Because ore grades of 30 ppm are usually needed before gold is visible to the naked eye, in most gold mines the gold is invisible. The average gold mining and extraction costs were about $317 per troy ounce in 2007, but these can vary widely depending on mining type and ore quality; global mine production amounted to 2,471.1 tonnes.After initial production, gold is often subsequently refined industrially by the Wohlwill process which is based on electrolysis or by the Miller process, that is chlorination in the melt. The Wohlwill process results in higher purity, but is more complex and is only applied in small-scale installations. Other methods of assaying and purifying smaller amounts of gold include parting and inquartation as well as cupellation, or refining methods based on the dissolution of gold in aqua regia.As of 2020, the amount of carbon dioxide CO2 produced in mining a kilogram of gold is 16 tonnes, while recycling a kilogram of gold produces 53 kilograms of CO2 equivalent. Approximately 30 percent of the global gold supply is recycled and not mined as of 2020.Corporations are starting to adopt gold recycling including jewelry companies such as Generation Collection and computer companies including Dell. Consumption
The consumption of gold produced in the world is about 50% in jewelry, 40% in investments, and 10% in industry.According to the World Gold Council, China was the worlds largest single consumer of gold in 2013, overtaking India.
It was also concluded that this may show that penis size overall affects sexual satisfaction since women chose between the two options they were given.A study published in 2002, conducted at Groningen University Hospital, asked 375 sexually active women (who had recently given birth) the importance of penis size. The results showed that 21% of women felt length was important and 32% felt that girth was important.A study conducted at the Australian National University, published in early 2013, showed that penis size influences a mans sex appeal, and the taller the man, the bigger the effect. The study showed 3D computer generated images at life-size, altering the height and other physical attributes, with women typically registering preferences in under 3 seconds. A preference for taller mens larger penis size was indicated. A US study published in 2015 of the stated preferences of a panel of 75 women using 3D-printed models as scale references showed a preferred penis length of 16 cm (6.3 inches) and a preferred circumference of 12.2 cm for long-term sexual partners, with slightly larger preferred sizes of a length of 16.3 cm (6.4 inches) and circumference of 12.7 cm for one-time sexual encounters. According to the study, however, when asked to estimate the length of their partnerss penis, most women would say a size significantly smaller than what their partner was recorded to be. This suggests that perception of size is not entirely accurate. The visual impression of the size is not necessarily in correlation with the feeling in the vulva and vagina.