Manufactured natural pozzolan, improved manufactured natural pozzolan-based cement and method of making and using same

Abstract

The present invention comprises a product. The product comprises a first mineral in particulate form and having a first pozzolanic reactivity and a second mineral in particulate form and having a second pozzolanic reactivity greater than the first reactivity, wherein the surface of at least some of the particles of the first mineral is at least partially covered with particles of the second mineral. A method of making the composition of the present invention is also disclosed.

Claims

1. A product comprising: a first mineral in particulate form having a volume-based average particle size of approximately 15 to approximately 60 μm and having a first pozzolanic reactivity, wherein the first mineral comprises: approximately 45% to approximately 55% by weight SiO.sub.2, approximately 5% to approximately 15% Al.sub.2O.sub.3, approximately 5% to approximately 20% Fe.sub.2O.sub.3 and approximately 1% to approximately 20% CaO; and an amorphous content of less than or equal to 25% by weight and approximately 5% to approximately 60% by weight Plagioclase Feldspar; and a second mineral in particulate form having a volume-based average particle size of approximately 0.1 to approximately 10 μm and having a second pozzolanic reactivity greater than the first pozzolanic reactivity, wherein the second mineral comprises: an amorphous micro or nano silica with a minimum of approximately 75% by weight glass or amorphous content; and wherein the amorphous micro or nano silica comprises approximately 50% to approximately 80% SiO.sub.2, approximately 5% to approximately 45% Al.sub.2O.sub.3, approximately 5% to approximately 20% Fe.sub.2O.sub.3, and approximately 1% to approximately 20% CaO.

2. The product of claim 1 further comprising a hydraulic cement.

3. The product of claim 2, wherein the hydraulic cement is portland cement.

4. The product of claim 1, wherein the first mineral has a reactivity of less than 100% as measured by ASTM C-618.

5. The product of claim 1, wherein the second mineral has a reactivity of greater than 100% as measured by ASTM C-618.

6. A product comprising: a first mineral in particulate form having a volume-based average particle size of approximately 15 to approximately 60 μm and having a first pozzolanic reactivity, wherein the first mineral comprises: a crystalline or amorphous mineral aggregate comprising less than or equal to 25% by weight glass or amorphous content, approximately 5% to approximately 60% by weight Plagioclase Feldspar, 0% to approximately 40% by weight Clinopyroxene, 0% to approximately 30% by weight Amphibole, 0% to approximately 30% by weight other minerals with a minimum of 45% by weight silicon dioxide (SiO.sub.2); and a second mineral in particulate form having a volume-based average particle size of approximately 0.1 to approximately 10 μm and having a second pozzolanic reactivity greater than the first pozzolanic reactivity, wherein the second mineral comprises: an amorphous micro or nano silica with a minimum of approximately 75% by weight glass or amorphous content; and wherein the amorphous micro or nano silica comprises approximately 50% to approximately 80% SiO.sub.2, approximately 5% to approximately 45% Al.sub.2O.sub.3, approximately 5% to approximately 20% Fe.sub.2O.sub.3, and approximately 1% to approximately 20% CaO.

7. The product of claim 6 further comprising a hydraulic cement.

8. The product of claim 7, wherein the hydraulic cement is portland cement.

9. The product of claim 6, wherein the first mineral has a reactivity of less than 100% as measured by ASTM C-618.

10. The product of claim 6, wherein the second mineral has a reactivity of greater than 100% as measured by ASTM C-618.

11. A method comprising: combining a first and a second mineral; the first mineral in particulate form having a volume-based average particle size of approximately 15 to approximately 60 μm and having a first pozzolanic reactivity, wherein the first mineral comprises: approximately 45% to approximately 55% by weight SiO.sub.2, approximately 5% to approximately 15% Al.sub.2O.sub.3, approximately 5% to approximately 20% Fe.sub.2O.sub.3 and approximately 1% to approximately 20% CaO; and an amorphous content of less than or equal to 25% by weight and approximately 5% to approximately 60% by weight Plagioclase Feldspar; and the second mineral in particulate form having a volume-based average particle size of approximately 0.1 to approximately 10 μm and having a second pozzolanic reactivity greater than the first pozzolanic reactivity, wherein the second mineral comprises: an amorphous micro or nano silica with a minimum of approximately 75% by weight glass or amorphous content; and wherein the amorphous micro or nano silica comprises approximately 50% to approximately 80% SiO.sub.2, approximately 5% to approximately 45% Al.sub.2O.sub.3, approximately 5% to approximately 20% Fe.sub.2O.sub.3, and approximately 1% to approximately 20% CaO.

