A modified washing oil-based composite collector and its preparation method and application

Abstract

The present invention discloses a modified wash oil-based composite collector, comprising the following components: modified wash oil, non-polar hydrocarbon oil and a modifier, wherein the modified wash oil is a product obtained after the wash oil has been subjected to an acid wash modification treatment. The present invention also discloses a preparation method of the modified wash oil-based composite collector, as well as its application in coal slime flotation. The present invention adopts acid to carry out an acid wash modification treatment on the wash oil, and the modified wash oil can effectively reduce the ash content of the clean coal; and by combining the modified wash oil with the non-polar hydrocarbon oil and the modifier, a synergistic effect is achieved, and the modified wash oil-based composite collector of the present application is used to carry out a coal slime flotation test, thereby reducing the ash content of the clean coal while increasing the yield of the clean coal, thereby realizing the resource utilization of the wash oil and providing a new collector for the flotation, deashing and upgrading of coal slime.

Description

Technical Field

[0001] The invention belongs to the technical field of coal flotation, and particularly relates to a modified wash oil-based composite collector, a preparation method thereof, and application thereof in coal slime flotation. Background Art

[0002] Coal slime is a byproduct of the coal washing process. It consists of a viscous mixture of fine coal particles, pulverized bone stone, and water. Open-air storage of coal slime not only occupies a large area but also causes widespread wind and water flow, easily causing secondary pollution. This has significant impacts on the environment, ecological landscape, and the safety of residents downstream of tailings ponds. The efficient and clean utilization of coal slime has been a key research topic in the coal washing industry for many years, but breakthroughs have been elusive. Therefore, the comprehensive and clean utilization of coal slime has become a thorny issue that the coal industry urgently needs to address.

[0003] Currently, flotation deashing and upgrading is an important, efficient, and economical method for recovering fine-grained coal slimes. Flotation utilizes the differences in surface hydrophilicity and hydrophobicity between mineral particles to separate them. It can process materials with a particle size of ≤0.1 mm. The addition of various conditioning agents can enhance the selectivity differences between minerals, resulting in high separation efficiency and suitability for processing low-grade, finely embedded ores. Current flotation reagents are quite simple. Traditional collectors used in coal slime flotation are primarily petroleum derivatives, such as kerosene and diesel. These collectors are non-renewable, and their excessive consumption in low-rank coal flotation inevitably results in energy waste, hindering the effective utilization of limited resources.

[0004] Collectors are the most important agents in the flotation process. They selectively act on the surface of the target mineral, increasing its hydrophobicity and floatability, promoting its attachment to air bubbles, and strengthening the firmness of this attachment. Conventional collectors used in coal slime flotation are primarily non-polar hydrocarbon oils. The collection performance of non-polar hydrocarbon oils is closely related to their chemical composition, which varies significantly depending on their origin, processing method, and fractionation temperature.

[0005] Wash oil is a distillation product produced during the coal tar distillation process. my country produces over one million tons of wash oil annually, boasting high production and a wide range of sources. Neutral compounds account for approximately 90% of wash oil, primarily aromatic hydrocarbons such as benzene and its high-boiling homologues, naphthalene, fluorene, and acenaphthene. Acidic compounds account for 3%-4%, primarily phenols. Alkaline compounds account for 6%-7%, primarily nitrogen-containing aromatics such as quinoline and pyridine. Currently, wash oil is primarily used to remove benzene from coke oven gas. Some factories have also developed and utilized it, but due to the limited availability of developed products and low returns, wash oil has not been effectively utilized.

[0006] Wash oil is primarily composed of aromatic hydrocarbons such as benzene and its high-boiling homologues, naphthalene, fluorene, and acenaphthene. These compounds have a strong ability to capture coal. Furthermore, wash oil is derived from coal and has a good affinity for coal, making it an excellent collector in coal slime flotation. Summary of the Invention

[0007] The present invention aims to at least partially address one of the technical problems in the related art. To this end, the present invention primarily aims to provide a modified wash oil-based composite collector, which, through the synergistic effect of its components, improves the capture performance and selectivity of existing composite collectors. The present invention also aims to provide a method for preparing and using the modified wash oil-based composite collector.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] In a first aspect, a modified washing oil-based composite collector comprises the following components: modified washing oil, non-polar hydrocarbon oil and a modifier, wherein the modified washing oil is a product obtained by acid-washing and modification of the washing oil.

