An oil-based composite collector, its preparation and application in coal flotation

Abstract

The present application relates to the technical field of floatation, in particular to a washing oil-based composite collector, which comprises modified washing oil, non-polar hydrocarbon oil and a compound of formula 1; the modified washing oil is an oil product obtained by modifying washing oil raw material with alkali liquor; the washing oil raw material is modified with alkali liquor, which unexpectedly improves the coal collecting capacity and floatation selectivity, and further cooperates with non-polar hydrocarbon oil and the compound of formula 1 to achieve synergy, further improving the coal collecting capacity and floatation selectivity.

Description

Technical Field

[0001] This invention belongs to the field of coal flotation technology, specifically relating to a method for preparing a compound coal flotation collector. Background Technology

[0002] In terms of coal preparation methods and processes, my country mainly uses wet heavy media coal preparation, wet jigging coal preparation, flotation coal preparation, and dry coal preparation to separate coal from gangue, achieving the removal of impurities, ash, and sulfur from raw coal. With the development of mineral resources, high-quality coal is being washed and utilized; however, low-rank coal types, as well as coal slime and tailings from washing, cause resource waste and environmental pollution. Therefore, clean and efficient coal flotation technology will receive further attention.

[0003] Coal preparation is the foundation of clean coal technology, a crucial means of deashing, upgrading, and value-added utilization, and plays a vital role in resource recovery, energy conservation, emission reduction, and environmental protection. my country boasts abundant and diverse coal reserves, but this also leads to significant differences in coal quality, necessitating the application of various coal preparation processes such as flotation, jigging, and heavy media. Flotation is currently the most mature and effective method for coal separation, utilizing the differences in surface physicochemical properties between minerals and gangue to achieve separation. During flotation, bubbles carry hydrophobic useful mineral particles to the surface, and the skimmed product is the concentrate; the remaining slurry contains hydrophilic gangue particles, generally used for tailings landfill, with some being recyclable. Collectors can alter the hydrophobic properties of mineral particle surfaces, interacting with them and thus influencing the generation of mineralized bubbles, which is a key factor determining the effectiveness of flotation separation. In coal flotation separation, non-polar hydrocarbon oils such as kerosene and diesel are commonly used as collectors. However, due to their small molecular weight, they are easily captured and adsorbed by the pores of coal, resulting in high collector consumption and weak collecting capacity in coal preparation. In addition, low-rank coal, coal slime or tailings have poor floatability, poor foaming stability and low concentrate yield. Therefore, developing a new type of collector with high efficiency and good selectivity is crucial to improving flotation separation effect and reducing coal preparation cost.

[0004] Wash oil originates from intermediate products in the petrochemical industry or as an important fraction with a distillation range of 230–300℃ during coal tar distillation. It is primarily used to wash and absorb various organic gases and benzene and naphthalene compounds from coke oven gas. The majority of it is sold at low prices as a raw material for fuel oil or carbon black production, and its utilization is not fully realized. my country has a relatively high yield and abundant supply of wash oil, with an annual output exceeding 1 million tons. Due to its strong dissolving power and slightly higher density than water, wash oil is easily dispersed in slurry and exhibits good stability. The aromatics, such as benzene and its derivatives, in wash oil have strong collecting ability and also possess some foaming and conditioning properties, making it a promising candidate for coal flotation collectors. However, research indicates that the direct flotation performance of wash oil (mainly referring to wash oil not used for washing and adsorption) in coal is not ideal and is costly. In particular, the used wash oil (referring to the washing oil after washing and absorbing coke oven gas) has a more complex composition and is classified as industrial hazardous waste, making it even more difficult to obtain flotation indicators that meet production requirements when used as a flotation collector. There is an urgent need in the industry for a technology that can effectively utilize wash oil as a resource.

[0005] Therefore, the preparation of collectors from industrial by-product wash oil through deep processing can effectively improve selectivity, enhance mineralization, and thus improve the separation effect of coal flotation. This not only provides a resource utilization method for by-product wash oil but also solves the problem of coal recovery from waste resources such as low-rank coal, coal slime, and gasification slag, achieving waste-to-waste treatment that is not only economically efficient but also safe and environmentally friendly. Summary of the Invention

[0006] To address the problem of unsatisfactory coal collection capacity of wash oil, the primary objective of this invention is to provide a wash oil-based composite collector, which aims to synergistically improve the collection performance of the composite collector through the combination of components, thereby realizing the resource utilization of wash oil.

[0007] The second objective of this invention is to provide the preparation of the aforementioned wash oil-based composite collector and its application in coal flotation.

