Screening method for collectors for simultaneous enrichment of lead and silver based on coordination chemistry and electrochemistry

Abstract

The present invention discloses a screening method for a collector for the simultaneous enrichment of lead and silver based on coordination chemistry and electrochemistry, comprising: obtaining electrochemical information on the solid-solid interaction between silver minerals and galena; obtaining galena, silver minerals, and their potential target ore-loving groups, and outputting a chk file; analyzing and quantitatively calculating the chk file to obtain orbital shapes and energy level information of the frontier molecular orbitals of the relevant minerals and ore-loving groups; preliminarily determining the target ore-loving groups of the silver minerals; thermodynamically determining whether the preliminarily determined target ore-loving groups have better adsorption properties for silver minerals than other ore-loving groups; and calculating the solvation free energy of derivatives of the target ore-loving groups with different carbon chain lengths and shapes to determine the final ore-loving agent. The present invention combines sulfide mineral flotation electrochemistry with flotation coordination chemistry for the first time, overcoming the limitations of previous agent screening designs and providing a new method for the research and development of special collectors for co-existing rare metal resources.

Description

Technical Field

[0001] The invention relates to mineral flotation, in particular to a method for screening a collector for simultaneous enrichment of lead and silver based on coordination chemistry and electrochemistry. Background Art

[0002] Silver is associated with many types of ores, generally with other metals. It rarely forms independently (only a few occur). It primarily occurs in lead-zinc ores. Under typical lead-zinc beneficiation conditions, silver can be concentrated to grades exceeding 2000 g / t in lead concentrate and around 200 g / t in zinc concentrate. Due to the similar properties of zinc and silver, metallurgical separation of zinc and silver is difficult, resulting in a relatively low valuation coefficient (only 0.2) in sales, and the silver grade must be at least 200 g / t. However, subsequent metallurgical separation of lead and silver is simple, and silver in lead concentrate has a higher valuation coefficient of 0.85. To maximize the value of associated silver, it is necessary to concentrate as much of it as possible into the lead concentrate.

[0003] Collectors act on mineral surfaces through physical adsorption, chemical adsorption, and surface chemical reactions. Collector adsorption is closely related to mineral flotation behavior. Within a certain collector concentration range, as the concentration increases, the adsorption capacity increases, and the flotation recovery rate significantly rises. After reaching a certain concentration, the recovery rate decreases as the concentration and adsorption capacity increase. At excessively high collector concentrations, the adsorption capacity may continue to increase, but the flotation recovery rate may not improve, or may even decrease. Therefore, finding the right collector and correctly controlling the dosage during flotation is crucial for optimal efficiency.

[0004] Previously, the flotation recovery of silver minerals associated with lead-zinc mines usually adopted the "trial and error method" to screen reagents. However, the reagents screened based on the "trial and error method" usually have poor accuracy and low efficiency in enhanced recovery of silver minerals associated with lead-zinc mines. Summary of the Invention

[0005] In response to the problem that the reagents screened based on the above-mentioned "trial and error method" usually have poor accuracy and low efficiency in enhanced recovery of silver minerals associated with lead-zinc ores, the present invention provides a screening method for lead-silver simultaneous enrichment collectors based on coordination chemistry and electrochemistry, and screens and designs targeted flotation collectors that are beneficial to the simultaneous enrichment and recovery of lead and silver.

[0006] In order to achieve the above object, the present invention provides a method for screening a collector for simultaneous enrichment of lead and silver based on coordination chemistry and electrochemistry, which comprises the following steps:

[0007] S1. Based on quantum chemical calculations and combined with the specific flotation environment, a mineral solid-solid interaction model was established to obtain electrochemical information on the solid-solid interaction between silver minerals and galena;

[0008] S2. Using first-principles quantum chemical calculations, galena, silver minerals, and their potential target ore-philic groups are obtained, and a chk file is output;

[0009] S3. By analyzing and quantitatively calculating the chk file, the orbital shape and energy level information of the frontier molecular orbitals of the relevant minerals and ore-philic groups are obtained;

[0010] S4. Based on the three principles of bonding, the ore-philic groups were screened by the coordination chemical properties of the frontier molecular orbitals of the minerals and the targeted ore-philic groups, and the targeted ore-philic groups of the silver minerals were preliminarily determined;

[0011] S5. Based on the initially determined targeted ore-philic group, determine thermodynamically whether its adsorption performance for silver minerals is better than that of other ore-philic groups. If so, proceed to step S6.

