The Effect of Cement Addition on the Performance of Ladle Porous Plugs and Well Blocks

Ladle Porous Plugs are the most critical functional element in the bottom argon blowing process for molten steel refining, and their use conditions are very harsh. Ladle Porous Plugs can be divided into two types according to the assembly method: internal integral Porous Plugs and External combination Porous Plugs. The Porous Plugs’ core needs to be protected by supporting brick. At present, the well blocks for ladle are generally casted and used directly after curing, drying, and baking. The well blocks mainly undergo the following effects during use. (1) The brick working face is repeatedly subjected to rapid cooling and heating, which easily causes the brick to break and peel off. (2) Corroded and penetrated by molten steel and slag. (3) It is strongly scoured and worn by high-temperature molten steel. Therefore, it is required that the well blocks for ladle should have high strength, good thermal shock resistance, and excellent slag erosion resistance.

Ladle Porous Plugs
Ladle Porous Plugs
Steel Ladle Well Blocks
Steel Ladle Well Blocks

Get Free Quote

    Free Quote

    Your Name (required)


    Your Email (required)

    Your Phone

    Required Products (required)

    Enquiry Information

    The well blocks for ladle often appear cracks, transverse fractures, and block-dropping phenomena during use. It seriously affects its service life, and improving its thermal shock resistance is an important way to increase its service life. At present, there are many kinds of research on Porous Plugs, but not much researches on well blocks for the ladle. In this work, the effect of cement addition on the performance of corundum spinel ladles Porous Plugs was studied. It is expected to increase the service life of the Porous Plugs block, enhance its safety factor, and meet the requirements of steelmaking plants.

    The effect of cement addition on the performance of ladle Porous Plugs and well blocks

    • (1) With the increase of cement addition, the normal temperature flexural strength and compressive strength of the sample after drying at 110°C gradually increase. The normal temperature flexural strength and compressive strength of the sample after being burned at 1560°C first increase, then decrease, and then increase. The linear change after burning first increases and then decreases. When the cement content is 6% (w), the strength is lowest. The apparent porosity and linear change rate after firing are the largest, and its performance is the worst.
    • (2) With the increase of cement addition, after three thermal shocks after water cooling at 1100°C, the strength retention rate of the sample after firing at 1560°C gradually increases, and the thermal shock resistance is improved. When the mass fraction of cement is 10%, the thermal shock resistance is the best.
    • (3) The anti-burst performance of the samples added with an anti-explosion agent is obviously improved. Especially the anti-explosive effect of sodium bicarbonate or sodium bicarbonate + polypropylene organic fiber composite is the best.
    • (4) The service life of high-purity corundum spinel bottom-blown argon-blown ventilating bricks with a cement addition amount of 6%-10% (w) and a compound explosion-proof agent has been increased from the original average of 31 times to an average of 36 times.
    steel ladle purging brick
    steel ladle purging bricks

    Get Free Quote

      Free Quote

      Your Name (required)


      Your Email (required)

      Your Phone

      Required Products (required)

      Enquiry Information

      Comparison of performance of chrome corundum Porous Plugs block and corundum-spinel Porous Plugs block

      Chrome corundum, as a traditional material for ladle Porous Plugs block, has played a very important role for a long time. Due to the insufficient performance of traditional chrome corundum bricks in thermal shock resistance, it is prone to cracks during use. It is very easy for molten steel to invade the brick body along the gas inlet that produces cracks, forming molten steel penetration, which will seriously affect the effect of argon blowing. In addition, chromium can also pollute the environment. Therefore, chrome corundum Porous Plugs block have been gradually replaced by corundum spinel Porous Plugs block with better performance. However, chromium corundum Porous Plugs blocks are better than corundum-spinel Porous Plugs blocks in terms of body stability and resistance to slag penetration.

      Performance Comparison of Chrome Corundum Brick and Corundum-Spinel Brick

      The material of chromium corundum is a sintered tabular corundum with compact structure, low porosity, and easy sintering as the main raw material. There are some differences in the performance of the two types of Porous Plugs blocks. Generally speaking, the volume density of the corundum-spinel Porous Plugs block is smaller than that of chrome corundum Porous Plugs block under the same particle size gradation. The porosity of corundum-spinel brick is lower than that of chrome corundum brick. This is because, during the firing process, the swelling of the body caused by the formation of spinel offsets part of the shrinkage caused by the fine powder, resulting in a decrease in porosity. On the other hand, the linear change rate of the corundum-spinel Porous Plugs block is slightly larger than that of the chrome corundum Porous Plugs block. That is to say, the volume stability of corundum-spinel Porous Plugs blocks is not as good as that of chrome corundum bricks, mainly because magnesia alumina spinel is generated during the firing of corundum-spinel Porous Plugs blocks.

