Deep gold mining has continued to prosper as a leading industry in the South. Acid mine drainage is caused when the iron sulfur pyrite, released from the mine... In addition, it is commonly used as a processing aid in industries including metal... with sodium, chlorine, boron, borax, bleach and high levels of phosphates.
In 2015, 27.6 million metric tons of marketable phosphate rock, or phosphorite, was mined in the United States, making the US the world's third-largest producer, after China and Morocco. The phosphate mining industry employed 2,200 people. The value of phosphate rock mined was US$2.2 billion.
Most mining of phosphate rock involves clearing large swaths of vegetation and digging up the soil beneath to reach the phosphate-ore-containing matrix 60 to 80 feet below the surface. This matrix is then transported by pipeline to a nearby plant, where the phosphate ore is forcibly separated from the sand and clay by a process known as .
The hashing stage (corresponding to metal extraction and recovery stages) is a little more complex for gold ores, as the optimal process flowsheet selection choice is heavily dependent on a good understanding of two fundamental geometallurgical parameters, the gold mineralogical associations, and the gold particle size and liberation .
Phosphate mining involves the extraction of ores containing chemical compounds rich in substances that contain the phosphate ion. These ores vary in their composition, and different varieties of phosphate rock require different mining techniques. Processing of the mined ore follows extraction.
The mining industry of Morocco is important to the national economy. Morocco is the world's largest producer of phosphate, and contains about 75% of the world's estimated reserves. Mining contributed up to 35% of exports and 5% of GDP in 2011.
Ore is removed from the crust by mining, either on the surface (open pit mining) or underground (shaft mining or room and pillar mining). Some minerals can be used in their natural form, for example sand in the building industry, phosphate rock for fertilisers and diamonds in jewellery.