A combined collector and its preparation method and application

Abstract

The present invention discloses a combined collector and a preparation method and application thereof. The combined collector is prepared from kerosene, long-chain alcohol and ammonium dodecyl polyoxyethylene ether sulfate according to a molar ratio of 20-200:10-150:10-100. The combined collector composed of kerosene, long-chain alcohol and ammonium dodecyl polyoxyethylene ether sulfate provided by the present invention has a better effect on flotation recovery of waste cathode carbon blocks of aluminum electrolytic cells, and can obtain better flotation effect compared with the commonly used single collector, and has high industrial application value.

Description

Technical Field

[0001] The invention belongs to the field of mineral processing engineering and the technical field of flotation separation of waste cathode carbon blocks of aluminum electrolysis cells, and specifically relates to a combined collector and a preparation method and application thereof. Background Art

[0002] Aluminum occupies an irreplaceable position among commonly used industrial raw materials. With the annual increase in the output of electrolytic aluminum, the number of waste cathodes dismantled from aluminum electrolytic cells cannot be underestimated. According to relevant statistics, about 5 to 10 kilograms of waste cathode carbon blocks are produced for each ton of metal aluminum produced by electrolysis. The main component of waste cathode carbon blocks is carbon. However, since the cathode carbon blocks are at high temperatures during operation in the electrolytic aluminum process, the carbon in the discarded cathode carbon blocks is basically highly graphitized. To a certain extent, this transformation is not only conducive to separation from other components, but also improves the recycling value of waste cathode carbon blocks. Therefore, it is of great significance to use certain technical means to recycle carbon powder and other valuable components in waste cathodes in aluminum electrolytic cells, both from the perspective of economic benefits and ecological benefits.

[0003] At present, the treatment methods for waste cathodes are mainly divided into two categories: wet treatment and fire treatment. It is subdivided into: flotation, combustion, high temperature hydrolysis, alkaline leaching, acidification and thermal decomposition. Compared with other methods, flotation has the advantages of low cost, environmental protection and cleanliness. Collectors are the key to determining the flotation effect. Generally, single components such as kerosene and diesel are used as collectors, but they have poor dispersibility in the slurry, large amount of foam, and unsatisfactory sorting effect. The amount of reagents used in the treatment process is large, resulting in increased costs and poor economic efficiency. Summary of the invention

[0004] In order to solve the technical problem of flotation of a large number of waste cathode carbon blocks in the electrolytic aluminum industry, the purpose of the present invention is to provide a combined collector and its preparation method and application. The present invention proposes a combined collector composed of kerosene, long-chain alcohol and ammonium dodecyl polyoxyethylene ether sulfate, and the combined collector is used in the flotation of waste cathode carbon blocks in aluminum electrolytic cells.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A preparation method of a combined collector comprises the following steps: uniformly mixing kerosene, long-chain alcohol and ammonium dodecyl polyoxyethylene ether sulfate in a molar ratio of 20-200:10-150:10-100 to obtain the combined collector.

[0007] Preferably, the long-chain alcohol is at least one of decanol, dodecanol and tetradecanol.

[0008] Preferably, the molar ratio of kerosene, long-chain alcohol and ammonium dodecyl polyoxyethylene ether sulfate is 20-120:10-50:10-80, more preferably 100:40:50.

[0009] The combined collector is prepared by the above-mentioned preparation method of the combined collector.

[0010] The above-mentioned combined collector is used as a collector in flotation recovery of spent cathode carbon blocks in aluminum electrolysis cells.

[0011] The use of the combined collector as a collector in flotation recovery of waste cathode carbon blocks of aluminum electrolysis cells comprises the following steps: crushing the waste cathode carbon blocks of the aluminum electrolysis cells to less than 2 mm, then adding water and grinding them to obtain slurry, adding the slurry to a flotation cell, and then adding an inhibitor, the combined collector and a frother for flotation.

[0012] Preferably, the mass ratio of the spent cathode carbon blocks of the aluminum electrolysis cell to water is 1:1.

[0013] Preferably, the grinding is performed to a fineness of -0.074 mm and a particle size content of 55 to 95%.

[0014] Preferably, the inhibitor is water glass, and the foaming agent is pine oil.

[0015] Preferably, the dosage of the combined collector is 100-2500 g / t.

[0016] Preferably, the dosage of the inhibitor is 100-1500 g / t.

[0017] Preferably, the amount of the foaming agent is 10-50 g / t.

[0018] The above flotation method is positive flotation for waste cathode carbon blocks of aluminum electrolytic cells. The products obtained after the flotation process are foam products and in-cell products, among which the foam product is the desired concentrate (high-quality carbon powder with a high carbon content) and the in-cell product is tailings.

