English:
[0002] Aggregates, which are essential ingredients of concrete, may be derived from natural sources with minimal processing or from naturally occurring materials that are heat treated. Aggregates may also be synthetic. Aggregates from natural sources, such as quarries, pits in ground, and riverbeds, for example, are generally composed of rock fragments, gravel, stone, and sand, which may be crushed, washed, and sized for use, as needed. Aggregates from natural materials that may be used to form aggregates include clay, shale, and slate, which are pyroprocessed, causing expansion of the material. OPTIROC and LECA are examples of commercially available expanded clay aggregates, for example. Synthetic aggregates may comprise industrial byproducts, which may be waste materials. LYTAG, for example, is a commercially available sintered aggregate comprising pulverized fuel ash ("PFA"), also known as fly ash. PFA is produced from the combustion of coal in power plants, for example.
[0003] Aggregates may be lightweight or normal weight. Lightweight aggregates ("LWAs") have a particle density of less than 2.0 g/m3 or a dry loose bulk density of less than 1.1 g/cm , as defined in ASTM specification C330. Normal weight aggregates from gravel, sand, and crushed stone, for example, generally have bulk specific gravities of from about 2.4 to about 2.9 (both oven-dry and saturated- surface-dry), and bulk densities of up to about 1.7 g/cm3. High quality LWAs have a strong but low density porous sintered ceramic core of uniform structural strength and a dense, continuous, relatively impermeable surface layer to inhibit water absorption. They are physically stable, durable, and environmentally inert. LWAs should also be nearly spherical, to improve concrete properties and provide good adherence to concrete paste. Suitable sizes for incorporation in concrete are in a range of from about 4.75 mm to about 25 mm, or 2.36 mm to 9.5 mm for coarse aggregates, in accordance with ASTM Specification C330. Smaller, fine aggregates, which are a byproduct of LWA production, may also be used, to replace sand in concrete, for example. For use in concrete, LWAs should have a sufficient crushing strength and resistance to fragmentation so that the resulting concrete has a strength of greater than 10 MPa and a dry density in a range of about 1.5 g/cm3 to about 2.0 g/cm3. Concrete containing LWAs ("LWA concrete") may also have a density as low as about 300 kg/m3.
[0011] Waste glass, which is removed from the MSW stream, is another waste product. Waste glass has been used in highway construction as an aggregate substitute in asphalt paving and as a granular base or fill material. Waste glass varies in sizes from between about 25 mm to about 100 mm.
[0014] The production of synthetic aggregates from incinerator bottom ash from municipal solid waste incinerators ("IBA") would avoid or mitigate some or all of the problems associated with waste disposal of IBA and quarrying for aggregate raw materials. However, it has been found that IBA may be difficult to pyroprocess into a product having desired characteristics, because it sinters and densities rapidly. IBA contains high concentrations of calcium containing minerals, such as calcium oxides, carbonates, and sulfates, as well as sodium and potassium oxides and sulfates. These minerals act as "fluxes." It is believed that these fluxes lower the melting point of the remaining compounds in the IBA, causing sintering and densification at lower temperatures than if lesser amounts of the fluxes were present. In addition, the composition of IBA is very variable, making its pyroprocessing behavior unpredictable. Variability in IBA composition may be due to several factors, such as the incineration procedures and variability in the wastes received and processed by the MSW incinerator. The wastes received may vary based on the time of the year and the geographic location where the wastes are generated.
[0018] The IBA and the second material may be mixed with an organic material, such as activated carbon waste, to increase the porosity of the aggregate. The organic material may comprise up to about 30% by dry weight of the mixture of IBA and the second material, for example.
