US1606867A - Drying of finely-divided carbonized fuel - Google Patents

Description

carbonized fuel, whetheruartificially fetentsd Nov.

' nniraeisraras warren snoannnrnen, Enwrir' nnsnn,

Lennon, nnennnn, assrenoas To MINERALS snrunarroni nears oonroaarron, or new roux, n. Y., A oonronarron. 1

AND-,WILIFIAM wanwrcrr srnnmne, on:

pur ne or rrnnnv-nrvrnnn c'hniaomznn F EL.

AMERICAN j NovDrawing. Application filed novemter-ao, 1e22, Serial m5. 02,251, and in Great Britain November a 1921. Rcnewed Apri122, 1926.

This invention consists in improvements in or relating to the drying 'of finely divided or naturally carbo'nized, such as coali In our previous United States Patent Ap: plication Serial-Nor 4%,106 Wehave .de--

scribed various -process of producing ag-' glon'ierate's from impure coal, coal dumps and the like adapted for the making of husuch conditions as to facilitate the separation of water therefrom without the production p of briquettesunder water-expelling pressure. lVe have found that various'agents such ascertain oils, tars andother hydrocarbons or carbonaceous liquids which are incapable of. forming briquettes of the carbbnizedmaterials such as coal under the conditions hereinafter described have the properties. (1) of coating the coal particles, and (2)- of causing the coal particles, when so coated,-'

to flocculate togetlier.-

\Ve have'further found that this flocculat ingefi'ect occurswith very small quantities of thelagents referred to when'the coal particles are agitated with the flocculating agent in sufiicient water to make aflmobile pulp, preferably with aeration. The quan 3 .titiesof the reagents may-be very small,-

stitialspaces a large proportion of water, j but owing to the fact that the surfaces of: the particles have become repellent of the H water, it is possible to remove contained water by filtration or draining, preferablyassisted by pressure, and thus the drying of the particles becomes a simple matter.- The removal of the water associated w th t the coated and fiocculated particles maybe assisted by pressure, but it is to be under'--' stoodthat it is not an objectof the present invention to convert the materials into bri-' quettes, and the coating and flocculating agent does not perform the function binding medium to form briquettes.

of a.

' The present invention offers particular advantages when the'coal particles are subs sequently to be made into coke because the .volatile materials in the flocculating agent are distilled in the coking-o er'at-ion and *rnay thereforebe recovered. re ov'er,"the presence of the flocculating agent assists the coking of special types of coal which would otherwise be unsuitablefor making int-0 coke.

The quantity of the fiocculating agent'employedshould be suflicient to produce the, flocculation at the temperature of-the foilcuit Water. .It maybe reduced by using a heated circuit, but preferably thetreatment is carried out at atmospheric temperature.

From 3- to '5% has been found sufficient when using as agent a-product such as anthracene oil, and'coal-tar, coal-tar oil and other re agents may 'be employed in like proportion. The following examplesillustrate various proceedures in accordance with the invention I Example to pass a screen of 0.4 mm.- aperture. The

ground coal was concentrated by flotation,

using 0.23 kilos." cresol' and 0.06 kilos. kerosene oil per ton of coal." The concentrates removed had a water-solid ratio of 1.3 1.

The. concentrates with their j associated water Wereplaced in a vessel of square lrori-' zontal section and. were I agitatedg by an aim peller rotating with a peripheral velocity ofabout 200 metres per mln'ute. By-pr'oduct coke-oven coal-tar was added during the agitation, the quantity ofltar amounting to 4%, ofthe weight of, thef'dry concentrates. The test was carried out at rootn temperature. The coalbecameintensely fiocculated and.

readily separablefrom the water. Removal of the bulk ofthe water was effected by draining; it could be assisted if desired by subjecting'the fiocculated coal to compression. Under a pressureof 310 kilos persquarecmthe' coal became substantially free from vwater, so-much sothat on drying it I 75 a, Goal froma Durham colliery was ground 5 in a water oven at a temperature of 100 C. for a period of 3 hours, theweight dimin ished by 2.7%,which'indicates the reduction in water content.

, -The coal was 'thus'fe'rmed' into a cake which, however, could 'be easily-crumbled between the fingers. 7 It will be understood that it is not essential to compress the coal into cakes in this way although this may be done both to assistremovalof the water and to facilitate handling of the treated material.

Example 11. 3

Coalfrom Powell Duffryn collieries was ground to pass a screen with'an aperture of 0.4 mm. :The coal was concentrated by floout at room temperature. An intense fiocculation was produced, and when some of the wet. flocculated coal was placed on a screen having 24 apertures per lineal centi-. metre, clear water ran through, and the greater part of the contained waterdrained away.

hen thewet flocculated coal was placed in a mould having slit-s for egress of water and subjected to a pressure of kilos. per square cm., some further water exuded and a cake was formed which contained 12%.

water.

