Abstract: A reactor for the combustion of sulfur includes reactor walls which form a symmetrical base area b, whereby at least two burners are mounted each with a burner holding device. All burner holding devices have the same distance to each other and each burner holding device has the same distance to the a center point z of the base area b. At least one burner holding device is arranged such that during operation the flame of said burner shows an angle ? between 0 and 45° to a center axis a, which is defined as the shortest connection between this burner holding device and the center point z.

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.