Reason of casting refractory material for high temperature resistance

Casting refractory material, its main characteristic is high early strength, 3-7 days maximum compressive strength can reach more than 30MPa, and the disadvantage is the volume stability of temperature difference, the intensity decrease, the maximum fall by up to 40%, so the requirements for compressive strength must meet the design requirements and national standards.

The temperature reduces the strength of the main factors are: Casting reaches a certain temperature with low calcium and high alumina cement fireproof material in the heating furnace heating process (350 DEG C), dehydration, transformation of the hydrate started hydrate of cement stone structure, compactness and strength decreased, the volume of pouring material change, this time to the strength of castable the lowest point, after stabilizing. With the heating temperature up to 1100 DEG C, cement stone gradually sintering, casting crystalline refractory mullite crystal transformation. With the temperature rising, mullite crystal growing, a glass matrix liquid phase pouring material, forming a high temperature sintering shape, strength increase. At about 1300 DEG C, casting refractory material strength can reach more than 60MPa, a remarkable characteristic of refractory materials under high temperature condition for this is pouring.

Anhydrous stemming and its main characteristics

Anhydrous stemming is to continuously improve the production of pig iron (especially after burning), with the traditional water stemming tadpole maintenance is not good situation, after repeated testing and improvement, a new type of refractory material is developed, which adapts some advanced refractory materials and chemical raw materials, with advanced and a unique process preparation, its advanced technology, excellent quality, less consumption, there is a water gun mud can not be comparable, the blast furnace iron mouth maintenance, flow stability, promote the safe production, plays a role is the key to reduce the accident potential.

The main characteristics of anhydrous stemming:

Compared with the traditional water gun mud, has the following advantages using anhydrous stemming:

1, less dosage, high strength. Anhydrous stemming each time only needs to install the 80-120kg, as the water gun mud made of new refractory materials, especially high strength, with clay content can be less ensuring tadpole depth; high temperature resistance, anti slag erosion, non stick iron slag, iron mouth without baking, is another characteristic of anhydrous stemming, from the tadpole maintenance is very convenient.

2, flow stability, an accident is not easy. The anhydrous stemming high strength, using drilling drilled iron mouth aperture always remains the same size; ensure the hot metal flow uniformity, reduce or avoid running large flow, diffuse iron slag, explosion accident occurred. At the same time, can greatly reduce the labor intensity of workers.

3, ensure net iron slag, promoting the furnace, using anhydrous stemming generally, aperture iron mouth than the use of water stemming from aperture small, under the same pressure, anhydrous stemming, can fully guarantee the blast furnace slag and iron out net, the hearth, active space, and promote the furnace operation, and is conducive to strengthening smelting, improve the management of the production of pig iron.

The operation of corundum castable

We usually do not know how many of corundum castable understand, then give you some tips and tricks, discuss with you today is the knowledge of its sample. The following summarizes the four o’clock related content, you can carefully read this:

1. When the sample production and maintenance, the ambient temperature is 20 ℃ ± 1 ℃. Using 40mm × 40mm × 160mm mold making.
2. When the ingredients must first aggregate, (A + B) and part of the cement binder Stir respectively, and then press the 93:7 (A + B): 0.15 Weigh aggregates, cement binder. The weighed aggregates, cement and additives used in the experiment into the dry mix mortar mixer for 2-3 minutes, then add clean tap water, add water to the total weight of material 4.8 to 6% (press the lower water, in pourable performance guarantee provided to minimize the amount of water), stir 3 to 5 minutes until construction material has good plasticity, can be cast.
3. Good material into the wet mix tryout, on the vibration table to make it sufficiently dense vibration.
4. Forming complete specimen placed 20 ℃ environment conservation with mold release after 36 ~ 48h, after stripping the sample before drying treatment after 48 hours and then the Nature Conservancy.

These are the relevant content corundum castable sample operation, we can refer to, and I hope to help you understand the product. Today’s content introduced here, want to know more you can continue to focus on our product knowledge.

China is already a big country of production of refractory materials

Refractories industry is developing with the development of the national economy, up to now, refractories industry is still in the development of the industry plays a vital role in. 1-3 months of 2014 China’s refractories production reached 24135668.45 tons, accumulated year-on-year growth of 9.51, in March production reached 9242563.07 tons, grow 11.89 compared to the same period.

The data can be seen, Shanxi province in 2014 1-3 month refractory cumulative year-on-year growth of larger, reached 15.22, and the area of March declined by 17.45 percentage points. Hebei is the largest decline in 1-3 months, the decline range 28.35, its output in March also decreased by 31.76, it is not difficult to see that, in spite of the refractory total output is rising, but the various regions, there are up and down, development is not stable.

