Particle Size Gradation of Alumina-Based Low-Cement Castables

To optimize the particle packing of the castable, different types of aluminum oxide micropowders can be used to form the matrix. These include calcined, semi-reactive, unimodal, or multimodal alumina micropowders. Effect of specific particle size distribution (PSD) of various alumina micropowders on low cement castable properties. And compare the addition of different types of water-reducing agents to understand their impact on the finished castables.

Rongsheng Low Cement Castable

Selection of Aluminum Oxide Powder

The alumina micropowders used in the test include calcined alumina micropowder, bimodal activated alumina micropowder, and single-modal activated alumina micropowder. The test was conducted using low-cement castables with tabular corundum as aggregate, and the castable formula was optimized using the particle gradation models of DINGE and FUNK. The constant coefficient is set to 0.27. The first series studies the application of 3um calcined alumina products, which are divided into castables without silica fume and castables containing silica fume. In the second series, 3um calcined alumina and different proportions of unimodal activated alumina are added as the matrix to achieve bimodal alumina performance. The final series examines the effect of bimodal alumina on the particle size distribution in low-cement castables. When the amount of water added in each series is constant, the construction performance, fluidity, cold flexural strength, and load softening temperature of the castables are measured.

The Influence of Aluminum Oxide Powder on Castables

Research shows that not only the d50 of alumina micro-powder but also its particle size distribution curve is crucial to optimizing the rheological properties of alumina-based low-cement castables. By adjusting the shape of its particle size curve, the possibility of using 3um calcined alumina to have suitable flowability in many castables increases. In applications that require lower water additions, the calcined product can be compounded with single-modal active oxidation micron powder to achieve the desired particle filling optimization. For bimodal alumina, controlling the particle size distribution, with the presence of very fine particles in d10 and good top cut in d90, can increase flowability, reduce mixing time, and improve physical properties. In addition to the particle size distribution of alumina, additives play an important role. There are differences from one alumina to another, and additives should be selected and adjusted according to the type of alumina.

High-Alumina Castables Refractory for Sale

60 Refractory Castable GL60 High Aluminum Refractory Castable Boiler Hot Blast Stove Refractory Castable

Refractory castables made of high-aluminum raw materials as aggregates and powders, and adding binders. It has high mechanical strength and good thermal shock resistance and abrasion resistance. It is mainly used as the lining of boilers, blast furnaces, heating furnaces, ceramic kilns, and other kilns.

GL60 high-aluminum refractory castable is synthesized from high-aluminum refractory aggregates, powders, binders, and admixtures in proportions. It has the characteristics of good high-temperature performance, high durability, wide operating temperature, and no shrinkage or damage. It is widely used in hardware, smelting, chemical industry, non-ferrous metals, and other industries, especially in the steel industry. Mainly used in rotary kiln front kiln mouth, dismantling furnace, kiln head cover, and other parts. High aluminum castables are divided into conventional and low steel types and steel types.

60 refractory castable, boiler hot blast stove refractory castable, is a refractory castable made of high alumina bauxite clinker as aggregate and powder, adding binder and dispersant. The integral lining material can be poured directly or refractory prefabricated parts can be spliced together.

RS refractory material manufacturer has an environmentally friendly, fully automatic unshaped refractory material production line. Our refractory products have been sold to more than 100 countries around the world. The product quality is reliable, and the formula of refractory materials can be customized according to the customer’s actual working conditions. For product packaging, we use 25kg/bag or 50kg/bag woven bags according to user needs and then use ton bags. Contact us for a free refractory lining solution and quote.

Do You Know the Difference between High Alumina Bricks and High Alumina Castables?

High alumina bricks and high alumina castables are both commonly used refractory materials and can be used in the construction of high-temperature industrial kilns. The common feature of both of them is that they contain a large amount of Al2O3 in their composition, and both of them can resist high-temperature erosion. But the difference between the two is still very big. So what are the differences between high alumina bricks and high alumina castables? As an experienced refractory material manufacturer, Rongsheng Refractory Materials Manufacturer has accumulated rich experience in high alumina bricks and high alumina castables.

