A thiourea-based dithiocarbonate collector and its preparation method and flotation application

Abstract

The present invention belongs to the field of mineral flotation, and specifically discloses a thiourea-based dithiocarbonate collector, a preparation method thereof, and a flotation application thereof. The thiourea-based dithiocarbonate collector molecule contains two complementary functional groups, thiourea and dithiocarbonate, and is used as a collector for metal mineral flotation. The collector has a special organic salt structure, good water solubility and dispersibility in the ore pulp, and solves the problem that the thiourea collector is inconvenient to use and has poor dispersibility in the flotation of non-ferrous metal sulfide ores; at the same time, the thiourea-based dithiocarbonate collector has both excellent capture selectivity and strong capture ability, and is particularly suitable for the recovery of associated gold and silver in non-ferrous metal sulfide ores, and improves the recovery rate of gold and silver; in addition, the thiourea-based dithiocarbonate collector reduces the peculiar irritating odor of the dithiocarbonate collector, and is environmentally friendly.

Description

Technical Field

[0001] The invention relates to the field of metal mineral flotation, and in particular to a thiourea-based dithiocarbonate collector and a preparation method and flotation application thereof. Background Art

[0002] Dithiocarbonate, also known as xanthate, has the advantages of strong capture ability and low price, and is the most widely used sulfide ore collector. However, the selectivity of dithiocarbonate is poor, especially for copper and associated precious metals such as gold and silver. In order to improve the selectivity of dithiocarbonate, a combined collector method is usually adopted, and a highly selective collector is compounded with it. Patent CN111068927B discloses a flotation agent and a beneficiation method for improving flotation recovery and improving the grade of gold concentrate. The composite collector composed of thiourea, isopentyl xanthate, etc. is used, and the gold recovery rate can reach 96.1%. Liu Guangyi et al. combined ethoxycarbonylthiourea (ECTU) with sodium butyl xanthate and applied it to Dexing Copper Mine. Compared with the traditional sodium butyl xanthate process, the gold grade was increased by 1.29 g / t and the gold recovery rate was increased by 7.16 percentage points (Liu Guangyi, Zhong Hong, Dai Tagen, et al. Separation of copper and sulfur by flotation of ethoxycarbonylthiourea under medium alkalinity conditions [J]. Journal of the Chinese Society of Nonferrous Metals, 2009, 19(3): 389-396). The composite collector composed of dithiocarbonate collector and thiourea collector showed good separation performance and chelating ability for precious metals such as gold and silver in the flotation of non-ferrous metal sulfide ores.

[0003] Although thiourea collectors show good selectivity for copper sulfide and associated gold and silver minerals, they also have the disadvantage of being difficult to disperse in the ore pulp. Commonly used thiourea collectors such as N,N′-diphenylthiourea are solid at room temperature and difficult to dissolve in water. During flotation, they need to be dissolved in organic solvents and then added or added to a ball mill, making the use of thiourea collectors during flotation very inconvenient.

[0004] In addition, dithiocarbonate has the pungent odor of organic thioacid salts, which causes serious odor pollution during production, transportation and use. In order to solve the pungent odor problem of xanthate, several solutions have been proposed. Chinese patent CN103817014A discloses a method for making xanthate into granules, which reduces the odor of xanthate products to a certain extent by adding a small amount of spices to the solvent method xanthate preparation system and granulating the xanthate.

[0005] In view of the problems of poor water solubility and inconvenience in use of thiourea collectors and poor selectivity and severe odor of dithiocarbonate collectors, innovation of collector structure at the molecular level is of great significance for developing new mineral processing agents, improving the comprehensive utilization of mineral resources and building green mines. Summary of the invention

[0006] In view of the defects of the prior art, the present invention provides a thiourea-based dithiocarbonate collector, a preparation method thereof and a flotation application thereof. The thiourea-based dithiocarbonate collector can solve the problem of the difficulty in dispersing thiourea and the irritating odor of dithiocarbonate through the synergistic coordination of thiourea and dithiocarbonate groups. At the same time, the collector has higher selectivity and strong collecting ability, and has a significant effect on the recovery of associated gold and silver in non-ferrous metal sulfide ores.

