TECHNICAL FIELD

The present disclosure relates to the field of metallurgy. The present disclosure particularly relates to a composition comprising hydrocarbon oil, solvent and non-ionic surfactant. The composition is a single flotation reagent which acts as both collector and frother for effective flotation of coal fines. The disclosure further relates to beneficiation process to obtain beneficiated coal fines employing said composition.

BACKGROUND OF THE DISCLOSURE
Froth flotation is a process of separating valuable minerals from gangue particles by utilizing the difference in their physico-chemical surface properties. In case of coal, flotation is the most widely used method of beneficiation used for the finer fraction (generally- 0.5 mm), especially for metallurgical coal which can cover the cost of beneficiation. Coal flotation makes use of natural hydrophobicity of the carbonaceous matter in coal. Air bubbles are introduced in the coal-water suspension where they get attached to the hydrophobic particles and carry them to the froth phase. The mineral matter in raw coal is comprised of hydrophilic mineral like clays (such as kaolinite and montmorillonite), quartz, and carbonate minerals such as calcite and dolomite, gypsum and pyrite. These hydrophilic particles stay wetted in the suspension and are removed later. Several parameters affect the coal floatation process which include feed material, chemicals, operational and equipment parameters. The chemical parameters are the type of reagents and their dosage. The reagents used for coal flotation are classified as collectors and frothers. The collectors used for coal flotation are mostly organic compounds with basic purpose to selectively form a hydrophobic layer on the coal surface in the flotation pulp and thus provide conditions for attachment of the hydrophobic particles to air bubbles and recovery of such particles in the froth product. Theoretically a high rank bituminous coal should require very less amount of collector for flotation owing to its natural hydrophobic nature. However, for low-rank coals or weathered coals containing greater amounts of oxygen, large collector dosages are required to obtain even moderate recovery of coal.

Hydrocarbons like kerosene, diesel oil and fuel oil are the most widely and commonly used collectors for coal flotation. But they are not very much suitable for low rank/high ash coals or oxidized coals because of their surface roughness and hydrophilic sites. Also, as the number of carbon atoms increases, their viscosity increases drastically which creates handling and feeding issues in the plant. Finally, mentioned oils are distillates of crude petroleum oil, they are very costly with limited resources. Because of their limited reserves they are preferred to be used as source of energy rather than as a reagent in coal beneficiation.

Frothers are heteropolar surface-active compounds, capable of adsorbing in the water-air interface. The frother molecules are arranged at the air-water interface and creates conditions for froth formation. The frother concentrates at the interface of water and air bubbles, forming an envelope around the bubbles, which prevents them from colliding or touching. Common examples of frothers used for coal flotation are pine oil, cresylic acid, methylisobutylcarbinol (MIBC), hexanol, octanol and 2-ethyl hexanol which have been used industrially for decades. But again, these frothers are not much effective for low rank coals as they are not selective in nature and entrain lot of fine ash particles into the froth phase which increase the overall product ash.

The existing collectors and frothers (mentioned above) are considered useful only in flotation of high or medium rank coals which have high ash content and more hydrophilic sites on their surface. However, the said collectors and frothers are not useful in flotation of low/lower rank coals, such as sub-bituminous coals. Further, the existing collectors and frothers have their limitation, such as lower performance, higher consumption, lower availability and handling issues. Thus, there is a need for better/improved reagents which are suitable for all kinds of coals unlike the existing collectors and frothers and overcome the mentioned limitations.

STATEMENT OF THE DISCLOSURE
Accordingly, the present disclosure provides for efficient and environmentally friendly composition comprising hydrocarbon oil, solvent and non-ionic surfactant which acts as both collector and frother, i.e., single reagent for effective flotation of coal fines.

The present disclosure further describes a process for preparing the composition, comprising- mixing the hydrocarbon oil and the solvent, followed by adding the non-ionic surfactant and continuing mixing to obtain the composition.

The present disclosure further describes a beneficiation process for coal fines comprising- mixing the composition described above and slurry comprising coal fines and solvent to obtain a mixture; supplying air to the mixture to create froth, followed by separating the froth from the mixture; and filtering the froth, followed by drying filtrate to obtain beneficiated coal fines.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURE
In order that the present disclosure may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figure. The figure together with detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, where:

FIGURE 1 shows the picture of mechanical flotation cell used in the present invention for beneficiation of coal fines.

