Iron Oxide Red
Iron oxide red, also known as Pigment Red 101, is a synthetic inorganic pigment widely used for its rich red color, good opacity, and permanence. It is a type of iron oxide (Fe2O3) and is created through controlled oxidation of iron. It’s one of the most commonly used red pigments in the world, and it provides a safe and stable colorant for various applications.
Chemical Composition:
- Chemical Formula: Fe2O3
- CAS Number: 1309-37-1
- Other Names: Red Iron Oxide, Venetian Red, Indian Red, Mars Red.
Physical Properties:
- Color: Deep red to reddish-brown (varies depending on formulation)
- Form: Fine powder
- Density: 5.2 - 5.3 g/cm³
- Stability: Extremely stable; resistant to UV degradation and high temperatures.
Manufacturing Process:
Iron oxide red is typically produced through one of the following methods:
- The Precipitation Method: In this method, iron salts (like iron sulfate or iron chloride) are reacted with an alkali (like sodium hydroxide), followed by heat treatment, leading to the formation of iron oxide.
- The Calcination Method: Iron compounds like iron hydroxide or iron sulfate are heated to a high temperature, causing them to undergo a transformation into iron oxide (Fe2O3).
Uses and Applications:
Iron oxide red is highly versatile and is used across various industries, including:.
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Ceramics:
- Iron oxide red is used in ceramics and pottery to produce rich red and brown shades.
- Commonly applied as a glaze or as part of the ceramic body.
- The usage rate can vary between 2% and 10% depending on the application.
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Cosmetics:
- Used in the formulation of makeup products such as blush, eyeshadows, and lipsticks.
- Typical usage rate: 1% to 5%, ensuring safety and aesthetic appeal.
- Mix 1/8 to 1/2 tea spoon of the oxide powder with distilled water for every 500 grams of the soap oils.
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Construction Materials:
- Often used in concrete, mortar, and other construction materials for coloring.
- Common usage rate in concrete: 0.5% to 3% by weight of the cement.
Key Advantages:
- Durability: Highly durable and resistant to weathering, making it ideal for outdoor applications.
- Non-toxic and Environmentally Friendly: Considered safe for human health and environmentally friendly compared to some organic pigments.
- Lightfastness: Iron oxide red exhibits excellent lightfastness, meaning it does not fade over time when exposed to sunlight.
- Heat Resistance: It can withstand high temperatures, making it ideal for use in products that will be exposed to heat.
Percentage and Usage Rate:.
- Ceramics: 2-10% depending on the glaze or body composition.
- Cosmetics: 1-5% for safe and attractive color.
- Construction Materials (Concrete/Mortar): 0.5-3% based on desired color..
Environmental and Safety Considerations:
Iron oxide red is considered non-toxic and environmentally safe, with no known hazardous effects when used according to safety guidelines. It is a stable pigment that does not degrade into harmful substances over time.
Conclusion:
Iron oxide red is a widely used inorganic pigment known for its stable, permanent red color. It finds applications in a variety of industries, including paints, coatings, ceramics, and cosmetics. With good lightfastness, weather resistance, and non-toxicity, it continues to be a popular choice for both commercial and industrial purposes.