[0035] Fig. 5 is an example of a method for producing aggregates, in accordance with an embodiment of the invention;
[0037] Fig. 7 is an example of another method for producing aggregates, in accordance with another embodiment of the invention;
[0040] Fig. 10 is a graph of density (g/cm3) versus pyroprocessing temperature (0C) for IBA and mixtures of IBA and kaoline, in accordance with an embodiment of the invention;
[0041] Fig. 11 is a graph of density (g/cm3) versus pyroprocessing temperature (0C) for IBA and mixtures of IBA and shale, in accordance with an embodiment of the invention; and
[0042] Fig. 12 is a graph of density (g/cm3) versus pyroprocessing temperature (0C) for IBA and mixtures of IBA and slate, in accordance with an embodiment of the invention;
[0046] Density increases with temperature from 1,060° to l,100°C because in this temperature range, as the product sinters, the fluxing agents in the BBA melt to form a liquid phase that fills pores between particles in the IBA by capillary action. Density increases as pores are filled and the volume of the sample decreases. In addition, smaller particles,,m the liquid phase diffuse toward the larger particles. The melted materials form a. rigid, glassy, amorphous skeleton or matrix upon hardening. As the processing temperature increases, more of the compounds in the IBA melt,: substantially eliminating, all the,pores .and forming a more glassy, crystalline solid matrix. At the temperature of maximum densification, essentially all of the pores are filled and the product is vitrified. v
[0051] As shown in Fig. 1, in an 60%/40% IBA/bentonite mix, for example, in order to produce a sintered lightweight aggregate having a density of from about 1.5 g/cm3 to about 1.8 g/cm3, the sintering temperature may be within a range of about 20° (from about l,085°C to about l,105°C). In a 40%/60% IBA/bentonite mix, similar densities may be achieved at a temperature within a 50°C range of from about l,080°C to about 1,13O0C. hi addition, increasing the bentonite concentration to 60% delays sintering as the maximum density is reached at about 1,1800C (in contrast to 1,1000C for 100% IBA and 1,1300C for 60%/40% IBA/bentonite). It is expected that further increases in bentonite to 80% and above would result in lightweight aggregates having densities of from about 1.5 g/cm3 to about 1.8 g/cm3 over a wider temperature range than the 40%/60% IBA/bentonite mix. The broader temperature ranges facilitate production of aggregates of desired density and other properties, despite variations in composition of the IBA. Fig. 1 is based on the results of Example 3, below.
[0052] It has also been found that the effects of variations in IBA composition on characteristics of resulting aggregates may be further mitigated by wet milling the IBA. Wet milling has been found to reduce material heterogeneity and produce more homogeneous slurries that are more suitable for further processing, than other commonly used techniques.
[0080] IBA and WG were processed as described above with respect to Fig. 5 and in more detail, below. In this example, WG was added to wet milled IBA powder before pelletization.
[0087] Tables B-D, below, summarize the physical and mechanical properties of aggregates formed by the process of Example 1. It is noted that the aggregates showed substantial changes in their physical properties with increasing concentrations of WG in the IBA/WG mixes.
[0092] Table B also shows the effect of WG addition on the water absorption capacities of the different aggregates. Lightweight aggregates, which are produced at temperatures less than the temperature of maximum densification, typically have some porosity. As maximum densification is approached, the size and number of the pores gradually decrease to zero, as the pores are filled with melted material. Aggregates containing high amounts of DBA exhibit a rapid reduction in water absorption with temperature, while high WG aggregates show a more gradual water absorption reduction with temperature. The 100% WG pellets have substantially less water absorption than all other mixes at all temperatures examined, due to the melted glass filling the pores produced by volatization.
[0093] Table C, below, summarizes aggregate crushing values ("ACVs") (%) for selected mixes of EBA1 fand WG, at specific pyroprocessing temperatures. The ACVs are provided at three different temperatures for different proportions of IBA to WG. ACV is inversely proportional to aggregate strength. The selected temperatures were those causing different product characteristics and different microstructures, for comparison. At the lower temperatures in each set, a sintered lightweight aggregate ("LWA") was produced in, accordance with a preferred embodiment of the invention.' At the middle temperatures, a well-sintered or vitrified, normal weight aggregate with small amounts of residual pores was produced, in accordance with an embodiment ©f the invention. At the higher temperatures, a vitrified LWA was produced, also in accordance with an embodiment of the invention.
