation process, fine grinding is required to achieve full dissociation of lead and zinc minerals, resulting in high beneficiation costs. Therefore, it is very necessary to strengthen the research on new beneficiation processes and new reagents for mixed lead-zinc ores. Developing a process suitable for ore characteristics and correctly selecting a reagent system are the basis for achieving lead and zinc separation and recovery.

[0004] Regarding the beneficiation method of difficult-to-select mixed lead-zinc ore, the prior art publication number CN 117772405 B discloses "A beneficiation method for difficult-to-select mixed lead-zinc ore". The beneficiation method for difficult-to-select mixed lead-zinc ore provided in this application processes sulfide ore and oxide ore separately, firstly classifies the sulfide ore according to the natural floatability difference of the ore, and then treats the oxide ore by gravity separation, thereby overcoming the adverse effect of using oxide ore beneficiation agents on the recycling of return water and solving the problem of poor flotation index of oxide ore.

[0005] The problem of this method is that, on the one hand, in addition to the conventional flotation process, spiral chute classification and shaking table gravity separation are used to recover oxidized lead-zinc ore during the flotation process, which has relatively high requirements for the equipment and site of the ore dressing plant and cannot be directly implemented by relying on existing equipment; on the other hand, among the ore dressing indicators of this method, except for the lead concentrate, zinc concentrate and lead-zinc mixed concentrate that can be directly used, the gravity separation concentrate obtained does not meet the requirements of the minimum grade of lead concentrate or the minimum grade of zinc concentrate because its main grade quality fraction does not meet the requirements of the minimum grade of lead concentrate or zinc concentrate, and is not even within the scope of the minimum grade of mixed lead-zinc concentrate. Therefore, how to effectively handle these products is a big problem for enterprises. Furthermore, if the lead and zinc indicators of the gravity separation concentrate that are not convenient for direct recycling are removed in this method, 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] In order to solve the problems existing in the background technology, the present application provides a flotation separation method for difficult-to-select mixed lead-zinc ore. The flotation separation method, by using specific reagents and conventional flotation processes and equipment, can achieve efficient separation and recovery of difficult-to-select mixed lead-zinc ore. In the entire flotation process, except for the lead concentrate and zinc concentrate obtained by flotation, the remaining products can be discarded. At the same time, according to the recovered lead concentrate and zinc concentrate that can be directly used, the recovery rate of the entire flotation lead is 89.92%, and the recovery rate of zinc is 75.34%.

[0007] For general lead-zinc ores, the conventional lead-zinc separation process is to prioritize the flotation of lead, and then activate the zinc to float the lead by suppressing zinc to float the lead, and then activate the zinc to float, so that lead concentrate and zinc concentrate can be obtained respectively; while for difficult-to-select lead-zinc ores, a mixed flotation process is often used to obtain mixed concentrates and flotation tailings respectively. The process of this application combines the two, first using the zinc suppression lead floating process to float the easy-to-float lead metal, and then mixed floating is carried out through the action of the reagent, and the difficult-to-select lead metal and a large amount of zinc metal are floated together, and the mixed coarse concentrate after floating is re-grinded to fully dissociate the fine and micro-particle embedded lead and zinc metal, and then the new reagent is used again to suppress zinc and float lead, and the lead metal is concentrated as lead concentrate, and the suppressed zinc minerals (separation flotation tailings) are activated to float zinc to obtain zinc concentrate.

[0008] In particular, the novel inhibitor in the present application is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, wherein polyferric chloride can effectively inhibit Fe 2+ , Fe 3+ Ions, and iron ions often exist in minerals in the form of sphalerite, so adding polyferric chloride can enhance the inhibitory effect of sphalerite; sodium cyanurate, with the chemical formula C3H4N3NaO3, is a reducing agent with reducing properties, which causes a chemical reaction on the surface of zinc minerals, promotes the reaction between the surface of zinc minerals and zinc sulfate, and improves the inhibitory effect; thiourea, an organic sulfur-containing compound with the chemical formula CH4N2S, is a vulcanization accelerator; sodium carbonate plays a role in adjusting the pH reaction environment of the agent, promoting a synergistic effect between different drugs such as zinc sulfate, sodium cyanurate, thiourea, and polyferric chloride, so as to effectively inhibit the symbiotic zinc ions in the gangue.

