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.

A device for producing expanded granulated material from mineral material in the form of grains of sand with an expanding agent includes a furnace with a furnace shaft, having an upper end and a lower end. A conveying section extends between the two ends and passes through a number of heating zones arranged separately from one another in a conveying direction. The device also includes at least one feeder in order to charge at least the unexpanded material into the furnace shaft at one of the two ends in the direction of the other of the two ends. At least one directing element is at least partly arranged in the furnace shaft and forms a gap with an inner wall of the furnace shaft, at least in the region of one of the two ends. The at least one feeder is designed for charging the material into the gap.

A method for the use of a clay including: less than 30% of kaolinite; and at least 20% of muscovite and/or illite; from 1% to 20% of smectite; the muscovite and/or illite/kaolinite weight ratio being greater than 1; for the preparation of a geopolymer precursor.

A method for the use of a clay including: less than 30% of kaolinite; and at least 20% of muscovite and/or illite; from 1% to 20% of smectite; the muscovite and/or illite/kaolinite weight ratio being greater than 1; for the preparation of a geopolymer precursor.

The use of a clay including: less than 25% of kaolinite; and at least 20% of muscovite and/or illite; the muscovite and/or illite/kaolinite weight ratio being greater than 1, for the preparation of a pozzolanic material.

The use of a clay including: less than 25% of kaolinite; and at least 20% of muscovite and/or illite; the muscovite and/or illite/kaolinite weight ratio being greater than 1, for the preparation of a pozzolanic material.

The invention relates to a method for producing an expanded granular material from sand grain-like mineral material which comprises a bound blowing agent, for example for producing an expanded granular material from perlite sand, wherein the sand grain-like mineral material is introduced into a feed opening at one end of a furnace shaft, conveyed along a thermal treatment section in a conveying direction, preferably by force of gravity, heated to a critical temperature while being conveyed through the thermal treatment section, starting at which temperature the sand grain-like mineral material plasticizes and begins to expand as a result of the blowing agent, and the expanded granular material is discharged at another end of the furnace shaft. In order to render the expanded granular widely usable, it is provided according to the invention that the sand grain-like mineral material is heated to a second temperature above the critical temperature after being heated to the critical temperature, which second temperature lies below a third temperature, starting at which third temperature the surface of the expanded granular material bursts, and wherein the second temperature is chosen depending on a desired density of the expanded granular material, so that a portion of the blowing agent remains in the granular material in bound form.

A method of manufacturing inorganic binder by reduction furnace slag includes a raw material preparation step, a stirring step, a maintaining step and a drying step. The raw material preparation step is to provide a powder mixture containing 30 wt % to 55 wt % of reduction furnace slag, and 45 wt % to 70 wt % of glass powder. The stirring step is to place the powder mixture in a mixing tank, and add an alkali activator to the mixing tank to stir and react to form mixed slurry. The alkali equivalent (AE) of the mixed slurry is 2% to 7%, and the water-binder ratio is 0.25 to 0.4. The maintaining step is to place the mixed slurry in a high-temperature and high pressure maintaining environment for a maintaining time to get a binder. The drying step is to dry the binder.

A method of manufacturing inorganic binder by reduction furnace slag includes a raw material preparation step, a stirring step, a maintaining step and a drying step. The raw material preparation step is to provide a powder mixture containing 30 wt % to 55 wt % of reduction furnace slag, and 45 wt % to 70 wt % of glass powder. The stirring step is to place the powder mixture in a mixing tank, and add an alkali activator to the mixing tank to stir and react to form mixed slurry. The alkali equivalent (AE) of the mixed slurry is 2% to 7%, and the water-binder ratio is 0.25 to 0.4. The maintaining step is to place the mixed slurry in a high-temperature and high pressure maintaining environment for a maintaining time to get a binder. The drying step is to dry the binder.