[0094] ACVs were lower and the strengths of the aggregates were higher at the temperature of maximum densification (middle temperature). Below that temperature, the densities were lower, the ACVs were higher, and the strengths of individual or bulk aggregates were lower. Above that temperature (middle), the ACVs started to increase as the density and aggregate strength decreased, due to increasing sample melting. The aggregate strengths show the same trend of aggregate densities with increasing temperature, increasing to a maximum value and then decreasing, as expected. The LWAs comprising EBA and WG in varying proportions in accordance with embodiments of the invention also have lower ACVs and higher strengths than LYTAG5 which has an ACV of about 34%, as noted below. TABLE C: AGGREGATE CRUSHINGVALUE (%
[0095] Based on the effect of pyroprocessing temperature and WG addition on the properties of the pyroprocessed aggregates, shown in Fig. 8 and Tables B and C, a 40%/60% IBA/WG mix, sintered at a temperature range of 1,0800C to l,190°C, which have densities from about 1.5 g/cm3 to about 2.6 g/cm3, is preferred. Such aggregates may be used in a range of applications, including as aggregates in concrete. The behavior of this mixture during sintering and other pyroprocessing and the final properties of the resulting LWAs may therefore be more easily controlled, than in an aggregate comprising 100% DBA. The reduced water absorption of aggregates of this combination is due to the melted glass, which fills the pores, including the surface pores of the aggregate.
[0096] Table D, below, summarizes certain physical properties (relative dry densities and water absorptions from Table B, and bulk densities) and mechanical properties (ACV from Table C) of aggregates comprising 40%/60% JBAJWG at three selected temperatures. The corresponding properties of the commercially available LYTAG (sintered PFA) and OPTIROC (expanded clay) aggregates are also given in Table D. The individual pellet properties are average values of 20 measurements and the bulk pellet properties are averages of 2 measurements.
[0097] A comparison of the properties of LYTAG and the aggregates comprising 40%/60% IBA/WG sintered at 1,0800C (referred to as LWA-I) or sintered at 1,1000C (referred to as LWA-2), shows that LWA-I had comparable relative dry density and bulk aggregate densities (relative density around 1.5 g/cm3, loose bulk density between 0.8 and 0.9 g/cm3). Sintered LWA-2 had slightly higher relative and bulk density than that of LWA-I and LYTAG. Both sintered aggregates showed significantly lower ACVs than that of LYTAG, indicating that they can resist higher stresses as a bulk when loaded in compression. OPTIROC has very low density, relatively low water absorption, and very low strength. This is to be expected since OPTIROC has a honeycombed microstructure of high volume of isolated spherical porosity.
[0098] In order to demonstrate the viability of the LWA-I and LWA-2. in concrete, a concrete mixture was designed and tested for fresh and hardened concrete. . The mix in this example is shown in Table E, which shows the proportions of individual constituents of concrete including LYTAG, OPTIROC, and LWA-I and - LWA-2, based ,on dry conditions of the aggregates. The mixtures were varied so that LYTAG and LWA-I and LWA-2 would achieve similar workability as measured by the slump test. The slump was slightly higher for OPTIROC. Since the aggregates were in an air-dry, state at the time of casting, the differences in the total water/cement ratios were due to differences in the water absorption of the aggregates... The>total water/cement ratio increased for the aggregates with increased water absorption. TABLE E: CONCRETE MIX RATIOS FOR THE LWA-I AND LWA-2
[00100] It is apparent that concrete from the sintered. LWA-I of the invention achieved comparable compressive strengths to the corresponding concrete made from LYTAG. However, researchers have reported significantly lower compressive strengths of concrete made with LYTAG at all ages. (See, for example, U.S. Pat. No. 2003/0047114Al issued on March 13, 2003 to Kayali, et al.) LWA-2 achieved higher compressive strengths at all ages, due to the higher aggregate densities, strengths and lower water absorptions.