A pressure of 160 kilos. per square cm. produced a cake containing 9% of water. Ineither case the cake'crumbled easily in the fingers.

It is possible to eifect not only the flocculation of the coal particles and the removal of the water therefrom, but also, in the same operation, it is possible toefi'ect the separation of the gangue and other ashf-orming materials from the coal particles. Thus, according to this invention, the

finely divided coal particles, mixed with gangue or other ash-forming materials, are suspended in sufiicient water to make" a mobile pulp. This pulp is then subjected to agitation (preferably with aeration) with a fio'culating agent of the kind hereinbefore described in quantity insufiicient to form an amalgam in which the interstitial spaces.

between the particles would be filled with the agent but sufiicient to coat the coal particles and filocculate them 111 water, the

'netefse'r" gangue particles not being so coated or flocculated, the gangue, with the water, being separated from the coal by draining or iiitration, with or without pressure, but without the productionof briquettes.

. Y Example III. I I lVaste coal or duff from the 1 Powell Duffryn mine in South Wales and contain ing Q3.04% of ash-was made up into a mo .bile pulp with-an'equal weight of water, and

the pulp was agitated with the addition of 4.75%" of by-product coke-oven coal-tar measured on the weight 'of'the crude coal so as to produce flocculation. The Wet flocculated coal was then transferred to a press and subjected to a pressure'of 31 0 kilos, per square cm., thereby extruding the water which carried the great proportion of the .gangue, The resulting cake contained only 13% of ash and 5.56%v of moisture. This test was carried out. at normaL atmospheric temperature.

Again the process of flocculating the coal particles may be carried out in such a way that the coal particles are coated and flocculated and separated in the form of a float supported by bubbles, while the gangue remains in the water. v

Ewampl l V.

The same material as in Example 3, viz, pulverized waste coal or duff fromthe Powell Dufirynmine'in South ales, was. mixed with its own weight of water toform a mobile pulp. 'Therewas added to this pulp the following reagents l.7% by-product coke-oven coal-tar, 0.075% cre'sol, 0.075% parafiin oil (these percentages being measuredon the weight of crude coal).

After agitation and aeration the flocculated coal, separated as a float supported by bubbles and wasremoved and subjected to. a pressure of 310 kilos. per square cm. The resulting cake contained only 5.76% of ash and 3.87% of moisture.

This test was carried out at normal tom perature.

Having thus described certain 'embodiments of our invention, we claim 1. A process -for,.producing carbonized fuel in finely divided form .which consists in agitating a mobile pulp of suitably finely divided carbonized fuel with a suitable flocculating agent having the characteristics of a frothing agent and. a coating oil under such conditions that the fuel is flocculated and coated with a water-repellent coating having so little adhesiv'eness as not to cause the fuel to form into briquettes under waterexpelling pressure, and separating and draining the flocculated fuel.

' 2. A rocess for reducing carbonized fuel in mely divided form which consists in. agitating a mobile pulp of suitablyfinely agent and a c-oating'oi'l under such 'co'nditions that the fuel is fioc'cul'alted and coated with a water-repellentboating having so litt l e adhesiveness as not to cause the 'fuel toform into briquettes under water-enp'elling pressure, and separating and draining thefuel in finely divided form which consists in agitating a mobile pulp of suitably finely divided carbonized fuelwith=a few percent of. a coal tar under. such 'conditionsth'at, the/fuel is flocculated and coated with a" l waterarepellent 'coa'ting'having so littleadculated fuel. I v

. inchr -hesiveness as not tofcause the fuel'tO "form into briquettes under water-expell1ng pressure, and separating and draining the floQ- 4. A process for producing. carbonized fuel in finely divided form whichconsists in agitating acm'obilepulp of suitably finely divided carbonized fuel-with'about three percent of a flocculati-ng agent' 'lin'der such conditions. that the fuel =-is -fiqcculated and coated with a w'atenrepellent coatinghaving so, little adhesiveness as not' to cause the fuel to fornilinto briquettes underwater' expelling pressure; and separating the floc Vculatedfuel and s'ubjecting' it to a water;

expelling pressure. a;

l 5. Ayprocess for, producingcarbomzed fuel in finely divide'd form which consists in agitating a mobile pulpofsuitably finely divided carbonized fuel with a; suitable flocculating agent undersuch conditions that the fuel is (fiocciilated and coated: with a water-repellent coating havingso little .adhesiveness' as not to cause thefuel to form into briquettes under water expelli 11g pres;

