Application of n-methyl-n-pentyl thiourea as collector in sulfur-oxygen mixed copper-cobalt ore and simultaneous flotation method

Abstract

The application provides application of n-methyl-n-pentyl thiourea as a collector in a sulfur-oxygen mixed copper-cobalt ore and a synchronous flotation method, and relates to the technical field of flotation. In view of problems of the traditional sulfur-then-oxygen process, such as a complicated process, a complex process, and influence of changes of oxidation and sulfidation rates on the flotation effect of the sulfidized copper-cobalt ore, the application provides a new flotation process and reagent, does not need to use a sulfidation agent for sulfidation, simultaneously floats and sulfidizes and oxidizes the copper-cobalt ore, and simultaneously floats the oxidized and sulfidized copper-cobalt ore by using an activator sodium dimethyl dithiocarbamate and a chelate collector n-methyl-n-pentyl thiourea. The flotation process of the application is simple, efficient, clean and efficient, and provides a new method, a new process and a new way for the flotation of the complex sulfur-oxygen mixed copper-cobalt ore.

Description

Technical Field

[0001] This invention relates to the field of flotation technology, and in particular to the application of n-methyl-n-pentylthiourea as a collector in sulfur-oxygen mixed copper-cobalt ores and a simultaneous flotation method thereon. Background Technology

[0002] Copper and cobalt are important industrial metals with wide applications in metallurgy, electronics, and chemical industries. Copper-cobalt oxide ores are one of the important ore resources for copper and cobalt, commonly found in copper-cobalt deposits. Due to the complex properties of complex sulfide copper-cobalt oxide ores, which contain both copper oxide and copper sulfide minerals, their flotation process is relatively complex.

[0003] Traditionally, the conventional sulfidation-flotation process for oxygen-sulfur mixed copper-cobalt ores typically follows a sulfur-first, oxygen-later sequence. The main advantage of this process is that it eliminates the influence of excessive sulfiding agent used in the flotation of oxidized ores on the sulfide ores, thus improving flotation efficiency. However, the traditional process also has some problems. First, the process flow is relatively cumbersome, requiring multiple steps and various reagents, increasing production costs and operational difficulty. Second, variations in oxidation and sulfidation rates affect the instability and effectiveness of sulfide copper-cobalt ores flotation, especially when flotating oxidized copper-cobalt ores. Precise dosage of sodium sulfide is crucial; insufficient sodium sulfide may result in suboptimal flotation of oxidized ores, while excessive sulfiding agent inhibits the flotation of oxidized copper-cobalt ores.

[0004] In recent years, with the gradual depletion of easily processed high-grade copper-cobalt mineral resources and the increasing awareness of environmental protection, the comprehensive utilization and flotation technology research of difficult-to-process sulfide copper-cobalt ores has received increasing attention. Regarding the flotation problem of mixed oxygen-sulfur copper-cobalt ores, researchers have begun to explore new flotation methods and reagents. Some studies have shown that flotating oxidized and sulfide copper-cobalt ores together without the need for sulfidation agents can simplify the process, reduce costs, and be more environmentally friendly. However, due to the poor flotation effect of oxidized ores under traditional methods, further improvements are needed.

[0005] Therefore, in order to solve the problems of traditional oxygen-sulfur mixed copper-cobalt ore flotation process, it is necessary to develop a new flotation process and reagents for simultaneous flotation of sulfided and oxidized copper-cobalt ores. This would improve flotation efficiency, simplify the process flow, reduce costs, and ensure stable flotation results under different oxidation and sulfidation states, while eliminating environmental pollution caused by sulfiding agents. Summary of the Invention

[0006] This invention provides the application of n-methyl-n-pentylthiourea as a collector in sulfur-oxygen mixed copper-cobalt ore and a simultaneous flotation method, the purpose of which is to solve the above-mentioned problems existing in the background art.