[0007] To achieve the above object, the present invention first provides a thiourea-based dithiocarbonate collector, the structural formula of which is shown in Formula I:

[0008]

[0009] Among them, R 1 is a C1-C8 hydrocarbon group, a C2-C9 alkylcarbonyl group or a C7-C9 arylcarbonyl group; R 2 is a straight-chain alkylene group of C1 to C8; Me is Na or K; and the thiourea-based dithiocarbonate collector is used as a collector for metal mineral flotation.

[0010] The thiourea dithiocarbonate compound represented by formula I of the present invention has good water solubility and dispersibility in ore pulp due to its special organic salt structure, thus solving the problem of inconvenient use and poor dispersibility of thiourea collector in flotation of non-ferrous metal sulfide ores.

[0011] At the same time, the compound of formula I can fundamentally solve the irritating odor problem of the xanthate collector through the hydrogen bonding action within the molecule; and the synergistic effect of the thiourea group and the dithiocarbonic acid group can enhance the flotation performance and improve the recovery rate and grade of the target ore.

[0012] Preferably, the R 1 is allyl, butyl, phenyl, p-tolyl, m-tolyl, benzyl, phenethyl, benzoyl or phenylacetyl; R 2 It is 1,2-ethylene or 1,3-propylene.

[0013] Based on a general inventive concept, the present invention also provides a method for preparing a thiourea-based dithiocarbonate collector, comprising the following steps:

[0014] S1, performing an addition reaction of an isothiocyanate having a structure of Formula II and an alcohol amine in a solvent to prepare a hydroxythiourea having a structure of Formula III;

[0015]

[0016] S2. Mix hydroxythiourea, caustic soda and carbon disulfide in a solvent at 0-10°C, and heat the mixture to react to obtain a thiourea-based dithiocarbonate collector.

[0017] Preferably, the solvent in steps S1 and S2 is one or more of water, dichloromethane, tetrahydrofuran, petroleum ether or acetone.

[0018] Preferably, the amount of solvent used in steps S1 and S2 is 0.2 to 3 L per mole of isothiocyanate.

[0019] Preferably, the molar ratio of the isothiocyanate, the amine, the caustic soda and the carbon disulfide is 1.0:1.0-1.1:1.0-1.3:1.0-3.0.

[0020] Preferably, the reaction temperature of step S1 is 0-30° C., and the reaction time is 1-4 h.

[0021] Preferably, the reaction temperature of step S2 is 15-30° C., and the reaction time is 1-6 h.

[0022] Based on a general inventive concept, the present invention also provides an application of a thiourea-based dithiocarbonate collector in mineral flotation, wherein the thiourea-based dithiocarbonate collector is used for the flotation of non-ferrous metal sulfide ores and their associated gold and silver minerals, wherein the non-ferrous metal sulfide ores are one or more of copper sulfide ores, lead-zinc sulfide ores, copper-nickel sulfide ores, and copper-molybdenum sulfide ores.

[0023] Preferably, the flotation process of the thiourea-based dithiocarbonate collector for non-ferrous metal sulfide ore is as follows: the non-ferrous metal sulfide ore is crushed and slurried; then the thiourea-based dithiocarbonate collector is added to the slurry for flotation, the amount of the collector is 20 to 200 g / t, and the flotation concentrate is collected.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention aims at the defects of existing thiourea collectors that are insoluble in water and have poor dispersibility in ore pulp, and innovatively proposes a thiourea-based dithiocarbonate collector and applies it to the field of metal mineral flotation. The thiourea-based dithiocarbonate collector provided by the present invention has a dual ligand structure of thiourea and dithiocarbonic acid, and the introduction of dithiocarbonic acid significantly reduces the hydrophobic constant (logP) of the collector, so that the thiourea molecule is changed from an organic structure that is insoluble in water to an organic salt structure that is easily dissociated in water, and dithiocarbonate itself has the characteristic of forming hydrogen bonds with water molecules, so that the thiourea-based dithiocarbonate collector has excellent dispersibility in water, which fundamentally solves the defects of traditional thiourea collectors that are insoluble in water and have poor dispersibility.

