KR20000011162A - Common molding method for producing fire-resistant material without plasticity or caulking - Google Patents

Abstract

PURPOSE: A common molding method for producing the fire-proof material is provided to produce the common-molded can-shaped fire-resistant material which is chemically combined and eliminates the plasticity and the sintering step. CONSTITUTION: The common molding method includes the steps of:mixing the aggregate with the chemical bonding agent to form the fire-proof composition able to be pressurized; arranging a metal can to pressure cavity dies; filling the metal can and the press cavity dies with the fire-proof composition; forming the fire-proof material and adjusting its size in the pressure cavity dies while pressurizing the fire-proof composition; and drying the fire-proof material at an adequate temperature to harden the chemical bonding agent.

Description

Joint molding method for producing refractory materials without firing or caulking

Methods for producing can shaped refractory articles are well known in the art. One of the prior art methods for producing can shaped refractory articles consists of mixing the refractory aggregate with a chemical binder or wetting agent to form a refractory composition of a pressurized consistency. This composition is pressed to form an article. The article is sized to form a ceramic bond, dried and fired. The article is assembled to the can, typically by using mortar in the joint between the can and the article, and placed in the can to achieve the correct final size of the article. Alternatively, the can shaped article can be dried again. This method of forming can-shaped refractory articles is expensive because it requires high temperature firing and individual can-forming methods to form ceramic bonds.

Another method for forming can-shaped refractory articles consists of mixing the refractory aggregate with a chemical binder to form a refractory composition of a pressurized consistency. This composition is pressed to form an article. The article is sized to form a ceramic bond and dried or cured. The article is assembled to the can, usually by using mortar in the joint between the can and the article, and placed in the can to achieve the correct final size of the article. Next, the can-shaped article is dried again. This method eliminated the hot firing step of the method described above, but still requires a can forming method.

Another method for forming can-shaped refractory articles consists of mixing the refractory assemblies to form a castable refractory material. The composition is cast into cans and mold assemblies to form the shape of the article so that the article is sized. The article remains mold at ambient temperature until the castable refractory material is set. The can shaped article is then removed from the mold and dried at high temperature. This method eliminates the high temperature firing and can forming steps, but limits the range of compositions used to form the article. In addition, the production rate is limited by the number of molds and the setting time of the castable refractory material.

Another method for producing can-shaped refractory products consists of mixing the refractory aggregate with a chemical binder to form a refractory composition of ramming consistency. The can is placed in the mold assembly. The fire resistant composition is compacted in a can and molded to form the shape of the article so that the article is sized. The can shaped article is then dried or cured to form a chemical bond. This method, where the refractory composition is compacted in a can and molded to form an article, takes a lot of time. In addition, molding the composition into a can and molding to form an article cannot be done at a relatively high pressure.

One of the problems with conventional methods for producing can-shaped refractory articles is that the firing and sintering steps required by some of the prior art methods require large amounts of energy and are expensive. These methods that do not require high temperature firing are sometimes undesirable because of limitations in the material selection or formation method. In addition, the step of forming and sizing individual cans of the conventional method is costly and time consuming.

It would be desirable to have a method for producing canned refractory articles that eliminates costly and problematic firing and sintering steps. It would also be desirable to have a method for producing a refractory article that eliminates time consuming individual can formation and sizing as required by prior art methods.

According to the present invention, there is provided a co-molding method for producing chemically bonded and co-molded can-shaped refractory articles, eliminating the costly and problematic firing and sintering steps of the prior art.

Furthermore, according to the present invention, there is provided a co-molding method for producing chemically bonded, co-molded can-shaped refractory articles, eliminating the time-consuming individual can forming and sizing as required by conventional methods. do.

In addition, according to the present invention there is provided a joint molding method for producing a chemically bonded, co-molded can-shaped refractory article, the joint molding method comprising:

(a) mixing the refractory aggregate with the chemical binder to form a pressurized refractory composition;

(b) placing the metal can into a pressure cavity die;

(c) filling said refractory composition into said metal can and pressure cavity die;

(d) forming and resizing the refractory article in the pressure cavity die while the refractory composition is subjected to high pressure; And

(e) drying the refractory article at a temperature sufficient to cure the chemical binder.

According to the present invention there is also provided a joint molding method for producing a chemically bonded, co-molded can-shaped refractory nozzle.

According to the present invention there is also provided a cavity molding method for producing a chemically bonded, co-molded can shaped refractory slide gate plate.

These and other aspects of the invention will be apparent to those skilled in the art upon reading and understanding the following.

