A process disclosed herein is related to the isolation and purification of substantially pure chemicals, including silica gel, sodium silicate, aluminum silicate, iron oxide, and rare earth elements (or rare earth metals, REEs), from massive industrial waste coal ash. In one embodiment, the process includes a plurality of caustic extractions of coal ash at an elevated temperature, followed by an acidic treatment to dissolve aluminum silicate and REEs. The dissolved aluminum silicate is precipitated out by pH adjustment as a solid product while REEs remain in the solution. REEs are captured and enriched using an ion exchange column. Alternatively, the solution containing aluminum silicate and REEs is heated to produce silica gel, which is easily separated from the enriched REEs solution. REEs are then isolated and purified from the enriched solution to afford substantially pure individual REE by a ligand-assisted chromatography. Additionally, a simplified process using one caustic extraction and one acidic extraction with an ion exchange process was also investigated and optimized to afford a comparable efficiency.

Methods of forming a metal-carbon composite body are provided which may comprise (a) subjecting a metallized biomass to pressure for a period of time to provide a compressed metallized biomass body, wherein the metallized biomass comprises a metallized biopolymer comprising a hydrocarbon backbone and a plurality of metallized functional groups distributed along the hydrocarbon backbone and covalently bound thereto; and (b) heating the compressed metallized biomass body according to a heating profile to carbonize the compressed metallized biomass body and provide a metal-carbon composite body comprising a covalently bound carbon matrix that extends in three dimensions to form a three-dimensional (3D) carbon network with metal distributed throughout the 3D carbon network. The metal-carbon composite bodies are also provided.

Methods of forming a metal-carbon composite body are provided which may comprise (a) subjecting a metallized biomass to pressure for a period of time to provide a compressed metallized biomass body, wherein the metallized biomass comprises a metallized biopolymer comprising a hydrocarbon backbone and a plurality of metallized functional groups distributed along the hydrocarbon backbone and covalently bound thereto; and (b) heating the compressed metallized biomass body according to a heating profile to carbonize the compressed metallized biomass body and provide a metal-carbon composite body comprising a covalently bound carbon matrix that extends in three dimensions to form a three-dimensional (3D) carbon network with metal distributed throughout the 3D carbon network. The metal-carbon composite bodies are also provided.

Provided is a method for manufacturing a nickel and cobalt mixed sulfide that is capable of stabilizing nickel and cobalt concentrations in the sulfidation end solution at low levels and of limiting decreases in nickel and cobalt recovery rates without increasing cost even when processing with a sulfuric acid acidic solution containing nickel and cobalt and a high iron ions concentration as the sulfidation start solution. This method generates a sulfidation reaction by blowing hydrogen sulfide gas into a sulfuric acid acidic solution comprising nickel and cobalt to obtain a mixed sulfide, wherein: the sulfuric acid acidic solution, which is the sulfidation start solution, contains iron ions at a rate of 1.0-4.0 g/L; and the sulfidation reaction is generated by blowing hydrogen sulfide gas into the sulfidation start solution and adding sodium hydrogensulfide (NaHS) obtained by absorbing hydrogen sulfide gas-containing exhaust gas, generated by the sulfidation, in an alkaline solution.

The present invention provides process for production of potassium ammonium sulfate compound fertilizer through the reaction of Epsom salt, obtained in course of chilling of concentrated sea bittern (32-33 Be), with potassium bitartrate, precipitated from such bittern, and ammonium hydroxide. While process integration was achieved through utilisation of Epsom salt; partial desulphatation of bittern, through crystallization of Epsom salt, resulted in about 17% improvement in K.sup.+ precipitation efficiency.

A present disclosure describes about an improved form of purified crystalline sodium nitrite. The said form of sodium nitrite may comprise a purity level between 99% to 99.2%. The form of sodium nitrite may also comprise an amount of sodium nitrate no greater than 0.7%. The present disclosure also relates to a method of obtaining an improved form of purified crystalline sodium nitrite with minimum impurities.

A present disclosure describes about an improved form of purified crystalline sodium nitrite. The said form of sodium nitrite may comprise a purity level between 99% to 99.2%. The form of sodium nitrite may also comprise an amount of sodium nitrate no greater than 0.7%. The present disclosure also relates to a method of obtaining an improved form of purified crystalline sodium nitrite with minimum impurities.

Provided is a production method of a nitride fluorescent material capable of producing a nitride fluorescent material having a higher emission intensity. The production method is for producing a nitride fluorescent material having a composition containing at least one element M.sup.a selected from the group consisting of Sr, Ca, Ba and Mg, at least one element M.sup.b selected from the group consisting of Li, Na and K, at least one element M.sup.c selected from the group consisting of Eu, Ce, Tb and Mn, and Al and N, which includes subjecting a raw material mixture containing elements constituting the composition of the nitride fluorescent material, along with SrF.sub.2 and/or LiF added thereto as a flux, to a heat treatment, wherein the amount of the flux is in a range of 5.0% by mass or more and 15% by mass or less relative to the total amount, 100% by mass of the raw material mixture and the flux.

Provided is a production method of a nitride fluorescent material capable of producing a nitride fluorescent material having a higher emission intensity. The production method is for producing a nitride fluorescent material having a composition containing at least one element M.sup.a selected from the group consisting of Sr, Ca, Ba and Mg, at least one element M.sup.b selected from the group consisting of Li, Na and K, at least one element M.sup.c selected from the group consisting of Eu, Ce, Tb and Mn, and Al and N, which includes subjecting a raw material mixture containing elements constituting the composition of the nitride fluorescent material, along with SrF.sub.2 and/or LiF added thereto as a flux, to a heat treatment, wherein the amount of the flux is in a range of 5.0% by mass or more and 15% by mass or less relative to the total amount, 100% by mass of the raw material mixture and the flux.

Provided is a method for manufacturing a nickel and cobalt mixed sulfide that is capable of stabilizing nickel and cobalt concentrations in the sulfidation end solution at low levels and of limiting decreases in nickel and cobalt recovery rates without increasing cost even when processing with a sulfuric acid acidic solution containing nickel and cobalt and a high iron ions concentration as the sulfidation start solution. This method generates a sulfidation reaction by blowing hydrogen sulfide gas into a sulfuric acid acidic solution comprising nickel and cobalt to obtain a mixed sulfide, wherein: the sulfuric acid acidic solution, which is the sulfidation start solution, contains iron ions at a rate of 1.0-4.0 g/L; and the sulfidation reaction is generated by blowing hydrogen sulfide gas into the sulfidation start solution and adding sodium hydrogensulfide (NaHS) obtained by absorbing hydrogen sulfide gas-containing exhaust gas, generated by the sulfidation, in an alkaline solution.