The application and protection of Metal resource
Public: admin Date: 8/10/2016 12:50:37 AM Hits: 693
- The procedure of refining metal elementary substance from mental minerals was called metal smelting. As early as the Spring and Autumn period, China has started to produce and use ironware. The output of iron and steel is once equal to a country??s level of industrial development. Different metal has different methods of smelting. The higher degree of acitivity the metal is, the harder the refining is. So according to the metal activity sequence table, it can be found that the refining of potassium,calcium,sodium,magnesium and aluminum are the hardest. For this reason, to refine the metal elementary substance from those metals we usually use electrolysis method in reality produce. To obtain those metals elementary substance by electrolyzing the inter-metallic compound. While those metals which are relatively not active are usually obtained by the chemical reaction between CO or other reducing agent and minerals, such as iron, molybdenum, tungsten and copper and so on. And less active metal such as mercury and silver are used to obtain by heating and decomposing their minerals. However, the most stable metal platinum and gold are exist as elementary substance form in the nature.So it can be directly purified from ore, which also explains that why the history that people using gold is first and then goes to the history of using bronze. And next is iron history and final is aluminum history.
However, the reserves of metal minerals are limited and non-renewable. According to the proven reserves and the consumption speed of present metal,some people estimate some mineral??s available years for mining(do not include recycling and so on ): silver 16 years; tin 17 years; gold 26 years; lead 26 years; zinc 27 years; copper 42 years; iron 195 years; aluminum 257 years. Under this condition, protecting metal resources has become extremely urgent problem.
After analyzing we found that we can solve this problem from follow aspects: the first step should be focused on the development phase. The resource should be developed in concentration way in order to avoiding the waste of associate metal which caused by the limited development condition. Actually, almost every metal mineral ore has the associate ore. Such as the Chinese Baiyunebo iron ore which contains a lot of rare earth. Under this condition, iron and rare earth should be developed at the same time. And then goes to the usage phase. First of all,we must have enough preparation of protecting metal corrosion. According to the reports, the quantity of scrapped metal equipment and material which caused by corrosion are equal to the 20 percent to 40 percent of the quantity of yields. The common metal protections for corrosion include follow: plastic bag, painting,oil,enamel,plated with more corrosion metal(such as copper, chromium and so on.). And incorporate stainless steel which made by added metal chromium or nickel powder. Second, do a good job of recycling and reusing the metal. Taking aluminum as an example, to produce 1 ton aluminum need at least 4 tons bauxite. The large consumption will quickly deplete the resource. But if the quantity of recycling and reusing reach half of the quantity of yields, the consumption of bauxite will reduce about 50 million tons per year. At the same time, it can also reduce plenty of energy consumption and reduce the emission of CO2, which have a great significant. The most important of all, we should try our best to develop new material instead of original metal material.