A method for preparing an electronic grade sulfuric acid from a waste sulfuric acid solution includes the steps of: performing, in sequence, a concentration treatment, a cracking treatment, and a purification treatment; performing a first oxidation treatment on sulfur dioxide; performing a first absorption treatment and a second oxidization treatment; performing an evaporation treatment; performing a first removal treatment on an acid mist containing metal ions and anion impurities; performing a second absorption treatment; and performing a second removal treatment on residual sulfur dioxide.

A method for preparing an electronic grade sulfuric acid from a waste sulfuric acid solution includes the steps of: performing, in sequence, a concentration treatment, a cracking treatment, and a purification treatment; performing a first oxidation treatment on sulfur dioxide; performing a first absorption treatment and a second oxidization treatment; performing an evaporation treatment; performing a first removal treatment on an acid mist containing metal ions and anion impurities; performing a second absorption treatment; and performing a second removal treatment on residual sulfur dioxide.

Process for the removal of particulate matter from an aqueous stream containing a concentrated acid, preferably concentrated sulfuric acid, the process including mechanical filtration by passing the aqueous stream through a filter unit, the filter unit including a metallic, ceramic or polymeric filter, or a filter including a filter aid on a septum. The aqueous stream is the exit stream of a sulfuric acid condenser, optionally the exit stream of a sulfuric acid concentrator arranged downstream the sulfuric acid condenser.

Process for the removal of particulate matter from an aqueous stream containing a concentrated acid, preferably concentrated sulfuric acid, the process including mechanical filtration by passing the aqueous stream through a filter unit, the filter unit including a metallic, ceramic or polymeric filter, or a filter including a filter aid on a septum. The aqueous stream is the exit stream of a sulfuric acid condenser, optionally the exit stream of a sulfuric acid concentrator arranged downstream the sulfuric acid condenser.

A method for preparing an electronic grade sulfuric acid from a waste sulfuric acid solution includes the steps of: performing, in sequence, a concentration treatment, a cracking treatment, and a purification treatment; performing a first oxidation treatment on sulfur dioxide; performing a first absorption treatment and a second oxidization treatment; performing an evaporation treatment; performing a first removal treatment on an acid mist containing metal ions and anion impurities; performing a second absorption treatment; and performing a second removal treatment on residual sulfur dioxide.

A method for preparing an electronic grade sulfuric acid from a waste sulfuric acid solution includes the steps of: performing, in sequence, a concentration treatment, a cracking treatment, and a purification treatment; performing a first oxidation treatment on sulfur dioxide; performing a first absorption treatment and a second oxidization treatment; performing an evaporation treatment; performing a first removal treatment on an acid mist containing metal ions and anion impurities; performing a second absorption treatment; and performing a second removal treatment on residual sulfur dioxide.

The invention relates to a method for manufacturing sulphuric acid, which involves converting sulphur dioxide SO.sub.2 into sulphur trioxide S0.sub.3, by injecting gaseous sulphur dioxide into a converter (1) inside which at least one mass (2) of a catalyst for the conversion is present, and according to which, during phases in which the injection of the gaseous sulphur dioxide is stopped, the space inside the converter (1) is heated in such a way as to maintain a minimum temperature of 200° C., and preferably 250° C., within each catalyst mass (2), characterized by the fact that the stopping of the injection of the sulphur dioxide is slaved to the starting of the heating, and vice versa.

The invention relates to a method for manufacturing sulphuric acid, which involves converting sulphur dioxide SO.sub.2 into sulphur trioxide S0.sub.3, by injecting gaseous sulphur dioxide into a converter (1) inside which at least one mass (2) of a catalyst for the conversion is present, and according to which, during phases in which the injection of the gaseous sulphur dioxide is stopped, the space inside the converter (1) is heated in such a way as to maintain a minimum temperature of 200° C., and preferably 250° C., within each catalyst mass (2), characterized by the fact that the stopping of the injection of the sulphur dioxide is slaved to the starting of the heating, and vice versa.

Disclosed is a process system and a process for converting the sulfur-containing flue gas into the sulfuric acid. The process system comprises: a flue gas preheater, which for preheating the sulfur-containing flue gas to 15˜30° C. above its dew point, and the flue gas preheater has a glass tube as a heat exchange tube; a flue gas fan for boosting the pressure of the preheated acid process gas and transporting one part of which to a combustion furnace, and the other part of which to a process gas steam heater; a sulfuric acid steam condenser for condensing SO.sub.3 generated by the combined reactor into sulfuric acid. The device of the present invention can resist the fluctuation of SO.sub.2 concentration in the feed gas, and can realize considerable economic benefits and rational utilization of energy.

Disclosed is a process system and a process for converting the sulfur-containing flue gas into the sulfuric acid. The process system comprises: a flue gas preheater, which for preheating the sulfur-containing flue gas to 15˜30° C. above its dew point, and the flue gas preheater has a glass tube as a heat exchange tube; a flue gas fan for boosting the pressure of the preheated acid process gas and transporting one part of which to a combustion furnace, and the other part of which to a process gas steam heater; a sulfuric acid steam condenser for condensing SO.sub.3 generated by the combined reactor into sulfuric acid. The device of the present invention can resist the fluctuation of SO.sub.2 concentration in the feed gas, and can realize considerable economic benefits and rational utilization of energy.