[00101] The compressive strength of concrete from sintered LWA-I at 7, 14 and 28 days was 47.3 MPa, 52.5 MPa and 58.6 MPa, which classifies it as high strength concrete. Comparable compressive strengths were obtained for concrete made with LYTAG. The very low strengths of concrete made with OPTIROC lightweight aggregates are attributed to the very low strengths, low densities, and high porosities of the aggregates. Concrete made with LWA-2 had a compression strength as high as 64.2 MPa at 28 days, which is higher than all the examined aggregates at all ages EXAMPLE 2
[00108] Table H, below, summarizes^ test results for aggregates comprising different proportions of IBA and GSR pyroprocessed at different temperatures. The data is plotted on the graph of Fig. 9. Table ,H also summarizes mechanical property results, Individual Aggregate Crushing Strengths ("IACS") for specific mixes of IBA and GSR, at specific temperatures. As above, increasing the GSR concentration in the mixes resulted in a broader temperature interval between the initial softening,, maximum densification, and complete or near complete melting of the samples, due to the modification of the chemical composition and mineralogy of the IBA with GSR. TABLE H: PHYSICAL PROPERTIES OF IBA/GSR AGGREGATES
[00112] Table I summarizes the physical (relative dry and bulk densities, water absorptions) and mechanical (IACS) of sintered aggregates from 40%/60% mixes of IBA/GSR at four different temperatures, along with the corresponding properties of the commercially available LYTAG aggregates. The temperatures selected were those causing different product characteristics and different microstructures, for comparison. The lower temperatures produce a porous, low density LWA, in accordance with a preferred embodiment of the invention. The high temperature produces a well-sintered or vitrified, non-porous, dense product.
[00115] The average chemical analyses of the clays bentonite and kaolin, shale, and slate used in these experiments are shown in Table J, below. The composition of the IBA used in Example 3 is the same as that used in Examples 1 and 2. The same equipment used in Example 1 is used here. . ..• .
[00123] Table K, below, summarizes test results for aggregates comprising different proportions of IBA and bentonite, pyroprocessed at different temperatures. The data is plotted on the graph of Fig. 1. Table K summarizes physical properties (relative dry densities, water absorptions) and mechanical properties (IACS and ASMI). As discussed above, increasing the clay concentration in the mixes resulted in a broader temperature interval between the initial softening, maximum densification, and melting of the samples, due to the modification of the chemical composition and mineralogy of the IBA. TABLE K: PHYSICAL PROPERTIES OF IBA/BENTONITE AGGREGATES
[00129] Table M summarizes the behaviour of aggregates produced from the mixes of IBA with bentonite and the other additives, kaolin, shale, and slate. The temperature ranges over which the aggregates pyroprocess, the corresponding density, water absorption, and ASMI ranges, as well as the temperatures of maximum densification for the different proportions of additive to DBA and the different additive materials, are shown. Figs. 10-12 show the relation between density (g/cm3) and temperature (°C) for various proportions of kaolin, shale,- and slate. It has been found ■that both clays bentonite and kaolin, as well as shale and slate, had similar effects on modifying the behavior of IBA with pyroprocessing, <due to their low calcium concentrations. However, slightly higher temperatures were observed for the densification of the pellets from the IBA/shale and 3BA/slate mixes due to the slightly higher amounts of silica and alumina present in both materials. . TABLE M: CHARACTERISTICS OF IBA/ADDITIVE AGGREGATES
[00130] Based on these Examples on pyroprocessed mixtures of waste glass, granite sawing residues, clays, such as bentonite and kaolin, shale, and slate, it is believed that furnace bottom ash ("FBA"), which is from the same source as pulverized fuel ash from MSW incinerators ("PFA"), may also be used to form lightweight and normal weight sintered and vitrified aggregates useful in concrete and in other applications. The FBA should be milled, preferably by wet milling with the IBA, to an appropriate particle size. Preferably, 95% by volume of the particles of the milled mix of IBA and FBA is less than about 30 microns. A chemical analysis of PFA is provided in Tables N and O, with and analysis of IBA for comparison. The pyroprocessing of IBA and PFA is discussed in more detail in Application No. 11/238,758, which was filed on September 28, 2005 and is incorporated by reference herein.
