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  Ultrafine nepheline syeniteUSPTO Application #: 20080015104Title: Ultrafine nepheline syenite Abstract: A useable particulate nepheline syenite having a grain size to provide an Einlehner Abrasive Value of less than about 100 is described. The particulate nepheline syenite is generally free from agglomeration and moisture free. At least 99% of the nepheline syenite particles have a size less than 10 microns. In practice, the nepheline syenite grain size is less than about 5 microns and the distribution profile of the particulate system is generally 4-5 microns. (end of abstract) Agent: Fay Sharpe LLP - Cleveland, OH, US Inventors: Jerry William Janik, Scott Van Remortel USPTO Applicaton #: 20080015104 - Class: 501128 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20080015104. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001]This application is a continuation of and claims priority from and benefit of the filing date of U.S. application Ser. No. 11/599,514, filed Nov. 14,2006; and U.S. provisional application Ser. No. 60/830,646, filed Jul. 13, 2006, the disclosures of which are both hereby incorporated by reference. [0002]The present invention relates to a novel product obtained by processing of a granular igneous rock and more particularly an improved method of processing nepheline syenite. BACKGROUND OF INVENTION [0003]In glass and ceramic manufacturing nepheline syenite provides alkalis that act as a flux to lower melting temperature of a glass and ceramic mixture, prompting faster melting and fuel savings. In glass, nepheline syenite also supplies aluminum which gives improved thermal endurance, increases chemical durability and increases chemical durability and increases resistance to scratching and breaking. Furthermore, nepheline syenite is used as a filler or extender in paints, coatings, plastics and paper. It is a desirable material because it contains no free silica and still functions as effectively as a free silica based filler or extender. The material is an inorganic oxide having mechanical characteristics similar to the free silica materials for which it is a substitute. These mechanical properties involve use of a fine grain particulate form of nepheline syenite which is abrasive. Consequently, the granular nepheline syenite has a tendency to abrade and erode rapidly equipment used in processing. It has been determined that by reducing the particle size of any organic oxide material, such as nepheline syenite, the abrasive properties of the material are reduced. It is common to provide nepheline syenite with relatively small particle size for the purpose of allowing effective dispersing in the product aided by use of nepheline syenite. The advantage of dispersing fine grain nepheline syenite in the carrier product is discussed in several patents such as Gundlach U.S. Pat. No. 5,380,356; Humphrey U.S. Pat. No. 5,530,057; Hermele U.S. Pat. No. 5,686,507; Broome U.S. Pat. No. 6,074,474; and, McCrary Publication No. US 2005/0019574. These representative patents showing fine grain nepheline syenite are incorporated by reference herein. They illustrate the advantages of providing this inorganic oxide in a variety of grain sizes for a variety of applications. In U.S. publication 2005/0019574 there is a discussion that microcrystalline silica is a preferred filler in plastics. Silica free silicate is a whole grain sodium potassium alumina silica available from Unimin Corporation, New Canaan, Conn. The particles of the finely divided material range from about 2 to about 60 microns. This material attempts to reduce wear on manufacturing equipment for material employing nepheline syenite as a filler or extender and also for glass manufacturing. In an attempt to accomplish this ultra-fine particle size for nepheline syenite, the granulated material was wetted and then ground in a slurry condition in a micro grinder. Thereafter, the ultra-fine particles were dried by a rotary kiln or other process drier. The ultra-fine particles are highly active and tend to agglomerate in the liquid carrier so that the end result contains agglomerates. Thus, a number of particles had an effective particle size substantially greater than a desired small size. Thus, effectiveness of providing nepheline syepnite with a controlled grain size less than 10 microns has been less than satisfactory. Thus, a nepheline syenite product with less than 5 microns was not a commercially viable product. It could only be made in a laboratory by assignee and was not available for any commercial use. THE INVENTION [0004]It has been discovered that the combination of a dry ball mill and an air classifier can produce nepheline syenite with more than 99% of the particles having a size of less than 5 microns. This result utilizes a standard fine grain ball mill with an air classifier of standard design, such as illustrated in English U.S. Pat. No. 4,885,832. This patent illustrates a representative air classifier and is incorporated by reference herein. Furthermore, an air classifier as illustrated in the attached brochures from Sturtevant Incorporated can also be used in practicing the present invention. The type of air classifier is not a requirement in the inventive process. [0005]A planetary ball mill to produce particles of nano scale is disclosed in an article by Frank Bath entitled Consistent Milling on a Nano Scale. This article is incorporated by reference herein as an appropriate ball mill for producing ultra-fine particles of nepheline syenite. The present invention relates to the method of dry processing a quartz free particulate igneous rock with at least orthoclase and microcline as constituents. Dry processing of particulates including grinding and air classification is disclosed in various prior patents. A representative dry processing system of the prior art is disclosed in Tomikawa 2005/0167534 incorporated by reference herein as background information. The invention relates to the conversion of ultra-fine quartz free particulate matter, such as nepheline syenite, by a method which does not use a wet based process as done in the prior art. The existence of dry systems and the desire to produce ultra-fine particles does not suggest the concept of making the ultra-fine particles by a ball mill combined with an air classifier. The background information is incorporated by reference herein does not teach that concept for producing an igneous rock particulate material such as nepheline syenite with a fine grain and with a restricted particle size range, such as 4-5 microns. [0006]In accordance with the present invention, there is provided a method of processing a useable particulated nepheline syenite. The method includes providing nepheline syenite with a maximum first grain size; milling the nepheline syenite in a ball mill operated substantially dry to produce a feed stock with particles substantially less than a given size; and using an air classifier to remove particles having a second grain size from the feed stock to provide an Einlehner abrasive value of less than 100. Indeed, the value is preferably less than 50. In practice, the second grain size is less than 10 microns and preferably less than 5 microns. The range