Improvement and using of furnace refractory material

Open hearth furnace masonry damage mainly caused by slag and liquid steel chemical erosion and high temperature corrosion and spalling. Open hearth is most easily damaged, is the weak link in the whole lining, directly related to the small yield of furnace. Therefore, all the countries take the thin furnace top as an important technical index of open hearth furnace; open hearth furnace life refers to the so-called top life. Enter sixty ages, the world each for open hearth furnace adopting ordinary alkaline brick masonry. China is widely used magnesia brick, the medium-sized open hearth furnace service life reached about 1000 times.

With the development of open hearth oxygen blowing intensified smelting, the production efficiency is improved, but the decline in life. To this end. We must improve the brick quality, development of new varieties, to meet the need of strict furnace smelting process. In this case, the British in the 1959 car developed directly combines the basic brick manufacturing, the key is using high purity raw materials, high pressure shaping and high temperature firing. In order to combine the firebrick and magnesia brick firing temperature and high temperature relation of bending strength. With increasing the burning amyl temperature, direct burning of magnesia chrome brick flexural strength increases, and magnesia brick to 1800 C strength decreases. As is said, in order to obtain the excellent combination of magnesium lead bricks, the sintering temperature should be greater than 1700 DEG C, the best sign about 1800 DEG C firing.

The formation of the smelting furnace slag layer

Infiltration of molten state in refractories copper matte with good mobility. Due to the surface in the reaction tower refractory lining is covered with a layer of dense with magnetic iron oxide for hanging slag layer is mainly composed of, so he struck the wall surface matte does not directly penetrate into the brick body, but first of all along the silicate slag channel infiltration within the material and the interaction and slag, slag at different depth generate Cu or Cu2O material.

Reaction tower wall surface slag although direct intrusion effectively prevents the copper matte, but did not completely eliminate the erosion caused by the matte of lining. Through the slag layer, there are still a small number of matte can penetrate through, and then along the brick body pores or cracks penetrate within the capillary channel brick. Because of the more close to the firebrickcenter, oxygen potential is higher, so into the brick body after the copper matte is prone to oxidation reaction. After reaction, the generated Cu2O exists between the lining the main crystal and the matrix, and no penetration into the other grains.

Molten copper oxide (CuO-Cu2O at 1140 DEG C when the low total soluble) will cause the increase of permeability refractory brick thermal conductivity, the resulting expansion of strong diathermy, lining spalling and, in which Cu is oxidized to CuO, the volume expansion of 75%; oxidized into Cu2O, volume increased by 64%. Therefore, from the microscopic structure, corrosion of matte on the reaction tower lining is mainly for the chemical structure of permeability, copper matte and the resulting stress reaction.

Selection and using of refractory brick

We all know that in the refractory brick selection time not only to understand the specifications, but also to understand its use in those aspects, at the same time should understand how to buy after inspection, this knowledge is much novice distress, today let technical personnel Yilong to tell you.

Refractory brick of species, which is mainly used to refractory clay and other made of refractory materials, color is light yellow and the pale brown, is mainly used for masonry smelting furnace, high temperature resistant, so called firebrick. When we want to know the specification is very much on the choice, we want to compare and make a decision, there is the specification must be consistent with the provisions of the state and the relevant departments, but also to carry out inspection, must not be careless when we want to have a look Is it right? Acceptance and our initial order the same, but also randomly selected several blocks out have a look, to avoid damage.

And we all know that there are many kinds of refractory brick,according to the different nature of each species, can be used in many related industries. The most commonly used industry is steel series, series, rotary kiln stove series, in the steel industry using refractory brick is to prevent the furnace or eruption out to cause some damage, so to use in the fire mouth, block the fire out; refractory brick in rotary kiln is used in lining of use inside, the protection of the kiln body safety; hot blast stove series is in refining device, pre buried iron etc. mainly using refractory brick.

The content of the refractory brick, for the knowledge you have some understanding of it, if you want to learn more about refractory brick can always consult us.  http://www.chinafirebrick.com

The matters attention during refractory brick package and transportation

Although firebrick is not fragile to glass products, firebrick in our transport and packaging, we also need some attention, next I will tell you knowledge about packaging and transportation of refractory bricks.

