Abstract: A method for the heat treatment of granular solids includes initially introducing solids into a first reactor configured as a flash reactor or fluidized bed reactor where they are brought into contact with hot gases at temperatures in the range 500° C. to 1500° C. Next, the solids are passed through a residence time reactor in which they are fluidized. The residence time reactor is configured in a manner such that it has various regions which are separated from one another, from which the solid can be withdrawn in a manner such that it is provided with a variety of residence times in the residence time reactor.

Abstract: A method for the heat treatment of granular solids includes initially introducing solids into a first reactor configured as a flash reactor or fluidized bed reactor where they are brought into contact with hot gases at temperatures in the range 500° C. to 1500° C. Next, the solids are passed through a residence time reactor in which they are fluidized. The residence time reactor is configured in a manner such that it has various regions which are separated from one another, from which the solid can be withdrawn in a manner such that it is provided with a variety of residence times in the residence time reactor.

Abstract: A process for separating heavy metals from a phosphoric starting material includes, in a step (i), heating the starting material to a temperature between 700 and 1,100° C. in a first reactor and withdrawing combustion gas. In a step (ii), the heated starting material at the temperature between 700 and 1,100° C. is transferred to a second reactor, chlorides of alkaline and alkaline earth metals are added and process gas is withdrawn.

Abstract: A process for operating a fuel fired reactor includes introducing fuel into the reactor and burning the fuel in the reactor by means of at least one main burner. Relevant parameters of the process are monitored. Within a predetermined critical operating range for an enforced shut down, a secondary, more stringent operating range is implemented as shut down criteria. The main burner is shut down upon one or more of the relevant parameters leaving the secondary operating range while at least one pilot burner continues to operate as long as the relevant parameters are maintained within the critical operating range.

Abstract: A process for operating a fuel fired reactor includes introducing fuel into the reactor and burning the fuel in the reactor by means of at least one main burner. Relevant parameters of the process are monitored. Within a predetermined critical operating range for an enforced shut down, a secondary, more stringent operating range is implemented as shut down criteria. The main burner is shut down upon one or more of the relevant parameters leaving the secondary operating range while at least one pilot burner continues to operate as long as the relevant parameters are maintained within the critical operating range.

Abstract: A process for separating heavy metals from a phosphoric starting material includes, in a step (i), heating the starting material to a temperature between 700 and 1,100° C. in a first reactor and withdrawing combustion gas. In a step (ii), the heated starting material at the temperature between 700 and 1,100° C. is transferred to a second reactor, chlorides of alkaline and earth alkaline metals are added and process gas is withdrawn.

Abstract: The method of continuously controlling pH of an acid scrubbing liquid includes continuously withdrawing a constant partial stream from the scrubbing liquid; continuously measuring a pH in the partial stream with a glass electrode; adding base at a first rate to the partial stream upstream of the glass electrode and continuing the adding until the measured pH is in a pH set-point range of from 2.5 to 11.5; after the pH is in the pH set-point range, changing the first rate of adding base to the constant partial stream to compensate any subsequently occurring pH deviations; during the changing of the first rate of base addition, measuring the first rate of base addition to obtain a measured first rate; and automatically controlling a pH of the acid scrubbing liquid using the measured first rate as a controlling parameter by selecting a rate set-point range of the first rate of adding base to the constant partial stream so that the measured pH can be brought into the pH set-point range of from 2.5 to 11.

Abstract: The acid scrubbing liquid which has a pH value below 3 and is used in a scrubbing zone to remove acid components from a gas. At least part of the scrubbing liquid is circulated. A partial stream of the scrubbing liquid at a constant rate is mixed with an alkaline solution stream which has a constant concentration and is supplied at a constant volume rate, the pH value of the resulting mixture is continually measured, a setpoint in the range from 5 to 9 is selected for the pH value of the mixture, and a neutral or alkaline correcting liquid is added to the scrubbing liquid in response to a decrease of the measured pH value below said setpoint. The scrubbing liquid may mainly consist of water.