Combined collecting agent for sulfur-oxygen bulk flotation of lead-silver oxide ore and application of combined collecting agent

Abstract

The invention discloses a combined collecting agent for sulfur-oxygen bulk flotation of lead-silver oxide ore and application of the combined collecting agent. The combined collecting agent comprises long-chain xanthate, branched-chain xanthate, thiophosphate or thiophosphinate according to the mass ratio of (1-10): (1-10): 1. Based on the structure-activity relationship of agent molecules and the synergistic collecting effect of the combined collecting agent, through the synergistic collecting effect of the multi-component combined collecting agent, the combined collecting agent shows higher collecting capacity and better selectivity on the surfaces of lead and silver minerals; the flotation performance of the collecting agent is obviously superior to that of a single collecting agent or an existing traditional lead-silver ore flotation collecting agent. The collecting agent is particularly suitable for the sulfur-oxygen bulk flotation process of the lead-silver oxide ore, the recovery rate of lead and silver metal in the complex lead-silver oxide ore can be effectively increased, and the collecting agent has good industrial application prospects.

Description

Technical Field

[0001] This invention relates to mineral flotation, and more specifically, to a combined collector for sulfur-oxygen mixed flotation of oxidized lead-silver ores and its application. Background Technology

[0002] With the increasing depletion of easily processed single-metal resources, complex lead-silver polymetallic ores have become an important source of lead and silver. In my country, lead-zinc ores are the main carriers of associated silver, with over 60% of silver resources occurring in these deposits. In the flotation practice of these minerals, because lead and silver have similar properties, and silver has a higher valuation factor in lead concentrate than in zinc concentrate, they often need to be recovered together.

[0003] Flotation, as the primary method for separating lead-silver ores, directly determines the silver recovery efficiency through its separation effect, while collector performance is the core factor affecting flotation effectiveness. However, with the increasing trend of "lean, fine, and complex" mineral resources, the development of low-grade, complex, and difficult-to-process ores has become an inevitable trend, and efficient flotation of oxide ores has become a global challenge. Traditional flotation processes and reagent systems are no longer sufficient to meet the current needs for efficient resource development and utilization. In existing flotation systems, collector performance is the key factor determining separation effectiveness. Traditional collectors, such as xanthates and dioxins, although technically mature and low-cost, have poor selectivity for silver minerals.

[0004] Extensive research in industrial flotation practices and related papers on lead-silver ore flotation has shown that conventional single collectors, such as butyl xanthate, are insufficient for the efficient enrichment of silver minerals, often resulting in the loss of over 20% or even 30% of silver in tailings. This makes the comprehensive recovery and utilization of lead-zinc ores containing associated silver a key challenge in lead-silver ore flotation. Current key technological bottlenecks in lead-silver ore flotation mainly stem from: the similar surface properties of silver minerals and associated gangue minerals, leading to insufficient selective recognition capabilities of existing collectors; low collection efficiency for fine-grained silver minerals; and the limited adaptability of traditional reagent systems to complex ores. These factors severely restrict the comprehensive utilization efficiency of lead and silver resources. Therefore, the performance deficiencies of existing collectors have become a crucial factor limiting the improvement of silver recovery rates.

[0005] Anionic collectors, such as xanthates and dioxins, are commonly used in the actual flotation of lead and silver ores. However, these collectors have limited adsorption capacity for lead oxide minerals and require pre-sulfidation with high doses of sodium sulfide. In actual production, key challenges arise, including uneven sulfidation, over-sulfidation, significant consumption of reagents by slime, and substantial pollution of beneficiation wastewater. The synergistic effect of combined collectors is considered an effective way to enhance flotation. Although some applications have been made, the specific mechanisms of action, especially the scientific essence of selective adsorption and enhancement through coordination regulation at the molecular / atomic level, remain unclear, limiting the rational design of highly efficient reagents and process optimization.

