Hematite(week magnetic ore) is refractory minerals. Before, the flotation and roasting-magnetic separating process are mainly used. For the past few years, due to the application of strong magnetic separator, undersize sieve etc new equipment and gravity separation equipment, reverse flotation process, hematite (week magnetic ore) dressing have got remarkable effect.
Hematite dressing process is suitable for hematite and impurities dissemination and particle size uneven thickness, including little magnetite, hematite of gangue mineral containing quartz, kaolin etc complex ore characteristics.
At present, hematite typical dressing process have three kind: continuous milling-week magnetic-strong magnetic-anion reverse flotation, stage grinding-coarse & fine separation-gravity-magnetic-anion reverse flotation and stage grinding-coarse & fine separation-magnetic-gravity- anion reverse flotation.
1.continuous milling-week magnetic-strong magnetic-anion reverse flotation,
The main features of this process:
(1) It have good adaption for iron ore process mineralogical characteristics. Aim at the feature of iron ore fine disseminated particle size and demanding fine grinding, use continuous milling method to grind almost all ore free liberation, then separation.
(2) The combined utilization of week magnetic-strong magnetic-anion reverse flotation realize the optimal combination of process. After continuous milling, use week magnetic separator-strong magnetic separator to discharge the primary slime and secondary slime. It rise the iron grade feeding into anion reverse flotation that is good for the anion reverse flotation getting high quality concentrated iron. And more importantly, week magnetic separator-strong magnetic separator removed the primary slime and secondary slime and it is create a good process condition for anion reverse flotation to play its role preferably.
(3) This process is easy to get preferable beneficiating index. At present, strong magnetic equipment is the ideal hematite tailings discarding equipment, anion reverse flotation is the most ideal process to get high grade concentrated iron from hematite.
2. stage grinding-coarse & fine separation-gravity-magnetic-anion reverse flotation
The features of this process: after once grinding of raw ore, classify by hydrocyclone, and then the coarse particle and fine particle are processed respectively. To Coarse particle, use spiral chute for gravity separation and get qualified coarse concentrated ore. To fine particle, use week magnetic-strong magnetic-reverse flotation separation and guarantee to get good beneficiation index and high quality fine concentrated ore. Gravity separation middlings secondary grinding and then return to hydrocyclone for classification. In this system, particle size of concentrated ore is main the gravity separation coarse concentrated ore, quantity of alkaline fine concentrated ore from reverse flotation separation is little, it is not like the continuous milling-week magnetic-strong magnetic-anion reverse flotation easily lead filtering difficultly.
(1)Use stage grinding process. After primary grinding, realize the preparation of sized raw ore with coarse particle and greatly reduce the capacity into secondary grinding. It's good for reducing cost. At same time, coarse concentrated iron ore is conducive to filter.
(2) high selective targeted. The dissociation during ore grinding is random. Dissociated ore under coarse grinding should be selected. By this process, select the dissociated coarse iron ore by gravity separation using spiral chute, then use high-efficiency and complex strong magnetic-anion reverse flotation process to get concentrate ore and discharge tailings. Combination of coarse particle beneficiation and fine particle beneficiation make this process economical and advanced.
(3) realize selection of narrow-size feed. During ore selecting, the selectable degree of ore is related to itself features, and also the particle surface-area to volume ratio. The beneficiation process of realizing selection of narrow size feed can largely stop the chaotic phenomena during flotation and increase the beneficiation efficiency.
3、stage grinding-coarse & fine separation-magnetic-gravity- anion reverse flotation.
The features of this process
(1) Using stage grinding process, then reduce the capacity feeding into second grinding section.
(2) strong magnetic discharging tailings in advance. The discharged tailings capacity by strong magnetic in advance is above 45% and great reduce the feeding capacity to follow-up section. Qidashan iron dressing plant use stage grinding-coarse & fine separation-magnetic, gravity, flotation joint processing, get concentrated iron grade 67.56% from 28.55% raw ore and the recycling rate is 78.92%. Sijiaying oxidized iron ore dressing plant use stage grinding-coarse & fine separation- strong magnetic- reverse flotation process, get concentrated iron grade 66.00% from 30.44% raw ore and the recycling rate is 80.00%. Baiyun Ebo iron dressing plant use continuous grinding-weak magnetic - strong magnetic- reverse flotation desulfurization process, get concentrated iron grade 64.39% from 32.67% raw ore and the recycling rate is 74.35%.
Guilin1500t/d limonite project Iron mining 3000t/d ,Laizhou
Hanking group 2000000 t/a Iron mining Huaibei 1600000 t/a iron tailings project