摘要:
A method of producing a supplementary cementitious material, includes providing at least one waste material selected from quarry sludge, aggregate washing sludge and road cleaning sludge, removing excess water from said waste material so as to provide a dry waste material, and either: mixing the dry waste material with a source of calcium sulphate to obtain a raw material mixture, and calcining the raw material mixture at a temperature of 700-900° C. to obtain the supplementary cementitious material, or: calcining the dry waste material at a temperature of 700-900° C. to obtain a calcined waste material, and mixing the calcined waste material with a calcined source of calcium sulphate to obtain the supplementary cementitious material.
摘要:
Surfactant-coated hemihydrate gypsum which is coated with 0.01 to 1 part by weight of a surfactant based on 100 parts by weight of hemihydrate gypsum, wherein the residual rate of the surfactant when the surfactant-coated hemihydrate gypsum is heated up to 300° C. is not less than 40 wt % of the amount of the surfactant before heating.
摘要:
Provided are cementitious compositions and related systems and methods. The cementitious compositions, or admixtures, according to the present invention generally comprise gypsum, a first alkaline component and glass. The admixture may further comprise fly ash, which is preferably obtained as a waste by-product from a coal-burning power plant. A method according to the present invention comprises an initial step of analyzing or receiving an analysis of a fly ash sample. Based at least in part on the analysis of the fly ash sample, a mix rate may be selected and an initial admixture can be formulated, which, when added to the fly ash sample, creates an alternative or additive to Portland cement for use in concrete, for example.
摘要:
Composition for building materials comprises of fly ash from flue gas desulfurization. The fly ash (βCaSO4 anhydrite), obtained from circulating fluidized bed flue gas desulfurization, is mixed with binder reactants at a ratio of 9:1. It's mainly used for non-structural cement mortar, bricks for paving walkways, brick wall decors, fire-resistant walls for interior partitions, plasterboards and so on. The binder reactants compose of 70% CaSO4.½H2O, 10% Na2SO4, 10% CaO, 5% NaOH, 0˜5% cement and 0˜5% starch. When the binder reactants are mixed with fly ash and water (30% to 40% of the above total weight), the hydration process of CaSO4 anhydrite is accelerated.
摘要:
Surfactant-coated hemihydrate gypsum which is coated with 0.01 to 1 part by weight of a surfactant based on 100 parts by weight of hemihydrate gypsum, wherein the residual rate of the surfactant when the surfactant-coated hemihydrate gypsum is heated up to 300° C. is not less than 40 wt % of the amount of the surfactant before heating.
摘要:
Provided are cementitious compositions and related systems and methods. The cementitious compositions, or admixtures, according to the present invention generally comprise gypsum, a first alkaline component and glass. The admixture may further comprise fly ash, which is preferably obtained as a waste by-product from a coal-burning power plant. A method according to the present invention comprises an initial step of analyzing or receiving an analysis of a fly ash sample. Based at least in part on the analysis of the fly ash sample, a mix rate may be selected and an initial admixture can be formulated, which, when added to the fly ash sample, creates an alternative or additive to Portland cement for use in concrete, for example.
摘要:
A process for producing a mineral foam includes (i) separately preparing one or more slurries of cement, and an aqueous foam for which a D50 of bubbles is less than or equal to 400 μm; (ii) homogenizing the one or more slurries of cement with the aqueous foam to obtain a slurry of foamed cement; (iii) casting the slurry of foamed cement and leaving the cast slurry of foamed cement to set.
摘要:
The present invention is based on solid-state reaction or reactions in the presence of small amounts of water, between phospho gypsum and agglutinating-neutralizing agents, principally though the application of oxy and hydroxy compounds, without discounting use of the respective carbonates of magnesium, aluminum and principally calcium, in addition to mixtures of these, and the subsequent preparation of self-hardening pellets which facilitate transport and handling. The technological process associated with the invention notably simplifies both the number and type of individual operations, and the preparation of pellets from mixtures of phosphor gypsum; it also reduces energy costs by operating at low temperatures (150°C.) during short periods (1-2 hours), while reducing the quantity of neutralizing agents, and minimizing the volume of water required for the process.
摘要:
The present invention concerns the application of a novel process for the physical and chemical conditioning of chemical gypsum or phospho gypsum, derived from the production of phosphoric acid, and its use as a retarding agent in the setting of Portland type cements or in the preparation of other construction materials. This conditioning is based on solid-state reactions or reactions in the presence of small amounts of water, between phospho gypsum and agglutinating-neutralizing agents, principally through the application of oxy and hydroxy compounds, without discounting use of the respective carbonates of magnesium, aluminum and principally calcium, in addition to mixtures of these, and the subsequent preparation of self-hardening pellets which facilitate transport and handling.The technological process associated with the invention notably simplifies the number and type of individual operations, and the preparation of pellets from mixtures of phospho gypsum, in addition to reducing energy costs by operating at low temperatures (150° C.) during short periods (1-2 hours), reducing the quantity of neutralizing agents, and also minimizing the volume of water required for the process.
摘要:
A flue gas desulfurization process is disclosed. Specifically the use of carboxylic acids to modify gypsum crystal habit in limestone forced oxidation. The technique is also applicable to other technologies where gypsum is produced as for example in phosphate fertilizer or paper industry.