Refractory material for torpedo car liner

Refractories for torpedo car liner, countries basically the same. In the complex structure and damageable parts, such as receiving iron mouth and nozzle etc., some with unshaped refractory materials instead of special-shaped brick, the use of more successful. America by phosphoric acid high alumina castable produced by iron mouth and spout lining, simple construction, no residue, long life. Japan, Germany, Britain and other countries of the torpedo car receiving iron mouth parts damaged,

the fire-resistant paint spray repair, also obtained better technical and economic results.

Foreign hot metal pretreatment with refractory materials generally use Al2O3 - SiO2 castables, the content of Al2O3 is 70% to 80%. If add SiC, C or Cr2O in the spray material, can effectively improve the anti slag corrosion, adding steel fiber will improve the spalling resistance. Recently developed zircon castable, the effect is relatively good. When the torpedo car using Al2O3 - SiC refractory brick, masonry should also be the same material of Al2O3 - SiC - C fire clay.

With the increasingly wide application of torpedo car, also put forward higher requirements on the selection of refractory lining, in addition to excellent, also should consider reasonable use question, in order to further extend the torpedo car life, and reduce the cost of.

Unshaped refractory --refractory mud introduction

Refractory clay is also called exothermic or joint material (powder material). Used as a refractory masonry building materials. By materials can be divided into clay, high alumina, and silica and magnesia refractory mud. Composed of refractory powder, binder and additive. Refractory raw materials can be made for almost all of the powder used to compound the fire clay. With refractory clinker powder and the amount of plastic clay as binder and plasticizer and made known common refractory clay, its strength at room temperature is low, formed at high temperature ceramics with high strength. Water, gas or heat hard binding material as the known chemical bond with refractory clay, below the form ceramic with temperature before that produce a certain chemical reaction and hardening

Selection of refractory slurry material, should consider and refractory masonry material consistent. Refractory clay except for building materials can also be used to smear method or spraying method is used as a protective coating of the lining of the body.

Mud properties and application of fire:

1. good plasticity, easy construction; high bond strength, anti erosion ability; high refractoriness, up to 1650 ± 50 ℃; anti slag is good; 5, good thermal spalling. Refractory clay is mainly used in the coke oven, glass furnace, hot blast furnace, and other industrial furnace.
2. the application of industry: metallurgy, building materials, machinery, petrochemical, glass, boiler, electric power, iron and steel, cement, etc…

Advantages of castable in refractory material

General portland cement concrete can not withstand high temperature operating conditions, precipitation of calcium hydroxide in the hydration process, it becomes calcium oxide at high temperatures; As aggregate of limestone under high temperature thermal decomposition, strength destroyed.strength destroyed.

Ordinary concrete can only be used below 300 ℃ low temperature parts of the foundation and chimney stove. The castable temperature up to 900 ℃ or more.

Compared with other refractory castable has some distinctive features:

(1)Castable has almost same refractoriness with the firebrick, but because castable without sintering, the larger contraction when heated first time, so the load is slightly lower than the softening point firebrick. Nevertheless, a measure of overall performance is better than firebrick.

(2) As the effect of low temperature cementation materials, castable has high temperature compressive strength. and because masonry's good integrity, furnace air tightness, not easily deformed, outside the furnace shell plate can be canceled, stoves resistance to mechanical vibration and shock performance is better than brick masonry. For example, the upper sidewall of soaking furnace, where mechanical abrasion and impact are more severe, life expectancy increased by several times than brick.

(3)Good thermal stability, most or all of the aggregate are clinker,;expansion and contraction of cementing material phase offset,

Relatively speaking,the thermal expansion of masonry is smaller than a brick, thermal stress is also small. And there are a variety of mesh, needle and chain crystalline phase structures, a strong resistance to temperature.For example, to pouring soaking furnace mouth and lid. Life expectancy to a year and a half.

(4)The production process is simple, eliminating the complex steps of brick making. Castable can be made into a variety of prefabricated blocks, and to mechanized construction, brickwork greatly accelerate the speed and improve the efficiency of more than ten times higher than bricklaying. Waste bricks can also use as aggregate, waste for profit.

Species and characteristics of clay

Alumino silicate clay is dominated by rocks, such as feldspar pegmatite granite, porphyry, gneiss, etc. The long-term weathering, and often through water transport and deposition are too many fine mineral mixture, its main chemical composition of SiO2, Al2O3, and water of crystallization. With different geological formation conditions, may also contain small amounts of alkali metal oxides, alkaline earth metal oxides and coloring oxides.

Varieties and uses a lot of clay, often according to mineralogical, geological origin, chemical composition, physical properties or industrial uses clay classification.

1. More clay minerals in the main types can be divided kaolin clay series, smectite and illite clay series. 
2. According generation, the clay can be divided into the native clay (Primary clay) and secondary clay (Secondary clay), the native clay is the generation after feldspar weathering of silicate hydrous kaolin and other minerals, quartz, etc., is not completely broken weathered residual debris in situ, and soluble salts were dissolved; secondary raw clay is a former clay transferred under dynamic conditions to the rest of the natural crystalline clay again.
3. According to the plasticity of clay can be divided into soft clay (strong plasticity clay), semi-soft clay (clay plasticity) and hard clay (clay plasticity weak), mostly secondary soft clay clay, because fine particles dispersed degree, so plasticity; hard clay and more by diagenesis ancient community, and the lack of free water is not easy to dip into the bulk, plasticity poor.

Some Western industrialized countries often comes down to the clay six categories, namely: Kaolin (Kaolin), fire clay (Fire clay), ball clay (Ball clay), bentonite (Bentonite), bleaching earth (Fuller, s earth) and the general clay (Common) where bentonite, fuller's earth and ordinary clay mainly composed of montmorillonite, illite and chlorite, etc., poor fire resistance.

Classification and habits at home and abroad, the refractory clay Category: kaolin, ball clay and fire clay. Natural clay minerals according to the above classification is not always a sharp distinction between, and sometimes a clay can contain a variety of clay, but the performance is also superimposed on each other, such as mineral composition and chemical composition of many hard clay and kaolin are very close; many balls soft refractory clay and the clay of the same physical properties. Regardless of how the kind of clay, clay determine its performance properties.

Use of recarburiser

Carbon additive is an additive used in steel making. It is an essential raw material for the production of high-quality steel. Further, also the production of the electrode paste material.

After pressing graphite powder,

can greatly increase the amount of scrap castings production, reducing the amount of pig iron or no iron in an electric furnace smelting, will increase carbon agent in the middle, (the latter part of the furnace discharge material put Recarburizer) added measure is 1-3% metal content. Recarburizer characterized by carbon absorption in liquid iron in effect, does not return slag, using carbon agent can greatly reduce the casting cost of production.

Advanced refractory and coatings are widely used in metallurgical industry, steel core light industry, electrical industry, carbon brush, electrode in battery industry, fertilizer industry catalyst. Graphite after processing, can produce graphite, graphite paper, graphite sealing materials and other graphite products, has become an important non-metallic mineral raw materials in various industrial sectors.