COAL BENEFICIATION

EFFECT OF ULTRASONIC TREATMENT IN NORMAL AND REVERSE FLOTATION OF COAL:

EFFECT OF ULTRASONIC TREATMENT IN NORMAL AND REVERSE FLOTATION OF COAL COMPOSED BY- AVISHEK MUKHERJEE. GEOLOGICAL SCIENCES. JADAVPUR UNIVERSITY. GUIDED BY- PRASAD KOPPARTHI. RESEARCH ANDDEVLOPEMENT TATA STEEL, JAMSHEDPUR.

COAL:

COAL Coal is an organoclastic sedimentary rock, composed essentially of lithiified plant debris. Coal is not a mineral, it is a rock. Origin of coal is purely vegetative.

TYPES OF COAL:

TYPES OF COAL COAL Sapropelic coal Humic coal Anthracite Bituminous Lignite (brown coal) Peat Cannel coal Boghead coal Another two types of coal: Paper coal Coloured coal

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Maceral It is mainly coal forming plant materials. It is organic components of coal analogous to the "minerals" of rocks. Macerals are defined according to their grayness in reflected light three types:- vitrinites:- Is one of the primary components of coals and most sedimentary kerogen. Vitrinite macerals when observed under the microscope show a box like, cellular structure, often with oblong voids and cavities which are likely the remains of plant stems. Internites:- Is considered to be the equivalent of charcoal and degraded plant material. Liptinites:- Is considered to be produced from decayed leaf matter, spores, pollen and algal matter. Resins and plant waxes can also be part of Liptinite macerals.

COAL FORMATION:

COAL FORMATION Two theories of Coal formation :- 1. In-situ theory. 2. Drift theory. Stages of coal formation:- 1. Biochemical stage. Plant materials  Peat. 2. Coalification stage. Peat Lignite Bituminous Sub- Bituminous Anthracite  Coal.

COMPONENTS OF COAL:

COMPONENTS OF COAL Both organic and in organic materials are present in the coal. Organic materials:- spores, pollens, tissues and some fibrous parts of plants. In organic materials:- mainly different types of silicate, carbonate and sulfide minerals. Indian coal the most common dominating mineral matter is argillaceous (clay minerals, quartz), carbonate (siderite and calcite), sulfide (mainly iron sulfide).

FROTH FLOTATION:

FROTH FLOTATION Froth flotation is a selective process and can be used to achieve specific separations of hydrophilic and hydrophobic minerals.

TYPES OF FLOTATION:

TYPES OF FLOTATION 1. Normal flotation- The economic minerals are floated with respect to the gangue minerals present. 2. Reverse flotation - In this type of froth flotation process in which mineral matter (gangue) is floated with respect to the economic mineral. Reverse flotation is generally applied when the impurity content of the feed material is high.

REAGENTS OF NORMAL FLOTATION:

REAGENTS OF NORMAL FLOTATION Collector Absorbed on the mineral surfaces and turned the minerals hydrophobic. Example-HSD, DTAB. Frother Frother is the chemical that helps to maintain reasonable stable froth. Example-Nalco.

APPLICATION OF FROTH FLOTATION:

APPLICATION OF FROTH FLOTATION Application of froth flotation is the separation of wanted and unwanted materials. Coal  Normal flotation. Iron ore Reverse flotation.

ULTRASONIC TREATMENT:

ULTRASONIC TREATMENT Ultrasonic sound coverts low energy AC current into high frequency sound waves. when ultrasonic sound passes through a solution then it help to loosen the bonds between coal and mineral particles.

REVERSE FLOTATION:

REVERSE FLOTATION In this type of froth flotation process in which mineral matter (gangue) is floated with respect to the economic mineral. Reverse flotation is generally applied when the impurity content of the feed material is high.

REAGENTS OF REVERSE FLOTATION:

REAGENTS OF REVERSE FLOTATION Depressant- Dextrin. Collector- DTAB(n-Dodecyl Trimethyl ammonium Bromide) Frother- MIBC (Methyl Isobutyl carbinol),Nalco

DESIGN OF EXPERIMENTS:

DESIGN OF EXPERIMENTS Designs of experiments (D.O.E) is a method to identify the important factors in a process, and also identify the possibility of estimating interactions. A CD(Kg/t) B FD(Kg/t) Interaction + - A high, B low. - + A low, B high. - - A and B both low + + A and B both high.

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Level Factor A C.D (Kg/t) Factor B F.D (Kg/t) Low (-) 1 0.1 High (+) 2 0.2 Base 1.5 0.15

EFFECT OF THE FACTORS:

EFFECT OF THE FACTORS Run Factor A C.D (Kg/t) Factor B F.D (Kg/t) Yield at 15% 1 2(+) 0.1(-) 48 2 1(-) 0.1(-) 54 3 2(+) 0.2(+) 55 4 1(-) 0.2(+) 52 Base 1.5(0) 0.15(0) 44

Main Effects:

Main Effects Effect of Collector doses [(48+55) – (54+52)]/4= -0.75 Effect of frother doses [(55+52)-(54+48)]/4= 1.25 Combined effect [(54+55)-(48+52)]/4= 2.25 The combined effect collector & frother showing much effect on flotation than individual dosages of collector & frother

RESULTS AND ANALYSIS (X , W.B) :

RESULTS AND ANALYSIS (X , W.B) Exp.No C.D(Kg/t) F.D(Kg/t) US Treatmet Yield% 12% ash 13% ash, 15% Ash, T1 2 0.2 No - - 48 T14 1min - 35 50 T2 1 0.1 No - 53 T15 1min - 48 54 T3 2 0.1 No - 33 55 T16 1min 10 22 56 T4 1 0.2 No - 40 51 T17 1min 12 18 27.5

RESULTS OF COAL SEAM X:

RESULTS OF COAL SEAM X

NORMAL FLOTATION:

NORMAL FLOTATION EXP. NO. COAL SEAM. C.D (Kg/t) F.D (Kg/t) TYPES OF FLOTATION ULTRASONIC TREATMENT T12 IX 1 0.1 NORMAL FLOTATION NO T13 IX 2 0.2 NORMAL FLOTATION NO.

REVERSE FLOTATION:

REVERSE FLOTATION EXP. NO. COAL SEAM DEXTRN DOSE DTAB DOSE SODIUM SILICATE DOSE TYPES OF FLOTATION ULTRASONIC TREATMENT T36 IX 0.2 0.4 0.0 REVERSE FLOTATION NO T37 IX 0.3 0.5 0.0 REVERSE FLOTATION NO T38 IX 0.4 0.6 0.0 REVERSE FLOTATION NO T39 IX 0.2 0.4 0.1 REVERSE FLOTATION NO

CONCLUSION:

CONCLUSION For X seam, West Bokaro, By treating with ultrasound there is chance to decrease the- ash content. The combined effect (C.D & F.D) is more significant than individual dosages on yield. IX seam, Jamadoba: In normal and reverse flotation Jamadoba IX seam is not responding at lower ash levels. coal & gangue seam has very poor floatable nature.

REFERENCES:

REFERENCES B.A Wills, Mineral processing technology. Tech scan, occurrence of mineral matter in coal, their origin and significance. Alok K. Singh, research and development Tata Steel. Coal petrology, by Stack. Coal geology by Ward. Coal reverse flotation. Part I: Separation of a mixture of sub bituminous coal and gangue minerals Kejian Ding, Janusz S. Laskowski. Minerals Engineering 19 (2006) 72–78.

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