In accordance with the strict specifications for the use of wooden pallets firebrick to packaging, but also do operate according to strict specifications in the transport, so when the light-light transport is necessary to do, if it is a relatively shallow body bucket at the bottom of the car when you need something bedding layer, in order to avoid delivery to destination when found damaged bricks; Similarly, in order to prevent damage firebrick, refractory bricks in place when the fork truck is not allowed to be smooth rollover conditions occur resulting in damage to the brick, there is piled remember firebrick body cause damage brick body, making unpacking the time to use the bundled disposable scissors blade cut, some people will probably be uncovered firebrick placement, although such an approach may allow, but when you have to be placed with a colored cloth exterior look, avoid getting wet when it rains, the last point is not to brick wasted.

By the content described above, for precautions firebrick packaging and transportation when you have more or less understand, you want more information about the firebrick knowledge please go to our website http://www.yilongrefractory.com query or consult.

Cause of refractory brick appear crack

Refractory brick is refractory material with certain shape and size, according to the material is usually divided into high aluminum brick and clay brick, lightweight refractory brick.Refractory brickis mainly used for lining, stoves and other parts of the chimney. Standard refractory brick is also known as the T-3 refractory brick is a brick, the most widely used, then the brick may appear crack phenomenon in the use process, crack damage occurred mainly in the baking stage. Baking time, have a variety of stresses, if the stress exceeds the limit strength of refractory allowed, will appear crack.

Yilong refractory company for your detailed account of the factors that lead to the crack which appeared firebrick:

(1) Temperature differential stress:

When baking kiln, firebrick inside in a certain temperature difference, resulting in stress.

(2) Crystal transition stress:

Refractory bricks in the heating process can occur crystal transition, changes in crystalline form if excessive, stress is too large, and cracking will produce the refractory bricks;

(3) Mechanical stress:

The role of non-elastic deformation produced in the mechanical load on the Ambassador firebrick caused damage.

The laying of firebrick in furnace

Drum type heating furnace is mainly composed of a cylinder, head, tube, pipe, oil (water) distribution pipe, smoke box, a chimney, saddle and the interface tube etc… The combustion of the fuel in the furnace, forming high temperature flue gas and release the heat, high temperature flue gas heat generated by a fire tube or pipe to heat conduction, convection, radiation, convection, the heat is transferred to the medium in the furnace, the temperature reached the process demand.

The heating furnace in the burner side fire tube entrance laying 1.2 ~ 2.4m long refractory brick, the fuel burns, ceramic fiber blanket generates a lot of heat in the refractory brick refractory brick surface, heat transfers to the outside, causing the distance refractory brick recent fire tube heat intensity is too high, local overheating, oxidation, axial, radial deflection indentation deformation.

Transfer station is widely used at present, self discharge process, silt into the furnace from the water discharge pipe, the heating medium convection heating furnace of sediment, stirring constantly, and finally fell on top of the fire tube and smoke pipe.

Can be found in dredging, heating furnace overhaul, the heating furnace tube sediment thickness more than 150mm, especially in the high temperature zone of the fire tube (refractory bricks in 100 ~ 500mm of maximum sediment thickness). Under such circumstances, is bound to cause loss, heat transfer efficiency of the heating furnace of local overheating, drum kits, perforation may happen at any time.

Comprehensive understanding of various acid-base refractories

There is a kind of important properties — acid-base properties of many physical and chemical properties of refractory materials we must fully understand.

Acid refractory material determines its using temperature environment, anti slag corrosion ability, refractoriness under load, changes in the volume after repeated burning and thermal shock resistance. A comprehensive understanding of the acidity of the refractory material can achieve the best material, be just perfect use.

How acidity refractory material? Acid refractory usually refractory SiO2 content greater than 93%. Basic refractory materials generally refers to the refractory material to Magnesium Oxide or Magnesium Oxide and calcium oxide as the main component. The main characteristics of acid refractories is erosion resistant acid slag at high temperature, but easy to react with alkaline slag. Acid refractory materials are commonly used silica refractory bricks and clay bricks. Silicon refractory brick is siliceous materials silica containing more than 93%, raw materials used in silica, silica refractory bricks, the acid resistance of slag erosion ability, high refractoriness under load, the volume does not shrink after repeated burning, or even a slight expansion; but vulnerable to the erosion of basic slag, thermal shock resistance difference. Silicon refractory brick is mainly used for thermal equipment of coke oven, glass kiln, acid furnace etc.. Clay refractory bricks with refractory clay as the main raw material, containing 30% ~ 46% of alumina, is a weak acid refractories, good thermal shock resistance, resistance to acid slag, wide application. Basic refractory refractory degree is higher, the ability to resist the strong alkaline residue. For example, magnesia brick, magnesia chrome brick, magnesite chrome brick, magnesite, dolomite brick, forsterite bricks etc.. Mainly used for basic steelmaking furnace, smelting furnace for non-ferrous metal and cement kiln etc.

