CN115106200A

CN115106200A - Coal dressing compound collecting agent, preparation method thereof and coal slime flotation method

Info

Publication number: CN115106200A
Application number: CN202111240556.4A
Authority: CN
Inventors: 黄根; 徐佳琪; 江鹏; 王若彤
Original assignee: China University of Mining and Technology Beijing CUMTB
Current assignee: China University of Mining and Technology Beijing CUMTB
Priority date: 2021-10-25
Filing date: 2021-10-25
Publication date: 2022-09-27

Abstract

The application provides a coal dressing compound collector, a preparation method thereof and a coal slime flotation method, wherein the coal dressing compound collector comprises the following raw materials in parts by weight: 50-80 parts of vegetable oil, 10-20 parts of alkane acid esters, 5-15 parts of aromatic acid esters and 5-15 parts of long-chain acid. According to the method, the vegetable oil, the alkane acid esters, the aromatic acid esters and the long-chain acid are compounded, so that the obtained compounded collecting agent contains polar groups and nonpolar groups, the polar groups are adsorbed to oxygen-containing sites on coal particles, and the nonpolar groups are adsorbed to hydrophobic sites on the surface of low-order coal, so that the flotation effect of the coal slime is effectively improved; and under the condition of similar ash content, the clean coal yield can be greatly improved, the efficient utilization of the coal slime is facilitated, and the economic benefit is improved.

Description

Coal dressing compound collecting agent, preparation method thereof and coal slime flotation method

Technical Field

The application relates to the technical field of coal dressing, in particular to a coal dressing compound collecting agent, a preparation method thereof and a coal slime flotation method.

Background

With the exploitation of high-quality coal resources and the rapid development of large-scale coal separation machinery, the content of coal slime in raw coal is increased. The flotation plays an important role in the quality improvement of the coal slime. Flotation is widely used in fine coal separation, and froth flotation is an effective method for separating fine particles through medicament and mechanical adjustment according to natural hydrophobicity difference among the particles. The flotation reagents commonly used for flotation include collecting agents, foaming agents and the like.

At present, the collecting agent commonly used for coal dressing is nonpolar hydrocarbon oil, such as kerosene, diesel oil and the like. The nonpolar hydrocarbon oil can be adsorbed on the surface of coal particles as a collector, so that the hydrophobicity is enhanced, and clean coal and gangue are separated. However, the nonpolar hydrocarbon oil such as diesel oil and kerosene has small molecular weight and is easily lost in the pores of coal, so that the dosage of the medicament is large. In the flotation of coal dressing, the dosage of the nonpolar hydrocarbon oil collecting agent is generally 1-4kg/1t coal slime, and the petrochemical products such as diesel oil and kerosene are not renewable. The excessive use amount of the collecting agent in the flotation process can cause the extreme waste of resources, so that the search for the high-efficiency environment-friendly collecting agent is the development trend of improving the flotation effect of the coal slime at present.

Disclosure of Invention

The application aims to provide the composite collecting agent for coal dressing, the preparation method thereof and the coal slime flotation method, wherein the composite collecting agent is environment-friendly, high in safety, low in cost and high in economic benefit, and can be used for remarkably improving the flotation effect of the coal slime and improving the collecting property of clean coal.

In order to realize the purpose, the invention provides the following technical scheme:

a coal dressing compound collector comprises the following raw materials in parts by weight: 50-80 parts of vegetable oil, 10-20 parts of alkane acid esters, 5-15 parts of aromatic acid esters and 5-15 parts of long-chain acid.

In some embodiments, the vegetable oil comprises at least one of rice bran oil, peanut oil, shea butter, and jojoba oil.

In some embodiments, the alkanoic acid esters include at least one of methyl laurate, methyl myristate, and methyl palmitate.

In some embodiments, the aromatic acid esters include at least one of diethyl phthalate, dibutyl phthalate, and dihexyl phthalate.

In some embodiments, the long chain acid comprises at least one of oleic acid and linoleic acid.

The application also provides a preparation method of the coal dressing compound collector, which comprises the following steps: mixing the above materials.

