CN1037165C - Pressure and filter aid filtration process for refining water glass - Google Patents
Pressure and filter aid filtration process for refining water glass Download PDFInfo
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- CN1037165C CN1037165C CN92110946A CN92110946A CN1037165C CN 1037165 C CN1037165 C CN 1037165C CN 92110946 A CN92110946 A CN 92110946A CN 92110946 A CN92110946 A CN 92110946A CN 1037165 C CN1037165 C CN 1037165C
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- filter
- water glass
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/32—Alkali metal silicates
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Abstract
The present invention relates to a refining technology of a filter aid of water glass, particularly to a pressure and filter aid filtration technology for refining water glass, which is suitable for various water glass, the specific weight top limit of which is 1.6. Refined water glass is clear and transparent, and can be used as a raw material of fine chemicals of a silicon series. Laboratory tests determine suitable filter aid grades, filter aid use modes and incorporation quantities for each refining process. A proper incorporation quantity is an economic optimum quantity which can fully use the size and the pressure of equipment under the precondition that filter aids are used as less as. The present invention preferably uses pressure leaf filters and plate and frame filter filters, wherein a special filtering medium plate of wire meshes is used on a plate and frame filter, and thus, a protective medium does not need precoating. The present invention provides three alternative technological processes.
Description
The present invention relates to a kind of pressure and filter aid filtration process for refining of water glass, belong to the process for refining of inorganic silicon chemical raw material.Be applicable to the refining of water glass (liquid sodium silicate or potassium silicate), the present invention is to use the diatomite of a series of different rate of permeation or the process for refining that pearlite filtering aid filters various water glass.The flocculating aids of different rate of permeation is selected for use for different water glass filtration procedurees, and process has been removed the water-insoluble (impurity) in the former water glass, makes it the degree that reaches transparent.
Water glass is a kind of important Inorganic Chemicals, except being used as washing composition and binder ingredients, be the raw material of making silicon series fine chemicals such as silica gel, molecular sieve, silicon sol, white carbon(ink), the quality of water glass has very big influence for the production and the quality of its derived product.
Be used for this purified method at present both at home and abroad and mainly contain three kinds, the gravity edge falls, centrifugal edge falls and and filtration.Gravity is the traditional method that present many factories use along falling, and equipment is huge, floor space is big.And, particularly when water glass proportion is big, often, still can not get comparison clear water glass along falling for a long time from weak effect.Temperature is to also very big along the influence of falling effect, and winter, the viscosity of water glass became big, and is just poorer along the effect of falling.Centrifugal edge falls and can obtain clarity than higher water glass, and University Of Tianjin successfully uses homemade S * C800 along falling whizzer, separates the water glass that obtains water insoluble matter content 0.029-0.09%, as the raw material (fluid engineering, No.9,1991) of fine product.It is higher that yet the slag liquid content falls in the edge in the whizzer, need add water " change slurry ", and then handle the flow process more complicated through whizzer.The effect of centrifugation wants force of gravity isolating good, but still have its inherent shortcoming: a certain impurity particle is removed or remains in the liquid, the size and the proportion that not only depend on particle itself, also depend on its position in centrifuge field, therefore in general be difficult to remove more up hill and dale the little solid particulate that makes solution seem muddy.The effect of centrifugation is subjected to the influence of temperature equally in addition, has to adopt insulation for this reason, even the measure of heating.Filter method, suitable as long as medium is selected, can obtain transparent water glass.South China Science ﹠ Engineering University adopts filter method, and it is good to obtain transparency, does not have muddy water glass (inorganic chemicals industry, No.5,1990) substantially.Polypropylene fibre filter cloth and primary colors cotton duck are used in thick, smart twice filtration that process comprises respectively.The efficient of ordinary filtration Purified Water glass is low, and the liquid loss is big, and filter cloth is easily stopped up by impurity particle.Impurity particle in the former water glass is very tiny, and the filter cake of formation is fine and close and compressible, so specific filtration resistance is big, filtration difficulty.And for the bigger water glass of proportion, newspaper originally can't industrial realization.Some factory is in order to address this problem, and with its dilution, after fall, filter, according to service requirements evaporation concentration (Anhui chemical industry, No.3,1991), energy consumption is big, flow process is complicated, and concentration process can bring some adverse influences again.
