Refractory lining

Abstract

The present invention relates to a precast ring for use in a furnace, a refractory lining comprising a precast ring and a dry vibration material and a method of forming a refractory lining.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a precast ring for use in a furnace, a refractory lining comprising a precast ring and a dry vibration material and a method of forming a refractory lining.BACKGROUND OF THE INVENTION

[0002] A range of refractory linings are known that are used in the operation of furnaces. The refractory linings are required to be mechanically stable and resistant to the harsh conditions in a furnace. This poses many challenges including maintaining the integrity of the refractory lining throughout the furnace for effective and safe operation. For example, it is often the case that the refractory lining towards the top of the furnace has a lower strength and can crumble or crack. This not only requires the lining to be repaired and / or replaced frequently, but such defects in the factory lining can also be unsafe and can even lead to explosions.

[0003] In order to form a mechanically sound refractory lining, a range of materials are used in the compositions of the lining. Some of the materials used, however, can be toxic. This is becoming an increasing problem in the industry due to the introduction of ever more stringent environmental regulations. Furthermore, the energy consumption in furnaces is also coming under scrutiny, requiring the use of more energy efficient furnaces.

[0004] The installation of refractory linings is also time intensive and can often lead to extended downtimes for the furnace. Taking all these factors together, it is becoming increasingly challenging to utilise furnaces in an efficient way whilst being safe and at the same time meeting the end market requirements.

[0005] It is therefore desirable to provide an improved way of operating a furnace to overcome the current challenges.SUMMARY OF THE INVENTION

[0006] The present invention is defined in the appended claims.

[0007] In accordance with a first aspect, there is provided a precast ring (1) wherein the ring (1) comprises a protrusion (2) on the bottom surface of the ring (3) for use in a furnace.

[0008] In accordance with a second aspect, there is provided a refractory lining comprising a precast ring (1) according to the first aspect and a dry vibration material.

[0009] In accordance with a third aspect, there is provided a method of forming a refractory lining according to the second aspect, comprising: forming a wall lining with a dry vibration material composition of up to about 85% of the total height of the furnace wall followed by vibrating; adding dry vibration material composition on top of the wall lining; placing the precast ring on the dry vibration material composition and filling any gaps behind the precast ring with more dry vibration material composition, followed by vibrating and sintering.

[0010] In accordance with a fourth aspect, there is provided a use of a precast ring according to the first aspect as refractory lining.

[0011] In accordance with a fifth aspect, there is provided a kit comprising a precast ring according to the first aspect and a dry vibration material.

[0012] Certain embodiments of the present invention may provide one or more of the following advantages: ease of installation and formation of refractory lining; elimination of the need for sintering the top ring on site; time saving method of installing the refractory lining on site; good mechanical strength of precast ring and subsequent refractory lining; improved safety when using the precast ring in a furnace; prevention of leakage out of the furnace when using the precast ring; reduced risk of accidents and / or explosions when using furnaces; optimised application when using a dry vibration material in refractory lining; precast ring able to withstand abrasive action, such as cleaning; precast ring able to withstand mechanical wear, such as when charging; application of a precast ring to reduce the down time of the furnace; hindering iron penetration at the most exposed areas; precast ring that counteracts slag attack; providing increased mechanical lifetime of the furnace; increased endurance of the refractory lining in a furnace; ability to use furnaces with refractory linings comprising boron free dry vibration material; and desired reduced environmental impact due to, for example, reducing or eliminating the use of boron and increased lifetime and efficiency of furnace.