[00131] While in the examples described above, one silicoaluminous material is mixed with the IBA to form aggregates, several of the silicoaluminous materials may be mixed with the IBA to form aggregates, as well.
[00132] The embodiments described herein are examples of implementations of the invention. Modifications may be made to these examples without departing from the spirit and scope of the invention, which is defined by the claims, below.

中文:
[0002]聚集体(它们是混凝土的主要成分)可以衍生自具有最小加工的天然源或经过热处理的天然产生的材料。聚集体也可以是合成的。得自天然源如采石场、地基中的矿井和河床的聚集体通常由岩屑、砾石、石料和沙子组成,可以视需要将它们压碎、洗涤和调整大小用以使用。得自天然材料可用来形成聚集体的聚集体包括粘土、页岩和板岩,将它们高温加工,引起材料的膨胀。例如,OPTIROC和LECA是可商购的膨胀粘土聚集体的实例。合成聚集体可能包含工业副产物,它们可能是废料。例如,LYTAG是可商购的烧结聚集体,其包括粉煤灰(“PFA”),亦称飞灰。例如,PFA是由发电厂中的煤炭燃烧产生的。
[0003]聚集体可以是轻重量或正常重量的。轻重量聚集体(“LWA”)具有由ASTM规格C330限定的小于2.0g/m3的颗粒密度或小于1.1g/cm3的干燥疏松堆积密度。得自例如砾石、沙子和碎石的正常重量聚集体具有约2.4-约2.9的堆积比重(既是烤干的又是饱和表面干燥的),和至多约1.7g/cm3的堆积密度。高质量LWA具有强但是低密度多孔的均匀结构强度的烧结陶瓷芯和致密、连续、较不透性的表面层以抑制吸水。它们是物理上稳定、持久且环境上惰性的。LWA应该还是接近球形的,以改进混凝土性能和为混凝土糊剂提供良好的粘附性。根据ASTM规格C330,对于粗聚集体来说,引入混凝土的适合的尺寸为约4.75mm-约25mm,或2.36mm-9.5mm。例如,也可以使用更小的细聚集体(它们是LWA生产的副产物),以替代混凝土中的沙子。对于在混凝土中的使用来说,LWA应该具有足够的压碎强度和耐破碎性以致所得的混凝土具有大于10MPa的强度和约1.5g/cm3-约2.0g/cm3的干密度。含LWA的混凝土(“LWA混凝土”)也可以具有低到约300kg/m3的密度。
[0011]从MSW流中除去的废玻璃是另一种废料。废玻璃已经在公路建筑中用作沥青铺路中的聚集体替代物并且用作颗粒基底或填料。废玻璃的尺寸为约25mm-约100mm。
[0014]由得自城市固体废物焚烧炉的焚烧炉底灰(“IBA”)制备合成聚集体将避免或减轻一些或所有与聚集体原材料的IBA和方形石的废料处理有关的问题。然而,已经发现IBA可能难以高温加工成具有所需特性的产物,原因在于它迅速地烧结和致密化。IBA含有高浓度的含钙矿物质,如氧化钙、碳酸钙和硫酸钙,以及钠和钾氧化物和硫酸盐。这些矿物质充当“助熔剂”。应该相信这些助熔剂降低IBA中其余化合物的熔点,而引起在比当更少量助熔剂存在时低的温度下烧结和致密化。另外,IBA的组成是高度可变的,使得其高温加工行为不可预知。IBA组成的可变性可以归因于若干因素,如焚烧程序和由MSW焚烧炉接收和加工的废料的可变性。所接收的废料可能基于一年中的时间和其中废料产生的地理位置改变。
