显示标签为“firebrick refractory”的博文。显示所有博文
显示标签为“firebrick refractory”的博文。显示所有博文

2017年1月11日星期三

Characteristics of lightweight mullite bricks

Lightweight mullite brick Features:
1. Low thermal conductivity, low heat capacity.
2. High purity, impurity content less.
3. High temperature, direct contact with the flame.
4. High strength, and has excellent thermal shock resistance. Applicable to metallurgy, petrochemical, building materials, ceramics, machinery and other industries of various industrial furnace hot surface lining and backing. Heat treatment furnace, resistance furnace, tunnel kiln, roller kiln, bell kiln, glass tank kiln and so on. The Refractory company products are widely used in many industries, such as: cracking furnace, reformer, heating device, refining device, regenerating device, hot air furnace.

Features:
Higher refractoriness, up to 1790 ℃ or more. The softening start temperature of the load is 1600 to 1700 ° C. Room temperature compressive strength of 70 ~ 260MPa. Thermal shock resistance is good. There are sintered mullite bricks and fused Mullite Insulating Firebrick. Sintered mullite brick to bauxite clinker as the main raw material, adding a small amount of clay or bauxite as binder, by molding, firing and made. Fused mullite refractory brick to high bauxite, industrial alumina and fireclay refractories as raw materials, by adding charcoal or coke fine particles as reducing agent, forming after the use of reduced melting method to manufacture. The fused mullite is more crystalline than the sintered mullite and has a better thermal shock resistance than the sintered product. Their high temperature properties depend mainly on the alumina content and the homogeneity of the mullite phase with the glass distribution.

2016年12月21日星期三

New type of high alumina brick lead smelting furnace in different parts of which use

Lead smelting of lead sulfide concentrate, usually contain a certain amount of Zn, in the smelting process is also the oxidation of ZnS, while part of the reduction, part of the re-oxidation into the lead-rich slag, part of the form of steam into the flue gas, With the flue gas rising again in the process of secondary air oxidation, or contact with other elements after oxidation, while the flue gas contains large amounts of SO2 gas and high oxygen partial pressure. In the melt contains a lot of PbO and metal Pb, along with other normal slag composition, that is, FeO, CaO, SiO2, Fe3O4 and other impurities.

Melt a large number of PbO and Pb are low melting point material, in the 1000-1150 ℃ melting temperature, have good mobility and penetration, it is easy to penetrate into the cracks within the refractory brick. Pb infiltration into the brick body gap, the oxygen is oxidized into PbO, the volume will increase about 20%, which will greatly fill the gap of high alumina brick.

In addition, during the use of high-alumina bricks, the melt penetrates into the high-alumina bricks along the capillary channels such as pores and cracks, and interacts with it to form a metamorphic layer different from the original Clay, High Alumina insulating bricks. When the furnace temperature Fluctuations, the metamorphic layer will crack, peeling, melt deeper into the brick, the thicker the metamorphic layer, the thicker peeling structure. If the local oxygen potential in the furnace is high, it is easy to reoxidize the Cr2O3 in the local high alumina brick, and Cr3 + is oxidized to cr6 +, so that PbO reacts with CrO3 due to the strong basicity, and low PbO · CrO3 is formed, Anti - scouring performance of Bottom Frame &Skid Platform Brick for Heating Furnace.

At the same time, and the formation of high alumina brick Cr2O3 and other substances are a lso low melting point material, is not conducive to the formation of high melting point solid phase material. ZN vapor in the flue gas, if combined with Fe2O3 in the high-alumina refractory brick for sale, is reduced to a low-melting FeO phase and Zn is oxidized to ZnO, the volume of ZnO will be expanded by 5-6 times, In the infiltration of parts of the expansion effect. SO2 components within the flue gas, etc. on the composition of high alumina brick also has a certain chemical effect.

The characteristics of these slag and flue gas characteristics of high-alumina smelting furnace metallurgical furnace use has special requirements.

