CN1202989C - Process for concentrating diluted sulfuric acid and removing impurities - Google Patents
Process for concentrating diluted sulfuric acid and removing impurities Download PDFInfo
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- CN1202989C CN1202989C CN 02113704 CN02113704A CN1202989C CN 1202989 C CN1202989 C CN 1202989C CN 02113704 CN02113704 CN 02113704 CN 02113704 A CN02113704 A CN 02113704A CN 1202989 C CN1202989 C CN 1202989C
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- sulphuric acid
- dilute sulphuric
- concentrating
- acid
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Abstract
The present invention discloses a method of concentrating a dilute sulfuric acid and removing impurities. The present invention is characterized in that hot air and the spray atomized dilute sulfuric acid are directly put into a dry concentrating tower for countercurrent contact, heating, evaporation and concentration, and the separated and precipitated impurities in the acid are separated from the concentrated sulfuric acid after being cooled. The present invention overcomes the problems of fouling and clogging of heat exchangers caused by impurities in the dilute sulfuric acid existing in prior evaporation-concentration equipment, the spray concentrating tower of the present invention overcomes the problems of temperature resistance and acid resistance of the dilute acid, and the present invention has the advantages of low device investment, simple production process and low operation cost.
Description
Affiliated technical field:
The present invention relates to a kind of concentrating and impurity removing method of dilute sulphuric acid.
Background technology:
When using Titanium White Production By Sulfuric Acid Process, no matter adopt ilmenite concentrate as raw material, still adopting titanium slag is that the raw material production titanium dioxide all will produce a large amount of dilute sulphuric acids.Because the difference of technology isolation technique, the amount of the dilute sulphuric acid that is produced and content are also different.Often be divided into two kinds: i.e. hydrolysis separates the filtrate behind the metatitanic acid, and its sulfuric acid content is at 17-25%; With filtering filter cake washing lotion, its sulfuric acid content is at 1-5%.The value that utilization is arranged after the former reclaims, can return in the production with or in other products productions; And the latter is too low because of concentration, and recovery value is little, uses in the lime usually
| Component | Content (%) | Component | Content (%) |
| Proportion | 1.32(g/cm 3) | H 2SO 4 | 22.26 |
| Fe 2O 3 | 5.03 | Al 2O 3 | 0.2 |
| MgO | 0.40 | TiO 2 | 0.68 |
| V | 0.03 | Cr | 0.006 |
| Nb | 0.004 | Pb | 0.015 |
| P | 0.005 | CaO | 0.43 |
Dispose with post precipitation.Concentrated dilute sulphuric acid of the present invention belongs to the former, and its typical component is as follows:
Because, except that sulfuric acid, also contain other a large amount of impurity, in this acid as the Fe of ferrous sulfate form
2O
3, the metatitanic acid form TiO
2, and sal epsom, Tai-Ace S 150, calcium sulfate etc.Production utilization to evaporation concentration brings bigger difficulty, effluxes also simultaneously to work the mischief to environmental protection.Now utilize method for processing and deficiency to be usually: A, vacuum-evaporation concentrate reclaims diluted acid.Its problem is to imitate at the initial stage of evaporation or the end of multiple-effect evaporation, because of very fast precipitation foulings of impurity compound such as the ferrous sulfate that contains in the spent acid, titanium oxide, calcium sulfate, graphite heat exchanger is stopped up, and needs mechanical cleaning, interchanger can be damaged accidentally; It is also undesired to produce, and the installation cost investment is expensive.B, in order to solve interchanger blocking problem in the vacuum-evaporation concentration method, the inventive method of patent CN1042527A prospectus adopts two-stage to concentrate three times to separate the impurity that removes in the disacidify.The first step adopt titanium dioxide calcining kiln tail gas with the dilute sulphuric acid pre-concentration of 20-24% to 26-29%, be separated in for the first time the residue that this separates out, the filtrate that separation is obtained cools to separate out iron vitriol again, carry out secondary separation, isolate solid formation one iron vitriol, obtain containing the dilute sulphuric acid of 30-35%; The 30-35% dilute sulphuric acid that contains that will obtain again then, carries out the sulfuric acid concentration that the second stage is concentrated into 60-71% with the vacuum-evaporation concentration method; At last, the postprecipitation thing in the acid is separated for the third time, obtain the sulfuric acid about 70%.This processing unit is many, technical process is long; It is energy-conservation that the surface seems, concentrates three times through two-stage and separate tediously long flow process, and it is not to have reduced but significantly increase that facility investment and direct evaporation concentrate expense, and operation is many, process cost is also many.C, document (phosphate fertilizer and the multiple fertile third phase in 2000, total the 15 volume) exercise question is " titanium white waste acid is used to produce the research of normal superphosphate " literary composition, and the author directly is mixed into 20% the titanium white production dilute sulphuric acid and 92% the vitriol oil sulfuric acid of 60% left and right sides concentration; Separate impurity compounds such as removing de-iron, titanium then, be directly used in the production normal superphosphate.Although advantages such as work simplification, facility investment are few are arranged, the moisture in 20% the dilute sulphuric acid is taken away by the normal superphosphate product, and supporting with it Production of Single Superphosphate ability must be 20-30 times of the titanium white production ability; With the industrial scale coupling calcium superphosphate of sulfuric acid method titanium pigment, an utterly inadequate amount is difficult to satisfy.And calcium superphosphate is to be worth lower lower concentration phosphate fertilizer, is subjected to transportation radius and restricts with fertile radius, can not obtain preferable economic benefit.Moreover, since dilute sulphuric acid bring excess moisture, produce calcium superphosphate and must adopt the dry method flow process, promptly dry phosphorus ore, dry grinding phosphorus ore etc., increased investment, energy consumption and the operation productive expense of the processing units of calcium superphosphate.Also have, 92% sulfuric acid is joined rare after-filtration, the removal of impurities filter plant doubles, and has also strengthened the load of separating impurity.
