铬铁粉矿球团烧结新工艺及固结机理研究

对铬铁精矿进行了常规烧结及球团烧结试验研究,并揭示了固结机理。常规烧结结果表明,在最优条件下,烧结矿成品率为73.16%,利用系数1.17t/(m2.h),烧结矿转鼓强度61.03%,固体燃耗115.80kg/t;球团烧结实验表明:在最优条件下,烧结矿成品率为77.18%,利用系数1.47t/(m2.h),转鼓强度83.78%,固体燃耗107.32kg/t。与常规烧结相比,球团烧结显著改善了烧结矿产质量,降低了固体燃耗。固结机理研究表明,在常规烧结中,烧结过程形成的液相量仅有17.1%,故烧结矿强度差,产量低;而球团矿烧结中,表层呈单个球团,中下层呈葡萄状粘结构。球团烧结矿固结以铬铁尖晶石、镁铁尖晶石再结晶为主,液相量19%左右,孔隙率下降。球团烧结矿强度由固相固结和液相粘结共同维持,因此,烧结矿强度好、产量高。球团烧结工艺是强化铬矿粉烧结、降低烧结能耗的有效途径之一。

Study of Chromite Fines Pellet Sintering and its Hardening Mechanism

The normal sintering and pellet sintering of chromite fines was studied and the consolidation mechanism was revealed.Results of normal sintering showed that under the optimum conditions,yield of 73.16%,productivity of 1.17 t/（m²·h）,tumble index of 61.03% and solid fuel consumption of 115.80  kg/t were achieved.In contrast the pellet sintering of chromite fines under optimum conditions indicated better sintering performance proven by the following dexes yield of 77.18%,productivity of 1.47 t/（m²·h）,tumble of 83.78% and solid fuel of 107.32  kg/t respectively.Consolidation mechanism showed that in normal sintering process，the liquid phase was only accounted for 19% and higher porosity，resulting in weak sintering and lower productivity.With regard to micro  pellet sintering，sinter from top and middle-lower bed is ding morphology，respectively.Recrystallization of ferro-chromium and ferro-magnesium spinel and some 19% liquid phase along with lower porosity play a significant role in consolidation of sinter made of chromite fines by micropellet sintering，leading to a strong sinter and higher productivity at lower solid fuel.Therefore，pellet sintering is an effective way to promote sintering of chromite fines at lower solid fuel consumption .