A process for operating an oxidizable combustion gas cleaning unit in a metallurgical plant, including the steps of: (a) passing an oxidizable combustion gas from a metallurgical reactor, in particular a blast furnace gas from a blast furnace, in a packed bed scrubber arrangement through a packed bed in countercurrent with a washing water or in a spray scrubber arrangement to remove cyanide compounds, in particular hydrogen cyanide, and to increase the removal of chloride compounds, in particular hydrogen chloride, from the combustion gas by solubilizing the cyanide and chloride compounds in the washing water, (b) collecting the washing water containing solubilized cyanide and chloride compounds at a bottom end of the packed bed or spray scrubber arrangement, and (c) collecting a cleaned oxidizable combustion gas at a top of the packed bed or spray scrubber arrangement, wherein a base is added to the washing water before step (a).

The present invention relates to a denitration and waste heat recovery integrated furnace, comprising a denitration system, a desulfurization system and a waste heat recovery system. An air outlet of the denitration system is connected to an inlet of a dust collector (4), an outlet of the dust collector (4) is connected to an air inlet of the desulfurization system, an air outlet of the desulfurization system is connected to an air compressor (6) of the waste heat recovery system, and the waste heat recovered by the air compressor (6) is used for heat energy utilization of other departments.

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.

The description relates to reducing hydrochloric acid in cement kilns. In one aspect, an aqueous copper-based chloride remediator is introduced into contact with combustion gases from a cement kiln. Injection is made into a defined introduction zone under conditions effective for HCl emissions control wherein the temperature is within the range of from 300 F. to 800 F., preferably from 550 F. to 750 F. The resulting gases are discharged from the defined zone following sufficient reaction time to reduce the HCl concentration in the gases.

A method for calcination includes providing a heated coarse solid particle stream with a carbon dioxide rich sorbent to a reactor having a rotatable container.

The present invention relates to a denitration and waste heat recovery integrated furnace, comprising a denitration system, a desulfurization system and a waste heat recovery system. An air outlet of the denitration system is connected to an inlet of a dust collector (4), an outlet of the dust collector (4) is connected to an air inlet of the desulfurization system, an air outlet of the desulfurization system is connected to an air compressor (6) of the waste heat recovery system, and the waste heat recovered by the air compressor (6) is used for heat energy utilization of other departments.

A method for treating exhaust gas in an exhaust gas treatment device of a system may involve withdrawing exhaust gas from a processing device for mechanically and/or thermally processing an inorganic material of the system. The material to be fed to the processing device may be preheated by heat exchange with the exhaust gas. Further, a temperature of the exhaust gas entering the exhaust gas treatment device may be adjusted by adapting the exchange of heat between the exhaust gas and the inorganic material. In some examples, the exhaust gas treatment device may comprise an oxidation catalytic converter and/or a reduction catalytic converter.

The invention relates to a process plant (20) for converting a solid input material into a solid process product. The process plant (20) includes a calciner which is connected to a heat exchanger (26) and to which the input material can be continuously supplied for heating in order to transform the input material into an intermediate product. In the process plant (20) there is a kiln for converting the intermediate product into the process product by means of thermal treatment, raw gas being produced in doing so. The process plant (20) has a raw gas line system (50) comprising a raw gas line (50.1) which extends from the kiln to the calciner and through which the raw gas can flow from the kiln into the calciner for transferring raw gas heat to the input material, and includes a cooling device for cooling the process product after the thermal treatment in the kiln by transferring heat from the process product to a cooling gas containing oxygen, as a result of which a hot gas containing oxygen is generated. According to the invention, in the process plant (20) there is a waste air purification device for oxidizing raw gas, which is connected to the calciner via a raw gas line system (50), wherein a hot gas line system which is used for supplying hot gas generated from the cooling device is attached to the raw gas line system (50). The invention also relates to a method for converting a solid input material into a solid process product and to a method for purifying raw gas produced during the manufacture of cement.

A reflow oven includes a chamber housing including surfaces that are in contact with heated air mixed with contaminants, including flux, and a water-soluble layer selectively applied to the surfaces of the chamber housing. Embodiments of the reflow oven include an acrylic-based layer, such as an acrylic paint. In one embodiment, the acrylic paint includes a water-soluble polymer, a polymer emulsion, and water. The water-soluble polymer includes butyl benzyl phthalate. In some embodiments, the acrylic paint includes 1-10% by weight butyl benzyl phthalate, 30-55% by weight acrylic polymer emulsion, and balance water. In a certain embodiment, the acrylic paint includes 1-5% by weight butyl benzyl phthalate, 35-50% by weight acrylic poly emulsion, and balance water. Methods of treating surfaces of the reflow oven are further disclosed.