CN101323452A - Method for preparing precipitated silica with boron sludge - Google Patents

Method for preparing precipitated silica with boron sludge Download PDF

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Publication number
CN101323452A
CN101323452A CNA2007101107631A CN200710110763A CN101323452A CN 101323452 A CN101323452 A CN 101323452A CN A2007101107631 A CNA2007101107631 A CN A2007101107631A CN 200710110763 A CN200710110763 A CN 200710110763A CN 101323452 A CN101323452 A CN 101323452A
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boron
sludge
precipitated silica
acid
silica
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肖莹
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Abstract

The invention discloses a method for preparing precipitated silicon dioxide by using boron slurry sludge; acid pickling boron slurry sludge is used for preparing the food-grade magnesium carbonate and obtaining secondary sludge; alkaline liquor is added into the secondary sludge and acid treatment is carried out to obtain silicic acid sol; finally, sodium silicate solution is added to precipitate silicon dioxide sediment. The invention leads the conversion rate of the magnesium in the boron slurry to be more than or equal to 87 percent and the yield of the silicon dioxide to be 76 percent to 77 percent. The method solves the comprehensive utilization problem of the silicon dioxide, which is not solved by the existing boron slurry comprehensive utilization technology, thus not only improving the comprehensive utilization rate of resources, but also solving the bad influence of the secondary boron slurry to environment fundamentally.