[0013] The details, examples and preferences provided in relation to any particular one or more of the stated aspects of the present invention apply equally to all aspects of the present invention. Any combination of the embodiments, examples and preferences described herein in all possible variations thereof is encompassed by the present invention unless otherwise indicated herein, or otherwise clearly contradicted by context.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The invention will further be illustrated by reference to the following figures: Fig. 1Schematic of furnace with the precast ring (1); Fig. 2Cross section of precast ring (1) showing the protruding portion (2) of the bottom surface (3) of the ring; Fig. 3Schematic of the ring (1) showing the bottom surface (3) (not seen in Figure), the top surface (5), the recesses (4) and the attachment portions (6); Fig. 4Schematic of the ring (1) showing the bottom surface (3), the top surface (5) (not seen in Figure), the recesses (4), the attachment portions (6) and the protruding portion (2);

[0015] It is understood that the following description and references to the figures concern exemplary embodiments of the present invention and shall not be limiting the scope of the claims.DETAILED DESCRIPTION

[0016] The present invention is based on the surprising finding that the use of a precast ring can improve the safety and usability of furnaces. The present invention can provide many benefits to the operation of furnaces, in particular electric furnaces, such as a core induction furnace (CIF). These operational benefits are evident when the furnace with a range of refractory linings, such as refractory linings comprising a dry vibration material (DVM).

[0017] The precast ring according to the invention can be manufactured off site and subsequently installed in the furnace on site. An improvement of efficiency when operating furnaces can be observed by using this route. The precast ring can be prefabricated, delivered to site and installed in the furnace by vibrating the ring with the DVM composition. The precast ring can be made to order according to the dimensions of a specific furnace.

[0018] The method of installation described herein may form a seamless, or near seamless, joint in the refractory lining contributing to a refractory lining with good mechanical properties. Without wishing to be bound by theory, it is considered that the formation of a seamless, or near seamless, joint according to the invention helps prevent leakage before, during and / or after the furnace is operation. This may also contribute to the increasing the safety of operating the furnace.

[0019] The precast ring can be used in a range of furnaces, such as coreless induction furnaces.

[0020] The precast ring comprises a protruding portion on the bottom surface of the ring. The protrusion is an integral part of the precast ring and forms a thinner edge away from the ring (see e.g. Fig 2). The protruding portion may be a one or more ridges, tapered portions and / or projecting portions. A protruding portion of this shape can be utilised to form part of a refractory lining in combination with a refractory material such as DVM. In some examples the protruding portion can form an airtight bond with the DVM to form the refractory lining.

[0021] The precast ring can form the upper part of the refractory lining that is in close proximity to the lid of the furnace. The use of a precast ring in this position may improve the overall strength of the refractory lining, especially as this part of the furnace is often prone to weaknesses in the refractory lining using known methods. Any increase in overall strength of the refractory lining leads to an improvement in the safety of operating the furnace.

[0022] The top part of the precast ring may comprise at least one recessed portion, such as two recessed portions or three recessed portions, whereby a section of the ring is absent, recessed, indented and / or cut out. The at least one recessed portion may be any shape, such as rectangular or circular. Such recessed portions can be tailored to a particular furnace to allow the furnace to freely function. For example, a recessed portion can allow space for the spout of the furnace. In some examples, the recessed portions may be flush with the one or more spout(s) of the furnace.

[0023] In some embodiments, the at least one recessed portion is at least partially chamfered, such as stepped or tiered. The recessed portion may be slanted. Without wishing to be bound by theory, it is considered that the shape of the recessed portion in this way helps avoid leakage out of the furnace and therefore contributes to the overall safety of operating the furnace.

[0024] In some embodiments the top surface of the ring comprises two or more attachment units. For example, the top surface of the ring may comprise three attachments units, or four attachments units, or five attachments units, or six attachments units, or seven attachment units. The attached units may be, for example, hooks or eyelets. The attachment units may be utilised to lower the ring into the furnace. The number of attachment units required is expected to be greater for larger structures. In some examples, a minimum of three attachments units are required to securely lower the ring into the furnace.