Summary of the invention:
The production method that concentrates and remove impurity that the purpose of this invention is to provide a kind of dilute sulphuric acid.This production method has shortened technical process, owing to do not use heat exchanger, thus solved interchanger precipitation fouling blocking problem; Owing to simplified technical process, only once separated and separate out in the acid and sedimentary impurity; And adopt corrosion resistant, temperature-resistant material at a low price, and reduced the investment of concentrated dilute sulphuric acid device, also reduced the process operation cost simultaneously.
The object of the present invention is achieved like this:
Production principle of the present invention is as follows: dilute sulphuric acid and elevated temperature heat gas counter current contact in spraying concentration tower is carried out flash evapn and is concentrated, and the impurity compound that contains in acid precipitates with the rising of temperature and acid concentration separates out.Its principle is as follows:
Concrete technology of the present invention is: dilute sulphuric acid is carried out atomisation from the spraying concentration tower cat head, carry out finishing evaporating concentration process after the counter current contacting heating with the warm air that enters at the bottom of the tower in spraying concentration tower; The steam of concentration and evaporation is got rid of from cat head, through the laggard exhaust fan of mist eliminator demist, gets rid of into atmosphere from chimney.Contain the sulfuric acid liquid of separating out precipitated impurities after concentrating and get rid of at the bottom of spraying concentration tower, through supercooler heat exchange cooling, the entrance pressure filter carries out solid-liquid separation again, and filtrate is concentrated vitriol, can return titanium white production or be used for phosphorous chemical industry production and other production; Filter cake washs with dilute sulphuric acid, and washing acid returns the evaporation concentration operation, and filter cake is used to produce ferrous salt or send sulfuric acid plant to produce sulfuric acid.Therefore, the invention is characterized in that this method comprises:
A, dilute sulphuric acid is carried out atomisation in spraying concentration tower;
B, atomizing dilute sulphuric acid carry out the counter current contact heat exchange with hot gas in spraying concentration tower, and rapid evaporation concentration;
C, dilute sulphuric acid feed liquid are in concentration process, and the impurity compound precipitation that is contained in is wherein separated out, and gets rid of at the bottom of the spraying concentration tower tower with concentrated feed liquid;
D, concentrated feed liquid are cooled off;
E, cooling feed liquid body carry out solid-liquid separation, and filtrate is concentrated vitriol;
F, filter cake wash with the dilute sulphuric acid before concentrating, and washing acid returns atomisation and concentrates;
G, washing leaching cake send ferrous salt production or send sulfuric acid plant to produce sulfuric acid.
The spray atomization of dilute sulphuric acid of the present invention is to take pressure atomization or centrifugal atomizing.
The warm air that the present invention contacts with dilute sulphuric acid comprises coal-fired cleaning of off-gas, boiler high temperature tail gas, Sweet natural gas and oil inflame warm air.
Spraying concentration tower of the present invention adopts liner heatproof, acid-proof ceramic tile, and the potash water glass clay is bonding, the hot gas direct heating.
The hot blast inlet temperature is 300-700 ℃ at the bottom of the spraying concentration tower tower of the present invention, and optimum temps is 450-600 ℃.
Spraying concentration tower tower top outlet temperature of the present invention is 70-150 ℃, and optimum temps is 80-120 ℃.
Concentrated vitriol of the present invention before carrying out solid-liquid separation promptly the cooling temperature before the entrance pressure filter be 40-90 ℃.
Filter cake after solid-liquid separation of the present invention is filtered washs with the dilute sulphuric acid before concentrating.
The part of concentrated vitriol of the present invention is mixed with dilute sulphuric acid before carrying out solid-liquid separation and is returned spraying concentration tower and concentrate.
