There is disclosed a cyclic process for producing taurine from monoethanolamine comprising the steps of: (a) recovering monoethanolamine sulfate from an aqueous mother liquor solution; (b) reacting the monoethanolamine sulfate with sulfuric acid to form an aqueous solution comprised of monoethanolamine bisulfate; (c) heating the aqueous solution comprised of the monoethanolamine sulfate and optionally added monoethanolamine sulfate to yield 2-aminoethyl hydrogen sulfate ester; and (d) reacting the ester with ammonium sulfite or an alkali sulfite to yield taurine.

There is disclosed a cyclic process for producing taurine from monoethanolamine comprising the steps of: (a) recovering monoethanolamine sulfate from an aqueous mother liquor solution; (b) reacting the monoethanolamine sulfate with sulfuric acid to form an aqueous solution comprised of monoethanolamine bisulfate; (c) heating the aqueous solution comprised of the monoethanolamine sulfate and optionally added monoethanolamine sulfate to yield 2-aminoethyl hydrogen sulfate ester; (d) reacting the ester with ammonium sulfite or an alkali sulfite to yield taurine and ammonium or alkali sulfate; (e) separating taurine and ammonium or alkali sulfate to give an aqueous mother liquor solution; and (f) recovering the monoethanolamine sulfate from the aqueous mother liquor solution and recycling to the monoethanolamine sulfate to step (b).

There is disclosed a cyclic process for producing taurine from monoethanolamine comprising the steps of: (a) recovering monoethanolamine sulfate from an aqueous mother liquor solution; (b) reacting the monoethanolamine sulfate with sulfuric acid to form an aqueous solution comprised of monoethanolamine bisulfate; (c) heating the aqueous solution comprised of the monoethanolamine sulfate and optionally added monoethanolamine sulfate to yield 2-aminoethyl hydrogen sulfate ester; (d) reacting the ester with ammonium sulfite or an alkali sulfite to yield taurine and ammonium or alkali sulfate; (e) separating taurine and ammonium or alkali sulfate to give an aqueous mother liquor solution; and (f) recovering the monoethanolamine sulfate from the aqueous mother liquor solution and recycling to the monoethanolamine sulfate to step (b).

There is disclosed a cyclic process for producing taurine from monoethanolamine comprising the steps of: (a) recovering monoethanolamine sulfate from an aqueous mother liquor solution; (b) reacting the monoethanolamine sulfate with sulfuric acid to form an aqueous solution comprised of monoethanolamine bisulfate; (c) heating the aqueous solution comprised of the monoethanolamine sulfate and optionally added monoethanolamine sulfate to yield 2-aminoethyl hydrogen sulfate ester; and (d) reacting the ester with ammonium sulfite or an alkali sulfite to yield taurine.

There is disclosed a cyclic process for producing taurine from monoethanolamine comprising the steps of: (a) reacting monoethanolamine with ammonium sulfate in the recycling mother liquor to yield monoethanolamine sulfate; (b) reacting the monoethanolamine sulfate with sulfuric acid to form 2-aminoethyl hydrogen sulfate ester; (c) subjecting the 2-aminoethyl hydrogen sulfate ester to a sulfonation reaction with ammonium sulfite to yield taurine and ammonium sulfate; (d) separating the taurine and the ammonium sulfate by means of solid-liquid separation; (e) removing the excess ammonium sulfite from the mother liquor to obtain an aqueous solution comprised of ammonium sulfate and (f) returning the aqueous solution to step (a) to complete the cyclic process.

A process for treating an ammonium fluorosulfate byproduct includes providing an ammonium fluorosulfate byproduct including primarily ammonium fluorosulfate and lesser amounts of fluorosulfonic acid and bis(fluorosulfonyl) imide, mixing the ammonium fluorosulfate byproduct with water, reacting the mixture of the ammonium fluorosulfate byproduct and the water at a hydrolysis reaction temperature to hydrolyze the ammonium fluorosulfate, the fluorosulfonic acid and the bis(fluorosulfonyl) imide to form ammonium bisulfate and aqueous hydrogen fluoride; and separating the ammonium bisulfate from the aqueous hydrogen fluoride.

A process for treating an ammonium fluorosulfate byproduct includes providing an ammonium fluorosulfate byproduct including primarily ammonium fluorosulfate and lesser amounts of fluorosulfonic acid and bis(fluorosulfonyl) imide, mixing the ammonium fluorosulfate byproduct with water, reacting the mixture of the ammonium fluorosulfate byproduct and the water at a hydrolysis reaction temperature to hydrolyze the ammonium fluorosulfate, the fluorosulfonic acid and the bis(fluorosulfonyl) imide to form ammonium bisulfate and aqueous hydrogen fluoride; and separating the ammonium bisulfate from the aqueous hydrogen fluoride.

The present invention relates to the processing of natural titanium-containing feedstock, mainly ilmenite concentrate, including ilmenite ores with a low TiO.sub.2 content, into products with high added value without generating any liquid or solid waste. The method according to the invention comprises the following stages: digesting ilmenite concentrate, processing the solid residue following ilmenite concentrate digestion, hydrolysis of titanium oxychloride, washing titanium oxides/hydroxides precipitate from impurities, calcination of titanium oxides/hydroxides precipitate, precipitation of iron hydroxides to obtain black, red and yellow iron oxide pigments, processing the mother liquor containing calcium chloride, regeneration of hydrogen chloride from ammonium chloride solution, obtaining ammonium sulfate and ammonium sulfate crystallization, obtaining crystalline ammonium chloride. The resulting products are pigments, pigment fillers, mineral fertilizers, construction materials, raw materials for the production of metals, and other products; they are used in various fields of application such as paint and coatings industry, pulp and paper industry, in the production of plastics, in metallurgy, in agricultural, construction industries and others.

A process for treating an ammonium fluorosulfate byproduct includes providing an ammonium fluorosulfate byproduct including primarily ammonium fluorosulfate and lesser amounts of fluorosulfonic acid and bis(fluorosulfonyl) imide, mixing the ammonium fluorosulfate byproduct with water, reacting the mixture of the ammonium fluorosulfate byproduct and the water at a hydrolysis reaction temperature to hydrolyze the ammonium fluorosulfate, the fluorosulfonic acid and the bis(fluorosulfonyl) imide to form ammonium bisulfate and aqueous hydrogen fluoride; and separating the ammonium bisulfate from the aqueous hydrogen fluoride.

A process for treating an ammonium fluorosulfate byproduct includes providing an ammonium fluorosulfate byproduct including primarily ammonium fluorosulfate and lesser amounts of fluorosulfonic acid and bis(fluorosulfonyl) imide, mixing the ammonium fluorosulfate byproduct with water, reacting the mixture of the ammonium fluorosulfate byproduct and the water at a hydrolysis reaction temperature to hydrolyze the ammonium fluorosulfate, the fluorosulfonic acid and the bis(fluorosulfonyl) imide to form ammonium bisulfate and aqueous hydrogen fluoride; and separating the ammonium bisulfate from the aqueous hydrogen fluoride.