Magnesium (Mg) is a versatile element with a variety of applications in modern society. Magnesite is mainly used in the production of magnesia refractory materials and products, new building materials, fine chemical materials, etc. Magnesia products (calcined, deadburned and fused) are widely used in a range of market applications.
Calcined Magnesia
Is used in agricultural and industrial applications, eg, as a feed supplement to cattle, fertilisers, electrical insulations, industrial fillers, and in flue gas desulphurisation.
Deadburned Magnesia
Is used almost exclusively for refractory applications in the form of basic bricks and granular refractories. Deadburned magnesia has the highest melting point of all common refractory oxides and is the most suitable heat containment material for high temperature processes in the steel industry. Basic magnesia bricks are used in furnaces, ladles and secondary refining vessels and in cement and glass making kilns.
Fused Magnesia
Fused magnesia is superior to deadburned magnesia in strength, abrasion resistance and chemical stability. Major applications are in refractory and electrical insulating markets. Producers of fused magnesia commonly fall into one of two categories: those producing refractory grades and those producing electrical grades. Few producers serve both markets on a mainstream basis.
Refractory Grade Fused Magnesia
The addition of fused magnesia grains can greatly enhance the performance and durability of basic refractories such as magcarbon bricks. This is a function of a higher bulk specific gravity and large periclase crystal size, plus realignment of accessory silicates. Refractory grade fused magnesia has exacting specifications and is normally characterised by the following:
Generally high magnesia content (minimum 96 per cent MgO and up to/exceeding 99 per cent MgO)
Low silica; lime:silica ratios of 2:1
Densities of 3.50 g/cm3 or more
Large periclase crystal sizes (>1000 microns)
Due to its excellent corrosion resistance, refractory grade fused magnesia is used in high wear areas in steel making, eg, basic oxygen and electric arc furnaces, converters and ladles.
Ultra high purity (>99 per cent MgO) grades have been used in high-tech applications such as optical equipment, nuclear reactors and rocket nozzles.
Electrical Grade Fused Magnesia
Fused magnesia is also used as an electrical insulating material in heating elements. Although electrical grades of fused magnesia have very tight specifications, they do not necessarily require the highest MgO contents or densities. Impurities such as sulphur and iron are particularly undesirable, but the product should contain sufficient silica to enhance its electrical properties. The following are characteristic of electrical grade fused magnesia:
leave your message here, we'll send you
an Email immediately.