Description

The method for preparing precipitated silica with boron sludge
Technical field
The present invention relates to the comprehensive utilization of chemical industry refuse, specifically, is the comprehensive utilization of the waste boron sludge in the borax preparation.
Background technology
Over founding the state surplus in the of 50 year, China's Borate industry development rapidly, the waste of production process discharging---boron sludge surpasses 1,600 ten thousand tons at the historical accumulation volume in its Liaoning, main place of production, and at present still with annual speed increment more than 1,000,000 tons.Boron mud major ingredient is: MgO, SiO 2Reach Fe, Ca, compositions such as Al, B.Its aqueous solution is alkalescence, pH value 8-9.It accumulates in a large number local environment has been caused severe contamination.
Contain higher MgO, SiO in the boron mud 2, Yingkou boron mud wet basis actual measurement content is respectively 33% and 24.6%, can be used for extracting various magnesium, silicon compound.The comprehensive utilization technique of having reported at present has phase transfer method, and carborization processing boric sludge is equipped with magnesium oxide technology and acid hydrolyzation processing boric sludge is equipped with flame-proof magnesium hydroxide technology.These three kinds of technologies are summarized as follows respectively:
Phase transfer method:,, make magnesiumcarbonate be converted into magnesium hydroxide with the reaction of the magnesiumcarbonate in milk of lime and the boron mud leaving of catalyzer.In carbonating tower, make purification kiln gas (CO then from the limestone kiln 2) react with magnesium hydroxide, make magnesium hydroxide be converted into the bigger Magnesium hydrogen carbonate of solubleness, obtain heavy magnesium water through solid-liquid separation again, the heavy magnesium water pyrolysis is generated the basic carbonate magnesium precipitate.Throw out washing, dehydration, drying, calcining, pulverizing are obtained magnesium oxide product.
The deficiency that this technology exists is: magnesium oxide is actually with Stan-Mag Magnesium Carbonate, and the form of Magnesium Silicate q-agent is present in the boron mud.With calcium hydroxide is that transforming agent makes it be converted into magnesium hydroxide, and transformation efficiency is 47%, and transformation efficiency is lower.Though saved boron mud calcination process, magnesium utilization efficiency is not high.Simultaneously, fire at lime, carbonization, pyrogenic processes will consume a large amount of energy.System's production cost is not low.Production process has a large amount of alkaline scrap material (major ingredient is an active silica) to produce in addition, can cause secondary pollution to environment, can not utilize the silicon resource in the boron mud.Exist long flow path in addition, complex procedures, the big deficiency that waits of facility investment.
Carborization: boron mud calcining, digestion are made and are contained the magnesium hydroxide slurry, in carbonating tower with purification kiln gas (CO from the limestone kiln 2) reaction, make magnesium hydroxide be converted into the bigger Magnesium hydrogen carbonate of solubleness, obtain heavy magnesium water through solid-liquid separation again, the heavy magnesium water pyrolysis is generated the basic carbonate magnesium precipitate.Throw out washing, dehydration, drying, calcining, pulverizing are obtained magnesium oxide product.
The deficiency that this technology exists: identical with phase transfer method, consume a large amount of energy, long flow path, complex procedures, facility investment is big.
Acid hydrolyzation: boron mud is dropped in the acidolysis groove, and with certain density sulfuric acid reaction, magnesium oxide wherein is converted into sal epsom and enters liquid phase, and the calcium sulfate of silicon-dioxide and generation does not enter liquid phase, removes after filtration with other insoluble sludge.Filtering institute's obtain filtrate major ingredient is sal epsom, with the ammoniacal liquor reaction, generates magnesium hydrate precipitate after purifying, filtering.Throw out makes the magnesium hydroxide products of different stage through rinsing, surface treatment, dehydration, drying, pulverizing.
The deficiency that this technology exists: boron mud treating processes need consume a large amount of sulfuric acid, and rate of decomposition is low, and production cost is higher.The acid waste residue that production process produces can cause secondary pollution to environment.Silicon is failed to utilize.
Summary of the invention
The present invention has overcome above-mentioned shortcoming, has proposed a kind of method for preparing precipitated silica with boron sludge.
The present invention solves the technical scheme that its technical problem takes:
A kind ofly prepare the method for precipitated silica with boron sludge, first acidleach boron sludge prepares food grade magnesiumcarbonate, and obtains secondary residue; Then secondary residue is successively added alkali lye and acid treatment obtains silicic acid sol, add sodium silicate solution at last and separate out precipitation of silica.
Described alkali lye is NaOH solution preferably, and described acid is hydrochloric acid or sulfuric acid preferably.
When described acidleach boron sludge prepares food grade magnesiumcarbonate,, add the hydrofluoric acid of 2% weight ratio, as activator in the gross weight of boron sludge.
After obtaining secondary residue, the secondary residue water rinse with producing after filtration with the NaOH solution reaction, makes SiO wherein then 2Be converted into water glass; Be that 1.040～1.070 hydrochloric acid under agitation condition is 1.160 sodium silicate solution reaction with relative density with relative density, treat that the dioxide-containing silica in the solution is 6.5-8.5%, when pH value is stabilized in 4.5 left and right sides, promptly get silicic acid sol; Under the condition that has sodium-chlor pH regulator liquid to exist, be that 1.074 sodium silicate solution reacts then, separate out precipitation of silica, make finished product through ageing, rinsing, solid-liquid separation, drying, pulverizing and screening then with silicic acid sol and relative density.
