High-pressure area of their associated cold fronts. The stronger the pressure difference, or pressure gradient, between a high-pressure system and a low-pressure system, the stronger the wind. The coriolis force caused by the Earth's rotation is what gives winds within high-pressure systems their clockwise circulation in the northern hemisphere (as the wind moves outward and is deflected right from the center of high pressure) and counterclockwise circulation in the southern hemisphere (as the wind moves outward and is deflected left from the center of high pressure). Friction with land slows down the wind flowing out of high-pressure systems and causes wind to
Pressure oxidation Pressure oxidation Pressure Oxidation is a process for extracting gold from refractory ore. The most common refractory ores are pyrite and arsenopyrite, which are sulfide ores that trap the gold within them. Refractory ores require pre-treatment before the gold can be adequately extracted. The pressure oxidation process is used to prepare such ores for conventional gold extraction processes such as cyanidation. It is performed in an autoclave at high pressure and temperature, where high-purity oxygen mixes with a slurry of ore. When the original sulfide minerals are oxidized at high temperature and pressure, it completely releases the trapped gold. Pressure