[0019] Compared with the prior art, the beneficial effects of the present invention include:

[0020] The present invention achieves the synergistic effect between the combined collectors, so that the collectors and other flotation reagents are evenly dispersed in the ore pulp, and the efficiency and effect of flotation are enhanced, so that the purity and recovery rate of carbon powder can be maintained at a good level with a small amount of reagents. The carbon content of the carbon powder concentrate obtained by flotation is more than 72%, and the carbon recovery rate is more than 95%. The method has a simple process flow, helps to solve the problem caused by the storage of waste cathode carbon blocks in aluminum electrolytic cells, and has significant economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1The four combined collectors prepared in Examples 1 and 2 are respectively used for flotation recovery of spent cathode carbon blocks from aluminum electrolysis cells, and the corresponding curves of fixed carbon content and recovery rate in the concentrate carbon powder are compared.

[0022] Figure 2 The four combined collectors prepared in Examples 3 and 4 are respectively used for flotation recovery of spent cathode carbon blocks from aluminum electrolysis cells, and the corresponding curves of fixed carbon content and recovery rate in the concentrate carbon powder are compared.

[0023] Figure 3 The four combined collectors prepared in Examples 5 and 6 were used for flotation recovery of spent cathode carbon blocks from aluminum electrolysis cells, and the corresponding curves of fixed carbon content and recovery rate in the concentrate carbon powder were compared. DETAILED DESCRIPTION

[0024] 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.

[0025] The XFD-1.0L single-tank flotation machine used in the following examples and comparative examples was purchased from Wuhan Prospecting Machinery Factory. 3 / h of aeration. The four types of ammonium lauryl polyoxyethylene ether sulfate were purchased from Colonial Chemical Company (Tennessee, USA), and the active ingredient content was 24-26%. The chemical formulas of the four types of ammonium lauryl polyoxyethylene ether sulfate are: (C 12 H 25 -(OC2H4)1-O-SO3NH4), (C 12 H 25 -(OC2H4)2-O-SO3NH4), (C 12 H 25 -(OC2H4)3-O-SO3NH4) and (C 12 H 25 -(OC2H4)4-O-SO3NH4), denoted as A1, A2, A3 and A4 respectively.

[0026] The calculation methods of the fixed carbon content and carbon recovery rate in the following examples and comparative examples are shown in formula (1) and formula (2), respectively.

[0027]

[0028] Where: η is the content of fixed carbon, %; S is the mass of the sample before incineration, g; Q is the mass of the sample after incineration, g.

[0029]

[0030] Where: W is the carbon recovery rate, %; F is the mass of the carbon flotated, g; η f is the fixed carbon content of the floated carbon, %; Y is the mass of the original sample, g; η y is the fixed carbon content of the original sample.

[0031] Example 1

[0032] The preparation methods of four combined collectors are as follows: kerosene, dodecanol and ammonium lauryl polyoxyethylene ether sulfate are uniformly mixed in a molar ratio of 150:100:100 to obtain the combined collectors. Among them, ammonium lauryl polyoxyethylene ether sulfate is taken from A1, A2, A3 and A4 respectively, and the corresponding combined collectors are A11, A22, A33 and A44.

[0033] The combined collector is used as a collector in flotation recovery of waste cathode carbon blocks in aluminum electrolysis cells, and the steps are as follows:

[0034] (1) Crushing and grinding: Use crushing equipment to crush the waste cathode carbon blocks of aluminum electrolysis cells to less than 2 mm, then add 1 kg of waste cathode carbon blocks and water in a mass ratio of 1:1 into a rod mill and grind until the grinding fineness is -0.074 mm and the particle size content accounts for 80%, to obtain a slurry.

[0035] (2) Flotation: 167 g of ore pulp was added to a flotation tank and stirred for 2 minutes, and water glass as an inhibitor was added in accordance with a standard of 300 g / t, a collector was added in accordance with a standard of 500 g / t, and pine oil was added in accordance with a standard of 40 g / t. The stirring speed was controlled at 1800 r / min. The collectors were A11, A22, A33 and A44, respectively.

[0036] (3) Dry and weigh the foam product and the product in the tank separately, and calculate the fixed carbon content and recovery rate in the concentrate carbon powder.

[0037] Example 2

[0038] The preparation methods of four combined collectors are as follows: replace the "kerosene, dodecanol and ammonium lauryl polyoxyethylene ether sulfate are uniformly mixed in a molar ratio of 150:100:100" in Example 1 with "kerosene, dodecanol and ammonium lauryl polyoxyethylene ether sulfate are uniformly mixed in a molar ratio of 100:40:50", and the rest are the same as Example 1.

