To enhance converter’s service life, the quality of refractory material is an important factor, while operation condition is another more important factor, because good working condition is the basis of long service life of converter linings. The other main method of prolong furnace lining service life is regular maintenance, as it can prolong several times of converter’s service life. Currently, measures can be taken for converter maintenance are:
For front and back large area, hot self flowing patching materials can be used for periodical repair. For trunnion and other parts, gunning patching mix can be used. If furnace lining is timely patched, the service life can reach to 8000 times or more, otherwise, the service life will only be more than 1000 times.
Slag spraying for furnace protection. This method is adding some quantity of light burned magnesia ball or dolomite, which makes slag’s melting point and viscosity increased, then by high pressure nitrogen, spraying the slag containing light burned magnesia and dolomite to furnace lining to decrease the damage to furnace lining during next smelting. Generally, one time of slag spraying is taken for every smelting. But this method need to consume large quantity of nitrogen, magnesia and dolomite, as well as large amount of heat, what’s more, smelting efficiency is decreased, so this method should be comprehensively appraised.
Before the development of magnesia carbon bricks, sintered or tar (pitch) bound magnesia bricks and magnesia dolomite bricks are mainly used in converter linings. The initial service life of magnesia bricks and magnesia dolomite bricks is 200~300 times for small converters. Since the successful application of magnesia carbon bricks to converter linings, the ratio of magnesia carbon bricks is higher and higher, now almost all converters’ working linings are constructed by magnesia carbon bricks. Permanent lining uses magnesia bricks, joint material adopts magnesia ramming mass. The service life of converter reaches to several thousand times without slag spraying, through slag spraying, the service life can reach to tens thousand of times. In normal circumstance, small size converters’ tapping temperature is higher and smelting condition is harsher, the quality of refractory materials are relatively lower, so the service life is relatively lower than middle and large scale converters.
Rotary Converter Refractory Material Index
Item
MC-14A
MC-14B
MC-18A
MC-10A
MC-18A
Application parts
Wall and bottom working layer
Wall and bottom working layer
Slag line
Wall and bottom working layer
Bottom & molten bath &slag line
Al2O3 % >
42
70
70
70
60
Fe2O3 %<
1.5
/
/
1.8
1.5
SiC % >
/
8
8
/
7
C %
/
/
5
/
2
Apparent porosity %
16
17
5
18
16
Bulk density g/cm3
/
3.0
2.85
2.8
2.6
Compression strength Mpa
50
56.3
77.1
44.6
30
Refractoriness ℃
1750
/
/
1790
/
Refractoriness under load ℃
1450
1450
/
1550
/
Thermal shock resistance /times
20
30
/
20
/
Rongsheng Kiln Refractory Company Main Advantages
Rongsheng kiln Refractory is professional high temperature kiln & furnace refractory products manufacturer with 20 years experience and established a sound pre-sale, in-sale and after sale service system.
Pre-sale service: Timely and accurately take in customer’s demand-consult our technical engineers for appropriate products or solutions-communicate with customers and finally confirm the order.
In-Sale Service: Quality control, production progress monitoring, delivery arrangement, production progress customer informing.