[0007] To achieve the above objectives, embodiments of the present invention provide the application of n-methyl-n-pentylthiourea as a collector in mixed sulfur-oxygen copper-cobalt ores and a simultaneous flotation method. Addressing the problems of cumbersome processes, complex procedures, and the impact of oxidation and sulfidation rate variations on the flotation effect of sulfide copper-cobalt ores in traditional sulfur-oxygen-oxygen flotation processes, an innovative flotation method and new reagents are proposed. Traditional oxygen-sulfur mixed copper-cobalt ore flotation processes typically employ a sequence of first flotating sulfide ores and then flotating oxide ores. Traditional sulfidation-flotation processes require precise control of sodium sulfide sulfidation; excessive sodium sulfide can inhibit the flotation of oxide copper-cobalt ores, while insufficient sodium sulfide results in poor activation and low recovery rates of oxide copper-cobalt ores. Therefore, addressing the problems of long processes, complex procedures, adverse effects of oxidation and sulfidation rate variations on the flotation effect of sulfide copper-cobalt ores, and difficulty in controlling the addition of sulfiding agents in traditional flotation processes, this invention proposes a novel flotation process and reagents that eliminates the need for sulfiding agents and simultaneously floats sulfide and oxide copper-cobalt ores. This invention relates to a novel activator, sodium dimethyl dithiocarbamate, and a chelate collector, n-methyl-n-pentylthiourea, as well as a new flotation method for simultaneously oxidizing and sulfiding copper-cobalt ores. This invention simplifies the flotation process, improves efficiency, and is clean and efficient, providing a new method, process, and approach for the flotation of complex sulfur-oxygen mixed copper-cobalt ores. This method features simple technology, low cost, low reagent consumption, fast mineralization rate, and high recovery rate, significantly improving the recovery rate of sulfur-oxygen mixed copper-cobalt ores.

[0008] One object of the embodiments of the present invention is to provide the application of n-methyl-n-pentylthiourea as a collector in sulfur-oxygen mixed copper-cobalt ores. n-methyl-n-pentylthiourea has the molecular formula C7H. 16 N2S, CAS: 169789-46-2, possesses a bifunctional structure. One functional group in the bifunctional group can form a chelating effect with the surface of copper-cobalt sulfide ore, while the other functional group can form a chelating effect with the surface of copper-cobalt oxide ore. The functional groups in the collector form coordination bonds with metal ions on the mineral surface, thereby covering the surface of the sulfur-oxygen mixed copper-cobalt ore with a hydrophobic coating, achieving the flotation of the sulfur-oxygen mixed copper-cobalt ore.

[0009] According to one aspect of the present invention, sodium dimethyl dithiocarbamate, with the molecular formula C3H7NS2Na and CAS number 128-04-1, is further used as an activator. It forms a stable cyclic chelate with copper and cobalt at the interface of copper-cobalt oxide ore, eliminating the need for sulfidation with a sulfiding agent. This activates copper-cobalt oxide ore while also activating copper-cobalt sulfide ore, exhibiting a better activation effect than sulfide ions and eliminating the adverse effects of excessive sodium sulfide on the flotation of copper-cobalt sulfide ore.

[0010] Another objective of embodiments of the present invention is to provide a simultaneous flotation method for sulfur-oxygen mixed copper-cobalt ores, comprising the following steps:

[0011] S1: Crush and grind the sulfur-oxygen mixed copper-cobalt ore to obtain ore powder;

[0012] S2: Add the ore powder and water to the flotation cell and stir, then add a pH adjuster;

[0013] S3: Add activator to activate;

[0014] S4: Add a collector to carry out a chelation reaction;

[0015] S5: Add frother for flotation.

[0016] According to one aspect of an embodiment of the present invention, in step S1, the particle size of the ore powder is 40% to 90% to 200 mesh.

[0017] According to one aspect of an embodiment of the present invention, in step S2, the pH value is adjusted to 7-9.

[0018] According to one aspect of an embodiment of the present invention, in step S3, the amount of activator used is 150-500 grams per ton.

[0019] According to one aspect of an embodiment of the present invention, in step S4, the amount of collector used is 150-450 grams per ton.

[0020] According to one aspect of an embodiment of the present invention, in step S5, the foaming agent is a terpene alcohol (2 # Oil).

[0021] Mechanism Explanation

[0022] The n-methyl-n-pentylthiourea chelate collector selectively forms cyclic chelates with copper and cobalt ions on the surface of oxygen-sulfur mixed copper-cobalt ore through the thiourea and amino functional groups, exhibiting strong selectivity. The pentyl and branched methyl groups of the collector have a wider hydrophobic surface than the straight-chain group, which improves the collecting ability. Under the action of sodium dimethyl dithiocarbamate, there is no need to use sodium sulfide for activation, and sulfide and oxidized copper-cobalt ore can be floated simultaneously.

