A considerable amount of waste slag from the pyrite roasting process is produced every year. Recovery of iron from the waste slag is of great interest for maximum use of mineral resource, reduction of environment impact and improvement of economical benefits to the related companies. The objectives of the present work are focused on: compare various options for recovery of iron from the waste slag and select the most advantageous option for industrial trial which is roasting of the waste slag under reducing condition followed by magnetic separation; investigate the optimum conditions for maximum recovery of iron from the waste slag. The experimental results show that under the treatment condition in this work about 70% of the iron was recovered from the waste slag, where the iron content in the concentrate is 57%. After the further treatment with chlorinated segregation-magnetic separation, the iron content in the recovered slag can reach 83%. After the treatment, sulphur content in the concentrate was reduced significantly and gangue materials, such as SiO 2 , Al 2 O 3 and TiO 2 , were reduced effectively. This paper is mainly focused on the results of reduction roasting-magnetic separation.À chaque anné e, on produit une quantité importante de dé chets de scorie provenant du procé dé de grillage de la pyrite. La ré cupé ration du fer des dé chets de scorie est d'un grand inté rê t pour l'utilisation maximale de la ressource miné rale, pour la ré duction de l'impact sur l'environnement et pour l'amé lioration des bé né fices é conomiques des compagnies associé es. Les objectifs de ce travail sont centré s sur: la comparaison des diverses options de ré cupé ration du fer à partir des dé chets de scorie et la sé lection de l'option la plus avantageuse pour un essai industriel incluant le grillage des dé chets de scorie avec ré duction, suivi par la sé paration magné tique; l'examen des conditions optimales d'une ré cupé ration maximale du fer à partir des dé chets de scorie. Les ré sultats expé rimentaux montrent qu'avec les conditions du traitement au cours de ce travail, on a ré cupé ré environ 70% du fer à partir des dé chets de scorie, où la teneur en fer dans le concentré é tait de 57%. Aprè s un traitement additionnel par sé gré gation chloré e-sé paration magné tique, la teneur en fer dans la scorie de recouvrement pouvait atteindre 83%. Aprè s le traitement, la teneur en souffre dans le concentré é tait ré duite significativement et les maté riaux de la gangue, comme le SiO 2 , l'Al 2 O 3 et le TiO 2 , é taient effectivement ré duits. Cet article se concentre principalement sur les ré sultats du grillage ré ducteur et sé paration magné tique.

Based on the benefication of the complex silicate ore containing scandium, the research about aid-leaching agent used in the leaching of the scandium concentrate was been conducted. And the suitable leaching agent and aid-leaching agent which the useful ions entered into leaching liquid and the harmful ions were kept in leaching residue were been found according to the experiment results. For the scandium of sample existed various complex silicate ore as isomorphism form, the research has adopted hydrochloric acid with aid-leaching agent to dissociate the silicate ore and make scandium entering into solution. The research results has shown that the scandium leaching rate could reach 92.06% under the optimal conditions which the hydrochloric acid concentration is 22.8%, the dosage of aid leaching agent is 6%, liquid solid ratio is 4:1, particle size of leaching material totally is less than 0.15mm and leaching time is 8h.

The scandium concentrate used in the leaching experiment was obtained from the rare earth ore containing scandium in Yunnan Province, the sample used in experiment is leaching liquid containing scandium which the content of scandium is 3.6g/t, with complex impurity composition. The main influencing factors of extraction in hydrochloric acid solution were acidity, mixing time, phase ratio etc. and the condition experiments about these factors were conducted. The results show that extraction of scandium from the hydrochloric acid solution in TBP is feasible. The optimal conditions are that pH of the solution is 1.26, dosage of TBP is 5% of the solution, dosage of kerosene is 10% of TBP, mixing time is 3 min, phase ratio is 1:10, washing time is 2, the oscillating time of stripping is 1~2 min and the stripping rate reach 99.89%.

Recovery of iron from the waste slag is of great interest for maximum use of mineral resource, reduction of environment impact and improvement of economical benefits to the related companies. This paper is mainly focused on the effect of the temperature on recovery of iron from waste slag of pyrite processing using reduction-roasting magnetic separation method. The experimental results show that under the treatment condition in this work about 70% of the iron was recovered from the waste slag, where the iron content in the concentrate is 57%. After the further treatment with chlorinated segregation-magnetic separation, the iron content in the recovered slag can reach 83%

Based on leaching experiments of complex silicate ore contenting scandium, the research has adopted extraction to concentrate scandium and separate impurity. The emphasis of this reaserch is the impact factors, so the experiments including extractant concentration, organic aqueous ratio, mixing time, organic phase washing, organic phase reextraction, have been conducted. The optimal conditions are that the concentration of extraction is 25%, the O/A is 1:10, the mixing time is 3min, the washing time is 3, the O/A of reextraction is 1:2.3, and the extraction rate of exceeding 98% and reextracion rate of 99.01% were obtained when adopting P501 as the extraction agent.