Hematite Concentrate from Tailings of Mineral Processing Plant
Technology Test of Hematite Concentrate from Tailings of Mineral Processing Plant in Михайловск Mining Company
Hematite Concentrate
Михайловск Mining Company is mainly engaged in processing hematite, magnetite, and itabirite mineral. Present mineral processing flow is including four-stages crushing, dry magnetic separation, four-stages ball milling, and five-stages wet low-intensity magnetic separation. According to the provisions of design in mineral processing plant, hematite can be recovered from anionic collector flotation after re-grinding of wet low-intensity magnetic separation. Obtained iron grade of hematite flotation concentrate is 58.4%. However, the designed recycling process of hematite has not been achieved in mineral processing plant, only the magnetic mineral concentrate is manufactured in mineral processing plant, of which the iron recovery is only 57%. Iron grade of mineral processing plant tailings is 26%-28%. Low iron recovery of concentrate determines the high power consumptions of mineral processing plant. Economic and technological pre-calculating result shows that it is reasonable for recovering hematite from tailings of Михайловск Mining Company mineral processing plant. In order to obtain hematite concentrate from tailings of Михайловск Mining Company mineral processing plant, various mineral processing methods have been tried in the past, such as positive flotation anions, anionic reverse flotation, high-intensity magnetic separation, spiral chute gravity concentration, and centrifugal concentrator gravity concentration. Only hematite concentrate with iron grade of 64.2% can be obtained by roasting magnetic separation, iron grade of hematite concentrate obtained by SB-40 Falcons concentrator is 61.1%, operating recovery rate is 8.0%, iron grade of hematite concentrate obtained by SB-40 Falcons concentrator after regrinding of tailings of mineral processing plant is 63.0%, operating recovery rate is 3.1%.
Arco Company recovers hematite from wet low-intensity magnetic separation of medium dissemination particle gravity concentrator through practice of Russian mineral processing. Magnetic separation—flotation is often adopted in some countries when deals with fine and medium dissemination particle of hematite—magnetic mineral, such as China, India, Liberia and Peru, and so on, gravity separation—magnetic separation—flotation is not often used in hematite recovery. Miha Noble Engineering Company develops a new technology of hematite recovery from wet low-intensity magnetic separation tailings under laboratory conditions, and expands the experiment together with Михайловск Mining Company. Expansive experiment proves the techniques process that obtains iron grade of 61.5%~62.7% from tailings of Михайловск Mining Company mineral processing plant, and the possibility of hematite concentrates. Such kind of iron concentrates is obtained under the circumstances of tailings without grinding. The recovery rate of iron concentrates from mineral processing plant of open expansive experiment with no grinding, concentration and scavenger is 21.6%~23.1h%. In the closed-circuit experiment of laboratory without grinding and scavenger, iron grade of iron concentrates is 64%~64.1%, recovery rate of mineral processing plant tailings is 28.1%~29.4%. In laboratory test, desliming overflow with mineral feeding rate of 65.6% and mineral feeding recovery rate of 43% enters to mineral processing plant tailings.
In expansive test, only magnetic separation tailing with mineral feeding rate of 43.5% and mineral feeding recovery rate of 30.4% is separated, which can explain the difference of obtained hematite to mineral recovery rate between laboratory test and expansive test. Products above the screen should be selected in next stage of test, installing sieve of 0.044mm sieve size in order to improve the efficiency of wet magnetic separation, concentration and scavenger should be added to flotation, so that closed-circuit operation can be effected, and mixing time of slurry and drug should be optimized. At this time, iron recovery rate of raw ore to iron concentrate is raised by 8%~9%, iron grade of concentrate without grinding can be reached to 63%~64 %( See chart 5). The result we obtained is not the final one, because the recommended techniques process can be optimized, so as to enhance the economic benefit of hematite concentrate from tailings of Михайловск Mining Company mineral processing plant.
Along with the long mining life of techniques optimization practice for low grade vanadium-titanium magnetic mineral processing, high grade iron mineral resource is decreasing progressively. Shortage of basic raw material of iron and steel industry is becoming very seriously, which is in urgent need of effective solutions. The newly found vanadium-titanium magnetic mineral resource in Luan Ping County, Cheng De City, characterizes with low grade, large storage, more fine particle, and unevenly coarse and fine particle. The exploring results indicated that recoverable reserves of mineral is three hundred million ton, average grade is 16.59%, it is low grade vanadium-titanium magnetic mineral. In order to develop low grade vanadium-titanium magnetic mineral, our company established and invested a mineral processing plant with an annual capacity of 200,000 ton fine iron powder. The established plant adopted two-stage open crush flow, which is stage grinding—magnetic beneficiation—cyclone and screening two concentrates—regrinding magnetic separation. Seen from the almost one year’s production, fragmentation into grinding can be reached to 25mm, and large amount of gangue minerals mixed together, raw minerals into grinding grade is only about 16%, and efficiency of control classification is low(<40％), tailings grade is remaining high(>11％), efficiency of grinding mineral is low(<40 t／h), both concentrates(<62％) and metal recovery rate(TFe<40％) are low, which not only caused product cost increasing, but also economic benefit decreasing. Therefore, it is inevitable and necessary that adopt essential measures, improve existing plant technical indicator, rationally and effectively develop mineral resource. The effective way is applying advanced technology and economic reasonable mineral processing techniques flow with combination of present construction conditions to improve the efficiency of equipment.
Hematite Concentrate from Tailings of Mineral Processing Plant
Fine crushing and stage grinding of discarding tailing is the process that is for magnetic plant to save energy and improve economic benefits, and together with high efficient mineral processing equipments, so as to realize potential the excavation and efficiency enhancement in internal enterprise. To optimize technical parameter and improve technical indicator through adjusting structure of techniques flow. Especially, throw the gangue minerals in advance while dealing with low grade ore can increase the ability of grinding mill and processing plant, improve overall effectiveness of sorting system. After a detailed study of flow and evaluation of technical feasibility, it is determined that use discarding tailings process of fine crush to improve sorting flow structure, use new high effective equipment to improve technology for existing mineral processing plant crush and grinding separation process, improve production capacity and processing plant production technical indicator by great increasing of equipment energy utilization and resource utilization. We have improved and optimized the former techniques flow in June, 2004. The former techniques flow changes for fine crush to discard tailings—stage grinding—strong magnetic beneficiation–regrinding magnetic separation—fine screening classification—strong magnetic scavenger. Nearly one-year production practice with optimized techniques flow indicates that new sorting technology enables us to obtain the satisfied indicators, such as raw mineral grade by manual grinding is 21.34%, concentrates is 66.81%, tailings is 8.18%, recovery rate is 70.27%, TFe recovery rate is 55.61%, MFe recovery rate is 92.26%. The mineral processing technology is characterized in advanced technology, high equipment energy utilization, stable production, efficient in minerals features, and low cost, it is the effective techniques that changes resource advantage to economic advantage for low grade vanadium-titanium magnetic mineral sorting.
