US 20060O84564A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2006/0084564 A1 Stancliffe (43) Pub. Date: Apr. 20, 2006

(54) REFRACTORY MIXES CONTAINING Publication Classification CONDENSED AND FURFURYL ALCOHOL, AND THEIR USES (51) Int. Cl. C04B 35/03 (2006.01) (76) Inventor: Mark R. Stancliffe, Bromyard (GB) (52) U.S. Cl...... SO1A94 Correspondence Address: (57) ABSTRACT Ashland Licensing and Intellectual Property This invention relates to refractory mixes produced by LLC mixing a refractory material with an organic binder and 5200 Blazer Parkway heating to a temperature of typically from about 50° C. to Dublin, OH 43017 (US) about 100° C. to form a stable composite granulate. The (21) Appl. No.: 11/247,987 refractor mixes comprise a major amount of a refractory material and a minor amount of a binder composition (22) Filed: Oct. 11, 2005 comprising (a) and (b) furfuryl alcohol. The refractory mixes are used to prepare shaped (e.g. bricks) Related U.S. Application Data and unshaped (e.g. blast furnace tap holes, troughs, and tundish liners) refractory products. The invention also (60) Provisional application No. 60/618,927, filed on Oct. relates to a process for preparing the refractory products 14, 2004. using the refractory mixes. US 2006/0084564 A1 Apr. 20, 2006

REFRACTORY MIXES CONTAINING tundish liners) refractory products. The invention also CONDENSED TANNIN AND FURFURYL relates to a process for preparing the refractory products ALCOHOL, AND THEIR USES using the refractory mixes. CLAIM TO PRIORITY 0008 Because the furfuryl alcohol and the condensed tannin react when the condensed tannin is dissolved in 0001) This application claims the benefit of U.S. Provi furfuryl alcohol at temperatures>40° C., it is not necessary sional Application No. 60/618,927 filed on Oct. 14, 2004, to use a catalyst to cure the refractory mix. the contents of which are hereby incorporated into this application. 0009 Because it is not necessary to use binder compo nents that contain free formaldehyde or free phenol, a refractory mix can be prepared that can be charged into the TECHNICAL FIELD OF THE INVENTION isostatic compression pattern where it is shaped and allowed 0002 This invention relates to refractory mixes produced tO Cure. by mixing a refractory material with an organic binder and heating to a temperature of typically from about 50° C. to 0010 Preferably, the binder contains 0% free phenol, 0% about 100° C. to form a stable composite granulate. The free formaldehyde, and 0% nitrogen. refractory mixes comprise a major amount of a refractory material and a minor amount of a binder composition DETAILED DESCRIPTION OF THE comprising (a) condensed tannin and (b) furfuryl alcohol. INVENTION The refractory mixes are used to prepare shaped (e.g. bricks) 0011. The detailed description and examples will illus and unshaped (e.g. blast furnace tap holes, troughs, and trate specific embodiments of the invention and will enable tundish liners) refractory products. The invention also one skilled in the art to practice the invention, including the relates to a process for preparing the refractory products best mode. It is contemplated that many equivalent embodi using the refractory mixes. ments of the invention will be operable besides these spe BACKGROUND OF THE INVENTION cifically disclosed. 0012 Condensed , also known as protoanthocya 0003. The iron and steel industry are the main users of nidins, are polymeric flavanoids extracted from plants, e.g. refractory products, e.g. shaped products such as bricks , , shoots, or of the plant. The condensed made from magnesia, dolomite, bauxite, and andalusite, and tannins used in the binder composition typically have an unshaped products used for blast furnace tap holes, troughs, average molecular weight of from about 500 to about and tundish liners. Typically, the products are made under 50,000, preferably from about 1,000 to about 25,000, most pressure (isostatically) and synthetic resins (phenolic resins preferably from about 1,000 to about 10,000. The condensed and furan resins) are used as binders. tannins typically have a viscosity of from about 0.1 poise to 0004 The materials used in the refractory products must about 200 poises, preferably from about 1.0 poise to about be such that the mixing of the oxide-based refractory com 100 poises, most preferably from about 5 poises to about 100 ponents with graphite and other additives, as well as 10-20% po1Ses. of added binder, yields a fine-grained, homogeneous granu 0013 The preferred condensed tannin, tannin from the late, which can be charged into the isostatic compression Quebracho tree of sulfonated quebracho, is derived from the pattern without separation occurring. Furthermore, the mix core of the tree of the genus , which is abundant must be dried to a certain extent to produce a free flowing, in Argentina and Paraguay. It constitutes about 30% of the storable granulate. dry weight of the from the core and is easily extracted 0005 Although there are some technologies available by means of hot water. that satisfy these requirements, they are often associated with environmental, health, and safety issues. Therefore, 0014. The binder is preferably prepared by mixing the there is a need for a binder, which in addition to providing condensed tannin with furfuryl alcohol such that the amount the performance aspects required for the majority of refrac of condensed tannin is typically from about 0.5 weight tory compositions, also provides improved environmental, percent to about 50 weight percent, based upon the weight percent of the mixture of condensed tannin and furfuryl health, and safety benefits in terms of emissions, exposures, alcohol, preferably from about 20 weight percent to about 40 and life cycle environmental impact. weight percent, most preferably from about 25 weight 0006 All citations referred to in this application are percent to about 35 weight percent. expressly incorporated by reference. 0015. A refractory material can be defined as a product composed of materials with a softening point of that is BRIEF SUMMARY OF THE INVENTION typically greater than 1500° C. Although any refractory can 0007. This invention relates to refractory mixes produced be used to prepare the refractory mix, preferably used are by mixing a refractory material with an organic binder and refractories selected from the group consisting of silicon heating to a temperature of typically from about 50° C. to carbide, silicates, magnesia, dolomite, bauxite, andalusite, about 100° C. to form a stable composite granulate. The and mixtures thereof. The refractories or softening point, of refractory mixes comprise a major amount of a refractory the mix is of obvious importance and is largely dictated by material and a minor amount of a binder composition the blend of refractories used. In addition to the refractory, comprising (a) condensed tannin and (b) furfuryl alcohol. the refractory mix preferably contains carbon-containing The refractory mixes are used to prepare shaped (e.g. bricks) material, particularly graphite and/or carbon black up to and unshaped (e.g. blast furnace tap holes, troughs, and 20%. The graphite content has an impact on other properties, US 2006/0084564 A1 Apr. 20, 2006

