Experimental Study On Beneficiation Of Ningnan Braided Hematite In Sichuan Province

Oolitic hematite is a kind of refractory ores, and its production process is complex, the grade of iron concentrate is too low to meet the requirements of smelting, and it costs too much in the production, so up till now, there is basically no development and utilization for that. But with the shortage of iron ore resources, coupled with the mine service life's being less and less, the current domestic mine all have possessed various resources, lots of research on beneficiability of oolitic hematite has been studied.In this paper, mineralogy on multi-element analysis, phase analysis, and size distribution has been studied. The results show that the ore in this region is low phosphorus and sulfur ore. The occurrence of iron ore is relatively simple, and in the form of high valence of iron oxide, distributing in hematite, of which ups to 96.07% of Fe, and the results show that, the ore oolitic hematite particles is characterized by coarse fraction. If regraded the oolitic hematite particles as the basic unit of beneficiation, then under the conditions that -0.59mm of grinding fineness,95% of the oolitic hematite particles can be liberated. After reduction roasting, most of hematite has been transformed to magnetite, but the aggregations still retain the original characteristics of oolitic hematite, magnetite and the gangue are arranged alternately in belt shape, and some grains of the hematite are still in the distribution of scattered remnants.Based on mineralogy study, this paper on beneficiation tests of oolitic hematite in Ningnan Huadan were studied. Exploratory experiments were conducted by conventional beneficiation methods, and the test results show that it is difficult to obtain the iron concentrate with more than TFe57% by high magnetic separation and high intensity magnetic separation- reverse flotation beneficiation processes. To further study a better process for this ore, many other beneficiation methods had been tried, and the final results show that it is feasible to treat the ore by roasting- magnetic separation- reverse flotation processes. And product inspection, sedimentation filtration test of product, quality analysis of the waste water of tailings were conducted for the products.Considered that the properties, types, and the characteristics of the ore, and based on the process mineralogy study, through the multi-methods comparison and test conditions with various process parameters, the optimum process as the principle of processing the oolitic hematite by using magnetization roasting-low intensity magnetic separation-anionic reverse flotation process was recommended. The test conditions were in a reducing atmosphere (plus local 2# coal 10%), the calcination temperature is at 750 degrees Celsius, the roasting time is not less than 90min (the longer is the roasting time, the higher is the magnetization rate, the better is the effect of roasting, and the higher is the recovery rate of iron concentrate), after water-cooled released, a relatively high quality of magnetic roasting ore can be obtained. The calcined ore under the conditions at the grinding fineness of -0.043mm accounted for 91.26%, the ore by using magnetization roasting -low intensity magnetic separation process (magnetic field intensity 1200 Oe), can yield 61.54%, TFe55.52% of grade, and the recovery rate of 80 94% of the low magnetic concentrate; under the grinding fineness of -0.043mm accounted for 90.07%, by using reduction magnetization roasting-low magnetic separation (magnetic field intensity of 2000 Oe)-anion reverse flotation process, iron concentrate yield 60.64%, TFe57.22% of grade, and at the recovery of 82.20%. And the iron concentrate is relatively high in both grade and recovery. Therefore, this process is feasible.