Antimony Ore

any of the natural mineral formations containing antimony in compounds and concentrations that make commercial use technically and economically feasible. Of the antimony ores proper, the major mineral is antimonite (Sb₂S₃), which contains up to 71.4 percent Sb; in rare cases, antimony ores are represented by complex sulfides of antimony, copper, mercury, lead, and iron (berthierite, jamesonite, tetrahedrite, livingstonite), as well as by oxides and oxychlorides (senarmon-tite, nadorite) of antimony. The content of Sb ranges from 1 to 10 percent in blanket deposits and from 3 to 50 percent in veins, with the average content varying between 5 and 20 percent. Antimony ores are formed through the filling of rock fissures by low-temperature hydrothermal solutions, as well as through the replacement of the solutions by antimony minerals.

There are two types of antimony deposits of industrial significance. The first type includes bedded bodies, lenses, pockets, and stockworks in consistent sheetlike formations deriving from metasomatic replacement of limestones by silica and antimony compounds under a shale cap rock (Chikuan Shan in China; Kadamdzhai, Tereksai, and Dzhizhikrut in Soviet Middle Asia). The second type of deposit comprises systems of steeply dipping quartz-antimonite crossveins in shales (Turgai, Razdol’noe, and Sarylakh in the USSR; Gravelotte in South Africa). Quartz-antimonite ores are practically monometallic, while the polysulfide complex ores sometimes contain admixtures of fluorite and of minerals of Hg, Au, Ag, Cu, Pb, Zn, W, Sn, and As.

As of 1974, estimated reserves of antimony ores in capitalist and developing countries were 1.6–1.8 million tons. Antimony ores are extracted mainly through underground mining. While lumps of rich ore in vein deposits do not require dressing, leaner ores are dressed using gravity and flotation methods yielding concentrates that are 30–55 percent Sb. Production of antimony concentrate is reflected in the following figures, which represent thousands of tons of Sb: 14–18 in South Africa, 11–14 in Bolivia, 3–5 in Mexico, 2–3 in Turkey, and 1–2 in Morocco. The annual production of antimony in capitalist and developing countries was 40,000–50,000 tons in 1974, of which 90 percent came from monometallic ores (one-third from blanket deposits, two-thirds from crossveins), 6 percent from complex ores, and 4 percent from antimony-containing ores.