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Tuesday, June 19, 2007

Iron Oxide

Iron Oxide
Formula : Fe2O3
Formula : FeO
Elements : Iron, Oxygen
CAS Number : 1309-37-1
CAS Number : 1332-37-2
CCOHS Record Number : 344
RTECS Number : NO7400000
RTECS Number : NO7525000 (fume)
Alpha-ferric oxide
Alpha-iron oxide
Anhydrous iron oxide
Anhydrous oxide of iron
Bauxite residue
Black oxide of iron
Blended red oxides of iron
Caput mortuum light
CI 77489
Colloidal ferric oxide
Diiron trioxide
English iron oxide red
Ethiops iron
Ferric Oxide
Ferric oxide hydrate
Ferrosoferric oxide
Ferrous ferrite
Ferrous oxide
Gamma-ferric oxide
Hydrated ferric oxide
Hydrous ferric oxide
Iron ferrite
Iron monooxide
Iron monoxide
Iron Oxide
Iron oxide (Fe203) , hydrate
Iron oxide (Fe2O3) , hydrate
Iron oxide (FeO)
Iron oxide red
Iron oxide, dust and fume
Iron oxide, spent
Iron oxides
Iron sesquioxide
Iron sponge, spent obtained from coal gas purification
Iron trioxide
Iron(2) oxide
Iron(II) oxide
Iron(II,III) oxide
Iron(III) oxide
Iron(III) oxide, aerosol
Iron(III) oxide
Natural iron oxides
Natural wuestite
Red iron oxide
Red oxide
Specular iron
Triiron tetraoxide
Triiron tetroxide

Common Names:

English : red oxide
French : oxyde rouge
German : Oxid rot
Italian : rosso ossido
Portuguese : vermelho óxido
Spanish : rojo óxido
Alternate Names:
English: English red, Indian red, light red, red iron oxide, Venetian red
French: rouge Indien
Spanish: rojo Indio
Mars red is the name given to the artificial substitute of natural red iron oxide.
Origin and History
Natural red iron oxide is based on the mineral ore hematite. The word hematite comes from the Greek word hema, meaning blood and was given the name "bloodstone" in ancient Greece (Theofrastus, c. 325 B.C.), implying that the mineral is blood red in color. Hematite is an important ore of iron and its blood red color in the powdered form lends itself well as a pigment. Hematite is among the oldest pigments known to humankind and has been used by every major civilization.SourceIn nature hematite rarely occurs as crystals but usually as nodules or earthen masses. The color of the crystalline form varies from steel-gray to black, while crypto-crystalline hematite is dull red to bright red. This common mineral is found in deposits of the most diverse types. There are several varieties of hematite, two of which are suitable for use as pigments: oolitic hematite, which is a friable earth composed of small rounded grains of dark red color that are lustrous and greasy to the touch; and hematite rose, a fine-crystalline and crypto-crystalline form of hematite of red color, which are usually encountered in friable earthen masses or reniform aggregates of bladed crystals in a circular arrangement giving the appearance of a rose. Red iron oxides (hematite) are found around the world and have been used as pigments since prehistory.Permanence and


calcium hypochlorite
carbon monoxide
hydrogen peroxide
Health & Regulatory Guidelines
EPA Regulations:
Marine Polutant: Yes
NIOSH Guidelines:
TWA: 5 mg/m³
IDLH: 2500 mg/m³
OSHA Regulations:
TWA: 10 mg/m³
TWA Vacated: 10 mg/m³

49 CFR 172.101 - Hazardous Materials Table

Hazardous materials description and proper shipping names :Iron oxide, spent, or Iron sponge, spent obtained from coal gas purification.
Kenneth Barbalace. Chemical Database - Iron oxide.
1995 - 2007. Accessed on-line: 6/19/2007