DETAILED DESCRIPTION OF THE DISCLOSURE
Definitions:
Unless otherwise defined, all terms used in the disclosure, including technical and scientific terms, have meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included for better understanding of the present disclosure.

As used herein, the singular forms ‘a’, ‘an’ and ‘the’ include both singular and plural referents unless the context clearly dictates otherwise.

The term ‘comprising’, ‘comprises’ or ‘comprised of’ as used herein are synonymous with ‘including’, ‘includes’, ‘containing’ or ‘contains’ and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps.

The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.

The term ‘about’ as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of ±10% or less, preferably ±5% or less, more preferably ±1% or less and still more preferably ±0.1% or less of and from the specified value, insofar such variations are appropriate to perform the present disclosure.

The present disclosure relates to a composition comprising hydrocarbon oil, solvent and non-ionic surfactant.

In some embodiments of the present disclosure, the composition is a single flotation reagent which acts as both collector and frother.

In some embodiments of the present disclosure, the composition is suitable and effective in flotation of all kinds of coals

In some embodiments of the present disclosure, the hydrocarbon oil has carbon chain length ranging from about 9 to 12 carbon atoms.

In some embodiments of the present disclosure, the hydrocarbon oil has carbon chain length of about 9 carbon atoms, about 10 carbon atoms, about 11 carbon atoms or about 12 carbon atoms.

In some embodiments of the present disclosure, the hydrocarbon oil includes but is not limited to dodecane.

In some embodiments of the present disclosure, the hydrocarbon oil is in an amount ranging from about 300 g/t to 500 g/t.

In some embodiments of the present disclosure, hydrocarbon oil is present in an amount of about 300 g/t, about 320 g/t, about 340 g/t, about 360 g/t, about 380 g/t, about 400 g/t, about 420 g/t, about 440 g/t, about 460 g/t, about 480 g/t or about 500 g/t.

In some embodiments of the present disclosure, the non-ionic surfactant is selected from a group comprising Polyethylene glycol tert-octyl phenyl ether, 4-Nonylphenyl-polyethylene glycol and a combination thereof.

In some embodiments of the present disclosure, the non-ionic surfactant is in an amount ranging from about 40 g/t to 60 g/t.

In some embodiments of the present disclosure, the non-ionic surfactant is in an amount of about 40 g/t, about 42 g/t, about 44 g/t, about 46 g/t, about 48 g/t, about 50 g/t, about 52 g/t, about 54 g/t, about 56 g/t, about 58 g/t or about 60 g/t.

In some embodiments of the present disclosure, the Polyethylene glycol tert-octyl phenyl ether is in an amount ranging from about 40 g/t to 60 g/t.
In some embodiments of the present disclosure, the Polyethylene glycol tert-octyl phenyl ether is in an amount of about 40 g/t, about 42 g/t, about 44 g/t, about 46 g/t, about 48 g/t, about 50 g/t, about 52 g/t, about 54 g/t, about 56 g/t, about 58 g/t or about 60 g/t.

In some embodiments of the present disclosure, the 4-Nonylphenyl-polyethylene glycol is in an amount ranging from about 40 g/t to 60 g/t.

In some embodiments of the present disclosure, the 4-Nonylphenyl-polyethylene glycol is in an amount of about 40 g/t, about 42 g/t, about 44 g/t, about 46 g/t, about 48 g/t, about 50 g/t, about 52 g/t, about 54 g/t, about 56 g/t, about 58 g/t or about 60 g/t.

In some embodiments of the present disclosure, the solvent includes but it is not limited to water.

In some embodiments of the present disclosure, the solvent is in an amount ranging from about 1.5 kg/t to 3 kg/t.

In some embodiments of the present disclosure, the solvent is in an amount of about 1.5 kg/t, about 1.6 kg/t, about 1.7 kg/t, about 1.8 kg/t, about 1.9 kg/t, about 2.0 kg/t, about 2.1 kg/t, about 2.2 kg/t, about 2.3 kg/t, about 2.4 kg/t, about 2.5 kg/t, about 2.6 kg/t, about 2.7 kg/t, about 2.8 kg/t, about 2.9 kg/t or about 3.0 kg/t.