The purpose of this invention is to provide a kind of pressure and filter aid filtration process for refining of water glass,, thereby obtain transparent product so that remove the water-insoluble impurity in the water glass.
The present invention adopts flocculating aids to filter, and the flocculating aids particulate mixes the filter cake specific filtration resistance is descended, thereby can be in industrial realization, and this is first characteristics of the present invention.Flocculating aids of the present invention filters refining.Can select rate of permeation suitable aid kind for use according to filtering object and requirement, thereby reach the ideal effect.Just because of the different a series of flocculating aidss of rate of permeation are arranged, so proportion can both filter refiningly up to 1.6 water glass, and can overcome the influence that season or temperature Change are often come.This is another characteristics of the present invention.The use of flocculating aids has precoating and mixes dual mode, is painted with each filtration in advance " fresh " filtration medium is provided.And protected filtration medium (precoating support material) original on the filter.Therefore media such as filter cloth that general filtration often has blocking problem gradually can not take place.The present invention adopts the plate and the Stainless Steel Cloth of materials such as soft plastics or aluminium to make filter media sheet, thereby can save the precoating process, and Stainless Steel Cloth just can be reused after water is rinsed well after the removal filter cake, and this is another characteristics of the present invention.
Because the proportion of water glass has nothing in common with each other, and factors such as proportion have significant effects to filtration, the also refining degree difference that need reach because refining back purposes of water glass is different, each water glass treating process all has its proper flocculating aids kind.The present invention recommends to use the super-cell series of Lanzhou oil-refining chemical head factory refining institute exploitation, and this series is suitable for the filtration of petroleum additive, also is suitable for other gluey viscous fluids.Series has comprised rate of permeation other diatomite filtering agent of 8 levels from 0.5-14 darcy (darcy).Other super-cells, pearlite filtering aid as long as rate of permeation is suitable also can be used, can reach identical effect but must improve its add-on.The present invention can be used for proportion up to 1.6 various water glass, potassium silicate or potassium silicate-sodium silicate water glass.Heavyly the high flocculating aids of rate of permeation to be selected, such as proportion about 1.2, the flocculating aids of rate of permeation 0.8-2 darcy can be used; Proportion 1.4, select the 8-10 darcy for use; Proportion 1.6 with the flocculating aids of 14 darcies.In practice, often need, from two, three rate of permeation grades selecting roughly, determine optimum kind through experiment.The main foundation that kind is selected is the clarification degree of Purified Water glass.Certain water glass is if use the different flocculating aids of rate of permeation to filter, and rate of permeation is high, clarification ability, but filtering velocity and throughput height.The measurement of clarity can be adopted two kinds of methods, and a kind of is to filter water solubles content in the water glass of back, and another kind is the transparency of water glass.The present invention uses spectrophotometer, is reference (transmittance 100%) with distilled water.Measure and calculate the transmittance of water glass, weigh and filter the purified effect.
Water-insoluble in the former water glass (solid impurity) content is the key factor that influences flocculating aids use-pattern and consumption.The water glass that foreign matter content is very low can adopt the mode of simple precoating, i.e. flocculating aids Depth Filtration (or claiming self-filtering).Along with foreign matter content increases, need in former water glass, mix flocculating aids, foreign matter content is high more, and the incorporation that needs is also many more.General pre-coated filter aid agent consumption is 0.5-2Kg/m
2Mixing the flocculating aids amount is 1-60Kg/m
3, recommend to adopt 5-50Kg/m
3Mix the filter media sheet that filter type can use the present invention to recommend, or other forms of Stainless Steel Cloth is as filtration medium, thereby saves the precoating step.If the medium that use filter cloth etc. is easy to stop up then must be protected with precoating.
