Method for concentrating titanium dioxide waste acid by adopting reverse osmosis process

Abstract

The invention relates to a method for concentrating titanium dioxide waste acid by adopting a reverse osmosis process. The method comprises the following steps: pressing titanium dioxide waste acid with acid concentration of about 20% in a filter to remove micro-grained suspended matters, pressurizing through a high-pressure pump, enabling a small part of titanium dioxide waste acid to penetrate through a reverse osmosis membrane through a reverse osmosis device to prepare clean fresh water, and feeding the clean fresh water to a clean fresh water storage tank for later use; reserving sulfate radicals and other impurities for a large part of titanium dioxide waste acid, feeding into a cooling crystallizing groove, stirring, fully separating out and settling the impurities, conveying concentrated waste acid into a pressure filter, and putting concentrated waste acid subjected to impurity removal into a circulating groove for reverse osmosis treatment; when the acid concentration is more than 40%, feeding titanium dioxide waste acid to a sulfuric acid production device, mixing with concentrated acid for increasing the concentration, and removing the impurities to prepare 98% concentrated sulfuric acid. According to the method, titanium dioxide waste acid is effectively concentrated until 98% concentrated sulfuric acid is prepared, so that the difficult problem of recycling of titanium dioxide waste acid is solved; and the method has the advantages of being low in process energy consumption, simple, effective, stable to perform, remarkable in economic and environmental benefits and the like.

Description

technical field

[0001] The invention relates to a method for concentrating titanium white waste acid by reverse osmosis. Background technique

[0002] Since the production of titanium dioxide by sulfuric acid method, the most difficult problem in environmental protection is the effective reuse of waste acid, because waste acid with an acid concentration of about 20% accounts for 70% of the treated waste. Calculated according to the F value of 1.9 in the production hydrolyzate, that is, 1 ton of titanium dioxide corresponds to 1.9 tons of sulfuric acid, about 70% of which enters the hydrolysis filtrate, that is, 100% of 1.33 tons of sulfuric acid, and the ferrous sulfate brought by the ratio of iron to titanium , the total adds up to nearly 1.7 tons of sulfate radicals, and the remaining 30% enters the dilute waste acid with washing water. Concentration and impurity removal treatment of waste acid for reuse or reuse has always been a serious problem that lingers and cannot b...

Examples

Embodiment 1

[0020] Use the corrosion-resistant dilute acid pump 1 to press the titanium white waste acid with an acid concentration of about 20% into the coarse filter 2 and the fine filter 3. After removing the suspended particles, pressurize through the corrosion-resistant high-pressure pump 4, and pass through reverse osmosis. Device 5, wherein a small part passes through the reverse osmosis membrane to make clean fresh water, walks the clean water side, and directly sends clean fresh water storage tank 6 for storage; most of them retain sulfate radicals and other impurities, so the concentration of sulfuric acid increases, Go to the concentrated water side, directly send the waste titanium white acid with an acid concentration of 30% to the cooling crystallization tank 7, and stir slightly at the same time to fully separate out and precipitate impurities, and then use the corrosion-resistant concentrated acid pump 8 to pump the concentrated waste The acid is poured into the filter pres...

Embodiment 2

[0022] Use the corrosion-resistant dilute acid pump 1 to press the titanium white waste acid with an acid concentration of about 20% into the coarse filter 2 and the fine filter 3. After removing the suspended particles, pressurize through the corrosion-resistant high-pressure pump 4, and pass through reverse osmosis. Device 5, wherein a small part passes through the reverse osmosis membrane to make clean fresh water, walks the clean water side, and directly sends clean fresh water storage tank 6 for storage; most of them retain sulfate radicals and other impurities, so the concentration of sulfuric acid increases, Go to the concentrated water side, send the waste titanium white acid with an acid concentration of 40% directly to the cooling crystallization tank 7, and stir slightly at the same time to fully separate out and precipitate impurities, and then use the corrosion-resistant concentrated acid pump 8 to pump the concentrated waste The acid is poured into the filter pres...

technical field

[0001] The invention relates to a method for concentrating titanium white waste acid by reverse osmosis. Background technique

[0002] Since the production of titanium dioxide by sulfuric acid method, the most difficult problem in environmental protection is the effective reuse of waste acid, because waste acid with an acid concentration of about 20% accounts for 70% of the treated waste. Calculated according to the F value of 1.9 in the production hydrolyzate, that is, 1 ton of titanium dioxide corresponds to 1.9 tons of sulfuric acid, about 70% of which enters the hydrolysis filtrate, that is, 100% of 1.33 tons of sulfuric acid, and the ferrous sulfate brought by the ratio of iron to titanium , the total adds up to nearly 1.7 tons of sulfate radicals, and the remaining 30% enters the dilute waste acid with washing water. Concentration and impurity removal treatment of waste acid for reuse or reuse has always been a serious problem that lingers and cannot b...

Examples

Embodiment 1

[0020] Use the corrosion-resistant dilute acid pump 1 to press the titanium white waste acid with an acid concentration of about 20% into the coarse filter 2 and the fine filter 3. After removing the suspended particles, pressurize through the corrosion-resistant high-pressure pump 4, and pass through reverse osmosis. Device 5, wherein a small part passes through the reverse osmosis membrane to make clean fresh water, walks the clean water side, and directly sends clean fresh water storage tank 6 for storage; most of them retain sulfate radicals and other impurities, so the concentration of sulfuric acid increases, Go to the concentrated water side, directly send the waste titanium white acid with an acid concentration of 30% to the cooling crystallization tank 7, and stir slightly at the same time to fully separate out and precipitate impurities, and then use the corrosion-resistant concentrated acid pump 8 to pump the concentrated waste The acid is poured into the filter pres...

Embodiment 2

[0022] Use the corrosion-resistant dilute acid pump 1 to press the titanium white waste acid with an acid concentration of about 20% into the coarse filter 2 and the fine filter 3. After removing the suspended particles, pressurize through the corrosion-resistant high-pressure pump 4, and pass through reverse osmosis. Device 5, wherein a small part passes through the reverse osmosis membrane to make clean fresh water, walks the clean water side, and directly sends clean fresh water storage tank 6 for storage; most of them retain sulfate radicals and other impurities, so the concentration of sulfuric acid increases, Go to the concentrated water side, send the waste titanium white acid with an acid concentration of 40% directly to the cooling crystallization tank 7, and stir slightly at the same time to fully separate out and precipitate impurities, and then use the corrosion-resistant concentrated acid pump 8 to pump the concentrated waste The acid is poured into the filter pres...

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