[0009] When this new sphalerite combination inhibitor is used, the sphalerite component on the surface is partially covered by the inhibitor component and the collector component. There are five surface inhibitor components. The adsorption amount of various inhibitors and collectors on the surface is measured by infrared. It is found that after inhibition by the new sphalerite combination inhibitor, the surface of the sphalerite mineral is preferentially adsorbed by the inhibitor component, and only a very small amount of collector component is adsorbed, which is beneficial to the flotation separation of lead and zinc and can significantly improve the inhibition effect of sphalerite mineral.

[0010] The novel sphalerite combination inhibitor of the present application inhibits the flotation of sphalerite to separate lead-zinc mixed concentrate, so that the collector on the surface of the sphalerite mineral is desorbed, and the inhibitor adsorption has a high reaction trend, so that the floatability of sphalerite is significantly reduced, and the hydrophobicity difference between galena and sphalerite is increased. Therefore, compared with the conventional sphalerite inhibitor, the novel sphalerite combination inhibitor of the present invention can significantly reduce the mutual content of lead and zinc concentrate, improve the recovery rate of lead and zinc metals, and increase production efficiency.

[0011] The technical solution provided by this application may have the following beneficial effects:

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

[0013] (2) The present application adds a new sphalerite combination inhibitor during separation and flotation. Since it is mainly composed of inorganic substances, it avoids the dilemma of difficult activation of zinc minerals after separation. The zinc that has been inhibited and reactivated often has better floatability, which is beneficial to improving the quality of zinc concentrate. In addition, due to the relatively stable complexation of the new sphalerite combination inhibitor, sodium cyanurate has high water solubility and stability and is not easy to decompose. However, it may decompose and produce toxic gases under strong acid or high temperature conditions. The test in the present application is carried out in an alkaline environment and at room temperature. Therefore, no free CN is produced in the slurry. - ion.

[0014] (3) The present application adopts the easy-to-select lead sulfide minerals in the preferential flotation ore, and then through mixed flotation, the difficult-to-select lead and the suppressed zinc minerals can be mixed and recovered to the maximum extent, and the minerality of the mixed concentrate is returned to the original state before the addition of the drug by de-medication and re-grinding. At this time, a new inhibitor is added to strongly suppress the zinc minerals in the mixed concentrate, so that lead and zinc can be better separated. This method realizes the efficient recovery of densely impregnated and fine-veined, complex and difficult-to-select mixed lead-zinc ores. In addition, compared with the traditional single ore dressing process, the separation method of the present invention avoids fine grinding in the original ore grinding stage, and only re-grinds the mixed concentrate, which greatly reduces the energy consumption of grinding, and greatly reduces the ore dressing cost for closely symbiotic difficult-to-select lead-zinc ores.

[0015] (4) The process processing cost and equipment configuration proposed in this application are much lower than those of the preferential flotation separation process, and the quality of the concentrate obtained is better than that of the preferential flotation alone. It is an efficient method for processing densely impregnated, fine-veined, and complex symbiotic ores, and has broad prospects for application and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] Figure 1 It is a schematic diagram of the process flow of the flotation separation method of the difficult-to-select mixed lead-zinc ore shown in the present application;

[0018] Figure 2 It is a schematic diagram of the process flow of the conventional method for preferential lead floating and zinc suppression separation shown in this application. DETAILED DESCRIPTION

[0019] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0020] Example 1: Flotation separation of refractory mixed lead-zinc ore

[0021] According to the process mineralogy study of the ore produced by a difficult-to-select mixed lead-zinc mine in Yunnan, the main elements that can be recovered in the ore 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%; zinc is mainly in the form of zinc sulfide, accounting for 82.11%. Among them, galena and sphalerite are medium-fine-grained, and pyrite is medium-coarse-grained. The cumulative distribution rates of galena, sphalerite and pyrite with an embedded particle size of +0.074mm are 49.7%, 59.4% and 65.9% respectively. The main factor affecting the recovery of lead and zinc is that the particle size of galena and sphalerite is fine (fine particles -0.01mm account for 10.5%, and fine particles +0.01-0.074mm account for 30.8%).