2016年10月18日星期二

Selection and Evaluation of Refractory

Selection and Evaluation of Refractory
    Before the rotary kiln operating cycle is mainly refractory material operating cycle impact is relatively large, but many companies blind pursuit of high-grade refractories, resulting in tons of clinker refractory consumption is not high, but the expense of high.
   Simple analysis, the kiln refractory Ladle Permeable Brick should pay attention to refractory bricks and kiln castable selection. In fact, after 14 years of production experience found that kiln castables as long as the two key indicators can be more than 1,600 degree refractoriness can be another indicator is the requirements of wear-resistant kiln refractory brick for sale more simple, The use of magnesia-chrome brick can be, behind the bold use of silicon Mo brick
    Preheater castable and alkali-resistant bricks must be careful not to over-high-grade can be grate cooler high-temperature zone and low wall wear-resistant castable with high temperature can be.

Refractory company Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

2016年9月5日星期一

Magnesia Carbon Brick

Magnesia carbon brick series used for the electric furnace are made by adoption of fused magnetite, high-purity magnesium sand and graphite as principal raw material, through high-pressure molding and low-temperature treatment. This product is mainly used for electric furnace lining, which enjoys advantages including high temperature resistance strength, corrosion and spalling resistance. According to the smelting conditions and the kind of smelting steel, different brands magnesia carbon bricks are available. Magnesia-carbon bricks are resin bonded bricks containing high-purity fused and or sintered magnesia and flake graphite as their main ingredients.


http://www.yilongrefractory.com/ProductServletOne?id1=1&id=1
E-mail:sales8@chinaelong.com

2016年7月31日星期日

How To Improve The Glass Phase Of Fused Cast AZS Block

Changxing Refractory Material
Changxing Refractory Material
The segregation of fused cast AZS is also caused by the glass phase. in theory, Al2O3, ZrO2 and SiO2 do not exist in the glass phase. When the alkali metal oxides(Na2O or K2O) are introduced, most SiO2 will enter the glass phase. Na2O constitutes the key components of refractory fiber felt glass phase with SiO2 and Al2O3. With the decreasing of Na2O, the glass phase decreases. But increasing the Na2O can reduce the viscosity of glass phase.

Iron, titanium, calcium, magnesium and other impurities should be avoided. The impurities can increase the glass phase but reduce the the viscosity of glass phase and pollute the glass melt.

SiO2 and Na2O are the main components tundish well block of the glass phase of fused cast AZS blocks. The content of SiO2 and Na2O is related to the amount of glass phase. Controlling the content of SiO2 and Na2O strictly is the key to ensure the performance of glass phase.

The main composition of Clay, High Alumina insulating bricks fused cast AZS block includes baddeleyite, corundum, a small amount of mullite, glass phase and pores. In order to reduce and eliminate the residual thermal stress, the glass phase is essential for fused cast AZS to act as a buffer for the thermal stress.

However, too much glass phase zirconium sizing nozzle will weaken the corrosion resistance. In the process of corrosion, the glass phase exudes first and be replaced with the high temperature glass melt, which will accelerate the corrosion. Accompanying the exudation of glass phase, bubbles give off, which will contaminate the glass melt.

Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

4 Ways for Fused Cast AZS Casting

Changxing Refractory Material
Changxing Refractory Material
There are 4 ways of fused cast AZS casting, including normal casting(PT), Tilt casting(QX), Reinforced casting(ZWS) and Void-free casting(WS).
PT-Normal casting
It adopts general casting coil grout risers and the riser will be removed in the hot state. The shrinkage cavity in refractories brick is located under the casting scar, due to volume shrinkage from liquid-solid transform and rapid solidification of a casting. The feasible limits of cavity can be evaluated and indicated by the volume-weight testing of blocks in-situ according to the technical specifications.
PT fused cast AZS block nozzle refractory is always cheap and used in the areas with no serious corrosion such as top crown, superstructure and feeder channel. The surface with scars should not be used as the working surface.
QX-Tilt casting
In this method, the mold is inclined at an angle. The shrinkage cavity in brick disperses at one end of the brick and a completely dense zone forms at another end. The feasible limits of cavity can be evaluated and indicated by the volume-weight testing of blocks in-situ according to the technical specifications. Meanwhile, blocks which height less than 900mm are not suitable to be manufactured by this process.
QX fused cast AZS block dry vibration mix is generally used in the sidewall of glass furnaces.
ZWS-Reinforced casting
Similar to WS, merely a few shrinkage voids remain in upper part of the body. A little part of the cavity will be remained at the end of the block after the header cutting. Block evaluation in-situ begins from the determination for the feasible size and deepness of cavity remainder at first and then to the volume-weight testing of blocks according to the technical specifications.
ZWS fused cast AZS block is always used in the sidewall of glass furnaces.
WS-Void-free casting
Additional liquid from the header fills sufficiently into a casting and the header is then cut off, so no shrinkage cavity exists in brick body. Block evaluation in-situ includes the refractory fiber felt acceptance or rejection for somewhat trace of cavity remainder which perhaps appeared and the volume-weight testing of blocks according to technical specifications.
WS fused cast AZS block has a wide application in the glass furnaces such as sidewall, tank bottom, feeder channel, doghouse, throat, dam wall, electrode wall and corner wall.

