Study On Reconcentration Test Of Anshan Type Hematite Reverse Flotation Tailings

The industrial type of Gongchangling concentrator flotation workshop selecting ore is Anshan type hematite in Angang Group. After the process flows of two roughing–one concentrating –three scavenging,the reverse flotation tailings iron grade is still as high as 16%,And give priority to with fine grain losses, as a non-renewable and irreplaceable mineral resources in the short term, serious loss and waste.The paper chooses reverse flotation tailings of Gongchangling concentrator for the study, experimental study on iron ore content of secondary separation. Analysis of the nature of raw ore can conclude: The grade of total iron in the raw ore is 16.65%, metallic minerals are mainly hematite and magnetite, and gangue minerals are mainly quartz. The size composition of raw ore is maldistribution, the content under 38μm is 34.02% with grade of 34.02%, and metal distribution rate is as high as 61.04%.So the recovery of iron minerals of under 38μm is the key of the whole test iron recovery.According to analysis results of the nature of original tailings, combine with researching on current separation process of iron ore, Test plan of “Enrichment by magnetic separation” and “Purification by flotation” was initially developed. On this basis of preliminary exploration test, two test plan of enrichment by magnetic separation of “fine grinding, strong magnetic,middle magnetic ” and “rough grinding, strong magnetic, fine grinding, middle magnetic” were work out. Main magnetic separation conditions, such as grinding fineness, magnetic field strength were optimized during the test. Considering recycling effect, operation cost and other factors, enrichment by magnetic separation choose one stage grinding process. The concentrate grade after separation is 41.71%, and the recovery is 81.05%, magnetic separation tailings grade is only 4.66%.Two devices of flotation machine and flotation column were compared via Purification by reverse flotation of the magnetic concentrate, to determine the optimum dosage of reagents, equipment parameters and their technological process. The tests show: on condition that average grade of flotation feed was 41.71%, the grade of concentrate was 64.56%,operating recovery rate of concentrate was 81.30% with close circuit of one roughing–one concentrating–one scavenging by flotation column.Using flotation column as a flotation device can get the final concentrate grade and recovery operation higher than 0.52% and 1.12% respectively.The all flow quantity and quanlity showed that, after the process flows of “fine grinding, strong magnetic,middle magnetic, close circuit of one roughing–one concentrating–one scavenging by flotation column”, on condition that average grade of flotation tailings were 16.65%, the grade of concentrate was 64.56%,all flow recovery rate of concentrate was 70.76% and the grade of comprehensive tailings was 5.96%,the iron minerals of reverse flotation tailings of Gongchangling concentrator were recycle effectively.Research on semi–industrial reconcentration tests based on laboratory tests,Experiments show that the grinding fineness has a great influence on semi–industrial reconcentration system。Due to the magnetic separation process and equipment,semi–industrial system magnetic tailings grade is much higher than the laboratory test of magnetic separation tailings grade。The tests show: on condition that average grade of flotation feed was 17.94%,after the process flows of “grinding, low magnetic, strong magnetic, close circuit of one roughing–one concentrating–one scavenging by flotation column”,the grade of concentrate was 63.12%,all flow recovery rate of concentrate was 50.17% and the grade of comprehensive tailings was10.43%.