Abstract: The objective of the invention is the development of a new process for producing sulfur from phosphogypsum. During this process, the phosphogypsum is mixed with a source of carbon and hydrogen forming a slurry after mixing. This source of carbon and hydrogen is a natural or synthetic organic polymer, as an example that is not limiting, biomass, used tires or plastic, kerogen or tars. The granules undergo a heat treatment (100 to 150° C.) to evaporate the mixing water. The product obtained undergoes a heat treatment (550 to 900° C.) under a neutral atmosphere and/or partially oxidizing. The generated gases are bubbled in deionized water, sodium hypochlorite solution or a basic aqueous solution which allows the trapping, among others, of organosulfur molecules and the precipitation of sulfur S8. Non-entrapped gases are recovered to extract volatile sulfur products.

Abstract: The objective of the invention is the development of a new process for producing sulfur from phosphogypsum. During this process, the phosphogypsum is mixed with a source of carbon and hydrogen forming a slurry after mixing. This source of carbon and hydrogen is a natural or synthetic organic polymer, as an example that is not limiting, biomass, used tires or plastic, kerogen or tars. The granules undergo a heat treatment (100 to 150° C.) to evaporate the mixing water. The product obtained undergoes a heat treatment (550 to 900° C.) under a neutral atmosphere and/or partially oxidizing. The generated gases are bubbled in deionized water, sodium hypochlorite solution or a basic aqueous solution which allows the trapping, among others, of organosulfur molecules and the precipitation of sulfur S8. Non-entrapped gases are recovered to extract volatile sulfur products.

Abstract: The subject of the invention is the development of a new process for producing phosphorus P4 from phosphoric acid. In this process, the phosphoric acid and a hydrophilic source of carbon and of hydrogen (biomass, kerogen, “STEP” purification plant sludge, organic polymer) are mixed, and the mixture is treated at a temperature of 80 to 150° C. in order to ensure grafting of the phosphates on the carbon backbone. The production of the phosphorus P4 is carried out by heat treatment of the precursor at a temperature at which phosphorus is produced. The temperature range is from 550° C. to 950° C. This process can be carried out at temperatures below those of conventional phosphorus production without the occurrence of the production of solid by-products normally formed in conventional phosphorus production. The process can be used to produce phosphoric acid for food or medical use.