A method for removing at least one impurity from metal-based nanoparticles, including at least two heating steps. During step 1, the temperature of the nanoparticles is increased to a temperature T.sub.1, and is then maintained at T.sub.1 during a heating time that is included between 1 second and 20 years, where T.sub.1 is included between 50 C. and 300 C. During step 2, the temperature of the nanoparticles is increased to a temperature T.sub.2, and is then maintained at T.sub.2 during a heating time that is included between 1 second and 20 years, where T.sub.2 is included between 300 C. and 600 C.

A method for removing at least one impurity from metal-based nanoparticles, including at least two heating steps. During step 1, the temperature of the nanoparticles is increased to a temperature T.sub.1, and is then maintained at T.sub.1 during a heating time that is included between 1 second and 20 years, where T.sub.1 is included between 50 C. and 300 C. During step 2, the temperature of the nanoparticles is increased to a temperature T.sub.2, and is then maintained at T.sub.2 during a heating time that is included between 1 second and 20 years, where T.sub.2 is included between 300 C. and 600 C.

A method for producing crystalline -Fe2O3 nanoparticles involving ultrasonic treatment of a solution of an iron (III)-containing precursor and an extract from the seeds of a plant in the family Linaceae. The method involves preparing an aqueous extract from the seeds of a plant in the family Linacae and dropwise addition of the extract to the solution of an iron (III)-containing precursor. The method yields crystalline nanoparticles of -Fe.sub.2O.sub.3 having a spherical morphology with a diameter of 100 nm to 300 nm, a mean surface area of 240 to 250 m.sup.2/g, and a type-II nitrogen adsorption-desorption BET isotherm with a H3 hysteresis loop. A method for the photocatalytic decomposition of organic pollutants using 10 the nanoparticles is disclosed. An antibacterial composition containing the crystalline -Fe.sub.2O.sub.3 nanoparticles is also disclosed.

A method for producing crystalline -Fe2O3 nanoparticles involving ultrasonic treatment of a solution of an iron (III)-containing precursor and an extract from the seeds of a plant in the family Linaceae. The method involves preparing an aqueous extract from the seeds of a plant in the family Linacae and dropwise addition of the extract to the solution of an iron (III)-containing precursor. The method yields crystalline nanoparticles of -Fe.sub.2O.sub.3 having a spherical morphology with a diameter of 100 nm to 300 nm, a mean surface area of 240 to 250 m.sup.2/g, and a type-II nitrogen adsorption-desorption BET isotherm with a H3 hysteresis loop. A method for the photocatalytic decomposition of organic pollutants using 10 the nanoparticles is disclosed. An antibacterial composition containing the crystalline -Fe.sub.2O.sub.3 nanoparticles is also disclosed.

Magnetic nanoparticles and synthesis of synthesis are described.

Pyrophoric material such as iron sulfide is frequently found in refinery equipment. When the equipment is opened to the atmosphere for maintenance, an exothermic reaction can take place that may cause injury to personnel and catastrophic damage to equipment. A process used to treat pyrophoric material uses sodium nitrite injected into a gaseous carrier stream to oxidize iron sulfides to elemental sulfur and iron oxides. The sodium nitrite solution may be buffered to a pH of about 9 with disodium phosphate or monosodium phosphate. A chemical additive that provides a quantitative measure of reaction completion may be added to the treatment solution.

Pyrophoric material such as iron sulfide is frequently found in refinery equipment. When the equipment is opened to the atmosphere for maintenance, an exothermic reaction can take place that may cause injury to personnel and catastrophic damage to equipment. A process used to treat pyrophoric material uses sodium nitrite injected into a gaseous carrier stream to oxidize iron sulfides to elemental sulfur and iron oxides. The sodium nitrite solution may be buffered to a pH of about 9 with disodium phosphate or monosodium phosphate. A chemical additive that provides a quantitative measure of reaction completion may be added to the treatment solution.

Dendronized metallic oxide nanoparticles, a process for preparing the same and their uses.

Dendronized metallic oxide nanoparticles, a process for preparing the same and their uses.

Processes are provided in which successive steps of hydrometallurgical value extraction may be carried out using the products of carbon capture and an electrolytic reagent-generating process. The electrolytic process provides an acid leachant and an alkali hydroxide, with the alkali hydroxide then available for use either directly as a precipitant in the hydrometallurgical steps, or available for conversion by carbon capture to an alkali metal carbonate that can in turn be used as the precipitant in the selective hydrometallurgical steps.