Device for echelon utilization of energy and improvement of borax yield in boron chemical production
By setting up a secondary heat exchanger at the connection between the carbon decan and the paddle tank, and combining the multiple filtration processes of the polypropylene diaphragm frame, the problems of low boron recovery and energy waste are solved, and efficient boron recovery and energy utilization are achieved.
Patent Information
- Application Number
- CN202420404535.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-04
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-03-04
AI Technical Summary
In the prior art, the recovery rate of boron is low, the heat of the flue gas is not fully utilized after calcination and desulfurization, and the steam consumption is large, resulting in energy loss and cost increase.
By setting up a secondary heat exchanger at the connection between the carbon desulfurization tank and the paddle tank, primary and secondary heat exchange is performed using the flue gas of the calcined desulfurization tower and secondary reslurry, combined with multiple filtration processes of the polypropylene diaphragm frame, the boron recovery rate is improved and energy loss is reduced through heat recovery.
It improves the boron recovery rate, saves energy consumption, reduces production costs, and achieves the improvement of energy cascade utilization and production efficiency.
Smart Images
Figure CN222585846U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of boron chemical industry, in particular to a device for improving recovery rate. Background Art
[0002] The wet boron concentrate from the boron filtration workshop is conveyed by a belt and enters the calcining furnace in the calcining workshop. The wet boron concentrate is re-burned and heated by the gas generated by the gas furnace at 1400°C. The flue gas at about 300°C after re-burning and desulfurization is directly discharged without effective utilization of the heat. The calcined cooked boron powder is transported to the batching room to add soda ash and mother liquor for batching. After the batching is completed, the slurry can be transported to the carbonization reactor for carbonization reaction. The lime kiln workshop calcines coal particles and limestone to produce white ash and kiln gas. The kiln gas is compressed by the washing and filtering air compressor to make the CO2 concentration reach 37% for carbonization reaction. The boiler workshop uses bituminous coal to heat the return water of the tailings pond to produce saturated steam for heating the carbonization reaction. The slurry is introduced into the kiln gas at a certain temperature and pressure to carry out carbonization reaction in the high-pressure reactor. After the carbonization reaction is completed, the slurry is filtered through a plate and frame filter press in a slurry tank. This process uses two steps of washing. First, the filter cake is rinsed with low-grade water for the first time, and then the 85°C hot water generated by directly heating the 20°C return water with saturated steam from the boiler is used for the second rinse to fully recover the boron components in the slag. After filtration, the slag is directly transported to the boron mud tailings pond, and the mixed stock liquid is then controlled and filtered by a small plate and frame filter press to form a clear stock liquid. At this time, the temperature of the clear stock liquid is about 80°C. The clear stock liquid is pumped into the crystallization tank for cooling and crystallization. The crystallization tank is cooled by coil water. The coil water is the return water from the tailings pond. The incoming water temperature is 18°C and the flow rate is 300m 3 / h. The maximum temperature of the tailings pond return water after heat exchange with the crystallization liquid is 45℃, and it is directly discharged to the ore dressing plant. The temperature of the crystallization liquid after cooling is 20℃, and then it enters the centrifuge and the mother liquor produced by centrifugation is re-transported to the batching room for batching, and finally produces 95% pure borax decahydrate. The defects of this scheme are as follows:
[0003] 1. The slag after the first filtration still contains soluble boron, and the existing technology directly transports it to the boron mud tailings pond, so the recovery rate of boron is low;
[0004] 2. The heat of the flue gas at about 300°C after calcination and desulfurization is not fully utilized and is directly discharged, resulting in energy loss;
[0005] 3. The 85°C hot water required for washing the plate and frame filter press is obtained by directly heating the 20°C tailings pond return water with boiler steam. This solution results in a large steam consumption, increased coal consumption, and increased costs;
[0006] 4. The temperature of the slurry after the carbonization reaction reaches 120°C. The heat in the slurry is not recovered again, and the slurry is directly filtered through a plate and frame filter press, resulting in heat loss. Utility Model Content
[0007] In order to solve the above technical problems, the purpose of the utility model is to provide a device for cascade utilization of energy and improving borax yield in boron chemical production, wherein a carbon decomposition tank is connected to a material paddle tank, an output pipeline of the material paddle tank is connected in parallel with a secondary re-slurry pipeline after secondary heat exchange and then connected to a polypropylene diaphragm plate frame for primary filtration; a filter residue output end of the polypropylene diaphragm plate frame is connected to a re-slurry tank, a filtrate output end of the polypropylene diaphragm plate frame is connected to a control filter tank, a re-slurry tank is connected to a primary re-slurry tank, a primary re-slurry tank is connected to a secondary re-slurry tank, and a re-slurry tank is connected to a return water pipe of a tailings pond;
[0008] The filter residues from the primary re-slurry tank and the secondary re-slurry tank are both transported to the boron mud tailings; a secondary heat exchanger is arranged on the slurry pipe connecting the carbonization tank and the slurry tank, and the secondary heat exchanger is for the slurry pipe after carbonization to exchange heat with the second softened water closed-loop circulation through a shell-and-tube heat exchanger, and the second softened water closed-loop circulation is then exchanged with the secondary re-slurry pipe through a shell-and-tube heat exchanger; the slurry output pipeline of the secondary re-slurry tank before the secondary heat exchange is exchanged with the flue gas pipeline of the calcination desulfurization tower through the primary heat exchanger; the primary heat exchanger is for the flue gas pipeline of the calcination desulfurization tower to exchange heat with the first softened water closed-loop circulation through a fluoroplastic heat exchanger, and the first softened water closed-loop circulation is exchanged with the slurry output pipeline of the secondary re-slurry tank through a shell-and-tube heat exchanger.
