The present disclosure concerns expandable silica particles having a coating comprising talc powder and kaolin powder provided on the outer surface of the expandable silica particle and expandable and expanded silica particles comprising silica fume and/or ultrafine quartz silica sand beneath the surface of the particles. Methods for producing expandable and expanded silica particles are disclosed, including a method using a vibration plate and a furnace having a vibration plate for carrying out that method. The expanded silica particles have high compressive strength, substantially uniform cell size and distribution, low water absorption, and low porosity on the outer surface. They are useful as a filler in matrix materials, like concrete or epoxy, as insulation material with various binder materials, and as water filtration medium.

The present disclosure concerns expandable silica particles having a coating comprising talc powder and kaolin powder provided on the outer surface of the expandable silica particle and expandable and expanded silica particles comprising silica fume and/or ultrafine quartz silica sand beneath the surface of the particles. Methods for producing expandable and expanded silica particles are disclosed, including a method using a vibration plate and a furnace having a vibration plate for carrying out that method. The expanded silica particles have high compressive strength, substantially uniform cell size and distribution, low water absorption, and low porosity on the outer surface. They are useful as a filler in matrix materials, like concrete or epoxy, as insulation material with various binder materials, and as water filtration medium.

The invention relates to a method for producing a supplementary cementitious material for use in a cement product or concrete, the method comprising the steps of activating clay to the supplementary cementitious material at between 600 to 1000 degree Celsius; treating the activated supplementary cementitious material under reduced conditions to form a reduced product and cooling the reduced product to 300-400 degrees Celsius by a quenching process under oxidizing conditions.

The invention relates to a method for producing an expanded granulate from sand grain-shaped mineral material (1) with a propellant, wherein the material (1) is fed into a vertically upright furnace (2) from above and said material (1) falls along a drop section (4) through multiple heating zones (5) in a furnace shaft (3) of the furnace (2), wherein each heating zone (5) is heatable using at least one independently controllable heating element (6), and the material (1) is heated to a critical temperature at which the surfaces (7) of the sand grains (15) plasticize and the sand grains (15) are expanded by the propellant. In order to enable setting a closed surface of the expanded granulate in a purposeful fashion, it is provided in accordance with the invention that upon detection of a first reduction in the temperature of the material (1) between two successive positions (9) along the drop section (4) the heating elements (6) are controlled along the remaining drop section (4) depending on the critical temperature.

The invention relates to a method for producing an expanded granulate from sand grain-shaped mineral material (1) with a propellant, wherein the material (1) is fed into a vertically upright furnace (2) from above and said material (1) falls along a drop section (4) through multiple heating zones (5) in a furnace shaft (3) of the furnace (2), wherein each heating zone (5) is heatable using at least one independently controllable heating element (6), and the material (1) is heated to a critical temperature at which the surfaces (7) of the sand grains (15) plasticize and the sand grains (15) are expanded by the propellant. In order to enable setting a closed surface of the expanded granulate in a purposeful fashion, it is provided in accordance with the invention that upon detection of a first reduction in the temperature of the material (1) between two successive positions (9) along the drop section (4) the heating elements (6) are controlled along the remaining drop section (4) depending on the critical temperature.

A reinforced concrete material is described comprising a cementitious material (22) in which graphene is substantially uniformly distributed. A method of production of concrete is also described comprising the steps of forming a substantially uniform suspension (20) of graphene with water, and mixing the suspension (20) with a cementitious material (22) to form a concrete material (28).

A reinforced concrete material is described comprising a cementitious material (22) in which graphene is substantially uniformly distributed. A method of production of concrete is also described comprising the steps of forming a substantially uniform suspension (20) of graphene with water, and mixing the suspension (20) with a cementitious material (22) to form a concrete material (28).

A method for heat treatment of a grain-shaped feed material uses a calcination device in order to remove carbonate or water of crystallization from the feed material. In order to continuously check the quality of the heat treatment process, the bulk density of the heat-treated material is measured continuously, wherein upon detection of a deviation of the determined bulk density from the at least one desired bulk density at least one heat treatment parameter of the heat treatment is adapted automatically or manually.

A method for heat treatment of a grain-shaped feed material uses a calcination device in order to remove carbonate or water of crystallization from the feed material. In order to continuously check the quality of the heat treatment process, the bulk density of the heat-treated material is measured continuously, wherein upon detection of a deviation of the determined bulk density from the at least one desired bulk density at least one heat treatment parameter of the heat treatment is adapted automatically or manually.

A reinforced concrete material is described comprising a cementitious material (22) in which graphene is substantially uniformly distributed. A method of production of concrete is also described comprising the steps of forming a substantially uniform suspension (20) of graphene with water, and mixing the suspension (20) with a cementitious material (22) to form a concrete material (28).