Feasibility of co-reduction roasting of a saprolitic laterite ore and waste red mud

Large scale utilization is still an urgent problem for waste red mud with a high content of alkaline metal component in the future.Laterite ores especially the saprolitic laterite ore are one refractory nickel resource,the nickel and iron of which can be effectively recovered by direct reduction and magnetic separation.Alkaline metal salts were usually added to enhance reduction of laterite ores.The feasibility of co-reduction roasting of a saprolitic laterite ore and red mud was investigated.Results show that the red mud addition promoted the reduction of the saprolitic laterite ore and the iron ores in the red mud were co-reduced and recovered.By adding 35wt%red mud,the nickel grade and recovery were 4.90wt%and 95.25wt%,and the corresponding iron grade and total recovery were 71.00wt%and 93.77wt%,respectively.The X-ray diffraction（XRD）,scanning electron microscopy,and energy dispersive spectroscopy（SEM-EDS）analysis results revealed that red mud addition was helpful to increase the liquid phase and ferronickel grain growth.The chemical compositions＂Ca O and Na_2O＂in the red mud replaced Fe O to react with Si O_2 and Mg Si O_3 to form augite.

Factor analysis on the purity of magnesium titanate directly prepared from seashore titanomagnetite concentrate through direct reduction

Magnesium titanate was prepared directly through external coal reduction of seashore titanomagnetite concentrate and magnesium oxide(MgO).The effects of roasting temperature and the type and dosage of reductants on the purity of generated magnesium titanate particles were systematically investigated.Scanning electron microscopy and energy-dispersive spectroscopy analyses were performed to characterize the magnesium titanate particles and observe their purity under different conditions.Results showed that the roasting temperature remarkably influenced the purity of magnesium titanate.At 1200,1300,and 1400℃,some magnesium ferrite and magnesium aluminate spinel were dissolved in magnesium titanate.However,as the roasting temperature increased to 1500℃,relatively pure magnesium titanate particles were generated because no magnesium ferrite was dissolved in them.The type and dosage of the reductants also remarkably affected the purity of magnesium titanate.The amount of fine metallic iron disseminated in the magnesium titanate particles obviously decreased when lignite was used as a reductant at a dosage of 70wt%.Thus,high-purity magnesium titanate particles formed.At a roasting temperature of 1500℃and with 70wt%lignite,the magnesium titanate product with a yield of 30.63%and an iron content of 3.01wt%was obtained through magnetic separation.

Correction of extreme hyperopia: artisan iris-fixated intraocular lens implantation for pseudophakia after clear lens extraction

A 22-year-old patient suffering from both-side extreme hyperopia with amblyopia was corrected with an Artisan iris-fixated intraocular lens (IOL) implantation followed to clear lens extraction (CLE) with posterior chamber (PC)-IOL implantation. The preoperative refraction values were +17.75DS -1.50DC × 168° for the right eye and +17.25DS -0.75DC × 8° for the left eye. The uncorrected visual acuity (UCVA) was 20/200 bilaterally and the spectacle-corrected visual acuity (BSCVA) was 20/50 bilaterally. One year after Artisan iris-fixated IOL implantation, bilateral BSCVA was 20/50 with a refraction of +1.25DS -0.75DC × 13° for the right eye and +1.50DS -1.00DC × 55° for the left eye. The outcomes of an Artisan iris-fixated IOL implantation followed to CLE with PC-IOL implantation were encouraging for the correction of extreme hyperopia. Long term follow-up examinations were necessary for further determination of the efficacy and safety of this combinational procedure.