[0012] S6. By quantifying the energy information of the calculated log file, the solvation free energy of the targeted ore-philic group derivatives with different carbon chain lengths and shapes is calculated, and the ore-philic group derivative with the smallest solvation free energy is selected as the final ore-philic agent.

[0013] Specifically, in step S1, based on the mineral solid-solid interaction model, density functional theory calculations are used to obtain electrochemical information of the solid-solid interaction between silver minerals and galena at a level not lower than the GGA-PW91 functional level.

[0014] More specifically, the electrochemical information of the solid-solid interaction between silver minerals and galena is: during the electrochemical process, galena with a low potential undergoes an anodic reaction to lose electrons, thereby becoming positively charged, while the silver mineral with a high potential accepts electrons and undergoes a cathodic reaction, thereby becoming negatively charged.

[0015] Preferably, in step S2, galena, silver minerals and their potential targeted ore-loving groups are obtained by means of first-principles quantum chemical calculations, at a level not lower than the B3LYP functional, the DEF2TZVP basis set, and with full consideration of the effects of dispersion and the solvation effects of minerals and ore-loving groups.

[0016] Further preferably, the potential targeting ore-philic group is monothiocarbonate, xanthate, trithiocarbonate, monothiophosphate, dithiophosphate, thiosulfate, thiosulfonate, dithiocarbamate, thiol, thiocarbamate, thiourea or thiocarbonamide.

[0017] Specifically, in step S3, the frontier molecular orbitals of the relevant minerals and ore-philic groups include the highest occupied molecular orbital HOMO and the lowest unoccupied molecular orbital LUMO.

[0018] Furthermore, in step S4, the LUMO orbital of the targeted ore-philic group of the silver mineral preliminarily determined is a targeted ore-philic group that can symmetry match the HOMO orbitals of argentite and elemental silver.

[0019] Furthermore, the LUMO orbital is p x Orbital mono(di)thiophosphate and thiosulfonate(sulfate) salts are preliminarily identified as the target mineralophilic groups of the silver mineral.

[0020] Furthermore, in step S6, the final ore-philic agent is determined to be diisobutyl dithiophosphate.

[0021] Through the above technical solution, the present invention achieves the following beneficial effects:

[0022] 1. This invention, based on the unique electrochemical properties of solid-solid interactions between sulfide minerals and the coordination chemical mechanism (forward / reverse orbital bonding) between common ore-philic groups and mineral surfaces, screens for targeted ore-philic groups for the simultaneous recovery of lead and silver. Based on these targeted ore-philic groups, hydrophobic groups are designed for these targeted ore-philic groups using solvation free energy, ultimately resulting in the design of a targeted flotation collector that facilitates the simultaneous enrichment and recovery of lead and silver.

[0023] 2. The present invention combines sulfide mineral flotation electrochemistry with flotation coordination chemistry for the first time, overcoming the limitations of previous reagent screening designs and providing a new approach for the research and development of special collectors for co-existing rare metal resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a technical roadmap for the screening and design of targeted collectors for the simultaneous recovery of lead and silver in Example 1 of the present invention;

[0025] Figure 2 It is a solid-solid interaction model between silver minerals and galena; Figure 3 This is a schematic diagram of the electrochemical behavior of the solid-solid interaction between silver minerals and galena;

[0026] Figure 4 The interfacial coordination mechanism of the targeted collector DIBMTP with galena and silver minerals, where (a) is the forward orbital bonding interaction between DIBMTP and galena, (b) is the reverse orbital bonding interaction between DIBMTP and the typical silver mineral argentite, and (c) is the reverse orbital bonding interaction between DIBMTP and the typical silver mineral elemental silver.

[0027] Figure 5 This is a flow chart of closed-circuit flotation of lead (silver) in Example 2 of the present invention. DETAILED DESCRIPTION

[0028] The following is a detailed description of the specific embodiments of the present invention in conjunction with the examples. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0029] Example 1 Screening of Collectors for the Simultaneous Enrichment of Lead and Silver Based on Coordination Chemistry and Electrochemistry

[0030] Screening route for collectors for simultaneous enrichment of lead and silver based on coordination chemistry and electrochemistry Figure 1 As shown:

[0031] S1. First, mineral flotation occurs in aqueous solution. The mineral particles in the slurry will inevitably undergo solid-solid interactions during the grinding, stirring and flotation processes. To this end, based on periodic quantum chemical calculations and combined with the collisions between mineral particles in a specific flotation environment, a mineral solid-solid interaction model was constructed, such as Figure 2 Based on this model, density functional theory (crystal DFT) calculations were performed at a level not lower than GGA-PW91 to obtain electrochemical information on the solid-solid interaction between silver minerals and galena. It was determined that galena (Pb 2+ →Pb 0 -0.125 V;S 0 →S 2- -0.447 V) undergoes an anodic reaction ( ) to lose electrons and thus become positively charged; while the typical silver mineral argentite (Ag + →Ag 0 0.799 V) accepts electrons and a cathode reaction occurs ( ), thus being negatively charged, such as Figure 3 shown.

