Abstract: A method for industrial refining of coal ash created in power plants and carbonaceous ashes produced in other combustion processes by separating coal from said ashes and returning it to use and by recovering a substantially coal-free ash fraction obtained in the refining. In the method, coal ash and at least one ash fraction created by gasification technique in combustion plants are carefully proportioned in relation to one another and formed into a slurry mixture by means of an efficient dispersion technique, the slurry being then led to a flotation step, where a fraction rich in coal and a siliceous fraction poor in coal and a fraction dissolving in the process water are separated by flotation.

Abstract: A method for industrial refining of coal ash created in power plants and carbonaceous ashes produced in other combustion processes by separating coal from said ashes and returning it to use and by recovering a substantially coal-free ash fraction obtained in the refining. In the method, coal ash and at least one ash fraction created by gasification technique in combustion plants are carefully proportioned in relation to one another and formed into a slurry mixture by means of an efficient dispersion technique, the slurry being then led to a flotation step, where a fraction rich in coal and a siliceous fraction poor in coal and a fraction dissolving in the process water are separated by flotation.

Abstract: Method for industrial processing of charcoal ash (1) created in the power plants by separating a carbonaceous product from the mentioned charcoal ash to be reused and by gathering essentially carbon free, siliceous ash products gained during the processing.

Abstract: Method for industrial processing of charcoal ash (1) created in the power plants by separating a carbonaceous product from the mentioned charcoal ash to be reused and by gathering essentially carbon free, siliceous ash products gained during the processing.

Abstract: The invention relates to a method for protecting reinforcement in concrete from the corrosion caused by chloride ions. According to the method, metallic copper and/or copper compounds are added to the concrete mass, in which mass the copper reacts with the chloride to form salts with a chloride content and of low solubility, thus substantially reducing the danger of steel corrosion caused by chloride. The copper or copper compound can also be brought into close contact with the concrete, for example in the form of a repair mortar.