[0026] 2. The sulfur atom and nitrogen atom in the thiourea group of the thiourea dithiocarbonate collector provided by the present invention can chelate with certain metal ions. At the same time, dithiocarbonate itself has the characteristic of forming insoluble salts with heavy metal ions. The thiourea dithiocarbonate synthesized by the present invention has a thiourea group and a dithiocarbonic acid group. On the one hand, the thiourea group and the dithiocarbonic acid group can produce a synergistic effect, strengthen the adsorption of the collector molecule on the mineral surface, and through R 1 and R 2 The hydrophobic group regulates the hydrophilic-hydrophobic balance and enhances the collection ability; on the other hand, due to the introduction of the thiourea group, the thiourea dithiocarbonate molecule forms an intramolecular conjugated structure, which reduces the energy of its highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), which is beneficial to improving the selectivity of the collector; on the other hand, the thiourea collector has the characteristic of chelating gold and silver from metal sulfide ores. The introduction of the thiourea group is also beneficial to the recovery of associated gold and silver in non-ferrous metal sulfide ores, and the recovery rate and recovery grade of gold and silver can be significantly improved.

[0027] 3. The thiourea dithiocarbonate provided by the present invention has a special dual ligand structure, which produces a new conjugated system in the molecule and the two functional groups between the molecules produce hydrogen bonds and associate with each other, thereby reducing the peculiar irritating odor of the dithiocarbonate collector, and the structure is stable, and no irritating odor will be generated due to decomposition during storage and use.

[0028] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of sodium O-(2-(3-benzoylthioureido)ethyl)dithiocarbonate prepared in Example 1 of the present invention;

[0030] Figure 2 This is the carbon NMR spectrum of sodium O-(2-(3-benzoylthiourea)ethyl)dithiocarbonate prepared in Example 1 of the present invention;

[0031] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate prepared in Example 2 of the present invention;

[0032] Figure 4 This is the carbon NMR spectrum of sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate prepared in Example 2 of the present invention;

[0033] Figure 5 This is the hydrogen nuclear magnetic resonance spectrum of sodium O-(2-(3-benzylthioureido)ethyl)dithiocarbonate prepared in Example 3 of the present invention;

[0034] Figure 6 This is the carbon NMR spectrum of sodium O-(2-(3-benzylthiourea)ethyl)dithiocarbonate prepared in Example 3 of the present invention;

[0035] Figure 7 It is the optimal configuration of O-(2-(3-benzoylthiourea)ethyl)dithiocarbonate at the B3LYP-D3 / 6-311+G(d) level in Example 1 of the present invention;

[0036] Figure 8 It is the optimal configuration of O-(2-(3-phenylthiourea)ethyl)dithiocarbonate at the B3LYP-D3 / 6-311+G(d) level in Example 2 of the present invention;

[0037] Fig. 9 It is the optimal configuration of O-(2-(3-benzylthiourea)ethyl)dithiocarbonate at the B3LYP-D3 / 6-311+G(d) level in Example 3 of the present invention;

[0038] Fig.10 is the HOMO of O-(2-(3-benzoylthiourea)ethyl)dithiocarbonate at the B3LYP-D3 / 6-311+G(d) level in Example 1 of the present invention ( Fig.10 A) and LUMO( Fig.10 B);

[0039] Fig.11 is the HOMO of O-(2-(3-phenylthiourea)ethyl)dithiocarbonate at the B3LYP-D3 / 6-311+G(d) level in Example 2 of the present invention ( Fig.11 A) and LUMO( Fig.11 B);

[0040] Fig.12 is the HOMO of O-(2-(3-benzylthiourea)ethyl)dithiocarbonate at the B3LYP-D3 / 6-311+G(d) level in Example 3 of the present invention ( Fig.12 A) and LUMO( Fig.12 B);

[0041] Fig.13 This is the infrared spectrum of sodium O-(2-(3-benzylthiourea)propyl)dithiocarbonate prepared in Example 4 of the present invention;

[0042] Fig.14This is a comparison diagram of the dispersibility of N,N′-diphenylthiourea and sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate in water in Experimental Example 1 of the present invention, wherein (1) is a photo before stirring, (2) is a photo during stirring, and (3) is a photo after stirring, a is a photo with N,N′-diphenylthiourea added, and b is a photo with sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate added;

[0043] Fig.15 This is a process flow chart of actual mineral flotation in Examples 5 to 7 of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0045] Example 1

