Method of producing cement clinker and a second calcined material

A method of producing a first calcined material, which is cement clinker, and a second calcined material, wherein the cement clinker is produced in a first production line that comprises:

• a preheater for preheating raw meal in counter current flow to hot exhaust gases coming from a clinker furnace, optionally a pre-calciner for pre-calcining the preheated raw meal, a clinker furnace for calcining the preheated and optionally pre-calcined raw meal in counter current flow to combustion gases of a clinker furnace burner to obtain cement clinker, and a clinker cooler for cooling the cement clinker, the cement clinker being produced in the first production line by carrying out the following steps:
• a) preheating raw meal in the preheater in counter current flow to hot exhaust gases coming from the clinker furnace,
• b) optionally pre-calcining the preheated raw meal in the pre-calciner,
• c) calcining the preheated and optionally pre-calcined raw meal in the clinker furnace in counter current flow to combustion gases of the clinker furnace burner to obtain cement clinker,
• d) cooling the cement clinker in the clinker cooler,
• wherein the second calcined material is produced from a raw material in a second production line that comprises a dryer for drying a raw material, optionally a crusher for crushing the dried raw material, a rotary kiln for calcining the dried and optionally crushed raw material to obtain the second calcined material, optionally a cooler for cooling the second calcined material, the second calcined material being produced from the raw material in the second production line by carrying out the following steps:
• e) drying a raw material in the dryer,
• f) optionally crushing the dried raw material in the crusher,
• g) calcining the dried and optionally crushed raw material in the rotary kiln to obtain the second calcined material,
• h) optionally cooling the second calcined material in the cooler,
• wherein the first production line and the second production line are connected by a first heat exchanging pipe for feeding a sensible heat of a hot gas from the first production line to the rotary kiln as a heat source for calcining the raw material, and
• wherein the first production line and the second production line are connected by a second pipe for introducing a rotary kiln exhaust gas coming from the rotary kiln into the first production line for the secondary combustion of the rotary kiln exhaust gas,
• wherein the first production line and the second production line are connected by a third heat exchanging pipe for feeding the sensible heat of a hot gas from the first production line to the dryer as a heat source for drying the raw material,
• wherein a sensible heat of a hot gas in the first production line is used as a heat source in the calcining step g) for calcining the raw material, and
• wherein the rotary kiln exhaust gas coming from the calcining step g) is introduced into the first production line for the secondary combustion of the rotary kiln exhaust gas.