Suitable flocculating aids kind and consumption generally must be definite through testing.Kind power face should select the clarification ability to reach requirement, and the highest flocculating aids of filtering velocity (filter amount), thereby obtain high as far as possible production efficiency; Use-pattern and incorporation aspect, then minimum with refining cost is target.Incorporation is low must not to be that production cost is minimum, because along with the reduction of incorporation, the filtration velocity of the Purified Water amount of glass passed through of the unit filtration area of phase all can correspondingly reduce weekly.Ideal filtration procedure is that the filter cake when filter allows in the space is full of, and the final pressure depreciation that reaches regulation just falls in filter pressure, can make full use of the ability of instrument size and pressure two aspects like this.Want the result that reaches such, must when filtration test, determine the good best flocculating aids amount of mixing.Incorporation is excessive, has not only wasted flocculating aids, and can make filtration before the final pressure that does not reach regulation is fallen, and allows the space to finish in advance because of filter cake fills up; Measure too smallly, then can not make full use of the filter cake space, fall and finish filtration cycle because of reaching final pressure in advance, the both is disadvantageous.Filtration test method commonly used has three kinds of constant voltage, constant speed and transformation one filtrations with varying rate.Constant pressure filtration equipment and operation are all fairly simple, but test-results is except that being used for identical industrial constant pressure filtration, and its amplification is relatively poor; Industrial filtration actual procedure has all been simulated in the two kinds of filtrations in back, has experienced pressure integrated stages from low to high, amplifies reliable.Filtration test require to be investigated length and filtration velocity, filtrate transmittance filtration cycle, and factor such as filter cake thickness.
The present invention can use various industrial filters to realize, and with pressure filter for more suitable, what at first consider to use is level or vertical vane pressure filter and plate-and-frame filter press.The leaf filter of band wire netting medium, available precoating also can directly be mixed flocculating aids without precoating.Particularly can unload filter cake automatically, and the leaf filter of blowback, backwash function is arranged, easy to use, be easy to realize time variable control.But the relative filtration area filtration area of this filter is little, and liquid-conveying amount is big, and the investment cost height of unit filtration area.Automatically plate-and-frame filter press because of the filtration medium that uses limits, needs precoating, an investment cost of equipment is also higher, but labour intensity is low, is easy to realize time variable control, filter and finish the back filter cloth, make it to keep clean and moist, obstruction or water glass drying can not take place harden through blowback and flushing.The common plate-and-frame filter press of band wire cloth medium is used in special recommendation of the present invention, can directly mix flocculating aids and filter, without precoating.This filter can be ordered goods specially to factory, also can transform voluntarily.The present invention is with two layers of soft plastic board, aluminium sheet or rubber one asbestos plate that 2-4mm is thick, and its shape is identical with the frame of filter, and special-purpose filter media sheet is made in middle hot pressing or inlay each Stainless Steel Cloth than the little 5-10mm of frame of a block length cross direction.Wire cloth recommend to adopt the order number or quite the order number be the Stainless Steel Cloth of 100-300, with the 150-250 order for more suitable.
This medium places between the plate and frame of filter, is easy to compress.Can not precoating during filtration, filter finish and the removal filter cake after needn't take off on the slave, water is rinsed well just and can be reused.Select any filter, factors such as visual its investment ability of factory, industrial scale, labour cost decide actually.
The pressure and filter aid filtration treating process of water glass may further comprise the steps:
(1) precoating---in the jar that band stirs, go into pre-coating solution and flocculating aids, be made into the precoating slurries, arrive filter with pump delivery then.The flocculating aids particle relies on the mode of " bridge formation " more long-pending than its big medium holes upper edge, forms precoated layer, and liquid returns the precoating jar by medium.Because the medium holes ratio helps the filter particle big, therefore need to form precoated layer gradually, and have certain intensity at leisure through circulation, unlikelyly destroyed by continuous flowing fluid.
(2) filter---mix the former water glass slurries of flocculating aids, with being pumped into filter, filtration medium or precoated layer have been held back the solid particulate in the stoste (comprising flocculating aids and impurity), form filter cake, and liquid then by filter cake, becomes Purified Water glass.