[0046] Preparation of Sodium O-(2-(3-benzoylthioureido)ethyl)dithiocarbonate

[0047] 1.63 g of benzoyl isothiocyanate and 20 mL of dichloromethane were added to a three-necked flask in sequence, and 0.67 g of ethanolamine was slowly added dropwise under stirring. After the addition was completed, the reaction was allowed to react for 2 h. The obtained reaction system was filtered with suction, and the filter cake was washed with dichloromethane to obtain 1-benzoyl-3-(2-hydroxyethyl)thiourea. The obtained 1-benzoyl-3-(2-hydroxyethyl)thiourea and 30 mL of carbon disulfide were added to a three-necked flask in sequence, and the mixture was stirred continuously. 0.5 g of powdered sodium hydroxide was added in batches, and the reaction was allowed to react for 4 h. The obtained reaction system was filtered with suction, and the filter cake was dissolved with acetone. The acetone system was filtered again, and petroleum ether was added to the filtrate to obtain sodium O-(2-(3-benzoylthiourea)ethyl)dithiocarbonate with a yield of 82.61%. The hydrogen nuclear magnetic resonance spectrum of sodium O-(2-(3-benzoylthiourea)ethyl)dithiocarbonate is shown in FIG. Figure 1 As shown: 1 H NMR / δppm: 11.71 (1H, -(O=)C-NH-); 7.31-8.04 (5H, -C6H5); 4.70 (1H, -NH-CH2-); 3.61 (2H, -O-CH2-); 3.53 (2H, -NH-CH2-); results of carbon nuclear magnetic resonance spectrum analysis Figure 2 As shown: 13C NMR / δppm: 193.18(1C,-C(=S)-S-); 183.80(1C,-C(=S)-NH-); 170.84(1C,-C( =O)-); 127.62-140.24 (5C, -C6H5); 60.21 (1C, -O-CH2-); 47.48 (1C, -NH-CH2).

[0048] Example 2

[0049] Preparation of Sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate

[0050] 1.35 g of phenyl isothiocyanate and 20 mL of dichloromethane were added to a three-necked flask in sequence, and 0.67 g of ethanolamine was slowly added dropwise under stirring. After the addition was completed, the reaction was allowed to react for 2 h. The resulting reaction system was filtered with suction, and the filter cake was washed with dichloromethane to obtain 1-phenyl-3-(2-hydroxyethyl)thiourea. The resulting 1-phenyl-3-(2-hydroxyethyl)thiourea and 30 mL of carbon disulfide were added to a three-necked flask in sequence, and the mixture was stirred continuously. 0.5 g of powdered sodium hydroxide was added in batches, and the reaction was allowed to react for 4 h. The resulting reaction system was filtered with suction, and the filter cake was dissolved with acetone. The acetone system was filtered again, and petroleum ether was added to the filtrate to obtain sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate with a yield of 86.05%. The hydrogen nuclear magnetic resonance spectrum of sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate is shown in FIG. Figure 3 As shown: 1 H NMR / δppm: 8.12 (1H, C6H5-NH-); 7.05-7.56 (5H, -C6H5); 4.81 (1H, -NH-CH2-); 3.54 (4H, -CH2-CH2-); The results of carbon nuclear magnetic resonance spectrum analysis are as follows Figure 4 As shown: 13 C NMR / δppm: 180.90 (1C, -C(=S)-S-); 140.21 (1C, -C(=S)-NH-); 123.24-128.83 (5C, -C6H5); 59.72 (1C, -O-CH2-); 47.05 (1C, -NH-CH2).