12. The method of claim 11, wherein the first mineral has a pozzolanic reactivity of less than 100% as measured by ASTM C-618 and the second mineral has a pozzolanic reactivity of greater than 100% as measured by ASTM C-618.

13. The method of claim 11 further comprising combining the first and second minerals with a hydraulic cement.

Description

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

(1) In one disclosure embodiment, the improved manufactured natural pozzolan of the present invention is made of a first mineral having a first pozzolanic reactivity at least partially coated by a second mineral having a second pozzolanic reactivity higher than the first reactivity. The second mineral also has a smaller particle size than the first mineral.

(2) The first mineral is a crystalline or amorphous mineral aggregate with a maximum of approximately 25% by weight glass or amorphous content, of approximately 5% to approximately 60% by weight Plagioclase Feldspar, 0% to approximately 40% by weight Clinopyroxene, 0% to approximately 30% by weight Amphibole, 0% to approximately 30% by weight other minerals with a minimum of 45% by weight silicon dioxide (SiO.sub.2) content including, but not limited to, basalt, meta-basalt, intermediate, andesite or any other type of rock, is ground to a fine particle size that passes a 45 μm (No. 325) sieve, with a maximum of approximately 35% by volume retention. The particle size of the first mineral is approximately 15 to approximately 60 μm (volume-based average particle size) or a particle size measured by a specific surface area of approximately 50 to approximately 200 m.sup.2/kg. The first mineral has a pozzolanic reactivity index of less than 100% when tested in accordance with ASTM C-618 at 7 and 28 days. The first mineral chemical composition is preferably approximately 45% to approximately 60% SiO.sub.2, approximately 5% to approximately 15% Al.sub.2O.sub.3, approximately 5% to approximately 20% Fe.sub.2O.sub.3, approximately 1% to approximately 20% CaO, approximately 0.5% to approximately 12% MgO, 0% to approximately 5% N.sub.2O, 0% to approximately 3% K.sub.2O and approximately 1% to approximately 10% others compounds (all percentages are by weight unless otherwise noted).

(3) The second mineral is an amorphous micro or nano silica, such as silica fume or any other type of nano or micro silica; or an aluminosilicate, such as Metakaolin, or any other type of calcined clay with a minimum of 75% by weight aluminosilicate (Al.sub.2O.sub.3:2SiO.sub.2), or any other type material with a minimum of 75% by weight glass or amorphous content, 0% to approximately 20% Plagioclase Feldspar, 0% to approximately 10% K-Feldspar 0% to approximately 10% Clinopyroxene, 0% to approximately 10% Amphibole, 0% to approximately 20% Kaolinite, 0% to approximately 10% Olivine, 0% to approximately 10% other minerals and a chemical composition of approximately 50% to approximately 80% SiO.sub.2, approximately 5% to approximately 45% Al.sub.2O.sub.3, approximately 5% to approximately 20% Fe.sub.2O.sub.3, approximately 1% to approximately 20% CaO, approximately 0.5% to approximately 12% MgO, 0% to approximately 5% N.sub.2O, 0% to approximately 3% K.sub.2O and approximately 1% to approximately 10% other compounds (all percentages are by weight unless otherwise noted) and a volume-based average particle size of approximately 0.1 to approximately 10 μm or a specific area fineness of approximately 300 to approximately 10,000 m.sup.2/kg. The second mineral has a pozzolanic reactivity index of greater than 100% when tested in accordance to ASTM C618 at 7 and 28 days. The properties above include all intermediate values.

(4) The second mineral is then deposited, fused, coated or otherwise disposed on to the surface of the first mineral. The proportion between the two minerals is of approximately 70% to approximately 95% of the first mineral and approximately 5% to approximately 30% of the second mineral when measured by weight or by volume. Various methods can be employed to deposit, fuse, coat or otherwise disposed the second mineral onto the surface of the first mineral, such as blending through air movement or electrostatic means. The particular method by which the coating of the first mineral by the second mineral is accomplished is not the subject of this inventions and can be any other means known in the industry that can achieve the coating of this first mineral by the second mineral, fused or deposited onto the surface area of the first mineral.