[0006] Flotation of oxidized lead-silver ores can be divided into preferential flotation and mixed flotation processes. Preferential flotation involves first collecting sulfide ores and then sulfiding the oxidized ores with a sulfidizing agent. This flotation system has many drawbacks, such as a long flotation process, a large number of equipment, high power consumption, large reagent consumption, and product quality being greatly affected by fluctuations in the properties of the raw ore. The sulfur-oxygen mixed flotation process simultaneously collects the sulfide and oxide phases in oxidized lead-silver ores. This process has advantages such as a shorter process flow and fewer equipment requirements; however, existing traditional collectors perform poorly in the sulfur-oxygen mixed flotation process.

[0007] Based on the structure-activity relationship of reagent molecules and the principle of synergistic coordination and collection of combined collector molecules, a combined collector suitable for sulfur-oxygen mixed flotation systems with both strong collection ability and good selectivity has been developed. This breakthrough overcomes the performance limitations of traditional single reagents and has become an urgent need to improve the comprehensive utilization level of silver resources. This is of great strategic significance for achieving the sustainable development of mineral resources. Summary of the Invention

[0008] To address the performance limitations of traditional single-agent flotation, this invention provides a combined collector for sulfur-oxygen mixed flotation of oxidized lead-silver ores and its application. This combined collector combines strong collecting ability with good selectivity, providing important support for improving the comprehensive utilization of lead-silver ores and promoting the green and sustainable development of mineral resources.

[0009] To achieve the above objectives, the present invention provides a combined collector for sulfur-oxygen mixed flotation of oxidized lead-silver ore, comprising long-chain xanthates, branched-chain xanthates, thiophosphates or thiophosphonates in a mass ratio of (1~10):(1~10):1.

[0010] Long-chain xanthate hydrocarbons have long chains and strong hydrophobicity. Once adsorbed onto the mineral surface, they can form a robust hydrophobic film, greatly improving the adhesion efficiency and firmness of mineral particles and bubbles, thus ensuring concentrate recovery rate.

[0011] The branched structure of branched xanthates makes their adsorption arrangement on mineral surfaces less compact than that of straight-chain xanthates, but it enhances their ability to identify specific minerals, thus improving selectivity and suppressing some gangue. Moreover, they are generally more water-soluble than long-chain xanthates, disperse faster in slurry, and can quickly adsorb onto mineral surfaces, acting as "pioneers" and "activators."

[0012] like Figure 2 The molecular orbital diagram and ESP shown indicate that the P=S or P-SH groups in thiophosphate or thiophosphonate molecules readily react with lead ions (Pb). 2+ ), silver ions (Ag) +This forms stable five- or six-membered ring chelates. This chemisorption is very strong and is the basis and key to the capture of lead oxide minerals (cerussite, ferruginous oxide) and silver minerals.

[0013] This invention, through the combination of long-chain xanthates and branched-chain xanthates, reduces the alignment energy and mutual repulsion of collector molecules on the mineral surface, increasing the adsorption density of collector molecules on the mineral surface while maintaining good collecting ability and selectivity, resulting in better flotation performance. Thiophosphates or thiophosphonates first anchor to the mineral surface through strong chelation, providing a more stable "base point" for the adsorption of long-chain xanthates. Long-chain xanthates spread around the "anchor point," forming a strongly hydrophobic layer; branched-chain xanthates fill the gaps, making the entire hydrophobic film more uniform and robust. While long-chain and branched xanthates have excellent synergistic effects and can effectively collect sulfide minerals, they are difficult to collect relatively "hydrophilic" oxidized minerals. Thiophosphates or thiophosphonates have relatively stronger collecting performance than xanthates in flotation; by utilizing their excellent collecting ability, the flotation effect on oxidized minerals can be improved. The combined collectors prepared using the linear xanthate, branched xanthate and thiophosphate or thiophosphonate obtained by the present invention can ultimately achieve enhanced collection of Pb and Ag through their synergistic coordination collection effect.

