Perlite filter aid is a powdery product made from selected smaller particle size of ore. After heated by purified gas, selective expanded in vertical kiln, and then grinded and purified, a collocation of certain particle size that obtained is perlite filter aid. It is white, and the appearance density of it is about 230~460kg/m3 The classify of it depends on its appearance density, collocation size-grade and the pore diameter deformed by selective expanding.
Compared with other filter aids like diatomite, it is with many merits, such as less harmful metal and nonmetal elements, light appearance density, faster filtration speed, better filtering effect, and so on.
Perlite filter aids have been used in speed filter production widely for beer and other beverages industry, pharmaceutical industry, paint industry, petroleum industry, and so on.
General production technology and features introduction of perlite filter aids
Production technology: Ore—Classify—Feed—Dry—Calcine/Melt—Cool—Crush—Air separate for multi-grade selection—Concentrate—Degranulate—Package
Introduction: Expanded perlite was grinded and then air separated, classified into many grades. Gently grind make the particles surface uneven, so that the surface of filter cake can be formed into jagged by crushing during the forming process. Since they will join bite each other to form rough filtration slits, and it contains many small channel, which is small enough to block the micron-sized particles and because of its 80%~90% of void ratio, a higher continuous penetration can still be remained.
The perlite filter aid we produced is a kind of white powder made up with amorphous glass particles. Potassium, sodium and aluminum silicate are the main components of it. It doesn’t contain organic matter, and sterilization has been achieved by high temperature combustion process during the production. Its bulk density is 20% lighter than diatomite. Each particle of GK–110 perlite filter aid is with very irregular curly flake-look. When it formed into filter cake, the avoid rate is up to 80%~90%, and particles are interlinked by many pores, so quickly filter can be obtained, and even super tiny particles smaller than 1 microns can be captured. The special advantage of using perlite as filter media is that solid can be intercepted while a high liquid flow can still be maintained. Because of its excellent chemical stability, non-potential contaminants, and extremely low content of heavy metal ion, which is normally 0.005%, it can be used in food industry.
Yanneng perlite filter aid is a kind of white or gray powder, made from small diameter spherical rhyolite glassy perlite ore, which has been crushed and selected and with reasonable size-grade. After selective roast and expanded at high temperature of 1200℃, with desulfurized clean natural gas as fuel, the ore will be grinded in high-speed grinding mill selected by airflow, and final product can be obtained. It is white or gray powder with a reasonable particle size distribution, with honeycomb-like spaces inside, with irregular curly flake-look and jagged mesh structure.
The unique ultra micro-channel structure of Yanneng perlite filter aid, makes it with better filter effect and obviously more economical than diatomite. And in the past 20 years, it has been wildly used to filter liquids for kinds of industries.
Application of Yanneng Perlite Filter Aid:
- For comestible: Beer, drink, juice, monosodium Glutamate, sugar, pharmaceuticals, vegetable oils, seaweed gel, citric acid, etc.
- For non-comestible: Petroleum, chemical Industry, fine chemical industry, bio-chemical industry, metallurgy, preparation, water treatment, filler, etc.
Machine model suitable for using Yanneng perlite filter aid:
A great deal of practical data show that Yanneng perlite filter aid has good applicability for filters. Using it can reach ideal results in all the following types of filters.
Positive pressure operation: Horizontal plate and frame press filter
Vertical leaf filter
Vallez filter
Horizontal leaf filter
Horizontal disc filter
Candle Kieselguhr Filter
Negative Pressure operation: Vacuum leaf filter
Rotary vacuum filter
Characteristics of Yanneng Perlite filter aid:
- Ultra-lightweight
The filter density of Yanneng Perlite filter aid is only 120~250kg/m3. This is about 20%~50% lower than other filter aids.
- Chemical stability
Yanneng perlite filter aid is a kind of white powder made up with inert amorphous glass particles. It is mainly composed of potassium, sodium, aluminum and silicon oxide. It is indissolvable in acid and alkali. The chemical stability of it is very good. It doesn’t contain organic matter, and after the roasting process at 1200℃, 100 aseptic can be realized.
- Economical
At the same coating thickness, with lighter density the amount of use can be reduced. If products is purchased in units of weight, since the ultra-lightweight of Yanneng perlite filter aid, integrated economy can be improved greatly. This is particularly significant in application for rotary drum vacuum filter.
- Hypertonicity
The unique gap structure of Yanneng perlite filter aid makes the permeability and filter effect of it is better than other filter aids.
- Easy coating, do not crack, easy to clean
- Safety in use
Yanneng perlite filter aid has no harm on human body, no influence on the essential characteristics of the leachate, and no potential contaminants.