including resistance to thermal shock and slag, thereby lac and furfural resin mixtures are used may be reduced or increasing wear resistance and service life. avoided because the furfuryl alcohol is largely consumed in 0016. The amount of binder used in an amount that is the reaction. The finished mix must be a dry free flowing, effective in producing a shape that can be handled or is storable granulate. self-supporting after curing. Typically, the amount of binder 0023 The granulate can now be isostatically pressed into is generally from about 1.0% to about 25.0% by weight a pattern at room temperature at pressures between 80-200 based upon the weight of the refractory, preferably from N/mm. The green shapes are removed from the tooling and about 5.0% to about 20.0% by weight. then fully cured by slowly increasing the temperature to 80° 0017 Although it is possible to mix the components of C. to 180° C. at a rate of 10° C. to 30° C. per hour, followed the binder with the refractory in various sequences, it is by carbonization in the absence of air at temperatures preferred to mix the Quebracho and furfuryl alcohol before ranging up to about 800° C. applying them to the refractory. We claim: 0018. The temperatures of the mix is raised by the 1. A heated refractory mix comprising: friction of mixing friction or external heating to between 50° (a) a major amount of a refractory; C. and 100° C. At this temperature the curing reaction (b) a condensed tannin; and between the Quebracho and furfuryl alcohol is accelerated sufficiently to form a dry but plastic granulate which nor (b) furfuryl alcohol: mally occurs between 15 and 60 minutes mixing. The such that the temperature of the refractory mix is from finished mix must be a dry free flowing granulate, which is about 50° C. to about 100° C. storage stable at room temperature. 2. The refractory mix of claim 1 wherein the amount of 0019. A shape is typically formed by isostatically press condensed tannin is from about 1.0 weight percent to about ing the granulate into a pattern at room temperature at 50 weight percent, based upon the weight percent of the pressures between 80-200 N/mm. The green shapes are mixture of condensed tannin and furfuryl alcohol then fully cured by slowly increasing the temperature at 80° 3. The refractory mix of claim 2 wherein the amount of C. to 180° C. at a rate of 10° C. to 30° C. per hour, followed condensed tannin is from about 10 weight percent to about by carbonization in the absence of air at temperatures 40 weight percent, based upon the weight percent of the ranging up to about 800° C., which generates the necessary mixture of condensed tannin and furfuryl alcohol binding carbon skeleton which significant increases strength 4. The refractory mix of claim 3 wherein the average and wear resistance. molecular weight of the condensed tanin is from about 1,000 to about 25,000 and the viscosity if from about 5 poises to EXAMPLE about 100 poises 5. The refractory mix of claim 4 wherein the condensed 0020. A refractory mix is prepared by mixing a refractory, tanin is tannin from the Quebracho tree. e.g. silicon carbide, silicates, magnesia, dolomite, bauxite 6. The refractory mix of claim 5 which also contains a and andalusite along with carbon in the form of graphite and carbon-containing material. carbon black, and the resin components either as individual 7. The refractory mix of claim 6 wherein the carbon addition i.e. Quebracho and furfural alcohol or as pre-blend containing material is selected from the group consisting of of Quebracho dissolved in furfuryl alcohol. The total resin graphite, carbon black, and mixtures thereof. addition can be between 1 and 25% and the weight ratio of 8. A refractory mix of claim 1, 2, 3, 4, 5, 6, or 7 which is Quebracho to furfuryl alcohol is from about 5 to 40 weight allowed to dry for a time sufficient to form free flowing, percent based upon the total weight of the Quebracho and storage stable granulates. furfuryl alcohol. 9. The refractory mix of claim 8 wherein said drying time 0021. The choice of resin addition and ratio of Quebracho is from 15 minutes to 60 minutes. to furfuryl alcohol depends on the refractory formulation 10. A process for making a refractory product comprising: and is such that a satisfactory fine-grained, homogenous (a) adding the refractory mix of claim 9 to a pattern; and granulate results that can be charged into an isostatic com pression pattern without separation occurring. (b) Subjecting the refractory mix to a pressure of from about 80 N/mm to about 200 N/mm to form a handle 0022. The temperature of the refractory mix is increased able product. by the friction of mixing or external heating to from about 11. The process of claim 10 wherein the handleable 50° C. to about 100° C. At this temperature the curing product is gradually subjected to increasing temperatures up reaction between the Quebracho and furfuryl alcohol is to 180°C. followed by carbonization in the absence of air at accelerated Sufficiently to form a dry but plastic granulate, temperatures up to about 800° C. which normally occurs from 15 and 60 minutes after mixing. The normal drying phase required when conventional nova k k k k k