Sunday, June 10, 2007

FAQs on Iron Oxide

What is the difference between Natural and Synthetic Iron Oxides ?
Three different iron oxide minerals normally are the basis for all Iron Oxide Pigments.These minerals are:Goethite (Yellow Iron Oxide) Hematite (Red Iron Oxide) Magnetite (Black Iron Oxide) These minerals can be produced naturally by geologic activities or can be synthetically produced in chemical reactions.
The color shade of the iron oxide is determined by the size of the individual mineral crystal.
Reds - Small Particle/Yellow Cast - Large Particle/Blue Cast Yellows - Small Particle/Green Cast - Large Particle/Red Cast Blacks - Small Particle/Brown Cast - Large Particle/Blue Cast
While the iron oxide mineral in both Naturals and Synthetics is similar, Natural Iron Oxides contain contaminates which often reduce their tinting strength in comparison to their Synthetic counterparts.
These contaminants are of two types:
(1) Those with coloring properties and those that act as an extender. The coloring contaminants are most often Manganite, MnO, which gives the Umbers their dark colored masstones.
(2) The non-coloring contaminants are most often natural extenders used in industry as industrial fillers, including clays, talc, and calcium carbonates.
How does particle size affect a pigment’s dispersibility ?
The color of a given pigment is determined by its particle size and shape. However, pigments are usually found as clusters of particles rather than individuals. These pigment clusters influence the tinting strength and grind that a given pigment can achieve.
The particles in the clusters are held together by many different mechanisms. The most common of these is the soluble material that cemented pigment particles together in the drying process. Another mechanism is the presence of electrical charges between individual particles. As pigment particles become smaller in size, decreasing in surface area, the strength of the electrical charge increases, making the pigment more difficult to disperse.
Pigment manufacturers can vary the dispersibility of a pigment by different grinding processes
which break down these pigment clusters into smaller clusters and particles.
The final customer will also break down these various pigment clusters in their processing. The degree of de-agglomeration depends on the energy of their dispersion process.
The actual grind of a product depends not only on the pigment but on the vehicle system in which it is being dispersed and the grinding technique used to disperse the pigment in the vehicle.
What are the heat stability properties of Pigments?
Most of the pigments that manufacturer markets are heat stable in most applications, with the exception of two important types of material. These include any pigments based on Yellow or Black Iron Oxides. Yellow Iron Oxides, FeO-OH, will begin to change into Red Iron Oxides at temperatures above 350 degrees Fahrenheit. Black Iron Oxides, Fe304, will begin to change into Red Iron Oxides at temperatures above 300 degrees Fahrenheit.
Groups of pigments containing these materials include:
Ochre Raw Sienna Synthetic Yellow Iron Oxide Synthetic Black Iron Oxide Raw Umber Many Brown Blends of Iron Oxides

The Iron Oxide Industry has addressed the problems of heat stability by developing heat stable yellows and blacks. These are not pure iron oxides, but rather combinations of yellow or black iron oxides processed together with other materials. These heat stable yellows are Zinc Ferrites; the blacks are Iron Manganese Oxides.
Can One manufacturer’s pigments be combined with other pigments?
Yes, any of manufacturer’s pigments can be combined with other pigments; this is how they are normally used. Most often the pigment is combined with the white pigment Titanium Dioxide to produce a tint shade.

This process is often used when a gray color is desired. Often color formulators will make a gray by combining a carbon black with a TiO2 white and shading to the tone of gray desired. A more effective gray can be achieved by matching the undertone of the dark pigments available with the desired end shade. This process requires a lot less expensive shading. Many of the greenish grays that we associate with office equipment, like computers, are achieved this way by mixing raw umber with TiO2 white.

Raw Umbers are also utilized as toning pigments because of their neutral shade. This enables a formulator to darken a color without affecting the chromaticity of the brighter color. This is often useful when formulating pastel shades using bright organic pigments.

Friday, June 1, 2007

The Blast Furnace:

Blast furnace is a type of metallurgical furnace used for smelting to produce metals, generally iron.

In a blast furnace, fuel and ore are continuously supplied through the top of the furnace, while air (or pure oxygen) is blown into the bottom of the chamber, so that the chemical reactions take place throughout the furnace as the material moves downward. The end products are usually molten metal and slag phases tapped from the bottom, and flue gases exiting from the top of the furnace.

According to this broad definition, bloomeries for iron, blowing houses for tin and smelt mills for lead would be classified as blast furnaces. However, the term has usually been limited to those used for smelting iron ore to produce pig iron, an intermediate material used in the production of commercial iron and steel.

How it works: The Blast Furnace:

The purpose of a blast furnace is to chemically reduce and physically convert iron oxides into liquid iron called "hot metal". The blast furnace is a huge, steel stack lined with refractory brick, where iron ore, coke and limestone are dumped into the top, and preheated air is blown into the bottom. The raw materials require 6 to 8 hours to descend to the bottom of the furnace where they become the final product of liquid slag and liquid iron. These liquid products are drained from the furnace at regular intervals. The hot air that was blown into the bottom of the furnace ascends to the top in 6 to 8 seconds after going through numerous chemical reactions. Once a blast furnace is started it will continuously run for four to ten years with only short stops to perform planned maintenance.

