Abstract: The invention relates to fine-particulate zirconium titanates or lead zirconium titanates and a method for production thereof by reaction of titanium dioxide particles with a zirconium compound or a lead and zirconium compound. The titanium dioxide particles have a BET surface of more than 50 m2/g. The lead zirconium titanates can be used for the production of microelectronic components.

Abstract: The invention relates to fine-particled alkaline-earth titanates and to a method for the production thereof by reacting alkaline-earth metal compounds with titanium dioxide particles. The titanium dioxide particles have a BET-surface greater than 50 m2/g. The titanium dioxide particles can have a very low sulphate, chloride and carbon content. The reaction can take place at a temperature below 700° C. The alkaline-earth titanate can have a BET-surface of 5-100 m2/g. Advantageously, it does not contain any hydroxyl groups in the crystal lattice. The alkaline-earth titanate can be used in the production of microelectronic components.

Abstract: The invention concerns a method for processing heavy metal-laden spent sulfuric acid. For this, iron-laden spent sulfuric acid or iron-laden sulfuric materials obtained therefrom are reacted with a material that contains iron chloride and optionally other metal chlorides, producing iron (II) sulfate. The spent sulfuric acid preferably derives from titanium dioxide production.

Abstract: The invention relates to fine-particulate zirconium titanates or lead zirconium titanates and a method for production thereof by reaction of titanium dioxide particles with a zirconium compound or a lead and zirconium compound. The titanium dioxide particles have a BET surface of more than 50 m2/g. The lead zirconium titanates can be used for the production of microelectronic components.

Abstract: The invention relates to fine-particled alkaline-earth titanates and to a method for the production thereof by reacting alkaline-earth metal compounds with titanium dioxide particles. The titanium dioxide particles have a BET-surface greater than 50 m2/g. The titanium dioxide particles can have a very low sulphate, chloride and carbon content. The reaction can take place at a temperature below 700° C. The alkaline-earth titanate can have a BET-surface of 5-100 m2/g. Advantageously, it does not contain any hydroxyl groups in the crystal lattice. The alkaline-earth titanate can be used in the production of microelectronic components.