[0051] Example 3

[0052] Preparation of Sodium O-(2-(3-Benzylthioureido)ethyl)dithiocarbonate

[0053] 1.49 g of benzyl isothiocyanate and 20 mL of dichloromethane were added to a three-necked flask in sequence, and 0.67 g of ethanolamine was slowly added dropwise under stirring. After the addition was completed, the reaction was carried out for 2 h. The obtained system was washed with water, and the organic layer was separated and rotary evaporated to obtain 1-benzyl-3-(2-hydroxyethyl)thiourea. The obtained 1-benzyl-3-(2-hydroxyethyl)thiourea, 30 mL of tetrahydrofuran, and 2.28 g of carbon disulfide were added to a three-necked flask in sequence, and the mixture was stirred continuously. 0.5 g of powdered sodium hydroxide was added in batches, and the reaction was carried out for 4 h. Dichloromethane was added to the obtained yellow solution, and the solution was filtered to obtain a light yellow solid, namely, sodium O-(2-(3-benzylthiourea)ethyl)dithiocarbonate, with a yield of 92.53%. The hydrogen nuclear magnetic resonance spectrum of sodium O-(2-(3-benzylthiourea)ethyl)dithiocarbonate is shown in FIG. Figure 5 As shown: 1 HNMR / δppm: 8.00 (1H, -CH2-NH-); 7.66 (1H, -CH2-C6H5); 7.23-7.34 (5H, -C6H5); 4.66 (2H, C6H5-CH2-); 4.28 (2H, -O-CH2-); 3.66 (2H, -NH-CH2-); The results of carbon NMR analysis are as follows Figure 6 As shown: 13 C NMR / δppm: 232.13(1C,-C(=S)-S-); 192.54(1C,-C(=S)-NH-); 127.05-137.72( 5C, -C6H5); 60.57 (1C, C6H5-CH2-); 47.76 (1C, -O-CH2-); 45.95 (1C, -NH-CH2).

[0054] The frontier molecular orbital energy calculation results of O-(2-(3-benzoylthioureido)ethyl)dithiocarbonate anion, O-(2-(3-phenylthioureido)ethyl)dithiocarbonate anion, and O-(2-(3-benzylthioureido)ethyl)dithiocarbonate anion prepared in Examples 1 to 3 in aqueous solution at the B3LYP-D3 / 6-311+G(d) level are shown in Table 1.

[0055] Table 1 Calculation results of frontier molecular orbital energies of collectors in aqueous solution at the B3LYP-D3 / 6-311+G(d) level

[0056]

[0057] The quantum chemical calculation results in Table 1 show that the HOMO energy of O-(2-(3-benzoylthiourea)ethyl)dithiocarbonate ion, O-(2-(3-phenylthiourea)ethyl)dithiocarbonate ion and O-(2-(3-benzylthiourea)ethyl)dithiocarbonate ion is close to the HOMO energy of O-isobutyldithiocarbonate. Due to the introduction of thiourea, the LUMO energy of O-(2-(3-benzoylthiourea)ethyl)dithiocarbonate ion, O-(2-(3-phenylthiourea)ethyl)dithiocarbonate ion and O-(2-(3-benzylthiourea)ethyl)dithiocarbonate ion is significantly reduced, and the LUMO and HOMO energy difference is reduced. It is expected that the thiourea sodium dithiocarbonate collector has a higher capture ability and selectivity.

[0058] Figure 7 , Figure 8 , Fig. 9 They are the optimal configurations of O-(2-(3-benzoylthioureido)ethyl)dithiocarbonate, O-(2-(3-phenylthioureido)ethyl)dithiocarbonate, and O-(2-(3-benzylthioureido)ethyl)dithiocarbonate at the B3LYP-D3 / 6-311+G(d) level respectively; Fig.10 , Fig.11 , Fig.12 They are the HOMO and LUMO of O-(2-(3-benzoylthioureido)ethyl)dithiocarbonate, O-(2-(3-phenylthioureido)ethyl)dithiocarbonate, and O-(2-(3-benzylthioureido)ethyl)dithiocarbonate at the B3LYP-D3 / 6-311+G(d) level. O-(2-(3-benzoylthioureido)ethyl)dithiocarbonate and O-(2-(3-phenylthioureido)ethyl)dithiocarbonate have a large conjugated structure formed by a benzene ring and a thioureido group, which improves the intramolecular stability and reduces the irritating odor produced by decomposition.

[0059] Example 4

[0060] Preparation of Sodium O-(2-(3-Benzylthioureido)propyl)dithiocarbonate

[0061] 1.49 g of benzyl isothiocyanate and 20 mL of dichloromethane were added to a three-necked flask in sequence, and 0.82 g of n-propanolamine was slowly added dropwise under stirring. After the addition was completed, the reaction was continued for 2 h. The obtained system was washed with water, and the organic layer was separated and rotary evaporated to obtain 1-benzyl-3-(2-hydroxypropyl)thiourea. The obtained 1-benzyl-3-(2-hydroxypropyl)thiourea, 30 mL of tetrahydrofuran, and 2.28 g of carbon disulfide were added to a three-necked flask in sequence, and the mixture was stirred continuously. 0.5 g of powdered sodium hydroxide was added in batches and the reaction was continued for 4 h. Dichloromethane was added to the obtained yellow solution, and the solution was filtered to obtain a light yellow solid, i.e., sodium O-(2-(3-benzylthiourea)propyl)dithiocarbonate, with a yield of 83.42%. The infrared spectrum analysis results of sodium O-(2-(3-benzylthiourea)propyl)dithiocarbonate are as follows: Fig.13 The infrared spectrum analysis is shown in Table 2.

