Precipitated silicaPrecipitated silica is a silica (SiO2) produced by precipitation from a solution containing silicate salts. As of 1999, more than 1M tons/y were produced, mainly for use in tires and shoe soles.[1]

Production

The production of precipitated silica starts with the reaction of an alkaline silicate solution with a mineral acid. Sulfuric acidand sodium silicate solutions are added simultaneously with agitation to water. Precipitation is carried out under alkalineconditions. The choice of agitation, duration of precipitation, the addition rate of reactants, their temperature and concentration, and pH can vary the properties of the silica. The formation of a gel stage is avoided by stirring at elevated temperatures. The resulting white precipitate is filtered, washed and dried in the manufacturing process. 

Na2(SiO2)7 + H2SO4 → 3.3 SiO2 + Na2SO4 + H2O

Precipitated silicas are synthesized by acidifying sodium silicate. In nearly all commercial processes, sulfuric acid is used as the acid source. Under standard conditions, the sodium silicate solution and the acid are fed simultaneously in a stirred vessel containing water. Precipitation is carried out under alkaline conditions. The choice of agitation, duration of precipitation, the addition rate of reactants, their temperature and concentration, and pH can vary the properties of the silica. The formation of a gel stage is avoided by stirring at elevated temperatures.

In the next stage, the precipitated silica slurry is washed to remove soluble salts. The washing conditions, although important, have a negligible effect on the final product properties. Different filter types such as filter presses, rotary, or belt filters can be used. The resultant filter cake with typical solid content between 15-25% is then dried. The most common drying techniques are spray drying and rotary drying, which give rise to different particle shapes, degrees of agglomeration, and to a lesser extent porosity. The dried silica may be subjected to milling and classifying steps to obtain a specific particle size distribution.

The precipitated silicas distinguish themselves from silica gels on the basis of pore structure. Precipitates typically have a broad meso/macroporous pore structure reflected in the pore size distribution, whereas gels generally have a more narrow microporous or mesoporous structure.

All Grace Davison precipitated silicas are synthetic amorphous silica products. In contrast to naturally occurring silicas, the synthetic origin of these materials eliminates the risk of contamination with crystalline quartz particles as it may well occur in mined products. Amorphous silica, in contrast to crystalline silica such as cristobalite or quartz, does not present a potential health hazard to workers with respect to irreversible lung injuries such as lung tumors or silicosis. 

Properties:

The particles are porous. Primary particles with a diameter of 5 - 100 nm, and specific surface area 5-100 m2/g.Agglomerate size is 1 - 40 µm with average pore size is > 30 nm. Density: 1,9 - 2,1 g/cm3.

Applications:

Filler , softener and performance improvement in rubber and plastics

Cleaning, thickening and polishing agent in toothpastes for oral health care

Food processing  and pharmaceuticals additive as anti caking, thickening agent, absorbent to

make liquids into powders.

Food rheology  modifier

Defoamer  component.

Product manufacturer and supplier:

A. B. Enterprises, MumbaiAddress: No. 202, Shradanand Building - 272 / 274, Samuel Street ,Mumbai - 400003, Maharashtra, Indiahttp://www.abenterpriseindia.com/Phone: 09953353451

Phone: 08447497512

Yash Chemicals, PuneAddress: Shop No. D -31, Gagan Avenue, Near Sai Service, Kondhwa-B. K. , Pune - 411048, Maharashtra, Indiahttp://www.yashchemicals.net/

Phone: 08377807557

Mahavir Chemical Industries, DelhiAddress: 16/3, W. E. A., Abdul Aziz Road, Karol Bagh , Delhi - 110005,Delhi, Indiahttp://www.mahavirquartz.com/

Phone: 08586925463

Shri Krishna Enterprises, DelhiAddress: B 402, Rishabh Tower, Karkardooma Community Center Opposite Karkardooma Metro Station, Delhi - 110092, Delhi, Indiahttp://www.skechemicals.co.in/

Phone: 08447499310

A. B. Enterprises, Mumbai

Address: No. 202, Shradanand Building - 272/ 274, Samuel Street ,Mumbai - 400003, Maharashtra, Indiahttp://www.abenterprisesindia.com/

