Process:
A process for the production of sintered alumina grains
from indigenously available cal-cined alumina.
Uses:
Finds major application in the manufacture of special
refractories such as slidegate plates, low cement castables,
high alumina bricks etc.
Salient Features:
The raw material such as, calcined alumina and suitable
additives are intimately mixed in proper proportions
and pellets are formed at optimum pressure. These pellets
are sintered at about 1700°C for 2/3 hours in air
/oxidising atmosphere. The sintered pellets are then
crushed, ground and sieved to desired fractions followed
by magnetic separation. The grains contain minimum 99.0%
alumina and have 5-6% A.P.
Environmental
Considerations: The process does not present
any effluent problem and is almost free from pollution.
Scale of Development:
The process has been developed on laboratory scale.
Commercialisation Status: Licensed
to M/s Tata Refractories Ltd., Belpahar (Orissa), 360
tpa and is in commercial production.
Major Raw Materials:
(i) Calcined alumina (minimum 99.5% Al2O3)
(b) Additives
Major Plant
Equipment/Machinery: Mixer, Briquetting press,
High temperature furnace, Jaw crusher, Roll crusher,
Ball Mill, Magnetic Separator. All indigenously available.
Techno-Economics:
A plant with 600 tpa capacity (based on 3 shifts per
day and 300 working days per annum) costs Rs. 125.00
lakhs. ROI is 45% at a selling price of Rs. 45,000/-
per tonne.
Technology Package:
Includes
(i) Process know-how
(ii) Details of equipment
(iii) Plant lay-out
(iv) Quality assurance methods. Assistance in setting
up the plant on separate terms.
Released Through:
NML/CSIR
Contact: Director
National Metallurgical Laboratory
Jamshedpur - 831007, India