[0022] The flotation separation method of the refractory mixed lead-zinc ore provided in the present application comprises the following steps:

[0023] (1) adding refractory mixed lead-zinc ore and a regulator into a mill, and subjecting the ore to grinding and classification, obtaining a slurry 1 to be treated with a 0.074 mm content of 70-80% and a pH of 8-10;

[0024] The adjusting agent is lime, and the dosage is adjusted according to the pH value, and the dosage is 500-800g / t;

[0025] (2) conveying the slurry 1 to be processed to a flotation machine, adding a conventional sphalerite depressant, a lead flotation collector and a frother in sequence, and then performing aeration flotation to obtain a lead rougher concentrate 1 and a lead rougher tailings;

[0026] Conventional sphalerite inhibitor is zinc sulfate, the dosage is 500-1000g / t; lead flotation collector is ethyl thiocyanate and 25# black medicine, the ratio of ethyl thiocyanate and 25# black medicine is 2:1, the dosage is 60-150g / t; frother is pine oil, the dosage is adjusted according to the foam situation, the dosage is 10-40g / t;

[0027] (3) conventional sphalerite inhibitor is added to the lead rough concentrate 1, and lead concentrate 1 is obtained after repeated concentration;

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

[0029] (4) adding sphalerite activator, sodium amyl xanthate and frother to the lead roughing tailings for flotation, and flotating the difficult-to-select lead and zinc minerals together to obtain a lead-zinc mixed rough concentrate and a mixed flotation tailings 1;

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

[0031] Mixed flotation tailings 1 are sequentially added with sphalerite activator, sodium amyl xanthate and frother, and then scavenged to obtain final mixed flotation tailings, which are discarded after repeated scavenging;

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

[0033] (5) adding activated carbon to the lead-zinc mixed coarse concentrate and then entering a mill for re-grinding and classification treatment to obtain a to-be-treated slurry 2 with a content of -0.074 mm of 92-95%, conveying the to-be-treated slurry 2 to a flotation machine, adding an adjusting agent to adjust the slurry pH to 9-12, and then sequentially adding a novel sphalerite combined depressant, a lead flotation collector and a frother to obtain a sorted lead coarse concentrate 2 with a high lead content and a separated flotation tailing;

[0034] The new sphalerite combined depressor is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, with a mass ratio of 3:3:1:2:1, and a dosage of 30-200g / t; the lead flotation collector is ethylthiocyanate, with a dosage of 40-80g / t; the adjusting agent is lime, with a dosage of 300-2000g / t; the foaming agent is pine oil, with a dosage of 5-20g / t;

[0035] (6) A novel sphalerite combined depressant is added to the lead rough concentrate 2, and lead concentrate 2 is obtained after repeated concentration;

[0036] The new sphalerite combined inhibitor is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, with a mass ratio of 3:3:1:2:1, and a dosage of 30-200g / t;

[0037] (7) adding a lead collector to the separated flotation tailings, and using the tailings after scavenging as the slurry to be processed 3; the lead collector is ethyl thiocyanate, and the dosage is 20-40 g / t;

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

[0039] (8) A conditioning agent is added to the zinc rougher concentrate for selection to obtain zinc concentrate, wherein the conditioning agent is lime, with a dosage of 50-300 g / t, and the pH value of the slurry is adjusted to 9-11; a sphalerite activator, a zinc collector and a frother are added to the zinc rougher tailings in sequence, and zinc tailings are obtained after scavenging, wherein the sphalerite activator is copper sulfate, with a dosage of 150-400 g / t, the zinc collector is sodium butyl xanthate, with a dosage of 30-60 g / t, and the frother is pine oil, with a dosage of 5-20 g / t.

[0040] By adopting the method of the present application, the lead concentrate 1 obtained has a lead grade of 67.28% and a zinc grade of 4.21%; the lead concentrate 2 has a lead grade of 64.48% and a zinc grade of 5.62%, and the lead recovery rate of the comprehensive lead concentrate is 89.28; the zinc concentrate has a zinc grade of 52.85% and a lead content of 2.80%; and the zinc recovery rate is 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 ratio of 1:1, lead is subjected to one roughing, three refining and three scavenging to obtain lead concentrate, the lead flotation tailings enter zinc flotation, copper sulfate is used as an activator, the dosage is 400-600g / t, butyl xanthate and amyl xanthate are combined as a collector in a ratio of 1:1, the dosage is 80-100g / t, and a flotation process of one roughing, three refining and four scavenging is adopted to obtain zinc concentrate.

