Talc

Steatite, Talc, French chalk or Soapstone - is chemically a hydrous Magnesium silicate with a basic formula of 3MgO 4SiO2 H2O. The crystal structure of pure talc is a brucite sheet (Mg12O12H4) sandwiched between two silica (SiO2) sheets, to form talc layers that are superimposed indefinitely. Each layer is electrically neutral It is one of the softest minerals and has characteristic soapy feel. Its hardness being 01 on Moh's Scale of hardness, it can be easily cut and scratched by nail. It possesses lubricating properties, high luster and sheen, chemical inertness, high fusion point, low conductivity to heat and electricity. The colour of the material varies from pure white to silvery white.

APPLICATIONS:-

Cosmetics:

Talc forms the base of many cosmetics.

Liquid or Powdered Formulations:

The platy crystalline structure of talc helps to impart a smooth feeling to liquid and powdered facial makeup applications. It assists in adhesion of the liquid or the powder to the skin, improves coverage, and helps to absorb unwanted skin oils. The smaller particle size talc can extend the more expensive white and color pigments (such as TiO2, iron oxides, and boron nitride) and when used as a filler or solid dilutant, can help reduce costs.

Typical uses include:

Liquid foundations, concealers, blushes, rouges and bronzing gels

Pressed face powders, eye shadows, blushes, foundations, eyebrow colors and eyeliners

Loose face or body powders, blushes, bronzers, and rouges

Creams and Lotions, face, hand and body creams and lotions: - Talc's slippery nature adds a lovely texture to a cream which spreads easily.

Solid stick deodorants: - Talc is an inert filler, essentially the solid equivalent of the water used as a dilutant. Talc imparts easy gliding properties to the stick. Talc can also help to lift the fragrance in a stick deodorant.

Dry shampoos: - Talc-based powdered shampoos are for those who cannot wash their hair because of time or disability. Because of talc's natural oleophilic properties, talc absorbs the oils and grime from the hair. Talc based dry shampoos can also be formulated for pets.

Ceramics

Talc is increasingly being used in the manufacture of artwares, jars, wall and floor tiles. It serves as a non-plastic ceramic material. The addition of talc in suitable proportions in the body of mixtures for porcelain, jars etc. prevents the crazing (cracking) effect on the glazes. The proportion of talc in the ceramic body may go upto 80%. It is valued for its refractoriness and stability, as well as extremely low shrinkage at high temperature. Talc converts into clino-enstatite at about 1300C. Between 800C to 840C, the water molecules are driven off and talc dissociates into enstatite and amorphous silica without undergoing any change in shape, the shrinkage being 0.0005 inch only.

Electrical Industry

In the manufacturing of ceramic electric goods, the talc should not contain more than 1.5% FeO and CaO. Some consumers do not regard CaO as having any harmful effect. Steatite suitable for the manufacture of 'lava' insulators must be dense, compact, uniform and homogeneous intexture, free from any inclusion and parting planes. It should not contain CaO more than 1.5% and Fe2O3; more than 1%. The iron oxide is a colourant and gives the fired shapes an unattractive colour. An increase of iron oxide above two per cent decreases the 'Q' value (ratio of reactance to resistance) and increases the dielectric constant. CaO imparts abrasiveness and usually a short vitrification range and sometimes a high firing shrinkage.

Paint industry

Talc is used in the production of decorative paints, industrial coatings, pigment pastes, primers, enamels, adhesives, putties and other products of the industry. Due to natural properties and fine grinding of talc it improves fluidity and coverage properties of paint, imparts corrosion, acid, thermal, air resistance to them, increase smoothness and stability of paint products.

Plastics

Both the Coated and Uncoated grades are used as reinforcing filler. Talc is being increasingly used in HDPE, PP, LDPE, PVC, ABS & thermosetting compounds. It is excellent filler due to blending characteristics and thermal and electrical resistant. It is chemically inert. It provides the smooth feel to plastic surface. Due to its chemical inertness, superior electrical and thermal resistance and other properties talc imparts stiffness, hardness, tensile strength of plastic products, improves quality of their surfaces, gives them electrical, chemical and thermal resistance.

Paper Industry

Talc is used in three stages of paper making - as a filler, to control pitch and stickiness and in paper coating. During the paper making process, the micro impurities can clog the paper machinery. Talc being hydrophobic absorbs these micro droplets thus controlling their stickiness and avoids clogging. High brightness of talc leads to reduction in usage of expensive whitening agents and helps in controlling gloss of the coat. Talc gives smoothness, yellow index, porosity, opacity to paper, improves its yellow index and reduces the deterioration of the machinery.

Rubber Industry

It acts as a filler /dusting agent/anti-sticking agent. Talc should be of fine mesh all passing through 200 mesh.

Textile Industry

Textile industry also prefers talc powder free from grit and colouration, which is used both for loading and bleaching certain types of cotton goods. Inferior grades are used in back filling textiles.

Detergents

In detergent powder also, Talc acts as a carrier of detergents and also reduces the cost. It is harmless to skin.

Insecticides & Pesticides: As an inert carrier for insecticides /pesticides dusts.

Foundry facings: For giving final finishes to the mould.

Animal feed and pharmaceutical