Furnace operation includes consecutive cycles of a heating step, a stopping step and a restarting step. The fuel and/or the oxidizing agent is preheated upstream of the furnace by indirect exchange with the discharged fumes through a medium passing through a chamber. A first wall separates the fumes from the medium in the chamber. The fuel and/or oxidizing agent is separated from the medium in the chamber by a second wall. During restarting, the medium's flow rate Dm is regulated to limit the heating rate of the first wall until it reaches the operational temperature at an end thereof.

The invention relates to the use of a hydraulic binder containing calcium aluminate, obtainable by a method in which a) prepared amorphous residual material rich in aluminium oxide and/or aluminium hydroxide is heated after the addition of a b) calcium ion-containing binder component and c) water, for the production of a constructing material.

A method for processing water treatment residuals, or other amorphous aluminium oxide or aluminium hydroxide rich waste residuals, for use in the manufacture of hydraulic binders, comprising heating the residuals to remove water and oxidise organic material contained therein, comprising controlling the temperature of the residuals during heating such that they are heated to a temperature no higher than 800° C., more preferably no higher than 650° C., to ensure that aluminium compounds in the WTR, in particular aluminium oxide and aluminium hydroxide, remain in an amorphous state. The method may comprise controlling the temperature of the water treatment residuals such that they are heated to a temperature between 350° C. and 650° C., more preferably between 400° C. and 500° C.

A method for processing water treatment residuals, or other amorphous aluminium oxide or aluminium hydroxide rich waste residuals, for use in the manufacture of hydraulic binders, comprising heating the residuals to remove water and oxidise organic material contained therein, comprising controlling the temperature of the residuals during heating such that they are heated to a temperature no higher than 800° C., more preferably no higher than 650° C., to ensure that aluminium compounds in the WTR, in particular aluminium oxide and aluminium hydroxide, remain in an amorphous state. The method may comprise controlling the temperature of the water treatment residuals such that they are heated to a temperature between 350° C. and 650° C., more preferably between 400° C. and 500° C.

The object of the present invention is to improve production efficiency of lithium hydroxide anhydride in a method for producing lithium hydroxide anhydride from lithium hydroxide hydrate by using a rotary kiln. The method for producing lithium hydroxide anhydride comprises steps of: supplying the lithium hydroxide hydrate to a region between a heating part which is the part of the furnace core tube surrounded by the heating furnace and one end of the furnace core tube; delivering the supplied lithium hydroxide hydrate toward the other end of the furnace core tube; feeding a drying gas with a temperature of 100° C. or higher to the region between the one end and the heating part of the furnace core tube, when the lithium hydroxide hydrate is supplied; and heating and dehydrating the lithium hydroxide hydrate by the heating furnace which is set to 230-450° C. during the lithium hydroxide delivering step, to form lithium hydroxide anhydride.

The object of the present invention is to improve production efficiency of lithium hydroxide anhydride in a method for producing lithium hydroxide anhydride from lithium hydroxide hydrate by using a rotary kiln. The method for producing lithium hydroxide anhydride comprises steps of: supplying the lithium hydroxide hydrate to a region between a heating part which is the part of the furnace core tube surrounded by the heating furnace and one end of the furnace core tube; delivering the supplied lithium hydroxide hydrate toward the other end of the furnace core tube; feeding a drying gas with a temperature of 100° C. or higher to the region between the one end and the heating part of the furnace core tube, when the lithium hydroxide hydrate is supplied; and heating and dehydrating the lithium hydroxide hydrate by the heating furnace which is set to 230-450° C. during the lithium hydroxide delivering step, to form lithium hydroxide anhydride.

Processes and plants for producing cement clinker, in which an oxygen-containing gas having a proportion of 15% by volume or less of nitrogen and a proportion of 50% by volume or more of oxygen is conveyed from a first section of the cooler directly adjoining the top of the furnace into the rotary furnace and is optionally additionally conveyed to the calciner, and where the total gas streams fed in to the combustion processes consist to an extent of more than 50% by volume (preferably more than 85% by volume) of oxygen.

Processes and plants for producing cement clinker, in which an oxygen-containing gas having a proportion of 15% by volume or less of nitrogen and a proportion of 50% by volume or more of oxygen is conveyed from a first section of the cooler directly adjoining the top of the furnace into the rotary furnace and is optionally additionally conveyed to the calciner, and where the total gas streams fed in to the combustion processes consist to an extent of more than 50% by volume (preferably more than 85% by volume) of oxygen.

This application discloses exemplary processes and systems for reducing mineral ring accumulation in calcination kiln. The processes and systems comprise inserting non-condensable gases (“NCGs”) in a preheating zone of a calcination kiln, upstream of the burner end. The pre-heating zone may be characterized by temperatures ranging from 1,300° F. to 1,750° F. The system may desirably comprise a plenum for inserting the NCGs into the rotating calcination kiln at the pre-heating zone.

In a method for reducing the NOx emissions of a rotary kiln of a clinker production plant, fuel supplied through a burner of the rotary kiln is burned along with primary air fed through the burner, wherein the primary air has a lower oxygen content and the primary air has an oxygen content reduced relative to that of the ambient air and a temperature increased relative to that of the ambient air, and the primary air is obtained by mixing ambient air with exhaust gas from the rotary kiln or from a heat exchanger connected to the rotary kiln and used for preheating raw meal. The primary air is further obtained by mixing with hot air, in particular waste air from a clinker cooler.