[0043] Zinc flotation tailings are the final tailings. The lead concentrate contains only 56.07% lead, 7.02% zinc, and 76.93% lead recovery. The zinc concentrate contains 40.65% zinc, 4.67% lead, and 59.47% zinc recovery. The main element grade of lead-zinc concentrate is low and the mutual content is high, resulting in a low recovery rate, which seriously affects the benefits of the enterprise.

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

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

[0046]

[0047] By adopting the flotation separation method of the present application, as the yield decreases, the concentrate grade increases, and the concentrate amount decreases, the concentrate transportation cost is also greatly reduced.

[0048] Example 2: Flotation separation of low-grade mixed lead-zinc ore

[0049] At a mine dressing plant in Yunnan, the process mineralogy study of the ore to be processed showed that the main elements that can be recovered for dressing are Pb and Zn, with grades of 2.94% and 3.22% respectively. Lead is mainly in the form of lead sulfide, accounting for 93.2%; zinc is mainly in the form of zinc sulfide, accounting for 91.93%. The main factor affecting the recovery of useful metals is the fineness of the mineral distribution: the particle size of lead ore is fine (microparticles -0.01mm account for 8.5%, fine particles +0.01-0.074mm account for 37.8%), and the particle size of sphalerite is fine (microparticles -0.01mm account for 9.3%, fine particles +0.01-0.074mm account for 29.3%).

[0050] The flotation separation method of the refractory mixed lead-zinc ore provided in the present application comprises the following steps:

[0051] (1) adding refractory mixed lead-zinc ore and a regulator into a mill, and subjecting the mill to grinding and classification treatment to obtain a slurry 1 to be treated having a 0.074 mm content of 75-85% and a pH of 8-10; the regulator is lime, and the amount used is 300-500 g / t;

[0052] (2) conveying the slurry 1 to be processed to a flotation machine, adding a conventional sphalerite depressant, a lead flotation collector and a frother in sequence, and then performing aeration flotation to obtain a lead rougher concentrate 1 and a lead rougher tailings;

[0053] Conventional sphalerite inhibitor is zinc sulfate, with a dosage of 400-700g / t; lead flotation collector is ethyl thiocyanate, 25# black medicine and butyl sodium xanthate, the ratio of ethyl thiocyanate, 25# black medicine and butyl sodium xanthate is 1:1:1, and the dosage is about 60-150g / t; the foaming agent is pine oil, with a dosage of 10-30g / t;

[0054] (3) conventional sphalerite inhibitor is added to the lead rough concentrate 1, and lead concentrate 1 is obtained after repeated concentration;

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

[0056] The lead roughing tailings are added with sphalerite activator, sodium amyl xanthate and frother for flotation, and the hard-to-select lead and zinc minerals are floated out together to obtain lead-zinc mixed rough concentrate and mixed flotation tailings 1. The ore in the scavenging operation is returned to the previous flotation operation in sequence. After 2-3 times of lead mixed scavenging, the scavenging tailings are the final tailings;

[0057] The sphalerite activator is copper sulfate, with a dosage of 100-500g / t; the amyl sodium xanthate is amyl sodium xanthate, with a dosage of 40-100g / t; the foaming agent is pine oil, with a dosage of 10-40g / t;

[0058] Mixed flotation tailings 1 are sequentially added with sphalerite activator, sodium amyl xanthate and frother, and then scavenged to obtain final mixed flotation tailings, which are discarded after repeated scavenging;

[0059] The sphalerite activator is copper sulfate, with a dosage of 50-250g / t; the amyl sodium xanthate is amyl sodium xanthate, with a dosage of 40-100g / t; the foaming agent is pine oil, with a dosage of 5-20g / t;