High Alumina Bricks Lining

The Difference between High Alumina Bricks and High Alumina Castables

1. Different forms

High alumina bricks are shaped refractory materials. It has a fixed shape and size. The general standard refractory brick size is 230*114*65mm. High aluminum castables are unshaped refractory materials. It has no fixed shape, generally exists in powder form, and is usually stored in bags.

2. Different production methods

The main production method of high alumina bricks is to form the well-proportioned raw materials through high pressure and then sinter them at high temperatures to form a fixed shape. The production method of high-aluminum castables eliminates the need for high-temperature sintering and high-pressure molding. It is directly bagged after the raw materials are proportioned.

3. Different construction methods

High alumina bricks can be used directly during construction, and usually need to be used with high-temperature cement during use. High-aluminum castables need to be stirred by adding water, then poured into a fixed mold, and then air-dried and shaped. After finalization, the entire kiln needs to be baked before it can be put into use.

High Alumina Castable Lining

The difference between high alumina bricks and high alumina castables. Among them, the biggest difference between the two is still in the form, one is in a fixed shape and the other is in powder form. Although both can be used as masonry for kilns, for some occasions with special shapes and difficult construction, the construction difficulty of castables is obviously lower than that of high alumina bricks.

How to Choose High Aluminum Castables?

We all know that high-aluminum castable is a refractory castable with relatively high alumina content. It is widely used in the construction of high-temperature kilns. It has the characteristics of superior fire resistance, high-temperature resistance, corrosion resistance, and oxidation resistance. Therefore, the range and frequency of use are very high. But it is very important for us to choose good high-aluminum castables when purchasing. Its quality determines the service life of the high-temperature kiln and the quality of the materials smelted during use.

First of all, we need to know that high-aluminum castables are composed of aluminates, silicates, oxides, etc. In order to ensure the effect in a high-temperature environment, we must strictly follow the requirements when proportioning raw materials. Incorrect raw material ratio will seriously affect the performance of the entire castable. Therefore, we need to confirm with the manufacturer’s technical personnel when purchasing and inform the technical personnel according to the occasion of use. Technicians will provide you with a variety of options based on your usage situation.

How to Choose High-Aluminum Castables

Secondly, we mainly look at the following aspects that affect the quality of high-aluminum castables during use. Including compressive strength, thermal stability, thermal conductivity, thermal expansion coefficient, etc. The testing agencies of these manufacturers will issue reports when they submit them for inspection, so we must ask the manufacturers for the inspection report when purchasing. From the report we will get some parameters we want if the parameters meet the standards or are above the standard line. It shows that the quality of high aluminum castable is good.

Also, when we purchase high-aluminum castables if the above two aspects meet the standards, we can first purchase some samples from the manufacturer for experiments. This can ensure to the greatest extent an effect on our future use. If the experiment is qualified, it will not be too late for us to purchase in large quantities. If we make large-volume purchases without conducting experiments in the early stage, our losses will be very large. This will not only be the cost of raw materials, but also our entire kiln may need to be reconstructed.

Everyone must know how to choose high-aluminum castables with good results. Finally, when purchasing, we must consider the overall cost and performance. In addition to considering various indicators of raw materials, understanding the manufacturer, brand, and market reputation of the product is also one of the important factors in ensuring the selection of high-quality high-aluminum castables.

In addition to the methods mentioned above, we also need to pay attention to the following points when purchasing high-aluminum castables. First of all, we must choose high-aluminum castables produced by regular manufacturers, so as to ensure the quality and performance of the product. Secondly, pay attention to the packaging method of high-aluminum castables. Generally speaking, the packaging should be tight and there should be no damage or air leakage to prevent the product from being damaged during transportation. In addition, carefully check the production date and shelf life of the product, and choose products with a recent production date and a longer shelf life to ensure product quality and performance. Finally, you should consult the manufacturer’s after-sales service to understand the after-sales guarantee and technical support of the product, so that you can get timely help and support if problems arise during use. By comprehensively considering the above factors, selecting high-aluminum castables with excellent performance and reliable quality can provide a strong guarantee for the construction of high-temperature kilns and the production of smelting materials.