The application also provides a coal slime flotation method, raw materials including coal slime pulp, a coal dressing compound collecting agent and a foaming agent are mixed to form foam, and then the foam is scraped to obtain clean coal;

the coal dressing compound collecting agent is the coal dressing compound collecting agent.

In some embodiments, the process of mixing the raw materials including the coal slurry, the coal preparation compounded collector and the foaming agent comprises:

adding the coal dressing compound collecting agent into the coal slime pulp, and uniformly mixing; then adding foaming agent and mixing uniformly.

In some embodiments, the concentration of the coal slurry is 40 to 100 g/L.

In some embodiments, 1 to 5kg of the compounded collector is used per ton of coal slurry pulp.

In some embodiments, the frother is used at 50-100g per ton of coal slurry.

In some embodiments, the time to scrape bubbles is 3-5 min.

The beneficial effect of this application:

the vegetable oil is used for replacing diesel oil or kerosene, fossil resources can be saved, and the vegetable oil is renewable, environment-friendly, high in safety and low in price, and has good economic benefits and environmental benefits; the vegetable oil, the alkane acid esters, the aromatic acid esters and the long-chain acid are compounded to obtain the compounded collecting agent which contains polar groups and nonpolar groups, the polar groups are adsorbed to oxygen-containing sites on coal particles, and the nonpolar groups are adsorbed to hydrophobic sites on the surface of low-order coal, so that the flotation effect of the coal slime is effectively improved; and under the condition of similar ash content, the clean coal yield can be greatly improved, the efficient utilization of the coal slime is facilitated, and the economic benefit is improved.

Detailed Description

The terms as used herein:

"prepared from … …" is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of … …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of … …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; no other elements are excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when the range "1 ~ 5" is disclosed, the ranges described should be construed to include the ranges "1 ~ 4", "1 ~ 3", "1 ~ 2 and 4 ~ 5", "1 ~ 3 and 5", and the like. When a range of values is described herein, unless otherwise specified, the range is intended to include the endpoints thereof, and all integers and fractions within the range.

In these examples, the parts and percentages are by mass unless otherwise indicated.

"part by mass" means a basic unit of measure indicating a mass ratio of a plurality of components, and 1 part may represent any unit mass, for example, 1g or 2.689 g. If we say that the part by mass of the component A is a part by mass and the part by mass of the component B is B part by mass, the ratio of the part by mass of the component A to the part by mass of the component B is a: b. alternatively, the mass of the A component is aK and the mass of the B component is bK (K is an arbitrary number, and represents a multiple factor). It is not to be misunderstood that the sum of the parts by mass of all the components is not limited to the limit of 100 parts, unlike the parts by mass.

"and/or" is used to indicate that one or both of the illustrated conditions may occur, e.g., a and/or B includes (a and B) and (a or B).

The application provides a compound collecting agent for coal dressing, which comprises the following raw materials in parts by weight: 50-80 parts of vegetable oil, 10-20 parts of alkane acid esters, 5-15 parts of aromatic acid esters and 5-15 parts of long-chain acid.

Optionally, in the raw materials of the coal dressing compound collector, the amount of the vegetable oil may be any one of 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts and 50-80 parts by weight; the amount of the alkane acid ester may be any of 10 parts, 12 parts, 15 parts, 18 parts, 20 parts and 10 to 20 parts; the amount of the aromatic acid esters may be any of 5 parts, 8 parts, 10 parts, 12 parts, 15 parts and 5 to 15 parts; the long-chain acid may be used in an amount of any of 5 parts, 8 parts, 10 parts, 12 parts, 15 parts and 5 to 15 parts.

The vegetable oil is renewable, harmless to the environment and human bodies, safe and environment-friendly, and lower in price compared with diesel oil and kerosene, and contains a large amount of fatty acid and stearic acid, and the carbon chains of the fatty acid and the stearic acid are longer, so that the vegetable oil can provide polar groups and nonpolar groups at the same time; polar groups and nonpolar groups also contained in the alkanoic acid esters and aromatic acid esters; the polar groups can be combined with oxygen-containing functional groups on the surface of the low-rank coal, and the nonpolar groups can be combined with the nonpolar surface of the low-rank coal, so that the floatability of the low-rank coal is improved.

