Due to the advancement of science and technology and the rapid development of society, the metallurgical industry has also developed rapidly, so that the demand for refractory materials has also increased with the development. Among them, the effect of bauxite as refractory is very significant, and bauxite rotary kilns are often used. It is processed and calcined. The bauxite referred to in the refractory industry usually refers to bauxite with alumina ≥ 48% after calcination, and a lower content of iron oxide. Bauxite is sintered at a high temperature of about 1350 degrees, and is converted from raw meal to clinker. So bauxite has two kinds of clinker and raw material, so what is the difference between the two? How to tell? Today, the editor of the bauxite manufacturer will take you to learn about it and make further detailed analysis for you.
First of all: the main difference between the two is the type of minerals, the raw meal is kaolinite and diaspore. The clinker is mullite. Bauxite clinker is processed and calcined from raw meal, which is the predecessor of clinker.
Bauxite, also known as bauxite and bauxite, is mainly composed of alumina, which is hydrated alumina containing impurities and is a kind of soil. The color is white or off-white, brownish-yellow or reddish due to iron content. The density is 3.9~4g/cm3, the hardness is 1~3, opaque, brittle, extremely difficult to melt, insoluble in water, soluble in sulfuric acid and sodium hydroxide solution. The bauxite raw stone is an alumina mineral containing crystal water, and the raw materials such as monohydrate bauxite and trihydrate bauxite are kaolinite and diaspore. It is the main raw material for the production of industrial alumina, refractory materials, abrasives, ceramics, high alumina cement and other products. Our country is extremely rich in bauxite reserves, which originate from Shanxi, Hebei and Shandong in the north of the Yellow River, through Henan and Guangxi in the middle to Guizhou and Yunnan in the southwest.
Bauxite raw materials can be divided into bauxite white materials, yellow materials and red materials according to their uses and colors. Due to different uses, bauxite yellow material does not look at a single aluminum content to customize the price. It can also be classified into 3 points, 4-5 points, and 6-10 points bauxite by point (aluminum-silicon ratio).
Bauxite clinker, referred to as high alumina material, is a solid block material calcined at high temperature in a rotary furnace. The main purpose of calcination is to remove crystal water and increase alumina content. The clinker is gray-white, light-yellow and dark gray bauxite clinker. Bauxite clinker can be divided into: bauxite fine powder: 170 mesh, 200 mesh, 325 mesh (manufacturers can produce various specifications according to customer requirements).
High alumina bauxite clinker has a refractoriness of up to 1780 °C, strong chemical stability, good physical properties, and a very significant refractory effect, so it is widely used in refractory materials and anti-corrosion materials in the metallurgical industry. The clinker is processed into fine powder and made into a mold and then precision cast, which is used in the military, aerospace, communications, instrumentation, machinery and medical equipment sectors.
Second: it can be identified by color. However, this method will have some drawbacks, and there will be inaccurate accuracy. It can also be sent to the relevant testing department. When bauxite is sintered at high temperature, the color will change when it is converted from raw material to clinker. The appearance changes from the original gray, dark gray, gray-yellow, gray-white, red-yellow and other colors to white, beige, brown-red, blue, and the blue deepens with the increase of aluminum content. The original earthy luster becomes corundum luster or grease luster, and sometimes slight molten stone or cracks appear on the surface. The color of bauxite clinker is affected by many factors, mainly due to the composition of raw materials and calcination conditions. For the composition: if the iron content is high, it will be reddish-brown, and the titanium content will be blue-brown. Calcination conditions include: fuel (gas fuel is different from coal fired fuel), type of kiln (rotary kiln and down-flame kiln), heating system for calcination, etc.
Bauxite is divided into metallurgy, chemical industry, refractory, grinding, cement and so on according to its use. Used to make refractory materials, this bauxite is called refractory bauxite.