of grain sizes is about 4-5 microns so the particles are ultra-fine size and concentrated within a limited distribution profile. The first grain size of the feed stock for the present invention is less than 1,000 microns and preferably less than 600 microns of a 25 mesh size. [0007]In accordance with the invention, the nepheline syenite is first ground into particles and sized so that the particles have a maximum grain size. Particles greater than this grain size are separated out and then ground to obtain a desired first grain size. The particles having first grain size are feed stock introduced into a ball mill operated dry to produce ultra-fine particles less than about 10 microns and preferably less than 5 microns. The resulting finely ground dry particles are then passed through an air clarifier to separate out the desired particles with a distribution profile of 4-5 microns. [0008]The primary object of the present invention is the provision of a method of processing particulate nepheline syenite in a dry system wherein the resulting particle size produces an Einlehner abrasive value less than 100 and preferably less than 50. [0009]Still a further object of the present invention is the provision of a method, as defined above, which method involves providing a feed stock of nepheline syenite with a low grain size conducive to use in a ball mill that is designed to produce an ultra-fine particle size material, such as a ball mill illustrated in the article by Frank Bath entitled Consistent Milling on a Nano Scale. [0010]Another object of the invention is the product produced by the novel method. [0011]A further object of the present invention is the provision of a method defined in the appended claims of this application wherein the ultimate grain size is less than 10 microns with a distribution profile of 4-5 microns. [0012]Yet another object of the invention is the production of nepheline syenite with a grain size of less than 5 microns by use of a dry processing system. [0013]These and other objects and advantages will become apparent from the following description taken together with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS [0014]FIG. 1 is a block diagram of the method used in practicing the preferred embodiment of the present invention; [0015]FIG. 2 is a schematic side elevational view representing a simplified air classifier to illustrate the general function of an air classifier in practicing the invention; [0016]FIG. 3 is a graph of the constructed line representing the relationship between the grain size of nepheline syenite and its abrasive characteristics; [0017]FIG. 4 is a graph comparing the distribution profile obtained between an experimental sub-5 micron product and the sub-5 micron product of the present invention; and, [0018]FIG. 5 is a schematic view of the method and equipment used in practicing the preferred embodiment of the invention as shown in FIG. 1. THE INVENTION [0019]The showings are for the purpose of illustrating the preferred embodiment of the invention and not for the purpose of limiting same, FIG. 1 is a block diagram of a method 100 wherein a particulate nepheline syenite is processed to obtain an ultra-fine grain size less than 10 microns and preferably less than 5 microns. The method is used to control the grain size of the nepheline syenite where at least 99% of the nepheline syenite is below a set selected ultra-fine particle size. Furthermore, the distribution profile is quite narrow, i.e. in the range of 4-5 microns. The invention does not produce particulate nepheline syenite with a large range of particle sizes that merely includes a mixture of ultra-fine particles and larger particles because the abrasive characteristic of the nepheline syenite particles increases drastically with increased particle size. Consequently, the invention involves at least 99% of the particle size being less than a set value, which value is preferably 5 microns. This is a different product than nepheline syenite wherein the particle size distribution profile is in the range of between 2 microns and 11 microns. It has not been practical to obtain a nepheline syenite having substantially greater than 99% of the particles less than 5 microns with a narrow distribution profile. This objective has been accomplished only in experimental environments utilizing a wet milling procedure. Such procedures result in agglomerations of the ultra-fine particles due to surface activity of the small particles. A substantial amount of process energy is required. These limitations have heretofore bode against obtaining such small ultra-fine particles, even though it is known that such particles reduce the Einlehner abrasive value or number. [0020]For the purposes of reducing abrasive properties of materials containing nepheline syenite particles to a low Einlehner Abrasion Value, the nepheline syenite particles must have a grain size less than 10 microns and preferably less than 5 microns. The present invention is a method of processing nepheline syenite which involves the combination of a dry ball mill and an air classifier. A representative method 100 employing the invention is illustrated in FIG. 1 where nepheline syenite in granular form is supplied at first process step 110. The mined particulate material is ground in a dry grinder 112 using standard mechanical equipment so the resulting particles can be within a certain particle size using grading step 114. In the grading step, which can be done by a screen such as a 16 mesh screen, the particles exiting along outlet line 114a have a first given value. The first value is in the general range of about 1,000 microns. The use of a mechanical 16 mesh screen in the grading step allows the particles flowing along output line 114a to have a size forming optimum feed stock for ball mill 120. If the size of the particles from the dry grinder 112 is greater than the mesh size at step 114, the larger particles are transported along output line 114b to sorter 116. At the sorter, larger unusable particles are ejected along output line 116a and smaller particles are redirected to the grinder 112 through. return line 116b. Thus, the inlet portion of method or system 100 produces a given first grain size which is conductive to subsequent processing according to the present invention. This grain size is selected to be 1,000 microns; however, this is only representative and the particles from output line 114a can have any particular given particle size. This is the first given grain size in method 100. In practice the graded nepheline syenite at outlet line 114a has a grain 25 mesh size (600 micron). Steps 110, 112 and 114 comprise a primary jaw and cone to reduce the mined product to clumps less than 6 inches, rotary kiln to dry the material, a cone crusher to reduce the rock to less than one inch and a tertiary crusher in the form of a vertical shaft impact crusher. The material is then graded to pass a 25 mesh screen and is provided at outlet line 114a. Continue reading... Full patent description for Ultrafine nepheline syenite Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Ultrafine nepheline syenite patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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