[0010] The inventors discovered during the coal slime flotation process using existing collectors that a small amount of nitrogen, oxygen, and sulfur heterocyclic functional group compounds contained in the wash oil affect the selectivity of coal during the coal slime flotation process. Therefore, they came up with the idea of ​​modifying the wash oil with acid solution. The acid-treated wash oil can improve the selectivity of the wash oil for coal; and after being combined with non-polar hydrocarbon oil and a modifier, a synergistic effect is further achieved, further improving its coal collection ability and selectivity.

[0011] In some specific embodiments, the weight ratio of the modified wash oil: non-polar hydrocarbon oil: modifier is 100:10-50:5-30; preferably 100:20-45:10-25; more preferably 100:30-40:15-20.

[0012] In some specific embodiments, the wash oil is a distillate at 230-300° C. cut from coal tar distillation.

[0013] In some specific embodiments, the non-polar hydrocarbon oil is one or more of shale oil, diesel and kerosene.

[0014] In some specific embodiments, the modifier is one or more of ethyl acetate, methyl acetate and methyl formate.

[0015] In certain specific embodiments, the acid solution is one or more of sulfuric acid, nitric acid and hydrochloric acid, and the mass concentration of the acid solution is 20%-50%, preferably 30%-40%.

[0016] In certain specific embodiments, the mass of the acid solution is 5%-15% of the mass of the wash oil, preferably 8%-12%.

[0017] In a second aspect, a method for preparing the aforementioned modified wash oil-based composite collector comprises the following steps:

[0018] 1) Add washing oil to a reaction vessel according to the recipe requirements, increase the temperature, and dropwise add acid solution for reflux reaction to obtain a mixture;

[0019] 2) separating the mixture into layers, cooling and standing, and collecting the upper oily liquid to obtain a modified wash oil;

[0020] 3) Evenly mix the modified washing oil, non-polar hydrocarbon oil and modifier to obtain the modified washing oil-based composite collector.

[0021] In certain specific embodiments, the reflux reaction temperature in step 1) is 60-150°C, preferably 80-120°C, more preferably 90-100°C, and the reflux reaction time is 30-240 min, preferably 70-200 min, more preferably 100-150 min.

[0022] In a third aspect, a modified wash oil-based composite collector or a modified wash oil-based composite collector prepared by the aforementioned preparation method is used in coal slime flotation.

[0023] Compared with the prior art, the present invention has at least the following advantages:

[0024] 1) In the present invention, acid wash modification treatment was performed on the wash oil using acid solution, and the modified wash oil was used in coal slime flotation deashing and quality improvement tests. It was verified that compared with the wash oil not treated with acid solution, the use of modified wash oil as a collector can reduce the ash content of clean coal, and the yield change is not much different. In other words, the modified wash oil can effectively reduce the ash content of clean coal;

[0025] 2) In the present invention, by combining the modified wash oil with the non-polar hydrocarbon oil and the modifier, a synergistic effect can be further achieved. The obtained modified wash oil-based composite collector is used to conduct a coal slime flotation test, thereby further reducing the ash content of the clean coal and increasing the yield of the clean coal.

[0026] 3) The modified wash oil-based composite collector provided by the present invention was used in the coal slime flotation deashing and quality improvement test, and the dosage of the agent was smaller than that of the traditional collector;

[0027] 4) The present invention not only realizes resource utilization of wash oil, but also provides a new collector for flotation deashing and quality improvement of coal slime. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present invention, the following briefly introduces the drawings required for the specific embodiments or the description of the prior art.

[0029] Figure 1 This is a schematic diagram of the process of applying the modified wash oil-based composite collector provided by the present invention to coal flotation. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and examples. The following examples are merely illustrative and non-restrictive, and should not be used to limit the scope of protection of the present invention.