[0014] Preferably, the mass ratio of long-chain xanthates to branched-chain xanthates is 1:1. As mentioned earlier, long-chain xanthates have strong collecting power, while branched-chain xanthates have strong selectivity. Although the combination of these two collectors will result in better flotation performance under synergistic effects, excessive strength in either collecting power or selectivity will lead to a decrease in the other. Specifically, a collector with stronger collecting power can improve the recovery rate of the concentrate, but cannot completely guarantee the grade of the concentrate, while selectivity has the opposite effect. At this mass ratio, the balance between the selectivity and collecting power of the reagents is optimal during the flotation process, ensuring a good recovery rate and grade in the final lead-silver concentrate.

[0015] Preferably, the long-chain xanthate is a linear xanthate with a carbon chain length ≥ 2, and is preferably n-butyl sodium xanthate, n-propyl sodium xanthate or n-pentyl sodium xanthate.

[0016] Preferably, the branched xanthate is a branched xanthate with a main carbon chain length ≥3 and a branch number ≥1, and is preferably isopentyl xanthate, isobutyl xanthate or isohexyl xanthate.

[0017] Preferably, the thiophosphate is one of sodium diisopropyl dithiophosphate, sodium diisobutyl dithiophosphate, and sodium di-n-butyl dithiophosphate, and the thiophosphonate is sodium diisopropyl dithiophosphonate, sodium diisobutyl dithiophosphonate, or sodium di-n-butyl dithiophosphonate.

[0018] A second aspect of the present invention provides the application of the above-described combined collector in the sulfur-oxygen mixed flotation of oxidized lead-silver ores.

[0019] One application method is as follows: The raw ore is ground to approximately 70% -200 mesh. Sodium sulfide is added during the grinding stage. In the roughing stage, sodium sulfide, xanthate, water glass, No. 2 oil, and the novel lead-silver ore combined collector prepared according to this invention are added at a dosage of 100-200 g / t. The roughing concentrate enters a primary cleaning stage, and the tailings enter a primary scavenging stage. The cleaning stage is set to 2-3 times, and the scavenging stage to 3-5 times. Only water glass is added in the cleaning stage, and only xanthate and sodium sulfide are added in the scavenging stage.

[0020] Through the above technical solution, the present invention achieves the following beneficial effects: The lead-silver ore combined collector of this invention has advantages such as wide availability of raw materials, good selectivity, strong collecting ability, and low dosage. It has performed well in the flotation practice of low-grade and difficult-to-process oxidized lead-silver ores and can be further promoted and applied in the field of lead-silver ore flotation. It has good frother properties, which are stronger than traditional xanthate collectors, thus reducing the amount of frother used. Compared with traditional black distillate collectors, which have weaker frother properties, it can significantly reduce the occurrence of "cell run-off" caused by increased reagent dosage in actual flotation production. The preparation process is simple and can significantly improve the flotation index of lead and silver in lead-silver ores and the comprehensive resource recovery rate, providing support for the efficient and green development of the mining industry. Attached Figure Description

[0021] Figure 1 This is a mineral processing flow chart for industrial flotation tests; Figure 2 This is a structural diagram of butyl xanthate, isopentyl xanthate, and diisobutyl dithiophosphate, along with their corresponding lowest unoccupied orbitals (LUMO), highest occupied orbitals (HOMO), and electrostatic potentials (ESP). Detailed Implementation

[0022] The specific embodiments of the present invention will be described in detail below with reference to examples. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0023] I. Preparation of the collector The formulations of the collectors in the examples and comparative examples are shown in Table 1.

[0024] Table 1. Collector Formulation

[0025] Weigh out the long-chain xanthate and branched-chain xanthate according to the above ratio, dissolve them completely, and stir evenly to obtain mixed solution M. Then weigh out thiophosphate or hypothiophosphate, dissolve them completely, and mix them with mixed solution M. Stir evenly to prepare the collector.

[0026] II. Laboratory Flotation Test The ore raw material was obtained from a complex and refractory oxidized lead-silver ore deposit in Kashgar, Xinjiang. The main valuable metals are Ag and Pb, with an Ag grade of 404 g / t and a Pb content of 2.40%. Sulfide flotation was used for the flotation tests, with water glass as the depressant, sodium sulfide as the sulfiding agent, No. 2 oil as the frother, and the collector prepared above. Each flotation test sample was 500 g, and a 3L XFD-II type flotation machine was used.

