A recirculated-suspension pre-calciner system is disclosed, comprising: a vortex cyclone dust collecting equipment including a plurality of devices, wherein a top device of the vortex cyclone dust collecting equipment is used as a feed system; a vertical combustion kiln; a blower; and a powder purge system, wherein powders in the feed system fall into the vortex cyclone dust collecting equipment and pass through a plurality of the devices to mix and exchange heat with flue gas comprising CO.sub.2, generating calcination reaction and releasing CO2 into the flue gas. and the steam is separated and transported to the feed system by the blower and acts as a carrier gas of powders.

A recirculated-suspension pre-calciner system is disclosed, comprising: a vortex cyclone dust collecting equipment including a plurality of devices, wherein a top device of the vortex cyclone dust collecting equipment is used as a feed system; a vertical combustion kiln; a blower; and a powder purge system, wherein powders in the feed system fall into the vortex cyclone dust collecting equipment and pass through a plurality of the devices to mix and exchange heat with flue gas comprising CO.sub.2, generating calcination reaction and releasing CO2 into the flue gas. and the steam is separated and transported to the feed system by the blower and acts as a carrier gas of powders.

A process for preparing metal chloride Mx+Clx, in which metal carbonate in solid form is reacted with a chlorinating agent selected from chlorine and oxalyl chloride to give metal chloride Mx+Clx, where the metal M is selected from the group of the alkali metals, alkaline earth metals, Al and Zn, Li and Mg, or Li, and x corresponds to the valency of the metal cation, and wherein metal M is additionally added as a reactant to the metal carbonate/chlorinating agent reaction.

A process for preparing metal chloride Mx+Clx, in which metal carbonate in solid form is reacted with a chlorinating agent selected from chlorine and oxalyl chloride to give metal chloride Mx+Clx, where the metal M is selected from the group of the alkali metals, alkaline earth metals, Al and Zn, Li and Mg, or Li, and x corresponds to the valency of the metal cation, and wherein metal M is additionally added as a reactant to the metal carbonate/chlorinating agent reaction.

An apparatus and method sinters or partially sinters green pellets in a selected temperature range to make proppant particles as the green pellets pass through a first central portion of the first vortex gas flow and exit the second end of the first cylindrical vessel and/or pass through a second central portion of the second vortex flow and exit the fourth end of the second cylindrical vessel.

A method for producing metal chloride M.sup.x+Clx includes reacting metal carbonate in solid form using phosgene, diphosgene and/or triphosgene to form metal chloride M.sup.x+Clx, wherein the metal M is selected from the group containing alkali metals, alkaline earth metals, Al and Zn, Li and Mg, or Li, for example, and x corresponds to the valency of the metal cations. An apparatus for performing such method is also disclosed.

A method for producing metal chloride M.sup.x+Clx includes reacting metal carbonate in solid form using phosgene, diphosgene and/or triphosgene to form metal chloride M.sup.x+Clx, wherein the metal M is selected from the group containing alkali metals, alkaline earth metals, Al and Zn, Li and Mg, or Li, for example, and x corresponds to the valency of the metal cations. An apparatus for performing such method is also disclosed.

A bauxite processing method including: preliminarily grinding bauxites; mixing the bauxites as ground with magnetic field treated water into a pulp; exposing the pulp in a reaction chamber to a rotating magnetic field created by rotating ferromagnetic elements, carried out in a vortex layer generated by ferromagnetic elements rotating at a speed of at least 2800 rpm, to achieve a magnetoelastic effect and provide forces and energies which enable metal reduction; and separating a resulting metal oxide mixture.

A bauxite processing method including: preliminarily grinding bauxites; mixing the bauxites as ground with magnetic field treated water into a pulp; exposing the pulp in a reaction chamber to a rotating magnetic field created by rotating ferromagnetic elements, carried out in a vortex layer generated by ferromagnetic elements rotating at a speed of at least 2800 rpm, to achieve a magnetoelastic effect and provide forces and energies which enable metal reduction; and separating a resulting metal oxide mixture.

The present invention relates to a process for the polymerization of olefin monomers in the presence of a catalyst system, using a tubular pre-polymerization reactor, wherein the tubular pre-polymerization reactor has a length L and the flow of a catalyst system is introduced in the tubular pre-polymerization reactor in the middle (30-70% of L) or the end (70-95% of L) of the tubular pre-polymerization reactor.