Phone: 08586972964

KK India Petroleum Specialities Pvt. Ltd., MumbaiAddress: No. 706, Palm Spring Center, Link Road, Malad West ,Mumbai - 400064, Maharashtra, Indiahttp://www.kkindia.co.in/

Phone: 08376808427

Caltron Clays & Chemicals Private Limited, Mumbai

Address: Office No. B - 37, Ashoka Super Market, S. V. Road, Goregaon West , Mumbai - 400104, Maharashtra, Indiahttp://www.caltron-clays.com/

Sodium silicate manufacturers (raw material)

Phone: 08447574103

Triveni Chemicals, VapiAddress: No. 135, Pancharatna Char Rasta, G. I. D. C. , Vapi - 396 195, Gujarat, Indiahttp://www.trivenichemical.com/

Phone: 08376808198

Triveni Aromatics And Perfumery Private Limited, Vapi

Address: No. 134, Pancharatna Char Rasta, G. I. D. C. , Vapi -386195, Gujarat, Indiahttp://www.trivenichemicals.com/

Phone: 08447497512

Yash Chemicals, PuneAddress: Shop No. D -31, Gagan Avenue, Near Sai Service, Kondhwa-B. K. , Pune - 411048, Maharashtra, Indiahttp://www.yashchemicals.net/

Phone: 09953352778

Suvidhi Industries, VapiAddress: Plot No. 572, Shed No. C1B / 73 100 Shed Area, G. I. D. C.,Vapi - 396195, Gujarat, Indiahttp://www.chemicalsupplier.in/

Phone: 08447573014

Bombay Lubricants Oil Company, MumbaiAddress: No. 601, Reena Complex, Near Bus Depot, Vidyavihar West, Mumbai - 400086, Maharashtra, Indiahttp://www.bombayoil.in/

Phone: 08447512263

Jay Dinesh Chemicals, AhmedabadAddress: No. 303/304, Muralidhar Complex, Near Fatehpura Post Office, Paladi , Ahmedabad - 380 007, Gujarat, Indiahttp://www.jaydineshchemicals.com/

Manufacturers of soda ash (raw material )

Phone: 08447569063

B. K. Chemicals, PuneAddress: B - 2, Shrushti Apartment, 1st Floor, . Near Century Enka Colony No. 2, Pune - Nasik Highway, Bhosari, Pune - 411039,Maharashtra, Indiahttp://www.bkchemicals.in/

Phone: 08447497512

Yash Chemicals, PuneAddress: Shop No. D -31, Gagan Avenue, Near Sai Service, Kondhwa-B. K. , Pune - 411048, Maharashtra, Indiahttp://www.yashchemicals.net/

Phone: 08447574103

Triveni Chemicals, VapiAddress: No. 135, Pancharatna Char Rasta, G. I. D. C. , Vapi - 396 195, Gujarat, Indiahttp://www.trivenichemical.com/

Phone: 08586925463

Shri Krishna Enterprises, DelhiAddress: B 402, Rishabh Tower, Karkardooma Community Center Opposite Karkardooma Metro Station, Delhi - 110092, Delhi, Indiahttp://www.skechemicals.co.in/

Phone: 08376805980

Surya Min Chem, Delhi

Address: Plot No. 87/1, Barwala, Main Bhawana Road, Behind Corporation Bank, Near DSIIDC Industrial Area, Bawana, Delhi -110039, Delhi, Indiahttp://www.suryaminchem.com/

Phone: 09953355229

D. D. Enterprises, Pune

Address: No. 501, Yugay Residency, Opposite Raja Mantri Garden, Near Hotel Sweekar, Erandwane, Pune - 411 004, Maharashtra, Indiahttp://www.ddenterprise.in/

Other applications of precipitated silica:

Used to make adhesives Chappals

Conveyor Belt  & Transmission belt 

 PVC Sheets

Railway Pads 

 Rice Rollers and Rubber Rollers

Rubber Products and Rubber Hoses

Silicon Tubes

Rubber and Solid Tyres 

Textile Cots And Aprons