Screening method of lead-silver synchronous enrichment collecting agent based on coordination chemistry and electrochemistry

Abstract

The invention discloses a screening method for a lead-silver synchronous enrichment collecting agent based on coordination chemistry and electrochemistry. The screening method comprises the steps that electrochemical information of solid-solid interaction of silver minerals and galena is obtained; the method comprises the following steps: acquiring galena, silver minerals and possibly potential targeted ore-philic groups thereof, and outputting a chk file; analyzing and quantitatively calculating the chk file to obtain the orbit shape and energy level information of the front molecular orbits of the related minerals and the ore-philic groups; preliminarily determining a targeted ore-philic group of the silver mineral; thermodynamically determining whether the adsorption performance of the preliminarily determined targeted ore-philic group on the silver minerals is superior to that of other ore-philic groups or not; and calculating the solvation free energy of the targeted ore-philic group derivatives with different carbon chain lengths and shapes, and determining the final ore-philic agent. According to the method, sulfide mineral flotation electrochemistry and flotation coordination chemistry are combined for the first time, the limitation of traditional agent screening design is overcome, and a brand-new method is provided for research, development and design of co-associated rare metal resource special-effect collectors.

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 metal is associated with many types of ores, usually with other types of metals, and rarely forms minerals alone (only a few form minerals alone). It is mainly associated with lead-zinc ores. Under normal lead-zinc beneficiation conditions, silver can be enriched to a grade of more than 2000 g / t in lead concentrate; it can also be enriched to about 200 g / t in zinc concentrate. Due to the similar properties of zinc and silver, it is difficult to separate zinc and silver metallurgically, and the valuation coefficient in sales is low (only 0.2), and the silver grade must be no less than 200g / t; while the subsequent metallurgical separation of lead and silver is simple, and the valuation coefficient of silver in lead concentrate is higher, reaching 0.85. In order to realize the value of associated silver, it is necessary to enrich the associated silver into the lead concentrate as much as possible.

[0003] The effects of collectors on the mineral surface include physical adsorption, chemical adsorption and surface chemical reaction. The adsorption of collectors is closely related to the flotation behavior of minerals. Within a certain range of collector concentration, as the concentration of the agent increases, the adsorption amount increases, and the flotation recovery rate increases significantly; after the concentration reaches a certain value, the recovery rate decreases with the increase in concentration and adsorption amount; when the collector concentration is too high, the adsorption amount can continue to increase, but the flotation recovery rate no longer increases, and even decreases. Therefore, in the flotation process, it is necessary to find a suitable collector and correctly control the dosage of the collector to obtain the best benefits.

[0004] Previously, the flotation recovery of silver minerals associated with lead-zinc ores 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 ores. Summary of the invention

[0005] In view of 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: S1. Based on quantum chemical calculations and combined with the specific flotation environment, a mineral solid-solid interaction model was established to obtain the electrochemical information of the solid-solid interaction between silver minerals and galena; S2. Using first-principles quantum chemical calculations, galena, silver minerals and their potential target ore-philic groups are obtained, and the chk file is output; 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 are screened through 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 are preliminarily determined; S5, based on the initially determined targeted ore-philic group, determine from a thermodynamic point of view whether its adsorption performance on silver minerals is better than that of other ore-philic groups, if yes, 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.

[0007] Specifically, in step S1, based on the mineral solid-solid interaction model, density functional theory calculation is adopted to obtain the electrochemical information of the solid-solid interaction between silver mineral and galena at a functional level not lower than GGA-PW91.

[0008] More specifically, the electrochemical information of the solid-solid interaction between silver minerals and galena is: in the electrochemical process, galena with a low potential undergoes an anodic reaction to lose electrons, thereby being positively charged, while the silver mineral with a high potential accepts electrons and undergoes a cathodic reaction, thereby being negatively charged.

[0009] Preferably, in step S2, by means of first-principles quantum chemical calculations, at a level not lower than B3LYP functional, DEF2TZVP basis set, and taking full account of the influence of dispersion and the solvation effect of minerals and ore-philic groups, galena, silver minerals and their potential targeted ore-philic groups are obtained.