[0008] Wash oil has unsatisfactory flotation performance for coal, especially used wash oil, which absorbs a large amount of harmful components due to long-term use, further reducing the flotation performance of coal. To address this problem, this invention provides the following solution:

[0009] A wash oil-based composite collector comprising modified wash oil, nonpolar hydrocarbon oil, and a compound of formula 1:

[0010] The modified wash oil is an oil product obtained by modifying wash oil raw materials with alkali solution;

[0011]

[0012] The R1 is H, halogen, C1-C4 alkyl, or C1-C4 alkoxy.

[0013] R2 is a C1 to C4 alkyl group.

[0014] To address the issue of unsatisfactory coal collection capacity and flotation selectivity of wash oil, this invention innovatively employs alkaline treatment to modify it, which unexpectedly improves its coal collection capacity and flotation selectivity. Furthermore, by combining it with non-polar hydrocarbon oils and compounds of Formula 1, synergistic effects can be achieved, further improving the coal collection capacity and flotation selectivity.

[0015] In this invention, the wash oil raw material can be wash oil in any state within the industry. For example, it can be unwashed oil with a distillation range of 230-300℃ collected from distillation in petrochemicals, or wash oil after unwashed oil has absorbed coke oven gas. The modification process of this invention has a modifying and upgrading effect on any wash oil, and for wash oil, the process of this invention can achieve better processing economic value.

[0016] In this invention, the alkaline modification treatment of wash oil and the combination of non-polar hydrocarbon oils and compounds of Formula 1 are key to synergistically improving coal collection capacity and flotation selectivity.

[0017] In this invention, the washing oil raw material and alkali solution can be mixed for modification treatment, followed by oil-water separation to obtain modified washing oil.

[0018] In this invention, the alkaline solution is an aqueous solution of at least one alkaline solute selected from alkali metal hydroxides, carbonates, and bicarbonates. This invention has found that using alkali metal hydroxides can achieve better modification and upgrading effects, which helps to further improve the flotation ability of the modified wash oil obtained from the treatment on coal, and helps to improve its combined synergistic effect with other components.

[0019] Preferably, the mass concentration of the alkaline solute in the alkaline solution is 10% to 50%, more preferably 20% to 30%.

[0020] Preferably, the alkaline solute in the alkaline solution is 5% to 30% of the mass of the washing oil raw material, and more preferably 10% to 20%.

[0021] In this invention, the temperature of the modification treatment stage is greater than or equal to 50°C, preferably 60°C to 150°C, more preferably 90°C to 120°C, and even more preferably 100°C to 120°C. In this invention, at the preferred treatment temperature, a better modified flotation and upgrading effect can be obtained.

[0022] In this invention, the modification treatment time can be adjusted as needed, for example, it can be 30 min to 240 min, and more specifically, it can be 100 min to 150 min;

[0023] In this invention, after modification, oil-water separation can be achieved using known methods and equipment, and the upper oily solution can be collected, which is the modified wash oil.

[0024] In this invention, based on the innovative alkaline modification treatment, the modified wash oil and non-polar hydrocarbon oil, as well as the combination of Formula 1, can achieve synergistic effects and unexpectedly further improve the flotation collection capacity and selectivity of coal.

[0025] In this invention, the non-polar hydrocarbon oil is at least one of diesel, kerosene, and white oil.

[0026] In this invention, in Formula 1, R1 is H; and R2 is a C1 to C3 alkyl group.

[0027] In this invention, the weight ratio of modified wash oil: nonpolar hydrocarbon oil: compound of formula 1 is 100:5-50:5-30, preferably 100:20-45:5-25; more preferably 100:30-40:10-20. Studies have found that at the preferred ratio, a better synergistic effect of the components can be obtained.

[0028] The present invention also provides a method for preparing the wash oil-based composite collector, wherein a modified wash oil is prepared based on the above method, and then the modified wash oil is compounded with a non-polar hydrocarbon oil and a compound of formula 1 to obtain the wash oil-based composite collector.

[0029] The present invention also provides an application of the aforementioned wash oil-based composite collector, using it as a collector for coal collection and flotation.

[0030] In this invention, coal can be flotated using the wash oil-based composite collector of this invention, based on existing flotation methods and principles. For example, conventional frothers can be added as needed during the flotation process.

[0031] In this invention, the dosage of the collector can be adjusted based on existing principles. For example, the dosage of the compound collector is greater than or equal to 1000 g / t, and considering the treatment effect and economy, it can be further 1000–3000 g / t, or even 1500–1800 g / t. The dosage of the foaming agent can be 100–2000 g / t, further 700–1200 g / t, and even further 850–1150 g / t.

[0032] Beneficial effects

[0033] In this invention, alkaline solution is used to modify the wash oil, which unexpectedly improves the wash oil's flotation collection ability and selectivity for coal.

[0034] Combining the modified wash oil and nonpolar hydrocarbon oil with the compounds of Formula 1 can unexpectedly achieve further synergy, which can further improve the flotation collection capacity and selectivity of coal.