[0060] (5) adding activated carbon to the lead-zinc mixed coarse concentrate and then entering a mill for re-grinding and classification treatment to obtain a to-be-treated slurry 2 with a content of -0.074 mm of 92-95%, conveying the to-be-treated slurry 2 to a flotation machine, adding an adjusting agent to adjust the slurry pH to 9-12, and then sequentially adding a novel sphalerite combined depressant, a lead flotation collector and a frother to obtain a sorted lead coarse concentrate 2 with a high lead content and a separated flotation tailing;

[0061] The adjusting agent is lime, with a dosage of 250-400g / t; the new sphalerite combined inhibitor is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, with a mass ratio of 3:3:1:2:1, and a dosage of 30-200g / t; the lead flotation collector is a combination of ethyl thiocyanate and 25# black medicine in a ratio of 4:1, with a dosage of 60-80g / t; the foaming agent is pine oil, with a dosage of 5-20g / t;

[0062] (6) A novel sphalerite combined depressant is added to the lead rough concentrate 2, and lead concentrate 2 is obtained after repeated concentration;

[0063] The new sphalerite combined inhibitor is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, with a mass ratio of 3:3:1:2:1, and a dosage of 30-200g / t;

[0064] (7) adding a lead collector to the separated flotation tailings, and using the tailings after scavenging as the slurry to be processed 3; the lead collector is ethyl thiocyanate, and the dosage is 20-40 g / t;

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

[0066] (8) A conditioning agent is added to the zinc rougher concentrate for selection to obtain zinc concentrate, wherein the conditioning agent is lime, with a dosage of 60-200 g / t, and the pH value of the ore pulp is adjusted to 10-12; a sphalerite activator, a zinc collector and a frother are added to the zinc rougher tailings in sequence, and zinc tailings are obtained after scavenging, wherein the sphalerite activator is copper sulfate, with a dosage of 350-500 g / t, the zinc collector is sodium butyl xanthate, with a dosage of 40-70 g / t, and the frother is pine oil, with a dosage of 5-20 g / t.

[0067] After experimental research, the process and reagents provided in this application were adopted, and after 2 months of trial production, lead concentrate 1 with a lead grade of 77.85%, a zinc grade of 2.39%, lead concentrate 2 with a lead grade of 75.43%, a zinc grade of 3.07%, and a total lead recovery rate of 86.92%; the zinc concentrate with a zinc grade of 52.02%, a lead grade of 1.96%, and 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, and lead concentrate is obtained after one roughing, three fines and three scavenging. The lead flotation tailings enter the zinc flotation, and copper sulfate is used as an activator in an amount of 450g / t, and butyl xanthate is used as a collector in an amount of 55g / t. A flotation process of one roughing, three fines and three scavenging is adopted to obtain zinc concentrate, and the zinc flotation tailings are the final tailings.

[0070] The lead concentrate obtained by the above process contains 63.92% lead, 6.83% zinc, and 71.24% lead recovery; the zinc concentrate contains 43.35% zinc, 4.67% lead, and 74.44% zinc recovery. The high inter-containment affects the profitability of the concentrator.

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

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

[0073]

[0074] Example 3

[0075] The difference between Example 3 and Example 1 is that the novel sphalerite combination inhibitor consists of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, and the mass ratios are 3:3:1:2:2 respectively.

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

[0077] Table 3 Example 3 Mixed lead-zinc ore test results (%)

[0078]

[0079]

[0080] Example 4

[0081] The difference between Example 4 and Example 1 is that the novel sphalerite combination inhibitor is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, and the mass ratios are 3:3:1:2:3 respectively.

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

[0083] Table 4 Example 4 Mixed lead-zinc ore test results (%)

[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 test results of Comparative Example 3 are shown in Table 5.

[0088] Table 5 Comparative Example 3 Mixed Lead-Zinc Ore Test Results (%)

[0089]

[0090]

[0091] Comparative Example 4

[0092] The difference between Comparative Example 4 and Example 1 is that the novel sphalerite combination inhibitor consists of sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, and the mass ratios are 3:1:2:1 respectively.

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

[0094] Table 6 Comparative Example 4 Mixed Lead-Zinc Ore Test Results (%)

[0095]

[0096] Comparative Example 5

[0097] The difference between Comparative Example 5 and Example 1 is that the novel sphalerite combination inhibitor consists of zinc sulfate, thiourea, polyferric chloride and sodium carbonate, and the mass ratios are 3:1:2:1 respectively.