[0062] Table 2 Infrared spectrum analysis of sodium O-(2-(3-benzylthioureido)propyl)dithiocarbonate

[0063] <![CDATA[Wave number (cm -1 )]]> Attribution 3264 NH stretching vibration absorption peak 3061 Ar-H stretching vibration absorption peak 2932 <![CDATA[Stretching vibration absorption peak of CH2]]> 2876 <![CDATA[Stretching vibration absorption peak of CH2]]> 1617 Stretching vibration absorption peak of benzene ring skeleton 1556 The deformation vibration absorption peak of NH 1453 <![CDATA[Deformation vibration absorption peak of CH2]]> 1342 <![CDATA[Deformation vibration absorption peak of CH2]]> 1292 The stretching vibration absorption peak of CN 1065 C=S stretching vibration absorption peak 1027 CS stretching vibration absorption peak 965 Stretching vibration absorption peak of CC 882 Absorption peak of CH out-of-plane bending vibration on benzene ring 735 Absorption peak of CH out-of-plane bending vibration on benzene ring 697 Absorption peak of CH out-of-plane bending vibration on benzene ring

[0064] Experimental Example 1

[0065] Evaluation of Dispersibility of Thiourea Dithiocarbonate Collector

[0066] At 20°C, 20 g of N, N'-diphenylthiourea and sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate prepared in Example 2 were weighed, 100 mL of distilled water was added, stirred for 30 min, filtered, and weighed after the filter cake was dried, and the solubility of the collector to be tested at 20°C was calculated. The results are shown in Table 3. The results show that the solubility of sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate in water is much greater than that of the commonly used thiourea collector N, N'-diphenylthiourea.

[0067] Table 3 Solubility test results

[0068] Collector Name Solubility (g / 100g water) Sodium O-(2-(3-phenylthioureido)ethyl)dithiocarbonate 3.6 N,N′-Diphenylthiourea ＜0.1

[0069] At 20°C, 0.1 g of each sample was added to 10 mL of water to test the dispersibility of N,N′-diphenylthiourea (a) and sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate (b). The specific dispersion effects are as follows: Fig.14 The following are the comparisons of the dispersion effects before stirring (1), during stirring (2) and after stirring (3). Fig.14It can be seen that before stirring, most of the sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate has been dissolved in the water, and N,N'-diphenylthiourea is almost not dispersed; during stirring, the sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate has been completely dissolved, and a small amount of N,N'-diphenylthiourea is dispersed in the water in the form of particles; after stirring, the sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate aqueous solution has been clarified, and N,N'-diphenylthiourea still exists in the form of solid. The results show that the dispersibility of sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate in water is significantly better than that of N,N'-diphenylthiourea.

[0070] The logP of O-isobutyldithiocarbonate anion, O-(2-(3-benzoylthioureido)ethyl)dithiocarbonate ion, O-(2-(3-phenylthioureido)ethyl)dithiocarbonate ion and O-(2-(3-benzylthioureido)ethyl)dithiocarbonate ion were calculated respectively, and the calculated values ​​(ClogP) are shown in Table 4.

[0071] Table 4 ClogP of collector

[0072] Collector molecule or anion name ClogP O-(2-(3-Benzoylthioureido)ethyl)dithiocarbonate 1.531 O-(2-(3-phenylthioureido)ethyl)dithiocarbonate 1.242 O-(2-(3-Benzylthioureido)ethyl)dithiocarbonate 1.719 N,N′-Diphenylthiourea 2.170 O-isobutyldithiocarbonate 1.946

[0073] From the results in Table 4, it can be seen that the ClogP of thiourea-based dithiocarbonate is lower than that of N,N′-diphenylthiourea, which also shows that the dispersibility of thiourea-based sodium dithiocarbonate collector is better in water. More importantly, the ClogP of thiourea-based dithiocarbonate is also lower than that of O-isobutyl dithiocarbonate, indicating that thiourea-based and dithiocarbonate have a synergistic effect, which is conducive to the dispersion of thiourea-based sodium dithiocarbonate collector in water.