The solid-liquid separation of impurity is taked vacuum filtration or pressure filter press filtration in the concentrated vitriol of the present invention.
Washings of the present invention returns the spraying enrichment process, and washing leaching cake washs with dilute sulphuric acid, and the dilute sulphuric acid after the washing returns the spraying concentration tower spraying.Washing leaching cake is used for other product processing, as send sulfuric acid process plants sulfuric acid or send ferrous saltworks to produce molysite.
The invention solves the material of dilute sulphuric acid equipment under concentration and evaporation high temperature, high etching condition, type of heating has been avoided the equipment scaling difficult problem of indirect heating.Described spraying concentration tower and material contact part are selected the heatproof acid resisting brick for use; the potash water glass clay is as caking agent; for preventing directly to contact the destruction that causes with overfire air at high-temperature zone heatproof, acid resisting brick; increase the acidproof mixed earth of one deck potash water glass in the high-temperature zone; prevent that warm air from directly contacting with ceramic tile, plays protection tile.
The present invention is because the employing dilute sulphuric acid is directly sprayed and the warm air Contact Heating concentrates, and the vacuum-evaporation that has replaced with expensive graphite heat exchanger indirect heating concentrates, and has reduced plant investment; Once heat flash liberation, shortened Production Flow Chart, simplified technology, significantly reduced the recovery production cost of dilute sulphuric acid.
Accompanying drawing and drawing explanation thereof:
Fig. 1 is a process flow sheet of the present invention
Among the figure: 1, spraying concentration tower 2, hotblast stove 3, gelled acid pump groove 4, water cooler
5, press filtration pump 6, pressure filter 7, gelled acid storage tank 8, scum dredger 9, blower fan
10, mist eliminator 11, chimney
Embodiment
Embodiment one:
With combustion of natural gas tail gas is thermal source, the simulation spraying concentration tower in per hour charging dilute sulphuric acid 133Kg (it mainly consists of: H
2SO
422.26%, FeSO
47H
2O 20.8%, MnSO
41.1%, MgSO
41.2%, CaSO
4H
2O 1.2%, TiO
20.45%), 560 ℃ of tower inlet temperatures, 103 ℃ of temperature outs, evaporated water 63Kg per hour, (it mainly consists of: H per hour to obtain 70Kg concentrated vitriol slip at the bottom of the tower
2SO
442.29%, FeSO
4H
2O24.11%, MnSO
42.09%, MgSO
42.28%, CaSO
42.01%, TiO
20.85%); , spissated sulfuric acid slip be cooled to temperature 65 ℃, carry out isolated by vacuum filtration and per hour obtain wet cake 33.83Kg, filtrate 36Kg (H thereafter
2SO
459.21%, Fe
2O
30.30%, MgO 0.71%, Al
2O
30.43%, TiO
20.06%).
Embodiment two:
By embodiment one spray concentrated, separate, after suction filtration, per hour the 33.83Kg wet cake carries out gradation with 22.26% dilute sulphuric acid 30Kg and washs, and obtains 27.06Kg wet cake (H
2SO
46.50%, H
2O 18.5%) and contain the diafiltration liquid 36.77Kg of sulfuric acid 35.40%, this washing lotion returns spraying concentration tower and dilute sulphuric acid merges as concentrating charging.
Embodiment three:
With coal-fired high-temperature gas, be φ 6 * 22m in specification, volume is 600m
3Spraying concentration tower in per hour charging dilute sulphuric acid 16.41t (it consists of: H
2SO
423.16%; FeSO
47H
2O 17.6%; MnSO
41.1%; MgSO
41.3%; CaSO
4H
2O 1.2%; TiO
20.5%) counter current contacting heating of spraying concentrates; 600 ℃ of hot blast inlet temperature of stabilizer, 95 ℃ of tower exit temperatures, evaporated water 9.0t per hour, (it consists of: H to obtain concentrating dilute sulphuric acid 7.4t
2SO
451.3%; FeSO
4H
2O 23.8%; MnSO
42.44%; MgSO
42.88%; CaSO
42.35%; TiO
21.11%).
Embodiment four:
It is concentrated to spray by embodiment three, and the concentrated dilute sulphuric acid that comes out at the bottom of the spraying concentration tower enters pressure filter and carries out solid-liquid separation through being cooled to 65 ℃; (it consists of: H per hour to obtain 4.02t separation concentrated vitriol
2SO
470.7%, Fe
2O
30.30%, MgO 0.71%, Al
2O
30.43%, TiO
20.06%) and 3.38t wet cake (liquid holdup 35%).