[0018]IBA和第二材料可以与有机材料,如活性炭废料混合,以增加聚集体的孔隙率。例如,有机材料可以占IBA和第二材料的混合物的干燥重量的至多约30%。
[0035]图5是根据本发明的一个实施方案的制备聚集体的方法的实例;
[0037]图7是根据本发明的另一个实施方案的制备聚集体的另一个方法的实例;
[0040]图10是根据本发明的一个实施方案的IBA和IBA和高岭土的混合物的密度(g/cm3)对高温加工温度(°C)的曲线图;
[0041]图11是根据本发明的一个实施方案的IBA和IBA和页岩的混合物的密度(g/cm3)对高温加工温度(°C)的曲线图;和
[0042]图12是根据本发明的一个实施方案的IBA和IBA和板岩的混合物的密度(g/cm3)对高温加工温度(°C)的曲线图;
[0046]在1060°C到1100°C内密度增加,因为在这一温度范围内,当产物烧结时,IBA中的助熔剂熔融形成液相,该液相通过毛细管作用填充IBA中颗粒之间的孔隙。当孔隙被填充并且样品的体积减小时,密度增加。另外,液相中较小的颗粒朝较大的颗粒扩散。熔融的材料在硬化后形成刚性、玻璃质、无定形骨架或基体。随着加工温度增加,IBA中更多的化合物熔融,从而基本上排除所有孔隙并形成更玻璃质、结晶的固体基体。在最大致密化的温度下,基本上所有孔隙被填充并且产物被玻璃化。
[0051]如图1所示,在60%/40%IBA/膨润土混合物中,例如,为了制备密度为约1.5g/cm3-约1.8g/cm3的烧结的轻重量聚集体,烧结温度可以在约20°C(从约1085°C-约1105°C)的范围之内。在40%/60%IBA/膨润土混合物中,在约1080°C-约1130°C的50°C范围内的温度下可以达到类似的密度。另外,将膨润土浓度增加到60%延迟烧结,因为最大密度在约1180°C下达到(相比,100%IBA在1100°C下达到,60%/40%IBA/膨润土在1130°C下达到)。预计进一步增加膨润土到80%和以上将在比40%/60%IBA/膨润土混合物更宽的温度范围内获得密度为约1.5g/cm3-约1.8g/cm3的轻重量聚集体。更宽的温度范围促进具有所需密度和其它性能的聚集体的产生,尽管IBA的组成有变化。图1基于以下实施例3的结果。
[0052]还发现IBA组成变化对所得聚集体的特性的影响可以进一步通过将该IBA湿研磨而减轻。与其它常用技术相比,湿研磨已经发现降低材料多相性和产生更适合于进一步加工的更均匀的浆料。
[0080]下面将根据上图5更详细描述的那样,加工IBA和WG。在这一实施例中,在造粒之前将WG添加到经湿研磨的IBA粉末中。
[0087]下表B-D概括了通过实施例1的方法形成的聚集体的物理机械性能。应该指出随增加IBA/WG混合物中WG的浓度聚集体显示出相当大的物理性能改变。
[0092]表B还显示WG添加对不同聚集体的吸水能力的影响。在小于最大致密化温度的温度下制备的轻重量聚集体通常具有某种孔隙率。当接近最大致密化时,孔隙的尺寸和数目逐渐地减少到零,因为孔隙被熔融材料填充。含大量IBA的聚集体随着温度显示吸水率的快速降低,而高WG聚集体随着温度显示更平缓的吸水率降低。100%WG粒料在所有研究的温度下比所有其它混合物具有显著更小的吸水率,这归因于填充孔隙的熔融玻璃通过挥发产生。