(3) unload cake and cleaning---after filtration finishes, residual liquid in the excavator, the removal filter cake, water is rinsed filtration medium well then.Under the situation about having, unload residual water glass in the preceding water displacement of the cake filter cake, and then removal.
According to the material and the structure of filter, every kind of filter all has the operating pressure and the maximum filter cake thickness that allows of regulation.The operating pressure of plate-and-frame filter press is at 0.6-1.0MPa, and it is 0.6MPa that recommendation falls in final pressure; Pressure leaf filter is at 0.2-0.6MPa, and recommendation is 0.6MPa following (determining occurrence according to the operating pressure of filter own).
Fig. 1 is a water glass pressure and filter aid filtration rectification flow synoptic diagram of the present invention.
Fig. 2 is that the another kind that the present invention recommends is simplified process flow sheet.
The present invention is described in detail below in conjunction with Fig. 1, in technique of the present invention, pre-coating solution uses is waterglass (for the first time available running water replaces) after filtering, its quantity is 1.25-1.3 times of precoating system (comprising precoating tank, filter and relevant pump, pipeline) volume, pre-coated filter aid agent consumption calculates by every square metre of filter area 0.5-2Kg, and suspension concentration is at 1-3. 5%. The filter aid mother liquor is prepared with the former waterglass of filtered, and concentration is 2-12%. At first start the precoating pump during operation, precoating speed is 0.1-0.5m3/m
2H, recommend adoption 0.15-0.25, pre-coating solution enters filter with filter aid, and liquid returns the precoating tank by medium, and the filter aid particle relies on the mode of " bridge formation " to form the precoated shet of thickness 1-5mm in the duct of medium. The precoating time generally calculates for 3 times with liquid-circulating, also can go out oral fluid by the observation filter and whether contain the situation that filter aid judges that precoating is finished. Precoating starts first mother liquor pump and raw liquor pump before finishing, and adjusts both flow-rate ratios, thereby guarantees that the drainage dosage that mixes reaches setting, and the rate of filtration is at 0.1-0.5m3/m
2, recommend adoption 0.2-0.3m3/m
2 Stop the precoating pump behind the stability of flow, begin to filter, liquid at first turns back to the precoating tank, treats that liquid level arrives original position, is changed into Purified Water glass finished-product tank. Along with filtration is carried out, filter cake thickness and resistance constantly increase, and fall until reach the filtration final pressure of regulation. Because incorporation determines that through overtesting this moment, filter cake thickness was also just about permissible value. Filter cake dries up with compressed air first, draws off after then washing with water, drying up. The backwash of filter medium water also keeps moist and clean state, for next filter cycle.
Fig. 2 is a kind of simplification of flowsheet that the present invention recommends, and is particularly suitable for planning to utilize original sheet frame filter to filter refining situation. Use above-mentioned stainless steel cloth special filtering dielectric-slab, saved the precoating step, mix filter aid and join former waterglass tank (this tank must be with mixing plant), saved the mother liquor system. The filtrate cycle at filtration initial stage is returned former waterglass tank, after becoming clearly, changes finished pot over to again. Generally after filter screen formed the thick filter cake of 3-4mm, the waterglass that passes through had just become clearly, therefore can determine to enter according to incorporation and the rate of filtration approximate time of finished pot. Also can adopt the mode that drainage adds former waterglass tank of mixing for the filter that uses the medium such as filter cloth or situation that must precoating, and save mother liquor filter aid system, this flow process has it to transform and uses the advantage of plate and frame filter press.
The present invention will be further described with embodiment below, should be understood that these embodiment are not limitation of the scope of the invention.
Example 1
A kind of potassium-sodium water glass that chemical plant on May Day, Lanzhou produces, outward appearance grey blue, modulus 2.65, proportion 1.45,45 ° of Be of concentration, 30 ℃ of viscosity are 190CP, transmittance 0.9% is in filtration area 7 * 10
-4m
2The constant pressure filtration testing apparatus carries out the test of flocculating aids incorporation.Filtration medium is an industrial filter cloth, and the flocculating aids rate of permeation of use is 10 darcies, and test-results is listed in table 1.