[0032] S2. Then, with the help of first-principles quantum chemical calculations, at a level not lower than B3LYP functional and DEF2TZVP basis set, and taking full account of the influence of dispersion and the solvation effect of minerals and ore-philic groups, the output chk files of galena, silver minerals and their potential target ore-philic groups (monothiocarbonate, xanthate, trithiocarbonate, monothiophosphate, dithiophosphate, thiosulfate, thiosulfonate, dithiocarbamate, mercaptan, thionocarbamate, thioureas and thioamide) are obtained.

[0033] S3. By analyzing the output file (chk file) of the quantitative calculation (cluster quantitative calculation), the orbital shape and energy level information of the frontier molecular orbitals (including the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO)) of the relevant minerals and ore-philic groups are obtained.

[0034] S4. Based on the three principles of bonding, namely orbital symmetry matching, maximum orbital overlap and similar orbital energy levels, the LUMO orbital is determined to be p x Orbital mono(di)thiophosphates and thiosulfonates (sulfates) can react with argentite (e g orbital) and the HOMO orbital symmetry of elemental silver (s orbital), which preliminarily determined it as the target ore-philic group of silver minerals; while the LUMO orbitals of other ore-philic groups are p z The orbital does not match the LUMO orbital of silver minerals and is not suitable for enhanced capture of silver minerals. Mineral-philic agents are screened based on the coordination chemical properties of minerals and targeted mineral-philic groups.

[0035] S5. Based on the preliminarily determined targeted ore-loving groups, namely monothiophosphate, dithiophosphate, thiosulfonate (sulfate) and thiosulfate, the interfacial adsorption simulation was carried out. The thermodynamics showed that monothiophosphate has better adsorption performance for silver minerals than other ore-loving groups and should be regarded as a targeted ore-loving group for the simultaneous recovery of lead and silver.

[0036] S6. By quantifying the energy information of the calculated log file, the solvation free energy of monothiophosphate derivatives with different carbon chain lengths and shapes was calculated, and the ore-philic group derivative with the smallest solvation free energy was selected as the final ore-philic agent. The final ore-philic agent was determined to be diisobutyl dithiophosphate (DIBMTP).

[0037] S7. Finally, the lead-silver simultaneous enrichment targeted collector DIBMTP developed by the present invention based on coordination chemistry and electrochemical regulation exhibits different coordination chemical properties to silver minerals and galena. The key to its ability to achieve simultaneous recovery of lead and silver lies in the difference in its surface coordination bonding mechanism: its coordination effect with galena is a forward orbital bonding effect, involving the HOMO (p y orbital) electrons with the LUMO+1 orbital of galena; while the coordination with silver minerals is a reverse orbital bonding interaction, involving the p x The LUMO orbital is characterized by the s orbital and e orbital of elemental silver and argentite. g The orbitals are the characteristic HOMO orbitals, such as Figure 4 As shown. Combining the electrochemical properties of the solid-solid interaction between silver minerals and galena and their coordination chemistry with flotation reagents, it is confirmed that the electrochemical interaction between silver minerals and galena promotes electron transfer from galena to silver minerals, rendering galena electron-deficient and enhancing its positive charge, which facilitates forward-orbital bonding with DIBMTP. Simultaneously, the silver mineral exhibits enhanced electron-donating capacity after receiving electrons, promoting reverse-orbital bonding with DIBMTP. The collector DIBMTP designed based on this method performed well in specific flotation experiments, significantly improving the recovery of silver from lead concentrate compared to using traditional collectors.