The present invention relates to a co-molding method for producing chemically bonded and co-molded can shaped refractory articles. In particular, refractory compositions comprising an aggregate and a chemical binder are relatively high pressure and co-molded to form an article and at a temperature sufficient to cure the chemical binder, not at a high temperature that is harmful to metal cans. To dry. More particularly, the present invention relates to a method for producing a co-molded can-shaped refractory nozzle and a co-molded can-shaped slide gate plate.

1 is a cross-sectional view of a pressure cavity die used in the cavity molding method of the present invention,

2 is a cross-sectional view of a nozzle made in accordance with the method of the present invention showing various elements constituting the nozzle,

3 is a cross-sectional view of a slide gate plate made in accordance with the method of the present invention showing various elements constituting the slide gate plate.

The present invention relates to a co-molding method for producing chemically bonded and co-molded can shaped refractory articles. The method of the present invention mixes a refractory assembly with a chemical binder to form a refractory composition, places a metal can into a pressure cavity die, fills the refractory composition into a metal can and a pressure cavity die, while the refractory composition is under high pressure, Forming and resizing the refractory article in the pressure cavity die, and drying the refractory article at a temperature sufficient to cure the chemical binder. The process of the present invention does not require costly and problematic firing steps as the use of chemical bonds eliminates the need for high temperature firing. As the steps of forming, canning and sizing in the present invention are all accomplished in one step, the method of the present invention also eliminates the individual canning and sizing of the prior art methods.

Chemically bonded, co-molded can-shaped refractory articles of the present invention are prepared by first mixing the refractory aggregate with a chemical binder to form a pressurized refractory composition. The refractory aggregate material may be in the form of granules or powder. Refractory aggregate particles range in size from about several microns to about one centimeter in diameter. In a preferred embodiment, the particle size of the refractory aggregate material is in the range of about -3 mesh to about -325 mesh. In one embodiment, the amount of refractory aggregate material in the fire resistant composition of the present invention is about 85% to about 97% by weight. In another embodiment, the amount of refractory aggregate material is from about 90% to about 98% by weight.

Refractory aggregates may be composed of aggregate materials known in the art. These aggregates may include alumina, mullite, alumina-silicate, silica, zirconia, alumina-zirconia, zirconia-mullite, magnesia, alumina-magnesia spinel, carbon, graphite, metal powder, antioxidants and combinations thereof It is not limited to these.

The refractory composition is further comprised of a chemical binder. The chemical binder used in the present invention may be any chemical binder known in the art for forming a refractory material. The chemical binder may be an inorganic material, an organic material, or a combination thereof. Inorganic materials that can be used as chemical binders are phosphates, silicates, sulfates, cements, alumina aquatic products and combinations thereof. Organic materials that can be used as chemical binders are resins, pitches, polyvinyl alcohols, and combinations thereof. Preferred organic materials used as chemical binders are resins. These resins include, but are not limited to, resole resins, novolac resins, liquid resins, powder resins, and combinations thereof. The fire resistant composition may be further composed of metal aluminum, silicon and magnesium metal or a combination thereof. The refractory composition may also consist of components such as the modifier or filler as long as the modifier and filler do not significantly change the properties of the nozzle.

Refractory compositions are formed by mixing refractory aggregates, chemical binders and other components by any means known in the art. For example, refractory aggregates and other components are pre-blended for a defined time and then mixed for a while. Next, a resin binder is added and the composition is further mixed for a defined time.

After the metal can is placed in the pressure cavity die, the refractory composition is filled into the metal can and the pressure cavity die. While in the die, the refractory composition is subjected to high pressure to shape, form and size the refractory article. The pressure applied is preferably from about 3 T / in ² to about 12 T / in ² .

Conventional presses used in the process include, but are not limited to, hydraulic presses, friction or screw presses, toggle presses and isostatic presses. Preferred presses are hydraulic presses because the pressure and size are easily controlled and the production speed is high.

One example of the pressure cavity die 10 in the present invention is shown in FIG. 1. The pressure cavity die 10 consists of an opening 11 surrounded by an upper pad 12, a bottom pad 13, a liner 14 and a liner holder 15. The liner 14 is located on the surface of the liner holder 15 closest to the opening 11. The bottom pad 13 is composed of several components. Facing pads 16 are located on the side of the bottom pad 13 closest to the liner 14. Adjacent to the facing pad 16 is a pad sleeve 17, which has one side in contact with the opening 11. Below the facing pad 15, adjacent to the bottom of the pad sleeve is a back pad 18. The center pad 19 is located at the bottom of the bottom pad 13. The metal can 20 is inserted in the opening 11 adjacent the liner 14 or on the top of the bottom pad 13 and adjacent the liner 14. Next, the refractory composition is filled into the opening 11 in the pressure cavity die and pressurized to shape, form, and size the refractory article.

