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Magnesia Refractory Bricks Mgo-C Magnesite Carbon Brick For Thermal
Equipment
The application experience of magnesia-carbon brick in converter, electric furnace and ladle shows that it is very suitable for steel smelting because of its superior high temperature resistance, slag erosion resistance and good thermal shock stability.Magnesia-carbon brick is applied to the slag line and the steel outlet with serious erosion because of its high fire resistance, high slag resistance and solubility, and high temperature creep rate of magnesia which is difficult to be wetting by slag and molten steel.So far, huge economic benefits have been created due to the extensive use of magnesia-carbon bricks in the steelmaking process and improved iron and steel smelting technology.At present, magnesia-carbon brick has some shortcomings, such as high price graphite consumption, increasing heat consumption, and continuous carburization into molten steel, which pollutes molten steel. In order to reduce the cost of raw materials and pure molten steel, the low carbonization of magnesia-carbon brick can solve these problems well.
The characteristics of magnesia-carbon brick are mainly reflected
in the following aspects:
1. Tissue compactness of magnesia-carbon brick
The structure compactness of magnesia-carbon brick depends on the
type and amount of binder and antioxidant, the type of magnesia,
the particle size and amount of graphite, etc. In addition, molding
equipment, brick pressing technology and heat treatment conditions
all have certain effects.In order to ensure that the apparent
porosity is below 3.0%, the forming pressure is 2t/cm2, and the
bulk density of the matrix part can be enhanced to improve the
corrosion resistance, magnesia-carbon bricks with particle size
less than 1mm are used in the air eye brick and the steel outlet
brick.Different binder also has certain influence on the
compactness of magnesia-carbon brick. The volume density of
magnesia-carbon brick is higher when the binder with higher carbon
residue rate is selected.Add different antioxidant effect on the
density of magnesia carbon brick are obviously different, and in
800 degrees, show porosity increases with the oxidation of
antioxidants, after more than 800 degrees, do not contain metallic
magnesium carbon brick show porosity does not change, but its
containing metal show porosity decreased obviously, 1450 degrees to
800 degrees only half, add metal show the lowest porosity of
aluminum magnesium carbon brick.
The heating rate of magnesia-carbon brick will also affect the
change of its apparent porosity. Therefore, when magnesia-carbon
brick is used for the first time, the temperature should be
increased at a low speed as far as possible to make the binder
decompose completely at a lower temperature. During the use of
magnesia-carbon brick, the influence of temperature difference on
porosity is also obvious, the greater the temperature difference,
the faster the porosity increases.
2. High temperature performance of magnesia-carbon brick
2.1 High temperature mechanical properties Different additives have
different effects on improving the high temperature strength of
magnesia-carbon bricks. The research shows that for the high
temperature bending strength above 1200°C, there is no
additive.Calcium boride & lt;Aluminum & lt;Aluminum
magnesium & lt;Aluminum + calcium boride <Aluminum
magnesium + calcium boride, where aluminum magnesium + boron
carbide between aluminum magnesium and aluminum magnesium + calcium
boride.
2.2 Thermal Expansion Property The participation expansion value of
magnesia-carbon bricks without metal addition is far lower than
that with metal addition, and the participation expansion value
increases with the increase of metal addition.
2.3 The thermal expansion and high temperature flexural strength of
magnesia-carbon bricks are different in different directions under
various anisotropy, which is mainly caused by the orientation of
flake graphite. The principle and method of bricklaying with
working lining are determined.Magnesia-carbon brick in vertical
direction has higher high temperature strength and lower thermal
expansion.
Because of the different working conditions of converter lining, the effect of magnesia-carbon brick is also different.