Embodiment five:
Press the wet cake of embodiment four after pressure filter separates, (it consists of: H per hour to use the 3.5t dilute sulphuric acid again
2SO
423.16%; FeSO
47H
2O 17.6%; MnSO
41.1%; MgSO
41.3%; CaSO
4H
2O 1.2%; TiO
20.5%) washs; Obtain washing dilute sulphuric acid 3.87t (its H
2SO
4Content is: 37.13%), this acid is returned embodiment three and is sprayed concentrated with the merging of raw material dilute sulphuric acid; Per hour obtaining simultaneously 3.01t filter cake (liquid holdup 31%) is used for vitriol works's processing sulfuric acid or send ferrous salt production to handle.
Claims (11)
1, a kind of concentrating and impurity removing production method of dilute sulphuric acid is characterized in that this method comprises:
A, dilute sulphuric acid is carried out spray atomization in spraying concentration tower;
B, atomizing dilute sulphuric acid carry out the counter current contact heat exchange with hot gas in spraying concentration tower, and rapid evaporation concentration;
C, dilute sulphuric acid feed liquid are in concentration process, and the impurity compound precipitation that is contained in is wherein separated out, and gets rid of at the bottom of tower with concentrated feed liquid;
D, concentrated feed liquid are cooled off;
E, cooling feed liquid are carried out solid-liquid separation, and filtrate is concentrated vitriol;
F, filter cake wash with the dilute sulphuric acid before concentrating, and washing acid returns atomisation and concentrates;
G, washing leaching cake send ferrous salt production or send sulfuric acid plant to produce sulfuric acid.
2, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: the spray atomization of dilute sulphuric acid is to take pressure atomization or centrifugal atomizing.
3, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: the warm air that contacts with dilute sulphuric acid comprises coal-fired cleaning of off-gas, boiler high temperature tail gas, Sweet natural gas and oil inflame warm air.
4, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: spraying concentration tower adopts liner heatproof, acid-proof ceramic tile, and the potash water glass clay is bonding, the hot gas direct heating.
5, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: the hot blast inlet temperature is 300-700 ℃ at the bottom of the spraying concentration tower tower.
6, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: spraying concentration tower tower top outlet temperature is 70-150 ℃.
7, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: concentrated vitriol before carrying out solid-liquid separation promptly the cooling temperature before the entrance pressure filter be 40-90 ℃.
8, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: the filter cake after solid-liquid separation is filtered washs with the dilute sulphuric acid before concentrating.
9, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: the part of concentrated vitriol is mixed with dilute sulphuric acid before carrying out solid-liquid separation and is returned the spraying concentration tower spraying and concentrate.
10, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: the solid-liquid separation of impurity is taked vacuum filtration or pressure filter press filtration in the concentrated vitriol.
11, according to the concentrating and impurity removing production method of the described a kind of dilute sulphuric acid of claim 1, it is characterized in that: washings returns the spraying enrichment process, and washing leaching cake washs with dilute sulphuric acid, and the dilute sulphuric acid after the washing returns the spraying concentration tower spraying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02113704 CN1202989C (en) | 2002-05-09 | 2002-05-09 | Process for concentrating diluted sulfuric acid and removing impurities |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02113704 CN1202989C (en) | 2002-05-09 | 2002-05-09 | Process for concentrating diluted sulfuric acid and removing impurities |
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|---|---|
| CN1376633A CN1376633A (en) | 2002-10-30 |
| CN1202989C true CN1202989C (en) | 2005-05-25 |
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ID=4742765
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|---|---|---|---|
| CN 02113704 Expired - Fee Related CN1202989C (en) | 2002-05-09 | 2002-05-09 | Process for concentrating diluted sulfuric acid and removing impurities |
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|---|---|
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2020150909A1 (en) | 2019-01-22 | 2020-07-30 | 成都千砺金科技创新有限公司 | Method for producing self-fitting nano-catalyst sewage treatment agent |
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| CN100581994C (en) * | 2008-01-09 | 2010-01-20 | 龚家竹 | Concentrating and impurity removing method for dilute sulfuric acid in titanium dioxide powder production process by employing sulfuric acid process |
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| CN110240164A (en) * | 2019-06-26 | 2019-09-17 | 威海恒邦化工有限公司 | The method and device of fluosilicic acid concentration |
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| CN111888831A (en) * | 2020-06-24 | 2020-11-06 | 刘发业 | Waste sulfuric acid recovery processing device and application thereof |
| CN113277480A (en) * | 2021-06-08 | 2021-08-20 | 安徽金星钛白（集团）有限公司 | Titanium dioxide waste acid treatment method |
| CN114632338B (en) * | 2022-03-28 | 2024-01-19 | 河北惠尔信新材料股份有限公司 | Titanium white water washing mother liquor concentration processing system |
-
2002
- 2002-05-09 CN CN 02113704 patent/CN1202989C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020150909A1 (en) | 2019-01-22 | 2020-07-30 | 成都千砺金科技创新有限公司 | Method for producing self-fitting nano-catalyst sewage treatment agent |
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|---|---|
| CN1376633A (en) | 2002-10-30 |
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