The ochre has other name ferritungstite, Tungstite Ferritungstite, Tungstite. Depending upon the colour, the ochres are called red ochre, yellow ochre, green earths, sienna, umber and by various other names. 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 Fe 2 O 3 having pigmentary quality. The principal use of ochre is as tinting colours. It is used for colour washes, distemper and oil paints. It is also used in making coloured paper. Ochres are the natural mineral pigments occuring in various shades and colours, generally ranging from yellow to red to brown. The colouring power is mainly due to oxides of iron.
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 elutrition. 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. 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.
Ochre occurrence
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 pnnsylvannia, USA, is known as metallic brown.
Ochre uses and application
The principal use of ochre is as tinting colours. It is used 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 prepareation of coloured paper pulp. Red oxide pigments are widely used as primers for painting structural steel, automobile bodies, ship bottoms etc.
Ochre 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 that occur as natural clay or earth.
Ochre crusher & ochre grinding mill
As the ochre’s application in industry you should use our ochre crusher and ochre grinding mill. When you get the primary ochre, it is always in different types of big block, so the ochre need to be crushed, sieved and graded into various sizes and thus coated abrasives of various fineness are prepared. In the process you may be use the ochre jaw crusher, ochre impact crusher, ochre cone crusher, vsi ochre crusher, mobile ochre crusher, trapezium ochre grinding mill, ochre ultrafine grinding mill, ochre ball mill grinder etc.