      Since the slits of slit-type Porous Plugs blocks are relatively narrow, generally about 200 μm. If the volume of the Porous Plugs block changes greatly during the firing process, it will affect the size of the slits, and ultimately affect the air permeability and blowing effect. As a result, the performance of the Porous Plugs block is reduced during the use, the blowing rate is reduced, and even the blowing is blocked. Since the thermal shock stability of the spinel is better than that of corundum, the thermal shock stability of the corundum-spinel Porous Plugs block is better than that of chrome corundum Porous Plugs block. The corrosion index of the two slag resistance is the same, but the slag penetration resistance of the chrome corundum brick is stronger than that of the corundum-spinel brick.

      Generally speaking, corundum-spinel Porous Plugs blocks are better than traditional chrome corundum Porous Plugs blocks in terms of performance. The traditional chrome corundum Porous Plugs block has been gradually replaced by it. Corundum-spinel Porous Plugs blocks are gradually becoming the mainstream ladle Porous Plugs blocks today.

      RS Refractory Bricks Factory
      RS Refractory Bricks Factory

      Get Free Quote

        Free Quote

        Your Name (required)


        Your Email (required)

        Your Phone

        Required Products (required)

        Enquiry Information

        Rongsheng Kiln Refractory Material Manufacturer

        Rongsheng is an experienced refractory material manufacturer and sales company. Rongsheng’s refractory products have served refractory lining projects in more than 60 countries around the world. We have a wealth of refractory lining solutions for refractory linings for steel smelting furnaces, glass kilns, and cement kilns. If you want to buy refractory materials for ladle, please contact us. We will provide you with services according to your specific needs.

          Get Free Quote

          Your Name (required)

          Your Email (required)

          Your Phone

          Required Products (required)

          Enquiry Information

          Non-Burning Bricks for Ladle

          Non-burning bricks for ladle include alumina-magnesia bricks, alumina-magnesia-carbon bricks, and magnesia-alumina-carbon bricks. The difference between their fired bricks is that they use water glass or phenolic resin as the bonding agent and undergo low-temperature treatment after molding. During the use of non-fired bricks for ladle, the alumina and magnesia in the matrix form spinel, and the carbon in the graphite and resin binder forms a carbon chain network structure. Therefore, the strength, slag resistance, and thermal shock resistance of refractory bricks for ladle are further improved. To get the price of refractory bricks for ladle for free, please contact Rongsheng refractory brick manufacturer. Next is the introduction of unburned bricks for a ladle.

          Alumina Magnesia Carbon Bricks
          Alumina Magnesia Carbon Bricks

          Get Free Quote

            Free Quote

            Your Name (required)


            Your Email (required)

            Your Phone

            Required Products (required)

            Enquiry Information

            Alumina-Magnesia Brick and Alumina-Magnesia-Carbon Brick

            First of all, let’s learn about the non-burning bricks for ladle combined with water glass, including alumina-magnesia brick and alumina-magnesia-carbon brick. The aggregate of the alumina-magnesia brick is generally first-grade bauxite, and the powder is super-grade bauxite clinker powder and first-grade magnesia powder. Use high modulus water glass as the bonding agent. After pressing, the finished product is treated at a low temperature of 150°C. The refractory brick is used on the large and medium-sized die-cast ladle, and its life span is generally 60 to 90 times.

            Alumina-magnesia-carbon bricks are successfully manufactured on the basis of alumina-magnesia bricks and magnesia-carbon bricks, and the production process is similar to that of magnesia-carbon bricks. Water glass is combined with alumina-magnesia-carbon bricks, and primary and secondary alumina clinker is used as a refractory aggregate. The first-grade or super-grade high-alumina powder is used as refractory powder, and 8%~13% of the first and second-grade metallurgical magnesia powder is blended. The carbon material adopts electrode powder, earthy graphite, or flake graphite, the amount of which is 3%~8%, and the water glass solution (m=2.4~3.0) is used as the binding agent. After forming, the finished product is processed at a low temperature of 200~250℃. The refractoriness of the water glass bonded alumina-magnesia-carbon brick is 1770℃, and the 4% load softening temperature is 1320~1340℃, which is caused by more Na2O in the binder. If high modulus sodium silicate is used to bring in less Na2O, the load softening temperature will increase to 1410℃, and the refractoriness will be 1790℃. This kind of refractory brick is widely used in medium and small ladle due to its better performance and low price. The refractory brick is applied to the mold-cast ladle, and the slag line area is built with magnesia carbon bricks, and its life span is 50-100 times.

