| 摘要 |
Process for reducing the cadmium content of phosphate ores, consisting in heating the ore to a temperature of approximately 1000 DEG C to 1100 DEG C in a very short period by suspending it in a stream of gas produced by the combustion of air and of a fuel in a static furnace 14, in maintaining the ore at a substantially constant temperature in 30, in a neutral or slightly reductive atmosphere for 10 to 30 minutes, and in then cooling the ore by means of an air stream in 20 to 26. To remove the disadvantages linked with the use of a fluidised-bed reactor for maintaining the calcined ore at temperature, this operation is performed in a rotary kiln 30 where a neutral or slightly reductive gas is circulated. <IMAGE>
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