[0010] Further preferably, the potential targeting ore-philic group is monothiocarbonate, xanthate, trithiocarbonate, monothiophosphate, dithiophosphate, thiosulfate, thiosulfonate, dithiocarbamate, thiol, thiocarbamate, thiourea or thiocarbonamide.

[0011] 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.

[0012] 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.

[0013] Furthermore, the LUMO orbital is p x Orbital mono(di)thiophosphates and thiosulfonates (sulfates) are preliminarily identified as the targeting ore-philic groups of the silver minerals.

[0014] Furthermore, in step S6, the final ore-philic agent is determined to be diisobutyl dithiophosphate.

[0015] Through the above technical solution, the present invention achieves the following beneficial effects: 1. The present invention is based on the unique electrochemical properties of solid-solid interactions between sulfide minerals, combined with the coordination chemical mechanism (forward / reverse orbital bonding) between common ore-loving groups and mineral surfaces, to screen targeted ore-loving groups for simultaneous recovery of lead and silver. Based on the screened targeted ore-loving groups, hydrophobic groups are designed for the targeted ore-loving groups with the help of solvation free energy, and finally a targeted flotation collector is screened and designed that is conducive to the simultaneous enrichment and recovery of lead and silver.

[0016] 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 method for the research and development of special collectors for co-existing rare metal resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a technical roadmap for screening and designing targeted collectors for simultaneous recovery of lead and silver in Example 1 of the present invention; Figure 2 It is a solid-solid interaction model between silver minerals and galena; Figure 3 It is a schematic diagram of the electrochemical behavior of the solid-solid interaction between silver minerals and galena; Figure 4 is the interface coordination mechanism between the targeted collector DIBMTP and galena and silver minerals, where (a) is the forward orbital bonding effect between DIBMTP and galena, (b) is the reverse orbital bonding effect between DIBMTP and the typical silver mineral argentite, and (c) is the reverse orbital bonding effect between DIBMTP and the typical silver mineral elemental silver; Figure 5 This is a closed-circuit flotation flow chart of lead (silver) in Example 2 of the present invention. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention is described in detail below in conjunction with the examples. It should be understood that the specific implementation described herein is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0019] Example 1 Screening of collectors for simultaneous enrichment of lead and silver based on coordination chemistry and electrochemistry Screening route for collectors for simultaneous enrichment of lead and silver based on coordination chemistry and electrochemistry Figure 1 As shown: S1. First, mineral flotation occurs in aqueous solution. The mineral particles in the slurry will inevitably interact with each other during the grinding, stirring and flotation process. To this end, based on periodic quantum chemical calculations and combined with the collision of 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 to obtain electrochemical information on the solid-solid interaction between silver minerals and galena at a level not lower than that of GGA-PW91 functional theory. 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.

[0020] S2. After that, with the help of first-principles quantum chemical calculations, at a level not lower than B3LYP functional, DEF2TZVP basis set, and taking into full account 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.

[0021] 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 electron orbital HOMO and the lowest unoccupied electron orbital LUMO) of the relevant minerals and ore-philic groups are obtained.

[0022] 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 targeted 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 the enhanced capture of silver minerals. The ore-philic agents are screened based on the coordination chemical properties of the minerals and the targeted ore-philic groups.

[0023] S5. Based on the preliminarily determined targeted ore-philic groups, namely monothiophosphate, dithiophosphate, thiosulfonate (sulfate) and thiosulfate, the interfacial adsorption simulation was carried out. It was determined from the thermodynamic point of view that the adsorption performance of monothiophosphate on silver minerals is better than that of other ore-philic groups, and it should be regarded as the targeted ore-philic group for the simultaneous recovery of lead and silver.

[0024] S6. By quantifying the energy information of the log file, the solvation free energy of monothiophosphate 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, and the final ore-philic agent is determined to be diisobutyl dithiophosphate (DIBMTP).

[0025] 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 with galena is a forward orbital bonding, 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 of DIBMTP x The LUMO with the characteristic orbital is similar to 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 chemical properties with flotation reagents, it can be confirmed that the electrochemical interaction between silver minerals and galena promotes the transfer of electrons from galena to silver minerals, making galena electron-deficient and enhancing its positive charge, which is conducive to its forward orbital bonding with DIBMTP. At the same time, silver minerals show enhanced electron-donating ability after receiving electrons, which promotes reverse orbital bonding with DIBMTP. The collector DIBMTP designed based on this method performed well in specific flotation experiments, and the recovery rate of silver in lead concentrate was significantly improved compared with the use of traditional collectors.

