Provided is a rotary sintering furnace. The rotary sintering furnace includes a furnace body assembly and a knocking device. The furnace body assembly includes a rotary furnace and a heat preservation housing. The rotary furnace is rotatably disposed through the heat preservation housing, and the heat preservation housing has a via hole. The knocking device is disposed outside the heat preservation housing. The knocking device includes a knocking member. The knocking is configured to movably pass through the via hole and knock on the rotary furnace.

The present invention concerns an apparatus and a method for manufacturing a product from a raw material. The apparatus comprises a rotary kiln having a first rotary kiln end and a second rotary kiln end, and a cooling unit which is connected to the second rotary kiln end, wherein a process direction is provided leading through the rotary kiln from the first rotary kiln end to the second rotary kiln end and further through the cooling unit, wherein the cooling unit is configured to transport the product in the process direction through the cooling unit for cooling the product, the rotary kiln comprising a burning unit at the second rotary kiln end, the burning unit being configured to receive a flammable material and an ignition gas to create heat inside the rotary kiln and to produce a combustion gas containing carbon dioxide, the rotary kiln being configured to transport raw material received at the first rotary kiln end in the process direction towards the second rotary kiln end, and, by using the heat, to transform the raw material into the product and into a resigning gas comprising carbon dioxide, characterized in that the apparatus comprises a gas outlet configured to remove an exhaust gas comprising the resigning gas and the combustion gas from the rotary kiln, and that the cooling unit is configured to transport a cooling gas in the process direction over the product.