What is dolomite refractory? How is its performance?

Materials and products made of dolomite manufacturers with some additives that change the performance of products belong to dolomite refractories. The raw material of dolomite refractory is dolomite, that is, the double salt of calcium carbonate CaCO3 and magnesium carbonate MgCO3. Generally dolomite contains 30.4% MgO, 21.9% CaO, and 47.7% CO2.

The process of producing dolomite raw materials for dolomite refractories is classified as follows: fine orange-crystalline (M) dolomite - less than 0.1 mm particles: medium crystalline (C) dolomite - 0.1-0.25 mm particles; Coarsely crystalline (K) dolomite - particles larger than 0.25 mm.

Dolomite sand 0-10 mesh manufacturers

Dolomite Supply

The quality of the dolomite raw material also depends on the chemical and mineral composition. According to the stipulation of the process condition MNTY660-50, the dolomite should contain not less than 17-19% MgO, 4-6% SiO2, and 4-5% trioxide. Oxides (fluxes), in burnt metallurgical dolomite, free MgO and CaO, are the most valuable constituent minerals because of their high refractoriness and slag resistance.

For the production of sintered dolomite, different methods are used depending on the nature of the raw materials: dry and wet pulverized raw materials are calcined in a rotary kiln, and acid dolomite is calcined in a shaft kiln.

Rotary kiln is used when calcining compact dolomite crushed to 0.5-40 mm by dry method, and compact and loose dolomite with low flux content (made into slag and passed through a sieve of 4900 holes/square centimeter).

What is fired in the shaft kiln is pre-crushed, dense and uniform, flux-deficient (0.8-1.5%) dolomite (block size 30-100 mm).

Dolomite is calcined at 1600-1700 ℃. When wet method is used, the calcination temperature can be reduced by 150-250 ℃. This is because the material is finely pulverized and there are additives (iron oxide).

There are several production processes for dolomite refractory products, the main one is the preparation of dolomite clinker, and this co-clinker is used to produce water-resistant dolomite bricks. To make bricks, the clinker is finely pulverized in a ball mill, the mud is processed in a mill and molasses and water are added at this point. When the green body is formed, the moisture content of the mud shake is 3-4%, and the pressure is 600-800 kg/square centimeter. After drying at 110-120°C for 12 hours, the green body is formed at 1550°C in a tunnel kiln.

The refractoriness of dolomite refractory material is above 1780℃; the softening under load of 2kg/square starts at 1550℃ and ends at 1610℃; the bulk density is 2.87g/cubic; the compressive strength limit is 100-150kg/ square inside.

The back walls of the open hearth and electric furnaces are made of dolomite bricks. Dolomite sand manufacturers