[0035] This invention realizes the resource utilization of washing oil, especially hazardous waste washing oil after cleaning and adsorption, which has significant environmental and economic advantages. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the process of applying the present invention to flotation. Detailed Implementation

[0037] The following examples are intended to illustrate the invention and not to further limit it.

[0038] This invention can achieve good modified coal flotation and upgrading effects on any wash oil in the industry. As a typical implementation example, unless otherwise stated, the wash oil mentioned in the following cases uses the following wash oil raw materials:

[0039] The wash oil feedstock is derived from the 230–300℃ distillate obtained through deep processing of coal tar. It is a yellowish-brown or brown oily liquid, primarily composed of neutral components such as benzene, naphthalene compounds, acenaphthene, fluorene, and oxyfluorene; acidic components such as phenols; and basic compounds such as quinoline and pyridine. Neutral components account for 89.12%, acidic components for 2.35%, and basic compounds for 6.61%.

[0040] As an example of a typical implementation scheme, unless otherwise stated, all compounds of Formula 1 used are of Formula 1-A (in Formula 1, R1 is H and R2 is ethyl).

[0041] Example 1

[0042] Step 1: Modification of wash oil raw materials:

[0043] The wash oil raw material was heated and stirred under reflux at 110°C for 130 min with a 20% NaOH solution. The amount of alkali used (referring to the amount of NaOH solute in the NaOH solution) was 10% of the wash oil raw material. After the reaction was completed, the mixture was allowed to stand and separate into layers. The lower aqueous phase solution was separated, and the upper organic phase was the modified wash oil raw material.

[0044] Step 2, preparation of the collector:

[0045] The modified wash oil raw material, diesel oil, and Formula 1-A were mixed evenly at a weight ratio of 100:40:10 to obtain a coal collector;

[0046] The third step is to perform flotation using the collector prepared in this example (see...). Figure 1 The specific steps are as follows:

[0047] Using long-flame coal slime (Aad = 36.22%) from a factory in Shenmu, Shaanxi Province as raw material, 400g of coal slime was weighed and ground in a conical ball mill. Water was added to control the grinding concentration at 45%, and the grinding time was 10 minutes. After grinding and dissociation, the fineness of the slurry obtained was -0.074mm, accounting for 95%. The slurry was added to a 1.5L flotation cell, and collectors and frothers were added. Then, the aeration switch was turned on, and roughing, scavenging, and cleaning operations were performed to obtain clean coal products and tailings.

[0048] The collector used was the one prepared in this example, with a dosage of 1600 g / t; the foaming agent used was 2... # Oil dosage is 900g / t; during the flotation process, roughing and scavenging are performed once, and cleaning is performed twice; closed-circuit flotation is carried out (see attached). Figure 1 (As shown); The experimental results under the above experimental conditions are as follows:

[0049]

[0050] Example 2

[0051] Compared with Example 1, the only difference is that the mass concentration of NaOH solution in the first step of the wash oil raw material modification is as follows: Group (I): 10%; Group (II): 30%; Group (III): 40%. In each group, the amount of sodium hydroxide relative to the wash oil is the same as in Example 1. The experimental results are as follows:

[0052]

[0053]

[0054] Example 3

[0055] Compared to Example 1, the only difference is that the alkaline solution used in the first step of the wash oil raw material modification is: Group (I): Na2CO3 solution; Group (II): NaHCO3 solution. In each group, the amount of solute in the alkaline solution relative to the wash oil is the same as in Example 1. The experimental results are as follows:

[0056]

[0057] Example 4

[0058] Compared with Example 1, the only difference is that the reaction temperature for the first step of the wash oil raw material modification reaction is as follows: Group (I): 50℃; Group (II): 80℃; Group (III): 90℃; Group (IV): 100℃; Group (V): 120℃. The experimental results are as follows:

[0059]

[0060] Example 5

[0061] Compared with Example 1, the only difference is that the reaction time for the first step of the wash oil raw material modification is: Group (I): 120 min; Group (II): 140 min; Group (III): 150 min. The experimental results are as follows:

[0062]

[0063] Example 6

[0064] Compared to Example 1, the only difference is the change in the ratio of alkali to washing oil raw material in the first step: Group (I): 5%; Group (II): 15%; Group (III): 20%. The experimental results are as follows:

[0065]

[0066]

[0067] Example 7

[0068] Compared to Example 1, the only difference is that in the second step of collector preparation, the diesel component was replaced by an equal weight of: Group (I): kerosene; Group (II): white oil. The experimental results are as follows:

[0069]