In some embodiments of the present disclosure, the solvent in the composition is about 20% of the total solvent used during flotation.

In some embodiments of the present disclosure, the composition comprises dodecane, water, Polyethylene glycol tert-octyl phenyl ether and 4-Nonylphenyl-polyethylene glycol.

In some embodiments of the present disclosure, the hydrocarbon oil in the composition having carbon chain length ranging from about 9 to 12 carbon atoms penetrate pore structure of coal effectively and assist in promoting the attachment of air bubbles onto the coal surface. If the carbon chain length in the hydrocarbon oil is more than 12, viscosity effects are observed, and the performance of the composition deteriorates. Thus, the hydrocarbon oil with carbon chain lengths ranging from 9 to 12 is effective in mediating advantageous result in terms of effective flotation of coal fines.
In some embodiments of the present disclosure, the dodecane employed in the composition has carbon chain length of about 12 carbon atoms. Thus, the dodecane is effective in penetrating pore structure of coal and assists in promoting the attachment of air bubbles onto the coal surface for effective flotation.

In some embodiments of the present disclosure, the non-ionic surfactant including but not limited to Polyethylene glycol tert-octyl phenyl ether and 4-Nonylphenyl-polyethylene glycol comprises hydrophilic head group and a hydrophobic tail and carries no charge and are non-toxic. During flotation, said non-ionic surfactant adsorb at the collector-water interface and reduce the surface energy required by the collector to spread on coal surface. As a result, said non-ionic surfactant help in spreading the hydrocarbon oil from the composition over the coal surface by formation of very fine droplets which in turn help in fast and increased attachment of coal to the hydrocarbon oil. Further, the hydrophilic head group of the non-ionic surfactant get attached to the polar sites (such as -OH, -COOH and -CO) present on the surface of the coals with the hydrophobic part oriented outwards, which converts hydrophilic sites on coal surface into hydrophobic thereby promoting their attachment to air bubbles and recovery of the coal fines into the froth phase.

The present disclosure further relates to process of preparing the composition described above.

In some embodiments of the present disclosure, the process of preparing the composition comprises mixing the hydrocarbon oil, the solvent, followed by adding the non-ionic surfactant and continuing mixing to obtain the composition.

In some embodiments of the present disclosure, the process of preparing the composition comprises mixing the hydrocarbon oil including but not limited to dodecane and the water, followed by adding Polyethylene glycol tert-octyl phenyl ether and 4-Nonylphenyl-polyethylene glycol, respectively and continuing mixing until stable composition is formed.

In some embodiments of the present disclosure, the process of preparing the composition comprises mixing about 300 g/t 500 gt of the hydrocarbon oil and about 1.5 kg/t to 4 kg/t of water, followed by adding about 40 g/t to 60 g/t of Polyethylene glycol tert-octyl phenyl ether and about 40 g/t to 60 g/t of 4-Nonylphenyl-polyethylene glycol and continuing mixing until stable composition is formed.

In some embodiments of the present disclosure, amount of solvent including but not limited to water is about 20% of the total solvent used during flotation.

The present disclosure further relates to beneficiation process for coal fines.

In some embodiments of the present disclosure, the beneficiation process for coal fines comprises:
- mixing the composition described above, and slurry comprising the coal fines and solvent to obtain a mixture; and
- supplying air to the mixture to create froth, followed by separating the froth from the mixture; and
- filtering the froth, followed by drying filtrate to obtain beneficiated coal fines.

In some embodiments of the present disclosure, the slurry is prepared by mixing coal fines and solvent at a speed ranging from about 500 rpm to 1000 rpm for a duration ranging from about 5 minutes to 10 minutes.

In some embodiments of the present disclosure, the slurry is prepared by mixing coal fines and solvent at a speed of about 500 rpm, about 550 rpm, about 600 rpm, about 650 rpm, about 700 rpm, about 750 rpm, about 800 rpm, about 850 rpm, about 900 rpm, about 950 rpm or about 1000 rpm for a duration of about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes or about 10 minutes.