Specifications and technical indicators of Yanneng perlite filter aids:
Category CK100 CZ200 CM300
Color White or light gray White or light gray White or light gray
Bulk Density ( Kg/m3 ) ＜150 ＜200 ＜250
relative rate of filtration (s/100ml) ＜30 30~60 60~180
penetration rate (Darcy) 10~2.0 2.0~0.5 0.5~0.1
suspended solids (volume percent) ≤15 ≤7 ≤4
pH value 6~9
Hygiene indicators of Yanneng perlite filter aids for comestible:
Category Water soluble% Hydrochloric acid soluble% As mg/kg Pb mg/kg Ignition loss % pH Fe2O3 %
Industry Standards ≤0.20 ≤2.0 ≤4.0 ≤4.0 ≤2.0 6 ~ 9 ＜2.0
SuperCell 0.12 0.68 1.5 1.3 1.44 7.2 0.76
Chemical composition of Yanneng perlite filter aid:
Category SiO2 Al2O3 Fe2O3 CaO MgO Others Ignition loss
Contents 74.95 12.83 0.76 0.08 0.56 9.83 1.44
NOTES: Yanneng perlite filter aid can be customized according to data or leachate characteristics provided by you. We provide comprehensive technical solution for free.
Technical Requirements for Operation of Yanneng perlite filter aid:
- Production technology:
Ore—Classify—Dry—Feed—Calcine/Melt—Cool—Crush—Air separate for multi-grade selection—Concentrate—Degranulate—Package
- Category of Applications
- Deep Bed Filtration:
Mix the right amount of filter aid with clean water or slurry in a feeding barrel, and then circular pre-coat with the suspension. The slurry is ready to be filtered when the clarity of it meet the requirements. From the start, the pre-coat becomes media for filtration. And normally, this method is suitable for deep bed filtration. The thickness of filter bed is 3~80 mm normally. In actual production, filter cake also can be constantly cut to obtain new filter bed, and to maintain relatively stable filter effect (e.g. rotary drum vacuum filter).
- Stack filtration:
Stack filtration contains 2 steps, pre-coating and addition. The thickness of pre-coat is about 2~3 mm. Main function of pre-coat is protecting filter media from contamination, and making sure clear filtrate can be obtained as soon as the addition step started. In the whole process, the thickness and structure of pre-coat is particularly important. particle size distribution You can select the filter aid and particle size distribution suitable for you, based on the nature of your material liquid (such as viscosity, particle size and content of impurities, compressibility of particles), the requirement , filter type and technology you use.
- Technical Requirements for Operation:
- Pre-coating:
By the arching function of filter aid, pre-coat layer can be formed on the filter media.
- Function of pre-coat layer:
(1) Prevent the plasma (liquid material to be percolated) particles blocking in filter media;
(2) Obtain qualified filtate from the begining of filtration;
(3) Make the filter media easy to be cleaned.
- Oeration:
mix the right amount of filter aid with clean water (or desinfected water) at the ratio of 5~10% (mass ratio) in a pre-coat tank. feeding barrel, and then cicular pre-coat with the suspension. Make the suspension cycle through the filter medium by circulating pump, to form good and stable pre-coat.
The thickness of pre-coat for pressure filter is about 2~4mm (with the amont of filter aid about 700~1000g/m2). But the thickness of pre-coat for rotary vacuum filter is need to be 8~15cm.
According to the requirement, pre-coat process can be devided into 2~3 steps, with using different types of filter aids. The typical pre-coating velocity for low viscosity liquid (about 1CP) is about 40L/m2.min. If the liquid viscosity is higher, then the velocity should be decreased, accordingly.
- Filtration:
After pre-coat done, 0.1~2.0% flter aid should be added quickly after the slurry feed into filter. During the percolate process, filter aid and the floating impurity particles in slurry combined, and form into a porous filter cake. So that the economic filtering velocity can be maintained. The amount of filter aid you need to add depends on impurity particles’ amount and the compressibility of them. The higher compressibility is, the more filter aid should be added. The ideal addition level for presure filter is that can make the filter cake almost fill the space for the residue when the pressure reaches the rated level. At this point, filtration cycle is completed, then go into the filter washing phase.
- Add filter aid directly: Add the filter aid at the same time with flurry into filter. Filter aid and the solids in flurry accumulate together on surface of the pre-coat or original filter layer, and form into new filter layer, to maintain a relatively stable rate of filtration. For this method, the particle size of filter aid only depends on the various features of the solids in the plasma, but not filter type.
- Recommendation addition level for some slurries:
- Beer: 0.5-2.0kg/1000L;
2． Pretreated new wine: 0.5-2.0kg/1000L;
- Pretreated press wine: 1.5 – 2.5kg/1000L;
- New wine without pretreatment: 2.0 – 4.0kg/1000L;
- Fermentation liquid of antibiotics: 10 – 100kg/1000L;
- Enzymic preparations: 10-50kg/1000L;
- Precautions for filtration process:
- The pressure difference between the entrance and export (△P) must be maintain relatively stable. Or else, The filter layer may drop out, and cause the filtration to fail eventually.
- As the filtration continuing, △P will also continue to increase. When △P reach the rated pressure, filtration should be ended.
- Control reflux time for pre-coat rationally. If filtrate clarity don’t meet the requirements, maybe you need to extend the reflux time.
- At the addition process, make the pump is working correctly all the time. When the addition of filter aid ended, △P will crease sharply, and cause filtration cycle shorten and filtrate reduction eventually.
- If a part of the filter layer begin to dropped out, and clarity of filtrate reduced, but it’s not very serious, may be filter amount should be increased to repair the filter layer, to recover the filtration.
