The discovery of metals was one of the major turning points of human civilization, carrying the species from the uncomfortable stone age into the glorious days of Bronze. Copper, zinc, and nickel have accompanied man since those early days, forming everything from weapons to pottery. These three metals are no less important now. Copper is weaved through the infrastructure of our homes in the form of wire and pipes, as well as in everything from musical instruments to the pigments for stained glass. Zinc is used in batteries, galvanization, and mixed with copper to form brass. Last but not least, nickel is used in batteries and used to form the ever popular stainless steel which is commonly used in cookware and jewelry along with various industrial and architectural uses. With all of this in mind, it is a shame indeed that many, many people still believe that the mining process remains relatively unchanged from those early days. To imagine that the mining process consist of dwarf like miners smacking rocks with pickaxes is a very sad oversight of the science of an industry that has seen enormous advances in efficiency and complexity. So without further ado, here is a record of the journey of copper, zinc, and nickel from ore to everyday use.
Copper is the most necessary of these three metals, and, therefore has seen the most advancement in the mining process. Though copper can be and, on occasion is, mined in underground mines, it is safer and simpler to extract from surface mines. Regardless of the the type of mine, the first priority is to separate the copper ore from the other rocks nearby. The most common method of extraction is a five step process. Firstly the miners use explosives to separate chunks of rock from the solid walls and haul them to processing plants. At these plants stones are ground into a thin powder to separate all of the elements of the rock. Grinding the stones into powder allows the use of water to draw attention to the copper in the mix. As copper is extremely hydrophobic, it can be easily sifted from the top of the large vats used in the process. However, iron and sulfur are also extremely hydrophobic so the copper must be smelted (the use of heat and chemicals to encourage oxidization in metals), which allows miners to separate copper from other metals with a margin of error of only about 1%. Before sale the copper is further purified through the use of electricity which allows the copper that is used in infrastructure (and formerly pennies) to be almost entirely pure with only .01% of a margin of error.
The mining of zinc is very similar to the mining of its fellow brass component copper. In fact copper and zinc are very often mined in the same locations, though with heavily varying concentrations of each. Like copper, stones containing zinc arefirst crushed and ground into a fine powder and tested for their level of hydrophobicity, which allows zinc to be separated from other minerals and metals. The process varies slightly after this point. The slightly purified zinc is “roasted” which is an affectionate industry term for throwing the ore into a furnace with temperatures of extremely high levels. This leaves the zinc only a few electric treatments away from being used in batteries and as a component of brass.
Never to be forgotten, nickel mining is a process almost identical to that of zinc. Both processes take advantage of the advances in the detection of varied hydrophobicity and are afterwards heated to heavy levels of heat. After this point nickel ore is entered into a three step chemical reaction known as the Mond process. The first of these steps introduces Syngas, or synthetic gas, into a chamber containing nickel ore which removes oxygen from the nickel ore. Next, carbon monoxide is released to form a metal called nickel carbonyl, which separates the occasional iron and cobalt that can follow nickel until this point in the mining process. Then the carbon monoxide and nickel carbonyl are then roasted again at temperatures of about 420 degrees Fahrenheit to create nickel in its purest form. However, nickel is not always required to go through the Mond process as stainless steel can be made with only 75% pure nickel. The purest nickel is used in plating other metals, in batteries, and in several tints such as green in glasses.
These three mining processes are the direct results of heavy advances in metallurgy, or the study of the properties of metal. Without science and technology backing these processes, society could not have progressed to its current state. Metals are the backbone of many of society’s structures, and without the development of processes similar to those discussed above there is very little likelihood that there would be light bulbs overhead or computer screens alight at this very moment.
Sources and suggested reading:
http://www.azcu.org/teachersCommodity2.php – Copper information
Rosenqvist, Terkel, Principles of Extractive Metallurgy- Book source, information on zinc and nickel mining