(5) An alternative method of coating, depositing or otherwise disposing the second mineral onto the surface of the first mineral is by inter-grinding the second mineral with the first mineral. Yet another method of coating, depositing or otherwise disposing the second mineral onto the surface of the first mineral is to employ autogenous grinding whereby the two minerals of different particle size are aiding in the grinding process itself. Another alternative method of coating, depositing or otherwise disposing the second mineral onto the surface of the first mineral is by mixing the first mineral with an aluminosilicate clay under elevated temperatures in a rotating kiln or blending and calcining the two minerals together. Another alternative method of fusing the second mineral onto the surface of the first mineral is by blending the two materials under elevated temperatures in a rotating kiln or any other high temperature blending equipment.

(6) The first mineral is slow to react on its own, however the second mineral has a higher pozzolanic reactivity. As such the pozzolanic reaction starts on the surface of the first mineral that is highly reactive due to the second mineral disposed thereon and then activating the first mineral that is less reactive. In other words, the manufactured pozzolan is activated by a two-stage pozzolanic reaction.

(7) Preferably a water reducer admixture is added to the process above. The water reducing admixture will not affect the pozzolanic reaction, however it could improve the water demand based on various types of aggregate and minerals used. Such water reducing admixtures are solids or liquids. Water reducing admixtures are known in the industry and include, but are not limited to, lignin, naphthalene, carboxylates or polycarboxylates.

(8) Preferred types of aggregates for the first mineral are igneous rocks. Igneous rock deposits are generally consistent in their chemical properties. Also, there are many different mining tailing deposits, both from closed and current mining operations, that meet the requirement of a minimum 70% by weight for the total sum of silicon dioxide, iron oxide and aluminum oxide (SiO.sub.2+Al.sub.2O.sub.3+Fe.sub.2O.sub.3) and can be used as the first mineral.

(9) The first mineral for use in the present invention can contain one or more of olivine, pyroxene, magnetite, quartz, hornblende, biotite, hypersthene, feldspathoids, plagioclase, calcite or other crystalline minerals or mixtures thereof.

(10) Basalt is an aphanitic (fine-grained) igneous rock with generally 45% to 55% silica (SiO.sub.2) containing essentially calcic plagioclase feldspar and pyroxene (usually Augite), with or without olivine. Basalts can also contain quartz, hornblende, biotite, hypersthene (an orthopyroxene) and feldspathoids. Basalts are often porphyritic and can contain mantle xenoliths. Basalt is distinguished from pyroxene andesite by its more calcic plagioclase. There are two main chemical subtypes of basalt: tholeiites which are silica saturated to oversaturated and alkali basalts that are silica undersaturated. Tholeiitic basalt dominate the upper layers of oceanic crust and oceanic islands, alkali basalts are common on oceanic islands and in continental magmatism. Basalts can occur as both shallow hypabyssal intrusions or as lava flows. The average density basalt is approximately 3.0 gm/cm.sup.3.

(11) Andesite is an abundant igneous (volcanic) rock of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is an intermediate type between basalt and dacite, and ranges from 57% to 63% by weight silicon dioxide (SiO.sub.2). The mineral assemblage is typically dominated by plagioclase plus pyroxene or hornblende. Magnetite, zircon, apatite, ilmenite, biotite, and garnet are common accessory minerals. Alkali feldspar can be present in minor amounts.

(12) In a disclosed embodiment, the present invention comprises an improved manufactured natural pozzolan (i.e., the combination of the first and second minerals) in powder form. The particle size of the powder is sufficiently small such that the improved manufactured natural pozzolan powder has pozzolanic properties. The improved manufactured natural pozzolan powder preferably having a volume average particle size (or a volume-based mean particle size) of less than or equal to 40 μm with a maximum 34% retained when passing through 325 mesh sieve, more preferably less than or equal to 20 μm with a maximum of 34% retained when passing through 325 mesh sieve, most preferably less than or equal to 15 μm with a maximum of 34% retained when passing through 325 mesh sieve, especially less than or equal to 10 μm with a maximum of 34% retained when passing through 325 mesh sieve, more especially less than or equal to 5 μm with a maximum of 34% retained when passing through 325 mesh sieve. The foregoing ranges include all of the intermediate values. To achieve the desired particle size, the improved manufactured natural pozzolan of the present invention can be ground using conventional means including, but not limited to, a ball mill, a roll mill or plate mill. A particle size classifier can be used in conjunction with the mill to achieve the desired particle size. Equipment for grinding and classifying the improved manufactured natural pozzolan to the desired particle size is commercially available from, for example, F. L. Smidth, Bethlehem, Pa.; Metso, Helsinki, Finland.

