CN-122010060-A - Sulfuric acid decoloring method

Abstract

The invention provides a sulfuric acid decoloring method, and belongs to the technical field of chemical separation and purification. In the sulfuric acid decoloring method, a colored sulfuric acid stock solution with the mass concentration of more than or equal to 80% is heated to a preheating temperature according to a preset heating speed or according to a preset heating speed and a preset stirring speed, the reaction is carried out at a constant temperature, then the sulfuric acid stock solution is sealed and kept stand, and solid-liquid separation is carried out, so that colorless and transparent sulfuric acid is obtained. The method changes the microenvironment atmosphere of the chromogenic chemical substances in the sulfuric acid stock solution by heating or heating and stirring, converts the microenvironment atmosphere into a precipitation mode to be separated out, finally obtains colorless transparent sulfuric acid, improves the quality of the sulfuric acid, improves the market application and the economic value, and simultaneously, has no other additionally added chemical reagents in the treatment process, obviously reduces the purchasing, storing and adding costs of raw materials, has better economy, simplifies the operation flow, reduces the requirements on professional skills of personnel and the manual intervention intensity, and realizes the simplicity of operation and the wide adaptability of process conditions.

Inventors

• LI CHUANLONG
• TAN TAO
• HUANG QIAO
• LONG SUAN
• GONG BO
• WANG TIANXIONG
• XU WEI
• ZHANG QI

Assignees

• 四川省达州钢铁集团有限责任公司

Dates

Publication Date

20260512

Application Date

20260106

Claims (8)

1. 1. A sulfuric acid decoloring method is characterized in that a sulfuric acid stock solution with a mass concentration of more than or equal to 80% and a color is heated to a preheating temperature according to a preset heating speed, the sulfuric acid stock solution is subjected to heat preservation reaction, then is subjected to sealing and standing, and solid-liquid separation is carried out, so that colorless and transparent sulfuric acid is obtained.
2. 2. The sulfuric acid decoloring method according to claim 1, wherein the preset heating rate is 2 ℃ per minute to 10 ℃ per minute; and/or the preset temperature is 30-120 ℃; And/or the reaction time of heat preservation is 5 min-5 h; And/or sealing and standing for 1-72 h; and/or the heating mode is water bath heating, oil bath heating, forced air drying box heating, vacuum drying box heating, steam heat exchange or microwave heating; And/or the solid-liquid separation mode is standing sedimentation, centrifugation or filtration.
3. 3. The sulfuric acid decoloring method according to claim 1 or 2, wherein the preset heating rate is 5 ℃ per minute to 7 ℃ per minute; And/or the preset temperature is 50-90 ℃; And/or the heat preservation reaction time is 10 min-3 h; And/or sealing and standing for 12-24 hours; and/or the heating mode is oil bath heating or forced air drying box heating; and/or the solid-liquid separation mode is standing sedimentation.
4. 4. The method for decoloring sulfuric acid according to claim 1, wherein the color of the sulfuric acid stock solution is iron-based color change.
5. 5. A sulfuric acid decoloring method is characterized in that sulfuric acid stock solution with color and mass concentration more than or equal to 80% is stirred and synchronously heated to a preheating temperature according to a preset heating speed and a preset stirring speed, the reaction is kept at a constant temperature, then sealing and standing are carried out, and solid-liquid separation is carried out, so that colorless and transparent sulfuric acid is obtained.
6. 6. The sulfuric acid decoloring method according to claim 5, wherein the preset heating rate is 2 ℃ per minute to 10 ℃ per minute; And/or, presetting the stirring speed to be 1-1200 rpm; and/or the preset temperature is 30-120 ℃; And/or the reaction time of heat preservation is 5 min-5 h; And/or sealing and standing for 1-72 h; and/or the heating mode is water bath heating, oil bath heating, steam heat exchange or microwave heating; And/or the solid-liquid separation mode is standing sedimentation, centrifugation or filtration.
7. 7. The sulfuric acid decoloring method according to claim 5, wherein the preset heating rate is 5 ℃ per minute to 7 ℃ per minute; and/or, presetting the stirring speed to be 1 rpm-800 rpm; And/or the preset temperature is 50-90 ℃; And/or the heat preservation reaction time is 10 min-3 h; And/or sealing and standing for 12-24 hours; and/or the heating mode is oil bath heating; and/or the solid-liquid separation mode is standing sedimentation.
8. 8. The method for decoloring sulfuric acid according to claim 5, wherein the color of the sulfuric acid stock solution is iron color.

