Search results
Results from the WOW.Com Content Network
Underground mine ventilation provides a flow of air to the underground workers of a mine with sufficient volume to dilute and remove dust and noxious gases (typically NO x, SO 2, methane, CO 2 and CO) and to regulate temperature. The source of these gases are equipment that runs on diesel engines, blasting with explosives, [1] and the orebody ...
For example, values of the Gibbs energy obtained from high-temperature equilibrium emf methods must be identical to those calculated from calorimetric measurements of the enthalpy and entropy values. The database provider must use recognized data analysis procedures to resolve differences between data obtained by different types of experiments.
Planning for the development of room and pillar mines operates in much the same way as other mining methods, [10] and begins with establishing ownership of the mine. . Following this, the geology of the mine must be analysed, as this will determine factors like the lifespan of the mine, the production requirements, and the cost to develop and
The most common example of roasting is the oxidation of metal sulfide ores. The metal sulfide is heated in the presence of air to a temperature that allows the oxygen in the air to react with the sulfide to form sulfur dioxide gas and solid metal oxide. The solid product from roasting is often called "calcine".
Calcination is thermal treatment of a solid chemical compound (e.g. mixed carbonate ores) whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen (i.e. gaseous O 2 fraction of air), generally for the purpose of removing impurities or volatile substances and/or to incur thermal decomposition.
Smelting involves more than just melting the metal out of its ore. Most ores are the chemical compound of the metal and other elements, such as oxygen (as an oxide), sulfur (as a sulfide), or carbon and oxygen together (as a carbonate). To extract the metal, workers must make these compounds undergo a chemical reaction.
‡ Second column of table indicates solubility at each given temperature in volume of CO 2 as it would be measured at 101.3 kPa and 0 °C per volume of water. The solubility is given for "pure water", i.e., water which contain only CO 2. This water is going to be acidic. For example, at 25 °C the pH of 3.9 is expected (see carbonic acid).
A classical example is the decomposition of mercuric oxide to give oxygen and mercury metal. The reaction was used by Joseph Priestley to prepare samples of gaseous oxygen for the first time. When water is heated to well over 2,000 °C (2,270 K; 3,630 °F), a small percentage of it will decompose into OH, monatomic oxygen, monatomic hydrogen, O ...