Table 1 flocculating aids incorporation test-results
| Help filter use-pattern agent and consumption | No flocculating aids | Precoating+mix flocculating aids | ||
| C f＝0 | C f＝1％ | C f＝3％ | ||
| Filter amount g | 0 | 50 | 110 | 205 |
| Filtration velocity * period L/m 2min×min | 3.57×20 | 7.86×30 | 14.6×45 | |
| Filter cake specific filtration resistance mKg -1 | 7.4×10 13 | 4.6×10 11 | 1.8×10 10 | |
Can see no pre-coated filter aid agent by the pick of table 1 number, filter cloth is stopped up by impurity rapidly, and filtration can't be carried out; Precoating on the filter cloth is not mixed flocculating aids (C but do not use
f=0), the filter cake specific filtration resistance that is formed by impurity is very big merely, reaches 7.4 * 10
13MKg
-1, filtration procedure can not be in industrial realization.Can see a kind of potassium-sodium silicate of proportion 1.45 from example 1, viscosity is 190CP, does not add flocculating aids, and filtration can't be carried out.The filter cake specific filtration resistance that records its impurity formation after the agent of employing pre-coated filter aid reaches 7.4 * 10
13MKg
-1, filter the level that does not reach industrial realization yet.Behind 1% flocculating aids, specific filtration resistance drops to 4.6 * 10 in former water glass
11, filtration can more successfully be carried out.It is generally acknowledged that specific filtration resistance is greater than 10
12MKg
-1Promptly awkward filter object.10
10-10
12For can industrial realization, 10
10It below is the process that is easy to realize.See from the result, along with C
fIncrease, process becomes and has industrial value.Water glass after the filtration is the grey blue transparence, and transmittance is brought up to 56-59%.
Embodiment 2
The 250g/L water glass that Lanzhou oil-refining chemical head factory catalyzer subsidiary factory is produced carry out flocculating aids filter refining, this water glass Na
2O content 87g/L, viscosity (20 ℃) 7.7CP, proportion 1.265, former water glass transmittance 13% is used to produce molecular sieve catalyst.
(1) filtration test
Filtration test adopts transformation method for changing speed, super-cell rate of permeation 0.87 darcy of use, filter area 7 * 10
-4m
2, table 2 is listed two groups of data in the consumption test.
The transformation speed change test of table 2 flocculating aids incorporation
| Mix flocculating aids g/100m1 | Filter pressure MPa | Filtration yield ml | Filtration velocity * period L/m 2min×min | Yield % | Transmittance % |
| 1.0 0.7 | 0.05-0.5 0.05-0.55 | 582 588 | 17.9×46.4 15.4×54.4 | 97 98 | 92 93 |
Can see use technology of the present invention by table 2 result, can have under the filtering velocity of industrial value, obtain transparent water glass.Incorporation 0.7 is compared with 1.0, and filtering velocity is low slightly, and the pressure that needs falls high slightly.All the other are suitable, so commerical test recommends to adopt the 0.7-1.0 incorporation.
(2) commerical test
On the automatic plate-and-frame filter press of the PF-25 of catalyzer subsidiary factory, carry out filter area 25m
2Flocculating aids kind and incorporation adopt the laboratory to recommend condition.Test is carried out 8 times altogether, below the average result for obtaining.
