A method and system for expanding sand grain-shaped raw material drops raw material downwards through a substantially vertical heated shaft equipped for forming a temperature profile, in which a shaft flow prevails wherein raw material expands as a result of heat transfer in the shaft to form expanded granulate, and the granulate formed is passed into a pneumatic conveying line with a conveying flow for further transport. The method and system continuously measure the bulk density of the expanded granulate to continuously check the quality of the expansion process, automatically or manually adapting the temperature profile in the shaft and/or automatically or manually reducing the feeding of raw material into the shaft upon detecting a deviation from at least one defined bulk density.

The present invention relates to methods for the mechanochemical activation of low-kaolinite feedstocks. The invention further relates to the activated materials obtainable by said methods and uses thereof. The invention further relates to compositions comprising the mechanochemically activated materials and a further material selected from the group consisting of asphalt, cement, geopolymers, polymers and combinations thereof. The invention further relates to concrete and methods of their preparation.

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 an expanded granulate (29) made of a sand grain-shaped mineral material (1) using a propellant; wherein the material (1) is fed to a substantially upright furnace (2); wherein the material (1) is conveyed along a conveying path (4) through a plurality of vertically separated healing zones (5) in a furnace shaft (3) of the furnace (2), wherein each heating zone (5) can be heated by at least one independently controllable heating element (6); wherein the material (1) is heated to a critical temperature at which the surfaces (7) of the sand grains (1) become plastic and the sand grains (1) are expanded through the propellant. It is provided according to the invention that the material (1) is fed together with an amount of air from below, wherein the material (1) is conveyed from bottom to top along the conveying path (4) by means of the amount of air which flows from bottom to top within the furnace shaft (3) and forms an air flow (14), and wherein the expanding of the sand grains (1) occurs in the upper half, preferably in the uppermost third, of the conveying path (4).

The invention relates to a method for producing an expanded granulate (29) made of a sand grain-shaped mineral material (1) using a propellant; wherein the material (1) is fed to a substantially upright furnace (2); wherein the material (1) is conveyed along a conveying path (4) through a plurality of vertically separated healing zones (5) in a furnace shaft (3) of the furnace (2), wherein each heating zone (5) can be heated by at least one independently controllable heating element (6); wherein the material (1) is heated to a critical temperature at which the surfaces (7) of the sand grains (1) become plastic and the sand grains (1) are expanded through the propellant. It is provided according to the invention that the material (1) is fed together with an amount of air from below, wherein the material (1) is conveyed from bottom to top along the conveying path (4) by means of the amount of air which flows from bottom to top within the furnace shaft (3) and forms an air flow (14), and wherein the expanding of the sand grains (1) occurs in the upper half, preferably in the uppermost third, of the conveying path (4).

Fibers of diverse materials find widespread use in inorganic binder compositions to improve the properties of the final cured composite materials. When using high amounts of fiber in inorganic binder slurries, problems arise due to the loss of workability because of unevenly distributed fiber content. The novel fibers according to the invention allow the use of large amounts of fiber without loss of workability and are particularly useful to control the rheology of the composite slurry mixtures.

A method for strengthening perlite microspheres may include providing a plurality of perlite microspheres, and heating the plurality of perlite microspheres at a temperature of at least about 600 C. for at least about five minutes to form strengthened perlite microspheres. A composition may include the strengthened perlite microspheres formed from the above-noted method. At least one of a drilling fluid and a well cement may include a slurry including at least one fluid, and a composition including strengthened perlite microspheres. A slurry may include at least one fluid and a plurality of perlite microspheres. The plurality of perlite microspheres may be strengthened by at least one of (1) heating the plurality of perlite microspheres at a temperature of at least about 600 C. for at least about five minutes: and (2) adding at least one metal component and at least one silicate component to the plurality of perlite microspheres.

A method for strengthening perlite microspheres may include providing a plurality of perlite microspheres, and heating the plurality of perlite microspheres at a temperature of at least about 600 C. for at least about five minutes to form strengthened perlite microspheres. A composition may include the strengthened perlite microspheres formed from the above-noted method. At least one of a drilling fluid and a well cement may include a slurry including at least one fluid, and a composition including strengthened perlite microspheres. A slurry may include at least one fluid and a plurality of perlite microspheres. The plurality of perlite microspheres may be strengthened by at least one of (1) heating the plurality of perlite microspheres at a temperature of at least about 600 C. for at least about five minutes: and (2) adding at least one metal component and at least one silicate component to the plurality of perlite microspheres.

The invention relates to a method for the expansion of sand grain-shaped raw material (1) in which the raw material drops downwards through a substantially vertical heated shaft (3) provided with means (2) for heating, in which a shaft flow (4) prevails and to a dosing element (6) which can be connected to a substantially vertical shaft (3) and a conveying line (7). In order to prevent the pressure fluctuations coming from the conveying line (7) in the area of the shaft (3), a dosing element (6) is attached between the shaft and the conveying (7) line, in which the quantity of granulate which goes over from the shaft (3) into the conveying line (7) is regulated via means for regulating so that a defined material collection of the granulate is formed as a buffer in the dosing element (6), which decouples the shaft flow (4) from the conveying flow.