| 摘要 |
The ashing of the solid fuels and the characterization of the mineral matter in these fuels have been of great importance for a long time. Low Temperature Ashing (LTA) is a method to ash solid fuels and it has been known since 1965. The problem has been that the ashing temperature could not be measured and consequently the ashing process could not be controlled. This invention called Very Low Temperature Ashing (VLTA) refers to obtaining an ashing of solid fuels (or ashes with uncombusted material) in such a way that no modifications, losses or damages of the original phases specially sulphide minerals occurs. In order to achieve this and to decrease and control the ashing temperature, the oxygen has been blended with helium in different quantities. The gas which is formed during the oxidation of the samples was analyzed simultaneously specially with regard to the SO2. According to the invention, the ashing temperature and the formation of SO2 can be controlled to low levels by regulating of the helium/oxygen mixture. It was surprisingly established that the ashing according to the invention occurs selectively with regard to the carbon in the samples. The expression "selective" refers to the fact that merely or principally the carbon in the samples oxidizes, while the sulphur compounds are unaffected in the samples. This selective oxidation occurs at an ashing temperature interval between 60-70 DEG C for all coal samples or solid fuels, regardless of the ranks (calorific values) of the samples. |
