Yunnan iron ore are mainly composed of hematite, specularite other minerals are siderite, goethite, pyrite, marcasite, there is a small amount of magnetite; gangue minerals are mainly quartz, microcline feldspar, ankerite, calcite, barite, kaolinite, there is a small amount of gray iron manganese. Anshan Iron and Steel Group Mining Company carried out the ore hydro-cyclone classification, coarse-coarse-grained re-election, fine-coarse-grained high intensity magnetic separation and flotation process these series of test. The results showed that the re-election of concentrate grade was up to 65.72%. Yield was 25.85%. However, the re-election of the part of the dam grade was up to 19.63%, and the yield was 2.53%; There were little part of magnetic and flotation concentrates amount dam grade higher. Therefore, they carried out the process of adjustment, the use of high intensity magnetic separation tailing re-election of a fine, heavy tail regrinding high intensity magnetic separation to positive flotation process, namely in the case of the grinding fineness is – 0 074 mm accounted for 65%, people use the high intensity magnetic separation tailing strong magnetic concentrate gives two paragraphs spiral Speedball to get the wet concentrate, and then conduct the re-election, finally is the re-election regrinding intensity magnetic separation strong magnetic concentrate tailing dam positive flotation (but not through impact crusher, hammer crusher).
The process of the indicator is 30.46%, 65.71% concentrate grade of the ore crystallographic sites. Dam grade is 16.45%, metal recycle yield is 65.71%. The results showed that people applicate neutral the magnetic roasting natural Dry cooling an off – site magnetic separation technology, put the closed mine in calcined at 700? calcined 70 min cooling to 400 to 300 C, cooled to room temperature and then discharged into the air, can be formed ferromagnetic magnetite and ugly roasted ore magnetic separation process, the test to obtain a grade of iron concentrate from 59.56% to 59.37%, iron recovery rate reaches 72.03 73.72% % these good indicators. Changsha Research Institute of Mining and Metallurgy of the ore with a single high intensity magnetic separation stage grinding stage sorting process and restore the roasting process beneficiation test. Single high intensity magnetic separation program for high intensity magnetic separation stage grinding time roughing, to shift (Featured a sweeping election, get the concentrate and tailing; regrinding middlings intensity magnetic separation after a rougher time sweep election throw away the final dam, concentrates of two final concentrate.the process indicators are as follows: the ore grade is 25.19%, concentrate grade is 57.75%), the tailing grade is 11.46%, the metal recovery is 68%. The restore roasting program refers to the two sections of continuous grindings which refers to total 5 times a weak magnetic separations. The indicators of the process are as follows:the ore grade is 25.52%, concentrate grade is 60.06%, dam grade is 70.50%, metal recovery rate is 82.00%.