Abstract: A device and process for fluorine recovery from smoke after phosphorus absorption by hydration in KPA, wherein the device comprises a first-stage and second-stage fluorine absorption tower, which are both fluidized counter-current washing towers. The device according to the present invention has simple structure, low investment cost, high raw material utilization rate, and good fluorine recovery effects.

Abstract: Disclosed is a method for phosphorus absorption by hydration and fluorine recovery for a fume exiting a kiln in a kiln process for the production of phosphoric acid, comprising the following steps: a fume containing P2O5 and fluorine exiting a kiln is introduced into a hydration tower, the fume performs heat and mass transfer with the spraying liquid, with most of the phosphoric acid produced being absorbed into the spraying liquid; the phosphoric acid solution falling from the spraying finally enters the acid solution circulating and spraying system; the fume discharged from a fume outlet then passes through a phosphoric acid mist capturing tower and a mist removing and separating tower successively, such that the phosphoric acid mist entrained in the fume exiting the hydration tower is further captured.

Abstract: A method for mass production of phosphoric acid with a rotary kiln, comprising the following steps: pretreating raw materials a carbonaceous reductant; preparing the pre-treated carbonaceous reductant powder; then evenly mixing the carbonaceous reductant powder and the silica powder to obtain a cladding material; mixing the cores and the cladding material for cladding treatment, drying and solidifying same to obtain composite pellets; sending the composite pellets into a rotary kiln for a reduction reaction; sending the high-temperature slag balls exiting the rotary kiln to a cooling device for comprehensive utilization; introducing the fume containing P2O5 and fluorine exiting the kiln into a hydration tower for absorbing phosphorus by hydration, then passing same through a phosphoric acid mist capturing tower and a mist removing and separating tower successively, and the fluorine-containing fume discharged from the mist removing and separating tower entering a subsequent fluorine recovery procedure.

Abstract: A rotary kiln for reducing phosphate ore in kiln phosphoric acid process, comprising a kiln body, a kiln head box, a kiln tail box and a driving device for driving the rotation of the kiln body, wherein a fuel burner is provided at the kiln head, a feed pipe and an outlet flue connected to an external hydration tower are provided at the kiln tail box, the upper part of the kiln body is provided with no air pipe, the outlet flue is provided in the radius range of the kiln body with the axis of the rotary kiln as a center, and the fume conveying direction in the outlet flue is substantially parallel to the axis direction of the rotary kiln or has an included angle of less than 45° thereto. The rotary kiln can effectively mitigate the phenomenon of ring forming in the kiln tail of the rotary kiln.

Abstract: Disclosed is an apparatus for preparing phosphoric acid from a fume exiting the kiln in a kiln phosphoric acid process, the apparatus comprises a hydration tower and an acid solution cyclical spraying system, a fume inlet of the fume exiting the kiln is disposed at a lower portion of the hydration tower, a fume outlet after hydration and absorption is disposed at the top, a spraying device is disposed in a cavity of the hydration tower above the fume inlet, a liquid inlet of the acid solution cyclical spraying system is disposed on a bottom of the hydration tower, a liquid outlet of the acid solution cyclical spraying system is connected to a liquid intake pipe of the spraying device. The present invention has the advantages of simple structure, reasonable layout, strong adaptability, high raw material utilization rate, reduced contaminant emissions, and high recovery rate of phosphoric acid etc.

Abstract: A method for mass production of phosphoric acid with a rotary kiln, comprising the following steps: pretreating raw materials a carbonaceous reductant; preparing the pre-treated carbonaceous reductant powder; then evenly mixing the carbonaceous reductant powder and the silica powder to obtain a cladding material; mixing the cores and the cladding material for cladding treatment, drying and solidifying same to obtain composite pellets; sending the composite pellets into a rotary kiln for a reduction reaction; sending the high-temperature slag balls exiting the rotary kiln to a cooling device for comprehensive utilisation; introducing the fume containing P2O5 and fluorine exiting the kiln into a hydration tower for absorbing phosphorus by hydration, then passing same through a phosphoric acid mist capturing tower and a mist removing and separating tower successively, and the fluorine-containing fume discharged from the mist removing and separating tower entering a subsequent fluorine recovery procedure.

Abstract: Disclosed is an apparatus for preparing phosphoric acid from a fume exiting the kiln in a kiln phosphoric acid process, the apparatus comprises a hydration tower and an acid solution cyclical spraying system, a fume inlet of the fume exiting the kiln is disposed at a lower portion of the hydration tower, a fume outlet after hydration and absorption is disposed at the top, a spraying device is disposed in a cavity of the hydration tower above the fume inlet, a liquid inlet of the acid solution cyclical spraying system is disposed on a bottom of the hydration tower, a liquid outlet of the acid solution cyclical spraying system is connected to a liquid intake pipe of the spraying device. The present invention has the advantages of simple structure, reasonable layout, strong adaptability, high raw material utilisation rate, reduced contaminant emissions, and high recovery rate of phosphoric acid etc.

Abstract: Disclosed is a method for phosphorus absorption by hydration and fluorine recovery for a fume exiting a kiln in a kiln process for the production of phosphoric acid, comprising the following steps: a fume containing P2O5 and fluorine exiting a kiln is introduced into a hydration tower, the fume performs heat and mass transfer with the spraying liquid, with most of the phosphoric acid produced being absorbed into the spraying liquid; the phosphoric acid solution falling from the spraying finally enters the acid solution circulating and spraying system; the fume discharged from a fume outlet then passes through a phosphoric acid mist capturing tower and a mist removing and separating tower successively, such that the phosphoric acid mist entrained in the fume exiting the hydration tower is further captured.

Abstract: A rotary kiln for reducing phosphate ore in kiln phosphoric acid process, comprising a kiln body, a kiln head box, a kiln tail box and a driving device for driving the rotation of the kiln body, wherein a fuel burner is provided at the kiln head, a feed pipe and an outlet flue connected to an external hydration tower are provided at the kiln tail box, the upper part of the kiln body is provided with no air pipe, the outlet flue is provided in the radius range of the kiln body with the axis of the rotary kiln as a centre, and the fume conveying direction in the outlet flue is substantially parallel to the axis direction of the rotary kiln or has an included angle of less than 45° thereto. The rotary kiln can effectively mitigate the phenomenon of ring forming in the kiln tail of the rotary kiln.

Abstract: A device and process for fluorine recovery from smoke after phosphorus absorption by hydration in KPA, wherein the device comprises a first-stage and second-stage fluorine absorption tower, which are both fluidised counter-current washing towers. The device according to the present invention has simple structure, low investment cost, high raw material utilization rate, and good fluorine recovery effects.

Abstract: A method for collecting carbon dioxide from flue gas. The method includes: 1) mixing an aqueous solution of sodium carbonate with an amino alcohol activator to yield a CO2 absorbent; spraying the CO2 absorbent into the flue gas to produce a sodium bicarbonate slurry; 2) thermally decomposing the sodium bicarbonate slurry to produce a highly concentrated CO2 gas and an aqueous solution of sodium carbonate; 3) returning the aqueous solution of sodium carbonate to step 1) to form the CO2 absorbent for recycling; 4) cooling the highly concentrated CO2 gas for condensing hot water vapor therein; 5) carrying out gas-liquid separation on the highly concentrated CO2 gas, removing condensed water to yield highly purified CO2 gas; and 6) drying, compressing, and condensing the highly purified CO2 gas. An apparatus for collecting carbon dioxide from flue gas according to the method is also provided.