Methods and apparatus for reducing the content of controlled acidic pollutants in clinker kiln emissions are disclosed. The methods and apparatus include introducing bypass dust produced during production of clinker into one or more locations between the preheater exhaust and the inlet to a dust filter including into a gas conditioning tower. Total bypass dust separated from the kiln exhaust gas may be used. The bypass dust can be separated into a fine and coarse portions. Fine or total bypass dust can be mixed with water to form a bypass dust slurry that can be introduced into the gas conditioning tower. Bypass dust can be used to reduce the content of acidic pollutants such as hydrogen chloride HCl and sulfur oxides SO.sub.x from clinker kiln emissions.

Methods and apparatus for reducing the content of controlled acidic pollutants in clinker kiln emissions are disclosed. The methods and apparatus include introducing bypass dust produced during production of clinker into one or more locations between the preheater exhaust and the inlet to a dust filter including into a gas conditioning tower. Total bypass dust separated from the kiln exhaust gas may be used. The bypass dust can be separated into a fine and coarse portions. Fine or total bypass dust can be mixed with water to form a bypass dust slurry that can be introduced into the gas conditioning tower. Bypass dust can be used to reduce the content of acidic pollutants such as hydrogen chloride HCl and sulfur oxides SO.sub.x from clinker kiln emissions.

Methods and apparatus for reducing the content of controlled acidic pollutants in clinker kiln emissions are disclosed. The methods and apparatus include introducing bypass dust produced during production of clinker into one or more locations between the preheater exhaust and the inlet to a dust filter including into a gas conditioning tower. Total bypass dust separated from the kiln exhaust gas may be used. The bypass dust can be separated into a fine and coarse portions. Fine or total bypass dust can be mixed with water to form a bypass dust slurry that can be introduced into the gas conditioning tower. Bypass dust can be used to reduce the content of acidic pollutants such as hydrogen chloride HCl and sulfur oxides SO.sub.x from clinker kiln emissions.

Process for the purification of a residue containing solids and mother liquor and having a chloride ion content greater than 5000 ppm by weight relative to the weight of the residue which comprises (a) piston washing said residue with a washing fluid and (b) recovering a purified residue.

A method for treating limestone comprising raw meal in a cement clinker plant can be improved by first reacting the raw meal with a carboxylic acid (ROOH), thereby producing at least Ca(RCOO).sub.2, wherein the symbol R represents an organic group and subsequently converting the such obtained Ca(ROO).sub.2 into calcined raw meal by thermally decomposing the produced Ca(RCOO).sub.2 and/or Ca(RSO2O).sub.2 to thereby obtain at least CaO, CO.sub.2 and RCOH and/or RCOR.

A method for manufacturing cement clinker includes the steps: preheating a raw meal in a first preheater using kiln off-gas to provide a partially preheated raw meal, preheating the partially preheated raw meal in a second preheater to provide preheated raw meal, precalcination of the pre-heated raw meal in a calciner being a circulating fluidized bed reactor by burning fuel with oxygen and recirculated calciner exhaust gas instead of air to provide a precalcined raw meal wherein at least 2 mbar overpressure are adjusted in the calciner, transferring the precalcined raw meal to a rotary kiln for sintering to provide the cement clinker, cooling the cement clinker, and capturing carbon dioxide from a calciner exhaust gas in a carbon dioxide purification unit.

The present disclosure relates to a visible light-catalyzed translucent concrete, and a preparation method and use thereof. The preparation method includes: extracting an iron oxide from a copper slag, mixing the iron oxide with TiO.sub.2 to obtain a photocatalyst, and then mixing the photocatalyst with an additive to obtain a photocatalytic slurry; preparing a concrete slurry using the copper slag after iron extraction as an aggregate; and pouring the photocatalytic slurry, the concrete slurry, and the photocatalytic slurry in sequence into a mold pre-laid with an optical fiber, to obtain the visible light-catalyzed translucent concrete. In the visible light-catalyzed translucent concrete, iron in the copper slag is used as a part of raw materials of the photocatalyst, and the copper slag after iron extraction is used as an aggregate to replace natural sand and gravel. This solves environmental pollutions caused by the copper slag and realizes resource utilization.