Lining furnace opening position is constantly impacted by cold state and hot state liquid steel, so the refractory material used in the furnace opening must be resistant to the scouring of high temperature slag and high temperature exhaust gas, and is not easy to hang steel and easy to clean up in time.The furnace cap part is not only subjected to serious slag erosion, but also to the temperature change of rapid cooling and rapid heating, as well as the comprehensive effect of high-temperature air flow of carbon oxidation and dust and high-temperature exhaust gas scouring, so the magnesia-carbon brick with strong slag erosion resistance and anti-spalling property is used.Lateral loading requirements magnesia carbon brick in addition to high slag erosion resistance, but also has the very high temperature is strong and has the quite good spalling resistance, so often used to join metal antioxidant high strength magnesium carbon brick, studies have shown that join aluminum magnesium carbon brick in low temperature when the high temperature strength of the composite to add metal aluminum and silicon metal samples is low, and at high temperature, the high temperature strength has increased.The slag line is the three-phase junction of furnace lining refractory material, high-temperature molten slag and furnace gas, which is the most severely corroded part by slag. Therefore, magnesia-carbon bricks with excellent slag corrosion resistance are needed to be laid, and magnesia-carbon bricks with high carbon content are needed in the slag line part.
Items | MT-12A | MT-12B | MT-12C | MT-14A | MT-14B | MT-14C |
MgO | 78 | 76 | 74 | 76 | 74 | 72 |
C | 12 | 12 | 12 | 14 | 14 | 14 |
Apparent porosity % ≤ | 4 | 5 | 6 | 4 | 5 | 6 |
Bulk Density g/cm3 | 2.98 | 2.96 | 2.95 | 3 | 2.96 | 2.95 |
Crushing Strength/Mpa ≥ | 40 | 40 | 35 | 40 | 40 | 35 |
Hot modulus of rupture(1450 C)/Mpa | 8 | 7 | 6 | 12 | 10 | 8 |
2. The use of magnesia-carbon brick on electric furnace
At present, the wall of electric furnace is almost all constructed
by magnesia-carbon brick, so the service life of electric furnace
is determined by the life of magnesia-carbon brick. The main
factors that determine the quality of magnesia-carbon brick include
the purity of magnesia, the type of impurities, the grain binding
state and grain size of magnesia-carbon brick from MgO.The purity,
degree of crystallization and scale size of the flake graphite as
the source of carbon introduction;Usually, thermosetting phenolic
resin is used as binder. The main influencing factors are the
amount of addition and carbon residue.Now have shown that adding
antioxidants magnesia carbon brick can change and improve its
matrix structure, but when used under normal operating conditions
of the furnace, antioxidants are not magnesia carbon brick of the
necessary raw materials, and only used for high FeOn arc furnace
slag, such as the use of direct reduced iron or have irregular
parts and electric furnace hot parts of the oxidation, add various
kinds of metal antioxidants can become an important part of
magnesia carbon brick.
The corrosion behavior of magnesia-carbon brick at slag line shows
the formation of obvious reaction dense layer and decarburized
loose layer.The reaction dense zone also becomes the slag invasion
zone, which is the erosion zone where the high temperature liquid
slag infiltrates into the interior of the magnesia-carbon brick
after a large number of pores are formed after decarburization.In
this region, FeOn in the slag is reduced to metallic iron, and even
the desorption phase and intergranular Fe2O3 in solid MgO are
reduced to metallic iron.The penetration depth of the slag into the
brick is mainly determined by the thickness of the decarburized
loose layer and usually terminates at the place where the graphite
remains.Under normal conditions, the decarburization layer in
magnesia-carbon brick is relatively thin due to the presence of
graphite.
There are two ways of steel outlet of electric furnace: tilting
steel outlet of trough and steel outlet of bottom of furnace.When
using the discharging tank to tilting the steel, magnesia-carbon
brick is basically not used, and Al2O3 or ZrO2 quality is selected,
and C, SiC and Si3N4 and other non-oxygen substances are added.When
the bottom of the furnace is used, the outlet is composed of an
external sleeve brick and an internal tube brick.At the bottom of
the furnace, the steel outlet is made of magnesia-carbon brick pipe
brick. The pore size of the pipe brick is determined by the furnace
capacity and the time of steel drawing, and the inner warp is
generally 140 ~ 260mm.