[0038] Example 2 Verification of the effect of DIBMTP on the simultaneous enrichment of lead and silver in silver-containing lead-zinc ores

[0039] The flotation process of the example concentrate in the Pb (Ag) closed circuit flotation process is as follows Figure 5 As shown, 500 g of 2 mm ore was ground in a ball mill to an appropriate fineness and then transferred to a flotation cell. Coarse and scavenging separations were performed in a 1.5-liter flotation cell, the first separation was performed in a 1.0-liter flotation cell, and the second and third separations were performed in a 0.5-liter flotation cell. During the flotation test, the required dosages of the depressant ZnSO4 and the collector DIBMTP were added to the flotation cell, with a conditioning time of 3 minutes for each reagent. During the flotation process, the mineral was separated at its natural pH (approximately 7.0) without the addition of a pH adjuster.

[0040] Meanwhile, the above DIBMTP was replaced by DDTC or DIBDTP for control experiments.

[0041] The results are recorded in Table 1.

[0042] Table 1 Indexes of various products in the closed-circuit flotation experiment of lead (silver)

[0043]

[0044] Results show that DDTC, suitable for high-alkali lime systems, cannot concentrate lead and silver minerals in an alkali-free, near-neutral medium. The lead and silver grades in the concentrate were only 7.71% and 216 g / t, with recoveries of 14.48% and 18.73%, respectively, failing to meet smelting standards (lead content of at least 30%). When DIBDTP was used as a collector, a lead concentrate with grades of 60.67% and 629 g / t, respectively, was obtained, with recoveries of 90.58% and 42.03%, respectively. Compared to DIBDTP, the use of DIBMTP significantly increased the silver recovery in the concentrate to 46.27%. While the lead recovery was similar, the silver recovery was significantly increased by approximately 4.2% compared to DIBDTP, demonstrating that DIBMTP is a highly effective silver-friendly collector.

[0045] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within 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 scope of protection of the present invention.

[0046] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0047] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for screening collectors for simultaneous enrichment of lead and silver based on coordination chemistry and electrochemistry, characterized in that: The steps include: S1. Based on quantum chemical calculations and in combination with the specific flotation environment, a mineral solid-solid interaction model was established. Based on the mineral solid-solid interaction model, density functional theory calculations were performed at a functional level not lower than GGA-PW91 to obtain electrochemical information on the solid-solid interaction between silver minerals and galena. The electrochemical information on the solid-solid interaction between silver minerals and galena is as follows: during the electrochemical process, galena with a low potential undergoes an anodic reaction to lose electrons, thereby becoming positively charged, while the silver mineral with a high potential accepts electrons and undergoes a cathodic reaction, thereby becoming negatively charged. S2. By means of first-principles quantum chemical calculations, under a B3LYP functional and a DEF2TZVP basis set no less than 0.05, and taking full account of the effects of dispersion and the solvation effects of minerals and ore-philic groups, galena, silver minerals, and their potential target ore-philic groups are obtained, and a chk file is output, wherein the potential target ore-philic groups are monothiocarbonates, xanthates, trithiocarbonates, monothiophosphates, dithiophosphates, thiosulfates, thiosulfonates, dithiocarbamates, thiols, thiocarbamates, thioureas, or thiocarbonamides; S3. By analyzing and quantitatively calculating the chk file, the orbital shape and energy level information of the frontier molecular orbitals of the relevant minerals and ore-philic groups are obtained; S4. Based on the three principles of bonding, the ore-philic groups were screened by the coordination chemical properties of the frontier molecular orbitals of the minerals and the targeted ore-philic groups, and the targeted ore-philic groups of the silver minerals were preliminarily determined; S5. Based on the initially determined targeted ore-philic group, determine thermodynamically whether its adsorption performance for silver minerals is better than that of other ore-philic groups. If so, proceed to step S6. S6. By quantifying the energy information of the calculated log file, the solvation free energy of the targeted ore-philic group derivatives with different carbon chain lengths and shapes is calculated, and the ore-philic group derivative with the smallest solvation free energy is selected as the final ore-philic agent.

2. The screening method according to claim 1, wherein In step S3, the frontier molecular orbitals of the relevant minerals and ore-philic groups include the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO).

3. The screening method according to claim 2, characterized in that In step S4, the LUMO orbital of the targeted ore-philic group of the silver mineral is preliminarily determined to be a targeted ore-philic group that can symmetry match the HOMO orbitals of argentite and elemental silver.

4. The screening method according to claim 3, wherein The LUMO orbital is p x Orbital monothiophosphate or dithiophosphate and thiosulfonate or thiosulfate are preliminarily determined to be the target ore-philic groups of the silver mineral.

5. The screening method according to claim 4, characterized in that In step S6, the final ore-philic agent is determined to be diisobutyl dithiophosphate.

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