Publish Time: 2026-05-21 Origin: 由AI辅助生成
Anyone who makes flash furnaces or reverberatory furnaces knows that the working environment of smelting furnaces is particularly harsh. The temperature in the furnace exceeds 1,300 degrees Celsius all year round, and the slag contains iron and silicon oxides, which are highly corrosive. Ordinary refractory materials are easily corroded and the surface layer falls off. In severe cases, the furnace body may be damaged, forcing the company to shut down for repairs and delay normal production.
How to adapt and select the lining of copper smelting furnace? Why can magnesia chrome bricks become the industry-recognized quality choice? Next, we will analyze it in depth from the three core dimensions.
Before we delve into the advantages of magnesia-chromium bricks, we must first understand what challenges copper smelting furnace linings face.
1. High temperature shock
During the flash smelting process of copper concentrate, the temperature in the furnace is usually between 1300°C and 1500°C, and local hot spots are even higher. Ordinary refractory materials have a low load softening temperature and are prone to softening and deformation at high temperatures, resulting in instability of the furnace lining structure.
2. Slag erosion
Copper smelting slag contains a large amount of FeO, Fe₃O₄ and SiO₂. These components are highly corrosive to alkaline refractory materials. Molten slag will penetrate into the brick body and react with the components in the brick body to generate a low melting point phase, resulting in a loose brick structure and reduced strength.
3. Thermal shock peeling
The temperature of a copper smelting furnace changes drastically during shutdown and startup. Ordinary refractory materials have poor thermal shock resistance and are prone to thermal stress when the temperature changes suddenly, causing cracking and peeling of the bricks, seriously affecting the life of the furnace lining.
In view of the above pain points, the reason why magnesia-chromium bricks have become the mainstream choice for copper smelting furnaces mainly relies on the following three points.
1. High softening temperature under load, resistant to high temperature deformation
The main components of magnesia-chromium bricks are periclase and magnesia-chromium spinel. The melting points of these two minerals are above 2000°C. The load softening temperature of magnesia chrome bricks is usually between 1600°C and 1700°C, which is much higher than the actual operating temperature of copper smelting furnaces. This means that in the working environment of 1300℃-1500℃, magnesia chrome bricks can maintain stable volume and strength without softening and deformation.
(Data description: According to the GB/T 3003-2017 standard, the load softening starting temperature of magnesia chrome bricks is ≥1600°C, and some high-purity products can reach above 1700°C)
2. Strong resistance to slag erosion and difficult penetration of molten slag
Magnesia chrome bricks have a special crystal structure inside, which is also the key to their resistance to slag corrosion. This structure is difficult to react with the iron oxides in the copper smelting furnace, and the slag cannot penetrate into the brick surface after it touches it.
With its good anti-penetration performance, it can greatly reduce slag corrosion and effectively extend the service life of the smelting furnace lining.
Although ordinary magnesia bricks are alkaline refractory materials, they do not have this kind of protective structure, and their erosion and corrosion resistance are not as good as magnesia-chrome bricks.
3. Good thermal shock resistance, reducing peeling damage
The thermal expansion coefficient of magnesia-chrome bricks is relatively low, and the magnesia-chromium spinel phase can absorb part of the thermal stress. Therefore, the thermal shock resistance of magnesia-chrome bricks is better than that of ordinary magnesia bricks. When the copper smelting furnace is frequently shut down, magnesia-chromium bricks are not prone to cracking and peeling due to sudden temperature changes, and the integrity of the furnace lining is better maintained.
Different types of copper smelting furnaces have different performance requirements for magnesia-chromium bricks. The following are selection suggestions for two common furnace types.
flash furnace
The reaction tower, sedimentation tank and rising flue of the flash furnace are the main application parts of magnesia-chrome bricks. Among them, the reaction tower has the most severe working conditions. It is recommended to use high-purity magnesia-chromium bricks (Cr₂O₃ content 15%-20%), and ordinary magnesia-chrome bricks (Cr₂O₃ content 8%-12%) can be used in the sedimentation tank.
reverberatory furnace
The roof and slag line of the reverberatory furnace are the most severely corroded. It is recommended to use electrofused magnesia-chromium bricks. These bricks have high density, low porosity, and stronger resistance to slag erosion.
When selecting copper smelting furnace lining materials, there are three core points: to withstand high temperatures, prevent slag corrosion, and withstand the impact of sudden temperature changes.
Magnesia-chromium bricks have strong heat resistance, pressure resistance, corrosion resistance, good thermal stability, and outstanding overall performance. They are a common main material for the lining of flash furnaces and reverberatory furnaces.
If you are not sure about the furnace lining material or want to know the specific parameters of the product, you can follow the official account. Inform you of the furnace type and production conditions, and our technical staff will help you match the appropriate material selection plan.
This article was generated with AI assistance and reviewed and published by Shengyuan Refractory Materials Technology Department