A process and system are disclosed for producing a lithium product from a solution comprising lithium nitrate. The solution comprising lithium nitrate can be obtained by reacting a lithium-containing metal silicate with nitric acid. The process and system comprise subjecting the solution comprising lithium nitrate to a first thermal treatment procedure (in one or more heated vessels) in which water and nitric acid (when present) are removed, and whereby a resultant lithium nitrate-rich crystal slurry is heated to produce a molten liquid. The process and system also comprise passing the molten liquid to a second thermal treatment procedure (in a further-heated vessel) in which the molten liquid is heated to substantially decompose lithium nitrate to lithium oxide.

A process and system are disclosed for producing a lithium product from a solution comprising lithium nitrate. The solution comprising lithium nitrate can be obtained by reacting a lithium-containing metal silicate with nitric acid. The process and system comprise subjecting the solution comprising lithium nitrate to a first thermal treatment procedure (in one or more heated vessels) in which water and nitric acid (when present) are removed, and whereby a resultant lithium nitrate-rich crystal slurry is heated to produce a molten liquid. The process and system also comprise passing the molten liquid to a second thermal treatment procedure (in a further-heated vessel) in which the molten liquid is heated to substantially decompose lithium nitrate to lithium oxide.

Disclosed isthe synthesis of novel supported metal catalytic materials for electromagnetic radiation absorption and chemical catalysis especially in the presence of plasma used in the conversion of nitrogen from air and hydrogen from water to useful products such as nitric acid, hydrogen, ammonia and fertilizers. These materials can also generate plasma when subjected to microwave irradiation thus form the basis of catalytic plasma reactors. They can be used in chemical looping reactions because plasma generation under microwave irradiation in air results in the reduction of catalyst oxides and oxidation of nitrogen.

Disclosed isthe synthesis of novel supported metal catalytic materials for electromagnetic radiation absorption and chemical catalysis especially in the presence of plasma used in the conversion of nitrogen from air and hydrogen from water to useful products such as nitric acid, hydrogen, ammonia and fertilizers. These materials can also generate plasma when subjected to microwave irradiation thus form the basis of catalytic plasma reactors. They can be used in chemical looping reactions because plasma generation under microwave irradiation in air results in the reduction of catalyst oxides and oxidation of nitrogen.

A process for producing nitric acid by the Ostwald process involves reacting ammonia with atmospheric oxygen as primary air to afford a NOx-containing gas stream in an ammonia oxidation reactor at a first pressure and absorbing the NOx-containing gas stream in water in an absorption apparatus at a higher, second pressure. Nitric acid is bleached with bleach air as secondary air at approximately the first pressure. The secondary air is brought to an operating pressure of the bleaching operation via a separate secondary air compressor or compressor stage. The separate secondary air compressor is independent of the compressor that brings the primary air to the first pressure. Compression to the second higher pressure at which the absorption of the NOx gases is performed in the absorption apparatus is provided only downstream of the bleaching operation.

A process for producing nitric acid by the Ostwald process involves reacting ammonia with atmospheric oxygen as primary air to afford a NOx-containing gas stream in an ammonia oxidation reactor at a first pressure and absorbing the NOx-containing gas stream in water in an absorption apparatus at a higher, second pressure. Nitric acid is bleached with bleach air as secondary air at approximately the first pressure. The secondary air is brought to an operating pressure of the bleaching operation via a separate secondary air compressor or compressor stage. The separate secondary air compressor is independent of the compressor that brings the primary air to the first pressure. Compression to the second higher pressure at which the absorption of the NOx gases is performed in the absorption apparatus is provided only downstream of the bleaching operation.

A process and system are disclosed for producing a lithium product from a solution comprising lithium nitrate. The solution comprising lithium nitrate can be obtained by reacting a lithium-containing metal silicate with nitric acid. The process and system comprise subjecting the solution comprising lithium nitrate to a first thermal treatment procedure (in one or more heated vessels) in which water and nitric acid (when present) are removed, and whereby a resultant lithium nitrate-rich crystal slurry is heated to produce a molten liquid. The process and system also comprise passing the molten liquid to a second thermal treatment procedure (in a further-heated vessel) in which the molten liquid is heated to substantially decompose lithium nitrate to lithium oxide.

A process and system are disclosed for producing a lithium product from a solution comprising lithium nitrate. The solution comprising lithium nitrate can be obtained by reacting a lithium-containing metal silicate with nitric acid. The process and system comprise subjecting the solution comprising lithium nitrate to a first thermal treatment procedure (in one or more heated vessels) in which water and nitric acid (when present) are removed, and whereby a resultant lithium nitrate-rich crystal slurry is heated to produce a molten liquid. The process and system also comprise passing the molten liquid to a second thermal treatment procedure (in a further-heated vessel) in which the molten liquid is heated to substantially decompose lithium nitrate to lithium oxide.

A method for reducing the NOx emission during start-up and shutdown events of a nitric acid plant, wherein the nitric acid plant comprises a tail gas treatment section including a first catalytic bed for removal of N.sub.2O followed by a second catalytic bed for removal of NOx, wherein during a start-up or shutdown the operation of said treatment section (10) is temporarily modified by adding a NOx reducing agent upstream of said first catalytic bed, so that said first catalytic bed provides reduction of NOx.

A method for reducing the NOx emission during start-up and shutdown events of a nitric acid plant, wherein the nitric acid plant comprises a tail gas treatment section including a first catalytic bed for removal of N.sub.2O followed by a second catalytic bed for removal of NOx, wherein during a start-up or shutdown the operation of said treatment section (10) is temporarily modified by adding a NOx reducing agent upstream of said first catalytic bed, so that said first catalytic bed provides reduction of NOx.