During preparation food grade magnesiumcarbonate, adopt following purification process: after oxidizer, adding assistant is transferred pH value to 7.5, heat then under 90 ℃ of conditions and react 30min, impurity such as iron, aluminium are almost completely precipitated, precipitated, the absorption of heavy metal major part, boron also are converted into the minimum metaborate of solubleness and enter solid phase.
Described auxiliary agent is light calcined magnesia or magnesia preferably, and described oxygenant is hydrogen peroxide or clorox preferably.
Precipitated silica claims white carbon black, silicate hydrate, fine silicic acid, light silicon dioxide again.Its molecular formula SiO 2, molecular weight 60.Outward appearance is white amorphous highly dispersed powders.Light weight, relative density 2.319～2.653.1750 ℃ of fusing points.Water insoluble and sour, can be dissolved in sodium hydroxide and hydrofluoric acid.In air, be the accumulative fine particle behind the absorption moisture.Surface-area and dispersive ability are big, and stable chemical performance is high temperature resistant, does not burn, and have very high electrical insulating property, porousness.Often because of its difference of creating conditions, the physics of product, chemical property have very big-difference.
Mainly as natural rubber and elastomeric strengthening agent, it is more suitable particularly to make the light-colour rubber goods for precipitated silica.Be filled in the silicone resin, can be made into anti-pyritous plastics more than 2000 ℃.Also as filler for plastic, lubricant and insulating material.In coating, be used for preventing the pigment precipitation.Also can be used as pesticide dispersing agent, paint flatting agent, the manufacturing etc. of the precipitation agent of phosphor powder when casting releasing agent, window of tube apply.
Production method is industrial the precipitator method, carborization and combustion method.The at present employing with quartz sand is the precipitator method of basic material more, promptly makes water glass by quartz sand, gets through precipitation, rinsing, oven dry, pulverizing with water glass and hydrochloric acid, sulfuric acid or nitric acid reaction again.It is the salt acid precipitation method of basic material, i.e. sol method technology that this project adopts with the secondary boron mud behind the extraction magnesiumcarbonate.
The invention has the advantages that:
The present invention is opening up a new way aspect the comprehensive utilization of boron mud, created a new recycling economy operational path.The present invention makes the magnesium transformation efficiency in the boron mud be not less than 87%, silicon-dioxide yield 76-77%.Having solved existing boron mud comprehensive utilization technique does not have the silicon-dioxide problem of complex utilization of solution, has not only improved the comprehensive utilization of resources rate, and has fundamentally solved the influence of secondary boron mud to environment.
Embodiment
Main production equipments: acidolysis, magnesium basic carbonate preparation and the production unit that ammonia recovery system adopted are known production system.
Precipitated silica prepares required major equipment: secondary boric sludge stock tank, chamber-type press filter, water glass storage tank, sodium silicate solution make-up tank, liquid caustic soda storage tank, caustic soda soln make-up tank, sodium chloride solution Preparation tank, the molten still of alkali, colloidal sol prepare still, precipitin reaction still, ageing tank, pulverizer, drying machine, pure water preparation system etc.
Embodiment 1: the acidleach boric sludge is equipped with food grade magnesiumcarbonate
Raw material:
A. boron mud: major ingredient is MgO 33wt%; SiO 222wt%;
B. sulfuric acid: technical grade, concentration 93%;
Activator: hydrofluoric acid.
Acidleach: will be not footpath exsiccant wet basis boron mud mix making beating by solid-to-liquid ratio 1: 1 with water, add 2% activator earlier, add the sulfuric acid of calculated amount after stirring evenly, about 90 ℃, reacted 30 minutes.Adding water after the slurry retrogradation transfers rare, control 3: 1 solid-to-liquid ratio, reaction is 90 minutes about 90 ℃, when pH value is stabilized in 7.5 left and right sides, oxidizer is hydrogen peroxide or clorox and reacts 10min that adding assistant (light calcined magnesia or magnesia) is transferred pH value then, heats then under 90 ℃ of conditions and reacts 30min, impurity bases such as iron, aluminium precipitate precipitated, the absorption of heavy metal major part fully at this moment.Boron also is converted into the minimum metaborate of solubleness and enters solid phase.
Acidolysis reaction: MgCO 3+ H 2SO 4+ 6H 2O → MgSO 4+ 7H 2O+CO 2↑
The purification of solution:
The removal of boron in a, the solution:
3RO+2H 3BO 3→R 3(BO 3) 2+3H 2O
In b, the solution. the removal of iron, lead, calcium:
Ca in the solution 2+Content very low, in the acidolysis process, though CaO in the boron mud and SO 4 2-Reaction has generated CaSO4, but as temperature of reaction during greater than 75 ℃, CaSO 4Solubleness less than 0.02g/100g solution, most of calcium salt removes by filter with insoluble sludge, and CaO content requirement≤0.6% in the product, so Ca 2+Can not influence quality product, AL 3+In reaction end pH value＞7 o'clock, almost all Al (OH) is separated out in hydrolysis 3Precipitation leaches with residue.Experiment showed, Fe 2+And Fe 3+It is the major impurity in the solution.According to the relation of saline hydrolysis pH value and oxyhydroxide solubility product, under the normal temperature in solution (pH=7.0-8.5) add 1.5L/m 3The oxygenant of solution, heating makes Fe 2+Be oxidized to Fe 3+, become Fe (OH) 3The precipitation and separate.Chemical reaction:
Remove Al 3+Hydrolysis reaction: Al 3++ 3H 2O → Al (OH) 3↓+3H +
The oxidizing reaction of Fe: 2Fe 2++ H 2O 2+ 2H +→ 2Fe 3++ 2H 2O
Remove the hydrolysis reaction of Fe: Fe 2++ 3H 2O → Fe (OH) 3↓+3H +
The adding of auxiliary agent can make the solution pH value change, and reaches 7.5--8.5, for oxidation and hydrolysis reaction provide condition.
With the ferric iron in the thiocyanate-method mensuration solution, content is less than 0.0015%.
The removal of c, heavy metal: adjuvant used have a greater activity, when removing boron, absorption such as the heavy metal in the solution, organic pigment can be removed.Also can in solution, add 150～200g/m 3The sodium sulphite of solution makes it to be converted into sulfide and removes.The reaction of sodium sulphite removal heavy metal is as follows:
Mn 2++Na 2S→MnS↓+2Na +
Pb 2++Na 2S→PbS↓+2Na +
2As 3++3Na 2S→As 2S 3+6Na +
The pH value of metal ion precipitation of hydroxide
PH value Fe 3+ Fe 2+ Al 3+ Mn 2+ Pb 2+
Begin precipitation 1.5 6.5 3.3 7.8 7.2
Precipitate fully 4.1 9.7 5.2 10.4 8.7
Add oxygenant, the about 20min filtration of auxiliary agent afterreaction.Filtrate is an Adlerika, is used to prepare food grade magnesiumcarbonate behind secondary-cleaned, and the filter residue major ingredient is an active silica, is used to prepare precipitated silica.
Boron mud rate of decomposition is analyzed: decomposing secondary residue with hydrochloric acid, is indicator with eriochrome black T, calcium carboxylate sodium salt, carries out complexometric titration with EDTA mark liquid, at first calculates calcium magnesium resultant, deducts calcium again, calculates the magnesium residual rate.Analytical results: boron mud contains MgO1.28%, rate of decomposition 93.9%.
(2), magnesiumcarbonate is synthetic: undertaken by known method.It is 60～80 ℃ that temperature of reaction, feed rate will be strict controlled in temperature of reaction, and feed rate 10～25L/min only in this way just can make the food grade magnesiumcarbonate product of dispersiveness, good fluidity.
Replacement(metathesis)reaction: MgSO 4+ 2NH 4HCO 3→ Mg (HCO 3) 2+ (NH 4) 2SO 4
Pyrolytic reaction: Mg (HCO 3) 2+ 2H 2O → MgCO 33H 2O+CO 2↑
5(MgCO 3·3H 2O)→4MgCO 3·Mg(OH) 2·4H 2O+CO 2↑+10H 2O
Magnesiumcarbonate mother liquor main component is an ammonium sulfate, volatilizes ammonia through the oxide compound reaction with alkaline-earth metal, makes Adlerika simultaneously.Ammonia obtains ammoniacal liquor through absorption.Adlerika and ammoniacal liquor recycle.
Ammonia still process reaction: MgO+ (NH 4) 2SO 4→ MgSO 4+ 2NH 3↑+H 2O
Inhale ammonia react: NH 3+ H 2O → NH 3H 2O
(3), product analysis:
Press the methods analyst of HG2790-1996 standard code, quality product meets the food grade requirement, concrete data such as following table:
Embodiment 2: the secondary boric sludge is equipped with precipitated silica
(1), secondary boron mud and tap water were mixed making beating by 0.3: 1, filter, carry out repeatedly four times.And with silicon tetrafluoride (SiF 4) volatilization method mensuration dioxide-containing silica.
(2), liquid caustic soda liquid is diluted to about 12%.
(3), the secondary boron mud (main component is an active silica) that acidolysis, filtration back are obtained washs to sulfur-bearing hydrochlorate≤0.5%.Be 12% sodium hydroxide solution then with concentration,, under 95-100 ℃ condition, soaked molten 120 minutes, make the silicon-dioxide in the boron mud be converted into water glass, obtain liquid sodium silicate after filtration by 115% batching of theoretical amount.Filtering the waste residue that is produced discards.
Chemical reaction: 2NaOH+SiO 2→ Na 2SiO 3+ H 2O
With the SiO in the silicon tetrafluoride volatilization method mensuration waste residue 2, residual 18.4%, leaching rate 77%.
(4), be that 1.040～1.070 hydrochloric acid is basal liquid with density, under agitation add the sodium silicate solution of relative density 1.16 gradually, SiO in solution 2Content reaches 6.5～8.5%, the pH value when 4.5 left and right sides, colloidal sol (m SiO 2N H 2O).
Chemical reaction: Na 2SiO 3+ 2HCl → H 2SiO 3(m SiO 2N H 2O)+2NaCl
(5), the relative density that adds calculated amount in reactor is 1.074 sodium silicate solution, under heating and agitation condition, slowly add colloidal sol and concentration and be 12% sodium chloride solution, the control reacting liquid pH value is 7.8～8.2, holding temperature is about 55-65 ℃, insulation reaction 40 minutes, have precipitation to separate out gradually this moment.
Chemical equation: H 2SiO 3(m SiO 2N H 2O) → SiO 2+ H 2O
(6), reaction finishes, and adds concentrated hydrochloric acid and adjusts pH value about 3～4, is incubated ageing discharging in 30 minutes.
(7), with the reaction throw out with water rinse to sodium chloride content less than 1.5%.Obtain the wet cake of precipitated silica through the pressure filter filtration.
(8), filter cake is about below 6% to water content with flash dryer (150 ℃ of mix temperature), promptly get silica product through screening again.
Evidence: silicon-dioxide ultimate yield average out to 76% in the boron mud.
(9), quality product:
The method that quality product is pressed HG/T 3061-1999 standard code detects, and the precipitated silica quality of producing meets rubber ingredients E class standard.
The precipitated silica target level of product quality
Figure A20071011076300121
More than the method for preparing precipitated silica with boron sludge provided by the present invention is described in detail, used specific case herein principle of the present invention and embodiment are set forth, the explanation of above embodiment just is used for helping to understand method of the present invention and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present invention, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.