[0025] In some embodiments, the precast ring has an inner diameter of from about 0.5 m (meters) to about 4.0 m (meters), for example from about 0.6 m to about 3.8 m, or from about 0.8 m to about 3.6 m, or from about 1.0 m to about 3.4 m, or from about 1.2 m to about 3.2 m, or from about 1.4 m to about 3.0 m, or from about 1.6 m to about 2.8 m, or from about 1.8 m to about 2.6 m, or from about 2.0 m to about 2.4 m.

[0026] In some embodiments, the precast ring has a total height from the bottom surface of the ring to the top surface of the ring of from about 300 mm to about 1500 mm, for example, from about 350 mm to about 1450 mm, or from about 400 mm to about 1400 mm, or from about 500 mm to about 1300 mm, or from about 600 mm to about 1200 mm, or from about 700 mm to about 1000 mm, or from about 800 mm to about 900 mm.

[0027] In some embodiments, the precast ring has a recessed portion with a height of from about 50 mm to about 1450 mm, for example, from about 100 mm to about 1400 mm, or from about 150 mm to about 1300 mm, or from about 200 mm to about 1200 mm, or from about 300 mm to about 1100 mm, or from about 400 mm to about 1000 mm, or from about 500 mm to about 800 mm, or from about 600 mm to about 700 mm.

[0028] In some embodiments the precast ring comprises the refractory material in an amount of at least about 70 wt.% based on the total weight of the precast ring, for example, at least about 75 wt.%, or at least about 80 wt.%, or at least about 85 wt.%, or at least about 90 wt.%, or at least about 95 wt.%, or at least about 98%, or at least about 99 wt.%, based on the total weight of the precast ring.

[0029] In some embodiments the precast ring comprises the fibres in an amount of at least about 30 wt.% based on the total weight of the precast ring, for example, at least about 25 wt.%, or at least about 20 wt.%, or at least about 15 wt.%, or at least about 10 wt.%, or at least about 5 wt.%, or at least about 2%, or at least about 1 wt.%, based on the total weight of the precast ring. In some embodiments the top section of the precast ring comprises more fibres than the bottom section of the precast ring. In some embodiments the fibres are selected from metal fibres, mineral fibres and / or plastic fibres. In some embodiments the metal fibres comprise steel and / or tungsten.

[0030] In some embodiments, the precast ring has a smooth surface. Such a smooth surface can have operational advantages, such as the reduction is unwanted material such as slag sticking to the surface.

[0031] A refractory lining according to the present disclosure may comprise a precast ring and a DVM. In some embodiments the DVM is boron free. Any known DVM can be used with the precast ring to form a refractory lining.

[0032] In some embodiments the precast ring makes up between about 15% to about 30% of the of the total height of the furnace wall. For example, the precast ring makes up about 20%, or up to about 22 %, or up to about 25% or up to about 28% the height of the furnace wall.

[0033] A method of forming a refractory may comprise driving the precast ring into the DVM refractory wall by about between about 10 mm to 80 mm. For example, the precast ring may be driven into the DVM by about 15 mm, or about 20 mm, or about 25 mm, or about 30 mm, or about 35 mm, or about 40 mm, or about 45 mm, or about 50 mm, or about 55 mm, or about 60 mm, or about 65 mm, or about 70 mm, or about 75 mm.

[0034] The dry vibration material composition used in the method has not been sintered and may be a loose material that this able to move freely and can fill up any gaps that are present. This dry vibration material composition is then compacted by vibration as part of the method according to the invention. Once compacted and sintered, the dry vibration material composition is no longer a loose, free flowing material.

[0035] In some embodiments the method causes the precast ring to be driven into the dry vibration material. This can occur by gravitational forces, aided by the vibration and / or pushed down mechanically.REFERENCE SIGNS

[0036] 1.Precast ring 2.Protruding portion 3.Bottom surface 4.Recessed portion 5.Top surface 6.Attachment Unit

Examples

Embodiment Construction

[0016]The present invention is based on the surprising finding that the use of a precast ring can improve the safety and usability of furnaces. The present invention can provide many benefits to the operation of furnaces, in particular electric furnaces, such as a core induction furnace (CIF). These operational benefits are evident when the furnace with a range of refractory linings, such as refractory linings comprising a dry vibration material (DVM).