According to the method, the vegetable oil replaces diesel oil or kerosene, and is compounded with alkane acid esters, aromatic acid esters and long-chain acid, so that the lightning and ignition point of the obtained compounded collector are higher than those of the diesel oil and the kerosene, the most important is that the compounded collector contains polar groups and nonpolar groups, the polar groups are adsorbed to oxygen-containing sites on coal particles, and the nonpolar groups are adsorbed to hydrophobic sites on the surface of low-order coal, so that the flotation effect of coal slime is effectively improved; under the condition of similar ash content, the coal dressing compound collecting agent can greatly improve the yield of clean coal, is beneficial to the efficient utilization of coal slime and improves economic benefits.

In some embodiments, the alkanoic acid ester is at least one of methyl laurate, methyl myristate, and methyl palmitate.

In some embodiments, the aromatic acid ester is at least one of diethyl phthalate, dibutyl phthalate, and dihexyl phthalate.

The application also provides a preparation method of the coal dressing compound collector, which comprises the following steps: mixing the raw materials uniformly; preferably, all raw material components are mixed in an ultrasonic dispersion mode to obtain the golden and uniformly dispersed compound collector.

The coal slime pulp is obtained by adding coal slime into a flotation tank, adding water, stirring and wetting, and the stirring time is about 2 min.

In some embodiments, the concentration of solids in the coal slurry is 40 to 100g/L, such as 40g/L, 100g/L, 50g/L, 60g/L, 70g/L, 80g/L, 90g/L, or 100g/L, etc.

In some embodiments, the amount of the compounded collector used per ton of coal slurry pulp is 1kg to 5 kg. Such as 1kg, 2kg, 3kg, 4kg or 5 kg.

In some embodiments, the frother is used in an amount of 50 to 100g, such as 50g, 60g, 70g, 80g, 90g, or 100g, etc., per ton of coal slurry.

In some embodiments, the time to scrape bubbles is 3-5 min.

Embodiments of the present application will be described in detail below with reference to specific examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present application and should not be construed as limiting the scope of the present application. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

50 parts of rice bran oil, 20 parts of methyl laurate, 5 parts of diethyl phthalate and 15 parts of oleic acid are taken and placed in a container, and are uniformly mixed by adopting an ultrasonic dispersion mode to obtain the compound collecting agent.

Example 2

Taking 60 parts of rice bran oil, 12 parts of methyl laurate, 8 parts of diethyl phthalate and 12 parts of oleic acid, placing the materials in a container, and uniformly mixing the materials in an ultrasonic dispersion mode to obtain the compound collecting agent.

Example 3

70 parts of rice bran oil, 15 parts of methyl laurate, 10 parts of diethyl phthalate and 10 parts of oleic acid are taken and placed in a container, and are uniformly mixed by adopting an ultrasonic dispersion mode to obtain the compound collecting agent.

Example 4

Taking 50 parts of rice bran oil, 12 parts of methyl laurate, 12 parts of diethyl phthalate and 8 parts of oleic acid, placing the materials in a container, and uniformly mixing the materials in an ultrasonic dispersion mode to obtain the compound collecting agent.

Example 5

Taking 80 parts of rice bran oil, 10 parts of methyl laurate, 15 parts of diethyl phthalate and 5 parts of oleic acid, placing the materials in a container, and uniformly mixing the materials in an ultrasonic dispersion mode to obtain the compound collecting agent.

Comparative example 1

Comparative example 1 differs from example 1 in that: removing the methyl laurate; otherwise, the same procedure as in example 1 was repeated.

Comparative example 2

Comparative example 2 differs from example 1 in that: removing the diethyl phthalate; the rest was the same as in example 1.

Comparative example 3

Comparative example 3 differs from example 1 in that: removing oleic acid; otherwise, the same procedure as in example 1 was repeated.

