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Method for enhancing whiteness of waste gypsum

A technology of waste gypsum and whiteness, applied in the field of phosphorus chemical industry, can solve the problems of high cost, complicated operation and low separation efficiency.

Pending Publication Date: 2021-08-06
KUNMING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problems of low separation efficiency, low benefit of resource recycling, complicated operation and high cost in the current whitening technology of waste gypsum, the present invention proposes a harmless whitening method that can effectively improve the whiteness of waste gypsum without affecting the later performance of gypsum. The method of whitening, the method of the present invention adopts water washing instead of pickling, which can further save energy consumption, and adopts technologies such as quenching and crushing and introducing multi-physics fields in the washing process, which can effectively make the whiteness of waste gypsum ≥ 92, which is Extensive and large-area resource utilization provides certain possibilities

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Embodiment 1: The method for enhancing whiteness of this waste gypsum is as follows:

[0019] (1) Take 1kg of desulfurized gypsum and put it into an industrial rotary kiln for carbonization. The carbonization temperature is 100°C and the carbonization time is 240 minutes;

[0020] (2) After the carbonization is completed, the carbonized product is directly poured into the water washing device, the solid-liquid ratio g:mL is 1:5, and the stirring speed is 120r / min;

[0021] (3) In the washing device, adjust the magnetic field and electric field intensity by adjusting the distance between the permanent magnets and the electrodes. First, set the magnetic field intensity to 38mT for 86 minutes, then turn off the magnetic field and turn on the electric field. The electric field intensity is set to 8V / m. The water washing process was controlled by multi-physics field for 156minm, and the solid was dried at 45°C for 90min after solid-liquid separation; the whiteness of the was...

Embodiment 2

[0022] Embodiment 2: The method for enhancing the whiteness of this waste gypsum is as follows:

[0023] (1) Take 1kg of fluorogypsum and put it into an industrial rotary kiln for carbonization, the carbonization temperature is 124°C, and the carbonization time is 180min;

[0024] (2) After the carbonization is completed, pour the carbonized product directly into the water washing device, the solid-liquid ratio g:mL is 1:7.4, and the stirring speed is 100r / min;

[0025] (3) In the washing device, adjust the magnetic field and electric field strength by adjusting the distance between the permanent magnets and the electrodes. First, set the magnetic field strength to 100mT and treat it for 58 minutes. Then turn off the magnetic field and turn on the electric field switch. Set the electric field strength to 19V / m and treat it for 55 minutes. The entire multi-physics field controlled water washing process lasted 113 minutes, and the solid was dried at 65°C for 76 minutes after sol...

Embodiment 3

[0026] Embodiment 3: The method for enhancing the whiteness of this waste gypsum is as follows:

[0027] (1) Take 1kg of phosphogypsum and put it into an industrial rotary kiln for carbonization, the carbonization temperature is 140°C, and the carbonization time is 120min;

[0028] (2) After the carbonization is completed, pour the carbonized product directly into the water washing device, the solid-liquid ratio g:mL is 1:8.7, and the stirring speed is 60r / min;

[0029] (3) Adjust the magnetic field and electric field strength by adjusting the distance between the permanent magnets and the electrodes in the water washing device. First, set the magnetic field strength to 220mT for 45 minutes, then turn off the magnetic field, turn on the electric field switch, and set the electric field strength to 30V / m for 40 minutes. The entire multi-physics field controlled water washing process was 85minm, and then dried at 65°C for 76min; the whiteness of the waste gypsum obtained after t...

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Abstract

The invention discloses a method for enhancing whiteness of waste gypsum, the method comprises the following steps: carbonizing the waste gypsum at high temperature, directly putting the waste gypsum into water for shock cooling and crushing without cooling, washing for 45-95 minutes in the presence of a magnetic field under the condition of stirring, then stirring and washing for 15-75 minutes in the presence of an electric field, and carrying out solid-liquid separation and solid drying to obtain the high-whiteness waste gypsum. According to the method, the whiteness of the waste gypsum can be greater than or equal to 92, the problem that the waste gypsum is limited in some fields due to low whiteness is solved, and the additional value of the waste gypsum is further improved; according to the method, most impurities in the waste gypsum can be removed, the content of the impurities in the waste gypsum is not selective, the applicability is wide, the treatment time is short, the treatment effect is high, secondary pollutants are avoided, and resource utilization of the waste gypsum is efficiently achieved.

Description

technical field [0001] The invention belongs to the technical field of phosphorus chemical industry, and in particular relates to a method for enhancing the whiteness of waste gypsum. Background technique [0002] Phosphogypsum is a kind of solid waste produced by decomposing phosphate rock with sulfuric acid in the wet process phosphoric acid process. About 4.5-6 tons of phosphogypsum are produced for every 1 ton of phosphoric acid produced (according to the production of phosphoric acid by wet process and 100% phosphoric acid). Among them, the total amount of phosphogypsum produced by the phosphating preparation industry has accounted for 70% of the total amount of phosphogypsum, and the total amount of phosphogypsum is still increasing year by year, with a growth rate of about 15%. The phosphogypsum discharged in my country is piled up at the place of origin every year. The utilization rate of phosphogypsum is very low nationwide, which has a negative impact on the local ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F11/46
CPCC01F11/468C01P2006/80C01P2006/60
Inventor 瞿广飞刘珊吴丰辉陈帮金刘亮亮赵晨阳
Owner KUNMING UNIV OF SCI & TECH