Abstract: A process may involve digesting raw phosphate with concentrated sulfuric acid and converting the raw phosphate to calcium sulfate in the form of dihydrate and/or hemihydrate, and phosphoric acid, separating off calcium sulfate as solid from a liquid phase of a suspension that is obtained, treating the calcium sulfate that is separated off or from a stockpile with an acid to give a suspension with purified calcium sulfate and P2O5-containing acid solution, separating off the purified calcium sulfate as solid from a liquid phase of a suspension obtained, using the P2O5-containing liquid phase as a portion of the sulfuric acid required for digesting the raw phosphate or as feedstock for treating phosphogypsum from the stockpile to give a suspension of purified calcium sulfate and P2O5-containing acid solution, which is thereafter processed.

Abstract: A process may involve treating calcium sulfate separated from phosphoric acid with acid to obtain a suspension comprising purified calcium sulfate, separating the purified calcium sulfate in solid form from a liquid phase of the suspension, treating the purified calcium sulfate with water or with a salt- and/or chelate ligand-containing aqueous solution to leach rare earths out of the calcium sulfate, separating the further-purified calcium sulfate in solid form from the liquid phase of the suspension, mixing the purified calcium sulfate that is separated off with admixtures and reducing agents to obtain a raw meal mixture for cement clinker production, burning the raw meal mixture to obtain the cement clinker and thereby forming sulfur dioxide as offgas, and feeding the sulfur dioxide as raw material to sulfuric acid production to produce the sulfuric acid.

Abstract: Process for producing activated carbon having a high catalytic activity, in which a carbonaceous material is brought into contact with nitrogen compounds, wherein the carbonaceous material is partially gasified with a mixture of steam, nitrogen and CO2 at temperatures above 800° C. in a manner known per se in a multistage fluidized bed and wherein a nitrogen compound is added into the furnace and/or at least one stage of the multistage fluidized bed.

Abstract: Process for producing activated carbon having a high catalytic activity, in which a carbonaceous material is brought into contact with nitrogen compounds, wherein the carbonaceous material is partially gasified with a mixture of steam, nitrogen and CO2 at temperatures above 800° C. in a manner known per se in a multistage fluidised bed and wherein a nitrogen compound is added into the furnace and/or at least one stage of the multistage fluidised bed.