Gravity Separation & Concentration Methods

Gravity Separation & Concentration Methods 2017-04-04T06:57:23+00:00
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Coal Tailing Treatment Method (14 replies and 1 comment)

Bill Rico
2 years ago
Bill Rico 2 years ago

What method would be best to use for the washing of coal tailings having ash of ranges from 45-54um

Dizzy Flores
2 years ago
Dizzy Flores 2 years ago

I have studied one paper regarding MGS for tailing used in turkey, size of coal is less than 0.5mm.

As re-flotation of the tailing is costly and reagents effective so can be go for MGS, for plant purpose?

Carmen Ibanz
2 years ago
Carmen Ibanz 2 years ago

Most certainly you can go for MGS for coal tailings. You will need to deslime beforehand. It is better that a small scale testwork is conducted in batch scale first. In the UK full scale plant trials have been conducted with very satisfactory results. You may contact Salter Cyclones on UK for details.

Bill Rico
2 years ago
Bill Rico 2 years ago

I surely contact them for further details. So that it can be implemented in India with proper economic and technical feasibility. As there is the need to recover clean coal from tailing which is generated from washing of Indian Coal.

Bill Rico
2 years ago

I am amazed that people are giving "sound" advice on this, such as 'certainly you can go for MGS'. All this with no knowledge of your coal tailings. Is the coal liberated from the ash minerals? If not what is the degree of locking and the size range? Have you undertaken heavy liquid analysis to ascertain what is the best that you could achieve?

Bill Rico
2 years ago
Bill Rico 2 years ago

I have performed size analysis of coal and also performed the re-flotation of that coal fraction.


Size Wt. in gm Wt.% Ash%

+0.5mm 58 27.75 46.44

+212 Micron 86 41.15 48.44

+150 Micron 13 6.22 44.80

+44 Micron 26 12.44 37.94

-44 Micron 26 12.44 25.96

Total 209 100 43.56

And in re-flotation it is observed that we can get nearly 25% yield of coal having ash of nearly 25-28%

Ace Levy
2 years ago
Ace Levy 2 years ago

But your original question implies that you would like to treat by gravity concentration. Why not carry out a full heavy liquid analysis on your tailings? This would indicate the best that you could achieve by gravity. If this best performance looks good, then you could proceed from there, maybe spirals, MGS.

Bill Rico
2 years ago
Bill Rico 2 years ago

I will perform full heavy liquid analysis to get the needful data from there and further look for other techniques.

Carl Jenkins
2 years ago
Carl Jenkins 2 years ago

I think the tailing need grinding to 80% minus 44 micron, and flotation,

Bill Rico
2 years ago
Bill Rico 2 years ago

But grinding is costly process and energy expensive process. This will increase the cost of production of the clean coal.

Zander Barcalow
2 years ago
Zander Barcalow 2 years ago

I would consider using multi gravity separator for separation of high value minerals like gold, platinum, tungsten etc. Why don't you try flotation for coal fines? It will be much cheaper.

Marshal Meru
2 years ago
Marshal Meru 2 years ago

You can do a test work and construct a wash ability curve this will help you determine the correct medium you can use for your separation depending on the specification of your final product.

Sugar Watkins
2 years ago
Sugar Watkins 2 years ago

Again with certainty I would suggest usability of MGS. Indian coals have substantial liberation at1mm/0.5mm size, usual size of slimes in India. You may do laboratory test with water only cyclones and observe how much of the coal you can recover from the slimes, particularly if you are working with coking coal. With non-coking coals using normal cyclones will be effective. I am speaking from experience and have supplied water only cyclones and hydrocyclones to coal washeries for this application. The only problem could be wear and you need to use special quality materials of construction. With MGS too his could be a problem along with capacity. Indian coals usually have 15-20% of watery feed as slimes and after desliming this would reduce. 400tph modules are common in India and single MGS having 20tph capacity for coal was available earlier, I do not know now. As suggested you may contact Salter Cyclones who can guide you, if you are interested.

The above was in response to your basic question regarding usability of MGS in coal slimes. However the cheapest option is using water only hydrocyclones and you may easily find the effectiveness in a hydrocyclones test rig using 5 in water only hydrocyclones.

Marshal Dienes
2 years ago
Marshal Dienes 2 years ago

You do sink- float test using zink chlorde liquid of specific gravities 1.3 and 1.4. Do the ash analyses of sink and float fractions, Let us have a look at these results and then think of beneficiation.

Jean Rasczak
2 years ago
Jean Rasczak 2 years ago

Like heavy liquid separation, MGS can certainly be used purely for academic purposes to assess the extent of their effectiveness for up gradation of coal containing 45-54% ash. I do not consider /recommend MGS for commercial enrichment of high ash coal.

Treve Mildren
7 months ago
Treve Mildren 7 months ago

The old Mozley MGS certainly wasn't worth consideration due to its inability to pull sufficient material to concentrate. Development work by Gravity Mining ltd in conjunction with the Camborne School of mines in 2016 has changed all of that. The MGS can now pull considerable concentrates with rather impressive feed rates. I am not sure that it's quite up to the scale that the coal industry would require but its now a serious contender.

The good old MeGaSep days with a photo of myself covered in Coal.

treve's phone oct 2014 022
treve's phone oct 2014 020

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