Forming a refractory article in a press provides several advantages over the method for making can shaped refractory articles in the prior art. One advantage is that forming the article in the press provides a better compaction of the refractory material. Another advantage is that forming in a press provides better size and shape control. Another advantage is that forming in a press requires less time than the ramming and casting method.

After molding and forming the refractory article, the article is removed from the die and dried. The article does not fire or sinter the nozzle but is dried at a temperature sufficient to cure the chemical binder. Typically, drying is performed at a temperature lower than the firing temperature in a suitable oven. Preferably, the refractory article is dried at a temperature of about 200 ^o F to about 800 ^o F.

In one embodiment, the co-molding method of the present invention produces a chemically bonded and co-molded can-shaped refractory nozzle as shown in FIG. 2 shows a cross section and the overall structure of the nozzle 30. The nozzle has a hollow chamber 31 located centrally in the core of the nozzle, an inner wall 32 forming the chamber 31 and an outer wall 33 forming the nozzle completely. The nozzle has an inlet 34 for receiving molten metal and an outlet 35 for releasing molten metal. The outer wall of the nozzle is surrounded by a metal can 36.

The nozzle is formed by mixing the refractory aggregate with a chemical binder to form a pressurized refractory composition. The refractory aggregate comprises about 50% to about 80% coarse aggregate and about 20% to about 50% fine aggregate. Preferably, the refractory aggregate comprises about 61% coarse aggregate and about 39% fine aggregate. The chemical binder is preferably a resin. The amount of resin present in the composition is from about 3% to about 15% by weight, preferably from about 6% to about 8% by weight. The metal can is placed in the pressure cavity die, and the refractory composition is filled in the metal can and the pressure cavity die. The fire resistant composition is subjected to a pressure of about 3 T / in ² to about 7 T / in ² to form the shape and size of the nozzle. Preferably, the fire resistant composition is subjected to a pressure of about 4 T / in ² to about 5 T / in ² . After molding and forming the nozzle, the nozzle is dried at a temperature of about 300 ^o F to about 700 ^o F, preferably at a temperature of about 350 ^o F to about 450 ^o F.

In another embodiment, the cavity molding method of the present invention produces a chemically bonded and co-molded can shaped refractory slide gate plate as shown in FIG. 3 shows a cross section and the overall structure of the slide gate plate 40. The slide gate plate 40 consists of a flat slide surface 41 mating with the plane of another plate, a boss 42 on the opposite surface mating with the nozzle and a bore 43. This plate is designed to fit with the slide gate. The top plate is fixed and the bottom plate is movable to completely or partially align with the bore. The flow of molten steel is controlled from complete flow to complete blockage by the degree of alignment and misalignment of the bores. The slide gate plate is placed in the metal can 44 except the slide surface and the boss.

The slide gate plate is formed by mixing the refractory aggregate with a chemical binder to form a pressurized refractory composition. The refractory aggregate comprises about 50% to about 80% coarse aggregate and about 20% to about 50% fine aggregate. Preferably, the refractory aggregate comprises about 62% coarse aggregate and about 38% fine aggregate. The chemical binder is preferably a resin. The amount of resin present in the composition is from about 2% to about 10% by weight, preferably from about 4% to about 6% by weight. The metal can is placed in the pressure cavity die, and the refractory composition is filled in the metal can and the pressure cavity die. The fire resistant composition is subjected to a pressure of about 5 T / in ² to about 12 T / in ² to form the shape and size of the plate. Preferably, the fire resistant composition is subjected to a pressure of 7 T / in ² to about 10 T / in ² . After the forming and forming of the plate. The plate is dried at a temperature of about 300 ^o F to about 700 ^o F, preferably at a temperature of about 350 ^o F to about 550 ^o F.

The co-molding method for producing chemically bonded and co-molded can shaped refractory articles of the present invention eliminates the firing and sintering steps required in the prior art for producing refractory articles. The firing step requires a large amount of energy that can be supplied by the final working environment in the method of the present invention. In addition, the co-molding method of the present invention can be adapted to the steps of individual molding, can forming and size in the prior art methods, as the steps of forming, can forming and sizing in the method of the present invention are all accomplished in one step. Remove

Other features and aspects of the invention will be appreciated by those skilled in the art upon reading and understanding the specification. These features, aspects, and expected variations and modifications of the results and examples disclosed are obvious within the scope of the invention, and the invention is limited only by the scope of the following claims.

