- REFRACTORIES DIVISION
- Monolithic Refractories
Monolithic Refractories
1. Castable
| General Castable | A castable is a type of concrete product. Its origin goes back to the Second World War, when castables started to replace bricks in boilers and petroleum refining plants in the US. A variety of additives are applied to improve the construction ability and water content during construction. A variety of products are used depending on the applications, such as float, inflow and gunning construction. |
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| Low Cement Castable | Low-cement castables use 2-5% alumina cement, whereas typical castables use 10-30% alumina cement. Low-cement castables have high strength and refractoriness and are vibrated into molds. After their development in Europe in the 1970s, low-cement castables started to be mass produced from the 1980s. Self-flowing castables that do not require vibration with significantly improved flow-ability were also developed. |
| Non Cement Castable | While low-cement castables or ultra-low-cement castables use about 2-5% alumina cement, non-cement castables do not use any alumina cement. Instead, non-cement castables use a special binder. These castables are mainly used in iron and steel making, especially in the ladles. |
| Non Wetting Castable | The refractories used in aluminum melting furnaces are weak against structural spalling and the pollution of molten metal due to the strong penetration and oxidation of aluminum. Wonjin’s non-wetting castable controls the wetting feature of molten metal in the operating conditions by adding a special oxide binder to the existing low-cement castable. Its superior performance is favorably evaluated in the market. |
| Light Weight Castable | Lightweight castables are monolithic refractories manufactured by adding alumina cement to insulating aggregate with refractoriness, such as perlite, vermiculite, and light aggregate. Castables for gunning construction using a small quantity of additives, as well as trowelling and pouring, are also used. In particular, we have numerous references in the petrochemical field. These castables are used in many places, such as in a variety of incinerators and industrial furnaces, to reduce fuel costs by preventing temperature losses and to reduce construction costs by reducing thickness. |
| Acid Proof Castable | Acid-proof castables have superior resistance against a variety of acids and are widely used to prevent damages by acidic gases and waste solutions from petrochemical and anti-pollution facilities. Wonjin offers a variety of castable ranges according to different operating conditions and temperatures, as well as construction types, such as trowelling, pouring, and gunning. |
2. Iron making
| Hot Iron Runner | Wonjin also offers trough refractories in monolithic form. Wonjin’s trough range consists of high-purity alumina, SiC, and special carbon. The products are vibrated into the mold on site before use. Among many others, shotcreting is becoming a common choice of practice nowadays. |
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| Full Cover | Wonjin also offers castables to cover the top of the trough to prevent damages by non-acid and thermal spalling of slag. These castables contain SiC and are vibrated into the mold on site. |
| Castable for Opening of Hot Metal Mixer Cars | Castable refractories used for the opening of torpedo cars are commonly damaged by careless cleaning of metal penetration, by corrosion and thermal impact, and by non-acid slag attack during desulfurization. Wonjin recommends low-cement castables containing SiC with high corrosion and wetting resistance. |
| Lance Castable | The lance forcibly injects and stirs highly reactive flux of CaO in the long pipe to remove phosphorous, silicon, and sulfuric acid during the primary steelmaking process in order to produce high-quality steel. Wonjin offers power injection lances and preliminary hot metal processing lances. They are highly recognized for their quality in a variety of applications. |
3. Steel Making
| Delta Section Castable | The delta section of an electric arc furnace requires quality refractories, as it has substantial thermal loads from the electrode. While MgO-Cr2O3 burned bricks were generally used in the past, the monolithic refractories became popularized with the development of low-cement castables. We have unique materials and the design ability to deliver large structures in pre-mold block types and also to manufacture a variety of materials for different operating conditions and purposes. |
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| Dry Ramming Mass | An eccentric bottom tapping (EBT) electronic arc furnace requires alternative material to replace the existing MgO ramming mass because of the prolonged stay of slag. Wonjin can substantially reduce costs as compared to an existing magnesia-based ramming mass, as the MgO-CaO-based dry-type ramming mass has fewer sintered layers, even after long operation, and provides excellent protection against slag attacks. The quality of dry ramming mass is widely recognized. |
| Spray Mass | Spray material is developed to quickly repair partial damages and to extend the working life of the lining of facilities such as converters, electric arc furnaces and RH degassers. Wonjin’s spray products contain silicate binders, improving the hot gunning ability with high refractoriness and strong resistance against slag corrosion, such as natural and sea magnesia. Recently, spray products containing phosphate binders and MgO-CaO-based aggregate have been developed and applied in a variety of areas. |
| Ladle Slip Casting Material | Ladle monolithic working linings were introduced to reduce costs for larger steel ladles. Such products and applications became popular to minimize waste while increasing life and automating operations. Wonjin’s product range includes Al2O3-MgO-based and AL2O3-spinel-based monolithic for ladle working linings. We also have substantial know-how on monolithic products for tundish safety lining and shotcrete materials. |
| Dam & Weir Blocks | Dam and weir blocks are precast blocks that are used to effectively control the flow of steel and remove slag during tundish processes. For effective separation and rising of large inclusion, the refractories for weir parts is made with porous materials for argon gas injection. Our filter dam using MgO-CaO-based material is well received among our customers, providing superior performance in effectively removing Al2O3-based inclusion. |
| Tundish Coating | Tundish coating mass is magnesia based and has superior dissolution ability, which easily prevents the inflow of non-metallic inclusion and steel penetration. Our wet-type products use magnesia and olivine as main materials, while our dry-type products are dolomite based. Dry-type products absorb non-metallic inclusion and solve the hydrogen pick-up problem: the disadvantages of existing slurry methods. Our products are favorably recognized in the special steel manufacturing industry in Korea. |
4. Shotcrete
Castable gunning shows porous characteristics due to the large addition of water, and low-cement castables require a mold. Shotcrete products overcome the shortcomings of these products.
Shotcrete pumps low-cement castable mixed with low water content and adds a fast-freezing binder at the hem of the nozzle in order to achieve less-porous construction. Its application is becoming popular for various incinerators, troughs of blast furnaces, ladles, and more.
5. Kneader
When a furnace or ladle gets damaged, the general method of repairing it is to spray, scorch, and thermal spray. The scorching method is the easiest of the three for repairing.
MgO aggregate (which is corrosion resistant) and a binder (which is resin and/or pitch) are used.
6. Plastic Refractories
Plastic refractories are manufactured with various liquid binders, clay, and water. They’re classified into patching, plastic, ramming, and stamp, according to the quantity of clay and water. Plastic refractories are applied to various types of furnaces, such as reheating or induction furnaces.
Construction is mainly done with an air rammer. Wonjin specializes in heating furnaces and provides a full service, from design and the delivery of materials to construction and technical consulting.
7. Mortar
Mortar is unshaped refractories, and its main use is as an adhesive for bricks. Various mortar products are produced, according to the characteristic and type of brick.
Mortar is classified into air-set mortar, which is hardened at normal temperature after construction, and heat-set mortar, which is sintered at high temperature after construction, and is applied to the entire area where refractories are used. Wet-type mortar, which is used in areas with non-ferrous metals, is highly praised for its superior adhesive strength and usage.
