Magnesia Chrome Brick is an alkaline refractory material fired from chromite and magnesia . The main components are chromium oxide and magnesium oxide . Good thermal stability , refractoriness above 2000 . The resistance to temperature changes and the resistance to alkali slag are good. It is used as a lining for masonry steelmaking furnaces , steelmaking electric furnaces , non-ferrous metal smelting furnaces , cement rotary kiln, etc. And magnesia-chrome brick as it is spinel and periclase as the main crystalline phase of refractory products. Performance is between chrome refractory and magnesia refractory.
Due to the adjustment of the metallurgical industry and the increase in refractory materials, most large and medium-sized cement plants in the country have promoted and used magnesia chrome bricks in the firing zone. Such refractory bricks have the advantage of high temperature resistance and are superior to other varieties of refractory materials used in rotary kiln firing belts. However, due to the different methods used, the fire resistance is also different.
Magnesia Chrome Brick
Magnesia Chrome Brick is a composite alkaline refractories containing chrome ore and sintered magnesia as raw materials and containing 18% to 30% of chromium oxide and 25% to 55% of magnesium oxide in an appropriate ratio . Generally, chrome ore is added in an amount of less than 50%, which is called magnesia chrome brick, and more than or equal to 50% is called magnesia chrome brick. In addition to its product fired in a weak oxidizing atmosphere chromium sintered brick, it can also be made unburned brick , cast bricks , fused chromium magnesia brick combined with bulk material and shape. It can be used in converter , induction furnace , furnace lining of non-ferrous metal smelting furnace, electric arc furnace , open hearth furnace , side wall of soaking furnace , etc. When the ratio of chrome ore to sintered magnesia is 50% each, the product has the greatest thermal shock resistance, sometimes called thermal shock stability chrome-magnesia brick, which is mainly used as an alkaline flat roof brick.
Magnesia refractories (magnesia refractories ) – refractory articles containing the basis of MgO. They are made from a mixture of calcined and raw materials, which after the addition of the binder are heat treated at a temperature of 1500-1900.
https://refractoriesmaterials.com/magnesia-chrome-brick/ have high fire resistance, which makes it possible to use them in processes associated with metal melt and slags, as well as in the lining of metallurgical aggregates. Magnesian refractory products have high resistance to interaction with metal melts and basic slags.
Magnesian refractory products are of three types:
Magnesian-silicate refractories – their basis is forsterite Mg2SiO4, to which 50-60% MgO, 25-40% SiO2 and binder additive are added. Magnesian-silicate refractories are formed with a binder additive and baked at 1450-1550 C (or used without roasting).
The main properties of magnesian-silicate refractories: the porosity is open 22-28%, the temperature of the beginning of softening under load is up to 1610-1620.
Magnesian-silicate refractories are used for lining the nozzles of the regenerators of open-hearth furnaces, and the glass-making furnaces, steel-laden ladles (including in the form of ramming masses), melting aggregates of CM, and also for the production of steel casting cups, etc. Unshaped magnesian-silicate refractories can be used as an additive in metallurgical powders .
Magnesian- spinel refractories have periclise and chromospinelide MgO in their composition. Burned at a temperature of 1700-1850℃, periclase chrome refractories have in their composition more than 60% MgO, and 5 to 20% Cr2O3. To obtain the necessary characteristics of the refractory, pure, more than 96%, MgO, and chromite concentrates are needed.
Magnesian-spinel refractories (also referred to as: chromite-periclase, made of a mixture of periclase powder with chromite ore and containing 40-60% MgO and 15-35% Cr2O3, periclase-spinel (> 40% MgO and 5-55% A12O3), spinel, consisting mainly of from spinel composition MgO o A1203 and chromite refractories (> 30% Cr2O3). Read more on this page: WWW.refractoriesmaterials.com