sure, and separating the-.fioceulated fuel and drainingit under a pressure-0f the order of magnitude of a :ton per square 'GJA process for producing1 tabs-tied fuel in nely :d-ivided form W ich' consists in agitating'a mobile pulp of suitably finely:- divided carbonized .fuel with a few per cent adhesiveness as; not to cause the fuel to form intobriquettes under water-expelling pressure, and separating the flocculated fuel and draining it under 'a p'ressure of the order of magnitude of a ton per squareinchJ m-fuel infinely divided form relatively free bile from ash, which consists inv agitating a 'mb bonized fuel with a suitable fiocculating of a coal. tar under such conditions ';that the fuel is fiocculated and coatedwith' :a' water-repellent coating. having so little pulp of suitably finely divided carbriquettes under water-expelling pressure; and separating the flocculated fuel and .ness'as not'to cause the fuel'to 'forin into draining it under water-expellingpressure,

w y the fuel is dbtained relatively-dr and relativelyfree f J k 8. .rocessfor producing carbonized fuel in finely divided form relatively free I from ash,v which consists in agitating a mo '3. A ,process for producing ,carbonlzed repellent coating having so little adhesive-f nessfas not; to cause the fuel to form into. briquettes under water-expelling pressure, andsepa-rating the flocculated fuel and draining it 'under water exp'ell'ing pressure, whereby the fuel is obtained relatively-dry and relatively free 'fromash, 3

under such conditions t hat' the'fuel flocculated and coated with a water-repellent coating 'having so little adhesivenesslas not.

to cause 'the fuel to form into briquettes ,unden water e rpellingl pressure, andJseparating the flocculated fuel and drainingit .under water -expelling pressure, whereby.

-tively free fiomash. c

-10. A process for producingbarbo'nized fuel in fi nely' divided form rlativelyfree the fuel is obtained relativelydry and relay 9. A process for producing" carbonizedh from ash which consists-in subjectingrsui'tablyfinely divided impure carbonized fuel r to; froth:flotationconcentration with a frothing: agent to produce a concentrate relatively free from ash, agitating a Inobile pulp of the concentrate with a few per cent of a'suitableflocculating agent under such conditions that the carbonized 'fuel'is"floc culated and coated with a water-repellent coating having 501 little adhesivene'ss as -not to: cause the fuel to form into briquettes .arating and draining thefiOccuIatedfdeL.

from ash which consists subjecting suit- '1l.4 A process for producing carbonized fuel in finely divided form relatively free under water ezipelling pressure and sepably finely divided impure carbonized fuel to -froth-flotation concentration with a frothing agent including a soluble element to produce a concentrate, agitating aa inc-'- bile pulp of the concentrate-with a. suitable -7. A process for producing carbonized flocculating agent. under such "conditions that thecarbonized fuel is flocculated and and draining the flo'cculatecl fuel.

12; A process for producing carbonized water-expelling pressure, and separating}- Ill) with a waterrepellent coating having solit-tle adhesiveness as not to cause the fuel to form into briquettes under water-expeh' ling pressure, and separating and draining the fioccnlated fuel.

13. A; process for producing carbonized fuel in finely divided form relatively free from ash which consists in subjecting suit-- ably finely divided impure carbonized fuel to froth-flotation concentration with a frothing agent containing a few per cent of a coal tar and an oily substance under such conditions that the carbonized fuel is flocculated and coated with a waterrepellent coating having so little adhesiveness as notto cause the fuel to form into briquettes under water-expelling pressure, and separatingand draining the fiocculated fuel.

14. A process for. producingcarbonized fuel in finely divided form relatively free from ash which consists in subjecting snitably finely divided impure carbonized fuel to froth-flotation concentration with a frothing agent under such conditions that the carbonized fuel is flocculated and'coated with .a water-repellent coating having so little conditions that the carbonized fuel is flocculated and coated with a water-repellent coating having so little adhesiveness as not to cause the fuel to form into briquettes under water-expelling pressure, and separating the fiocculated fuel and draining it under Water 'to froth-flotation concentration with a few per cent of a coal tar under such conditions 'that the carbonized fuel is .flocculated and coated with a water-repellent coating hav.--

ing-so little adhesiveness as not to cause the fuel to form. into briquettes under water-expelling pressure, and separating the flocculated fuel and draining it'under water-expelling pressure. v 17. A process for producing carbonized fuel in finely divided form relatively free fuel in finely divided form relatively free from ash which consists in'subjecting suitably finely divided impure carbonized fuel to froth-flotation concentration with a frothing agent containing a few per cent of a coal tar product under such conditions that the carbonized fuel is flocculated and coated with a water-repellent coating havingso little 'adhesiveness as not to cause the fuel toform into briquettes under watere'xpelling pressure, and separating the flocculatcd fuel and draining it under a pressure of the order of magnitude of a ton per square inch.

In testimony whereof we have signed our names to this specification.

\VALTER BROADBRIDGE.

EDWIN EDSER.

WILLIAM WARWICK STEN NIN G. I