A method of separating different constituents of a fine fraction that is produced in a prior method for separating a concrete for deconstruction. The method allows the reuse of these different constituents in the production of a new cement and/or of a new concrete, the fine fraction including sand and at least 30% by mass of hydrated cement paste.

An apparatus for producing pozzolanic material from consumer waste includes a glass separator unit to remove glass material from the waste and a size reduction unit downstream the glass separator unit. The glass separator unit includes a tubular outer member and an inner helical member extending inwardly from the inner surface of the tubular outer member and defining an open central bore. The tubular outer member and the open central bore define respective coaxial longitudinal axes that are disposed at an angle relative to a horizontal reference plane, with the inlet higher than the outlet. Non-glass/non-ceramic material is output through the open outlet end of tubular outer member utilizing a flow of water. The glass/ceramic material is output to the size reduction unit through the open inlet end of the tubular outer member utilizing the rotating inner helical member of the glass separator unit.

An apparatus for producing pozzolanic material from consumer waste includes a glass separator unit to remove glass material from the waste and a size reduction unit downstream the glass separator unit. The glass separator unit includes a tubular outer member and an inner helical member extending inwardly from the inner surface of the tubular outer member and defining an open central bore. The tubular outer member and the open central bore define respective coaxial longitudinal axes that are disposed at an angle relative to a horizontal reference plane, with the inlet higher than the outlet. Non-glass/non-ceramic material is output through the open outlet end of tubular outer member utilizing a flow of water. The glass/ceramic material is output to the size reduction unit through the open inlet end of the tubular outer member utilizing the rotating inner helical member of the glass separator unit.

Methods for reducing moisture content of alkaline earth metal carbonate may include introducing alkaline earth metal carbonate having a moisture content ranging from about 0.1% by mass to about 10% by mass into a primary crusher and operating the primary crusher to obtain alkaline earth metal carbonate particles having a top cut particle size d.sub.90 of 90 microns or less. The method may also include introducing the particles into a primary grinder and operating the primary grinder to obtain reduced-size alkaline earth metal carbonate particles having a median particle size d.sub.50 of about 60 microns or less. The method may further include introducing the reduced-size particles into a classifier mill and operating the classifier mill to obtain further-reduced-size alkaline earth metal carbonate particles having a median particle size d.sub.50 of about 12 microns or less, and a moisture content of about 0.15% by mass or less.

A method of separating different constituents of a fine fraction that is produced in a prior method for separating a concrete for deconstruction. The method allows the reuse of these different constituents in the production of a new cement and/or of a new concrete, the fine fraction including sand and at least 30% by mass of hydrated cement paste.

Methods for reducing moisture content of alkaline earth metal carbonate may include introducing alkaline earth metal carbonate having a moisture content ranging from about 0.1% by mass to about 10% by mass into a primary crusher and operating the primary crusher to obtain alkaline earth metal carbonate particles having a top cut particle size d.sub.90 of 90 microns or less. The method may also include introducing the particles into a primary grinder and operating the primary grinder to obtain reduced-size alkaline earth metal carbonate particles having a median particle size d.sub.50 of about 60 microns or less. The method may further include introducing the reduced-size particles into a classifier mill and operating the classifier mill to obtain further-reduced-size alkaline earth metal carbonate particles having a median particle size d.sub.50 of about 12 microns or less, and a moisture content of about 0.15% by mass or less.

A grinding device suitable for operating inside a flotation cell which includes three zones including a collecting zone in which particles are collected though a settling process, a grinding zone in which particles undergo a size reduction process and a pumping zone from which milled particles are recycled to the flotation cell.

A grinding device suitable for operating inside a flotation cell which includes three zones including a collecting zone in which particles are collected though a settling process, a grinding zone in which particles undergo a size reduction process and a pumping zone from which milled particles are recycled to the flotation cell.

Methods for preparing and compositions including untreated and surface-treated alkaline earth metal carbonate particulates are described. For example, a method for processing alkaline earth metal carbonate may include introducing alkaline earth metal carbonate into a stirred media mill, and dry grinding the alkaline earth metal carbonate in the stirred media mill to produce an untreated alkaline earth metal carbonate particulate having certain characteristics. In some examples, the method may include introducing carboxylic acid and/or carboxylic acid salt into the stirred media mill, and dry grinding the alkaline earth metal carbonate and the carboxylic acid and/or carboxylic acid salt in an integrated dry grinding and surface-treating process in the stirred media mill to produce a surface-treated alkaline earth metal carbonate particulate. In some examples, heating may be added during the dry grinding process.

Methods for reducing moisture content of alkaline earth metal carbonate may include introducing alkaline earth metal carbonate having a moisture content ranging from about 0.1% by mass to about 10% by mass into a primary crusher and operating the primary crusher to obtain alkaline earth metal carbonate particles having a top cut particle size d.sub.90 of 90 microns or less. The method may also include introducing the particles into a primary grinder and operating the primary grinder to obtain reduced-size alkaline earth metal carbonate particles having a median particle size d.sub.50 of about 60 microns or less. The method may further include introducing the reduced-size particles into a classifier mill and operating the classifier mill to obtain further-reduced-size alkaline earth metal carbonate particles having a median particle size d.sub.50 of about 12 microns or less, and a moisture content of about 0.15% by mass or less.