[0093]下表C概括了在特定高温加工温度下IBA和WG的所选混合物的聚集体压碎值(“ACV”)(%)。对于不同的IBA与WG的比例,在三种不同温度下提供ACV。ACV与聚集体强度成反比。为了对比,所选的温度是引起不同产物特性和不同微结构的那些。在每组中的较低温度下,根据本发明的一个优选的实施方案制备烧结的轻重量聚集体(“LWA”)。在中间温度下,根据本发明的一个实施方案,制备了良好烧结或玻璃化的,随着少量残余孔隙的正常重量聚集体。在较高的温度下,还根据本发明的一个实施方案,制备了玻璃化的LWA。
[0094]在最大致密化温度(中间温度)下,ACV更低并且聚集体的强度更高。在那一温度以下,密度更低ACV更高,各个或堆积聚集体的强度更低。在那一温度(中间)之上,随着密度和聚集体强度降低ACV开始增加,这归因于增加样品熔融。正如所料,随着增加温度聚集体强度显示聚集体密度的相同趋势,增加到最大值然后降低。如下所指出,根据本发明实施方案的以不同比例包含IBA和WG的LWA还具有比LYTAG更低的ACV和更高的强度,该LYTAG具有约34%的ACV。
[0095]基于高温加工温度和WG添加对高温加工的聚集体的性能影响,图8和表B和C所示,在1080°C-1190°C的温度范围下烧结的40%/60%IBA/WG混合物是优选的,它具有约1.5g/cm3-约2.6g/cm3的密度。这些聚集体可以在应用范围中使用,包括用作混凝土中的聚集体。在烧结和其它高温加工期间这一混合物的行为和所得的LWA的最终性能因此可以比包含100%IBA的聚集体更容易地控制,这一组合的聚集体的降低的吸水率归因于熔融玻璃,其填充孔隙,包括聚集体的表面孔隙。
[0096]下表D概括了在三个所选温度下包含40%/60%IBA/WG的聚集体的某些物理性能(相对干燥密度和吸水率(得自表B),和堆积密度)和机械性能(得自表C的ACV)。商购的LYTAG(烧结PFA)和OPTIROC(膨胀粘土)聚集体的相应性能也在表D中给出。各个粒料性能是20个测量值的平均值,堆积粒料性能是2个测量值的平均值。
[0097]LYTAG和在1080°C下烧结(称为LWA-1)或在1100°C下烧结(称为LWA-2)的包含40%/60%IBA/WG的聚集体的对比表明LWA-1具有类似的相对干燥密度和堆积聚集体密度(相对密度约1.5g/cm3,疏松堆积密度为0.8-0.9g/cm3)。烧结的LWA-2比LWA-1和LYTAG具有略高的相对密度和堆积密度。两种烧结的聚集体显示比LYTAG显著低的ACV,这表明它们作为整体当受压负载时可以抵抗更高的应力。OPTIROC具有非常低的密度,较低的吸水率和非常低的强度。这是预期的,因为OPTIROC具有隔离的球形气孔的高体积蜂窝状微结构。
[0098]为了说明LWA-1和LWA-2在混凝土中的可行性,设计混凝土混合物并测试新鲜和硬化的混凝土。在这一实施例中的混合物在表E中示出,它示出了包括LYTAG、OPTIROC和LWA-1和LWA-2的混凝土的各个成分的比例,基于聚集体的干燥条件。改变混合物以致LYTAG和LWA-1和LWA-2将达到由塌落度试验测量的类似的可加工性。OPTIROC的塌落度略高。因为聚集体在浇铸的时候处于风干状态,所以总水/胶结物比例的差异归因于聚集体吸水率的差异。随着吸水率增加聚集体的总水/胶结物比例增加。
[00100]显然,得自本发明的烧结LWA-1的混凝土达到与由LYTAG制成的相应混凝土类似的抗压强度。然而,研究人员已经报道用LYTAG制成的混凝土在所有时候具有显著较低的抗压强度。(例如参见,Kayali等人于2003年3月13日发布的美国专利号2003/0047114A1)LWA-2在所有时候达到较高的抗压强度,这归因于较高的聚集体密度、强度和较低的吸水率。