Claims (6)

1. one kind prepares the method for precipitated silica with boron sludge, and it is characterized in that: the acidleach boron sludge prepares food grade magnesiumcarbonate, and obtains secondary residue; Then secondary residue is successively added alkali lye and acid treatment obtains silicic acid sol, add sodium silicate solution at last and separate out precipitation of silica.
2. according to claim 1ly prepare the method for precipitated silica with boron sludge, it is characterized in that: described alkali lye is NaOH solution, and described acid is hydrochloric acid or sulfuric acid.
3. according to claim 1ly prepare the method for precipitated silica, it is characterized in that: when described acidleach boron sludge prepares food grade magnesiumcarbonate,, add the hydrofluoric acid of 2% weight ratio, as activator in the gross weight of boron sludge with boron sludge.
4. according to claim 1ly prepare the method for precipitated silica with boron sludge, it is characterized in that: after obtaining secondary residue, the secondary residue water rinse with producing after filtration with the NaOH solution reaction, makes SiO wherein then 2Be converted into water glass; Be that 1.040～1.070 hydrochloric acid under agitation condition is 1.160 sodium silicate solution reaction with relative density with relative density, treat that the dioxide-containing silica in the solution is 6.5-8.5%, when pH value is stabilized in 4.5 left and right sides, promptly get silicic acid sol; Under the condition that has sodium-chlor pH regulator liquid to exist, be that 1.074 sodium silicate solution reacts then, separate out precipitation of silica, make finished product through ageing, rinsing, solid-liquid separation, drying, pulverizing and screening then with silicic acid sol and relative density.
5. the method for preparing precipitated silica with boron sludge according to claim 1, it is characterized in that, during preparation food grade magnesiumcarbonate, adopt following purification process: after oxidizer, adding assistant is transferred pH value to 7.5, heats then under 90 ℃ of conditions and reacts 30min, and impurity such as iron, aluminium are almost completely precipitated, precipitated, the absorption of heavy metal major part, boron also are converted into the minimum metaborate of solubleness and enter solid phase.
6. according to claim 5ly prepare the method for precipitated silica with boron sludge, it is characterized in that: described auxiliary agent is light calcined magnesia or magnesia, and described oxygenant is hydrogen peroxide or clorox.
CNA2007101107631A 2007-06-11 2007-06-11 Method for preparing precipitated silica with boron sludge Pending CN101323452A (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102167339A (en) * 2010-11-19 2011-08-31 王嘉兴 Method for preparing sodium metasilicate anhydrous from filter residue obtained by treating boric sludge
CN102502661A (en) * 2011-10-25 2012-06-20 黑龙江大学 Method for preparing nanometer silicon dioxide through taking alkali type activated sludge carbon as raw material
CN102815728A (en) * 2012-08-31 2012-12-12 中国矿业大学(北京) Method for preparing nano-sized magnesium hydroxide and nano-silica by utilization of boron mud
CN108300331A (en) * 2018-02-10 2018-07-20 雷春生 A kind of metal-polishing liquid
CN112574504A (en) * 2020-11-20 2021-03-30 应急管理部沈阳消防研究所 Aerogel prepared by boron mud waste, flame retardant and modification application of aerogel
CN116282096A (en) * 2023-05-12 2023-06-23 中科镁基（北京）科技有限公司 Comprehensive utilization method of boric sludge

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102167339A (en) * 2010-11-19 2011-08-31 王嘉兴 Method for preparing sodium metasilicate anhydrous from filter residue obtained by treating boric sludge
CN102502661A (en) * 2011-10-25 2012-06-20 黑龙江大学 Method for preparing nanometer silicon dioxide through taking alkali type activated sludge carbon as raw material
CN102502661B (en) * 2011-10-25 2013-07-24 黑龙江大学 Method for preparing nanometer silicon dioxide through taking alkali type activated sludge carbon as raw material
CN102815728A (en) * 2012-08-31 2012-12-12 中国矿业大学(北京) Method for preparing nano-sized magnesium hydroxide and nano-silica by utilization of boron mud
CN108300331A (en) * 2018-02-10 2018-07-20 雷春生 A kind of metal-polishing liquid
CN112574504A (en) * 2020-11-20 2021-03-30 应急管理部沈阳消防研究所 Aerogel prepared by boron mud waste, flame retardant and modification application of aerogel
CN116282096A (en) * 2023-05-12 2023-06-23 中科镁基（北京）科技有限公司 Comprehensive utilization method of boric sludge

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Application publication date: 20081217