(13) In one disclosed embodiment of the present invention, the improved manufactured natural pozzolan preferably has a chemical composition of approximately 45% to approximately 65% by weight SiO.sub.2, approximately 5% to approximately 30% by weight Al.sub.2O.sub.3, approximately 5% to approximately 15% by weight Fe.sub.2O.sub.3, approximately 5% to approximately 15% by weight CaO, approximately 1% to approximately 15% by weight MgO, less than or equal to approximately 5% by weight Na.sub.2O. In addition to the foregoing, other compounds can be present in minor amounts, such as K.sub.2O, TiO.sub.2, P.sub.2O.sub.5, MnO, various metals, rare earth trace elements and other unidentified elements. When combined, these other compounds represent less than 10% by weight of the total chemical composition of the improved manufactured natural pozzolan mineral.

(14) In another disclosed embodiment, the improved manufactured natural pozzolan in accordance with the present invention preferably has a density or specific gravity of approximately 2.5 to approximately 3.1.

(15) An improved manufactured natural pozzolan in accordance with the present invention is a combination of crystalline and amorphous (glassy) combination in varying proportions. Preferably, the improved manufactured natural pozzolan in accordance with the present invention preferably comprises approximately 0% to 99% by weight amorphous form, more preferably 10% to approximately 80% by weight amorphous form, most preferably approximately 20% to approximately 60% by weight amorphous form, especially approximately 30% to approximately 50% by weight amorphous form. The crystalline portion of the improved manufactured natural pozzolan preferably comprises approximately 3% to approximately 20% by weight olivine, approximately 5% to approximately 40% by weight clinopyroxene, approximately 5% to approximately 60% by weight plagioclase, and approximately 0% to approximately 10% (or less than 10%) by weight other minerals including, but not limited to, magnetite, UlvoSpinel, quartz, feldspar, pyrite, illite, hematite, chlorite, calcite, hornblende, biotite, hypersthene (an orthopyroxene), feldspathoids sulfides, metals, rare earth minerals, other unidentified minerals and combinations thereof. The foregoing ranges include all of the intermediate values.

(16) The improved manufactured natural pozzolan in accordance with the present invention can be used as a supplementary cementitious material in concrete or mortar mixes. The improved manufactured natural pozzolan in accordance with the present invention is not by itself a hydraulic cement, but is activated by CaOH (hydrate lime) produced by the hydration of hydraulic cements, such as portland cement, or by other minerals or compounds having reactive hydroxyl groups, such as CaO (quick lime). In addition, the improved manufactured natural pozzolan in accordance with the present invention when mixed with cement may improve the cement nucleation process thereby improving the cement hydration process. The improved manufactured natural pozzolan in finer particles generally yields shorter set times and accelerated hydration in blended cements. Finer particle size of the improved manufactured natural pozzolan increases the rate of hydration heat development and early-age compressive strength in portland cement. This acceleration may be attributable to the improved manufactured natural pozzolan particle size (nucleation sites), its crystalline make-up and chemical composition. The improved manufactured natural pozzolan in accordance with the present invention can be used in combination with any hydraulic cement, such as portland cement. Other hydraulic cements include, but are not limited to, blast granulated slag cement, calcium aluminate cement, belite cement (dicalcium silicate), phosphate cements and others. Also, the improved manufactured natural pozzolan in accordance with the present invention by itself can be blended with lime to form a cementitious material. In one disclosed embodiment, blended cementitious material for cement or mortar preferably comprises from approximately 10% to approximately 90% by weight hydraulic cement and approximately 10% to approximately 90% by weight of the improved manufactured natural pozzolan in accordance with the present invention, more preferably approximately 20% to approximately 80% by weight hydraulic cement and approximately 20% to approximately 80% by weight of the improved manufactured natural pozzolan in accordance with the present invention, most preferably approximately 30% to approximately 70% by weight hydraulic cement and approximately 30% to approximately 70% by weight of the improved manufactured natural pozzolan in accordance with the present invention, especially approximately 40% to approximately 60% by weight hydraulic cement and approximately 40% to approximately 60% by weight of the improved manufactured natural pozzolan in accordance with the present invention, more especially approximately 50% by weight hydraulic cement and approximately 50% by weight of the improved manufactured natural pozzolan in accordance with the present invention. In another disclosed embodiment of the present invention, the cementitious material for concrete or mortar preferably comprises approximately 50% to approximately 90% by weight hydraulic cement and approximately 10% to approximately 50% by weight of the improved manufactured natural pozzolan in accordance with the present invention. The foregoing ranges include all of the intermediate values.