[00101]得自烧结LWA-1的混凝土在7、14和28天的抗压强度为47.3MPa、52.5MPa和58.6MPa,这将它分类为高强度混凝土。用LYTAG制成的混凝土获得类似的抗压强度。用OPTIROC轻重量聚集体制成的混凝土的非常低的强度归因于该聚集体的非常低的强度、低的密度和高的孔隙率。用LWA-2制成的混凝土在28天具有高达64.2MPa的抗压强度,这比所有经研究的聚集体在所有时候的都高。
[00108]下表H概括了在不同温度下高温加工的包含不同比例的IBA和GSR的聚集体的试验结果。在图9的曲线图上将数据绘图。表H也概括了机械性能结果,即在特定温度下IBA和GSR的特定混合物的各个聚集体压碎强度(“IACS”)。如同上述,增加混合物中GSR浓度实现样品的初始软化、最大致密化和完全或接近完全熔融之间的更宽的温度间隔,这归因于具有GSR的IBA的化学组成和矿物学的改变。
[00112]表I概括了在四个不同温度下得自IBA/GSR的40%/60%混合物的烧结聚集体的物理(相对干燥和堆积密度、吸水率)和机械(IACS)性能,以及商购LYTAG聚集体的相应性能。为了对比,所选的温度是引起不同产物特性和不同微结构的那些。根据本发明的一个优选的实施方案,较低的温度产生多孔、低密度LWA。高温产生良好烧结或玻璃化的、无孔、致密产物。
[00115]用于这些实验中的粘土膨润土和高岭土、页岩和板岩的平均化学分析在下表J中示出。用于实施例3的IBA的组成与用于实施例1和2的相同。在此使用在实施例1中使用的相同设备。
[00123]下表K概括了在不同温度下高温加工的包含不同比例的IBA和膨润土的聚集体的试验结果。在图1的曲线图上将数据绘图。表K概括了物理性能(相对干燥密度、吸水率)和机械性能(IACS和ASMI)。如上所讨论,增加混合物中粘土含量实现样品的初始软化、最大致密化和样品熔融之间的更宽的温度间隔,这归因于IBA的化学组成和矿物学的改变。
[00129]表M概括了由IBA与膨润土和其它添加剂、高岭土、页岩和板岩的混合物制备的聚集体的行为。对于添加剂与IBA的不同比例和不同添加剂材料,示出了聚集体高温加工的温度范围,相应的密度,吸水率和ASMI范围,以及最大致密化温度。图10-12示出了高岭土,页岩和板岩的各种比例的密度(g/cm3)和温度(°C)之间的关系。已经发现粘土膨润土和高岭土,以及页岩和板岩都对改进IBA在高温加工下的行为具有类似的效果,这归因于它们的低钙浓度。然而,对于得自IBA/页岩和IBA/板岩混合物的粒料的致密化,观察到略高的温度,这归因于这两种材料中存在的略高量的二氧化硅和氧化铝。
[00130]基于与废玻璃,花岗岩锯切残渣,粘土如膨润土和高岭土,页岩和板岩的高温加工的混合物有关的这些实施例,应该相信炉底灰(“FBA”),它与来自MSW焚烧炉(“PFA”)的粉煤灰来自相同来源,也可以用来形成在混凝土和其它应用中有用的轻重量和正常重量的烧结和玻璃化聚集体。所述FBA应该与IBA一起受到研磨,优选通过湿研磨进行,以达到合适的颗粒尺寸。优选地,IBA和FBA的经研磨的混合物的95体积%的颗粒小于约30微米。为了对比,将PFA的化学分析与IBA的分析在表N和O中提供。IBA和PFA的高温加工在于2005年9月28日提交的申请号11/238,758中进行了更详细地论述,该文献在此作为参考资料引入。
[00131]虽然在上述实施例中,将一种硅铝材料与IBA混合形成聚集体,但是也可以将数种硅铝材料与IBA混合形成聚集体。
[00132]在此描述的实施方案是本发明的执行实施例。在不脱离由下面权利要求限定的本发明精神和范围的情况下可以对这些实施例作出修改。