[0039] The combined collector is used as a collector in flotation recovery of waste cathode carbon blocks in aluminum electrolysis cells, and the steps are as follows: the same as in Example 1.

[0040] Comparative Example 1

[0041] The application of kerosene as a collector in flotation recovery of spent cathode carbon blocks in aluminum electrolysis cells is as follows:

[0042] (1) Crushing and grinding: Use crushing equipment to crush the waste cathode carbon blocks of aluminum electrolysis cells to less than 2 mm, then add 1 kg of waste cathode carbon blocks and water in a mass ratio of 1:1 into a rod mill and grind until the grinding fineness is -0.074 mm and the particle size content accounts for 80%, to obtain a slurry.

[0043] (2) Flotation: 167 g of ore pulp was added to a flotation tank and stirred for 2 min. Then, 300 g / t of water glass as an inhibitor, 500 g / t of kerosene as a collector, and 40 g / t of pine oil were added to the ore pulp in sequence. The stirring speed was controlled at 1800 r / min.

[0044] (3) The foam product and the product in the tank were dried and weighed respectively, and the fixed carbon content and recovery rate of the concentrate carbon powder were calculated. According to the calculation, the fixed carbon content of the concentrate carbon powder obtained by flotation was 67.58%, and the carbon recovery rate was 85.96%.

[0045] Comparative Example 2

[0046] The collector in Comparative Example 1 was replaced with dodecanol, and the other steps were the same as those in Comparative Example 1. The fixed carbon content in the concentrate carbon powder obtained by flotation was 43.52%, and the carbon recovery rate was 56.31%.

[0047] Comparative Example 3

[0048] The collector in Comparative Example 1 was replaced by A2, and the other steps were the same as those in Comparative Example 1. The fixed carbon content in the concentrate carbon powder obtained by flotation was 57.89%, and the carbon recovery rate was 62.35%.

[0049] Comparative Example 4

[0050] The collector in Comparative Example 1 was replaced by dodecanol and kerosene in a molar ratio of 40:100, and the other steps were the same as Comparative Example 1. The fixed carbon content in the concentrate carbon powder obtained by flotation was 68.11%, and the carbon recovery rate was 87.52%.

[0051] Comparative Example 5

[0052] The collector in Comparative Example 1 was replaced by dodecanol and A2 in a molar ratio of 100:100, and the other steps were the same as Comparative Example 1. The fixed carbon content in the concentrate carbon powder obtained by flotation was 61.47%, and the carbon recovery rate was 78.64%.

[0053] Comparative Example 6

[0054] The collector in Comparative Example 1 was replaced by kerosene and A3 in a molar ratio of 100:50, and the other steps were the same as Comparative Example 1. The fixed carbon content in the concentrate carbon powder obtained by flotation was 70.35%, and the carbon recovery rate was 89.75%.

[0055] Example 3

[0056] The preparation methods of four combined collectors are as follows: the steps are as follows: replacing "kerosene, dodecanol and ammonium dodecyl polyoxyethylene ether sulfate are uniformly mixed at a molar ratio of 150:100:100" in Example 1 with "kerosene, decanol and ammonium dodecyl polyoxyethylene ether sulfate are uniformly mixed at a molar ratio of 150:100:100", replacing "adding water glass as an inhibitor at a standard of 300 g / t, adding a collector at a standard of 500 g / t, and adding pine oil at a standard of 40 g / t" with "adding water glass as an inhibitor at a standard of 300 g / t, adding a collector at a standard of 1000 g / t, and adding pine oil at a standard of 40 g / t", and the rest are the same as Example 1.

[0057] The combined collector is used as a collector in flotation recovery of waste cathode carbon blocks in aluminum electrolysis cells, and the steps are as follows: the same as in Example 1.

[0058] Example 4

[0059] The preparation methods of four combined collectors are as follows: the steps are as follows: replacing "kerosene, dodecanol and ammonium dodecyl polyoxyethylene ether sulfate are uniformly mixed at a molar ratio of 150:100:100" in Example 1 with "kerosene, decanol and ammonium dodecyl polyoxyethylene ether sulfate are uniformly mixed at a molar ratio of 100:40:50", replacing "adding water glass as an inhibitor at a standard of 300 g / t, adding a collector at a standard of 500 g / t, and adding pine oil at a standard of 40 g / t" with "adding water glass as an inhibitor at a standard of 300 g / t, adding a collector at a standard of 1000 g / t, and adding pine oil at a standard of 40 g / t", and the rest are the same as Example 1.