[0027] 500g of crushed raw ore was added to a ball mill along with 500g of water and ground to a -200 mesh density of 72%. The ore was then poured into a flotation machine, and water was added to a volume of 3L. The mixture was stirred for 3 minutes, followed by the addition of 2000g / t of water glass. After stirring for another 3 minutes, 2500g / t of Na₂S was added for sulfidation for 10 minutes. Following sulfidation, the aforementioned collector was added at a dosage of 100g / t, and the mixture was stirred for 3 minutes. Then, 20g / t of No. 2 oil was added, and the mixture was stirred for one minute before aeration and flotation. The flotation time was set to 10 minutes. The comparison results of the flotation tests are shown in Table 2.

[0028] Table 2 Laboratory flotation test data

[0029] III. Industrial Flotation Test The industrial experiment was conducted in a workshop of a lead-silver oxide ore beneficiation plant in Kashgar, Xinjiang. This workshop has a daily ore processing capacity of 150 tons, operates on an eight-hour, three-shift system, and uses the same collector as in Comparative Example 8. The combined collector was replaced with the collector obtained in Example 3, and the flotation process was adjusted, with everything else remaining unchanged. The adjusted flotation process is as follows: Figure 1 As shown, during the commissioning process, the flotation parameters of the concentrator workshop were monitored and compared with those of the traditional combined collectors previously used in the concentrator. The comparison results of the industrial flotation test are shown in Table 3.

[0030] Table 3 Industrial commissioning flotation data

[0031] The laboratory flotation test results obtained from Examples 1-5 and Comparative Examples 1-8 show that the lead-silver ore collector prepared according to the present invention has good collecting ability and selectivity for lead and silver. Under the same ore raw materials and flotation conditions, compared with traditional collectors such as sodium butyl xanthate and butyl ammonium black reagent, the collector prepared according to the present invention exhibits better collecting performance and flotation indicators for Pb and Ag. Meanwhile, the flotation test results obtained from Comparative Examples 1-6 show that reagents synthesized outside the scope of protection of the present invention or single-component reagents cannot achieve good collection of lead-silver ore.

[0032] As can be seen from the industrial flotation test results of Example 3 and Comparative Example 8, the lead-silver ore collector prepared according to the present invention can significantly improve the various flotation indicators of Pb and Ag and the comprehensive resource recovery rate, and can obtain considerable economic benefits in industry.

[0033] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0034] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0035] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A combined collector for sulfur-oxygen mixed flotation of oxidized lead-silver ores, characterized in that, Including long-chain xanthates, branched-chain xanthates, thiophosphates or thiophosphonates in a mass ratio of (1~10):(1~10):

1.

2. The combined collector according to claim 1, characterized in that, The mass ratio of the long-chain xanthate to the branched-chain xanthate is 1:

1.

3. The combined collector according to claim 1, characterized in that, The long-chain xanthate is a linear xanthate with a carbon chain length of ≥2.

4. The combined collector according to claim 3, characterized in that, The long-chain xanthate is n-butyl sodium xanthate, n-pentyl sodium xanthate, or n-propyl sodium xanthate.

5. The combined collector according to claim 1, characterized in that, The branched xanthates are branched xanthates with a main carbon chain length ≥3 and a branch number ≥1.

6. The combined collector according to claim 5, characterized in that, The branched xanthate is isopentyl xanthate, isobutyl xanthate, or isohexyl xanthate.

7. The combined collector according to claim 1, characterized in that, The thiophosphate is one of sodium diisopropyl dithiophosphate, sodium diisobutyl dithiophosphate, and sodium di-n-butyl dithiophosphate, and the thiophosphonate is sodium diisopropyl thiophosphonate, sodium diisobutyl thiophosphonate, or sodium di-n-butyl thiophosphonate.

8. The application of the combined collector according to any one of claims 1 to 7 in the sulfur-oxygen mixed flotation of oxidized lead-silver ores.

9. The application according to claim 8, characterized in that, The dosage of the combined collector is 100~200g / t.

Images