[0023] Sodium dimethyl dithiocarbamate has a fixative group, dithiocarboxylic acid, and two hydrophobic methyl groups. The dithiocarboxylic acid functional group chemically adsorbs copper and cobalt ions from copper-cobalt oxide ore, breaking through the hydration film of copper-cobalt oxide ore and replacing sodium sulfide to activate copper-cobalt oxide ore. Its outstanding advantage is that it can activate both copper-cobalt oxide ore and copper-cobalt sulfide ore, while sodium sulfide only forms a copper-cobalt sulfide film on the surface of copper-cobalt oxide ore to produce an activation effect. It is only a sulfidation effect and has no collecting effect. Therefore, the amount of sodium dimethyl dithiocarbamate used is much lower than that of sodium sulfide.

[0024] The above-described solution of the present invention has the following beneficial effects:

[0025] 1. This invention innovatively employs an n-methyl-n-pentylthiourea chelating collector, which can selectively adsorb on the surface of both oxidized and sulfide copper-cobalt ores, enabling simultaneous flotation of oxidized and sulfide copper-cobalt ores. This collector has a wider hydrophobic surface due to its pentyl and branched methyl groups compared to straight-chain collectors, thus improving its collecting ability and effectively enhancing the hydrophobic collecting and selectivity of flotation, thereby increasing the grade and recovery rate of mixed sulfur-oxidized copper-cobalt ores.

[0026] 2. This invention innovatively uses sodium dimethyl dithiocarbamate as an activator, eliminating the need for sulfiding agents. It activates oxidized copper-cobalt ore, achieving simultaneous sulfidation and oxidation flotation under the activation of sodium dimethyl dithiocarbamate, resulting in a short flotation process and high efficiency.

[0027] 3. This invention not only eliminates the need for sulfiding agents, but also requires minimal amounts of activators and trapping agents, exhibiting strong selectivity for mixed sulfur-oxygen copper-cobalt ores. Furthermore, it simultaneously recovers oxidized and sulfide copper-cobalt ores through flotation, simplifying the process, reducing costs, improving flotation efficiency, and ensuring stable flotation results under different oxidation and sulfidation conditions.

[0028] 4. This invention can also be applied to the flotation of oxide ores such as lead oxide ore and antimony oxide ore. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic flowchart of a simultaneous flotation method for sulfur-oxygen mixed copper-cobalt ore according to an embodiment of the present invention;

[0031] Figure 2 These are flotation results diagrams of Examples 1-4 and Comparative Examples 1-3 of the present invention;

[0032] Figure 3 These are flotation results diagrams for Embodiments 1 and 5-7 of the present invention;

[0033] Figure 4 These are flotation results of Embodiment 1 and Comparative Examples 4-6 of the present invention;

[0034] Figure 5 These are flotation test results of Embodiment 8 and Comparative Example 7 of the present invention. Detailed Implementation

[0035] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0036] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0037] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0038] The recovery rate of the flotation test in the following examples has an error of 3%.

[0039] This invention addresses existing problems by providing the application of n-methyl-n-pentylthiourea as a collector in sulfur-oxygen mixed copper-cobalt ores and a simultaneous flotation method.

[0040] Example 1

[0041] The sample used in this embodiment is a mixed oxygen-sulfur copper-cobalt ore: copper sulfide ore is chalcocite and bornite, cobalt sulfide minerals are chalcocite and cobalt sulfide, etc.; copper oxide ore is malachite and chrysocolla, cobalt oxide ore is hydrocobaltite and cobalt carbonate; the oxygen-sulfur ratio is 1:1.

[0042] The above-mentioned simultaneous flotation method for sulfur-oxygen mixed copper-cobalt ore includes the following steps:

[0043] The S1 ore sample was crushed and ground to ensure that the fineness of the ore powder reached 60%-200 mesh.

[0044] S2 adds 10g of oxygen-sulfur mixed copper-cobalt ore with a fineness of 65%-200 mesh and 100mL of water to a 150mL flotation cell, and adds a small amount of sodium carbonate as a pH adjuster to maintain the pH value between 7 and 9.

