In an aspect, provided herein are methods for producing sulfuric acid and hydrogen gas, the methods comprising steps of: providing sulfur dioxide formed by thermal conversion of a sulfur-containing species; electrochemically oxidizing said sulfur dioxide to sulfuric acid in the presence of water; and electrochemically forming hydrogen gas via a reduction reaction. In some embodiments, the methods comprise a step of thermally converting said sulfur-containing species to said sulfur dioxide. Systems configured to perform these methods are also disclosed herein. Also provided herein are methods and systems for producing sulfuric acid and hydrogen gas by electrochemically forming the sulfuric acid and the hydrogen gas in a mixture comprising a sulfur material, a supporting acid, and water. Also provided herein are methods and systems for producing a cement material.

In an aspect, provided herein are methods for producing sulfuric acid and hydrogen gas, the methods comprising steps of: providing sulfur dioxide formed by thermal conversion of a sulfur-containing species; electrochemically oxidizing said sulfur dioxide to sulfuric acid in the presence of water; and electrochemically forming hydrogen gas via a reduction reaction. In some embodiments, the methods comprise a step of thermally converting said sulfur-containing species to said sulfur dioxide. Systems configured to perform these methods are also disclosed herein. Also provided herein are methods and systems for producing sulfuric acid and hydrogen gas by electrochemically forming the sulfuric acid and the hydrogen gas in a mixture comprising a sulfur material, a supporting acid, and water. Also provided herein are methods and systems for producing a cement material.

Methods for removing heavy metals from a phosphoric acid solution produced in a wet process for manufacturing phosphoric acid, comprising treating the wet-process phosphoric acid solution with a small amount of a solid adsorbing material and a complex reagent to form a heavy metal complex-contaminated solid adsorbing material, and removing the contaminated solid adsorbing material to yield a treated phosphoric acid solution having a low heavy metal content.

The present disclosure discloses a method for graded utilization of fluorine and silicon resources in a phosphate ore. While the phosphate ore reacts with sulfuric acid, a fluorine-containing and silicon-containing tail gas is produced. SiO.sub.2 and H.sub.2SiF.sub.6 solution with a high concentration are obtained by concentrating and filtering a solution containing HF and H.sub.2SiF.sub.6 formed after tail gas is absorbed by water. Crude SiF.sub.4 and a solution containing HF and H.sub.2SO.sub.4 are obtained by extracting, adsorbing, and dehydrating the H.sub.2SiF.sub.6 solution. SiF.sub.4 with a 5N purity is obtained after the crude SiF.sub.4 is adsorbed and distilled, at the same time, an impurity-enriched SiF.sub.4 is returned to operations of concentration and filtration to react with the solution containing HF and H.sub.2SiF.sub.6 to generate the H.sub.2SiF.sub.6 and SiO.sub.2. High-purity HF and waste sulfuric acid are obtained after the H.sub.2SO.sub.4 solution containing HF is separated by steam stripping and distillation.

The present disclosure discloses a method for graded utilization of fluorine and silicon resources in a phosphate ore. While the phosphate ore reacts with sulfuric acid, a fluorine-containing and silicon-containing tail gas is produced. SiO.sub.2 and H.sub.2SiF.sub.6 solution with a high concentration are obtained by concentrating and filtering a solution containing HF and H.sub.2SiF.sub.6 formed after tail gas is absorbed by water. Crude SiF.sub.4 and a solution containing HF and H.sub.2SO.sub.4 are obtained by extracting, adsorbing, and dehydrating the H.sub.2SiF.sub.6 solution. SiF.sub.4 with a 5N purity is obtained after the crude SiF.sub.4 is adsorbed and distilled, at the same time, an impurity-enriched SiF.sub.4 is returned to operations of concentration and filtration to react with the solution containing HF and H.sub.2SiF.sub.6 to generate the H.sub.2SiF.sub.6 and SiO.sub.2. High-purity HF and waste sulfuric acid are obtained after the H.sub.2SO.sub.4 solution containing HF is separated by steam stripping and distillation.

A urea phosphate calcium sulfate (UPCS) fertilizer granule and methods for making and using the same are disclosed. The granule can include urea phosphate and a urea-calcium sulfate (UCS) adduct. The granule can include 22 wt. % to 28 wt. % nitrogen (22 wt. % to 28 wt. % N), an amount of phosphorus equal to that provided by 5 wt. % to 10 wt. % P2O5 (5 wt. % to 10 wt. % P), 2 wt. % to 8 wt. % sulfur (2 wt. % to 8 wt. % S), and 5 wt. % to 11 wt. % calcium (5 wt. % to 11 wt. % Ca).

In an aspect, provided herein are methods for producing sulfuric acid and hydrogen gas, the methods comprising steps of: providing sulfur dioxide formed by thermal conversion of a sulfur-containing species; electrochemically oxidizing said sulfur dioxide to sulfuric acid in the presence of water; and electrochemically forming hydrogen gas via a reduction reaction. In some embodiments, the methods comprise a step of thermally converting said sulfur-containing species to said sulfur dioxide. Systems configured to perform these methods are also disclosed herein. Also provided herein are methods and systems for producing sulfuric acid and hydrogen gas by electrochemically forming the sulfuric acid and the hydrogen gas in a mixture comprising a sulfur material, a supporting acid, and water. Also provided herein are methods and systems for producing a cement material.

In an aspect, provided herein are methods for producing sulfuric acid and hydrogen gas, the methods comprising steps of: providing sulfur dioxide formed by thermal conversion of a sulfur-containing species; electrochemically oxidizing said sulfur dioxide to sulfuric acid in the presence of water; and electrochemically forming hydrogen gas via a reduction reaction. In some embodiments, the methods comprise a step of thermally converting said sulfur-containing species to said sulfur dioxide. Systems configured to perform these methods are also disclosed herein. Also provided herein are methods and systems for producing sulfuric acid and hydrogen gas by electrochemically forming the sulfuric acid and the hydrogen gas in a mixture comprising a sulfur material, a supporting acid, and water. Also provided herein are methods and systems for producing a cement material.

Process for recovering phosphorus from ashes coming from combustion plants that are fed with renewables and/or waste materials as solid fuel, comprising a phase of mixing said ashes coming from combustion plants that are fed with renewables and/or waste materials as solid fuel with a sulfuric acid solution, in order to extract the phosphorus therein contained; a system for carrying out said process is also described.

Process for recovering phosphorus from ashes coming from combustion plants that are fed with renewables and/or waste materials as solid fuel, comprising a phase of mixing said ashes coming from combustion plants that are fed with renewables and/or waste materials as solid fuel with a sulfuric acid solution, in order to extract the phosphorus therein contained; a system for carrying out said process is also described.