(17) The present invention can be used with conventional concrete mixes. Specifically, a concrete mix in accordance with the present invention comprises cementitious material, aggregate and water sufficient to hydrate the cementitious material. The cementitious material comprises a hydraulic cement and the improved manufactured natural pozzolan in accordance with the present invention. The amount of cementitious material used relative to the total weight of the concrete varies depending on the application and/or the strength of the concrete desired. Generally speaking, however, the cementitious material comprises approximately 25% to approximately 40% by weight of the total weight of the concrete, exclusive of the water, or 300 lbs/yd.sup.3 (177 kg/m.sup.3) of cement to 1,200 lbs/yd.sup.3 (710 kg/m.sup.3) of cement. In ultra-high performance concrete, the cementitious material exceeds the 40% by weight of the total weight of the concrete. The water-to-cement ratio by weight is usually approximately 0.25 to approximately 0.7. Relatively low water-to-cement materials ratios by weight lead to higher strength but lower workability, while relatively high water-to-cement materials ratios by weight lead to lower strength, but better workability. For high performance concrete and ultra-high performance concrete, lower water-to-cement ratios are used, such as approximately 0.15 to approximately 0.25. Aggregate usually comprises 70% to 80% by volume of the concrete. In ultra-high performance concrete the aggregate is less than 70% of the concrete by volume. However, the relative amounts of cementitious material to aggregate to water are not a critical feature of the present invention; conventional amounts can be used. Nevertheless, sufficient cementitious material should be used to produce concrete with an ultimate compressive strength of at least 1,000 psi, preferably at least 2,000 psi, more preferably at least 3,000 psi, most preferably at least 4,000 psi, especially up to about 10,000 psi or more. In particular, ultra-high performance concrete, concrete panels or concrete elements with compressive strengths of over 20,000 psi can be cast and cured using the present invention.

(18) The aggregate used in the concrete in accordance with the present invention is not critical and can be any aggregate typically used in concrete. The aggregate that is used in the concrete depends on the application and/or the strength of the concrete desired. Such aggregate includes, but is not limited to, fine aggregate, medium aggregate, coarse aggregate, sand, gravel, crushed stone, lightweight aggregate, recycled aggregate, such as from construction, demolition and excavation waste, and mixtures and combinations thereof.

(19) The reinforcement of the concrete in accordance with the present invention is not a critical aspect of the present invention, and, thus, any type of reinforcement required by design requirements can be used. Such types of concrete reinforcement include, but are not limited to, deformed steel bars, cables, post tensioned cables, pre-stressed cables, fibers, steel fibers, mineral fibers, synthetic fibers, carbon fibers, steel wire fibers, mesh, lath, and the like.

(20) The preferred cementitious material for use with the present invention comprises portland cement. The cementitious material preferably comprises a reduced amount of portland cement and an increased amount of supplementary cementitious materials; i.e., the improved manufactured natural pozzolan in accordance with the present invention. This results in cementitious material and concrete that is more environmentally friendly. The portland cement can also be replaced, in whole or in part, by one or more pozzolanic materials. Portland cement is a hydraulic cement. Hydraulic cements harden because of a hydration process; i.e., a chemical reaction between the anhydrous cement powder and water. Thus, hydraulic cements can harden underwater or when constantly exposed to wet weather. The chemical reaction results in hydrates that are substantially water-insoluble and so are quite durable in water. Hydraulic cement is a material that can set and harden submerged in water by forming insoluble products in a hydration reaction. Other hydraulic cements useful in the present invention include, but are not limited to, calcium aluminate cement, belite cement (dicalcium silicate), phosphate cements and anhydrous gypsum. However, the preferred hydraulic cement is portland cement.

