A method for producing a pozzolanic product by hydrothermal treatment of a feedstock including silicate, aluminate, and/or aluminosilicate materials, and a source of calcium ions, wherein the feedstock has a molar ratio of Ca:(Si+Al) from 0.4 to 1.2 and a maximum content of hydrated cement paste of 10 wt.-%, to provide a hydrate product, and subsequent carbonation of the hydrate product to provide a pozzolanic product including calcium carbonate and silica gel, alumina gel and/or silica-alumina gel. A pozzolanic product is obtainable by the method. The pozzolanic product is used as a supplementary cementitious material for manufacturing a composite cement including the pozzolanic product and a hydraulic cement.

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. The coal ash is arranged to have the highest proportion in the mixture to be taken to flotation, the ashes from combustion plants being dosed into said mixture in an amount that does not cause the maximum amounts of harmful substances to be exceeded in the qualities of the carbonaceous product and the silicate product poor in coal to be obtained.

The invention comprises a method of making a hydraulic cement clinker. The method comprises delivering a natural calcium-iron-aluminosilicate mineral from one or more of hyaloclastite, lava, scoria, volcanic glass, volcanic ash, or any other mineral of a basaltic or intermediate basaltic chemical composition and blending it in ground form with limestone, calcium oxide or calcium hydroxide. The blended mixture is calcined in a portland cement clinker kiln at an elevated temperature and for a time sufficient to form a hydraulic cement clinker.

The invention comprises a method of making lime, dolomitic lime, hydraulic cement such as portland cement clinker and co-products such as pozzolan, acids, alumina, silica and the like while producing reduced amounts of carbon dioxide. The method comprises combining hyaloclastite with a first acid to form a first salt, combining the first salt with a second acid to form a second salt and heating the second salt to form an oxide.

The invention comprises a method of making lime, dolomitic lime, hydraulic cement such as portland cement clinker and co-products such as pozzolan, acids, alumina, silica and the like while producing reduced amounts of carbon dioxide. The method comprises combining hyaloclastite with a first acid to form a first salt, combining the first salt with a second acid to form a second salt and heating the second salt to form an oxide.

The invention comprises a method of making lime, dolomitic lime, hydraulic cement such as portland cement clinker and co-products such as pozzolan, acids, alumina, silica and the like while producing reduced amounts of carbon dioxide. The method comprises combining hyaloclastite with a first acid to form a first salt, combining the first salt with a second acid to form a second salt and heating the second salt to form an oxide.

Embodiments relate to the development of binder agents, and specifically to a hydrated silicate aluminate binder agents. The binder agents, whether combined or not with hardener agents, offer significant improvements in terms of mechanical strength and water resistance compared to soluble sodium-based silicates when used as agents for inorganic and organic substrates.