[0017]The precast ring according to the invention can be manufactured off site and subsequently installed in the furnace on site. An improvement of efficiency when operating furnaces can be observed by using this route. The precast ring can be prefabricated, delivered to site and installed in the furnace by vibrating the ring with the DVM composition. The precast ring can be made to order according to the dimensions of a specific furnace.

[0018]The method of installation described herein may form a seamless, or near seamless, joint in t...

FIELD OF THE INVENTION

[0001] The present invention relates to a precast ring for use in a furnace, a refractory lining comprising a precast ring and a dry vibration material and a method of forming a refractory lining.BACKGROUND OF THE INVENTION

[0002] A range of refractory linings are known that are used in the operation of furnaces. The refractory linings are required to be mechanically stable and resistant to the harsh conditions in a furnace. This poses many challenges including maintaining the integrity of the refractory lining throughout the furnace for effective and safe operation. For example, it is often the case that the refractory lining towards the top of the furnace has a lower strength and can crumble or crack. This not only requires the lining to be repaired and / or replaced frequently, but such defects in the factory lining can also be unsafe and can even lead to explosions.

[0003] In order to form a mechanically sound refractory lining, a range of materials are used in the compositions of the lining. Some of the materials used, however, can be toxic. This is becoming an increasing problem in the industry due to the introduction of ever more stringent environmental regulations. Furthermore, the energy consumption in furnaces is also coming under scrutiny, requiring the use of more energy efficient furnaces.

[0004] The installation of refractory linings is also time intensive and can often lead to extended downtimes for the furnace. Taking all these factors together, it is becoming increasingly challenging to utilise furnaces in an efficient way whilst being safe and at the same time meeting the end market requirements.

[0005] It is therefore desirable to provide an improved way of operating a furnace to overcome the current challenges.SUMMARY OF THE INVENTION

[0006] The present invention is defined in the appended claims.

[0007] In accordance with a first aspect, there is provided a precast ring (1) wherein the ring (1) comprises a protrusion (2) on the bottom surface of the ring (3) for use in a furnace.

[0008] In accordance with a second aspect, there is provided a refractory lining comprising a precast ring (1) according to the first aspect and a dry vibration material.

[0009] In accordance with a third aspect, there is provided a method of forming a refractory lining according to the second aspect, comprising: forming a wall lining with a dry vibration material composition of up to about 85% of the total height of the furnace wall followed by vibrating; adding dry vibration material composition on top of the wall lining; placing the precast ring on the dry vibration material composition and filling any gaps behind the precast ring with more dry vibration material composition, followed by vibrating and sintering.

[0010] In accordance with a fourth aspect, there is provided a use of a precast ring according to the first aspect as refractory lining.

[0011] In accordance with a fifth aspect, there is provided a kit comprising a precast ring according to the first aspect and a dry vibration material.

[0012] Certain embodiments of the present invention may provide one or more of the following advantages: ease of installation and formation of refractory lining; elimination of the need for sintering the top ring on site; time saving method of installing the refractory lining on site; good mechanical strength of precast ring and subsequent refractory lining; improved safety when using the precast ring in a furnace; prevention of leakage out of the furnace when using the precast ring; reduced risk of accidents and / or explosions when using furnaces; optimised application when using a dry vibration material in refractory lining; precast ring able to withstand abrasive action, such as cleaning; precast ring able to withstand mechanical wear, such as when charging; application of a precast ring to reduce the down time of the furnace; hindering iron penetration at the most exposed areas; precast ring that counteracts slag attack; providing increased mechanical lifetime of the furnace; increased endurance of the refractory lining in a furnace; ability to use furnaces with refractory linings comprising boron free dry vibration material; and desired reduced environmental impact due to, for example, reducing or eliminating the use of boron and increased lifetime and efficiency of furnace.

