BACKGROUND TO THE INVENTION There are large quantities of discard quality or duff coal fines which are available but generally not commercially usable in that form. For the coal to be useful as a source of domestic heating it needs to be agglomerated into briquettes or similarly sized products. This need to be achieved in a manner which will enable the agglomerated product to withstand normal handling to reach its location for combustion without substantial disintegration back into fines. The agglomeration must also be effected in a manner which will not materially interfere with the normal burning of coal.

Duff coal fines have in the past been agglomerated using binders such as starch or molasses in high dosage rates with consequent expense. Molasses also forms a containment in the combustion environment which is highly undesirable.

In the result these binders are not really adequate for their purposes.

OBJECT OF THE INVENTION It is the object of this invention to provide a material which will enable the coal fines to be utilise as agglomerated masses.

In this specification all constituent percentages are percentages by weight.

SUMMARY OF THE INVENTION In accordance with this invention there is provided a material for agglomerating coal fines for use in combustion at temperatures below 1300° C which material comprises a mixture of carboxy cellulose and guar gum each in a proportion of 0.1% to 6.0% of agglomerated product.

Further features provide for the carboxy cellulose to be carboxy ethyl methyl cellulose and to be of high viscosity, particularly of the order of 20,000 cps.

The invention also provides an agglomerated product of coal fines in a mixture in the range of 5.0 mm to 0.05 mm mixed with a material as defined above.

Still further features of this invention provide for there to be an approximately even mixture of size of coal particles and for there to be a carboxy cellulose quantity of about 1.5% and guar gum quantity of about 0.5% of the final mixture and for the mixture to include a quantity of between 1% and 5% of agglomerating material as mixed.

DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION These and other features of this invention will become apparent from the following description of one embodiment thereof.

Duff coal fines having a particle size range of between 0.05 mm to 5 mm are obtainable and has an analysis as follows:- Particle distribution 0.05 mm to 0.5 mm 25% 0.5 mm to 1 mm 25% 1 mm to 6 mm 50% Ash content 2.0% to 45% Volatile material 1% to 48%

Where the ash content is in excess of 20% it is desirable that this contente reduced before the fines are agglomerated. This can be effectively done by washing and separating in well known flotation and centrifuging processes. The fines should also be dried to a moisture content of around 2% and this can be effected in a cyclone separator for example. Treatment in this manner renders the fines a good quality coal for general domestic use for heating and cooking.

The fines are then mixed with agglomerating material prepared from:- Carboxy methyl ether cellulose 1.5% Guar gum 0.5% Coal fines 96% and Water content 2% The cellulose will have a viscosity of the order of 20,000 cps and the coal fines preferably has a fairly even mixture between small and large size range particles.

Mixing can be effected at ambient temperature in standard mixing equipment such as concrete mixers similar to the Eimich type mixer.

After mixing the material is briquetted in any convenient manner for example in a modified brick making machine using low pressures.

Using a mixture of the agglomerating material at a dosage rate from 0.5% to 1.5% set out above it is possible to achieve a green strength after curing at 50° C to 100°C of between 5 mPa to 18 mPa. The agglomerating material forms a strong film around the fine coal particles which adhere to each other in a manner without interference with the high volatiles present in the coal. Because the compounds are non-reactive they do not change the standard properties of the coal.

The resultant dried briquettes sustain and burn evenly up to a temperature of about 1200°C.

It will be appreciated that the specific example given above can be varied particularly with regard to the kind of coal used. Generally however the coal used will be duff coal which even after reduction of the ash content would not be suitable for use in the smelting industry.

The properties of the constituents of the agglomerated material may of course vary dependant on the particular circumstances in which the material is to be used but determination of the most satisfactory properties can readily be made by experiment by a suitably skilled person in the art.

The invention thus provides a satisfactory agglomerated coal product particular suitable for domestic and general heating purposes from a product of basically waste material.