The throughput 0.934m of each filtration cycle
3/ m
2
Filtration velocity 0.27m
3/ m
2h
Length filtration cycle (comprising various operations and non-productive operation) 8h
Actual capacity 2.8m
3/ m
2d
Refining yield 98.5%
Purified Water glass transmittance 92.5%
Flocculating aids energy consumption (comprise precoating and mix) 1.13Kg/m
3
Claims (1)
1, a kind of process for refining of water glass may further comprise the steps: 1. precoating; 2. filter; 3. unload cake and cleaning; It is characterized in that precoating is to add pre-coating solution and flocculating aids in the jar that band stirs, be made into the precoating slurries, arrive filter with pump delivery then, the flocculating aids particle relies on the mode of " bridge formation " more long-pending than its big medium holes upper edge, form precoated layer, liquid returns the precoating jar by medium; It is the super-cell or the pearlite filtering aid of 0.5-14 darcy that said flocculating aids is selected rate of permeation for use, and the consumption of pre-coated filter aid agent is 0.5-2Kg/m
2, the amount of mixing flocculating aids is 1-60Kg/m
3, the filtration working pressure range is 0.2-1.0MPa, precoating speed 0.1-0.5m in the said precoating process
3/ m
2H, filtration velocity is 0.1-0.5m in the said filtration procedure
3/ m
2H.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN92110946A CN1037165C (en) | 1992-09-25 | 1992-09-25 | Pressure and filter aid filtration process for refining water glass |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN92110946A CN1037165C (en) | 1992-09-25 | 1992-09-25 | Pressure and filter aid filtration process for refining water glass |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1084491A CN1084491A (en) | 1994-03-30 |
| CN1037165C true CN1037165C (en) | 1998-01-28 |
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ID=4945055
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN92110946A Expired - Fee Related CN1037165C (en) | 1992-09-25 | 1992-09-25 | Pressure and filter aid filtration process for refining water glass |
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Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9108855B2 (en) | 2011-09-05 | 2015-08-18 | Nissan Chemical Industries, Ltd. | Method for producing purified alkali silicate aqueous solution and silica sol |
| CN102961907A (en) * | 2012-11-23 | 2013-03-13 | 陈广海 | Special pressure filter tank for filter press |
| CN103143203B (en) * | 2013-03-06 | 2015-04-22 | 山东阜丰发酵有限公司 | Device and method for pre-spraying filter aid by utilizing plate and frame filter |
| CN103818915A (en) * | 2014-03-10 | 2014-05-28 | 福建正盛无机材料股份有限公司 | Method for preparing high-transparency liquid soluble silicate |
| CN104261419B (en) * | 2014-10-14 | 2016-05-25 | 龙星化工股份有限公司 | A kind of production method of liquid sodium silicate |
| CN105110346A (en) * | 2015-08-24 | 2015-12-02 | 昌邑市龙港无机硅有限公司 | Filtering refining technology for liquid-state sodium silicate |
| CN105197948B (en) * | 2015-09-08 | 2018-02-27 | 昌邑市龙港无机硅有限公司 | A kind of production method of anhydrous sodium metasilicate |
| CN113499635A (en) * | 2021-06-30 | 2021-10-15 | 重庆中轻装备有限公司 | Mature vinegar filtering process method and system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU415233A1 (en) * | 1970-11-27 | 1974-02-15 | нефтепереработке , нефтехимии | METHOD FOR GETTING SOLUTION OF LIQUID GLASS |
| SU823284A1 (en) * | 1978-07-24 | 1981-04-23 | Ереванский Отдел Неорганическихматериалов Всесоюзного Орденатрудового Красного Знаменинаучно-Исследовательского Инсти-Тута Химических Реактивов И Особочистых Веществ | Method of producing sodium silicate solution |
| EP0363197A2 (en) * | 1988-10-06 | 1990-04-11 | Unilever Plc | Preparation of sodium silicate |
-
1992
- 1992-09-25 CN CN92110946A patent/CN1037165C/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU415233A1 (en) * | 1970-11-27 | 1974-02-15 | нефтепереработке , нефтехимии | METHOD FOR GETTING SOLUTION OF LIQUID GLASS |
| SU823284A1 (en) * | 1978-07-24 | 1981-04-23 | Ереванский Отдел Неорганическихматериалов Всесоюзного Орденатрудового Красного Знаменинаучно-Исследовательского Инсти-Тута Химических Реактивов И Особочистых Веществ | Method of producing sodium silicate solution |
| EP0363197A2 (en) * | 1988-10-06 | 1990-04-11 | Unilever Plc | Preparation of sodium silicate |
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| CN1084491A (en) | 1994-03-30 |
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