摘要:
A method for remediating alkali silica reactions prevents the reaction from starting by mixing a micro silica additive to an ozonated cement mix, with the micro silica constituting a micro sand that has no more than a 15-18 micron mean particle size and a top size of around 30-40 microns. In one embodiment the micro silica mixed at 8% results in a reduction in mortar expansion on average greater than 96% when used with ozonated Class C fly ash.
摘要:
A method of producing cementitious mixtures containing fly ash as one of the cementitious components, under air entrainment conditions is described. The method involves forming a mixture comprising water, cement, fly ash, optionally other cementitious materials, aggregate, conventional chemical admixtures, and an air entrainment agent and agitating the mixture to entrain air therein. Additionally, at least one amine sacrificial agent is included in the mixture. The cementitious mixtures and hardened concretes resulting from the method and fly ash treated with sacrificial agent, or air entrainment agent/sacrificial agent combinations, are also described.
摘要:
The invention concerns a method for beneficiation of fly ash particles comprising: determining the heat value of the fly ash particles; comparing the determined heat value of the fly ash particles with a minimum heat value K; feeding an inlet of a combustor (5) with a feed material comprising the fly ash particles and, in case the determined heat value is lower than the minimum heat value K, fuel in sufficient quantity to assure that the heat value of the raw material is greater than or equal to the minimum heat value K; supplying an upstream airflow to the combustor (5) so as to carry the feed material in suspension from the inlet to an outlet of the combustor; operating the combustor (5) at a temperature of at least 700° C.; collecting beneficiated fly ash particles from the airflow at the outlet of the combustor (5). The invention also concerns an installation for implementation of the said method.
摘要:
Disclosed is a method for removing unburned carbon from fly ash at low cost and within a short time. The method comprises the steps of adding a collecting agent to fly ash directly, agitating/mixing the mixture in a mixer (5), adding water to the resulting mixed material in a mixing vessel (7) to yield a slurry, applying a shearing force to the slurry in a submerged stirrer (9), and performing flotation separation of unburned carbon in a flotator (15).
摘要:
Compositions are provided for increasing the electrical conductivity of concrete or controlled low-strength materials (flowable fill). One composition sets to produce a concrete and includes portland cement, water, aggregate, and particulate matter including a sorbent and a contaminant absorbed, adsorbed or entrapped by the sorbent. The sorbent may be activated carbon, and the contaminant may be mercury or a compound containing mercury. Another composition is a self-compacting, cementitious flowable fill composition that includes portland cement, water, and particulate matter including a sorbent and a contaminant absorbed, adsorbed or entrapped by the sorbent. The sorbent may activated carbon, and the contaminant may be mercury or a compound containing mercury. The compositions may also include carbon fibers.
摘要:
The disclosure provides an ultralow-carbon clinker-free cement, prepared from the following raw materials: granulated blast-furnace slag, gypsum and calcium oxide-based materials. The granulated blast-furnace slag accounts for 65%-95% of the total weight of the raw materials, the gypsum accounts for 4.5%-34.5% of the total weight of the raw materials, and the balance is the calcium oxide-based material. A weight percentage of calcium oxide and/or calcium hydroxide in the total weight of the raw materials is controlled to be 0.05%-0.75%. The disclosure further provides a method for preparing the ultralow-carbon clinker-free cement and application of the ultralow-carbon clinker-free cement in the preparation of concrete, mortar or cement products. The ultralow-carbon clinker-free cement of the disclosure has the advantages of high early strength, ultrahigh long-term strength, low shrinkage, carbonation resistance, low carbon emissions, etc.
摘要:
The disclosure provides an ultralow-carbon clinker-free cement, prepared from the following raw materials: granulated blast-furnace slag, gypsum and calcium oxide-based materials. The granulated blast-furnace slag accounts for 65%-95% of the total weight of the raw materials, the gypsum accounts for 4.5%-34.5% of the total weight of the raw materials, and the balance is the calcium oxide-based material. A weight percentage of calcium oxide and/or calcium hydroxide in the total weight of the raw materials is controlled to be 0.05%-0.75%. The disclosure further provides a method for preparing the ultralow-carbon clinker-free cement and application of the ultralow-carbon clinker-free cement in the preparation of concrete, mortar or cement products. The ultralow-carbon clinker-free cement of the disclosure has the advantages of high early strength, ultrahigh long-term strength, low shrinkage, carbonation resistance, low carbon emissions, etc.
摘要:
Fly ash contaminated with activated carbon is treated to neutralize the activated carbon by placing the contaminated fly ash in a rotary mill and introducing ozone. The result is that entrained air in concrete made from activated fly ash will contain greater than 4 percent entrained air.
摘要:
A method comprising; a step in which unburned carbon contained in coal ash is mechanically separated with a classifier; a step in which the coal ash from which part of the unburned carbon has been removed with the classifier is pulverized or disaggregated with a pulverizer; a step in which water is added to the coal ash pulverized or disaggregated with the pulverizer to obtain a slurry; a step in which a scavenger is added to the slurried coal ash; a step in which a shear force is applied to the slurry containing the scavenger to cause the scavenger to selectively adhere to the unburned carbon contained in the coal ash; a step in which a foaming agent is added to the slurry in which the scavenger has adhered to the unburned carbon; and a step in which the unburned carbon is floated on the slurry containing the foaming agent together with bubbles and is separated.
摘要:
Disclosed is a method for removing unburned carbon from fly ash at low cost and within a short time. The method comprises the steps of adding a collecting agent to fly ash directly, agitating/mixing the mixture in a mixer (5), adding water to the resulting mixed material in a mixing vessel (7) to yield a slurry, applying a shearing force to the slurry in a submerged stirrer (9), and performing flotation separation of unburned carbon in a flotator (15).