Patent GB-769458-A (GB)
Title: Improvements in and relating to the production of metal chlorides and to the recovery of metals, and more particularly copper
IPC: C01G3/05
Filed: 1954-09-24
Abstract: Metal chlorides are produced from primary material containing the metals <PICT:0769458/III/1> by heating the material in direct contact with heating gases to a temperature approximating the chlorination temperature and thereafter moving the heated material without the heating gases into a separate receptacle in which it is subjected to the action of a mixture of gaseous hydrochloric acid, water vapour and inert gases to form metal chlorides.  The invention is not applicable to hydrolysible or nonvolatile chlorides and is particularly directed to copper.  As shown in the Figure and described in an example a copper ore containing small amounts of iron and aluminium is mixed with 0.4 per cent of sodium chloride and introduced from a hopper 2 into a heating vessel 5 which is heated by combustion of fuel and air from lines 8 and 9 to a temperature of 900 DEG C., the furnace effluent gases leaving at 4. The heated material passes through hopper 7 to a chlorination chamber 12 where it is subjected to the action of a mixture of hydrochloric acid gas brought in through line 19, water vapour from line 23, uncondensed vapours from a condenser 25 entering through line 20, and inert gases due to the combustion by means of air of fuel fed to a combustion chamber 14 downstream from a mixing chamber 13 which communicates with the reaction space 12. The ore freed from its copper content passes to a steam generator 33 for discharge at 44 whilst the steam evolved is passed through lines 21 and 23 to the chlorination chamber.  The gases containing cuprous chloride leave the chlorination chamber through line 24 and are condensed in a condenser 25 maintained at 600 DEG C. whereby cuprous chloride is collected at 26 and separated from ore dust, whilst the uncondensed vapours are recycled through line 20 or passed in part through a line 32 to a scrubbing tower 38 for recovery of any metals which they may contain.  The cuprous chloride obtained may be reduced with hydrogen in a reduction oven 28 whereby metallic copper is produced and removed at 43; gaseous hydrochloric acid, also produced, is sent through line 29 to storage 42 and for recycling in closed circuit to the chlorination chamber through line 19.  The reduction in vessel 28 may be effected by admitting cuprous chloride either in the liquid or vaporous state with hydrogen from a generator 31, preferably by means of concentric or adjacent nozzles at the outlet of which the cuprous chloride and hydrogen burn with a stable flame.  The hydrogen may be in atomic form, that is it is passed through an electric arc at high voltage before being brought to the reduction chamber.  Alternatively water gas or cracking gases may be employed.ALSO:Metals, especially copper, are obtained by chlorinating an ore to obtain metal chlorides and reducing these to metal.  The cuprous chloride obtained by chlorination may be reduced with hydrogen in a reduction oven whereby metallic copper is produced and removed gaseous hydrochloric acid, also produced is sent to storage and for recycling in closed circuit to a chlorination chamber.  The reduction in vessel 28 may be effected by admitting cuprous chloride either in the liquid or vaporus state to the reduction oven with hydrogen from a generator, preferably by means of concentric or adjacent nozzles at the outlet of which the cuprous chloride and hydrogen burn with a stable flame.  The hydrogen burn with a stable flame.  The is it is passed through an electric arc at high voltage before being brought to the reduction oven. Alternatively water gas or cracking gases may be employed.