Comparative example 4

Comparative example 4 differs from example 1 in that: replacing 50 parts of rice bran oil with 40 parts, and replacing 15 parts of oleic acid with 4 parts; otherwise, the same procedure as in example 1 was repeated.

Comparative example 5

Comparative example 5 differs from example 1 in that: replacing 50 parts of rice bran oil with 90 parts, and replacing 15 parts of oleic acid with 17 parts; the rest was the same as in example 1.

Firstly, taking the compounded collecting agent prepared in the examples 1-5 and the comparative examples 1-5 and diesel oil as collecting agents, respectively carrying out flotation tests on the inner Mongolia long flame coal, wherein the specific flotation method comprises the following steps:

(1) adding the coal slime into a flotation tank, adding water, stirring and wetting for 2min to obtain coal slime pulp with the concentration of 100 g/L.

(2) Adding a collecting agent into the coal slime pulp obtained in the step (1), wherein the amount of the collecting agent used in each ton of coal slime pulp is 4 kg; and then stirring for 1min, adding a foaming agent sec-octanol, wherein the amount of the foaming agent sec-octanol used in each ton of coal slime pulp is 100g, stirring to form stable foam, and scraping for 3min to obtain clean coal.

The results of the flotation tests are shown in table 1 below.

TABLE 1 comparison of the flotation effect of diesel and compounded collectors on long-flame coal

Name of collector	Yield of clean coal/%)	Ash content of clean coal/%)
			Diesel oil	25.79	14.48
Compounded collector of example 1	58.85	14.33
			Example 2 compounded collector	60.61	14.59
Example 3 compounded collector	57.62	14.21
			Compounded collector of example 4	55.23	14.15
Example 5 compounded collector	62.39	14.66
			Compound collector of comparative example 1	51.34	14.89
Compound collector of comparative example 2	53.16	14.66
			Compound collector of comparative example 3	50.44	14.84
Compound collector of comparative example 4	51.15	14.75
			Compound collector of comparative example 5	48.13	14.55

Compared with the compound collector prepared in the comparative example and the compound collector directly using diesel oil as the collector, the compound collector prepared in the embodiment of the application has higher clean coal yield when being applied to the flotation of long-flame coal under the same use amount of the collector.

Secondly, the compound collecting agent prepared in the examples 1 to 5 and the comparative examples 1 to 5 and diesel oil are used as collecting agents, flotation tests are respectively carried out on the coking coal of a certain coal preparation plant in Shanxi, and the specific flotation method is as follows:

(1) adding the coal slime into a flotation tank, adding water, stirring and wetting for 2min to obtain coal slime pulp with the concentration of 80 g/L.

(2) Adding a collecting agent into the coal slime pulp obtained in the step (1), wherein the amount of the collecting agent used in each ton of the coal slime pulp is 1.5 kg; and then stirring for 1min, adding a foaming agent sec-octanol, wherein the amount of the foaming agent sec-octanol used in each ton of coal slime pulp is 80g, stirring to form stable foam, and scraping for 4min to obtain clean coal.

The results of the flotation tests are shown in table 2 below.

TABLE 2 comparison of flotation effect of diesel oil and composite collector on coking coal

Name of collector	Yield of clean coal/%)	Ash content of clean coal/%)
			Diesel oil	76.74	15.59
Compounded collector of example 1	81.04	15.46
			Example 2 compounded collector	82.61	15.63
Example 3 compounded collector	80.49	15.06
			Compounded collector of example 4	80.99	15.39
Compounded collector of example 5	84.62	15.98
			Compound collector of comparative example 1	80.10	15.65
Compound collector of comparative example 2	79.28	15.39
			Compound collector of comparative example 3	78.15	14.54
Compound collector of comparative example 4	77.44	14.66
			Compound collector of comparative example 5	79.15	15.62

As can be seen from table 2 above, the composite collector prepared in the embodiment of the present application, compared with the composite collector prepared in the comparative example and the collector directly using diesel oil, has a higher yield of clean coal when applied to the flotation of coking coal under the same amount of the collector.