[0013] The details, examples and preferences provided in relation to any particular one or more of the stated aspects of the present invention apply equally to all aspects of the present invention. Any combination of the embodiments, examples and preferences described herein in all possible variations thereof is encompassed by the present invention unless otherwise indicated herein, or otherwise clearly contradicted by context.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The invention will further be illustrated by reference to the following figures: Fig. 1Schematic of furnace with the precast ring (1); Fig. 2Cross section of precast ring (1) showing the protruding portion (2) of the bottom surface (3) of the ring; Fig. 3Schematic of the ring (1) showing the bottom surface (3) (not seen in Figure), the top surface (5), the recesses (4) and the attachment portions (6); Fig. 4Schematic of the ring (1) showing the bottom surface (3), the top surface (5) (not seen in Figure), the recesses (4), the attachment portions (6) and the protruding portion (2);

[0015] It is understood that the following description and references to the figures concern exemplary embodiments of the present invention and shall not be limiting the scope of the claims.DETAILED DESCRIPTION

[0016] The present invention is based on the surprising finding that the use of a precast ring can improve the safety and usability of furnaces. The present invention can provide many benefits to the operation of furnaces, in particular electric furnaces, such as a core induction furnace (CIF). These operational benefits are evident when the furnace with a range of refractory linings, such as refractory linings comprising a dry vibration material (DVM).

[0017] The precast ring according to the invention can be manufactured off site and subsequently installed in the furnace on site. An improvement of efficiency when operating furnaces can be observed by using this route. The precast ring can be prefabricated, delivered to site and installed in the furnace by vibrating the ring with the DVM composition. The precast ring can be made to order according to the dimensions of a specific furnace.

[0018] The method of installation described herein may form a seamless, or near seamless, joint in the refractory lining contributing to a refractory lining with good mechanical properties. Without wishing to be bound by theory, it is considered that the formation of a seamless, or near seamless, joint according to the invention helps prevent leakage before, during and / or after the furnace is operation. This may also contribute to the increasing the safety of operating the furnace.

[0019] The precast ring can be used in a range of furnaces, such as coreless induction furnaces.

[0020] The precast ring comprises a protruding portion on the bottom surface of the ring. The protrusion is an integral part of the precast ring and forms a thinner edge away from the ring (see e.g. Fig 2). The protruding portion may be a one or more ridges, tapered portions and / or projecting portions. A protruding portion of this shape can be utilised to form part of a refractory lining in combination with a refractory material such as DVM. In some examples the protruding portion can form an airtight bond with the DVM to form the refractory lining.

[0021] The precast ring can form the upper part of the refractory lining that is in close proximity to the lid of the furnace. The use of a precast ring in this position may improve the overall strength of the refractory lining, especially as this part of the furnace is often prone to weaknesses in the refractory lining using known methods. Any increase in overall strength of the refractory lining leads to an improvement in the safety of operating the furnace.

[0022] The top part of the precast ring may comprise at least one recessed portion, such as two recessed portions or three recessed portions, whereby a section of the ring is absent, recessed, indented and / or cut out. The at least one recessed portion may be any shape, such as rectangular or circular. Such recessed portions can be tailored to a particular furnace to allow the furnace to freely function. For example, a recessed portion can allow space for the spout of the furnace. In some examples, the recessed portions may be flush with the one or more spout(s) of the furnace.

[0023] In some embodiments, the at least one recessed portion is at least partially chamfered, such as stepped or tiered. The recessed portion may be slanted. Without wishing to be bound by theory, it is considered that the shape of the recessed portion in this way helps avoid leakage out of the furnace and therefore contributes to the overall safety of operating the furnace.