In some embodiments of the present disclosure, the solvent includes but is not limited to water.

In some embodiments of the present disclosure, the coal fines have particle size ranging from about less than or equal to 0.5 mm.

In some embodiments of the present disclosure, the coal fines have particle size of about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm or about 0.5 mm.

In some embodiments of the present disclosure, the slurry has pulp density ranging from about 10 % to 12 % solids by weight.

In some embodiments of the present disclosure, the slurry has pulp density of about 10 % solids by weight, about 11 % solids by weight or about 12 % solids by weight.

In some embodiments of the present disclosure, mixing of the composition and the slurry is carried out at a speed ranging from about 500 rpm to 1000 rpm for a duration ranging from about 5 minutes to 10 minutes.

In some embodiments of the present disclosure, mixing of the composition and the slurry is carried out at a speed of about 500 rpm, about 550 rpm, about 600 rpm, about 650 rpm, about 700 rpm, about 750 rpm, about 800 rpm, about 850 rpm, about 900 rpm, about 950 rpm or about 1000 rpm for a duration of about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes or about 10 minutes.

In some embodiments of the present disclosure, the air is supplied at a rate ranging from about 3 lpm to 6 lpm.

In some embodiments of the present disclosure, the air is supplied at a rate of about 3 lpm, about 3.5 lpm, about 4 lpm, about 4.5 lpm or about 5 lpm, about 5.5 lpm or about 6 lpm.

In some embodiments of the present disclosure, the drying is carried out at a temperature ranging from about 90 ºC to 110 ºC for a duration ranging from about 20 minutes to 60 minutes.

In some embodiments of the present disclosure, the drying is carried out at a temperature of about 90 ºC, about 92 ºC, about 94 ºC, about 96 ºC, about 98 ºC, about 100 ºC, about 102 ºC, about 104 ºC, about 106 ºC, about 108 ºC or about 110 ºC for a duration ranging from about 20 minutes, about 22 minutes, about 24 minutes, about 26 minutes, about 28 minutes, about 30 minutes, about 32 minutes, about 34 minutes, about 36 minutes, about 38 minutes, about 40 minutes, about 42 minutes, about 43 minutes, about 44 minutes, about 46 minutes, about 48 minutes, about 50 minutes, about 52 minutes, about 54 minutes, about 56 minutes, about 58 minutes or about 60 minutes.

In some embodiments of the present disclosure, the composition in an amount ranging from about 1.5 kg/t to 4.5 kg/t is mixed with the slurry.

In some embodiments of the present disclosure, the composition in an amount of about 1.5 kg/t, about 2.0 kg/t, about 2.5 kg/t, about 3.0 kg/t, about 3.5 kg/t, about 4.0 kg/t or about 4.5 kg/t is mixed with the slurry.

In some embodiments of the present disclosure, the beneficiated coal fines has ash content ranging from about 12% to 15%.

In some embodiments of the present disclosure, the beneficiated coal fines has ash content of about 12%, about 13%, about 14% or about 15%.

In some embodiments of the present disclosure, the yield of the beneficiated coal fines is ranging from about 40% to 50%.

In some embodiments of the present disclosure, the yield of the beneficiated coal fines is about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49% or about 50%.

In some embodiments of the present disclosure, ash content in tailings (waste steam) is ranging from about 39% to 55%.

In some embodiments of the present disclosure, ash content in tailings (waste stream) is about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54% or about 55%.

In some embodiments of the present disclosure, the composition in an amount ranging from about 1.5 kg/t to 4.5 kg/t is added to the slurry comprising coal fines and water inside a flotation cell followed by vigorous mixing and then air at a rate ranging from about 3 lpm to 6 lpm is flown through the slurry to form air bubbles and carry the low ash coal particles to the froth phase where it is collected in a separate tray. The froth obtained is filtered and dried at a temperature ranging from about 90 ºC to 110 ºC for a duration ranging from about 20 minutes to 60 minutes and weighed to calculate the yield after which ash analysis of the froth is carried out to determine its ash content to obtain beneficiated coal fines. The remaining slurry in the flotation cell is transferred to another tray and subjected to filtration and drying, followed by measuring weight of the filtrate to determine yield of the tailings and ash content.