The middle block and low block magnesia-carbon brick were used in
the outlet of an electric furnace in a steel mill, and the sintered
magnesia-carbon brick was replaced by the sintered magnesia-carbon
brick on both sides of the copper outlet, and the furnace life was
increased from about 60 to more than one time.The magnesia-carbon
brick at the slag line after use is kept intact and does not stick
slag.The slag line does not need refilling furnace, which reduces
the labor intensity and improves the purity and productivity of
molten steel.
3, aluminum magnesium carbon brick in the use of ladle
When MGO-C brick is used in refining ladle furnace and ladle, it is
mainly used in clearance and slag line.According to the operating
conditions, the refractory materials used in these parts must have
high temperature resistance, heat shock resistance, resistance to
slag erosion caused by mechanical erosion.So in the past,
magnesia-chrome refractories were used for these parts, but because
of the pollution of chromium to the environment, the amount has
been reduced, and now magnesia-carbon bricks are used.
Packaging
1. 1 ton bags in container, 25 MT/20'FCL.
2. 25kg bags in container, 25 MT/20'FCL
3. 25kg bags in ton bags, then in container, 25 MT/20'FCL
4. as the customer' request
Packaging of SK37 High Alumina Refractory Brick
1.on wooden pallets with plastic cover: wooden pallet size :930*930
or 1000*1000mm,
2.Load weight of each pallet: 1.5-2.0 tons,
Shipping of SK37 High Alumina Refractory Brick
1.Our packaging is as per customer’s request
2.Normal goods delivered by sea transport
3.Sample shipping by express
4.We will shipping and delivery goods timely, quality and quantity
guaranteed, and also in accordance with the contract and customer's
requirement completely.
Delivery:
15-30 days working day for large quantity. The shipment we will
arrange as soon as possible. Of course, if it is a custom products,
the shipping time will delay.
Sample:
Usually by EMS, DHL, UPS, TNT, FedEx. Anyway you like. Bulk order: Usually by sea.
Payment:
It can be through T/T, L/C at sight. The specific terms determined
according to the quantity of the goods, etc.
Your inquiry related to our product & price will be replied
within 24 hours.
Export:
Our products have been exported to many countries: Australia,
Chile, USA, Russia, UK, Indonesia, etc., good quality have be
approved by our clients.
1.Timely response,
Timely response to your inquiry, multiple choice recommendations based on your demand,quickly respond mails and provide solutions.
2.Free sample of dry ramming mass
Sample and trial order are accepted for the quality evaluation
3.Strict quality control
Arrange production on time and control quality strictly.
4.Shorter delivery time.
Book the earliest vessel or plane to guarantee the delivery time.
5.Professional Services
Provide all the detailed news and pictures from order to delivery;offer relative export documents and original certificate if needed;warm and considerable after-sale service.
Henan hongtai kiln refractory co., LTD. : "quality first, reputation first, customer first: it is our
aim."Scientific management, strong technical force, perfect testing
means, advanced technological equipment and stable product quality
are the guarantee of quality service.Henan hongtai kiln
refractories co., LTD sincerely hopes to cooperate with you hand in
hand and in good faith.
Henan hongtai kiln refractory co., LTD. Main products are high alumina brick, clay brick, fused zirconium
corundum brick, fireproof ball lightweight insulation brick,
wear-resistant pouring material, corundum pouring material, low
cement high strength pouring material, impermeable material,
self-flowing material, plastic material, and various types of
refractory materials.For different industries, the cement industry
with anti-flaking high-alumina bricks, alkali resistant bricks,
phosphate bricks;Boiler industry USES all kinds of brand
wear-resisting brick, corundum brick, mullite brick and other
finalizing materials.The company insists on "product quality is the
life, enterprise integrity is the foundation", in the fierce market
competition, won many users' trust and praise.The products are sold
all over the country, as far as Vietnam, India, Korea, Pakistan,
kazakhstan, other southeast Asian countries and regions.