Reduction furnaces, copper

Refractories for Electric Reduction Furnaces. Carbon hearth linings are used in submerged-arc, electric-reduction furnaces producing phosphoms, calcium carbide, all grades of ferrosilicon, high carbon ferrochromium, ferrovanadium, and ferromolybdenum. Carbon is also used in the production of beryllium oxide and beryllium copper where temperatures up to 2273 K ate requited. 

Chemistry. Fire refining of bhster copper is achieved by oxidation, fluxing, and reduction. The copper is partially oxidized by blowing air into the fire-refining furnace, where the copper oxide and the impurities that oxidize preferentially react. 

The reduction of copper ores in the electric furnace has been studied by Juschkewitsch.1 Stephan 2 has given an account of its application to the extraction of copper from its ores. 

Reduction Reactor—First place a 5 mm plug of quartz wool in the bottom of the tube. Fill the tube with reduced copper. Insert a 10 mm thick plug of quartz wool. Slide the reduction tube into the reduction furnace and secure with the o-ring fittings. 

Decomposition of water vapor on specially prepared iron powder in a furnace at S50-650°C., and subsequent reduction of the oxide formed with tank hydrogen at 650-800°C., as described by Zhavoronkov et al. (1955). About 10 gm. of water can be handled at a time and by using an alternating process fairly large quantities of deuterium-free water can be prepared. The deuterium evolved can be used to make deuterium oxide by the reduction of copper oxide. 

Many nonferrous metals can be extracted by reduction smelting, eg, copper, tin, nickel, cobalt, silver, antimony, and bismuth. Blast furnaces are sometimes used for the smelting of copper or tin, but flash and reverberatory furnaces are more common for metals other than lead. 

Blast furnaces are charged through the top with coke, flux (usually iron metal and siUca), and scrap while air is iajected through tuyeres continuously at the bottom just above the black copper. The coke (100 kg/1 slag) bums to maintain furnace temperatures of 1200°C, provides the reductant, and maintains an open border. A charge of 10 t/h is typical. The furnace produces a molten black copper that contains about 80% copper. The 2iac, lead, and... 

The washed slime is dried and melted to produce slag and metal. The slag is usually purified by selective reduction and smelted to produce antimonial lead. The metal is treated ia the molten state by selective oxidation for the removal of arsenic, antimony, and some of the lead. It is then transferred to a cupel furnace, where the oxidation is continued until only the silver—gold alloy (dorn) remains. The bismuth-rich cupel slags are cmshed, mixed with a small amount of sulfur, and reduced with carbon to a copper matte and impure bismuth metal the latter is transferred to the bismuth refining plant. 

Since hydrogen burns cleanly and reacts completely with oxygen to produce water vapor, this makes it more desirable than fossil fuels for essentially all industrial processes. For example, the direct reduction of iron or copper ores could be done with hydrogen rather than smelting by coal or oil in a blast furnace. Hydrogen can be used with conventional vented burners as well as unvented burners. This would allow utilization of almost all of the 30 to 40% of the combustion energy of conventional burners that is lost as vented heat and combustion by-products. 

Reduction of a copper(II) oxide with coper at elevated temperatures in a furnace ... 

A large fraction of the iron and steel produced today is recycled scrap. Since scrap does not require reduction, it can be melted down directly in an electric arc furnace, in which the charge is heated through its own electrical resistance to arcs struck from graphite electrodes above it. The main problem with this process is the presence of tramps (i.e., copper from electrical wiring, chromium, nickel, and various other metals) that accompany scrap steel such as crushed automobile bodies and that lead to brittleness in the product. Tin in combination with sulfur is the most troublesome tramp. Only the highest quality recycled steel—specifically, steel with no more than 0.13% tramps—can be used for new automobile bodies, and usually reprocessed scrap has to be mixed with new steel to meet these requirements. 

To implement an easy and automated means for chemical vapour generation procedures (hydride generation for arsenic, selenium, etc., and cold vapour mercury), which allows for a reduction on the interferences caused by first-row transition metals (such as copper and nickel). FI methods may be readily coupled with almost all the atomic-based spectroscopic techniques (including graphite furnace atomisers). 

As reported elsewhere, the experiments were used to demonstrate the major process steps with recycle of the uranium. Most experiments were conducted in an alumina-lined tube furnace with the uranium in an alumina boat. Hydrogen gases were produced and measured. Reduction of CuO to copper metal, determined by weight loss, was the primary method used to measure the amount of reductant produced. X-ray diffraction analysis was used in most cases to confirm the uranium species. 

---