The present invention pertains to a process for producing captured carbon dioxide. Calcium carbonate may be reacted with sulfur dioxide to produce calcium sulfite and gaseous carbon dioxide. Calcium sulfite may be thermally decomposed to produce gaseous sulfur dioxide. The processes may be used in conjunction with combusting various fuels such as a carbonaceous fuel, or a sulfurous fuel, or a nitrogenous fuel, or a hydrogen fuel, or a combination thereof.

A method of recovering iron from a zinc sulfate solution according to an embodiment of the present disclosure is associated with recovering iron from a zinc sulfate solution produced by a leaching process in which zinc ore is dissolved in sulfuric acid. The method comprises a conditioning process including a step of reducing a conditioning process input solution, which is the zinc sulfate solution, and an iron precipitation process for recovering iron as hematite, including a step of pressurizing and oxidizing an iron precipitation process input solution discharged from the conditioning process. The iron precipitation process is performed at a temperature ranging from 135° C. to 150° C. and a pressure ranging from 5 barg to 10 barg.

A method of recovering iron from a zinc sulfate solution according to an embodiment of the present disclosure is associated with recovering iron from a zinc sulfate solution produced by a leaching process in which zinc ore is dissolved in sulfuric acid. The method comprises a conditioning process including a step of reducing a conditioning process input solution, which is the zinc sulfate solution, and an iron precipitation process for recovering iron as hematite, including a step of pressurizing and oxidizing an iron precipitation process input solution discharged from the conditioning process. The iron precipitation process is performed at a temperature ranging from 135° C. to 150° C. and a pressure ranging from 5 barg to 10 barg.

A method of recovering bromide from bromine-containing smelting ash relates to the field of high efficient separation and recovery of bromine by total wet method. It especially relates to the method of high efficiency separation of bromine salt and lead, zinc recovery of circuit board smelting ash by two-step method. It mainly comprising: sub-molten salt leaching, washing, separate Lead and zinc by adjusting the pH of industrial sulfuric acid, membrane separation and concentration, reuse of water, crude bromine salt recovery by evaporation crystallization of bromine salt. Compared with the traditional baking and recycling process of ash, the invention adopts sodium hydroxide submolten salt leaching technology and membrane separation and concentration technology, to reduce the reaction temperature and tailings discharge greatly, which has a good effect of energy saving and emission reduction.

A method of recovering bromide from bromine-containing smelting ash relates to the field of high efficient separation and recovery of bromine by total wet method. It especially relates to the method of high efficiency separation of bromine salt and lead, zinc recovery of circuit board smelting ash by two-step method. It mainly comprising: sub-molten salt leaching, washing, separate Lead and zinc by adjusting the pH of industrial sulfuric acid, membrane separation and concentration, reuse of water, crude bromine salt recovery by evaporation crystallization of bromine salt. Compared with the traditional baking and recycling process of ash, the invention adopts sodium hydroxide submolten salt leaching technology and membrane separation and concentration technology, to reduce the reaction temperature and tailings discharge greatly, which has a good effect of energy saving and emission reduction.

The present invention pertains to a process for producing captured carbon dioxide. Calcium carbonate may be reacted with sulfur dioxide to produce calcium sulfite and gaseous carbon dioxide. Calcium sulfite may be thermally decomposed to produce gaseous sulfur dioxide. The processes may be used in conjunction with combusting various fuels such as a carbonaceous fuel, or a sulfurous fuel, or a nitrogenous fuel, or a hydrogen fuel, or a combination thereof.

The present invention pertains to processes of, for example, preparing zinc oxide and other substances. In one embodiment an exemplary process pertains to reacting ammonium chloride with zinc oxide to form a zinc chloride, gaseous ammonia, and gaseous water vapor. The zinc chloride may be reacted with sulfuric acid to form a zinc sulfate and hydrochloric acid. The zinc sulfate may be decomposed to produce zinc oxide among other substances.

The invention relates to the field of efficient separation and recovery of bromine by full wet method, especially to a two-step separating method of bromide and recovery of lead and zinc from printed circuit board Incineration ash. It mainly includes first sodium hydroxide alkaline leaching, secondary sodium peroxide alkaline leaching, pH adjustment, separate lead and zinc, bromide evaporation and crystallization to recover crude bromide and other steps. Compared with traditional comprehensive recovery process of ash, the invention uses sodium hydroxide to dissolve bromide, lead and zinc, and uses the strong oxidation of sodium peroxide in alkaline environment, copper bromide and other bromine are oxidized and leached; through two-step method, the efficient leaching of bromine, lead and zinc is realized, silver and other precious metals are enriched at the same time. It is beneficial to subsequent recovery of precious metals and has the characteristics of short tail liquid discharge.

The invention relates to the field of efficient separation and recovery of bromine by full wet method, especially to a two-step separating method of bromide and recovery of lead and zinc from printed circuit board Incineration ash. It mainly includes first sodium hydroxide alkaline leaching, secondary sodium peroxide alkaline leaching, pH adjustment, separate lead and zinc, bromide evaporation and crystallization to recover crude bromide and other steps. Compared with traditional comprehensive recovery process of ash, the invention uses sodium hydroxide to dissolve bromide, lead and zinc, and uses the strong oxidation of sodium peroxide in alkaline environment, copper bromide and other bromine are oxidized and leached; through two-step method, the efficient leaching of bromine, lead and zinc is realized, silver and other precious metals are enriched at the same time. It is beneficial to subsequent recovery of precious metals and has the characteristics of short tail liquid discharge.

A method of recovering bromide from bromine-containing smelting ash relates to the field of high efficient separation and recovery of bromine by total wet method. It especially relates to the method of high efficiency separation of bromine salt and lead, zinc recovery of circuit board smelting ash by two-step method. It mainly comprising: sub-molten salt leaching, washing, separate Lead and zinc by adjusting the pH of industrial sulfuric acid, membrane separation and concentration, reuse of water, crude bromine salt recovery by evaporation crystallization of bromine salt. Compared with the traditional baking and recycling process of ash, the invention adopts sodium hydroxide submolten salt leaching technology and membrane separation and concentration technology, to reduce the reaction temperature and tailings discharge greatly, which has a good effect of energy saving and emission reduction.