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Saturday, May 26, 2007

Description : Red Ochre (Earthy Haematite)

Class : Oxides & Hydroxides

The earthy form of haematite is red ochre, yellow ochre is an earthy from of limonite (a mix of iron hydroxides and oxides). Both red and yellow ochre is used as a pigment and is often used as body paint with a spiritual significance by many tribal peoples across the world.

A pigment is a material that changes the color of light it reflects as the result of selective color absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which the material itself emits light. Many materials selectively absorb certain wavelengths of light. Materials that humans have chosen and developed for use as pigments usually have special properties that make them ideal for coloring other materials. A pigment must have a high tinting strength relative to the materials it colors. It must be stable in solid form at ambient temperatures.

For industrial applications, as well as in the arts, permanence and stability are desirable properties. Pigments that are not permanent are called fugitive. Fugitive pigments fade over time, or with exposure to light, while some eventually blacken.
ISO standards define various industrial and chemical properties, and how to test for them. The principal ISO standards that relate to all pigments are as follows:
ISO-787 General methods of test for pigments and extenders ISO-8780 Methods of dispersion for assessment of dispersion characteristics

Many manufacturers of paints, inks, textiles, plastics, and colors have voluntarily adopted the Colour Index International (CII) as a standard for identifying the pigments that they use in manufacturing particular colors.

Friday, May 25, 2007

Red ochre in Rajasthan

Red ochre

The dry ingredient, ochre, was mixed with some type of liquid raw material to create a rough paint. The liquid material was usually seal oil or cod liver oil.
Red ochre is pigment made from naturally tinted clay.Chemically,it is hydrated iron (III) oxide.
Ochres are non-toxic, and can be used to make an oil paint that dries quickly and covers surfaces thoroughly.

To manufacture ground ochre, ochre clay is first mined from the ground. It is then washed in order to separate sand from ochre, which can be done by hand. The remaining ochre is then dried in the sun and sometimes burned to enhance the natural color.

About the chemical structure:

Chemical name: Anhydrous iron(III)-oxide

Formula: Fe2O3

How Red Ochre is made:


Natural mineral consisting of silica and clay owing its color to iron oxide. It is found throughout the world, in many shades, in hues from yellow to brown, and faint blue. The best brown ochre comes from Cyprus. The pigment has good hiding power and excellent permanence in all media.
Natural variety of pigment:
Colored earth is mined, ground and washed, leaving a mixture of minerals - essentially rust-stained clay. Ochre can be used raw (yellowish), or roasted for a deeper (brown-red) color from loss of water of hydration. Produces a quick-drying oil paint. Brief description of Red Ochre: Earthtones from cream to brown

Names for Red Ochre:

Pronounciation: red oak • ur

Alternative names: earth pigments

Word origin: The name "Red Ochre" comes from Greek ochros = yellow, pale yellow.

Non-English names: German :Roter Ocker Chemical name: Anhydrous iron(III)-oxide

Further reading:
Red Ochre and Yellow ochre, from Pigments through the ages

Projects reviewed by Expert Committee (Mining) of MoE&F list of mining projects appraised during year 2005, 2006 and Till Feb'2007 Rajasthan State

WII is currently represented on the Expert Committee for Environmental Appraisal of mining projects of Ministry of Environment & Forests (Govt. of India) to facilitate in environmental decision making. Projects reviewed by Expert Committee (Mining) of MoE&F

List of mining projects appraised 2005,2006 and Till Feb'2007 from Only Rajathan State can be viewd on following link.

A 100% family owned business was established in 1972 in Rajasthan, in the North-West of India, where high quality & extensive Mineral deposits of Wollastonite & Calcite were discovered. The deposits were located in an inaccessible mountainous region inhabited by an uneducated tribe. The absence of basic infrastructure like power, water, roads and skilled work force did not deter Wolkem from staking its claim on what was to emerge as one of the most important Wollastonite deposits worldwide and calcite deposits in India. These early hardships forged Wolkem into a company that is today:

The world's largest producer of Wollastonite
India's largest producer of Calcite (GCC)
India’ leading producer of Wet Ground Calcium Carbonate (WGCC)
A One – Stop – Shop for industrial Minerals like Talc, Kaolin, Dolomite, Calcite, WGCC and Wollastonite.
A recognized supplier of surface treated / modified industrial minerals
Has 13 mines and processing plants, across 7 states/provinces of India
Produces over 80mineral grades
Sells to over 20 diversified customer industries
Exports to over 20countries across 4continents
Employs over 2000people
A company which regularly wins awards for its exceptional performance in Mining, R&D, Exports, Health and Safety, Environment Management and Social Welfare
One of the first few Industrial Mineral companies in India to get the ISO9001and 14001 certification for its mines and processing plants

Lee Universal Enterprises is supplying minerals from Udaipur, Chittorgarh,Rajasthan. Gujarat and Karnataka.
Mineral mining & processing center-India of high quality white china clay, alumina grade bauxite ore, high alumina clay, cement grade red ochre, levigated china clay koalin for tiles and ceramic, Our minerals are used in various applications.

Company owning mines, processing and supplying minerals like high alumina clay, white china clay, red ochre, levigated china clay, bauxite ore and fine iron ore.

Mines Production per Annum
High Alumina Clay : 1 lakh tons
White China Clay : 3 lakh tons
Red Ochre : 11 lakh tons
Bauxite : 1.2 lakh tons
Levigated China Clay P-100 : 3000 tons
Levigated China Clay P-300 : 10,000 tons
Bauxite ore 48% alumina content : 50,000 m.t. per month
Fine Iron ore 63.5% Fe grade : 50,000 m.t.per month
Mainly these minerals are trusted by corporates secotrs.
Inquiry :