(21) In a disclosed embodiment of the present invention, concrete or mortar comprises a hydraulic cement, the improved manufactured natural pozzolan in accordance with the present invention, aggregate and water. Preferably, the cementitious material used to form the concrete or mortar comprises portland cement and the improved manufactured natural pozzolan powder, more preferably portland cement and the improved manufactured natural pozzolan having a volume average particle size (or volume-based mean particle size) of less than or equal to approximately 40 μm with a maximum of 34% retained when passing through 325 mesh sieve, most preferably portland cement and the improved manufactured natural pozzolan having a volume average particle size of less than or equal to approximately 20 μm with a maximum of 34% retained when passing through 325 mesh sieve, preferably less than or equal to 15 μm with a maximum of 34% retained when passing through 325 mesh sieve, preferably less than or equal to 10 μm with a maximum of 34% retained when passing through 325 mesh sieve, more preferably less than or equal to 5 μm with a maximum of 34% retained when passing through 325 mesh sieve. The foregoing ranges include all of the intermediate values.

(22) In another disclosed embodiment of the present invention, concrete including an improved manufactured natural pozzolan in accordance with the present invention can include any other pozzolan in combination with hydraulic cement.

(23) The portland cement and the improved manufactured natural pozzolan in accordance with the present invention can be combined physically or mechanically in any suitable manner and is not a critical feature of the present invention. For example, the portland cement and the improved manufactured natural pozzolan in accordance with the present invention can be mixed together to form a uniform blend of dry cementitious material prior to combining with the aggregate and water. Or, the portland cement and the improved manufactured natural pozzolan in accordance with the present invention can be added separately to a conventional concrete mixer, such as a transit mixer of a ready-mix concrete truck, at a batch plant. The water and aggregate can be added to the mixer before the cementitious material, however, it is preferable to add the cementitious material first, the water second, the aggregate third and any makeup water last.

(24) Chemical admixtures can also be used with the concrete in accordance with the present invention. Such chemical admixtures include, but are not limited to, accelerators, retarders, air entrainments, plasticizers, superplasticizers, coloring pigments, corrosion inhibitors, bonding agents and pumping aid.

(25) Mineral admixtures can also be used with the concrete in accordance with the present invention. Although mineral admixtures can be used with the concrete of the present invention, it is believed that mineral admixtures are not necessary. However, in some embodiments it may be desirable to include a water reducing admixture, such as a superplasticizer.

(26) Concrete can also be made from a combination of portland cement and pozzolanic material or from pozzolanic material alone. There are a number of pozzolans that historically have been used in concrete. A pozzolan is a siliceous or siliceous and aluminous material which, in itself, possesses little or no cementitious value but which will, in finely divided form and in the presence of water, react chemically with calcium hydroxide at ordinary temperatures to form compounds possessing cementitious properties (ASTM C618). The broad definition of a pozzolan imparts no bearing on the origin of the material, only on its capability of reacting with calcium hydroxide and water. The general definition of a pozzolan embraces a large number of materials, which vary widely in terms of origin, composition and properties The most commonly used pozzolans today are industrial by-products, such as slag cement (ground granulated blast furnace slag), Fly Ash, silica fume from silicon smelting, and natural pozzolans such as highly reactive Metakaolin, and burned organic matter residues rich in silica, such as rice husk ash.

(27) The improved manufactured natural pozzolan in accordance with the present invention is a previously unknown natural pozzolan. It can be used as a substitute for any other pozzolan or in combination with any one or more pozzolans that are used in combination with any hydraulic cement used to make concrete or mortar.

(28) It is specifically contemplated as a part of the present invention that concrete formulations including an improved manufactured natural pozzolan in accordance with the present invention can be used with concrete forms or systems that retain the heat of hydration to accelerate the curing of the concrete. Therefore, in another disclosed embodiment of the present invention, concrete in accordance with the present invention can be cured using concrete forms such as disclosed in U.S. Pat. Nos. 8,555,583; 8,756,890; 8,555,584; 8,532,815; 8,877,329; 9,458,637; 8,844,227 and 9,074,379 (the disclosures of which are all incorporated herein by reference); published patent application Publication Nos. 2014/0333010; 2014/0333004 and 2015/0069647 (the disclosures of which are all incorporated herein by reference) and U.S. patent application Ser. No. 15/418,937 filed Jan. 30, 2017 (the disclosure of which is incorporated herein by reference).

