Analysis of low cement castables for cement kilns has a strong shock resistance

Not the same product, will bring a different effect, low cement castable cement kiln to bring what effect. Low cement castables mainly bauxite as raw material, high-performance calcium aluminate cement dosage is only 2 to 6%. The main production of ingredients than: brown steel jade 15-24, silicon carbide 6-15, coke 20, white mud 12-16, tar 18-20. Calcium oxide content is low, can reduce the formation of eutectic phase, improve the refractoriness, high temperature strength and slag resistance, for the cement kiln plays a very important role.

The raw materials were dried for 24 hours and then dried at 110 ℃ for 24 hours, respectively, and heat treated at 300 ℃, 500 ℃, 700 ℃, 900 ℃, 1100 ℃, 1300 ℃ and 1500 ℃ for 3h. (PM), linear change rate (PLC), room temperature flexural strength (MOR), room temperature compressive strength (CCS), room temperature wear resistance and thermal expansion coefficient and heat resistance of the samples were measured. Seismic performance. The results show that with the increase of heat treatment temperature, the volume density of low cement refractory castable in cement kiln decreases first and then increases again. The change rate of line decreases first and then decreases The strength of the room temperature and the compressive strength at room temperature increased first and then increased. Cement kiln with low cement castable after 1500 ℃ heat treatment after the wear less than 1300 ℃ heat treatment after the wear and tear.

So that the use of low cement castables in cement kilns has a strong shock resistance. Cement kiln construction qualified rate increased by 2%, punctuality rate also increased by about 6%, it is important that the cement kiln safety factor and service life has been improved greatly, and fully reduce the cost of secondary construction of cement kiln.

What is the role of refractory cement in refractory castables

Refractory castable is made of refractory cement (10% to 15% by weight) and refractory aggregate. Therefore, refractory cement is also an indispensable part, but it also causes a series of properties of refractory castables The decline.
The main reasons for the following reasons:
1, in order to complete the hydration of cement, stirring too much water (10% to 15%) caused by ceramic refractory castable significantly higher porosity, density decreased.
2, calcium aluminate hydrate in the middle temperature stage has a strong dehydration and recrystallization effect, destroying the hard material in the castable structure, so that refractory castable in the temperature stage of the sharp decline in strength.
3, cement binder will be more calcium into the castable, resulting in ceramic refractory castable load softening temperature drop, thermal shock stability performance deterioration. In view of the problem of poor performance of ordinary refractory castable, low cement refractory castable effectively avoids the regret of high temperature performance. The so-called low-cement refractory castables, which contain less than 8% of the cement content, and less than 4% is called ultra-low cement refractory castable. In contrast, the general Refractory company castable above mentioned deficiencies are converted into low cement refractory castable advantage. Its structure is dense. Low porosity, high refractoriness, high softening temperature, high temperature strength, good thermal shock stability. But because of its low cement content, resulting in a long time of condensation, early strength in the winter and low temperature conditions, construction is particularly unfavorable. So in the masonry, to give full attention.

Low Cement Castable is More Widely Used in Aluminum Industry Than Before

Low cement castable mainly uses alumina material and silica powder as raw materials. It is a kind of powder materials, and is constituted by refractory material together with some agglutinant.

With the development of aluminum industry, the Clay, High Alumina insulating bricks for aluminum alloy melting furnace and holding furnace has been changed from phosphate combined high alumina brick to low cement castable which can prevent molten aluminum permeate refractory products. At the same time, it can extend service life of refractory material at high temperature.

When comes to the heating surface of aluminum, aluminum alloy melting furnace and holding furnace, the low cement castable has taken place of the phosphate combined with high alumina brick. The reasons are as bellow, there is smaller pore size in the structure of low cement castable, molten aluminum and aluminum alloy cannot permeate refractory company easily. It can avoid the oxide in refractory restoring from aluminum. At the same time, the low cement castable possesses high wear resistance. In recent years, as the low cement castable uses molten aluminum as additive, which increase the wetting agent, so the performance has been improved. This kind refractory material has taken place of traditional phosphate combined high alumina brick and low cement castable gradually.