[0026] Example 2 Verification of the effect of DIBMTP on the simultaneous enrichment of lead and silver in silver-containing lead-zinc ores 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 raw ore with a particle size of 2 mm was ground to a suitable fineness in a ball mill and then transferred to a flotation cell. Among them, coarse and scavenging were carried out in a 1.5-liter flotation cell, selection one was carried out in a 1.0-liter flotation cell, and selection two and selection three were carried out in a 0.5-liter flotation cell. In the flotation test, the required dose of depressant ZnSO4 and collector DIBMTP were added to the flotation cell, and the adjustment time of each reagent was 3 minutes. During the flotation process, the mineral was beneficiated at a natural pH value (about 7.0) without adding a pH adjuster.

[0027] Meanwhile, the above DIBMTP was replaced by DDTC or DIBDTP for control experiments.

[0028] The results are recorded in Table 1.

[0029] Table 1 Indexes of each product in the closed-circuit flotation experiment of lead (silver)

[0030] The results show that DDTC, which is suitable for high-alkali lime system, cannot concentrate lead and silver minerals in alkali-free near-neutral medium. The lead and silver grades in the concentrate are only 7.71% and 216g / t, and the recovery rates are 14.48% and 18.73%, which do not meet the smelting standards (lead content is not less than 30%). When DIBDTP is used as a collector, a lead concentrate product with lead and silver grades of 60.67% and 629 g / t, respectively, can be obtained, and the lead and silver recoveries are 90.58% and 42.03%, respectively. Compared with DIBDTP, the recovery rate of silver in the concentrate is significantly increased to 46.27% when DIBMTP is used as a collector. When the lead recovery rate is similar, the silver recovery rate is greatly increased by about 4.2% compared with DIBDTP as a collector, which shows that DIBMTP is a silver-friendly collector with good performance.

[0031] 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, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0032] 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 further describe various possible combinations.

[0033] In addition, 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 combined with the specific flotation environment, a mineral solid-solid interaction model was established to obtain the electrochemical information of the solid-solid interaction between silver minerals and galena; S2. Using first-principles quantum chemical calculations, galena, silver minerals and their potential target ore-philic groups are obtained, and the chk file is output; 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 are screened through 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 are preliminarily determined; S5, based on the initially determined targeted ore-philic group, determine from a thermodynamic point of view whether its adsorption performance on silver minerals is better than that of other ore-philic groups, if yes, 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, characterized in that In step S1, based on the mineral solid-solid interaction model, density functional theory calculation is used to obtain the electrochemical information of the solid-solid interaction between silver minerals and galena at a functional level not lower than GGA-PW91.

3. The screening method according to claim 2, characterized in that The electrochemical information of the solid-solid interaction between silver minerals and galena is: in the electrochemical process, galena with low potential undergoes an anodic reaction to lose electrons, thereby being positively charged, while the silver mineral with high potential accepts electrons and undergoes a cathodic reaction, thereby being negatively charged.

4. The screening method according to claim 1, characterized in that In step S2, by means of first-principles quantum chemical calculations, at a level not lower than B3LYP functional, DEF2TZVP basis set, 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 targeted ore-philic groups are obtained.

5. The screening method according to claim 4, characterized in that The potential targeting ore-philic groups are monothiocarbonate, xanthate, trithiocarbonate, monothiophosphate, dithiophosphate, thiosulfate, thiosulfonate, dithiocarbamate, thiol, thiocarbamate, thiourea or thiocarbonamide.

6. The screening method according to claim 1, characterized in that 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.

7. The screening method according to claim 6, 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.

8. The screening method according to claim 7, characterized in that The LUMO orbital is p x Orbital mono(di)thiophosphates and thiosulfonates (sulfates) are preliminarily identified as the targeting ore-philic groups of the silver minerals.

9. The screening method according to claim 8, characterized in that In step S6, the final ore-philic agent is determined to be diisobutyl dithiophosphate.

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