It is used in antifriction alloys (such as Babbitt metal), in bullets and lead shot, cable sheathing, type metal (for example, for linotype printing machines, solder (some " lead-free" solders contain 5% Sb), in pewter, and in hardening alloys with low tin content in the manufacturing of organ pipes. In lead–acid batteries, this addition improves the charging characteristics and reduces generation of unwanted hydrogen during charging. For most applications involving lead, varying amounts of antimony are used as alloying metal. It often reacts with materials that do not react with either acid separately.Īntimony forms a highly useful alloy with lead, increasing its hardness and mechanical strength. Aqua regia is a mixture of hydrochloric and nitric acids. It does dissolve in some hot acids, however, and in aqua regia. It also does not react with cold water or with most cold acids. It does not combine with oxygen in the air at room temperature. Isolating antimony from its oxide is performed by a carbothermal reduction.Īntimony is a moderately active element. This material is often used directly for the main applications, impurities being arsenic and sulfide. The sulfide is converted to an oxide and advantage is often taken of the volatility of antimony oxide, which is recovered from roasting. Antimony can be isolated from the crude antimony sulfide by a reduction with scrap iron. Most antimony is mined as the sulfide lower grade ores are concentrated by froth flotation, while higher grade ores are heated to 500–600☌, the temperature at which stibnite melts and is separated from the gangue minerals. The extraction of antimony from ores depends on the quality of the ore and composition of the ore. The industrial methods to produce antimony are roasting and subsequent carbothermal reduction or direct reduction of stibnite with iron. It was established to be an element around the 17 th century.įor some time, China has been the largest producer of antimony and its compounds. Antimony compounds have been known since ancient times and were used for cosmetics metallic antimony was also known, but it was erroneously identified as lead. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Its density is 6.68 grams per cubic centimeter.Īntimony is a toxic chemical element with symbol Sb and atomic number 51. It is a relatively soft material that can be scratched by glass. The melting point of antimony is 630☌ (1,170☏) and its boiling point is 1,635☌ (2,980☏). It can also be prepared as a black powder with a shiny brilliance to it. It has a scaly surface and is hard and brittle like a non-metal. Antimony is a silvery-white, shiny element that looks like a metal.
0 Comments
Leave a Reply. |