In some embodiments of the present disclosure, the coal fines taken to mix with the solvent depends on the pulp density of the slurry to be prepared. Upon combining the coal fines and solvent, sufficient mixing of the coal fines and the solvent is carried out by rotating the agitator at a speed greater than 1000 rpm to obtain slurry. To the slurry, the prepared composition is added, and uniform mixing is carried out, followed by supplying air at a rate of more than 4 lpm which results in the formation of air bubbles to obtain a stable froth. The low ash coal particles because of their hydrophobic nature get attached to the air bubbles and come to the froth phase where they are recovered in a tray using scraper. The froth is collected after which the air flow is cut off and mixing is stopped. The obtained froth is filtered and dried to obtain the beneficiated coal fines.

In some embodiments of the present disclosure, the parameters that are varied during beneficiation of coal fines are amounts of hydrocarbon oil and non-ionic surfactants.

In some embodiments of the present application, in the composition, the hydrocarbon oil acts as a collector making the coal particles more hydrophobic while the non-ionic surfactants get attached with hydrophilic sites present on the coal surface of coal with their hydrophobic part oriented outwards. This mechanism converts such hydrophilic sites into hydrophobic ones, thereby promoting their attachment to air bubbles, thus provides high yield of beneficiated coal fines.

In some embodiments of the present disclosure, the parameters that are consistent during the beneficiation of coal fines are the above described pulp density, the mixing speed, the air flow rate, mixing time and collection time.

In some embodiments of the present disclosure, the collection time is ranging from about 2.5 minutes to 3 minutes.

In some embodiments of the present disclosure, the collection time is about 2.5 minutes, about 2.6 minutes, about 2.7 minutes, about 2.8 minutes, about 2.9 minutes or about 3 minutes.

The advantages of the composition described above are:
- The composition acts as both a collector and frother, thus providing improved yield of beneficiated coal fines at an acceptable ash value (15% or below).
- The composition is a single reagent for flotation of coal fines. Thus, bringing down the cost of flotation and handling issue associated with addition of multiple reagents (subsequent addition) during flotation in flotation circuit.
- The composition leads to higher yield of beneficiated coal from high ash coal.

It is to be understood that the foregoing descriptive matter is illustrative of the disclosure and not a limitation. While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the embodiments without departing from the principles of the disclosure. Those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein. Similarly, additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in art based upon description provided herein.

Descriptions of well-known/conventional methods/steps and techniques are omitted so as to not unnecessarily obscure the embodiments herein. Further, the disclosure herein provides for examples illustrating the above-described embodiments, and in order to illustrate the embodiments of the present disclosure, certain aspects have been employed. The examples used herein for such illustration are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, following examples should not be construed as limiting the scope of the embodiments herein.

EXAMPLES

Example 1: Beneficiation of coal Fines
The slurry of coal-A was prepared by mixing coal-A and water to obtain pulp density ranging from about 10% to 12% by weight.

Table 1 describes the constituents of Coal-A
Parameters (%) Coal A
Ash 34.72
Volatile Matter 21.11
Moisture 1.89
Fixed carbon 43.08
Total 100
Table 1:
The composition was added to the slurry of coal-A inside a flotation cell followed by vigorous mixing and then air was flown at a rate of about 3 lpm to 6 lpm into the slurry to form air bubbles and carry the low ash coal particles to the froth phase where it was collected in separate tray. The froth obtained was filtered and dried at a temperature of about 90 °C to 110 °C for a duration of about 20 to 30 minutes and weighed to calculate the yield after which ash analysis of froth was carried out to determine its ash content. The remaining slurry in the flotation cell was also transferred to another tray and subjected to filtration and drying and weight of the dried material was measured to get the yield of the tailings and ash analysis was carried out.
Table 2 illustrates the results of the flotation/beneficiation of Coal-A with the composition of the present disclosure.

