A method for producing a dust-reducing and dust-absorbing material from a nonmetallic mineral and a raw material from a cement plant. The method includes calcining the limestone block, to obtain quicklime; cooling the quicklime at ambient temperature, drying and pulverizing the quicklime, to obtain a first powder essentially consisting of a quicklime powder and a calcium carbonate powder; fully drying and grinding a nonmetallic mineral, to obtain a nonmetallic mineral powder; mixing the first powder and the nonmetallic mineral powder, stirring to be uniform, to obtain a mixture, and ball milling the mixture, to obtain a nano-powder; adding a dust-absorbing material to the nano-powder, adding water and mixing, and pouring the resulting mixture into a mold, and stoving; and air drying the resulting mixture, to obtain a cavernous dust-reducing and dust-absorbing material.

Provided herein are compositions, methods, and systems comprising vaterite and magnesium oxide.

Provided herein are compositions, methods, and systems comprising vaterite and magnesium oxide.

A method for reducing combustion temperature and/or thermal radiation within a lime kiln of a pulp production plant, which kiln is a rotary kiln having a kiln tube (1) internally covered with refractory tiles (13) and having a burner (2) supplied by fuel for heating of the rotary kiln by a flame (3). The effects are achieved by supplying calcium carbonate containing particles to the flame (3) and/or to surrounding area around the flame (3). The particles are supplied into the rotary kiln by at least one lance (9) to the upper part of the flame (3). Calcium oxide containing particles may be supplied to the rotary kiln to areas surrounding the flame (3) for reducing the thermal radiation to an area over the flame (3) and/or to the area at the side of the flame (3), where the refractory tiles (13) of the kiln are rotating downwards.

Method of operating a long direct-fired inclined counterflow rotary kiln for the thermal treatment of material and counterflow rotary kiln adapted for same, whereby material to be treated is introduced into the kiln at the inlet end and treated material is evacuated from the kiln at the outlet end, whereby a main combustion zone extends inside the kiln over a distance of ¼ to ⅓ of the internal length L.sub.int of the kiln, whereby a supplementary combustion zone in which supplementary combustion takes place with an oxygen-rich oxidant extends inside the kiln over a distance from the inlet end of at most ¼ of the internal length L.sub.int, and whereby no combustion takes place in a heat exchange zone located between the main combustion zone and the supplementary combustion zone.

Provided herein are compositions, methods, and systems comprising vaterite and magnesium oxide.

Provided herein are zero carbon dioxide (CO.sub.2) emission processes and systems to carry out the processes, comprising a) calcining limestone in a cement plant in an electric kiln to form a mixture comprising calcium oxide and a first gaseous stream comprising clean carbon dioxide, wherein the clean carbon dioxide comprises no gaseous or non-gaseous components from combustion of fuel; b) treating the mixture comprising calcium oxide with a N-containing salt solution under one or more dissolution conditions to produce a first aqueous solution comprising calcium salt; and c) contacting the first aqueous solution with the first gaseous stream comprising clean carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising vaterite, aragonite, calcite, or combinations thereof.

Provided herein are zero carbon dioxide (CO.sub.2) emission processes and systems to carry out the processes, comprising a) calcining limestone in a cement plant in an electric kiln to form a mixture comprising calcium oxide and a first gaseous stream comprising clean carbon dioxide, wherein the clean carbon dioxide comprises no gaseous or non-gaseous components from combustion of fuel; b) treating the mixture comprising calcium oxide with a N-containing salt solution under one or more dissolution conditions to produce a first aqueous solution comprising calcium salt; and c) contacting the first aqueous solution with the first gaseous stream comprising clean carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising vaterite, aragonite, calcite, or combinations thereof.

A method for producing a dust-reducing and dust-absorbing material from a nonmetallic mineral and a raw material from a cement plant. The method includes calcining the limestone block, to obtain quicklime; cooling the quicklime at ambient temperature, drying and pulverizing the quicklime, to obtain a first powder essentially consisting of a quicklime powder and a calcium carbonate powder; fully drying and grinding a nonmetallic mineral, to obtain a nonmetallic mineral powder; mixing the first powder and the nonmetallic mineral powder, stirring to be uniform, to obtain a mixture, and ball milling the mixture, to obtain a nano-powder; adding a dust-absorbing material to the nano-powder, adding water and mixing, and pouring the resulting mixture into a mold, and stoving; and air drying the resulting mixture, to obtain a cavernous dust-reducing and dust-absorbing material.

A method for the thermal treatment of mineral raw materials such as limestone or dolomite is shown and described, which includes at least the following steps of a. providing a mineral bulk material and a conductive material and b. placing the mineral bulk material and the conductive material into a kiln, generating an electromagnetic field inside the kiln, thermally treating the mineral bulk material in the kiln by means of electromagnetic excitation of the conductive material in the electromagnetic field, and removing the thermally treated mineral bulk material and the conductive material from the kiln. Using the method described, even large quantities of mineral bulk material can be efficiently converted.