[0074] Experimental Example 2

[0075] Odor Evaluation of Thiourea Dithiocarbonate

[0076] The response values ​​of the organic sulfide sensor W2W to sodium O-isobutyl dithiocarbonate (sodium isobutyl xanthate) and sodium O-(2-(3-benzylthiourea)ethyl) dithiocarbonate prepared in Example 3 were tested using the electronic nose test method. The test results are shown in Table 5.

[0077] Table 5 Electronic nose test results

[0078] Collector Name W2W sensor response value Sodium O-(2-(3-benzylthioureido)ethyl)dithiocarbonate 13.20 Sodium O-isobutyldithiocarbonate 17.50

[0079] The electronic nose test results in Table 5 show that the response value of the organic sulfide sensor W2W to sodium O-(2-(3-benzylthiourea)ethyl)dithiocarbonate is 13.20, which is 24.57% lower than that of sodium O-isobutyldithiocarbonate, indicating that the organic sulfide odor of sodium O-(2-(3-benzylthiourea)ethyl)dithiocarbonate is less than that of sodium O-isobutyldithiocarbonate.

[0080] Example 5

[0081] Flotation experiment of a gold-containing copper slag with thiourea dithiocarbonate

[0082] A gold-containing copper slag contains 1.02% copper and 0.15g / t gold, the grinding fineness of -200 mesh accounts for 80%, the pulp pH is adjusted to 8, and O-(2-(3-phenylthiourea)ethyl)sodium dithiocarbonate prepared in Example 2 and conventional O-isobutyldithiocarbonate are added in an amount of 40g / t respectively for a roughing flotation. The flotation results are shown in Table 6.

[0083] Table 6 Flotation test results of a gold-containing copper slag

[0084]

[0085] The flotation results show that, compared with sodium O-isobutyl dithiocarbonate, the collector of the present invention has an 8.23 ​​percentage point increase in copper grade of flotation concentrate and a 19.09 percentage point increase in copper recovery rate when the dosage is the same; the gold grade is increased by 0.71 g / t and the gold recovery rate is increased by 11.97 percentage points, indicating that the collector of the present invention, sodium thiourea dithiocarbonate, has a better collection ability for copper sulfide ores and gold than the traditional collector, sodium O-isobutyl dithiocarbonate, and significantly improves the recovery rate and grade of copper and gold.

[0086] Example 6

[0087] Flotation experiment of thiourea dithiocarbonate on a gold and silver mine in Henan

[0088] A gold and silver ore in Henan Province contains 44.89 g / t of silver and 1.84 g / t of gold, and the grinding fineness of -200 mesh accounts for 72%. The pH value of the ore pulp is adjusted to 8 with sodium carbonate, and a roughing flotation is carried out using sodium O-(2-(3-benzoylthiourea)ethyl)dithiocarbonate prepared in Example 1, sodium O-(2-(3-phenylthiourea)ethyl)dithiocarbonate prepared in Example 2, and sodium O-isobutyldithiocarbonate, respectively. The flotation results are shown in Table 7.

[0089] Table 7 Flotation test results of a gold and silver mine in Henan

[0090]

[0091] The flotation results show that, compared with sodium O-isobutyl dithiocarbonate, the collectors O-(2-(3-benzoylthiourea)ethyl) sodium dithiocarbonate and O-(2-(3-phenylthiourea)ethyl) sodium dithiocarbonate can increase the silver grade of the flotation concentrate by 406.54 and 284.55 g / t, respectively, and the silver recovery rate by 9.22 and 6.00 percentage points, respectively; the gold grade can increase by 15.60 and 12.26 g / t, respectively, and the gold recovery rate can increase by 8.21 and 9.24 percentage points, respectively, indicating that the collectors of the present invention have good collection effects on gold and silver.