Technology requirements for refractory of ladle

With the development of steel-making technology, ladle is not only the container transportation of molten steel, but also bear the molten steel processing and refining function. With the development of steel residence in refining, ladle time prolonged, molten steel temperature increased, and accompanied by strong stirring, vacuum treatment, arc heating and the slag erosion, puts forward higher requirements for steel tundish refractory:

1. Dense layer formed a semi molten state under high temperature, and reduce the slag sticking;
2. A swelling must in the process of using, thus to form a whole, not cracking, spalling; especially the bottom of the bag can not because of shrinkage cracking cause fall off;
3. Ladle as the intermittent operation, through high temperature cooling — repeated thermal cycling, fire brick must have good thermal shock resistance and spalling resistance;
4. In order to maintain the cleanliness of molten steel in ladle, ladle should have good corrosion resistance, high temperature to minimize the refractory material into the molten steel;
5. From the economic point of view, requirements of ladle lining construction of a good performance and reasonable price. Lining refractories from amorphous to amorphous materials products

Three classification of refractory material according to temperature

Refractory material is a class of inorganic non metallic materials which the fire degree not lower than 1580 ℃. Refractoriness is refractory cone specimen under no load condition, resistance to high temperature without melting temperature in Celsius. Here we introduce three classification index of refractory material:

Can be divided into the ordinary refractory material: 1580 ~ 1770 ℃ refractoriness, refractoriness 1580 ~ 1770 ℃ is equivalent to Al2O315% ~ SiO2-Al2O3 two yuan in 45% refractory products, the main mineral composition of raw materials are the kaolinite.

Can be divided into high-grade  refractory materials:refractoriness 1770 ~ 2000 ℃, high aluminum bricks, magnesia brick, Mo to ordinary products, magnesia brick, of common magnesia chrome brick, brick belongs to this class of olive.

Can be divided into super refractory material: Refractory degree is higher than 2000 ℃, pure oxide products, casting products, high purity magnesia chrome brick, magnesia spinel brick, non oxide products belonging to this class.

Commonly used ladle castable varieties

1. Clay brick, clay brick and A12O3 content in ordinary during 30%-50%, low price. It is important for ladle backing layer and ladle bottom.
2. High alumina brick. The content of A12O3 brick during 50%-80%, it is important for the working layer of ladle.
3. Wax brick. The brick is characteristic of high content of SiO2. In general more than 80%, than the corrosion resistance and the mass of clay bricks, and without residue. Used in ladle wall and the bottom of the bag.
4. Zircon brick. The brick mainly for ladle slag line. The content of ZrO2 in ordinary brick during 60%-65%.
5. Magnesia carbon brick. The brick for ladle slag line, special apply to multiple ladle continuous casting sessions. The content of MgO in ordinary brick in 76% and, in the meantime the carbon content of 15%-20%. Its characteristic is to slag corrosion, corrosion resistance, good peeling property.
6. Alumina magnesia castable. The castable for ladle body, its characteristic is the utility in molten steel, casting material of MgO and A12O3 and Al ovate spinel, improved the lining slag resistance and thermal shock resistance.
7. Alumina magnesia carbon brick. This brick is on aluminum magnesium casting material basically developed ladle lining, has a long service life.
8. Unfired brick. Now the ladle for fire brick materials, almost all can be made compared to unburned brick. Its characteristic is compared with the producer process simple, low unit price. The brick itself has certain machine intensity and corrosion resistance, easy construction and masonry

If ladle for refining itself, you can also choose the MgO-Cr2O3-A12O3 series and MgO-CaO-C series refractory castable, important: magnesia chrome brick, magnesia chrome brick, aluminum dolomite brick. As in the brick of ladle lining containing graphite material, preferably coated with a layer of chemical synthetic coating at the surface, the dike in siopao, lining surface compound loose, affect the using life.

Where have better refractory brick

Either online or in real life, if want to buy Bricks, people always ask to refractory brick where do good, want to buy it, sure to buy good quality, reliable manufacturers, after all, refractory brick is directly related to the safety problem of an enterprise’s normal operation production and people, so important, how can people do not attach importance to. So we must find a refractory brick manufacturers do well, which can let people use at ease comfortable. So today I will introduce a manufacturing fire brick is particularly good manufacturers to you, it is Luoyang Yilong refractory Co. Ltd, the company production of refractory brick that people can buy  with nothing to fear.