[0009] The carbon decomposition tank is connected with a batching tank, a steam delivery pipeline, a carbon dioxide delivery pipeline and a gas recovery device.
[0010] The batching tank is connected with the soda ash delivery pipeline, the cooked boron powder input pipeline and the mother liquor input pipeline.
[0011] The cooked boron powder input pipeline is connected to the cooked boron powder output end of the calcining furnace; the calcining furnace is connected to the wet boron fine powder input end and the coal gas input end.
[0012] The utility model has the advantages that, while the recovery rate of boron is improved through multiple filtrations, heat recovery and utilization of different processes are carried out ingeniously through the combination of different heat exchangers, energy saving and environmental protection, and improved production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is a schematic diagram of equipment connection of the utility model. DETAILED DESCRIPTION
[0014] The utility model is described in detail below in conjunction with the accompanying drawings. As shown in the figure, the carbon decomposition tank 1 is connected to the material paddle tank 2, and the output pipeline of the material paddle tank 2 is connected in parallel with the secondary re-pulping pipeline 25 after the secondary heat exchange and then connected to the polypropylene diaphragm plate frame 7 of the primary filtration; the filter residue output end of the polypropylene diaphragm plate frame is connected to the re-pulping tank 9, and the filtrate output end of the polypropylene diaphragm plate frame is connected to the control filter tank 8, and the re-pulping tank 9 is connected to the primary re-pulping tank 10, and the primary re-pulping tank 10 is connected to the secondary re-pulping tank 11; the filter residues of the primary re-pulping tank and the secondary re-pulping tank are both transported to the boron mud tailings 20, and the re-pulping tank 9 is connected to the tailings pond return pipe 21;
[0015] A secondary heat exchanger is arranged on the slurry pipe connecting the carbonization tank 1 and the slurry tank 2, and the secondary heat exchanger is for the slurry pipe after carbonization to exchange heat with the second softened water closed-loop circulation 6 through the shell-and-tube heat exchanger 3, and the second softened water closed-loop circulation 6 then exchanges heat with the secondary re-slurry pipe through the shell-and-tube heat exchanger 3; the slurry output pipeline 26 of the secondary re-slurry tank before the secondary heat exchange exchanges heat with the flue gas pipeline of the calcination desulfurization tower 12 through a primary heat exchanger; the primary heat exchanger is for the flue gas pipeline of the calcination desulfurization tower to exchange heat with the first softened water closed-loop circulation 5 through the fluoroplastic heat exchanger 4, and the first softened water closed-loop circulation 5 exchanges heat with the slurry output pipeline 26 of the secondary re-slurry tank through the shell-and-tube heat exchanger 3.
[0016] The carbon decomposition tank is connected to the batching tank 13 , the steam delivery pipeline 14 , the carbon dioxide delivery pipeline 19 and the gas recovery device 15 .
[0017] The batching tank 13 is connected to the soda ash delivery pipeline 16 , the cooked boron powder input pipeline 17 and the mother liquor input pipeline 27 .
[0018] The cooked boron powder input pipeline 17 is connected to the cooked boron powder output end of the calcining furnace 18; the calcining furnace 18 is connected to the wet boron powder input end 22 and the coal gas input end 23.