(29) The following examples are illustrative of selected embodiments of the present invention and are not intended to limit the scope of the invention. All percentages are by weight unless noted otherwise.

EXAMPLE 1

(30) The first mineral is a basalt-type aggregate with a chemical make-up of approximately 48% SiO.sub.2, 13% Al.sub.2O.sub.3, 10% Fe.sub.2O.sub.3, 12% CaO, 10% MgO, 1.5% N.sub.2O, 0.3% K.sub.2O and the balance being other compounds. The basalt-type aggregate has an amorphous content of approximately 15% of approximately 30% clinopyroxene, approximately 40% plagioclase feldspar, approximately 15% olivine and the balance being other minerals. The basalt-type aggregate is placed in a ball mill and ground to a volume-based average particle size of 30 microns. The second mineral is metakaolin with a chemical make-up of approximately 53% SiO.sub.2, 40% Al.sub.2O.sub.3, 3% Fe.sub.2O.sub.3, 0.5% CaO, 0.5% MgO, 0.1% N.sub.2O, 1% K.sub.2O, and approximately 75% by weight amorphous content, of approximately 3% by weight K-feldspar, approximately 10% kaolinite and the balance being other minerals, with an average volume-based particle size of approximately 10 microns. The basalt-type aggregate particles and the Metakaolin particles are blended together with a proportion of 80% basalt-type aggregate particles and 20% Metakaolin. The resulting product has Metakaolin particles disposed on the surface of the basalt-type aggregate particles. The resulting improved manufactured pozzolan has improved properties in accordance with the present invention.

EXAMPLE 2

(31) The first mineral is a basalt-type aggregate with a chemical make-up of approximately 48% SiO.sub.2, 13% Al.sub.2O.sub.3, 10% Fe.sub.2O.sub.3, 12% CaO, 10% MgO, 1.5% N.sub.2O, 0.3% K.sub.2O and the balance being other compounds. The basalt-type aggregate has no amorphous content of approximately 35% clinopyroxene, approximately 50% plagioclase feldspar, approximately 15% olivine and the balance being other minerals. The basalt-type aggregate is placed in a ball mill and ground to a volume-based average particle size of 20 microns. The second mineral is silica fume with a chemical make-up of approximately 98% SiO.sub.2 and the balance being other elements and having a volume-based average particle size of 1 micron. The basalt-type aggregate particles and the silica fume particles are blended together with a proportion of 85% basalt-type aggregate particles and 15% silica fume particles. The resulting product has silica fume particles disposed on the surface of the basalt-type aggregate particles. The resulting improved manufactured pozzolan has improved properties in accordance with the present invention.

EXAMPLE 3

(32) The first mineral is a basalt-type aggregate with a chemical make-up of approximately 55% SiO.sub.2, 15% Al.sub.2O.sub.3, 8% Fe.sub.2O.sub.3, 9% CaO, 4% MgO, 3% N.sub.2O, 0.9% K.sub.2O and the balance being other compounds. The basalt-type aggregate has no amorphous content of approximately 18% clinopyroxene, approximately 5% K-feldspar, approximately 10% Clino-amphibole and the balance being other minerals. The basalt-type aggregate is placed in a ball mill and ground to a volume-based average particle size of 30 microns. The second mineral is metakaolin with a chemical make-up of approximately 53% SiO.sub.2, 40% Al.sub.2O.sub.3, 3% Fe.sub.2O.sub.3, 0.5% CaO, 0.5% MgO, 0.1% N.sub.2O, 1% K.sub.2O, and approximately 75% by weight amorphous content, of approximately 3% by weight K-feldspar, approximately 10% kaolinite and the balance being other minerals, with an average volume-based particle size of approximately 10 microns. The basalt-type aggregate particles and the Metakaolin particles are blended together with a proportion of 70% basalt-type aggregate particles and 30% Metakaolin. The resulting product has Metakaolin particles disposed on the surface of the basalt-type aggregate particles. The resulting improved manufactured pozzolan has improved properties in accordance with the present invention.

(33) It should be understood, of course, that the foregoing relates only to certain disclosed embodiments of the present invention and that numerous modifications or alterations may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.