Why dare to say so, because the refractory material of our nation’s most famous in the country only a few places, but Henan Luoyang is one of them, so that the only good refractory raw materials to produce the refractory brick have good quality, If you want to buy refractory brick, especially welcome to our company to purchase, we will provide the high quality service and product to make you satisfied. If any quality problems appeared in the process of using, we can be solved in time for you.

Customer demand is our goal to struggle, we believe that the quality of the raw materials for the production of quality products, excellent staff to provide quality services. With “integrity, pragmatic, efficient, innovation” for the purpose of the us to the best quality products, the best quality service, warmly welcome new and old customers at home and abroad to visit our company.

Cause of carbon containing refractories not suitable for using in the Nickel Converter.

Due to the poor wettability of molten slag and graphite, graphite to refractory oxides can greatly reduce the infiltration depth of slag refractory material, thereby reducing the thermal spalling and flaking refractories. Therefore, in the iron and steel industry especially some intermittent production equipment such as hot metal pretreatment tank (or bucket), oxygen converter, electric furnace, ladle, extensive use of carbon containing refractories, and achieved good results. Naturally want to carbon containing refractories used in copper, nickel converter, but the effect is not ideal. The former Soviet Union, Japan and China have in copper or Nickel Converter tried MgO – C, C, but the effect is not ideal.

Why the carbon containing refractories in the iron and steel industry especially the effect of oxygen converter steel making is very good, but in the smelting of copper, nickel converter is not ideal?

Metal melt the iron and steel industry is the Fe.c melt. The blast furnace gas contains large amounts of CO, carbon in liquid iron at or near saturation; natural, blast furnace, hot metal pretreatment tank available carbon and carbon containing material. The important task of oxygen converter steel making is to reduce the carbon in liquid iron, steel will precipitate a large number of CO gas, in iron making, converter, oxygen pressure is very low.

Copper or nickel converter blowing to the matte or ice nickel (nickel matte, ice is Cu – Fe – S or Ni – Fe-s sulfide melt) FeS oxidation in the melt of FeO, into the molten slag.

As long as the partial pressure of CO is less than CO equilibrium partial pressure 5.02 × 105 kPa, carbon refractories in carbon will be oxidized. While copper, nickel converter, CO partial pressure is small, far more than the CO equilibrium partial pressure 5.02 × 105 kPa much smaller; thus in refractories containing carbon, oxidation tendency is very large, it is easy to be oxidized. So the copper or Nickel Converter with carbon containing refractory lining, the use effect is not ideal.

Refractory industry will develop to green

In the development of our domestic industry, basically can achieve energy-saving environmental protection industry is not a lot, but refractory industry today we say it is belongs to the field of energy development.

In this industry, refractory materials, various types of products  , such as refractory brick, refractory castable etc. products, however, these two products are able to do energy-saving green development. Now with the major industry continue to emerge,  the state pay more attention to the refractory material production, and the development trend is apparent.

In fact, for the resources of our country market, we must also understand some of it, like oil, coal and other natural resources are declining, and the state is always in search for new products to replace the natural resources, but not too ideal. But in the domestic resources are becoming scarce today, appear energy-saving environmental protection refractory material model,

let this situation has improved, the state has approved the development of this industry. Because the development of this industry can promote the sustainable development of the country, and to other industry has brought a lot of use.

For the development of refractory products green, low carbon, our country has not given up, and to make great improvement, the development strategy in the global green economy, only the development of refractory industry of our country mainly, to comprehensive economic in China has greatly improved, and perhaps one day as a big refractory materials can also be the global market.

Difference between refractory brick and insulation brick

Effect of heat insulation brick is used to heat preservation, reduce heat loss, refractory brick is mainly used to withstand flame burn. Insulating brick is generally not direct contact with the flame, and refractory brick general direct contact with the flame.

The main difference between the following points:

• Insulation performance

Thermal conductivity of thermal insulation brick in general 0.2-0.4 (average temperature 350 ± 25 ℃) w/m.k, and refractory brick of heat conduction coefficient in 1 (the average temperature 350 ± 25 ℃) than w/m.k, which can obtain insulating brick insulation performance than the refractory brick insulation performance is much better.

• Refractoriness

Insulating brick refractoriness generally below 1400 degrees, and refractory refractory degree is above 1400 degrees.

• Density

Insulating brick is generally a lightweight thermal insulation material, density in 0.8-1.0g/cm3 and refractory brick of basic density is above 2.0g/cm3.

To make a long story short insulating brick is generally emphasized the insulation performance of it, does not pay attention to its refractoriness fire brick, and on the contrary. Different locations will use different materials, in the purchase of materials at the same time, to choose their own use.