摘要:
New cement binders characterised by comprising: 30-80% by weight of a first component comprising MgO and at least one magnesium carbonate having the general formula: w MgC0 3 . x MgO. y Mg(OH) 2 . z H 2 0 (A) in which w is a number equal to or greater than 1; at least one of x, y or z is a number greater than 0 and w, x, y and z may be (but need not be) integers and 20-70% by weight of a second component comprising a least one silicon and/or aluminium oxide containing material are disclosed. They can be used to produce building materials (cements, mortars, grouts and the like) having improved structural properties relative to prior art materials. In particular, their manufacture is less energy intensive than e.g. Portland cement making them environmentally friendly in the sense that processes for their manufacture have a relatively low carbon footprint.
摘要:
A method and system for processing an input fuel gas and steam to produce separate CO2 and output fuel gas streams. The method comprises the steps of using a decarbonizer segment for reacting at least a solid sorbent with the fuel gas and steam to remove carbon from the input fuel gas and to produce the output fuel gas stream in an exhaust gas from the decarbonizer; using a calciner segment for reacting the solid sorbent from the decarbonizer segment therein to release the CO2 into the CO2 gas stream; wherein CO2 partial pressures and temperatures in the decarbonizer and calciner segments respectively are controlled such that the temperature in the decarbonizer segment is higher than the temperature in the calciner.
摘要:
A process for producing a highly calcined and uniformly calcined product from a feedstock. The process comprising the steps of grinding the feedstock to powder, preheating the powder, and calcining the powder in a reactor plant that comprises a number of reactor segments in which a flash calciner is used in each progressive reactor segment to incrementally react the powder by raising the temperature in each segment. The last segment may be a high-temperature reactor that has a controlled residence time and temperature that may allow controlled finishing of the calcination process to achieve a desired degree of calcination and sintering of the product; and cooling of the product.
摘要:
A process for producing a cement binder composition comprising one or more magnesium carbonates having the general formula w MgCO 3 . x MgO. y Mg(OH) 2 . z H 2 O in which w is a number equal to or greater than 1, at least one of x, y and z is a number greater than 0 and w, x, y and z may be (but need not be) integers is described. The process is characterised by the steps of (a) heating magnesite to liberate carbon dioxide gas and produce a solid product comprising magnesium oxide and (b) contacting an aqueous mixture comprising the magnesium oxide produced in step (a) with a source of carbonate ions at a temperature in the range 25 to 120°C to produce at least one of the magnesium carbonates, (c) optionally heating the magnesium carbonate product(s) of step (b) at a temperature from 45 to 500°C and (d) blending the magnesium carbonate(s) produced in step (b) or optional step (c) with at least magnesium oxide to produce a cement binder composition. The process is suitable for processing either naturally occurring magnesite ore or for magnesite produced by inter alia, mineral carbonation of magnesium silicate, carbonation of magnesium hydroxide or the treatment of sea water with carbon dioxide in the presence of inorganic base.