[0045] S3 is activator sodium dimethyl dithiocarbamate 400 g / ton;

[0046] S4 contains 350 g / ton of collector n-methyl-n-pentylthiourea;

[0047] S5 contains the foaming agent terpene alcohol (2) # After stirring the oil for 2 minutes, flotation was carried out, and the foam was scraped for 3 minutes.

[0048] Example 2

[0049] The difference lies in the amount of sodium dimethyl dithiocarbamate used as the activator, which is 200 grams per ton of ore; otherwise, it is the same as in Example 1.

[0050] Example 3

[0051] The difference lies in the amount of sodium dimethyl dithiocarbamate used as the activator, which is 300 grams per ton of ore; otherwise, it is the same as in Example 1.

[0052] Example 4

[0053] The difference lies in the amount of sodium dimethyl dithiocarbamate used as the activator, which is 500 grams per ton of ore; otherwise, it is the same as in Example 1.

[0054] Example 5

[0055] The difference is that the oxygen-sulfur mixed copper-cobalt ore sample used has an oxygen-sulfur ratio of 2:1, while the rest is the same as in Example 1.

[0056] Example 6

[0057] The difference is that the oxygen-sulfur mixed copper-cobalt ore sample used has an oxygen-sulfur ratio of 3:1, while the rest is the same as in Example 1.

[0058] Example 7

[0059] The difference lies in the fact that the oxygen-sulfur mixed copper-cobalt ore sample used has an oxygen-sulfur ratio of 4:1, while the rest is the same as in Example 1.

[0060] Example 8

[0061] The difference is that the amount of n-methyl-n-pentylthiourea is 400 g / ton, otherwise it is the same as in Example 1.

[0062] Comparative Example 1

[0063] The difference is that the activator sodium dimethyl dithiocarbamate was not added; otherwise, it is the same as in Example 1.

[0064] Comparative Example 2

[0065] Sodium dimethyl dithiocarbamate was replaced with sodium sulfide at a rate of 800 g / ton, otherwise the same as in Example 1.

[0066] Comparative Example 3

[0067] Replace n-methyl-n-pentylthiourea with thiourea, otherwise the same as in Example 1.

[0068] Comparative Example 4

[0069] The collector n-methyl-n-pentylthiourea was replaced with butylammonium black powder, and everything else was the same as in Example 1.

[0070] Comparative Example 5

[0071] The collector n-methyl-n-pentylthiourea was replaced with butyl xanthate, and everything else was the same as in Example 1.

[0072] Comparative Example 6

[0073] The collector n-methyl-n-pentylthiourea was replaced with benzohydroxyoxime acid, and everything else was the same as in Example 1.

[0074] Comparative Example 7

[0075] Replace n-methyl-n-pentylthiourea with 500 g / ton butyl xanthate, otherwise the same as in comparative example 2.

[0076] like Figure 2 As shown, the recovery rates of Examples 1-4 and Comparative Examples 1-3 after flotation at different amounts of activator and collector are as follows: ① When the activator dosage is 0 g / ton, the recovery rate is 64.3%; ② When the activator dosage is 200 g / ton, the recovery rate is 75.6%; ③ When the activator dosage is 300 g / ton, the recovery rate is 79.2%; ④ When the activator dosage is 400 g / ton, the recovery rate is 84.5%; ⑤ When the activator dosage is 500 g / ton, the recovery rate is 81.8%; ⑥ When the sodium sulfide dosage is 800 g / ton, the recovery rate is 78.1%; ⑦ When the collector is thiourea, the recovery rate is 35.3%. The above experimental results show that the activator used in this invention has a strong activation effect. At the same dosage, sodium dimethyl dithiocarbamate is more effective than sodium sulfide. When the dosage of sodium dimethyl dithiocarbamate is 400 g / ton, the recovery rate reaches its maximum (84.5%), and as the dosage of the activator increases, the recovery rate initially increases and then remains relatively constant, while sodium sulfide only achieves 78.1%. Compared to thiourea, n-methyl-n-pentylthiourea achieves an 84.5% recovery rate for copper flotation, while thiourea achieves only 35.3%. This is because the n-methyl-n-pentylthiourea chelating collector has a unique hydrophobic structure with pentyl and branched methyl groups, resulting in strong collecting ability. Thiourea, lacking hydrophobic hydrocarbon chains, has no collecting ability for oxidized copper ores. Therefore, the flotation process and reagents used in this invention can achieve better flotation results for oxidized ores without the need for sulfide agents.