Description

Sulfuric acid decoloring method Technical Field The invention relates to the technical field of chemical separation and purification, in particular to a sulfuric acid decoloring method. Background The coke oven gas has complex components, contains water vapor, tar gas, ammonia, benzene hydrocarbon, hydrogen sulfide, other sulfide and other impurities besides the target clean coke oven gas, and can obtain qualified products by sequentially carrying out multiple purification procedures such as gas cooling, naphthalene removal, tar removal, desulfurization, deamination, debenzolization, pressurizing and conveying and the like. Notably, sulfuric acid is a high-added-value chemical byproduct recovered in the coke oven gas purification process, and has important economic value. However, the sulfuric acid is contacted with carbon steel equipment (such as a storage tank, a pipeline, a valve and the like) in the conveying, storing or transporting links in the production process, the liquid can gradually appear purple or purple red, the abnormal color change phenomenon can directly lead to the quality degradation of the sulfuric acid product, the market application and the economic value of the sulfuric acid are seriously influenced, and the sulfuric acid becomes a key pain point of coking enterprises in the recycling of byproducts. Disclosure of Invention The invention provides a sulfuric acid decoloring method for solving the problems of low market application and economic value of sulfuric acid with color, which changes the microenvironment atmosphere of chromogenic chemical substances in sulfuric acid stock solution by heating or heating and stirring, so that the chromogenic chemical substances are converted into precipitation, colorless transparent sulfuric acid is finally obtained, the quality of sulfuric acid is improved, the market application and economic value are improved, and meanwhile, no other additional chemical reagent is added in the treatment process, so that the raw material purchasing, storing and adding cost is obviously reduced, the economy is better, the operation flow is simplified, the requirements on professional skills of personnel and the manual intervention intensity are reduced, and the simplicity of operation and the wide adaptability of technological conditions are realized. The technical scheme adopted by the invention is as follows: The sulfuric acid decoloring method includes heating sulfuric acid stock solution with color and mass concentration not less than 80% to preheating temperature, maintaining the temperature for reaction, sealing and letting stand, and solid-liquid separation to obtain colorless transparent sulfuric acid. According to the technical scheme, the method is designed aiming at colored sulfuric acid stock solution with mass concentration of more than or equal to 80%, the decoloring requirement of a core application scene is met, the efficient separation of colored impurities and sulfuric acid is realized through a standardized flow of heating-heat-preserving reaction-sealing standing-solid-liquid separation, colorless transparent sulfuric acid is finally obtained, the quality degradation problem of sulfuric acid caused by color change is thoroughly improved, the market application value and the economic value of sulfuric acid are restored, the decoloring is realized only through a physical and chemical effect in a treatment flow without complex chemical reagent addition, the sulfuric acid is prevented from being polluted by introducing new impurities, the product purity is ensured, the quality requirement of high-added-value chemical byproducts is met, the operation steps are simple and easy to understand, special custom equipment is not needed, quick landing application of coking enterprises and the like is facilitated, and the technical popularization threshold is reduced. Further, the preset heating speed is 2-10 ℃ per minute; and/or the preset temperature is 30-120 ℃; And/or the reaction time of heat preservation is 5 min-5 h; And/or sealing and standing for 1-72 h; and/or the heating mode is water bath heating, oil bath heating, forced air drying box heating, vacuum drying box heating, steam heat exchange or microwave heating; And/or the solid-liquid separation mode is standing sedimentation, centrifugation or filtration. According to the further optimized technical scheme, the preset heating speed is limited to 2-10 ℃ per minute, heating efficiency is guaranteed, uneven local reaction of sulfuric acid, incomplete impurity separation, balanced decolorizing effect and operation efficiency caused by too fast heating are avoided, the preset temperature is covered in a wide range of 30-120 ℃, colored sulfuric acid treatment requirements of different pollution degrees can be flexibly adjusted according to the color depth and impurity content of sulfuric acid stock solution, multi-element selection is provided for heat preservation reaction time (5 min-5 h) and se