High Alumina Grade Sintered Mullite from China

Sintered mullite

Introduction

Mullite is a kind of advanced raw material, with unified thermal expansion, good thermal shock resistance, high refractoriness under pressure, low creep value, high hardness and good chemical corrosion resistance.?Because natural mullite is rare, sintering and electromelting mullite are widely developed.

Mullite is a series of products, according to different sintering methods and formulas can produce different grades of products.

Processing

1.?Mineral separation and determine the appropriate formula based on the chemical composition of the raw materials. Different grade of the products, also different formula. Such as 45% content alumina grade mullite, 60% content alumina grade mullite, 70% content alumina grade mullite, etc.

2.?After crushing the various raw materials needed, they are evenly mixed together, and wet-milled into a 325 mesh slurry with a water content of about 60%.

3.?Most of the water is removed with a filter press and?dried to make the water less than 10%.

4.?Remove metal impurities and squeeze the dry mud into sticks, then dry again to make the moisture less than 1%.

5.?The dried stick slurry is calcined in a rotary kiln or a tunnel kiln. Depending on the product grade, the calcination temperature is also different, such as 45% mullite at 1500 degrees, 60% mullite at 1650 degrees, 70% mullite at 1750 degrees, etc.

6.?After the calcination reaches the peak temperature, the temperature is slowly lowered to form the mullite ore phase.

7.?After being completely cooled, it can be crushed, screened, bagged, etc.

There are three main grades of mullite:

1.?Low alumina mullite with about 45% alumina;

2.?Medium alumina mullite with about 60% alumina;

3.?High alumina mullite with about 70% alumina.

?

Application

Mullite ore is used in the production of high temperature refractories, ceramics, metallurgy, foundry, electronics and other industries.?It has high temperature resistance, high strength, small thermal conductivity, energy-saving effect and other characteristics.

Mullite is mainly used in the following applications:

First,?Refractory material field.

Refractories prepared from mullite are widely used in high-temperature equipment such as muffle furnaces, calciners, boilers and rotary kilns. The high temperature resistant equipment prepared by mullite is not only high temperature resistant, but also long life and corrosion resistant.

Mullite refractory castable generally uses mullite aggregate as raw material,?and configured into a kind of low temperature insulation refractory material, generally used in petrochemical industry tube heating furnace, light diesel fuel, sulfur recovery device, steam boiler, etc. The advantage of mullite refractory castable is that its refractory temperature is higher than other thermal insulation castables, so it can be directly contacted with the flame and used directly as the lining of the furnace.

?

Second, Electrical field.

Modern computer systems are composed of ultra-high performance integrated circuits, which has led to extensive research into ceramic substrates with low dielectric constants. The application of mullite in the field of electrical properties is reflected in its ability to serve as an excellent substrate material, it has?a very low dielectric constant and can bear high?line density. Therefore, mullite ceramics and mullite-based glass-ceramic composites are used as high-performance integrated circuit materials.

Third, Other Fields.

Mullite has many applications in other fields?as well. For example, mullite can be used as permeable ceramic components, which are characterized by high mechanical strength, more uniform distribution of pores and good permeability. In addition, mullite composites can be used as catalyst carriers with good chemical stability and heat resistance, and can be loaded with a variety of catalysts for petroleum cracking, automotive exhaust treatment, and wastewater treatment. Mullite ceramic alloys can also be used for brake pad linings, which are now widely used in aircraft and high speed rail?systems as well as automotive brake pads due to the material's better heat and wear resistance than polymer-prepared brake materials.

?

?

Characteristics of mullite

* Uniform expansion

* Excellent thermal shock stability

* High load softening point

* Small high temperature creep value

* High hardness

* Good chemical resistance

All the characteristics make mullite the best choice as a refractory.

Know more information about refractory, please follow us and can also visit our webisite:https://www.seppe.cn

Any inquiry of mullite can contact by email: [email protected]