Cenospheres

1 、Cenospheres
Cenospheres are lightweight, inert, hollow, nonmetallic  spherical materials, composed largely of silica  ( SIO₂) and alumna (AL₂O3). The compositions of cenospheres are similar with glass and ceramics.Their diameter are from 15 to 300 u m .
Cenospheres have become space-age material since it emerged in the 1970s .its appearance are light gray or off white with good flowability and loosenen. Those hollow glass particles have also been called hollow ceramic spheres and microspheres. Due to their unique combination of spherical shape , high strength in compressing , good sound thermal insulation, cenospheres are utilized as a high performance filler material,that can replace other mineral filler.
 

1. physical properties of cenospheres

Hollow sphere.15-300 u m in diameter and are spherical,hollow. Due to the good flowablity , lightweight, cenospheres can be used as filler materials.
 
Low bulk densities.cenospheres bulk density are 0.35-0.45g/cm3, providing up to four times the bulking capacity of normall fillers.They can greatly reduce product cost , resin demand and weight of the end products.
 
Low cost. Cenospheres are 3times less expensive than man-made hollow glass sphere.
 
High compressive strength. The shell thickness of of cenosphere is about 10% of the radius. The inside of the  shell consists mainly of CO2 and N2. Due to the above spherical shape, cenospheres can produce higher commpressive stength.
Low thermal conductivity.
 
Good sound isolating.
 
Good insulation. Cenospheres conduct very litlle  electricity  and are ideal insulators used for making many electric device.
 
Stability in chemicals.The alumino-sillcate  shell is resistant to water, any organic solvents, acids or weak alklis. Like most glasses,cenospheres are not resistant to strong alkalis.
 
Thermal stability. Thermal stability in temperature
Noninflammable.
Resistant to water.
Low shrinkage. Cenospheres are one of  the  few  products  in the  filler  industry today that can meet the requirements for low shrinkage. Cenospheres can reduce shrinage when utilized in high volume loadings.
 
         Physical  properties of cenospheres

Size (u m)	Bulk Density (g/cm3)	Specific Gravity	Compressive Strength (kg/cm3)	Thermal Conductivity (kc/Mh℃)	Specific Resistance (Ω/cm2)	Melting Point (℃)	shap	Color	Water Content%
15-300	0.35-0.45	0.6-0.8	100-350	0.05-0.1		1450	spherical	Grey Light Grey Off white	≤1

  
        Chemical composition of cenospheres

Sio2	Al2o3	Fe2o3	Cao	Mgo	Na2o2,k2o	C	Tio2
55-65	26-35	1-5	0.2-0.6	1-2	0.5-4.0	0.01-2	0.5-2

 

1. Application of cenospheres

   Cenospheres are extremely free flowing power composed of hard shellde , small spheres. The advantages of it are ultra low density, nonpoisonous, corrosion-resisting, thermal stable, high partial strenth, good insulating, suond isolating, low water absorption, low thermal conductivity. Thus they are extensively used in the rubber, equipment of glass fiber reinforced plastic, polyester, plastic as filler. Cenospheres also are utilized for coating, paint and oil industry. It can not only reduce the weight of end product and product cost but also increase the strength.
Application of cenospheres
 
Ceramics
 
Refractories, castables, tile, fire bricks, aluminum cement,insulating materials, coatings plastics BMC, SMC,injection molding moulding,extruding,PVC flooring,film,nylon,high density polyethyene, low density polyethyene, polyethyene construction specialty cements, mortars, grouts,stucco,roofing materials, acoustical panels, coatings, shotcrete,gunite recreation marine craft, flotation devicees,bowling balls, surf boars, kayaks, golf equipment,footwear, lawn & technology oil well cements,drilling muds, industrial coatings, grinding materials, aerospace coatings & composites, explosives, propeller blades
 
High polymer filler
Building materials
Oil industry
Coating and panit
Sound and heat insulation materials
4,specification of cenospheres

TYPE	BP11	BP21	BP31	BP41	BP51	BP61
Diameter (Ų m)	15-300	150-300	15-175	15-150	15-100	15-75

 
        Qualification text of cenospheres

1. Particle size range:
2. Average bulk density (g/cc):0.33-0.65
3. Moisture: 1%
4. Color: deep grey-greyelight grey-off white

 
                 Particle size distribution
 

Particle size (ų)	15-300	150-300	15-175	15-150	15-100	15-75
type	BP11	BP21	BP31	BP41	BP51	BP61
%passing 400 microns	100	100	100	100	100	100
%passing300 microns	97-100	99-100	100	100	100	100
%passing 175 microns	75-95	60-80	99-100	100	100	100
%passing 150 microns	60-90	5-20	75-90	90-100	100	100
%passing 100 microns	30-65	5-10	45-65	40-60	95-100	100
%passing 75 microns	20-35	2-5	20-40	15-30	20-50	90-100
%passing 45 microns	2-5	0.1-1.0	2-5	2-10	2-10	5-20