Thirdly, taking the compounded collecting agent prepared in the examples 1-5 and the comparative examples 1-5 and diesel oil as collecting agents, respectively carrying out flotation tests on high-ash coal difficult to separate from Tangshan mine, wherein the specific flotation method comprises the following steps:

(1) adding the coal slime into a flotation tank, adding water, stirring and wetting for 2min to obtain coal slime pulp with the concentration of 60 g/L.

(2) Adding a collecting agent into the coal slime pulp obtained in the step (1), wherein the amount of the collecting agent used in each ton of the coal slime pulp is 1 kg; and then stirring for 1min, adding a foaming agent sec-octanol, wherein the amount of the foaming agent sec-octanol used in each ton of coal slime pulp is 60g, stirring to form stable foam, and scraping for 5min to obtain clean coal.

The results of the flotation tests are shown in table 3 below.

TABLE 3 comparison of flotation effect of diesel oil and composite collector on high-ash coal difficult to separate

Name of collector	Yield of clean coal/%)	Ash content of clean coal/%)
			Diesel oil	67.37	14.33
Compounded collector of example 1	74.71	13.61
			Compounded collector of example 2	76.25	14.58
Example 3 compounded collector	73.26	13.55
			Example 4 compounded collector	72.52	13.36
Example 5 compounded collector	78.95	14.95
			Compound collector of comparative example 1	71.15	13.47
Compound collector of comparative example 2	70.43	13.62
			Compound collector of comparative example 3	68.05	13.56
Compound collector of comparative example 4	70.19	13.05
			Compound collector of comparative example 5	69.33	14.62

As can be seen from table 3 above, compared with the compound collector prepared in the comparative example and the collector directly using diesel oil, the compound collector prepared in the embodiment of the present application is applied to the flotation of high-ash coal difficult to separate, and the clean coal yield is higher with the same amount of the collector.

In the embodiment of the application, when the rice bran oil is replaced by the other vegetable oil, the oleic acid is replaced by the linoleic acid, the methyl laurate is replaced by the other alkane acid ester, and the diethyl phthalate is replaced by the other aromatic acid ester, the flotation effect of the prepared composite collector is equivalent to that of the embodiment when the composite collector is applied to the coal slime flotation.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Moreover, those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the application and form different embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is only for enhancement of understanding of the general background of the application and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.

Claims

1. The coal dressing compound collector is characterized by comprising the following raw materials in parts by weight: 50-80 parts of vegetable oil, 10-20 parts of alkane acid esters, 5-15 parts of aromatic acid esters and 5-15 parts of long-chain acid.

2. The coal dressing compounded collector of claim 1, wherein the vegetable oil comprises at least one of rice bran oil, peanut oil, shea butter, and jojoba oil.

3. The coal dressing compounded collector of claim 1, wherein the long-chain acid comprises at least one of oleic acid and linoleic acid.

4. A coal dressing compounded collector according to claim 1, characterized in that the alkane acid esters include at least one of methyl laurate, methyl myristate and methyl palmitate;

preferably, the aromatic acid esters include at least one of diethyl phthalate, dibutyl phthalate, and dihexyl phthalate.

5. A preparation method of a coal dressing compound collector is characterized in that the coal dressing compound collector is the coal dressing compound collector in any one of claims 1 to 4; the preparation method comprises the following steps: mixing the above materials.

6. A coal slime flotation method is characterized in that raw materials including coal slime pulp, a coal dressing compound collecting agent and a foaming agent are mixed to form foam, and then the foam is scraped to obtain clean coal;

the coal dressing compound collector is the coal dressing compound collector in any one of claims 1 to 4.

7. The coal slime flotation method according to claim 6, wherein the step of mixing the raw materials comprising the coal slime pulp, the coal dressing compound collector and the foaming agent comprises the following steps:

8. The coal slurry flotation method according to claim 6, wherein the concentration of the coal slurry is 40-100 g/L.

9. The coal slurry flotation process according to claim 6, wherein 1-5kg of the compounded collector is used per ton of the coal slurry.

10. The coal slurry flotation process as recited in claim 6, wherein 50-100g of the frother is used per ton of the coal slurry;

preferably, the foam scraping time is 3-5 min.