At present our country has large production of refractory materials,but the overall technological level and industrial structure still have greater disparity with the international advanced level, the development trend is also big ups and downs, these problems are restricting the development of the industry. If not promptly improved, if things go on like this, the industry will face more backward embarrassing situation.

In future development, refractories industry must speed up the adjustment of industrial structure, eliminate backward production capacity, improve the level of production technology, to the international market as the guide, and gradually to the development of low energy consumption, high quality, to win in the market competition in the stability, better development!

Matters needing attention during the construction of the castable refractory

Refractory castable is a widely used refractory products, it is there for many industries are very popular, because often used to this kind of refractory products, so today Xiaobian to introduce the construction of refractory castable, should pay attention to the related matters.

The first step in the pre construction should be strictly examined, including: (1) to form a clear structure of castable refractory equipment is, and it will be clean. (2) to know have the process holes (3) construction require the use of the equipment must be in good condition, so we can ensure that the work can be carried out smoothly, (4) to know how is refractory castable packaging and delivery date, check whether the product failure. Using the second step is the construction of templates you can use steel or hard wood. But must ensure that the template has a very good rigidity, also is the strength to be good enough, so as to ensure not to use when running, will not shift, leakage. The use of wood template you must brush on a layer of waterproof paint, but steel template will be used in addition to mold agent, want to save template words, must be cleaned before use.

The final point to note is the lining refractory castable, stirring time, time can not be less than 5 minutes, can not use ordinary mixer, and to the use of forced mixer, must first dry mixed before mixing, then adding 80% solvent mixing, slowly stirring to obtain suitable work consistency. If there is something still unknown that you can contact us freely.

Refractory ramming material and its characteristics

Refractory ramming material is bonded granular material consists of very high proportion and the proportion of very low and other ingredients, even all the grain, powder material, to the strong pound bulk material to fight the way construction.

Because the ramming material is mainly used for direct contact with the melt, the grain, powder material must have high volume stability, compactness and erosion resistance, used for induction furnace should also be provided with insulation.

Bonded ramming choice should be appropriate, some without bond, some only add a small amount of flux. Acidic castable material commonly used sodium silicate, ethyl silicate, silica gel bonded, the dry ramming material with borate; alkaline ramming material used magnesium chloride and sulfate; often use carbon containing higher at high temperature can be formed with organic carbon and temporary binder. The dry ramming material and fluxing agent amount of iron. Chrome ramming material used to mount pin.

Other unshaped refractory materials compared with similar material ramming material, a dry or semi dry loose,

rely on the strong ramming to obtain compact structure, only the heating to the sintering temperature, the combination will have the strength. Castable refractory after forming, according to the characteristics of mixed hardening, adopt different heating methods to promote the hardening or sintering.

Such as containing inorganic chemical bond, self hardening reached a considerable strength after baking mould; containing thermoplastic carbon mixture, after cooling has considerable strength and release, before use should be rapidly heated and coking; without bond hardening at room temperature, often with a model for sintering in the ramming.

Three common kinds of refractory castable

Refractory castable is monolithic refractories that widely produced and used currently. Mainly used for the construction of various heating furnace lining and so on overall structures. Some high quality varieties can also be used for smelting furnace.

Such as aluminates cement castable can be widely used for various heating furnace and other no residue, no corrosion of thermal equipment, and is the main varieties of refractory castable unshaped refractory materials, according to the different of the cementing material, curing and molding mechanism can be divided into three that hydraulic, air hardening and fire hard.

1. Hydraulic refractory castable: Using cement as the cementing material pouring in the hardening process require water to take part in a chemical reaction, forming a gel hardening strength, are hydraulic refractory castable. Cement is to determine the strength of castable (especially the atmospheric temperature strength) of the main factors, but its refractory degree is relatively low, so in that room temperature strength necessary, should as far as possible to reduce the amount of cement. If in order to compactness and construction workability, can be appropriate to increase the refractory powder. Reduce the amount of cement is also one of the measures to reduce the cost of. The construction should be strictly prevent aluminate cement and Portland cement, lime mixture. Because these two kinds of different chemical composition of the mixture will produce water aluminum acid calcium three, which greatly reduced strength.
   
2. Air hardening castable: Refers to the cementing agent in the maintenance of the absorption of CO2 in the air gradually solidified hardening. Refractory castable is the most commonly used water glass refractory concrete. Water glass refractory castable besides the performance of high-temperature resistance, it is acid resistant, abrasion performance, so often used as chemical equipment lining. Water glass, refractory castable process hardening under natural conditions is very slow, need to add coagulant in the construction (sodium fluorosilicate, high alumina cement).
3. Fire refractory castable: Using phosphoric acid and phosphate castable binder, need to pass through the heating and baking to obtain the strength and high temperature performance, so that the fire refractory castable.