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

[0099] Table 7 Comparative Example 5 Mixed Lead-Zinc Ore Test Results (%)

[0100]

[0101]

[0102] Comparative Example 6

[0103] The difference between Comparative Example 6 and Example 1 is that the novel sphalerite combination inhibitor consists of zinc sulfate, sodium cyanurate, thiourea and sodium carbonate, and the mass ratios are 3:3:1:1 respectively.

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

[0105] Table 8 Comparative Example 6 Mixed Lead-Zinc Ore Test Results (%)

[0106]

[0107] Comparative Example 7

[0108] The difference between Comparative Example 7 and Example 1 is that the novel sphalerite combination inhibitor consists of zinc sulfate, sodium cyanurate, thiourea and polyferric chloride, and the mass ratios are 3:3:1:2 respectively.

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

[0110] Table 9 Comparative Example 7 Mixed Lead-Zinc Ore Test Results (%)

[0111]

[0112]

[0113] Comparative Example 8

[0114] The difference between Comparative Example 8 and Example 1 is that the novel sphalerite combination inhibitor consists of zinc sulfate, sodium cyanurate and sodium carbonate, and the mass ratio is 3:3:1 respectively.

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

[0116] Table 10 Comparative Example 8 Mixed Lead-Zinc Ore Test Results (%)

[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 sphalerite combination inhibitor, but uses the conventional zinc sulfate inhibitor.

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

[0121] Table 11 Comparative Example 9 Mixed Lead-Zinc Ore Test Results (%)

[0122]

[0123] Comparative Examples 1 and 2 of the present application both adopt conventional preferential flotation processes. In Example 1, the zinc grade of lead concentrate 1+2 is calculated by weighted average method for lead concentrate 1 and lead concentrate 2, and the zinc grade is 4.70%, while the zinc grade in Comparative Example 1 is 7.02%; in Example 2, the zinc grade of lead concentrate 1+2 is calculated by weighted average method for lead concentrate 1 and lead concentrate 2, and the zinc grade in Comparative Example 2 is 2.63%, while the zinc grade in Comparative Example 2 is 6.83%. It can be seen that the zinc grade of the lead concentrate obtained by the conventional preferential flotation process is greater than the zinc grade of the lead concentrate 1+2 obtained by the process flow of the present application.

[0124] Comparative Example 3 adopts the conventional mixed flotation process, and only the mixed concentrate is obtained, and the lead grade of the mixed concentrate is only 33.94%, and the zinc grade is only 22.06%, which does not meet the requirements of qualified products. It can be seen that the product obtained by the conventional mixed flotation process is unqualified and cannot achieve the effect of lead and zinc separation.

[0125] The method of Example 1 of the present application is adopted, in which the novel sphalerite combined inhibitor is composed of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, and the mass ratio is 3:3:1:2:1, to obtain 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, and the mass ratio is 3:1:2:1, to obtain lead concentrate 1 with a lead grade of 62.77% and a zinc grade of 4.21%. The lead concentrate 2 contained 54.36% lead and 9.83% zinc, the zinc concentrate contained 2.87% lead and 51.10% zinc; in comparative example 5, a new sphalerite combined inhibitor was used, which was composed of zinc sulfate, thiourea, polyferric chloride and sodium carbonate, with a mass ratio of 3:1:2:1, to obtain a lead concentrate 1 with a lead grade of 67.01% and a zinc grade of 4.20%, a lead concentrate 2 with a lead grade of 59.13% and a zinc grade of 7.63%, and a zinc concentrate with a lead grade of 2.85% and a zinc grade of 48.09%; in comparative example 6, a new sphalerite combined inhibitor was used, which was composed of zinc sulfate, sodium cyanurate, thiourea and sodium carbonate. , the mass ratio is 3:3:1:1, and the lead concentrate 1 has a lead grade of 67.55% and a zinc grade of 4.22%, the lead concentrate 2 has a lead grade of 59.52% and a zinc grade of 7.40%, and the zinc concentrate has a lead grade of 2.76% and a zinc grade of 49.57%; Comparative Example 7 uses a new sphalerite combined inhibitor composed of zinc sulfate, sodium cyanurate, thiourea and polyferric chloride, and the mass ratio is 3:3:1:2, and the lead concentrate 1 has a lead grade of 67.01% and a zinc grade of 4.23%, the lead concentrate 2 has a lead grade of 63.58% and a zinc grade of 5.87%, and the zinc concentrate has a lead grade of 2.79% and a zinc grade of 52.00 %; Comparative Example 8 uses a new sphalerite combined inhibitor composed of zinc sulfate, sodium cyanurate and sodium carbonate, with a mass ratio of 3:3:1, to obtain a lead concentrate 1 with a lead grade of 66.95% and a zinc grade of 4.26%, a lead concentrate 2 with a lead grade of 62.68% and a zinc grade of 5.70%, a zinc concentrate with a lead grade of 2.82% and a zinc grade of 52.48%; Comparative Example 9 uses a conventional zinc sulfate inhibitor to obtain a lead concentrate 1 with a lead grade of 67.08% and a zinc grade of 4.22%, a lead concentrate 2 with a lead grade of 24.82% and a zinc grade of 28.54%, a zinc concentrate with a lead grade of 16.23% and a zinc grade of 37.68%.

