Experimental Study On Sulfur-removal And Silicon-reduction Of A High Sulfur Iron Ore From Dungun,Terengganu,Malaysia

Iron ore is one of the important raw materials of steel production,in order to meet the demand of iron ore for industrialization development,China long-term import a large amount of iron ore from Australia,Brazil,India and other countries,and the source of imports is developing in the direction of diversification.The iron ore this thesis studied on were produced in Dungun,Terengganu,Malaysia,has the characteristics of high sulfur.In order to develop and utilize this resource effectively,make it meet the iron ore industry indicators,an experimental study on sulfur-removal and silicon-reduction of this iron ore have been conducted.The experiment studied the X-ray fluorescence spectrometry analytical method of the iron ore and its calcined products at first,and established the test method of test simples.Then the process mineralogy analysis of the iron ore have been conducted by using X-ray powder diffraction technique,X-ray fluorescence spectrometry analysis,thin section identification and other methods.Based on process mineralogical analysis results,experiment used magnetic separation method to conduct silicon-reduction processing of iron ore.Based on the previous study on the phase change of pyrite during heating,experiment used calcination method to conduct sulfur-removal processing of magnetic separation products.By a large munber of experiments and analysis of test data,the study results and progress obtained is as follow.1.Study on XRF analytical method of a high sulfur iron ore and its calcined products from Dungun,Malaysia?1?Compared to Std-Oxide standard,the test precision of the iron content has larger ascension by using the new test standards FeS1 and FeS2.For the determination of Si O₂ content,the test effect of FeS1 standard was optimal.For the determination of sulfur content,the test values of Fe S1 standard and FeS2 standard are not ideal.?2?For the iron ore without calcine processing and its magnetic separation products,the test standard experiment selected was Std-Oxidel standard.For calcined products,the experiment selected Std-Oxidel standard for the determination of sulfur content,selected FeS1 standard for the determination of TFe,SiO₂,and other compositions'content.2.Process mineralogy research of a high sulfur iron ore from Dungun,Malaysia?1?The TFe?total iron?content of iron ore is 23.65%,and the iron ore has a large number of gangue,the SiO₂ content accounts for most of the proportion,reach to32.14%,the content of MgO,CaO,Al₂O₃ are also high,close to 10%.In addition to the S content is 2.08%which exceeded the iron ore industry indicators,the content of other impurity elements is low.The iron ore containing a small amount of useful elements which are Ti and Mn,their content is around 0.2%.?2?The mineral composition of iron ore include magnetite,pyrrhotite,pyrite which are the main form of Fe element,quartz,cordierite,clinochlore,calcite,minnesotaite,which are composed of SiO₂,MgO,Al₂O₃,CaO.?3?Most quartz particles are embedded among the magnetite and pyrrhotite which are infection distribution.Pyrite is embedded among other minerals.Most of other gangue minerals are distributed similar to the form of quartz or pyrite.The granularity of magnetite,pyrrhotite,quartz concentrated between 0.1⁰.15 mm,pyrite concentrated between 0.05⁰.1 mm,and other gangue minerals concentrated between0.05⁰.15 mm.3.Experimental study on silicon-reduction by magnetic separation of a high sulfur iron ore from Dungun,Malaysia?1?The optimal magnetic field intensity for magnetic separation is 80 KA/m,the TFe and SiO₂ content of the magnetic concentrate of this intensity are 40.26%and18.76%,production rate and iron recovery rate are 25.75%and 43.82%.?2?The TFe and SiO₂ content of the magnetic concentrate which granularity is-80 mesh are 42.35%and 14.44%,production rate and iron recovery rate are26.10%and 46.73%.According to the granularity distribution of various mineral in iron ore,the optimal granularity for magnetic separation is 200 mesh.4.Experimental study on sulfur-removal by calcination of magnetic concentrate of a high sulfur iorn ore from Dungun,Malaysia?1?During the calcination process of magnetic concentrate,most of the state are exothermic and weightlessness.The mechanism of sulfur-removal is during the calcination process pyrite transformed into pyrrhotite at first,and eventually transformed into magnetite,the sulfur in pyrite and pyrrhotite was removed in the form of sulfur dioxide.?2?With the increasing of calcination temperature,the effect of sulfur-removal is more obvious.When the calcination temperature reach to 1000??holding time 1 h?,The S content of calcined product is reduced to 0.27%,meet the iron ore industry indicators for iorn making.With the temperature continue to increasing,the S content can be further reduced,and meet the iron ore industry indicators for steel making.?3?With the increasing of calcination temperature,the holding time needed to meet the iron ore industry indicators is shorter.The optimal calcination temperature and holding time for calcination are 1050?and 40 minutes.