The present application relates to a process for the purification of waste materials or industrial by-products, the process comprising the steps of: a) Preparing a composition (C) by blending or mixing waste materials or industrial by-products comprising chlorine (B) with one or more materials comprising heavy metals (HM) b) Reacting (B) and (HM) by thermal treatment of (C) c) Separating evaporated heavy metal chloride compounds (HMCC) d) Obtaining a solid material after the thermal treatment step.

A method for treating and utilizing bypass dusts from a cement production process involves a) contacting the bypass dust with an aqueous phase and mixing the same to obtain a suspension, wherein water-soluble components of the bypass dust are dissolved in the aqueous phase; b) performing a solid/liquid separation, in particular a vacuum filtration or a filter press filtration, to separate the solids contained in the suspension, wherein a brine remains; c) precipitating a partial amount of the heavy metals present in the brine, and optionally Ca, and separating the precipitate from the brine; and d) subjecting the brine to an electrocoagulation, wherein a flocculate containing the heavy metals remaining in the brine is separated.

A method for treating and utilizing bypass dusts from a cement production process involves a) contacting the bypass dust with an aqueous phase and mixing the same to obtain a suspension, wherein water-soluble components of the bypass dust are dissolved in the aqueous phase; b) performing a solid/liquid separation, in particular a vacuum filtration or a filter press filtration, to separate the solids contained in the suspension, wherein a brine remains; c) precipitating a partial amount of the heavy metals present in the brine, and optionally Ca, and separating the precipitate from the brine; and d) subjecting the brine to an electrocoagulation, wherein a flocculate containing the heavy metals remaining in the brine is separated.

The present application relates to a process for the purification of waste materials or industrial by-products, the process comprising the steps of: a) Preparing a composition (C) by blending or mixing waste materials or industrial by-products comprising chlorine (B) with one or more materials comprising heavy metals (HM) b) Reacting (B) and (HM) by thermal treatment of (C) c) Separating evaporated heavy metal chloride compounds (HMCC) d) Obtaining a solid material after the thermal treatment step.

In methods of and/or plants for manufacturing cement clinker, the amount of chloride bypass exhaust gas 79 can be substantially decreased, when using previously cooled chloride bypass exhaust gas 81 and/or cooled kiln exhaust gas as coolant for the chloride bypass exhaust gas 39 prior to deducting the chloride bypass exhaust gas 39.

In methods of and/or plants for manufacturing cement clinker, the amount of chloride bypass exhaust gas 79 can be substantially decreased, when using previously cooled chloride bypass exhaust gas 81 and/or cooled kiln exhaust gas as coolant for the chloride bypass exhaust gas 39 prior to deducting the chloride bypass exhaust gas 39.

In methods of and/or plants for manufacturing cement clinker, the amount of chloride bypass exhaust gas 79 can be substantially decreased, when using previously cooled chloride bypass exhaust gas 81 and/or cooled kiln exhaust gas as coolant for the chloride bypass exhaust gas 39 prior to deducting the chloride bypass exhaust gas 39.

A method for manufacturing clinker includes sintering raw meal in a kiln to clinker, preheating the raw meal (prior to sintering the raw meal) in a preheater using a main flue gas stream from the kiln as heat source, dedusting the main flue gas downstream of the preheater at a temperature below the boiling point of mercury (thereby obtaining mercury loaded dust) and withdrawing a bypass flue gas stream from the kiln. The method is configured to efficiently remove mercury from the manufacturing process if mercury in the bypass flue gas is vaporized by injecting of at least a fraction of the mercury-loaded dust into the bypass flue gas stream. Subsequently, the bypass flue gas is dedusted and cooled down. Thereby, the mercury can be adsorbed by injecting an adsorbent (such as activated charcoal) into the bypass flue gas. With subsequent removal of the adsorbent, mercury is finally removed from the manufacturing process.

A method for manufacturing clinker includes sintering raw meal in a kiln to clinker, preheating the raw meal (prior to sintering the raw meal) in a preheater using a main flue gas stream from the kiln as heat source, dedusting the main flue gas downstream of the preheater at a temperature below the boiling point of mercury (thereby obtaining mercury loaded dust) and withdrawing a bypass flue gas stream from the kiln. The method is configured to efficiently remove mercury from the manufacturing process if mercury in the bypass flue gas is vaporized by injecting of at least a fraction of the mercury-loaded dust into the bypass flue gas stream. Subsequently, the bypass flue gas is dedusted and cooled down. Thereby, the mercury can be adsorbed by injecting an adsorbent (such as activated charcoal) into the bypass flue gas. With subsequent removal of the adsorbent, mercury is finally removed from the manufacturing process.

A method and a corresponding plant for denitrifying bypass exhaust gases in a cement clinker production plant. Raw meal is sintered in a rotary kiln and deacidified in a calciner. A rotary kiln inlet chamber is connected to the calciner directly or by a riser duct. Bypass exhaust gas is drawn off near the inlet chamber. This exhaust gas is guided into a first mixing chamber, in which the exhaust gas is cooled to between 800 and 950 C., then the exhaust gas is guided through a reaction pipeline segment, wherein the dwell time is between 0.5 and 3 seconds and ammonia, aqueous ammonia solution, or ammonia-releasing substances are injected for denitrification. Then the exhaust gas is guided into a second mixing chamber, in which the exhaust gas is cooled to between 150 to 250 C. Then the exhaust gas is guided to a filter for dust removal.