Effect of Aluminum Dihydrogen Phosphate Solution on High Aluminum Refractory plastic refractory

Refractory plastic refractory is an important variety of unshaped refractory materials, which can be divided into raw clay and composite binders such as aluminum sulfate, phosphoric acid, phosphate, water glass and resin.

Phosphoric acid or acid phosphate combined with plastic refractory is characterized by good medium-high temperature bonding strength, good wear resistance and good thermal shock resistance. Acid phosphate combined with high aluminum plastic refractory products are widely used as wear-resistant lining materials for thermal equipment such as circulating fluidized bed boilers and garbage incineration boilers.

Most of the plastic refractory needs to be stirred in the construction site. With the influence of temperature, humidity and human factors, there are often sites with unstable binder addition, which brings uncontrollable quality to the construction.

As a phosphate manufacturer, I will talk with you today about the effect of the addition amount of aluminum dihydrogen phosphate solution on high aluminum refractory plastic refractory.
sample preparation

The basic formula is as follows: the addition amount of primary alumina aggregate in vertical kiln is 54%, the mixed powder of inverted alumina fine powder, alumina fine powder, flint clay fine powder and binding clay is 38%, phosphoric acid with concentration of 42.5% is 5%, and hardening accelerator is 3%. Weighing materials according to the basic formula, uniformly stirring the aggregate and the mixed powder, slowly adding phosphoric acid, fully mixing, sealing and blocking the materials for 24h. The trapped test material is added with hardening accelerator and 8%, 9% and 10% aluminum dihydrogen phosphate respectively for stirring. The stirred test material is tamped and smeared in a 40mm×40mm×160mm, 100mm ×100mm×30mm mould for later use. After natural curing, the sample is dried at 110 ℃ for 24 hours and then heat treated at 850 ℃ in an electric furnace. According to GB/T3001-2007, GB/T5072-2008, GB/T18301-2001 and YB/T5200-1993 standards, the conventional physical properties after demoulding, drying and 850 ℃ heat treatment are detected.
Finally, the following three conclusions are drawn
1. Effect of Aluminum Dihydrogen Phosphate Addition on Construction Performance of plastic refractory
With the increase of aluminum dihydrogen phosphate addition, the plastic refractory group gradually softens and generates fluidity, which is easy to fall during construction.
When the addition amount of aluminum dihydrogen phosphate is less than 8%, the aggregate is hard and needs ramming construction.
When the aluminum dihydrogen phosphate is added in an amount of 9%, the material mass is moderate in hardness and easy to construct;
When the amount of aluminum dihydrogen phosphate added is 10%, the aggregate will be soft and drop after construction. The experiment shows that the material has the best on-site construction performance with the addition of 8% ~ 9% aluminum dihydrogen phosphate.
2. Too much aluminum dihydrogen phosphate will affect the apparent porosity and bulk density of plastic refractory
The apparent porosity increases with the addition of aluminum dihydrogen phosphate, while the bulk density decreases with the addition of aluminum dihydrogen phosphate.
3. Excessive addition of aluminum dihydrogen phosphate will affect the strength and wear resistance of plastic refractory
Excessive addition of aluminum dihydrogen phosphate solution will also lead to obvious decrease in compressive strength and flexural strength, and increase in wear ( decrease in wear resistance ).
For the high-alumina wear-resistant plastic refractory in this experiment, with the increase of the amount of solution, the mass of plastic refractory material gradually softens, and the addition amount is more than 9%, and the material is easy to fall after construction. The apparent porosity of the sample increases with the increase of solution addition, while the bulk density decreases with the increase of solution addition. The demoulding strength, drying strength and strength after 850 ℃ heat treatment show obvious downward trend with the increase of solution amount, and the wear resistance decreases, etc.
Therefore, Zhengzhou Yucai Phosphate Chemical Factory reminds all users to carry out on-site construction in strict accordance with the construction instructions. On the premise of ensuring the construction performance, the addition amount of binder should be strictly controlled.