[0024] In some embodiments the top surface of the ring comprises two or more attachment units. For example, the top surface of the ring may comprise three attachments units, or four attachments units, or five attachments units, or six attachments units, or seven attachment units. The attached units may be, for example, hooks or eyelets. The attachment units may be utilised to lower the ring into the furnace. The number of attachment units required is expected to be greater for larger structures. In some examples, a minimum of three attachments units are required to securely lower the ring into the furnace.

[0025] In some embodiments, the precast ring has an inner diameter of from about 0.5 m (meters) to about 4.0 m (meters), for example from about 0.6 m to about 3.8 m, or from about 0.8 m to about 3.6 m, or from about 1.0 m to about 3.4 m, or from about 1.2 m to about 3.2 m, or from about 1.4 m to about 3.0 m, or from about 1.6 m to about 2.8 m, or from about 1.8 m to about 2.6 m, or from about 2.0 m to about 2.4 m.

[0026] In some embodiments, the precast ring has a total height from the bottom surface of the ring to the top surface of the ring of from about 300 mm to about 1500 mm, for example, from about 350 mm to about 1450 mm, or from about 400 mm to about 1400 mm, or from about 500 mm to about 1300 mm, or from about 600 mm to about 1200 mm, or from about 700 mm to about 1000 mm, or from about 800 mm to about 900 mm.

[0027] In some embodiments, the precast ring has a recessed portion with a height of from about 50 mm to about 1450 mm, for example, from about 100 mm to about 1400 mm, or from about 150 mm to about 1300 mm, or from about 200 mm to about 1200 mm, or from about 300 mm to about 1100 mm, or from about 400 mm to about 1000 mm, or from about 500 mm to about 800 mm, or from about 600 mm to about 700 mm.

[0028] In some embodiments the precast ring comprises the refractory material in an amount of at least about 70 wt.% based on the total weight of the precast ring, for example, at least about 75 wt.%, or at least about 80 wt.%, or at least about 85 wt.%, or at least about 90 wt.%, or at least about 95 wt.%, or at least about 98%, or at least about 99 wt.%, based on the total weight of the precast ring.

[0029] In some embodiments the precast ring comprises the fibres in an amount of at least about 30 wt.% based on the total weight of the precast ring, for example, at least about 25 wt.%, or at least about 20 wt.%, or at least about 15 wt.%, or at least about 10 wt.%, or at least about 5 wt.%, or at least about 2%, or at least about 1 wt.%, based on the total weight of the precast ring. In some embodiments the top section of the precast ring comprises more fibres than the bottom section of the precast ring. In some embodiments the fibres are selected from metal fibres, mineral fibres and / or plastic fibres. In some embodiments the metal fibres comprise steel and / or tungsten.

[0030] In some embodiments, the precast ring has a smooth surface. Such a smooth surface can have operational advantages, such as the reduction is unwanted material such as slag sticking to the surface.

[0031] A refractory lining according to the present disclosure may comprise a precast ring and a DVM. In some embodiments the DVM is boron free. Any known DVM can be used with the precast ring to form a refractory lining.

[0032] In some embodiments the precast ring makes up between about 15% to about 30% of the of the total height of the furnace wall. For example, the precast ring makes up about 20%, or up to about 22 %, or up to about 25% or up to about 28% the height of the furnace wall.

[0033] A method of forming a refractory may comprise driving the precast ring into the DVM refractory wall by about between about 10 mm to 80 mm. For example, the precast ring may be driven into the DVM by about 15 mm, or about 20 mm, or about 25 mm, or about 30 mm, or about 35 mm, or about 40 mm, or about 45 mm, or about 50 mm, or about 55 mm, or about 60 mm, or about 65 mm, or about 70 mm, or about 75 mm.

[0034] The dry vibration material composition used in the method has not been sintered and may be a loose material that this able to move freely and can fill up any gaps that are present. This dry vibration material composition is then compacted by vibration as part of the method according to the invention. Once compacted and sintered, the dry vibration material composition is no longer a loose, free flowing material.