[0031] When expressing a certain amount, concentration or other value or parameter in the form of a range, preferred range, or preferred upper and lower numerical limits, it should be understood that it is equivalent to specifically disclosing any range by combining any pair of upper range limits or preferred numerical values ​​with any lower range limit or preferred numerical value, without considering whether the range is specifically disclosed. Unless otherwise indicated, the numerical range values ​​listed herein include the endpoints of the range and all integers and fractions within the range.

[0032] Unless otherwise indicated, all percentages, parts, ratios, etc. herein are by weight.

[0033] The materials, methods, and examples herein are illustrative and, unless otherwise indicated, are not to be construed as limiting.

[0034] The wash oil in the following embodiments is derived from a fraction product with a distillation range of 230-300°C obtained by deep processing of coal tar. It is a yellowish-brown or brown oily liquid, mainly composed of neutral components such as benzene and its homologues, naphthalene compounds, acenaphthene, fluorene, and dibenzofuran; acidic components such as phenols; and alkaline compounds such as quinoline and pyridine. Among them, neutral components account for 90.38%, acidic components account for 3.6%, and alkaline compounds account for 6.02%.

[0035] Example 1

[0036] The present invention provides a method for preparing a modified washing oil-based composite collector, which comprises the following steps:

[0037] 1. Modification of washing oil

[0038] The wash oil was added to a three-necked flask equipped with a reflux device and a magnetic stirrer; 30% sulfuric acid was added to a separatory funnel, where the mass of the sulfuric acid solution was 9% of the mass of the wash oil; the reaction apparatus was heated to 95°C, the stirrer was started, and the separatory funnel was opened to add sulfuric acid dropwise and reflux for 120 minutes; the reaction mixture was poured into a separatory funnel, cooled and allowed to stand for 30 minutes. When stratification occurred, the lower aqueous phase solution was removed and the upper oily liquid was collected to obtain the modified wash oil;

[0039] 2. Preparation of modified washing oil-based composite collector

[0040] The modified wash oil is mixed with diesel and ethyl acetate in a weight ratio of 100:35:15 to obtain a modified wash oil-based composite collector;

[0041] 3. This application uses the modified wash oil-based composite collector prepared in this example to perform coal slime flotation operations

[0042] Using coking coal slime (Aad=49.32%) from a factory in Inner Mongolia as raw material, 300g of coal slime was weighed, and pulp was obtained through pulping and grinding. The pulp was added to a flotation tank for flotation test to obtain clean coal products and tailings.

[0043] The collector is the modified washing oil-based composite collector prepared in this example, with a dosage of 1500 g / t; the frother is T82, with a dosage of 1000 g / t; during the flotation process, the roughing and scavenging times are 1, and the cleaning times are 3; a closed-circuit flotation test of coal slime is carried out (see Appendix). Figure 1 The test results under the above experimental conditions are as follows:

[0044]

[0045] Example 2:

[0046] Compared with Example 1, the only difference is that the reaction temperature of the wash oil modification is: Group (1): 80°C; Group (2): 90°C; Group (3): 100°C; Group (4): 110°C. The test results are:

[0047]

[0048] Example 3:

[0049] Compared with Example 1, the only difference is that the reaction time of the washing oil modification is: Group (1): 110 min; Group (2): 130 min; Group (3): 140 min. The test results are:

[0050]

[0051]

[0052] Example 4:

[0053] Compared with Example 1, the only difference is the type of acid used in the wash oil modification: Group (1): nitric acid; Group (2): hydrochloric acid. In each group, the concentration of the acid is the same, and the mass of the acid relative to the amount of wash oil is the same as in Example 1. The test results are:

[0054]

[0055] Example 5:

[0056] Compared with Example 1, the only difference is the concentration of the acid solution, which is: Group (1): 20%; Group (2): 50%. The test results are:

[0057]

[0058] Example 6:

[0059] Compared with Example 1, the only difference is the ratio of acid solution to washing oil, which is: Group (1): 8%; Group (2): 10%; Group (3): 11%. The test results are:

[0060]

[0061] Example 7:

[0062] Compared with Example 1, the only difference is that the diesel component in the collector preparation is replaced by the following weights: Group (I): kerosene; Group (II): shale oil. The test results are:

[0063]

[0064] Example 8:

[0065] Compared with Example 1, the only difference is that the weight of the ethyl acetate component in the collector preparation is replaced by: Group (I): methyl acetate; Group (II): methyl formate. The test results are:

[0066]

[0067]

[0068] Example 9:

[0069] Compared with Example 1, the only difference is the weight ratio of each substance in the collector preparation: Group (1): modified wash oil, diesel, modifier = 100:25:25; Group (2): modified wash oil, diesel, modifier = 100:30:20; Group (3): modified wash oil, diesel, modifier = 100:40:10. The test results are:

[0070]

[0071] Example 10:

[0072] Compared with Example 1, the only difference is that the amount of flotation collector used in the flotation process is: Group (I): the modified wash oil-based composite collector described in Example 1, the amount of which is 1200 g / t; Group (II): the modified wash oil-based composite collector described in Example 1, the amount of which is 1700 g / t.

[0073]

[0074] Example 11:

[0075] Compared with Example 1, the only difference is that the amount of flotation frother used in the flotation process is: Group (I): the frother described in Example 1, the amount of which is 800 g / t; Group (II): the frother described in Example 1, the amount of which is 1200 g / t.

[0076]

[0077] Comparative Example 12

[0078] Compared with Example 1, the only difference is the type of collector: Group (I): the collector is a single shale oil; Group (II): the collector is a single kerosene; Group (III): the collector is a single unmodified wash oil; Group (IV): the collector is a single modified wash oil; Group (V): no diesel is added to the collector of Example 1; Group (VI): no modifier is added to the collector of Example 1; other operating methods and conditions are the same as Example 1.

[0079] The test results are:

[0080]

[0081] In summary, the modified wash oil-based composite collector provided by the present invention first uses acid to modify the wash oil by pickling, removing substances in the wash oil that have an adverse effect on flotation and improving its selectivity for coal in coal slime flotation. The acid-modified wash oil is then combined with a non-polar hydrocarbon oil and a modifier and used as a collector for coal slime flotation deashing and upgrading. It was found that these can interact synergistically, further improving the collector's coal collection capacity and selectivity. Experimental results show that compared with conventional collectors, the modified wash oil-based composite collector has lower clean coal ash content, higher yield, and improved coal slime separation efficiency.

[0082] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. Application of a modified wash oil-based composite collector in coal slime flotation, characterized in that: The modified wash oil-based composite collector comprises the following components: modified wash oil, non-polar hydrocarbon oil and a modifier, wherein the modified wash oil is a product obtained by acid-washing and modification of the wash oil; The weight ratio of the modified washing oil: non-polar hydrocarbon oil: modifier is 100:10-50:5-30; The modifier is one or more of ethyl acetate, methyl acetate and methyl formate.

2. The use according to claim 1, characterized in that The wash oil is a distillate at 230-300° C. cut during coal tar distillation.

3. The use according to claim 2, characterized in that The non-polar hydrocarbon oil is one or more of shale oil, diesel and kerosene.

4. The use according to claim 3, characterized in that The acid solution is one or more of sulfuric acid, nitric acid and hydrochloric acid, and the mass concentration of the acid solution is 20%-50%.

5. The use according to claim 4, characterized in that The mass of the acid solution is 5%-15% of the mass of the wash oil.

6. A method for preparing a modified washing oil-based composite collector as claimed in any one of claims 1 to 5, characterized in that: The steps include: 1) Add washing oil to the reaction vessel according to the recipe requirements, increase the temperature, and dropwise add acid solution for reflux reaction to obtain a mixture; 2) The mixture is separated into layers, cooled and allowed to stand, and the upper oily liquid is collected to obtain a modified washing oil; 3) Evenly mix the modified washing oil, non-polar hydrocarbon oil and modifier to obtain a modified washing oil-based composite collector.

7. The preparation method according to claim 6, characterized in that The reflux reaction temperature in step 1) is 60-150° C., and the reflux reaction time is 30-240 min.

Images