The present disclosure broadly relates to a process for recovering magnesium as magnesium oxide and fibrous amorphous silica from serpentinite feedstocks. More specifically, but not exclusively, the present disclosure relates to metallurgical and chemical processes for recovering magnesium oxide and fibrous amorphous silica from serpentinite feedstocks. The process broadly comprises applying a sufficient amount of shear deformation force to the serpentine feedstocks to produce a particulate material of reduced size; subjecting the particulate material to magnetic separation to produce a primary magnetic separation product and iron-reduced tailings; and digesting the iron-reduced tailings into nitric acid, producing a magnesium-rich pregnant solution and insoluble solids. The process further comprises adjusting the pH of the pregnant solution to values ranging from about 5.0 to about 7.0.

The present disclosure broadly relates to a process for recovering magnesium as magnesium oxide and fibrous amorphous silica from serpentinite feedstocks. More specifically, but not exclusively, the present disclosure relates to metallurgical and chemical processes for recovering magnesium oxide and fibrous amorphous silica from serpentinite feedstocks. The process broadly comprises applying a sufficient amount of shear deformation force to the serpentine feedstocks to produce a particulate material of reduced size; subjecting the particulate material to magnetic separation to produce a primary magnetic separation product and iron-reduced tailings; and digesting the iron-reduced tailings into nitric acid, producing a magnesium-rich pregnant solution and insoluble solids. The process further comprises adjusting the pH of the pregnant solution to values ranging from about 5.0 to about 7.0.

A thermophotovoltaic (TPV) system, comprises a substrate, an emitter material adhered to the substrate, and a thermophotovoltaic (TPV) cell. The emitter material is a typically a metal oxide doped nickel oxide sol-gel material, in which the metal is magnesium or zirconium, and in which the sol-gel material comprises 97-99 mol % metal oxide, and about 1-3 mol % nickel oxide dopant. Providing an emitter material as a sol-gel allows the material to be coated on to surfaces providing better adherence to the surface, and also provides excellent heat stability. A sol-gel material is also described.

A thermophotovoltaic (TPV) system, comprises a substrate, an emitter material adhered to the substrate, and a thermophotovoltaic (TPV) cell. The emitter material is a typically a metal oxide doped nickel oxide sol-gel material, in which the metal is magnesium or zirconium, and in which the sol-gel material comprises 97-99 mol % metal oxide, and about 1-3 mol % nickel oxide dopant. Providing an emitter material as a sol-gel allows the material to be coated on to surfaces providing better adherence to the surface, and also provides excellent heat stability. A sol-gel material is also described.

A process for generating a metal sulfate that involves crystallizing a metal sulfate from an aqueous solution to form a crystallized metal sulfate in a mother liquor with uncrystallized metal sulfate remaining in the mother liquor; separating the crystallized metal sulfate from the mother liquor; basifying a portion of the mother liquor to convert the uncrystallized metal sulfate to a basic metal salt; and using the basic metal salt upstream of crystallizing the metal sulfate. So crystallized, the generated metal sulfate may be battery-grade or electroplating-grade.

A hierarchical porous honeycombed nickel oxide microsphere and a preparation method thereof are disclosed. The method includes mixing nickel sulfate hexahydrate, urea, water and glycerol, to obtain a mixed solution; subjecting the mixed solution to a hydrothermal reaction, to obtain a precursor; and calcining the precursor, to obtain the hierarchical porous honeycombed nickel oxide microspheres.

A hierarchical porous honeycombed nickel oxide microsphere and a preparation method thereof are disclosed. The method includes mixing nickel sulfate hexahydrate, urea, water and glycerol, to obtain a mixed solution; subjecting the mixed solution to a hydrothermal reaction, to obtain a precursor; and calcining the precursor, to obtain the hierarchical porous honeycombed nickel oxide microspheres.

The present invention relates to a composite having the ability to stably and reliably detect a target gas even in a moist environment. The composite of the present invention includes: a nanostructure of an oxide semiconductor selected from the group consisting of SnO.sub.2, ZnO, WO.sub.3, NiO, and In.sub.2O.sub.3; and a CeO.sub.2 additive loaded on the nanostructure. The oxide semiconductor nanostructure is uniformly loaded with CeO.sub.2. The composite of the present invention can rapidly detect an analyte gas with high gas response irrespective of the presence and concentration of moisture. The present invention also relates to methods for preparing the composite, a gas sensor including the composite as a material for a gas sensing layer, and a method for fabricating the gas sensor.

The present invention relates to a composite having the ability to stably and reliably detect a target gas even in a moist environment. The composite of the present invention includes: a nanostructure of an oxide semiconductor selected from the group consisting of SnO.sub.2, ZnO, WO.sub.3, NiO, and In.sub.2O.sub.3; and a CeO.sub.2 additive loaded on the nanostructure. The oxide semiconductor nanostructure is uniformly loaded with CeO.sub.2. The composite of the present invention can rapidly detect an analyte gas with high gas response irrespective of the presence and concentration of moisture. The present invention also relates to methods for preparing the composite, a gas sensor including the composite as a material for a gas sensing layer, and a method for fabricating the gas sensor.

A method for producing a nickel cobalt complex hydroxide includes first crystallization of supplying a solution containing Ni, Co and Mn, a complex ion forming agent and a basic solution separately and simultaneously to one reaction vessel to obtain nickel cobalt complex hydroxide particles, and a second crystallization of, after the first crystallization, further supplying a solution containing nickel, cobalt, and manganese, a solution of a complex ion forming agent, a basic solution, and a solution containing said element M separately and simultaneously to the reaction vessel to crystallize a complex hydroxide particles containing nickel, cobalt, manganese and said element M on the nickel cobalt complex hydroxide particles crystallizing a complex hydroxide particles comprising Ni, Co, Mn and the element M on the nickel cobalt complex hydroxide particles.