[0070] Example 8

[0071] Compared with Example 1, the only difference lies in the weight ratio of the substances in the second step of collector preparation: Group (I): modified wash oil, diesel oil, Formula 1-A = 100:30:20; Group (II): modified wash oil, diesel oil, Formula 1-A = 100:35:15; Group (III): modified wash oil, diesel oil, Formula 1-A = 100:45:5. The experimental results are as follows:

[0072]

[0073] Example 9

[0074] Compared with Example 1, the only difference is that the dosage of flotation reagents in the third flotation step is as follows: Group (I): the collector described in Example 1, dosage is 1400 g / t; Group (II): the collector described in Example 1, dosage is 1800 g / t; Group (III): frother 2 # Oil, dosage 700g / t; Group (IV): Foaming agent 2 # Oil, dosage: 1100g / t. Experimental results:

[0075]

[0076] Comparative Example 1

[0077] Compared with Example 1, the only difference is the type of collector: Group (I): collector is single diesel oil; Group (II): collector is single kerosene; Group (III): collector is single unmodified wash oil feedstock; Group (IV): collector is single modified wash oil feedstock; Group (V): the modified feedstock in the collector of Example 1 is replaced by an equal amount of unmodified wash oil feedstock; Group (VI): diesel oil is not added to the collector of Example 1; Group (VII): Formula 1-A is not added to the collector of Example 1; Group (VIII): Formula 1-A is replaced by an equal amount of 2-octanol. Other operating methods and conditions are the same as in Example 1, for example, the mechanism of the flotation process and the dosage of each reagent are the same as in Example 1.

[0078] The test results are as follows:

[0079]

[0080] In summary, the coal collector prepared by the present invention using modified wash oil raw materials can improve the hydrophobicity of coal surface, enhance the selectivity of coal, increase the compatibility of slurry, strengthen the mineralization effect, and reduce the ash content of concentrate, thereby improving the coal beneficiation effect.

Claims

1. A wash oil-based composite collector, characterized by, It comprises modified washing oil, non-polar hydrocarbon oil and compound of formula 1: The modified washing oil is oil product after washing oil raw material is modified by alkali liquor; Formula 1 R1 is H, halogen, C1-C4 alkyl or C1-C4 alkoxy; R2 is C1-C4 alkyl; The washing oil raw material is un-washed oil with distillation range of 230-300°C collected in petroleum chemical industry, or is washed oil after un-washed oil is washed and absorbed coke oven gas; The alkali liquor is aqueous solution of at least one basic solute of alkali metal hydroxide, carbonate or bicarbonate; the mass concentration of basic solute in alkali liquor is 5%-30% of the mass of washing oil raw material; The weight ratio of modified washing oil, non-polar hydrocarbon oil and compound of formula 1 is 100:5-50:5-30.

2. The oil-based complex collector according to claim 1, wherein The mass concentration of basic solute in alkali liquor is 10%-50%.

3. The oil-based complex collector according to claim 1, wherein The mass concentration of basic solute in alkali liquor is 10%-20% of the mass of washing oil raw material.

4. The oil-based complex collector according to claim 1, wherein The temperature of modification treatment stage is greater than or equal to 50°C.

5. The oil-based complex collector according to claim 4, wherein The temperature of modification treatment stage is 60-150°C.

6. The oil-based complex collector according to claim 5, wherein The temperature of modification treatment stage is 90-120°C.

7. The oil-based complex collector according to claim 6, wherein The temperature of modification treatment stage is 100-120°C.

8. The oil-based complex collector according to claim 1, wherein The time of modification treatment is 30-240 minutes; after modification treatment, the oily solution in upper layer is collected, which is the modified washing oil.

9. The oil-based complex collector according to claim 8, wherein The time of modification treatment is 100-150 minutes.

10. The oil-based complex collector as claimed in claim 1, wherein The non-polar hydrocarbon oil is at least one of diesel oil, kerosene and white oil.

11. The oil-based complex collector as claimed in claim 1, wherein In formula 1, R1 is H and R2 is C1-C3 alkyl.

12. The oil-based complex collector as claimed in claim 1, wherein The weight ratio of modified washing oil, non-polar hydrocarbon oil and compound of formula 1 is 100:20-45:5-25.

13. The oil-based complex collector according to claim 12, wherein The weight ratio of modified washing oil, non-polar hydrocarbon oil and compound of formula 1 is 100:30-40:10-20.

14. A method of preparing the oil-based composite collector of any one of claims 1 to 13, characterized by, The modified washing oil is prepared, and then it is compounded with non-polar hydrocarbon oil and compound of formula 1 to prepare the washing oil-based composite collector.

15. Use of the oil-based composite collector of any one of claims 1 to 13, characterized in that, It is used as collector for coal collection and flotation.

16. The use of an oil-based complex collector according to claim 15, characterized in that, Foaming agent can be added according to need in the process of flotation.

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