The following specification (particulararly) describes the nature of the invention and the manner in which it is to be performed:
3. THE HYDRATED LIME POWDER OR BURNT LIME POWDER OF DIFFERENT PURITY LEVELS AND FLY ASH ARE IN THE FIRST STAGE MIXED WITH WATER AND WITH OR WITHOUT ACCELEATOR AND/OR AN INDUSTRIAL WASTE OR OXIDES AS COLOURING AGENT. AFTER MIXING THEY ARE TAKEN TO REACTORS OR STACKING SALOS FOR REACTION OVER A PERIOD OF 3 TO 4 HOURS. THE MIX IS THEREAFTER TAKEN FOR REMIXING WITH ADDITION OF SOME MOISTURE INCASE OF NEED AND THE RESULTANT MIX THEREAFTER IS TAKEN TO HIGH SPEED PRESSES WITH ROBOTIC FEATURES.AFTER GIVING NECESSARY SHAPE, THE GREEN BRICKS THEREAFTER PASS ON TO THE AUTOCLAVES FOR STEAM CURING AT A TEMPERATURE OF OVER 200 PSI. THE RESULTANT PRODUCT AFTER STEAM CURING FOR 3 TO 5 HOURS IS AN AUTOCLAVED FLYASH BRICK.

Claim
1. A method of manufacturing an autoclaved fly ash brick comprising steps of:
(a) Dosing of fly ash with hydrated or burnt lime of different purity levels with water and with or without accelerator and with or without industrial waste or oxides as colouring Agent in to mixer,
(b) Mix is allowed to stay in reactor for a period of 3-4 hours during which mass is cured and calcium hydration process is completed,
(c) Second wet mixing of mass may be carried out to ensure appropriate moisture content,
(d) Mix is then shaped with the use of automatic high speed press,
(e) Finally, the hardening of thus shaped green brick is carried out in autoclave at 200 psi and 250 degree centigrade with curing in the steam for 3-5 hours to obtain autoclaved fly ash brick.

2. An Autoclaved fly ash brick obtained from the method as claimed in claim 1 wherein fly ash contains carbon as loss on ignition at 100 degree centigrade 7% maximum, Fe203 in R203 at 18% maximum, sulphur as S02 at 0.2 % maximum, sulphide as S at 1.95 gm/cu cm and granulation 5% maximum .06 mm mesh.
3. An Autoclaved fly ash brick obtained from the method as claimed in claim 1wherein lime contains calcium oxide CaO at 80% minimum, magnesium oxide Mgo at 2% maximum and granulation of quicklime if supplied as powder .063 mm max.0.1% and residue of sieve mesh .08 max 80 %.
4. An Autoclaved fly ash brick obtained from the method as claimed in claim Ifly ash content is up to 90 % and lime is 8 to 10 %.