[0060] The combined collector is used as a collector in flotation recovery of waste cathode carbon blocks in aluminum electrolysis cells, and the steps are as follows: the same as in Example 1.

[0061] Comparative Example 7

[0062] The application of kerosene as a collector in flotation recovery of spent cathode carbon blocks in aluminum electrolysis cells is as follows:

[0063] (1) Crushing and grinding: Use crushing equipment to crush the waste cathode carbon blocks of aluminum electrolysis cells to less than 2 mm, then add 1 kg of waste cathode carbon blocks and water in a mass ratio of 1:1 into a rod mill and grind until the grinding fineness is -0.074 mm and the particle size content accounts for 80%, to obtain a slurry.

[0064] (2) flotation, adding 167 g of ore pulp into a flotation tank and stirring for 2 min, and then adding 300 g / t of water glass as an inhibitor, 1000 g / t of kerosene as a collector, and 40 g / t of pine oil into the ore pulp in sequence, and controlling the stirring speed to 1800 r / min;

[0065] (3) The foam product and the product in the tank were dried and weighed respectively, and the fixed carbon content and recovery rate of the concentrate carbon powder were calculated. According to the calculation, the fixed carbon content of the concentrate carbon powder obtained by flotation was 65.68%, and the carbon recovery rate was 75.67%.

[0066] Example 5

[0067] The preparation methods of four combined collectors are as follows: the steps are as follows: replacing "kerosene, dodecanol and ammonium lauryl polyoxyethylene ether sulfate are uniformly mixed at a molar ratio of 150:100:100" in Example 1 with "kerosene, tetradecanol and ammonium lauryl polyoxyethylene ether sulfate are uniformly mixed at a molar ratio of 150:100:100", replacing "adding water glass as an inhibitor at a standard of 300 g / t, adding a collector at a standard of 500 g / t, and adding pine oil at a standard of 40 g / t" with "adding water glass as an inhibitor at a standard of 300 g / t, adding a collector at a standard of 300 g / t, and adding pine oil at a standard of 40 g / t", and the rest are the same as Example 1.

[0068] The combined collector is used as a collector in flotation recovery of waste cathode carbon blocks in aluminum electrolysis cells, and the steps are as follows: the same as in Example 1.

[0069] Example 6

[0070] The preparation methods of four combined collectors are as follows: the steps are as follows: replacing "kerosene, dodecanol and ammonium lauryl polyoxyethylene ether sulfate are uniformly mixed at a molar ratio of 150:100:100" in Example 1 with "kerosene, tetradecanol and ammonium lauryl polyoxyethylene ether sulfate are uniformly mixed at a molar ratio of 100:40:50", replacing "adding water glass as an inhibitor at a standard of 300 g / t, adding a collector at a standard of 500 g / t, and adding pine oil at a standard of 40 g / t" with "adding water glass as an inhibitor at a standard of 300 g / t, adding a collector at a standard of 300 g / t, and adding pine oil at a standard of 40 g / t", and the rest are the same as Example 1.

[0071] Comparative Example 8

[0072] The application of kerosene as a collector in flotation recovery of spent cathode carbon blocks in aluminum electrolysis cells is as follows:

[0073] (1) Crushing and grinding: Use crushing equipment to crush the waste cathode carbon blocks of aluminum electrolysis cells to less than 2 mm, then add 1 kg of waste cathode carbon blocks and water in a mass ratio of 1:1 into a rod mill and grind until the grinding fineness is -0.074 mm and the particle size content accounts for 80%, to obtain a slurry.

[0074] (2) Flotation: 167 g of ore pulp was added to a flotation tank and stirred for 2 min. Then, 300 g / t of water glass as an inhibitor, 300 g / t of kerosene as a collector, and 40 g / t of pine oil were added to the ore pulp in sequence. The stirring speed was controlled at 1800 r / min.

[0075] (3) The foam product and the product in the tank were dried and weighed respectively, and the fixed carbon content and recovery rate of the concentrate carbon powder were calculated. According to the calculation, the fixed carbon content of the concentrate carbon powder obtained by flotation was 63.45%, and the carbon recovery rate was 70.23%.

[0076] The combined collector is used as a collector in flotation recovery of waste cathode carbon blocks in aluminum electrolysis cells, and the steps are as follows: the same as in Example 1.

[0077] Figure 1 The four combined collectors prepared in Examples 1 and 2 are respectively used for flotation recovery of waste cathode carbon blocks in aluminum electrolysis cells, and the corresponding curves of fixed carbon content and recovery rate in concentrate carbon powder are compared, wherein the horizontal axis represents A1~A4, respectively representing dodecyl polyoxyethylene ether ammonium sulfate with different chemical formula structures selected when preparing the combined collector, and the arrows near each curve indicate the corresponding vertical axis.