Casting is a manufacturing process by which the melt is poured into a mold to be solidified. Although the process is short, it is a complex process and every step is related to the quality of the final products.

Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

2016年6月26日星期日

Refractory Application in the Walls of Glass Furnace Regenerators

Assembled Bricks for Blast Tuyere
Good abrasion resistance, good thermal shock stability, high temperature strength, good erosion resistance.

Application

It is widely used in Blast furnace tuyere, the circumference of the tube outlet, mixed air entrance, flue gas pipeline, turning tube etc..
Chemical corrosion is not as strong as in the checkers because refractory brick for sale are protected by the masonry and only one side is exposed to the chemical attack. Load is higher than on the overhung zones, but temperature is lower. Periclase based refractories, mullite and sillimanite bricks are suitable for this application.
Characteristics of this area are: high load, low temperature and a reduced chemical attack. Basic materials with 90-92 percent MgO, mullite, sillimanite and 44 per cent Al2O3 “super duty” are suitable for this application.
The internal separation walls are insulating castable fully immersed in the high temperature environment and therefore the operating conditions are severe. They must resist loading at high temperature, and thus they must have high values of refractoriness under load and therefore high creep resistance.
Basic materials are suitable within the temperature limits indicated in the top zone (1,460-1,480°C), while different grades of mullite according to the different zones of the separation wall can be used.

In the glass furnace, walls of the regenerators are used to limit thermal losses. The main operating factors to be considered are temperature, repeated temperature cycling, airborne particulates, volatiles and load. Fuel and glass composition must also be considered when deriving the refractory specifications.
The walls in four zones as with checkers are subjected to different conditions:
1) Top zone: from the crown skewbacks to one meter under first row of checkers;
2) Mid zone: from the end of the top zone to 1,000°C;
3) Condensation zone: from 1,000°C to 700°C;
4) Lower zone: from 700°C to the Bottom.
The operating conditions are the same as for the crown but with minor load. Low iron basic refractories with a high periclase content and high grade mullite (95-97 percent mullite) are suitable for this area. As far as basic refractories are concerned the operating temperature must be under 1,500°C (1,460-1,480°C) to avoid creep.
Provided the target wall is exposed to the same conditions as the other top zone walls, then the refractory material will be as for the rest of the top zone. However, in the event the target wall is subject to excessive waste gas impingement then fused cast AZS block is recommended.
Checkers protect the mid zone wall. Temperature and load are lower compared to the top area, thus basic ladle refractory refractories with 95 per cent MgO or a good mullite are suitable for this area.

refractory company Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

http://www.yilongrefractory.com/AllProductServlet?id=1&number=20

2016年6月1日星期三

Molding methods of refractories and widely used refractories

Assembled Bricks for Blast Tuyere
Good abrasion resistance, good thermal shock stability, high temperature strength, good erosion resistance.It is widely used in Blast furnace tuyere, the circumference of the tube outlet, mixed air entrance, flue gas pipeline, turning tube etc..
There are many refractory material molding methods, such as common molding method, vibration extrusion method, extrusion method, pounding method and so on.
At present, when it comes to the production of firebrick refractory  materials, the most frequent way of molding refractory material is machine pressure molding method which is a way using brick molding machine and mold to compress the clay material into body. because the clay contains 5% water it is called semi-dry molding method. Machine molding is with compact structure, high strength, narrow drying and firing way, and size is also easy to control.castable  It can be divided into the single side pressure, and double sides pressure which can reduce the phenomenon of layer density.
refractory company The common refractory material are AZS brick, corundum brick, magnesite chrome brick, directly silica carbide, silicon carborundum brick, nitrides, silicides, sulfide, boride, carbide and other non oxide refractories materials; Calcium oxide, chromium oxide, aluminum oxide, magnesium oxide and so on..

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