The common refractory materials for glass melting furnaces are mainly divided into four types: fused cast refractory materials, sintered refractories, unshaped refractories and insulating refractories. Each type of material contains several types. The chemical composition, physical properties, dimensional error and appearance type of refractory materials should meet the national or industrial standards, and the latest revised version should be selected, otherwise it is not allowed to leave the factory. According to actual needs, glass enterprises may require suppliers to supply performance indicators not listed in national standards or industry standards. Some performance indicators of refractory materials may be higher than current standards. Refractory enterprises shall conduct contracts on both sides. Production and supply.
1. Melted refractory
The fused cast refractory material has excellent resistance to glass liquid corrosion and alkali vapor corrosion resistance, and is a building material for key parts of the glass melting furnace. Commonly used types are Al2O3-ZrO2-SiO2 system containing ZrO233%, 36%, 41% zirconium corundum brick and Al2O3 system α-β alumina brick and β alumina brick. The melting process has two kinds of oxidation method and reduction method, and the reduction method has been gradually eliminated in China. Casting methods include general casting (PT), oblique casting (QX), quasi-non-shrinkage casting (ZWS), and non-shrinkage casting (WS). In addition to the general physical and chemical properties, such bricks are resistant to glass corrosion, bubble precipitation rate and glass phase bleed temperature, which are important performance indicators.
The fused cast refractory material shall meet the performance requirements of the current standard rules of JC493 and JC494.
2, sintered refractory
Sintered refractory materials are important supporting refractories for many glass melting furnaces. Commonly used are silica brick, alkaline brick, zircon brick, zirconium mullite brick, mullite brick, sillimanite brick, high alumina brick, clay brick and so on.
Sintered refractory materials shall comply with the performance requirements of current standard rules such as YB/T5014, JC/T616, JC497, YB/T5011, GB/T2988, YB/T5108, YB/T5106, JC/T638, JC495.
3. Unshaped refractory
The amount of amorphous refractory currently accounts for only 3%-4% of the refractory content of the furnace, but it is very important for the furnace kiln age. Generally, the amorphous refractory material should be the same material as the shaped refractory material (such as fused cast refractory material, sintered refractory material). Thus, the common types are comparable to their corresponding shaped refractory compositions.
Unshaped refractory materials should meet the performance requirements of current standard rules such as GB/T2984, GB/T14982, YB/T384, YB/T5009, YB/T5083, JC498.
4, insulation refractory
The insulating refractory material requires small bulk density, low thermal conductivity, good heat preservation effect, high refractoriness and mechanical strength, and does not react with the refractory material in contact. Commonly used insulating refractories are heat-insulating bricks, heat-insulating panels and heat-insulating (lightweight) castables, heat-insulating coatings and refractory fibers.
Insulation refractory materials should meet the performance requirements of current standard rules such as GB/T3994, GB/T3995, YB386, GB10699.
The scale error and appearance quality of large-scale shaped products not clearly listed in the standard shall be agreed between the supply and demand sides. Complete sets of refractory materials should generally be pre-assembled and shipped out. The refractory materials should be cold-worked with diamond tools. It is strictly forbidden to use SiC tools. Detailed performance requirements are agreed upon by both suppliers and customers.
When purchasing refractory materials, glass companies should select suppliers that meet the refractory quality standards and should provide clear performance requirements in the contract. The new construction project shall solicit the opinions of the Planning Department and purchase according to the requirements. The supplier shall supply the report on the physical and chemical properties and appearance quality of the batch of bricks.
In order to ensure the quality of refractory materials is stable and reliable, and meet the contract performance requirements, glass enterprises can entrust professional performance units to supervise the production of refractory materials.
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