Barium ferrate purity of the synthesized barium ferrate by performing the reaction at low temperature in the absence of carbon dioxide and by rapidly filtering and drying the precipitate. Addition of a soluble sodium barium salt to an alkali metal ferrate solution produces a maroon precipitate of barium ferrate, a crystal which has the same structure as barium chromate and has approximately the same solubility. The wet method employs chemical and electrochemical techniques. Barium ferrate, BaFeO can be prepared by adding barium oxide to a mixture NaClO and ferric nitrate at room temperature (29± 1 °C). The precipitate formed can then be
Calamine brass Calamine brass Calamine brass is brass produced by a particular alloying technique using the zinc ore calamine directly, rather than first refining it to metallic zinc. Direct zinc smelting appears to have been unknown in Europe until the mid-18th century, even though the alloyed calamine brass was in use for centuries, and metallic zinc was produced directly via reducing-atmosphere smelting in India and China from the 12th century CE onwards. Brass is an alloy of copper and zinc and, when it was first developed, methods for producing metallic zinc were unknown. Metallurgists wishing to produce brass thus used calamine (actually