pyrite - the name of a group of minerals that are compounds of metals from the group of tin, nickel, iron, cobalt, and platinum.The compounds may be as sulfur and arsenic, and antimony or selenium.
Roasting pyrite suggests that the feedstock is light in color, metallic luster, hardness of from 3 to 7. The iron or iron pyrite (formula FeS2), also known as pyrite, is a valuable industrial raw materials from which the sulfur dioxide (production in the cells).In appearance mineral represents the mass of fine crystals of regular shape yellowish gray with a hardness of 6-6.5.The composition of pure pyrite includes about 47 percent iron, and about 53 percent sulfur.
Calcination pyrite accompanied by the passage of a number of chemical reactions, the first of which provides for expansion of the mineral iron sulfide and sulfur in the vapor state (temperature about 500 C).Then burn sulfur vapor, sulfur dioxide giving and gives iron sulphide oxide or mixed oxide.Wherein sulphide is burned incompletely, forming a "candle," which may include fayalite and other substances, depending on the impurities in the feedstock.
Roasting pyrite can produce in the gas phase a certain amount of SO3, admixed with SO2.This substance acts on the equipment corrosion manner, so to reduce the SO3 gas temperature at the outlet of the furnace equipment should be around 850C, and then quickly drop to 400C.
Roasting pyrite practiced in many countries, asThis item belongs to the common.In Russia, this mineral is mined in Soymenskoy country, Kalitvinskom field, about Kushva, theological plants in the Caucasus, Ryazan and Smolensk regions, and in other places.Abroad, especially famous Spanish field (Aguas Tenidas especially where the material does not contain copper, but has a higher sulfur content) further exploited in the development of the US, France, Norway, Sweden.To sulfuric pyrites in nature often blended arsenic species of the substance that gives very harmful admixture in the production of the cells.Therefore, manufacturers try to use clean raw material.For example, Russian factories in St. Petersburg, working on Swedish pyrites.
Firing iron pyrites (and sulfur) produced in ovens, where the raw material is fed through the screw or nozzle.Then it is mixed with a mass of solid material, which is already in aggregate (in a fluidized bed on the grill, under which air is supplied from the bottom), after which the chemical reactions take place, enabling gas (assigned) and candle (partially poured through special pipes).Also from the excessive heat of the furnace is given by water cooling elements.
Roasting pyrite will be successful if the contact surface with the air feed is large enough.Therefore mineral is often processed into a pulverized state (in appropriate furnaces), when the particle size is so small that the oxygen easily penetrates inside the mass of substance.Furthermore, temperature is important becauseminerals in this class are often baked at temperatures higher than 900 C. In order to solve this problem is also used as a processing dust air mixture that allows the material to burn at temperatures up to 1000 C, which improves production efficiency.