[0019] The principle of the utility model is:
[0020] The slurry after carbonization is subjected to secondary heat exchange with the secondary re-slurry through a heat exchanger and then enters the slurry tank. The slurry flowing out of the slurry tank is mixed with the secondary re-slurry and then enters the primary filtration process. After the primary filtration, the mixed stock liquid enters the controlled filtration process. The filter residue enters the boron mud re-slurry process. The re-slurry of the boron mud re-slurry process enters the primary re-slurry process. The re-slurry of the primary re-slurry process enters the secondary re-slurry process. The re-slurry of the secondary re-slurry process is subjected to primary heat exchange with the flue gas of the calcination desulfurization tower through a heat exchanger and then is subjected to secondary heat exchange with the slurry after carbonization through a heat exchanger and then is mixed with the slurry flowing out of the slurry tank, and the cycle is repeated.
[0021] The flue gas of the calcination desulfurization tower is 150°C after desulfurization, the secondary re-slurry is 25°C before the first heat exchange with the flue gas of the calcination desulfurization tower, and is 50°C after the first heat exchange; the slurry after carbonization is 125°C, and is 85°C after the second heat exchange with the 50°C secondary re-slurry through the heat exchanger; the secondary re-slurry is 85°C after the second heat exchange;
[0022] The filter residues from the first and second re-slurry are discharged to the boron mud tailings pond.
[0023] The first filtration process uses a polypropylene diaphragm plate frame. The moisture content of the boron sludge is reduced from 40% to 30%;
[0024] The primary heat exchange is that the flue gas from the calcination desulfurization tower exchanges heat with the first softened water closed-loop circulation through a fluoroplastic heat exchanger, and the first softened water closed-loop circulation exchanges heat with the secondary re-slurry through a shell and tube heat exchanger.
[0025] The secondary heat exchange is that the slurry after carbonization exchanges heat with the second softened water closed-loop circulation through a shell-and-tube heat exchanger, and the second softened water closed-loop circulation exchanges heat with the secondary re-slurry through a shell-and-tube heat exchanger.
[0026] The boron mud re-slurry process is to mix the boron mud at 80°C after the first filtration with the tailings pond return water at 18°C to form a re-slurry at 25°C.
[0027] The water temperature of the first closed-circuit softened water in the primary heat exchange is 80°C; the water temperature of the second closed-circuit softened water in the secondary heat exchange is 95°C.
Claims
1. A device for cascade utilization of energy and improving borax yield in boron chemical production, characterized in that: The carbonization tank is connected to the material paddle tank, the material paddle tank output pipeline is connected in parallel with the secondary re-slurry pipeline after the secondary heat exchange and then connected to the polypropylene diaphragm plate frame of the primary filtration; the filter residue output end of the polypropylene diaphragm plate frame is connected to the re-slurry tank, the filtrate output end of the polypropylene diaphragm plate frame is connected to the control filter tank, the re-slurry tank is connected to the primary re-slurry tank, and the primary re-slurry tank is connected to the secondary re-slurry tank; the filter residues of the primary re-slurry tank and the secondary re-slurry tank are all transported to the boron mud tailings; the re-slurry tank is connected to the return water pipe of the tailings pond; A secondary heat exchanger is arranged on the slurry pipe connecting the carbonization tank and the slurry tank, wherein the slurry pipe after carbonization exchanges heat with the second softened water closed-loop circulation through a shell-and-tube heat exchanger, and the second softened water closed-loop circulation exchanges heat with the secondary re-slurry pipe through a shell-and-tube heat exchanger; the slurry output pipeline of the secondary re-slurry tank before the secondary heat exchange exchanges heat with the flue gas pipeline of the calcination desulfurization tower through a primary heat exchanger; the primary heat exchanger exchanges heat with the flue gas pipeline of the calcination desulfurization tower through a fluoroplastic heat exchanger and the first softened water closed-loop circulation, and the first softened water closed-loop circulation exchanges heat with the slurry output pipeline of the secondary re-slurry tank through a shell-and-tube heat exchanger.
2. The device for cascade utilization of energy and improving borax yield in boron chemical production according to claim 1, characterized in that: The carbon decomposition tank is connected with a batching tank, a steam delivery pipeline, a carbon dioxide delivery pipeline and a gas recovery device.
3. The device for cascade utilization of energy and improving borax yield in boron chemical production according to claim 2, characterized in that: The batching tank is connected with the soda ash delivery pipeline, the cooked boron powder input pipeline and the mother liquor input pipeline.
4. The device for cascade utilization of energy and improving borax yield in boron chemical production according to claim 3, characterized in that: The cooked boron powder input pipeline is connected to the cooked boron powder output end of the calcining furnace; the calcining furnace is connected to the wet boron fine powder input end and the coal gas input end.