            Magnesia Carbon Bricks for Ladle
            Magnesia Carbon Bricks for Ladle

            Get Free Quote

              Free Quote

              Your Name (required)


              Your Email (required)

              Your Phone

              Required Products (required)

              Enquiry Information

              Resin-Bonded Alumina Magnesia Carbon Brick

              The raw materials of resin-bonded alumina-magnesia-carbon bricks use first-grade or super-grade bauxite clinker, white corundum, sub white corundum, and magnesia-alumina spinel as aggregates and powders. The magnesia powder is made of high-quality sintered magnesia or fused magnesia with Mg>95%, and mixed with flake graphite, high-quality silicon carbide and alumina powder or SiO2 powder. The phenolic resin binder is used for high-pressure molding, and the bricks are then processed at a low temperature of about 200°C to become the finished product. The refractory brick has the advantages of excellent strength, corrosion resistance, peeling resistance, thermal shock resistance, and non-sticky slag. However, the thermal conductivity is relatively large, and heat insulation measures must be taken during use.

              It is better to directly add an alumina-magnesia spinel compound fired material into the alumina-magnesia-carbon bricks than doping with magnesium oxide. Because magnesia oxide can form spinel with alumina during use. Synthetic alumina-magnesia spinel should generally be sintered in a rotary kiln at a temperature greater than 1600°C. The higher the temperature, the better the quality. Its bulk density is 2.95~3.10g/cm3, and its content of alumina and magnesia should be greater than 91%. The fused magnesia-alumina spinel is more expensive. To ensure the quality of refractory bricks, suitable magnesia-alumina spinel should be selected.

              Resin-bonded alumina-magnesia-carbon bricks have been widely used in the continuous casting ladle of many steel plants. On the 50-100t steel ladle for continuous casting, mid-grade alumina-magnesia-carbon bricks are used as lining. The slag line area is built with high-quality magnesia carbon bricks, and the service life is generally 50 to 80 times, up to 100 times.

              In the 1990s, a large number of high-quality alumina-magnesia-carbon bricks and magnesia-carbon bricks for slag line areas were used in the lining of refining furnaces. The service life of the refining bag is more than 30 times, and the service life of LF(V) of 40~90t is about 50 times.

              Magnesia Alumina Carbon Bricks
              Magnesia Alumina Carbon Bricks

              Get Free Quote

                Free Quote

                Your Name (required)


                Your Email (required)

                Your Phone

                Required Products (required)

                Enquiry Information

                Magnesia Alumina Carbon Brick

                The production process of magnesia-alumina-carbon brick and alumina-magnesia-carbon brick is basically the same. It is the pre-synthetic spinel mixed with fused magnesia, and the difference in linear expansion coefficient between the two forms micro-cracks during high temperature and cooling use to buffer the thermal stress generated by temperature changes and reduce thermal spalling. Because the elastic modulus of spinel (MA) and periclase (M) are quite different, the former (0.012~0.022)×106MPa, the latter (0.059~0.49)×106MPa. Tough spinel helps to improve the thermal shock resistance of refractory bricks. In addition, the carbon material is added to the periclase-spinel, and about 10% graphite is added. After making it evenly distributed in the refractory brick body, the carbon atoms form a staggering network structure at high temperature, so that the material has a good high-temperature performance. In addition, graphite has high surface tension and a small wetting angle, which can effectively prevent the penetration of molten slag.

                For example magnesia-alumina-carbon bricks for 75t LF lining of a steel plant. MgO 71%, Al2O3 13%, C 10%, apparent porosity 3%, bulk density 3.08g/cm3, compressive strength 50MPa, high temperature flexural strength (1400°C) 8MPa. The slag line uses high-quality MgO-C bricks, with a service life of more than 50 furnaces.

                RS Refractory Bricks Factory
                RS Refractory Bricks Factory

                Contact Rongsheng

                  Free Quote

                  Your Name (required)


                  Your Email (required)

                  Your Phone

                  Required Products (required)

                  Enquiry Information

                  Rongsheng Refractory Brick Manufacturer

                  Rongsheng is an experienced refractory manufacturer. Rongsheng’s refractory brick products have been recognized by customers in more than 60 countries around the world. Rongsheng’s project of refractory materials for ladle also has very strong competitiveness. If you need to buy refractory materials for ladle, please contact us. We will provide you with services according to your specific needs. You are welcome to consult and learn more about non-burning bricks for ladle.

                    Get Free Quote

                    Your Name (required)

                    Your Email (required)

                    Your Phone

                    Required Products (required)

                    Enquiry Information