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Alumina Chemical Composition

Hangzhou JWG Technology Co.Ltd | Updated: Oct 26, 2017

Bauxite (commonly known as high alumina clay or high bauxite) refers to a mineral containing refractory clay. Refractory clay, refers to the refractor degree greater than 1580 ℃, can be widely used in a variety of industrial furnace lining materials, the main component of aluminosilical mineral raw materials, according to its physical and chemical properties, ore structure and industrial characteristics, Divided into soft and semi-soft clay, hard clay and high alumina clay. Soft clay is generally soil-like. Low hardness, easy to fly in water, after the formation of plasticity can be plastic mud group, with strong adhesion, commonly used as a refractory products, alumina content of less than 35%. Semi-soft clay is poorly finely dispersed, or partially submerged, and the contaminated portion is mixed with the liquid to form a plastic clay, which is often used as a binder and as a binder. Hard clay is usually massive or plate-like, generally not in the water, do not have plasticity, alumina content of 36% to 50%, refractoriness 1670 ℃ ~ 1770 ℃, mainly used for the production of clay refractory products.

High alumina clay The main mineral is alumina, and bauxite as a mineral, because of its chemical composition varies, or is a symbiotic ore, in the international collectively referred to as bauxite.

Bauxite nature of bauxite, also known as bauxite or bauxite, the main mineral composition of a water diaspore, boehmite, gibbsite, is a Mohs hardness of 1 to 3 between Ore, usually smelting aluminum and the production of refractory the most commonly used raw ore, the main component is alumina, the Department of impurities containing hydrated alumina, is a kind of soil minerals. Density 3.9 ~ 4g / cm3, opaque, crisp, extremely difficult to melt, insoluble in water, soluble in sulfur. Bauxite bauxite processing process 1. High temperature calcination: raw materials into the calciner for high temperature calcination, some can also be used to dry the way. 2. Crushing and milling: The calcined material is crushed by a jaw crusher or a hammer crusher and then sent to a Raymond Mill. After the broken material into the mill production system, the entire milling, grading and other operating processes are completed in the milling machine automation, machine personnel should pay close attention to electronic control cabinet instrument data. Qualified bauxite powder released by the discharge valve, packaging products. Bauxite processing equipment calcination equipment: bauxite rotary kiln, the equipment calcination mechanism is advanced, the finished product quality is high, the overall operation of a high degree of automation, safety and environmental protection. Crushing equipment: jaw crusher or hammer crusher, large particles of bauxite crushed. Milling equipment: the general use of bauxite Raymond has been able to meet the needs of bauxite powder particle size, uniform milling.

Chemical constituents and effects of bauxite

Bauxite mineral composition is mainly water diaspore (hard mellite), kaolin, illite, montmorillonite, impurity minerals are ilmenite, limonite, pyrite, tourmaline, calcite, quartz, etc. , Its chemical composition is mainly alumina, alumina and water, and contains a small amount of titanium oxide, iron oxide, calcium oxide, magnesium oxide, potassium oxide, alumina and organic impurities.

The alumina is the main beneficial component of bauxite, the higher the alumina content, the higher the refractoriness. Silica in the clay mostly aluminosilicate exists, a small amount of free silica exists. Free silicon oxide can weaken the plasticity and cohesion of clay. Iron minerals (iron oxide) are the most common harmful impurities in refractory clay, which can reduce the refractoriness and slag resistance of the products and produce refractory products. Calcium magnesium carbonate and sulfate minerals, the content can be reduced for a long time to reduce the fire resistance of clay, increase the product sintering shrinkage, reduce the load softening temperature and make products crack, titanium dioxide in the refractory clay with the content of different Effect, the amount of titanium oxide in the sintering can play a role in flux, can promote sintering, but excessive titanium dioxide is to reduce the refractoriness and produce network cracks. Potassium oxide and sodium oxide in the clay content can reduce the load softening temperature. Organic matter is one of the ubiquitous impurities in clay. When the content is too high, it can reduce the slag resistance and increase the loss of the product.


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