[0092] Example 7

[0093] Flotation experiment of a lead-zinc ore with thiourea dithiocarbonate

[0094] A lead-zinc ore contains 1.65% lead and 96.55g / t silver, and the grinding fineness of -200 mesh accounts for 85%. The pH value of the ore pulp is adjusted to 8. A composite reagent consisting of O-(2-(3-benzylthiourea)ethyl)dithiocarbonate, O-isobutyldithiocarbonic acid and Mac-12 and O-isobutyldithiocarbonate are used for a rough flotation. The flotation results are shown in Table 8.

[0095] Table 8 Flotation test results of a lead-zinc ore

[0096]

[0097] The flotation results show that, compared with the composite reagent composed of sodium O-isobutyl dithiocarbonate and Mac-12 and sodium O-isobutyl dithiocarbonate, the lead grade of the flotation concentrate of the collector O-(2-(3-benzylthiourea)ethyl)dithiocarbonate is increased by 7.08 and 18.33 percentage points, and the lead recovery rate is increased by 11.60 and 15.30 percentage points, respectively, when the dosage is the same; the silver grade is increased by 324.01 g / t and 673.19 g / t, and the silver recovery rate is increased by 9.33 and 2.61 percentage points, respectively, indicating that the collector thiourea dithiocarbonate has better lead and silver collection ability than the composite reagent composed of sodium O-isobutyl dithiocarbonate and Mac-12 and sodium O-isobutyl dithiocarbonate.

[0098] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A thiourea dithiocarbonate collector, characterized in that: Its structural formula is shown in Formula I: Among them, R 1 is a C1-C8 hydrocarbon group, a C2-C9 alkylcarbonyl group or a C7-C9 arylcarbonyl group; R 2 is a straight-chain alkylene group of C1 to C8; Me is Na or K; and the thiourea-based dithiocarbonate collector is used as a collector for metal mineral flotation.

2. A thiourea-based dithiocarbonate collector according to claim 1, characterized in that: The R 1 is allyl, butyl, phenyl, p-tolyl, m-tolyl, benzyl, phenethyl, benzoyl or phenylacetyl; R 2 It is 1,2-ethylene or 1,3-propylene.

3. A method for preparing a thiourea dithiocarbonate collector as claimed in any one of claims 1 to 2, characterized in that: The steps include: S1, performing an addition reaction of an isothiocyanate having a structure of Formula II and an alcohol amine in a solvent to prepare a hydroxythiourea having a structure of Formula III; S2. Mix hydroxythiourea, caustic soda and carbon disulfide in a solvent at 0-10°C, and heat the mixture to react to obtain a thiourea-based dithiocarbonate collector.

4. The preparation method according to claim 3, characterized in that: The solvents in steps S1 and S2 are one or more of water, dichloromethane, tetrahydrofuran, petroleum ether or acetone.

5. The preparation method according to claim 3, characterized in that: The amount of solvent used in steps S1 and S2 is 0.2 to 3 L per mole of isothiocyanate.

6. The preparation method according to claim 3, characterized in that: The molar ratio of the isothiocyanate, the amine, the caustic soda and the carbon disulfide is 1.0:1.0-1.1:1.0-1.3:1.0-3.

0.

7. The preparation method according to claim 3, characterized in that: The reaction temperature of step S1 is 0-30° C., and the reaction time is 1-4 hours.

8. The preparation method according to claim 3, characterized in that: The reaction temperature of step S2 is 15-30° C., and the reaction time is 1-6 hours.

9. Use of the thiourea dithiocarbonate collector according to any one of claims 1 to 2 or the thiourea dithiocarbonate collector prepared by the preparation method according to any one of claims 3 to 8 in mineral flotation, characterized in that: The thiourea-based dithiocarbonate collector is used for the flotation of non-ferrous metal sulfide ores and their associated gold and silver minerals. The non-ferrous metal sulfide ores are one or more of copper sulfide ores, lead-zinc sulfide ores, copper-nickel sulfide ores, and copper-molybdenum sulfide ores.

10. The flotation application according to claim 9, characterized in that: The flotation process of the thiourea-based dithiocarbonate collector for non-ferrous metal sulfide ore is as follows: the non-ferrous metal sulfide ore is crushed and slurried; then the thiourea-based dithiocarbonate collector is added to the slurry for flotation, the amount of the collector is 20-200 g / t, and the flotation concentrate is collected.

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