The Process :

Iron oxides can come to the blast furnace plant in the form of raw ore, pellets or sinter. The raw ore is removed from the earth and sized into pieces that range from 0.5 to 1.5 inches. This ore is either Hematite (Fe2O3) or Magnetite (Fe3O4) and the iron content ranges from 50% to 70%. This iron rich ore can be charged directly into a blast furnace without any further processing. Iron ore that contains a lower iron content must be processed or beneficiated to increase its iron content. Pellets are produced from this lower iron content ore. This ore is crushed and ground into a powder so the waste material called gangue can be removed. The remaining iron-rich powder is rolled into balls and fired in a furnace to produce strong, marble-sized pellets that contain 60% to 65% iron. Sinter is produced from fine raw ore, small coke, sand-sized limestone and numerous other steel plant waste materials that contain some iron. These fine materials are proportioned to obtain a desired product chemistry then mixed together. This raw material mix is then placed on a sintering strand, which is similar to a steel conveyor belt, where it is ignited by gas fired furnace and fused by the heat from the coke fines into larger size pieces that are from 0.5 to 2.0 inches. The iron ore, pellets and sinter then become the liquid iron produced in the blast furnace with any of their remaining impurities going to the liquid slag.

The final raw material in the ironmaking process in limestone. The limestone is removed from the earth by blasting with explosives. It is then crushed and screened to a size that ranges from 0.5 inch to 1.5 inch to become blast furnace flux . This flux can be pure high calcium limestone, dolomitic limestone containing magnesia or a blend of the two types of limestone.

Since the limestone is melted to become the slag which removes sulphur and other impurities, the blast furnace operator may blend the different stones to produce the desired slag chemistry to create optimum properties such as has a low melting point and a high fluidity.
All of the raw materials are stored in an ore field and transferred to the stockhouse before charging. Once these materials are charged into the furnace top, they go through numerous chemical and physical reactions while descending to the bottom of the furnace.
The iron ore, pellets and sinter are reduced which simply means the oxygen in the iron oxides is removed by a series of chemical reactions.
At the same time the iron oxides are going through these purifying reactions, they are also beginning to soften then melt and finally trickle as liquid iron through the coke to the bottom of the furnace. The coke descends to the bottom of the furnace to the level where the preheated air or hot blast enters the blast furnace. The coke is ignited by this hot blast and immediately reacts to generate heat.

Since the reaction takes place in the presence of excess carbon at a high temperature the carbon dioxide is reduced to carbon monoxide.
The product of this reaction, carbon monoxide, is necessary to reduce the iron ore as seen in the previous iron oxide reactions.
The limestone descends in the blast furnace and remains a solid while going through it s first reaction.

This reaction requires energy and starts at about 875°C. The CaO formed from this reaction is used to remove sulphur from the iron which is necessary before the hot metal becomes steel.


This article was prepared by John A. Ricketts, Ispat Inland, Inc.

This article is based on proprietary information kindly supplied by:-

ATSI Engineering

415 Commerce

Dr.Amherst NYUSA

Red Hills :Rocks and Minerals

The rugged topography of the Red Hills doesn't fit the stereotypical portrait of the Kansas landscape. Located in southern Kansas, mostly in Clark, Comanche, and Barber counties, the Red Hills are part of the Permian deposits that geologists call red beds. They get their color from iron oxide (rust), which turns bright red when exposed to oxygen.
During the latter part of the Permian Period, about 260 million years ago, several thousand feet of brick-red shales, siltstones, and sandstones--along with interbedded layers of gypsum and dolomite--were deposited in Kansas. These Permian deposits have been exposed by erosion along the southern border of the state, forming a series of relatively flat-topped red hills, capped by light-colored gypsum or dolomite.

Source:Kansas Geological Survey staff,April 1999

Sunday, May 27, 2007

ITALY’s Red Ochre; Umber, Earthbrown, Brown Ochre

Due to contain iron and manganiferous clay or tone, Umber’s colour is brown. As manganese content increase, brown colouring also increases. This type of Umber brown ochre’s brown ground found in Italy, Cyprus, and flat country Netherlands.

RED PIGMENT : Red Ochre / Red Earths

RED PIGMENT Name : Red Earths / Red Ochre

Composition : Iron(III) oxide chromophore (Fe2O3 + clay + silica)

Band Wavenumbersa / cm-1 and Relative Intensities b: 220vs; 286vs; 402m; 491w; 601w
Excitation Wavelength and Power : 632.8 nm 3 mW
Hematite : Hematite has the formulae Fe2O3.

