(19)
(11) EP 0 050 412 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.08.1982 Bulletin 1982/31

(43) Date of publication A2:
28.04.1982 Bulletin 1982/17

(21) Application number: 81304187

(22) Date of filing: 14.09.1981
(84) Designated Contracting States:
AT BE CH DE FR GB IT LI LU NL SE

(30) Priority: 17.10.1980 US 197853

(71) Applicant: ATLANTIC RESEARCH CORPORATION
 ()

(72) Inventor:
  • Scheffee, Robert Stephen
     ()

   


(54) A process for making fuel slurries of coal in water and the product thereof


(57) A process for making fluid, stable slurries of finely divided coal in water, which can be sufficiently highly loaded to serve as fuel, comprises: a) Admixing:

(i) ultrafine coal particles having a maximum size of 10 µm MMD in an amount comprising from 10 to 30% by weight of the slurry,

(ii) larger coal particles within the size range of from 20 to 200 µm MMD in an amount sufficient to provide a desired total coal concentration in the slurry, (iii) water, and,

(iv) a minor amount of dispersant consisting essentially of an alkaline earth metal salt of an organosulfonate in which the organic moiety is multifunctional, and

b) subjecting the mixture to high shear at a rate of at least 100 sec-1.


Preferably, calcium lignosulphonate is used as the dispersant and the pH is maintained in the range of 5 to 8 using an inorganic alkali metal buffer salt.
The slurry thus produced exhibits thixotropic or Bingham fluid-like properties enabling prolonged periods of storage with subsequent restoration of fluid characteristics to enable use as a fuel.





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