[0078] Depend on Figure 1 It can be seen that when "kerosene, dodecanol and ammonium dodecyl polyoxyethylene ether sulfate are uniformly mixed in a molar ratio of 100:40:50" and "ammonium dodecyl polyoxyethylene ether sulfate is selected as A2", after flotation recovery, the fixed carbon content and recovery rate in the concentrate are the highest. Further, under the same addition conditions, the flotation recovery effect of the combined collector prepared by the present invention is still better than that of using kerosene alone.

[0079] Figure 2The four combined collectors prepared in Examples 3 and 4 are respectively used for flotation recovery of waste cathode carbon blocks in aluminum electrolysis cells, and the corresponding curves of fixed carbon content and recovery rate in concentrate carbon powder are compared, wherein the horizontal axis represents A1~A4, respectively representing dodecyl polyoxyethylene ether ammonium sulfate with different chemical formula structures selected when preparing the combined collector, and the arrows near each curve indicate the corresponding vertical axis.

[0080] Depend on Figure 2 It can be seen that when "kerosene, decanol and ammonium dodecyl polyoxyethylene ether sulfate are uniformly mixed in a molar ratio of 100:40:50" and "ammonium dodecyl polyoxyethylene ether sulfate is selected as A2", the fixed carbon content and recovery rate in the concentrate are the highest after flotation recovery. Furthermore, under the same addition conditions, the flotation recovery effect of the combined collector prepared by the present invention is still better than that of using kerosene alone.

[0081] Figure 3 The four combined collectors prepared in Examples 5 and 6 are respectively used for flotation recovery of waste cathode carbon blocks in aluminum electrolysis cells, and the corresponding curves of fixed carbon content and recovery rate in concentrate carbon powder are compared, wherein the horizontal axis represents A1~A4, respectively representing dodecyl polyoxyethylene ether ammonium sulfate with different chemical formula structures selected when preparing the combined collector, and the arrows near each curve indicate the corresponding vertical axis.

[0082] Depend on Figure 3 It can be seen that when "kerosene, tetradecanol and ammonium dodecyl polyoxyethylene ether sulfate are uniformly mixed in a molar ratio of 100:40:50" and "ammonium dodecyl polyoxyethylene ether sulfate is selected as A2", the fixed carbon content and recovery rate in the concentrate are the highest after flotation recovery. Furthermore, under the same addition conditions, the flotation recovery effect of the combined collector prepared by the present invention is still better than that of using kerosene alone.

[0083] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a combined collector, characterized in that: The method comprises the following steps: uniformly mixing kerosene, long-chain alcohol and ammonium dodecyl polyoxyethylene ether sulfate in a molar ratio of 20-200:10-150:10-100 to prepare the combined collector; the long-chain alcohol is at least one of decanol, dodecanol and tetradecanol; and the combined collector is used as a collector in flotation recovery of waste cathode carbon blocks of aluminum electrolytic cells.

2. The method for preparing a combined collector according to claim 1, characterized in that: The molar ratio of the kerosene, the long-chain alcohol and the ammonium lauryl polyoxyethylene ether sulfate is 20-120:10-50:10-80.

3. The method for preparing a combined collector according to claim 2, characterized in that: The molar ratio of the kerosene, the long-chain alcohol and the ammonium lauryl polyoxyethylene ether sulfate is 100:40:

50.

4. The method for preparing a combined collector according to claim 1, characterized in that: The application of the combined collector as a collector in flotation recovery of waste cathode carbon blocks of aluminum electrolysis cells comprises the following steps: crushing the waste cathode carbon blocks of aluminum electrolysis cells to less than 2 mm, then adding water and grinding them to obtain slurry, adding the slurry to a flotation cell, and then adding an inhibitor, the combined collector and a frother for flotation.

5. The method for preparing a combined collector according to claim 4, characterized in that: The mass ratio of the waste cathode carbon block of the aluminum electrolytic cell to water is 1:1; the grinding is performed to a fineness of -0.074 mm, and a particle size content of 55-95%.

6. A method for preparing a combined collector according to claim 4 or 5, characterized in that: The inhibitor is water glass, the foaming agent is pine oil; and the dosage of the combined collector is 100-2500 g / t.

7. The method for preparing a combined collector according to claim 6, characterized in that: The dosage of the inhibitor is 100-1500 g / t; the dosage of the foaming agent is 10-50 g / t.

8. A combined collector prepared by the preparation method of a combined collector according to any one of claims 1 to 3.

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