Process and facility for thermal treatment of a sulfur-containing ore

Abstract

A process for thermal treatment of a sulfur-containing ore in which the ore is calcined at temperatures of between 600 and 1200° C. in the presence of oxygen in a reactor so that between 1 and 90% by weight of sulfur contained in the ore is burned to sulfur dioxide and impurities contained are driven off in gaseous form. The exhaust gas being produced and containing the sulfur dioxide is fed into a gas purification comprising at least one component and/or the calcined ore is fed into at least one further process stage. An exhaust gas from the gas purification and/or the process stage and/or a gas used for cooling within the gas purification or for cooling within a further process stage is at least partially returned back into the reactor as recycling gas having a temperature of >100° C.

1 .- 17 . (canceled) 
     
     
         18 . A method for thermal treatment of a sulfur-containing ore comprising:
 calcining the ore at temperatures of between 600 and 1200° C. in the presence of oxygen in a reactor so that between 1 and 90% by weight of the sulfur contained in the ore is burned to sulfur dioxide and impurities contained are driven off in gaseous form;   feeding exhaust gas produced containing the sulfur dioxide into a gas purification comprising at least one component wherein an exhaust gas from the gas purification is at least partially returned back into the reactor as recycling gas having a temperature of >100° C.; and   operating the reactor in an autothermic manner.   
     
     
         19 . The method according to  claim 18 , wherein the calcined ore is fed into at least one further process stage, and that an exhaust gas from the process stage and/or a gas used for cooling within the further process stage is at least partially returned back into the reactor as recycling gas having a temperature of >100° C. 
     
     
         20 . The method according to  claim 18 , wherein the driven off impurities including arsenic and/or antimony are contained in amounts of between 1 and 10% by weight, based on their content in the sulfur-containing ore used, and/or that the ore contains at least 70% by weight of copper, cobalt, gold and/or nickel. 
     
     
         21 . The method according to  claim 18 , wherein the oxygen content of the recycling gas is used as command or control variable for controlling or regulating the temperature in the reactor. 
     
     
         22 . The method according to  claim 18 , wherein the recycling gas is used as fluidization gas in the reactor being designed as a fluid bed reactor or as combustion air in the reactor being designed as a rotary kiln. 
     
     
         23 . The method according  claim 18 , wherein the recycling gas has a temperature of between 100 and 600° C. 
     
     
         24 . The method according to  claim 18 , wherein the recycling gas has a proportion of oxygen of between 3 and 20% by weight. 
     
     
         25 . The method according to  claim 18 , wherein the recycling gas is a mixture of several exhaust gases and/or gases which are used for cooling. 
     
     
         26 . The method according to  claim 18 , wherein the ore after the reactor is fed into a melt and exhaust gas from this melt and/or a gas from a cooling downstream of it is returned back into the reactor as recycling gas or constituent of the recycling gas. 
     
     
         27 . The method according to  claim 18 , wherein the gas purification comprises a process for producing sulfuric acid from the sulfur dioxide contained in the exhaust gas and from this process gas is returned back into the reactor as recycling gas or constituent of the recycling gas. 
     
     
         28 . The method according to  claim 27 , wherein the SO 2  with addition of air is reacted to SO 3  and a gas which is poor in oxygen and that the gas which is poor in oxygen is returned back into the reactor as recycling gas or constituent of the recycling gas. 
     
     
         29 . The method according to  claim 28 , wherein the SO 3  is absorbed with sulfuric acid in at least two stages, that the sulfuric acid between two series-connected stages is guided through at least one heat exchanger, that in this heat exchanger air is used as heat transport medium and that this air is returned back into the reactor as recycling gas or constituent of the recycling gas. 
     
     
         30 . The method according to  claim 29 , wherein the gas which is poor in oxygen from the reaction of SO 2  to SO 3  and heated air from the at least one heat exchanging between both absorption stages are mixed such that a specific oxygen content of between 3 and 20% by weight is adjusted with which the temperature in the reactor is controlled or regulated. 
     
     
         31 . A facility for thermal treatment of a sulfur-containing ore, comprising a reactor for operating a process according to  claim 18 , wherein the ore is calcined at temperatures of between 600 and 1200° C. in the presence of oxygen, so that from sulfur contained in the ore SO 2  is formed, further comprising a gas purification comprising at least one component and/or at least one further process stage treating the ore, wherein a return line for an exhaust gas from the gas purification into the reactor is provided and that the reactor is an autothermal reactor. 
     
     
         32 . The facility according to  claim 31 , wherein at least one further process stage is treating the ore and that a return line for an exhaust gas from the further process stage into the reactor and/or a return line for gas which is used in a cooling within a further process stage into the reactor is provided. 
     
     
         33 . The facility according to  claim 31 , wherein the reactor is designed as a fluidized bed reactor. 
     
     
         34 . The facility according to  claim 31 , wherein the reactor features coils for a gaseous or liquid cooling medium.