[0077] like Figure 3 As shown, the recovery rates of Examples 1 and 5-7 under different oxygen-sulfur ratios are as follows: ① When the oxygen-sulfur ratio is 1:1, the recovery rate is 83.8%; ② When the oxygen-sulfur ratio is 2:1, the recovery rate is 81.7%; ③ When the oxygen-sulfur ratio is 3:1, the recovery rate is 79.6%; ④ When the oxygen-sulfur ratio is 4:1, the recovery rate is 77.5%. The experimental results show that the recovery rate is highest when the oxygen-sulfur ratio is 1:1. However, when the oxygen-sulfur ratio is too high, the recovery rate decreases. The flotation process and reagents of this invention can achieve stable flotation effects under different oxidation and sulfidation rates.

[0078] like Figure 4As shown, the recovery rates of different collectors in Examples 1 and Comparative Examples 4-6 after flotation are as follows: ① Butylammonium black powder: 70.5% recovery rate; ② Butyl xanthate: 71.2% recovery rate; ③ Benzyl hydroxamic acid: 78.8% recovery rate; and ④ Chelating collector n-methyl-n-pentylthiourea: 83.8% recovery rate. Based on the comprehensive analysis of the experimental results, the chelating collector n-methyl-n-pentylthiourea used in this invention exhibits higher flotation performance than other collectors, demonstrating a significant advantage in improving the flotation recovery rate of copper-cobalt ore.

[0079] like Figure 5 As shown, the flotation results of Example 8 and Comparative Example 7 indicate that: ① the concentrate grade of the flotation process of this invention is 8.89%, and the copper recovery rate is 82.5%; while ② the concentrate grade of conventional sulfide flotation is 7.22%, and the recovery rate is 72.32%. A comprehensive analysis of the flotation results of Example 8 and Comparative Example 7 (see Table 1 below) shows that the sodium dimethyl dithiocarbamate used in this invention as an activator and n-methyl-n-pentylthiourea as a collector eliminates the need for sulfide agents and requires less activator. This results in stronger selectivity and collection for the flotation of mixed copper-cobalt ore with sulfur and oxygen compared to conventional sulfide-flotation.

[0080] Table 1. Flotation comparison test (%) between Example 8 and Comparative Example 7

[0081]

[0082] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for simultaneous flotation of a copper-cobalt ore, characterized in that, It comprises the following steps: S1: crushing and grinding the sulfur-oxygen mixed copper-cobalt ore to obtain ore powder; S2: adding the ore powder and water into a flotation tank and stirring, and then adding a pH regulator; S3: adding an activator for activation; S4: adding a collector for chelation; S5: adding a frother for flotation; The sodium dimethyl dithiocarbamate is used as the activator; the n-methyl-n-pentyl thiourea is used as the collector; the n-methyl-n-pentyl thiourea has a bifunctional structure; one of the two functional groups can form a chelation with the surface of the copper-cobalt sulfide, and the other functional group can form a chelation with the surface of the copper-cobalt oxide; the functional groups in the collector form coordination bonds with the metal ions on the surface of the minerals, so that the surface of the sulfur-oxygen mixed copper-cobalt ore is covered by the collector to be hydrophobic.

2. The simultaneous flotation method of a copper-cobalt sulphide-oxide ore according to claim 1, characterized in that, In step S1, the particle size of the ore powder is 40%-90% 200 mesh.

3. The simultaneous flotation method of a copper-cobalt sulphide-oxide ore according to claim 1, characterized in that, In step S2, the pH value is adjusted to 7-9.

4. The simultaneous flotation method of a copper-cobalt sulphide-oxide ore according to claim 1, characterized in that, In step S3, the amount of the activator is 150-500 g / t.

5. The simultaneous flotation process of a copper-cobalt sulphide-oxide ore according to claim 1, characterized in that, In step S4, the amount of the collector is 150-450 g / t.

6. The simultaneous flotation process of a copper-cobalt sulphide-oxide ore according to claim 1, characterized in that, In step S5, the frother is terpene alcohol.

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