Zinc white
Composition and Properties of Zinc White
Zinc white is zinc oxide with the formula ZnO.
Names
Snow white, Chinese whitePW 4, CI 77947Zinc: from German Zink, perhaps related to Zinke “prong, point;” said to have been used first by Paracelsus (c. 1526) on analogy of the form of its crystals after smelting. Zinke is from Old High German zint “a point, jag,” from Proto-Germanic *teng– “tine”From Online Etymology Dictionary
Preparation
Zinc oxide can be prepared in three different ways1. Indirect (French) process: metallic zinc is vaporized at approximately 1000 °C at which temperature it spontaneously ignites and forms zinc oxide.2. Direct (American) process: the starting material for this process are either zinc ores or industrial byproducts. In the first step, the zinc-containing material is reduced by a carbon-containing agent such as anthracite at high temperatures. The zinc vapour is then ignited and forms zinc oxide.3. Wet process: Soluble zinc salts are treated with a solution of sodium carbonate or sodium hydroxide. The resulting precipitation of zinc carbonate or hydroxide is then calcinated at about 800 °C to form zinc oxide.
History of Use
Zinc white has been known as a mineral since antiquity but was not used as a pigment until the 18th century. The following graph gives the frequency of its use in the paintings of the Schack Collection in the Bavarian State Art Collections in Munich (1).Examples of use
Quote
He’s so slow, so unimaginative, so lifeless. Like zinc white. I see it’s a sort of tyranny he has over me. He forces me to be changeable, to act. To show off. The hateful tyranny of weak people.
Source: John Fowles