Claims (30)

In a joint molding method for producing a chemically bonded and co-molded can-shaped refractory article: (a) mixing the refractory aggregate with the chemical binder to form a pressurized refractory composition; (b) placing the metal can into the pressure cavity die; (c) filling said refractory composition into said metal can and pressure cavity die; (d) forming and resizing the refractory article in the pressure cavity die while the refractory composition is under high pressure; And (e) drying the refractory article at a temperature sufficient to cure the chemical binder. The refractory assembly of claim 1, wherein the refractory aggregate is alumina, mullite, alumina-silicate, silica, zirconia, alumina-zirconia, zirconia-mullite, magnesia, alumina-magnesia spinel, carbon, graphite, metal powder, antioxidants and these A joint molding method, characterized in that it is selected from the group of combinations of. The method of claim 1, wherein the chemical binder is an inorganic material. 4. The method of claim 3 wherein the chemical binder is selected from the group of phosphates, silicates, sulfates, cements, alumina aquatic products and combinations thereof. The method of claim 1 wherein the chemical binder is an organic material. 6. The method of claim 5 wherein the chemical binder is selected from the group of resins, pitches, polyvinyl alcohols, and combinations thereof. 7. The method of claim 6 wherein the chemical binder is a resin. 8. The method of claim 7, wherein the synthetic resin is selected from the group of resol resins, novolak resins, liquid resins, powder resins, and combinations thereof. The method of claim 1 wherein the fire resistant composition is subjected to a pressure of about 3 T / in ² to about 12 T / in ² . The method of claim 1, wherein the refractory is dried at a temperature in a range from about 200 ^° F to about 800 ^° F. 10. In a joint molding method for producing a chemically bonded and co-molded can-shaped refractory nozzle: (a) mixing the refractory aggregate with the chemical binder to form a pressurized refractory composition; (b) placing the metal can into the pressure cavity die; (c) filling said refractory composition into said metal can and pressure cavity die; (d) forming and resizing the refractory article in the pressure cavity die while the refractory composition is under high pressure; And (e) drying the refractory article at a temperature sufficient to cure the chemical binder. 12. The method of claim 11, wherein the refractory aggregate comprises about 50% to about 80% coarse aggregate and about 20% to about 50% fine aggregate. 13. The method of claim 12 wherein the refractory aggregate comprises about 61% coarse aggregate and about 39% fine aggregate. 12. The method of claim 11 wherein the chemical binder is a resin binder. 15. The method of claim 14 wherein the amount of synthetic resin binder in the refractory composition is from about 3% to about 15% by weight. 15. The method of claim 14 wherein the amount of synthetic resin binder in the refractory composition is from about 6% to about 8% by weight. 12. The method of claim 11 wherein the fire resistant composition is subjected to a pressure of about 3 T / in ² to about 7 T / in ² . 12. The method of claim 11 wherein the fire resistant composition is subjected to a pressure of about 4 T / in ² to about 5 T / in ² . The method of claim 11, wherein the fire resistant article is molding cavity characterized in that the drying at a temperature of about 300 ^o F to about 700 ^o F range. The method of claim 11, wherein the fire resistant article is molding cavity characterized in that the drying at a temperature of about 350 ^o F to about 450 ^o F range. In a joint molding method for producing a chemically bonded and co-molded can shaped refractory slide gate plate: (a) mixing the refractory aggregate with the chemical binder to form a pressurized refractory composition; (b) placing the metal can into the pressure cavity die; (c) filling said refractory composition into said metal can and pressure cavity die; (d) forming and resizing the refractory article in the pressure cavity die while the refractory composition is under high pressure; And (e) drying the refractory article at a temperature sufficient to cure the chemical binder. 12. The method of claim 11, wherein the refractory aggregate comprises about 50% to about 80% coarse aggregate and about 20% to about 50% fine aggregate. The method of claim 22 wherein the refractory aggregate comprises about 62% coarse aggregate and about 38% fine aggregate. 22. The method of claim 21 wherein the chemical binder is a resin binder. 25. The method of claim 24 wherein the amount of resin binder in the refractory composition is from about 2% by weight to about 10% by weight. 25. The method of claim 24 wherein the amount of resin binder in the refractory composition is from about 4% to about 6% by weight. 22. The method of claim 21 wherein the fire resistant composition is subjected to a pressure of about 5 T / in ² to about 12 T / in ² . 22. The method of claim 21 wherein the fire resistant composition is subjected to a pressure of about 7 T / in ² to about 10 T / in ² . The method of claim 21, wherein the refractory is dried at a temperature in a range from about 300 ^° F to about 700 ^° F. The method of claim 21, wherein the fire resistant article is molding cavity characterized in that the drying at a temperature of about 350 ^o F to about 550 ^o F range.