It has a relative hardness of 7.It is the most abundant and important ore or iron.

OCHRES are the natural mineral pigments occurring in various shades and colours, generally ranging from yellow to red to brown. The colouring power is mainly due to oxides of iron. They are also called 'coloured earths'. Ochre is a colouring mineral. The hydrous iron oxide imparts yellow colour and the unhydrous red colour. The amount of iron oxide (Fe2O3) in ochre is quite variable. It may be as low as about 20%, going up to 70%. The natural mineral pigment dominates in the market because of its cheapness, abundance in occurrence and good pigmentary quality. Depending upon the colour, the ochres are called red ochre, yellow ochre, green earths, sienna, umber etc.

In addition to red ochre, the red oxide of iron, commonly called 'red oxide', is an important natural pigment. It results from the alteration of hematite and ferruginous laterite and consists essentially of Fe2O3 having pigmentary quality.

Red oxide usually contains about 70% Fe2O3 . Sienna is a brownish yellow containing about 60% Fe2O3 with some quantity of manganese oxide. Due to a huge deposit located in Sienna in Italy it is called as Sienna. Sienna is marketed in the raw and burnt (calcined) states. The colour of the latter is brownish red.

Umber is named after A Central Italy based department first tested Red Ochre so it was name in Umber.Umber is a greenish brown containing some 45% Fe2O3 and 15% MnO2. Umber of good quality, called Turkish Umber, is found on the island of Cyprus. Numerous deposits of colouring earths occur in various parts of the world. Preparation of pigments from red oxide requires an elaborate process. Since it is hard, it has to undergo milling and finally separation of the coarse particles by elutriation.

Ochres being friable are crushed and lixivated, just like china-clay, to obtain extremely fine-textured material of uniform colour. Refining by elutriation followed by drying often improves both iron content and colour.

Application or uses of Ochres: Mainly its use is as tinting colours and for colour washes, distemper and oil paints. It is also used in making coloured paper. For this particular use ochre and china-clay or soapstone, after dissolving in water in paste form, are acreened and added in the beater for the preparation of coloured paper pulp. Red oxide pigments are widely used as primers for painting structural steel, automobile bodies, ship bottoms, etc.
Properties of Ochres: The staining power, brilliance and fineness of texture are the main properties by which an ochre is judged for its quality and value in industry. The tint should be wholly of the inorganic ingredient.

Occurrence in Persian Gulf and Spain : The highest red oxides are found along the Persian Gulf and in Spain. The Persian deposit is mined on the Omur island. A brown oxide found in Pennsylvania, USA, is known as 'metallic brown'.

Pigment Information :Ochre is a natural earth containing silica and clay tinted by hydrous forms of iron oxide, such as yellow-brown limonite or brown-yellow to green-yellow goethite, and traces of gypsum or manganese carbonate. Limonite is a general term used to describe all forms of hydrated iron oxide minerals (FeO(OH)) that occur as natural clay or earth.
Limonite includes the minerals goethite, akaganeite and lepidocrocite. To be considered an ochre, the content of iron oxide must not be less than 12%. Depending upon the content of hydrated iron oxide, the color of ochre varies from light yellow to golden to orange.
The higher the content of iron oxide in an ochre the greater its tinting strength and hiding power. Most yellow ochres are normally not calcined as heat does relatively little to alter their color. Like red iron oxides (hematite), they are found around the world and have been used as pigments since prehistory. French ochre, historically one of the best grades of limonite, contains about 20% iron oxide and is high in silica. In Russia, high quality ochres can be obtained from the Izyumskyy deposit in Ukraine, and the Zhuravskoye, Skarnovskoye and Dubovikovskoye deposits in the Voronezh region, and the Lyubytinskoye deposit near Novgorod.

Oil Absorption and Grinding: Ochre absorbs a medium amount of oil. It slows the drying of oil paint, but forms an excellent film.
Toxicity : Ochre is not considered toxic, but care should be used in handling the dry powder pigment to avoid inhaling the dust.Ochre, Gold :Gold ochre is a natural earth containing clay tinted by hydrated iron oxide, such as yellow-brown limonite or brown-yellow to green-yellow goethite. Ochre, Warm Red :Warm red ochre is a natural earth containing clay tinted by hydrated iron oxide that gives an exceptionally warm orange red hue.

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 :