Composition of the present disclosure Coal-A feed ash% Beneficiation/Flotation result
Product ash% Yield % Tailing ash %
Hydrocarbon
oil
(gpt) Polyethylene glycol tert-octyl phenyl ether (gpt) 4-Nonylphenyl-polyethylene glycol (gpt)
300 50 50 34.72 14.23 40.38 49.44
60 34.72 14.55 41.44 49.35
60 50 34.72 14.84 41.73 49.69
60 34.72 14.78 42.09 50.32
400 50 50 34.72 14.53 42.63 51.05
60 34.72 14.34 42.88 51.62
60 50 34.72 14.86 43.15 51.48
60 34.72 14.52 43.26 52.05
500 50 50 34.72 14.83 43.37 53.09
60 34.72 14.79 43.82 53.17
60 50 34.72 14.92 44.61 54.78
60 34.72 14.95 44.09 53.91
Table 2:

Table 3 illustrates the results of the flotation/beneficiation of Coal-A using the commercially available collector and frother.
Commercial Collector- Nalco (gtp)
Commercial Frother- Nalco (gpt)
Beneficiation/Flotation result
Product ash% Yield % Tailing ash %
300 100 15.31 39.23 48.67
300 110 15.22 38.92 48.51
300 110 15.22 38.92 48.51
300 120 15.64 41.97 48.92
400 100 15.67 40.89 48.47
400 110 16.03 41.89 49.64
400 110 16.03 41.89 49.64
400 120 16.72 41.85 51.55
500 100 16.48 40.82 50.68
500 110 16.45 41.06 50.72
500 110 16.45 41.06 50.72
500 120 17.02 42.73 51.44
Table 3:
The data in Tables 2 and 3 demonstrate that the composition of the present disclosure provides for better results when compared to available commercial collector and frother. There is an increase in yield by about 1 % to 2% by using the composition when compared to commercial collector and frother. By using the composition, the product ash content is also maintained at a lower value (at least 1% less) when compared to commercial collector and frother.
The yield using the composition of the present disclosure is more than 2% and the ash reduction of the product is about 1%. Moreover, by using the composition of the present disclosure, the yield does not drop below the critical mark of 40% and product ash content is not more than 15%, considering the high ash content in the feed.

Example 2: Beneficiation of coal Fines
The slurry of coal-B was prepared by mixing coal-B and water to obtain pulp density ranging from about 10% to 12% by weight.
Table 4 describes the constituents of Coal-B
Parameters (%) Coal B
Ash 25.47
Volatile Matter 23.74
Moisture 1.77
Fixed carbon 48.92
Total 100
Table 4:
The composition was added to the slurry of coal-B inside a flotation cell followed by vigorous mixing and then air was flown at a rate of about 3 lpm to 6 lpm into the slurry to form air bubbles and carry the low ash coal particles to the froth phase where it was collected in separate tray. The froth obtained was filtered and dried at a temperature of about 90 °C to 110 °C for a duration of about 20 to 30 minutes and weighed to calculate the yield after which ash analysis of froth was carried out to determine its ash content. The remaining slurry in the flotation cell was also transferred to another tray and subjected to filtration and drying and weight of the dried material was measured to get the yield of the tailings and ash analysis was carried out.
Table 5 illustrates the results of the flotation/beneficiation of Coal-B with the composition of the present disclosure.
Composition of the present disclosure Coal-B Feed ash% Beneficiation/Flotation result
Hydrocarbon
oil
(gpt) Polyethylene glycol tert-octyl phenyl ether (gpt) 4-Nonylphenyl-polyethylene glycol (gpt)
Product ash% Yield % Tailing ash %
300 50 50 25.47 12.65 48.55 39.89
60 25.47 12.74 48.80 39.76
60 50 25.47 13.08 48.28 40.02
60 25.47 12.72 48.53 40.23
400 50 50 25.47 13.02 48.69 40.51
60 25.47 13.21 49.92 40.56
60 50 25.47 13.48 50.04 40.81
60 25.47 13.37 50.31 40.78
500 50 50 25.47 13.28 49.97 39.84
60 25.47 13.61 50.63 39.62
60 50 25.47 13.66 50.37 40.85
60 25.47 13.45 50.29 40.59
Table 5:

Table 6 illustrates the results of the flotation/beneficiation of Coal-B using the commercially available collector and frother.
Commercial Collector- Nalco (gpt)
Commercial Frother- (gpt)
Beneficiation/Flotation result
Product ash% Yield % Tailing ash %
300 100 13.36 45.62 37.62
300 110 13.51 45.66 37.53
300 110 13.51 45.66 37.53
300 120 13.14 45.04 38.06
400 100 13.64 45.73 36.44
400 110 13.73 45.92 37.61
400 110 13.73 45.92 37.61
400 120 14.48 45.87 36.82
500 110 14.39 46.02 36.85
500 110 14.26 46.11 37.93
500 110 14.26 46.11 37.93
500 120 14.74 46.21 37.75
Table 6:

The data in Tables 5 and 6 demonstrate that the composition of the present disclosure provides for better results when compared to available commercial collector and frother. The composition leads to yield above 48% whereas the product ash content is on lower side, i.e., below 14%. However, the commercial collector and forther provide yield which less than 47%. The yield gain observed by using the composition of the present disclosure is more than 3% and the ash reduction of the product is about 1%.

WE CLAIM:

1. A composition comprising a hydrocarbon oil, solvent and non-ionic surfactant.
2. The composition as claimed in claim 1, wherein the non-ionic surfactant is selected from a group comprising Polyethylene glycol tert-octyl phenyl ether, 4-Nonylphenyl-polyethylene glycol and a combination thereof.
3. The composition as claimed in claim 1, wherein the solvent is water.
4. The composition as claimed in claim 1, wherein the hydrocarbon oil is dodecane.
5. The composition as claimed in claim 1, wherein the hydrocarbon oil is in an amount ranging from about 300 g/t to 500 g/t.
6. The composition as claimed in claim 1, wherein the non-ionic surfactant is present in an amount ranging from about 40 g/t to 60 g/t.
7. The composition as claimed in claim 1, wherein the solvent is present in an amount ranging from about 1.5 kg/t to 3 kg/t.
8. The composition as claimed in claim 1, wherein the composition comprises dodecane, solvent, Polyethylene glycol tert-octyl phenyl ether and 4-Nonylphenyl-polyethylene glycol.
9. The composition as claimed in claim 8, wherein the Polyethylene glycol tert-octyl phenyl ether is present in an amount ranging from about 40 g/t to 60 g/t; and wherein the 4-Nonylphenyl-polyethylene glycol is present in an amount ranging from about 40 g/t to 60 g/t.
10. A process for preparing the composition as claimed in claim 1, said process comprises mixing the hydrocarbon oil and the solvent, followed by adding the non-ionic surfactant and continuing mixing to obtain the composition.
11. A beneficiation process for coal fines, said process comprises:
- mixing the composition as claimed in claim 1, and slurry comprising the coal fines and solvent to obtain a mixture;
- supplying air to the mixture to create froth, followed by separating the froth from the mixture; and
- filtering the froth, followed by drying filtrate to obtain beneficiated coal fines.
12. The process as claimed in claim 11, wherein the slurry is prepared by mixing coal fines and solvent at a speed ranging from about 500 rpm to 1000 rpm, for a duration ranging from about 5 minutes to 10 minutes; and wherein the solvent is water.
13. The process as claimed in claim 12, wherein particle size of the coal fines is ranging from about less than or equal to 0.5 mm.
14. The process as claimed in claim 11, wherein pulp density of the slurry is ranging from about 10 % to 12 % solids by weight.
15. The process as claimed in claim 11, wherein the mixing is carried out at a speed ranging from about 500 rpm to 1000 rpm for a duration ranging from about 5 minutes to 10 minutes.
16. The process as claimed in claim 11, wherein the air is added at a rate ranging from about 2 lpm to 4 lpm.
17. The process as claimed in claim 11, wherein the drying is carried out at a temperature ranging from about 90 °C to 110 °C, for a duration ranging from about 20 minutes to 60 minutes.
18. The process as claimed in claim 11, wherein the composition is in an amount ranging from about 1.5 kg/t to 4.5 kg/t.
19. The process as claimed in claim 11, wherein the beneficiated coal fines has ash content ranging from about 12% to 15%.
20. The process as claimed in claim 11, wherein the yield of the beneficiated coal fines is ranging from about 40% to 50%.
21. The process as claimed in claim 11, wherein ash content in tailings (waste stream) is ranging from about 39% to 55%.