[0035] In some embodiments the method causes the precast ring to be driven into the dry vibration material. This can occur by gravitational forces, aided by the vibration and / or pushed down mechanically.REFERENCE SIGNS

[0036] 1.Precast ring 2.Protruding portion 3.Bottom surface 4.Recessed portion 5.Top surface 6.Attachment Unit

Examples

Embodiment Construction

[0016]The present invention is based on the surprising finding that the use of a precast ring can improve the safety and usability of furnaces. The present invention can provide many benefits to the operation of furnaces, in particular electric furnaces, such as a core induction furnace (CIF). These operational benefits are evident when the furnace with a range of refractory linings, such as refractory linings comprising a dry vibration material (DVM).

[0017]The precast ring according to the invention can be manufactured off site and subsequently installed in the furnace on site. An improvement of efficiency when operating furnaces can be observed by using this route. The precast ring can be prefabricated, delivered to site and installed in the furnace by vibrating the ring with the DVM composition. The precast ring can be made to order according to the dimensions of a specific furnace.

[0018]The method of installation described herein may form a seamless, or near seamless, joint in t...

Claims

1. A precast ring (1), wherein the ring (1) comprises a protruding portion (2) on the bottom surface (3) of the ring (1) for use in a furnace.

2. The precast ring (1) according to claim 1, wherein the furnace is a coreless induction furnace.

3. The precast ring (1) according to claim 1 or claim 2, wherein the top part of the ring comprises at least one recessed portion (4).

4. The precast ring (1) according to any preceding claim wherein the at least one recessed portion (4) is at least partially chamfered.

5. The precast ring (1) according to any preceding claim wherein the top surface (5) of the ring (1) comprises two or more attachment units (6).

6. The precast ring (1) according to any preceding claim, wherein the inner diameter of the ring (1) is from about 0.5 m to about 4.0 m.

7. The precast ring (1) according to any preceding claim, wherein the total height of the ring (1) from the bottom surface (3) of the ring to the top surface (5) of the ring is from about 300 mm to about 1500 mm.

8. The precast ring (1) according to any preceding claim, wherein the recessed portion (4) has a height of from about 50 mm to about 1450 mm.

9. The precast ring (1) according to any preceding claim, wherein the ring (1) comprises a refractory material.

10. The precast ring (1) according to claim 9, wherein the refractory material is present in an amount of at least 70 wt.% based on the total weight of the precast ring.

11. The precast ring (1) according to any preceding claim, wherein the ring (1) comprises fibres.

12. The precast ring (1) according to claim 11, wherein the fibres are selected from metal fibres, mineral fibres and / or plastic fibres.

13. The precast ring (1) according to claim 12, wherein the metal fibres comprise steel and / or tungsten.

14. The precast ring (1) according to any one of claims 11 to 13, wherein the fibres make up at least about 30 wt.% based on the total weight of the precast ring.

15. A refractory lining comprising a precast ring (1) according to any one of claims 1 to 14 and a dry vibration material.

16. A refractory lining according to claim 15, wherein the dry vibration material is boron free.

17. A refractory lining according to claim 15 or claim 16, wherein the precast ring is from about 15% to about 30% of the total height of the furnace wall.

18. A method of forming a refractory lining according to any one of claims 15 to 17, comprising: - forming a wall lining with a dry vibration material composition of up to about 85% of the total height of the furnace wall followed by vibrating; - adding dry vibration material composition on top of the wall lining; - placing the precast ring on the dry vibration material composition and filling any gaps between the precast ring and the furnace with more dry vibration material composition, followed by vibrating and sintering.

19. The method of claim 18, wherein the precast ring is driven into the dry vibration material by between about 10 mm to 80 mm.

20. Use of a precast ring (1) according to any one of claims 1 to 14 as a part of a refractory lining.

21. A kit comprising a precast ring (1) according to any one claims 1 to 14 and a dry vibration material.

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