[0126] It can be seen that the zinc content in the lead concentrate 2 using four of the zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate is 5.62% higher than that in Example 1. The zinc inhibition effect of the lead concentrate 2 obtained by using the conventional zinc sulfate inhibitor in Comparative Example 9 is even worse, and the zinc content in the lead concentrate 2 is as high as 28.54%. Therefore, the novel sphalerite combination inhibitor of the present application, zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate produce a synergistic effect to reduce the zinc content in the ore.

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

[0128] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A flotation separation method for difficult-to-select mixed lead-zinc ore, characterized in that: The following steps are involved: A. Preferentially float part of lead (1) lime is added to the refractory mixed lead-zinc ore, and the ore is subjected to grinding and classification treatment to obtain a slurry 1 to be processed with a pH value of 8-10; a conventional sphalerite inhibitor, a lead flotation collector and a frother are sequentially added to the slurry 1 to be processed, and then flotation is performed to obtain a lead crude concentrate 1 and a lead crude tailings; (2) conventional sphalerite inhibitor is added to the lead rough concentrate 1, and lead concentrate 1 is obtained after concentration; B. Mixed flotation of lead + zinc (1) adding sphalerite activator, sodium amyl xanthate and frother to the lead coarse tailings for flotation to obtain lead-zinc mixed coarse concentrate and mixed flotation tailings 1; (2) adding sphalerite activator, sodium amyl xanthate and frother in sequence to the mixed flotation tailings 1 and then scavenging to obtain the final mixed flotation tailings; C. Lead and zinc separation flotation (1) Adding activated carbon to the lead-zinc mixed coarse concentrate for regrinding treatment to obtain a slurry 2 to be treated, adding lime to adjust the pH to 9-12, and then sequentially adding a novel sphalerite combination inhibitor, a lead flotation collector and a frother to obtain a lead coarse concentrate 2 and a separation flotation tailings through lead-zinc separation flotation; (2) adding a novel sphalerite combined depressant to the lead rough concentrate 2, and then concentrating the lead concentrate 2 to obtain the lead concentrate 2; (3) adding a lead collector to the separated flotation tailings, and using the scavenged tailings as the slurry 3 to be processed; adding lime, sphalerite activator, zinc collector and frother in sequence to the slurry 3 to obtain a zinc rougher concentrate and a zinc rougher tailings through flotation; (4) concentrating the zinc rougher concentrate to obtain zinc concentrate; (5) Zinc rougher tailings are scavenged to obtain zinc tailings; Wherein, the conventional sphalerite inhibitor is zinc sulfate; The novel sphalerite combined inhibitor consists of zinc sulfate, sodium cyanurate, thiourea, polyferric chloride and sodium carbonate, and the mass ratio of the 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 the zinc sulfate, the sodium cyanurate, the thiourea, the polyferric chloride and the sodium carbonate is 3:3:1:2:

1.

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

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

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

6. The method according to claim 1, characterized in that The grinding fineness of the ore pulp 2 to be processed is -0.074mm and the content accounts for 92%-95%.

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

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