A method for obtaining metals of the 8th to 14th groups, in particular raw copper, comprises the following steps: i) providing and melting down a mixed feed comprising electronic waste in a smelting reactor, so that a first melt with a first metallic phase and a first slag phase is formed; ii) separating out the first slag phase from the smelting reactor; iii) refining the remaining first metallic phase by means of an oxygen-containing gas, possibly with the addition of copper-containing residual materials, so that a second, copper-enriched slag phase is formed; iv) possibly separating off the second slag phase and repeating the step; v) separating off the refined first metallic phase from the smelting reactor; and vi) adding a further mixed feed comprising electronic waste to the remaining second, copper-enriched slag phase and repeating process steps i) to vi).

A process and an apparatus are disclosed for improved recovery of metal from hot and cold dross, wherein a dross-treating furnace is provided with a filling material with capacity to store heat. This filling material is preheated to a desired temperature by injection of an oxidizing gas to burn non-recoverable metal remaining in the filling material after tapping of the recoverable metal contained in the dross and discharging of the treatment residue. When dross is treated in such furnace, the heat emanating by conduction from the filling material is sufficient to melt and separate the recoverable metal contained in the dross, without addition of an external heat source, such as fuel or gas burners, plasma torches or electric arcs and without use of any salt fluxes. Furthermore, the recovered metal being in the molten state can be fed to the molten metal holding furnace without cooling the melt.

A method for removing phosphorus and boron impurities in an industrial silicon melt by secondary refining is provided. According to the present disclosure, inorganic zinc chloride is adopted as an impurity removal medium and is quickly decomposed into zinc and chloride ions at high temperatures; the phosphorus and boron impurities can react with the zinc and chloride ions to yield low-melting and high-melting compounds during contact with a silicon melt, the low-melting compounds volatilize and escape from the industrial silicon melt at the high temperature of the secondary refining. The high-melting compounds are segregated at the grain boundary along with silicon solidification and removed by crushing and pickling, or sink to the very bottom of the silicon melt and are removed by cutting off a deposition layer at a bottom of a silicon ingot after the silicon melt is solidified.

A method for removing phosphorus and boron impurities in an industrial silicon melt by secondary refining is provided. According to the present disclosure, inorganic zinc chloride is adopted as an impurity removal medium and is quickly decomposed into zinc and chloride ions at high temperatures; the phosphorus and boron impurities can react with the zinc and chloride ions to yield low-melting and high-melting compounds during contact with a silicon melt, the low-melting compounds volatilize and escape from the industrial silicon melt at the high temperature of the secondary refining. The high-melting compounds are segregated at the grain boundary along with silicon solidification and removed by crushing and pickling, or sink to the very bottom of the silicon melt and are removed by cutting off a deposition layer at a bottom of a silicon ingot after the silicon melt is solidified.

A gas injection device for introducing a process gas into a non-ferrous metal melt and/or slag, in particular a copper melt and/or copper slag, including a hollow-cylindrical lance which is formed from a refractory material and/or graphite, preferably includes a refractory material and/or graphite. The lance has an inlet opening for the process gas and a gas injection module connected to the hollow-cylindrical lance and formed from a refractory material and/or graphite, preferably including a refractory material and/or graphite, with at least one outlet opening for the process gas. The outlet opening includes at least one throughflow element formed from a ceramic material via which the process gas can be introduced into the melt.

A gas injection device for introducing a process gas into a non-ferrous metal melt and/or slag, in particular a copper melt and/or copper slag, including a hollow-cylindrical lance which is formed from a refractory material and/or graphite, preferably includes a refractory material and/or graphite. The lance has an inlet opening for the process gas and a gas injection module connected to the hollow-cylindrical lance and formed from a refractory material and/or graphite, preferably including a refractory material and/or graphite, with at least one outlet opening for the process gas. The outlet opening includes at least one throughflow element formed from a ceramic material via which the process gas can be introduced into the melt.

A method for removing phosphorus and boron impurities in an industrial silicon melt by secondary refining is provided. According to the present disclosure, inorganic zinc chloride is adopted as an impurity removal medium and is quickly decomposed into zinc and chloride ions at high temperatures; the phosphorus and boron impurities can react with the zinc and chloride ions to yield low-melting and high-melting compounds during contact with a silicon melt, the low-melting compounds volatilize and escape from the industrial silicon melt at the high temperature of the secondary refining. The high-melting compounds are segregated at the grain boundary along with silicon solidification and removed by crushing and pickling, or sink to the very bottom of the silicon melt and are removed by cutting off a deposition layer at a bottom of a silicon ingot after the silicon melt is solidified.

A method for removing phosphorus and boron impurities in an industrial silicon melt by secondary refining is provided. According to the present disclosure, inorganic zinc chloride is adopted as an impurity removal medium and is quickly decomposed into zinc and chloride ions at high temperatures; the phosphorus and boron impurities can react with the zinc and chloride ions to yield low-melting and high-melting compounds during contact with a silicon melt, the low-melting compounds volatilize and escape from the industrial silicon melt at the high temperature of the secondary refining. The high-melting compounds are segregated at the grain boundary along with silicon solidification and removed by crushing and pickling, or sink to the very bottom of the silicon melt and are removed by cutting off a deposition layer at a bottom of a silicon ingot after the silicon melt is solidified.

The invention concerns a method for feeding an optical cored wire into a molten metal bath and an immersion system and an immersion nozzle to carry out the method. The optical cored wire (6) is decoiled, a feeding and straightening device (4) with a plurality of rollers (20, 21) conducts feeding of the optical cored wire (6) in a feeding direction towards the metal bath (11) as well as a first straightening of the optical cored wire (6), and subsequently a separated further plurality of non-motor driven nozzle straighteners (13) arranged between the feeding and straightening device (4) and the metal bath (11) conducts a second straightening of the optical cored wire (6). Very high precision of temperature measurement can thereby be achieved.

The invention concerns a method for feeding an optical cored wire into a molten metal bath and an immersion system and an immersion nozzle to carry out the method. The optical cored wire (6) is decoiled, a feeding and straightening device (4) with a plurality of rollers (20, 21) conducts feeding of the optical cored wire (6) in a feeding direction towards the metal bath (11) as well as a first straightening of the optical cored wire (6), and subsequently a separated further plurality of non-motor driven nozzle straighteners (13) arranged between the feeding and straightening device (4) and the metal bath (11) conducts a second straightening of the optical cored wire (6). Very high precision of temperature measurement can thereby be achieved.